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VERITAS
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UNIVERSITY OF MICHIGAN
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THE GIFT OF
Prof. Henry Kraemer
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I
1
Chemical Library
S
585
B777
E5
1845
LONDON:
Printed by Schulze and Co., 13, Poland Street.
TO THE RIGHT HONOURABLE
JOHN CHARLES, EARL SPENCER,
THIS VOLUME, IS BY PERMISSION,
MOST RESPECTFULLY INSCRIBED,
BY
HIS LORDSHIP'S MOST OBLIGED
AND OBEDIENT HUMBLE SERVANT,
GEORGE LAW.
333889
THE
AUTHOR'S PREFACE.
In the work now published, I present the results of the
inquiries in which I have been engaged for many years, and
which were undertaken in the hope of throwing light upon
various points of practical agriculture. My first idea was, to
confine myself to the mere re-impression of the several papers
which I had communicated from time to time to different
periodicals, with the addition of a quantity of inedited matter
which I had by me. But upon more mature consideration,
I was led to believe that I should be doing a useful thing
did I fill up the numerous gaps which must necessarily occur
between papers published isolatedly, at dates more or less
remote from one another, and treating of the most dissimilar
subjects. I have thus been led, in addition to my own obser-
vations, to give those of numerous writers on almost every
branch of agricultural science, being only careful to confine
myself in each instance to the most authentic practical con-
clusions; for it is certain, that practical data have the most
direct interest for rural economy, both in itself and in its
bearings upon the general science of political economy.
I have a farther reason for the plan I have adopted,
which I am the less disposed to pass by in silence, inasmuch
as it may plead my excuse with those who might be disposed to
criticise the tone, perhaps somewhat too didactic, of my work.
I was invited, in conjunction with several other professors
α
vi
AUTHOR'S PREFACE.
attached to a great educational institution, to give a course
embracing my views upon the science of agriculture. I con-
sented to this, and prepared my lectures; but motives, to
which I was entirely a stranger, having prevented the project
from being carried out, I made up my mind to publish, not
the lectures such as I should have delivered them, but the
documents which would have formed the ground-work of my
teaching.
The first part of this work treats in succession of the phy-
sical and chemical phenomena of vegetation; of the compo-
sition of vegetables and their immediate principles; of fermen-
tation; and of soils. The second comprises a summary of
all that has yet been done on the subject of manures, organic
and mineral; a discussion of the subject of rotations; general
views of the maintenance and economy of live stock; finally,
some considerations on meteorology and climate, and on the
relations between organised beings and the atmosphere.
I have endeavoured, therefore, to give a summary view of
the several questions of rural economy that admit of scientific
treatment. It may be found, perhaps, that the number of
these questions is still extremely small. Nevertheless, in
regarding the multitude of inquiries that have been instituted
within a very few years only, in viewing especially the ever-
increasing interest attached to researches bearing upon
practical agriculture, we are bound to anticipate progress, and
to hope for conclusions important as regards science, profitable
with reference to practice, and useful to mankind.
EDITOR'S INTRODUCTION.
THE following work is submitted to the agricultural public
in the fullest confidence that it stands in need of no recom-
mendatory strictures on the part of those who have under-
taken to present it in its present form to the English agricul-
turist. In the person of its distinguished author the man of
science is most happily associated with the practical farmer-the
accomplished naturalist, the profound chemist and natural
philosopher, the friend and fellow labourer of Arago, Biot,
Dumas, and all the leading minds of his age and country—
surely the collected and carefully recorded experience of
such a man, experience by which the conclusions of the mem-
ber of the Institute have been tested and weighed by those
of the farmer of Bechelbronn, must have value in the
estimation of every educated mind, and cannot fail to be espe-
cially welcome to that class of readers who are professionally
engaged in the practical application of the noble science
which his labours have contributed to illustrate and advance.
M. Boussingault's title to consideration indeed is recognized
wherever letters and civilization have extended their influence.
When the following pages were confided to the editor it
was the impression both of the publisher and himself that in
viii
EDITOR'S INTRODUCTION.
the course of the work many points would necessarily arise
demanding elucidation, others calculated to provoke controversy
or challenge investigation, and others again which could be
rendered available or instructive to the British agriculturist only
by means of copious explanation, showing with what modifi-
cations and under what circumstances the views advanced might
be applicable to the art as exercised in the climate and soil of
this country. But the minute and analytical perusal indispen-
sable in the operation of investing the Author's thoughts and
expressions with an English garb, has demonstrated the
fallacy of this impression, and if possible has augmented the
admiration of the untiring patience, the vast experience and
the astute, circumstantial and elaborate accuracy of the ac-
complished author, in whose researches the reader will find
the profoundest sagacity, combined with a childlike simplicity
which communicates to his work a charm not necessarily in-
herent in the subject.
This is not intended to imply an unqualified approval in
every instance of the illustrious philosopher's manner of
dealing with his own facts and observations; nor yet with
his style of writing, which is sometimes very diffuse. Still,
instead of having as was expected, to pause at each step of the
author's progress, and dissert upon his views upon this or that
particular branch of his subject, the observations of the com-
mentator must of necessity be restricted in a great degree to
an indication of such parts of the work as in his judgment
are the most valuable and instructive, together with such in-
cidental objections as appear to be of sufficient importance to
require stating at length.
The chemical portion of the work is of inestimable value,
and conducted with consummate skill and knowledge; and
with a minuteness and accuracy perfectly unexampled. At
the same time the results of the writer's researches, as well
EDITOR'S INTRODUCTION.
ix
as the means and processes by which these results were ob-
tained, are displayed with such absolute perspicuity as to be
intelligible and instructive to every agricultural inquirer, how-
ever superficial his previous acquaintance may be with the
details of chemical science.
G
Nothing from the pen of the Editor could throw additional
light upon the Author's concise and most interesting elucida-
tion of vegetable physiology: his exposition is at once mas-
terly and complete, and contains much that is both valuable
and new.
And even when the novelty of the facts which he
adduces, or the originality of the inferences deduced and un-
folded may admit of question, they are still deserving of the
most respectful attention from the new and striking lights
in which he presents them to the agricultural reader, and
the clear and convincing way in which he demonstrates
their inter-dependency and their most intimate connexion
with many of the most important pecuniary and pro-
fessional interests of the cultivator. Every intelligent farmer
will find his account not merely in a repeated perusal of this
portion of the work, but in regarding it as a text-book and
manual to be kept by him for permanent reference and con-
sultation.
The arrangement of the subject, naturally and judiciously
adopted by the writer, presents the consideration of soils as
the first topic for the observations of the agricultural com-
mentator; but on this head the distinguished author is so
thoroughly explanatory and judicious, that nothing is left for
the Editor but to acquiesce, to approve, and to recommend
him with admiring confidence to the patient consideration and
study of the intelligent inquirer.
At page 335 the subject of manures is taken up, and dis-
cussed with characteristic minuteness through many succeed
ing pages.
X
EDITOR'S INTRODUCTION.
It may perhaps be objected, that the various theories
respecting the origin, nature, efficacy, and relative nature of
the different manures in use, as well as the various modes of
their production, concoction, and application, which M. Boussin-
gault has here collated and elucidated, contain nothing new;
that they have, in fact, under one form or other, been long
familiar to practical men; but without impugning the justness
of this opinion, the Editor has long been convinced that the
subject has received, generally, far less care and attention than
it so eminently deserves; and in short, that it is much ne-
glected by many who are accounted not merely intelligent,
but scientific agriculturists; and while admitting that
much valuable information has been frequently given to the
agricultural world by the repeated experiments of several
enterprising individuals both in Scotland and England, he still
most urgently recommends a careful study of this part of the
work, which will probably lead the reader to the conclusion
that the methods and practice recommended by the Author
are, upon the whole, those best worthy of adoption. In pages
340 and 341 will be found some very urgent warnings against
what he (M. Boussingault) regards as the prevalent and
pernicious custom of turning dung-heaps "frequently." If,
however, by the term "frequently" a course not exceed-
ing three complete turnings of the heap be comprehended, the
Editor can by no means coincide with this opinion; a long
experience having convinced him that there are many circum-
stances under which the Author's recommendations would be
found not merely over cautious, but positively injurious. For
drill crops, for instance, when it happens that the farm dung
is somewhat rough, which must generally be the case towards
the close of every season, when the animal dejections are
scanty and the great bulk of the already ripened manure has
been carried out upon the land, and the fresh additions have
EDITOR'S INTRODUCTION.
xi
not had the advantage of being compounded with matter
already concocted, an extra turning is very advantageous.
Every farmer will, of course, turn his heap once, for the
purpose of thoroughly mixing the various ingredients and
different qualities of manure which it contains; the extra
turning, even admitting that it may to a certain extent pro-
mote the over decomposition of the manure, and dissipate the
ammoniacal principles which it is important to preserve, is
not attended with so great a loss in this respect as that which
is inevitable from keeping open the drill by the application of
coarse dung, which cannot fail to be attended with a most
serious loss of the more volatile principles, sometimes even
laying the manure quite bare, and in the case of turnips, not
only materially obstructing the operation of sowing but often
giving a false bed to the seed.
Our Author brings forward the authority of several eminent
inquirers in support of his own favourite view of the use of
fresh or unfermented manure; but however plausible their
theories may appear, and however just may be their views in
the abstract, there are many intermitting circumstances con-
nected with the general economy of a farm, which must
govern and determine their adoption, and in which the
practical cultivator must be guided by his own judgment alone.
To the Author's 6th chapter the reader may be advanta-
geously referred, as containing a very full and valuable descrip-
tion and discussion, under the head of mineral manures, of the
different varieties of the class usually denominated stimulants,
and concluding with a brief but lucid and interesting account
of WATER, considered as an agent of vegetation, and of its
importance for manuring purposes.
The composition and preparation of liquid manures, as well
as the various means of procuring and preserving them, will
be found to have engaged much of the Author's attention;
xii
EDITOR'S INTRODUCTION.
and he justly points to the rapidity of their ameliorating action
as a peculiar excellence, not otherwise attainable; at the same
time admitting that in the majority of cases, the great
and unavoidable expense attending their application, however
moderate may be the prime-cost of the material, has always
operated as an insuperable obstacle to their general adoption.
In the justice of this vital objection, most practical agricultu-
rists who have used them to any extent, will readily concur;
and it will not be uninteresting to the reader to learn that
there is reason to believe that it will henceforth be effectually
obviated by the use of a very simple and convenient apparatus,
devised by Mr. Smith of Deanston, a zealous and able friend
of agriculture, who at the Highland Society's meeting at
Glasgow in autumn last, explained the details of his con-
trivance; and the Editor has reason to suppose that the
particulars will be given in a report of the proceedings of the
meeting, in the forthcoming January publication of the
Highland Society's Transactions.
The Editor is anxious to direct especial attention to the
Author's 7th Chapter, wherein he treats of the organic and
inorganic manures, and of crops; of the elements of manures
and of crops, with their relations inter se, &c.-a section of
the work which presents in synopsis, a more copious and
complete body of new, interesting and important facts, of a
nature more valuable to the practical farmer, than has ever
been collected in any previous treatise on agricultural science.
The great mass of this invaluable information is condensed, as
it were, for practical reference, and displayed in copious and
elaborate tabular data-a form which, though not attrac-
tive, has enabled the writer to comprise within succinct
and manageable limits, a quantity of instruction which, in a
more discursive shape, must have distended the work to
double its actual size. The tables adverted to, present not
EDITOR'S INTRODUCTION.
xiii
merely the results of multifarious experiments in illustration
of the important subject of rotation-cropping, but also these
results as especially affected by the application of the various
manures to which the several experimenters had recourse. The
rotations reported may appear strange and curious, and some-
times, perhaps, even amusing to the farmers of England and
Scotland; but not more so, in all probability than those,
which are followed in many parts of our Island, would appear
to the cultivators of that part of Europe, where our author's
agricultural experiments have been carried on, and where the
bulk of his analyses have been obtained: indeed, locality and
climate, and their inseparable concomitants, will in every
country be found to prescribe and control the sorts of crops
which may be rendered the most subservient to the permanent
advantage both pecuniary and economical of the husbandman.
Thus, with regard to the Author's more didactic observations
and positive directions on the subject of rotations, there is no
reason to doubt that, in relation to the soil, climate, and
geographical position of the east of France, where his
experimental course of rotations has been conducted, they are
highly judicious, and have not been prescribed and recorded
without mature consideration. Moreover, they are marked
like the deductions and inferences upon which they are
founded, by his usual acumen, patience, and sagacity; but
in their application to the more circumscribed range of culture
to which the agriculturist is limited in the ruder and more
fickle climates of north and south Britain, the practice of
the cultivator must be governed mainly by his own judgment
and experience in the circumstances by which he finds himself
surrounded.
The interesting and ample instruction conveyed in the
observations of this acute and profound observer upon the
food and alimentary treatment of the various species of cattle,
xiv
EDITOR'S INTRODUCTION.
accompanied as they are by minute details of the results
obtained in the shape of organic and inorganic elements, can-
not be too urgently recommended to the attentive considera-
tion of every one interested in the important branch of rural
economy to which they more particularly relate.
The Author's strictures comprehend the economy of the do-
mestic animals with the exception of sheep, a subject from
which he professedly abstains, for the very sufficient reason, that
in his opinion, his opportunities of obtaining accurate informa-
tion thereupon have not been sufficiently ample to enable
him to discuss it with confidence and advantage. His theory
in favour of the superior fattening quality of hay and the
grasses in general above that which is found in tubers and
roots (though apparently supported by his usual convincing
appeal to experiment) will be received with considerable allow-
ance by the practical farmer.
We have many instances, in the present day, of theories
ably, plausibly, nay even satisfactorily established, which are
nevertheless met by opposite results in practice; and the
hesitation which the Editor ventures to intimate upon the
particular point in question, will, he doubts not, be readily
concurred in by many experienced feeders. It will be generally
admitted that the boiled or steamed potato possesses a much
higher nutritive value than that which belongs to it when in the
raw state. In the former case, however, it requires to be
mixed with some other root which is not characterized
by the same constipating property, such as beet, turnips,
&c. the Swede (Rutabaga), or any of the harder sorts
of turnips form a complete counteractive to the dan-
gerous constipating tendency of the boiled potato when
given alone.
There are many different substitutes or equivalents in the
shape of mashes, containing leguminous ingredients which are
EDITOR'S INTRODUCTION.
XV
admitted to be fully as nutritious as the potato, still there are
circumstances connected with market value which render it a
most valuable resource in farm alimentation. The popular
notion that (when used as the food of horses), the boiled or
steamed potato is what is vulgarly called "soft meat," tend-
ing to unfit them for active work, is daily losing ground; for
not only is it rapidly getting into more general use among
the farmers of England and Scotland, but even postmasters
are adopting it for horses employed in road work.
The Meteorological section of the volume will be found no
less instructive to the agriculturist than fascinating to the
general reader; no equally complete and extensive body of
new and interesting facts has ever before been presented in
a collected form to the agricultural world.
It will be observed that the capital, the all-important subject
of Draining, as the great master-engine of agricultural improve-
ment, is merely touched upon by our Author in a cursory
way; should this excite a feeling of disappointment, it must
be borne in mind that he has accomplished all, and more
than all, that he proposed to himself, which was not to write
a complete work on practical tillage, but rather as his title
implies, on "Rural Economy," i. e., the economic production
and application of the produce of the soil under the guidance
of chemical and physiological science.
With reference to the weights and measures made use
of in the original, it may be proper to state, that (against
strong temptation to let them stand as in the French,
merely adding a table of equivalents) they have all but in-
variably been reduced into their corresponding quantities
in the English standards. Grammes, in the more de-
licate experiments, have been reduced into grains troy,
assuming the gramme as equal to 15.438 grains; in less
delicate experiments, grammes have been converted into
xvi
EDITOR'S INTRODUCTION.
גי
pennyweights (dwts.) and ounces troy.
:
Kilogrammes are
given in lbs. avoirdupois; and where the quantity was large,
they are often brought into tons, cwts., qrs., &c.: the French
kilogramme is taken at 2.2 lbs. avoirdupois. The Litre, or
usual French measure of liquids has been reduced into
pints, calculating the French measure at 1.76 pints English
imperial measure. The Hectolitre, employed in measuring
grain is rendered into bushels, &c. estimating it at 22 gallons
English dry measure. The old French Quintal is also some-
times employed this measure of weight has been either
reduced to its proper corresponding quantity, 1 cwt., 3 qrs.,
24 lbs. English, or where odd numbers might be disregarded,
it has been called 2 cwts. The Are, or French super-
ficial measure of quantity, has been calculated throughout
at 120 square yards English; the Hectare at 2.4 acres
English. Metres, centimetres and millimetres have been
reduced into English feet and inches, assuming the metre
as equal to 39.370 inches. Finally, and to conclude our list
of reductions, (would that it had been shorter!) the degrees
of the centigrade thermometer have been brought into de-
grees of the only scale in familiar use among us, viz. Fahren-
heit's.
The labour of reducing these weights and measures into their
English equivalents has been immense; and errors, in spite of
the best care which could be exerted, have doubtless in various
instances crept into the reductions. Slight discrepancies
between aggregate sums and their component quantities will
also be apparent here and there, an inexactness which arises
from the number of decimal places not having always been
carried out far enough.
Our Author often quotes English agricultural writers
whose weights, &c., he has always been at the pains to reduce
into their corresponding French equivalents. Not having at
EDITOR'S INTRODUCTION.
xvii
all times the works referred to at command, the Editor was com-
pelled to bring back the French weight or measure into the cor-
responding English one by calculation. Thus from not know-
ing the precise equivalent adopted by M. Boussingault, some
trivial discrepancy between the computed and the original
weights, &c., may have resulted; but as the quantities that
have been treated in this way are especially important as
relative, scarcely ever as absolute quantities, the error where it
occurs can be of no real consequence.
In the translation the Editor has endeavoured (not always
with perfect success) to be as little technical as possible, with
a view to the convenience of the general reader. Among
the faults of execution for which he ventures to solicit the
agricultural reader's indulgence, is the occasional adoption of
terms which are rather French than English. Many of these
words are, in the original, not merely technical but local and
provincial, and are not inserted in any of the dictionaries.
Moreover, in the description of certain processes and opera-
tions, the Author has occasionally employed terms for which
there is no English equivalent; and the Translator had fre-
quently no other choice than that of either leaving the sense
of the passage obscure and defective, or on the other hand, of
adopting the barbarisms in question, which he fears will
scarcely fail to be offensive to the professional prepossessions
of the agricultural reader. In a very few places he has
ventured slightly to condense the style of the original in
order to keep the volume within moderate dimensions,
occasionally throwing the information contained in a table
into the text or narrative; and where the Author ap-
peared to him to be forgetting the rural economist in the
mere chemist, as where for example he describes the special
modes of preparing and purifying indigo, &c. he has made bold
to retrench details, and give the results or conclusions only.
b
xviii
EDITOR'S INTRODUCTION.
All analyses bearing on the practical subject, whether it
was the soil that produced, the crop that was grown, or the
animal which fed on that crop, have been scrupulously re-
tained. In conclusion, the reader is particularly recommended to
peruse an admirable little work, the joint production of Messrs.
Dumas and Boussingault, entitled in the original: "Essai
de Statique Chimique des Etres organisés," which has been
presented in a clear English translation, under the title of:
"An Essay on the Chemical and Physiological Balance of Or-
ganic Nature," and may be regarded as a most valuable intro-
ductory aid to the perfect comprehension of Boussingault's
Philosophy of Agriculture, and as a key to the more scientific
and technical portions of the work now submitted to the publie.
The Publisher begs to state that this Second Edition has
been thoroughly revised, and all the tables recalculated and
carefully corrected.
JULY, 1, 1845.
CONTENTS.
CHAPTER I.
PHYSICAL PHENOMENA OF VEGETATION.-VEGETABLE PHYSIOLOGY
§ 11.-Chemical phenomenon of vegetation
Germination.
Germination of wheat
Continued Germination of peas
Continued germination of wheat
§ III.-Evolution and growth of plants
Experiment I.-Growth of Red Clover during three months
Experiment II.-Growth of peas
Experiment III.-Growth of wheat
Experiment IV.-Growth of clover
Experiment V.-Vegetation of oats
Sap of the Bambusa Guaduas.
Sap of the banana plant (Musa Paradisica)
·
§ Iv.-Of the inorganic matters contained in plants-their origin-of
the chemical nature of sap
Quantity of ashes contained in the different parts of vege-
tables, according to M. de Saussure
Composition of the substances found by M. de Saussure
Alkaline salts and insoluble substances contained in ashes
Alkaline salts and insoluble substances of ashes, according to
M. Berthier
Milky saps
Sap of the papaw-tree (Carica Papaya)
Sap of the cow-tree .
•
Composition of the ashes of several plants analysed by M.
Berthier
•
•
Page
1
pand
18
19
24
25
26
29
44
45
46
47
49
54
55
58
59
60
ib.
74
75
ib.
76
ib.
b 2
XX
CONTENTS.
Milky sap of the Hura Crepitans (Ajuapar)
Milky sap of the poppy (Opium)
Milk of the Plumeria Americana
Sap of the caoutchouc-tree
Gummy and resinous saps
Saccharine saps
OF THE CHEMICAL CONSTITUTION OF VEGETABLE SUBSTANCES.
§ 1. Quarternary azotised principles of vegetables
CHAPTER II.
Composition of legumine obtained from different seeds
§ 11.-Proximate principles with a ternary composition: of starch
Inuline
•
Of woody matter and cellular tissue
Density of different kinds of wood, according to Brisson
Of sugar.
Beet-root sugar
Palm sugar
Grape sugar.
Saccharine principles not fermentable
Gum
Vegetable jelly: pectine and pectic acid
Of vegetable acids
Of the vegetable alkalies
Of fatty substances
Of essential oils
Of resin
Caoutchouc
Vegetable wax
Chlorophylle .
Of colouring matters
•
Barks
Leaves
Seeds
Fleshy or pulpy fruits
•
·
§ III.-Composition of the different parts of plants
Roots and tubers
CHAPTER III,
•
•
•
•
•
•
. 91
. 101
. 102
. 106
. 138
. 148
. 154
. 156
. 157
. 158
. 159
. 161
. 165
ib.
. 175
. 177
. 178
. 179
. 181
ib.
•
Page
78
79
80
ib.
82
ib.
194
ib.
204
. 207
. 214
242
·
85
OF THE SACCHARINE FRUITS, JUICES, AND INFUSIONS USED IN THE
PREPARATION OF FERMENTED AND SPIRITUOUS LIQUORS
86
89
248
CONTENTS.
xxi
OF SOILS
Classification of soils
OF MANURES
Excretions of the horse
Excretions of the cow
Excretions of the pig
Animal excrements
OF MINERAL MANURES OR STIMULANTS
Calcareous manures
Of alkaline salts
CHAPTER IV.
•
Of ammoniacal salts.
Of water
CHAPTER V.
Wheat-straw.
Red clover
•
Table of the comparative value of manures, deduced from ana-
lyses made by Messrs. Payen and Boussingault
. 391
CHAPTER VI.
OF THE ROTATION OF CROPS
§ 1. Of the organic matter of manure and of crops
Potatoes
Wheat
•
CHAPTER VII.
Growth of sainfoin upon soils gypsed and ungypsed in 1792,
1793, and 1794
Comparative growths of white clover, gypsed and ungypsed, by
Mr. Smith
426
Experiment with field-beet or mangel-wurzel, opening the ro-
tation with manured soil, 1842
Mineral substances contained in the crop
Turnips
Oats.
Oat straw
Field beet or mangel wurzel .
Rye.
Rye-straw
White peas
Pea straw
258
. 290
Jerusalem potato or artichoke
Dried stems of Jerusalem artichokes
309
. 350
ib.
•
351
. 375
Page
399
. 400
. 417
•
•
433
435
. 439
446
452
. ib.
. 462
463
ib.
ib.
•
424
•
464
. 465
ib.
. 466
ib.
467
ib.
ib.
468
ib.
xxii
CONTENTS.
Table of the proportions of water contained in different sub-
stances
Composition of the same substances dried in vacuo at 230° F.
Relations of manures to crops
Desiccation of half-made or half-decayed manure
Experiment I.
Experiment II.
Experiment III.
Analyses of half-made manures
Composition of the manures analysed
Rotation course, No. 1
Rotation course, No. 2
Rotation course, No. 3
Rotation course, No. 4
Continuous Jerusalem potato crop, No. 5
Quatrennial rotation, adopted by M. Crud, No. 6
Summary
§ 11. Of the residue of different crops
M
Potato tops or haum
Leaves of field beet or mangel wurzel
Composition of dry leaves.
Wheat stubble
Clover roots.
•
•
Composition of the roots
Oat stubble
Summary of the foregoing results
§ 1.—Of the inorganic substances of manures and crops
•
CHAPTER VIII.
•
§ 1. Origin of animal principles.
•
•
•
471
ib.
474
. 475
. ib.
ib.
476
ib.
ib.
•
Composition of the ashes proceeding from the plants grown
at Bechelbronn
Mineral substances taken up from the soil by the various crops
grown at Bechelbronn upon one acre
Table of the mineral matters of the crops and manures in the
course of a rotation
. 477
. 479
480
ib.
ib.
487
ib.
ib.
•
•
OF THE FEEDING OF THE ANIMALS BELONGING TO A FARM; AND OF
THE IMMEDIATE PRINCIPLES OF ANIMAL ORIGIN.
. 488
490
•
Page
Of the food of animals and feeding
Experiments on the maintenance of horses
Experiment
I. .
Experiment II.—Introduction of Jerusalem potatoes into the
ration
Experiment III.-Ration of hay and potatoes
469
ib.
470
•
ib.
•
ib.
ib.
ib.
•
504
. ib.
•
. 519
492
493
497
539
ib.
540
541
CONTENTS.
xxiii
•
§ 11. Of the inorganic constituents of food.
II
Page
Experiment VI.-Jerusalem potato for a portion of the bay. 543
Experiment VII.-Introduction of field beet or mangel wurzel
into the ration
Experiment VIII.—Introduction of the Swedish turnip into the
. 545
. 546
ration and replacing a portion of the hay.
Experiment IX.-Introduction of carrots into the ration
Experiment X.-Boiled rye as a substitute for oats
Table of the nutritive equivalents of different kinds of forage 549
547
553
MANURE
§ 1.-Horned cattle
P
CHAPTER IX.
OF THE ECONOMY OF THE ANIMALS ATTACHED TO A FARM.—OF STOCK
GENERAL, AND ITS
ITS RELATIONS WITH THE
IN
PRODUCTION OF
-Of the fatty constituents of forage; considerations on fattening 562
•
Table of milch-kine three years of age and upwards
•
§ 1. Fattening of cattle
§ IV. Of horses
§ v. Of hogs
VI. Of the production of manure
•
544
Experiment III.-One hundred and ninety-three days after
the calving
§ 11.-Milch-kine
Experiment I.-Two hundred days after calving.
. 601
. 606
Experiment II.-Two hundred and seven days after calving . ib.
Experiment III.-Two hundred and fifteen days after calving. 607
Experiment IV.-Two hundred and twenty-nine days after calving ib.
Experiment V.-Two hundred and forty days after calving . 608
Experiment VI.-Two hundred and seventy days after calving ib.
Experiment VII.-Two hundred and ninety days after calving
Experiment VIII.
ib.
609
ib.
Experiment IX.-Thirty-five days after calving
Second Series. Experiment I.-Begun one hundred and
seventy-six days after the calving
Experiment II.-One hundred and eighty-two days after
the calving
579
. 582
. 596
610
ib.
ib.
Experiment IV.-Two hundred and four days after the calving 611
. 613
624
. 630
. 639
xxiv
CONTENTS.
Experiment IV.-Substitution of oats and straw for a portion
of the hay
542
Experiment V.-Potatoes substituted for a portion of the hay. 543
•
CHAPTER IX.
METEOROLOGICAL CONSIDERATIONS :
§ 1.-Temperature
. 645
§ 11. Decrease of temperature in the superior strata of the atmo-
sphere
§ III.
1.—Meteorological circumstances under which certain plants grow
in different climates
Cultivation of wheat, Alsace .
Cultivation of wheat in America
Intertropical region
Cultivation of barley
Cultivation of maize or Indian corn
•
V
•
Page
653
654
. 655
ib.
•
•
549
ib.
656
. 657
. 658
660
•
Cultivation of the potato
Cultivation of the indigo plant
§ IV.-Cooling through the night; dew, rain
§ v.-On the influence of agricultural labours on the climate of a
country in lessening streams, &c.
673
CORRECTIONS.
Page 12 line 15
22
28
32 last line of text
39
31
39
33
48 last table
The plant contained: before culture
after culture
125
125
130
153
181
182
186
187
193
69
20
69
last line
78
20
79
7 of note
88 in table last column
102
6
193
198
199
199
200
200
201
207
211
213
215
215
216
231
235
237
238
238
246
246
267
274
"
283
289
289
297
308
319
341
360
362
2222222
366
363
90 feet read 91 feet
6 to 10 inches read 2 to 13 inches
155
18 to 20 inches read 23 to 24 inches
6 inches read 7 inches
155
155
6 inches read 8 inches
166 lust line but one (240 Fahr.) read (39° Fahr.)
173
28
178
25
816 lbs. read 840lbs.
250lbs of turpentine,
301bs of essence and 220lbs of rosin are read
275lbs of turpentine, 331bs of essence, and 242lbs of rosin are
100 grains read 92 grains
334° to 424° Fahr. read 302° to 392. Fahr.
20
5
17
19
6
15
21
15
12
21
14
15
4
7
28
13
12
30
COENGOME
5
"
7
26
32
for (lodicea cocus nucifera) read (loidoicea cocos nucifera)
th toth of an inch read ths to ths of an inch
398 cubic inches read 389 cubic inches
99.4 cubic inches read 99.6 cubic inches
52.2 cubic inches read 52.3 cubic inches
read the following:
58.3 read 58.8
27
rages read ranges
4 in table 10lbs read 7lbs
18
28
28
3
5 from
last line
DERRHE
17
29
23
11
•
Difference
lime....51.69 read lime....51.19
Magnesia....14.35 read Magnesia... 4.35
verticas read urticas
Carbon. Hydrogen. Oxygen.
5.97
0.74
6.46
18.52
2.23
13.32
+12.60
+1.49
+6.86
in Guaduas read from Guaduas
second line for 20.5 read 23.5
at 253° Fahr. and having been melted at 367° Fahr. read 221º Fahr. and
having been melted at 334° Fahr.
45º and 90° F. reud 44.6º and 89.4° F.
130° F. read 131° F.
1124lbs read 116lbs
100lbs read 110lbs
61 tons, 8 cwt. 0 qr. 2 lbs.; read 61 tons, 7 cwt. 2 qrs. 20 lbs.;
26 tons, 17 cwts. 3 qrs. 2 lbs. read 26 tons, 3 cwt. 3 qrs. 6 lbs.
(334° or 352° F.) read (302° or 320º F.)
Difference due to phosphoric acid....2.789 read Difference due to
phosphoric acid....2.778
282 line before note i. e. from 0.380 to 0.760 or nearly 3rd to 3ths of a lb. avoird.; read i. e.
ths of a lb. avoird.;
from 0.330 to 0.660 or nearly rd to
1.840lbs avoird, read 1.540lbs. avoird.
bottom for (25º to 27º F.) read (57° to 59° F.)
(45° F.) read (77° F.)
3 from bottom for frequently no more than about
3 inches; read frequently no
more than about 6 inches;
15
of between 9,000 and 10,000 square acres. read of 8880 square acres.
49° or 50° F. read 46° to 53° F.
employs its evenings read employ their evenings
43.7lbs read 46lbs
13.120 feet read 15.120 feet
25 to 30 bushels read 23 to 28 bushels
1.0 read 0.16
200lbs of marketable cork; as many as 480lbs however have been taken
from a single tree; the mean produce may be reckoned at about
100lbs per tree; read 2201bs of marketable cork; as many as 968lbs
however have been taken from a single tree; the mean produce
may be reckoned at about 110lbs per tree;
1 cwt.; read 124lbs
2lbs to 24lbs reud 2.2 to 3.3lbs.
18 pecks read 14 pecks
2 bushels read 24 bushels
Azote.
0.50
0.86
+9.36
6 to 7 bushels read 64 to 7 bushels
Tuscany....96 read Tuscany……..66
planted with about 1040 shrubs, will yield about 940 or 950lbs which
is at the rate of somewhat less than 1lb per shrub; read planted
with about 1060 shrubs, will yield about 2000 to 2100lbs., which
is at the rate of somewhat less than 2lbs per shrub
nearly 3 feet; read 3 feet 3 inches;
6 or 7 to 9 or 10 feet apart read 7 to 11 feet apart
6 to 7 inches read 3 to 4 inches
definitively read ultimately
from 40 to 50 bushels read from 40 to 60 bushels.
800 weight read 800 cwt.
power read powder
would cost £12 16s read would cost 11 13s 4d
•
Page 369 line 25
372
378
379
386
389
396
398
403
413
415
422
428
430
433
433
437
❤
· 437
439
441
448
448
454
480
491
518
519
519
522
527
539
539
559
570
570
589
601
606
606
608
611
624
623
628
for 7 tons, read 6 tons,
7 of the table for Sulphate of lime....0.5 read Sulphate of lime....5.0
about 12 pints read 14 pints
629
629
27222
676
678
678
21
21
1
11
3
12
19
last line
5
14
11
containing 4lbs. 16 dwts. of azote, leave 16lbs. 2 oz. of ash read
containing 4lbs. 5 dwts. of azote, leave 17lbs. 5 oz. 1 dwt. of ash
(2lbs. 8 dwts.) read (2lbs. 2 dwts.)
441
14
443 2 last lines of note for 2. 16.9 grs. of sulphate of ammonia were mixed with 123.2 grs.
of chalk, and from 924 to 1071 grs. of silicious sand. read
2. 23.1 grs. of sulphate of ammonia were mixed with 123.5. grs.
of chalk, and from 926 to 1080 grs. of silicious sand.
49° read 48.2°
54º read 53.6º
11
14
27
40
20
12
15
20
5
1
DE FEREENE ANGLãn
16
36
28
26
27
16
13
19
21
about 4 square feet read about 4 square feet
from 1300 to 1400 gallons per acre; read from 13,000 to 14,000 gal-
31
13
30
lons per acre;
424° to 930° Fahr. read 392º to 572° Fahr.
0.729 of a lb. read 0.792 of a lb.
(5ths) read (155¸ths)
constitutional read constituent
magnificent read good
gypsing read gypsoming or plastering
constituted by read cropped with
toth of its bulk, read to
of its bulk,
there falls on an average 3.92, nearly 4 inches of rain, which would
amount in round numbers to 982 tons per acre. read there falls on
CANCE
an average 3.22, nearly 31 inches of rain, which would amount
in round numbers to 98 tons 4 cwt. per acre.
28
30
242 square yards read 292 square yards
From the ungypsed..12 2,, 3 read From the ungypsed..12,, 3 2
""
""
weigh 2 cwts. 8lbs. read weigh 2 cwts. 1 qr.
3 cwt. 1 qr. 201bs. read 3 cwt. 1 qr. 18lbs.
82 cwts. read 81 cwts. 3 qrs. 10lbs.
handy work read hand labour
for 3 dwts. read 4 dwts.
repose read rest
3.3lbs butter read 3.33lb butter
67.5 read 6.75
delightful read very useful
azote per 100, 1.15 read azote per 100, 0.15
100 of green clover or represent 23. read 220 of green clover, repre-
sent 50.
2801bs. of the tubers read 616lbs. of the tuber
100lbs of hay read 220lbs of hay
35 to 108 grains of saline read 3,550 to 4160 grains of saline
wheat chaff 22lbs. read wheat chaff 2.2lbs.
5
7
629
30
633
2
650
19
649.4 feet read 639,9 feet
652 third line from bottom for 8260 feet read 8200 feet
656
58° and 59° F. read 57° and 58° F.
656
51º and 52° F. read 50 and 51° F.
59° F. read 65° F.
657
658
79° F. read 59º F.
668
oil-cake 22lbs read oil-cake 2.2lb
rate of 1.8lb read rate of 18 g.
neat cattle 463 grains, sheep 305 grains, read 478 grains, sheep 370
grains
14
24
last line
6
5 from bottom for Alexander, a colt, weighed at birth, 110lbs.; at the age of
128 days, 3371bs.; increase 227lbs., or about 1.8 per diem: 51
days afterwards, 190lbs.: increase 105lbs or per day 1.4lb. read
Alexander, a colt, weighed at birth, 110lbs; at the age of 128
days, 345lbs.; increase 235 lbs., or about 1.8 per diem: 51 days
afterwards, 385lbs.: increase 40lbs., or per day
ths.
allied with beet, read mixed with beet
The cow fed on hay alone gave 65.42
seven days, or 9.34 pints per day.
gave 68.42 pints of milk in the
pints per day.
9.3 pints read 9.8 pints
14.9 pints reud 15.4 pints
wrought read worked
100lbs. read 220lbs.
day 1.10lb. read day 1.11b
960 read 880
368.6lbs. read 369.6lbs.
to the read to this
pints of milk in the course of
read The cow fed on hay alone
course of seven days, or 9.85
more read greater
1300 feet read 1440 feet
from 10,000 to 13,000 and 14,000 feet read from 6500 to 9800 feet
62º read 60".
RURAL ECONOMY.
CHAPTER I.
PHYSICAL PHENOMENA OF VEGETATION.-VEGETABLE PHYSIOLOGY.
THE operations of agriculture having for their object the pro-
duction of plants which are either essential as food, or useful in
the arts and industrial processes of man, it is well to begin with
a summary view of the principal organs of which vegetables are
composed; and by the instrumentality of which, under certain
influences which we shall seek to appreciate, all the phenomena
of their existence are manifested.
Plants fixed in the soil by their roots, live in the atmosphere
by the concurrence of their green parts under the combined actions
of light, heat, and moisture. We shall by and by ascertain at
the cost of what elements, and under what conditions, their
growth and complete development are accomplished.
The seed, which is the final result of vegetable life, and of
which the aim is the reproduction and multiplication of the
species, should first receive our attention. The seed is, if we
may so speak, the starting point of all husbandry; it is with very
few exceptions the first point on which the industry of the
farmer exerts itself.
Nature, to insure the preservation of seeds, has had recourse
to infinite care and foresight, which are in some measure an
assurance of their importance. The seed is often placed in the
middle of an abundant fleshy pulp, which serves to afford it
nourishment or manure at the time of its future development.
Sometimes, as in leguminous plants, it is lodged between thick
and tough membranes, or is covered with hard but flexible scales,
B
2
VEGETABLE PHYSIOLOGY.
as in the gramineous plants; or again it is enveloped in a woody
substance of extreme hardness, as in stone fruits.
Nature does not shew herself less provident in furnishing
means for scattering seeds, and propagating vegetable species at
great distances. There are, indeed, seeds which, furnished with
light silky plumes or wings, flutter in the air, and are transported
afar by the winds. Others by means of a viscous, hard, imper-
meable envelope float on rivers, and descend their courses without
suffering the slightest change, or losing their germinating power.
There are seeds again of a sufficiently coherent texture to resist
the digestive action of the stomachs of animals that feed on the
fruits which contain them, and which are consequently often
found deposited at great distances from the plant which produced
them; they are thus frequently dropped to germinate and
flourish at the tops of the steepest mountains. By these admi-
rable provisions of nature then, the air, the water, and even
animals themselves become the vehicles by which the migration
of various vegetable species over the surface of the globe is effected.
We distinguish in seeds the kernel, and the integument
which covers or incloses it. In the kernel, the embryo exists,
which as its name indicates is destined to reproduce the plant of
which the seed is the issue. The embryo is formed of several
essential parts:-1st. of the radicle; 2nd. of the gemmule,
plumule, or rudiment of the stem, which by its extension en-
genders the organs that are to vegetate above the ground; 3rd.
of cotyledons which form the greatest portion of the kernel, and
which are destined to support the plant during the first periods.
of its existence.
In most cases, the cotyledons are formed of two lobes which
separate during the act of germination. The plumule presents
itself under the form of a little white point which penetrates into
the interior of both cotyledons. The radicle is of a slightly conical
shape, and is first seen when it projects externally from the seed.
The seeds of gramineous plants do not separate into two parts at
the commencement of their indepedent existence. They are, in fact,
seeds which have but a single cotyledon. As plants which spring
from seeds of one or of more cotyledons present capital diffe-
rences in their organisation at large, and mode of development,
SEEDS.
3
botanists have established two grand divisions among them into-
monocotyledonous vegetables, and dicotyledonous or polycotyle-
donous vegetables.
When the seed is gathered in its state of perfect maturity it is
completely inert, its vital functions are wholly suspended, and it may
be kept often for a very long time without being made to grow.
The length of time during which seeds may be kept, however,
varies extremely, according to the species. There are plants, for
instance, the seeds of which preserve for an indefinite period
their germinative power; there are others, on the contrary, which
lose it very speedily.
From various observations which appear to deserve every con-
fidence, the seeds :-
Of Tobacco have germinated after having been
kept for
Stramonium
"
>>
9)
""
**
"D
"
"
">
"
the Sensitive plant
Wheat
Wheat
Melons
Cucumbers
Haricots
Idem
Rape
Rye
10 years.
25
60
100
10
41
17
33
. 100
17
140
"
""
"
>>
"
"
"
""
♪♪
(Duhamel.)
(Pliny.)
(Duhamel.)
(Friewald.)
(Roger Galen.)
(Gerardin.)
(Lefébure.)
(Home.)
The seeds of the coffee plant are perhaps those which lose the
property of germinating most speedily; planters are well aware
that they must be sown almost immediately after they are taken
from the bush. Oleaginous seeds are generally preserved with
great difficulty, so also are those of rubiaceous plants, of the
laurels, myrtles, &c.*
In practical agriculture there is always much advantage, and
additional security in sowing the most recent seed, even of
kinds which are known to be the longest lived. It frequently
happens, even after a very short time, that a certain proportion
of these seeds die: they have, perhaps, not been gathered under
circumstances favourable to their complete preservation. It is,
*Decandolle, Physiology, page 622.
B 2
4
VEGETABLE PHYSIOLOGY.
"">
therefore, only when he is compelled to do so, that the farmer
trusts wheat to the ground which has been gathered in former
years; and experience has proved that in using such seed, it is
necessary to increase very considerably the quantity sown.
The inactivity of the seed ceases so soon as it is brought into
contact with water and the air under the influence of a sufficient
temperature. Sown in moist earth, a seed absorbs water, and swells
considerably; the pellicle which covers it becomes distended, and
ends by bursting; the radicle and the plumule appear, and be-
come more and more distinct; the root penetrates the ground;
the plumule by and by grows into a stalk which gets greener and
greener, increases rapidly, and augments the number of its leaves,
so that the young plant acquires vigour every day.
At a
certain period, flowers appear; and these are succeeded by fruit,
the final term of which is the maturity of the seed. The phe-
nomena of vegetation then cease. The whole of the organs of
annual plants now wither and die; the work of reproduction,
of multiplication is accomplished. Thus begins and ends the
existence of the plants which are the usual subjects of our
husbandry.
With regard to biennial plants and trees, which possess more
than this ephemeral existence, things pass differently. The plant
vegetates so long as the temperature of the atmosphere and
moisture of the soil are favourable to it; during the cold season
the leaves fall, and the growth is suspended; but the plant
revives anew on the return of spring. Those vegetables, the
stem of which is generally ligneous, and whose roots penetrate
deeply into the ground have a power of resisting cold, and brave
the rigours of the winter. In these latitudes, the renewal of the
vegetation of trees in the spring presents an obvious analogy
to the process of germination: the evolution of the buds re-
presents this process very closely; and the phenomena at large,
which we observe in annual plants, are for the major part re-
produced: there is increase of size in the stem and root, sprout-
ing of leaves, inflorescence, ripening of fruits, production of seeds,
and then suspension of function.
In the tropics, where the temperature is nearly uniform
throughout the year, vegetation gocs on without interruption;
STEM.
5
LO
it only varies in its vigour, and this is determined by the abun-
dance or the paucity of rains and dews. The leaves which have
concurred in the production of the fruit, and in perfecting the
seed, fall as it were exhausted; but they are soon replaced,
and their fall is only perceived by their presence on the surface
of the ground.
The perfect plant, therefore, whether it be studied among
annuals, or among trees that endure for a century, has
analogous organs, destined to fulfil the same functions, to con-
duce to the same end-the reproduction of the seed. These
organs, which we shall study in succession: are, 1st. The roots;
2nd. The stem; 3rd. The leaves; 4th. The appendages of the
fructification.
When we follow the progress of a seed set in a proper soil,
we observe that from their very first appearance, the roots seek
or tend towards the interior of the earth; the plumule, or young
stem, on the contrary, takes a direction diametrically opposite;
it grows vertically and seeks the air.
The lateral shoots in herbaceous plants, and the young branches
of shrubs form various angles with the principal stem or trunk.
The first tendency of the branches is to rise vertically; but as
they gain length and weight, they bend more or less down-
wards yielding to the power of gravitation. Mr. Knight
shewed, by a series of ingenious experiments, that the direction
taken by the roots and branches is mainly due to this force.
This able observer arranged a wheel of wood in such a way
that he could make it turn with different velocities in planes
variously inclined to the horizon. The wheel, which was kept
in motion by a stream of water, could be made to revolve verti-
cally or horizontally at will.
A number of beans were planted upon the circumference of
the wheel, in circumstances known to be indispensable to their
germination and growth. By giving the wheel a sufficient velo-
city, it was easy to make the centrifugal force greater than the
centripetal force. In Mr. Knight's apparatus, this happened when
the wheel in the vertical plan performed one hundred and fifty re-
volutions in a minute. The whole of the radicles were then seen
to turn their suckers beyond the circumference in lines which were
6
VEGETABLE PHYSIOLOGY.
prolongations of the radii of the wheel, and their growth took
place in planes perpendicular to its axis.
The stems took a completely opposite direction, and after a
time their summits attained the centre or axis of the wheel.
In causing the wheel to revolve in a horizontal plane, the same
effects were still observed, when the rapidity of rotation was
sufficient to annul the action of terrestrial gravitation. But
when the motion was so far diminished, as merely to modify
or to lessen the force of attraction, without entirely annulling
it, the plant took a course comprised in a plane which formed
a certain angle with the circumference of the wheel. With a
certain velocity, the roots were inclined 10° below the horizontal
plane in which the wheel moved, and the stems then formed an
angle of the same magnitude above the same plane. The
angle of deviation formed in this position of the wheel was
always smaller in proportion as the rapidity of rotation was
greater.
Now, since gravitation influences the position which vegeta-
bles present, as these beautiful experiments of Mr. Knight
demonstrate, a practical conclusion which seems to follow from
the fact is this, that the number of plants which may be placed
upon a certain extent of soil, does not depend solely on the
extent of surface; and that the power of production of a field
which is very much sloped, does not exceed its horizontal
projection. With regard to creeping plants, and with reference
to meadows, it is clear that this principle is not rigorously
exact; but in so far as plants with isolated stems are concerned,
many agricultural philosophers, and among the number Davy,
have admitted it as perfectly indisputable. This opinion as M.
Corrard has judiciously observed, is founded on the geometrical
principle, which in itself is perfectly true, that an inclined plane
cannot be cut by a greater number of vertical perpendiculars
of a determinate thickness, than the horizontal plane which
serves it for a base. Thus, says Corrard, as buildings which rest
on an inclined plane are raised perpendicularly to the horizon,
it has been concluded that an inclined plane can hold no larger
*
* Agricultural Chemistry, vol. 1.
+ B. Corrard, Verhandel. von der Maatsch. te Haarlem, vol. xv. p. 308.
STEMS.
7
an extent of building than would the horizontal plane which
it covers; so that inclinations of surface do not actually add to
the extent of towns. It is further a matter of absolute cer-
tainty, that as rain falls vertically, the quantity of water collected
upon the eaves of a house is precisely the same as that which
would be guaged in the same place upon a horizontal surface,
equal to that of the building. But we should very much deceive
ourselves, adds Corrard, if upon the same principle we inferred
that on the surface of an inclined plane we could not have a
tree more than upon the much smaller horizontai plane which
serves as its base.
For although plants grow perpendicularly to the horizon,
and may in this respect be considered as so many vertical per-
pendiculars or laminæ, still from circumstances which are peculiar
to them, we cannot here apply with propriety the geometrical
principle in question. Because to make the application exact,
it were necessary to suppose that plants required no space
around them to thrive, and that the whole surface of the
ground might be covered with their steins without any space
being left between them, and without this proximity interfering
with their growth and vigour.
But such a supposition is impossible, inasmuch as it is
absolutely necessary that plants should have a certain amount
of space both in the ground and in the atmosphere, in which
to extend their roots and stretch forth their branches. Sup-
posing, therefore, the inclined plane to be of considerably
greater extent than the horizontal plane which supports it,
it will necessarily afford to a larger number of plants, the spaces
which their roots require for their growth and nourishment. In
other words, upon the inclined surface there will be a larger
quantity of vegetable earth, and more of the nutritious juices
favourable to vegetation; and for these reasons the space which
must always exist between plants may be less than on the
horizontal plane. Consequently all the conditions necessary to
fertility being assumed as equal, the inclined plane will be
capable of supporting a larger number of vegetables having
vertical stems than the horizontal plane.
The organization of different parts of plants, so worthy in
8
VEGETABLE PHYSIOLOGY.
all respects of exercising the sagacity of physiologists, need not be
made a subject of minute research in this place. Generalities
suffice in our agricultural science. This organization, however
complex it is in appearance, is probably much more simple than
is usually believed; we might perchance find the proof of this
simplicity in the readiness with which organs, the most dis-
similar in their external forms and so different in their func-
tions, undergo modification and transformation one into another,
it might almost be said at the will of the observer. Thus
tubers, those fleshy amylaceous bodies, which accumulate on
the subterranean stems of certain vegetables, such as the potatoe,
give birth to a plant which differs in nothing from that which
would arise from the seed of the same vegetable. Certain
leaves, those of the orange, of the ficus elastica, &c., will
do the same. Woody stems, branches severed from the tree
and planted in the ground, produce roots and become inde-
pendent plants. If the branches of certain shrubs be buried,
and their roots be exposed to the air, these last are soon seen
covered with buds and leaves; whilst the buried branches ac-
quire a fibrous capillary structure, and in no great length of time
they both present the appearance and exercise the functions of
roots. This singular mutation readily succeeds with the willow,
and it was upon this plant that the English vegetable physio-
logist, Woodward, effected it for the first time.*
The intimate structure of the roots, trunk and branches,
present considerable similarity, Divided perpendicularly to
their longitudinal axis, three different zones, so dissimilar that
it is impossible to confound them, are discovered in the
different concentric layers which make up their mass; these
are the BARK, the WOOD, and the PITH. A more careful
examination shews that each of these zones may be further
subdivided.
The exterior of the bark is covered by an extremely thin, nearly
transparent and porous pellicle, formed by an assemblage of little
adherent scales; this is the cuticle, or epidermis which encloses
the entire vegetable. As it is extensible within certain narrow
limits only, it gives way and cracks in proportion as the body
* Davy's Agricultural Chemistry.
BARK.
9
of the tree increases in size. The pores of the epidermis are
minute openings or mouths which communicate with the exte-
rior by an oval orifice, surrounded by a kind of contractile
margin. It has been remarked that moisture tends to close
these pores, and that drought and the action of solar light tend
on the contrary to make them open. The chemical nature
of the cuticle which covers the bark appears to indicate that it
is destined to defend the plant against the too direct action of
external influences. In certain trees, the cuticle is covered with
wax or resin. The most remarkable example of this kind,
which can be quoted, is that of the wax tree (ceroxilon
andicola) which grows abundantly upon the slopes of the Andes.
This tree (a palm) which attains a height of between 130
and 164 English feet, is covered over the whole surface of its
trunk with a mixture of wax and resin.* In gramineous
plants, the epidermis is almost entirely formed of silica. The
bark of the birch tree is covered with a pellicle of an unctuous
nature, capable under the agency of nitric acid of yielding
a peculiar suberic (the) acid.†
After the epidermis, in going from the circumference towards
the centre, a layer of cellular tissue appears, which is designated by
many physiologists under the name of the herbaceous envelope.
In the cork oak, the cork represents the tissue by which the
liber or true bark is covered, an organ formed of a vascular tissue,
which with care can be separated into numerous very thin flakes
or layers, which have been aptly compared to the leaves of a book.
The origin of the liber, or bark, is found in the most cen-
tral part of the trunk; it is the result of the exudation of
the woody parts, as Duhamel, with the same wonderful sa-
gacity which characterizes all his works, has proved. Having
cut away a portion of the bark of a tree in full vigour,
and taken care to preserve the incision from contact with the
air, he perceived that from the surface of the wood laid
bare, and the edges of the bark adhering to it, a viscuous
matter exudes, which accumulates, acquires consistency and
* Boussingault, sur le Palmier à cire. Annales de Chimie et de Phy-
sique, 2e série, t. 59. p. 19.
† From the observations of M. Chevreul.
10
VEGETABLE PHYSIOLOGY.
ends by becoming cellular, thus regenerating the liber which had
been taken away. Grew called this viscous secretion cambium,
a title which it still retains. It is now generally admitted that
cambium proceeds from the descending sap.
The liber is a very important organ in vegetables; we know
for instance that it is necessary for the success of a graft, that
its liber penetrate or be penetrated by that of the tree on which
it is grafted.
The woody layers are situated under the liber. Those which are
at the greatest distance from the axis of the trunk, although
they present the fibrous structure, and the principal characteris-
tics of the woody tissue, still differ from it in being less
hard and less tenacious; this zone, which at the first glance is
easily distinguished from the wood properly so called, is the
alburnum, the soft or false wood. Its fibres are much looser,
and its colour paler than that of the wood beneath it, the diffe-
rence of shade being particularly apparent in the dye and deeply
coloured woods.
The alburnum becomes harder and tougher with age, and
passes into the woody tissue, the duramen or hard wood,
properly so called. The wood begins where the alburnum
terminates, and reaches to the centre, to the pith or medullary
canal.
In dicotyledonous trees, a certain quantity of wood is formed
during vegetation at the expense of the alburnum; whilst on
the opposite side towards the bark, the alburnum increases in
about an equal proportion: so that in our climates, the alburnum
grows each year from a new concentric layer; but in tropical
countries, where the dicotyledonous trees vegetate without interrup-
tion, the annual concentric layers are scarcely perceptible. To
prove the conversion of alburnum into woody tissue, Duhamel
inserted a metallic wire into it in several places. At the end of
a few
years he found that the wire had become engaged in the
proper woody layers.
The most central zone of the trunk or stem is traversed by
the medullary canal or sheath, which is usually filled with the
pith, a diaphanous spongy matter, consisting almost entirely of
cellular tissue.
PALMS.
11
The pith sends ramifications towards the external parts of the
trunk. Its use is not exactly determined; and notwithstanding
the high purposes ascribed to it by some physiologists, we have
many reasons for believing that its functions are not of great
importance. Experiment proves, in fact, that the pith may be
removed from young trees without killing them, without even
stopping their growth. One of the least unquestionable offices
assigned to the pith, is that of its being a reservoir for moisture
with which it supplies the plant in times of drought, and when
the ground does not furnish a sufficient quantity of water.
The internal structure and progressive development of the
stem of monocotyledonous plants differs essentially from those
which we have just been describing in connection with dico-
tyledonous plants.
If a perpendicular transverse section of the trunk of a
palm tree be examined, the same arrangement of zones
which is observed in the dicotyledonous plants of our climates
will not be perceived. The regions of the outer bark, of the
liber or true bark, of the alburnum, and of the wood, forming so
many concentric circles round a canal which is their com-
mon centre are no longer distinguishable. The trunk of the
palm tree presents a more homogeneous appearance. The pith
is disposed through the whole substance of the stem, and the
woody tissue, presenting a fibrous texture disposed longitudi-
nally, is found intimately mixed, or felted, as it were, with the
medullary substance. The bark, if there be any, is always
very indistinct; sometimes reduced to a simple epidermis, it is
with difficulty distinguished from other parts of the trunk. In
the beginning, and when it first appears above the ground, a
palm tree puts forth a system of leaves, the adhering extremi-
ties of which are attached in the same plane, and usually sur-
round the neck of the root. At the second shoot, a system
similar to the preceding one appears, which throws off the out-
side leaves, and interrupts their power of vegetating. These
leaves wither, bend towards the earth and fall off, leaving a
projecting circular ring on the stem, the only vestige of their
existence. The same phenomenon takes place periodically. In
the centre of the crown of leaves or branches, which terminates
12
VEGETABLE PHYSIOLOGY.
the palm tree plant, a bud appears which is at first small and
blanched;* but soon displays the most vigorous powers of
vegetation. Its growth, inflorescence, and progress towards
maturity are indicated by the decay and fall of the leaves.
which had hitherto protected it. The age of a palm tree, or
rather the number of times that it has fructified, or become
crowned with fresh leaves, is calculated by the number of
woody circles which are found marked on the stem.
Its power
of lasting seems to have no other limits than the resistance
which the base offers to the weight it supports. In these co-
lossal trees, a sensible diminution in the diameter of the stem
is often perceptible towards the top, and in most of the species
it is a fact equally well proved that the fruit decreases in
quantity when they have attained a certain epoch of their exis-
tence. In the cocoa-nut tree (lodicea cocus nucifera) the
period of this decrease shews itself at about the age of thirty
years, although this tree continues to bear for nearly a
century.†
The leaves, the forms of which are so various, present how-
ever the greatest analogy in their organization: the green mem-
branous substance of which they are almost entirely composed,
is an extension of the parenchyma; the envelope which covers
them answers to the epidermis.
It is in the leaves that the sap is subjected to the action of
the atmosphere; it is there concentrated and peculiarly modi-
fied. According to the position of leaves upon the plant, their
under sides, or those turned towards the ground, are distin-
guished from their upper sides which meet the light from
above..
The upper side of the leaf is covered with a thick and
frequently shining epidermis; this epidermis is sometimes
indued with a substance rich in silicious matter, as in rushes.
In the Steppes of South America, I observed a tree, called
Chapparal, the leaves of which are so highly silicious, that they
* This bud, in certain species of palm trees is sought after as food, and
is often spoken of as the cabbage of the palm tree.
† Information communicated by Mr. Codazzi. The trunk of certain
species of palm trees shews an enlargement towards the middle of its
height, as in the palma barrigona of Choco.
FLOWER.
13
are used for polishing metals. Generally speaking, the covering
of the upper surface of leaves is a matter which is something
of the nature of wax or resin. The epidermis which covers
the lower surface is formed in most cases of a very thin,
rough membrane, full of cavities and frequently covered with
hairs or down.
The appearance and position of the leaves are not the same
during the day and night. In the dark, simple leaves incline to
fold up; in compound leaves, as in those of the acacia and sen-
sitive plant, the same thing is still more marked; the effect
can even be produced at will. If during the day a sensitive
plant is placed in a dark room, the leaves immediately close; on
lighting the room even with candles, they open again as if under
the influence of the solar light;* Linnæus, who first paid atten-
tion to this class of phenomena, admits that plants in the absence
of light experience a sort of sleep.
The flower is the forerunner of the fruit, the fruit is the
medium in the heart of which the seed is developed. The
organs which constitute the flower are the calyx and the corolla,
destined to support, nourish and protect the pistil and the
stamina, which are the essential parts; the calyx is a green.
membrane which surrounds the corolla, and in certain flowers
replaces it.
The corolla is monopetalous or polypetalous according as it is
composed of one or of several pieces. The stamens occupy
the interior of the corolla; they are terminated by summits of
a vascular texture; these are the anthers; the powder which
covers and sticks slightly to them is designated under the name
of pollen..
The pistil placed in the middle of the flower is composed of
the ovary, the style and the stigma.
•
The ovary encloses the germ, the embryo of the seed; but
this embryo is only developed by the action of the pollen. The
style is in some sort the tubular prolongation of the ovary; it
supports the stigma, which is the glandular part that receives
the fecundating influence of the pollen.
From what has now been said, the pistil may be consi-
* Observation of M. de Candolle.
14
VEGETABLE PHYSIOLOGY.
dered as the female organ of the flower, the stamens as the male
organs.
Many flowers combine the organs of the two sexes. These
flowers are hermaphrodites; those which only contain one organ,
are called unisexual. Both male and female flowers are pro-
duced together on certain plants; in others, the flowers are all
only of one sex, male or female. Polygamous plants are those
which shew a union of male and female flowers, or which have
hermaphrodite flowers on the same stem.
In some flowers, the sexual organs at the period of fecunda-
tion acquire the property of motion, so as to facilitate this grand
act. The stamens, for example, are seen in certain plants to
approach the stigma, to deposit their pollen on it, and then to
withdraw. It occasionally happens again that stamens, which
are at first naturally in a position inclined with reference to
the pistil, become suddenly straightened in such a way as to
cast their pollen on the female organ, after which they resume
their original position. In certain flowers a very considerable
evolution of caloric has been perceived on the approach of the
period of fecundation. In some arums, for example, the tem-
perature has been observed to rise to 40° and even 50° cent.
(104° to 122° Fahr.) It is probable that this phenomenon is
quite general, and that it only varies in point of intensity.
Fecundation accomplished, the office of the flower is at an
end. It collapses, withers, and dies. But the impregnated
ovary enlarges by degrees, until it has attained maturity, when it
presents two distinct parts, which by their union compose the
fruit: these parts are the pericarp, and the seed-the husk or
shell and the grain. The pericarp always surrounds the seed;
but it sometimes happens that it is so thin and delicate that it
blends with the seed.
The germination of seeds, the evolution of new plants, is only
accomplished under certain physical conditions which demand
our consideration.
We have already said incidentally, that in order that a seed
may germinate, it must be in contact with moisture, have com-
munication with the air, and be under the influence of a certain
temperature. The same conditions continue to be indispensable
ROOTS, SAP.
15
after the seed has sprung, and the plant has been organised;
and in addition the access of light is now imperative.
Roots seek in the soil the moisture which is requisite to vivify
the whole vegetable. These organs are terminated by hair-like
fibres of extreme delicacy, and having spongioles at their extre-
mities it is by these spongioles that absorption is effected.
The following experiment is sufficient to prove that this is the
case let such a plant as a turnip be placed with the hair-like ex-
tremities of its root plunged in water, and the plant will continue
to live, although almost the whole body of the root is in the
air; let things be now so arranged that the hair-like filaments
of the root are not in the water, but that the bulb or body of
the plant is so the leaves will soon droop and wither.
The force which brings into play the suction power of the
roots, resides in almost every part of the plant: thus a root de-
prived of its spongioles, a stem, a branch and a leaf, exert this
suction power when plunged in water. But the absorption
effected in this way has a limit, and we soon discover the neces-
sity of making fresh sections of the extremities, which have
no power of renovation like the filaments furnished with spon-
gioles, which terminate a root.
We are still ignorant of the cause which produces the
ascent of liquids in vegetables, and which carries them to the
remotest leaves, in spite as it were of the laws of hydrostatics.
We readily conceive how the spongioles of the roots, surrounded
by earth abundantly charged with moisture, should imbibe by
the simple effect of porosity. We can also understand how,
after having been modified by the spongioles, the water and the
principles contained in it should be transformed into sap; but
the porosity of the extremities of the roots, and the chemical
modification effected by the spongioles upon the fluid imbibed,
give no kind of explanation of the rapid ascent of the sap. The
force which occasio..s this rise is very considerable, as was de-
monstrated by Dr. Stephen Hales in a series of ingenious ex-
periments more than a century ago.
Hales adapted a tube bent at a right angle and filled with
water, to the extremity of the root of a pear tree, the point of
which had been cut off; the extremity of the tube opposite to
16
VEGETABLE PHYSIOLOGY.
that which was connected with the root dipped into a bath of
mercury. In a few minutes a portion of the water contained
in the tube was absorbed, and the mercury rose above the surface
of the bath to the extent of eight inches. In the beginning
of April, Hales cut off a vine stem at the distance of thirty-
three inches from the ground. The stem had no lateral
branches, and its cut surface, which was nearly circular, had a
diameter of 7ths of an inch. To this section, he adapted a reversed
syphon and things being so disposed, he poured in a quantity
of mercury, which after a time, and from the effect of the
pressure exerted by the sap as it escaped, rose in one of
the arms of the syphon, and remained stationary at the
height of thirty-eight inches above its original level. This
column of mercury, it is obvious, represents a pressure very
much greater than that of our atmosphere.
The ascent of the sap in trees takes place by the woody
layers. It is easy to obtain conviction of this by making a
plant absorb a watery solution of cochineal. By making sec-
tions in the stem at different heights, we can readily trace the
coloured liquid in its progress; it is undoubtedly the course
which the natural sap would have taken. We see no indication
of the colouring matter in the pith nor in the bark, the woody
tissue alone is coloured, sometimes entirely, but more ge-
nerally in its younger parts only. The dyeing which results from
this injection of the wood is in lines, and parallel with the axis
of the trunk, like the woody fibres themselves; but in some
cases the sap may deviate from the rectilinear course. Hales
showed this by the following experiment: upon a tree he made
four notches, one above the other; each notch occupied one
quarter of the trunk and reached to its centre. In this way the
whole of the woody fibres were cut through at different heights,
so that to continue its ascent the sap must necessarily expe-
rience a series of lateral deviation, which in fact took place.
The ascending sap of vegetables, as it has hitherto been
procured for examination, is an extremely watery fluid, holding
in solution very small quantities of divers saline and organic
substances. Having attained the leaves, the sap there under-
goes modification, and becomes concentrated by losing water.
THE SAP EXHALATION.
17
It at the same time experiences through the agency of the
atmospheric air, under the influence of light, a great modifi-
cation in its constitution. Thus elaborated, the sap takes a des-
cending course; following the liber, it retrogrades towards the
soil, and therefore performs a kind of circulation in its passage
through the plant. The descending course of the sap is demon-
strated by throwing a ligature round the trunk of a tree; after a
time there is formed, above the part that is tied, an enlargement
which is owing to the accumulation of the principles of the sap; but
below it the tree experiences no increase. The descending course
of the elaborated sap is no effect of simple gravity; because, if the
ligature be thrown around a pendant branch, the enlargement still
forms between the ligature and the free extremity of the branch.
The descending sap passing through the cortical layers must neces-
sarily contribute to their formation; and it is almost certain, as
appears from the capital experiment of Duhamel, that it is the
cambium which is changed into liber, and so concurs in the
growth of trees. The concentration of the ascending sap, which
occurs during its passage through the leaves, by the simple effect
of evaporation, is the phenomenon which is spoken of under the
name of the exhalation of plants: this exhalation of plants, it
is easily understood, is favoured by a high temperature, dryness
and motion of the air. In favourable circumstances, the water
escapes in the state of vapour. Hales compared the watery
exhalation of plants to the perspiration of animals, and made
many experiments to ascertain the quantity of watery vapour
which they usually throw off.
Hales planted a sun-flower in an air-tight vessel, the top of
which was sealed hermetically by a leaden cover. This cover
was pierced by two holes: one for the passage of the stem of
the plant, the other for the introduction of the water necessary
to its growth. For a fortnight the apparatus was regularly
weighed, and our ingenious experimenter found that the green
parts of the sun-flower threw off on an average about twenty
ounces of water in twelve hours of the day. The evaporation
was always increased during dry and warm weather; moist
air lessened it; during the night season, the evaporation was
с
18
CHEMICAL PHENOMENA OF VEGETATION.
sometimes no more than three ounces, and it occasionally hap-
pened that it was nil.
Vegetable life appears to be intimately connected with the
phenomenon of evaporation. From the inquiries which I have
myself undertaken on this subject, so well deserving the atten-
tion of observers, it would appear that a plant grows only when
it transpires, and that in hindering this transpiration, we in
fact arrest vegetation.
-
We now associate with the phenomenon of exhalation the
source or accumulation of certain substances which are met
with in considerable quantity in the organization of plants, al-
though scarcely a trace of them can be detected in the water
with which they are supplied. The water evaporating, leaves
these substances behind; and as the mass of liquid imbibed
by the roots and exhaled by the green parts is very consi-
derable, it is easy to conceive how they should finally come to be
present in rather large quantity.
A portion of the water which a plant in full vigour absorbs,
must necessarily enter into its constitution; the water exhaled
by the leaves, therefore, cannot equal the whole of that which
has been absorbed by the roots. Sennebier endeavoured to
ascertain the relation which exists between the absorption and
the exhalation, and he found in the particular case which he
observed, that about of the water absorbed was fixed, and
became a constituent part of the vegetable.
]
§ II. CHEMICAL PHENOMENA OF VEGETATION.
THE chemical phenomena of vegetation are accomplished by
the concurrence of the elements of the atmosphere, of water,
and of certain organic substances which exist as constituents
of the soil.
The action of the atmosphere upon plants presents two
phases perfectly distinct from one another: germination, and
vegetation properly so called, which last comprises the develop-
ment, the growth, and the multiplication of species.
GERMINATION.
19
GERMINATION.
WE have ascertained that a seed considered with reference to
its organization; consists, 1st. of an embryo which includes the
germs of the root and of the stem; and 2nd, of the cotyledon, or
cotyledons. Considered with reference to their chemical compo-
sition, seeds exhibit a certain similarity of constitution. They
contain: 1st. starch and gum; 2nd. a highly asotized matter
analogous to the caseum of milk and animal albumen; this is
the matter which is commonly and very improperly designated
under the name of gluten, and of vegetable albumen; 3rd.
a fatty or oily matter, rich in carbon and hydrogen. Seeds
contain either fixed oils, such as hemp seed, rape seed, &c. or
volatile oils, as aniseed, cummin seed, &c. The different prin-
ciples which are associated in the seeds vary considerably in their
relative proportions: they also vary slightly in their nature. One
seed, that of the colewort, for example, will contain more than
forty per cent of its weight of oily matter, while another,
such as wheat, will only contain a few hundredths. Oats may
contain ten or twelve per cent of caseum or gluten; in certain
varieties of wheat, analysis indicates a much larger quantity.
The proportions of starch, gum, sugar, or mucilage do not vary
less. It almost always happens, that these different substances
are found associated in the same seed; sometimes one predo-
minates and the others only enter in very small proportion.
After burning, the ashes of seeds are always found composed
of phosphates, sulphates, and alkaline and earthly chlorides.
These ashes also contain silica, and certain carbonates produced
by the destruction of salts formed by organic acids.
If some seeds, sufficiently moistened, are placed under a
bell glass containing atmospheric air confined over quicksilver,
all the signs of germination will soon be perceived. In the
course of a few days, provided the temperature has been suffi-
ciently high, germination will have made a certain progress. Sup-
posing that the temperature of the bell-glass has not varied,
and that the atmospheric pressure remains the same, we gene-
rally find that the air, in which germination has been proceeding,
has not changed its original volume; but it has been modified
C 2
20
CHEMICAL PHENOMENA, &c.
in its composition: a notable quantity of carbonic acid has been
formed, and a portion of oxygen has disappeared. The volume
of carbonic acid produced, represents for the most part the
volume of oxygen which has disappeared. Now we know that
carbon being burnt in a certain volume of oxygen gas, pro-
duces sensibly an equal volume of carbonic acid gas. It was
the knowledge of this fact that induced M. de Saussure to say,
that in germination, carbonic acid is produced by the combus-
tion of a portion of the carbon which enters into the composi-
tion of the seed.
Germination and the appearance of carbonic acid, (which
is always its consequence) take place as readily in pure oxygen
gas, as in atmospheric air; but if placed in an atmosphere
deprived of oxygen, seeds cease to germinate. Consequently,
germination is out of the question in azote, in hydrogen, or in
carbonic acid, however favourable they may be in reference to
humidity and temperature. Some formation of carbonic acid
is indeed to be observed under such circumstances, but then
this gas is the result of the decomposition and putrid fermen-
tation of the seed. It is therefore by means of the oxygen
which it contains, that atmospheric air concurs in the germina-
tion of seeds.
Rollo was the first who ascertained the production of carbo-
nic acid, during the germination of seeds in an atmosphere of
oxygen; but it was M. Theodore de Saussure, who by delicate
eudiometrical experiments, demonstrated the phenomena in all
their nicety, by proving that the oxygen consumed was replaced
by a corresponding volume of carbonic acid.*
There are some seeds, for instance, peas, and the seeds of
aquatic plants, which have the property of germinating under
water. Some observers have, from this fact, come to the
premature conclusion that atmospheric air, and consequently
oxygen were by no means necessary to germination. Saus-
sure has explained this anomaly by referring to the constant
presence of air in a state of solution in water.
In fact,
having placed some seeds of the polygonum amphibium under
* Saussure, Recherches chimiques sur la Végétation, p. 10.
GERMINATION.
21
water, deprived of its air by long-boiling, Saussure proved
that germination could not take place.*
Under like circumstances, the quantity of carbonic acid
generated in a given time, is by so much greater, the larger
the quantity of oxygen in the atmosphere which immediately
surrounds the germinating seed. Carbonic acid gas is of all
the gases which have been tried, that which is most unfavourable
to germination; and one way of hastening the process is to place
under the receivers which cover the seed, some substance capable
of absorbing it as fast as it is formed-quick lime, for example.
By this arrangement the radicular increase is sensibly ac-
celerated.†
1
100
10
The quantity of oxygen gas necessary to germination, is not
the same in reference to all seeds; lettuce, the french-bean,
and the field-bean require about part of their respective
weights; while less is sufficient for wheat, barley, purslane,
&c. Saussure moreover came to the conclusion that the carbonic
acid generated by these different seeds in germinating is
proportioned to their mass, and altogether independent of
their number.‡
Inasmuch as seeds during germination yield carbonic acid to
the atmosphere, it is quite obvious that they must lose some
part of their original weight. And this they do in fact; but
the loss experienced by seeds which have germinated is always
greater than that which would have resulted from the destruc-
tion of carbon that takes place. Saussure attributed this excess
of loss to the volatilization of a portion of the water which
entered into the composition of the seed.|| According to
Saussure, therefore, the phenomena of germination resolve
themselves into the diminution of carbon and of the elements
of water. It is, nevertheless, doubtful whether the chemical
actions are so simple as this; we know, for example, that M.
Becquerel considered the organic acid which appears during
* Saussure, Recherches chimiques, &c. p. 3.
† Idem, p. 26.
‡ Idem, p. 13.
|| Idem, p. 20
22
CHEMICAL PHENOMENA, &c.
germination as acetic acid, whereas it is much more likely that
it should be the lactic acid. There is certainty of the for-
mation of an acid during germination; to prove its develop-
ment it is sufficient to make a few moist seeds sprout on
blue litmus paper, which speedily acquires the permanent red
tint indicating the presence of an acid.
The volume of the air in which seeds germinate is not absolutely
invariable. On examining, with renewed attention, the action
of germinating seeds on a limited volume of air, M. de Saussure
ascertained that certain seeds have the property of diminishing
the bulk of this atmosphere, while others perceptibly augment it.
It must be admitted, therefore, that during germination, the
volume of carbonic acid produced is now greater, now less than
the volume of oxygen gas that is consumed. The nature of the
results obtained, appears, however, to vary in regard to the same
class according to the stage of the germination.
Elementary analysis appeared to me the most satisfactory
means of investigating the subject of germination. I shall here
recapitulate a few attempts that have been made in this direction,
less however with a view to the final settlement of the question,
than to point out the general method of procedure to those who
would enter farther upon this interesting portion of physiology.
The experiments I allude to were made upon the seed of trefoil
and on wheat.
The seed, on being dried at a heat of 110° cent. (230° Fahr.),
lost 0.120 of water. Duly moistened, it was placed to sprout on
a porcelain plate. As soon as the radicle had attained a length
of from 4th to th of an inch, each seed was placed in a stove,
the temperature of which was sufficiently high to check the
growth immediately. The complete desiccation was then termi-
nated over an oil bath at a temperature of 110° cent. (230°
Fahr.)
The seed put to germinate weighed 2.474 grammes (38.193
grains troy); perfectly dry, its weight would have been 2.405grms.
(37.128 grains troy). When germinated, the seed, also quite
dry, weighed 2.241grms. (34.596 grains troy.)
GERMINATION.
23
Analysis gives us the composition of
THE SEED BEFORE germinaTION.
Carbon.
Hydrogen
Azote
Oxygen
•
50.8
6.0
7.2
36.0
100.0
THE SEED AFTER GERMINATION.
51.5
"
""
1.049 of carbon,
1.404 of oxygen,
"
""
RESULTS OF EXPERIMENT.
Grains troy.
Carbon.
Azote.
Seed placed to germinate 38.193 contg. 18.865
Seed after germination. 34.596
Difference
3.597
Hydrogen. Oxygen.
2.223 13.369 2.670
2.176 11.840
17.815
2.763
1.050 — .047 — 1.529+ .093
The total loss then during germination was 0.164grm.,
(2.531grs.), while the loss due to the carbon, only amounts to
0.068grm. (1.049gr.): the analysis shows besides that in this
particular case, the excess of the loss over and above that
which is to be ascribed to the carbon, is not altogether due to
the elements of water, inasmuch as it is partly expressed by
carbonic oxide: for
M
6.3
8.0
34.2
100.0
represent 2.453 of carbonic oxide.
Supposing this to be so, and if this first period of the germina-
tion of the clover had been conducted in a close vessel, the
volume of atmospheric air would have been increased; because
1 volume of carbonic oxide + a volume of oxygen-1 volume
of carbonic acid gas. It is consequently evident that for each
volume of carbonic oxide produced from the seed, there is one
half of this volume added to the total volume of the atmosphere.
It will not perhaps be useless to advert to the circumstance
that the increase of volume, which in the experiment I have just
related must have amounted to about twenty-five cubic inches,
would certainly have passed undetected, even if the operation had
been conducted in a close vessel. For inasmuch as several
quarts of atmospheric air must have been used to place 38.193grs.
of seed in conditions favourable for germination, it may readily
be imagined that the increase of volume must have been too
small a fraction of the total mass of air to be appreciated with
any certainty.
C 3
24
CHEMICAL PHENOMENA.
GERMINATION OF WHEAT.
The wheat employed on being dried lost 2.562 grains of mois-
ture. Thirty-one particles were arranged for germination, which
process was suspended immediately after the appearance of the
radicles. The young stalks were hardly visible. The germinated
grain looked slightly shrivelled: on being crushed, after having
been dried, it scarcely differed in appearance from ordinary wheat
reduced to powder, a considerable quantity of starch being still
recognisable.
The wheat before germinating, taken as dry, and free from
ashes, weighed 2.439grms. or 37.653grs. troy.
The seed when germinated and gathered, under the same
condition, weighed 2.365grms. or 36.510grs. troy.
Elementary analysis gives for the composition of:
Carbon.
Hydrogen
Azote
Oxygen
WHEAT NOT GERMINATED.
46.6
5.8
3.45
44.15
100.0
Wheat placed to germi-
nate
37.653 contg. 17.47
Wheat when germinated 36.510
17.15
Difference
1.143
رو
>>
""
RESULTS OF EXPERIMENT.
Grains troy.
Carbon.
در
C
3:5
در
Hydrogen. Oxygen. Azote.
2.176
2.145
0.032 0.031 -0.073 +0.062
16.56 1.281
15.83 1.343
OF THE GERMINATED WHEAT.
47.0
5.9
3.7
43.4
100.0
-
0.324 of a grain of carbon +0.432 of a grain of oxygen re-
present 0.756 of a grain of carbonic oxide; 0.030 of a grain of
hydrogen would require 0.247 of a grain of oxygen to form
water. Now, the oxygen remaining, abstraction made of that
which enters into the formation of the carbonic oxide, is 0.293
of a grain.
In the first period of its germination, therefore, wheat, like
clover seed, experiences a loss which may in great part be re-
ferred to the elimination of carbonic oxide. The chemical compo-
sition of these two kinds of seed at more advanced periods of their
germination, no longer presents relations so simple. We easily
discover that carbon continues to be eliminated; but the loss no
GERMINATION.
25
longer corresponds with that which the oxygen of the seed ought
to suffer, in order that the total loss should be represented by a
definite compound of carbon. The phenomenon, in fact, becomes
extremely complex; and we can even perceive that it must
be so, when we reflect that in proportion as the green parts
are evolved, a new chemical action is set up, entirely different
from that which takes place in the earliest periods of the germi-
nation; the green matter of vegetables having, as we shall
find, the singular faculty of decomposing carbonic acid gas, and
assimilating its carbon under the agency of light.
This action of the green matter begins to be manifested long
before the first phases of germination have entirely ceased; so
that during a certain time two opposite forces are at work simul-
taneously. One of these, as we have seen, tends to discharge
carbon from the seed; the other tends to accumulate this ele-
ment within it. So long as the first of these forces predominates,
the seed loses carbon; but with the appearance of the green matter
the young plant recovers a portion of this principle; finally, when
by the progress of the vegetation, the second force surpasses the
first in energy, the plant grows, increases, and advances to maturity.
The presence of light is indispensable to the manifestation of
the chemical force by which the green parts of plants appropriate
the gaseous elements of the atmosphere. Germination, on the
contrary, may take place in absolute darkness; and it would be
curious to inquire into the issues of vegetation begun and ended
under such circumstances, in which the organs produced by the
seed would have no power to fix any of the principles of the
atmosphere to repair the loss of carbon which the seed suffers.
It is evident that this loss of carbon must have a limit, which is
probably that of germination.
CONTINUED GERMINATION OF PEAS.
Ten peas, weighing together 2.237grms. or 34.534grs. troy,
taken as quite dry were put to germinate in a dusky room, the
temperature of which was maintained between 12° and 17° cent.
(54° and 63° Fahr.) The experiment, begun the 5th of May
was ended on the 1st of July.
The germinated peas when dried, weighed 1.075grm. or
16.595grs. troy.
c4
26
CHEMICAL PHENOMENA, ETC.
Composition of the peas:
BEFORE GERMINATION.
Carbon
Hydrogen
Azote.
Oxygen
Ashes.
Peas set to ger-
minate
•
Peas which had
germinated 16.595
Difference
-17.939
Grains troy.
Carbon
Hydrogen
Azote
Oxygen
Ashes
46.4
6.1
4.2
40.1
3.1
100.0
•
SUMMARY OF THE EXPERIMENT.
"
""
""
Carbon. Hydrogen. Oxygen. Azote. Salts, Earths.
34.534 contg. 16.055 2.115 13.847 1.451 1.065
7.302 1.003 6.128 1.111 1.065
-8.753-1.112 — 7.719-0.340
0.000
Peas, during their germination, pushed to this extreme term,
therefore, suffered a loss of about 52 per cent., the loss being
referable to each of their constituent elements, which are
summed up in carbon, water and ammonia:
BEFORE GERMINATION.
>>
•
""
7.719 of oxygen taking 0.972 of hydrogen to form water;
0.339 of azote requiring 0.077 of hydrogen to form ammonia;
In this experiment, therefore, we see that a seed weighing
3.458grs. troy, suffered a daily loss of about 0.077 of a grain troy
of carbon.
45.5
5.7
3.4
43.1
2.3
100.0
CONTINUED GERMINATION OF WHEAT.
On the 5th of May, 46 corns or grains of wheat, supposed to
be quite dry, and weighing 1.665grm. or 25.704grs. troy, were
set to germinate in the dark.
On the 25th of June, the germinated wheat, when dried,
weighed 0.713grm. or 11.007grs. troy.
Composition :
1.049 which represents as nearly as possible the
quantity of hydrogen eliminated.
After GERMINATION.
44.0
6.0
6.7
36.9
6.4
100.0
>>
"
>>
"
در
AFTER GERMINATION,
41.1
6.0
8.0 supposed.
39.5
5.4 calculated.
100.0
GERMINATION.
27
Wheat placed to
•
•
SUMMARY OF THE EXPERIMENT.
Grains troy.
germinate 25.704 contg. 11.702 1.466 11.084 0.879 0.586
Wheat germi-
nated
Difference
11.007
-14.697
ور
>>
Carbon. Hydrogen. Oxygen. Azote. Salts, Earths.
4.523 0.663 4.353 0.879 0.586
-7.179-0.803-6.731 0.000 0.000
During the germination, continued for fifty-one days, conse-
quently this wheat lost 57 per cent., and the loss may be wholly
referred to the elements of carbonic acid and water, i. e. to car-
bon, hydrogen, and oxygen.*
These results of the elementary analysis of seeds of different
kinds, before and after germination, tend, therefore, to show that
the chemical phenomena which take place in the earliest periods
of germination, continue to go on even after the organic matter
of the seed has been changed into a proper vegetable, imperfect
undoubtedly, but still possessing the essential organs of plants,
-roots, a stem and leaves. Deprived of light, the blanched
vegetable may be said to vegetate in a negative manner, ex-
pending, exhaling the elementary principles contained in the
seed whence it sprung.
The general practice of sowing seeds at some depth in the
ground, led to the belief, for a long time, that light was
prejudicial to germination. Sennebier had even inferred so
much from his experiments, which appeared to derive con-
firmation from those of Ingenhousz, and which were instituted
for the express purpose of discovering the comparative influences
of sun-light and darkness on the germination and growth
of vegetables. But M. de Saussure showed that the pre-
judicial influence attributed to the light was connected with
the drying of the seed, in consequence of its exposure to a
higher temperature. M. de Saussure caused seeds to ger-
minate at the same time under two bell-glasses of equal
capacity. One of these shades was opaque, the other was
* The small quantity operated on prevented any estimates being made of
the azote lost. Its proportion was supposed not to have varied. It is
extremely probable, however, that there was some slight disengagement of
azote as in the preceding experiment.
† Saussure, Rech. Chimiques. p. 23.
C 5
28
CHEMICAL PHENOMENA, ETC.
transparent, and so placed as to receive the diffused light of
day. The temperature was the same in either. The seeds
sprung simultaneously under both glasses.* Within a few
days, the vegetation under the transparent shade was most ad-
vanced; which is exactly what we should have expected from
all that has already been said of the functions of the organized
parts subjected to the action of light.
We are indebted to M. de Humboldt for a number of very
curious observations on the property which chlorine possesses
of stimulating or favouring germination. This action of chlo-
rine is so decided, that it is apparent even upon old seeds
which will not germinate when placed under ordinary circum-
stances. The experiments of M. de Humboldt were made in
the first instance, on the common cress, (lepidium sativum).
The seeds were placed in two test tubes of glass, one of which,
contained a weak solution of chlorine, the other common
water. The tubes were placed in the dark, the temperature
being maintained at about 15° cent. (59° Fahr.) In the
chlorine solution, germination took place in six or seven hours;
from thirty-six to thirty-eight were required before it was
manifest in the seeds in the water. In the chlorine, the radi-
cles had attained the length of 0.0585 Eng. inch, after the lapse
of fifteen hours, whilst they were scarcely visible at the end
of twenty hours in the seeds submerged in water.†
In the botanical gardens of Berlin, Potsdam, and Vienna,
this property of chlorine has been made available to excellent
ends; by its means many old seeds, upon which a great variety
of trials had already been made in vain to make them sprout,
were brought to germinate. At Schoenbrunn, for instance,
they had never succeeded in raising the clusea rosea from the
seed; but M. de Humboldt succeeded at once, by forming a
paste of peroxide of manganese, with water and hydrochloric
acid, in which he set the seeds of the clusea, and then placed
them in a temperature of from 62° to 75° cent. (143° to
167° Fahr.) It seems very likely that this discovery of M.
de Humboldt may yet be taken advantage of in our everyday
* De Saussure, op. cit. p. 23.
‡ Humboldt, Flora Fribergensis subterranea, p. 156.
+
EVOLUTION AND GROWTH.
29
husbandry. It is quite certain that the whole of the seed which
we commit to the ground, does not spring up, especially when
we are forced to have recourse to seed that is two or three years'
old; the loss is then frequently very considerable. But a solution
of chlorine, or a mixture which would evolve it, could not cost
much, its use would add little or nothing to the very trifling
expense which is generally incurred in pickling the wheat that is
employed as seed.
§ III.-EVOLUTION AND GROWTH OF PLANTS.
As germination advances, we see those organs acquiring
shape and size which had appeared at first in the rudimentary
state. The roots extend in length, and increase in number,
and their extremities become covered with capillary fibres. The
stem as it rises puts forth branches in all directions which
become covered with leaves. The cotyledons which had
nourished the young plant during the first days of its existence,
wither and fall. Under the influence of the solar light, the vege-
tation progresses amain, and the organic matter, which finally
constitutes the plant when it has attained maturity, weighs vastly
more than the same matter which existed previously in the seed.
To quote a single instance from the family of annual plants, a
seed of field beet of the weight of .06175 of a grain, may by
the end of the autumn give birth to a root which with its leaves
shall weigh 162099grs., or upwards of 28lbs.*
This immense and rapid assimilation can have no other
source than the soil, the air and water. Without, at this time,
pausing to consider the useful influence which the soil, and the
substances it contains, exert upon the entire development of vege-
tables, we shall here assume it as a general principle that water
and the air of the atmosphere alone, are capable of furnishing
them with all the elements which enter into their composition,
to wit-carbon, hydrogen, oxygen, and azote. In other words,
a seed may germinate, vegetate, give birth to a plant which
shall attain to complete maturity by the mere concurrence of
* Actual weight of a beet-root grown at Bechelbronn in 1841.
30
EVOLUTION AND GROWTH.
water and the gases, or vapours which are diffused through the
atmosphere. This fact is demonstrated by the following ex-
periment:-
In a sufficient quantity of properly moistened roughly pounded
brick-dust, (which had been heated to redness in order to destroy
every trace of organic matter,) a few peas were sown on the
9th of May, and the pot was transferred to a green-house in order
to protect the plants from the dust and impurities which always
fly about in the open air.
On the 16th of July, the peas, which looked extremely well
and healthy, were in flower. Each seed had sent forth one stem,
and each stem, abundantly covered with leaves, bore a flower.
On the 15th of August the pods were ripe; no more water
was given, and by the end of the month the plants were dry.
The length of the stalks varied from about three feet three
inches to five feet; but they were extremely slender, and the
leaves not more than one third the ordinary size. The pods
were 1.3 inch, by from 0.3 to 0.4 of an inch broad. They
generally contained two peas each; one contained a single pea
only, but this was almost twice the size of any of the others.
In the course of three months, therefore, these peas came to
perfect maturity-ripe seeds were gathered. The analysis of
the crop, which I shall give by and by, in connexion with
another question which we shall have to discuss, showed that
the harvest obtained under the conditions indicated, contained a
considerably larger proportion of each of the elements found
than was originally contained in the seed from which it sprung.
Carbon being the predominating principle in plants, it is our
first duty to inquire into the origin of so much of this element
as is assimilated in the course of vegetation.
Carbon is met with in very small quantity in the atmos-
phere in the state of carbonic acid, and as this is one of the
most soluble of the gases which enter into the constitution of
the air, water always contains a considerable quantity of it in
solution. Carbonic acid may therefore be in relation with
plants by the medium of the air amidst which they live, and
of the water which is no less indispensable to their existence.
We have now to ascertain in what way this gas evolves and sets
free its carbon in favour of living vegetables.
ASSIMILATION OF CARBON.
31
Bonnet, having put some fresh leaves at the bottom of a jar
containing spring water, observed that when exposed to the
rays of the sun, they gave off bubbles of air. He sought to
ascertain whether this disengagement of gas was due to the
leaves, or to the liquid in which they were contained. For the
spring water, he therefore substituted water deprived of its air
by boiling, and he found that the leaves exposed to the sun's
light in this water, no longer gave off any bubbles of air.
Bonnet, therefore, concluded, that the gas which he collected
in his first experiment, proceeded from the water.
In 1771, Priestley discovered, that by emitting oxygen, plants
had the property of ameliorating atmospherical air, which had
been vitiated by the respiration of animals or by combustion.*
This unexpected discovery immediately arrested the attention
of vegetable physiologists. Nevertheless, Priestley was not yet
master, so to speak, of the capital experiment which he had
announced to the world of science. He had not seized all the
circumstances which assure its success. Occasionally the leaves
which were the subjects of experiment did not cause the disen-
gagement of any gas; occasionally, too, the air disengaged far
from being oxygen,-far from ameliorating the atmosphere, was
found to be carbonic acid gas. It was Ingenhousz who made
out the influence of the solar light upon the phenomenon in ques-
tion. He proved, by a vast number of distinct experiments,
that leaves exhale oxygen when they are exposed to the light
of the sun. He perceived, moreover, that in the dark they
vitiate the air, rendering it improper for respiration and com-
bustion.t
But the origin of the oxygen disengaged from water by leaves
exposed to the light of the sun still remained to be discovered.
It was Sennebier who took this important step, by showing
that it was to the carbonic acid generally contained in water
that leaves exposed to the sun's light owed their faculty of
evolving oxygen gas. With this interesting fact, it was easy to
render an account of all the anomalies that had been successively
announced boiled water, as Bonnet had observed, could not
:
* Experiments and Observations, vol. 11.
† Experiments on Vegetables.
32
EVOLUTION AND GROWTH.
afford any air, and spring water should usually give more than
river water as Ingenhousz had noticed, for the simple reason
that boiled water neither contains carbonic acid gas nor any
other kind of air; and that well water generally contains a larger
quantity of carbonic acid in solution than river water.
In giving the grand features in the history of this brilliant
discovery of the eighteenth century, it may be said that Bonnet was
the first who observed the phenomenon of the gaseous evolution
effected by the leaves of vegetables ;* that Priestley announced
that the gas disengaged was oxygen; that Ingenhousz demon-
strated the necessity of the solar light to the production of the
phenomenon; finally, that it was Sennebier, to whom was re-
served the honour of showing that the oxygen gas obtained
under these circumstances is the product of the decomposition.
of carbonic acid.
It was, however, matter of supreme interest to study this
decomposition of carbonic acid in its last details. It was im-
perative, for instance, to ascertain what relation existed between
the volume of the oxygen disengaged and the volume of the
carbonic acid decomposed. This was admirably accomplished
by M. Theodore de Saussure in a long series of remarkable
experiments of which I shall here endeavour briefly to state the
main results.
The conclusion which follows naturally from the discovery of
Sennebier, was that carbonic acid exercised a favourable influence
on vegetation by supplying plants with the carbon which enters
into their constitution. Percival ascertained by direct experi-
ment the accuracy of this inference by placing plants in a current
of atmospheric air, mixed with a pretty large proportion of this
gas. By means of a comparative experiment, he saw that a
plant in such circumstances, made much greater progress than
one subjected to a current of ordinary air.† The researches of
Saussure, in confirming in all respects those of his predecessors,
added this farther very important fact that to act beneficially
upon vegetables the carbonic acid must be mixed with oxygen.
:
Under a bell glass of the capacity of 398 cubic inches,
* Sur l'usage des feuilles dans les plantes, p. 31.
† Manchester Memoirs, vol. II.
DECOMPOSITION OF CARBONIC ACID.
33
placed over mercury, with a delicate film of water swimming
on its surface, he introduced three young peas, which displaced
aboutths of the included air. The atmosphere was composed
of common air, and carbonic acid gas in different proportions.
The experiments were conducted successively in the sunshine
and in the shade. In the sun, the apparatus received daily the
direct action of the light during five or six hours: when the light
was too vivid it was somewhat lessened by shading. In the sun-
light, the plants lived for several days in an atmosphere composed
of equal parts of air and carbonic acid; they then faded. But
they died much more speedily in atmospheres which contained
two-thirds, or three-fourths, or a fortiori which consisted entirely
of carbonic acid. The young plants throve decidedly when the
atmosphere contained about th of carbonic acid; their growth
was evidently more vigorous here than it was in simple air; and
at the conclusion of one experiment which extended over ten
days, almost the whole of the carbonic acid was found replaced by,
or changed into oxygen: the peas had assimilated the carbon.
The smallest quantity of carbonic acid added to the air,
was found injurious to the plants when they were kept in the
shade. Young peas lived only six days under such circum-
stances, when the atmosphere around them consisted of a quarter
of its volume of carbonic acid. They lived ten days when
the proportion of this gas did not exceed a twelfth; but then
they scarcely grew at all in the mixture: they certainly made
much less progress than they would have done in common air.
Saussure concluded, from these experiments, that carbonic acid
was useful to growing vegetables only when present along with
oxygen, and that it ceases to be so when the atmosphere
contains more than th of its volume of the gas.
To determine the proportion of oxygen set at liberty during
the decomposition of carbonic acid by plants, Saussure com-
posed an atmosphere of common air and carbonic acid, the
latter in the proportion of 0.075; the mixture was confined
under a bell-glass of the capacity of 5.746 litres or 10.112
pints standing over mercury as in the former experiments.
Seven plants of the periwinkle were introduced into the appa-
ratus, their roots dipping into 15 cub. centim. or 5.9 cub. inches
D
K
34
EVOLUTION AND GROWTH.
of water—the water was limited as much as possible in order
that the absorption of carbonic acid, which must of course take
place, might be thrown out of the reckoning. The experiment
was continued for six days, during which the plants received the
direct rays of the sun from five to eleven o'clock in the morning.
On the seventh day, the plants were withdrawn. They had
preserved their freshness. All the corrections made for tempe-
rature and pressure, the volume of the atmosphere in which they
had lived was not found changed by more than about 20 cubic
centimetres, 7.8 c. in. a quantity which is within the possible errors
of computation; but the composition of the air had undergone
very notable changes: the carbonic acid had disappeared, and
the eudiometer proclaimed 0.24 of oxygen instead of the 0.21
which it contained originally.*
Before: Volume of atmosphere
After:
""
Exp. 2.
.")
RESULTS OF THE EXPERIMENTS.
c. inches.
"
""
0.
The periwinkles, consequently, had caused 169.6 cubic inches
of carbonic acid to disappear, and given off upwards of one
hundred and fourteen cubic inches of oxygen. Had the whole
oxygen of the carbonic acid been set at liberty, this volume
would have been precisely equal to that of the acid gas de-
composed; but as no more than one hundred and fourteen
cubic inches of oxygen were obtained, it must be inferred that
the periwinkles had fixed 54.6 cubic inches of this gas.
This is the conclusion, indeed, to which M. de Saussure
came, and subsequent experiments have confirmed its accuracy.
The following table contains a summary of five experiments
that were instituted:
Exp. 1. Carbonic acid disappearing
Azote Oxygen Carb. acid
2262 contng. 1653 439.3 169.6
1707 554.0
0
+54 +114.7 -169.6
2262
"
د.
c. inches.
c. inches
169.6 Oxygen disengaged. 114.7
Azote disengaged 54.6
169.3
•
121.6 Oxygen disengaged.
Azote disengaged
* Saussure, Recherches chimiques, p. 40.
•
88
33
121
DECOMPOSITION OF CARBONIC ACID.
35
Exp. 3. Carbonic acid disappearing
Exp. 4.
Exp. 5.
66
"I
"
""
9)
""
c. inches.
58.5 Oxygen disengaged.
Azote disengaged
c. inches.
47.6
8.2
55.8
120.4 Oxygen disengaged. 96.8
Azote disengaged
7.8
104.6
72.4 Oxygen disengaged. 49.6
Azote disengaged 22.4
71.0
•
There is one remark which it is impossible to avoid making
in surveying this table; it is to the effect, that the azote disengaged
represents almost exactly the volume of oxygen which it would
be necessary to add, in order that the oxygen collected should
represent the whole of that which entered into the constitution
of the carbonic acid decomposed. It is probable that the excess
of azote which appeared in all these experiments was present
in principal part in the air contained and condensed within the
tissues of the plants, or held in solution in the water which
bathed their roots. It would be difficult to assign it any other
origin; such, for instance, as that from changes in the azotised
principles of the plants which were the subject of experiment. In
his first experiment, in fact, M. de Saussure fixes the weight of
the dry matter of the seven periwinkle plants at 41.6 grains.
Now, from numerous determinations of azote which I have had
occasion to make in regard to plants of very different ages and
species, I think I can say that these periwinkles, taken as dry,
did not contain more than 0.385 grain of azote; this in reference
to the weight assumed by M. de Saussure would be 1.042grs. or
20.8 cubic inches of azote; and the volume of azote disengaged
in this first experiment was 54.7 cubic inches. It is proper
further to observe that the state of health which the plants
presented on the conclusion of the experiment does not allow
us to suppose a total decomposition of the azotised matters
which entered into their constitution. These various considera-
tions lead us to infer that the excess of azote collected must
have been displaced by oxygen. We are, therefore, at liberty
to presume, from the experiments now referred to, that the
D 2
36
EVOLUTION AND GROWTH.
volume of oxygen produced probably represents the volume of
carbonic acid decomposed.
The necessity of oxygen gas in the decompounding action
which plants exposed to the light exert so energetically upon
carbonic acid, leads us to study particularly the phenomena
which oxygen exhibits in connexion with growing plants.
When a number of freshly gathered and healthy leaves are
placed during the night under a bell glass of atmospheric
air, they condense a portion of the oxygen; the volume of
the air diminishes, and there is a quantity of free carbonic
acid formed, generally less than the volume of oxygen which has
disappeared. If the leaves which have absorbed this oxygen
during their stay in the dark, be now exposed to the sun's
light, they restore it nearly in equal quantity, so that all cor-
rections made, the atmosphere of the bell glass returns to its
original composition and volume.
Leaves in general have the same effects, when they are placed
alternately in the dark and in the light; there is, however, a very
obvious difference in the intensity with which the phenomena
are produced, according to the nature of the leaves. The quantity
of carbonic acid formed during the night is by so much the
less, as the leaves are more fleshy, thicker, and therefore more
watery. The green matter of fleshy leaved plants, of the cactus
opuntia, to quote a particular instance, does not produce any
sensible quantity of carbonic acid in the dark: but these leaves
condense oxygen, and exhale it again like those which are less
fleshy, when they are brought into the sun, after having been
kept for some time in the dark.
Saussure applied the names of inspiration and expiration
of plants to these alternate effects, led by the analogy,-
somewhat remote, it must be confessed, which the phenomenon
presents with the respiration of animals.
The inspiration of leaves has certain limits; in prolonging
their stay in the dark, the absorption becomes less and less:
it ceases entirely when the leaves have condensed about their
own volume of oxygen gas. And let it not be supposed that
the nocturnal inspiration of leaves is the consequence of a
merely mechanical action, comparable, for example, to that
DECO POSITION OF CARBONIC ACID.
37
exerted by porous substances generally upon gases. The proof
that it is not so is supplied by the fact that the same effects do
not follow when leaves are immersed in carbonic acid, hydrogen
or azote. In such circumstances there is no appreciable di-
minution of the atmosphere that surrounds the plant. The
primary cause of the inspiration of oxygen by the leaves of
living plants is, therefore, obviously of a chemical nature.
With the facts which have just been announced before us,
it seems very probable that during the nocturnal inspiration, the
carbonic acid which appears is formed at the cost of carbon
contained in the leaves, and that this acid is retained either
wholly or in part, in proportion as the parenchyma of the leaf
is more or less plentifully provided with water. A plant that
remains permanently in a dark place, exposed to the open air,
loses carbon incessantly; the oxygen of the atmosphere then
exerts an action that only terminates with the life of the plant :
a result which is apparently in opposition to what takes place
in an atmosphere of limited extent. But it is so, because in
the free air the green parts of vegetables can never become
entirely saturated with carbonic acid, in as much as there is a
ceaseless interchange going on between this gas, and the mass
of the surrounding atmosphere; there is then, incessant pene-
tration of the gases, as it is called. There is a kind of slow
combustion of the carbon of a plant which is abstracted from
the reparative influence of the light.
The oxygen of the air also acts, but much less energetically
upon the organs of plants that do not possess a green colour.
The roots buried in the ground are still subjected to the
action of this gas. It is indeed well known, that to do their
office properly, the soil must be soft and permeable, whence
the repeated hoeings and turnings of the soil, and the pains
that are taken to give access to the air into the ground in
so many of the operations of agriculture. The roots that
penetrate to a great depth, such as those of many trees, are no
less dependent on the same thing; the moisture that reaches
them from without brings them the oxygen in solution, which
they require for their development. It is long since Dr.
Stephen Hales showed that the interstices of vegetable earth
38
EVOLUTION AND GROWTH.
still contained air mingled with a very considerable proportion
of oxygen. The roots of vegetables, moreover, appear generally
to be stronger and more numerous as they are nearer the
surface. In tropical countries various plants have creeping
roots which often acquire dimensions little short of those of the
trunk they feed.
If a root detached from the stem be introduced under a bell-
glass full of oxygen gas, the volume of the gas diminishes,
carbonic acid is formed, of which a portion only mingles with
the gas of the receiver, a certain quantity being retained by
the moisture of the root. The volume of the gas thus retained
is always less than that of the root itself, however long the
experiment may be continued. In these circumstances, whether
in the shade or the sun, roots act precisely as leaves do when
kept in the dark. Roots still connected with their stems, give
somewhat different results.
When the experiment is made with the stem and the leaves.
in the free air, whilst the roots are in a limited atmosphere of
oxygen, they then absorb several times their own volume of this
gas. This is because the carbonic acid formed and absorbed
is carried into the general system of the plant, where it is
elaborated by the leaves, if exposed to the same light, or simply
exhaled if the plant be kept in the dark.
The presence of oxygen in the air which has access to the
roots is not merely favourable; it is absolutely indispensable to
the exercise of their functions. A plant, the stem and leaves
of which are in the air, soon dies if its roots are in contact with
pure carbonic acid, with hydrogen gas or azote. The use of
oxygen in the growth of the subterraneous parts of plants,
explains wherefore our annual plants, which have largely deve-
loped roots, require a friable and loose soil for their advanta-
geous cultivation. This also enables us to understand wherefore
trees dic, when their roots are submerged in stagnant water,
and wherefore the effect of submersion in general is less in-
jurious when the water is running, such water always con-
taining more air in solution than that which is stagnant.
The woody parts, the fruit, and those organs of plants in
general which have not a green colour, stand in the same.
DECOMPOSITION OF CARBONIC ACID.
39
relations to oxygen as the roots: they merely change this
gas into carbonic acid, which is then transported to the plant.
at large to suffer decomposition by the green parts. In this
action we observe a displacement, a kind of translation of the
carbon of the lower to the upper parts of plants.
The decomposition of carbonic acid by plants admitted, we have
still to examine whether, in the phenomena of vegetation, the
leaves decompose the carbonic acid of the atmosphere directly, or
the acid gas, previously dissolved in the water, which moistens
the ground, be conducted by the way of absorption into the tis-
sues of vegetables there to suffer decomposition. The quantity
of carbonic acid contained in the air is so small, and the growth
of plants, on the contrary, is often so rapid, that it might
reasonably be suspected that the carbon which they require was
introduced in great part by this way of absorption. In that
series of beautiful experiments in which M. Saussure exposed
plants to the influence of atmospheres more or less charged
with carbonic acid, the water in which their roots were plunged
was in contact with the mixed atmospheres. It was therefore
possible that the carbonic acid gas entered the vegetables in
the solution by the roots.
Sennebier made an experiment to show that leaves decompose
both the carbonic acid which is in contact with them externally
and that which is dissolved in the water absorbed by their woody
tissue. He took two branches of a peach-tree, and introduced
them into a couple of bell-glasses filled with water from the
same spring.* The lower end of each branch dipped into a flask.
One of the flasks was filled with water charged with carbonic
acid ;
the other contained air: the two bell-glasses were exposed
to the light. The leaves of the branch whose extremity dipped
into the solution of carbonic acid, disengaged 99.4 cubic inches
of oxygen gas under the bell which covered it; the leaves of the
other branch only produced 52.2 cubic inches in the same time.
This experiment does not perhaps afford all the sufficient
evidence of the decomposition of gaseous carbonic acid as it oc-
curs in the atmosphere, and mixed with a great mass of air. It
appears, however, that the leaves of plants have the power of
* This was common water containing carbonic acid.
40
EVOLUTION AND GROWTH.
decomposing the gaseous carbonic acid which is mixed with the
air, and that even with surprising rapidity.
In the summer of 1840, I introduced into a balloon of the
capacity of about twelve quarts and a half, and furnished with
three tubulures or openings, the branch of a vine in full growth
and bearing twenty leaves. The woody part of the branch was
fixed by means of a collar of caoutchouc to the lower orifice
of the balloon; a fine tube, intended to establish a communica-
tion between the interior of the vessel and the outer air, was
introduced into the superior tubulure; the lateral opening com-
municated by means of a tube with an apparatus which mea-
sured with great accuracy the quantity of carbonic acid contained
in the atmosphere.
In this experiment the air, before reaching the apparatus for
measuring the carbonic acid, passed through the great balloon
containing the vine branch. The rate with which the air passed
through the apparatus was regulated by the flow of an aspirator,
and was at the rate of about twelve quarts per hour.
The apparatus was exposed to the sun; the experiment be-
ginning at eleven and finishing at three o'clock.
In one experiment it was found, all corrections made, that
the atmospheric air, after having passed through the balloon,
contained in volume 0.0002 of carbonic acid gas; the air of the
adjoining court contained at the same moment 0.00045 of car-
bonic acid.
In another experiment, the air after having passed over the
leaves, contained but 0.0001 of carbonic acid; the air of the
court containing 0.0004 of the same gas. In traversing the
space in which the vine branch, exposed to the light of the sun,
was included, therefore the air was deprived of three fourths of
the whole quantity of carbonic acid which it contained.
In operating with the same apparatus during the night, op-
posite results were obtained; the air in traversing the balloon
generally acquired a quantity of carbonic acid, the double of
that which the atmosphere contained at the same moment.
I conceive that it is by such a method as this, that the general
phenomena of vegetable respiration in plants still connected with
the soil ought to be studied.
ASSIMILATION OF AZOTE.
41
The experiments which I have now related must satisfy every
one, that the leaves of living plants actually assimilate the carbon
which occurs in our atmosphere in the state of carbonic acid;
they also explain the well-known fact that plants thrive better
in air that is in motion, and frequently renewed, than in a per-
fect calm.
From all we have seen up to this time then, we feel au-
thorized to conclude that the greater proportion if not the
whole of the carbon which enters into the constitution of vege-
tables is derived from the carbonic acid of the atmosphere. The
experiments cited, show how the vital force acts at first on the
oxygen of the air during germination, and next upon its carbonic
acid during vegetation properly so called. But in none of the
experiments which have been quoted, have we seen anything
which could lead us to suspect that the azote of the atmo-
sphere was absorbed in sensible quantity.
It is true, indeed, that at one time Priestley, and after him,
Ingenhousz, thought that they had observed an absorption of
azote during the growth of plants in confined atmospheres. But
the experiments which have been since performed by Saussure
have not confirmed their conclusions upon this point. Saussure
even thought that he had perceived a slight exhalation of azote.
Nevertheless, the presence of azote in vegetables being incon-
testible, and the assimilation of this principle during their
growth being in some sort demonstrated by the fact that seeds
are multiplied, physiologists were led to imagine that the azote
was derived from the soil. And in nature, indeed, the growth
of a plant does not take place at the sole cost of water and the
atmosphere. The roots which attach it to the earth there also
find elements of nutrition. In ordinary circumstances the growth
of a plant takes place by the simultaneous concurrence of the
food which the roots encounter in the ground, and that which
the leaves abstract from the gaseous elements of the air. As it
is further acknowledged that the food which is supplied by the
soil is for the most part azotised, manures have therefore been
regarded as the principal and even as the exclusive source of
the azote which is met with in vegetables. The observations of
Hermbstædt, in showing that the grain which was grown under
42
EVOLUTION AND GROWTH.
the influence of the most highly azotised manures, contained
the largest quantity of gluten, gave a certain force to this view.
Nevertheless there are facts well-established in agriculture which
induce us to think that in many cases vegetables find in the
atmosphere a part of the azote which is necessary to their con-
stitution.
The majority of crops exhaust the soil; but there are still
some which render it more fertile. We shall see, by and by,
when treating of the rotation of crops, that, if after having cut
a field of trefoil once, the second crop be ploughed down, new
fertility is communicated to the ground, in spite of the con-
siderable mass of forage which had previously been taken from
it. It appears therefore evident, that in ploughing down
this second crop we restore such a quantity of organic or or-
ganizable matter, that all things taken into account, the ground
actually receives more from the atmosphere than was taken
away from it in the first cutting.
The latest experiments of physiologists would seem to show
that plants merely take carbon from the air, and appropriate the
elements of water. But the ideas which are now generally
adopted in regard to active principle of manures make it diffi-
cult to conceive that the soil, by receiving non-azotised matters
only, could acquire the degree of fertility which is certainly
obtained from the cultivation of those crops that are called
ameliorating, a fertility which enables us to follow these crops
with others, rich in azotised principles.
There is therefore reason for believing that the ploughing in
of certain green crops, and fallowing, are not effectual merely by
introducing carbon, hydrogen, and oxygen, but azote also into
the soil. And it is absolutely necessary that this should be so,
in order that the fertility of those lands may be maintained
which, from their position, can receive no manures from without.
Let us take, for example, a farm laid out for the growth of
white crops, and the rearing of cattle. Every year there is an
exportation of grain, of flesh, and of the produce of the dairy;
that is to say, there is incessant exportation without any percep-
tible importation of azotised matter. Nevertheless, the soil
maintains its fertility; its losses are repaired by the principles
ASSIMILATION OF AZOTE.
43
which in a good system of cultivation pass from the atmosphere
into the earth; and among the number of these fertilizing prin-
ciples it is beyond all question that azote must be present, in
order that so much of this element as has been exported may be
replaced.
The best established facts in agriculture therefore concurred
in showing that azote is among the number of the elements that
are fixed by plants during their growth. Still as this truth
had not been proved by the experiments of physiologists, the
question had to be considered as yet undecided. It was with
the hope of clearing up everything in connexion with it that I
undertook the series of experiments, the chief features of which
I shall now detail.*
I had necessarily to follow a method of inquiry different from any
which had yet been taken; I had no chance of arriving at more
definite results than those which had been already come to, had
I chosen the old line of investigation. I therefore called in the
aid of elementary analysis, with a view of comparing the com-
position of the seed with the composition of the harvest produced
from it, at the sole cost of water and the air. By proceeding in
this way I believed that the problem was capable of solution;
without flattering myself that I have completely resolved it,
I conceive that something has been done in the right direction.
The subject is one of the most delicate imaginable, and he who
enters on it requires indulgence.
For soil I made use of burned clay or silicious sand freed from
all organic matter by proper calcination. In this soil, moistened
with distilled water, were sown the seeds whose weight was
known. By a number of preliminary trials, the quantity of
moisture which seed of the same kind, of the same growth, and
taken at the same moment, lost by drying, commenced in the
stove and finished in an oil bath, at 110° C. (230° F.), was ascer-
tained. The porcelain vessels, in which the experiment was con-
ducted, were placed in a glass house at the end of a large garden.
During the whole term the windows were kept closed; but
the sun shone on the house all day. To remove the produce,
* Boussingault, Annales de chimie et de physique, t. LXVII, p. 5, 2e
série, année 1838.
D 3
44
EVOLUTION AND GROWTH.
the vessels were dried by a gentle heat. The roots of the plants
then came out readily; to free them completely from any adher-
ing sand they were moved about in a little distilled water, but
never rubbed or bruised, for fear of loss; it seemed even pre-
ferable to leave a little sand adhering. The harvest was then
dried in the stove so that it might be powdered; and the com-
plete desiccation was effected in the oil bath in vacuo.
In ascertaining previously by incineration the weight of the
ashes contained in the seed, that of the produce, freed from all
saline and earthy matter, became exactly known.
Elementary analysis then proclaimed the composition of the
produce; and it was only necessary now to compare it with the
composition of the seed, to have ascertained the proportion and
the nature of the elements which had been assimilated during
the vegetation.
GROWTH OF RED CLOVER DURING THREE MONTHS.
In the beginning of August a quantity of seed was sown,
which, being dry, and free from ashes, would have weighed
1.586gramme, or 24.48grs. troy. The crop presented a very
good appearance; the clover was from three to three and a half
inches in height. The largest leaves could be included in a
circle of about two inches in diameter. The length of the roots
varied between two and four inches. Dried and bruised, the
colour of the produce was a deep green.
The plant gathered quite dry, and supposed free from ash,
weighed 4.106 gramme, or 63.38 grs. troy; analysis showed it
to consist of
=
FIRST EXPERIMENT.
Carbon
Hydrogen
Azote
Oxygen
>>
In the seed.
50.8
6.0
7.2
36.0
100.0
RESULTS.
24.48grs. troy contg. according to analysis 12.44 1.466 8.815 1.759
63.38
32.141 4.183 24.654 2.402
In the produce.
50.7
6.6
3.8
38.9
100.0
>>
38.90 grs. gained during the growth +19.97 +2.717+15.839 +0.649
ASSIMILATION OF ELEMENTS.
45
Thus, in the course of three months, the elementary matter of
the seed had nearly doubled, and the azote of the plants gathered
shows an excess of 0.042gramme, or 0.648gr. troy above the
azote of the seed sown.
Carbon
Hydrogen
Azote
Oxygen
SECOND EXPERIMENT.
GROWTH OF PEAS.
Five peas, very nearly of the same weight and together
weighing 1.211gramme, or 18.69grs. troy, were planted on the
9th of May in a soil of recently burned clay in rough powder.
On the 16th of July, the plants began to bloom, each pea
having furnished a stem bearing a single flower.
On the 15th of August the pods were quite ripe; the stems
were then from 39 to 47 inches in height. The leaves were
smaller than those of the same peas grown in manured earth.
The length of the pods was about 1.37 inch, by a breadth of about
0.43 inch. Four of these pods each contained two seeds; the fifth
had only one, but it was much larger than any of the others.
The nine peas gathered and dried in the sun, weighed
1.674gram. or 25.84grs.; after desiccation in vacuo, at 110° C.
(230° F.) they weighed 1.507gram. or 23.26grs. troy; on com-
bustion they yielded 0.9 per cent. of residue.
The roots, the stems, the pods and the leaves, dried at 230° F.
weighed 3.314gram. or 51.16grs. troy; and by combustion
gave 10.3 per cent. of ashes.
As the result of several experiments, it was ascertained that peas,
exactly in the condition of those which had been planted, con-
tained 91.4 per cent. of dry matter, and left by incineration
3.14 per cent. of residue. The five peas planted, taken as dry
and free from ashes, would therefore have weighed 1.072gram.
or 16.54grs. troy.
Analysis shewed in the:
Peas sown.
48.0
6.4
4.3
41.3
100.0
Peas collected.
54.9
6.8
3.6
34.7
100.0
Straw and roots.
52.8
6.2
1.6
39.4
100.0
D 4
46
EVOLUTION AND GROWTH.
A
Seeds 16.549 grs. contng
Crop 68.560
*
""
+52.011 grs. by cultivation.
!
From this experiment it appears that 16.549grs. of seed found
in the air and obtained from the water with which they had
been supplied during their growth, 52.01grs. of elementary
matter in the course of ninety-nine days' growth, during the
warmest months of the year; and that the quantity of azote
originally contained in the seed was more than doubled in the
produce arrived at maturity.
The seed dried
The seed dried
Grain by culture
RESULTS.
Carbon
Hydrogen
Azote
Oxygen
Forty-six wheat corns were sown in burnt sand at the begin-
ning of the month of August. At the end of September, the
stalks were from fourteen to fifteen inches in height. The
greater number of the lower leaves were yellow. The roots
were of very considerable length, and formed a kind of mat,
which made it difficult to wash and free them from sand.
Azote
Carbon Hydrogen Oxygen
7.950 1.065 6.823 0.710
36.680 4.384 25.951 1.559
+ 28.730 +3.319+ 19.128+0.849
THIRD EXPERIMENT.
* Peas
GROWTH OF WHEAT.
RESULTS OF ANALYSIS.
Seeds.
46.6
5.8
3.45
44.15
در
100.0
RESULTS.
Grs.
Carbon
25.38 contog 11.84
46.65
22.16
21.27
Crop.
48.2
5.8
2.0
44.0
100.0
Straw and shells
Total weight of the crop
C
Hydrogen Oxygen
11.19
20.57
1.43
2.67
+10.32 +1.21 +9.38 +0.05
In the course of three months' growth, therefore, the weight
of the seed had, so to speak, doubled; but the gain in azote was
22.66
45.89
68.55
Azote
0.87
0.92
ASSIMILATION OF ELEMENTS.
47
scarcely appreciable. Nevertheless, this experiment upon the
wheat had been conducted under precisely the same circum-
stances as that made upon the clover. The two crops grew in
the same apparatus; they were watered with the same water
which they received very nearly in the same quantity; the seed
was even sown in vessels having exactly the same extent of
surface, in order that either crop might be exposed to the
same chances of error arising from the accidental presence of
dust in the atmosphere.
The plants produced under the circumstances indicated were
far from presenting the vigour which they would have shown
had they been grown in the open field. After three months of
growth, the clover was much less forward than some which had
been sown, for comparison, in a manured and gypsumed soil
at the same time. The wheat shewed the same weakness; and
after the second month, I observed that each new leaf which was
developed upwards in the stem, caused one of those at the lower
part to droop and grow yellow. The peas, although they reached
maturity, had much smaller leaves, and both fewer and smaller
seeds than similar plants grown at large.
It is well known that it is in great part due to the fertility
of the soil in which seeds are grown that the health and vigour
of young plants must be ascribed. A celebrated agriculturist,
Schwartz, ascertained for example that young coleworts or
cabbage plants exhausted in a remarkable manner the soil in
which they were raised for transplantation. The good effects
of the first nourishment obtained in a well manured soil must
extend subsequently to every part of the vegetable; and it is easily
understood that a plant which has languished in its earliest periods
of existence can never acquire a good constitution afterwards.
It therefore became interesting to carry out experiments of
the nature of those already related, in connexion with plants
vigorously organized, and which had been raised in the first
instance in a fertile soil.
FOURTH EXPERIMENT.
GROWTH OF CLOVER.
In a field of clover sown in the spring of the preceding year,
48
EVOLUTION AND GROWTH.
several plants as like one another as possible were chosen. The
earth adhering to the roots was removed by careful washing
under a small stream of water; the plants were then made
dry between leaves of blotting paper, and exposed for a few
hours in the air. Three of these plants preserved for analysis
weighed when green 6.750grammes or 104.20grs. troy.
Three other plants weighing 6.820gram. or 105.28grs. troy,
were set in sand recently calcined and moistened with distilled
water. The transplanting took place on the 28th of May, and
the plants were forthwith protected from dust.
For some days they seemed to languish, but by and bye they
became remarkably vigorous. In a month the clover had grown
to twice its original height, and the leaves were of the most
beautiful green: the plants had in all respects as fine an appear-
ance as the clover of the same age which had been left growing
in the field. The flowers shewed themselves upon the 8th of
July, and by the 15th the flowering was complete: an end was
put to the experiment on the 1st of August.
Carbon
Hydrogen
Azote.
Oxygen
RESULTS OF THE ANALYSIS.
BEFORE CULTURE.
>>
43.42
5.40
3.75
47.43
100.00
RESULTS.
>>
""
>>
"
AFTER CULTURE.
53.00
6.51
2.45
38.14
100.00
The trefoil transplanted, weighed when dry and freed from ashes
After sixty-three days' culture on barren soil, it weighed.
Gained during culture.
Carbon. Hydrogen. Oxygen.
The plant contained: before culture. 5.92 0.74 6.46
after culture 18.52 2.23 13.32
Difference .+12.60 +1.49
•
13.64
34.96
21.32
Azote.
0.50
0.864
+6.86 +0.35
Thus in two months' growth at the cost of the air and
water, the clover had, so to say, tripled its quantity of organic
matter; and the weight of azote contained in it was very nearly
doubled.
ASSIMILATION OF ELEMENTS.
49
FIFTH EXPERIMENT.
Carbon
Hydrogen
Oxygen
Azote
VEGETATION OF OATS.
I always failed in my attempts to transfer wheat plants from the
ordinary soil in which the grain had been sown to barren sand;
they never survived the transplantation. It was not different
with oat plants; they also always died. It was first supposed
that the delicate radicles of these plants had been injured in the
process of taking them up and freeing their roots from adhering
vegetable soil; but I soon saw that this could not have been the
case, for the same plants, treated precisely in the same manner,
took very promptly when transplanted to garden mould, and
even when they were put with their roots in pure water.
It was
with water, therefore, that the following experiment was con-
ducted.
June 20th, several oat plants were taken up from a field, and
their roots were washed and cleansed.
Three plants preserved for analysis, weighed 159.011grs.
Four plants, the subjects of experiment, weighed 221.729grs.
troy. They were protected from dust, their roots dipping into a
vessel containing distilled water, which was regularly kept up to
the same level. By the middle of July the stalks of these
plants had grown to twice their former length; and at this time
it would have been difficult to have distinguished them from
those growing in the open field. By the end of July the clus-
ters had formed; and on the 10th of August the grain seemed
ripe. The plants were, therefore, taken up and dried in the stove,
and reduced to powder to complete the desiccation at 110°
cent. (230° Fahr.)
ANALYSIS OF THE OAT PLANTS.
Transplanted.
53.0
6.8
36.4
3.8
100.0
Gathered.
48.0
6.2
44.0
1.7
100.0
E
50
EVOLUTION AND GROWTH.
The oats when transplanted
contained
After 48 days of growth in dis-
tilled water they contained
SUMMARY.
Carbon
Hydrogen
12.767 1.636
Oxygen
Azote
8.768 0.910
23.157
2.979 21.180 0.818
+1.343 +12.412 -0.092
+10.390
The analysis, therefore, indicates a trifling loss of azote.
In recapitulating the conclusions obtained from these experi-
ments, we find :
First. That clover and peas grown in a soil absolutely with-
out manure, acquired a very appreciable quantity of azote, in
addition to a large quantity of carbon, hydrogen, and oxygen.
Second. That wheat and oats grown in the same circum-
stances, took carbon, hydrogen, and oxygen from the air and
water around them; but that analysis showed no increase of
azote in these plants after their maturity.
The mode of experimenting followed had it in view simply to
determine the assimilation of azote by certain vegetables, with-
out entering into the question of the means by which this was
effected; and, indeed, in reference to the point, I can only offer
conjectures.
Azote may enter the living frame of plants directly, or, as
M. Piobert has maintained in the state of solution in the water,
always aerated, which is taken up by their roots.* The observa-
tions of vegetable physiologists are not generally favourable to
this view. It is farther possible that the element in question
may be derived from ammoniacal vapours, which, according to
some philosophers, exist in infinitely small proportion in our
atmosphere. These vapours, dissolved by rains and dews, would
readily make their way into plants, and might there undergo
elaboration.
It is long since Saussure alluded to the probable influence of
ammoniacal vapours upon vegetation. Prof. Liebig has more
recently maintained the same opinion, and has taken particular
pains to prove that rain-water always contains a very minute.
quantity of carbonate of ammonia in solution.
To this cause, which must have the effect of infusing an
azotised principle into the tissues of plants, must be added
* Piobert, Mém. de l'Académie de Metz, 1837.
ASSIMILATION OF ELEMENTS.
51
another, which is perhaps not the least energetic. It is this,
that under certain electrical influences, of which M. Becquerel
has made a particular study, hydrogen in the nascent state, in
contact with azote, may actually give rise to ammonia. By
means of this view, it becomes easy to conceive how non-azotised
organic substances, under the mere influence of the putrid fer-
mentation, might give origin to ammoniacal salts, which would
then exercise a fertilizing action on the soil.
During the growth of plants, a portion of the water absorbed
by the roots is evidently assimilated; and this circumstance
enables us to conceive the formation of many of the im-
mediate principles of vegetables, the chemical composition of
which is precisely represented by carbon and the elements of
water; such are starch, sugar, etc. We can also understand the
presence of those principles, which have further a certain propor-
tion of oxygen in excess, inasmuch as we have ascertained that
during the decomposition of carbonic acid by the green parts
of vegetables, the whole of the oxygen is not eliminated. But
there are substances elaborated by plants which, with reference
to oxygen, contain a quantity of hydrogen much greater than
is requisite to form water; such are the resins and other car-
burets of hydrogen in the cone-bearing trees, and the fat oils in
the oleaginous seeds. This excess of hydrogen led several phy-
siologists to conclude that water was decomposed in the course
of vegetation, that there was fixation of its hydrogen and disen-
gagement of its oxygen gas.
Nevertheless, the presence of hydrogen in excess in certain.
immediate vegetable principles is no decisive proof of the dis-
junction of the elements of water; and if no definitive conclusion
has been come to on the point, up to the present moment, it is
because these hydrogenized principles are produced in plants which
live under the influence of certain organic substances that are met
with in the soil, where they act as manures, their composition
being always complex, and often highly hydrogenized.
The experiments of M. de Saussure do not lead us to suspect
the decomposition of water; inasmuch as by keeping plants for
a whole month, under receivers filled with atmospheric air
freed from carbonic acid, no apparent evolution of oxygen was
E 2
52
EVOLUTION AND GROWTH.
observed. Operating in the same manner with air containing a
certain proportion of carbonic acid, the quantity of oxygen dis-
engaged was always less than that which entered into the con-
stitution of the acid decomposed.
This is the place to observe, and in connexion with these
very experiments of M. de Saussure, how little satisfactory this
partial decomposition of carbonic acid, which corresponds to no
definite proportion, appears. We already feel the difficulty of
conceiving that this acid should be completely reduced by a
living plant; that is to say, that the whole of its carbon should
become assimilated. The entire separation of a body so greedy
of oxygen as carbon from its most highly oxygenated compound,
must needs excite the greatest astonishment.
The readiest conception suggested by the facts is this; that
by the agency of the solar light, and under the influence of the
green matter, carbonic acid is turned into carbonic oxide by
losing a portion of its oxygen. This modification appears more.
in conformity with the ascertained principles of chemical and
physiological science. Still it must be allowed, that facts agree
as little with this mode of viewing the question as with that
which assumes the entire decomposition of the carbonic acid.
On the first assumption, the proportion of oxygen set at liberty
is too small; in the second, it is too great.
The negative results of M. de Saussure, in relation to the
separation of the elements of water during vegetation, were
obtained in the absence of carbonic acid, whilst the experiments
which established the decomposition of this latter body, were
necessarily made under the influence of moisture. It is possible,
therefore, that the water and the carbonic acid underwent simul-
taneous decomposition; and it becomes interesting, taking this
view, to inquire whether the hypothesis according to which
carbonic acid undergoes transformation into carbonic oxide does
not acquire a certain degree of probability by calling in the effect
of the decomposition of water in the phenomena observed.
One volume of the gaseous oxide of carbon takes half a
volume of oxygen gas to form one volume of carbonic acid.
Reciprocally, one volume of carbonic acid gas, in undergoing
transformation into the oxide of carbon, will give one volume
of the oxide,+ a volume of oxygen gas.
ASSIMILATION OF ELEMENTS.
53
Thus, in the hypothesis which we now discuss, for each
volume of carbonic acid that is modified by the vegetation,
there will be half a volume of oxygen gas disengaged. Any
oxygen more than this half volume which appears, must be
regarded as proceeding from the decomposition of water, the
hydrogen of which will have been assimilated by the plant at
the same time as the carbonic oxide derived from the carbonic
acid; and this view would perhaps enable us to conceive how
the volume of oxygen which is disengaged during the process.
of vegetation, may exceed the volume which ought to be pro-
duced, if the carbonic acid decomposed really passed into the
state of carbonic acid.
We may perchance obtain a more convincing proof of the
separation of the elements of water, in analyzing plants grown in
a soil absolutely without any organic matter capable of affording
them hydrogenous elements.
In fact, if a plant which is grown under such circumstances,
contains hydrogen in any larger proportion than that which
were necessary to transform its oxygen into water, we might
conclude with some certainty that the elements of water had
been separated; the objection made on the score of the presence
of manure would then be got rid of entirely. The analyses
which have already been laid before the reader supply data for
this investigation; it has only to be ascertained whether, in the
elements gained in the course of vegetation, the hydrogen is in
excess with reference to the oxygen or not. The following table
presents a summary view of our experiments:
Experiment 1. Clover
Experiment 2. Peas
Experiment 3. Wheat
Experiment 4. Transplanted Clover
Experiment 5. Oats
•
Oxygen Hydrogen Hydrogen Hydrogen
assimilated assimilated forming water in excess
18.926 2.717 2.362 0.355
19.096 3.319 2.392 0.926
9.386 1.204 1.172 0.030
6.854 1.497 0.849
12.412 1.343 1.543
0.648
39)
In the four first experiments, the hydrogen gained evidently
exceeds very sensibly the quantity required by the oxygen to
form water. The experiment with the oats, indeed, presents an
exception; but it must be remembered that here a loss of azote
E 3
54
INORGANIC CONSTITUENTS.
was ascertained. These analyses, therefore, appear to indicate
an assimilation of hydrogen in the course of vegetation, in con-
sequence of a decomposition of water analogous to that of
carbonic acid, and very probably effected by the same means.
III. OF THE INORGANIC MATTERS CONTAINED IN PLANTS-
THEIR ORIGIN OF THE CHEMICAL NATURE OF SAP.
S
When a plant is burned, there always remains a residue,
which is commonly designated as the ash. Every part of a
plant gives a residue of the same essential kind; but it varies
in its quantity and somewhat also in its composition. Equal
weights of dry herbaceous plants leave more ashes than woody
plants.* In a tree, the trunk gives more ash than the branches,
and these give less than the leaves.† The residue left by the com-
bustion is commonly composed of salts,—alcaline chlorides, with
bases of potash and soda, earthy and metallic phosphates, caustic
or carbonated lime and magnesia, silica, and oxides of iron and
of manganese. Several other substances are also met with there,
but in quantities so small that they may be neglected.
The principles usually met with in the ashes of vegetables,
are always found in the soil, which exercises the greatest in-
fluence upon the nature and quantity of the saline and earthy
matters which remain after the combustion of plants. Those
which grow in a soil derived from silicious rocks, yield ashes
that are richer in silica than those that are produced in a
calcareous soil. But according to M. de Saussure, the quality
of the manure has a still more decided influence on the nature
of the ash, than the geological constitution of the soil; according
to this observer, plants of the same species which have grown
upon a calcareous sand, and upon a granitic sand, contain the
same kind of ashes, if they have been manured with the same
dung; and different species, although growing in the same earth,
* Kirwan, Memoirs of the Royal Irish Academy, vol. v.
† Pertuis, Annales de Chimic, Ire série, t. xix.
ASHES.
55
do not contain the saline and earthy constituents of their ashes in
the same proportions.*
QUANTITY OF ASHES CONTAINED IN THE DIFFERENT PARTS OF VEGETABLES,
ACCORDING TO M. DE SAUSSURE.†
NAME OF THE PLANT.
Oak leaves
Ditto do.
Oak branches barked
Bark of these branches
Oak wood distinct from alburnum
Alburnum from same wood.
Bark of same tree.
Liber of the preceding bark
Leaves of poplar
Ditto
ditto
Trunk of ditto
Bark of trunk of ditto
Spanish mulberry-tree wood
Alburnum of mulberry
Bark of ditto
Liber of ditto
Chesnut-tree leaves
Ditto
ditto
Flowers of chesnut-tree
Ripe chesnuts
Peas flowering
Peas in pod
Beans in flower
Ditto in pod
Bean straw
Beans
Jerusalem artichoke in flower
Ditto in seed
Wheat straw
Wheat
Bran
Indian corn straw
Indian corn
Barley straw
Barley
Oats
Pine-tree leaves (Jura)
Ditto ditto (Brocken)
Pine-tree branches without leaves
Times when taken for
analysis.
10 May
27 September
10 May
* Saussure, Recherches chimiques, p. 283.
+ Saussure, ibid.
May
September
10 May
23 July
10 May
5 October
20 June
20 June
20 June
Ashes.
0,053
0,055
0,004
0,060
0,002
0,004
0,060
0,073
0,066
0,093
0,008
0,072
0,007
0,013
0,089
0,088
0,072
0,084
0,071
0,034
0,095
0,081
0,122
0,066
0,115
0,033
0,137
0,093
0,043
0,013
0,052
0,084
0,010
0,042
0,018
0,031
0,029
0,029
0,015
56
INORGANIC CONSTITUENTS.
All these estimates of ashes refer to plants dried during
several weeks in a stove heated to 25° cent. (77° Fahr.) By
such drying, however, vegetable substances are very far from
losing the whole of the water which they contain. The quan-
tities of ashes, therefore, mentioned by M. de Saussure, if they
be referred to vegetables absolutely dry, are somewhat too small.
I present a few estimates of ashes from analyses which I
have had occasion to make of some of those plants which are
the usual subjects of cultivation with us. The drying here was
always performed with care in an oil-bath heated to 110° cent.
(230° Fahr.)*

Wheat straw
Wheat
Rye straw
Rye
Oat straw
Oats
Potatoes
Beet-root
Substance dried at 230° Fahr.
Turnip
Jerusalem artichoke
Stems of ditto
White peas
Pea straw
Clover hay
Meadow hay
After grass (meadow)
•
* Ann. de Chimie, t. 1. pag. 234. 3e. série.
+ Traité des Essais, t. I. page 259.
•
•
Ashes.
0,070
0,024
0,036
0,023
0,051
0,040
0,040
0,063
0,076
0,060
0,028
0,031
0,113
0,077
0,090
0,100
We owe to M. Berthiert the following results of the incine-
ration of different kinds of wood burned in the state in which
they are generally used.
ASHES.
57

Fir
Birch.
False ebony
Hazel
White mulberry
Saint Lucia wood
Elder
Judea-tree
Oak (branches)
Oak bark
Kind of wood.
Lime-tree
Poplar, bark
Box wood
Oak barked, ash, pine, birch, &c.
Thorn
Aspin-tree
Oak bark
Black wood
Mahogany
Ebony
Oak (faggot)
Fearns
•
Ashes.
0,0083
0,0100
0,0125
0,0157
0,0160
0,0160
0,0164
0,0170
0,0250
0,0600
0,0500
0,0020
0,0036
0,0040
0,0050
0,0060
0,0120
0,0149
0,0160
0,0160
0,0220
0,0450
We possess several analyses of ashes from different parts of
the same plants in the researches of MM. de Saussure and
Berthier. As the knowledge of these saline substances may
prove highly important in our agricultural applications, and
as it further completes, in some sort, the facts that bear
upon the chemical phenomena of vegetation, I here add a
table of the results obtained by the skilful analists just
quoted:
58
INORGANIC CONSTITUENTS.

No. of analysis.
1
2
3
369C A W
4
5
7
8
9
10
11
COMPOSITION OF THE SUBSTANCES FOUND BY M. DE SAUSSURE.
Plant, or particular part which yielded the ash.
Chesnuts
Menyanthes trifoliata in flower
(buckbean)
The same cleared of seed
Beans
Wheat straw
Selected wheat
Wheat bran
Indian corn straw
Indian corn
Barley straw
Barley in the husk
0,120 | 0,280
0,030 0,510
0,005 0,003 | 0,002
0,150
chloride.
0,120 0,572
Idem.
""
traces
0,050 0,020 0,005 0,083
0,060
0,020 0,140 0,310 0,375 | 0,028 | 0,007 0,060
0,259 | 0,439 | 0,020 0,009 | 0,225
0,005 | 0,022
0,062 0,050 0,020 | 0,030
|
0,020 0,030 0,125 0,010 0,615 0,010 0,078
0,445 0,320
0,002 0,150
0,005 0,002 | 0,076
0,465 0,300
0,002 0,140
0,005 0,002 0,086
0,050 0,097 0,013 0,025 0,590 0,010 0,180 0,005 0,030
0,036 0,475 0,002 0,003 | 0,140
0,010 | 0,001 0,083
0,078
0,035 0,005 0,160 0,125 | 0,570 | 0,005 | 0,022
0,092 0,015 0,003
0,325 0,092 0,015 | 0,003 | 0,180
0,355 0,003 | 0,027
>>
>>
در
given
along
with the
د.
**
>>
در
""
ASHES.
59
Horn-beam
Oak
Oak bark
ALKALINE SALTS AND INSOLUBLE SUBSTANCES CONTAINED IN THE ASHES OF:
Lime-tree
Wood of St. Lucia
Elder
Judea tree
Hazel
Chinese mulberry
White mulberry
Ditto ditto
Orange or lance-wood
White oak
Birch
False ebony
Fir
Wheat straw
Potatoe stems
•
Alkaline salts.
0,189
0,120
0,050
0,108
0,160
0,315
0,190
0,154
0,189
0,150
0,250
0,096
0,075
0,160
0,315
0,500
0,090
0,042
Insoluble salts.
0,811
0,880
0,750
0,892
0,840
0,685
0,810
0,846
0,811
0,850
0,750
0,904
0,925
0,840
0,685
0,500
0,810
0,958
Nature of soil.
Clayey, sandy and ferruginous.
Very dry, argillaceous, calcareous soil.
Sandy, somewhat calcareous.
The same.
Ditto.
Ditto.
Ditto.
Ditto.
Calcareous and argillaceous soil.
Grown in the open field.
Sandy clay.
From Norway, part of a plank.
Grown in a strong and calcareous soil.
Siliceous and calcareous sand.
then analysed separately.
each species of ash examined; and the two kinds of salts were
termined the relation of the insoluble to the soluble matters in
In his researches upon the same subject, M. Berthier de-
60
INORGANIC CONSTITUENTS.

Soluble
compounds.
Insoluble
compounds.
ALKALINE SALTS AND INSOLUBLE SUBSTANCES OF ASHES ACCORDING TO M. BERTHIER.
Carbonic acid
Sulphuric acid
Hydrochloric acid
Silica
Potash
Soda
Water
·
Carbonic acid
Phosphoric acid
Silica
Lime
Magnesia
Oxide of iron
Oxide of manganese
Carbon and loss
•
•
•
Sulphate of potash
Chloride of potassium
Carbonate of potash
Silicate of potash
Silica
0,793
} |
1,000
00
1,000 1,000
""
""
1
|0,332 | 0,396 | 0,385 0,398 0,340 | 0,314 | 0,340 | 0,370 | 0,187 | 0,271 | 0,420 | 0,335 | 0,414 | 0,310 | 0,190 | 0,230
0,100 | 0,008
| | | |
0,028 | 0,063 | 0,083 | 0,075 | 0,048 0,054 0,116 0,018 0,019 | 0,030 | 0,043 | 0,184 | 0,042 | 0,012|
|
|0,050 | 0,038 | 0,011 | 0,020 | 0,018 | 0,032 | 0,024 0,042 0,131 | 0,077 | 0,029 | 0,060 | 0,033 | 0,055 | 0,080 | 0,080 | 0,750|
| | |
0,386 | 0,548 | 0,501 | 0,518 | 0,488 0,492 0,460 | 0,424 | 0,556 0,467 | 0,461 | 0,450 | 0,503 | 0,522 | 0,456 | 0,398 | 0,058|
|0,078 | 0,006 | 0,008 | 0,012 | 0,070 | 0,025 | 0,072 | 0,044 | 0,072 | 0,052 | 0,046 | 0,070 | 0,010 | 0,030 | 0,090 | 0,044
0,016
0,003 | 0,005
|
0,005 0,013 0,010 0,010 0,005
""
0,034
|0,00
12/8
0,001 0,005 | 0,011 | 0,013 | 0,040
0,018
0,074 | 0,006 | 0,008 | 0,018 | 0,007
"
""
"
0,035
>>
0,141 | 0,025
0,060
0,155
"",
"
**
""
""
""
""
".
"
"
"
""
| 0,056
0,996 | 0,996 | 1,000 | 0,993 | 0,992 | 0,995 | 0,991 | 0,868 | 1,000 | 0,991 | 1,000 | 1,000 | 1,000 | 1,000 | 1,000 | 0,995 | 1,000|
•
Carbonate of lime.
Sulphate of lime
Phosphate of lime.
Magnesia
0,240 | 0,232 | 0,274 | 0,200 | 0,240 | 0,249 | 0,202 | 0,226
100,000
| | | |
0,081 0,060 0,075 0,060 | 0,064 0,031 | 0,051 | 0,080
| |
0,001 0,007 0,018 | 0,100 | 0,004 0,005 | 0,005 | 0,004
0,002 | 0,008 | 0,016 | 0,010 | 0,002 | 0,010 | 0,005 | 0,010
10,676 0,688 10,607 10,630 0,070 0,705 10,782 0,080
Oxide of iron
Oxide of manganese
•
1,000 | 1,000 | 1,000 | 1,000 | 1,000 | 1,000 | 1,000 | 1,000
COMPOSITION OF THE ASHES OF SEVERAL PLANTS ANALYSED BY M. BERTHIER.
Wheat
straw.
"
""
Fern.
0,007
2 =
0,730
0,248
0,010
0,005
0,230 | 0,370
0,083
"
0,040 | 0,040
"
"
0,520
}0,115 0,590
0,988 | 1,000
0,004
0,032
""
0,170
0,302
0,023 0,080 0,031 | 0,020|
0,002 0,020 | 0,003 | 0,130
0,010 | 0,017 | 0,010 | 0,350|
0,654 0,500]

0,130
0,715
0,096
0,023
Horse-tail
grass.
Heath.
Tansy.
0,120
0,114
0,050
0,012
0,068
0,033
0,090
0,167
ME
0,375
0,280
0,165
0,434
0,505
0,062
0,144
0,022
0,030
0,130
0,010
0,014
0,061
0,100
0,002
0,007
0,002
""
Observations.
""
""
""
""
""
The wheat straw was from
a strong calcareous soil.
The tansy was from a sandy
garden soil.
ASHES.
61
A remark made by Berthier, and arising out of the preceding
analyses, is the absence of alumina in the constituent principles
of the ashes examined. The results previously obtained by M. de
Saussure fully confirm this remark; and if in some cases traces
of alumina were detected, the circumstance was attributed to the
clay which might accidentally have adhered to the plants. Ac-
cording to M. Berthier the absence of alumina is probably owing
to its insolubility in water, and its weak affinity for the organic
acids. The soluble salts of alumina with mineral acids are, it is
well known, unfavourable to vegetation, and in an arable soil
they could not exist long with calcareous or alcaline carbonates:
they would be immediately decomposed.
However, alumina appears actually to have been observed in
the state of salt in the juices of certain plants; lycopodium
complanatum, an infusion of which is employed as a mordant in
dyeing, contains tartrate of alumina ;* the same salt has been
detected in verjuice; and as we shall see presently, Vauquelin,
found acetate of alumina in the sap of the birch-tree.
I may
add that in a considerable number of analyses of ashes, produced
from plants and seeds of my own growing, I always obtained
traces of alumina; but I would not venture to affirm that the
earth here was not accidental.
Silica is met with in only very small quantity in the ashes of
wood. It is found, on the contrary, in considerable proportion
in the ashes of several annual and biennial plants, and more
especially in those of the cereals. Sir Humphrey Davy found as
much as 0.9 of silica in the epidermis of the common cane.
If we compare the ashes of the same species of wood grown
in soils of different kinds, we see, says M. Berthier, that they
may differ very perceptibly; which seems to establish the fact that
the soil exercises a certain degree of influence on their constitu-
tion. Thus oak-wood from Roque des Arcs, grown in a decidedly
calcareous soil, yielded ashes almost entirely consisting of car-
bonate of lime, whilst those left by an oak from the department
of la Somme, contained much magnesia and phosphate of lime.†
* Berzelius, Traité de Chimie, t. iv, p. 130, French translation.
† These ashes were from the carbon of the oak; the insoluble part gave
0.14 of phosphate of lime, and 0.08 of magnesia.
E 4
62
INORGANIC CONSTITUENTS.
The ashes from a white mulberry of Nemours contained more
than 0.10 of phosphoric acid, whilst scarcely any traces of it were
found in those of a similar mulberry from the calcareous soil of
Provence. The most remarkable inference, deducible from the
analyses of M. Berthier is that which is connected with the compo-
sition of the ashes yielded by trees growing in the same soil. It is
observed that, for analogous species, the ashes also bear the closest
analogy; and on the contrary, it is found that trees of very distinct
genera yield ashes of quite a different quality; results which lead
to this important conclusion, that plants possess the faculty of
selecting in the soil the substances which are best suited to their
special organizations. This is a point which we shall have an
opportunity of discussing, when we come to treat of rotations
of crops.
The substances composing the ashes of vegetables, are not
all in the state in which they existed in the vegetable tissue.
In plants there constantly exist organic acids, which in general,
are combined with mineral bases. During the incineration of
plants these organic acids are destroyed, and the result of their
destruction is an alcaline carbonate, if the pre-existing acid was
united with soda or potash ; a calcareous vegetable salt, again, yields
carbonate of lime; and a magnesian salt gives magnesia, from
the well known inability of this earth to retain carbonic acid at a
high temperature. Thus, the greater part of the carbonates which
enter into the composition of vegetable ashes, are formed by the
mere fact of incineration. The salts which resist the action of a
strong heat, as the phosphates, sulphates, and chlorides, are the
only ones which in the ashes retain the state in which they
existed in the living plant.
GAS
Water being the vehicle which must convey the mineral salts
from the soil into the vegetable, we do not always perceive how they
can penetrate. To explain the presence in plants of a salt so in-
soluble as the neutral phosphate of lime, M. de Saussure admits,
from satisfactory experiments, that vegetable juices contain the
double phosphate of potash and lime, and of potash and mag-
nesia.* Besides, several bodies considered in chemistry as inso-
* Saussure, Recherches chimiques, &c. p. 321.
ABSORPTION OF SALTS.
63
luble, are not so absolutely. Silica seems to possess a certain
degree of solubility,—at least, M. Payen has met with it in con-
siderable quantity in the water of the artesian well of Grenelle,
and in the water of the Seine. We know, moreover, that several
insoluble earthy salts are dissolved in virtue of the carbonic acid
always contained in the waters with which the soil is soaked.
Lastly, it is not improbable that certain insoluble salts have their
origin in the plant itself, engendered there by the successive
arrival and reciprocal action of soluble salts.
It now remains for us to examine by what means saline
substances are introduced into the tissues of vegetables, and
within what limits the water, which is essential to living
plants, may be charged with them; for it is within what may
be called common experience, that saline solutions of certain
degrees of concentration, oftentimes act injuriously on vegetation.
The spongioles which terminate roots have too close a tissue
to allow any thing but fluids to pass through them. All at-
tempts to make them absorb solid bodies in a state of minute
division, and held in suspension in water, have been ineffectual.
In these attempts the spongioles have acted precisely like perfect
filters, with which those that we employ in our laboratories
cannot be compared. Further, the weakest solutions are not en-
tirely absorbed by certain roots; a kind of separation takes place ;
a portion of the dissolved salt appears to abandon the water
at the moment of its penetrating the spongiole. This follows
from the researches of M. de Saussure, instituted with a view
to ascertain: 1st. if plants absorb substances dissolved in water in
the same proportion as they absorb water;* 2ndly. if plants
make a selection among different substances held in solution in
the same liquid.†
In solutions severally containing eight ten thousandths
(0.0008) of each of the following substances: chloride of po-
tassium, chloride of sodium, nitrate of lime, sulphate of soda,
hydrochlorate of ammonia, acetate of lime, sulphate of copper,
* Saussure, Recherches chimiques, &c. p. 247.
† Ib. p. 253.
64
INORGANIC CONSTITUENTS.
sugar candy, gum arabic, and extract of humus.* Several
entire plants with their roots, of the polygonum persicaria
(lakeweed or redshanks,) which had lived for some time in
distilled water, until their roots had commenced growing, were
immersed.
The plants lived in the shade during five weeks, throwing out
roots in one of the solutions mentioned. They languished, without
showing any appearance of growth in the solution of hydro-
chlorate of ammonia, and could only be kept alive in the sugared
water, which soon became changed, by renewing it frequently.
They died at the end of from eight to ten days, in gum water,
and in the solution of acetate of lime. They held out but for
two or three days in the water which contained sulphate of copper.
Observations precisely similar made on the bidens cannabina
presented the same results, with the sole difference, that this
plant lived for much shorter times than the redshanks.
To estimate in what proportion the substances dissolved were
absorbed, relatively to the water, M. de Saussure made use of
the solutions previously employed; but he brought the experi-
ment to a close when the plants had taken up precisely half the
liquid which was feeding them. Each solution fed a sufficient
number of plants to allow of this condition being fulfilled in
two days. Half of the liquid remaining after each experiment was
analysed, and the quantity of salt found therein, showed, by the
difference between this and the quantity originally contained, the
amount which had penetrated the vegetable. Representing by
one hundred parts the whole of the substance originally dissolved,
it is evident that fifty of those parts must enter the plant, if the
absorption of the saline substances be in proportion to that of
the solvent. But the experiment proved, that in taking up half
the volume of the liquid, the polygonum had absorbed but:
15 parts of chloride of potassium,
13
chloride of sodium,
4
nitrate of lime,
>>
">
* This entered into the solutions only in the proportion of two ten
thousandths (0,0002.)
ABSORPTION OF SALTS.
65
14 parts of sulphate of soda,
12
8
29
9
5
47
">
6
48
""
sugar,
gum,
extract of humus,
sulphate of copper.
Under the same circumstances the bident took :
رو
در
رو
,,
16 parts of chloride of potassium,
chloride of sodium,
15
8
nitrate of lime,
10
17
8
32
8
>>
>>
""
در
در
""
353
hydrochlorate of ammonia,
acetate of lime,
1:3
""
sulphate of soda,
hydrochlorate of ammonia,
acetate of lime,
sugar,
gum,
extract of humus,
sulphate of copper.
It follows from these experiments that the plants absorbed
some part of the different substances presented to them; but
without exception, they took up the water in greater proportion
than the matters dissolved.
On multiplying and varying these experiments, M. de Saussure
always arrived at the same general results. The plants uniformly
took up more of the alkaline than of the calcareous salts, and more
sugar than gum, though the quantities of the different substances
absorbed varied considerably.
The sulphate of copper presented, in the course of these re-
searches, an anomaly which is readily explained. We see that
this salt, evidently injurious to vegetation, was taken up in a
large dose. This arises from its corrosive action on the roots:
sulphate of copper disorganizes the spongioles; and these organs
once destroyed, absorption takes place with more rapidity and
in greater abundance. A root deprived of spongioles is in
the condition of a stalk, or branch, the fresh section of which
is immersed in a liquid. Observation proves, in fact, that
substances in a state of solution, which by reason of their
F
66
INORGANIC CONSTITUENTS.
viscidity are incapable of making their way into a healthy root,
are, on the contrary, readily taken up by a cut stalk or branch,
in quantity sufficient to dye it deeply, if it was a colouring
matter that was presented for absorption.
In the preceding experiments, the solution contained only a
single substance. In those which follow, M. de Saussure dis-
solved in the water two or three salts, a mixture of sugar and
gum, &c., in order to ascertain whether the plants would make
any selection from mixed solutions.
In 25 fluid ounces of water two or three species of salt were
dissolved, the weight of each species being nearly 10 grains troy.
Each ounce of water would therefore contain either ths or ths
of a grain of saline or soluble matter. As in the preceding
experiments, the plants were made to absorb precisely one half
of the solutions. Analysis pointed out the quantity and the na-
ture of the substances which remained in the liquid not absorbed,
and consequently the salts which had penetrated the vegetable.
In reducing this table, which exhibits the results obtained, the
weight of each particular salt in the solution is represented by
100 parts.
Substances in the solution
with which the experiment was made.
100 parts by weight.
Sulphate of soda effloresced
Chloride of sodium
Sulphate of soda effloresced
Chloride of potassium
Acetate of lime
Chloride of potassium
Nitrate of lime
Hydrochlorate of ammonia
Acetate of lime
Sulphate of copper
Nitrate of lime
Sulphate of copper
Sulphate of soda
Chloride of sodium
Acetate of lime
Gum
Sugar.
•
•
Weight of the several sub- Weight of the several sub-
stances taken up by the stances taken up by the
Polygonum in imbibing Bident in imbibing one
one half of the solution. half the solution.
12
22
27
12
17
со со
33
4
16
31
34
17
34
6
10
traces
26
34
7
20
10
17
5
0
16
25
15
35
39
9
56
13
16
traces
21
46
ABSORPTION OF SALTS.
67
M. de Saussure confirmed these results in experimenting on
the common peppermint, (mentha piperita), Scotch pine, and
common juniper. The substances absorbed in greatest propor-
tion by the polygonum and bident were also those that were
taken up in largest quantities by these plants.
The section of the roots, even their destruction, favours, as
we have already said, the introduction of the matters dissolved.
Plants whose roots had been removed, no longer selected the
substances dissolved in so striking a manner as they did pre-
viously; after mutilation they absorbed them almost indiffer-
ently, in larger doses, and perceptibly in the same proportion as
the water which held them in solution.
Roots with their spongioles entire, therefore, suffer one sub-
stance in solution to penetrate the plant in preference to another.
The chlorides of potassium and of sodium, for instance, find
entrance more readily than the acetate or nitrate of lime; sugar
more readily than gum; and precisely as when isolated, are these
substances when combined, absorbed in much less proportion
than the menstruum or water of solution.
M. de Saussure is not disposed to admit that the preference
which plants evince for certain salts, for certain dissolved sub-
stances, results from any particular faculty, from any special affi-
nity. He rather inclines to believe, that it should be attributed
to the degree of fluidity, or of viscidity communicated to the
water by the different substances dissolved; thus the acetate and
nitrate of lime, with the same proportion of liquid, form more
viscid solutions, which pass with more difficulty through a filter,
than the alkaline sulphates and chlorides; and these latter salts
in solution were absorbed by vegetables in greater abundance
than the calcareous salts. Gum, which imparts more viscidity
to water than sugar, is also less capable of being absorbed. Fi-
nally, pure water, more fluid than any of the solutions tried, was
also that which vegetables preferred to any other.
In the results of the incinerations which we have mentioned,
it is obvious that in many plants salts are met with in very
small proportion. This circumstance has induced several phy-
siologists to consider the mineral substances found in vegetables
F 2
68
as purely accidental, and consequently unnecessary to their ex-
istence. M. de Saussure, however, observes that this scantiness.
is no true indication of their inutility, and he mentions that the
ph sphate of lime, which forms an element in the organization of
an animal, does not probably amount to one five hundreth part
of the entire mass. We shall add, that as the phosphate of lime
was met with by M. de Saussure in the ashes of all vegetables
which he examined, and as all the analyses performed since the
original labours of this celebrated chemist have tended to con-
firm the accuracy of his general conclusions, we have no ground
for supposing that plants could exist without the intervention of
saline matter. There are annual plants which, when burned,
leave more than 10 per cent of residue; and vegetables cultivated
in soils free from saline or alcaline matter, and watered with dis-
tilled water, though they will live and ripen their seeds in some
instances, still they never acquire the vigour which they possess
when grown in a fertile soil.
Duhamel ascertained that marine plants languish in soils des-
titute of chloride of sodium; and this is so much the more
readily conceived, as those plants which furnish ashes abounding
in carbonate of soda, always contain organic acids combined with
the alkaline base. Borage, the nettle, &c., thrive only in places.
where they meet with nitrates; and it is easy to discover that
plants when dried contain a notable quantity of either nitrate
of potash or of lime. The vine more especially requires alca-
line dressings, in order that the large quantities of potash taken
from the soil in the tartrate of potash of the grape may be re-
placed.
INORGANIC CONSTITUENTS.
The organic acids, so different in their composition and in
their properties, which are met with in the different vegetable
families, are always found combined in the state of neutral or
acid salts. The proportion of base combined in a plant with a
vegetable acid may be readily ascertained from the ashes
for by the effect of incineration the base passes into the state of
an alcaline or earthy carbonate. The vegetable acids undoubtedly
perform important functions in the organism of vegetables, and
their formation probably depends on the influence of the bases
;
CONCLUSIONS OF LIEBIG.
69
with which they form salts. The nature of the oxide or base
itself appears to be of little importance; it is enough that it be
present in the plant. It is known that certain bases may mu-
tually replace each other, equivalent for equivalent.
These principles assumed, Prof. Liebig draws a remarkable in-
ference from the composition of the ashes of different kinds of
wood; namely, that for each vegetable family the sum of the
oxygen of the bases combined with the organic acids will be a
constant number; or, in other words, the species of one and the
same family will contain the same number of basic equivalents
combined with vegetable acids.
Thus, 100 parts of the ashes of a Breven pine-tree analysed
by Saussure, contain:
Carbonate of potash . 3.60 Oxygen of the potash a . 0.41
lime
7.33
lime
46.34
magnesia. 6.77
magnesia 1.27
Carbonates 56.71
""
>>
>>
>>
The ashes of a pine from Mount La Salle yielded :
Carbonate of potash 7.36 Oxygen of the potash. 0.85 1 8.95 ox.
lime . 8.10
lime. 51.69
magnesia 0.00
58.55
Potash and Soda
Lime
Magnesia
Potash
Soda
Lime
Magnesia
M. Berthier found in the ashes of a fir-tree from Allevard the
following bases:
16.8
29.5
3.2
49.5
. 14.10
20.70
12.30
14.35
51.45
Oxygen
>>
""
??
23
>>
>>
One part of the alcalies containing 1.20 of oxygen was com-
bined with mineral acids, forming sulphates, phosphates and
a chloride. The oxygen of the bases combined with the carbonic
acid is consequently reduced to 11.62.
The ashes of a Norway fir, according to the same analyst con-
taining:
Oxygen
>>
9.01 ox.
د.
2.40
5.30
3.45
1.69
3.421
8.2012.82
1.20
12.84 oxygen.
70
TRANSITION OF INORGANIC INTO ORGANIC MATTER.
In this ash the bases belonging to the inorganic salts contain
1.37 of oxygen.
The oxygen of the bases of the carbonates, or
in other words of the bases which formed organic salts in the
tree, therefore, becomes 11.47. The numbers 9.01 and 8.95 on
the one hand, and 11.62 and 11.47 on the other, which repre-
sent the quantity of oxygen of the whole of the bases in the
ashes obtained from plants of the same species, differ so little,
that they may be considered as identical.
Accurate analyses of ashes of plants of the same species
grown in soils of different kinds, will determine, says Prof. Liebig,
whether the fact, deduced from the composition of the ashes of
the pine and fir-tree, constitutes a definitive law.*
Be this as it may, the utility of alcalies in vegetation cannot be
a matter of doubt; many usages in agriculture prove it in the
clearest manner; and, according to M. Liebig, the fact of the forma-
tion of the organic alcaloides in plants affords an additional proof
of it. M. Liebig thinks that the organic alcalies have a particular
tendency to form in the absence of mineral bases; thus potatoes
which germinate in cellars, under conditions where the soil can-
not supply them with potash, soda, or lime, develope an organic
alcali, solanine, which is not found in the tubers of this vegetable
as usually cultivated. In the cinchonas, quinine and cinchonine
are combined with quinic acid; but there is frequently found qui-
nate of lime also. According to the same chemist, the latter base
holds the place of a vegetable alcali in the organism; the more
prevalent it is in the soil, the less rich will the cinchona plant be
in quinine and cinchonine. These ingenious views certainly de-
serve the careful attention of physiologists; they are calculated
to add new interest to the study of the chemical constitution
of the ashes of vegetables.
The inorganic substances contained in vegetables evidently
come from the soil. By growing seeds, as M. Lassaigne did, in
flowers of sulphur, moistened with distilled water, the plant pro-
* Liebig, Chimie Organique, Introduction, p. cxi.
† Liebig, idem. p. cxiv.
忄
​+ Liebig, idem.
SAP.
71
duced contained neither more nor less saline and earthy matter
than was originally present in the seed.
The water absorbed by the roots, then, becomes charged during
its stay in the ground with the various soluble substances which
may be met with there, and which generally contribute to its fer-
tility; such especially are the salts derived from decomposed organic
substances. Water charged with small quantities of the soluble
substances diffused through the soil, constitutes the ascending sap.
When it has penetrated the plant, immediately after its passage
by the spongioles of the roots, perhaps even whilst traversing
these parts, the organic matters dissolved in the fluid appear to un-
dergo important modifications; for in the sap substances are de-
tected which could not have existed in the water which moistened
the soil. During its ascent the sap increases in density, as was
ascertained by Mr. Knight, according to whom, the sap of an
acer platanoides, taken at the level of the ground, has a
density of 1.004; at 6 feet above it this density becomes
1.008, and at 13 feet, 1.012. From this Mr. Knight con-
cluded that the sap took up nutritive matter deposited in the
vegetable tissues which it traversed in its ascent.* We have al-
ready seen that the sap, after being elaborated in the green parts
of trees, takes a route the reverse of that which it followed at
first, and we therefore spoke of this modified sap as the descend-
ing sap.
It is very possible that in Knight's observations the
liquid examined was a mixture of the two saps.
-
We should not be over hasty in concluding that the action of
the two species of sap was exerted separately in promoting the
development of the plant; it is very probable, as Dutrochet
thinks, that the modified sap, by insinuating itself into the per-
meable tissue of the vegetable is continually mixed with the
ascending sap, in order to concur in promoting the growth of
the buds. The difficulty of obtaining each particular sap
separately, if such a separation is really possible, prevents the
analytical conclusions we have, from possessing all the accuracy
that seems desirable.
* Decandolle, Physiologie, t. 1. p. 204.
† Dutrochet, sur la Structure, &c. p. 36.
C
72 TRANSITION OF INORGANIC INTO ORGANIC MATTER.
Vauquelin has studied the sap of the birch-tree, of the horn-
beam, of the beech, of the chesnut, and of the elm.
The sap of the hornbeam (Carpinus sylvestris) was obtained
in the months of April and May. At this period it is colour-
less and clear as water; its taste is slightly saccharine; its odour
resembles that of whey; it reddens turnsole paper. The sap of
this tree contains: water in very large quantity, sugar, extrac-
tive matter,* and free acetic acid, acetate of lime and acetate of
potash, in very small quantity.
This sap left to itself presents in succession all the phenomena
of the vinous and then of the acetous fermentation.†
The sap of the birch-tree reddens turnsole intensely; it is
colourless, and has a sweet taste. The water which forms the
greater part of it, holds in solution: sugar, extractive matter,
acetate of lime, acetate of alumina, and acetate of potash.
When properly concentrated by evaporation, it ferments on
the addition of yeast, and then yields alcohol on distillation.
The presence of the acetate of alumina may appear extraor-
dinary in this sap, for this reason, that alumina has not yet been
discovered in the ashes of the birch-tree.
Sap of the beech (Fagus sylvestris). The analysis was
made in March and April. The colour of the sap was a tawny
red; it had the taste of an infusion of tanner's bark: it red-
dened turnsole slightly. It contained, in very small quantity:
acetate of lime, acetate of potash, acetate of alumina, extractive
matter, tannin, acetic acid, and gallic acid.
The sap of the chesnut-tree, according to Vauquelin, who,
for want of a sufficient quantity of the fluid, was able to study
it but very superficially, contains: mucilage, nitrate of potash,
and the acetates of potash and lime.
The sap of the elm was examined at three periods; first, at
the commencement of April, then some days after, and lastly,
a month later. At the beginning of April its colour was yellow,
its taste sweet and mucilaginous; it was scarcely acid. Analysis
* Probably azotised.
† Vauquelin, Annales de Chimie, t. xxx1, p. 20, lère série.
i
SAP.
73
indicated water 1027.90, acetate of potash 9.23, organic mat-
ter 1.06, carbonate of lime 0.80.
At the second period it contained a little more extractive
organic matter, and a little less carbonate of lime and acetate of
potash. The last examination showed that these two salts had
still further diminished in quantity. When exposed to the air,
the sap of the elm undergoes decomposition and becomes al-
kaline: the acetate of potash passes into the state of carbonate.
M. Regimbeau found in the sap of the vine :* bitartrate of
potash, tartrate of lime, mucilage, and free carbonic acid.
The sap of the maple-tree contains a very considerable quan-
tity of sugar. In Canada this sap properly treated yields sugar,
which is identical with that of the cane. The nature of the
sap is subject to variations; and Duhamel states, that at a cer-
tain season it loses its saccharine taste, and acquires an herba-
ceous flavour.t
Liebig and Will detected the presence of ammoniacal salts in
the sap of the maple and birch-tree, and in the tears of the
vine. M. Biot examined the sap of a considerable number of
trees, and ascertained that the sugar in them often exists
in two different states; in that of cane-sugar, properly so
called, and in that of grape sugar, which, as chemists admit,
differs from the former only in the possession of an additional
equivalent of water. The saps which M. Biot examined, con-
tained besides some animal matter (albumine) and a gummy
matter; he found no free carbonic acid. The object which he
had in view, namely to study the changes which occur in the
nature of sugar did not lead M. Biot to notice the minute
quantities of salts with organic acids which Vauquelin met with
in saps.
The trunk of a walnut-tree, tapped on the 11th of February,
yielded a sap containing some cane-sugar. The saps of the
sycamore, of the acer negundo, and of the lilac-tree, contained
the same species of sugar; but that of the birch-tree held in
* Journal de Pharmacie, t. XVIII, p. 36.
† Annales de l'Agriculture Française, t. v, 2ème séric, p. 339.
74
TRANSITION OF INORGANIC INTO ORGANIC MATTER.
solution some grape sugar. In the sycamore and birch-tree,
M. Biot observed an extremely interesting fact. He ascertained,
on felling these trees, that the greater portion of the descending
sap was accumulated towards the middle of the trunk. That of
the birch-tree was acid and saccharine; the sap of that portion of
the trunk which was buried in the ground, contained no sugar,
but a substance possessing the principal characters of gum.* It
was probably an effect of the season; for Knight states, that he
never could discover the least trace of saccharine matter during
winter in the alburnum either of the stem or of the roots of the
sycamore.†
SAP OF THE BAMBUSA GUADUAS.
The guaduas grows in the hot and marshy countries of the
tropical regions; this grass frequently attains the enormous
height of from 65 to 100 feet. Its stem, which is hollow, is
divided through its entire length into joints spaced rather
regularly at distances of from 11 to 12 inches. Each joint in-
dicates the presence of a woody partition, which seems to divide
the stem of the guaduas into so many super-imposed tubes. On
perforating it immediately above a knot, a clear limpid fluid
flows out, which cannot be distinguished from the purest water.
This indeed is a store of water of which travellers have fre-
quently availed themselves. This sap, as I have been assured
by the inhabitants of the countries where I observed the guaduas,
never completely fills the hollow space included between two
joints. Analysis satisfied me that the sap of the guaduas is
almost pure water. Re-agents detected merely traces of sul-
phates and chlorides. On evaporating a considerable quantity
of it, I was able to discover, independently of these traces of
soluble salts, a very small proportion of organic matter and of
silica; the latter substance is probably the element which pre-
dominates in the sap of the guaduas.
* Annales du Muséum d'Histoire Naturelle, t. 11.
+ Knight, quoted in Annales de l'Agriculture Française, t. v, 2c série,
p. 338.
SAP.
75
SAP OF THE BANANA PLANT (MUSA PARADISICA).
The sap of the banana possesses a well-marked astringent
taste; it reddens tincture of litmus. Immediately after escap-
ing from the plant, it is limpid and colourless, like water;
nevertheless, it possesses the property of imparting a yellow
colour to stuffs immersed in it. Exposed to the air it becomes
turbid, and throws down flocculi of a dirty rose colour. It is to
the action of oxygen that this deposit is owing; for it takes
place only in contact with the air. After the formation of this
deposit, the sap no longer colours stuffs immersed in it. From
a chemical examination which I instituted of the sap of the
banana, during my sojourn on the banks of the Magdalena, I
think I may state that it contains: gallic acid, acetic acid, chlo-
ride of sodium, salts of lime and potash, and silica.
The sap of vegetables, elaborated during its passage through
the leaves, acquires additional consistence. It generally contains
peculiar principles, which are the result of this elaboration, and
these now constitute the liquid which is usually designated by
the name of the particular juice of the plant from which it is
procured. This proper juice or sap is generally obtained by
making an incision which penetrates a little below the bark.
The characters and properties of the elaborated or descending
sap, are extremely various. It may, however, be divided into
milky sap, saccharine sap, gummy sap and resinous sap, accord-
ing to the nature of the juices dissolved or suspended in the liquid.
As several of the peculiar juices of vegetables contain principles
employed in the arts or in medicine, they have been more care-
fully studied, and their history is more complete than that of
the ascending saps. I do not propose to give a monograph of
these juices; in this place I shall only mention those which have
been examined with some care.
MILKY SAPS.
The milky saps, as their name indicates, have the appearance
of milk; they owe this milky appearance to globules of insolu-
ble matter, minutely divided and suspended in a liquid.
76 TRANSITION OF INORGANIC INTO ORGANIC MATTER.
SAP OF THE PAPAW-TREE (CARICA PAPAYA).
The carica papaya grows in tropical regions. The sap, which
is extracted from the fruit by incision, is white and excessively
viscous, In a specimen of this sap, which came from the Isle
of France, Vauquelin found water in large quantity, and also a
matter, having the chemical properties of animal albumen,* and
lastly fatty matter.
I took occasion to verify the correctness of the results
obtained by Vauquelin, on the milk of the fruit of the carica
papaya during my sojourn at Caracas, where I examined the
sap which flowed from the trunk of the tree itself. This sap
is less milky, and much more fluid than that which flows from
the fruit; it had the appearance of milk-and-water. Its odour
is rather nauseating, even when coming from the plant; its
taste slightly sour. When exposed to the air it soon coagulates.
It contains a considerable portion of matter, which may be com-
pared to animal fibrine, and sugar, wax, and resin, in small
quantities.
Evaporated and burnt, it leaves a saline residue. This juice is
employed by the inhabitants for medical purposes.
SAP OF THE COW-TREE.
Among the number of astonishing vegetable productions
observed in the equinoctial regions, is a tree which yields a milky
juice in abundance, similar in its properties to the milk of
animals. At the time I left Europe, M. de Humboldt expressly
recommended me to direct my attention to the milk of the
cow-tree. A short time after my arrival in the Cordilleras, on
the shore of Caraccas, M. Rivero and myself were able to comply
with the wishes of the distinguished traveller.†
The milk we examined came from the Palo de Leche, the
milk tree, which is extremely common in the environs of
Maracaibo.
Vegetable milk possesses the same physical characters as that
* Vauquelin, Annales de Chimie, t. XLIX. p. 219, 1re série.
† Rivero and Boussingault, Annales de Chim. et de Phys. t. xxIII.
p. 229, 2e série.
SAP.
77
of the cow, with this sole difference, that it is, in a slight degree,
viscous; its flavour is agreeable, slightly balsamic. With re-
spect to chemical properties, these differ perceptibly from those
which are peculiar to animal milk. Acids do not curdle it;
alcohol scarcely coagulates it.
Under the action of gentle heat, light pellicles are seen to
form on the surface of vegetable milk. On evaporating it over
a water bath, an extract is obtained resembling fritters; and
if the action of the fire be continued for a certain time, oily
drops are observed, which increase in proportion as the water
is dissipated, and ultimately form a liquid of an oily appear-
ance, in which a fibrinous substance floats, which dries and
becomes tough in proportion as the temperature increases.
odour is then diffused, exactly like that of meat frying in fat.
An
By the mere action of heat, then, the milk of the Palo de
Leche is separated into two distinct portions: the one fusible,
of a fatty nature, the other fibrinous, and presenting all the cha-
racters of animal substances.
If the evaporation of vegetable milk is not carried too far,
the fatty matter may be obtained unchanged; it then possesses
the following properties :-it is white, translucent, sufficiently
solid to resist the impression of the finger; it fuses at 140°
(Fahr.); boiling alcohol dissolves it completely; it is equally
soluble in potash.
The fibrinous matter presents all the characters of fibrine,
obtained from the blood of animals; for this reason we have
called it fibrine. In fact, when put on a hot iron, it swells up,
fuses, and becomes carbonized, exhaling the odour of grilled meat.
Treated with weak nitric acid, it gives out nitrogen gas; by
distillation, it disengages ammoniacal vapours in abundance.
The presence and nature of this animalized matter in the
milk of the cow-tree, explains how this milk acquires the odour
of old cheese on becoming changed. We considered the fatty
matter of the milk as analogous to bees' wax; I may even say
that we made wax-candles of it. However, the property
of being completely dissolved in hot alcohol, combined with its
ready solubility in potash, establish a well-marked difference
78 TRANSITION OF INORGANIC INTO ORGANIC MATTER.
between it and the wax of insects. This is a question which
can only be completely cleared up by elementary analysis, and
we were altogether without the means of making any minute
examination of the wax of vegetable milk.
In the water which holds the wax and animal matter in
suspension, we met with some saline substances and a free acid,
the nature of which we were unable to determine. We did not
succeed in detecting the presence of caoutchouc in vegetable
milk. According to our researches this milk should contain :
1. A fatty substance similar to bees' wax;
2. An animal substance, similar to animal fibrine;
3. Water, salts, a free acid, and a little sugar.
By incineration, we obtained ashes from the milk in which
were found phosphate of lime, lime, magnesia and silica.
During their excursions in the Cordilleras, the inhabitants
frequently drink the milk of the cow-tree. M. de Rivero and
myself also used it during our sojourn at Maracaibo.
The tree which produces the milk which we examined, is,
according to M. de Humboldt, the galactodendron dulce, of the
family of the verticas, or fig-trees. But several trees are known
in the mountains along the coast, which yield a milky juice, and
which are often confounded with that just described. For
instance, in the environs of Maracaibo, according to M. Des-
vaux,* the clusia galactodendron, yields an abundance of very
pleasant vegetable milk; this milk, however, does not seem to
contain much animalized matter; at least it does not putrify
perceptibly, and instead of the waxy matter, a substance much less
fusible and of a resinous character is procured from it.
MILKY SAP OF THE HURA CREPITANS, (AJUAPAR).
The sap of the hura crepitans is dreaded, and not without
good reason; it is enough to be exposed to the emanations.
of this milky juice, when recently extracted, to be seriously
Renseignements communiqués par M. Adolphe Brongniart.
*
SAP.
79
affected by it. The use which is made of it, to poison the water
of rivers, in order to obtain the fish, is a sufficient indication of
its pernicious qualities.*
This vegetable sap would perfectly resemble that of the cow-
tree, if it were not slightly yellowish. It has no smell; its taste,
which is very little marked at first, soon causes very violent
irritation. It reddens the colour of turmeric; mineral acids
produce in it a white and viscous curd; the surrounding fluid is
clear and of a yellow colour. Left to itself the milky sap of the
hura crepitans, yields all the products of the putrefaction of
caseum. It contains 1. An azotised substance similar to
gluten, or caseum. 2. A vesicating oil. 3. A crystallized sub-
stance, having an alcaline reaction.
4. Malate of potash.
5. Nitrate of potash. 6. A salt of lime (the malate ?). 7. An
odorous azotised principle.
:
MILKY SAP OF THE POPPY, (OPIUM).
The milky sap which, by concreting, furnishes the opium of
commerce, is obtained by making longitudinal incisions in the
capsules of the poppy. The operation takes place before the fruit
is ripe, and after the fall of the flower.
The concrete sap is brown, firm, of an acrid and bitter taste, and
of a peculiar sickening odour. Opium contains a number of
principles, the study of which has exercised for a considerable
time the ingenuity of the most skilful chemists. It was in this
substance that Sertuerner found the first vegetable alcali which
was discovered, morphine. After numerous trials made on
opium, it was found to contain:-1. Morphine (vegetable alcali).
* Rivero et Boussingault, Annales de Chim. et de Phys. t. XVIII. p. 430,
2e série.
What I shall now state may give an idea of the energy with which this
milky juice acts on the animal economy: when M. Rivero and myself
examined the milk of the hura-crepitans, we became affected with erysipelas;
the affection continued for several days. The milk had been sent to us
in guaduas by Dr. Roulin; the messenger who brought it was seriously
affected by it; and along the road the inhabitants of the houses where he
lodged, felt the same effects.
80 TRANSITION OF INORGANIC INTO ORGANIC MATTER.
2. Codeine (the same). 3. Narceine. 4. Meconine. 5. Para-
morphine. 6. Pseudo-morphine. 7. Meconic acid. 8. Resin.
9. Fatty matters. 10. Caoutchouc. 11. Gum. 12. Basso-
rine. 13. Ulmine. 14. Woody substance. 15. Mineral salts
with bases of lime, magnešia and potash.
MILK OF THE PLUMERIA AMERICANA.
The plumeria, when one of its branches is broken, yields a
considerable quantity of milky juice. At the time when I
examined this juice, the tree was entirely destitute of leaves.
The milk of the plumeria is perfectly white, it is very fluid when
it flows from the plant, but soon after deposits a crystalline
sediment. The taste is slightly bitter, and it has an acid re-
action. The milk of the plumeria appears to contain no
animalized matter. I was only able to detect a very large pro-
portion of resinous matter held in solution or suspended in water;
and indications of potash, lime, and magnesia, combined with
an organic acid.
SAP OF THE CAOUTCHOUC TREE.
Caoutchouc is found in the sap of many trees, and in that
of a great number of herbaceous plants; but it is the hævea
caoutchouc, the jatropha elastica, peculiar to South America;
the ficus Indica, and the artocarpus integrifolia, which grow
in the East Indies, that yield the caoutchouc, so well-known in
commerce, and which has been converted to so many useful
purposes in the arts.
The caoutchouc tree is particularly common in Choco and
forests near the equator. To obtain the elastic gum, the
Indians incise the tree below the bark, when there issues a
copious discharge of milky sop, which will remain fluid for
a considerable time, if it be kept from contact with the air. I
have seen it carried to great distances, in wooden vessels her-
metically closed.
When spread out in thinnish layers, it soon
coagulates, and acquires the singular elasticity which characte-
rizes caoutchouc. The action of the oxygen of the air may
possibly have some influence in producing this coagulation, un-
S
SAP.
81
less, what I am about to state be the effect of a prompt evapo-
ration of the water of the sap. I have often made a small
incision in the trunk of an hevea from which milk imme-
diately flowed, and by reason of its viscidity, trickled down the
tree in a stream of a certain thickness; this milk was at first
extremely fluid, but after from one to two minutes' exposure to
the air, it suddenly coagulated, so that on raising the drop
from the lower end, I obtained a long string or ribband of
perfectly elastic caoutchouc.
In Guiana the Indians fashion the caoutchouc into the bottles
which are so common in trade: they make a clay-mould, and this
they cover by immersing it in the milk freshly drawn from the
tree; they allow the sap to coagulate, which it does very speedily,
especially if it be exposed to the smoke of a wood-fire. This
first layer being coagulated, they continue the same process until
the desired thickness is obtained. The mould is then broken
and taken out piecemeal from the interior of the caoutchouc
bottle which has been formed.
The workmen of Quito, who are very dexterous in manufac-
turing caoutchouc, make shoes and buskins of it, by applying it
in the milky state over moulds of the proper fashion. They also
render tissues impervious, by spreading it in the same state
between two pieces of stuff or cloth; the interposed milk becomes
coagulated, and forms a thin clastic layer, very preferable
to the caoutchouc applied by the aid of solvents.
The Indians of Choco sometimes procure this substance by
felling the tree, and receiving the milk which then flows in a
stream into large wooden moulds, generally formed from a hollow
stem of the guaduas. By keeping the mould open, the milky
mass coagulates after some time. Several of these masses of
caoutchouc, which were brought to me by the Indians of the
Chami nation, were but slightly elastic, their colour also was
extremely deep. It is probable, that by proceeding in this way,
the milky juice is mixed with large quantities of the internal sap
which is much less milky.
Several trees in the valley of the Magdalena which bear the
name of caoutchouc, which, however, are neither the hevea, nor
the jatropha, also yield a coagulable juice, which may be con-
G
82 TRANSITION OF INORGANIC INTO ORGANIC MATTER.
founded with the elastic gum; it is, I believe, caoutchouc
combined with a large quantity of wax, and probably also of
resin; this caoutchouc possesses but little elasticity.
M. Faraday found in the milk of the hevea: in 100 parts:
Water
Caoutchouc
Bitter azotised matter soluble in water and alcohol
A substance soluble in water and alcohol (sugar)
Animal matter
56
32
7
3
2
100
As this milk will remain fluid for a considerable time, pro-
vided it is protected from the air, advantage has been taken of
this property to convey it to Europe. It is sent in well filled,
hermetically sealed bottles.
GUMMY AND RESINOUS SAPS.
I place under this head the saps of those trees which yield
gum from incisions in their trunk, as the acacia vera, and acacia
Arabica, which grow in Arabia, and from which gum Arabic is
obtained; the acacia Senegal also furnishes a species of
gum. In general, in very warm countries, the mimosas produce
gummy matters in abundance.
The elaborated sap of the coniferæ,
of the coniferæ, and terebinthaceae
consists chiefly of resinous matter, dissolved in an essential oil
composed of carbon and hydrogen, similar to the essence of tur-
pentine. The balsams of Peru and Tolu are obtained by incising
the bark of the trees which produce them. In Choco, where I
have seen numerous incisions made in the lower part of the
trunk of the Tolu trees, the balsam flows slowly on account of
its thickness; it does not, apparently, contain any water.
SACCHARINE SAPS.
The sap of the fraxinus ornus, and that of the fraxinus
rotundifolia, yield manna on drying or becoming thick. The
sap of several palms contains a considerable quantity of saccha-
rine matter. At Java, for instance, crystalline sugar is extracted
from the arenga saccharifera. In several places, the sap of
SAP.
83
palm trees is subjected to fermentation in order to prepare vinous
liquors.
The Cocos butyracea (palma de vino) is very common in
the valley of the Rio-Grande de la Magdalena. From a super-
ficial examination which I made of it, its sap contains sugar, an
azotised matter, and some soluble salts.
By fermentation, it produces a vinous liquor sufficiently alco-
holic to produce intoxication. In order to procure it, the natives
of Benadillo first fell the tree, taking care, when it is down,
to give the trunk a slight inclination from the summit towards
the lower extremity or foot. They then make a hole towards
the base of the trunk sufficiently large to hold from fifteen to
eighteen pints, the orifice of which they plug up with leaves.
The woody tissue, to all outward appearance, contains but little
moisture; but in ten or twelve hours after the operation, the
cavity is found full of a liquid, of a well marked vinous odour,
and of a sourish taste, owing probably to the carbonic acid
which is disengaged in large quantity. The wine thus obtained
is rather agreeable. A palm-tree of from 50 to 60 feet in
height, and of which the trunk towards the base is from 20 to
24 inches in diameter will yield from twenty to thirty pints of
wine in twenty-four hours during ten or twelve days. The
wine must not be allowed to remain too long after it has
collected, otherwise it becomes sour.
Sugar is far from being the only useful substance afforded by
palms. There are several of these trees which are truly asto-
nishing by reason of the many important uses to which they
may be applied; and it is not without reason that the mis-
sionaries have styled the palm, the tree of Providence, the bread
of life. Such more especially is the Cocos mauritia, which
grows in the plains of the Apure and Oronoko; its young
shoots serve as aliment; from its fruit whilst still green, a
farinaceous food may be obtained; and when perfectly ripe, it
yields oil in abundance. Hammocks, and various kinds of cloth
are made of the fibrous portion of the bark of this tree; the
young leaves serve to make hats, mats, and sails for ships; the
tissue which surrounds the fruit furnishes the Indians with
clothing; the sap ferments and yields wine; the trunk before
G 2
84
TRANSITION OF INORGANIC INTO ORGANIC MATTER.
fructification contains an amylaceous marrow, of which bread is
made; this marrow, on becoming putrid, produces a vast mul-
titude of large white worms which the Indians value as a most
delicate dish; finally, the woody part of the mauritia affords
excellent timber for building.
It is not necessary to enumerate farther the principles pro-
duced by vegetables; we must now study them in reference to
their elementary composition.
85
CHAPTER II.
OF THE CHEMICAL CONSTITUTION OF VEGETABLE SUBSTANCES.
FROM the very first period of vegetable life, during germina-
tion, the immediate principles which constitute the seed are
destroyed or changed. The young plant, in developing its
organs, creates new substances which are added to the tissues.
already existing, so as to complete or extend them. In order to
account for the productions or changes which take place in the
organism of vegetables, it is expedient first to study the intimate
nature, and general characters of the materials which compose
them. Unfortunately, in the present state of science, this study
is as yet but little advanced; and, notwithstanding the efforts
which chemical physiology has made in recent times, there
still remain numerous and important questions to be solved.
Carbon, hydrogen, oxygen, azote, combined in some cases
with minute quantities of sulphur or phosphorus, are the only
elements required by nature to give rise to that almost endless
variety of vegetable substances, so different in their properties,
as well as in their uses. In the food which sustains the life of
animals, as in the virulent poison which destroys it, these same
elementary bodies are always found combined in various and
dissimilar proportions.
The immediate principles of the vegetable kingdom may be
divided into three groups, if we look to the number of the
elements which constitute these principles as they exist in the
several bodies:
1º. Quarternary, containing, carbon, hydrogen, oxygen,
azote.
2º. Ternary, containing, carbon, hydrogen, oxygen.
3º. Binary, containing, carbon and hydrogen, or carbon and
oxygen, or carbon and azote.
86
CHEMICAL CONSTITUTION OF VEGETABLES.
It is by the examination of the immediate principles which
exist in the seed, that we should approach the study of the com-
position of vegetables, and this the more, as we shall find these
principles diffused throughout the organs of plants. Once we
shall have fully considered their properties and their elementary
composition, it will be sufficient merely to indicate where they
are to be met with in the organism.
§. 1. QUARTERNARY AZOTISED PRINCIPLES OF VEGETABLES.
It has now for some considerable time been ascertained that
several seeds contain azote, inasmuch as azotised matters,
nearly similar to those obtained from the tissues of animals, can
be extracted from them. M. Gay-Lussac expressed this fact
in the most general manner, by laying it down as a law that
every seed contains a principle abounding in azote.*
Azotised animal matters, when heated in close vessels, yield
an ammoniacal product; and to satisfy ourselves of the gene-
rality of the law laid down by Gay-Lussac, all that is necessary
is to subject any seed whatever to dry distillation.
We do not always, indeed, obtain an ammoniacal liquor im-
mediately in this way; rice, for instance, when heated in a
retort, yields a product, having an acid reaction; but it is easy
to demonstrate in the acid liquor, the presence of ammonia by
the addition of lime, which at once sets it free. Peas, kidney-
beans, in a word all the legumens hitherto experimented on
yield a liquor directly, having a highly alcaline reaction. These
differences, in the products of the dry distillation of seeds, are
explained in a very natural way. Throwing the husk out of
the question, we may consider a seed as formed of two parts;
one, non-azotised, possessing a ternary composition, and yield-
ing by the action of heat a liquid with an acid reaction; the
other having a quarternary composition, consequently azotised,
and yielding an ammoniacal liquor, so that the acid or alcaline
*Gay-Lussac, Annales de Chimie et de Physique, t. LIII. p. 110,
2e série.
AZOTISED PRINCIPLES.
87
reaction of the product, really depends on the predominance
of one or other of these two distinct ingredients.
M. Gay-Lussac subjected every kind of seed he could procure
to distillation, and all yielded ammonia either directly or indi-
rectly. I shall add that the numerous analyses which I have
had occasion to make for several years back support the gene-
rality of the principles laid down by the above celebrated chemist.
M. Payen has come to the same conclusion, and has further
shown that at the period of germination the azotised matter of
seeds is determined towards the parts that are most recently or-
ganized. Thus the spongioles situated at the extremities of the
radicles constantly produce ammoniacal vapours during their de-
structive distillation by heat, even though proceeding from seeds
which, when distilled, yield an acid liquor wherein ammonia only
becomes sensible on the addition of lime.*
The animalized or azotised substance is extracted readily
cnough from certain seeds, and has consequently been known to
exist in them for a very long time. It is found in wheat for ex-
ample in different states, and is obtained with great ease by
simply kneading a mass of dough under a small stream of
water by which the starch is carried off, and by and by there
remains in the hand a greyish highly elastic substance of a pe-
culiar heavy odour; this is the gluten of chemists. By this
simple process of analysis, however, we are enabled in many
cases to estimate the quality of a sample of flour with reference
to its richness in gluten, a substance which is rightly considered
as the most essential among the nutritive elements of the cereals.
The washings collected and allowed to stand, soon become
clear: the starch which was suspended in the liquid subsides,
accompanied by flakes of an animalized matter. If the clear
liquor be decanted and boiled, a white froth appears upon its sur-
face, which, skimmed off, is found to have the appearance of
coagulated white of egg, and which in fact has all the characters
of animal albumen. The water from which the albumen is solidi-
fied necessarily contains all the soluble substances of the flour.
On evaporation, it leaves substances similar to gum and sugar,
and traces of saline matters.
Payen, Mémoire sur la composition chimique des végétaux, p. 7.
88
CHEMICAL CONSTITUTION OF VEGETABLES.
With the exception of the starch, which contains very little
foreign matter, the different substances obtained by this process
of washing are far from being in a state of purity. I have said
that all seeds contain fatty substances, but in the products of
the operation just described, no oily matter was detected. As it
cannot be discovered in perceptible quantity in starch, nor in
the substances soluble in water, it must remain attached to the
gluten; and this is actually the case. The gluten, the coagu-
lated albumen then, are not pure proximate principles; fat or
oil may be obtained from them; and further by examining com-
mon gluten carefully we learn that it contains several azotised
substances, which differ from one another. By boiling crude
gluten with alcohol we ultimately obtain a fibrous greyish re-
sidue, called by M. Dumas vegetable fibrine. On cooling, the
alcoholic liquor lets fall a substance which in its properties re-
sembles the caseum or curd of milk. Lastly, if the cold alco-
holic solution be concentrated, a pultaceous substance separates
from it, called by Messrs. Dumas and Cahours glutine.
Analysis, accordingly, indicates the presence of four azotised
substances in wheat; and when these are all combined in the
mass of gluten obtained by washing a lump of dough, they re-
tain fatty matters, from which they may be freed by means of
alcohol and ether. The following, according to MM. Dumas
and Cahours, is the composition of the azotised principles of
wheat, dried at 140 centig. (284° F.)*
Carbon. Hydrogen.
53.2
7.0
53.7
7.1
53.5
7.1
53.3
7.2
Fibrine
Albumen
Caseine (caseum)
Glutine
•
Azote.
16.4
15.7
16.0
15.9
Oxygen, Sulph.
& Phosphorus.
23.4
20.5
23.4
23.6
Legumine. Some vegetables, particularly some seeds, contain
a substance different from any of those just described. This M.
Braconnot was the first to notice in the seeds of the family of
the Leguminosa, and it has been since detected by Dumas and
Cahours in many different seeds. Legumine, which plays an
important part in the nutrition of animals, is obtained by di-
* Dumas et Cabours, Annales de Chimic et de Physique, p. 390,
3e série.
QUARTERNARY OR AZOTISED PRINCIPLES.
89
gesting a quantity of pea or bean meal, or crushed peas or beans
in tepid water for two or three hours; the pulp is then pounded
in a mortar, and afterwards mixed with its own weight of cold
water; after one hour's maceration it is pressed through a cloth.
On standing, the liquid throws down some fecula. Filtration is
employed to have the liquor perfectly clear; upon which a quan-
tity of acetic acid diluted with from eight to ten times its weight
of water is gradually added, when a snowy floculent precipitate
of legumine falls. This is collected in a filter and washed with
water; the legumine is then treated with alcohol, dried, and
pulverized, preparatory to digestion in ether, in order to free it
from fatty matters.
Legumine thus prepared has a pearly or lustrous appearance.
It is insoluble in alcohol and ether. Cold water dissolves it in
large quantity. On boiling the watery solution, legumine is
coagulated and falls in flocculi analogous to those formed by al-
bumen under the same circumstances. Weak hydrochloric acid
throws down legumine from its watery solution like the acetic
acid; the concentrated acid, again, dissolves it, acquiring a violet
tint, a character which also belongs to albumen; but that legu-
mine is actually distinct from albumen is proved by the circum-
stance of its being precipitated by phosphoric acid with three
atoms of water, which albumen is not. The alcalies dissolve
legumine at common temperatures.
COMPOSITION OF LEGUMINE, OBTAINED FROM DIFFERENT SEEDS.
Carbon
Hydrogen
Azote
Oxygen.
Sweet
Almonds.
Lentils.
*


Kidney
Beans.
6.7
50.9 50.9 50.7 50.8 50.7 50.5 50,5| 50.7
6.7 6.7 6.7 6.7
6.9 6,7 6.8
18.8 18.6 18.8 18.6 18.8 18.2 18,2 17.6
23.6 23.8 23.8 23.9 23.8 24.4 24,6| 24.9
100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
These same azotised compounds, or substances differing but
little from them, are very probably those that are now recog-
nised as distributed through the whole body of every vegetable.
* Dumas et Cahours, Annales de Chimic et de Physique, t. vi. p. 423.
3c série.
90
CHEMICAL CONSTITUTION OF VEGETABLES.
verses.
M. Payen after having ascertained the presence of these sub-
stances in the radicles and spongioles, proved it in nearly all the
organs. The examination was extended to a great number of
species of different families. The ascending sap of a fig-tree
(ficus carica), that of the lime-tree, of the black poplar, of the
vine, have all yielded ammoniacal vapours under the influence of
fire; so also do the buds, the young leaves, the stigmas, the
anthers, &c.* Thus, according to M. Payen, the nutritious juices.
which ascend from the extremities of the radicles to the terminal
points of the leaves, carry an azotised principle which accumu-
lates in all the growing organs, at the same time that it is de-
posited within the entire extent of the canals which the sap tra-
It might therefore be supposed that in the latter situa-
tion the azotised substance was associated with matters of ter-
nary constitution so as to form membranes and tissues. But
from the various organs of the many species studied, M. Payen
succeeded in dissolving out by means of alcalies, and entirely
eliminating the animalized substances, without causing the
slightest rent or erosion in the tissues perceptible with the mi-
croscope; whence it may fairly be concluded that if these sub-
stances everywhere and always accompany the young tissues of
plants they still form no integral part of them. The ani-
malized matter seems consequently to preserve a kind of inde-
pendence with reference to the organs which secrete, which con-
vey, and which contain it; it preserves a sort of mobility which
allows of its displacement. And it was in fact necessary that
this should be so; for as the period of maturity approaches we
see the azotised substance carried more particularly towards the
generative organs, and finally become fixed as it were, and accu-
mulated in the seeds. I have had frequent occasion to satisfy
myself that the trefoil, the red-beet, the turnip, &c., contain much
less azote after ripening their seeds than they did previously; and
all husbandmen know that the straw or refuse of plants that
have run to seed forms very indifferent fodder for cattle.
G
The cambium, that peculiar globulo-cellular matter which is
constantly found accumulated where the vegetable is forming
* Payen, Mémoire sur les développemens des végétaux, p. 36.
† Idem, p. 42.
TERNARY PRINCIPLES-STARCH.
91
woody tissue, contains, acccording to MM. Mirbel and Payen,
the same azotised principle of an animal nature, in conjunction
with ternary substances, whose composition, as we shall pre-
As the
sently see, is represented nearly by carbon and water.*
cellular tissue is evolved at the expense of the cambium, the
animalized matters show a tendency to quit the consolidated or-
gan. The departure of these matters at the epoch of the
growth of the cells, explains satisfactorily wherefore the interiors
of old trees contain but a few thousandths of azote, whilst all the
organs of recent formation always contain several hundredths.
With the assistance of chemical analysis it is possible to follow
the appearance and the removal of the azotised matter; thus in
the alburnum and wood it is observed to diminish in quan
tity from the circumference to the centre; this diminution is also
observed in the branches, proceeding from their extremities to
their point of junction with the trunk.
II.-PROXIMATE PRINCIPLES WITH A TERNARY COMPOSITION.
OF STARCH.
Starch is contained in the cells of vegetables under the form
of small white granules which have no crystalline structure.
In the year 1716, Leuwenhoeck ascertained that these
granules were globular bodies more or less regular in their
contours. He believed that he could perceive each globule
enclosed in an envelope, a kind of sac different in its nature from
the matter which it contained. M. Raspail, a few years ago,
confirmed by his own researches the observations of Leuwenhoeck;
he further attempted to measure the diameter of the globules
in different kinds of starch, and came to the conclusion that
their capsule is insoluble, and that it is the internal part alone
which is soluble in hot water.† Since then MM. Payen and
Persoz have ascertained that if the globules of starch be really
* De Mirbel et Payen, Comptes rendus de l'Académie des Sciences. t. xvI.
p. 98.
† In 1812, Villars, in a paper on the structure of the potatoe, had already
estimated the volume of the globules of different kinds of starch.
92
CHEMICAL CONSTITUTION OF VEGETABLES.
4000
surrounded by a capsule, it must be present in a quantity
scarcely appreciable—a quantity not exceeding 4th of the weight
of the starch. These first researches were followed by the
subsequent observations of M. Payen, who has devoted himself
to the study of the amylaceous principle with a zeal and perse-
verance which must secure him the gratitude of chemists and
physiologists.
M. Payen has examined a vast number of fœculæ micros-
copically; the largest granules he observed were obtained from
one of the varieties of potatoe, from the menispermum palmatum,
and the canna gigantea.
The globules of starch frequently exhibit a polyhedal ap-
pearance, a figure which evidently results from their mutual
pressure as they have lain in the cells of the vegetable. Not-
withstanding a great general analogy of form, the granules of
the starch of different species of vegetables, still present peculiar
physiognomies, so that they can be distinguished in many
instances by the practised eye. A character common to the
majority of fœculæ, however, is roundness of contour, when their
particles have not been compressed by their contact in con-
tiguous cells.
Microscopical and chemical researches alike show that starch
is homogeneous in properties, as in composition; that its globules
are composed of concentric layers, the external of which have
exactly the same characters as the internal layers.* In the
natural state, starch is insoluble in water and in alcohol; it is
very ductile, and under the influence of certain agents it exhibits
a great degree of contractility.
Feculas retain water with considerable force; the quantity
retained varies with the temperature at which the drying was
accomplished. Thus the fecula of the potatoe, which is moist
and porous, even when subjected to strong pressure, still retains
45 per cent. of water. This is the green or raw starch of
manufacturers. Dry starch is very hygrometric. If after being
dried it is placed in an atmosphere saturated with moisture, at
20° centig. (68° Fahr.) it will absorb nearly 36 per cent. of
water, and its bulk increases in the ratio of one to one and a
* Fritzche, Annales de Poggendorf, t. xxxII. p. 129.
TERNARY PRINCIPLES-STARCH.
93
half; in this state starch is brilliantly white, and its grains
adhere so closely that they form a mass of sufficient firmness to
take the impress of a seal; starch in this state, however, pressed
upon paper yields no perceptible trace of moisture; it is too
hard and adherent to pass through a sieve; and when thrown on
a metal plate heated to 125° (257° Fahr.) its particles imme-
diately unite and form a cake. The starch of commerce, in the
state in which it is usually found in shops, contains 18 per
cent. of water; it is either pulverulent or readily reducible to
powder, though by slight pressure in the hand, it may be formed
into a mass or ball. After drying in vacuo at the ordinary
temperature, starch retains no more than 10 per cent. of moisture;
a temperature not less than 140° (284° Fahr.) is required to
dry it completely; the water which it retains at this temperature
belongs to its constitution, and cannot be taken from it except
by combining it with bases.*
MM. Collin and Gaultier de Claubry discovered the im-
portant character of starch, that of yielding a fine blue or violet
colour on combining with iodine.† According to M. Payen,
the colour is more intense, nearer to blue and more lasting, in
proportion as the starch is more strongly compressed; the effect
of separation is to turn the blue to shades of violet which
approach redness as the substance is looser. The same fecula,
according to the degree of its aggregation in plants, is seen to
assume shades, which are first reddish, then violet, and eventually
of a more decided blue colour, under the action of iodine.‡
M. Lassaigne has noticed a very curious property of the
combination of iodine and starch: if an amylaceous fluid, having
the decided blue colour, be heated to 89° or 90° C. (193° or 194°
Fahr.) the solution becomes completely blanched; but it resumes
its former tint as the liquid cools.§
This property, which starch possesses of striking a blue
colour with iodine, renders one of these bodies an excellent
test for the other. However, as the iodine must exist in the
* Payen, Mémoire cité, p. 88.
+ Collin et Gauthier de Claubry, Annales de Chimie, t. xc. p. 92.
Payen, Mémoire cité, p. 105.
§ Lassaigne, Journal de Chimie Médicale, t. ix. p. 510.
94
CHEMICAL CONSTITUTION OF VEGETABLES.
free state to produce its effect, it is necessary, when the blue
colour does not show itself at once, in a solution in which iodine
is suspected, and to which starch has been added, to add a few
drops of sulphuric acid, so as to decompose the hydriodic acid in
cases where it may exist.
It is familiarly known that if raw starch be mixed with boiling
water, the result will be a thick, paste-made starch. According
to M. Payen, the change that takes place in the state of the
fecula is owing to a swelling, a rupture, or disgregation of its
granules. By heating a drachm of starch, mixed with about a
couple of ounces of water to about 60° cent. (140° Fahr.) the
microscope shows us that the smallest or youngest grains,
those possessed of the least cohesion, have absorbed a conside-
rable quantity of water, and that the expansion of the contents
has caused a certain number of the globules to burst; at this
temperature, however, some grains of fecula are observed, which
do not appear to have yet attained their maximum of enlargement,
and whose contents consequently are not yet diffused through
the liquid; it is only between 72° and 100° cent. (161.6° and
212° Fahr.) that the maximum of expansion becomes general
and that the solution acquires its greatest consistency.*
The remarkable property possessed by starch of making a
glutinous solution or thick paste with water under the influence
of heat, led M. Payen to conjecture that a contrary effect would be
produced by lowering the temperature-that the starch might
be recovered in its original state of distinct globules by suitable
management; and this he in fact accomplished by an ingenious
procedure. Starch appears to suffer no actual change when
diffused in water by exposure to a temperature of 212° Fahr. ;
the granules have only swollen to about thirty times their
original dimensions by the imbibition of a large quantity of
water.
We have already seen how starch may be extracted from
wheaten flour; this method, however, is not the one that is
usually followed to procure this useful substance, so large a
quantity of which is consumed in the arts. Formerly, starch
* Payen, Mémoire cit. p. 96.
TERNARY PRINCIPLES-STARCH.
95
was universally obtained from grain,-wheat; at present the
potato furnishes a still larger quantity than grain. In the
equatorial regions of South America, starch is abundantly pre-
pared from the Yuca (Jatropha manihot), and from several spe-
cies of palm.
To obtain starch from wheat, the grain is either coarsely ground
and mixed with water in large tubs; or it is put to steep in
sacks until it is so soft that a process of kneading suffices to
set the starch at liberty.
Starch from potatoes. The potatoes are grated after having
been well washed, and the pulp being thrown on a sieve, the
starch is carried off by the water and deposited in suitable ves-
sels. The washings in the manufacture of potato starch soon
become putrid by reason of the azotised matter which they con-
tain, and until lately occasioned much annoyance, until M.
Dailly conceived the happy idea of turning them to account as
liquid manure.
Starch of the Yuca or Jatropha manihot. The manihot
yields very large roots, rich in starch. These are taken up a
little after the flowering, when the fecula is most abundant. To
extract the starch, precisely the same process is employed as in
the case of the potato. In South America the manioc is dis-
tinguished into yuca dulce (mild) and yuca brava (malignant);
the latter epithet applying to the jatropha containing poisonous
juice. The two yucas are, however, but one and the same
species; at least a skilful botanist, M. Goudot, who resided for
several years in America, could not perceive any specific
differences between them. The poisonous principle of the
yuca brava must be very volatile, or readily destroyed by heat,
for the root may be eaten with impunity after it has been roasted,
while the animals who eat it in the raw state soon experience
the most distressing effects.
The Indians seldom prepare starch from the jatropha; but the
root frequently constitutes the staple of their food. It is from
the yuca brava that they obtain the cassava which supplies
the place of bread with them. Among the Indians in the
country near the river Malta, one of the principal tributaries of
the Oronoko, I have seen the cassava prepared in the follow-
96
CHEMICAL CONSTITUTION OF VEGETABLES.
ing manner: the roots of the manioc were scraped on a sort of
rasp formed of small fragments of flint stuck into a plank; the
pulp was then put to drain in a long strainer made of the entire
bark of a species of fig; the juice having drained away, water
was added to finish the washing; the liquid came out nearly
clear and without bringing away any perceptible quantity of
starch. To form the pulp into cakes of cassava, it was spread
out on an earthern dish placed over the fire; the process was
complete when the cassava was dry, and slightly toasted on
the outside. Cassava bread is not very palatable, but it pos-
sesses the property of keeping for a long time in spite of heat
and moisture, and is frequently an indispensable article of pro-
vision with the South American traveller. The Indians say that
they cannot obtain cassava from the yuca dulce.
Starch from palms. In the Moluccas and Philippine Is-
lands, and in the plains of Apure, there are certain palms which
yield a species of fecula. This fecula is found in a soft substance,
generally situated in the centre of these trees. The marrow of
these palms is dried, and when sifted presents itself in the form
of grains, which in commerce bear the name of sago.
None of the amylaceous principles or feculas obtained by the
processes which I have mentioned are absolutely pure; even sup-
posing all the soluble substances to have been removed by wash-
ing, they still retain fatty matters, azotised principles, and
colouring substances. Starch is purified by following up the
water washings by the action of alcohol, of acetic acid and
of ammonia. Starch in its state of greatest purity, and dried at
100° cent. (212° Fahr.) contains, according to the analysis of M.
Jacquelain :
Carbon
Hydrogen
Oxygen
44.9
6.3
48.8
100.0*
By slight roasting, amylaceous feculas undergo considerable
changes; they become soluble in water, and then present the
* Jacquelain, Annales de Chimie et de Physique, t. LXXIII. p. 181,
2e série.
STARCH.
97
properties of gum.* Starch thus roasted, supplies the place of
gum in various manufacturing processes; still it should not be con-
founded with gum in a chemical point of view. The acids act with
more or less energy on starch, and give rise to different products.
Nitric acid, when it is diluted with water, merely dissolves
fecula; but at a certain degree of concentration it exerts a de-
structive action. In this reaction several acids are formed,
among others oxalic acid. By employing very dilute sulphuric
acid, Kirchhoff succeeded in changing starch into a saccharine
substance similar to the sugar of the grape. The operation
may be performed in a leaden or silver pan, or, what is prefer-
able, especially when the process is carried on upon the great
scale, in wooden vessels, in which the liquid mass is heated by
steam. According to M. Couverchel, several organic acids are
capable of changing fecula into sugar in a similar manner; such
are oxalic, tartaric and malic acids.
The artificial conversion of starch into grape sugar has not
yet been satisfactorily accounted for. The acid employed does
not seem to undergo any change; it is found in its original
state and quantity after the operation. M. de Saussure thinks
that the effect of the reaction is the fixation of water; thus
100 parts of fecula yielded him 110.40 parts of sugar.†
M. Couverchel and M. Guérin, on the contrary, state that the
quantity of sugar obtained was less than that of the starch they
employed.
•+
Gluten exerts a reaction on starch similar to that produced
by acids; Kirchhoff discovered, that under the influence of the
azotised matters which are met with in flour, the fecula is con-
verted into sugar. Two parts of starch being mixed with four
parts of cold water, on adding twenty parts of boiling water, a
thick paste is produced; if into this one part of dry, powdered
gluten be introduced, and the mixture be kept at the temperature
of 60º cent. (140° Fahr.), the paste becomes more and more
liquid, so that the mixture may be filtered at the end of
from six to eight hours. By concentration a syrup is obtained,
* Vauquelin and Bouillon Lagrange, Bulletin de Pharmacie, t. III, p. 54.
↑ Saussure, Bibliothèque britannique, t. LVI, p. 333.
‡ Kirchhoff, Journal de Pharmacie, t. 11, p. 250.
H
98
CHEMICAL CONSTITUTION OF VEGETABLES.
in which small crystals of sugar are perceived. It is well known
that during the act of germination, fermentable saccharine
matter is produced. Kirchhoff concluded from his experiments,
that this production of sugar in germination is attributable to the
reaction of the gluten on the starch. Germinating grain, barley-
malt for instance, reacts rapidly and powerfully on any fecula
with which it is brought into contact; a fact well known to, and
constantly taken advantage of, by manufacturers of spirits from
potatoes and raw grain, large mashes of which are rapidly con-
verted into sweet fermentable liquids under the action of a little
malt.
These facts, it is evident, cannot be explained by Kirchhoff's
experiment; in the fermentation of the potatoe, the mass of fe-
cula to be converted into sugar is too great compared with the
quantity of gluten which exists in the malted barley. Further,
the gluten in grain which has not germinated, scarcely exerts
any appreciable action. The principle which, in the preceding
operations, converts the starch into sugar must therefore become
developed during germination. This important point in the art
of the distiller has been investigated with great ingenuity by M.
Dubrunfaut ;* and MM. Persoz and Payen succeeded in sepa-
rating the peculiar matter in barley malt which possesses the
property of converting starch into sugar. This matter has been
called diastase.
Diastase exists in the seeds of all the cereals which have ger-
minated; it is met with more especially near the germs, it
seems even that the radicles contain none of it. Nor is diastase
observed in the shoots or roots of the potato; it is to be met
with only in the tubers, around the eyes or points where the
young sprouts are developed, precisely as M. Payen has remarked,
in the place where we should conceive its presence to be necessary
for effecting the solution of the fecula. It is also found to exist in
the bark and beneath the buds of trees, always in contact with
Diastase is generally obtained from malt, and when
starch.
* Dubrunfaut, Mémoires de la Société royale d'Agriculture, année 1823,
p. 146.
↑ Payen and Persoz, Annales de Chimie et de Physique, t. LIII, p. 73 :
t. LVI, p. 337, 2e série.
DIASTASE.
99
carefully prepared, its peculiar power is such, that one part by
weight is sufficient completely to liquefy two thousand parts of
starch. Diastase is solid, white, amorphous, insoluble in pure
alcohol, soluble in water and weak alcohol. The solution very
readily undergoes change; it becomes acid, and then no longer
exerts any action on fecula. When dried, it keeps much better;
still, at the end of two years, it seems to have lost its distinguish-
ing properties. Diastase has no action on vegetable tinctures, on
albumen, gluten, cane-sugar, gum-arabic, or the woody fibre.
That which more especially characterizes it, is its powerful ac-
tion on fecula; it may be advantageously used to separate and
purify the preceding substances, when they are mixed with
starch. The presence of diastase in malt explains the pheno-
menon of the liquefaction of starch effected by the action of
a small quantity of that substance. This solution is not effected
by gluten, nor by hordeine, as M. Dubrunfaut had imagined.
By the action of diastase, or of malted barley, the starch on
being liquefied is not entirely converted into sugar; there are
other distinct products to be considered in this change. The
syrup obtained by concentrating the liquefied starch, contains
sugar capable of undergoing the vinous fermentation, and a
gummy matter, dextrine. These two substances may be sepa-
rated by means of dilute alcohol, which dissolves the sugar and
leaves the gum untouched. The relative quantities of dextrine
and sugar produced by the action of diastase are variable, and
depend both on the temperature at which the process is con-
ducted, and on the continuance of the reaction. In the first
period of the process, the dextrine predominates; but it becomes
less and less by degrees, and finally gives place to sugar.
M. Guérin ascertained a curious fact, which shows how the
diastase developed in plants may act on their starch: reaction
takes place even at ordinary temperatures. In one of M.
Guérin's experiments, at a temperature no higher than 20° cent.
(68° Fahr.) a quantity of starch, at the end of twenty-four hours,
was converted into syrup, which yielded 77 per cent. of saccha-
rine matter.*
Pure dextrine. M. Payen freed dextrine from the sugar
* Guérin, Annales de Chimie, t. Lx, p. 42, 2e série.
H 2
100
CHEMICAL CONSTITUTION OF VEGETABLES.
which usually accompanies it by precipitating a syrup of fecula
previously dissolved in dilute alcohol, by means of alcohol nearly
free from water. Dextrine well dried, and reduced to powder,
has a specific gravity of 1.51. The specific gravity of pure
starch is 1.51, that of the sugar of starch 1.61.*
M. Payen found dextrine dried at a temperature of 212º Fahr.
to consist of:
Carbon
Hydrogen
Oxygen
44.3
6.0
49.7
100.0†
a composition identical with that of starch.
We have seen that water, acidulated with sulphuric acid,
transforms starch into sugar; and that in this respect, the acid
acts precisely in the same way as malted barley, like which,
the acid first causes the fecula to pass into the state of dextrine:
by checking the reaction at the proper moment, this substance
may thus be obtained, as was shown by Messrs. Biot and Persoz.‡
When starch, for instance, is triturated with concentrated sul-
phuric acid, if the mixture be diluted with half its volume of
water, and be left at rest for an hour, alcohol will throw down
almost the whole of the starch employed in the state of dextrine.
M. Payen has remarked that starch is never met with in the
vegetable tissues whilst in the rudimentary state; the spongioles,
the radicles, the foliaceous buds, the interior of the ovules contain
none of it. Nor is starch found in the epidermis, nor in the
primary cells of the subjacent tissues. This proximate principle
scems to be excluded from those parts of vegetables that are
more directly exposed to atmospheric influences: it is only met
at a certain depth; and the globules which constitute starch
increase in number and in size in the cells most remote from
the surface. The subterraneous organs of plants,-certain bulbs,
most tubers abound in amylaceous matter. It might be main-
tained that light modified this substance, at the very moment
•
* Payen, Mémoires cités, p. 169.
† Idem, p. 157.
Biot and Persoz, Annales de Chimie et de Physique, t. LII. p. 73,
2e série.
INULINE.
101
that it was subjected to the vital influence, and that it was only
preserved in the dark.
On the globules of some species of fœcula there is found a
point or hilum, which, according to some observers, serves to
fix them to the parietes of the cells which enclose them. It
often happens, however, that no hilum can be distinguished,
even by the help of the most powerful microscopes; to render it
apparent, recourse must be had to desiccation, which, by causing
the globular mass to shrink, allows the part carrying the hilum,
to project, by reason of its stronger cohesion. M. Payen does
not regard the hilum as a point of permanent attachment,
connecting the grain of starch to the interior wall of the cell. He
considers it as the orifice of the duct by which growth is effected
through intersusception. In support of this view, M. Payen
observes, that in a great number of vegetable cells, especially in
those of the potato, and of the rhizomas, the globules of starch
are developed in such quantity, that it is actually impossible that
each of these should be united directly to the inner wall of the
cell.*
INULINE.
This substance, discovered by Rose in the Inula helenium,
presents certain analogies with starch. It forms the greater
part of the solid matter of the tubers of the Jerusalem Artichoke
and Dahlia, which do not contain starch. Inuline is dissolved
in boiling water; on cooling it is deposited in globules, which,
under the microscope, appear diaphanous, adhering to one another
like strings of beads; exposed to a temperature of 367° Fahr. it
melts completely and acquires new properties, becoming soluble
in cold water and in alcohol. Inuline is transformed into dex-
trine and sugar by the mineral acids; but it possesses certain pro-
perties which show it distinct from true starch. In the first place,
it is not coloured by iodine; and then acetic acid, which is without
action on starch, produces with inuline precisely the same effects
as the sulphuric, phosphoric and hydrochloric acids; finally,
diastase, whose reaction upon starch is so peculiar, so prompt
* Payen, Mémoires cités, p. 183.
102
CHEMICAL CONSTITUTION OF VEGETABLES.
and so powerful, does not cause any change in inuline. It is
therefore easy to separate these two substances when they are
mingled, by treating the mixture either with acetic acid, which
dissolves the inuline, or with diastase, which liquefies the starch.
Inuline has been analyzed by M. Payen, after having been dried
at 253° Fahr. and having been melted at 367° Fahr. In both
cases it has the same composition.
Carbon
Hydrogen
Oxygen
. 46.6
6.1
49.3
100.0
The composition here is obviously the same as that of starch
and dextrine.
OF WOODY MATTER AND CELLULAR TISSUE.
The most solid part of plants, that which forms in some
sort their skeleton, is the wood in trees, the woody fibre in
herbaceous plants. Woody fibre, as it used to be prepared and
considered, viz.: by the reaction of certain agents which have
the property of dissolving the gummy, resinous and saline sub-
stances which are commonly associated with it, consists, in fact,
of two substances, one the cellular substance, constituting the
tissue of wood and of all the organs of plants, the other the
woody substance, properly so called, filling, and in some sort
consolidating the cells. This distinction between these two
elements of wood was first made by M. Mohl; but M. Payen
was the first who fixed the opinion of chemists and of vegetable
physiologists upon the true nature of these immediate principles.*
By treating the vegetable tissue in its nascent and still gelatinous
state-the unimpregnated kernel of the almond, of the apricot
tree, &c. the membraneous matter of the cambium of the cucum-
ber, the spongioles of radicles, leaves, wood, &c., with different
menstrua, M. Payen obtained the cellular tissue in the state of
purity, and having an elementary composition almost identical,
from whatever source derived; a fact which may be seen from
the following table, which gives the composition of cellular
* Dumas, Comptes rendus, vol. vi. p. 53.
WOOD.
103
Ovules of the almond tree .
tissue from different sources after having been dried at 352°
Fahr.

""
""
Pith of the elder
Cotton
Endive
Banana
Leaves of the agave
Cotton of the Virginian Poplar
Heart of oak
Pine tree.
Perisperm of the phytelaphas
Mushroom
Woody tissue of the oak
of the beech
of the box
of the willow
of the oak
of the beech
of the aspen
Wood in the natural state
of the oak.
>>
>>
""
"
of the apple and pear
of the helianthus annuus
>>
"
The primary tissue, consequently, which constitutes the ske-
leton of wood is still isomeric or identical in elementary compo-
sition with starch. With mineral acids the cellular tissue further
undergoes changes which assimilate it with starch; for on treat-
ing it with sulphuric acid it is changed into dextrine and sugar.
The composition of the cellular tissue differs considerably
from that of the woody fibre as it has hitherto been obtained
after the action of solvents, and been examined by preceding
chemists. Pure wood or woody tissue consists of the following
proportions of elements :
""
>>
of the beech
of the herminiera
Carbon.
Hydrogen.
Oxygen.
}
Carbon Hydrogen Oxygen
43.6
6.1
44.7
6.1
44.1
6.2
43.4
6.0
44.4 6.1
43.4
6.1
43.2 6.5
44.7 6.4
44.1
6.5
44.5
6.0
44.4 7.0
44.1 6.3
44.5 6.7
"
""
>>
52.5 5.7 41.8 Gay-Lussac and Thénard.
51.5 5.8 12.7
>>
50.0 5.6 44.4 Prout.
49.8 5.6 44.6
49.7 6.0 44.3 Payen.
6.144.5
6.4 45.6
49.4
48.0
54.4
6.239.4
54.4
6.3 39.3
47.2
5.3 46.9
""
"
50.3
49.2
49.7
50.6
49.5
50.5
50.3
48.9
49.4
49.5
48.6
49.6
48.8

>>
Authorities.
},
From these analyses it appears that wood in the natural state
H 3
104
CHEMICAL CONSTITUTION OF VEGETABLES.
contains more carbon than woody tissue obtained by the way of
purification, and that this latter substance is also richer in carbon
than the cellular tissue which necessarily forms part of it. In
the purified woody tissue, therefore, the cellular tissue is asso-
ciated with the principle which fills its cells, or which encrusts
it, and it is to this matter that M. Payen has applied the name of
incrusting matter; it is wood properly so called; it is that which
gives to wood its hardness, its tenacity; it predominates in hard
wood and in knots; it corresponds with the duramen of physiolo-
gists, and constitutes almost the whole of the hard particles which
are met with in woody pears and in cork, and which are hard
enough to blunt well tempered steel instruments. As this in-
crusting matter is friable in many instances it may be pulverized
and separated from the tissue which surrounds it, this last tear-
ing or yielding in shreds under the pestle. By means of the
sieve the incrusting matter may in this simple way be obtained
nearly in a state of purity. The analysis of M. Payen shows
it to consist of:
Carbon
Hydrogen
Oxygen
53.8
6.0
40.2
100.0
Deducting resinous matters susceptible of solution in alcohol
or ether, and gummy and other substances which are soluble
in water, the tissues of vegetables must consequently possess an
elementary composition which varies between that of the cellular
tissue and that of the encrusting matter: these are the extreme
terms, and the entire composition of the mixed tissues will be
by so much the richer in carbon as they contain less cellular
tissue. The encrusting matter being soluble in alkaline lyes, it
was by treating wood with solutions of soda and potash that M.
Payen succeeded in obtaining the cellular tissue, which is much
less susceptible of the action of these agents. But treatment of
different kinds, which it is not necessary to enter upon in this
place, is required to procure the substance in a state of perfect
purity.*
* For an account of these see Payen in proceedings of the Academy of
Sciences, vol. ví. p. 1055.
WOOD.
105
The facts which have just been exposed, in regard to the che-
mical composition of wood, corroborate the observations of phy-
siologists. We now understand much better than we did for-
merly the changes which the cells of vegetables experience as
they grow and become aged: it is by the appearance of the
encrusting woody matter that their walls thin, transparent, and
colourless at first, get thick, become opaque, and acquire con-
sistence. By means of the dissections effected by M. Payen
with the aid of purely chemical means, we may obtain assurance
that the tissues of all vegetables, whether phonogamous or
cryptogamous, may be reduced to a single substance, cellular
tissue, having an invariable composition, and forming the vesicles
or bladders of the cellular mass of plants.
This matter exists nearly in an isolated state in the thick walls
of the cells of the perisperms of various seeds, those of the
date for example. From the microscopic researches of M. Payen
and A. Brongniart, it appears that the matter which is added to
the young cells is not deposited upon the inner surface of their
walls, but that it penetrates and insinuates itself into their
tissue. The relation of the cellular to the woody matter in the
development of the walls of cells varies very much, some peri-
sperms containing nothing but pure cellular tissue, whilst the
stony concretions of the pear and of cork consist almost entirely
of encrusting woody matter.
Wood, in the general acceptation of the word, is the solid
part of the trunk and branches; the properties and aptitudes of
the substance vary greatly, according to the plant which has pro-
duced it. Wood is of higher density than water, and if it floats
in this fluid it is only because of the air with which its pores
are filled. Saw-dust, chips, and larger pieces of wood sink
when the air which they contain is expelled and replaced by
water. The specific gravity of the white woods, such as those
of the willow and pine, is about 1.46, that of the heaviest woods
such as those of the oak and the becch, 1.53.
106
CHEMICAL CONSTITUTION OF VEGETABLES.
DENSITY OF DIFFERENT KINDS OF WOOD ACCORDING TO BRISSON.

Pomegranate
Guaiac, Ebony
Box
Oak of 60 years old, the
heart
Medlar
Olive
Spanish Mulberry
Beech.
Ash
Hornbeam
Yew
Apple.
Plum
Maple
Cherry
1.35
1.33
1.32
Orange
Quince
Elm, the trunk
Walnut
1.17
Pear
0.94 Spanish Cypress
0.92
Lime
0 89
Hazel
0.85
Willow
0.84
Thuya .
0.80
Pine
0.80 Spanish white Poplar
0.79
Pine
0.78
0.75 Cork
0.75
•
Poplar.
•
0.70
0.70
0.67
0.67
0.66
0.64
0.60
0.60
0.58
0.56
0.55
0.52
0.49
0.38
0.24
It must not be forgotten, however, that age, climate, and soil
exert a marked influence upon the specific gravity of the same
species of wood.
Wood, according to the use for which it is intended, is distin-
guished into fire-wood, building timber and dye wood. When
first cut down, all timber contains a considerable quantity of water;
100 parts of walnut-tree dried at 212° Fahr. lost 37.5 parts by
weight; of white oak, 41 parts; of maple 48. On an average,
the quantity of water contained in green-wood may be esti-
mated at about 40 per cent.; and drying or seasoning for
eight or ten months will not cause the loss of more than about
25 per cent. of water. The wood which is used for burning
almost always contains about a quarter of its weight of moisture,
which not only does not assist in producing heat, but actually
dissipates a great deal during its conversion into vapour. It is,
therefore, highly advantageous in all operations where wood is
the fuel, only to employ that which is thoroughly dry. So well
is this fact ascertained, that in some manufacturies the wood is
previously dried in stoves before being consumed in the furnace.
The composition of woody matter may be represented by
carbon and water of carbon the mean may be stated at 52,
of hydrogen and oxygen, in the proportions which form water, at
48. The definitive products of its combustion ought conse-
WOOD.
107
quently to be carbonic acid and water. The heat disengaged
during this combustion, necessarily proceeds from the union of
the combustible elements of the wood with the oxygen of the
atmosphere. But in this particular case, the hydrogen being
already present with the proportion of oxygen required for its
combustion, it may be regarded as already burned, the state of
condensation in which the oxygen exists, being considered.
The heat produced by the wood, therefore, depends solely on
the quantity of carbon which it contains.
Natural philosophers in France, agree in designating as unity
in reference to caloric, the quantity of heat necessary to raise a
kilogramme, or 2.2lbs. avoirdupois of water, one degree of the
centigrade thermometer, (1°.8 F.) The following table, by
Rumford, is intended to shew the different calorific or heating
powers of different kinds of wood, and its interpretation is this:
since 1 kilogramme or 2.2lbs. avoird. of lime-tree gave out
3460 units of heat, it follows that this quantity of the com-
bustible would suffice to raise by 1 degree centigrade, (1º.8 F.),
for example, from 10° to 11° cent. 3460 kilogrammes, or
7612lbs. avoirdupois of water.
Kinds of wood.
Lime-tree dry
The same thoroughly stove dried.
Beech dry, four years seasoned
The same well dried in a stove
•
•
Elm, from four to five years seasoned
Oak, fire-wood
Ash, dry
Wild cherry
Fir, dry
The same well dried in a stove
Poplar, seasoned
The same well dried in a stove
Hornbeam.
Oak, dry
•
•
Units of heat
evolved.
3460
3960
3375
3630
3037
3550
3075
3375
3037
3750
3450
3712
3187
3300
From the experiments of Clement, it appears that the heating
power of charcoal is equal to 7050 units. Dry wood con-
taining, as we have seen, 52 per cent. of charcoal, its heating
108
CHEMICAL CONSTITUTION OF VEGETABLES.
power has been deduced theoretically, as equal to 3666. Mr.
Marcus Bull in America, made a series of experiments to de-
termine the relative quantities of heat given out by different
kinds of wood, from which M. Peclet has been led to conclude
that the same weight of dry wood of every kind has the same
heating power, and that this for a kilogramme, or 2.2lbs.
avoird. of wood dried by artificial means, is equal to 3500 units,
whilst the same quantity of the same wood having been cut and
seasoned during from ten to twelve months, and containing from
20 to 25 per cent. of water, is no higher than about 260
units.
By way of comparison I shall here add the heating power of
the several combustibles in general use, in contrast with that of
wood:
1 kilogrm. or 2.2lbs. avoird. of wood-charcoal produces 7226 units of heat
6000
3005
6400
""
"
""
"
coal
peat
peat charcoal
""
"
""
Although the same quantities of wood, brought to the same
degree of dryness, appear to have the same absolute calorific
power, all are not alike adapted to the same purposes. Hard
woods burn slowly, and give out less heat in a certain time than
the less compact kinds of wood. This is the reason why fir is
preferred to oak in furnaces where the object is to obtain the
most intense heats. It were foreign to our object to enter upon
any consideration of the various qualities, or of the adaptation
to particular uses of different species of timber. I may, how-
ever, add a table of the ordinary dimensions of well-grown trees
of different kinds, such as are commonly found in these coun-
tries:
TREES.
109

The spruce fir
Larch
Poplar
Pine
•
Plane
Oak, Elm
Birch
Beech
Lime
Ash
Willow.
Chestnut
Chestnut (another variety)
Maple
Service.
Acacia
Hornbeam
Mulberry
Wild Pear
Crab
Walnut
Trees.
•
Usual height of
Trunk.
Feet.
26 to 100
19
65
16
65
"9
10
13
13
""
16,,
13, 48
48
39
26
"
""
>>
48
>>
10,,
6
20
6, 16
>>
23
Usual
Diameter.
Inches.
47.2
39.3
31.8
34.2
362
31.4
29.5
28.3
25.9
23.6
11.8
36.2
28.3
28.3
17.7
19.2
21.2
16.5
14.1
12.9
36.2
These may be taken as the measurement of trees at their full
growth, and fit for felling. The soil being of the same quality,
the dimensions of trees depend especially upon their age; indi-
vidual trees of the same species, however, occasionally acquire
extraordinary dimensions.
Every one must have noticed the rapidity with which young trees
grow; but is the growth the same for every period of the exist-
ence of trees, or do they attain a certain determinate size like
animals, and then cease from further increase? We have found
that in those climates where vegetation is suspended for a por-
tion of the year, the increase in the diameter of trees takes place
periodically by the addition of a concentric layer of woody
tissue; so that it is possible to determine the age of a dicotyle-
donous tree by the number of its concentric rings, counted at
the bottom of the trunk. With a view to ascertain the amount
of increase in the woody layers at different periods of vegetable
life, De Candolle measured their thickness, and found that if the
annual increase presented a certain regularity, it was still very far
A
H 4
110
TREES TIMBER.
from being absolute even in the case of a single species. The
oak especially offered striking anomalies; thus a trunk which had
grown slowly in diameter was found to have increased more
rapidly as it got older. He found young trees of the same
species, the growth of which, very slow at first, by and bye
became accelerated, and then fell off in a third period of their
existence. From the whole of his observations, De Candolle
concludes that the growth of our common European trees having
gone on with a certain rapidity to the age of from about fifty
to seventy years, then became slower, but continued regular to
extreme age. The inequalities of growth, conspicuous in the
different thicknesses of different rings, he thinks are mainly due
to the kind of soil which the mass of the roots encountered in
their progress, or to the removal of other trees which grew in
the vicinity. The diminished thickness of the rings, after trees,
have passed a certain age, he ascribes to the depth to which the
roots have now penetrated, and their consequent remoteness from
the air; and farther, to the resistance opposed to the expansion
of the trunk by the bark which has now become thick, hard, and
unyielding. Mr. Knight found that old pear trees, relieved of
their outer bark, formed more wood in a couple of summers
afterwards, than they had made in the twenty years that preceded
the operation.*
The forests of intertropical countries produce a vast number
of gigantic trees, many of which might doubtless be turned to
excellent use; but the information we have on the trees of these
latitudes is very imperfect. In New-Granada, the wood which
is known under the name of wood of St. Martha (astroneum
graveolens ?) is frequently employed for building purposes as well
as for making furniture. It is very hard and more beautiful than
mahogany, its colour being deeper. M. Goudot measured a tree
of this kind, which was 1.6 metre or 5 feet 2 inches in diameter,
including the alburnum and had 32 centimetres or upwards of 12.5
inches of heart wood. Belfreys, having supports of this wood
are met with, which have stood for more than a century exposed
to all the inclemencies of the weather. This tree grows in the
dry soils of the hottest regions of South America and seldom at
* De Candolle, Vegetable Physiology, p. 975.
TREES-TIMBER.
111
an elevation of more than about fifteen hundred feet above the
level of the sea.
FIND
Cedar (cedrela odorata) is never attacked by insects, doubtless
because of its aromatic odour; this valuable property makes it
invaluable as building timber. The tree attains to large
dimensions. M. Goudot measured one in the forest of Quindiu
in South America, which was upwards of 150 feet in height by
more than 6 feet in diameter. It grows freely through a zone
of considerable breadth, from a height of about 3280 to 6560
feet above the level of the sea, a circumstance which, according
to my own observations, would indicate the extreme temperature
of the district which it inhabits to be between 66° and 76° Fahr.
į
There are several other beautiful and useful timber trees of
the Cordilleras-the Nogal (juglans...?) which grows between
6500 and 9800 feet above the sea line; the escobo, the pino
(taxus montana Willd.) whose region lies between the 9800 and
11400 feet of elevation; the arayan and the guayacan,—all
are serviceable in one direction or another. The caracoli (ana-
cardium caracoli) and the fig (Ignerones) are trees which
attain to extraordinary sizes, and afford light woods that prove
useful in various circumstances. Under the tropics, indeed, the
trees generally exhibit a luxuriance of vegetation which strikes
European travellers with amazement; M. Goudot, for example,
measured a bombax (B. pentandrum) no more than sixty years
old, the trunk of which was 8 metres or 26 feet in circum-
ference, and whose boughs covered a circular area of 39 metres
or 127 feet in diameter.
+
There is a beautiful tree which grows in the valley of Arragua
in Venezuela, the Zamang, a species of mimosa, according to
Humboldt, one of which, in particular, is greatly celebrated, and
under the shade of which I rested on the 24th of January, 1823.
This magnificent tree is to be distinguished at the distance of a
league; its branches form a hemispherical crown, of 187 metres
or 613 feet in circumference, extending like a vast umbrella,
the points approaching to within from 10 to 16 or 18 feet of
the ground. The trunk of this extraordinary tree is nearly 65
feet in height and upwards of 94 feet in diameter. This tree is
an object of veneration with the Indians. It does not seem to
H 5
112
TREES-TIMBER.
have altered in its appearance since it was first particularly noticed;
the earliest conquerors of Venezuela, seem to have met with it
in the same state as it is at the present time. When Humboldt
measured the Zamang de Turmero, its branches on one side were
entirely stripped of their leaves. Twenty years afterwards I
found it green in every part; but the leaves and branches with
the southern aspect were not so numerous nor so vigorous as the
others.
The dragon tree of Orotava in the Island of Teneriffe is one
of the oldest vegetable monuments of the present world. Hum-
boldt gives it a diameter of 17 feet, and its height, as stated by
M. Ledru, is upwards of 65 feet. When Teneriffe was discovered
in 1402, this tree appears to have had the same dimensions
which it presents at the present time.
The mahogany (cedrela mahogani) is a very long-lived
tree. In Jamaica it sometimes acquires a diameter of upwards
of 6 feet, and Sir W. J. Hooker has calculated that two centuries
at least are required to supply timber of the large scantling
which we constantly see in the yards of our timber merchants
and cabinet-makers.
The Hymenca courbaril one of the largest trees of the
Antilles yields, like mahogany, a timber that is hard and in great
request among cabinet-makers and inlayers. It sometimes
grows to 19 feet in diameter.
The Baobab (Adansonia digitata) lives for centuries, and
acquires extraordinary dimensions. Adanson saw one in the
Cape de Verdes, in the trunk of which an inscription was found,
which was covered by three hundred layers of wood; it had
been cut by two English travellers three centuries before. From
positive observations collected by Adanson, a table has been
constructed to show the progress and probable age of the baobab :
Age of the Baobab.
1 year,
20 years
30
100
1000
2400
5150
Diameter of the Trunk.
0.11 feet,
1.04
2.41
.9.84
14.76
19.03
31.99
Height.
5.25 feet
16.40
23.30
30.84
61.68
68.24
76.76
SIZE AND LONGEVITY OF TREES.
113
De Candolle has remarked that this longevity of the baobab
is made the more surprising by the softness and liability of its
wood to decay. But again, it must be considered that the great
diameter of the trunk, in relation to the height, gives the tree a
stability which is possessed by no other-by enabling it to resist
violent gales of wind.
It strikes me that there may very well be some mistake in
Adanson's estimates of the age of the baobab. When we
see such irregularity in the growth of trees of the same species
planted in the same soil, little reliance can be placed on any de-
ductions drawn from the size of the trunk when the concentric
rings cannot be counted. In proof of this I here give the mea-
surements of two baobabs planted in 1821 in the Botanical
Garden of French Guiana. In 1842 these trees were found:
feet.
No. 1. Length of stem from
ground to first branches. 7.70
No. 2. Do.
. 10.82
feet.
Diameter of the base . 5.41
Do. at origin of branches 4.23
Diameter of base
. 2.65
Do. at origin of branches
1.50
In the tree No. 2 the branches were puny and nowise in rela-
tion with the size of the trunk.
The deciduous cypress (taxodium distichum) is a tree that is
very abundant in Mexico, and in the southern parts of the United
States. At Chapultepec there is one of these trees called the
Cypress of Montezuma, which tradition says flourished in the
reign of that Prince. In 1831 the tree was still vigorous, and
its trunk was 41 feet in circumference. There is another cypress
near Oaxaca, under the shade of which Fernando Cortez is still
reported to have rested; the trunk of this tree is upwards of 39
feet in circumference, and it is 105 feet in height. Michaux
measured several taxodiums in the Floridas which approached
these two in their dimensions.
We have only uncertain data in regard to the age which
palms may attain to; their sizes, however, are well known. In
Egypt, according to M. Delille, the date-trees are generally about
65 feet in height. In the Andes of Quindiu several ceroxylons
were measured, the trunks of which were from 195 to 230 feet
I
114
SIZE AND LONGEVITY OF TREES.
in height! Martius assigns the following as the extreme
dimensions of the palms of the Brazils: from 85 to 127
or 128 feet in height, by a diameter of from 7 to about
121 inches.
Among several palms (areca oleracea) planted in the Bota-
nical Garden of Cayenne in 1821, the tallest twenty years after-
wards was 48 feet from the ground to the bottom of the crown,
and 3 feet in circumference at the base; at 6 feet from the
surface of the ground the circumference was only 2 feet 1 inch,
and a small fraction. As the palms and baobabs will be carefully
protected in the Botanical Garden of Cayenne, an opportunity
will be afforded future observers of following these plants in
their growth with a perfect assurance of being correct as to their
age.
Particular trees of different kinds have occasionally acquired
remarkable dimensions and lived to great ages in Europe. An
elm is mentioned which grew on the promenade of Morges, the
age of which, reckoned from the number of concentric layers,
must have been three hundred and thirty-five years; its trunk
was above 18 feet in diameter. The lime is another tree which
in temperate countries sometimes grows to a great size. The one
planted at Freiburg to commemorate the victory of Morat in
1476, in 1831 was 14 feet in diameter. Near the same place
there is another tree of the same kind which must be older than
the last, in as much as it was already celebrated for its size a
century ago; in 1831 this tree was upwards of 38 feet in cir-
cumference, and about 74 feet in height. The lime tree of
Neustadt is scarcely less curious for its size and the immense
spread of its branches than for the historical circumstances con-
nected with it. Looking back to old documents, this tree must
already have been of great size in 1229; in a poem written in
1408 we are told that this tree was then supported by sixty-seven
props; in 1654 it had eighty-two stone pillars to support its
branches, and in 1831 the number had increased to one hundred
and six. The circumference of the trunk at 6 feet from the
ground measured very nearly 39 feet. An old measurement
made one hundred and fifty years before corresponds very
r
[.
SIZE AND LONGEVITY OF TREES.
115
nearly with this, a fact which shows that in the course of a cen-
tury and a half the trunk of the lime tree of Neustadt had not
grown perceptibly. It is said to be from seven to eight hundred
years old. The old lime tree of Chaillé in 1801 was upwards
of 49 feet in circumference.
The beech grows rapidly whilst young; but in more advanced
age with extreme slowness. In 1818 Deluc saw several beeches
near Geneva, the trunk of which was from 14 to 16 feet in dia-
meter.
De Candolle measured a larch two hundred and fifty-five years
old the trunk of which was upwards of 5 feet (5.84ft.) in dia-
meter; and a larch of no more than fifty-four years growth has
been measured which was more than 3 feet 4 inches in diameter.
The celebrated chesnut tree of Mount Etna has been stated
to be upwards of 191 feet in girth, (about 63 feet in diameter)
and must therefore be the largest tree described up to the pre-
sent time; but the tree has been supposed to be formed by
several trunks springing from a common root which have grown
together. Other remarkable chesnut trees are mentioned.
The plane is one of the largest growing trees of temperate
countries. A traveller who visited the valley of Bujukdere, near
Constantinople, met with a plane upwards of 95 feet in height,
and the trunk of which, hollow internally down to the level of
the ground, was more than 158 feet in circumference. A plane
tree which grew in Norfolk and was of the age of thirty-one
years, was 74 feet in circumference according to Hunter. Cy-
press trees often attain to a very great age. In the garden of
the palace of Grenada there is one which has stood for more
than three centuries. At La Somma, near Milan, a cypress is
shown which in 1794 was 17 feet in circumference.*
Tradition has it that an orange tree of the convent of St.
Sabina at Rome, was planted by St. Dominic in the year 1200;
this tree still exists. The orange tree of Versailles, known
under the name of the Francis I. is rather more than three hun-
dred years old. In 1804 orange-trees were shown in the green-
houses of Bonn three centuries old, and of which the trunks
* De Candolle, Physiologic, p. 994.
I 2
116
SIZE AND LONGEVITY OF TREES.
were nearly 29 inches in circumference.* In South America
I had myself occasion to observe citron trees of great age and
of very considerable dimensions; the trunks of several of these
trees were nearly 27 inches in diameter.
A sycamore tree of the village of Trons, in the Grisons, more
than five hundred years old, is at this time between 8 and 9
feet in diameter.
Many oaks have been described which had survived from
eight hundred to one thousand years. Hunter saw one of these
trees still extremely vigorous which was 11 feet in diameter.
Evelyn, who in his delightful work entitled Sylva has given a
list of the largest oaks known in his day in England, speaks of
one growing in Welbeck Lane which must have been eight
hundred and sixty years old at least, and the diameter of whose
trunk at the base was upwards of 11 feet.
The olive is one of the trees that reaches a great age; Piconni
describes one of about seven centuries old, and a circumference
of about 25 feet.
The cedar of Lebanon grows vigorously and long, especially
in soils that are sufficiently loose and permeable. According to
M. Paul Vibray of Sologne, the growth of this tree is more
rapid than that of the coniferi in general. The cedars which
grew on Mount Lebanon, and were measured by Nauwolff in
1574, and again by Labillardière in 1787, are generally allowed
to be about the age of one thousand years. De Candolle, how-
ever, thinks that this age is exaggerated, and in contradiction
with observations made on trees the age of which is positively
known. The following are a few of the measurements which
have been reported by different observers:
"
››
Cedar of Chelsea
of Paris
40
of ditto
83
Environs of London 200
Ditto.
113
of Mount Lebanon. 600
30
of Sologne
The yew, as is well known, produces a very hard,
* De Candolle, Physiologie, p. 999.
A
"
""
""
Age.
83
feet in circumference.
12
7
9.4
16
14
36.4
5.3
Observers.
Thouin.
Loiseleur.
Hunter.
Ditto.
Maundrel.
M. Vibray.
close, and
AGE FOR FELLING.
117
enduring wood, qualities which contribute greatly to the longevity
of trees. Some of the oldest trees known have been yews. Here
are a few that have been particularly described:
Where they grow.
Probable age.
1220
County of York
Ditto
1220
1287
County of Surrey
Fortheringal (Scotland). 2580
County of Kent
2800
•
•
Circumference.
28.24
13.84
30.11
62.33
62.59
Observers.
Pennant.
Ditto.
Evelyn.
Pennant.
Evelyn.
According to Duhamel it is extremely difficult to fix upon
any age as the best in a general way for felling trees, with a
view to obtaining the largest quantity of sound available timber.
When the tree is too young, the timber has not all the excellence
which it would have gained with greater age; when too old, the
pores are obstructed, and it has begun to decay in the parts
of oldest formation, so that it is not uncommon to find wood in
the centre of the trunk which is lighter than that of the circum-
ference. In trees which have already fallen into a certain state.
of decay, the worst timber in them is decidedly that which is
taken from the centre at the base of the trunk; and, indeed,
the wood of the centre generally is then of inferior quality to
that of more recent formation. Very aged timber always
perishes first in those parts which have formed the most internal
layers of the tree. It is, therefore, an obvious and grave error
to suffer any tree to stand that has given the slightest indica-
tions of decay, in as much as that which is ordinarily the most
valuable timber is likely to be altogether lost. Neither the age
nor the dimensions are always the indications of the proper
period for felling trees; exposure, soil, situation, have immense
influence upon their growth, vigour, and general qualities. Trees
ought to be cut just when they are on the turn; the proper
moment is that which precedes immediately the alteration of the
heart; and although the destructive effects of age are princi-
pally felt in the interior, this intestine disorder is nevertheless
proclaimed externally; the whole tree suffers when it has taken
place.*
* Duhamel, Exploit. des bois, t. 1. p. 126.
I 3
118
SEASON FOR FELLING.
Duhamel has given the following characters as indicating
incipient decay, or decline of vigour in trees :*
1. A tree, the top of which forms one uniform rounded mass.
is not strong; a vigorous tree always throws out certain
branches which surpass the others in luxuriance of growth.
2. When a tree comes into leaf prematurely in the spring,
and particularly when the leaves turn, and fall prematurely in
the autumn, it is a certain sign of weakness.
3. When several of the top or leading branches of a tree die,
even at their mere extremities, the wood in the centre is be-
ginning to undergo alteration.
4. When the bark quits the trunk, or becomes cracked here
and there, we may be satisfied that the tree is far gone in-
ternally.
5. Mosses, lichens, and funguses growing upon the bark, and
red or black spots appearing upon it, always lead to a suspicion
of change in the wood.
6. When the sap is observed to flow from crevices in the
bark, the death of the tree is at hand.
In France, the cutting down of the smaller wood, such as is
used for firing, takes place at from twenty to thirty years; in the
forests, the trees are commonly felled at from one hundred to
one hundred and thirty years old, and a few trees are generally
left as reserves, and for special purposes, till they have attained
the age of from two hundred to two hundred and fifty years.
The prevalent opinion among foresters, with regard to the
proper season for felling is, that it should be done when the sap
is in the state of greatest repose, or when it is present in least
quantity in the trees. The season fixed by the old law of
France, (1669), was from October to March inclusive. But
the experiments of Duhamel tend to show that this is not
actually the season when trees contain the smallest proportion of
sap, and that fellings made at other times of the year have had
very satisfactory results. All things well weighed, says the
illustrious cultivator, our only safe guide in such matters is
observation; and from numerous experiments he concluded that
*Duhamel, Exploit. des bois, t. 1. p. 133.
SEASON FOR FELLING.
119
there was actually as much sap in trees in winter as in summer,
and that the spring and summer were the seasons most favour-
able for the speedy drying of the timber. Trees felled in
summer, were even found by Duhamel to yield timber which
stood better, and lasted longer than those that were cut down in
winter; while he found the wood of equal strength in either
case. He concluded, therefore, that the season of the year at
which timber was felled, had no influence upon its quality or
durability.*
There is, in fact, no general rule observed in different coun-
tries as to the period at which timber is felled. The French
still go on cutting from October to March; the English fell in
the winter. Convenience of different descriptions appears often
to decide the question as to season. In order to procure bark
for the tanneries, an act was passed by the English Parliament
in 1603, prohibiting all felling of oak timber during the dead
season, the penalty for infringement of the act being confiscation
of the timber felled, or fine to the amount of twice its value.
An exception, however, was still made in regard to timber
destined for the public service in ship building, &c. The price
of bark afterwards rose to such a height, that it was found most
profitable to cut in the spring; and the practice then became so
general, that it by and by became necessary to offer premiums
to induce proprietors of oak forests to fell timber in the winter
season, for the sake of the British navy. The inhabitants of the
county of Stafford appear at a somewhat early period to have
sought to combine the advantages of the bark trade, with a
fulfilment of the conditions that entitled them to the premium
on winter-felled timber: they stripped the trees of their bark in
the spring, and felled them the following winter. And Buffon
and Duhamel showed subsequently, that by barking trees two
or even three years before cutting them down, the white external
wood could be rendered nearly as hard and durable as the heart
wood of the tree. The recommendation of this procedure by
these two distinguished men has not been followed in France;
but ever since 1770 the Dutch have adopted it, and it is now
* Duhamel, op. cit. t. 1. p. 400.
120
INFLUENCE OF SOIL ON TIMBER.
practiced in many parts of England, particularly in the royal
forests.
It is quite certain that the nature of the soil exerts a consider-
able influence on the rapidity of growth, and quality of the
timber. The oak, the elm, &c., which have been grown in a
damp soil will not be so hard and compact as the same trees
reared on a dry plot. Duhamel found, that although the trees
which came in swampy bottoms were very sappy and wet, they
were still lighter than others of the same kind which had grown
on a dry bank. Their white wood is thick in comparison with
their hard wood; they are brittle, and do not readily take, or
keep the shapes into which they are bent for ship-building or for
staves; and then their pores being large and open, and the
whole wood being without that kind of varnish which impreg-
nates good timber, they are readily permeable and unfit for the
manufacture of vats, &c.-to say nothing of their being much
more perishable. Such soft and porous timber is altogether im-
proper for out of door constructions and for ship-building; but
it answers extremely well for indoors and cabinet work; for the
latter it has even certain advantages, it is easily wrought; and
once fairly seasoned, it is neither so apt to warp nor to crack as
harder wood. It was very probably to guard against any excess
of
in trees, so prejudicial in a general way to the timber they
yield, that the Romans, according to Vitruvius, surrounded those
that were destined to be cut down with a trench six months
before hand.*
sap
Trees which have grown in a good soil sufficiently drained
have a fine bark, and their white wood is moderate or small in
quantity. Their woody layers, indeed, are apt to be thinner
generally, than those of trees that have grown in a wet soil; but
they are much harder, and tougher, their grain is more even and
close, and their pores are filled with an encrusting matter.
They are consequently very heavy, even when thoroughly dry,
and with time and due seasoning they become extremely hard,
and in the same degree acquire durability. Duhamel was led by
his experiments to conclude that the difference in point of
* Duhamel, Expl. des bois, t. 1. p. 46.
INFLUENCE OF SOIL ON TIMBER.
121
density of timber grown in a marshy soil, and in one that was
well drained and dry, was occasionally in the ratio of five to
seven.
The denser, dry-grown timber, supports a relatively much
greater weight without breaking than the marsh-grown timber;
and when it does yield, it gives way by a large and splintering
surface, whilst the softer less dense wood snaps off short. In
brief, there is no question as to which kind of timber is the
most valuable; and measures ought to be taken by landed pro-
prietors and timber-growers at all times, not merely to grow
trees, but to grow them under such circumstances as shall insure
their yielding good available timber when they have come to
maturity.
If wet soils then be unfavourable to the growth of timber
of the highest value, in ship-building especially, what has been
said must be taken as of application to those trees only which
will grow in a great variety of soils. Damp and even marshy
lands are well known to be favourable and even indispensable
to certain trees, which, by their nature, delight in the neighbour-
hood of water; but these are generally kinds which are rather
sought after for their height than for their strength and
durability.
Excessively dry soils, on the other hand, have also their disad-
vantages for forest cultivation. In such ground, trees seldom
acquire a sufficient growth to admit of their being applied to any
important purpose. It is certain, however, that absolute uni-
formity is never encountered in any piece of timber. The woody
layers that have been formed in a wet or a dry year, in a warm
or a cold year, feel and manifest the effects of the varying
meteorological influences. They are of different thicknesses and
densities, and when carefully examined, are found to present the
characters of the timber grown in soils of the most opposite
description in point of wetness and dryness.
The treatment of trees after they are felled, the drying and
seasoning of the timber, are points of the highest importance.
* Duhamel, t. 1. p. 57.
I.
1 4
it.
122
SEASONING.
Standing trees contain a large quantity of water in their compo-
sition. After being cut down the moisture is dissipated, rapidly
at first, much more slowly afterwards. This drying process is,
of course, favoured or retarded by the varying states of heat and
moistness of the atmosphere. At length there comes a time
when the wood no longer suffers any sensible change by longer
exposure to the air; or if it does, the change is now on the one
side, now on the other, and merely in harmony with the hygro-
metric state of the atmosphere. Timber has then lost the whole
of the moisture which it can get rid of by this mode of drying;
it is now fit for use; it is seasoned, to use the technical ex-
pression.
Timber is sometimes seasoned by previous total immersion
in water. It has been held that this process favoured the
thorough drying, by dissolving out certain deliquescent salts,
which are found in the sap, and prevented after-shrinking.
However this may be, it is quite certain that in warm countries
especially, it is advantageous to sink fresh-cut timber in water,
with a view to prevent it from splitting, apparently in conse-
quence of drying too quickly. The old Venetians sank, for a
season in the sea, the oak timber which was destined for the
construction of their gallies. Elm and beech, in particular, are
said to improve greatly by the process of submersion in salt
water, and to dry afterwards perfectly by simple exposure to the
air. *
Mr. John Knowles, who made a particular study of the
means most generally employed in seasoning timber, has given
an account of a series of experiments undertaken in the Arsenals
of Deptford and Woolwich, to determine the rate of drying and
ultimate degree of dryness attained by timber variously treated-
unprepared and prepared by previous submersion in water. The
pieces of timber were placed vertically, now in the position they
had occupied in growing, now in that opposed to this; and it
was found that, circumstances the same, they dried more quickly
in the former than in the latter. The general results of these
experiments were as follows: 1st. That the pieces of timber were
* Knowles, Maritime and Colonial Annals, 1825.
DECAY.
123
best seasoned by being kept about thirty months in the air, but
in the shade and protected from wet. 2nd. That they lost more of
their original weight after six months' alternate immersions and
dryings, than by being kept under water for six months and
then dried. Ship-builders are generally agreed that it is not
expedient to make use of timber until three years after it is cut.*
Duhamel advises strongly, that in ship-building all timber
from trees already on the decline should be rigorously rejected;
and this the rather that the most careful examination often
fails at first to perceive any alteration in the heart-wood of such
trees, although it never fails to show itself by and bye at a
sufficient interval after the felling. This is undoubtedly a precept
which it would be well to bear constantly in mind; but timber
does not always carry within itself the germs of its speedy decay;
and that which has been seasoned with the most scrupulous care,
and was originally of the best quality, does not escape the rot
when it is placed under unfavourable circumstances any more
than that which was of inferior worth and less carefully treated.
Wood appears to perish or decay through three principal
and appreciable causes, which all require similar conditions to
come into play, viz.: stagnant air, sufficient warmth, and
moisture. Like the generality of organic substances, wood,
when moistened in contact with the oxygen of the air, and under
the influence of a sufficiently high temperature undergoes decom-
position of a kind which has been compared to a slow combus-
tion, upon which we shall find occasion to say more by and bye.
It is with a view to escape this kind of decay as much as
possible that timber is never, or ought never, to be employed in
the construction of ships and buildings until it has been thoroughly
seasoned.
Besides this first cause of decay, which may be prevented in a
great measure by using certain precautions, wood has still two
redoubtable enemies, insects and certain plants of the family of
the cryptogamiæ. In one case, the wood perishes because it is
fed upon by certain animals which live and grow at its expense;
in the other, it decays because it serves as the soil to one crop of
fungus after another which luxuriate on its surface, whilst their
* Dupin, Ann. de Chimie, t. xvII. p. 277.
124
DECAY
roots penetrate deeply into its interior. There is nothing in either
accident which excites astonishment, now that we know the inti-
mate constitution of wood. We know, in fact, that among the
number of soluble principles which impregnate the woody tissue,
there is an azotised matter analogous in its composition to those
that exist so abundantly in all the ordinary esculent vegetables.
There is, therefore, in wood ample nourishment for the insects
which we find living on it; and if I state now (reserving to my-
self the opportunity of demonstrating the fact) that all organic
azotised matter becomes an active manure by decaying, we shall
understand how it happens that plants, which have the power of
living in dark, warm, and damp places, wax and multiply in the
joistings of houses, and in the ribs and planks of ships, causing
a dry rot, which separates the integral layers of the wood, and
reduces the strongest beams to dust.
The rapidity with which wood is, in some circumstances, devour-
ed by insects is almost incredible. Some years ago the thermites,
or white ants, spread in such strength through the docks and
arsenals of Rochelle and Rochefort, that in a very short space of
time serious damage was done. A learned entomologist, M.
Audouin, commissioned by the ministry to take information on
the subject, reported that the ravages committed by these insects
had been very considerable. But it is principally in warmer
climates, where the temperature is steady throughout the year,
and where there is no winter that the thermites occasion the
most alarming injury. At Popayan, for example, it is difficult
to meet in a building, even of recent construction, with a piece
of wood which is not gnawed and ant-eaten. The hardest and
most compact woods do not always resist the attacks of these
insects, which, farther, do not spare every kind of odorous wood,
cedar for instance. In such countries it is altogether impossible
to preserve books and papers. I remember, in connexion with
this matter, that having received instructions to examine the
archives of Anserma, one of the oldest towns in Popayan, in
1830, I found nothing but books illegible and in pieces; never-
theless, the date of the documents, which it was my business to
consult, could not have been older than the year 1600.
The dry rot, which results from the development and growth
DRY-ROT.
125
of cryptogamic plants upon wood is the curse of navies. Mr.
Knowles is of opinion that this disease of timber has been known
from the most remote antiquity; he believes that he can even
recognize dry-rot in the sore called house-leprosy, mentioned in
the 14th chapter of Leviticus. A ship attacked by dry-rot,
becomes in a very short space of time unfit for sea. The
Foudroyant of 80 guns is often quoted as an instance of its
destructive powers: launched in 1798, she had to be taken into
dock and almost rebuilt so soon as 1802.*
The fungi which induce dry-rot have been studied by
Sowerby. Mr. Knowles signalizes two species in particular;
one of which he describes under the name of Xylostroma
giganteum, the other under that of Boletus lacrymans. The
Xylostroma does not extend beyond the part where it is deve-
loped; but the Boletus, on the contrary, is propagated with
frightful rapidity, and disorganises deeply and to a great distance
around the texture of the wood where it once appears. These
fungi are generally found on board ship, between the planking
and the ribs, in damp situations, and where the air is scarcely,
if ever, changed.†
The temperature most favourable to the development of dry-
rot has been found to lie between 7° and 32° cent. or 45° and
90° F. These are the extreme limits: below the minimum
vegetation languishes; above the maximum, the fungi droop.
With this piece of information it was hoped that vessels might
be freed from dry-rot by raising the temperature sufficiently.
The trials were made in winter in the "Queen Charlotte," the
air in the lower part of the ship being raised as high as 55° cent.
or 130° F. But the general result did not answer expectations
for although the fungi were destroyed in the lower part of the
vessel, it was found that their growth was rather favoured in
places at a certain elevation above the kelson. The warm air,
in fact, as it rose through the timbers became robbed in its
course, and deposited the greater portion of the moisture which
it had taken up at a lower level. Above the orlop deck, con-
sequently, there was just about the temperature and the
* Dupin, Ann. de Chimie, t. xvII p. 290.
† Dupin, Ann. de Chimie et de Physique, t. xvII, p. 291, 2e série.
126
PRESERVATION OF TIMBER.
quantity of moisture most favourable to the development of the
fungi. The evil was therefore only transplanted, not destroyed.
It was now proposed to heat the "'tween decks" at the same
time as the hold, making use of due ventilation; but this
method of proceeding has not been put into practice.
The extreme slowness of the growth of trees stands in strong
contrast with the rapidity of their decay when they are reduced
to the shape of timber and employed in constructions of almost
every kind. In countries well advanced in civilization, every
description of industry tends to consume timber, at the same
time that an increasing population is every day contracting the
extent of forest land, and diminishing the number of trees
grown. In some countries, indeed, it is certain that the production
of wood for all purposes, firing, &c., &c., is no longer in relation
with its consumption. The price of the article, necessarily high,
is therefore tending continually to rise; and it is not surprising
that various measures have been suggested and essayed of
giving this perishable material greater durability.
The well known great durability of certain trees, the teak,
ebony, lignum vitæ, &c. naturally led to the conclusion that the
fatty or resinous matters which they contain have the property of
preserving the wood against the greater number of the ordinary
causes of decay; and unctuous and resinous matters appear in
fact to have been the means most anciently employed to preserve
wood from the air, from moisture, and from the attacks of in-
sects. But it is scarcely necessary, at the present time, to say
that these varnishes only accomplish the object proposed in
their application in a very imperfect way; paint and varnishes
crack, rub, or scale off with the slightest friction; nor do they
always remove the causes of internal decay; on the contrary,
by preventing more complete dryness they sometimes even pro-
voke or favour them, when applied to tender, that is, imperfectly
seasoned wood. Merely laid on the surface, indeed, it has always
been seen that varnishes of any kind were but indifferent protec-
tors; that a really good preserver ought to penetrate the sub-
stance of the wood, and unite with the tissue itself. But herein
lay the whole difficulty; how was the needful penetration to be
effected? for the number of chemical substances, from which
PRESERVATION OF TIMBER.
127
good effects might reasonably be anticipated, is pretty consider-
able,—unless indeed we find ourselves prevented from using them
by the consideration of the price; for it is imperative that any
preservative proposed be extremely cheap.
For a long time the only process for effecting the penetration
of timber by substances proposed for its preservation was to
macerate them for a longer or shorter time in a solution of the
substance. But this means was found as tardy of accomplish-
ment as it was ordinarily imperfectly effected; to have got to
the heart of logs of large scantling, years would have been required.
Any delay, however, in such circumstances is of itself a cause
of enhanced price of the article. By and by a variety of pro-
cesses, the element in one being pressure, in another exhaustion,
were put in practice, and very satisfactory results obtained. M.
Breant showed, that by means of strong pressure he could fill
the largest logs from one end to the other with any unctuous or
resinous substance proposed in the course of a few minutes. M.
Moll, a learned German, proposed creosote introduced in the
state of vapour by forcing, as an effectual means of preserving
timber, which it probably would be found; but the high price
of the antiseptic, were there no other objections, would neces-
sarily be an obstacle to its general employment. The same ob-
jection applies to the bichloride of mercury (Kyan's patent); and
arsenic is inadvisable from its deleterious effects upon the animal
economy. Some workmen are said to have lost their lives in
consequence of working timber which had been impregnated
with a solution of white oxide of arsenic.
It had been observed that vessels engaged in the lime trade
lasted long; and then it was naturally thought that by impreg-
nating the wood to be used for ship-building with lime it would
be rendered more durable. But the result did not answer ex-
pectation; the timber treated with lime did not even seem to
last the usual time.*
Such was the state of the question when Dr. Boucherie made
a highly important communication to the Royal Academy of
Sciences on the preservation of timber. Some estimate of its
* Dupin, Ann. de Chimie, t. xvII. p. 286.
+ Idem, t. LXXIV. p. 113.
128
PRESERVATION OF TIMBER.
nature may be formed from the list of subjects discussed in this
remarkable paper.
1. To protect timber against dry-rot and the ordinary wet-rot.
2. To increase its hardness and strength.
3. To preserve its flexibility and elasticity.
4. To counteract its alternate contraction and expansion in
consequence of the varying state of moistness and temperature
of the atmosphere.
5. To diminish its inflammability and combustibility.
6. To give it a variety of permanent colours and odours.
In the whole of his experiments M. Boucherie set out from
this proposition, the truth of which appears indisputable and to
require no comment, viz: That all the changes which wood un-
dergoes proceed or depend upon the soluble matters which it
contains. In conformity with this idea the first step towards giving
durability to timber was, either to render these matters insoluble
and inert, or to remove them entirely. M. Boucherie, therefore,
in his first trials sought to render the matters insoluble by
charging the wood with a substance capable of combining
chemically and forming a precipitate with the soluble matter left
by the sap. To resolve this problem, M. Boucherie investigated
the reactions between the soluble matter of wood, which it was
his object to precipitate, and a variety of low priced chemical
agents. He found that the pyrolignite of iron combined the
greatest number of desirable properties: it is very cheap, the
oxide of iron forms stable compounds with the greatest number
of the organic substances which are found in the sap of vegeta-
bles, and to conclude, the crude pyrolignite contains a notable
quantity of creosote.
The facts upon which M. Boucherie relies as proving the pre-
servative powers of the pyrolignite of iron flow from numerous
experiments performed either on vegetable substances which in
themselves readily and rapidly undergo changes; or upon billets.
of wood of different kinds. A quantity of flour, the pulp of
carrots, beet-roots, &c. impregnated with the pyrolignite resist
decomposition in a very remarkable manner in contrast with the
same substances when they have not been prepared in any way.
The wood which was selected for trial, was generally of the
PRESERVATION OF TIMBER.
129
-most perishable kind. In December 1838, several empty hogs-
heads and barrels made of the best timber unimpregnated
and impregnated with the pyrolnignite were placed together in
the dampest parts of the great cellars of Bordeaux. In August
1839, it was easy to see that the unimpregnated tubs were already
deeply stricken, and after from two to three years they fell to
pieces with the slightest force; the casks made of the prepared
wood, however, were as sound as on the first day of the ex-
periment.*
M. Boucherie concluded from his experiments instituted with
a view to the settlement of the question, that about th of the
weight of the wood in its green state of the pyrolignite was
adequate to precipitate and render insoluble all the principles
obnoxious to change, which were contained in the woody tissue.
M. Boucherie, whilst he regards the pyrolignite of iron as at
once the most powerful, and one of the cheapest preservatives of
timber, nevertheless indicates several soluble salts, which are
readily available in consequence of their low price, and also very
effectual when the wood, which they are to preserve, is not kept
constantly wet. Solutions of common salt, of chloride of lime,
the mother-water of salt-marshes, &c. were all tried and found
useful: casks, the wood of which had been prepared with the
chlorides, after having been long kept in very damp cellars,
came out as fresh as those which had been impregnated with
the pyrolignite of iron; the flexibility of the wood preserved
with these alkaline and earthy salts was farther as great as at
the beginning of the experiment.
Having now come to a conclusion in regard to the substances.
most effectual in preserving wood, the next business was to make
them penetrate its tissue most intimately. Maceration, M.
Boucherie, soon found, like his predecessors in the same path,
to be insufficient, the substances in solution only penetrating a
very little way. He then tried various processes of injection;
but all inferior to that imagined by M. Breant, and therefore
less effectual. He then bethought him of effecting the needful
penetration of the wood in the green state, and before it had
been sensibly altered by drying and seasoning; he asked himself
* Comptes Rendus, t. 11. p. 896.
K
130
PRESERVATION OF TIMBER.
if the force which determines the ascent of the sap might not be
taken advantage of after the tree was cut down, as a means of de-
termining the entrance of a solution of pyrolignite of iron? And
all his trials in this direction answered his expectations fully.
M. Boucherie had, in fact, discovered a means of securing the
penetration of the minutest pores of the largest log by a substance
capable of rendering it incorruptible. No one before M. Bou-
cherie thought of taking advantage of an admitted physiological
fact for such a purpose. He announces the principle upon
which he proceeds in these terms: "If a tall tree be cut down
at the proper season, and the bottom of the trunk be then
immersed in a saline solution, weak or strong, the liquid is power-
fully drawn up into the tree, penetrates its most intimate tissues,
rises to its smallest branches and even to its terminal leaves."*
In the month of September, a poplar, upwards of 90 feet
high and nearly 16 inches in diameter, was cut, and the bottom
of its bole plunged in a vessel, containing a solution of pyrolignite
of iron marking 8° of the areometer of Beaumé; in the course
of six days it had absorbed upwards of 66 gallons of the fluid.
In his first experiments, M. Boucherie procured the needful
absorption by placing the bottoms of his trees in vessels con-
taining the solution; but this mode of proceeding was obviously
full of difficulties and open to many objections: the weight of a
green tree of large size, with the whole of its top and branches is
often enormous, and to raise a mass of the kind once down
again into the perpendicular was no easy task; it implied recur-
rence to certain mechanical means which are not always at hand,
and necessarily expensive. M. Boucherie, therefore, tried other
modes of making the trees absorb; he adapted a sac of imper-
meable material to the bottom of the trunk laid on the ground,
and into this sac he poured his solution, and this method
answered very well. He next took advantage of one or more
of the roots to effect the imbibition. He next bored a hole into
the bottom of the trunk, still erect; and having brought the cavity
thus made to communicate with a reservoir, he still succeeded.
This last plan was still farther simplified in proceeding as follows :
the trunk of the tree is pierced by an auger through nearly the
* Ann. de Chimie, t. LXXIV. p. 132.
-
PRESERVATION OF TIMBER.
131
whole diameter. Into the auger-hole thus made, a narrow saw
is passed, by working which on either side, the trunk is divided
internally to a very considerable extent, and the majority of its
sap vessels are thus cut across and made accessible. An im-
pervious cloth is then tied round the trunk, below the opening,
and this is made to communicate with the reservoir of liquid.*
M. Boucherie was almost necessarily led, in the course of his
experiments, to inquire whether the absorbing power of trees
differed at different seasons or not. He ascertained by trials
made in the months of December and February, that though
in the oak, the hornbeam and the plane, the solution of pyrolignite
of iron always rises several feet and even several yards, yet that
in the colder season of the year, it never rises so high as it does
in summer, in spring, and especially in autumn, the season in
which the power of ascent is most remarkable. This conclusion
is obviously of interest physiologically. It proves that if winter
be a season of repose for the sap, it is not so absolutely. There
is one remarkable exception to the general fact now announced,
and this occurs among the resinous trees that keep their leaves
till the spring. It has been ascertained, by direct experiment,
that the ascent of the sap continues through the whole course
of the winter in the cone-bearing trees, and this to such an
extent, that it is always possible to impregnate every part of
their trunk by the way of simple absorption at any period of
the year.
As M. Boucherie remarks, this fact might even have
been foreseen from the fresh and green state of the leaves of
these trees.
It now became important, in connexion with the practical
application of M. Boucherie's views, to ascertain whether or not
the penetration was energetic in the ratio of the vigour of
the tree itself, in proportion as it was more numerously provided
with branches, more thickly covered with leaves. Experiment
showed that the penetration still takes place after the removal of
the greater number of branches, provided only the leading bough
or terminal crown be left. A stem furnished with a number of
leafy branches continues, as has been said, to imbibe, though
separated from the roots; but for how long a time will it
* Boucherie Ann. de Chimie, t. LXXIV. p. 134, 2e séric.
K 2
132
PRESERVATION OF TIMBER.
continue to do so ? This was a capital point to determine.
At the end of September, the bottom of a pine tree about 14
inches in diameter was first put into the solution 48 hours
after it had been felled; nevertheless the imbibition was complete.
In June the same success attended the experiment made on a
plane that had been cut for thirty-six hours. Still it is certain
that the penetration takes place with so much the more energy
as it is arranged close upon the time of the felling. The power
by which it is determined declines rapidly after the first day is
passed, and by the tenth day it is almost entirely gone.
favourable circumstances these ten days suffice to effect the
complete impregnation of the largest stem. In one of his
experiments upon a poplar, M. Boucherie saw the absorbed
liquid reach the height of about 95 feet in seven days.
In
In the white woods it is found that there is an axis of variable
diameter in different cases which escapes or rather which resists
impregnation. In hard woods the parts which are not penetrated
are the inner or undermost circles of the heart. M. Boucherie,
after having ascertained these facts, explains them thus: in the
white woods, according to the testimony of the workmen, the
central part which resists the penetration is at once the weakest
and the most perishable portion of the log; there is no longer
any circulation, any life there; it is dead wood interred in the
midst of the living woody layers. This absence of penetration
of the woody tissue appears on some occasions elsewhere than in
the centre of the trunk and branches; it presents itself under the
most various forms and in different parts of the trunk; it ap-
pears to depend, as has been said, on the presence of wood ab-
stracted from the influence of vital phenomena, and which, im-
penetrable itself, presents a barrier or an obstacle to the passage
of the solution to other parts; it is thus that a knot, or a piece of
rotten wood is generally found as the starting point of the zones
that have escaped imbibition. As to the non-penetration of
the most central parts of the heart of oak, elm, &c., M. Bou-
cherie views it as affording unquestionable proof of the fact that
there the living juices of the tree had long ceased to circulate.
The distinction generally drawn between the white or soft, and
the perfect or hard wood, rests on the differences of colour pre-
PRESERVATION OF TIMBER.
133
sented by a transverse section of the trunk. In the oak, for
example, the external and nearly white concentric layers are held
as the soft and valueless portion of the log, and are commonly
hewn away in squaring it; the darker more central portions con-
stitute the heart-wood, the valuable timber. But according
to M. Boucherie the distinction is different when the fact of
penetrability is taken as the guide, and all that portion of the
trunk which imbibes is considered as alburnum or soft wood, and
all that does not imbibe is regarded as hard wood. The albur-
num in this way is so much extended that it may be found con-
stituting three-fourths of the whole mass of the trunk. Once
introduced, the pyrolignite of iron, according to M. Boucherie, is
not only useful in preserving the wood, it also increases the den-
sity of the timber. Impregnated with this salt of iron, wood
becomes so hard as powerfully to resist the tools of the carpen-
ter and joiner, who even complain of the increased difficulty with
which it is worked.
Flexibility and elasticity in timber are qualities in request for
certain purposes, particularly for ship-building. The fir timber
of the north of Europe is much more prized than that of the
south, especially for masting, on account of its greater flexibility
and elasticity, qualities which appear to depend in a great mea-
sure on the quantity of moisture retained; to increase these
qualities M. Boucherie has even introduced by imbibition
a deliquescent salt, such as the muriate of lime, which re-
tains moisture powerfully as is well known, and seems to
have the power of giving a remarkable degree of suppleness
to wood. The experiments, contrived to show the effects of
deliquescent salts were made upon deal, which is allowed to be
one of the most brittle woods. After having impregnated it
with concentrated solutions it was sawed into very thin veneers,
some of which I have seen in the possession of M. Boucherie,
which after being strongly twisted and bent in various senses,
immediately regained their original flatness and evenness when
they were left free.
Warping, or shrinking is occasioned by alternate shrinking
and swelling in consequence of varying hygrometric states of the
atmosphere. When timber is worked before it is thoroughly
seasoned,—and this is apt to happen in regard to pieces of large
134
PRESERVATION OF TIMBER.
scantling especially-the shrinking is of course extremely con-
spicuous when the time necessary to complete desiccation has
elapsed. It is this inconvenience which makes it imperative on
builders of all kinds, ship-builders more especially, to keep stocks
which necessarily absorb a considerable amount of capital. It
has long been a question with engineers to find a remedy for
this state of things. Seasoning, indeed, is now effected some-
what more quickly by squaring the logs at the time the trees are
cut down; but the loss of time is still very considerable. The
mode of seasoning by the stove or vapour has been abandoned
as too costly.
After having found that the shrinking and separation of
pieces of carpentry did not begin to take place until the timber
was upon the point of losing the last third of the moisture
which it contained at the time of being cut, M. Boucherie thought
that to prevent all warping and shrinking it would be enough to
retain this quantity of water in combination with the woody
tissue; in other words, to prevent complete desiccation, Facts
have proved the correctness of this view. Pieces of wood kept
at a certain unchanging degree of moistness by means of a de-
liquescent salt infused into their pores, do not change their bulk
or form, in spite of extreme variations in the hygrometric state
of the air. Such pieces of wood, however, exhibit great dif-
ferences in point of weight under the influence of different cir-
cumstances.
Several planks of great breadth and extremely thin were
prepared with chloride of lime and joined together; some of
them were left unpainted, others were painted on one side, or on
both sides; after the lapse of a year these planks were found not
to have shrunk or warped, whilst similar planks of the same
thickness and kind of wood, but unprepared, were found to have
cast in an extraordinary way.
*
M. Boucherie has done more than this: he has not only had
it in view to preserve wood and to prevent it from warping,
qualities so desirable, he has made use of the same faculty of
imbibition to impregnate the wood with a variety of beautiful
colours, and thus to give even the most common kinds tints that
*Boucherie, op. cit. p. 151.
PRESERVATION OF TIMBER.
135
will admit of their being used in the construction of costly fur-
niture. The pyrolignite of iron alone gives an agreeable brown
tint that harmonizes excellently with the natural colour of the
harder parts of so many trees which usually resist penetration.
By following up the pyrolignite with an infusion of nutgalls or
oak-bark, the mass of the wood is penetrated with ink, which
presents a black, blue, or grey colour, according to circumstances;
a solution of another salt of iron succeeded by one of prussiate
of potash will cause a precipitate of prussian blue in the wood,
&c.; in short, by the numerous reactions of this kind with
which chemistry is familiar, a great variety of colours may be
obtained.
Among the number of useful properties communicated to
wood by impregnation with saline solutions, that of being ren-
dered little apt for combustion ought not to be omitted. M.
Gay-Lussac was the first who thought of rendering vegetable
tissues incombustible by means of saline impregnations.* By
incombustible, we are not to understand unalterable by a red
heat; for every one must see that the protecting power of no
salt can extend so far as this; but tissues which take fire very
readily, and burn with great rapidity, cease from giving any
flame, and merely smoulder after they have been impregnated
with certain salts; they take fire with difficulty, go out of them-
selves, become charred, and are incapable of propagating fire.
And this is exactly what happens with wood which has been
properly charged: it burns, and is reduced to ashes with extreme
slowness, so that two huts exactly alike, built one of charged
wood, and the other of ordinary wood, having been set fire to at
the same moment, the latter was already burned to the ground,
when the interior of the former was scarcely charred.†
The ingenious process of impregnating wood by the way of
vital inspiration is not without certain objections. In the first
place, it can only be performed at those periods of the year when
the sap is in motion, and the trees are covered with their leaves.
This time, however, is limited to a few months of the year and
the usual practice being to fell timber in the winter, wont and
* Ann. de Chimie, t. xvII. p. 211, 2e série.
† Idem, t. LXXIV. p. 152, 2e série.
136
PRESERVATION OF TIMBER.
autumn.
usage are opposed to cutting down trees in the spring and
To meet these objections, M. Boucherie engaged in
new experiments, which led him to a means of impregnating
timber at all seasons, in winter as well as spring and autumn, and
in a very short space of time; this second method is applicable to
wood that has already been squared as well as to the round trunk,
provided it has been recently felled.
To impregnate timber by this process, the logs are placed
vertically, and the upper extremities are fitted with an imperme-
able sack for the reception of the saline solution destined to
charge them; the fluid enters from above, and almost at the
same moment the sap is seen to begin running out below.
There are some woods which include a large quantity of air in
their tissues; in this case the flow does not go on until this air
has been expelled; once begun, it goes on without interruption.
The operation is terminated when the fluid, which drips from
the lower part, is of the same nature as that which is entering
above. In my opinion this method must be preferable to that
by aspiration. In the second mode of proceeding, in fact, we
accomplish our object by a true displacement; almost the whole
of the sap is expelled, and the saline solution introduced has
only to subdue or neutralize the very small quantity of soluble
organic matter which may remain adhering to the woody tissue.
By accomplishing such a displacement by means of simple water
we should undoubtedly obtain results favourable to the preserva-
tion of timber, inasmuch as we should have freed it from
almost the whole of those matters which are regarded as the
most alterable themselves, and the first cause of rotting in
timber. The rapidity with which the fluid introduced is sub-
stituted for the sap which it displaces, and the quantity of this
expelled sap which may be readily collected, exceeds any thing
that could have been imagined before making the experiment;
thus the trunk of a beech tree about 52 feet in length by 332
inches in diameter, and consequently forming a cube of some-
what more than 29 feet and a half, gave in the course of twenty-
five hours upwards of 330 gallons of sap, which were replaced
by about 350 gallons of pyroligneous acid. The liquid which
penetrates in this way acts so effectually in displacing the sap,
DYE-WOODS.
137
that M. Boucherie says we can readily procure, or extract by its
means the saccharine, mucilaginous, resinous and coloured juices
contained in trees. It would, perhaps, be possible, and I beg to
suggest this idea to colonial planters, to apply the method of
displacement to the extraction of the colouring matters of dye
woods. The trade in dye-woods does not extend beyond locali-
ties favourably situated for exportation, so that at a certain
distance from the shores of the ocean, or the banks of rivers, it
is found absolutely impossible to carry on a trade, the material
of which is so heavy and bulky as timber. The greater number
of the colouring matters found in wood being
sible to export them in the state of extract.
of this kind have already been made, and if they have not been
successful, the obvious cause of this lies in the method which
has been followed, and which has hitherto consisted in treating
the wood reduced to chips by means of boiling water, and then
reducing the coloured solution obtained; but it is obvious that
in the remote forests of America, or of Africa, where all me-
chanical means are wanting, nothing but failure could attend
upon such a procedure. By the method of M. Boucherie, the
main difficulties appear to be got over; there is nothing more
to be done, in fact, than to get the trees into the state of logs,
and these are generally readily transportable, after which one or
more evaporating pans seem all that are further necessary.
Dye-woods.-The greater number of these woods belong to
the family of leguminosæ; the principal kinds met with in
trade are:
soluble, it is pos-
Various attempts
1. Mahogany wood (hæmatoxylon campechianum) of a
reddish yellow, which becomes brown with age; this wood, be-
sides a variety of alkaline and earthy salts, of volatile oil and un-
azotised matter, contains a particular colouring principle, called
hematine, discovered by M. Chevreul.*
The mahogany grows in the hot intertropical regions of
America; Mexico and some of the West India Islands export
considerable quantities.
Pernambuco or Brazil-wood is the name given in trade to
the trunks of several trees of the genus Casalpinia. The
* Chimie appliquée à la teinture, 30e leçon, p. 88.
138
SUGAR.
Casalpinia crista of Jamaica, the C. sappan of Japan, the
C. echinata of Santa Martha, afford kinds that are very much
prized. In point of chemical composition Brazil-wood agrees
with Campechy wood; the colouring matter which characterizes
it has been named Braziline by M. Chevreul; it is obtained in
small crystals of an orange colour.
This wood comes to Europe in faggots of about 39 inches in
length. Red Saunders-wood is furnished by the Ptœrocarpus
santalinus; it contains a peculiar dye-stuff, santaline, observed
by M. Peltier.*
To conclude, the yellow dye-woods of commerce are Fustic,
Rhus cotinus, of the family of turpentine trees, a native of
the south of Europe, and the Cuba and Tampico woods, which
are probably varieties of the Morus tinctoria.
OF SUGAR.
Sugar is met with in almost every part of vegetables; it has
been found in flowers, in leaves, in stems, and in roots. It is
less abundant in seeds; and it may even be said that the quan-
tity of saccharine matter contained in vegetables in general is
invariably diminished at the period of formation of the seed.
Sugar, consequently, as well as starch, appears to contribute to
the production of the seed.
The very characteristic taste of sugar generally suffices to
proclaim its presence; nevertheless, it would be a great mis-
take did we rely upon this character alone for discovering the
presence of sugar; several substances possess a very decided
sweet taste, without being on that account sugar, in the sense
which chemists attach to the name. True sugars, according to
chemists, have one property which distinguishes them from all
substances with which they may have, in other respects, the
greatest analogy; this characteristic property is that of becom-
ing changed under the influence of water, a suitable temperature
and contact with yeast, into alcohol and carbonic acid. It is cer-
tain, nevertheless, that certain bodies which do not belong to the
chemical genus, sugar, may, under the influence of fermentation,
yield alcohol. I have already quoted starch as coming under
* Chevreul, Chemistry applied to dying, 30th lecture, p. 94.
SUGAR.
139
this head; but it has been distinctly ascertained, as I have also
said, that such substances, under the influence of the ferment
itself, are first changed into sugar, which subsequently undergoes
the vinous fermentation.
It is admitted at the present time that fermentable sugars
must be divided into two principal species, in harmony with
characters which are most easily appreciated. One of these
presents itself in the shape of hard, transparent crystals, and is
met with in sufficient quantity to be profitably extracted from
the juice of the cane and the beet, the sap of the maple and of
certain palms; the other is obtained with some difficulty in the
solid state, being most frequently and readily procured in the
form of syrup; the taste of this is less sweet, less decided; it
exists in the grape and the greater number of fruits. The
chemical characters of these two kinds of sugar, which are de-
signated cane-sugar and grape-sugar, are somewhat different;
and the elegant researches of M. Biot have shown, that from
some of their physical properties, particularly the action of
their solutions upon polarised light, they cannot be regarded
as constituting one and the same species. In the vegetable
kingdom, these two kinds of sugar are frequently met with
mixed; and there are certain chemical means which enable us
readily to transform cane-sugar into grape-sugar. The inverse
transformation has not yet been accomplished; but there is no-
thing which leads us to conclude that it is impossible; and the
time perhaps is not very remote when the sugar which is manu-
factured from potato-starch may be changed into crystallized
sugar, similar to that which is obtained from the cane.
Crystallized sugar. Cane-sugar is readily obtained in large
transparent crystals, which are known under the name of sugar-
candy. Sugar is fusible; under the action of a regulated tem-
perature, it acquires a dark-red colour, and passes into the state
of caramel; a higher temperature effects its decomposition. It
is much less soluble in alcohol than in water; highly concen-
trated alcohol indeed only dissolves an extremely small quantity
of sugar.
M. Peligot's analysis of cane-sugar shews it to be com-
posed of:
140
SUGAR.
Carbon
Hydrogen
Oxygen
Carbon
Hydrogen
Oxygen
Such is the composition of sugar dried at the temperature of
boiling water; but the substance, like the majority of organic
matters, still contains a certain proportion of constitutional water,
which it abandons when it combines with certain bases. Thus
sugar combines with oxide of lead, and forms a true saccharate,
in which the sugar deprived of its water of constitution, plays
the part of an acid; this combination, which presents itself to
us under the form of white mammillated crystals, analysed by
M. Peligot, would indicate the following as the composition of
anhydrous sugar:
Carbon
Hydrogen
Oxygen
47.1
7.2
57.46
111.76
Ordinary sugar, deprived of its water of composition in any
other way, has the same elementary composition; thus caramel
obtained by heating sugar to 180° cent. (356° Fahr.) until it no
longer loses watery vapour, has, according to M. Peligot, the
composition of anhydrous sugar, such as it is found in combi-
nation with oxide of lead.
Setting aside all theoretical considerations, it is obvious that
to have anhydrous sugar reconstituted ordinary hydrated sugar, it
were necessary to add to 100 parts 11.76 of water, containing
1.3 hydrogen and 10.46 oxygen, the 111.76 parts then contain
in elements:
per cent
42.1
6.4
51.5
100.0*
"
>>
47.1
42.1
6.4
51.5
100.0
5.9
47.0
100.0
common sugar.
"
>>
Common sugar may therefore be viewed as composed of 100
anhydrous sugar, and 11.8 water.
The whole of the sugar which comes from South America
* Annales de Chimie, vol. LXVIII, p. 124, 2e série.
SUGAR-CANE.
141
and the West Indies, and a large proportion of that which
comes from the East Indies, is extracted from the juice of the
sugar-cane.
In America three principal varieties of sugar-cane are culti-
vated, the creole, the Batavian, and the Otaheitan. The Creole
cane has the leaf of a deep green, the stem slender, the knots
very close together. This species, a native of India, reached the
new world after having passed through Sicily, the Canaries, and
the West India Islands. The Batavian cane is indigenous in
the Island of Java; its foliage is very broad and has a purple
tint; the sap of this variety is much employed in making rum.
The Otaheite cane is that which is most extensively grown at the
present time; it was introduced into the West India Islands and
neighbouring continent by Bougainville, Cook, and Bligh in
their several voyages, and is certainly one of the most important
acquisitions which the agriculture of tropical countries owes to
the voyages of naturalists. This variety of cane grows with ex-
traordinary vigour : its stem is taller, thicker, and richer in juice
than that of the other species. I observed it along the whole coast
of Venezuela, of New Grenada, and of Peru; far from having
degenerated by its transplantation to the American continent, it
appears to have preserved all its original qualities without altera-
tion.
The sugar-cane is propagated by cuttings. Pieces of the stem
about 18 or 20 inches long, and having several buds or eyes, are
placed two or three together in holes a few inches in depth, and
are covered with loose moist earth. From a fortnight to three
weeks are required for the shoots to show themselves above
ground. The space to be left between each clump of plants de-
pends much on the fertility of the soil; in the most fertile soils
the distance may be about a yard, or a little more; and along the
rows the spaces may be about 18 inches. Where land is of no
great value it is found more advantageous to give greater space,
and so to favour the access of the air and the light. It is not
uncommon to see plantations where the canes are spaced at dis-
tances of between 4 and 5 feet. The time at which the setting
of the slips takes place cannot be definitively indicated; it de-
pends entirely upon the epoch at which the periodical rains
142
SUGAR-CANE.
are anticipated. But in places where irrigation is possible, the
setting goes on through all the months of the year. The holes for
the reception of the slips are usually dug with a hoe, and a negro
will make from sixty to eighty holes in the course of a day. When
the ground has been previously ploughed, as it is in some of the
West India Islands, he will make twice as many. Loose rich
soils when they have a certain moisture, are the best adapted to
the sugar-cane; it does not thrive in an argillaceous soil, which
drains with difficulty. In these moist soils the slips are not laid
horizontally and covered, but with one end projecting a little
way out of the ground. When the young shoots are covered
with narrow and opposed leaves, watering is particularly advan-
tageous, and the plants are repeatedly hoed until they have ac-
quired sufficient vigour to choke noxious weeds. About the 9th
month after the plantation of the slips, the shaft of the sugar-cane
begins to lose its leaves, the most inferior falling first, the others
in succession, so that when arrived at maturity, it only presents
a tuft of terminal leaves. The flowering generally takes place
with the conclusion of the year; and the cane is held sufficiently
ripe in from two to three months after this epoch, when the stem
has acquired a yellow or straw colour. The planters, however,
are by no means agreed as to the proper period of the sugar-cane
harvest,―some even insist upon cutting before the flowering, be-
lieving that the quantity of sugar diminishes on the appearance
of the flower. It is unquestionable, however, that the period
that elapses between the planting and the harvest, must vary
with the nature of the soil, and especially with that of the climate;
whilst in some places the cane may be cut when it is a year old,
doubtless there are others where it requires to stand from fifteen
to sixteen months. In Venezuela, where the Otaheite cane is
grown at the level of the sea, and where the mean temperature
of the year is between 81° and 82° Fahr., the cane ripens accord-
ing to Colonel Codazzi in eleven months. In districts at greater
elevations under the same parallels of latitude, where the climate
is of course not so hot, the cane requires a longer time to
come to maturity; where the mean temperature is about 78°
Fahr. twelve months are required; where it is about 74° Fahr.
fourteen months become necessary; and where it is no
*
SUGAR-CANE.
143
The
more than about 67° Fahr., sixteen months are requisite.
Otaheite cane grows to very different heights; in very favour-
able circumstances it will reach a height of 16 feet and up-
wards, but its general height may be stated at from 9 to 101
feet. Great cane plantations are divided into squares of from
100 to 120 yards on the side, each of which coming to maturity
in succession, the labour is easily performed, both in regard to
field-work and the manufacture of the sugar.
The cane is cut close to the root, and before being carried to
the mill, the terminal tuft of leaves is struck off. These heads in
the green state afford excellent food for horses and cattle; when
dry they are used for thatching houses. After the first cutting,
fresh sprouts arise, which require no other attention than hoeing.
In good soils one planting will yield five or six harvests by suc-
cessive shoots; but I have heard planters affirm, that the produce
in sugar diminishes from year to year. In Venezuela, cane-pieces
are replanted every five or six years.
The cane with its top struck off is carried to the mill, where
the juice is expressed, and the stems which are spoken of under
the name of trash, are dried and used as fuel.
The expressed juice contains crystallizable sugar, an azotised
substance analogous to albumen, and some saline matters dissolved
in a large quantity of water, which is dissipated by boiling, and
the sugar finally won by crystallization. The manufacturing
process is conducted with very different degrees of perfection in
different places. In some the produce is obtained almost without
admixture of molasses, in others the quantity of this article which
drains away from the sugar is very large. It is now generally
agreed that molasses proceeds in great part from imperfections
in the manufacturing processes employed, especially to changes
which the sugar undergoes in the course of its concentration by
boiling at a high temperature. By the employment of what
are called vacuum pans of various construction-pans from which
the pressure of the atmosphere is removed either by the air-pump,
or the condensation of the vapour as fast as it is formed, rapid
evaporation is effected at a temperature much below that of
boiling water, by which it is found that the relative quantity of
* Codazzi, Geography of Venezuela, p. 141.
BX
144
SUGAR-CANE.
sugar to that of molasses is greatly increased. It was long
believed, indeed, and that on the authority of the first chemists,
that there were two kinds of sugar contained in the sugar-cane,
one crystallizable, the other uncrystallizable, and constituting
the molasses or treacle. The researches of M. Peligot* have
shown definitively that this conclusion is erroneous, that the
cane contains no sugar that is not crystallizable, and that the
preexistence of uncrystallizable sugar or molasses is entirely
chimerical. M. Plagne had indeed come to the same conclusion
some considerable time ago-as far back as 1826; but his
labours were not made known by publication till 1840. M.
Casaseca, professor of chemistry at Havannah, has very lately
confirmed these conclusions, so important for the sugar husbandry
of the world. The composition of the juice of the sugar cane
is therefore less complex than it was once believed to be; making
abstraction of very minute quantities of an albuminous azotised
substance, of several salts and a little silica, substances which
altogether do not amount to more than two or three hundredths,
cane juice may be said to consist of water and of crystallizable
sugar in the proportion of from 17 to 20 per cent. The
Otaheite cane analyzed by M. Peligot actually yielded :
Water
Woody matter
Soluble matter (sugar)
This conclusion was verified by M. Dupuy at Guadaloupe in
1841, who, operating on the spot, found the composition to be
as follows:
Water
Woody matter
Soluble matter (sugar)
Salts
72.1
9.9
18.0
100.0
•
72.0
9.8
17.8
0.4
100.0
The analyses of the Creole cane made by M. Casaseca at
* Ann. Maritimes et Coloniales, Aug. 1842.
+ Vide Comptes Rendus, 1844.
Peligot, op. cit.
SUGAR-CANE.
145
Havannah appears to indicate a larger quantity of woody
fibre:
Water
Wood
Sugar
65.9
16.14
17.7
100.0
The quantity of sugar yielded by the cane, differs considerably.
M. Codazzi assigns 6 and 15 per cent as the extremes, and 7
per cent. as the mean. M. Dupuy gives 7.1 per cent. as the
average. The quantity is, of course, first and most intimately
connected with the quantity of juice obtained. But the produce
of juice is extremely variable. In Guadaloupe the juice varies
between 56 and 62 per cent. of the cane subjected to pressure.
The generality of mills do not in fact enable us to obtain more
than about 56 per cent.
At New Orleans the usual quantity
obtained is said to be 50, and in Cayenne only 36 per cent. At
Havannah, according to M. Casaseca, the ribbon cane yields 45,
the crystalline 35, and the Otaheitan 56 per cent. of juice.
The Otaheite cane was examined by M. Peligot under a variety
of circumstances of age, growth, part of plant, &c. &c. The
following table contains the condensed results of his experiments:

First shoots
Second do. from original sprouts
Third do. from second do.
do.
Fourth do. from third
Inferior part of cane
Middle part of do.
Superior part of do.
Knots
Cane of eight months
Cane of ten months
Water.
73.4
71.7
71.6
73.0
73.7
72.6
72.8
70.8
73.9
72.3
Soluble matters Woody fibre.
(sugar).
17.2
17.8
16.4
16.8
15.5
16.5
15.5
12.0
18.2
18.5
8.9
10.5
12.0
10.2
10.8
10.9
11.7
17.2
7.9
9.2
It would therefore appear, making exception always of the
knots which occur in the course of a cane, that the composition
of the plant in its various states and conditions, is almost
identical. M. Peligot's important paper, whilst it informs us of the
average composition of the Otaheite cane, satisfies us that the
gummy and mucilaginous substances and the uncrystallizable
sugar, the existence of which was held as demonstrated, are, in
L
146
SUGAR-CANE.
fact, nowise constituents of the sugar cane.
Whence we may
conclude with M. Peligot that every drop of molasses which
drains from the sugar is the produce of the manufacture; an
opinion to which I assent the more readily from having myself
seen oftener than once, the juice of the cane yield nothing but
crystallizable sugar. These analyses further demonstrate more
powerfully than could any discussion, the imperfection of the
processes usually followed in manufacturing sugar. They prove
in fact that in the mill rather more than a third of the whole
juice contained in the cane is left in the trash. This loss might
be considerably diminished were more perfect pressure employed
in extracting the juice. But it appears that the planters are
indisposed to crush the trash too much, as by this it is rendered
less fit for fuel, a considerable quantity of which, by the present
mode of manufacture, is indispensable. M. Dupree, however,
says that by insisting on obtaining from 65 to 66 per cent, of
juice in all cases, the trash is still left with all its value as a com-
bustible. The trash on coming from the mill appears quite dry.
I have seen some, which, after having been pressed twice con-
secutively, looked as if it were impossible by any farther amount
of pressure to express more liquid. Nevertheless it was enough
to taste this pressed cane, to be satisfied that it still contained a
considerable quantity of sugar. To procure this without using
more powerful machinery, M. Peligot proposed to steep the trash
in water, and to press it a second time. By this means a weak
juice is obtained, which added to the first pressings, raises the
produce of sugar from 7 to 10 per cent. upon the whole amount
of cane employed. By following this process, suggested by
theory, upon the great scale, M. Dupree has succeeded in obtain-
ing th more than the usual quantity of sugar without making
any change in his apparatus and without finding the trash too
much shaken to be burned under his coppers. In some cir-
cumstances the increase in the quantity of juice which this pro-
cedure implies, might be found an objection on account of the
larger quantity of fuel acquired for its evaporation; but wherever
a supply of wood is to be had, M. Peligot's method ought
undoubtedly to be applied.
5
* Peligot, Maritime and Colonial Annals, August, 1842.
SUGAR-CANE.
147
The very dissimilar quantities of crystallizable sugar obtained
from canes which as we have seen all contain very nearly the
same quantity of this substance, prove that the processes of con-
centration and purification of the sap also contribute to the loss
which has been indicated. M. Peligot has pointed out several
causes which concur to deteriorate sugar; among the number:
1. A viscous fermentation which renders the sap thick and
stringy, like mucilage, by which the boiling becomes difficult and
the crystallization of the sugar which has escaped change, is ren-
dered imperfect. 2. An acidity which takes place when the juice
is not run at once into the coppers and boiled, an acidity which
requires the addition of lime to destroy or to prevent it. The
alkaline earth, as I have had occasion to say, is by no means in-
dispensable; its utility under ordinary circumstances is probably
confined to assisting the defecation by forming an insoluble pre-
cipitate with some of the organic substances which are always
met with in small quantities in cane juice; perhaps also to
making an earthy soap with the fatty matters which adhere to
the cane and are expressed in the crushing. When lime is added,
to correct acidity, it forms an acetate or a lactate, salts which are
peculiarly soluble, uncrystallizable, and which necessarily retain
a quantity of sugar in the syrupy state.
3. The presence
of certain mineral salts in the cane. Common salt for in-
stance, in combining with sugar forms a deliquescent com-
pound, in which one part of salt is united with six parts of
sugar; such a compound as this of course renders a large quan-
tity of syrup indisposed to crystallize. It is therefore impossible
to be too cautious, according to M. Peligot, in the choice of
manure for a cane-field; that which contains any common salt
must needs be injurious in one way, however advantageous it
may be in another. The entire absence of this salt in the soil of
plantations which are very remote from the sea shore is perhaps
one of the causes which increase the quantity of sugar obtained
from the crop, and make it more easily manufactured in such
situations.
M. Codazzi reckons the quantity of white sugar produced by
a hectare of land (2.473 acres), planted with the Otaheite cane,
in the province of Caraccas, at 1875 kilogrammes, or 36cwt. 3qrs.
L 2
148
BEET AND BEET SUGAR.
9lbs. avoir.; which is at the rate of 15cwt. 1qr. 10lbs. per acre.
Taking 7 per cent. as the average quantity of sugar obtained,
the weight of cane brought to the mill must obviously have
amounted to 18 tons, 15cwt. 3qrs. and 10lbs. ; or 7 tons,
16cwt. 2qrs. 11lbs. per acre. Assuming the average composition
of the plant to be:
Wood (dry)
Sugar (minimum)
Water
11.0
15.5
73.5
100.0
one acre of land will consequently yield a crop of:
cwt.
17
•
qrs.
lbs.
0
17
1
5
0
17
7 16
2 11
The trash of the sugar-cane undergoes rapid fermentation: it
soon exhales a distinct smell of vinegar, and almost the whole
of the sugar which is left in it is destroyed.
Wood (dry)
Sugar
Water
tons.
0
1
5
4
15
BEET ROOT SUGAR.
The presence of sugar in the beet was observed by Margraff;
and Achard of Berlin by and by attempted the extraction of this
sugar on the large scale; but it was only during the period of
the continental system that the manufacture of sugar from the
beet acquired such perfection in France as made it profitable.
The beet so generally cultivated at the present time is derived,
according to Thaer, from the Beta vulgaris. The two principal
varieties of this root are the red beet, which has been grown
for a very long time in kitchen gardens, and the white beet.
Between these two extremes there are numerous varieties having
a flesh colour of various intensity, a yellow tint, &c. The seeds
of the same plant in fact frequently produce varieties of decidedly
different shades of colour; the red and the white beet, however,
appear to be the most constant; and Thaer has said that the in-
termediate varieties are crosses between them.
The field beet has a large root which grows in great part
above the ground; it is a very hardy plant and has been culti-
vated for a very long time in various parts of the continent as
BEET AND BEET-SUGAR.
149
food for cattle, and is now also very common in England. The
root which has hitherto been preferred for the manufacture of
sugar, is conical, of a rose colour without, and its concentric in-
ternal layers are also coloured; but it appears that the white beet
of Silesia is the more productive. The beet thrives in almost all
kinds of soil provided only they be sufficiently manured. In
Alsace it succeeds in light, and in strong argillaceous soils
indifferently. Another precious quality which this root possesses
is that of succeeding in the most dissimilar climates: it is grown
to purpose both in the north and in the south of France.
The beet is sown at once in the field, or in a bed and trans-
planted; the latter method appears now to obtain a decided pre-
ference inasmuch as it leaves plenty of time for the preparation
of the soil, and especially for accumulating and carrying out
manure.
In a piece of ground well broken up by delving or ploughing,
and highly manured, which need not be of greater extent than
th of the entire surface to be planted, the seed is sown in lines
or drills as soon as the spring frosts are no longer to be appre-
hended. The transplanting in the east of France takes place
about the middle of May, and even in the beginning of June.
The plants are generally set about 15 inches apart. In the
north the beet harvest does not begin before the end of Septem-
ber, and generally ends in the course of the month of October.
The gathering is delayed as long as possible, inasmuch as the
roots increase visibly to the very end of the season. But gather-
ing the beet at a very late period in those countries where the
winter seed has to follow this crop, is attended with more than
one disadvantage. Without speaking of the difficulties that are
incidental to wet seasons, a late seed time is generally unfavour-
able for wheat. To meet this difficulty I have been accustomed
for some time to take up my crop of beet at the period when it
became necessary to prepare the land for winter seed, that is to
say more than a month before the general harvest of the root.
In doing so I relied upon the interesting fact ascertained by M.
Peligot in the course of his chemical inquiries, viz: that the com-
position of the beet is identical at every age. In this prema-
ture or anticipated beet harvest, a less weight of root is of
course gathered than would have been obtained at a later period;
150
BEET AND BEET-SUGAR.
but the nutritious powers of these beet roots are the same as
they would ever have been. The grand questions to be determin-
ed were, whether the roots would keep or not, and whether the
cattle would eat them from the pile as freely as from the field.
All this was ascertained in the course of the winter: the beet
kept perfectly, the cattle ate it as freely as ever.
The pro-
cedure to be adopted therefore to secure a crop of beet of ave-
rage weight, storing nevertheless some considerable time before
the usual period, is simply to transplant somewhat more closely,
and to put less space between the drills. If experience decides
in favour of this method, the sole inconvenience which attends
the cultivation of the beet in a freshly manured soil, and as the
first crop in the rotation, that namely of causing a late and un-
favourable seed time for winter corn, will be completely got over.
The beet which grows above the ground is best gathered with
the hand; kinds that grow under ground require to be loosened
by running a plough along the drill, &c. In Alsace it is the
custom to take away the leaves, and to trim the roots upon the
ground; the refuse thus obtained constitutes a considerable mass
of manure which it is well to plough in immediately.
To extract the sugar of the beet the plant is washed aud
rasped, and the pulp is then subjected to the action of a power-
ful press. Like the juice of the cane, the juice of the beet
speedily undergoes a change; it is therefore immediately heated
to 70° cent. or 158° Fahr. and a little lime is mixed with it to
neutralize acid and favour the clarification, by combining
with albumen. The liquor is skimmed, and in the course of
an hour becomes quite limpid, and of a pale yellow colour. The
liquor is then run upon a filter containing animal charcoal, and
from that is transferred to a boiler where it is properly reduced,
the process being in all respects the same as in the manufacture
of cane sugar.
In France, the produce of each 110lbs. weight of beet is es-
timated at 4.56, or somewhat more than 44lbs. of white sugar.
The amount of loss in the manufacture may be conceived from
the actual composition of the beet, which, by the process fol-
lowed by M. Peligot,* and which consists essentially in drying a
Ch
* Recherches sur l'analyse de la betterave à sucre.
BEET AND BEET-SUGAR.
151
certain weight of the root, cut into thin slices, and then ex-
hausting the matter with boiling alcohol of moderate density,
appears to contain from 4 or 5, up to 9, 10, 11, and even
nearly 12 per cent. of sugar. This analysis of M. Peligot has
been confirmed by the experiments of M. Braconnot,* who
found the white beet of Silesia to have a very complex composi-
tion, comprising as many as twenty-one different ingredients;
among the number, crystallizable sugar, albumen, woody matter,
phosphate of magnesia, phosphate of lime, oxalate of potash, and
oxalate of lime, oxide of iron, an ammoniacal salt in small quan-
tity, &c. On an average the analysis of M. Peligot would lead
us to conclude, that the beet contained in 100 parts:
Water
Matter soluble in water (sugar)
Insoluble substances, (woody tissue)
87
8
5
100
from which it appears that no more than about ths of the
sugar contained in the beet-root is extracted.
As in crushing
the cane, so in squeezing the rasped pulp of the beet, a part
of the loss is owing to a certain quantity of sugar being left in
the expressed pulp. In fact, with the presses generally in use,
whilst from 60 to 70 per cent of juice is obtained, the root ac-
tually contains 95 per cent. The loss here, however, is of less
consequence than it is in the cane, the trash of which is used
for fuel, whilst the pulp of the beet serves as food for cattle.
The pulp, indeed, is found to possess very nearly the same
amount of nutritive power as the root which produced it.
One of the considerations, which is of the very highest impor-
tance in connexion with the production of sugar from the beet, is
inherent in the difficulty of preserving the root after it is full-
grown. Gathered at the end of autumn the root suffers no less
from severe frost, than it does from mild open weather: frost
destroys its organization, and in mild winters vegetation con-
tinues at the expense of the sugary principle, which had been
formed during the growth. If the beet actually contains
at every period of its existence the same quantity of sugar,
* Annales de Chimie, vol. LXXII. page 442, 2nd. series.
L 3
152
BEET AND BEET-SUGAR.
there would probably be a great advantage in not waiting for the
period of complete maturity; by sowing somewhat thicker than
wont, any difference of weight would probably be made up,
and then there would be no risk of loss from keeping.
The quantity of beet gathered from a given extent of land
necessarily varies with the soil, the pains bestowed upon the crop,
and the quantity of manure that has been used; the following
are a few particulars from official documents:
Pas de Calais
Department of the North
Department of Cher
Ton.
12
14
15
PRODUCE PER ACRE.
Cwt. Qrs.
17
0
6
1
11
0
Lbs.
4
23
1
but in other departments the produce is considerably smaller, so
that the average for the whole country has been estimated at
not more that 10 tons, 9cwt. 1qr. 13lbs. per acre; an average
which approaches very closely to that which I have obtained
from my own farm at Bechelbronn, calculated during a period
of seven years.
Assuming 4ths lbs. of sugar to be obtained from every
110lbs. of beet, the produce in sugar from an English acre in
the course of seven months will amount in the present state
of things to 9cwt. 3qrs. 22lbs. By way of comparison I
shall here remind the reader that an English acre of land laid
out in Otaheite sugar cane yields in the course of about four-
teen months, 15cwt. 1qr. 10lbs. I find from my accounts
for 1841, that to manage an English acre of land under beet-root
in Alsace, 45.6 days of a man, and 14.1 days of a horse was
the amount of labour expended. In a document upon the
sugar plantations of Guadaloupe which I have seen, it is
stated that a domain of 150 hectares, or 360 acres is worked by
150 negroes, which, reckoning the time that the crop is on the
ground, at fourteen months, would bring the number of days
Such an ex-
labour by a man, to 177 per English acre.
penditure of labour must in the nature of things absorb the
greater part of the profits; and, indeed, in a commission of
inquiry into the laws connected with the sugar trade, it was
shewn in reference to the plantation in question, that the cost
MAPLE SUGAR.
153
of cultivation and manufacture was equal to the value of the
produce. Still the cane presents one considerable advantage
over the beet, that namely, of furnishing the fuel necessary to
the boiling, an advantage which will be better understood, when
it is known, that in the manufacture of every 110lbs. weight of
beet sugar, the consumption of coal amounts to 22lbs.
In countries where sugar is cheap, it becomes an ordinary
article of diet; in the public market places of the great towns
of South America, one of the rations commonly exposed for
sale consists of brown sugar and cheese. M. Codazzi estimates
the quantity of sugar consumed by each inhabitant of Venezuela
at 110lbs. In England it amounts to about 22lbs. In Ireland
to no more than 4lbs. and 4ths. In Holland it is 15 lbs. In
France it is 8lbs. In Italy 2lbs, and in Russia but 1lb.
per head.
Maple sugar. (Acer saccharinum.) The maple is very
common in the east of the United States of America. The tree
is occasionally met with in clumps of several acres in extent, but
it is more commonly found dispersed in the forest, growing
among pines, poplars, ashes, &c. The tree grows particularly
in rich soils, and attains the height of the oak; the trunk being
often more than 3 feet in diameter. The maple becomes covered
with flowers in the spring before the appearance of the leaves.
It is supposed to be in its prime at the age of about twenty
years. The sap of the maple is obtained by piercing the trunk
to the depth of from 6 to 10 inches. A piece of wood to serve
as a gutter is placed in the hole, and the sap is received in a
vessel placed underneath. It is usual to pierce the tree first on
the side that is towards the south; when the flow of sap begins
to lessen, it is tapped upon the north side. The best season for
making maple sugar is the beginning of spring, February, March,
and April; the sap continues to flow during five or six weeks.
The quantity of sap obtained is found to be largest when the
days are hot, and the nights cold; the quantity collected in the
course of twenty-four hours will vary from about half a pint to
30 pints and more; the temperature of the air has the most
marked influence upon the flow of the sap; it ceases completely,
for instance, in those nights when it freezes after a very hot day.
154
· PALM SUGAR.
The maple does not appear to suffer from reiterated per-
foration; trees are mentioned which were still flourishing after
having yielded sugar for forty-two consecutive years. In certain
cases, which, however, must be held as exceptions to the rule, as
many as 183 pints of sap have been tapped from a maple in the
course of twenty-four hours, which yielded 44lbs. of crystallized
sugar. A maple of ordinary dimensions, in a good year will
yield, on an average, about 198 pints of sap, producing 5lbs.
of sugar. The sap of the maple must therefore contain about
2.2 per cent. of its weight of marketable sugar. It has been found,
that with care and attention the maple becomes more produc-
tive; maples around which other forest trees have been felled,
or which have been transplanted into gardens, yield a sap which
is not only more abundant, but also richer in sugar, which, in
fact, contains about 3 per cent of sugar.
The manufacture of maple sugar presents no peculiarity;
precisely the same process is followed, as in the case of the cane
and beet. Unless very speedily boiled down, the sap ferments,
and undergoes change; in some parts of the United States,
indeed, a vinous liquor is made of the sap, by allowing it to run
into spontaneous fermentation.
PALM SUGAR.
The palm which in the southern parts of India furnishes
crystallized sugar in large quantity, is the cleophora of Gaert-
ner, and reaches a height of about 100 feet.
height of about 100 feet. Its fruit hangs
in clusters upwards of a yard in length. The natives pro-
cure the sap by cutting short one of the shoots that is about to
flower and carry fruit, and hanging under the cut part of a cala-
bash or other vessel, into which the fluid distils; in a large plan-
tation such an apparatus is seen connected with each palm-tree;
the
sap
is removed every morning, and it is enough to reduce it
evaporation to obtain the sugar, which differs in no respect
from the finest sugar of the cane; in the unrefined state it is
known over the whole of the East under the name of jaggery,*
* This is the generic name for sugar, and is obviously either the Latin
word saccharum, or from the same root as the Latin word. The cocoa-
nut-tree treated in the same way as the cleophora yields abundance of
sugar, which is also known under the name of jaggery.-ENG. ED.
PALM SUGAR.
155
and is then a kind of moist and sticky muscovado sugar. The
sap of the palm-tree obtained in the way above-indicated, is often
turned into a vinous liquor, which is much prized in many
places. The pith of the tree yields sago. The palm-trees cultivat-
ed in India consequently yield three most useful products; sugar,
oil, and the farinaceous article of diet called sago. In rearing
the cocoa-nut palm those nuts are selected for seed which fall
naturally, and they are dried in their husk. The ground which
is to be sown is dug to a depth of 18 or 20 inches, and it is
left to settle for three or four days. Some portion of the surface
is then taken away, and the fresh soil is covered to the depth of
about 6 inches with sand. The nuts are then placed upon the
ground so prepared and covered over with a little sand and a
light stratum of vegetable mould; they are then watered for
three days consecutively; in the course of three months the
young palms are fit to be transplanted, and they are set at the
distance of about 20 feet every way from one another. For
their reception in the permanent plantation, holes are dug of
about 2 feet in depth, in which a layer of sand about 6 inches in
depth is put, upon which the young plants, still adhering to the
fruit, are placed; the hole is then filled with sand, and the sur-
face is covered with a little earth. The young trees require
watering every day during about three years. The palm begins
to be productive at the age of seven or eight years, and it con-
tinues to yield fruit or sap for the manufacture of sugar during
a very considerable period without causing any further cost for
cultivation.* The sap of the greater number of the palms ap-
pears to be rich in saccharine matter; it is obvious indeed that
every sap that is capable of supplying a vinous liquor by fermen-
tation may also furnish sugar; and if the palms have not gene-
rally been grown with a view to this product it is because the
fruit must then be given up, and both in India and South Ame-
rica the produce in the shape of oil from the nuts of the palm
is almost always more valuable than that which can be had in
the shape of sugar.†
* Buchanan. A journey from Madras, &c. vol. 1. p. 155.
† In British India the cocoa-nut palm is beginning to be extensively cul-
tivated as a means of producing sugar. A considerable portion of the East
156
GRAPE SUGAR OR GLUCOSE.
GRAPE SUGAR.
We have already said that starch acted upon by acids, and by
malted barley, is changed into a saccharine fermentable sub-
stance which, both in regard to flavour and physical properties,
differs in many respects from the sugar which we have hitherto
been engaged in studying. As this substance exists naturally in
the grape it has been called grape sugar, a name for which the
generic term glucose has been lately substituted in France, this
term being used to include all the sugars that are analogous to
grape sugar. Grape sugar occurs in the form of small white
and very soft crystals, grouped in tubercular masses; it softens
at 60° (140° Fahr.), and becomes quite syrupy at 90° (194°
Fahr.) Alcohol free from water dissolves none of it; but diluted
alcohol takes up a considerable quantity.
In the grape this sugar is associated with cream of tartar,
tartrate of lime, and several other saline matters. It is easily
extracted from the fruit; but the grape sugar of commerce is
now universally prepared from starch; large quantities, indeed,
are manufactured on the continent for the preparation of spirit,
and for the amelioration of wine, beer, cyder, &c., in short, to
supply sugar wherever it is defective in the natural or artificial
musts that are subjected to fermentation. In England consider-
able quantities are also manufactured; but here the law does not
allow it to be used in the same advantageous direction as in
France and Germany; all that is made is employed for mixing
with adulterating cane sugar, which is an article of higher price.
The sugar that is made from starch, and that is obtained from
the grape are identical in composition, as is that also which is
found in the urine of persons labouring under diabetes.
Carbon
Hydrogen
Oxygen
Grape Sugar. Sugar of Starch.
(Saussure.)
(Guerin.)
36.1
36.7
6.8
7.0
56.5
56.9
100.0
100.0
100.0
India sugar now brought to market is manufactured from the palm-tree.
It is not improbable, indeed, that the palm of one species or another will
one day supersede the sugar-cane and the beet as the source of all the sugar
consumed in Europe.-ENG. ED.
Diabetic Sugar.
(Peligot.)
36.4
7.0
56.6
MANNA.
157
Like cane sugar, grape sugar in combining with certain bases
abandons a portion of its constitutional water.
which it is combined with the oxide of lead it contains:
In the state in
Carbon
Hydrogen
Oxygen
From these analyses it appears that crystallized grape sugar
consists of:
Anhydrous glucose.
Water
Carbon
Hydrogen
Oxygen
Water
•
On comparing the two kinds of sugar in the crystallized
state it becomes evident that glucose or grape sugar does not
differ from cane sugar, except in containing a larger quantity of
water. In fact the composition of grape sugar may be repre-
sented in this way:
J Hydrogen
Oxygen.
42.2
6.2
51.6
8}
43.3
6.3
50.4
100.0
1.8
14.0
100
19
15.8
100 of cane sugar.
115.8 of grape sugar.
The cane, the beet, the palm, the maple, the vine, and
starch turned into glucose, are the sources from whence all the
sugar of commerce is obtained at the present day, although at-
tempts more or less successful have also been made to extract sugar
from the pine-apple, from the chestnut, from the sweet orange, and
from the stem of the maize or Indian corn. It appears that be-
fore the conquest the Mexicans prepared a syrup from the stem
of the Indian corn, which was sold in the market places. Pallas
could not obtain more than about 3 per cent of crystallized
sugar from maize, but in an experiment which I made in South
America along with M. Roulin, the quantity of raw sugar ob-
tained from this plant was 6 per cent.
SACCHARINE PRINCIPLES NOT FERMENTABLE.
Manna; mannite. This saccharine principle is met with in
different plants; it has been found in the expressed juice of onions,
158
GUM.
and in that of asparagus; in the alburnum of several species of
pine-trees, and in different mushrooms. Manna, which is an ex-
udation from the fraxinus ornus and larch, contains nearly 4ths
of its weight of mannite, and it is therefore from this substance
that mannite is usually obtained, although it can also be had
from the juice of the beet and the onion; but then it is neces-
sary to destroy the cane or grape sugar which they contain by
previous vinous fermentation, and M. Pelouze has even main-
tained that the mannite thus prepared is a product of fermen-
tation.*
Carbon
Hydrogen
Oxygen
Mannite crystallizes in very white semi-transparent needles;
it has a slightly sweet taste, and is soluble in water. According
to Liebig and Opperman it contains :
·
5
GUM.
39.6
7.7
52.7
100.0
Liquorice. This substance which is obtained from the root
of the Glycirrhiza glabra is too well known to require par-
ticular consideration; it is soluble both in water and in al-
cohol.
Gum is a substance very extensively diffused in the vegetable
kingdom; there is, perhaps, no plant which does not contain
some. Gum is divided into two kinds; gum, properly so called,
the type of which we have in gum-arabic, and vegetable mu-
cilage, such as we meet in gum-tragacanth.
Gum in dissolving in water produces a thick and adhesive
fluid. It is insoluble in alcohol. Some plants contain such a
quantity that upon infusion they seem to give, as it were,
nothing else such are the althea, the malva officinalis, &c.
Gum does not crystallize, it is met with in concrete masses
which result from the solidification of the drops which flow
* Annales de Chimie, vol. XLVII. p. 419. 2nd. series.-The refuse wash
of the distiller appreciated by the taste, appears to contain a considerable
quantity of saccharine matter, which is probably mannite.-ENG. Ed.
PECTINE, PECTIC ACID.
159
spontaneously from the trees that yield it: by long boiling with
dilute sulphuric acid it is changed into glucose. Nitric acid
alters it, and several new products are the result, among the number
of which is mucic acid. Gum arabic, according to the analysis
of M. Gay Lussac and Thénard consists of:
Carbon
Hydrogen
Oxygen.
42.3
6.9
50.8
100.0
To obtain vegetable mucilage, a quantity of linseed is treated
with water and expressed. It is also obtained by steeping gum
tragacanth in about 1000 parts of water and pouring off the
solution which covers the mucilaginous mass. The mucilage
then forms a jelly more or less consistent, which diluted with a
large quantity of water forms a ropy viscid fluid. Dried again
this mucilage becomes hard and translucid; in water it regains
its former state.*
VEGETABLE JELLY-PECTINE AND PECTIC ACID.
It is well known that the juice of all fruits contains a gela-
tinous substance to which many of them owe the property of
forming jellies. This matter may be obtained by means of
alcohol. If into a quantity of currant juice lately expressed, a
portion of alcohol be poured, a gelatinous precipitate is formed
after a certain time; this jelly subjected to graduated pressure
and washed with diluted alcohol, gives the gelatinous principle in
a state of tolerable purity: this is pectine discovered by M.
Braconnot.
Pectine dried is in membranous semi-transparent picces
resembling isinglass. Thrown into about one hundred times its
weight of water it swells considerably and at length dissolves
completely, giving rise to a stiff jelly. By increasing the
quantity of water, a mucilaginous solution, having a slightly
milky aspect is obtained.
Pure pectine is quite insipid; it does not affect the colour of
litmus, the weaker acids have no effect upon it; a slight excess
* Berzelius, Chemistry, vol. v.
160
PECTINE, PECTIC ACID.
of potash or of soda does not change it obviously, and nevertheless
pectine is singularly modified under the influence of these alkalies,
being changed into a particular body, having acid reaction; for
on saturating the alkali employed, it immediately coagulates into
a transparent gelatinous mass-pectic acid. As pectine acted
upon by the fixed alkalies undergoes so remarkable a change, we
may be allowed to conclude with M. Braconnot, that the pectic
acid which is found ready formed in plants, has a similar origin,
a view moreover which tends to confirm that formerly announced
by Vauquelin, when he ascribed the development of the acids
of vegetables to the presence of alkalis.*
Gelatinous pectic acid immediately becomes defluent upon the
addition of a few drops of solution of ammonia. By evaporating
this solution in a porcelain dish we obtain an acid pectate of am-
monia, which swells in distilled water, dissolves in it, and thickens
a large quantity of the fluid. As ammonia has no reaction upon
pectine, M. Braconnot has taken advantage of this negative
property to determine if pectic acid exists or not, ready formed
in certain plants. Thus in treating carrots with cold water,
rendered slightly ammoniacal, a liquid is obtained, from which an
acid immediately throws down a precipitate of pectic acid.f
Pectine and pectic acid, therefore, may exist together in vege-
tables, and M. Jacquelain has proved that the acid there is often
in a state of combination as an alkaline or earthy pectate. It
is to these pectates that M. Payen ascribes the origin of the
carbonates of the same bases, which are met with in the ashes
of plants, the organic acid having of course been destroyed by the
combustion.‡
M. Braconnot has described an easy process for obtaining
pectic acid in large quantity from carrots.§
M. Fremy has published analyses of pectine and pectic acid,
which present this remarkable peculiarity that the one has
exactly the same elementary composition as the other.
* Braconnot, Annals of Chemistry, vol. XLVII. p, 274, 2d series.
† Braconnot, Op. cit, vol. xxx. p. 99.
Payen, Proceedings of the Academy of Sciences, vol. xv. p. 907.
§ Op. cit. vol. xxx. p. 97.
VEGETABLE ACIDS.
161
Pectine.
Carbon. 42.9
Hydrogen 5.1
Oxygen 52.0
100.0
•
OF VEGETABLE ACIDS.
Pectic acid.
42.8
5.2
52.0
100.0
I have thought it right to speak at some length of these two
principles as they appear to play an important part in the
phenomena of vegetable life. A careful study of pectine and
pectic acid will very probably aid in throwing light upon the
metamorphoses which organic substances undergo in the act of
vegetation. Pectic acid has been found in every plant in which
it has been sought for; M. Braconnot discovered it in the
turnip, carrot, beet, peony, in all bulbs, in the stalks and leaves
of herbaceous plants, in the wood and bark of all the trees
examined, in all kinds of fruit, apples, pears, plums, cucumbers,
&c. M. Braconnot is even very much inclined to think that
pectic acid may constitute the essential principle in the cambium
or organizable matter of Grew and Duhamel.*
q
In the series of bodies which we have now considered, one
only, sugar, possesses the property of crystallizing. All the
others are amorphous and their globular disposition and gela-
tinous qualities have led to the presumption that they form in
some sort the line of demarcation between things without and
things endowed with life. It was also imagined that these
amorphous matters, that these products of the vegetable organi-
zation, almost organized themselves, would alone suffice for the
nourishment of animals. This idea, however, is not well founded;
for if it be true that albumen, caseine, legumine, starch and gum,
arc powerful elements of nutrition, it is equally so that sugar
may perform an important part in this process, by acting in the
same manner as starch, the oils and other principles of ternary
* Braconnot, op. cit. vol. xxvI. p. 171.
M
む
​162
VEGETABLE ACIDS.
composition in becoming like them a useful, often an indis-
pensable auxiliary of azotised alimentary matters.
This disposition to consider the amorphous state of the more
important immediate principles of vegetables as a special and
distinctive character, cannot be maintained beside the recent
observations of Mitscherlich. This illustrious chemist has found,
that if the mineral precipitates which are deposited in liquids,
are in many cases formed of crystals more or less regular, they
are also sometimes composed of small spheres or aggregated
masses, the particles of which do not unite in a regular way as
crystals, but remain separated by a thin layer of fluid. Ex-
amined under the microscope these masses present themselves
under the form of flocks and of shreds, having a granular or gela-
tinous appearance, and which remain soft and flexible like fresh
vegetable or animal substances so long as they are kept under
water; it is only in drying that they become pulverulent or
acquire the vitreous aspect.
The substances, the chemical constitution of which we have
still to examine may in general be obtained in the crystallized
state; their individuality seems more decided; they are more
stable, better characterized, and their specific properties often
assimilate them to inorganic bodies. Such, for example, are
the acids formed in the course of vegetable existence.
;
Vegetable acids present all the general characters of mineral
acids, whilst they participate in the properties inherent in
organic substances. Thus they form salts by uniting with bases;
with potash, soda, ammonia, they form salts soluble in water
the other bases produce compounds that are soluble or insoluble
according to the nature of the acid. These acids, free or
uncombined, are very frequently met with in fruit, sometimes in
the leaves, more rarely in the seeds and roots; but in combina-
tion with bases they are met with in almost all parts of plants.
Already very numerous, they are increasing rapidly with the
progress of discovery; with the exception of a very few employed
in the arts, their study forms a subject of no great interest. I
* Berzelius, Ann. Report, 1841, p. 20.
VEGETABLE ACIDS.
163
shall therefore confine myself to a few of the most extensively
distributed of these acids.
Oxalic acid. This acid exists free in the hairs of the cicer or
chick-pea, and united with potash constituting an acid salt, the
binoxolate of potash in the wood sorrel and the common or
garden sorrel. It is from the former of these plants that the
salt called salt of lemons, but which is, in fact, the binoxolate of
potash is still extracted in some countries. The juice of the
wood sorrel is expressed and yields about 0.003 of its weight of
the salt, from which, by ordinary chemical manipulation, the
oxalic acid is readily obtained. At the present time this acid
is prepared artificially by the action of nitric acid upon starch; it
is a powerful acid, and its affinity for lime is such that it takes
this base even from its union with sulphuric acid.
Tartaric acid is met with above all in the grape in the state
of bitartrate of potash, a salt which is deposited upon the sides
of the casks in which wine is kept. After having been properly
purified, it is known in commerce under the name of cream of
tartar, from which the tartaric acid can readily be obtained.
Another particular acid, the racemic acid, the composition
of which is identical with that of the tartaric acid, has been
discovered in the tartar of the wines grown on the Upper
Rhine.
Citric acid. This acid is found in the juice of many plants,
and abundantly in the juice of lemons, oranges, currants, &c. It
is from the lemon and the lime that the citric acid employed in
the arts is generally obtained.
Tannic acid. A certain substance which is met with in the
bark of particular trees, and which has the valuable property of
rendering the hides of animals with which it is combined, insus-
ceptible of putrefaction, is familiarly known under the name of
tannin. The art of the tanner is founded upon this property of
tannin. A solution of gelatine being poured into an infusion of
tannic acid, an insoluble precipitate, formed by the union of the
acid with the animal matter, is immediately produced.
macerating a piece of raw hide in a solution of tannin, the same
combination takes place even into the very interior of the tissue ;
By
M 2
164
VEGETABLE ACIDS.
the whole of the tannin quits the solution by degrees to combine
with the gelatine of the skin.
It is not in the bark only that tannin is encountered, it has
been found in different organs of plants. Sir Humphry Davy
has stated these quantities of tannin as constituents of 100
parts of the following substances:
Nutgalls
Oak bark
Chesnut bark
Elm bark
Willow bark
Inner white bark of an aged oak
The same of young oaks
The same of the Indian chesnut
The inner coloured bark of the oak
Sicilian sumac
Malaga sumac
Souchong tea
Green tea
Bombay catechu
Bengal catechu
27.4
6.3
4.3
2.7
2.2
15.0
16.0
15.2
4.0
16.2
10.4
10.0
8.5
54.3
48.1
Gallic acid. This acid is found united with tannin in the
greater number of barks, or along with the astringent principles
of plants. Gallic acid appears to be the product of a kind of
fermentation undergone by tannin, as the process by which it is
prepared seems to indicate, and which consists essentially in
exposing for about a month a quantity of nutgalls reduced to
powder and kept constantly moistened. The solution of gallic
acid does not precipitate gelatine.
I have added in a table the composition of the principal
vegetable acids. I shall speak of the composition of fat acids
when I come to treat of fatty substances.
The different vegetable acids do not vary essentially in com-
position, save in a single instance. With one exception they
consist of definite proportions of carbon, hydrogen and oxygen.
The exception alluded to is the hydrocyanic acid, which contains
no oxygen, but a large quantity-nearly 52 per cent. of azote.
FATTY SUBSTANCES.
165
OF THE VEGETABLE ALKALIES.
The alkaline bases which are formed in the course of vegeta-
tion always contain a certain proportion of azote. Their general
properties are those of alkalies; their watery or alcoholic solu-
tions restore the blue colour of the reddened tincture of turnsole,
and they constitute salts by combining with acids. In their
manner of behaving they bear a certain analogy to ammonia.
Like ammonia, the organic alkalies combine with the hydrates of
the oxacids, and when they are deprived of their water of crys-
tallization they fix the hydracids without losing weight.
The discovery of the vegetable bases is due to Sertuerner,
who in 1804 indicated the existence of morphine in opium.
The majority of the vegetable alkalies are insoluble, or little
soluble in water; all are soluble in alcohol; some of them are
sufficiently volatile to be susceptible of distillation.
In elementary composition they are all very much alike,
consisting of various but in each instance definite proportions
of carbon, hydrogen, oxygen and azote, the carbon varying
from about 50 to 75, the hydrogen from 6 to 12, the oxygen
from 8 or 9 to 27 and even 37, and the azote from 1.6 to 12,
28 and even 35 per cent.
OF FATTY SUBSTANCES.
Under this title I comprise all the oily substances, liquid or
solid, and those that are analogous to wax, which are found dis-
seminated in different organs of plants. A character common
to almost all fatty substances is insolubility in water. They dis-
solve in sensible quantity in alcohol, and especially in ether. Fatty
substances may be divided into two classes: one including those
which are easily modified by the action of alkalies, and which form
soaps ; the other not susceptible of this action, not susceptible of
saponification, or at all events, that are only attacked by alkalies
in very particular circumstances.
166
FATTY SUBSTANCES.
When a mixture of fat oil and a solution of caustic alkali are
heated, the oil is soon observed to incorporate with the alkaline
liquid. After boiling for some time, if the alkali is in excess, clots
or flocks appear, and in removing the excess of liquid a white mass
is obtained which is soluble in water-the oil is saponified; and
the product of the saponification is combined with a portion of the
alkali which has been employed. If into a hot solution of this
soap a quantity of hydrochloric acid be poured, the acid seizes
upon the potash or the soda, setting at liberty the fatty body
which had been combined with the alkali and which collects on
the liquid. It is easy to discover that the fatty matter thus
collected is no longer the same as that which had been originally
employed; for example, it is completely soluble in boiling alco-
hol, which on cooling deposits brilliant pearly crystals of a fatty
substance possessing acid properties. By evaporating the alcohol
from which these crystals are formed, an additional quantity is
obtained, and when the alcohol is entirely dissipated another
unctuous body is obtained having also acid properties. Three
acids having distinguishing characters are in fact obtained by the
action of alkalies upon fatty substances: the stearic, margaric,
and oleic acids. The alkalies consequently transform neutral oily
bodies into acid substances, as first shown by the admirable re-
searches of M. Chevreul, before whose time it was always
assumed that soap was the result of a direct union of fatty
matters with alkalies. The fatty acids are not the only pro-
ducts of saponification, there are several others, particularly
glycerine, which, however, need not occupy us particularly
here.
The experiments of M. Chevreul would lead us to view all
fatty matters as combinations of glycerine playing the part of a
base with particular acids; these combinations, analogous to salts
if their constitution be merely considered, are generally mixed
together in oils and fats; thus the union of stearic acid and gly-
cerine forms stearine, which is fusible at the temperature of
about 62° cent. (144° Fahr.) Stearic acid melts at 72° cent.
(162º Fahr.) Oleine remains fluid at 4° cent. (24° Fahr.), and
oleic acid is liquid. An oil is therefore by so much the more
FATTY SUBSTANCES.
167
consistent as a larger quantity of solid fatty acid enters into its
composition, and it is on the contrary by so much the softer and
more liquid as this acid is itself more fluid. The wax of the
Myrica cerifera, for example, is sufficiently hard to be reduced
to powder, and is almost entirely formed of stearine.
the fluid vegetable oils oleine always predominates. It is
easy to separate these different fatty compounds from one
another.
In
Besides the solid and liquid acids which are obtained
from fatty substances, there are others known which are
volatile.
Fatty bodies absorb oxygen from the air. This absorption is
at first extremely slow, scarcely appreciable; but once begun, it
goes on with great rapidity; so rapidly, indeed, that if a large
surface be exposed to the air, if, for example, a quantity of rags or
tow be impregnated with oil, the mass may take fire. The conse-
quence of this oxidation is always a thickening of oil, and there
are some which become completely solid in its course; these are
designated by the title of drying oils, and are in particular re-
quest for the manufacture of varnishes. Nut oil which has re-
mained long exposed to the air acquires the consistence of jelly,
and its unctuous properties have so entirely disappeared that it
no longer stains paper.
The alteration which fatty substances undergo in contact with
air and moisture is still more remarkable. The oils which are
inodorous and without taste soon acquire under these circum-
stances a strong smell and a disagreeable flavour. Fleshy fruits
which contain a large quantity of oil, such as the olive and the
oleaginous seeds, when moistened suffer true fermentation, the
result of which is the separation of the fatty acids from the gly-
cerine.
Oils subjected to the action of a high temperature are also
greatly modified. The glycerine which they contain is decom-
posed, and gives rise to various pyrogenous products: stearic
acid is changed into margaric acid, and oleic acid into sebacic
acid, a crystallizable volatile acid which is soluble in hot
water.
168
FATTY SUBSTANCES.
The fatty substances of plants are principally accumulated in
the fruit, and particularly in the seed. In the herbaceous parts
they are less abundant, less perfectly elaborated. Oils appear to
be included in the vegetable tissue under the form of globules,
or minute drops. In such an oily seed as the common almond,
when it is growing, we perceive that the cellular tissue is in the
first instance full of a colourless and transparent fluid; but as the
seed advances, each cell is seen to become filled with numbers
of little oil globules which increase continually in size and num-
ber until the kernel is ripe; there is at the same time a quantity
of azotised matter deposited in the midst of the liquid, which
disturbs its transparency; it is this deposit which thickens the
walls of the cells.* The capillary force which retains fatty prin-
ciples combined with the tissue of certain seeds must be very
considerable, for having boiled some rape-seed, which contained
50 per cent of oil, in water, there was not a trace of oily matter
perceptible upon the surface of the liquid. Butter appears to be
kept diffused in milk by something of a similar force, for milk
when boiled yields but a very small quantity of this substance.
M. Dumas and I maintain that the oil of seeds is intended for
the production of heat by undergoing combustion at the period
of germination; a series of experiments performed in my labo-
ratory by M. Letellier supports this opinion.
Having ascertained by a preliminary trial the quantity of oily
substance contained in a certain weight of seed, some of the
same kind was put to germinate, and the quantity of oil which it
contained was tested at two periods of the germination; it
was found that in the course of this process a considerable pro-
portion of the fatty substance had disappeared; one gramme or
15.438 grains of rape-seed before germination contained 0.50
of oil; after the first period of germination, namely, when the
cotyledons had began to turn green, the quantity of oil was found
reduced to 0.43, and at the end of the second period, when the
cotyledons had become quite green and the radicles were from
3.9 to 4.6 inches long, the oil was reduced to 0.28.
* Dumas, Chemistry, vol. v.
OIL.
169
It would be extremely interesting to ascertain the extreme loss
which the oily principles of seeds sustained in the course of
the commencement of vegetation, and to follow the return of
the same principles in proportion as the plant advanced to-
wards maturity. M. Letellier is going on with these experi-
ments.
The numberless uses to which oil is put, make its manufacture
an object of the highest importance. Vegetable oils are generally
obtained from olives, from oleaginous seeds, and from the nut of
certain palms. Oil is separated by pressure; it may often be
extracted from the seed in the natural state, in which case the
produce is of fine quality, but seldom abundant. The castor oil
bean, for example, yields its oil under the simple action of the
press. In America, however, to obtain this oil, the seeds are
first roasted slightly, and being bruised they are then boiled in
water; the oil readily separates from the roasted seed. A
similar process is sometimes followed in procuring cacao
butter.
In the extraction of oil from the common oleaginous seeds,
they are first ground or bruised in a proper apparatus; the
paste or powder which they now form is generally heated, and
being put into woollen sacks, and these inclosed in hair bags,
they are subjected to the operation of the press; after one pres-
sure, the magma which remains in the bags is crushed anew,
heated, and pressed again. The oil obtained by the second
pressing is never so pure as that procured by the first.
The oil-cake is taken out of the bags, completely dry in ap-
pearance, but it still contains a large proportion of oil-from 8
to 15 per cent of its weight. It is used in fattening cattle and
as manure. Oil, when newly expressed, is always turbid and very
mucilaginous; it becomes clear by standing; but it always re-
tains certain substances which lessen its quality, particularly
when it is intended for burning in lamps.
Greater obstacles are encountered in extracting the oil from
some of the pulpy fruits than from seeds. In extracting olive-
oil, the olives are crushed under millstones; and the paste which
results being put into flat baskets of wicker-work, is subjected
170
OIL.
to the press. The first pressing yields virgin oil, which is used
for the table. Having removed the baskets from the press,
their contents are mixed with a little boiling-water, replaced, and
pressed again, by which a new quantity of oil is obtained. But
the pulp is not yet exhausted; by special treatment it still yields
a quantity of oil of inferior quality, which is employed in the
manufacture of soap.
The fruit of the palm yields the oil which it contains with
great readiness. I have extracted a butter of excellent quality and
very agreeable taste by simply boiling the nuts or berries of the
Palma real in water. The cocoa-nut yields two qualities of
oil, according to the mode of extraction. To prepare the best
kind, the fleshy part of the fruit is grated, and the pulp being
pressed, a milky fluid is obtained, which yields the oil by boiling.
An inferior quality of oil is obtained by causing the cocoa-nuts
to putrify; when the putrefaction has advanced to a certain stage,
the oily pulp is thrown into copper vessels and exposed to the
sun, and the oil which then rises to the surface is skimmed off.
This oil is brown, and has a strong smell; it contains fatty acids
which have probably been set at liberty by the putrid fermenta-
tion.
The value of the produce in oleaginous seeds of a given ex-
tent of land, and the quantity of oil which these seeds will yield,
depend, as may readily be conceived, on a variety of causes which
it is not always easy to appreciate with precision; such as cli-
mate, the nature of the soil, the system of husbandry followed,
&c. The observations of M. Gaujac of Dagny on the various
plants usually cultivated for the sake of their oleaginous seeds,
will however suffice to give a notion of their comparative pro-
ductiveness in oil and cake:
OIL.
171
Crop.
WINTER CROPS.
Colewort
Rocket
Rape.
Swedish turnip
Curled colewort
Turnip cabbage.
•
SPRING CROPS.
Gold of Pleasure
Sunflower.
•
Flax
White poppy
Hemp
Summer rape
Of oil
Of cake
Seed produced
per acre in
Cwts. qrs. lbs.
•
19 2 16
15 3 0
17 0 21
15 3 23
17 0 21
15
1 3
17
3
20
16 1 13
15 3 23
10 2 26
8 0 20
12 1 2
Whole quantity
of Oil obtained
per acre in lbs.
avoird.
875.4
320.8
641.6
595.8
641.6
565.4
545.8
275.0
385.0
561.0
229.0
412.5
lbs.
1130.5
1384.9
Oil
obtained
per cent. per cent.
Cake
40
18
33
33
33
33
54
73
62
62
62
61
M. Matthew de Dombasle made some comparative experiments
at Roville on the cultivation of oleaginous plants. The results
obtained by this skilful agriculturist are much less favourable
than those of M. Gaujac. Instead of 19cwt. 2qrs. 16lbs. of
colewort seed yielding 875.4lbs. of oil per acre, M. de Dom-
basle only obtained 11cwt. 2qrs. 21lbs. yielding 392.8lbs. of
oil; and the other kinds of seed in proportion. But as I have
said already, the fertility of the soil, and the labour and pains
bestowed upon it, may have contributed to the differences
observed, because here the influence of climate may be overlooked.
There is one circumstance, however, which may explain the
great differences in the quantity of oil obtained, which is the
perfection of the press employed to extract it. In a general
way oil presses are so imperfect that they all leave a quantity of
oil, more or less, in the cake.
NOONRO
Here are two examples: from 2763lbs. avoird. of fine
colewort seed, gathered in 1842, and weighing 534lbs. per
bushel, I obtained :
27
72
15
80
22 69
46
25
30
52
70
62
M 3
172
OIL.
In other terms, per cent.:
Oil
Cake
Loss
100.00
but by a careful analysis of the same seed in the laboratory,
50 per cent. of oil was obtained.
2nd. In 1840 and 1841, I made some experiments on the
cultivation of the madia sativa, intermixed with carrots in
a fertile soil, well manured with farm dung. The crop of the
year 1840 was good; it required one hundred and twenty-
seven days to come to maturity. The produce per hectare, of
2.4 acres English measure, was
The seed gave:
40.81
50.12
9.07
Seed, husks deducted
Dried leaves employed as litter
Carrots without their leaves
Of oil
Of cake
100 of seed gave:
Oil
Cake
Loss
lbs.
2424
7700
31966
635.8
17067.6
26.24
70.72
3.04
100.00
These results agree pretty nearly with those which have
been published by other agriculturists; but the seed of this
madia, which in the press gave 26.24 of oil per cent, actually
yielded 41 per cent by analysis in the laboratory; this difference
between practical results and those of the laboratory, shows us
how large a quantity of oil is generally left in the cake. When
the cake is used for feeding cattle, the loss is perhaps less to be
regretted, inasmuch as the oily matter evidently assists in the
fattening; but when the cake is used as manure, the oil which
it contains is almost entirely lost.
It is often of importance to the agriculturist to ascertain
precisely the quantity of fatty principles contained in oleaginous
seeds. For this purpose, it is enough to bruise a given quantity
OIL.
173
of the seed and to digest it in successive portions of sulphuric
ether. After a first digestion, the seed is bruised or pulverised
anew, and the bruising is now accomplished without difficulty.
The process may be concluded by boiling with a mixture of
equal parts of ether and alcohol. The ethereal solutions are
decanted from the seed into a porcelain dish, the weight of which
is known. The ether evaporates spontaneously and the oil
remains, the weight of which is then taken.
The following sums may be taken as a pretty accurate estimate
of the average quantity of oil yielded by the different oleaginous
seeds: Colewort, winter rape, and other species of cruciferous
plants from 30 to 36 and 40 per cent.; sunflower about 15
per cent. ; linseed from 11 to 22; poppy from 34 to 63;
hempseed from 14 to 26; olives from 9 to 11; walnuts 40 to
70; brazil nuts 60; castor oil beans 62; sweet almonds 40 to
54; bitter almonds 28 to 46; madia sativa 26 to 28 per cent.
The quantity of oil yielded by any seed subjected to the press
is always considerably less than that which it contains, and the
oil retained in the cake appears to be in larger proportion as
the starch, the woody tissue and the albuminous matters are
more abundant. Thus maize, or Indian corn, which contains
from 8 to 10 per cent. of fluid oil, gives mere traces of its pre-
sence under the press.
The oily and fleshy fruits such as those of the olive and the
palm, yield a considerable quantity of oil. In the southern
countries of Europe, particularly those which are so well pro-
tected that their olive-trees escaped the severe winter of 1789,
as many as about 8164lbs. of oil per acre are obtained with proper
care. The trees which were killed during this memorable winter,
sprouted again from the roots, and at the present day yield from
about one quarter to one half the above quantity, according to
the spaces left between them, which vary considerably. Under
similar circumstances in regard to climate, it will readily be un-
derstood that the quantity of produce will be influenced by the
quantity of manure put into the ground. In some countries
the olive is never manured, save indirectly; that is to say, the
ground between the trees is only manured with a view to another
crop, which is grown between them; in other countries, again,
174
OIL.
in the neighbourhood of Marseilles, for instance, it is the prac-
tice to manure the olive plantations directly every three or four
years.
The olive enjoys remarkable longevity; I have mentioned one
more than seven centuries old, and the term of the tree's existence
appears only to be limited by the severe winters which cause it
to die from time to time. The produce must of course depend
upon the age of the trees which compose a plantation. Up to
eleven years, M. Gasparin shows that an olive-tree still remains
all but unproductive; and that the capital, and the interest upon
the capital expended in this husbandry, must necessarily exceed
the value of the produce up to the thirtieth year.
Yet there are
soils which are favourable to the olive, and which are useful for
nothing else; a hole in a rock suffices it, if the climate be
favourable and it receive a proper dose of manure. But the
grand cause of the disadvantages attending the cultivation of the
olive in France is connected with the periodical occurrence of
severe winters which kill it; in an interval of one hundred and
twelve years, from 1709 to 1821, the olive plantations have
suffered three great mortalities, which give a mean duration of
about forty years to each planting.
The cocoa-nut tree is one of those which yields the largest
quantity of oil with the least labour. The tree grows vigorously
in all hot countries at no great distance from the sea-shore;
wherever the temperature is from 78° to 82° Fahr., there the
cocoa-nut thrives. It is also found on the banks of great rivers;
and the common practice in planting the cocoa-nut is to put a
little salt in the hole. When transplanted far from the banks
of rivers, it thrives best in the neighbourhood of human habita-
tions, which has led the Indians to say that the cocoa-nut tree
loves to hear men talking under its shade. It is a tree which
requires a soil impregnated with saline substances, and these are
never wanting near the habitations of man. The tree bears its
first flowers at the age of four years; it produces fruit the fol-
lowing year, and continues to fructify until it is eighty years old.
The spikes generally bear about twelve cocoa-nuts, and the
number of nuts yielded by a tree in the course of a year may
taken at about fifty, which will yield about 4 litres, or rather
be
ESSENTIAL OILS.
175
more than 7 pints of oil. Somewhere about ninety trees are
generally found upon the acre of land, and these are capable of
yielding about 825lbs. of oil annually.
*
The cocoa-nut tree must, therefore, be regarded as among
the most productive in oil, and also as the plant which requires
the least outlay in its cultivation. Many species of palm
yield oils of a very agreeable flavour for the table, and the pro-
duce of all answers admirably for the manufacture of soap. In
the same proportion as agricultural industry extends in the
equatorial regions of the globe, will the production of palm-oils
increase, and this must necessarily influence the cultivation of the
olive in a very serious way. The cultivation of the tree being
already threatened in Europe by that of the mulberry, and the
prodigious extension in the trade in palm-oil upon the coasts of
Africa in the course of the last few years, justify this conclu-
sion. In 1817, palm-oil was considered as among the list of
mere medicinal substances. At this period a London perfumer
thought of making it into a soap for the toilet-table. From this
time it became the staple of a bartering trade, which has been
by so much the more profitable to the nations engaged in it,
as the purchase is always effected by manufactured articles, such
as cotton and woollen goods, hardware and crockery, arms,
powder, &c. The future extent of this traffic may be imagined
when it is known that in 1817 the importation of palm-oil into
England did not much exceed 140,000lbs., and that in 1836 it
exceeded 70,000,000lbs! In taking an acre of surface for unity,
I find that on an average the
Spring oleaginous plants yield
Winter oleaginous plants
The olive (south of Europe)
The Palm (America) .
OF ESSENTIAL OILS.
330lbs. of oil.
550
550
825
در
"
},
Aromatic plants owe the odours which characterize them to
certain volatile principles, which by reason of certain properties
which they have in common with fat oils, such as insolubility in
water, solubility in ether and alcohol, inflammability, &c., are
* Codazzi, Resumen de la Geografia de la Venezuela, p. 133.
M 4
176
ESSENTIAL OILS.
generally designated as essential oils. They are met with in all
parts of plants; but in one plant the oil is principally found in
the flower, in another in the leaves, in another in the bark, &c.
It sometimes happens that different parts of the same plant con-
tain oils of different kinds. From the orange-tree, for instance,
three distinct oils are obtained, as the flower, the leaf, or the
rind of the fruit is treated. In some cases the volatile principle
is so thoroughly imprisoned in the vegetable cells, that drying
does not dissipate it; in others, as in the greater number of
flowers, the oil is formed on the surface, and is volatilized imme-
diately after its formation.
Essential oils are less volatile than water; nevertheless they
rise with the vapour of water, and it is by distillation that they
are generally extracted. The plant is put into a still or alembic
containing water, and heat is applied; the vapour formed is
condensed in the receiver, and the essence, by reason of its less
density, is found swimming on the surface of the water which
has been distilled. Some volatile oils are obtained by pressure,
those of the citron and bergamotte for example.
The volatile principles of plants present somewhat varied phy-
sical properties. They are generally limpid and lighter than
water; yet there are some which are more dense, and
some, such
as camphor, which are solid. With reference to their composition,
volatile oils may be divided into three classes; 1st. Oils com-
posed entirely of carbon and hydrogen. 2nd. Oils composed of
carbon, hydrogen, and oxygen. 3rd. Essential oils containing
sulphur; in addition to which, the essential oil of mustard seed
contains azote.
The essential oils undergo a change by long contact with the
air: they absorb oxygen, and many of them become acidified;
under the influence of this gas, the oil of bitter almonds is
changed into benzoic acid, the oil of cinnamon into cinn-amic
acid; in a general way acetic acid is produced. The volatile
oil obtained from any plant almost always contains two distinct
principles, which may be separated by careful distillation; one of
these principles is a carburet of hydrogen, the other an oxy-
genated oil. Camphor is combined with essential oils in many
plants of the labiate family. It exudes from certain laurels; it
RESINS.
177
Carbon
Hydrogen
Oxygen
is from the Laurus camphora that all the camphor of commerce
is extracted in the East, the extraction being effected precisely
by the same process as other essential oils. The chips of the
Laurus camphora are put into iron stills, surmounted by earthen-
ware capitals, in the inside of which a number of ropes made of
rice-straw are stretched; the camphor rises and is condensed on
the surface of these cords in the state of a grey powder; it is
refined by sublimation.
According to M. Dumas, camphor contains:
OF RESIN.
79.2
10.4
10.4
100.0
Essential oils almost always hold certain substances in solu-
tion which make them viscid or sticky. The balsams which
exude from the bark of certain trees are nothing more than
solutions of resin in essential oils. When the volatile oil has
been dissipated by evaporation, the resin remains in the solid
state. There is further a natural relation in point of constitu-
tion between essential oils and resins. The greater number of
essences absorb, as we have said, oxygen from the atmosphere,
and by this absorption they become thick, and are changed into
resins; so that in one case the resin may be a product of the
oxidation of an essential oil, in another it may merely be set at
liberty by the dissipation of the essence which held it in solu-
tion.
The resins constitute friable, or soft solids. They are fusible,
extremely inflammable, and fixed. The resins are inodorous
when pure: any odour which particular resins possess is generally
attributed to the essential oil which they still retain. The resins
are insoluble, or very sparingly soluble in water; some of them
dissolve readily in alcohol and in ether, and there are some also,
such as copal, which are only soluble in very small quantity.
Some resins shew acid reaction; they combine with bases, neu-
tralizing them. The greater number of resinous matters ob-
tained from plants are regarded by chemists as mixtures of
N
178
CAOUTCHOUC.
several particular resins, the study of which is not yet much ad-
vanced. Some resins are much employed in the arts, such as
colophony and copal, &c. Several balsams are also in familiar
use, particularly as medicines, such as the balsam of tolu, bal-
sam of copaiba, &c.
Colophony, or rosin, is extracted from different kinds of the
genus Pinus. In the Landes, or sandy plains of Bordeaux, it
is the maritime pine which yields it. When the tree is from
thirty to forty years of age, incisions are made in the trunk,
beginning at the lower part, two or three times a week, and these
are continued to the height of from 6 to 10 feet from the
ground; the last notch generally reaches this height about four
years after the tree has been notched for the first time. After
this a new series of notches is begun on the opposite side, setting
out from the ground as before, and in this way the whole circum-
ference of the tree finally presents a series of notches, so that a
tree will continue to yield turpentine during a period of sixty
years. The turpentine which exudes from the notches is col-
lected in a hole dug in the ground.
Crude turpentine always contains a quantity of intermixed
foreign matters, earth, stones, leaves, &c. It is purified by being
melted, and filtered hot through a bed of straw. By distillation
it is separated into essential oil, which is condensed in the re-
ceiver, and colophony, or rosin, which remains in the still. From
250lbs. of turpentine 30lbs. of essence and 220lbs. of rosin are
generally obtained.
Copal is the produce of a tree which is somewhat common in
Madagascar, and which M. Perrotet has determined to be the
Hymenæa verrucosa. The balsam or sap which exudes from
the bark solidifies by contact with the air, and the resin is ga-
thered in the state in which it is met with in commerce.
CAOUTCHOUC.
The caoutchouc which we have mentioned as forming a con-
stituent in the sap of certain trees possesses some properties.
which assimilate it with the resins. Thus pure ether, free from
alcohol, dissolves it. The greater number of the essential oils
also dissolve it, particularly when hot. It is a solution of Indian
VEGETABLE WAX.
179
:
rubber in rectified coal-tar oil or naphtha, which is now used so
extensively for making stuffs waterproof. According to Fara-
day pure caoutchouc is composed of:
Carbon
Hydrogen
VEGETABLE WAX,
87.2
12.8
100.0
Some plants produce a considerable quantity of a substance
which bears a great resemblance to bees'-wax, and which in some
of its properties approaches fatty bodies. Proust discovered that
vegetable wax formed part of the green fecula of a great num-
ber of vegetables. In the common cabbage it occurs in large
quantity. It is often met with forming a varnish on the surface
of leaves, fruit, and barks; the substance, however, is far from
being identical; it almost always results from the combination of
several distinct principles which have not yet been sufficiently
studied, but among which there are obviously some true fatty
substances, that is to say, bodies capable of saponification, and
matters analogous to resins. I shall here mention a few of the
vegetable waxes which are best known.
Wax of the palm. This is the product of the Ceroxylon an-
dicola, which is very abundant on the central Cordillera of New
Granada. I believe that I met with the lower limit of the cero-
xylon upon the borders of the torrent of Tochecito, at the height
of 8200 feet above the level of the sea, and I followed it to an
absolute elevation of about 9800 feet. The extreme mean tem-
peratures comprised between these two limits may be valued at
from 11° to 18° cent.; 51.8° to 64.4° Fahr. Towards the supe-
rior limit, the ceroxylon is exposed to a cold during the
night which approaches the freezing point of water; it is there-
fore frequently met with in company with the great oak of
America, whose climate it stands very well.
The Indians obtain the wax by scraping the bark of the palm:
the scrapings are then boiled in water; the wax swims, without
however melting; it is merely softened, and the impurities which
it contains are deposited. The matter thus purified is formed
into balls and set to dry in the sun. It is with this substance,
N 2
180
VEGETABLE WAX.
to which, however, a small quantity of fat, is often added to ren-
der it less brittle, that the cakes of wax and the candles which
are found in the commerce of the country are formed. After it
has been melted, the cera de palma is of a deep yellow colour,
slightly translucid, as brittle as resin, and presenting a waxy
fracture well characterized. Its melting point is a little above
that of boiling water. Boiling alcohol dissolves it readily; in
cooling the solution sets into a gelatinous mass. Ether dissolves
it, as do the alkalies also.
The wax of the palm consists of two principles; one, fusible
above the temperature of the boiling point of water, has all the
physical properties of bees'-wax; the other has the properties of
resin. The composition of these substances upon analysis ap-
pears to be:
Carbon
Hydrogen
Oxygen
Wax.
81.6
13.3
5.1
100.0
Resin.
83.7
11.5
4.8
100.0
Wax of the Myrica cerifera.-This wax is procured by
boiling the fruit of several species of myrica in water. The tree
is extremely common in Louisiana and the temperate regions of
the Andes. The fruit yields as much as 25 per cent. of wax,
and a single shrub will supply from 26 to 33lbs. of berries per
The crude wax is green and brittle; to be made into
candles, it requires the addition of a certain quantity of fat.
According to M. Chevreul the wax of the myrica is saponifiable.
annum.
Wax of the sugar-cane.-The sugar cane, particularly the
violet variety, is covered with a powder or bloom of a waxy na-
ture, which melts at the temperature of 82° cent. (179.6° Fahr.)
This wax is so hard that it can be pulverized; it may be made
into candles which for the brilliancy of their light are not inferior
to those of spermaceti. M. Avequin, who directed attention to
this subject, found by his experiments that a hectare (nearly 21
acres English) of the violet cane would furnish about 220lbs. of
This wax is entirely soluble in boiling alcohol; ether does
not dissolve it in the cold. It appears to constitute a perfectly
definite immediate vegetable principle, the composition of which,
according to M. Dumas, is the following:
wax.
COLOURING PRINCIPLES.
181
Carbon
Hydrogen
Oxygen
CHLOROPHYLLF.
81.4
14.1
4.5
100
OF COLOURING MATTERS.
The green matter which colours the leaves of vegetables is so
designated. The attempts which have been made to isolate this
matter, render it probable that it is somewhat of the nature of
the vegetable waxes. Pelletier and Caventou endeavoured to
procure it by treating with cold alcohol, the pulp remaining
after expressing all the juices from the leaves of various her-
baceous plants. By evaporation of the alcoholic liquor, a sub-
stance of a deep green colour was obtained, which is chlorophylle,
a matter soluble in ether, in alcohol, the oils and the alkalies.
Heated, it softens and is decomposed before it melts. Acetic
acid dissolves it in very appreciable quantities, so do the sul-
phuric and hydrochloric acids; water precipitates it from these
acid solutions. Berzelius says that chlorophylle exists only in
very small quantity in plants, the leaves of a large tree will not
perhaps contain more than about 100 grains.
The matters which colour the different parts of plants are
extremely numerous; they present great varieties of shade, but
are in general derived from red, yellow, and green. It is seldom
that the colouring matter of a plant exists isolatedly, it is almost
always allied with one or several immediate principles, which are
themselves frequently coloured. Thus red colouring matters are
generally combined with yellow principles, which having nearly
the same properties, one is with great difficulty separated from
another.
Colouring matters are solid, inodorous, and have little taste.
Some are soluble in water, others only dissolve in alcohol or in
ether. All combine with the alkalies, and several of them
unite intimately with acids; the greater number are powerfully
affected, undergo a true destruction, on exposure to the
sun's rays, especially when in contact with moist air. It is
182
INDIGO.
familiarly known that vegetable tissues of all kinds, bees'-wax,
&c. are bleached by exposure to the sun and air; a high tempe-
rature acts like light: some vegetable colours are altered, bleached,
when they remain exposed for a time to a temperature of from
334° to 424° Fahr. The oxygen of the air, which so quickly
destroys certain colours, developes others under particular cir-
cumstances.
Alkalies and acids, by uniting with vegetable colours, almost
always modify their tints and often change them entirely. Many
blucs, for instance, become reds, under the agency of acids,
greens or yellows under that of alkalies. By neutralizing the
acid or the alkali, the colour generally resumes its original tint.
Several substances, which are colourless in the state in which
they are formed in vegetables, become coloured by the united
action of oxygen and an alkali, such as orceine, which is oxydated
and becomes blue under the simultaneous contact of air and
ammonia. The greater number of vegetable-colouring matters
are destroyed and bleached by chlorine. Many of the same
matters unite intimately with alumina and oxide of tin to form
lakes, insoluble compounds in which the colours remain fixed;
thus a coloured liquid often becomes colourless when it is shaken
with an hydrate of alumina. Charcoal, in a state of extreme
subdivision, acts like alumina, and is a powerful discharger of
colours in every day use in the arts. Colouring matters are
generally ternary compounds, though some of them also contain
azote; and several of them exhibit the remarkable phenomenon
that in undergoing oxidation in contact with ammonia they
assimilate the azote of this alkali. I shall now indicate the origin
and the mode of preparing a few of the more important of these
colouring matters.
Indigo. This substance, so essential in the art of dyeing, has
been one of the great staples of trade with Asia from the most
remote times. For a long while indigo was regarded in Europe
as a mineral substance found in India; it used to be designated
Indian or India stone whence the name of indigo. It was not
until after the discovery of America that the true nature of this
dye stuff was known, although before this period indigo had
been made in Arabia, Egypt, and even in the Island of Malta.
INDIGO.
183
Indigo is volatile, so that to obtain it pure, it is enough to
put a small quantity into a platinum capsule, to cover it with a
lid and to expose it to heat. Indigo is volatilized in the state
of violet coloured vapour, and collects in crystals upon the middle
part of the sides of the capsule. Indigo gives nothing to water
or to ether. Alcohol takes up a very small quantity of it; con-
centrated sulphuric acid dissolves and modifies it.
All bodies greedy of oxygen appear to reduce or deoxidize
this colouring principle; it changes to a yellow, and becomes
soluble in water in contact with alkalies; by exposing the alka-
line liquor charged with the uncoloured indigo to the air, it ab-
sorbs oxygen rapidly, and the indigo becomes insoluble and is
precipitated with its original blue colour. It is most easy, as said,
to disoxidize indigo; it is sufficient to bring it into contact with
hydrogen gas in the nascent state, a condition which is readily
secured by throwing iron or zinc filings into water containing
the colouring matter previously dissolved in sulphuric acid. The
disengagement of the hydrogen has scarcely commenced before
the deep blue colour of the solution declines in intensity, and
by and by it becomes of a very pale grey. When the discharge
of colour is completed, and no more hydrogen is disengaged, the
colourless indigo begins to react upon the air, it absorbs oxygen,
becomes again oxidized, and by and by the liquid has resumed
its deep blue. This property of indigo of becoming soluble in
alkaline solutions under the influence of disoxidizing bodies, is
taken advantage of in our laboratories to obtain indigo in a state
of purity, and in the arts to prepare a dyeing liquid. If a mix-
ture be made of 15 parts of the indigo of commerce reduced
to fine powder, 10 parts of the sulphate of the protoxide of iron,
15 parts of lime and 60 parts of water, and it be left for several
days in a closed vessel, a colourless liquid is obtained. The liquid
decanted and exposed to the air, deposits the whole of its in-
digo after a time. It is with similar ingredients that the dyer
prepares his bath for blue colours. It is into the alkaline liquor
so prepared that the stuff to be dyed is dipped; it is then hung
up in the air, where it soon becomes blue; it is re-dipped and
re-exposed again and again, until it has acquired the depth of
tint required, after which it is washed. The indigo regenerated
184
INDIGO.
by the action of the air remains fixed in the stuff, and proves,
as all the world knows, one of the most solid of colours.
Chemists are not agreed as to the true nature of colourless
indigo which may be obtained in the solid state.
Some regard
it as indigo disoxidized, others as indigo hydrogenized. On the
latter supposition, the hydrogen fixed would be derived from the
water decomposed, the oxygen of which would be transferred to
the bodies greedy of this element, which are brought into play.
The latter of these views appears to have the ascendant at the
present time.
However this may be, the following is the com-
position of indigo in each of its states, as determined by M.
Dumas:
Carbon
Hydrogen.
Azote
Oxygen
Blue Indigo. White Indigo.
73.1
4.0
10.8
12.1
100.0
73.0
4 5
10.6
11.9
100.0
The plants which have hitherto been cultivated for the pro-
duction of indigo with any profit are not numerous; they
belong to the genera Indigofera, Isatis et Nerium; it is the
genus Indigofera which is most generally cultivated, and the
species designated argentea is found to be the most profitable.
M. Chevreul has ascertained that in the living plant the indigo
is not coloured, and that it is consequently during its extraction
that it becomes blue. The experiments of M. Pelletier upon
the Polygonum tinctorium have confirmed the old researches of
M. Chevreul. After having dried a leaf, Pelletier digested it
with ether in a closed flask. The whole of the chlorophylle
was dissolved, and the leaf became completely blanched; by
exposing it afterwards to the air, it turned blue if it contained
indigo.
In the republic of Venezuela, where I had an opportunity of
studying the cultivation of the indigo-bearing plants, I saw that
those soils were preferred which were light and susceptible of
irrigation, a condition indeed which seems to me all but indis-
pensable to the profitable exercise of agriculture within the
tropics. Indigo requires a warm climate; at an elevation of
INDIGO.
185
about 3250 feet, English, above the level of the sea, where the
mean temperature is not more than from 72° to 75° Fahr. the
indigo husbandry cannot be carried on with advantage. Never-
theless the Indigofera sylvestris is met with at an elevation of
about 4900 feet above the level of the sea; but the attempts
that have been made to obtain colouring matter from the plant
have proved fruitless. In the valley d'Aragua, where the best
plantations are met with, the plant is sowed in lines, the holes
destined to receive the seed being about 1 inch in depth, and
somewhat more than 25 inches apart. A pinch of seed is
dropped into each hole, and is covered with a little earth. The
sowing takes place in soils that are moist but well drained, or in
situations generally which have no system of irrigation at the
period of the first rains. The seeds shoot in the course of the
first week; hoeing is performed in the course of the month.
The first cutting takes place when the plant is coming into
flower; from fifty to sixty days generally intervene between the
sowing and this cutting; but the time necessary for the deve-
lopment of the leaves depends of course upon the climate. In
the neighbourhood of Maracaibo where the mean temperature
is about 78° Fahr, the gathering does not take place before the
third month. The second cutting is performed from 45 to 50
days after the first; and in this way several successive crops are
obtained, until it is seen that the plant begins to degenerate. In
good soils the indigo will last for two years; in soils of inferior
quality the crop is generally annual.
The indigo harvest is immediately transported to tanks or large
rectangular reservoirs built of masonry, and disposed on different
levels, the superior reservoir or steeping tank being much larger
than the two others. In the valley d'Aragua, there are some
which are upwards of 20 feet long by 15 feet wide, and 20
inches in depth.
The second or mashing tank, is narrower and deeper than
the former. The third reservoir or depositing tank, receives the
liquor from the mashing tank, and in it the indigo subsides.
In some manufactories the third tank is not used, the deposition
taking place in the mashing tank itself.
The leaves, as the name implies, are thrown into the
186
INDIGO.
steeper, covered with water, and kept down by planks loaded
with stones; fermentation soon begins, and is allowed to continue
during about eighteen hours; and in the management of this
first operation lies much of the art of the indigo-maker. By
continuing it too long some portion of the colouring matter is
destroyed; by stopping it prematurely, a quantity of indigo is
left in the leaves. The fermentation judged to be sufficiently
advanced, the liquor is run off into the battery, and vigorously
stirred until the grain is deposited. The fluid is then either let
into the subsider, or left in the battery, and the deposition is
complete at the end of about twenty hours; the supernatent
fluid is drawn off, and the indigo paste is scooped out and
placed upon cloths to drain. When sufficiently firm, it is
divided into lumps, and these are set in the shade to dry. In
the valley d'Aragua it is estimated that with a good soil and
careful management, each hectare of surface will yield 280lbs.
of marketable indigo,* which is at the rate of about 112lbs.
per English acre.
In Carolina the cultivation of indigo appears to be much less
productive than in the equinoxial regions, and the produce is of
inferior quality. There they sow in drills in the commencement
of the rainy season which follows the vernal equinox, and the
first crop is gathered about the beginning of July; the second is
secured two months afterwards, and when the autumn is mild,
a third but insignificant gathering takes place at the end of
September. One negro is allowed to be able to work nearly
two acres and a half of ground, from which about 160lbs. of
indigo are obtained.
In the East Indies, upon the Coromandel coast, the growth
of indigo takes place upon sandy soils which are not irrigated,
and in which vegetation is only possible during the rainy season.
The loamy soils that admit of being irrigated are almost always
reserved for the growth of rice. Immediately after the rains have
set in, in December, the land receives two superficial ploughings ;
the indigo is sown broad-cast, and the seed is harrowed in by
dragging a faggot of bamboos over the surface, or by treading in
by means of a flock of sheep. The first and principal gather-
* Cadozzi, Resumen de la Geografia de Venezuela, p. 144.
INDIGO.
137
ing takes place in March; any other crop that may be won is
purely casual, and entirely dependent on the rain that falls.
The crop rarely fails to feel the effects of the droughts which so
frequently take place upon the Coromandel coast. It is never
abundant, and the plants have little vigour. The harvest takes
place after the flowering season. The crop is dried in the sun;
the plant is then beaten with switches, by which the leaves
are detached from the stems, after which they are exposed anew
to the sun to secure their being perfectly dry. They are then
reduced to coarse powder and handed over to the indigo maker,
for in India the planter is never himself the manufacturer of the
dye-stuff.
On the coast of Coromandel, indigo is always extracted from
the dried leaves, which bruised and broken, are infused in three
or four times their bulk of cold water during two or three
hours; the infusion is then filtered through a loose stuff made
of goat's hair; the filtered liquor is beaten for two hours, and
after this about five gallons of lime-water are added for every
100lbs. of dried leaves; the mixture is stirred, and then left to
settle. When the deposit has formed, the supernatent liquor is
drawn off, the sediment is washed with a little boiling water,
and being thrown upon a cloth, the indigo is drained and dried.
It is then pressed, and the paste is cut into cubical lumps which
are thoroughly dried in the air, and of which each weighs nearly
3 ounces.
In the Indian method of manufacturing indigo, all is accom-
plished, as appears, without fermentation. This indigo is little
esteemed in commerce; it is heavy, of a pale blue, without
much of the coppery aspect, rough on the broken surface, and
presents here and there white points and vegetable débris. An
acre of land on the Coromandel coast will produce from 48 to
49lbs. of indigo annually.
In spite of the high price of indigo, so small a quantity would
scarcely cover the cost of production, were not the wages of the
Indian labourer exceedingly low. The whole expense of
producing a kilogramme, or 2lbs. avoird. of indigo, according
to M. Plagne, amounts to 3 francs, 20 cents, or about
2s. 8d.
188
INDIGO.
The cultivation of the indigo plant has been attempted several
times in the south of Europe, particularly in Spain and Italy.
There is no doubt but that indigo may be grown in Europe in
those situations where for three or four months of the
year the
temperature is truly tropical; but it seems probable that indigo
can never be advantageously introduced into the agriculture of
temperate countries.
Before indigo was so extensive an article of commerce as it is
now, the south of France used to furnish almost all the mar-
kets of Europe with a blue dye, which was the best then
known; this was woad or pastel, the produce of the Isatis tinc-
toria.
The isatis is sufficiently hardy to stand the cold of winter.
In the south it is sown in March, and the seed springs in from
eight to ten days. When the plant has five or six leaves, it is
hoed with care.
The crop is gathered when the leaves have ac-
quired their greatest size, when they even begin to fade a little.
The preparation of woad bears a certain resemblance to that of
indigo, and need not detain us here.
The Polygonum tinctorium has of late attracted the attention
of European cultivators. The plant is a native of China where
it has been cultivated from time immemorial; it was brought
into France and propagated under the care of M. de Lille. In
the course of three months the plant has thrown out all its
leaves, and in the south of France it never fails to ripen its seeds.
From some experiments that have been made, the leaves of the
polygonum appear to contain about the five-thousandth of their
weight of indigo, and as the acre of land will yield between
11,000 and 11,900lbs. weight of leaves, the produce of colour-
ing matter will come to upwards of 561lbs.
The indigo obtained from the polygonum by the methods
generally practiced is not always of fine quality. It contains
matters which, having been dissolved in the water used for
maceration, had subsequently been precipitated. M. Vilmorin
proposed to adopt on the great scale and in the manufactory,
the methods which are used for purifying indigo in the labo-
ratory, and which consists, as we have scen, in reducing
coloured and insoluble indigo to the colourless and insoluble
ORCHIL.
189
state by means of a salt of the protoxide of iron in contact with
an alkali, and subsequently to restore its colour, and effect its
precipitation by contact with the oxygen of the air. It is ob-
vious that this method is perfectly applicable to the treatment
of the whole of the indigoferous plants, and I believe that its
adoption would be a great improvement.
Orchil. This colouring matter, of a deep purple, is prepared
from certain lichens or lung-worts; that which is most prized
is the rocella tinctoria, a native of the Canaries and Cape
de Verd Islands. The variolaria dealbata, the var. asper-
gillia, and the lichen corallinus, which grow upon the rocks of
Auvergne, and on the Alps and Pyrenees, yield a produce of
inferior quality.
To obtain the orchil, the lichens are steeped for several days.
in their own weight of stale urine. Into the mixture about
5 per cent. of slaked lime in powder, a small quantity of arse-
nious acid, and a little alum are introduced. Fermentation is
by and by set up in the mass, which soon acquires the charac-
teristic colour of the orchil, but the tint is never complete until
the expiration of about a month.
Orchil readily communicates its peculiar colour to water and
to alcohol; the watery solution, which is of a fine crimson,
becomes colourless in a few days when it is kept in a flask her-
metically sealed; it regains its colour by exposure to the air.
The colour which is acquired during the manufacture of orchil
indicates that the lichens which yield it contain principles which
are colourless in themselves, but which possess the singular
property of becoming tinted under the influence of oxygen and
ammonia; for in the preparation of orchil, the addition of urine
and of lime have no other purpose beyond the introduction and
development of this alkaline base. This view is shown to be
correct, moreover, by the facts brought to light by MM. Heeren
and Robiquet in their inquiries into the chemical constitution of
the lichens. These chemists, in fact, succeeded in extracting from
several of the lichens which yield orchil a variety of colourless
crystalline principles, in particular orcine, a substance which may
be procured in very regular quadrangular prisms, and which is
soluble in water and in alcohol. The watery solution of orcine
190
MADDER.
mixed with ammonia and exposed to the air, becomes gradually
of a deeper and deeper red until it has the colour of blood. The
result of this oxidation of orcine under the action of ammonia
is a colouring principle, orceine, into the constitution of which
azote enters, an element which formed no part of orcine; the
analyses of these two substances made by M. Dumas, show this
fact very distinctly:
Carbon
Hydrogen
Oxygen
Azote.
1
Dry orcine.
67.8
6.5
25.7
Carbon
Hydrogen
Oxygen
100.0
Orceine.
55.9
5.2
31.0
7.9
100.0
The lichens furnish several other principles analogous to orcine
in their property of acquiring colour under similar circum-
stances.
Turnsole. This colouring matter is met with in commerce.
in two states, in mass and in thin cakes, and is procured from
various lichens which have not yet been accurately specified; in
any case the substance is obtained by a process which differs little
from that used in the manufacture of orchil. According to
Mr. Kane, the colouring principles of turnsole are naturally red:
they only become blue by combining with a base. The colour-
ing matters which predominate in turnsole are erythrolitmine
and azolitmine, which are united with lime, potash and am-
monia, and further mixed with a considerable quantity of chalk
and sand. The analyses of Kane show these two substances
to have the following composition :-
Erythrolitmine.
55.6
8.4
36.0
100.0
100.0
Turnsole occurs in trade in the shape of thin cakes, made up
of chips, which are coloured by the juice of chroyophoria tinctoria,
a plant of the euphorbiaceous family, and of which the dyeing
properties appear to have been known to the earliest naturalists.
Madder. The root of the madder plant, so commonly em-
Azolitmine.
49.8
5.4
oxygen and azote 44.8
MADDER.
191
ployed in dyeing, contains more than one colouring matter; but
the most important of these and that which constitutes the most
useful element in the root, is alizarine, which was discovered by
M. Robiquet.
This substance is scarcely soluble in boiling water, but it is
soluble in alcohol and still more so in ether, to which it imparts
a golden yellow colour. Alkaline liquors dissolve it and acquire
a violet shade extremely agreeable to the eye.
Alizarine is
sublimed by the action of heat in the form of brilliant red
needles.
Madder (rubia tinctorum,) is a native of the south; but as it
stands the winter, it is now cultivated almost all over Europe;
the plant is propagated by seeds, but there are certain advantages
in using the sprouts which it throws out in the spring and
which readily take root. The plant requires a friable soil,
sufficiently moist and highly manured to receive it; the soil
must be previously trenched or have had a very deep ploughing.
In the East of France the planting takes place in April or May.
The sprouts which are to be transplanted must be about
6 inches long. When the plant has struck root, the ground is
cleaned, and fifteen or twenty days afterwards it is hoed; in the
course of the summer several other hoeings are required. In
Alsace, madder is planted in rows and in patches, a certain
interval between each patch being left, the earth of which, in the
month of March of the following year, is thrown over the ground
that is planted.
In the neighbourhood of Haguenau, madder occupies the
ground during two years; the crop is gathered about the middle
of November. In some districts the plant remains in possession
of the soil for five or six years. It is generally allowed that the
amount of produce increases with time; but in those countries,
such as Alsace, where the plant is liable to be attacked by frost,
it is generally thought prudent to gather it at the end of two
years; the harvest is then profitable, and in the course of the
third or fourth or any succeeding winter it might run the risk of
such severe frost as would destroy it entirely. In southern
countries the growers say that a crop of the fourth year exceeds
very considerably one of the third year; but it might be made a
192
SAFFRON.
question whether the increase actually compensates for the longer
occupation of the soil. And then when the cultivation is too
much prolonged, a species of fungus is developed around the
root and kills it. The crop of madder is gathered with the hoe,
a laborious and costly process; the roots are then dried in stoves
and sent to the mill, so that it is in the state of powder that
madder is met with in commerce.
In Alsace, where madder remains two years in the ground,
the mean produce per acre is estimated at about 3,300 lbs. of
dried roots, which is equal to an annual crop of about 1650
lbs. In the south of France the mean annual produce amounts
to something less than this or to about 1560lbs. ;* but the
quantity has been estimated at a considerably lower amount still,
Besides its roots, madder yields an abundance of leaves which
are excellent forage.
Reseda luteola, or dyers' weed, is a plant in common use,
and owes its properties as a dye-stuff to the presence of a yellow
crystalline principle, luteoline, discovered by M. Chevreul. This
substance is soluble in ether, alcohol, and alkaline solutions.
Dyers' weed is sown in autumn, stands through the winter,
and ripens in the month of August following. The plant is
gathered when it begins to turn yellow, and it is in a marketable
state after it is dried. An acre of land will produce about
1833lbs. weight of marketable dye-weed.
Saffron. This plant is cultivated in the south of France and
in Austria, but appears to be a native of Asia. Saffron requires
a light and yet fertile soil in order to produce abundantly, al-
though it may also be cultivated in soils of middling quality.
The ground trenched one spit deep, is set out with bulbs from an
old plantation. In the south the transplanting takes place in the
month of June. The first flowers appear towards the middle of
October; they are few during the first year. They are gathered,
and the pistils removed; the gathering continues for about a
fortnight. In the course of the year, which follows the planting,
the ground receives a surface dressing; it is freed from weeds,
and the withered leaves are removed. The next gathering takes
place at the same period as the former, but the flowers are now
* De Gasparin, Agricultural Memoirs, vol 11. p. 243.
ROUCOU-CHICA.
193
much more abundant, and the same process is continued until
the roots are taken up, which they are in France at the end of
the second year; but in Austria the culture is continued for a
much longer period in the same piece of ground. The extrac-
tion of the pistils is an occupation in which the whole family of
the saffron grower takes part and employs its evenings; in the
course of an evening of five hours, eight persons will generally
have drawn 250 grammes or about 8 ounces of saffron. In some
places the pistils are dried in the sun, in others by being exposed
in a sieve over a fire of twigs; the latter process appears to be
the better one.
M. de Gasparin estimates at about 110lbs. the saffron which
is gathered in the course of two years from about 24ths acres
of land; this would give a mean annual produce of about
43.7lbs. per English acre, and the price of saffron being from
27 to 28 shillings per pound, the value of the produce may easily
be reckoned. In Austria, where the crop is allowed to occupy
the ground for three years, the produce has been estimated at
about 194lbs. per acre per annum.
Roucou is a dye-stuff extracted from the fruit of the Bixa
orellana, a tree which is extremely common in the hot regions
of Southern America.
Chica. This and the former dye-stuff are in use among the
native Americans for staining the skin. It is obtained from the
leaves of the Bignonia chica, which are of a beautiful green
when fresh, but become red by drying.
Chica has the colour of cinnabar: it is without taste and with-
out smell; a mass of this pigment may be compared to a mass
of indigo, it only differs from this substance in its colour. Like
indigo, it acquires the metallic polish when rubbed with a hard
body. It dissolves in alcohol, and in alkaline solutions; it mixes
readily with grease, and it is with such a mixture that the Indians
paint their bodies. Chica has been employed in cotton dyeing,
and the colour is found to stand the sun perfectly.
194
THE POTATO.
II. COMPOSITION OF THE DIFFERENT PARTS OF PLANTS.
The immediate principles, the history of which has now been
sketched, are met with in greater or lesser quantities in different
parts of plants; some of them are accumulated in the roots,
others in the seeds, the bark, the leaves, &c. To complete the
study of the chemical constitution of vegetables we have still to
examine with reference to their composition certain parts or
organs which present sufficient interest either from their exten-
sive employment or their importance in an agricultural point of
view.
ROOTS AND TUBERS.
The Potato (Solanum tuberosum). This plant is a native of
South America. Two English travellers, Messrs. Caldcleugh and
Baldwin were so fortunate as to meet with it lately in the wild
state in Chili, and not far from Monte Video. It is probable
that the cultivation of the potato spread from the mountains of
Chili to the chain of the Andes, proceeding northwards and ob-
taining a footing successively in Peru, at Quito, and upon the
plateau of New Granada. This, as Humboldt observes, is pre-
cisely the course which the Incas took in their conquests. The
potato does not appear to have been introduced into Mexico
until after the European invasion of that country; and it is well
ascertained that it was not known there under the reign of Mon-
tezuma, although there are not wanting some who maintain that
the potato was found in Virginia by the first colonists sent
thither by Sir Walter Raleigh. It is said that it was then brought
into England by Drake; but it seems well established that long
before Drake's time, namely, in 1545, a slave merchant, John
Hawkins by name, had introduced tubers of the potato from the
coasts of New Granada into Ireland. From Ireland the new
plant passed into Belgium in 1590. Its cultivation was at this
time neglected in Great Britain, until it was introduced by
Raleigh at the beginning of the seventeenth century. When
the potato came from Virginia to England for the second time
it was already disseminated over Spain and Italy. It has been
THE POTATO.
195
ascertained that the potato has been cultivated on the great
scale in Lancashire since 1684; in Saxony since 1717; in Scot-
land since 1728; in Prussia since 1738.* It was about the year
1710 that the potato began to spread in Germany, and that it
there became a plant in common use; it had, indeed, before this
time been cultivated in gardens; and had even made its appearance
at the tables of the rich some time previously. The severe dearth
of the years 1771 and 1772+ seemed necessary to lead the Ger-
mans to cultivate this useful plant upon the great scale. From
this time it was shown that it was a substitute for bread; and once
fairly introduced, men were not long of perceiving the many re-
commendations which it possesses as an article of food. In fact,
of all the useful plants which the migrations of communities
and distant voyages have brought to light, says M. Humboldt,
there is none since the discovery of the cereals, that is to say,
from time immemorial, which has had so decided an influence
upon the well-being of mankind. In less than two centuries it
may be said literally to have overspread the earth, or to have
been welcomed in every country suited to its cultivation, so that
at the present day it is found growing from the Cape of Good
Hope to Iceland and Lapland. "It is an interesting spectacle,"
adds the illustrious traveller quoted, "to see a plant, a native of
mountains situated under the equator, advance towards the pole,
and growing even more hardily than the grasses which yield us
grain, brave the inclemencies of the North." The potato, like
all other tubers is a collection, an exuberance which is evolved.
upon the subterraneous stems. Its varieties, which are very nu-
merous, present rather remarkable differences in regard to size,
form, colour of the surface and of the interior, taste, and the
time which they require to come to maturity.
+
Next to water, fecula or starch is the principle which predo-
minates in the potato, but it also contains a certain quantity of
azotised matter. Vauquelin has published a detailed account of
the soluble matters which are met with in the potato, and which,
strange to say, have been neglected in the greater number of
* Humboldt, Essai Politique, t. 1. p. 461.
† Thaer, Principes raisonnés d'Agriculture, t. iv. p. 119.
Humboldt, op. cit. t. 11. p. 463.
0 2
196
THE POTATO.
analyses of this useful vegetable which have been published. In
100 parts of potatoes he found: asparagine 0.1, albumen 0.7,
azotised matter not defined 0.4, citrate of lime 1.2, and unde-
termined quantities of citrate of potash, free acetic acid, phos-
phate of potash, and phosphate of lime.
In examining forty-eight varieties of potato he found that
they contained in 100 parts: first from 1 to 14 of pulp; second,
from 2 to 3 of soluble or extractive substances; third, from 20
to 28 of starch; fourth, from 67 to 78 of water.*
:
In a variety grown in the neighbourhood of Paris, Henry
found the following ingredients, viz. pulp 6.8, starch 13.3, al-
bumen 0.9, uncrystallizable suger 3.3, acids and salts 1.4, fatty
matter 0.1, and water 74.2-100.0
The proportion of starch varies considerably in the different
varieties; M. Payen has ascertained the extent of this diversity
in a certain number of varieties grown in the same soil and
under the same circumstances. The results are contained in the
following table:
Varieties.
The Rohan
The great yellow
TheScotch shaws
The late Iceland
The Segonzac
The Siberian
The Duvillers.
•
One of
seed
potatoes Produce per Acre.
pro-
duced.
tons. cwts. qrs. lbs.
58 14 14 2 16
∞∞ + 30
37
32 8
56
32
8
40
10
40 10
9 8 0 27
14
In 100 parts.
Dry
matter.
Water.
Starch. Starch per acre.
24.8
75.2
16.6
31.3
68.7
23.3
3 2 2
69.8
22.0
6 1 23
30.2
20.6
28.8
79.4 12.3
3 2 2
71.2 | 20.5
4
2 12 22.2
77.8 14.0
4 2 1
2 12 21.7 78.3 13.6
tons.cwts.qrs lbs.
2 90 12
2 33 4
1 16 0 1
1 15 1
1
1
1 2
1
14 0
14 0 5
8 2 16
8 0 12
In the particular circumstances under which this experiment
was made, therefore, it is obvious that the Rohan variety con-
tained the largest quantity of nutritive matter and starch.
Potatoes which have been exposed to a temperature a few
degrees below the freezing point of water, undergo so great a
change in their texture, that it becomes difficult afterwards to
extract the starch which they contain. They besides acquire so
disagreeable a flavour, as all the world knows, that cattle some-
* Thenard's Chemistry, vol. v. p. 82.
THE POTATO.
197
times refuse to eat them. After having ascertained that a
potato has the same chemical composition before and after
congelation, M. Payen examined the starchy substance under the
microscope, and found that the starch obtained from a frozen
tuber presented itself in compound granular masses, four or five
times the size of the largest natural grains of starch. The pulp
which remained upon the sieve in the preparation of this starch,
was formed by a collection of cells, for the most part full of starch.
It would therefore appear, that in consequence of the changes
of volume of the fluid successively congealed and liquefied, the
adhesion between the cells was destroyed: they become separable
with the slightest force, and merely part one from another by the
action of the grater without being torn; the larger number
remain unbroken and still filled with starch. This fact enables
us to understand how potatoes, which have been frozen, will yield
nearly the whole of their starch if they be treated before they are
thawed. The cells then sealed up by the congealed water
resist sufficiently to be broken by the teeth of the grater.
Potatoes which have been frozen, are generally less farinaceous,
at the same time that they have a decidedly sweet taste, which,
according to M. Payen, is owing to vegetation having already
made some progress in the tubers before congelation; and we
know that during germination there is always a formation of
sugar at the expense of the fecula. Frosted potatoes have
always a disagreeable taste, and a most unpleasant smell, so that
in many places they are thrown upon the dunghill. The effect
of the frost, in fact, is to set the juices which are enclosed in the
tissue of the potatoe at liberty, and the higher temperature
which accompanies and follows a thaw, exposes these juices to
be acted upon immediately by the air of the atmosphere, the
consequence of which is, that they behave like all other vegetable
juices left to themselves, they become putrid. The putrid odour,
the acrimony which are developed in the frosted potato, are by
so much the more remarkable as a certain layer which exists
immediately under the skin, and presents various shades of
colour, tawny red or violet is more highly developed. The tissue
of this layer, examined under the microscope, was found by M.
Payen to be totally without starch, but it contains the greater
198
THE POTATO.
part of the (strong smelling) colouring principles.* These
principles which give such unpleasant qualities to frosted potatoes
appear to be soluble or at least destructible by long exposure to
the open air. Thus if frosted potatoes be spread upon the
ground and exposed to the weather, they dry spontaneously,
become hard, whitened, and they may then be preserved for a
very long time. This method of making use of frosted potatoes
has been several times employed in practice, and it might perhaps.
be recommended for general adoption, were it only ascertained
that by such treatment the tubers did not lose a great proportion
of their most nutritive principle, viz.: albumen. However this
may be, it is by a similar process that the natives of the Andes of
Peru preserve and render more transportable the tubers which
form a principal element in their food. In the steepest parts of
the Peruvian Cordillera, nearly at the superior limit of vegetation,
where a miserable field of barley and of Quinoa is only seen here
and there, various tubers are collected in the hollows of the
surface such as the Maca, the Oca, the Ulluco.
To preserve
these they are exposed for several days to the alternate action
of the frost and of the sun. At these great elevations, which
are upwards of 13,120 feet above the level of the sea, it al-
ways freezes in clear nights when the air is moderately calm.
During the day the rays of the sun, which strike with great
force, dry the tubers rapidly, the watery juices of which, have been
shed into the amylaceous tissue by the effect of the preceding
night's frost. Thoroughly dry they may be kept for more than
a year by being stored and protected from moisture. Various
other modes of preparation are practised in regard to the other
kinds of tubers which have been mentioned. By previously
boiling the common potato, pealing it and exposing it alter-
nately to the frost of the night and the heat of the sun, until
it is completely dry, the Indians prepare one of their most
agreeable and wholesome articles of subsistence.
The potato thrives in soils of very various kinds, provided it
be sufficiently fertile, and the climate is favourable. This crop,
like the beet, is generally planted in freshly manured ground,
and is succeeded in the autumn by a winter crop of corn-wheat
Payen, Journal of Practical Agriculture, vol. 1. p. 498.
*
THE POTATO.
199
or rye. The potato is set when apprehensions of frost are no
longer entertained; in the east of France the setting is generally
ended about the middle of May. In Alsace the cuttings of the
potato are dropped at the distance of about a foot from each
other in furrows made by the plough, the furrows being from
18 inches to nearly 2 feet apart. When the plants are from 10
to 12 inches high, and the weather is dry, the furrows are lightly
earthed up.
In dry soils the earthing plough must not be
carried very deeply; and I may say that in the elevated table
lands of America, where the natural drought of the climate is
often to be apprehended, I have seen very fine crops of potatoes
which had never been earthed up at all. The potato, like all
plants that are hoed, requires considerable care; but this care, as
it is immediately profitable, is still more so remotely upon the
white crops which are to follow. M. Crud reckons at 58.3 the
number of days' work that are required upon an acre of land
which has received between 19 and 20 tons of manure. This is
very nearly what we have found to be the truth at Bechelbronn,
where for the same extent of surface, manured in the same way,
we reckon fifty days' labour of a man and rather better than
eleven days of a horse.
In Europe the potato harvest takes place at the end of
autumn. In the intertropical Cordillera, where the cultivation
depends principally upon the heat of a very steady climate, the
potato remains in the ground from four to seven months, as it
is cultivated at a greater or less height above the level of the
sea; it succeeds best where the mean temperature rages between
13° and 18° centigrade (56° and 65° Fahr.) In Venezuela,
indeed, it is still cultivated in places where the temperature is
not far from 24° centigrade (75.5° Fahr.) but I am doubtful
that the culture is then advantageous. In warm and moist
regions the potato yields a large quantity of top, and few tubers.
I have gathered some very bad ones at Riosucio de Engurama,
a village situate at the distance of about 5900 feet above the
level of the sea, where the mean and constant temperature is
about 22° centigrade (72° Fahr.)
The produce per acre, noted by different observers, is as
follows:
200
JERUSALEM ARTICHOKE.
Countries.
Tons. Cwts. Qrs. lbs.
Prussia
5
18
1
5
14
Palatinate, mean of ten years
Austria, mean of thirteen years 9
3 10
Brabant
11
2
17
13
25
West Flanders
Pays de Waes
Pays de Tongres
England
England
Ireland
Alsace
Alsace (Bechelbronn)
Neighbourhood of Paris .
Venezuela
9
10
6
10
9
9
8
5
11
9
7
11
17
13
8
14
2
9
9
14
8
2
213
0
0
3
0
2
0
3
3127
1
16 1
7
25
14
8
12
13
20*
There is an obvious relation between the
potato planted and the amount of the crop.
25 to 30 bushels per acre are usually planted. In some places
too much seed is used, in others not enough. It were very
desirable that certain experiments were undertaken which should
fix the proper quantity of seed-potato to be used for each
variety of soil and situation.
quantity of seed-
In Alsace from
The Jerusalem Artichoke (Helianthus tuberosus). This
plant is generally believed to be a native of South America, but
M. de Humboldt never met with it there, and according to
M. Correa, it does not exist in Brazil. The property which the
tubers of this plant have of resisting the cold of our winters, and
several botanico-geographical considerations, lead M. A. Brong-
niart to presume that the plant belongs to the more northern
parts of Mexico.
The Jerusalem artichoke rises to a height of from 9 to 10
feet; it flowers late, and I have not yet seen it ripen its seeds.
It is propagated by the tubers which it produces, and which are
regarded, for good reason, as most excellent food for cattle;
in times when the potato was not very extensively known, it
also entered pretty largely into the food of man; when
boiled, its taste brings to mind that of the artichoke, whence the
name.
* This is the produce of two harvests, which they gather in the same
year.
JERUSALEM ARTICHOKE.
201
The tuber of the Jerusalem artichoke, from an analysis of
M. Braconnot, appears to contain in 100 parts:
Uncrystallizable sugar
Inuline
Gum
Albumen
Fatty matter
Citrates of potash and lime
Phosphates of potash and lime
Sulphate of potash
Chloride of potassium
•
Malates and tartrates of potash and lime
Woody fibre
Silica
Water
Of dry matter
Water
14.80
3.00
1.22
0.99
0.09
1.15
0.20
0.12
0.08
0.05
1.22
0.03
77.05
100.00
M. Payen found a larger proportion of sugar in this tuber than
that stated above, and he ascertained that the fatty matter
consists chiefly of stearine and elaine. In the Jerusalem arti-
choke I myself found:
20.8
79.2
100.0
One trial for azote would lead me to conclude that M. Bra-
connot had estimated the albumen too low in his analysis, or as
is more probable, that several azotised principles had escaped
him. The dried tuber gave me 0.16 of azote, a number which
would indicate 1.0 as the proportion of vegetable albumen.
There are few plants more hardy and so little nice about soil as
the Jerusalem artichoke; it succeeds everywhere with the single
condition that the ground be not wet. The tubers are planted
exactly like those of the potato, and nearly at the same time;
but this is a process that is performed but rarely, inasmuch as
the cultivation of the helianthus is incessant, being carried on
for many years in the same piece; and after the harvest, in spite
of every disposition to take up all the tubers, enough constantly
escape detection to stock the land for the following year, so
that the surface appears literally covered with the young plants
202
JERUSALEM ARTICHOKE.
on the return of spring, and it is necessary to thin them by
hoeing. The impossibility of taking away the whole of the
tubers, and their power of resisting the hardest frosts of winter,
is an obstacle almost insurmountable to the introduction of this
plant, as one element in a regular rotation. Experience more and
more confirms the propriety of setting aside a patch of land for
the growth of this productive and very valuable vegetable root.
Of all the plants that engage the husbandman, the Jerusa-
lem artichoke is that which produces the most at the least ex-
pense of manure and of manual labour. Kade states that a
square patch of Jerusalem artichokes in a garden was still in
full productive vigour at the end of thirty-three years, throwing
out stems from 7 to 10 feet in length, although for a very long
time the plant had neither received any care nor any manure.*
I could quote many examples of the great reproductive power
of the helianthus; I can affirm, nevertheless, that in order to
obtain abundant crops, it is necessary to afford a little manure.
I shall show in another chapter, however, that this is manure
well bestowed.
Like all vegetables having numerous and large leaves, the
helianthus requires air and light; it ought, therefore, to be
properly spaced. The original planting of course takes place in
lines, but in the succeeding crops and those which are derived
from small tubers accidentally left in the ground, the order is
of course lost; it is only necessary to destroy a sufficient num-
ber of the young sprouts which show themselves in the spring,
to leave those plants that are preserved with a sufficient space
between them. When the plants are somewhat advanced, the
ground should receive one or two diggings with the spade, and
a hoeing or two to destroy weeds.
The leaves of the helianthus are used in many places as
forage, the stems being cut a few inches from the ground;
the gathering takes place at different periods of the year, but
probably to the detriment of the tubers; it may be lucrative to
destine the leaves for the nutriment of cattle, but I believe we
have to choose between the green crop and the crop of tubers.
It is unquestionable that the premature removal of the green
* Schwertz, Culture of Forage Plants.
THE CARROT.
203
stems must prove injurious to the roots; in my own farm the
leaves are never removed, and my opinion is that it is vastly
more advantageous to depend upon the crop of tubers alone.
The tubers are gathered as they are wanted, for not dreading
the frost, they may remain in the ground the whole of the win-
ter; they do not require, like the potato, to be collected and
pitted at a certain period; they require no particular situation,
no particular care for their preservation; the only disadvantage
that accompanies their being left in the ground, is that during
very hard frosts the labour required to get at them is very
great. During winter the woody stems of the plant die and dry
up, they are then useful as combustible matter; but a better use
of them perhaps is to make them enter in certain proportions
into the litter of the hog-stye; the pith there absorbs a large
quantity of the liquid manure. Schwertz estimates the mean
quantity of dry leaves and stems at 3 tons, 1 cwt. 1 qr. and
13 lbs. per acre. The following quantities of tubers have actually
been gathered in Alsace.
Sandy soils.
Soils of the best quality
At Bechelbronn (mean)
Bechelbronn crops of 1839-40
Tons. Cwts. Qrs. Ibs.
4
3
3
6
10
13
10
14
8
16
8
3
0
2 27
8
The Carrot (Daucus carota).-This root is frequently cul-
tivated, particularly by intercalation; it is frequently grown
along with the poppy, where the seed is raised for the sake of
its oil, occasionally also being sown with white crops in the
spring, it comes to maturity after them in the autumn; it is a
plant that is much liked by animals, but which by no means
possesses the very high value as an article of food which is
generally ascribed to it by husbandmen. The carrot requires a
deep, somewhat loose and homogeneous soil, fresh manure, and
much care in the cultivation. Schwertz taking the mean of
three years, estimates the produce per acre, at 13 tons, 18 cwt.
1 qr. and 2 lbs. of roots, and about one-third the same quantity
of green leaves which are valuable as fodder and as elements of
manure. In a field at Bechelbronn where this vegetable had
been intercalated with the madia sativa, we obtained upwards of
0 3
204
CINCHONA BARKS.
5 tons of roots in addition to our principal crop of oleaginous
seed. The carrot contains a large quantity of water in its con-
stitution-87.6 per cent., according to some of my experiments.
The juice of the carrot contains sugar, albumen, a crystal-
lizable colouring principle, called carrotine, a volatile oil, fatty
matters, pectic acid, pectine, starch, malic acid and alkaline, and
earthy phosphates.
The Parsnip (Pastinaca sativa). This plant is not very
extensively cultivated, yet it has the advantage of standing the
winter in the open field. It has been recommended as very
useful in fattening cattle. In its composition it must assimi-
late with the carrot and beet. Drappier obtained as much as 12
per cent. of cane-sugar from the parsnip.*
BARKS.
Cinchona barks. The barks of cinchona, which are employed
with so much success in medicine, are the produce of different
species of a family of trees which grows in the mountains of
South America; the active principle of all the varieties of bark
resides in the vegetable alkalies, quinine, cinchonine, and cin-
chovatine.
The medicinal properties of bark were made known to Euro-
peans in 1638, on the occasion of an obstinate fever from which
the Countess of Chincon, vice-Queen of Peru, suffered at Lima
in that year. A Corregidore of Loxa, who had been cured by
the Indians whilst affected in the same way, recommended the
bark. The medicine was completely successful; and to show
her gratitude, the vice-Queen had large quantities brought down
from the mountains for distribution amongst persons affected
with fever. It was from this circumstance that the bark was
at first known under the name of the Countess's powder. By
and by, the members of the College of Jesuits having been
charged with its distribution, it of course became the Jesuits'
bark or powder. Lastly, the Cardinal de Lugo having brought
it to Rome, the new medicine was known under the name of
the Cardinal's powder.
The cinchonas are met with principally in forests at a consi-
* Berzelius, Chemistry, vol. 11. p. 199.
WILLOW BARK.
205
derable elevation above the level of the sea, in a temperate cli-
mate, and growing in a stony soil. The proper period for
gathering is known by the circumstance of the inner surface of
the bark when detached from a branch acquiring in a few
minutes a red, yellow, or orange tint, according to the species.
The trees are cut down one or two days before the process of
barking begins, by which the operation is rendered more easy,
and the cuticle is no longer liable to be rubbed off. The bark
of the trunk and branches is removed by means of a large knife,
in strips or bands, which are kept as broad as possible. The
bark is placed upon cloths and put to dry in the sun, each piece
being kept isolated, in order to facilitate the drying, and espe-
cially to favour the quilling or rolling up; when the bark is
dried in a heap, and when the pieces touch, it often acquires a
most disagreeable odour in consequence of incipient putrefac-
tion, and the quilling does not take place.* The bark when
thoroughly dry is packed in bullocks' hides and sent to Europe.
From my own observations and those that have been supplied
me by M. Goulot, the different species of bark appear to be
distributed upon the mountains of New Granada in the follow-
ing order:
Grey bark, C. lancifolia
White bark, C. ovalifolia
Red bark, C. oblongifolia
Yellow bark, C. cordifolia
Heights where
most abundant.
6545 feet
4264
2296
1968
در
""
"
Temperature.
19º (66½½ F.)
21° (70 F.)
24º (75/ F.)
25° (77 F.)
Pelletier and Caventou discovered in the grey bark: 1st. cin-
chonine in combination with quinic acid; 2nd. a fatty substance ;
3rd. red and yellow colouring matters; 4th. tannin; 5th. quinate
of lime; 6th. gum; 7th. starch; 8th woody matter. In the yellow
and red bark these learned chemists found the same principles,
and moreover quinate of quinine.
Barks of the Willow and Poplar. Decoctions of these
barks are often employed with success in the treatment of inter-
mittent fever. In searching after the active principle of these
medicines, M. Roux discovered the particular substance, sali-
cine, in the bark of the willow (salix helix), the medicinal effect
* Ruiz, Quinologia.
0 4
206
CORK.
of which is analogous with that of the febrifuge principles of the
true barks. M. Braconnot has further succeeded in obtaining
another crystalline matter from the leaves of the aspen (populus
tremula) populine.
Cork. The oak which yields cork is known in Spain under
the name of the alcornoque. It forms extensive forests upon
the abrupt slopes of the Pyrenees, where it is often seen grow-
ing upon arid and stony soils, that seemed doomed to eternal
sterility. The cork oak has flexible and strong roots, which
creep over the naked surface of the granitic masses, turning
round blocks, and searching everywhere for fissures and collec-
tions of sand and alluvium, into which they penetrate deeply in
search of the nourishment necessary to the tree. At maturity
the alcornoque rises to a height of sixty-five feet, and its trunk
may be three feet and a quarter in diameter.
In the Spanish Pyrenees, the superior limit of the cork-tree
region, is that of the vine, about 1640 feet above the level of
the Mediterranean. In France this tree grows luxuriantly in
the communes of Passa, Lauro, &c., the mean elevation of which
is 1148 feet. In Spain as in France, the soils on which the
cork forests grow are of primitive origin; and it is said on good
authority that the cork-tree only grows on soils derived from
granite, gneiss, mica, slate, or porphyry, and never on soils of
calcareous origin.
The cork tree is reproduced spontaneously on these siliceous
soils, among cistuses and heaths; but the reproduction in this
way is so slow, that art often interferes advantageously to aid it.
There are many varieties of cork oak; and as that which is
covered with a smooth and greyish cuticle, yields the article
which is most prized in commerce, the seeds of this variety ought
to be selected for sowing. The acorns of the cork oak are tumid,
of considerable size, and a sweet taste; the acorns ripen from
October to December, and are much employed as food for hogs.
The Catalonians sow the acorns in a cultivated soil at the same
time that they plant the vine, and for twenty or twenty-five
years the produce of the vine compensates the outlay upon the
young cork trees; but the produce of the vine diminishes as the
cork tree overshadows it, and finally there comes a time when
LEAVES.
207
the vines die out completely. The cork-tree is of slow growth, and
at four years of age it may be from thirty-six to forty inches in
height, and requires incessant care until the trunk is from seven
to ten feet high, at which time it may be about twenty years of
age; and its total height, including its branches, may be about
twenty-two feet.
The barking of the cork tree begins about the middle of
July, and may be continued so long as the sap is in motion.
When stripped off, good cork is formed of from ten to twelve
layers, each of which indicates an annual deposition. The two outer
layers constitute the cuticle; the others adhere closely together,
and although of variable thickness they present a homogeneous
mass. The time for removing the cork is indicated by the
interior acquiring a slightly rosy tint, which happens about the
tenth year. The barking is performed by means of an axe,
with which a cut is made the whole length of the trunk, care
being taken not to wound the woody layers; two other cross
cuts are then made at the top and bottom of the trunk. By
means of the handle of the axe, which is shaped like a wedge,
forced into the vertical cut, the cork is then loosened and strip-
ped from the living bark beneath it, the whole covering of the
tree being often taken away in a single piece, although it is
more commonly removed in two pieces. The process of barking
is very easy when the sap is abundant.
The cork tree must be about forty years of age before its
bark has any commercial value; that of a tree of twenty years
is always treated as rubbish. An oak a century old may furnish
200lbs of marketable cork; as many as 480lbs however have
been taken from a single tree; the mean produce may be
reckoned at about 100lbs. per tree; to fit it for the market, cork
undergoes a variety of preparations which need not detain us here.
LEAVES.
The herbaceous parts of vegetables have all a very similar
composition, if they be regarded in the most general point of
view. The leaves and green stems, along with the woody fibre
which forms in some sort their skeleton, always contain albumen
or an analogous azotised principle, saccharine and gummy sub-
208
TOBACCO.
stances, chlorophylle, wax, fatty and resinous substances, free or
combined acids, and frequently also essential oils. Such is the
general constitution which chemists agree in assigning to
clover, hay, leaves, in a word to green forage of all kinds;
nevertheless, to this constitution, which may be regarded as stan-
dard, we have frequently other particular matters added, some of
which we have already studied, and which by their medicinal
properties, or the economic uses they possess, render the
plants that contain them of high importance in an agricultural
point of view. I shall here only speak of two of these plants,
tobacco and tea, the leaves of which, almost in universal use, are
a source of great commercial prosperity to the people who culti-
vate them.
Tobacco (Nicotiana tabacum), a native of America, appears
to have been introduced into Spain and Portugal about the
middle of the sixteenth century by Fernandez de Toledo. Its
name is generally believed to be derived from that of the Island
of Tobago, one of the West India islands, at no very great dis-
tance from the coast of Venezuela, whence the first importations
were made. Nicot, the French Ambassador to Portugal, first
made its use known in France, whence the name nicotiana. At
the present time, the cultivation of tobacco appears to have
spread almost over the whole surface of the globe.
Tobacco requires a somewhat friable soil, rich in humus; it
consequently succeeds in lands just broken in. In America the
mode of cultivation and of preparation are almost every where
the same.
In Venezuela the seed is sown in a very rich loam, and after
from forty to fifty days, the young plants are transplanted in
rows, distant a little more than three feet from one another, the
plants being about two feet apart; the transplanted plant is gene-
rally covered with a banana leaf for a few days to preserve it from
the burning rays of the sun. When the plant is about eighteen
inches high, a bud is formed at the superior extremity; this bud
and any others that may appear, are removed as well as any sprouts
which show themselves on the stem. By this treatment the to-
bacco becomes bushy and thick; by and by the leaves acquire a de-
cidedly blue tint, and the time of gathering is indicated by the
TOBACCO.
209
appearance of a stain of a deep blue colour near the pedicle. The
leaves do not all ripen simultaneously, so that the business of the
planter, in gathering those that appear ripe, is incessant for a
certain time.
After they are gathered, the leaves are carried under sheds
where they are disposed two and two upon hurdles arranged for
their reception. The tobacco soon becomes yellow and pliant;
and the ribs of the leaves, having been removed, they are twisted
into a rope which is coiled up into a mass of the weight
of from sixty to eighty pounds. These coils are placed
upon a bed made with damaged leaves and the ribs which
have been removed. The whole is covered, and left to
ferment during forty-eight hours, a little water being supplied if
the tobacco appears too dry; during the fermentation the tem-
perature rises, and the process having been carried sufficiently far,
the coils are exposed separately to the air; they are then un-
rolled, and hung up under sheds to dry completely.
The vertical zone in which the cultivation of tobacco within the
tropics is carried on, is extensive; it reaches from the level of the
sea to an elevation of about 5900 feet above it. The time dur-
ing which the crop remains on the ground varies according to
the mean temperature of the place; according to M. Codazzi,
the leaves are gathered one hundred and fifty days after the
sowing in the hottest regions of the coast of Venezuela. In more
elevated situations, where the thermometer ranges from 65° to
68° Fahr., the first leaves are not fit to be gathered until after
about seven months and a half from the sowing.
In Ceylon, tobacco is cultivated almost precisely as in
America. There they also prevent the plant rising in height, and
limit the number of leaves upon each stem according to the
quality of tobacco which they desire to grow. By leaving
the plant with no more than from ten to twelve leaves, the most
esteemed quality is obtained; if eighteen or twenty leaves be
left, the tobacco is far from having the same strength. Lastly,
by leaving the plant to itself, by suffering the stem to run up
and to flourish, a large crop is obtained, but the produce is not
esteemed. The leaves gathered from the plant in this state of
maturity are often held fit for consumption after being simply
P
210
TOBACCO.
dried without further preparation. The tobacco is then
yellow, extremely mild, and perfectly suited to the immoderate
use made of it by the Cingalese.
If the mode of cultivation enables the tobacco grower to ob-
tain a superior quality at the cost of quantity, it is still indubit-
able that climate exercises the chief influence on the quality of
the article. That which is grown in the temperate regions of
the Andes, in Virginia, and in Europe, can in no way be com-
pared with the tobacco of the Havannah, of Varinas, of Giron,
of the valley of Cauca. The cultivation of tobacco has appeared
to me more especially advantageous in localities where the mean
temperature does not fall below 75° Fahr.
Tobacco is decidedly a plant of a hot climate; there only does
it yield a produce of the best quality. In Venezuela, where its
cultivation is followed with great skill, and in situations where
the temperature of the climate keeps from 70° to 80° Fahr.,
about five plants are held necessary to produce 1lb. of tobacco;
and as a mean, 11cwt. 1qr. 23lbs. of the prepared article are
produced from an acre of unmanured land.
In Alsace, tobacco is sown about the middle of March; the
transplanting takes place in the beginning of June, and the har-
vest follows in autumn. The husbandry is very similar to that
which has been already described, each plant being left with
eight or ten leaves. Schwertz reckons the produce at about
15 quintals per hectare of two and a half acres, which is equal
to about 12cwt. 1qr. per English acre. Thaer estimates the
produce in Prussia at 11cwt. 3qrs. 13lbs. per acre.
100
The consumption of tobacco has lately increased considerably
throughout the whole of Europe. In France, government sold to-
bacco in one form or another to the extent of 31,116,340lbs. in
the course of the year 1837. Public documents show that in 1841
there were in France 8,158 hectares, or 19,579 acres under to-
bacco, which yielded 21,261,064lbs. of the article; the differ-
ence between the quantity produced and the quantity consumed
is of course supplied by importation.
The virtues of tobacco very probably reside in the volatile
vegetable alkali, nicotine, which it contains. The analyses of
M. Posselt and Kiemann show the leaf tobacco to be composed
as follows: Nicotine 0.07, extractive matter 2.87, gum 1.74,
TEA.
211
a green resin 0.27, albumen 0.26, gluten 1.05 malic acid
0.51, malate of ammonia 0.12, sulphate of potash 0.05,
chloride of potassium 0.06, nitrate and malate of potash 0.21,
phosphate of lime 0.17, malate of lime 0.72, silica 0.09,
woody matter 4.97, and water 86.84,-100.00. During the
fermentation of the leaves, there is always a formation of am-
moniacal salts.
Tea, the use of which is and has so long been universal
in the Chinese empire, began to be known in Europe in the seven-
teenth century, when it was imported by the Dutch East India
company. In 1669, the importation of tea into England did
not exceed 1 cwt.; in 1833, the East India Company set aside
for the consumption of Great Britain alone nearly 24,200,000
of pounds!
The tea plant commonly attains a height of from three to
about five feet. In China it blossoms in the early part of the
spring, and ripens its seeds in December and January. Its
branches are covered with short thick leaves of a deep green
colour and elliptical form. It is one of the most hardy plants,
and thrives from the equator to the forty-fifth parallel of north
latitude; but the districts best adapted to its growth appear to
be comprised between the twenty-fifth and thirty-third degrees
of latitude.* Tea requires a moist climate, and a light and
sandy soil. No manure is given, and no attention is paid to the
nature of the soil where irrigation is practicable.
The shrub is propagated from seed. Several seeds are
dropped into holes at the distance of from three to six feet apart,
and the plant begins to produce from the third year, the gather-
ing is done by the hand, the leaves being picked off; but a few arc
always left upon each branch. The number of gatherings made
in the same year varies from one to three, according to the age
of the plant. It is very seldom indeed that a fourth gathering
is practised. In China the tea harvest begins about the middle
of April, a period at which the leaf buds appear surrounded by
a slight cottony down. The first gathering is very small, but it
constitutes the highest-priced tea, the Shou-chun or tea of the
first growth. The second gathering takes place in June, when
* Robinson, a Descriptive Account of Assam, p. 131.
P 2
212
TEA.
the branches are covered with leaves of a pretty deep colour;
these leaves are very abundant, but inferior in quality to the
buds of the former gathering; they constitute the tea called
Urh-chun, or tea of the second growth. The third gathering is
performed a month later, and the produce passes by the name
of the San-chun, or tea of the third growth. The leaves are now
of a deep green colour, tough, and are manufactured into the
most common kinds of tea.
Considerable plantations of tea are now established in Assam,
in British India, and in the Brazils, and it seems not improbable
that the plant may be cultivated at some future day in Europe.
According to Guillemin, who studied the cultivation and pre-
paration of tea in the Brazils, the leaves are dried as soon as
they are gathered. From four to six pounds are thrown into an
iron pot, the interior of which is polished, and which may be some-
what more than three feet in diameter, by about a foot in depth.
The temperature of the pot is maintained at about the boiling
point of water; a negro stirs the leaves in all directions with
his hand, until they become quite soft and pliant, so that they
can be moulded into pellets by movement between the hands.
When the leaves are in this state, they are thrown upon a tray
made of bamboo, and strongly kneaded for a quarter of an hour,
so as to force out a green sap of a disagreeable taste. The
kneaded leaves are then returned to the pot, and dried com-
pletely, being all the while stirred about with the hand, being
separated when they stick together, and being continually tossed
up in order to prevent them adhering or getting scorched by
remaining too long in contact with the metal. During this pro-
cess, which lasts for some half hour, a large quantity of dust is
disengaged, which proceeds from the cottony down with which
the leaves are covered. By this rapid drying, the leaves crisp
and curl up of themselves, and acquire the appearance of the
tea that is in every-day use. On being taken from the drying pot,
the tea is thrown upon a sieve of a certain mesh, and the leaves
which have rolled themselves up into the smallest compass, and
which are those which proceed from the buds, are separated from
the others; these after having been winnowed, receive a new touch
of the fire, when they acquire a leaden grey colour, and consti-
C
TEA.
213
tute the tea of the best quality, which in the Brazils passes by
the name of Imperial or Uchim tea. The leaves which remain
upon the sieve are heated, winnowed, and sifted again, and the
produce is fine Hyson tea; and by the same means other varie-
ties are procured, until at length a kind remains upon the sieve
consisting of the leaves that have not become rolled up, which
being added to the broken particles derived from the winnowing
operations, is called family tea, because it is consumed upon the
spot.
During, and for some time after the drying, tea exhales an
herbaceous and not very pleasant odour, which however becomes
modified in the course of time. The aroma of the Chinese
teas is said to be communicated to them by a highly odorous
plant, which is believed to be the Olea flagrans. It is also said
that the green tea is coloured by means of indigo; but it is pos-
sible that the shades of colour of the different kinds of tea
depend solely upon the degree of roasting which they have un-
dergone. Guillemin has said nothing of the produce of the tea
shrub in Brazil. In China, according to a manuscript of M.
Carpena, a shrub with care will produce annually during thirty
or forty years from 2lbs. to 24lbs. of marketable tea.
From the analysis of M. Mulder, tea appears to contain:
1st. A volatile oil. 2nd. Chlorophylle. 3rd. Wax and resin.
4th. Gum. 5th. An extractive matter. 6th. A colouring
matter. 7th. Azotised substances analogous to albumen. 8th.
Woody fibre and inorganic salts. 9th. A particular crystalline
principle,-theine or coffeine, which is ranked among the
vegetable alkalies, and which is also met with, as implied by the
name in coffee this new principle crystallizes in colourless
needles of a silky aspect and bitter taste. It is little soluble in
alcohol and in ether; water dissolves about th of its weight, and
it sublimes without undergoing decomposition; it is by sublima-
tion, in fact, that Mr. Stenhouse proposes to obtain it from
tea
This is undoubtedly the principle which communicates to tea
its bitter taste, and several of its properties; experiment has
shown, that when administered even in considerable doses it
produces no ill effect on the animal economy; different kinds of
214
WHEAT.
tea, as might have been presumed, contain it in different pro-
portions. M. Stenhouse obtained from 100 parts of
Hyson .
Congou
Assam.
Twankay, green
•
•
1.09 of Coffeine
1.02
1.37
0.98
">
""
**
SEEDS.
Wheat. This valuable grain is the produce of several kinds
of triticum-winter wheat, and spring wheat, T. hybernum, and
T. æstivum, spelter, T. Spelta, and T. monocon.
Wheat is sown either upon a fallow or upon land that has
carried some forage crop, or such a crop as beans and peas. It re-
quires a stiff rich soil, containing a certain proportion of calcareous
earth, and abounding in organic matter; it does not thrive well
in soils where the sandy element predominates over the clayey. For
seed the best grain is selected; but this and all other precautions
do not suffice to preserve the plant from many diseases, such as
smut, rust, mildew. Farmers are wont, before putting their seed
wheat into the ground, to prepare it in various ways with a view
to destroying the germs of certain parasites which are believed
to adhere to it externally. The process is generally called pick-
ling, or limeing, because milk of lime, in which the seeds are
put to steep for twelve or fifteen hours, is often employed in its
course. Means that are said to be more efficacious have also
been recommended: some make use of alum, others of sulphate
of iron, sulphate of zinc, sulphate of copper, sulphate of soda,
and even white oxide of arsenic. All these means appear to
conduce to the same result. We employ sulphate of copper,
which indeed is the custom in a considerable part of Alsace, and
I can assure the reader that our fields of wheat are never in-
fected. 100 grammes, or about 3 ounces troy are allowed to a
hectolitre or sack of nearly 3 bushels of wheat; the salt is dissolved
in as much water as is held requisite for the submersion of the
grain, which is steeped in the solution during about three
quarters of an hour, after which it is thrown into baskets to
drain, and being then spread out on the flour it is dried before
being sown.
The season at which wheat is sown in autumn ought to vary
WHEAT.
215
with the climate, and nothing can be more displaced than those
precise dates which are set down by the majority of writers.
The great point to be held in view is, that the young plant may
have got a certain length before the frost sets in, that the roots
may have penetrated to a depth which shall protect them from
the severe cold of the winter. In each district, experience has
already proclaimed the proper time for sowing, and this can
rarely or never be departed from without detriment. In the east
of France, in Alsace, the sowing of winter wheat generally takes
place in the first week in October; in the southern hemisphere,
in certain parts of Chili, for example, the wheat is sown in
April, and is exposed to the cold weather of June, July, and
August. The quantity of seed sown may vary from about
7 pecks to 18 pecks and more per acre. Farmers generally agree,
however, that we have seed enough when we employ about 2 bush-
els to the acre; this is the quantity which is used at Bechelbronn;
but in the same district, and even on contiguous fields, we fre-
quently see proportions of seed employed which vary in the ratio
of from one half to twice the quantity specified, without, so far
as I know, any sufficient reason being given for this parsi-
mony or prodigality. It is, however, a question of the very
highest importance to ascertain the proper quantity of seed.
The question may be considered in two ways: 1st. with reference
to the produce of a given extent of surface, and 2nd. with reference
to the produce from the grain sown. It is quite certain that
in sowing thick, a larger produce per acre will be obtained than
by sowing very thin; but on the other hand, thin sowing yields.
a larger number of times the quantity of seed put into the
ground. The reasons which should guide us in determining
the dose of seed are numerous and extremely complex; they
must evidently be taken in connexion with the value of the
ground and of cultivation, the price of wheat and of straw, the
cost of labour and of manure. Thus in countries where the
rent of land is extremely low it may be a good practice to scat-
ter but a moderate quantity of seed over a large extent of sur-
face. I remember a field in the neighbourhood of Pampeluna,
where the wheat was growing in isolated tufts, all extremely
vigorous and very heavy in the car; the ground had had but
216
WHEAT.
sixty to eighty times the seed.
fitable crop; nevertheless I am
yielded more than from 6 to 7
very little preparation; nevertheless they expected to gather from
This, without doubt, was a pro-
satisfied that it could not have
bushels per acre.
For the same reasons the first settlers of the United States
must have followed a somewhat similar mode of cultivation.
"An English farmer," says Washington in a letter addressed to
Arthur Young, "must have a very indifferent opinion of our
soil when he hears that with us an acre produces no more than
from 8 to 10 bushels of wheat; but he must not forget that in
all countries where land is cheap and labour is dear, the people
prefer cultivating much to cultivating well.”
In Alsace we do not reckon any crop profitable which yields
less than from 19 to about 23 bushels per acre; and in these
circumstances we do not receive back more than from 9 to 10
times the seed.
Nevertheless, it must be allowed, even in these extreme cases
in which the value of ground is so different, inasmuch as it may
vary in the ratio of from 1 to 1000, that there are certain limits
with reference to the seed which must not be passed; and there
is without doubt an opportunity of making a series of curious
and useful experiments with the view of ascertaining the truc
ratios which exist between the produce and the seed. I am well
aware that the results of experiments of this kind have already
been made public; but I know also that these data have not been
deduced from a sufficient number of facts perfectly comparable
with one another, and noted under a variety of climatic influences;
in a word, that they are not such as they ought to be, to put an
end to the uncertainty which still exists in the minds of the
best informed farmers and rural economists upon the sub-
ject.
In Europe the wheat that is sown in autumn generally stands
upon the ground for from nine to ten months. The time, how-
ever, varies considerably with the climate; in the Andes it is in
proportion to the proper temperature of each place.
Wheat, which is now an important article of agricultural pro-
duce in America, was introduced from Europe very shortly after
the Conquest. The first particles of wheat sown in Mexico be-
WHEAT.
fore 1530 are said to have been found by a negro belonging to
Fernando Cortez among the rice destined for provision to the
army.*
Wheat was brought into Quito by a Fleming, Father
Jose Rixi, a monk of the order of St. Francis. I was shown in
the Convent of St. Francis the vessel in which the first seed is
said to have come from Europe.
In Mexico, where the ground can be irrigated, and this, all
things else being the same, always yields the best crops, wheat
is watered at two different periods: when it has sprung and when
it is shooting into ear. According to M. de Humboldt, who
has collected so much that is interesting upon the agriculture of
New Spain, the richness of the harvest is truly surprising: irri-
gated soils often yield from 40 to 60 times the seed; 16 for 1
is reckoned an indifferent crop, and taking the whole of Mexico,
the mean produce may be estimated at from 22 to 25 for 1.
The cultivation of wheat is especially lucrative in districts
which enjoy a mean temperature of from 18° to 19° C. (65° to
67° F.); yet it may be pursued amidst plantations of coffee-trees
and sugar canes, although I doubt whether it can be there ex-
tremely productive. The extreme limits of the growth of wheat
in the Cordilleras, according to my own observations, correspond
with the mean temperatures of from 12° to 23.5° C. (54° to
75° F.) M. Codazzi estimates at 37 for 1 to the mean produce of
wheat in Venezuela.
217
The hectolitre of wheat in France (22.009 gallons, something
less than a sack of 3 bushels English) is held to weigh on an
average of 169.4lbs., or 61.6, say 611lbs. per bushel; but this
weight varies according to the quality of the grain between
56 and 64lbs. the bushel.
The following is a table of the mean produce of the wheat
crop in different countries from documents that may be relied
on:
* Humboldt's Essay on New Spain, vol. 11.
P 3
218
Localities.
Germany: Moeglin
Lavanthal
Saalfelden
Lombardy: irrigated lands
WHEAT.

non irrigated lands
ditto
Average of Venetian Lombardy
England: the best soils
average
Brabant and Flanders
France: Alsace (after tobacco)
Bechelbronn
Environs of Paris
Oise
America: (East of the Alleghanies).
rich lands
middling ditto
Mississipi; rich lands.
middling ditto
Venezuela (Valley of Aragua)
temperate regions
Produce per
acre (seed de-
ducted.)
Bushels.
26.9
22.3
18.4
24.6
15.9
10.2
15.9
34.4
23.7
28.8
29.7
22.3
25.2
21.5
35.2
9.9
44.3
27.5
44.0
14.0
Authorities.
Thaer.
Burger.
Lurzer.
Burger.
Dandolo.
Verra.
Burger.
Arthur Young.
Arthur Young.
Schwertz.
Schwertz.
Lebel & Boussing.
Dailly.
Official statistics.
Blodget.
Humboldt.
Codazzi.
The Cereals besides their principal produce, their farinaceous
seeds, yield another, which is of great importance in rural
economy; this is straw, which no European agricultural estab-
lishment could do without. After having been used as food
and as litter for cattle, it is returned to the ground as manure, and
contributes powerfully in preventing the exhaustion of the soil,
which the cultivation of wheat always produces. The quantity
of straw which can be reckoned on in a farm, is of course, in
proportion to the soil under white crops. The relative weight
of grain and straw, however, varies considerably according to
circumstances; in a wet year, for instance, the wheat crop con-
tains a relatively large proportion of straw, and a small proportion
of grain; in dry years the contrary relation obtains. Lands recently
and abundantly manured, yield a larger quantity of straw than
clover breaks. Thick sowing always yields a large quantity in
WHEAT.
219
contrast with the grain; lastly, climate exerts the most marked
influence upon the two kinds of produce which we are con-
sidering. The differences which are observed between one year
and another in the same districts in consequence of very diffe-
rent meteorological conditions are not less remarkable. I shall
quote a single instance. The years 1840, 1841, and 1842
gave us crops of grain at Bechelbronn which were far from
excellent; in the first the rains were too abundant, and in the
second the drought was too long continued. In these opposite
circumstances, the weight of the straw to that of the grain
was:
In 1840-41 :: 100: 24
In 1841-42 :: 100 : 90
the latter harvest, in fact, occasioned a complete dearth of litter
in our establishment. In ordinary years we procure about
38 of grain for a 100 of straw, a relation which agrees with
those that have been reported by different observers, who vary
in their calculations from 33 and 35 to 41, 44 and 50 of
grain to 100 parts of straw.
In the cereals the amylaceous matter which constitutes the
principal part of the seed is surrounded by a flexible perisperm
of the nature of woody tissue. The object of grinding is to
break this case and to reduce the interior of the grain to powder.
In France the grinding of wheat is performed by a succession
of operations. In England it is completed at once. The French
mode, however, appears to yield the largest quantity of fine
flour.
Fine flour
Second flour
Bran
Loss
English.
58
3}}
14
26
2
72
French.
66
8} 74
S
23
3
The proportion of flour furnished by the cereals, does not,
however, depend alone upon the mode of grinding, but also upon
the nature of the grain. Wheat, for instance, of different kinds,
yields 78, 83 and 85 per cent. of flour.
220
WHEAT.
:
Spelter. This grain is so firmly enclosed in the husk, that
it cannot be freed by threshing; so that, in the countries where
this grain is grown the mills are provided with an apparatus for
husking it. Schwertz made many experiments in Wurtemberg
to determine the quantity of flour yielded by spelter, and he
found that from 100 of grain he obtained 90 of husked grain,
and 8.7 of bran; there was a loss of 1.3. The quality of the flour
always varies according to the wheat from which it is procured
it contains moisture in variable proportions, gluten in variable
proportions, and finally various quantities of woody matter. The
wheat of the south is harder and tougher than that of the north, and
appears richer in azotised principles; as it contains less moisture
it also keeps better; it is undoubtedly in consequence of the
large quantity of water which our northern wheats contain that
we meet with such indifferent success when we attempt
to keep them for any length of time in our granaries. The
wheat of Alsace, for example, frequently contains from 16 to
20 per cent. of moisture; and I have ascertained, by various ex-
periments, that it is almost impossible to keep it without change,
in vessels hermetically sealed. To secure its keeping, the pro-
portion of water must be reduced to from 8 to 10 per cent. and
this is nearly the quantity of moisture contained in the hard and
horny wheat of warm countries. I am therefore of opinion that
we shall never succeed in these countries in keeping wheat for
any length of time, in the magazines of fortified towns, for
example, whatever care be taken.
The flour of the cereals, particularly that of wheat, absorbs a
large quantity of water, and forms a paste, which is by so much
the firmer and more elastic, as the flour contains a larger pro-
portion of gluten: the azotised principle of wheat has, in fact,
the remarkable property of being extensible like a membrane
when it is moist, and this property it communicates to the whole
of the paste or dough. In order to be brought into the state of
dough fit for making bread, flour will absorb from 55 to 70 per
cent. of water. The quantity of bread obtained necessarily
depends upon the heat and length of exposure in the oven; but
in a general way, from 100 of flour, 130 of the best white
WHEAT.
221
bread of Paris is procured.
In the country the bread is gene-
rally less baked than in Paris or London, and therefore retains
more water; so that from 100 of flour, 140, 145, and 146 of
bread are made; thus, admitting 16 per cent. of moisture as
existing in wheat originally, we have of absolute dry matter 641,
57, and 56 in different kinds of bread.
Bread is by so much the more nutritious as it is made from
flour containing a larger proportion of gluten; to add any starch
therefore is to prejudice the interests of the consumer; neverthe-
less it is the practice to do so almost openly; when potato
starch is at a low price, the adulteration frequently begins with
the miller and is extended under the baker. The quantity of
gluten contained in different kinds of wheat varies greatly.
Vauquelin found in the
Flour of French wheat .
Flour from hard Odessa wheat
Flour from soft Odessa wheat
Flour from the baker's .
Gum
Gluten. Starch. Sugar. or dextrine.
. 11.0 71.5 4.7
3.3
14.6 56.5 8.5
4.9
12.0 62.0 7.6
5.8
. 10.2 72.8 4.2
2.8
.
•
Water. Bran.
10.9
12.0 2.3
10.0 1.2
10.0
The method of analysis employed by Vauquelin, whose re-
sults are given above, by means of washing, is however far from
being very accurate; it is impossible to prevent the loss of some
gluten which passes with the starch, and the vegetable albumen
is entirely lost by reason of its solubility in water; and then to
dry gluten is a very long and delicate process; and if we would
pretend to any degree of accuracy, we must ascertain the
quan-
tity of fatty matter contained in the samples. I therefore
thought that with reference to the azotised principles particu-
larly, the better way would be by proceeding to ascertain these
by immediate ultimate analysis.
The four azotised principles which we have already admitted
have very nearly the same elementary composition; the mean
proportion of azote in each is 0.16. With this datum it is evident
that if a particular sample of flour is found to contain 0.04 of
azote, it may be inferred that this azote represents 0.25 of gluten,
albumen, fibrine and caseine, dried at 140° C. (284° F.), and as
222
WHEAT.
•
these are the most valuable elements in flour, I took the pains to
ascertain their proportion in a considerable number of varieties of
wheat, the whole of which were grown in the same year, in the
same soil, which was well manured, and under climatic influences
that were identical; nor did I restrict myself to the azotised
matters of these samples; I also endeavoured to ascertain the
precise relative quantities of bran and of flour. The following
table contains the results of my experiments.
WHEAT.
223
Variety of wheat.
Triticum spelta rufa mutica
Small spelter, T. monococon
Great spelter
Mecca wheat
Bearded wheat
Winter wheat, T. hybernum
Common wheat (mouret)
Reyel wheat
Red Egyptian wheat
•
A large wheat growing in 4 ranks.
Fine red wheat of Roussillon
Red Marcel wheat
Dantzic wheat
Wheat from the North
Fine red wheat (pays de Foix)
Smyrna wheat
Bengal wheat
Tangarok wheat
Hard African wheat
Cape wheat
Russian wheat
Sicilian wheat
Giant St. Helena wheat
Subernac wheat (Pyrenees)
Character of the grain.
small, thin.
middling.
very large.
horny, long.
small, brown.
middling.
reddish.
yellow, fine.
small, hard.
hard.
reddish.
large.
soft.
pretty hard.
soft.
white, hard.
ditto.
small.
grey, hard.
yellow, large.
wrinkled.
small, red.
hard, very large.
well formed.
In 100 of the grain.
Bran.
21.9
20.8
26.9
32.0
13.2
38.5
23.5
14.0
15.0
15.0
16.0
21.5
24.0
20.5
18.5
19.0
21.5
23.5
24.5
19.0
18.0
19.5
25.0
20.5
Flour.
78.1
79.2
73.1
68.0
86.8
61.5
76.5
86.0
85.0
85.0
84.0
78.5
76.0
79.5
81.5
81.0
78.5
76.5
75.5
81.0
82.0
80.5
75.0
79.5
Azote.
3.85
3.97
3.53
3.71
3.63
2.92
3.77
3.00
3.45
3.27
3.61
3.04
3.63
3.58
3.57
3.18
2.97
3.86
4.25
2.92
3.53
3.89
3.35
3.04
In 100 of the flour.
Gluten and
albumen.
24.1
24.8
22.1
23.8
22.7
18.3
23.5
18.7
21.6
20.4
22.6
19.0
22.7
22.4
21.9
19.9
18.6
24.1
26.5
18.2
22.1
24.3
20.9
19.0
Starch
sugar, gum,
water.
75.9
75.2
77.9
76.2
77.3
81.7
76.5
81.3
78.4
79.6
77.4
81.0
77.3
77.6
78.1
80.1
81.4
75.9
74.5
81.8
77.9
75.7
79.1
81.0
Appearance of the flour.
greyish, coarse.
soft.
very coarse.
yellow, coarse.
very coarse,
yellowish, soft.
coarse.
very white, soft.
yellowish, rough.
somewhat coarse.
white, very soft.
yellowish, soft.
white, very soft.
yellowish.
white, very soft.
white, rather rough.
soft, white.
white, extremely fine.
yellow, very coarse.
white, very soft.
yellowish, very soft.
yellow, coarse.
ditto.
white, very soft.
224
The quantity of gluten and albumen contained in these
samples of flour is much larger than that usually indicated; I
have given reasons which explain, to a certain extent, this
difference. I ought to add, however, that the varieties of wheat,
the flour of which was analyzed, were all grown in the rich
soil of the garden, a circumstance which as Hermbstädt has
shown, exerts the most powerful influence in increasing the
quantity of gluten in wheat.
It was already known, from the experiments of Tessier, that
the proportion of gluten in the same species of wheat might
vary in the ratio of from 12 to 36 per cent. of the weight of
the flour, according to the nature of the soil and the quantity
of manure. But it was Hermbstädt who first made truly com-
parative observations on the action of the excrements of different
animals on the culture of the cereals.
The excrements made use of by this able cultivator in his
inquiries were always dried in the air at a temperature of 12½°C.
(544°F.), and equal areas of the same soil were sown with equal
weights of winter wheat, and had a similar dose of manure of
one kind or another spread over them. One hundred parts of
the flour obtained from wheat thus grown yielded :
With human urine
""
>>
>>
""
رد
"
bullock's blood
human excrement
sheep's dung
goat's ditto
horse ditto
WHEAT.
pigeon's ditto
cow's ditto
""
Soil not manured
Gluten.
35.1
34.2
33.1
22.9
32.9
13.7
12.2
12.0
9.2
Starch.
39.3
41.3
41.4
42.8
42.4
61.6
63.2
62.3
66.7
Bran, soluble mat-
ter and moisture.
25.6
25.5
25.5
34.3
24.7
24.7
24.6
25.7
24.1
It is apparent, therefore, that in general, for the exception
only refers to the pigeon's and horse dung, the wheat grown
in ground manured with the most highly azotised matters
yields the largest quantity of gluten.
By way of adding to and confirming these conclusions or
Hermbstädt, I shall give the results of an experiment of my
own made in 1836, in which the same variety of wheat was
WHEAT.
225
grown in the open field, and in garden ground very highly ma-
nured. The grain was analysed after having been dried at
110° C. (230° F.) and gave:
Carbon
Hydrogen
Oxygen
Azote
Ashes
From the open field. From the garden ground.
46.10
45.51
5.80
5.67
43.40
43.00
2.29
3.51
2.41
2.31
100.00
100.00
In the produce of the garden there were 21.94-very nearly
22 per cent. of gluten and albumen; in that of the open field
no more than 14.31 per cent. of the same principles.
Davy was of opinion that the wheat of warm climates was
richer in azotised principles than that of temperate lands. South-
ern countries are known to produce harder, tougher grain, the
flour of which contains more gluten than the soft and more
friable wheat of the north; and the inquiries of M. Payen ap-
pear to bear out the conclusion of the illustrious English che-
mist. M. Payen, in fact, found in the hard wheat of Africa
3.00 of azote, equivalent to 18.7; and in that of Venezuela 3.50
of azote, equivalent to 21.9 of gluten and albumen. The
experiments quoted above, however, prove that we may
have
wheat grown in Europe fully as rich in azotised elements as any
that is grown between the tropics; the influence of the soil in
this direction is probably more than the influence of climate.
In all the analyses of wheaten and other flour published up to
the present time, we find no mention made of the fatty matters
which they contain; and late views in regard to the special part
which these matters play in nutrition make it very necessary to
supply the omission. Along with MM. Dumas and Payen, I
therefore determined the quantity of fatty matter contained in a
considerable number of the vegetables and vegetable substances
used as food, from which it appears that grain of different kinds
contains from 2 to 10 per cent of oil. One hundred parts of winter
wheat gathered at Bechelbronn lost 14.5 of water by drying at
110 C. (230 F.) and therefore contained 85.5 of dry matter.
100 of this dry wheat gave 13.7 of bran and 86.3 of flour.
226
RYE.
Various analyses showed the composition of this wheat and
its parts to be as follows:
Dry matter.
Bran
Flour
Wheat
•
Gluten and Starch.
Albumen.
20.0
13.4
14.3
Brabant
Flanders
Austria.
England
France
73.2
63.2
•
Glucose.
(Sugar.)
5.6
Gum.
28.8
4.2
12.4
Fatty
matter.
5.5
2.1
1.6
Woody Ashes.
tissue.
45.7
Rye (Secale cereale.) Rye is an important article of food,
particularly in the north of Europe where the people live upon
it almost entirely. It is a very hardy plant, and will thrive in
soils which are altogether unfit to grow wheat. In the husban-
dry of the north this grain occupies the place of wheat in the
south; it requires much the same treatment, and stands upon
the ground for nearly the same length of time. The bushel of
rye weighs on an average about 60lbs. avoird. The usual quan-
tity of seed sown is from 10 to 11 pecks per acre, and the pro-
duce per acre, the seed being deducted, has been stated as follows:
Bushels.
23.0
32.4
20.6
22.0
19.0
7.5
1.5
:
The German agriculturists say, that the weight of the straw
to the weight of the rye produced is in general as 100 is to 47;
others say as 100 is to 50, and some have taken it even as high
as 100 to 33. The relation seems to differ extremely in diffe-
rent years. At Bechelbronn, for example, in 1840-41 we had
63 of grain to 100 of straw; in 1841-42 we had but 25 of
grain to 100 of straw.
Rye yields flour that is not so white nor so fine as that of
wheat, which is in consequence of the woody covering of the
grain getting ground, in great part, in the mill. If but from
50 to 65 parts per cent. of flour be taken from rye it is white and
looks well. The dough made with rye flour is not very ad-
hesive; it contains little vegetable fibrine, the azotised principle
which gives gluten its elastic properties. It is this want of ve-
getable fibrine which renders it more difficult to make good light
BARLEY-OATS.
227
bread of rye than of wheaten flour, although experiment shows
that rye flour of the first quality will form as large a proportion
of bread as wheaten flour; 100 of rye flour have given 145 of
bread.
Rye bread is more hygrometric than that of wheat, and con-
sequently remains for a longer time soft and fresh. Rye gene-
rally contains 24 of bran to 76 of flour; by drying at 230 F. it
loses about 17 per cent. of water. Analyses of a dried sample
grown at Bechelbronn yielded :
Gluten and albumen (azotised principles united)
Starch
Fatty matters
Sugar (glucose?)
Gum
Woody matter and salts (phosphates)
Loss
Of flour
Bran
Water.
Barley (Hordeum vulgare.) The usual produce of barley
varies much from 15 or 20 to 50, 60 and even 70 bushels
per acre; the average for France is stated at about 43 bushels;
and the weight of the bushel may be taken on an average at
about 504lbs. The ratio of the straw to the grain varies
very much, but may be taken generally at that of 100 to 50.
Barley contains:
10.5
64 0
3.5
3.0
11.0
6.0
2.0
100.0
68.6
18.4
13.0
100.0
Dried, this grain gave 0.0214 of azote, which represents 13.4
per cent. of gluten and other azotised principles.
Oats (Avena sativa.) When oats yield 43 or 44 bushels per
acre, the
crop is a fair one. At Bechelbronn we have frequently
had upwards of 45 bushels per acre.* Schwertz states the relation
between the straw and the grain as 100 is to 60.
* This would be reckoned a poor crop in the North of England and
Scotland, where 80, 90 and even 100 bushels of oats per acre are fre-
quently grown.-ENG. ED.
Q 2
228
MAIZE.
Some oats gathered in 1841-42 yielded 78 of meal and 22
of husk per cent.
One hundred parts of these oats lost by drying at 230° F.,
20.8 of water; thus dried analysis showed that they contained:
Of starch
"
در
gluten, albumen, &c.
fatty matter
,, sugar (glucose)
,, gum
woody matter, ashes, and loss
•
46.1
13.7
6.7
6.0
3.8
21.7
100.0
Maize (Zea mais). This is the true wheat of the Ameri-
cans, and it is now generally allowed that the plant is a native.
of the New World. It is also well known that maize was intro-
duced into Spain long before potatoes. Oviedo states in his
work, printed in 1525, that he had seen it growing in Anda-
lusia and the neighbourhood of Madrid. The cultivation of this
useful plant was observed everywhere on the discovery of Ame-
rica by Europeans, from the most southern parts of Chili to
Pennsylvania in the north; and in the neighbourhood of the
equator, from the level of the sea to the high table lands of the
Andes. Garcilasso gives a particular description of the pro-
cedure followed by the Incas in the cultivation of this plant, the
kind of manure, &c. At Cusco the Indians manured with hu-
man excrement dried and reduced to powder. On the coasts
they employed in one place guano, in others, as the dusty and
sterile soils of Attica, Atiquiba, &c., they made use of the offal
of fish.
The uses of maize are very numerous. In America it is made
into cakes, which are a substitute for bread; by fermentation a
vinous liquor is prepared from it, called chicha. Before the con-
quest, the Mexicans manufactured a syrup from the expressed juice
of the stems. In describing to Charles V the various articles of
provision that were met with in the march to Tlatclolclo, Cortez
says, "They sold us the honey of bees, wax, and honey from the
stems of the maize plant." Maize when ground and boiled makes
a kind of pudding in universal use, and the ear, when nearly ripe,
MAIZE.
229
whether boiled in water or roasted in the ashes, is held a luxury
by all classes. In the tropical Cordillera maize is advantageously
cultivated from the level of the sea to the height 9186 feet above
it; that is to say, it thrives in temperatures which vary be-
tween 14° and 27.5° C. (57.5° and 81.5° F.); this circumstance
explains its very general introduction into Europe.
Maize succeeds on all soils when they are properly manured ;
I have seen beautiful crops upon the most sandy soils and upon
the stiffest clays; it requires much the same management as
our ordinary grain crops; the climate alone should decide as to
whether its introduction into a particular district is opportune or
not; a certain degree of heat is necessary to ripen it, and above
all, the cold to which it is exposed must not be too severe. It is
for this reason that in the east of Europe the maize is sown in
spring when there is no longer any apprehension of frost;
there would be a real advantage in sowing late, were it not
for fear of the frosts of autumn at the season of ripening. The
susceptibility of maize to frost and climate generally, appears
to me very analogous to that of the vine; and I doubt whether
it would be wise to attempt its cultivation on the great scale
where the grape does not ripen in ordinary years.
Maize is sown either with the dibble or with the hand, fol-
lowing a furrow opened by the plough; I believe that it ought
never to be sown broadcast, for it is a plant that requires room;
it is only in the hottest countries that the drill system is
less necessary. In Alsace the drills are about 2 feet apart, and
the seeds are sown at the distance of about a foot from each
other. This very considerable space left between the maize
plants appears to authorise the general custom that prevails
of interposing some other crop in the fields under Indian
corn; that which is most generally interposed is either the
dwarf haricot or the potato. I observed the same custom in
the more temperate valleys of the Andes, where it is almost
as necessary as in Europe to leave free spaces between the plants
to give them air and sun; but the plant is cultivated alone in
the hotter regions. Soon after maize has sprung it receives
a first hoeing, and after it has got to a certain height a second;
230
MAIZE.
in Alsace, for instance, it is customary to hoe towards the end
of June; but I never saw any operation of the kind performed
between the tropics; the only care they seemed to take of their
fields of Indian corn was to pull up foul weeds. In Europe it
is usual to take away the sprouts which rise beside the principal
stem; this precaution is also unnecessary in equatorial countries
where the ground is fertile; the more lateral stems that rise the
better, as they all become richly laden with grain. I may also
say as much for the system of topping which prevails among us,
that system which consists in removing the extremity of the
stem which bears the male flowers after the fecundation has
been effected. The leaves and heads of stems which are ob-
tained by this operation, compose a forage by no means to be
despised.
The time during which the crop of maize remains on the
ground is greatly influenced by the mean temperature of the
climate; in hot intertropical countries the grain ripens in less
than three months, and there are even farms upon which four
considerable crops are gathered in the course of the year. On the
temperate plateau or table-land of Bogota, the plant ripens in
six months; in Alsace about the same length of time is re-
quired, although at Bechelbronn in 1836, the maize which was
Sown on the 1st of June was gathered ripe on the 1st of
October. Maize is dried either in exposing the spikes stripped
of their covering upon the floor of a well ventilated granary, or
by hanging them up in bunches or sheaves under sheds or
under the eaves of the house. In warm countries the drying is
accomplished by one or two days' exposure to the sun, after
which the spikes are stored. The maize is freed from the
stem with the hand in small farms, with the flail in larger
establishments. In America the operation is never done until
the moment when the grain is wanted, as it is said that the
grain is less subject to be attacked by insects when it is kept in
the ear.
When animals are fed on maize they are accus-
tomed to separate it for themselves.
The produce in Indian corn varies greatly, as appears by the
following table in different countries:
MAIZE.
Countries.
Lavanthal
Carinthia
Austria and Moravia
Hungary and Croatia
Tuscany
France (climate of Paris)
Alsace
Venezuela
Produce in Bushels
per Acre.
81
55
24
42
96
29
43
. 147
231
By far the finest crops of Indian corn in America are obtained
upon breaks of virgin soil. I do not hesitate to say that the
husbandman gains from six hundred to seven hundred times his
seed under such circumstances. The mode of proceeding upon
these breaks, which I have frequently witnessed, deserves to
fix attention for a moment.
The planter chooses the end of the rainy season for cutting
down the trees and the brushwood: every thing remains where
it falls until it is sufficiently dry; fire is then set to the heap,
and the burning extends and lasts even for weeks; all the smaller
branches are completely consumed, nothing but the charred
trunks of the larger trees remain. As the rainy season is about
to return, a man, with a pointed stick in his hand, goes over the
burnt surface, making a hole of no great depth at intervals,
into which he throws two or three particles of Indian corn, over
which he draws a little earth, or rather ashes, by a slight motion
of his foot. This primitive mode of sowing terminated, the
planter takes no further heed of the crop; his habitation is often
so remote, that he never visits it until harvest time: the rain
and the climate do all the work: it is unnecessary to hoe, the
burning having destroyed all the plants that were indigenous to
the soil, nothing rises but the grain which has been sown. In
such fields, stems of Indian corn are frequently seen of the
height of from twelve to fourteen feet. It rarely happens that
more than three consecutive crops are taken from the burnt soil;
and the last, though still very superior to anything which we can
obtain by our regular husbandry, is not to compare with the
first. As there is no want of forest, it is held preferable to
make a fresh break.
232
RICE.
Taking the seed as unity, it is found from documents now pos-
sessed, that 1 of seed will yield: In Mexico (an indifferent har-
vest) 150; in New California (beyond the tropics) 80; Alsace
(the plants very far apart) 190; Venezuela (an ordinary crop)
238. Besides the grain and the straw, the husks and the cores
of Indian corn are all extremely valuable upon the farm as
forage and as affording manure.
Maize has been analysed by M. Payen, and found to contain:
starch 71.2, gluten, albumen, &c. 12.3, fat, oil 9.0, dextrine
and glucose 0.4, woody tissue 5.9, and salts 1.2; 100.0. I
found 0.02 of azote in a sample of dry maize, which I analysed,
a quantity which indicates 12.5 of gluten and albumen, a result
that coincides exactly with M. Payen's analysis.
Rice (Oriza sativa). Rice is an aquatic plant which can
only be grown in low moist lands that are easily inundated. The
ground is ploughed or stirred superficially, and divided into
squares of from twenty to thirty yards in the sides, separated
from each other by dykes of earth, about two feet in height,
and sufficiently broad for a man to walk upon. These dykes
are for retaining the water when it is required, and to permit of
its being drawn off when the inundation is no longer necessary.
The ground prepared, the water is let on, and kept at a certain
height in the several compartments of the rice-field, and the
seedsman goes to work. The rice that is to be used as seed
must have been kept in the husk; it is put into a sack, which is
immersed in water, until the grain swells and shows signs of
germination; the seedsman walking through the inundated
field, scatters the seed with his hand as usual, the rice imme-
diately sinks to the bottom, and may even penetrate to a certain
depth into the mud. In Piedmont, where the sowing takes
place at the beginning of April, they generally use about 55lbs.
of seed per acre. The rice begins to show itself above the sur-
face of the water at the end of a fortnight; as the plant
grows, the depth of the water is increased, so that the stalks
may not bend with their own weight. About the middle of
June this disposition is no longer to be apprehended; the rice
is no longer so flexible as it was, so that the water can be
RICE.
233
drawn off for a few days to permit hoeing, after which the
water is let on and maintained to the height of the plant; in
July it is usual to top the stalks, an operation which renders the
flowering almost simultaneous. Rice generally flowers in the
beginning of the month of August, and a fortnight later the
grain begins to form. It is at this period especially that the
stalks require to be supported, and this is effectually done by
keeping the water at about half their height. The rice field is
emptied when the straw turns yellow. The harvest generally
takes place at the end of September. In the Isle of France,
rice is cultivated in very damp soils, upon which a great deal of
rain falls, but which are not flooded artificially; I have seen the
same process followed in other tropical countries which I have
visited, but I do not think that the produce is so great, or the
crop so certain as where inundation is employed. In Piedmont,
the usual return from a rice-field is reckoned at about 50 for 1
of seed. At Muzo, in New Granada, the paddy-fields which
are not inundated, under the influence of a mean temperature of
26° cent. (79° Fahr.) yield 100 for 1.
Three kinds of rice yielded, on analysis, the following quan-
tities of
Carolina. Piedmont.
89.5
90.1
3.8
0.2
0.3
0.7
Woody tissue
5.1
Phosphate of lime
0.4
0.4
Chloride of potassium, phosphate of ditto, &c.
Starch
Gluten, albumen, &c.
Fatty matters
Sugar (glucose?)
Gum
3.9
0.3
0.11
0.1 J
5.1
Rice.
86.9
75
0.8
0.5
3.4
}0.9
100.0 100.0 100.0
M. Payen's analysis indicates a proportion of azote, the
double of that found by M. Braconnot. In a trial for azote,
which I made myself, I found 1.2 of this element per cent.
which would show the amount of albumen and gluten to be 7.5,
a quantity that corresponds exactly with M. Payen's valuation.
Coffee (Coffea Arabica). The habit of using the infusion of
coffee appears to have been introduced into Europe about the
234
COFFEE.
middle of the sixteenth century. The first public establish-
ments for the sale of the drink were opened in Constantinople
in the year 1554.
year 1554. The use of coffee remained for a long time
confined to the East; but by degrees it spread, and at the pre-
sent day the consumption of the article in Europe exceeds
660,000,000 of pounds annually. The greater portion of
coffee consumed in Europe is the produce of America, and yet
it is not more than a century since it was first grown in the
new world.
The coffee plant thrives between the tropics in situations.
where the mean and nearly constant temperature is between
22° and 26° C. (71.5° and 80° F.)
Coffee is rarely sown in a nursery; the seeds are made to
germinate still surrounded by their natural pulp, and wrapped
up in leaves of the banana. The young plants after seven or
eight days of germination, are put into the ground. In the
valley d'Aragua an acre of ground of good quality is generally
laid out with about 1040 plants. The coffee plant flourishes in
the course of the second year; when left to grow unimpeded it
will attain a height of from 23 to 26 feet, but it is seldom
allowed to grow so high, its upward progress being checked by
pruning; the planters of Venezuela generally keep it at a height
of from 5 to 6 feet. The shrub receives the care of the planter
during the first two years; the ground must be kept free from
weeds, and the growth of parasites must above all be prevented.
To thrive, the coffee plant requires frequent rains up to the time
of flowering. The fruit bears a strong resemblance to a small
cherry, and is ripe when it becomes of a red colour, and the pulp
is soft and very sweet. As the berries never ripen simulta-
neously, the coffee harvest takes place at different times, each
requiring at least three visits made at intervals of from five to
six days. A negro will gather from 10 to 12 gallons of fruit in
the course of a day.
Two beans are found in the interior of each berry; in order
to free these from the pulp which surrounds them, they are
passed through a kind of mill, and the coffee is steeped in water
for twenty-four hours in order to free it from the mucilaginous
COFFEE-COCOA.
235
;
matter which adheres to it; it is then dried by being spread out
upon a floor under a shed. In the coffee plantations of Vene-
zuela which I visited, I saw them proceed in another way. The
berries were exposed to the sun upon a piece of ground some-
what inclined, and spread out to about three inches in thickness
the pulp soon enters into fermentation, and a very distinct
vinous odour is exhaled, and the juice altered either flows away
or dries up; at the end of a fortnight or three weeks the berries
are all dry and shrivelled, and they then undergo two tritura-
tions, one to obtain the seeds or beans, the other to detach a
thin pellicle which surrounds them. Three bushels of berries
will yield from 85 to 90lbs. of marketable coffee.
During the destruction of the sugary matter contained in the
pulp of the berry, a considerable quantity of spirit is produced and
dissipated. M. Humboldt, struck with the readiness with which
the berry of the coffee plant runs into fermentation, expresses his
surprise that no one ever thought of obtaining alcohol from it.
In an old work, however, I find the following passage: "The in-
habitants of Arabia take the skin which surrounds the coffee
bean and prepare it as we do raisins; they form a drink with it
for refreshment during the summer."* This vinous liquor
appears to enjoy all the exciting properties which are esteemed
in the infusion of coffee.
The coffee plant continues to produce to the age of forty to
forty-five years; it bears to a considerable extent even in the
third year. Some shrubs yield from 17 to 22lbs. of dry coffee
beans; but this is a very large quantity. An acre of land in the
valley d'Aragua, planted with about 1040 shrubs, will yield
about 940 or 950 lbs., which is at the rate of somewhat less.
than 1 lb. per shrub.
Coffee contains the same active principle as tea, coffeine, but
in less proportion; the researches of different chemists have also
shown the presence of a particular acid called coffeic acid, of
fatty matters, a volatile oil, a colouring matter, albumen, tannin,
and alkaline and earthy salts.
Cocoa (Theobroma cacao). The ancient Mexicans cultivated
* Mem. of the Academy of Inscriptions, vol. xxш, p. 214.
236
COCOA.
the cocoa-tree, and with its seeds prepared tablets similar to the
chocolate of modern times; the use of cocoa appears to have
been introduced after the conquest into the other parts of the
continent; nevertheless the cocoa-tree is indigenous in the hot
and humid forests of South America; M. Goudot discovered
several species in New Granada, among others, that which is
known at Muso under the name of the Cacao montaraz; this
cocoa-tree, which attains a height of from 25 to 30 feet, yields
a considerable quantity of fruit; the natives prepare a chocolate
from its beans, which is extremely bitter, and which they regard
as an excellent febrifuge. The wild Indians still appear to be
ignorant of the profit that may be made of the seeds of the
cocoa-tree; they only eat the pulp or fruit which surrounds them.
Cocoa was introduced into Europe by the Spaniards, and in no
long space of time this production of the New World became
the object of a very considerable traffic.
It is a fact well known to the husbandmen of tropical coun-
tries that a virgin soil is quite indispensable to the success of a
cocoa plantation; nothing but failure has followed attempts to
replace the sugar cane, indigo, maize, &c. with cocoa, a plant which
to succeed requires a rich, deep, and moist soil, heat and shade
nothing suits it better than a forest brake, the surface of which
is susceptible of irrigation.
All the important cocoa plantations which I visited had a
common physiognomy: they were all situated in the hottest
regions, at a short distance from the sea near torrents, or on the
banks of great rivers. The cocoa husbandry ceases to be
profitable in localities which have not a mean temperature of at
least 24° C. (75.2º Fahr.) and I have had occasion to take part
in attempts that were as fruitless as expensive to cultivate the
cocoa trce in a brake where the heat of the climate from my own
observations did not exceed 22.8° C. (73° Fahr.) Under the
influence of this temperature, the trees presented a very good
appearance; in the course of a few years they flowered, but the
fruit, which was always small, rarely came to maturity. When
a piece of land has been selected for a cocoa plantation, they
begin by establishing a good system of shade. Occasionally a
certain number of trees, with large and leafy crowns are left
COCOA.
237
standing; but in general certain plants, which grow rapidly, are
had recourse to as a means of procuring shade. In the neigh-
bourhood of Caracas they shade with the erythrina umbrosa;
and in some plantations they take advantage of the shade of the
banana; finally the two modes of procuring shade are frequently
conjoined.
In the province of Guayaquil they plant the beans of the
cocoa directly. In Venezuela they prefer raising the plant in a
nursery, which is always selected of the most fertile soil, and
deeply trenched. The seeds are sown immediately before the
setting in of the rains, and germination takes place in from eight
to ten days. In a good soil, at two years of age the cocoa plant
will have attained a height of nearly 3 feet; it is then pruned
by having two of its upper branches removed, and is trans-
planted. In the upper valley of the Rio Magdalena, where
there are many valuable cocoa groves, the sowing is performed
in ground well prepared and protected by screens made with
palm leaves; here the young cocoas are transplanted when they
are six months old. During the whole of the time that the
plants remain in this nursery they continue to be well shaded;
and they are watered once a week by water poured upon the
screens.
The tree seldom comes into flower under thirty months old.
I have known planters who always destroyed these first flowers,
and who never suffered any fruit to ripen before the fourth year,
and that too under the most favourable circumstances in regard
to climate, in situations where the mean temperature was 27.5°
C. between 81° and 82° Fahr. In less favourable situations it
is necessary to wait six or seven years before gathering the first
fruits of a cocoa plantation. There are few arborescent plants
which have so small a flower, and especially a flower so dispro-
portionate to the size of its fruit as the cocoa tree. The diameter
of a bud, measured at the moment of its expansion, does not
exceed 4 millemetres-0.157 of an English inch. The flowers
appear principally upon the trunk of the tree itself; they rarely
show themselves beyond the middle of the larger branches;
occasionally they appear upon the roots which happen to be
above the ground.
238
COCOA.
To receive the young plants grown in the nursery, the ground
properly shaded is first freed from weeds. Trenches are then
cut, either to season the ground or to irrigate it when requisite.
The young plants are set in rows at regular and considerable
distances, which vary, however, with the quality of the soil; and
the general opinion is, that the better the soil the greater should
be the space from tree to tree. Thus in the valley of del Tuy,
in the neighbourhood of Puerto Cabello, the cocoa trees are set at
the distance of about 16 feet apart in the best soils, and at the
distance of about 13 feet only in soils of inferior quality. In the
windward islands where the soil is generally less fertile than on
the continent, the trees stand at the distance of from 6 or 7 to 9
or 10 feet apart. A reason for this practice may be readily
assigned; in the more fertile soils the trees grow more vigorously,
the branches spread farther, and consequently require a larger
space.
Once the cocoa-tree is in the plantation, it is regularly pruned
to prevent its branches becoming too numerous. It sometimes
happens that the branches show a tendency to bend down
towards the ground, in which case they are fastened up around
the trunk, until they acquire strength and a better direction.
The soil around the trunk is hoed from time to time to the
extent of about a yard in circumference, and the capillary roots,
which spring from the base of the trunk, are removed in the
course of the operation.
From the fall of the flower to the complete ripeness of the
fruit there elapses an interval of four months. The fruit is of an
elongated form, slightly bent, and terminated in a point, its
length is about 9 inches, and its greatest diameter, which is near
the point of attachment, is from 6 to 7 inches. Externally, the
cocoa-nut pod is furrowed longitudinally. Its colour varies from
a greenish white to a reddish violet, the latter being the more
common tint. Internally the flesh of the fruit is generally white,
although it has sometimes a rose-colour; it is sweet and acid, and
of a very agreeable flavour. The seeds are generally twenty-five in
number in each fruit, and at first are white; they are oleaginous
and slightly bitter; in drying they acquire a brown tint. The
fruit is known to be ripe by its colour, and particularly by the
COCOA.
239
ease with which it is gathered from the tree. There are two grand
cocoa harvests in the course of the year, at six months' interval;
still, in old and large plantations the harvest is almost incessant,
as it is not uncommon to observe, on the same cocoa tree, ripe
fruit and fresh flowers. To obtain the seeds the fruit is opened
with a piece of wood, having a rounded extremity. The produce
is classed according to its quality, care being taken to throw out
all the beans that are not sufficiently ripe or that are damaged;
they are then exposed in the sun. Every evening the day's
gathering is collected into a heap under a shed, and a brisk
fermentation is soon set up, which would become destructive
were it suffered to continue. Next day the heap is scattered,
and the drying goes on in the sun, several days' exposure being
required before the drying is complete. Occasionally the drying
is retarded and rendered difficult by the occurrence of rain, so that
there would certainly be many advantages in effecting it by the
stove. It has been found that 100lbs. of fresh beans give from
45 to 50lbs. of dry and marketable cocoa. In Venezuela, a
cocoa tree which is over seven or eight years old, will yield
annually for more than forty years over 141b. (1.65lb.) of dry
and marketable cocoa. An acre of ground, which in good
plantations will be set with about two hundred and thirty-three
trees, produces in a middling year about 383lbs. weight.
The cocoa tree appears to yield most abundantly when it is about
twelve years of age, and its produce in the fertile lands of Upper
Magdalena, according to M. Goudot, is greatly superior to what
it is in Venezuela. At Gigante, for example, each adult tree
yields 4.4lbs. of dry cocoa annually, and the produce of an acre
there may be estimated at 733lbs.
Cocoa beans contain albumen, a particular principle, theo-
bromine, analogous to coffeine, a colouring matter and a large
quantity of oil or fat, which from experiments made in my
laboratory, appears to amount to 43 per cent. The presence of
a large quantity of albumen and fatty matter in cocoa explains
its highly nutritious qualities. It is indeed one of the most
wholesome and restorative articles of sustenance known. Never-
theless very opposite statements have been made upon the
virtues of cocoa, or chocolate of which the cocoa-bean forms the
Q 3
240
PEAS, BEANS, ETC.
basis. Benzoni, in his History of the New World declared
chocolate to be a drink that was fitter for hogs than men; and
Father Acosta declares the taste for cocoa to be unreasonable.
On the other hand, Fernando Cortez and one of his gentlemen
followers, are perhaps guilty of exaggeration when they say,
"that he who has taken a cup of chocolate may march the rest
of the day without other aliment!"* Without going the whole
of this length with Cortez, I still allow that chocolate is one of
the best articles for travelling upon, especially in the uninhabited
forests of South America, where it is a matter of the highest
moment to have the bulk and weight of the necessary rations
as small as possible.
Seeds of leguminous plants. The leguminous plants that are
cultivated as food for man are beans, peas, haricots, and lentils;
vetches are grown exclusively for the use of cattle.
Leguminous plants scarcely ever open rotations; but they
very often wind them up. Speaking generally, however, they
may follow any crop.
any crop. In discussing Indian corn, I have said that
haricots and beans might be advantageously intercalated with it.
The meteorological observations I have made in different.
countries lead me to conclude that to succeed, leguminous plants
require a temperature which in the mean does not fall below from
14° to 15° C. (57° to 59° F.) Hot climates agree with them
perfectly; I have followed them from the sea-board of the equa-
torial Andes to a height of from 8200 to 9800 feet above the
level of the sea. Schwertz has given the following statement.
of the produce of the different leguminous plants generally cul-
tivated :


Plants.
Haricots
Beans
Peas
Lentils
Vetches
Weight per
bushel in lbs.
52.0
70.4
63.2
68.0
68.0
Produce per acre
in bushels.
acre
27.8
27.6
16.0
18.4
17.6
Weight of dry straw
or haulm per acre.
Tons. Cwts. qrs. lbs.
1
1
2 2 15
4
2 6
1 4 2 6
The analyses we have of leguminous vegetables show the fol-
lowing proportion of elements:
* Humboldt, Travels, vol. v. p. 285.
PEAS, BEANS, ETC.
241
Legumine
Starch
Fatty matters
Sugar (glucose?)
Gum
•
•
Woody fibre, pectic acid
Salts, phosphates, &c.
Water and loss
Haricots.
22.0
41.0
3.0
0.3
4.0
8.0
3.2
17.5
100.0
Feverolles.
27.5
38.5
2.0
2.0
4.5
10.0
3.0
12.5
100.0
Peas.
20.4
47.0
2.0
2.0
5.0
11.0
3.0
9.6
100.0
R
Lentils.
22.0
40.0
2.5
1.5
7.0
12.0
2.5
12.5
100.0
Besides these principles a quantity of tannin has always been
found in the skin of the seed of all leguminous plants.
The Hop (Humulus lupulus). From its very general
use in making beer, the hop has become an object of great
importance, both in an agricultural and commercial point of
view.
The hop may be cultivated in any soil that is of sufficient
depth and fertility; it thrives especially in rich and turfy
loams, such as those of Haguenau, where there are many beauti-
ful hop gardens. The plant is propagated in the spring by setting
the sprouts or radicular buds in ground trenched to the depth of
19 inches at least, at intervals of about 6 feet 6 inches from
one another. Within a few weeks the young hop plant is grow-
ing lustily; and as it is a climber it is trained upon a pole of from
19 to 23 feet in height. The ground is usually hoed towards
the end of June. The first crop from a new plantation is always
trifling in amount; the ground is then manured. The following
spring all the eyes or buds that have become developed near the
root are removed, except six or seven, which are left to shoot.
The hop harvest generally occurs about the middle of
September: the poles are pulled up, the stems are cut, and
the strobiles are picked off into baskets by hand, and imme-
diately carried to the stove or kiln, where they are dried with
a very gentle heat, in order not to dissipate their fine aromatic
particles.
A hop garden produces very variously in different countries.
and districts, and in different years. The produce of an acre in
hops has been stated to be:
242
FRUITS.
Cwts.
12
qrs. lbs.
3 14
3
8
3
8
(Roville mean of 10 years)
74 0 0
[England from 9 to 10, and from 12 to 14 cwt.]
The strobiles of the hop are covered with a yellow pulverulent
substance, which has been held to furnish in principal part the
extractive matter that is so valuable in brewing. To procure
this substance it is enough to sift a quantity of hops after they
have been dried by a gentle heat. This yellow powder, which
appears to be the useful principle in the hop, and consequently
gives it its value, is not found in the same proportion in the pro-
duce of all hop gardens. This clearly appears from the in-
quiries of Messrs. Payen and Chevalier. They found, for ex-
ample, that whilst 100 parts of the hops of Belgium contained
18 of yellow substance and 70 of mere leaf, those of England
contained no more than 10 of yellow matter and 87 of leaf, and
those of Germany the still smaller quantity of 8 of yellow matter
to 88 of leaf. This yellow pulverulent matter contains wax,
resin, gum, a bitter principle, certain azotised principles, a
volatile oil, and salts, among others acetate of ammonia.
In Flanders
Germany (mean of 10 years)
France, (near Paris)
9
9
FLESHY OR PULPY FRUITS.
The fleshy fruits almost all contain the same principles, but in
very different proportions. It is consequently the predominating
principle which in some sort characterizes each variety, which
gives it its flavour, odour, &c.: sugar, albumen, gum, starch,
acids, fixed oils, essential oils, woody fibre, are almost invariably
found associated in the pulp with a larger or smaller quantity of
water. An ingenious classification of fruits has been formed on
the basis of the predominance of the different substances which
have just been enumerated: thus those fruits in which the
starchy principle predominates, are feculent or amylaceous fruits;
those in which the sugar predominates are saccharine fruits, and
so on.
M. Bérard has analysed a great number of fruits in the course
of his researches on their ripening.* It is proper to say, how-
ever, that some of the principles brought to light by modern
* Ann. de Chimie, t. xvI. p. 225, 2nd. series.
BANANA,
243
analysis do not figure in M. Bérard's list of elements; among
the number pectic acid, gallic acid, small quantities of volatile
oils, and of salts of potash formed by vegetable acids.
Albumen and gluten
Colouring matter
Vegetable tissue
Gum
Sugar
Malic acid
Citric acid
Lime
Water
•
Apricots.
"
Peaches.
0.2 0.9 0.9
0.1
1.9 1.2
5.1 4.9
16.5 11.6
1.80 1.1
Currants.
0.1
74.4 80.2
Cherries.
0.6
Green gage
plums.
Pears.
8.0
1.1
0.8
3.2
6.0 18.1
2.4 2.0 0.6
0.3
0.1
1.1
2.2
2.1 2.1
24.8 11.5
0.1
0.2
0.3
0.3
0.1
81.3 74.9
74.9 71.0 83.9
100.00 100.0 100.0 100.0 100.0 100.0
1
Banana. Of all the pulpy fruits, the banana is that perhaps
which is most extensively used as food by man. It is the usual
nourishment of the inhabitants of most of the countries between
the tropics, where its cultivation is as important as that of the
cereals and farinaceous roots in the temperate zone.
The ease
with which it is cultivated, the small space of ground it occupies,
the certainty, the abundance, and the continuance of its produce,
the diversity of food it yields according to the degree of maturity,
make the banana an object of admiration with the European tra-
veller. In climates where man scarcely feels the necessity of clothing
himself, or of raising a shed for his protection, he is seen gathering
almost without labour supplies of food as abundant as they are
wholesome and varied from the banana tree. It is the banana
which has given rise to that proverb so consoling and so true,
which is frequently heard between the tropics, viz: "No one dies
of hunger in America;" he who is hungry will be welcomed and
fed in the very poorest cabin. Botanists distinguish three prin-
cipal varieties of the banana: 1st. the Musa paradisica; 2nd.
the Musa sapientium; 3rd. the Musa regia.
The American origin of the banana has been called in ques-
tion. Oviedo in his natural history of the Indies affirms that it
was brought from the Canary Isles to St. Domingo by a monk.
R 2
244
BANANA.
ཟ
Foster adopted this opinion, which is corroborated, says M. de
Humboldt, by the complete silence of the first travellers who
visited the New World in regard to it. Nevertheless, the testimony
of the Inca Garcilasso de la Vega proves obviously that the
banana flourished in America before the arrival of the Spaniards;
in his royal commentaries he speaks of the banana as constitut-
ing the chief food of the Indians in the warmest parts of Peru.
The banana is every where cultivated in the neighbourhood of
the equator in situations at no great height above the level of the
sea. The cultivation is most profitable, the crop is most abun-
dant, and attains maturity in the shortest space of time in low
lying districts where the mean temperature is from 24° to 27.5°
C. (75.5° to 82° F.) Some estimate may be formed of this
from the low price of the banana in such districts; upon the bor-
ders of the great river de la Magdalena, I gave one franc or about
10d. for about 220lbs. weight of the fruit. The days' wages of
a man being generally about 1s. 8d., it is beyond all doubt the
cheapest food that can be had in the world.
In looking at the cultivation of the banana at different heights
in the equatorial Cordilleras, I arrived at the following conclusions:
Temperature 25° C. (between 82° and 83° F.) the cultivation
extremely advantageous; at 24° C. (between 75° and 76° F.)
the cultivation advantageous; at 22° C. (71° and 72° F.) the cul-
tivation middling; at 19° C. (or between 66° and 67° F.) the
cultivation disadvantageous.
The banana is propagated by means of suckers or offsets. It re-
quires a rich and humid but well drained soil, the plantation being
arranged a little before the setting in of the rains. The earth is
freed from weeds and dug either entirely or more generally only
at regular distances here and there, where it is proposed to set
the new plant, a space of 6 feet at least being left between each.
The plant throws up several shoots, generally 6 or 7, each of
which will be allowed to grow and to carry fruit; when a greater
number make their appearance some of them are cut away. The
time which passes between planting the slip and gathering the
fruit varies according to the situation; in the hottest districts
near the level of the sea the banana comes into flower about nine
months after it has been planted; and in three months more the
BANANA.
245
fruit has formed and become ripe. In cold situations an interval
of four months will elapse between the flowering and the ripen-
ing of the fruit. The care required by a banana plantation is
not very great, the principal duty being to hoe around the young
plants. As the banana is renewed by stems which arise continu-
ally from the neck of the root, it is easily understood that the
plant will go on yielding fruit for an indefinite length of time
when the fructification is complete in one stem, the leaves, &c.
wither and fall, and give place to a new stem. It is thus that
the gatherings from the banana go on successively at short inter-
vals, and that the same plant presents at one and the same mo-
ment fruit that is ripe, fruit that is half ripe, fruit that is be-
ginning to be formed, flowers, and finally young stems, which
are rising as preparations for the future. Thus no crop is
more assuring to the planter than the banana. Climatic circum-
stances may sometimes delay, but can never destroy the hopes of
the husbandman. The extraordinary droughts which under the
burning climates of the equator so frequently interrupt or destroy
ordinary herbaceous plants, rarely exert any pernicious influence
upon the banana plantation, the thick shade of which presents a
constant obstacle to the evaporation of moisture. During the
dry season when for whole months the Heavens preserve their
purity, and no drop of rain falls to refresh the earth, the soil
which surrounds the banana still continues moist. It looks every
morning as if it had been watered during the night; this salu-
tary effect is produced by the nocturnal radiation of the leaves
into the clear sky. These leaves, whose extent of surface is
considerable, always fall several degrees below the temperature of
the surrounding air, and thus condense the watery vapour con-
tained in the atmosphere, which drips down to the foot of the
plant.
The produce of a banana plantation depends first upon the
distance at which the bananas are placed, and next upon the
climate. It is generally estimated in the very warm climates,
that a crop of bananas will weigh about 44lbs., and that from
an adult plant three crops will be obtained in the course of a
year. In temperate countries, and towards the superior limits of
the banana plant, they do not reckon on more than two crops.
246
BANANA.
According to M. de Humboldt, the produce per acre, in hot
countries where the mean temperature is about 82° Fahr.,
will amount to 75 tons, 8 cwt. 1 qr. 17 lbs.; at Cauca,
where the temperature is about 79° Fahr. the produce amounts
to 61 tons, 8 cwt. 0 qr. 2 lbs. ; at Ibagué, where the tem-
perature is not higher than about 72° the produce according
to M. Goudot's estimate is 26 tons, 17 cwt. 3 qrs. 2 lbs. The
pulp of the banana is surrounded by a pod or husk of some
thickness, which is easily detached, and of which account must
be taken if we would estimate the actual weight of the truly
alimentary matter afforded. In a general way, and when the
banana is ripe, the shell may be estimated at about 36.8, the
edible banana at 73.2 per cent.
The Musa paradisica is the variety of banana generally cul-
tivated, and it also yields the heaviest crops. The fruit of the
other two varieties mentioned is much smaller; but it is of a
much more delicate flavour. The ripe fruit of the banana is of
the consistence of a pear, it is very sweet and slightly acid. In
the common variety, I found crystallizable sugar, gum, an acid
(probably the malic), gallic acid, albumen, pectic acid, woody fibre,
and alkaline and earthy salts. Dried in the sun, 1000 parts of
ripe banana were reduced to 439 parts; so that they contained
561 parts of water. The green or unripe banana has a white and
almost insipid flesh; in this state it scarcely contains any sugar; it
is starch that predominates; in this state, therefore, it is made a
substitute for bread, for the potato, or Indian corn; it may be
considered a farinaceous vegetable. After having removed the
rind, the banana is dressed by being roasted under the ashes un-
til the outer part is slightly brown, it is then served up at table
and constitutes a kind of soft bread, very agreeable to the
palate, and greatly preferable, in my opinion, to the produce so
much vaunted of the bread-fruit tree. In the expeditions which
are undertaken into the forest, and when the habitations of man
are to be quitted for some considerable time, the green banana
is always made a principal part of the provision; but then it
is previously dried, first to lessen its weight, and then to destroy
its vitality so far as to prevent it ripening; this drying is per-
formed in a baker's oven, into which the green bananas, stripped
BANANA.
247
of their husks, are introduced, and where they are kept for
about eight hours; on being taken out, the bananas are hard,
brittle, translucent, and present the appearance of horn;
100 lbs. of the green fruit give but 40 of dry substance. The
banana thus prepared is called fifi, and will keep for a great
length of time without change; to prepare it for food, it is put
to steep in water, and then boiled; by adding a little salted meat,
a very substantial and nutritious meal is prepared. I once made
a voyage on the Pacific, in a vessel which was principally victualled
with dried bananas, which were served out to the company like
biscuit.
When ripe, the banana is no longer farinaceous; as it ripens,
its starch is changed into gum and sugar, and an acid is deve-
loped. But between the farinaceous and the sugary or perfectly
ripe state, there is one intermediate in which it is generally
eaten. Roasted in the ashes, the banana has then a taste which
brings to mind that of the chesnut; it is also eaten as a vege-
table boiled in the usual way in water. Completely ripe, the
fruit is eaten raw or dressed, it is then extremely sweet; a very
common practice is to fry it, cut in slices, in grease.
I have no data upon which to estimate the nutritive value of
the banana, still I have reasons for believing that it is more nu-
tritious than the potato. I have seen men do a great deal of
hard labour upon an allowance of about 6 pounds of half-
ripe bananas, and two ounces of salted meat per diem.
248
CHAPTER III.
OF THE SACCHARINE FRUITS, JUICES, AND INFUSIONS USED IN THE PRE-
PARATION OF FERMENTED AND SPIRITUOUS LIQUORS.
THE juice of all the sweet fruits when expressed and left to
itself under the influence of a suitable temperature, presents the
remarkable phenomenon of fermentation, in the course of which
the sugar disappears completely, and is replaced by alcohol, the
change from first to last being accompanied by the disengage-
ment of carbonic acid gas.
Sugar alone does not suffice to cause the vegetable juices,
which contain it, to ferment: for example, a solution of pure
sugar in distilled water will remain for a very great length of
time without suffering the least change; exposed to the open
air it would evaporate, and the saccharine matter would be found
in the same state as it was before solution. If however a small
quantity of that azotised principle which we have called albu-
men, gluten, &c. be introduced into the solution, fermentation
will speedily be set up, and will run through its usual course;
it would therefore appear to be upon this principle that the
commencement and continuance of fermentation depends. Fer-
mentation is not set up immediately in the juice of fruits; a
certain time longer or shorter always elapses before it is mani-
fested; the reason of this is, that the albumen or gluten which
always enters into the constitution of these juices, must itself
have undergone a certain change in order to act as a ferment.
The proof of this is comprised in the fact that all vinous liquors
contain a very small but constant quantity of carbonate of am-
monia, as was shown by M. Doebereiner. These azotised prin-
ciples which, in the fresh state remain without action upon sweet
juices, act immediately as powerful ferments when they are em-
ployed after having been exposed for some days to the contact
of air and moisture; after, in a word, they have themselves
begun to suffer change. The quantity of ferment used up or
consumed in exciting and maintaining the fermentation of sac-
THE VINOUS FERMENTATION.
249
charine juices is so small, that we are led to believe that it really
acts by its presence or contact alone. This view appears the
more likely, when we know that, after having added an azotised
substance to induce fermentation rapidly in a liquid which, be-
sides sugar, contains albumen, we find from six to eight times
the quantity of ferment after the phenomena have ceased, which
had been added in the first instance; that is to say, we find the
whole, or almost the whole, of the original ferment, and, in ad-
dition, that which has been produced by the azotised principles
pre-existing in the matter subjected to fermentation; this fact
is seen every day in the process of making beer.
The ferment or yeast thus produced is but little soluble in
water, and in composition bears a remarkable affinity to the
azotised matters from which it is derived; M. Dumas has in
fact found it to be composed of:
Carbon
Hydrogen
Azote
Oxygen
Sulphur
Phosphorus
Carbon.
Hydrogen
Oxygen
100.0
Under the influence of ferment, sugar becomes entirely changed
into alcohol and carbonic acid. The composition of grape-
sugar-which appears to be the only one that is susceptible of
fermentation, for cane-sugar before undergoing this process.
passes into the state of grape-sugar, as was demonstrated by
M. Henry Rose-the composition of grape-sugar is as follows:
Carbon
Hydrogen
Oxygen
•
•
50.6
7.3
15.0
100.0
and the constitution of the substances which are produced in
the process of fermentation, viz. alcohol and carbonic acid being
as under:
100.0
27.1
36.4
7.0
56.6
Anhydrous alcohol. Carbonic acid. Water.
52.19
27.27
13.02
34.79
>>
72.73
100.0
11.1
88.9
100.0
250
CYDER AND PERRY.
It appears that the composition of 100 parts of grape-sugar may
be expressed by:
Alcohol
Carbonic acid
Water
Carbon.
46.16 containing 24.24
11.12
44.45
9.09
>>
""
"
Hydrogen.
6.05
36.36
""
1.01
Oxygen.
16.17
32.33
8.08
100.00
7.06
58.58
by which it would appear that during the transformation of hy-
drated grape sugar into alcohol and carbonic acid, the combined
water is set at liberty.
The first fermented vegetable juice of which I shall speak
is cane-wine, or guarapo of the South Americans, a drink which
is in common use wherever the sugar-cane is cultivated. It is
prepared from the juice of the sugar-cane suffered to run into
fermentation.
The chicha of South America is a fermented liquor prepared
from Indian corn, and constitutes the wine of the Cordilleras.
The grain is steeped for six or eight hours in water, bruised
upon a stone and boiled; the pulp which results is then diffused
through 4 times its volume of water, and the temperature
being from 60° to 65° F. a violent fermentation is soon set up
in the fluid which begins to subside after a period of twenty-four
hours, when the chicha is potable, and now constitutes a liquor
of an agreeable and decidedly vinous flavour, in high repute with
those who have acquired a taste for it, although its muddy ap-
pearance and the sediment which it always lets fall in the vessel
into which it is received, render it somewhat unpleasant at first
to European eyes. The Indians, however, always drink it in the
muddy state, and even shake the cask before turning the tap.
The truth is, that chicha is at once a drink and a very nutritious
food.
Guarazo is another vinous liquor which the Indians prepare
with rice much in the same manner as they proceed with Indian
corn.
Cyder and Perry. In countries where the vine is not culti-
vated, a substitute for wine is found in the fermented juice of a
variety of sweet pulpy fruits, more particularly of apples and
pcars. Of the numerous varieties of apples which are grown in
WINE.
251
cyder countries, the preference is generally given to one which
has a rough and somewhat bitter taste. The fruit is gathered
by shaking or beating the trees, and the few that remain are
taken off by the hand; the fruit is piled up in large backs
placed in cellars. It is crushed about two months after it is
gathered, and the pulp is left for ten or twelve hours to macerate
in the juice in order to give the rusty or yellow colour which is
esteemed in cyder. The pulp is pressed and the juice is run into
large vats or tuns in which it undergoes fermentation, which
having gone on for about a month, the temperature being from
55° to 58° F., the liquor is racked off into smaller vessels, in which
the fermentation goes on slowly, and the cyder is preserved.
The fermentation of cyder is, or always ought to be slow; still
with time, the whole of the sugar is transformed into alcohol, if
the process be not interfered with.
Wine. Grape-juice contains, 1st. grape-sugar; 2nd. albumen
and gluten; 3rd. pectine; 4th. a gummy matter; 5th. a colour-
ing matter; 6th. tannin; 7th. bitartrate of potash; 8th. a fra-
grant volatile oil, or cream of tartar; 9th. water. It is obvious,
therefore, that grape-juice contains within itself the elements
necessary for the production of the vinous fermentation. The
relative proportions of these different elements, however, are
singularly modified according to the nature of the vine, the
quality of the soil, and especially the heat of the climate. There
are indeed few crops that are so much at the mercy of the
atmosphere as that of the vine; even in the vineyards tha are
most favourably situated, it is rare that wines of equal quality
and flavour are produced in two consecutive years; and in dis-
tricts upon the verge of the productive limits of the vine, under
what may be called extreme climates, where the vine only exists
in virtue of hot summers, its produce is still more variable, more
inconstant. The limits to the culture of the vine in Europe
are generally fixed where the mean temperature is from 10° to
11º C. (50° to 52° F.); under a colder climate no drinkable
wine is produced. To this meteorological datum must be
added the farther fact that the mean heat of the cycle of vege-
tation of the vine must be at least 15° C. (59° F.) and that of
the summer from 18° to 19° C. (from 65° to 67° F.) Any
252
WINE.
country which has not these climatic conditions cannot have
other than indifferent vineyards, even when its mean annual
temperature is above what I have indicated. It is impossible,
for instance, to cultivate the vine upon the temperate table-lands
of South America, where they nevertheless enjoy a mean tempe-
rature of from 17° to 19° C. (about 62.6º to 66.2º F.), because
that which characterises the climate of these elevated equinoxial
countries is the constancy of the temperature; the vine grows,
flourishes, but the grapes never become thoroughly ripe. In
these equatorial countries good wine cannot be made where the
constant temperature is not at least 20° C. (or 68° F.)
In France the vine begins to sprout towards the end of March,
and the vintage generally occurs in the course of October. As
the quality of wine depends mainly on the ripeness of the grapes,
of course the vintage does not take place until this is complete,
or until there is no longer any prospect of improvement.
The must of the grape is procured by treading and pressing
the fruit; the juice is run into vats, and the fermentation takes
place in cellars; different procedures, however, are followed in
different places. The fermentation having subsided in the
larger vessels, the wine is drawn off into smaller casks, which
are carefully filled up from time to time, and in which it is pre-
served.
Wine may be defective, especially by wanting strength and
being too acid. Sharp wine contains an excess of cream of
tartar and free vegetable acids, and is always the produce of
grapes which have not been completely ripe. The deficiency of
strength is due to the same cause; for it is well known that as
the grape ripens its acids disappear and are replaced by sugar.
This deficiency of saccharine matter in the must, is now
habitually supplied by the addition of a quantity of artificial
grape-sugar, prepared from starch. In warm countries, where
the grape always ripens, the quantity of tartar is small, the sugar
then predominates greatly, sometimes to such an extent that
the azotised substance of the must is insufficient as a ferment,
and it is then that we have wines of too sweet a flavour, such as
those of Lunel and of Frontignac. When these musts, which
are so rich in sugar, contain the proper quantity of ferment they
WINE.
253
produce very strong wines, in which, of course, the sweet flavour
no longer predominates; such are the dry wines of southern
vineyards, of which that of Madeira may be taken as the type.
There are some wines which participate at once in the properties
that distinguish the two varieties that I have mentioned, or that
show one of them in excess according to circumstances; such are
the wines of Xeres, Alicant, Malaga, &c. Some of these wines are
what are called boiled wines, that is to say, a portion of the must
as it flows from the press, is concentrated to a fourth or a fifth
of its original bulk by boiling, and this being added to the rest,
the strength of the resulting wine is increased. Sometimes the
concentration of the juice is effected by drying the grapes partially.
It is in this way that the celebrated Hungarian wine, called
Tokay, is prepared; the clusters are left upon the vines after they
are ripe, and alternately exposed to the cold of the night, which
probably decomposes to a certain extent the texture of the grapes,
and to the heat of the sun, they shrivel and become partially dry.
In this state the grapes are subjected to pressure, and a very
sweet must, as may be conceived, flows from them. In less
favourable climates, where the rains of autumn prevent the
drying of the clusters upon the vine stocks, the same thing is
effected by laying the bunches upon straw in open or well-aired
granaries or sheds. It is with the must procured from grapes
so treated, that the sweet and often strong wines, which are
called vins de paille, or straw wines, are obtained. Wines when
stored in the cask, always deposit with time a copious sediment,
the lees. This sediment, in which tartar predominates, appears
to be the consequence of an increase in the proportion of
alcohol in the liquor. The alcohol may increase from two
causes: first, by the fermentation which, though nearly insensible,
goes on in most wines so long as there is any sugar left un-
changed: and next from mere keeping. It is well known, in
fact, that wine put into the best casks, and kept in a well-ven-
tilated cellar, loses a very perceptible quantity by evaporation;
it is found necessary to fill up the casks from time to time;
the loss has taken place through the pores of the wood, in
virtue of an attraction exerted between the substance of the
wood and the included liquid; and as this attraction is much
I
R 3
254
WINE.
greater between the organic matter and water than between
organic fibre and alcohol, it is easy to conceive how wine kept in
wood should improve. The very same thing, in fact, appears to go
on in regard to wine in corked bottles: the cork does not oppose
all evaporation, and it seems probable that it is not merely upon
some new and little known change of a chemical nature in the
constitution of the wine that its improvement and mellowing in
bottle depend, but also upon the loss of a certain quantity of
its water through the pores of the cork.
Throwing quality, flavour, &c. out of the question, it is well
known that a vineyard cultivated in the same way year after
year, receiving the same quantity of the same kind of manure,
of which the vintage is managed in the same manner, the wine
made by the same method, &c. yields a produce which differs
greatly in regard to the quantity of alcohol it contains in different
years. The vineyard of Schmalzberg, for example, near Lamperts-
loch, which has been under my management for several years,
yields wines of the most dissimilar characters from one year to
another. Some idea of this may be formed from the differcnt
quantities of alcohol, which the wine of different years contains:

Years.
Of the whole term of
the growth of the
vines.
Mean temperature.
Of the summer.
Of the beginning of
autumn.
2
1833 14°.7C. 58°.4F. 1,7°.3C. 63°.1F. 11°.4C. 51°.5F.
63°.1
1834 17.3
20°.3 68°. 17°.0
1
63°
1835 15°.8 60°.4 19°.5 67° 12º.3 54°
1836 15°.8 60°.4 21°.5 71° 12º.2 54°
1837 15°.2 59°.3 18°.7 66° 11°.9 54°
Wine
per acre
in gal-
lons.
Pure al-
cohol
per cent.
Pure al-
cohol
per acre.
in galls.
15.5
46.3
311 5.0
41311.2
625 8.1
544 7.1 38.6
184 7.7 14.2
50.6
If we now inquire how the meteorological circumstances of
each of these five years influenced the production of our wine we
see at once that the mean temperature of the days which make
up the period of the cultivation of the wine has a perceptible
influence. The temperature of the summer was 17.3° C.
(63.1° Fahr.) of the year which yielded the strongest wine, and
only 14.7° C (58.4° Fahr.) in 1833, the wine of which was
scarcely drinkable.
WINE.
255
A hot summer is naturally favourable to the vine: the mean
heat of 1833 did not exceed 171° C. (631 Fahr.); with the
exception of this year, which must be regarded as one of the
very worst, the three favourable summers, 1834, 35, and 36,
show a mean temperature of about 20° C. (68° Fahr.) It is
not, however, with the warmest summer that we find the
strongest wine to correspond. Besides the sustained heat,
which is necessary during the whole year's growth of the vine,
it would appear that a mild autumn was a condition necessary
to the perfect ripening of the grapes: this is one of the essential
conditions. We see, in fact, that in 1834, the months of
September and October presented the extraordinary temperature
of 17° C. (62.6° Fahr.) whilst in 1833 the temperature of the
same months did not rise higher than 11.4° C. (52.5° Fahr.) I
shall here add, that the year 1811, so remarkable over Europe
for the quantity and the excellence of its wines, was distinguished
by the high temperature of the early part of its autumn; we
find, in fact, from the excellent series of observations with which
M. Herrenschneider has presented Alsace, that in this year, after
a summer the mean temperature of which was 19.6° C. (67.2°
Fahr.), the heat of the months of September and October was
maintained at 15° C. (59° Fahr.) the usual temperature of the
months of September and October not being higher than about
11.5° C. (52.7° Fahr.)
If we deduct from these observations the years 1833 and
1837, which were decidedly bad, it seems that we must con-
clude that meteorological influences have a greater effect
upon the quality of wines, than upon the whole quantity of
alcohol formed; thus although the wine of 1836 was very in-
ferior to that of 1834, it actually yielded a larger proportion of
alcohol from the acre.
In Alsace, in order that a year may be favourable to the vine,
the temperature of those months, during which the plant is alive,
must be sensibly superior to the mean: a fact which appears
from M. Herrenschneider's long series of observations. In a
climate where the vine requires such a condition to succeed, it is
obvious that its cultivation can never be advantageous; and this,
in fact, is the case; the cultivation of the vine would indeed be
R 4
356
WINE.
altogether ruinous, were it not for the circumstance that the
value of wine increased in a much greater ratio than its quality,
so that one good year often indemnifies the grower for many bad
years. Another consideration is this, that the vine, like the
olive, grows and thrives in situations where it would be difficult
to put anything else.
The produce of a vineyard also depends upon its age; and it
would be curious to examine the progressive increase of the
quantity of wine yielded. This information I am able to give in
connexion with a vineyard established in Flanders; I only regret
that I have no means of presenting parallel observations from a
country more favourable to the vine. The vineyard of Schmalz-
berg was planted in 1822, with new cuttings from France, and
from the borders of the Rhine. The vines are trained as espaliers,
and are now rather more than four feet in height. The vineyard
began to yield wine in 1825, and the following table shows the
results in the successive years up to 1837:
Years.
1825
1826
1827
1828
1829
1830
1831
Wine per Acre in
Gallons.
68.75
199.9
0.0
156.7
56.0
0.0
153.0
Years.
1832
1833
1834
1835
1836
1837
Wine per acre in
Gallons.
209.9
311.6
413.4
626.0
544.5
184.2
The mean quantity of wine furnished by this vineyard from
the date of its plantation, is 224 gallons per acre. M. Ville-
neuve reckons the mean produce of many vineyards in the
south-west of France at from about 146 to 192 gallons per
acre, considerably less frequently than our vineyard at
Schmalzberg; and official documents, whilst they give the mean
produce of the vine for the whole of France as 170.9 gallons
per acre, state the whole of the wine produced over the country
at 976,906,414 gallons.
From documents recently published, the whole produce of
the vineyards of the German States brought to market appears
to be 59,180,000 gallons.
WINE.
257
Pulque. This is a vinous liquor, indigenous to Mexico and
some parts of Peru, and is prepared from the sap of the Agave
Americana. When this plant is about to flower, a hole is made
into the upper part of its stem, which by and by becomes filled
with juice, and is removed two or three times in the course of
the twenty-four hours; this sap is very sweet, runs quickly into
fermentation, and yields the liquor called Pulque. The flow of
sap continues for two or three months, and a single plant will
yield from six to eight quarts per day. In the neighbourhood
of a large town, which insures a ready sale for the produce, a
plantation of Agave is one of the most profitable possessions; in
the neighbourhood of Cholula there are single plantations which
are worth from £8,000 to £12,000.
In
258
CHAPTER IV.
OF SOILS.
THE solid mass of our earth does not every where present the
same physical characters, or the same chemical composition.
In traversing a mountainous country of any extent, we seldom
fail to observe a notable difference in the nature and relative
position of the rocks which compose it; the idea which forces.
itself upon the mind in such circumstances is, that these mineral
masses have not had the same origin, that they have been formed
and placed in their several situations at distinct and often dis-
tant epochs.
In examining attentively the inequalities which mark the sur-
face of the globe, we soon perceive that those rocks which gene-
rally form the most elevated points, the axis or skeleton of
mountain chains, result from the agglomeration or intimate
mixture of different mineral substances which may be isolated
and separately studied.
-
These crystalline masses are frequently covered to a certain
depth, and even completely concealed by rocks of more recent
formation, the fragmentary elements of which proclaim their origin
from the attrition or breaking down of the strata which support
them. The regular stratification of these superimposed rocks,
the configuration of their minute particles, the remains of or-
ganized beings which are found in them, proclaim them to be
deposits which have taken place successively and from the ocean.
The formation of the crystalline rocks probably dates from the
pe-
riod at which the crust of the globe became solid. These elements,
intimately mingled by fusion, combined as they cooled, accord-
ing to the laws of affinity, to constitute the mineral species which
we encounter; just as it happens that mineral species, identical
with those which we observe in nature, are produced and cry-
stallize during the consolidation of certain scoriæ from our
furnaces.
SOIL.
259
The various circumstances which have accompanied the cool-
ing of the crust of the globe, have doubtless occasioned the
differences which we observe in the distribution of the minerals
that enter into the composition of rocks. Thus granite and
mica schist which present so dissimilar a structure, are neverthe-
less, and very certainly, varieties of the same species, and con-
tain quartz, felspar, and mica. In sienite, the mica is replaced
by amphibolite, and in protogenite by talc. In trachite, a
volcanic rock, both of older and more recent date, quartz is almost
entirely wanting; the amphibolite is replaced by pyroxenite, and
the felspar which is encountered is no longer identical in its
chemical composition with that which enters into the constitu-
tion of granite. The limestone rock which belongs to the
same Plutonic epoch, is granular or saccharoid; occasionally the
intervention of magnesia makes it pass into dolomite.
The sedimentary strata do not vary less in their composition.
The causes which segregated the rocks of igneous origin, appear
to have destroyed or removed one or several of their elements
before their new consolidation; one of the most common de-
posits, sand-stone or grit, is almost wholly composed of grains of
quartz, amidst which particles of mica are frequently encoun-
tered; but felspar is extremely rare. In the oldest sedimen-
tary strata of the series, as in the greywackes, the igneous ele-
ments are met with more complete and less altered. The
structure of the calcareous rocks of this epoch is often compact,
clayey; it becomes porous and friable in deposits of more recent
date.
Twi
The stratified rocks must have been deposited in parallel
superimposed layers, and these strata, horizontal in the begin-
ning, have been forced into the inclined and perpendicular posi-
tions which they now occupy by the tumefaction or rising of the
masses upon which they rest. The organic remains which they
present, frequently in such quantity, proclaim that in the period
when the revolutions of the globe took place that gave them
birth, there were already animated beings and plants growing
upon the surface of the earth. The production of sedimentary
strata is an obvious proof that the igneous rocks of which they
are the product, must have been segregated, so as to form beds
s 2
260
SOIL.
of gravel, and sand, and clay. The elements of all stratified
rocks must necessarily have passed through these different states
before the powerful causes which consolidated them, of the na-
ture of which we cannot now form an estimate, came into play.
The disintegration of the crystalline igneous rocks proceeds
under our eyes, as it were, from the combined actions of water
and the atmosphere.
Water by reason of its fluidity, penetrates the masses of
rocks that are at all porous, it filters into their fissures. If the
temperature now fall, and the water comes to congeal, it sepa-
rates by its dilatation the molecules of the mineral from one an-
other, destroys their cohesion, and produces clefts which slowly
reduce the hardest rocks to fragments, and then to powder.
During the frozen state, the ice may serve as a cement, and con-
nect the disintegrated particles; but with the thaw, the slightest
force, currents of water, the mere effect of weight suffices to carry
the fragments to the bottom of the valley, and the rubbing and
motion to which these fragments of rocks are exposed in tor-
rents, tend to break them still smaller, and to reduce them
to sand.
The quantity of earthy matter brought down by streams
and rivers is considerable: an idea may be formed of it from the
thickness of the slime or mud deposited by a river which has
overflowed its banks. In many situations the arable soil is either
formed entirely, or is powerfully ameliorated by such alluvial de-
posits. The fertilizing powers of the mud of the Nile are well-
known; according to Shaw, the waters of this river carry with
them about the 132nd part of their volume; those of the Rhine,
at the periods of its great increase, bring down more than the
100th part; and Dr. Barrow, from observations made in China,
estimates at the 200th part of the volume of the mass of fluid,
the mud and slime which are carried towards the sea by the
Yellow river. These fluviatile deposits accumulate at the mouths
of great rivers and gradually encroach upon the ocean; this is
very conspicuous, for example, at the mouths of the Elbe,
where, at the turn of the tide, when there is an interval of
calm, the earthy matters which are held in suspension are preci-
pitated, and a sediment results, which is thrown up by the next
SOIL.
261
waves upon the beach. By these successive deposits, the beach
rises gradually, and an extensive alluvium is formed which re-
mains dry at neap and ordinary tides. These new lands, the
fertility of which is truly surprising, constitute the polders of
which the Dutch make so much. During spring tides and
storms from particular quarters, these polders would of course
be all submerged, had not the active industry of the inhabitants
raised dykes, which successfully oppose the waters of the
ocean.
Besides the mechanical causes of the destruction of rocks
already quoted, there is a chemical action depending upon
meteorological influences, which exerts a powerful influence upon
the constituent elements of crystalline rocks. Felspar, amphi-
bolite, mica, and the protoxide of iron suffer decomposition in
certain circumstances with surprising rapidity, without our being
able to foresee, and still less to explain, this singular tendency to
destruction. In granite, for example, the felspar and the mica
lose their vitreous and crystalline state, they become friable,
earthy, and are transformed into an argillaceous substance, which
is known in the arts under the name of kaoline, and which is
extensively used in the manufacture of porcelain; amphibolite,
and pyroxenite, undergo an alteration of the same kind. In
these minerals the protoxide of iron passes to the state of the
maximum of oxidation. The air and moisture appear to exert
a great influence upon this alteration, which frequently extends to
a great depth, as we see in the beds of porcelain earth, which
are worked in various granite districts, and as I have myself
ascertained, in a bed of decomposed syenitic porphyry where
there are very extensive subterraneous works. In these works,
which are carried on in auriferous strata, the alteration in the
felspar and amphibolite can be followed to a depth of nearly
330 feet. In the midst of the rocks so changed, we every here
and there meet with masses which have resisted the decomposing
action, and still possess all their original hardness and freshness.
Historical monuments also show us unalterable granites; such is
that, for instance, which now forms the obelisk in the square of
San Giovanni di Laterano at Rome, and which was cut at Siena,
under the reign of a King of Thebes, thirteen hundred years
before the Christian era. Such is further the obelisk of the
262
Place of St. Peter, which was consecrated to the sun by a son
of Sesostris more than three thousand years ago.
The schists, by reason of their structure, wear away with
much greater facility. Calcareous rocks resist atmospherical
agencies somewhat better; but their softness in general suffers
them to be readily attacked by mechanical causes, and water
even acts upon them as a solvent through the medium of the
carbonic acid which it always contains. The resistance of the
greywackes, and of the sand stones depends in a great measure
on the nature and cohesion of the cement which unites their par-
ticles; their power of resisting, however, is generally inconsiderable,
and these rocks fall down pretty rapidly into sandy soils.
The modifications experienced by the constituent minerals of
rocky masses, do not happen solely from changes in the mole-
cular state of their elements; their chemical nature is further
deeply changed, and some of their original principles disappear.
The felspars, for example, into the constitution of which, potash
and soda enter, abandon almost the whole of these alkalies, in
passing into the state of kaoline. This is made manifest by a
comparison of the analyses of the mineral in its two states.
Besides the alkali which is lost, we also perceive that in kaoline,
the proportion of alumen relatively to that of silica, is much
greater than in the undecomposed felspar, a fact, which, accord-
ing to M. Berthier, demonstrates that the alkali is removed in
the state of silicate.
SOIL.
The final result of the disintegration of rocks and of the
decomposition of the minerals which enter into their constitution,
is the formation of those alluviums which occupy the slopes of
mountains that are not too steep, the bottoms of valleys and the
most extensive plains. These deposits, however formed, whether
of stones, pebbles, gravel, sand or clay, may become the basis of
a vegetable soil, if they are only sufficiently loose and moist.
Vegetation of any kind succeeds upon them at first with diffi-
culty. Plants which by their nature live in a great measure at
the expence of the atmosphere, and which ask from the earth
little or nothing more than a support, fix themselves there when
the climate permits. Cactuses and fleshy plants take root in
sands; mimosas, the broom, the furze, &c. show themselves upon
gravels. These plants grow, and after their death either in
SOIL.
263
part or wholly, leave a debris which becomes profitable to suc-
ceeding generations of vegetables. Organic matter accumulates
in the course of ages even in the most ungrateful soils in this way,
and by these repeated additions they become less and less sterile.
It is probable that the virgin forests of the new world have thus
supplied the wonderful quantity of vegetable mould, in which the
present generation of trees is rooted. At Lavega de Supia, in
South America, the slipping of a porphyritic mountain covered
completely with its debris, to the extent of nearly half a league,
the rich plantations of sugar cane which were there established.
Ten years afterwards I saw the blocks of porphyry shadowed
by thick groves of mimosas; and the time perchance is not very
remote when this new forest will be cleared away and the stony
soil, enriched with its spoils, will be restored to the husbandman.
The chemical composition of the earth, adapted for vegeta-
tion, must of course participate in the nature of the rocks and
substrata from which it is derived; and the elements which
enter into the constitution of mineral species ought to be found
in the soils, which, by the effect of time or human industry, may
serve for the reproduction of vegetables. It is on this account
that it becomes interesting to know the composition of the
minerals, which are the most abundantly dispersed in the solid
mass of the globe.
The solid part of our planet, as is well known, occupies but
one third of its whole surface. The ocean occupies two thirds,
and the majority of the rocks of sedimentary formation must
have been primarily deposited at the bottom of the sea. These
rocks will therefore be apt to contain the saline substances
which are met with in sea water, and it is a fact that many of
the secondary sandstones show unequivocal traces of these
substances. Deltas and low downs, left by the ocean, are con-
stantly being brought under tillage, and the fierce winds of the
sea frequently carry saline matters to vast distances, even to the
centre of great continents; lastly, as we shall see by and by,
the ocean supplies agriculture with powerful manures. Analysis
shows that sea water contains, besides chloride of sodium or
common salt, hydrochlorate of magnesia, sulphate of soda,
sulphate of magnesia, sulphate of lime, carbonate of lime, carbo-
nate of magnesia, and a quantity of carbonic acid, to which
264
SOIL.
must be added the substances discovered in the mother waters
of salt marshes, and which occur with reference to the others in
quantities so small as to escape direct analyses of any moderate
portions of sea water: these substances are iodides, bromides, and
certain ammoniacal salts.
The minerals most generally found in rocks are quartz, felspar,
mica, amphibolite, pyroxenite, talc, serpentine and diallage.
Quartz is frequently composed of silica nearly in a state of purity;
but I may save time by presenting in a single table the compo-
sition of the principal mineral species such as we find it indicated
by the best chemical analysts:
Minerals.
Felspar of Lomnitz
Ditto
Domite
Ditto Albite of Finland
Ditto Albite of Arendal
Siberian Mica
Mica from the United-States.
•
Amphibolite of Pargas
White Pyroxenite.
Green ditto
•
Serpentine
Ditto, another kind
Spezian Diallage
Talc from St. Bernard
Ditto from St. Gothard.
•
•
Silica.
Alu-
mina.
Lime.
COMPOSITION.

Mag-
Po-
nesia. tash.
66.8 17.5 1.3
61.0 19.2
68.0 19.6 0.7
68.7 19.9
42.0 16.1
48.5 33.9
45.7 12.2 13.8
54.6
54.9 0.2
42.3
24.9
23.6
44.2
43.1 0.3 0.5 40.4
47.2 3.7 13.1 24.4
58.2 traces
62.0
12.0
11.5
1.6
traces
26.0 7.6
11.3
18.8
18.0
16.5
33.2
30.5 2.8
Oxide
Soda. of
Iron.
11.1
9.1
Oxidel
of
Mang-
anese.
08
4.2
0.2
0.5
0.3 traces
4.9
Flu-
oric Water
acid.
0.7
1.3
7.3 0.2 1.5
1.8
2.0
44
0.4
0.2
1.2
7.4
4.6
2.5
2.0
3.0
13.3
12.5
3.2
3.5
0.5
If we now compare the analyses of the ashes of vegetables
which we have already given with those just indicated, we see
that the mineral substances which meet us in plants also exist in
the soil independently of any addition from manure.
We may
therefore lay it down as a principle that the mineral substances
encountered in vegetables are obtained in the soil, and that the
whole of these substances come from rocks which form the solid
crust of our planet. I ought, however, to observe in this place
that the phosphates, which are so constantly present in plants
that it is to be presumed they are essential to their organization,
do not figure among the elements of crystalline rocks; we only
meet with phosphoric acid in the strata of a more recent
geological epoch, strata the formation of which has indeed fol-
lowed the appearance of organized beings; so that it would be
quite fair to maintain that this acid had been introduced into
SOIL.
265
these new strata by the animated beings which are buried in
them. Still the phosphates are by no means wanting in the
rocks of igneous origin. In metalliferous strata, to quote those of
more common occurrence only, we find phosphate of lead, of cop-
per, of manganese, and of lime; it is even difficult to discover a
ferruginous mineral which does not contain a larger or smaller
dose of phosphoric acid. And I must here add that if phosphoric
acid has been rarely indicated as a constituent of mineral sub-
stances, this is by no means from its uniform absence there, but
because it escaped the researches of the analyst, in the same way
as iodine and bromine for a long time escaped notice in all
the analyses that were made of sea water. Chemists, in fact,
only discover those bodies readily which exist in some very ap-
preciable quantity in the compounds they examine. The sub-
stances whose presence is not foreseen, those which only enter in
extremely small quantity into a mineral are apt to pass the eyes
even of the most skilful and conscientious unperceived.
The ashes of every vegetable examined up to the present time
show us phosphates, and yet these salts have never been detected
in any of the analyses of saps, (not very numerous it is true),
which we possess ; it is nevertheless all but certain that the sap
must contain phosphoric acid in some state of combination or
another.
Thaer compares the soil in husbandry to the raw material
upon which the industry of the manufacturer is exercised; the
comparison would perhaps be more exact were the soil likened to
the mechanical agents he uses; and, in fact, even as the pros-
perity of manufactures and the perfection of their produce de-
pend upon the perfection of the machinery employed, so are the
quality and the quantity of crops connected in the most inti-
mate manner with the quality of the soil. The highest skill of
the husbandman, even under a favourable climate, and otherwise
in the most advantageous circumstances may all be made nu-
gatory by the incessantly renewed difficulties which meet him in
a barren soil.
To be truly fit for agriculture the earth ought to present
several essential qualities; a soil, for instance, must be suffi-
ciently open, sufficiently loose to permit the roots of plants to
penetrate it, and to prevent the water from stagnating upon it.
266
SOIL-SAND AND CLAY.
The matter of which it is composed must farther be of such a
kind that the air may insinuate itself into it and be renewed,
without, however, too rapid a desiccation following.
A great deal has been written since Bergman's time upon the
chemical composition of soils. Chemists of great talent have
made many complete analyses of soils noted for their fertility;
still practical agriculture has hitherto derived very slender bene-
fits from labours of this kind. The reason of this is
The reason of this is very sim-
ple; the qualities which we esteem in a workable soil depend
almost exclusively upon the mechanical mixture of its elements;
we are much less interested in its chemical composition than in
this; so that simple washing which shows the relations between
the sand and the clay tells of itself much more that is important
to us than an elaborate chemical analysis. The quality of an
arable soil depends essentially on the association of these two
matters. Sand, whether it be siliceous, calcareous, or felspathic,
always renders a soil friable, permeable, loose; it facilitates the
access of the air and the drainage of the water, and its influence
is more or less favourable as it exists in the state of minute sub-
division, or in the state of coarse sand or of gravel.
:
Clay possesses physical properties entirely opposed to those of
sand; united with water it forms an adhesive plastic paste,
which once moistened becomes almost impermeable. With such
characters it will easily be conceived how it is impossible to
work to advantage a soil that is entirely argillaceous. The pro-
per character, or if you will, the quality of a soil depends then
essentially on the element which predominates in the mixture of
sand and clay that composes it; and between the two extremes
which are alike unfavourable to vegetation, viz. the completely
sandy soil and the unmixed clay, all the other varieties, all the
intermediate shades can be placed. It is rare indeed that arable
soils are formed solely of sand and clay; not to mention.
certain saline substances which are generally encountered al-
though in small quantity, we always find the remains of organic
matters, remains which constitute that part of a soil which has
been designated under the somewhat vague name of humus.
Although a soil which is entirely without humus may be cultivated
by calling in the aid of manure, and as humus consequently need
not be regarded as indispensable, still this matter generally enters
SOIL-ITS ANALYSIS.
267
in certain proportions into the constitution of soils. The soils
of forest lands contain a large quantity of it, and some soils are
mentioned, which are very rich in this substance and which yield
abundant crops of grain for ages and with very little attention.
In examining a soil, attention ought to be directed, 1st. to the
sand, 2nd. to the clay, 3rd. to the humus which it contains. It
would further be useful to inquire particularly in regard to cer-
tain other principles which exert an unquestionable influence
upon vegetation, such as certain alkaline and earthy salts.
Vegetable earth dried in the air until it becomes quite friable
may nevertheless still retain a considerable quantity of water, and
which can only be dissipated by the assistance of a somewhat
high temperature. It is therefore proper in the first instance to
bring all the soils which it is proposed to examine comparatively,
to one constant degree of dryness. The best and quickest way
of drying such a substance as a portion of soil is to make use
of the oil-bath; a quantity of oil contained in a copper vessel is
readily kept at an almost uniform temperature by means of a
lamp. A thermometer plunged in the bath shows the degree to
which it is heated; the substance to be dried is put into a
glass tube of no great depth and sufficiently wide; or into a
porcelain or silver capsule, if the quantity to be operated upon
be somewhat considerable; these tubes or vessels are placed in
the oil so as to be immersed in it to about two-thirds of their
height. For the desiccation of soils the temperature may be
carried to 150° or 160° C. (334º or 352º F.) The weight of
the vessel is first accurately taken, and a given weight of the
matter to be dried is then thrown into it, after which it is ex-
posed to the action of the bath. If we operate upon from 600
to 700 grains, the drying must be continued during two or
three hours; the weight of the capsule with its contents, after
having been wiped thoroughly clean, is then taken. It is placed
anew in the bath, and its weight is taken a second time after an
interval of fifteen or twenty minutes; if the weight has not
diminished, it is a proof that the drying was complete at the
time of the first trial. In the contrary case, the operation must
be continued, and no drying must be held terminated until two
consecutive weighings, made at an interval of from fifteen to
twenty minutes, show any thing more than a very trifling dif-
268
SOIL-ITS ANALYSIS.
ference. Davy points out another and much more simple
method, which although far from accurate, may nevertheless
suffice in many general trials. The soil to be dried is put into
a porcelain capsule heated by a lamp, and a thermometer with
which the mass may be stirred, is placed in its middle, and
shows the temperature at each moment. Lastly, in many cir-
cumstances the marine bath may suffice. In drying, the main point
is to do so at a known temperature, and one which may be repro-
duced; for the absolute desiccation of a quantity of soil could
not be accomplished except at a heat close upon redness, and
this would of course alter or destroy the organic matters it
contains.
The organic matters contained in ordinary soils consist in part
of pieces of straw and of roots, which are usually separated by
sifting the earth through a hair sievo; the gravel and stones
which the soil contains are separated in the same way.
The earth sifted is now washed. To accomplish this, it is
introduced into a matrass with three or four times its bulk of
hot distilled water, the whole is shaken well for a time, the
matrass is left to stand for a moment, and then the liquid is
decanted into a wide porcelain capsule. The washing is con-
tinued, fresh quantities of water being added each time until the
whole of the clay has been removed, which is known by the
fluid becoming clear very speedily; the sand which remains is
then washed out into another capsule. The argillaceous particles
or the clay and all the matters held in suspension in the water are
thrown upon a filter and dried; the desiccation is completed
by the same process and under the same circumstances as that
of the soil had been. The sand is in like manner dried with
the same care.
If we would ascertain the nature and quantity of the soluble
salts, the whole of the water used in the washing must be put
together and evaporated, which may be done upon a sand bath.
The evaporation is pushed to dryness, and the salts that remain,
having been previously weighed, are thrown into a small plati-
num capsule, in which they are heated to a dull red by means
of a spirit lamp, in order to burn out the organic salts, and thus
distinguish by means of a subsequent weighing between them
and the inorganic salts.
SOIL ITS ANALYSIS.
269
The sand may be silicious or calcareous. The presence of
carbonate of lime is readily ascertained by treating it with an
acid which will form a soluble salt with lime, such as hydro-
chloric, nitric or acetic acid. Effervescence shows the presence
of a carbonate; the quantity of which may be estimated by
weighing the sand dry before and after its treatment with the
acid, particular care being of course taken to wash the remain-
ing sand well before setting it to dry. This, however, is an
operation of little use, the great object is to ascertain the quan-
tity of sandy matter. Had we a particular interest in ascertain-
ing the presence and estimating the quantity of the earthy
carbonates contained in a sample of soil, it would be advisable
to make a special inquiry, inasmuch as the finely divided cal-
careous earth being carried off along with the clay in the course
of the washing, the sand obtained never contains the whole of
the carbonate of lime.
The argillaceous matter procured by the washing is far from
being pure clay; it contains a quantity of extremely fine sand,
particles of calcareous earth, and if the soil contain humus,
the more delicate particles of this substance will also be in-
cluded.
To determine the quantity of humus, recourse is generally
had to its destruction by heat. A known weight of dried earth
is heated to redness in a capsule, and constantly stirred for a
time, and when no more of those brilliant points or sparks,
which are indications of the combustion of carbon, are observed,
it is set to cool and then weighed. This is the method which has
been generally followed by Davy and others. It would be diffi-
cult to find a method more convenient than this, but it is unfortu-
nately very inaccurate. Soils dried at a temperature at which
organic matter, such as humus, &c., begins to change, still re-
tain a considerable quantity of water in union with the clay.
This water is disengaged at the red heat required for the com-
bustion of the organic matters; and as their quantity is estimated
by the loss of weight on the subsequent weighing, it is obvious
that the loss from the dissipation of water is added to that which
proceeds from the destruction of the humus. It is undoubtedly to
this cause of error that we must ascribe the large proportions of
270
-ITS ANALYSIS.
SOIL-
;
humus mentioned in the soils examined by Thaer and Einhoff
it is therefore better to restrict the examination to the determi-
nation of the presence or absence of humus than to attempt to
ascertain its quantity by so imperfect a method.
Priestley and Arthur Young were already aware that a more
delicate operation was required to determine the quantity of
humus. They recommend calcination of the soil in a close
vessel, and that the gaseous products should be collected. This
mode of proceeding, however, would have but slight advantages
over that which I have just criticised, inasmuch as the volume
of gas collected varies with every difference of heat employed.
The only method in my opinion which we have of learning
the quantity of humus, of organic debris, which is contained in
a soil, is that of an elementary analysis. It is by burning a
known quantity of earth thoroughly dried by means of the oxide
of copper, aided by a current of oxygen, that the carbon and hy-
drogen may be determined. But the most important point of all is
to ascertain the amount of azote included in the organic remains
of the soil; and we have happily precise means in our elementary
analysis of ascertaining the quantity of azote, from which the
amount of azotised organic matter may be accurately inferred.
say
It may be very useful to determine the presence or absence
of carbonate of lime in a soil; this knowledge would of course
guide us in our applications of lime, marl, &c. Two modes
may be employed for this purpose; 1st. the soil may be treated
by nitric acid slightly diluted with water. Any effervescence
will denote the presence, in all probability, of carbonate of lime.
I in all probability, because the disengagement of carbonic
acid gas under such circumstances generally indicates the pre-
sence of carbonate of lime; it is not, however, a special character,
because the disengagement may be due to the presence of any other
carbonate. It is well to boil the acid solution upon the sample
of soil that is analysed; the part which is not dissolved is thrown
upon a filter and washed with distilled or rain water boiling hot.
Into the clear filtered liquor which results from all the portions
of water used in the washing, a little ammonia is added; if any
precipitate falls, it is collected upon a filter and washed; to the
new liquors obtained by this washing, a solution of oxalate of
SOIL-ITS ANALYSIS.
271
ammonia is added. If there be any lime present, it is
thrown down in the state of oxalate, and the liquor, having
been left at rest for five or six hours, becomes completely
clear; the addition of a few drops of the solution of oxa-
late of ammonia to this clear fluid satisfies us whether the
whole of the lime has been precipitated or not. The oxalate of
lime is received upon a filter, washed and dried; it is then
thrown into a platinum capsule along with the piece of filtering
paper upon which it was collected, and is heated to a dull red
until the paper of the filter is completely consumed and no
further trace of carbon appears; the capsule is then taken from
the fire or from over the spirit lamp, and cooled; when cold,
the matter which it contains is moistened with a concentrated
solution of carbonate of ammonia.
The matter is then dried, great care being taken that nothing
is lost by particles flying out, and the capsule is again heated to
a dull red; when cold it is weighed accurately, and the quantity
of matter contained then becomes known. This matter is car-
bonate of lime, 100 of which represents 56.3 of lime and 43.7
of carbonic acid. I have said that in arable soil other carbonates
may be met with besides that of lime; calcareous soils, for ex-
ample, very commonly contain carbonate of magnesia. If we
would ascertain the quantity of this earth the mode of proceed-
ing which I have just particularly indicated enables us to do so;
we have but to evaporate the liquid from which the oxalate of
lime was deposited, and then to calcine the product of the eva-
poration in a platinum capsule. Any nitrate of magnesia which
may exist there will be decomposed at a dull red heat, as well as
any oxalate of ammonia which may have resulted from ammonia
added in excess. By treating the residue of the calcination with
water we obtain the magnesia, which being washed has only to
be calcined and its weight ascertained by weighing.
2nd. If we would be content with a simple approximation we
may judge of the quantity of calcareous carbonate contained in
a vegetable soil by measuring the quantity of carbonic acid
which we obtain from it. We counterpoise upon the scale of a
balance a phial containing some diluted nitric acid; we weigh a
certain quantity of the earth to be analysed, and this is added by
272
SOIL-ITS ANALYSIS.
degrees to the acid. If the earth contains carbonates, efferves-
cence ensues. The liquid is shaken with care, and having
waited a few minutes in order to let the carbonic acid which is
mixed with the air of the phial escape, the phial with its con-
tents is again put into the balance. If there has been no disen-
gagement of carbonic acid it is clear that to restore the equili-
brium it will be sufficient to add to the opposite scale the weight
of the earth which was put into the phial; whatever is wanting of
this weight represents precisely the weight of carbonic acid
which has been disengaged. Presuming this acid to have been
combined with lime, the weight of the calcareous carbonate can
be calculated exactly.
Sulphate of lime is an occasional constituent of soils; to ascer-
tain its presence and quantity, the following is the method of
procedure :
The earth well pulverized is first roasted for a considerable
time in a crucible or platinum capsule, until all the organic mat-
ter is completely destroyed; it is advisable to operate on about
100 grammes, or about 3.2 ounces troy of soil. After this operation
the matter is boiled in 4 or 5 times its weight of distilled water
for some time; water being added to replace that which is dissi-
pated by evaporation; we then filter, re-wash, and having added
all the liquors we evaporate in a capsule until the volume of the
liquid is reduced to a few drachms. To the liquid thus concen-
trated we add its own bulk of alcohol. If the solution contains
sulphate of lime it will be deposited, and the deposit being re-
ceived upon a filter and washed with weak alcohol, its weight is
taken after having been dried and calcined. This salt is fre-
quently seen deposited in the form of fine colourless needles on
the cooling of the sufficiently concentrated solution; but the ad-
dition of alcohol is always useful, because the sulphate of lime
which is not very soluble in water, is altogether insoluble in weak
spirit, which on the contrary dissolves certain alkaline and
earthy salts whose presence would interfere with the accuracy of
the result.
It may be matter of great moment to determine the existence
and the quantity of phosphates contained in a soil destined for
cultivation. Although the search for phosphoric acid may per-
SOIL-ITS ANALYSIS.
273
haps require a certain familiarity with chemical analysis. I shall
nevertheless indicate the method of procedure. It is much to
be desired that enlightened agriculturists should not remain
strangers to manipulations of this kind.
The soil to be analysed must be first deprived of all organic
matters by calcination. After having reduced it to a very fine
powder it is to be boiled for about an hour with three or four
times its weight of nitric or hydrochloric acid. The solution is
then diluted with distilled water, and filtered; the matter which
remains upon the filter is generally silica or alumina which has
escaped the action of the acid. After having reduced the wash-
ings by evaporation, and added them to the acid liquor, ammonia
in solution is poured in. Taking the simplest instance, the preci-
pitate which falls upon the addition of this alkali may contain, 1st.
phosphoric acid in union with the peroxide of iron and lime;
2nd. oxide of iron and of manganese; 3rd. silica. This pre-
cipitate, which is usually of a gelatinous appearance, is received
upon a filter, well washed and dried, when the precipitate is rea-
dily detached from the filter. It is thrown into a platinum
capsule which is raised to a white heat, after which the weight
of the residue is taken. The precipitate after calcination is
thrown into a small glass matrass, and dissolved by hot hydro-
chloric acid. If there is any silica undissolved, its quantity is
merely estimated if it be very small, if it be a larger quantity it
is to be collected upon a filter and weighed. To the new acid
solution, about three times its weight of alcohol is added, the
mixture is shaken, and pure sulphuric acid is then instilled drop
by drop until there is no longer any precipitate. The precipitate
is sulphate of lime, which is thrown upon a filter, where it is
washed with diluted alcohol; it is then dried, calcined, and the
weight of the sulphate of lime obtained, permits us to calculate
that of the lime which formed part of the precipitate thrown
down by the ammonia in the first instance. 100 of sulphate of
lime are equivalent to 41.5 of pure lime.
The alcoholic liquor is concentrated in order to expel the
spirit; as it is acid, it is saturated with ammonia until a slight
precipitate begins to be formed, which is not re-dissolved upon
shaking the mixture. A few drops of the hydrosulphate of
T
274
SOIL-ITS ANALYSIS.
ammonia are then added, upon which the iron and the man-
ganese fall in the state of sulphurets. As a part of the metals
has been precipitated in the state of oxide by the ammonia
added in the hydrosulphate, it is well to digest for eight or ten
hours, because the hydrosulphate of ammonia always ends by
changing the metals present into sulphurets, which being washed,
dried, and reduced to the state of oxides by calcination in a
platinum capsule, are weighed.
If the first ammoniacal precipitate did not contain phosphoric
acid, its weight ought to be reproduced by adding that of the
lime to that of the metallic oxides proceeding from the calcina-
tion of the sulphurets. Any loss which is noted after this,
is due, if the process has been well conducted, to phosphoric
acid, which had not been collected, but which has re-
mained in the state of phosphate of ammonia in the liquid
treated by the hydrosulphate. To determine with precision the
presence of phosphoric acid, the liquid in question must be
evaporated to dryness, and the residue heated strongly in a
platinum capsule. After the dissipation and decomposition of
the ammoniacal salts, there remains watery phosphoric acid,
distinguishable by its powerful acid reaction, its syrupy con-
sistence and its fixity.
By way of example, I shall give the results obtained in an
analysis of this kind:
From the acid liquor ammonia, threw down of :
Phosphates and metallic oxides
These gave of sulphate of lime
Equivalent to lime
Hydrosulphate of ammonia caused a precipitate, which
calcined gave of metallic oxides
Lime and metallic oxides together
Difference due to phosphoric acid
grs. troy
8.012
8.768
3.012
1.620
5.233
2.789
The analysis for phosphoric acid may be simplified by em-
ploying a process conceived by M. Berthier, and which is
founded upon the strong affinity of this acid for the peroxide of
iron and the insolubility of the phosphate of the peroxide of
iron in dilute acetic acid. If to a fluid containing at once phos-
phoric acid, lime, peroxide of iron, alumina and magnesia in
solution, ammonia be added, the precipitate will contain the
SOIL-ITS ANALYSIS.
275
whole of the phosphoric acid. The acid will be in great part
combined in the state of phosphate of iron, if the peroxide of
iron be in quantity more than sufficient to neutralize it, a con-
dition which must be frequently expected in an arable soil ;
however to make sure of this point it is well to add a certain
quantity of the peroxide of iron to the soil, whi h is to be
analysed. Besides the phosphate of iron the precipitate may
contain phosphate of lime, phosphate of alumina, and certainly
ammoniacal magnesian phosphate. Finally, with these phosphates
will be found associated alumina and oxide of iron, the latter
especially if it has been introduced in excess. The precipitate
collected upon a filter and washed, must then be treated with
dilute acetic acid, which will dissolve the lime, the magnesia,
and the excess of the oxides of iron and alumina, and there will
remain phosphate of iron or phosphate of alumina, because the
latter salt is as insoluble as the former in acetic acid. Whenever
the precipitate in question, therefore, leaves a residue which is
insoluble in vinegar the presence of phosphoric acid may be
inferred; this residue may consist of basic phosphates of iron or
alumina or of a mixture of the two salts, and no great error
will be committed if one hundred parts of this residue calcined,
be assumed as representing fifty of phosphoric acid.
The presence of silica in the precipitate insoluble in acetic
acid may, however, lead to error.
To make sure that the pre-
cipitate is formed by a phosphate it must be re-dissolved in
hydrochloric acid, and the acid solution evaporated to dryness.
so as to render the silica, which may exist in it, insoluble. By
treating the residue with hydrochloric acid again, the phosphates
alone will be dissolved. The presence of phosphoric acid may
otherwise be determined by treating the phosphate of iron in
solution in the way which I have already indicated.
From what precedes, it must be obvious that the most
carefully conducted chemical analysis of a soil, only leads us to
the discovery of certain principles which exist in very small
quantity, although their action is unquestionably useful to vege-
tation. As to the determination of the relative quantitics of
sand and loam, this rests upon simple washing; and a chemist
would spend his time to very little purpose, in seeking by means
T 2
276
SOIL ITS ANALYSIS.
of elementary analyses to determine the precise composition of
these substances. The finest part carried off by the water will
always show properties analogous to those of clay; the sand
which is generally silicious, will exhibit the characters of quartz;
and the calcareous fragments, which are mixed with it, will
exhibit those that belong to carbonate of lime. It will be
sufficient then in connexion with the mineral constitution of
arable soils, to expose very briefly the general properties of
clay or loam, of quartz, and of carbonate of lime, substances.
in fact, which form the bases of all arable lands. Pure
clay composed of silica, alumina and water, does not contain
these substances in the state of simple mixture. The inquiries
of M. Berthier have satisfactorily shown that clay is an hydrated
silicate of alumina. When we remove a portion of the alumina.
from clay, for example, by treating it with a strong acid, the silica
which is set at liberty will dissolve in an alkaline solution, which
would not be the case were the silica present in the state of
quartzy sand, however fine.
Pure clays are white, unctuous to the touch, stick to the
tongue when dry, and when breathed upon give out an odour
which is well known, and is commonly spoken of as the argil-
laceous odour. This property of dry clay to adhere to the
tongue is owing to its avidity for water. It is known, in fact,
that dry clay brought into contact with water, first swells, and
finally mixes with it completely. Duly moistened it forms a
tough and eminently plastic mass. Exposed to the air, moist
clay as it dries, shrinks considerably, and if the drying be rapid,
the mass cracks in all directions. It is to an action of this
kind that we must ascribe the cracks and deep fissures which
traverse our clayey soils in all directions during the continuance
of great droughts.
The constitutional water of clays is retained by a very
powerful affinity, and does not separate under a red heat; pure
clay has a specific gravity of about 2.5; but the weight is
frequently modified by the presence of foreign matter, for it
contains sand, metallic oxides, carbonate of lime, carbonate of
magnesia, and frequently even combustible substances from
bitumen to plumbago, all of which admixtures of course
SOIL-ITS ANALYSIS.
277
modify the properties which are most highly esteemed in clays,
such as fineness, whiteness, infusibility, &c.
Quartz is abundantly distributed throughout nature, and is
met with in very different states in the form of transparent
colourless crystals constituting rock crystal, as sand of different
fineness, finally in masses constituting true rocks. Quartz is
the silica of chemists, and a compound according to them of
oxygen and silicon, in the proportion Berzelius says of 100 of
the radical to 108 of oxygen.
Silica in a state of purity occurs in the form of a white pow-
der, and having a density of 2.7. It is infusible in the most
violent furnace, but it not only melts in the intense heat which
results from the combustion of a mixture of hydrogen and
oxygen gas, but it is even dissipated in vapour. As generally
obtained, silica is held insoluble in water; still when in a state of
extreme subdivision it is soluble; and then its insolubility is pro-
bably not so absolute as is generally supposed, for M. Payen has
found notable quantities in the water of the artesian well of Gre-
nelle, and in that of the Seine. Silica exists especially in very
appreciable quantity in certain hot springs where the presence of
an alkaline substance favours its solution; the water of the hot
springs of Reikum in Iceland contain about th parts of
its weight of silica; and the thermal spring of Las Trinche-
ras, near Puerto Cabello, deposits abundant silicious concretions.
The water of this latter spring, which is at the temperature of
210° F., besides silica contains a quantity of sulphurated hydro-
gen gas, and traces of nitrogen gas. Rock crystal when colour-
less and transparent may be regarded as pure silica; in the
varieties of quartz which mineralogists designate as calcedony,
agate, opal, &c. the silica is combined with different mineral
substances, particularly oxide of iron and of manganese, alumina,
lime, and water.
Carbonate of lime, considered as rock, belongs to every epoch
in the geological series, and frequently constitutes extensive
masses. When pure it is composed of lime 56.3, carbonic acid
43.7 ; and its density is then from 2.7 to 2.9. It dissolves
with effervescence without leaving any residue in hydrochloric or
nitric acid. Exposed to a red heat its acid is disengaged, and
quick lime remains. Carbonate of lime is insoluble in water,
4
1000
278
SOIL-ITS ANALYSIS.
but it dissolves in very considerable quantity under the influence
of carbonic acid gas. When such a solution is exposed to the
air the acid escapes by degrees, and the carbonate is deposited,
by which means those numerous deposits of carbonate of lime
are produced which we see constituting tufas and stalactites.
The solubility of carbonate of lime in water acidulated with car-
bonic acid, enables us to understand how plants should meet with
this salt in the soil, inasmuch as rain water always contains a
little carbonic acid.
The mineral substances which we have now studied taken
isolatedly would form an almost barren soil; but by mixing
them with discretion a soil would be obtained, presenting
all the essential conditions of fertility, which depend as it
would seem much less on the chemical constitution of the
elements of the soil than on their physical properties, such as
their faculty of imbibition, their density, their power of conduct-
ing heat, &c. It is unquestionably by studying these various
properties that we come to form a precise idea of the causes
which secure or exclude the qualities we require in arable soils.
This has been done very ably by M. Schübler, and his admirable
paper will remain a model of one application of the sciences to
agriculture.*
The researches of M. Schübler were directed to the mineral
substances which are generally found in soils, viz.: 1st. silicious
sand; 2nd. calcareous sand; 3rd. a sandy clay containing about
ths of sand; 4th. a strong clay containing no more than about
2
ths of sand; 5th. a still stronger clay containing no more than
about th of sand; 6th. nearly pure clay; 7th. chalk, or carbo-
nate of lime in the pulverulent state; 8th. humus; 9th. gypsum;
10th.light garden earth, black, friable, and fertile, and containing in
100 parts: clay 52.4, quartzy sand 36.5, calcareous sand 1.8, calca-
reous earth 2.0, humus 7.3; 11th. an arable soil composed of clay
51.2, silicious sand 42.7, calcareous sand 0.4, calcareous earth
2.3, humus 3.4; and 12th. an arable soil taken from a valley
near the Jura, containing clay 33.3, silicious sand 63.0, calca-
reous sand 1.2, calcareous earth and humus 1.2, loss 1.3.
The object of these inquiries was to ascertain 1st. the specific
gravity of soils; 2nd. their power of retaining water; 3rd. their
* Schübler, Annals of French Agriculture, vol. XL. p. 122, 2nd. series.
1
SPECIFIC GRAVITY OF SOIL.
279
consistency; 4th. their aptitude to dry; 5th. their disposition to
contract whilst drying; 6th. their hygrometric force; 7th. their
power of absorbing oxygen; 8th. their faculty of retaining heat;
and 9th. their capacity to acquire temperature when exposed to
the sun's rays.
Specific gravity of soils. The weight of soils may be com-
pared in the dry and pulverulent state, or in the humid state, or
the specific gravity of the particles which enter into their com-
position may be determined. This last information is easily
obtained by the following method: take a common ground stop-
per bottle, weigh it stoppered and full of distilled water; let it
then be emptied, in order that a known quantity of the soil, in
the state of powder and quite dry, may be introduced into it. A
quantity of water is now poured in, and the phial is shaken to
secure the disengagement of all air bubbles; the phial is then
filled with distilled water, and when the upper part has become
clear the stopper is replaced; the phial is then wiped dry and
weighed again. The difference between the weight of the phial
full of water plus that of the matter, and the weight of the
phial containing the matter and the water mixed, gives the
weight of the water displaced by this matter. Thus :
Weight of the phial full of water
Weight of the matter
•
Weight of the phial containing the mingled earth
and water
Difference of water displaced
60.0
24.0
84.0
74.4
9.6
which is the weight of the volume of water equal to that of
the matter introduced into the phial; we have consequently for
the specific gravity of the earth 3-2.5, the weight of the water
having been taken as 1.
This number represents the mean specific gravity of the iso-
lated particles of the powder which has been examined. But we
must not from this density pretend to deduce the weight of a
particular volume of soil, a cubic foot or a cubic yard for in-
stance; we should come to far too high a number. The weight
of a given volume of earth must be determined immediately by
ramming it into a mould or measure of a known capacity.
From M. Schübler's experiments it appears, 1st. that silicious
280
IMBIBING POWERS OF SOIL.
and calcareous sandy soils are the heaviest of any; 2nd. that clayey
soils are of least density; 3rd. that humus or mould is of much
lower density than clay; 4th. that a compound soil being gene-
rally by so much the heavier as it contains a larger proportion of
sand, and so much the lighter as it contains a larger quantity of
clay, of calcareous earth, and of humus, it is possible from the
density of a soil to infer the nature of the principles which pre-
vail in it. In the course of his experiments M. Schübler found
that artificial mixtures always gave higher densities than those
that ought to have resulted from the several densities of each of
the sorts of substance which formed the mixture.
Imbibition of water. The power which soils possess of retain-
ing water or of resisting the too rapid dissipation of their moisture
is highly important in its influence upon their fertility. This fa-
culty is measured comparatively in the following manner; a given
quantity of soil is taken, say from 3 to 400 grains; it is dried
until it ceases to lose weight; it is then made into a thin paste
and thrown upon a moistened filter; when it has ceased to
drop it is weighed. The increase of weight is plainly due to
the quantity of water retained by the soil, thus:
Weight of the dry soil
Weight of the moistened filter
375.0
Weight of the filter and moistened earth . 525
Water absorbed
150
In the experiment quoted, 100 of dry earth absorbed or
imbibed 50 of water. The following table contains the result
of experiments made on the imbibing power of different soils.
Kind of earth.
Silicious sand
Gypsum
Calcareous sand
300.0
75.0
Sandy clay
Strong clay
Sandy clay
Fine calcareous earth
Humus
•
Water absorbed by
100 parts of the earth.
25
27
29
40
50
70
85
. 190
}
CONSISTENCY OF SOIL.
281
•
Kind of earth.
Garden earth
An arable soil
Another arable soil
Water absorbed by
100 parts of the earth.
89
52
48
It appears, therefore, that the silicious and calcareous soils
and the gypsum have the least affinity for water; the clayey
soil retained by so much the more as it contained a smaller
quantity of sand; the fine calcareous earth retained 15 per
cent. more than the pure clay; whilst the calcareous sand re-
tained 41 per cent. less. This fact proves how much the state
of sub-division must influence the physical properties of soils;
and it is easily to be understood that in noting the presence of
calcareous matter in an arable soil we are carefully to indicate
the form and degree of sub-division in which it occurs; humus,
however, is the substance which shows itself most greedy of
moisture, and we perceive from this fact wherefore soils rich in
this principle have so strong an affinity for water.
Consistence, tenacity, friability of soils. The consistence
or tenacity of soils is an important property which agriculturists
indicate when they speak of soils being strong or stiff, and
light, the amount of power expended in ploughing being taken
as a measure of these qualities. To compare different soils under
the point of view of their tenacity in the dry state, M. Schübler
moulded various kinds, duly moistened, into equal and similar
parallelopipedes. When these solids were completely dry, he
placed either extremity upon a fixed support, and by means of
the scale of a balance hung exactly from the middle of the
prisms, he added weights gradually until they gave way; the
weight, supported by each parallelopiped immediately before it
broke, expressed its tenacity.
In working a damp soil we have not only to overcome its force
of cohesion, but further and principally to get the better of its
adhesion to our implements. This consideration led M. Schüb-
ler to estimate, always comparatively, the power which it is
necessary to expend in working soils of different descriptions.
As the material which enters into the construction of agricul-
tural instruments is in general iron and wood, he did no more
than ascertain the disposition of the soil to adhere to these two
substances. In the experiments, the results of which we shall
282
TENACITY ON SOIL.
immediately detail, two discs were employed, one of iron, the
other of beech-wood, having equal surfaces. The disc was con-
nected with the extremity of the arm of a very delicate balance;
it was then brought into perfect contact with the moist soil, and
when it adhered, the opposite scale of the balance was loaded
until the adhesion was overcome. In experiments of this kind
it is obviously indispensable that the soil in each instance should
have the same degree of humidity; they were tried, consequently,
at the point of saturation with water.
Pure dry clay possessed the greatest tenacity, and its power
was expressed by the number 100; the tenacity possessed by
other matters was then compared to that of pure clay. The
following table exhibits the results of the two series of experi-
ments, viz. those having reference to the tenacity and those
having reference to the force of cohesion.

Kind of soil.
Silicious sand
Calcareous sand
Fine calcareous earth
Gypsum
Humus
Sandy clay
Stiff clayey soil
Strong clay
Pure clay
Garden earth
Earth from Hoffwyll
Earth from the Jura
Tenacity of soil, Tenacity express- Cohesion in the
that of pure clay
ed in weight.
being 100.
moist state.
0.
0.
5.0
7.3
8.7
57.3
68.8
83.3
100.0
7.6
33.0
22.0
kil.
0.
0.
0.55
0.81
0.97
6.36
7.64
9.25
11.10
0.84
3.66
2.44
kil.
0.17
0.19
0.65
0.49
0.40
0.35
0.48
0.78
1.22
0.29
0.26
0.24
Vertical adhesion
to iron and to
wood on a surface
of 3937 square
inches.
kil.*
0.19
0.20
0.71
0.53
0.42
0.40
0.52
0.86
1.32
0.34
0.28
0.27
M. Schübler finds, from his experiments, that a dry soil is
very easily worked when its tenacity does not exceed 10, that
of pure clay being 100 in the moist state. Soils are further
worked with ease when their adherence to a surface 3.937 inches
square is represented by a weight of from 0.15 to 0.30 kil.;
i. e. from 0.380 to 0.760 or nearly 3rd to
ths of a lb. avoird.;
* The abbreviate kil. in the above table signifies killogramme, a weight
equal to 2.2lbs. avoirdupoise. As the weights are principally interesting in
their relations to one another, it has not been thought necessary to reduce
them to English weights.
DRYING OF SOILS.
283
the latter term passed, the difficulty of working increases rapidly,
and a very considerable force is required when the adherence to
the same surface amounts to 0.70 kil. or 1.840lbs. avoird.
The tenacity of a wet soil is not, however, in the direct ratio
of its faculty of imbibition. Loams and loose calcareous soils
which absorb much more water than clay are nevertheless much
less tenacious; and then water actually makes sandy soils
stiffer than they are when dry.
Every practical farmer knows how much more friable stiff wet
soils become from the effects of frost. The water in expanding
as it becomes solid pushes apart the molecules of the soil, and it
is to this action that the advantages of autumn ploughing are
with justice ascribed. M. Schübler found that the cohesion
of a stiff clay, which was equal to 68 fell to 45, when before it
was tried the clay was exposed to the frost.
Disposition of the soil to become dry. The faculty of throw-
ing off by evaporation any excess of water with which it may be
charged, is as essential to constitute a good soil as is that of re-
taining moisture in due proportion. Those soils which throw
off too slowly the excess of moisture they have acquired during
the winter, occasion much trouble to the husbandman. They
are perfectly unworkable in the spring, and consequently can
only be sown very late. M. Schübler tried the retentive powers
of the soil by the following method. A metallic disc, furnished
with a narrow rim, was suspended to the arm of a balance.
Over this disc, the soil to be tried and previously brought to the
point of saturation with moisture, was spread as evenly as pos-
sible. The weight of the disc thus charged was noted, and it
was weighed anew, after having been kept for four hours in a
temperature of 18.75° cent. (65.75° Fahr.) The weight of
the water lost by evaporation was obtained by a second weighing;
the complete desiccation of the soil was then completed in the
stove. The following is the detail of one operation:
Weight of the moist earth
Weight after four hours' exposure to the air
Water evaporated
Weight of the moist earth
Weight after complete desiccation
Whole quantity of water contained in the soil tried
310
260
50
310
200
110
284
SHRINKING OF SOILS.
Thus 100 of water of imbibition lost 45.5 during exposure to
the air for 4 hours at a temperature of about 66° Fahr. A
more severely accurate method might readily be contrived, but
that employed by M. Schübler appears sufficient for ordinary
purposes. His results, in regard to the different kinds of soil he
tried, are these :
Kinds of soil.
100 parts of the water
contained in the soil lose
in the course of 4 hours
at 66 deg. Fahr.
88.4
75.9
Silicious sand
Calcareous sand
Gypsum
Sandy clay
Stiffish clay
71.7
52.0
45.7
BET
Stiff clay
Pure clay
Calcareous soil
Humus
Garden earth
Arable soil of Hoffwyll
Arable soil of the Jura
34.9
31.9
28.0
20.5
24.3
32.0
40.1
Of all the substances examined, sand and gypsum are ob-
viously those which allow the water to pass off most rapidly by
evaporation. The calcareous or chalky soil again has a high
retentive power; but it varies much in different instances, appa-
rently in consequence of different degrees of fineness; it is
however surpassed by humus, and the garden soil which was
tried. Humus is therefore at the head of the list of substances
in reference to retentive properties.
All soils shrink more or less in drying, and form cracks, in the
way already indicated; the shrinking has been estimated by
means of prisms of soils measured in the moist state, and after
being dried in the shade :
Kind of soil.
Carbonate of lime in fine powder
Sandy clay
Stiffish clay
Stiff clay.
Pure clay
Humus
Garden earth
Arable soil of Hoffwyll
Arable soil of Jura
•
100 parts cube shrink to
950
940
. 911
886
817
846
851
$80
905
HYGROMETRIC POWER OF SOILS.
285
Gypsum, silicious, and calcareous sand do not appear in this
table, because they do not shrink in drying. The humus ap-
pears to have shrunk the most; and dry humus is liable to
swell in the same proportion when it is moistened. This pro-
perty explains the obvious elevation of certain turfy or mossy
soils at the period of the rains.
Hygrometric property of soils.
Agriculturists allow that
those soils which have the property of attracting moisture from
the atmosphere are generally among the most fertile. This
hygrometric property must not be confounded with that in virtue
of which moisture is retained. It appears to depend especially
on the porousness of a soil, and probably also in some degree
on the deliquescent salts which it contains, even in very small
quantity. Davy was disposed to regard the hygrometric pro-
perty of soils as a certain index of their good quality; and the
experiments of M. Schübler upon the point, all tend to confirm
the accuracy of this view. In M. Schübler's experiments, the
increase of weight of dry soils was ascertained by exposing them
for a certain time in an atmosphere kept at the point of satu-
ration with moisture, and at the same temperature, between
60° and 65° Fahr. :
Kind of soil.
Silicious sand.
Calcareous sand
Gypsum
Light clay
Stiffish clay
Strong clay
Pure clay
•
Chalky soil in fine powder.
Humus
•
Garden earth
Arable soil of Hoffwyll
Arable soil of Jura .
500 centigrammes, or 77.165 grains troy, of
soil spread upon a surface of 36,000 millimètres,
or 141.48 square inches, absorbed in,
12 hours.
Grains.
0
.154
24 hours. 48 hours. 72 hours.
Grains.
Grains.
Grains.
0
0
0
.231
.231
.231
0.077
0.077
0.077
0.077
1.617 2.002
2.156
2.156
1.925
2.310
2.618
2.695
2.310
2.772
3.080 3.157
2.849 3.234
3.696 3.773
2.002 2.387
2.695 2.695
8.470 9.240
6.160
7.469
3.465 3.850
4.004
2.695
1.232 1.771 1.771 1.771
1.078 1.463 1.540 1.540
From the results comprised in the preceding table, we may
conclude; first, that the faculty of absorbing lessens as soils ac-
286
ABSORPTION OF OXYGEN BY SOILS.
quire moisture; second, that humus is the most hygrometric of
all the substances examined; third, that the clays which absorb
the largest quantity of moisture are those which contain the
smallest proportion of sand; and fourth, that silicious sand and
gypsum do not absorb moisture in any appreciable quantity.
Absorption of oxygen gas by arable soils. Humboldt had
already observed, before the year 1793, that argillaceous soils,
the lydian stone, certain schists, and humus, deprived the air
of its oxygen. He had also observed that the sides of the large
cavities dug in the salt mines of Saltzburg, absorbed this gas,
and thus rendered the stagnant atmosphere of the workings
irrespirable and incapable of supporting combustion. Finally,
this illustrious observer had satisfactorily ascertained, at the same
period, that earth taken from the galleries of these mines, only
became fertile after having been exposed to the atmosphere for a
considerable length of time. I have quoted these curious obser-
vations, because they are, so far as I know, the first which es-
tablished the necessity of the presence of oxygen in the interstices
of the soil, or, as M. Humboldt then said, and indeed as may
still be maintained, the utility of a previous oxidation of the
soil.
All our agricultural facts indeed confirm this view of the
necessity of air in the interstices of the soil that is destined for
the growth of vegetables. When by ploughing very deeply, for
example, we bring up a portion of the subsoil into the arable
layer, in order to increase its thickness, we always lessen the fer-
tility of the ground for a time; in spite of the action of manures,
and of any treatment we may adopt, a certain time must elapse
before the subsoil can produce an advantageous effect; it is ab-
solutely necessary that it have been exposed to the atmospheric
influences, and it is then only that deep ploughing, which gives
the arable layer a greater thickness, pays completely for the
expense it has occasioned.
I am disposed to ascribe the absorption of oxygen gas by
clayey soils to the oxide of iron, which they almost always
contain, and which is in the minimum state of oxidation, when
the clay lies at a certain depth. In the performance of some
soundings in a tertiary soil of the department of the lower
CAPACITY FOR HEAT OF SOILS.
287
Rhine, which I performed in 1822, I had occasion to observe
that the clays brought up white by the borer, very speedily
became blue by exposure to the air; and that in gaining colour
they condensed oxygen. I propose returning upon this fact to
show the important part which this simple superoxidation
probably plays in the amelioration of soils.*
M. Schübler again has studied the action of oxygen gas upon
the component parts of arable soils, and according to him the
absorption of this gas cannot be doubted; it is very trifling in
connexion with sand and gypsum, very decided as regards clay,
loam, and humus. As M. de Humboldt and M. de Saussure
had already done, M. Schübler observed humus to change a
portion of the oxygen which it fixed into carbonic acid; but in
general the other substances or soils or elements of soils upon
which he experimented appeared to absorb the oxygen by the
intermedium of the protoxide of iron, from which they are never
altogether free. Besides this cause due to the superoxidation of
a metal, M. Schübler thinks that a certain portion of the
oxygen disappears by condensation within the pores of some
soils; and in support of his opinion he appeals to the admirable
observations of M. de Saussure, on the condensation of the
gases by porous bodies. Starting from the fact that the roots.
of plants require the presence of oxygen in order to thrive, he
ascribes a greater power to the gases compressed or condensed
within the interstices of the soil. But the action of the air upon
the roots of vegetables is readily conceivable in soils of a loose
nature, especially if they have been sufficiently worked, without
the necessity of having recourse to such an explanation.
Capacity of soils for heat. The quantity of heat which a
soil will receive, retain, or throw off in a given time, depends
upon the conducting power which it possesses. M. Schübler
endeavoured to measure this power comparatively by measuring
* Austin proved, that during the oxidation of metallic iron under water
there is a constant production of ammonia. Certain experiments com-
menced some time ago, and which I still continue, will establish in the most
precise manner, as I hope, the fact that this formation of ammonia likewise
takes place during the passage of the protoxide of iron to the state of
hydrated peroxide. The theoretical conclusions deducible from this fact
and the economic applications which may flow from it must be obvious.
288
HEAT RECEIVED FROM THE SUN BY SOILS.
the rates of cooling. In a vessel of the capacity of 595 cubic
centimetres or 234.2 cubic inches filled with the substance to
be tried, a thermometer was placed with its bulb in the centre.
The temperature having been brought up to 62.5° C. (144.5°
Fahr.) the time was noted which each substance required to
fall to 21.2° C. or about 70° Fahr. the temperature of the sur-
rounding air being 16.2° C. or about 61° Fahr.
Kind of soil.
Calcareous sand
Silicious sand
Gypsum
Sandy clay
Stiffish clay
Stiff clay
Pure clay
Calcareous soil
Humus
Garden earth
Arable soil of Hoffwyll
Arable soil of the Jura
Power of retaining
heat, that of cal-
careous sand being
100.
100 0
95.6
73.2
76.9
71.1
68.4
66.7
61.8
49.0
64.8
70.1
74.3
Time which 234.2
cubic inches of
soil required to
cool from 144º to
70° Fahr. The
temperature of the
surrounding air
being about 61°
Fahr.
h. m.
3.30
3.27
2.34
2.41
2.30
2.24
2.19
2.10
1.43
2.16
2.27
0.36
The general observations which these experiments suggest
are that for equal volumes calcareous or silicious sand possesses
greater powers of retaining heat than any of the other sub-
stances tried. This fact explains the high temperature and the
dryness which sandy soils maintain even during the night in
summer. Humus is obviously the substance which possesses
the highest conducting powers.
sun.
Degrees in which soils become heated under exposure to the
There is no one who has not had occasion to observe the
high temperature which bodies acquire when exposed to the rays
of the bright sun. There are some, such as dry sand, slates,
and certain coloured rocks, which become burning hot. It is by
the heat of the sun that the soil before it is shaded by the leaves
and stems of plants rises in temperature and throws off the ex-
cess of moisture which it had imbibed in the winter. Agricul-
turists all know how different the degree in which this heating
HEAT ACQUIRED FROM THE SUN.
289
takes place, even in soils that are close to one another. A light
coloured, moist, clayey soil will heat much less than a dark co-
loured, calcareous, or sandy soil. The differences in the heat ac-
quired in various soils depend, 1st. on the state of their surface;
2nd. on their composition; 3rd. on the quantity of water which
they contain; and 4th. on the angle of incidence of the sun's
rays. M. Schübler, by a method which is far from being unob-
jectionable, but which may be excused, considering the difficulties.
of the subject, measured the temperature acquired by different soils
exposed to the sun for the same length of time, and in circum-
stances as nearly alike as possible; the numbers obtained are
given in the following table:

Soils.
Silicious sand, yellowish grey
Calcareous sand, whitish grey
Bright gypsum, whitish grey.
Poor clay, yellowish
Stiff clay
Argillaceous earth, yellowish grey .
Pure clay, bluish grey
Calcareous earth, white
Humus, blackish grey
Garden earth, blackish grey
Arable earth of Hoffwyll, grey
Arable earth of the Jura, grey
•
•
Highest temperature acquired by the upper layer,
the mean temperature of the atmosphere being
25º C. (77° F.)
The soil moist, degrees
centigrade.
the soil dry, degrees
centigrade.
37.25 (9.9° F.)
37.38
36.25
36.75
37.25
37.38
37.50
35.63 (96°.1 F.)
39.75 (103º.5 F.) | 47.37
37.50
45.25
36.88
44.25
36.50
43.75
44.75 (112°.5 F.)
44.50
43.62
44.12
44.50
44.62
45.00
43.00 (109º.4 F.)
U
In comparing the circumstances which concur in assisting the
action of the sun's rays in raising the temperature of the soil, it
appears that the colour and moistness of the soil, and the angle
of incidence of the sun's rays are the most influential; they may
occasion differences in the temperature acquired of from 14° to
15º C. (25° to 27° F.) The nature of the surface and the com-
position of the soil are far from producing such marked diffe-
rences; although according to M. Schübler the effect of incli-
nation is very decided, and may occasion a difference to the
amount of 25° C. (45º F.)
290
SOILS.
CLASSIFICATION OF SOILS.
Agriculturists class soils according to their fertility and the
cropping which they will stand to advantage. In practice two
grand divisions have been adopted: strong soils, and light soils;
every soil belongs wholly or in part to one or other of these
divisions.
In strong soils clay is the predominating element; in light
soils it is sand which prevails. The first are stiff, little perme-
able, and slow in drying; the second are loose, dry speedily and
readily, are permeable and less difficult to labour. Humus al-
ways adds to the qualities of these two kinds of soil, though
possessed of properties so opposite; but its utility is especially
remarkable in argillaceous or clayey soils, the extreme stiffness
of which it diminishes.
Stiff or strong soils share in the advantages and disadvan-
tages peculiar to clay; they absorb a great deal of moisture, and
they do not dry readily, retaining obstinately a considerable quan-
tity of water. The humus which they contain and the manures
which are spread upon them in the course of cultivation remain
with them for a long time, preserved as it were from the too
active agency of atmospheric influences; the fertilizing power of
these substances is further rarely interfered with by too great
a degree of dryness in the soil. Nevertheless, in very wet sea-
sons and in years of extraordinary drought the advantages which
I have enumerated disappear. In wet seasons clay lands become
immoderately humid, sometimes they approach the state of mere
puddle; and on the contrary under severe and long continued
drought they become so hard that the roots of vegetables can
no longer penetrate them, and then they crack in all directions,
and the roots perish for want of being properly covered. I
might add that severe frost is the cause of effects disadvan-
tageous in the same degree; so that very stiff clays are liable
to the same bad effects under the influence of two causes dia-
metrically opposed: the great heat of summer and the severe
cold of winter.
In such soils all agricultural operations are often impractica-
ble; changed into a liquid mud, neither horse nor plough can be
CLASSIFICATION.
291
put upon them, or baked into a mass having the hardness of
stone, the share will not penetrate them.
Light soils rarely accumulate an excess of moisture in their
interstices, so that they are liable to suffer under want of rain
of even short continuance. They are worked with infinitely
greater ease, and at much less expense; vegetation upon them is
quicker and harvests earlier; but manure is less profitable than
in clayey soils, because the rains dissolve and carry it away.
The defects of these two kinds of soils are precisely of a na-
ture to compensate one another, and it is in fact by a mix-
ture, or that which is equivalent to a mixture of these two
extreme kinds of soil, that those lands are formed which are ad-
mitted to be the best adapted to cultivation and the most fertile of
all. Messrs. Thaer and Einhoff, in submitting to mechanical
analysis an immense number of arable soils, and in studying at
the same time the system of culture best adapted to these soils
and to their relative fertilities, have given us results of great
importance and which may be made the basis of a practical
classification of arable soils.*
An argillaceous or clayey soil properly so called, generally
contains about 40 per cent. of sand. If the quantity of sand
be less than this, the crop from such a soil will be more or less.
precarious and the tenacity will be such that considerable
difficulty will be experienced and necessary expence incurred in
working it; such a clayey soil (having at least 40 per cent. of
sand), when it contains a sufficient quantity of humus and is
properly treated, may be regarded as favourable for wheat.
Barley succeeds better than wheat when the quantity of sand is
as low as 30 per cent. With less than 30 per cent. oats will
thrive. Wheat may still be advantageously cultivated upon
lands that contain from 40 to 50 per cent. of sand; beyond this
term, when the soil contains from 50 to 60 per cent. of sand, it
is more advantageous to grow barley. Such a soil will not be
completely pulverized by reiterated ploughing, as will that which
contains a larger proportion of silicious matter, and it does not
become hard and cracked under drought like lands that are more
* Thaer's Rational Principles of Agriculture, (in French), vol. II.
p. 115.
U 2
292
SOILS.
essentially clayey, because it retains a sufficiency of moisture; it
is equally well adapted for trefoil of all kinds, for tubers, for
plants with tap roots, and for many other crops of great mar-
ketable value, such as cabbage, flax, tobacco, &c. It is almost
always accessible, a circumstance which allows of the greatest
care being bestowed upon the crops which are raised upon it.
In soils which yield on washing from 60 to 80 per cent. of sand,
we cannot reckon securely on the success of wheat. At 70 of
sand, it ceases to be well adapted to the cultivation of this
grain, except with especial precautions; but it is still well
adapted to barley, and it is in such a soil especially that rye
succeeds best.
Land with such a dose of sand is always easily laboured, but
it is more apt to be overrun by foul weeds than a soil that is
decidedly argillaceous. Manures are speedily consumed in it for
the reason already given; it is, therefore, advantageous to
manure such land frequently, laying on less dung at a time. A
soil having 75 per cent. of sand, is qualified by Thaer as an oat
soil, and even up to 85 per cent. of sand it may be regarded as
suitable to this grain; this term passed, nothing but rye or
buck-wheat ought to be sown upon it, and that only after it
has had a sufficient dose of manure. The reiterated ploughings
which some of these sandy soils require to get rid of the foul
weeds which rush up in such quantities upon them, sometimes
render them so open that rye will not succeed. The best course
is then to lay them down in grass, and allow them to become
consolidated by rest.
It is extremely difficult, at least in this climate of ours, to
make anything of soils that contain 90 per cent of sand; in times
of drought they become true moving sands. As we have already
shown, calcareous matter may replace silicious sand in the part
which it plays in an arable soil; like sand, calcareous matter
tends to destroy the strong cohesion of the particles of clay: but
it appears that chalk or lime, especially when it is in a state of
minute subdivision, besides this effect, really contributes to the
amelioration of wheat lands.
The following table comprises the results obtained by Thaer
and Einhoff. I must observe, however, and from causes which
CLASSIFICATION.
293
have been already explained as influencing the determination of
the humus, that this substance is evidently estimated at much
too high a figure in several of these analyses, which deserve to be
made anew under the precautions that are now familiarly
known.


Soils according to com-
position.
Clay with humus
ditto
ditto
Marly soil
Light soil with humus
Sandy soil, humus
Argillaceous land
Marly soil
•
Argillaceous land
Stiffer argillaceous land
Clay
Stiff argillaceous land
ditto
Sandy clay
ditto
Clayey sand
ditto
Sandy soil
ditto
ditto
•
Usually designated.
Rich wheat land
ditto
ditto
ditto
Meadow land
Rich barley land
Good wheat land
Wheat land
ditto
ditto
ditto
Barley land of the 1st class
ditto
2nd class
ditto
ditto
Oat land
ditto
Rye land
ditto
ditto
ditto
·
•
Clay.
Sand.
74 10
B27128;
79
40 22
14 49
20 67
58 36
56 30
60 38
48 50
63 30
38 60
33 65
28 70
23.5 75
18.5 80
14 85
90
95
97.5
342
9
Lime or chalk.
4 11.5
6 4 8.5
10 4 6.5
12
36
10 27
3 10
2
:
··
··
Humus.
•
··
4
'*°*~~~~NNNÄ
2
2
1.5
1.5
platt
1
1
0.75
0.5
Schwertz has given a summary of the opinions of Thaer upon
the value of different soils from an eminently practical point of
view. Agreeing with this distinguished agriculturist that it is
well to judge of the soil by its produce, he also forms a scale of
comparison after the different kinds of grain, taking as extreme
terms wheat and barley, the first succeeding in bad argillaceous
soils, the second still growing in sandy soils of the poorest
description. In these extreme or boundary soils, wheat and
barley succeed very indifferently indeed; but between the two
extremes are comprised every variety of soil which results from
the fusion of the strongest or stiffest with the lightest soils, from
the most tenacious clay up to loose sand. In these mixed
soils of intermediate qualities, wheat and barley gradually ap-
proach one another, taking the place successively of barley, oats,
and buck wheat, until they meet in the middle of the scale in a
kind of neutral soil, upon which every variety of grain may be
grown.
294
SOILS.
Schwertz arranged his scale in the following manner :*
0. Stiff clay.
1. Wheat land.
2. Rye and buck wheat land
2. Wheat and oat land.
•
3. Rye, buck wheat and oat land
3. Wheat, oat, and barley land.
4. Rye, oat, and small barley land. 4. Wheat and large barley land.
5. Wheat, rye, barley, and oat land.
The species of soil which suit these different crops, are:
1. Light dry sand
1. Cold stiff clay.
2. Moist, very slightly argillaceous sand 2. A lighter moist clay
3. Argillaceous sand
3. A warm dry clay.
4. Sandy clay
4. Rich clay.
0. Moving sand
1. Rye land
5. Clay.
The preceding considerations are more than sufficient to give
a precise idea of what is to be understood in regard to the com-
position of arable soils. Nevertheless, with a view to making
the subject more complete, I shall quote a few of the analyses
of arable soils published by different chemists at a time when a
certain importance was attached to researches of this kind. I
may remark generally, that from the whole of the analyses of
good wheat lands which have hitherto been made, it appears that
carbonate of lime enters in considerable quantity into their com-
position; and theory in harmony with practice, tends to show
that it is advantageous to have this earthy salt as a constituent
in the manures which are put upon soils that contain little or
no lime.
Analysis of a soil under the variety of rape called colza, by
M. Berthier:
Silica
Alumina .
Peroxide of iron
Lime
Magnesia
Carbonic acid
Water
•
This soil was dried in the air, after
powder; it lost 34 per cent. by drying.
78.2
7.1
4.4
1.9
0.8
1.4
5.8
99.6
having been reduced to
It is remarkable that
* Precepts of Practical Agriculture (in French) p. 49.
CLASSIFICATION.
295
it contains no trace of organic matter, the rather as it was held
favourable for colewort. M. Berthier believes that this soil
would gain in fertility by the addition of a certain quantity of
calcareous matter, and M. Cordier* explains its inability to
grow grain to advantage from the deficiency in lime. The stalk
of the grain grown in this soil is weak, especially in wet
seasons, and the seed is particularly apt to shake out when it is
ripe.
If the presence of lime in a wheat soil is a guarantee against
loss by shaking in harvest, M. Berthier's analysis is still far
from proving that the presence of lime in a soil is indispensable,
inasmuch as beautiful wheat crops are grown in the neigh-
bourhood of Lisle without lime. In proof of this fact, I shall
here cite the analysis of one of the most fertile soils in the world,
the black soil of Tchornoizem, which Mr. Murchison informs
us constitutes the superficies of the arable lands comprised
between the 54th and 57th degrees of north latitude along the
left bank of the Volga as far as Tcheboksar, from Nijni to
Kasan, and stretching over a still more extensive district upon
the Asiatic side of the Ural mountains. Mr. Murchison is of
opinion that this land is a sub-marine deposit formed by the
accumulation of sands rich in organic matters. The Tchornoi-
zem is composed of black particles mixed with grains of sand;
it is the best soil in Russia for wheat and pasturage; a year or
two of fallow will suffice to restore it to its former fertility after
it has been exhausted by cropping; it is never manured.
M. Payen found in this black and fertile soil:
Organic matter
Silica
Alumina
Oxide of iron
Lime
Magnesia
Alkaline chlorides
Phosphoric acid, a trace
Loss
6.95 (containing 2.45 per cent. of azote).
71.56
. 11.40
5.62
0.80
1.22
1.21
. 1.24
* On the Agriculture of French Flanders, p. 232, (in French).
100.00
296
SOILS.
Bergman gives the following as the composition of a fertile.
soil in Sweden:
Carbonate of lime
Gravel
Silicious sand
Alumina
Silicious sand and silica
Alumina
100.0
Several fertile soils of Senegal, examined by M. Laugier,
contained :
Oxide of iron
Carbonate of lime
Organic matter and water
Loss
•
Silica
Alumina
Carbonate of lime
Oxide of iron
Phosphate of magnesia
Sulphate of lime
Azotised organic matter
Water and loss
•
LOCALITIES.
Rawei. Doukitt. Diague.
72.0
89.0
87.0
3.6
10.0
3.4
8.0
trace
trace
4.4
10.0
1.6
•
•
100.0
100 0 100.0
100.0
M. Plagne, who has studied the agriculture of the Coro-
mandel coast, divides the soils he met with there into argil-
laceous or clayey, sandy, and mixed, and gives their several
compositions as follows:
'Argillaceous.
22.0
59.0
3.5
2.5
>J
Silica and sand
Alumina
Oxide of iron
Phosphate and sulphate of lime
Organic matter
Water
""
100.0
>>
5.0
8.0
100.0
30
30
26 Clay
14
}
3.0
3.6
0.5
3.6
0.3
Sandy.
82.0
6.5
3.5
4.0
. 2.0
Chinese soil.
76.0
9.0
99
1.0
1.0
3.0
99.9
* Robinson, Account of Assam, p. 130.
"
2.0
100.0
Roso.
78.0
7.0
5.2
trace
9.0
08
The soils in which the tea plant is grown in Assam and
China have been examined by Mr. Piddington;* they contain
respectively:
Mixt.
64.0
19.5
2.5
4.0
trace
7.0
3.0
100.0
N'Dick.
91.0
1.8
3.0
0.5
3.0
0.7
Assam soil.
84.8
4.5
7.0
traces
1.5
2.3
100.1
CLASSIFICATION.
297
Sir Humphry Davy found the various soils most generally
cultivated in England, to have the following composition:

Districts.
County of Kent
Norfolk
Middlesex
Worcestershire
Vale of the Teviot
Salisbury
Districts.
(66.3 5.2 3.3 4.8 0.8 12
88.9 17 1.2 7.0
0.3
60.0 12.8 11.6 11.2
60.0 16.4 14.0 5.6
83 3 7.0 6.8 0.7
9.112.7 6.4 57.3
From Thor (Vaucluse)
Alluvium of the Rhone
From Palus, near Orange
Old deposit of the Rhone
From the plains near Orange
Neighbourhood of Auch
Humus.
7.5
3.4
2.5
5.0
4.0
1.5
··
··
92.5
2.3
55.5
32.5
50.0
3.5
0.6
4.4
12 2.8
0.8 1.4
1.8 12.7
8.0 0.5 4.9 5.0 Rich soil, under hops
Ditto, under turnips
··
6.0
53.5
43.5
56.0
48.0
73.0
..
··
Calca-
reous Clay. Sand.
matter.
0.3
93:::
..
M. Gasparin has published analyses of the soils of the south
of France. Instead of destroying the humus and organic mat-
ter by calcination, as Davy and the generality of analysts did,
M. Gasparin dissolved out the humus by means of a strong
alkaline solution. This method of procedure is, however, at
least as liable to objection as the other.
Loss.
1.5
42.7 {
1.0
11.5 {
2.0
23 0
..
··
• A
Remarks.
··
Very good soil, wheat
Very fertile soil
Good soil
Excellent grazing soil

Remarks.
Middling wheat soil.
Well adapted for madder, wheat,
and lucern.
Bad wheat land.
Good wheat land, very indifferent
for madder.
Ditto, bad for madder.
ness.
There is an important element which must always be taken
into the account in estimating the value of soils, no matter what
their special composition, this element is their depth or thick-
In running a deepish furrow in a cultivated field, we
generally distinguish at a glance the depth of the superficial
layer, which is commonly designated as the mould or vegetable
earth; this is a layer generally impregnated with humus, and
looser and more friable than the subsoil upon which it rests.
The thickness of this superficial layer is extremely variable; it is
frequently no more than about 3 inches; but it is also encountered
of every depth from 3 or 4 to 12 or 13 inches. It must be held
an exceptional and unusual case when it has a depth of 3 feet
298
DEPTH OF SOIL.
or more. Nevertheless, we do meet with collections of vegetable
soil of great depth, deposited by rivers, washed down into the
bottoms of valleys, or accumulated on the surface, as in the vir-
gin forests or vast prairies of America. Depth of mould or
vegetable soil is always advantageous; it is one of the best con-
ditions to successful agriculture. If we have depth of soil, and
the roots of our plants do not penetrate sufficiently to derive
benefit from the fertility that lies below, we can always by working
a little deeper bring up the inferior layers to the surface, and so
make them concur in fertilizing the soil. And independently of
this great advantage, a deep soil suffers less either from excess
or deficiency of moisture; the rain that falls has more to
moisten, and is therefore absorbed in greater quantity than by
thin soils, and once imbibed it remains in store against drought.
The layer upon which the vegetable earth rests is the subsoil,
which it is of importance to examine, inasmuch as the qualities
and consequently the value of an arable soil have always a cer-
tain relation with the nature and properties of this subjacent
stratum. Frequently and especially in hilly countries the mi-
neral constitution of the subsoil is the same as that of the soil,
and any difference that the former may present is owing espe-
cially to the presence of humus, and to the looser condition.
which results from the growth of vegetables, from ploughing,
&c., and not from atmospheric influences. By deep ploughing
done cautiously, the thickness of the layer of arable land may
be increased at the expense of the subsoil, and when plenty of
manure can be commanded the operation will go on with con-
siderable rapidity. Still it is maintained, and indeed in many
cases it is unquestionable, that the soil loses temporarily some
portion of its fertility by the introduction of a certain quantity of
the subsoil, and that under ordinary circumstances several years
elapse before any amelioration becomes perceptible.
In plains, in high table lands the analogy in point of consti-
tution between the soil and subsoil is not so constant. In such
situations the arable land is frequently an alluvial deposit pro-
ceeding from the destruction or disintegration of rocks situated
at a great distance. When the superior strata possess proper-
ties that are entirely different from the subsoils, it may be under-
DEPTH OF SOIL.
299
stood how the vegetable earth may be improved by the addition
of a certain dose of the subsoil, and this is the case in which
the amelioration is the least expensive. The impermeability of
the subsoil is one grand cause of the too great humidity of a
cultivated soil. A strong soil, very tenacious through the excess
of clay which it contains, has its disadvantageous properties con-
siderably lessened if the subsoil upon which it rests is sandy;
1st. from the evident amelioration which must result from an
admixture of the two layers, and next because it is always a
positive advantage in having a soil which has a strong affinity
for water superposed upon a subsoil which is extremely per-
meable. The inverse situation is scarcely less desirable; a light
friable soil will have greater value if it lies upon a bottom of a
certain consistency, and capable of retaining moisture; with this
condition, however, that the clayey layer shall not be too uneven
in its surface, that it shall not present great hollows in which
water may collect and stagnate; an impermeable subsoil to act
beneficially in such circumstances must have a sufficient inclina-
tion to admit of its draining itself. The most essential distinc-
tion, then, in regard to the nature of subsoils is into permeable
and impermeable. Acquainted with the nature of vegetable
earth, it is easy to judge of the advantages or disadvantages
which will be presented by subsoil having the faculty of retain-
ing or of permitting the escape of moisture.
In some situations, particularly upon the slopes of hills, the
layer of arable land is of very limited thickness, and it is not un-
common to see it lying upon rocks of the most dense descrip-
tion, such as granite, porphyry, basalt, &c.; in such circum-
stances the substrata are unavailable, and there is nothing for it
then in the way of amelioration except to transport directly ve-
getable earth from other situations. Mica schist is perhaps the
least intractable rocky subsoil; the plough often penetrates it, and
in the long run it becomes mingled with the arable layer. It is
generally agreed that limestone rocks form a less unfavourable
substrate. There are in fact some calcareous rocks which ab-
sorb water, and crumble away, and the roots of various plants,
such as cinquefoin, penetrate them deeply; but there are many
limestone rocks so hard that they resist all decomposing action
for a very long period of time.
300
SOILS IN REFERENCE TO CLIMATE.
The qualities which we have thus far sought to determine in
soils do not depend solely on their mineral constitution or their
physical properties, nor yet on those of the subsoils which sup-
port them. These qualities to become obvious require that the
soils shall be placed in certain conditions which must not be left
out of the reckoning. Such are those of the climate enjoyed
and of the position more or less inclined to the horizon in one
direction or another. The precepts which we have laid down are
especially applicable to the arable lands of Germany, England,
and France. But in generalizing it would be proper to say that
clayey lands answer better in dry climates, and light sandy soils
in countries where rains are frequent. Kirwan made this re-
mark long ago in connexion with numerous analyses of wheat
lands. The conclusion to which this celebrated chemist came
was this, that the soil best adapted for wheat in a rainy country
must be viewed in a very different way with reference to a
country where the rains are less frequent. The fertility of light
sandy soils is notoriously in intimate relationship with the fre-
quent fall of rain. At Turin, for example, where a great deal
of rain falls, a soil which contains from 77 to 80 per cent of
sand is still held fertile, whilst in the neighbourhood of Paris,
where it rains less frequently than at Turin, no good soil con-
tains more than 50 per cent of sand. A light sandy soil which
in the south of France would only be of very inferior value,
presents real advantages in the moist climate of England.*
Irrigation supplies the place of rain, and in those countries or
situations where recourse can be had to it, the question in re-
gard to the constitution of soils loses nearly the whole of its in-
Land that can be irrigated has only to be loose and per-
meable in order to have the whole of the fertility developed
which climate and manure can confer. Sandy desarts are sterile
because it never rains. Upon the sandy downs of the coasts
of the Southern Ocean, a brilliant vegetation is seen along the
course of the few rivers which traverse them; all beyond is dust
and sterility. I have seen rich crops of maize gathered upon
the plateau of the Andes of Quito in a sand that was nearly
moving, but which was abundantly and dexterously irrigated.
terest.
A sandy and little coherent soil is by so much the more fa-
* Sinclair's Practical Agriculture.
SOILS IN REFERENCE TO CLIMATE.
301
vourably situated as it lies in the least elevated parts of a dis-
trict; it is then less exposed to the effects of drought; any
considerable degree of inclination is unfavourable to such a soil,
inasmuch as the rain drains off too quickly, and because it is
itself apt to be washed away. It is to prevent this action of the
rains, that the abrupt slopes of hills are generally left covered
with trees; and the deplorable consequences which have followed
from cutting down the woods in mountainous countries are fami-
liarly known.
Strong soils, on the contrary, are better placed in opposite
circumstances. A certain inclination is peculiarly advantageous
to them; and, indeed, in working clayey lands that stand
upon a dead level, we are careful to ridge them in such a way as
to favour the escape of water.
In countries situated beyond the tropics, where consequently
shadows are cast in the same direction throughout the whole
year, the exposure of a piece of land is by no means matter of
indifference. In our hemisphere, the lands which have a consi-
derable inclination and a northern exposure, receive less heat
and light, and remain longer wet than those that slope towards
the south; vegetation consequently is less forward upon the
former than the latter lands: but, on the contrary, the latter
are less exposed to suffer from want of rain; and it is a fact,
now well ascertained from data collected in Switzerland and in
Scotland, that the slopes which descend towards the north, if
they be only not too abrupt, are actually the most productive.
This kind of anomaly is explained by the frequence and rapidity
of the thaws which take place upon slopes that lie to the
south. Frost when not too intense, is certainly less injurious to
vegetables than too rapid a thaw; and it is easy to understand
that in situations where, from the mere effect of nocturnal radia-
tion, vegetables are covered almost every morning through
the spring with hoar frost, a rapid thaw must take place every
day immediately after the rise of the sun. With a northern
exposure, the frost occurs in the same measure; but the cause
of its cessation does not operate so suddenly, the fusion of the
rime being effected by the gradual rise in temperature of the
surrounding air. In other respects, it is obvious that the ad-
302
IMPROVEMENT OF SOILS.
vantages and disadvantages of different exposures are connected
with the nature and the constitution of soils. The same may be
said with reference to means of shelter from the action of pre-
vailing winds. Stiff wet lands are much benefited by the ac-
tion of free currents of air; our stiff soils at Bechelbronn remain
impracticable for our ploughs during but too long a period of
the spring, when they have not been well dried in the months of
March and April by strong winds from the east. Light and
sandy soils, again, require to be well sheltered. The whole ob-
ject of studying the soil, is its amelioration; the industry of
the agriculturist is, in fact, more effectually bestowed, and exerts
a greater amount of influence upon the soil than upon all the
other and varied agents which favour vegetation.
To improve a soil is as much as to say that we seek to mo-
dify its constitution, its physical properties, in order to bring
them into harmony with the climate and the nature of the crops.
that are grown.
In a district where the soil is too clayey our
endeavour ought to be, to make it acquire to a certain extent
the qualities of light soils. Theory indicates the means to be
followed to effect such a change; it suffices to introduce sand
into soils that are too stiff, and to mix clay with those that are
too sandy. But these recommendations of science which, indeed,
the common sense of mankind had already pointed out, are sel-
dom realized in practice, and only appear feasible to those who
are entirely unacquainted with rural economy. The digging up
and transport of the various kinds of soil according to the ne-
cessities of the case, are very costly operations, and I can quote
a particular instance in illustration of the fact: my land at Be-
chelbronn is generally strong; experiments made in the garden
on a small scale showed that an addition of sand improved it
considerably. In the middle of the farm there is a manufactory
which accumulates such a quantity of sand that it becomes trou-
blesome; nevertheless, I am satisfied that the improvement by
means of sand would be too costly, and that all things taken into ac-
count, it would be better policy to buy new lands with the capital
which would be required to improve those I already possess
in the manner which has been indicated. I should have no dif-
ficulty in citing numerous instances where improvements by
IMPROVEMENT OF SOILS.
303
mingling different kinds of soil were ruinous in the end to
those who undertook them.
A piece of sandy soil, for example, purchased at a very low
price, after having been suitably improved by means of clay,
cost its proprietor much more than the price of the best land
in the country.
Great caution is therefore necessary in under-
taking any improvement of the soil in this direction,-in changing
suddenly the nature of the soil. Improvement ought to take
place gradually and by good husbandry, the necessary tendency
of which is to improve the soil. Upon stiff clayey lands we put
dressings and manures which tend to divide it, to lessen its
cohesion, such as ashes, turf, long manure, &c. But the hus-
bandman has not always suitable materials at his command, and
in this case, which is perhaps the usual one, he must endea-
vour, by selecting his crops judiciously, crops which shall agree
best with stiff soils, and at the same time meet the demands of
his market, to make the most of his land. In a word, the
true husbandman ought to know the qualities and the defects of
the land which he cultivates, and to be guided in his operations
these; and in fact it is only with such knowledge that he
can know the rent he can afford to pay, and estimate the amount
of capital which he can reasonably employ in carrying on the
operations of his farm.
In an argillaceous or clayey soil, which we have seen above.
is the best adapted for wheat in these countries, it would be
absurd to persist in attempting to grow crops that require an
open soil.
Clayey lands generally answer well for meadows, and
autumn ploughing is always highly advantageous to them by
reason of the disintegrating effects of the ensuing winter frost.
Chalk occupies a large space in recent formations; as a
general rule, the soil it supports immediately is of no great
fertility. Sir John Sinclair proposed to improve such soil by
growing green crops and consuming them upon the spot.
Properly treated, the chalky soils of England produce trefoil,
turnips, and barley, and they are particularly adapted to cinque-
foin. It is doubtful whether in France, where the climate is
not so moist as in England, chalky lands could be treated to
advantage on the English plan. Recent inquiries have shown
hat chalk contains a small quantity of phosphate of lime, a salt,
304
IMPROVEMENT OF SOILS.
as we shall see by and bye, whose presence is always desirable in
arable lands.
Turf or turfy soils yield rich crops when we succeed in con-
verting the turf into humus. The grand difficulty in dealing
with turf is to dry it properly, inasmuch as it is generally found
at the bottom of valleys or of old lakes and swamps. By a
happy coincidence, turfy deposits frequently alternate with layers
of sand, of gravel, of clay, and of vegetable earth, which have
been accumulated at the same epoch. By a mixture, by a
division of these different materials, preceded in every case,
however, by proper draining, mere peat bogs may be turned
into good arable soil. Pyritic turf, however, shows itself more
intractable, it rarely yields anything of importance. To improve
such a soil it is absolutely necessary to have recourse to
substances of an alkaline nature such as chalk or lime, wood-
ashes, &c., which have the property of decomposing the sulphate
of iron which is formed by the efflorescence of the pyrites.
Turfy lands can also be brought into an arable state, with the
help of paring and burning. Scotch agriculturists, who are very
familiar with reclaiming land of this kind, hold, that the best
method of improving turf or bog lands, is to turn them into
natural meadows. Where the wet and soft state of the soil
does not allow cattle to be driven upon it, the crop of hay
should only be cut once, the second crop should be left standing.
By proceeding in this way mere bogs have been turned into
productive meadows.* Turfy lands thoroughly drained and
improved, present many advantages connected with their natural
but not excessive moistness. In the neighbourhood of Ha-
guenau, magnificent hop gardens are found upon bottoms of this
kind; madder also thrives in it equally well, and for certain
special crops it is in my opinion one of the richest soils.
Sandy soils do perfectly well in countries which are not
exposed to long droughts; their cultivation is attended with little
expense, and they grow excellent crops of turnips, potatoes,
carrots, and rye; but it is well to exclude clover, oats, wheat,
In
and hemp, which require a soil of greater consistence.
southern countries, a system of irrigation is absolutely necessary,
* Sinclair, Practical Agriculture.
་
MOVING SANDS-DOWNS.
305
in connexion with the cultivation of sandy soils if they are not
watered, they remain nearly barren; the only mode of making
them productive is to lay them out in plantations of timber.
Those moving sandy plains of great extent, which are found
in the interior of many continents, seem at first sight stricken
with eternal barrenness. Nevertheless, the mobility of the sand
of the desart, which permits it to be swept hither and thither,
and to be tossed about like a liquid mass, depends less upon the
total absence of argillaceous particles than upon the want of
the moisture necessary to agglutinate or to fix its grains. The
burning steppes of Africa and America have their oases here and
there, the surface of which, moistened by a spring, is green with
vegetation; and whenever sandy plains are bathed by a river, it is
possible to render them fit for cultivation. In Spain, for
instance, in the neighbourhood of San Lucar de Baromeda, a
powdery soil of extreme dryness has been fertilized by the hand
of man.
The mammillated downs of San Lucar are covered
on the surface by a layer of quartzy sand, so loose that it is
blown about by the wind; but by a happy disposition of things,
a lower stratum of these downs is kept constantly moist by the
waters of the Guadalquiver, and it is only necessary to remove
the superficial sand, and to level the surface in order to have
a loose soil which unites in the highest degree two essential
conditions of fertility, viz: openness, and a constant supply of
moisture, which penetrates the soil in virtue of its permeability;
under the influence of a fine climate and manure, the mar-
ket gardens established in the midst of this desart are re-
markable for the rapidity and the vigour of their vegetation.
To avoid great expense, the labour of removing the sand is
only undertaken in places where the layer is least thick; and
what is removed being heaped up as a mound around the soil
which is cleared, a kind of boundary wall is formed, which is not
without its use in affording shelter, and which becomes pro-
ductive itself by the plantations of vines and fig trees that are
made upon it with a view mainly to its consolidation. In the
same way in Alsace, in the plains of Haguenau, the soil which
was a moving desart of sand, has, in the course of less than
forty years, become one of the most fertile under the influence
X
306
DOWNS ARREST OF MOVING SANDS.
of incessant cultivation; in the same way also it is that in
Holland, mountains of sand, which had been accumulated by
the winds, have been fixed. This sand, which rests upon a wet
bottom, draws up the moisture by capillary attraction, and so
becomes fit to support certain vegetables. These downs, which
may be said to have come out of the sea, have a constant ten-
dency in many places to encroach upon the cultivated lands. To
oppose their progress, the Dutch sow them with the arundo
arenaria, the long and creeping roots of which bind together the
moving mass and imprison the particles of sand within a kind of
net work. These masses of sand become fixed in this way; but
they remain nearly or altogether unproductive.
It is therefore a problem of the highest importance in many
instances to fix permanently masses of sand blown up from the
sea, by covering them with productive plantations. This problem
was studied and successfully resolved by M. Bremontier, a French
engineer, who by sagacity in the choice of means and perse-
verance in their employment gave a complete and practical
solution of the question among the downs of the Gulf of
Gascony.*
The downs formed by the sand which is thrown up by the
ocean between the mouths of the Adour and the Girond, occupy
a surface of 75 square leagues and have a mean elevation of
from 60 to 70 feet. They form a multitude of hillocks, which
appear connected by their bases, the crowns of many of them
rising to a height of 160 feet and upwards. Under the influence
of the prevailing west winds, these masses of sand move with a
mean celerity of about 80 feet per annum, covering forests and
villages in their progress. A part of the little town of Mimizan
is already invaded, and it has been calculated that in the course
of twenty centuries, things proceeding at their present rate
the rich territory of Bordeaux, will have completely disappeared.
In their progress these moving masses of sand choke up the
beds of rivers, and increase the disastrous effects they produce
otherwise by causing formidable inundations.
>
The sands of the Gulf of Gascony, like those of Holland
and the Low Countries, are not altogether without moisture; a
* Annals of French Agriculture, vol. xxv11. p. 145.
ARREST OF MOVING SANDS.
307
very short way below the surface they are moist, and even pre-
sent a certain degree of cohesion. This, in fact, might have
been predicated, for otherwise the wind which brings them from
the sea would have dispersed them in clouds of dust and to great
distances; but no such dispersion takes place. Downs advance
slowly, at the rate already indicated, and by rolling over, as it were,
upon themselves. The sand driven by the wind creeps up on the
flanks of the ridges as upon an inclined plane; after having got over
the summit of the hillocks already formed, it falls down the oppo-
site slope, and accumulates at the base. The action of the wind
is only exerted upon so much of the sand as is rendered loose
and moveable by its dryness; but the moist part is exposed, dried,
and swept away in its turn; in this way the whole mass of
sand which was at first deposited upon the west aspect of the
hillocks is carried to the east, where it is in the shelter. By
this process, under the influence of a wind which blew steadily
for six days, a hillock has been seen to advance towards the
interior of the country through a space of 31 feet.*
The moisture contained in the sand proceeds from the rains,
from the surface water that filters through it and displaces the
salt water which impregnated it originally. The very slight
trace of sea-salt that finally remains in it has no unfavourable
influence on vegetation.
Once aware of the fact that certain plants throve in the
sands of downs, Bremontier saw that they alone were ca-
pable of staying their progress and consolidating them. The
grand object was to get plants to grow in moving sand, and to
protect them from the violent winds which blow off the ocean,
until their roots had got firm hold of the soil.
Downs do not bound the ocean like beaches. From the base
of the first hillocks to the line which marks the extreme height
of spring tides, there is always a level over which the sand
sweeps without pausing. It was upon this level space that Bre-
montier sowed his first belt of pine and furze seeds, sheltering
it by means of green branches, fixed by forked pegs to the
ground, and in such a way that the wind should have least hold
upon them, viz. by turning the lopped extremities towards the
* D'Aubuisson, Geognosy, vol. 11, p. 467.
X 2
308
wind. Experience has shown that by proceeding thus, fir and
furze seeds not only germinate, but that the young plants grow
with such rapidity, that by and bye they form a thick belt, a
yard and more in height. Success is now certain. The plan-
tation so far advanced, arrests the sand as it comes from the
bed of the sea, and forms an effectual barrier to the other belts
that are made to succeed it towards the interior. When the
trees are five or six years of age, a new plantation is made con-
tiguous to the first and more inland, from 200 to 300 feet in
breadth, and so the process is carried on until the summits of
the hillocks are gradually attained.
It was by proceeding in this way that Bremontier succeeded
in covering the barren sands of the Arrachon basin with useful
trees. Begun in 1787, the plantations in 1809 covered a sur-
face of between 9,000 and 10,000 square acres. The success of
these plantations surpassed all expectation; in sixteen years the
pine trees were from thirty-five to forty feet in height. Nor was
the growth of the furze, of the oak, of the cork, of the willow, less
rapid. Bremontier showed for the first time in the annals of
human industry, that moveable sands might not only be stayed
n their desolating course, but actually rendered productive.
Like all other inventors, this benefactor of humanity was soon the
object of jealousy among his contemporaries. Doubts were of
course entertained at first of the possibility of consolidating the
moving sands of downs; and when this was demonstrated, the
honour of originality was denied him. The ingenious engineer
defended himself with moderation, and demanded an inquiry;
n the course of which it was satisfactorily proved that nothing
of the same kind had been attempted by others previously to the
year 1788. The labours of Bremontier must be regarded as
another of those remarkable struggles which the industry of man
has successfully waged with the elements.
ARREST OF MOVING SANDS.
309
CHAPTER V.
OF MANures.
WHATEVER may be its constitution and physical properties,
land yields lucrative crops only in proportion as it contains an
adequate quantity of organic matter in a more or less advanced
state of decomposition. There are favoured soils in which this
matter, designated by the name of humus, or mould,* exists by
nature, while there are others, and they form the majority, which
are either totally destitute of it, or contain it but in insignificant
proportion. To become productive, these soils require the in-
tervention of manure; for this there is no substitute, neither the
labour which breaks them up, nor the climate which so power-
fully promotes their fecundity, nor the salts and alkalies which
are such useful auxiliaries of vegetation. Not that land entirely
destitute of organic remains is incapable of producing and deve-
loping a plant. We have already seen that the atmosphere,
light, heat, and moisture, suffice for its existence; but in such a
condition, vegetation is slow and often imperfect; nor could agri-
cultural industry be advantageously applied to a soil which ap-
proached so near to absolute sterility.
Plants, considered in their entire constitution, contain carbon,
water (completely formed, or in its elements), azote, phosphorus,
sulphur, metallic oxides united to the sulphuric and phosphoric
acids, chlorides, and alkaline bases in combination with vegetable
acids; many of these elements form no part of the atmosphere, and
are necessarily derived from the soil. Moreover, the manures most
generally made use of are nothing but the detritus of plants, or the
remains or excretions of animals, including by the very fact of
their origin the whole of the elements which constitute organized
beings; and although it is very probable that certain tribes of
* Mould or vegetable earth, as the word is generally used, is not exactly
humus; but as it derives its principal qualities from the presence of the
humus of the chemist, I shall generally employ the terms as synonymous.
-ENG. ED.
310
MANURES.
plants are more adapted than others to appropriate the azote or
the ammoniacal vapours of the atmosphere, experience proves
that azotised organic remains contribute in the most efficacious
manner to the fertility of the soil. Besides, we are far from
being able to affirm that the carbon of plants is derived from
the carbonic acid of the atmosphere. Doubtless this acid is its
principal source; but it is possible that certain elements of car-
buretted dungs may be directly assimilated.
The writers who have treated of manures, have generally
formed them into two grand classes:
1st. Manures of organic origin, in which are again found all
the elements of the living matter.
2nd. Mineral manures, saline or alkaline, which are particu-
larly designated under the name of stimulants, thus ascribing
to them the faculty, purely gratuitous, of facilitating the assimi-
lation of the nutriment which plants find in dung, and of stimu-
lating and exciting their organs. Such a distinction has no
real foundation, and nothing shows so much how scanty our
knowledge upon this subject has hitherto been as this tendency
in the ablest minds to connect vegetable nutrition with the
feeding of animals.
All the agents employed by the agriculturist to restore, pre-
serve, and augment the fecundity of the soil, I shall term
Manures. In my view gypsum, marl, and ashes are manures,
as much as horse-dung, blood, or urine; all contribute to the
end proposed in employing them, which is the increase of vege-
table production. The best manure, that which is in most
general use, is precisely that which by its complex nature con-
tains all the fertilizing principles required in ordinary tillage.
Particular cultures may demand particular manures; but the
standard manure, such as farm dung, for example, when it is
derived from good feeding supplied to animals with suitable and
abundant litter, affords all the principles necessary to the deve-
lopment of plants; such manure contains at once all the usual
elements which enter into the organization of plants, and all the
mineral substances which are distributed throughout their tis-
sues; in fact, carbon, azote, hydrogen, and oxygen are found
therein united with the phosphates, sulphates, chlorides, &c.
In order to be directly efficacious, every manure must present
DECAY OF ORGANIC MATTERS.
311
this mixed composition. Ashes, gypsum, or lime spread upon
barren land, would not improve it in any sensible degree;
azotised organic matter, absolutely void of saline or earthy sub-
stances, would probably produce no better effect; it is the
admixture of these two classes of principles, of which the first
is derived definitively from the atmosphere, whilst the second
belongs to the solid part of the globe, which constitutes the
normal manure that is indispensable to the improvement of soils.
Dead organic matter, subjected to the united influence of
heat, of moisture, and of contact with the air, undergoes radical
modifications, and passes by a regular course of transformation
into a condition more and more simple. The tissues, so long
as they form a part of the animated being, are protected against
the destructive action of the atmospheric agents; in plants and
animals this protection is not extended beyond the period of
their existence; destruction commences with death, if the ac-
cessory circumstances are sufficiently intense; and then ensue
all the phenomena of decomposition, of that putrid fermentation
which at the expense of the primitive elements of the organised
being, generates bodies more stable and less complicated in
their constitution, and which present themselves in the gazeous
and crystalline conditions, forms which are affected by the inor-
ganic bodies of nature in general.
The mineral substances which had been taken up in the
organization become freed, and are thus again restored to the
earth. The organized substances which change the most
rapidly are precisely those into which azote enters as a con-
stituent principle. Left to themselves, whether in solution or
merely moistened, these substances exhibit all the characteristic
signs of putrefaction; they exhale an insupportable odour; and
the result of their total and complete decomposition is finally
the production of ammoniacal salts. The water wherein the
phenomenon is accomplished facilitates it not only by weaken-
ing cohesion and enabling the molecules to move more freely,
but it assists also by the very affinity which each of its own
principles bears to the elements of the substance subjected to the
putrescent fermentation. Proust observed that during the decom-
position of gluten immersed in water, a mixture of carbonic acid
312
and of pure hydrogen gas is disengaged, a phenomenon which
he explains by the decomposition of the water; at the same
time are produced ammoniacal salts, among which are acetates
and lactates, whose acids are generated by the very act of fer-
mentation. As a striking example of the agency of water in
the transit of azote into the ammoniacal state in a quarternary
compound, we may take the putrefaction of urea.
Urea is found in the urine of man and of quadrupeds; its
composition, according to M. Dumas is:
MANURES.
Carbon
Hydrogen
Oxygen
Azote
The animal substances dissolved in urine, as the mucus of the
bladder, &c., undergo on contact with the air a modification which
causes them to act upon urea like ferments. By their influence
the elements of water react upon this substance, and trans-
form it into carbonate of ammonia.
Carbonate of ammonia is composed of:
Carbonic acid 56.41, containing
and
Ammonia 43.59, containing
Previous to fermentation 100
of urea, contains
After fermentation, 130 of carbo-
nate of ammonia contains
°}
. 20.0
6.6
26.7
46.7
100.0
}
ƒ Carbon
agen
Hydrogen
Azote
But 100 of urea have been found to produce by fermentation
130 of carbonate of ammonia.
·
20.00
15.39
41.02
7.69
35.90
Carbon. Hydrogen. Oxygen. Azote.
20.00 6.60 2.67 46.7
53.3 46.7
Difference 0.0
3.4
26.6
0.0
So that during its transformation, the urea has gained 3.4 of
hydrogen, and 26.6 of oxygen.
In water the hydrogen is to the oxygen as 1 to 8. (:: 1:8).
Now it is precisely in this proportion that hydrogen and
oxygen are found to be acquired by the urea in passing into the
state of carbonate of ammonia; whence it follows that the ele-
ments of water are fixed in the process.
10.00
DECAY OF ORGANIC MATTERS.
313
The putrefaction of azotised substances is far from always
presenting results equally precise; most frequently in decom-
posing they pass through a series of changes, still very ob-
scure, before they attain their ultimate limit, viz: the produc-
tion of ammoniacal salts. Thus from putrefying caseum diffused
in water, M. Braconnot obtained, among other products
and ammoniacal salts, a very remarkable substance which he
calls aposepedine.
Aposepedine when purified is a white crystalline substance,
soluble in water and in alcohol, capable of combination with the
metallic oxides; azote is one of its elements.
This substance although engendered by the act of putrefac-
tion is nevertheless itself capable of putrefying and giving birth
to the last products of the spontaneous decomposition of azotised
matter.
One of the most striking characteristics, at least that which
is most readily remarked, is the fetid odour which animal sub-
stances exhale during putrefaction. It is not always the smell
of ammonia which predominates; that of sulphuretted hydrogen
gas is often very strong; yet that is not the emanation which is
most repulsive: miasmata and nauseous principles are also de-
veloped which seem to be the changed matter itself carried away
by the gases that are disengaged.
Sulphur, like phosphorus, is almost always a constituent of or-
ganic bodies; its minute proportion, however, would be insuffi-
cient to give out the hepatic odour so intense as we often find it
during putrefaction. The production of sulphuretted hydrogen
is connected with the very curious fact, first appreciated by M. O.
Henri, that sulphates dissolved in a medium impregnated with
azotised matter in decomposition, do themselves undergo an
actual reduction, pass into the state of sulphurets, and imme-
diately give out sulphuretted hydrogen, either by the action of the
carbonic acid of the atmosphere, or by that which is formed
during the putrefaction of the organic matter. It is by a simi-
lar action exerted upon sulphate of lime that M. Henri explains
the origin of the sulphureous waters of Enghien, near Paris;
and M. Fontan in his important work on mineral waters has
generalised this explanation.
The causes of the destruction of sulphates under such circum-
314
MANURES.
stances is easily understood. During the decomposition of or-
ganised substances, the carbon belonging to them forms carbonic
acid gas, by combining both with the oxygen of the substances
themselves, and with the oxygen of the water, it is probable that
the oxygen of the sulphuric acid contributes equally to this for-
mation, and that the sulphur is liberated.
The hydrogen of the decomposed water, as well as that of the
solid matter, in contact with sulphur in the nascent state, com-
bines with it to form sulphuretted hydrogen, which straightway
reacts upon the base of the sulphate, producing from it, as we
know, water and a metallic sulphuret. This sulphuret being un-
able to exist when exposed to the continued disengagement of
carbonic acid gas which takes place in the centre of the mass in
putrefaction, yields, as a definite result, a carbonate on the one part,
and sulphuretted hydrogen on the other.
The faculty which azotised organic bodies possess of undergo-
ing spontaneous decomposition in presence of water, and under
the influence of heat, seems to depend upon the tendency
which azote has to unite with hydrogen in order to form am-
monia.
This tendency is perhaps the determining cause of the phe-
nomenon of fermentation taken in the most general acceptation
of the term. Organic bodies void of azote decompose less casily,
and the kind of alteration which they undergo from the action of
water and air, differs in many respects from the putrefaction of
azotised matter. Of this the difficulty experienced in effecting
the fermentation of vegetable substances is a proof. Neverthe-
less, the vegetable refuse which goes to the dunghill, all without
exception, contains azotised elements, often, it is true, in ex-
tremely minute proportions; but we know that there is no ex-
ample of a vegetable organic tissue from which they are com-
pletely excluded.
The refuse of plants, the most amply endowed with azote such
as cabbage, beet-root, beans, &c., are certainly those which are
susceptible of the most rapid and complete putrid fermentation;
straw, on the contrary, when alone, undergoes it slowly and im-
perfectly, the small quantity of the azotic principle which it
contains is changed, and reacts upon the ligncous particles which
surround it; but the effect is soon arrested, and even ceases entirely,
DECAY OF ORGANIC MATTERS.
315
unless substances richer in azote concur. The woody matter
of the straw is exactly in the condition of sugar which has not
had a dose of ferment sufficient for its total transformation into
alcohol.
Most organised substances, whether they belong to the
animal or vegetable kingdom when placed in certain conditions,
undergo the profoundest changes from the action of hydrogen;
these alterations ought to be studied with all the more care, be-
cause in practical agriculture we are interested successively in
fostering or preventing the causes which produce them, accord-
ing as our object is to accelerate the decomposition of vegetable
refuse for manure, or to adopt the precautions which experience
suggests, in order to preserve the produce of our harvests unchang-
ed. Organic substances moistened and exposed to the air under
a temperature, the minimum of which (I believe after several ex-
periments) may be fixed at 48° or 50° F., seize upon the oxygen
and absorb it, in part, in order to form water with their hydrogen,
and carbonic acid with their carbon. When these substances are
accumulated in a mass sufficiently great, the heat produced is not
rapidly dissipated, the temperature rises, and promotes the re-
action to such a degree as to produce active burning, a con-
flagration, in place of the slow combustion manifested at first.
It is not very unusual to see hay, which had been gathered in
too damp a condition, take fire in the stack; and the high tempe-
rature acquired by wet rags placed in the fermenting vats of
paper mills, and the copious production of carbonic acid
which results, show that we are right in assimilating this kind of
action to the phenomenon of combustion. This sluggish com-
bustion is not peculiar to azotised organic substances: it takes
place equally in those destitute of azote. The alteration of organic
matters, the combustion which goes on at a low temperature
by the action of the air, differs in its results from the decomposi-
tion which is effected in the midst of a liquid mass. We have
seen, for example, that gluten fermenting under water, disengages
hydrogen gas. Now Berthollet has established, and Saussure has
confirmed his observations, that an azotised body in putrefaction,
the whole of whose parts are in contact with the air, never con-
tributes either hydrogen gas or azote to the confined atmosphere
S
316
MANURES.
in which it is placed; and on the other hand, Saussure has
shown, that organic substances which do not emit hydrogen gas
during their spontaneous decomposition in a medium void of
oxygen, do not alter the volume of an atmosphere of which this
gas forms a part; on the contrary, these substances condense
oxygen as soon as they attain that stage of their alteration in
which they give out hydrogen.
In pursuing with persevering sagacity the study of putrefac-
tion, M. de Saussure discovered the cause of this condensa-
tion; it consists in the fact, that an organic substance in course
of spontaneous decomposition, acts in some respects like the
platina sponge placed in a mixture of oxygen and hydrogen gas;
we know that platina recently heated and introduced into a
mixture of these two gases, determines their union in the pro-
portions required to constitute water. Now by substituting for
the metal some moistened seeds, previously deprived of their
germinating faculty, the same effect is produced: the two gases
combine until one of the two entirely disappears. When this
combustion of hydrogen, proceeding from the decomposition of
organic substances, takes place in the body of the atmosphere
which contains azote, it is possible that a minute quantity of
ammonia may be produced together with water; nor is it going
too far to suppose, that manures very slightly azotised, take up
azote from the atmosphere during their fermentation; that during
the act of vegetation itself, the hydrogen proceeding from the
decomposed water, or yet more, that which makes part of the
essential oils formed by plants, may, in oxidating afresh, in-
troduce atmospheric azote into their composition.
Dead organized matter, such as wood, straw, or leaves, exposed
to wet, and for a long time to the action of the air, ends by be-
coming transformed into a brown substance, which when damped
is almost black, which falls to powder when dry, and which is
commonly known by the name of humus or mould.
This is, so to speak, the last term of the decomposition of
organic matter; mould appears to belong already to the mineral
kingdom; and whatever may be the diversity of its origin, it pre-
sents a sufficient number of pcculiar characteristics to be consi-
dered a distinct substance. In fact, the atmosphere continues to
DECAY OF ORGANIC MATTERS.
317
exert its action upon mould; its inflammable elements are dis-
sipated by a slow and imperceptible combustion, giving place to
water and carbonic acid. But in this ulterior decomposition,
those fetid products which characterize putrid fermentation are no
longer observed.
Wet saw-dust placed for some weeks in an atmosphere of
oxygen, forms a certain quantity of carbonic acid, and the volume
of the gas does not perceptibly diminish. The wood at the surface
acquires a deep-brown colour. Several experiments made by
Saussure, prove that dead wood does not absorb the oxygen
gas of the atmosphere; it transforms it into carbonic acid, and
the action takes place as if the carbon of the organic matter
alone experienced the effects of the oxygen; for the gaseous vo-
lume remains the same. The loss, however, undergone by the
ligneous fibre, during its exposure to the air, is greater than it
ought to be if carbon alone were eliminated: whence Saussure
concludes, that whilst the woody matter loses carbon, it also lets
some of its constituent water escape.
As a consequence of these observations, the relative proportion
of carbon ought to augment in the humid wood changed by the
action of the atmosphere, since we have established, that by this
action the woody fibre suffers loss in the elements of water besides
what it loses in carbon. This is confirmed by the following ana-
lyses. The first, made upon some oak wood, previously purified
by washing in water and in alcohol, we owe to Messrs. Thenard
and Gay-Lussac; the succeeding one to Messrs. Meyer and Will:
Carbon
Hydrogen and oxygen, water
Id. rotten. Id. rotten.
53.6 56.2
43.8
46.4
Oak wood.
52.5
47.5
100.0 100.0 100.0
Wood decomposed under water, without being in direct con-
tact with the air, undergoes a different modification; it is
blanched instead of blackened, and the carbon far from increas-
ing is diminished. Saussure thinks, that this kind of alteration
depends mainly on the loss of the soluble and colouring princi-
ples of the wood, principles containing more carbon than the
ligneous matter itself; so that pure woody fibre exposed wet to
-
318
MANURES.
the action of the air would yield products analogous to those
which result from its decomposition under water.
The damp linen rags which are fermented in paper manufac-
tories afford a product which is white, and but slightly coherent.
The mass, which heats excessively during the operation, loses
about 20 per cent of its original weight. This is exactly
what takes place in wood decayed by the alternate action
of water and air, namely, it becomes white and extremely
friable.
Some oak arrived at this stage of decomposition contained,
according to Liebig:
Carbon
Hydrogen
Oxygen
Ashes
47.6
6.2
44.9
1.3
100.0
Compared with the composition of oak wood when sound,
these numbers show that during its modification the wood has
lost carbon, and that it has gained hydrogen. The elements of
water must necessarily have intervened, and become fixed
during the reaction. Ligneous fibre decaying under water is not
thereby completely protected from the atmosphere. Water
always holds some air in solution, and the oxygen of that air
reacts exactly as if it were in the gaseous state.
Upon all the phenomena of decomposition connected with
fermentation, with putrefaction or with dilatory combustion,
heat exerts an influence which has certainly not been sufficiently
appreciated. Organic bodies sunk in a large mass of water
are not exposed to changes of temperature so various and
abrupt as when they are placed in the atmosphere; their decom-
position is more gradual, more uniform, and the soluble materials
which they contain, or which are the result of the alteration they
are undergoing, are in a great measure dissolved. Temperature
may also produce great differences in the final result of the
decomposition. Peat which is derived, as we know, from the
slow decomposition of submerged plants, does not appear to be
formed in the swamps of warm climates; it has, perhaps, never
been encountered in the stagnant waters of the equinoctial
DECAY OF ORGANIC MATTERS.
319
regions; there the woody fibre appears to be totally dissipated in
carbonic acid gas, and in marsh gas, the probable source of the
insalubrity of those countries. Lakes with peat bottoms are
not found except on the very high table-lands of the Andes in lo-
calities where the mean temperature does not exceed 49° or 50° F.
The alkalies are powerful agents in the decomposition of cer-
tain organic substances, whether in determining or in accele-
rating it. There are some, indeed, which experience no change
without their intervention, whatever may be the other conditions
favourable to decomposition. Thus, according to M. Chevreul,
many colouring substances may be preserved in solution almost in-
definitely, without change in contact with gallic acid; but the pre-
sence of a very small quantity of free alkali suffices for their imme-
diately acquiring the power of absorbing oxygen, and at the same
time of acquiring a brown tint. M. Chevreul observed that
3.087grs. of hematine dissolved in potash will absorb 3.857grs.
of oxygen in forming 0.925 of carbonic acid. The oxygen which
enters into the carbonic acid, therefore, represents nothing like the
quantity which was fixed by the solution, and it is almost certain
that this gas likewise re-acted upon the hydrogen of the colouring
matter. The use of the alkalies for accelerating the destruction
of organized matter has been long known to agriculturists.
Straw, fern, and the ligneous parts of plants are sometimes
stratified with quick-lime, in order to facilitate their disintegra-
tion, and consequently their decomposition. The utility of this
old practice cannot be disputed while confined within certain
limits; but it is often abused; for it is beyond doubt, that
alkalies mingled indiscriminately with manure become in reality
more injurious than advantageous for the end proposed in their
introduction.
The appearance of a certain brown substance, little so-
luble in water, but easily dissolving in alkalies, is a characteristic
proper to all vegetable matter under decomposition; a charac-
teristic which becomes more marked as the decomposition ad-
vances towards its last stage, namely, the production of humus.
This substance is ulmine, which, on account of some acid pro-
perties which it possesses, is also named ulmic acid. It forms a
part of mould, and M. P. Boullay constantly found it in the
water of dunghills.
320
MANURES.
In 1797 Vauquelin discovered ulmine united with potash in
the matter of the exudation from the ulcer of an elm tree.
In 1804 Klaproth confirmed this observation. M. Braconnot
succeeded in obtaining ulmine artificially by subjecting woody
fibre to the action of alkalies. This substance is easily procured
by carefully heating in a silver capsule, and continually stirring a
mixture of equal parts of potash and of saw-dust slightly damped.
At a certain time the woody matter softens and suddenly dis-
solves; the mass then begins to swell up, and the fire is slaked.
The product obtained dissolves almost totally in water. The so-
lution is of a very deep brown colour, and contains as principal
ingredient ulmine combined with potash; the ulmine is precipi-
tated by the addition of a sufficient quantity of weak sulphuric
acid. After having been washed and dried, ulmine is black and
brittle, and resembles jet; while still wet, it reddens turnsole
paper, and its solution in potash forms with several salts, and by
the way of double decomposition, insoluble ulmates. M. Peligot
assigns to ulmine the following composition:
Carbon
Hydrogen
Oxygen
72.3
6.2
21.5
100.0
Dunghills, rotten wood, and mould always contain a brown
substance, which possesses properties very similar to those which
characterize ulmine obtained by the action of alkalies upon
ligneous fibre.
Mould which contains this ulmine in abundance, and in the
condition most favourable to vegetation, ought on that account
to be examined with attention. Its history has, indeed, been so
ably traced by M. de Saussure, that science at the present day
can add but little to the important deductions of the celebrated
author of the Recherches Chimiques.
M. de Saussure defines vegetable mould (humus) to be the black
substance which covers dead vegetables after they have been long
exposed to the combined action of water and oxygen. His ex-
periments refer to mould nearly pure; that is, separated by a fine
sieve from the vegetable remains which are always mixed with
it; to mould which had been gathered on high rocks, or from the
HUMUS.
321
trunks of trees, where it could not have been exposed to ad-
mixture or to any influence, other than that of the spontaneous
decomposition by which it had been produced. All the varieties
of mould collected in this way appeared fertile, especially when
they were previously mixed with gravel, which supplies support
to the roots of plants, and permits the access of the air. That
variety, however, must be excepted which was obtained from the
interior of trees, and had been formed in such a situation that
the rain-water which entered found no free outlet; the humus
then contained extractive principles, derived in part from the
living plant, and which seemed to obstruct the pores of the
vegetable to which it was applied as manure.
In making comparative calcinations in close vessels of diffe-
rent varieties of humus, and of plants similar to those from
which they had proceeded, and collecting the charcoal on one
hand, and the volatile and gaseous matters on the other, M. de
Saussure discovered that they contained, for the same weight, a
larger quantity of carbon and of azote than the vegetables
whence they proceeded. The larger proportion of azote in
the humus seems to imply that during their decomposition, ve-
getables do not throw off this element; but to this cause must
be added that which might be connected with the spoils of in-
sects which live in humus.
Weak acids have no other effect upon humus than to dissolve
out the metallic, earthy, and alkaline elements which it contains.
The more powerful acids, such as the sulphuric acid, frequently
cause a disengagement of acetic acid. Alcohol scarcely acts
upon humus, merely dissolving out of it a few hundredth parts
of resinous matter, which probably pre-existed in the vegetable.
Potash and soda dissolve humus almost completely, causing an
evolution of ammonia. From this solution, acids throw down a
brown, inflammable powder, possessing the characters which we
have recognised in ulmine. The ulmine which is separated in
this way, is far from corresponding with the weight of the
matter treated with the alkalies, which is evidently due to the
humus containing principles which are not precipitated from the
alkaline solution.
A quantity of humus which yielded no more than one tenth
Y
322
HUMUS.
of ashes by incineration, only lost one eleventh of its weight
under repeated treatments with boiling water. The humus thus
exhausted, was exposed in a moist state to the action of the
air for three months, and gave a new quantity of soluble matter
under renewed washing with water; and the same effect is con-
stantly reproduced. By exposing moist insoluble humus to the
air, therefore, a quantity of soluble extractive matter is formed.
This matter, obtained by evaporating the water which is charged
with it, is not deliquescent; it yields ammonia on distillation.
The watery solution, brought to the consistence of syrup, is
neutral to re-agents, and its taste is sensibly sweet.
It is familiarly known that the alkaline salts, which enter into
the constitution of vegetable juices, but rarely exhibit the re-
actions that are proper to them; the plant or the sap must be
dried and incinerated before their presence can be ascertained.
It is the same with regard to the salts contained in humus.
J
Humus, as I have already observed, is the last term in the
putrefaction of vegetable organic matter; its elements have ac-
quired a stability which enables them to resist all fermentation.
M. de Saussure preserved humus for a whole year in vessels
filled with distilled water, and plunged in mercury, without re-
marking any emission of gas. Still it is unquestionable that
the organic portion of humus is completely destructible when
exposed moist to the action of the air; in the course of time it is
dissipated, and by and by there remains nothing more than the
fixed saline and earthy matters which it contained. This fact
M. B. de Saussure had already perceived from his observations
upon the vegetable soil that occurs in the country between San
Germano and Turin. This destructibility of vegetable earth,
says M. de Saussure, sen., is a fact without exception; and as
often as agriculturists have proposed to supply the place of ma-
nure by repeated ploughings, they have had sad experience of its
truth the soil is gradually impoverished, and fertile fields ulti-
mately become barren. I may add, that the nature of the cli-
mate has a vast influence upon the dissipation of the fertilizing
principles of the soil, and that Europeans are certainly in error
when they object to the superficial ploughings or hoeings which
the land so commonly receives in tropical countries. It is there
NITRIFICATION.
323
well known that too much stirring of the soil is often prejudicial
even in irrigated lands, where consequently the bad effects can-
not be attributed to too great a degree of dryness. The infor-
mation which has lately reached the Academy of Sciences upon
the agriculture of the French possessions in Africa, tend to make
us perceive that the same cause produces the same effects in
Algeria, and that it is not without reason that the Arabs only
work their lands, that are preparing for grain crops, very super-
ficially.
:
Humus is, in fact, dissipated by a process of slow combustion
in the air in contact with oxygen, it produces carbonic acid, as
is proved by the experiments of M. de Saussure. Pure humus,
moistened with distilled water, confined in bell-glasses placed over
mercury, formed carbonic acid, causing the disappearance of the
oxygen of the air. The volume of the acid gas formed, correspond-
ed in volume with that of the oxygen which had disappeared. Hu-
mus, therefore, in contact with air, gives off carbonic acid, and the
phenomenon here still takes place as if carbon were not alone con-
sumed. The loss experienced is greater than that which ought to
occur from the quantity of carbon which unites with the oxy-
gen; and Saussure concluded that there is, at the same time, a loss
of the elements of water. The capital fact which results from these
experiments of Saussure, the deduction directly applicable to the
theory of manures is this: that humus is dissipated when it is ex-
posed to the air, and that during the slow combustion which it
undergoes, it is a constant source of carbonic acid gas.
To complete the views that may throw light on the part
played by manures, I have still to speak of an important pheno-
menon which occasionally takes place under the same conditions
as those that accompany the decomposition, the putrefaction
of animal matters: I mean the spontaneous formation of nitric
acid-the occurrence of nitrification as it is called. Nitric acid re-
sults from the union of azote with oxygen. Such at least is
the constitution of this acid when it is combined in salts; but
in its isolated state, it is always united with a certain quan-
tity of water. It has not yet been obtained, and it appears in-
deed not to exist, in the perfectly dry or anhydrous state. The
azote, therefore, does not combine directly with the oxygen;
Y 2
324
PRODUCTION OF NITRE AND NITRATES.
there must be, at all events, the intervention of water, and to
effect the union of the two gases by means of the electric spark,
the mixture, according to Cavendish, must be moist. Never-
theless, the combination of azote with oxygen appears to be
singularly favoured by the presence of earthy or alkaline bases,
seeing that in nature the nitrates are met with in a certain
abundance; but the circumstances which determine their for-
mation are still involved in deep obscurity.
Three distinct origins may be assigned to the natural
nitrates 1st. certain soils, still indifferently studied, show an
efflorescence of nitrate of potash on their surface, or by lixi-
viation yield large quantities of this salt. Such is the source of
the saltpetre which is imported from India.
According to M Proust, the soil of certain localities in the
neighbourhood of Saragossa is an inexhaustible mine of salt-
petre. I have myself seen near Latacunga, a short way from
Quito, upon a soil formed of trachytic debris, a similar produc-
tion of nitre taking place as it were under my eyes.
2nd. On the coast of Peru, in the desert of Tarapaca,
at a short distance from the port of Iquique, and in an argilla-
ceous soil of extremely recent formation, there are numerous
stratified deposits of nitrate of soda, analogous to, and perhaps
contemporaneous with the deposits of common salt which are
worked upon the same coast, in the desert of Sechura, near
the equator. This is, so far as I know, the only instance of a
nitrate being dug out of the bowels of the earth as a mineral
mass. The nitrate of soda of Tarapaca, reaches Europe at
the present time in large quantities, and supplies the place of
nitrate of potash in many chemical processes. Various experi-
ments have also been made upon the value of the salt as a
manure; but at present these experiments have been very con-
tradictory, and further experience seems necessary before any de-
finitive judgment can be come to on the matter.
3rd. The greater number of the soils that are exposed to
animal emanations-heaps of rubbish proceeding from buildings
that have been long inhabited, the soil of stables, cow-houses,
cellars, &c., almost always contain a quantity of nitrates. In
countries where rain seldom falls, and where consequently these
PRODUCTION OF NITRE AND NITRATES.
325
salts, which are extremely soluble, can accumulate in the soil, in
Egypt, for example, the ruins of ancient cities are at the present
time true nitre-beds. It is with the formation from nitre in such
circumstances that we feel particularly interested. The presence
of the salt is frequently proclaimed in our agricultural opera-
tions; it is formed during the preparation of our dunghills, in
the midst of our cultivated fields, and we discover it in the
plants which we gather. We are by so much the more inte-
rested in discovering its existence, and in ascertaining its mode of
action, as in the actual state of our knowledge we are still unable
to say whether or no nitre is an auxiliary in the phenomena of
vegetation, and contributes to the production of the azotised prin-
ciples which enter into the organization of plants.
To have nitrates formed, the presence of azotised organic
matter is not sufficient; it is further necessary that this matter
during its decomposition be in contact with alkaline, calcareous,
or magnesian carbonates. It has been observed that rocks of a
crystalline structure do not nitrify so readily when they are with-
out the substances which have just been named. The calca-
reous and magnesian rocks which are most favourable to nitrifi-
cation, under the influence of animal emanations and of
vegetables in a state of decomposition, are those which are
the least coherent, or which are the most porous, such as chalk,
tufa, &c. In those countries where the soil does not undergo
spontaneous nitrification, certain arrangements of circumstances,
known to favour the production of saltpetre, are made artificial
nitre-beds are prepared. In the north of Europe where the
rocks are granitic, in a hut or shed built of wood, a mixture is
made of common earth, of calcareous sand or marl, and of
wood-ashes. This heap is watered with the urine of herbivorous
animals, and the mixture is stirred or shifted from time to
time to favour the access of the air; and with the same view,
the workmen are very careful never to beat or press the heap,
which is generally from two to two and a half feet in thick-
ness, and usually of the whole length of the hut or shed.
Experience has shown that the process of nitrification goes ou
best in the shade. In Prussia, the practice is to wet with the
water of a dunghill a mixture composed of five parts of vegetable
326
THEORY OF THE FORMATION OF NITRIC ACID.
earth, and one part of wood-ashes and straw. With this kind
of mortar, solid walls or masses from twenty to four and twenty
feet in length, by about six feet and a half in thickness, are
built, rods of wood being introduced during the construction in
considerable numbers, and in such a way that they can be pulled
out when the mass has acquired sufficient solidity; by this
means it is obvious that a very free access of air is secured to
the interior of these nitre walls, which are always built in damp
places, and thatched over with straw to preserve them both from
the sun and the rain. The mass is watered from time to time,
and after the lapse of a year, the materials are held sufficiently
impregnated with saltpetre to be worth lixiviating.
In these artificial nitre-beds we perceive the object to be,
to combine the circumstances under which the nitrates are
formed in the soil of stables, and in the cellars of human habi-
tations. Organic matters, rich in azote, are, in fact, brought
into contact with earthy alkaline carbonates. The necessity
that is felt in the arrangement of nitre-beds for the introduc-
tion of substances of animal origin, leads us to presume that
the greater part of the nitric acid which is produced, is derived
from the azote of these substances. But whether this azote
combines with the oxygen of the air, or with the oxygen of the
organic principles, we do not know—we are still ignorant of the
way in which the acidification is effected.
Professor Liebig, setting out from the fact that azotised or-
ganic substances always produce ammonia during their putre-
faction, and next perceiving that during the combustion of am-
moniacal gas, mixed with a large excess of hydrogen, there is
always oxidation of the azote, concludes that nitrification is the
result of the slow combustion of the ammonia which is the pro-
duct of the azotised matters in progress of decomposition. The
azote of ammonia is indeed oxidated under favour of divers
conditions which it is easy to secure. In burning animal sub-
stances by means of oxide of copper, it is well known how many
precautions must be taken to prevent the appearance of nitrous
acid; and on the contrary, by taking measures to favour the pro-
duction of this acid, for example, by passing a current of ammo-
niacal gas over peroxide of iron or manganese in a red hot tube,
THEORY OF THE FORMATION OF NITRIC ACID. 327
abundance of nitrate of ammonia is obtained. The same result
follows exposure of a mixture of oxygen and ammoniacal gas
to the action of incandescent spongy platinum. The determin-
ing cause of the acidification of the azote, which forms an
element of the ammonia, is probably due to this, that during the
combustion two bodies are formed which are capable of com-
bining immediately: nitric acid, on one hand, and on the other
water, without which this acid could not exist. The phenome-
non, however, only takes place in this instance at a considerably
elevated temperature. At ordinary temperatures, combustion of
the elements of ammonia has not as far as I know yet been
observed; and in a series of experiments which I under-
took, proceeding all the while upon ideas completely in con-
formity with those advanced by Liebig, I did not succeed in
forming any nitrates by enclosing mixtures of chalk, potash,
&c., in an atmosphere composed of oxygen and ammoniacal
vapour.
In a communication made to the Academy of Sciences, M.
Kuhlman announces that he had ascertained the presence of
nitrate of ammonia in the products of the putrefaction of animal
matter. If this announcement be confirmed, if nitric acid be in
reality one of the numerous products of the putrid fermentation,
the nitrification of soils in contact with organic matters would
be readily explicable. I must say, however, that I have sought
in vain for nitrate of ammonia in the product of the putrid
fermentation of caseum. And after all, we should still be at a
loss to account for the formation of nitre in many places, where
it appears to be produced in the absence of organic matter, as in
the saltpetre soils of India, South America, and Spain. Dr.
John Davy, who visited the nitre districts of Ceylon, and Proust,
who long inhabited the Peninsula, have given it as their opinion
that the nitre appears in soils which contain no vestiges of or-
ganic matter. The assertion of Proust, however, is open to
suspicion, inasmuch as in his memoir he affirms that the lands
close to those that produce the nitre are extremely fertile, so
that they yield abundant crops without ever receiving manure.
But at the present day, it is a law that every fertile soil must
contain or receive dead organic matter. In Ceylon, according
328
DETECTION OF NITRATES IN THE SOIL-MANURES.
to Davy, the caverns, the walls of which become covered with
an efflorescence of saltpetre with such rapidity, have a fertile and
thickly wooded soil lying over them, the percolations from which
may readily penetrate their interior. The observations which I
had an opportunity of making upon the nitre soils near Lata-
cunga were not perhaps of sufficient precision; but I think I
can affirm that the soil was not without humus: patches were per-
ceived here and there that were covered with turf. It must still be
admitted, however, that in the localities which have been parti-
cularly indicated there must exist some peculiar and permanent
cause of nitrification; inasmuch as in other and fertile soils, salt-
petre only appears as it were accidentally, and never in extra-
ordinary quantity.
Whatever the value of the ingenious but still very imperfect
theories of nitrification, it is still of importance to ascertain the
existence or absence of nitrates in the soil. Wollaston recom-
mended a process which enables us to do this very readily. It is
founded on the property possessed by the aqua regia-a mixture
of the nitric and hydrochloric acids-to dissolve pure gold, which,
as is familiarly known, resists the action of either of these
acids applied separately. The soil in which the presence of a
nitrate is suspected is treated with boiling distilled water, and
thrown upon a filter. The filtered fluid is reduced by evaporation
to a very small quantity, which is then poured into a test tube,
and a little pure hydrochloric acid is added; some particles of leaf
gold are then introduced, and the fluid is stirred with a glass rod.
If any nitrates have been present, the particles of gold are specd-
ily dissolved.
Having now described the circumstances which determine, and
the phenomena which accompany the decomposition of dead or-
ganic matter, I have next to treat of manures in particular, of
their preparation, of their application, and of their relative values.
Speaking generally, the manure which is derived from the
dejections of animals, supplied in a farm-yard with abundance of
food and of litter, used with the double object of cleanliness and
health, is the best of all. The principal substances which con-
tribute day by day to increase the mass of our dunghills are
straw, and the excretions and urine of horned cattle, horses,
FARM-YARD DUNG.
329
hogs, &c. These various substances, besides the organic ele-
ments which enter into their composition, farther contain the
various mineral substances which are indispensable to the de-
velopment of vegetables. Animal excrements of every kind, in
fact, when they are burned, leave quantities of ashes which are
frequently very considerable, and in which are encountered the
same saline and earthy ingredients that pre-existed in the
forage with which the animals were supplied. Excrements,
therefore, necessarily vary in their composition according to the
kind of food that is consumed, and the nature and the state of
health of the animal which produced them. Those of the her-
bivora have never been sufficiently examined. Thaer and Einhof
have merely ascertained that cow-dung contains an extractive
principle, partly coagulable by heat, and that remains of the
food may be separated from it. All excrementatious matters, in
fact, contain a certain quantity of the alimentary matter which
has escaped digestion, especially when animals are abundantly
supplied with food. Some albuminous matter is also found
there; but the substance after vegetable remains that appears to
predominate is bilious.*
We know that after mastication, the food, mingled with sa-
liva and the secretions of the mucous glands, passes into the
gullet, and from thence into the stomach. There it imbibes
gastric juice, turns sour, becomes modified, and is finally con-
verted into a kind of pulp which is called chyme. Once formed,
chyme passes into the small intestines, where it encounters the
bile and pancreatic juice, which modify it, and cause it to sepa-
rate into chyle, which is absorbed by the vessels of the bowels,
and excrementitious residue, which descends into the large in-
testines, where it becomes a fetid mass that is expelled from time
by the animal.
The bile which accompanied the fecal matter is secreted by
* The latest inquiries of the physiological chemists would lead us to
suspect that this was not the case. Bile ought only to be an occasional,
and even an unnatural constituent of animal excrement, if these views be well
founded. It seems that the elements of bile added to the elements of
starch supply the precise elements of fat; a substance so abundantly
formed in the process of digestion. The bile that is poured into the upper
part of the alimentary canal is probably all used up in forming fat.-
ENG. ED.
330
MANURES-URINE.
the liver, and is familiarly known as a viscid, bitter fluid of a
yellowish green colour and a peculiarly nauseous odour. Accord-
ing to M. Thenard, the bile of the ox contains:
Water
Picromel*
Fatty matter
Soda, phosphate of soda, chlorides of potas-
sium and sodium, sulphate of soda
Phosphate of lime, oxide of iron
700
69
15
10
1
795
Urine is a liquid secreted by the kidneys from arterial blood;
it
passes into the bladder by the uretus. Its composition varies
according to the animals which produce it. Urea is its most
characteristic principle; and in the water which it always con-
tains in large proportion, various saline substances and animal
matter, which is regarded as mucus of the bladder, are encoun-
tered. The urine of the horse, according to M. Chevreul, con-
tains carbonate of soda, of lime, and of magnesia, sulphate of
soda, chloride of sodium, hippurate of soda, urea, and a red
coloured oil.
The urine of horned cattle has a similar composition, with
this difference, that it is much more watery. In the urine of our
cow houses which had undergone change, I have ascertained the
presence of the alkaline carbonates, of common salt, and of the
reddish oil mentioned above. Having at various times had oc-
casion to evaporate considerable quantities of the urine of the
horse, I always observed that on coming to the boiling point, a
quantity of azotised matter which resembled albumen was co-
agulated. I also perceived in the urine of herbivorous animals,
a volatile acid to which its odour is probably owing.
* Picromel, discovered in the bile of the ox by M. Thenard, is colour-
less, and of the consistence of syrup. It produces upon the tongue an
acrid and bitter sensation, which rapidly changes to a flavour slightly su-
gary. The recent researches of Messrs. Tiedemann and Gmelin have dis-
covered in ox bile substances which had escaped the first investigations.
These chemists found: 1st. a substance having the smell of musk, and
which is probably one of the causes of the odour peculiar to the excrement
of kine; 2nd. fatty substances; 3rd. biliary resin; 4th. a crystallized
substance called taurine; 5th. biliary sugar, of which azote forms one of
the elements. According to Messrs. Tiedemann and Gmelin, the picromel
of M. Thenard results from the union of sugar and biliary resin.
MANURES- -URINE.
331
In the urine of the camel, M. Chevreul found the carbonates of
lime and magnesia, silica, sulphate of lime, and oxide of iron, in
very small quantities; chloride of potassium, carbonate of
potash, sulphate of soda, in small quantities; sulphate of potash
in large quantity; urea; an alkaline hippurate; and a reddish oil.
The urine of the rabbit, according to Vauquelin, contains:
carbonate of lime, of magnesia, and of potash, chloride of po-
tassium, sulphate of potash, sulphur, urea, and mucus.
The urine of birds is distinguished by the large proportion of
uric acid it contains. Food, however, has a great influence
upon this proportion; highly azotised aliments increasing it con-
siderably. Wollaston observed that the excrements of a fowl
which was fed upon herbage contained only 2 per cent of uric
acid. That of a pheasant fed upon barley contained, on the
contrary, 14 per cent; and that of a falcon which fed upon flesh
alone, yielded scarcely anything but uric acid. The urine of an
ostrich was found by Fourcroy and Vauquelin to contain uric
acid in the proportion of about one sixteenth of its mass.
I have already given the composition of urea. Hippuric acid
is an azotised acid which is readily obtained by adding a little
hydrochloric acid to the fresh urine of the horse reduced by
evaporation to about one tenth of its original volume, when a
granular crystalline mass is precipitated. If the urine have
been stale instead of fresh, benzoic acid and not hippuric acid is
obtained; benzoic acid was, in fact, long admitted as one of
the elements of the urine of herbivorous animals; but it is
derived from the transformation of hippuric acid into benzoic acid
and ammonia, the change being produced by contact with the
organic matters which putrify so quickly in urine. Liebig was
the author of this observation; it was in operating upon un-
changed urine that he discovered hippuric acid. The following
is its composition:
Carbon
Hydrogen.
Oxygen
Azote
60.7
5.0
26.3
8.0
Uric acid has not yet been met with in the urine of mammi-
100.0
332
MANURES-THE PUTREFACTIVE FERMENTATION.
ferous herbivora; but it exists in that of man, having been first
discovered in calculi from the bladder; whence it received the
name of lithic acid. Liebig's analysis shows it to be composed
of:
Carbon
Hydrogen
Oxygen
Azote
36.1
2.4
28.2
33.4
100.0
The litter most commonly used to absorb the urine of stall-
kept animals is wheat straw, which consists in principal part of
lignine or woody fibre: like all vegetable tissues, however,
it contains an azotised principle, and substances that are soluble
in caustic alkalies. In the ashes of straw, we have indicated
silica as abundant, and various alkaline and earthy salts. The
proportion of azote appears to vary in the ratio of from 3 to 6
per 1000.
An analysis which I made of dry wheat straw
gave the following elements:
Carbon
Hydrogen
Oxygen
Azote
Ashes
48.4
5.3
38.9
00.4 to 0.6
07.0
100
Agriculturists have, in all ages, admitted that the most power-
ful manures are derived from animal substances, an opinion or
rather a fact, which expressed in scientific language, amounts to
this, that the most active manures are precisely those which
contain the largest proportion of azotised principles. It is
obvious indeed from everything which precedes, that all the
substances which contribute to form farm dung, contain azote ;
and that into many of them, such as uric acid, hippuric acid
and urea, this element enters very largely.
When we consider the immediate changes which all highly
azotised substances undergo in the process of putrefaction, we
can foresee that in their transformation into manure, they must
MANURES-VALUE OF AMMONIACAL SALTS.
333
give origin to ammoniacal salts; and well established facts
prove beyond doubt that salts, having ammonia for their base,
must be ranked among the most powerful of all the agents in
promoting vegetation. It is sufficient, for instance, to bear in
mind that in the productive husbandry of Flanders, putrid urine
is the manure that is employed with the greatest success; but
we have seen that by putrefaction, the urea of the urine is en-
tirely changed into carbonate of ammonia. The fields of
Flanders are consequently fertilized with a solution of carbonate.
of ammonia in water.
Along a great extent of the coast of Peru, the soil which
consists of a quartzy sand mixed with clay, and is perfectly
barren of itself, is rendered fertile, is made to yield abundant
crops by the application of guano; and this manure which
effects a change so prompt and so remarkable, consists almost
exclusively of ammoniacal salts. It was with this fact before
me that in 1832, when I was on the coasts of the Southern
Ocean, I adopted the opinion which I now proclaim in regard
to the utility of the salts having a basis of ammonia in the
phenomena of vegetation. I have stated my views on this
subject in a memoir published in 1837.* Previous to this
publication, however, M. Schattenmann, one of the most in-
genious manufacturers of Alsace, had already directed the atten-
tion of husbandmen to this important matter, by reminding
them that it is the custom in Switzerland to add sulphate of iron
or green vitriol to the urine-vats, for the purpose of changing
the carbonate of ammonia into the sulphate, and thus obtaining
a fixed instead of a highly volatile salt, liable to escape and to
be lost. In a communication made in 1835 to the agricultural
association of Bauchsweiler, M. Schattenmann announced posi-
tively that the drainings from dung hills thus prepared, applied
upon meadow lands, produced very great effects.
Such, to the best of my knowledge, are the practical facts
which establish the useful influence of ammonia on the growth
of plants far better than the experiments of the laboratory could
have done. Nevertheless it must be acknowledged that long
* Annales de Chimie, t. LXV. 2e série, p. 301.
334
MANURES-PREPARATION OF DUNG.
1
300
before the dates above quoted, Davy had shown that water
containing th of carbonate of ammonia is singularly favour-
able to the growth of wheat, far more so, under circumstances
exactly similar than the hydrochlorate and the nitrate of the
same base; and this influence, it is important to observe, Davy
ascribed to the fact that carbonate of ammonia contains car-
bon, hydrogen, oxygen and azote, in a word, all the elements
that are essential to the organization of plants. The illustrious
English chemist concluded from his experiments, that the
well known efficacy of soot, as a manure, is due in part to the
volatile alkali which it contains.
Professor Liebig in adopting these opinions, has sought to
generalize them; he has attempted to show, by very delicate
experiments, that the air which lies immediately over the sur-
face of the ground, always contains carbonate of ammonia, and
that the same salt can be detected in rain and snow, and in
spring water. The ammonia of the atmosphere, according to
Liebig, concurs with that which is developed in manures, in the
formation of the azotised principles proper to vegetables. These
ingenious ideas correspond exactly with those which M. de
Saussure made public in 1802, when he ascertained that the
gaseous azote of the air is not directly absorbed by plants. "If
azote be a simple substance, and not an element of water," says
this celebrated observer, "we must admit that plants do not as-
similate it, save in vegetable and animal extracts, and in the
ammoniacal vapours or other compounds soluble in water which
they absorb from the soil, or from the atmosphere. It is im-
possible," he continues, "to doubt the presence of ammoniacal
vapours in the atmosphere when we see that the pure sul-
phate of alumina, exposed to the air, ends by becoming changed
into the ammoniacal sulphate of alumina.” *
GAB
In agricultural establishments, in which the importance of
manure is duly appreciated, every precaution is taken both for
its production and preservation. Any expense incurred in im-
proving this vital department of the farm, is soon repaid be-
yond all proportion to the outlay. The industry and the intel-
ligence possessed by the farmer, may indeed almost be judged of
* Recherches Chimiques, p. 207.
MANURES-THE DUNG-HEAP.
335
at a glance by the care he bestows on his dunghill. It is truly
a deplorable thing to witness the neglect which causes the vast
loss and destruction of manure over a great part of these coun-
tries. The dunghill is often arranged as if it were a matter of
moment that it should be exposed to the water collected from
every roof in the vicinity, as if the business were to take advan-
tage of every shower of rain to wash and cleanse it from all it
contains that is really valuable. The main secret of the admir-
able and successful husbandry of French Flanders may perhaps
lie in the extreme care that is taken in that country to collect
Our
everything that can contribute to the fertility of the soil.
agricultural societies, which are now so universally established,
would confer one of the greatest services on the community if
they would encourage by every means at their command eco-
nomy of manure; premiums awarded to those farmers who
should preserve their dung-hills in the most rational and advan-
tageous manner would prove of more real service than premiums.
in many other and more popular directions.
:
The place where the dung of a farm is laid, ought to be
rather near to the stables and cow-houses. The arrangements may
be varied to infinity, but they ought all to combine the following
conditions 1st. That the drippings from the heap should
not run away, but should be collected in a tank or cistern under
ground. 2nd. That no water, except the rain which falls on the
dung-heap, or any water that may be thrown upon it on purpose,
should be allowed to drain into this reservoir. 3rd. That the
place for the dunghill be of size enough to avoid the necessity of
heaping the manure to too great a height. The ground upon
which the dung is piled, ought to slope gently one way or an-
other—from each side towards the centre is best-so that the
drippings may be collected in the tank or cistern. It is also de-
sirable that the soil underneath should be clayey and imperme-
able; where it is not so, it becomes necessary to puddle, to
cement, or to pave the bottom of the dung-hill stance as well as
the bottom and sides of the tank or cistern. The water which
runs from the heap should be thrown back upon it occasion-
ally, by means of a pump and hose, so as to preserve it in a
state of constant moistness. The opening into the tank, which
336
MANURES-THE DUNG-HEAP.
is best placed immediately under the centre of the dung-heap,
is closed by means of a strong grating in wood or iron, the bars
being sufficiently close to prevent the solid matters from pass-
ing through. One very important arrangement, one which in
fact must on no account be overlooked, is that the drains from
the stables and cow-houses be so contrived, that they all run to
the dung-hill. The litter, however abundant, never absorbs the
whole of the urine, especially at the time when the cattle are
upon green food; and it would be quite unpardonable in the
husbandman did he not take measures to secure this, the most
valuable portion of the manure at his disposal.
The litter mixed with the droppings of the animals, and
soaked with their urine, ought to be carried from the stables to
the dung-hill upon a light barrow. The practice of dragging out
the manure with dung-hooks, which is often permitted when the
field upon which it is to be spread is at no great distance, ought
on no account to be allowed; the loss from the practice is al-
ways considerable.
Materials ought not to be thrown on the dung-hill at ran-
dom or hap-hazard; they should be evenly spread and divided;
an uneven heap gives rise to vacancies, which by and by become
It is of much
mouldy, to the great detriment of the manure.
importance that the heap be pretty solid, in order to prevent too
great a rise of temperature, and too rapid a fermentation, which
are always injurious. Particular care must also be taken that
the heap preserves a sufficient degree of moistness, not only of
its surface but of its entire mass, which is effected by water-
ing it frequently. At Bechelbronn, our dung-heap is so firmly
trodden down, in the course of its accumulation, by the feet of
the workmen, that a loaded waggon drawn by four horses can
be taken across it without very great difficulty. The thickness
of the heap is not a matter of indifference: besides the conve-
nience of loading, which must not be forgotten, any great
thickness may become injurious by causing the temperature to
rise too high; circumstances occurring which should compel us
to keep a mass in this state for any length of time, the
decomposition would make such progress as to occasion very
great loss. Experience has shown, that the thickness of a
PREPARATION OF MANURE.
337
dung-heap ought not to exceed from about four feet and a half
to six feet and a half; it ought certainly never to exceed the
latter amount.
With a view to prevent the drying of the dung-heap and its
consequences, too great a rise in temperature and destruction
of manure, it is the practice in some places to arrange the
dung-heap on the north side of a building, which is undoubtedly
advantageous, but not always to be realized, especially in con-
nexion with a farm of some magnitude, where the immediate
vicinity of a large mass of matter in a state of putrid fermen-
tation is not only unpleasant, but may be unwholesome. In the
north of France, the dung-heap is sometimes shaded from the
sun by means of a row of elms, and the shelter thus secured is
vastly preferable to that which it has been proposed to obtain by
means of a roof or shed, which, besides other inconveniences,
would be found costly at first, liable to speedy decay, &c. If
circumstances, such as the smallness of the farm, the permeable
nature of the soil, &c., prevent the construction of a reservoir,
there is risk of the dung-water being quite lost; but such waste
may be prevented by covering the bottom of the pit or stance
for the dung-heap with a bed of sand, peat, marl, or any other
dry and porous substance capable of absorbing liquids. This
practice is often followed by the farmers of Alsace.
In some farms, the different kinds of dung arc piled apart from
one another in particular heaps; that of the stable being put by
itself, as well as that of the cow-house, that of the hog-stye, an
that of the sheep-pen. In great establishments, such a separation
is often one of necessity; but the advantages which are ascribed
to it are questionable at least, and the remarks that have been
made upon it by writers do not appear founded on any accurate
observation. Without denying that certain crops answer better
when special manures are employed, it still seems to me more
advantageous to pile every kind of manure together, when the
difficulties of the situation are not such as to make this either
particularly inconvenient or expensive. In this way, indeed, a
dung-heap of medium constitution is obtained, which is re-
garded with reason as that, the application of which to the soil is
attended with the greatest advantages in the majority of in-
Z
338
PREPARATION OF MANURE.
stances. The distinction which some have sought to make be-
tween the relative qualities of manures of different origins is far
too absolute; and this is the reason, without doubt, which ren-
ders it so difficult to bring the observations of different agricul-
turists to agree. Thus, according to Sinclair, the dung of the
hog-sty is the most active of all, the richest in fertilizing princi-
ples; according to Schwertz, on the contrary, it is the most
indifferent manure of the farm-yard.
The fact is, that manures, which are the produce of the same
animals, often present greater differences in regard to quality,
than manures which proceed from different sources. I shall
show by and by that the value of manure depends especially
upon the feeding, the age, and the condition in which the
animal is placed that produces it. It is well known that the
dung of cattle, fed during winter upon straw, is greatly inferior to
that which they yield when consuming food of a more nutritious
quality.
When the litter mixed with animal excrements is accumu-
lated in sufficient quantity in the pit or on the dung stance, fer-
mentation speedily sets in, and abundance of vapour is disen-
gaged. As carbonate of ammonia is among the volatile pro-
ducts of this decomposition, it is of importance to hold it
under control; this is done by keeping the heap in a state of
proper moistness, and in excluding as much as possible the ac-
cess of air. The daily addition of fresh quantities of litter from
the stables and stalls, contributes powerfully to impede the dis-
persion of the volatile elements, which it is so important to
preserve in manure; duly spread upon the heap, each addition be-
comes, in fact, a fresh obstacle to evaporation; it forms a covering
which plays the part of a condenser, at the same time that it
protects the inferior layers from the direct contact of the air. So
long as the dung-heap is kept up and attended to in this way,
the fermentation is limited to the inferior layers of the mass.
Thaer even satisfied himself that air collected from the surface of
a dung-heap, undergoing moderate fermentation, does not con-
tain much more carbonic acid than that which is taken from the
mass of the atmosphere. Neither does a vessel containing nitric
acid, when placed upon the fermenting mass, produce those dense
PREPARATION OF MANURE.
339
white vapours which are a certain indication of the presence of
ammonia. The slow decomposition which it is of so much
importance to effect, is not readily secured save in masses suf-
ficiently trodden down, and in which the litter of different
kinds has been spread as evenly as possible.
It is an important point that the manure should be carried out
o the field before the upper portions recently added begin to
undergo change, otherwise the whole mass enters into full
fermentation, and the volatile elements, being no longer arrested
by the upper layer, escape and are lost. One means of prevent-
ing this loss in any case (which however can but rarely occur) in
which there was a necessity for suffering the mass to become
made through its whole thickness, would be to cover it with a
layer of vegetable mould, in which the volatile principles would
be condensed; the layer of earth would in fact thus be converted
into a most powerful manure.
The loss of carbonate of ammonia, during the fermentation
of farm-dung, is further prevented by the use of certain salts
which have the power of changing the volatile carbonate into a
fixed salt. It was with a view of bringing a re-action of this
kind into play, that M. Schattenmann, the able director of the
manufactories of Bauchsweiler, proposed to add to dung-heaps,
in the course of their accumulation and preparation, a certain
quantity of sulphate of iron or of sulphate of lime, either of
which is decomposed by the carbonate of ammonia evolved, an d
a fixed ammoniacal salt (the sulphate) is produced.* The loss
of ammonia from dung-heaps in the course of regulated fermen-
tation, must not however be estimated too highly; when the de-
composition is carefully conducted, the mass having been well
trodden and properly damped, the loss is really very small.
The gentle fermentation, secured by these means, has characters
which differ essentially from those that accompany the rapid pu-
trefaction which never fails to take place when matters are not
well managed. As an example of the rapid and injurious fer-
mentation of which I speak, I may cite that which frequently
takes place in piles of horse-dung: every one must have seen
such dung-hills loosely thrown together, left to themselves,
* Annales de Chimie, 3e série, t. iv, p. 116.
Z 2
340
PREPARATION OF MANURE.
without any addition of water, acquiring a very intense heat in
the course of a few days, and have even heard of their taking
fire. I have seen piles of this kind reduced to their merely
earthy constituents! Such are never the results of the mo-
derate and gradual decomposition which farm-dung ought
never to exceed. When the pit or stance is emptied, in which
a slow and equal fermentation has taken place, the superior layer
is seen to be very nearly in the same state in which it was when
it was piled; the layer immediately beneath this one is changed
in a greater degree, and sometimes exhales a slight ammoniacal
odour. In the lower strata, the modification is yet greater in de-
gree: the straw has lost its consistency, it is fibrous and breaks
into pieces with the greatest ease; the mass is also progressively
darker in colour as we go deeper, and on the ground it is com-
pletely black; the smell which this part of the heap exhales,
is that of sulphuretted hydrogen, and when it is tested, sul-
phate of iron is discovered; no doubt these sulphurous pro-
ducts are all the consequence of the decomposition, under the
influence of the organic matter, of the sulphates which were con-
tained in the manure. This is the sign by which I know that
farm-dung is duly prepared; the presence of sulphurets and of
the hydrosulphate of ammonia will have no ill effect upon vege-
tation; for scarcely is the manure spread upon the ground,
than these products are changed into sulphates, and then the
manure emits that musky smell which is peculiar to it. Fur-
ther, there is no doubt but that the state in which a carefully
tended dung-heap is found in the end, is due to the circumstances
in which it has been placed and kept during the whole time of
its preparation, its constituent elements would have gone through
a totally different course in the progress of their modification
had they been left exposed to the open air. To be satisfied
of this, it is enough to remark the powerful and purely ammo-
niacal smell which meets us in a warm stable, especially during
the summer season, upon the ground of which the urine of the
animals it contains is left to decompose.
From what has now been said, it will be understood how
destructive to good manure is the custom which obtains in cer-
ain countries of turning dung-heaps frequently, of airing them as
PREPARATION OF MANURE.
341
Treated in this
it were in order to hasten decomposition.
way, stable litter, &c., does in fact decompose much more
rapidly; but it does so, and I own that I do not myself
clearly perceive the object proposed by it, at the expense of the
quality; for it is very evident that the volatile principles
must be dissipated and lost in the same proportion as their
points of contact with the air are multiplied.
The plan of collecting all the litter of the farm into one par-
ticular and appropriate place is that which is generally adopted.
Nevertheless there are countries in which the dung is left to
accumulate in the cattle-stalls, it being merely covered with
fresh straw every day. The ground thus rises continually under
the feet of the cattle, so that it is necessary to have moveable
cribs which can also be raised by degrees. This method is so
far convenient, that the necessity for cleaning out the stable con-
tinually is avoided; but little is gained in the end in the matter
of labour, for the same mass of manure has still definitively to
be removed. The fermentation of the manure would be greatly
accelerated by the usual high temperature of the stables, did not
the feet of the cattle tread the mass very closely, and this and
the daily addition of straw together produce the same effect as
I have indicated in treating of the management of the dung-
heap out of doors: it condenses vapours and volatile particles,
and prevents evaporation. The fact is, that in stalls and stables.
in which the dung is allowed to accumulate in this way, we are
not sensible of any very offensive odour, and the animals which
live in them breathe without inconvenience, it being always un-
derstood that all communication with the exterior is not inter-
rupted, which in fact it ought never to be, even in cases where
the stables and stalls are kept perfectly clean. This method of
proceeding becomes almost impracticable when cattle are fed
upon food that is not dry, but on the contrary that is extremely
watery, such as roots, green clover, &c.; the quantity of urine that
is then passed is so considerable, and the excrements themselves.
are so copious and so liquid, that an enormous quantity of straw
would be required to absorb the liquid parts; in spite of any
reasonable addition of litter, indeed, the animals would still be
exposed to be kept in the mire, which would doubtless become a
powerful cause of insalubrity among them.
342
LIQUID MANURE.
In Belgium, according to Schwertz, manure is accumulated in
the stables by guarding against the inconveniences which the
last mode of proceeding generally implies. The cattle are placed
upon a kind of platform raised above the pavement of the stable,
and the droppings being withdrawn from under them, are
trodden down and allowed to accumulate upon the floor.
One inconvenience attending the use of straw, is that it is
frequently dear; it is also scarce in some countries. In those
parts of Switzerland, for instance, where all the available lands
are meadows, they are obliged to economise litter as much as
possible, so that they even wash it, and thus make it serve re-
peatedly. Although it would be difficult to give a reason for
a practice which has the effect of increasing the bulk of the ma-
nure adding to the expense of transport, and at the same time
diminishing its quality, it is, nevertheless, a fact that this mode
of proceeding has been long in use in various Cantons. We
probably only sec here another means of securing even the last
particle of the excrementitious matters passed by cattle, the
process employed being in fact identical with that used by the
chemist in his most delicate analyses. In Switzerland, the urine
that is passed by the cattle flows along a gutter which commu-
nicates with a large reservoir containing water, in which not
only are the solid excrements diffused, but in which the litter is
washed, this being changed only twice a week. The reservoir
is constructed under the floor of the cow-house itself in order
to be protected from the frost. The fermentation of a mass
so diluted is scarcely perceptible, and save from leakage there is
no loss of decomposing animal matter. The liquid manure is
raised by means of a pump, and carried to the meadow in tubs
placed upon carts. In Switzerland, it is also the usage to employ
the urine of cattle separately as manure, under the name of
purin; to this liquid manure, a quantity of sulphate of iron is
frequently added with the view of bringing the volatile carbo-
nate to the state of the fixed sulphate of ammonia as I have
already said.
Liquid manures have their advantages and their inconve-
niences. We shall immediately discuss their value compari-
tively with that of solid manures, and we shall be led to adopt
he opinion of M. Crud in regard to them, viz., that the
VALUE OF FRESH AND MADE MANURES.
343
advantages ascribed to them in Switzerland are exaggerated.
Whatever the form under which manures are applied, the
question has been warmly discussed, whether it be to the interest
or disadvantage of the agriculturist to employ them before or
after they have undergone fermentation?
Organic substances, however, are in no condition to favour the
growth of vegetables until they have undergone material changes
which modify their nature. One of the results of this change,
as we have seen, is the development of ammoniacal salts. Fresh
manure, such as it comes from the stable, introduced imme-
diately into the ground, there undergoes precisely the same
changes, and gives rise to the same products as it does when
subjected to preparation in a dung-heap in the manner already
described; there is only this difference, that being scattered and
mixed with a large quantity of inert matter, the decomposition
takes place much more slowly than it does in the heap. The
question which has been so actively discussed, therefore, reduces
itself to this: is it advantageous to have the manure fermented
in the soil it is intended to fertilize? We may be allowed to ex-
press surprise that such a question should have been raised in
the present day, and still more that the affirmative answer should
have been disputed by agriculturists of distinguished merit.
Some have even gone so far as to maintain that fresh excre-
ments were injurious to vegetation. Proofs to the contrary arc
readily obtained; it is enough to recollect that in the grazing
and folding of sheep and kine, the dung and urine pass
directly into the ground of our pastures and fields, and who shall
say that the land is not benefited by what it thus receives? Un-
questionably fresh manure in excess proves injurious to vege-
tables, but as much may be said in regard to the best fermented
dungs.
•
M. Gazzeri, an Italian chemist, has devoted himself with the
most laudable perseverance to inquiries having for their ob-
ject to show that the general custom of leaving manures to
become decomposed before leading them out to the field is
attended with a considerable loss of fertilising principles, and that
it is therefore advantageous to use them in the state in which
they come from the stable. To remove all doubts which might
344
VALUE OF FRESH AND MADE MANURES.
yet be entertained upon the effects of unfermented manures, M.
Gazzeri showed that wheat could be successfully grown in land
which had received an extraordinary dose of pigeon's dung, which
is regarded as one of the most active of all manures; and horse
droppings, taken at the moment they were passed, mixed with
earth, in the proportion of one fourth of the whole bulk, had
no injurious effect on the growth of the cereals. To ascertain
the amount of loss which fresh manures suffered from fermen-
tation, M. Gazzeri placed certain quantities, ascertained by weight,
to putrefy under favourable circumstances; and the decomposi-
tion completed, he weighed them again. In this way, he ascer-
tained that horse-dung in the course of four months, lost more
than the half of the dry matter which it contained before
its putrefaction. Davy indeed had already shown that there is
a loss of volatile principles, during the decomposition of fresh
manures, that must be useful to vegetation. Davy's experiment
consisted in introducing manure into a retort, the extremity of
which communicated with the soil under turf, and he found that
in the course of a few days the grass which was thus exposed
to the emanations from the retort, grew with particular luxuri-
ance. Although it appears certain, then, that in conducting the
preparation of manure in the heap with prudence, the volatile
and ammoniacal principles which appear in the course of the
putrefaction may be retained, it is nevertheless unquestionable
that the employment of manure directly and without previous fer-
mentation, would most effectually prevent the loss of matters that
must be valuable. Thaer, Schwertz, Mr. Coke, and others,
have consequently admitted the advantages of the latter proce-
dure. In agreeing with them completely, which I do, it still
remains certain that on the greater number of farms, dung-
heaps must be formed as matter of necessity. Manure is only
available at certain determinate seasons of the year; it cannot
be carried out and spread as it is produced. In Alsace it is car-
ried out to the fields on which it is to be spread whenever cir-
cumstances will permit, and without regard to its more or less
advanced state of decomposition. The circumstances which lead to
its being kept in the pit for two or three months, also lead to the
manure being half or more than half matured before it is led out;
VALUE OF FRESH AND MADE MANURES.
345
and this, after all, is perhaps the best state in which it can be put
into the ground. It is then easily incorporated with the soil, and
its fertilizing principles are already in that condition which enables
them to act within a limited time with greater energy than they
would do were the manure employed quite fresh. This is the
condition in which our manures almost always are at Bechelbronn
when we carry them out: it rarely happens that they have been
three months on the stance before their removal. Speediness
of action is a point which is not without importance. Fresh
dung will always act more slowly than that which has reached
a certain point of decomposition, and the advantage which
mostly accrues to the farmer in forcing his crops, will often in-
duce him to use manure that has ripened in the pit or stance.
In warm and moist countries, as may be conceived, it is almost
matter of indifference whether the dung be put into the ground
quite fresh, or in a state of deco mposition further advanced; its
decomposition, aided by the heat of the climate is always effected
rapidly enough. But it is otherwise in cold climates, where the
temperature which excites and maintains vegetation is often
of short duration, and must at once be taken advantage of.
During a great part of the year, the ground is so cold that
organic substances buried in it are preserved with comparatively
little change. Under such climatic conditions, there is no doubt
that manures in a state of forwardness are to be preferred. It
is probably from such motives that the extensive use of liquid
manures in Switzerland is derived, the action of these being, so
to speak, immediate; and it is with such manure that in Flan-
ders, the cultivation of various plants that are of great value in
manufacturing processes, is carried on.
When the fermentation of manure has been managed dis-
creetly, and all the precautions requisite to prevent the dissipation
of ammoniacal salts and the loss of soluble elements have been
taken, there is the immense advantage attending it, besides ob-
taining immediate action, that a manure is produced of greater
value under a smaller bulk and a less weight. The dung-heap
often loses a third of its bulk in undergoing fermentation, a cir-
cumstance which occasions an important saving in carriage. A
like saving may be effected with reference to fresh manures by
346
SPREADING OF MANURE.
drying them in the sun, which I have sometimes seen done;
they are thus reduced to one third or one fourth of their original
weight, and when the distance to which they have to be carried
is great, there may be real advantage in proceeding in this way.
An objection of some moment made to the use of fresh dung
to corn lands is, that it usually contains the seeds of weeds and
the eggs of insects which nothing but putrefaction will destroy.
This objection of course loses all its weight when the land
that is manured is to receive a crop which admits of hoeing;
and the custom which obtains with us at Bechelbronn of using
manure in every state of decomposition to the first crop in the
rotation, is a guarantee that fresh manure is really productive of
no inconvenience in practice. Another difficulty pointed out by
Thaer is that of covering in dung so long and full of straw as
fresh stable or stall dung. This objection disappears when the
manure is laid in furrows formed by the plough, as is done in
Alsace, by which means the covering in is effected by a single
operation.
If opinions are still divided upon the question whether dung
ought to be employed before or after fermentation, they are no
less so as to the mode of spreading it, and the best periods
for laying it on the land. It may be imagined that the con-
clusion come to upon the first question necessarily influences the
opinions held on the second. Those who believe that manure
may be advantageously used in the state in which it comes from
the stables, are altogether indifferent in regard to the times of
carrying it out. They take advantage of every leisure moment
that occurs for performing this necessary work, which is no
trifling advantage; it is the practice which we follow at Bechel-
bronn-we carry out our manure as we find opportunity. The
lands which are to be manured in the spring have frequently their
supply carried out during winter when the frost enables us to get
upon them. The dung first shot down in little heaps, at regular
distances, is afterwards spread as equally as possible, frequently
even upon the snow; and I have never seen any ill effect from
the practice. The custom which some farmers have of keeping
dung in large heaps in the field, in order that it may be all spread
and worked under at the same time by the plough is certainly ob-
SPREADING OF MANURE.
347
jectionable; the places upon which these heaps have been laid
are evidently too strongly manured; no manure, save that
which is quite fresh and very long in the straw, or which it is
proposed to spread immediately in furrows ought ever to be laid
down in large heaps upon the field.
The method which I have recommended of leaving manure
spread over the surface of the fields, exposed to the weather for
several weeks or months, has been severely criticised. By such
exposure, it has been said the dung must lose its volatile ele-
ments, and the rain must wash out and carry off its more soluble
parts. Influenced by such fears, some farmers do not spread
their dung until the moment of ploughing it in. Such diversity
of opinion among practical men, all personally interested in de-
riving the greatest possible amount of advantage from the
manure they employ, must not be thought of lightly:
when different modes of procedure in agriculture are the
subjects of debate, we must not be in too great a hurry to
come to general conclusions. Climate is not without its influ-
ence in the question which now engages us. In Alsace experi-
ence has pronounced in favour of the practice followed; but in
other countries there may be very good reasons for not pro-
ceeding in the same way. In Alsace, where the annual depth of
rain amounts to 26.7 inches, no more than 4.3 inches fall
during the three months of December, January and February.
In a district where a larger quantity of rain falls during the
winter, the manure would probably suffer from the procedure
followed in Alsace.
The quality of the manure must also be taken into considera-
tion. A dung-hill which contained a large proportion of carbo-
nate of ammonia, which exhaled a strong smell of volatile alkali,
would infallibly lose in value by any unnecessary or prolonged
exposure to the air; but the loss becomes insignificant when
the manure, by good management, is brought to contain but a
small proportion of volatile ammoniacal salts, as happens with
manures which have received additions of gypsum; or other-
wise, when the dung-heap has been carried out fresh, and at a
season so cold that it can be kept without material change until the
period arrives for spreading it over or working it into the ground.
When the rains are not excessive, the soluble parts of manure
348
ELEMENTARY COMPOSITION OF MANURE.
spread upon the ground penetrate and remain in its upper stratum,
exactly as happens when instead of being buried, it is spread upon
the herbage in full growth. The plan of top-dressing is often of
great use, and is another and a practical proof of how little de-
triment results from leaving manure exposed to atmospherical
vicissitudes. The procedure by top-dressing has arisen from
necessity: it was first resorted to with the view of giving the
land an addition to the inadequate dose of manure which it had
received before it was sown; but it has been found to answer so
well in many districts, that it has been continued. We have
employed it at Bechelbronn upon various occasions even to hoed
crops, and with decided advantage, the main one being that time
was gained for the production of manure.
In the district of Marck, the practice of top-dressing lands
sowed with winter grain, is rapidly gaining ground; the dressing
takes place when the blade is already above ground; and expe-
rience proves that the passage of the waggons over the field,
and the feet of the horses and the men, cause no appreciable
mischief; all traces of them very soon disappear. Nevertheless it
is decidedly better to take advantage of a hard frost when the land
will bear carts, &c., for the performance of the process. This
plan, according to Schwertz, is found to answer extremely well
in Switzerland for hemp, and indeed for almost everything else.
In my opinion, top-dressing ought to be viewed as a means of
giving the soil, already under a crop, the manure which we had
been compelled to refuse it at an earlier period. Still Thaer
assures us, and his authority is always of great weight, that
he has too frequently seen the good effects of top-dressings
to beans, peas, and leguminous crops in general, not to be
satisfied of the general advantages of the method, in con-
nexion with light soils especially, in which the sowing may
have been late.
The elementary composition of farm-dung is a point which
is not undeserving of consideration. I have made repeated ana-
lyses of that of Bechelbronn, operating upon it in a medium state
of decomposition. The animals which had produced this dung
were thirty horses, thirty oxen, and from ten to twenty hogs. The
absolute quantity of moisture was ascertained by first drying in
the air a considerable weight of dung, and after pounding,
ELEMENTARY COMPOSITION OF MANURE.
349
continuing and completing the drying of a given quantity in the
oil bath in vacuo at a temperature of 230° F.
The dung prepared in the winter of the year
1837-8 contained
1838-9
Prepared in summer of 1839
>>
•
Analysis yielded the following results:
Times of preparation.
Winter 1837-8
Spring of 1838
1839
""
•
"
Medium
Water
Carbon.
Azote.
Oxygen.
25.8
32.4
1.7
32.5
26.0
1.7
38.7
28.7
1.7
36.4
19.1
2.4
40.0
27.6
2.4
34.5
27.6
2.0
On the average, farm dung dried at 238° contains:
Carbon
Hydrogen
Oxygen
Azote
Salts and earths
20.4
22.2
19.6
Hydrogen.
3.8
4.1
4.5
4.0
4.3
4.3
20.7
79.3
per cent. of
dry matter.
35.8
4.2
25.8
2.0
32.2
100.0
When moist its composition is represented by:
Carbon
7.41
Hydrogen.
0.8"
Oxygen
5.34
Azote
0.41
6.67
Salts and earths
Water
79.30
Ashes.
36.3
35.7
26.4
38.1
25.7
31.5
100.0
The constitution of dung-heaps must of necessity vary; thos,
however, which have a common origin do not seem to present
very great differences in the proportion of their elements. Thus
horse dung, in the south of France, yielded on analysis in the dry
state 2.4 per cent. of azote. This manure contained only 61
per cent. of moisture.
Did we bat know the composition and the quantity of the ex-
350
COMPOSITION OF FARM-YARD DUNG.
I
cretions passed in the course of the twenty-four hours by the
various animals which contribute to the production of manure,
we should be able to determine approximatively what the ele-
ments are which have been eliminated in the course of the fer-
mentation. It would be sufficient to compare the elementary
matter in the litter or fresh dung as it comes from the stable
with that which exists in the fermented or prepared manure.
have data which I think sufficient to enable me to institute this
comparison. It must always be borne in mind, however,
that the analyses which I shall now detail were made upon the
excrements of a single individual of each kind. It would cer-
tainly have been preferable to have had average analyses of
average qualities; but the object I had in view, when I under-
took these experiments, was quite different from that which I
have now before me.
EXCRETIONS OF THE HORSE.
The horse was fed upon hay and oats. The urine and the
excrements together contained 76.2 per cent of moisture. In
twenty-four hours the excretions weighed moist 34.2 lbs.;
dry 8.1 lbs.
:
Their composition was found to be:
Carbon.
Hydrogen
Oxygen.
Azote
Salts and earth
Water
In the dry state.
38.6
5.0
36.4
2.7
17.3
">
100.0
*
EXCRETIONS OF THE COW.
Moist dittoj
9.19
1.20
8.66
4.13
4.13
76.17
100.0
The cow was fed upon hay and raw potatoes. The urine and
the excrements together contained 86.4 of moisture. The
weight of the excretions in twenty-four hours was: moist.
80.5lbs.; dry 10.9lbs.
* The size of the horse was rather below the average usual size of farm
horses.
COMPOSITION OF FARM-YARD DUNG.
351
Their composition by analysis was :
Dry.
39.8
4.7
+
Carbon
Hydrogen.
Oxygen
Azote
Salts and earth.
Water
35.5
2.6
17.4
""
100.0
EXCRETIONS OF THE PIG.
Dry.
38.7
Carbon
Hydrogen.
Oxygen
4.8
32.5
Azote
3.4
Salts and earth. 20.6
Water
The pigs, upon which the observations were made, were from
six to eight months old. They were fed upon steamed potatoes.
The urine and the excrements lost by drying 82 per cent. of
moisture. The average of the excretions yielded by one pig
in twenty-four hours was: moist 9.1 lbs.; dry 1.6lb.
Composition:
Carbon
Hydrogen.
Oxygen
Azote
Salts and earth.
Water
د.
100.0
Dried.
48.4
5.3
38.9
0.4
7.0
Wet.
5.39
0.61
4.81
0.36
2.36
86.44
100.00
The litter that is generally employed is wheat-straw. This
straw, in the condition in which it is used, contains 26 per cent.
of moisture.
Its composition is:
100.0
Moist.
6.97
0.86
5.85
0.61
3.71
82.00
100.00
Undried.
35.8
3.9
28.8
00.3
5.2
26.0
K
100.0
At Bechelbronn each horse receives daily as litter 4.4 lbs. ;
cach cow, 6.6lbs. ; cach pig, 4.1lbs. of straw.
R 3
352
COMPOSITION OF FARM-YARD DUNG.
To the stables and the cow-houses together are given every
twenty-four hours 132.0lbs. of straw for thirty horses; 198.0lbs.
for thirty horned cattle; 66.0 lbs. for sixteen pigs; making
396.0 lbs. of straw, estimated when dry at 292.6 lbs.
The composition of the materials which constitute the dung
produced in one day are set forth in the following table:

Excretions yielded
in 24 hours by
Thirty horses
Thirty horned cattle
Sixteen pigs
Straw used in litter.
42.3
35.8
Weight
when dry
In the dry state.
Carbon. Hydrog. Oxygen. Azote.
36.7
5.0
4.2
lbs.
lbs.
245.08 1028.28
327.36 2416.48
26.40 146.74
292.60
396.00
25.8
Weight
in the wet
state.
1.9
The average or mean composition of this mixture may be
taken as follows:
2.0
14.1
Carb.
32.2
lbs.
94.60
130.24
10.12
141.68
I
Elements of the dry matter.
Hydrog. Oxygen. Azote. Salts &
earths.
9.4
lbs.
12.32
15.40
1.32
8.58
15.62 113.74
Salts. Carbon. Hydrog. Oxygen. Azote. Salt, Water.
7.4
That of the resulting Dung.
1.2
lbs. lbs.
89.10 6.60
116.16
lbs.
783.20
2089.12
0.88 5.50 120.34
1.10 20.46 103.40
8.58
In the wet state.
| 0.9 |
8.2
5.3
1
lbs.
42.46
56.98
0.4
0.4
Water
constitu.
ting the
wet matter

1
3.2
6.7
77.6

79.3
On comparing the composition of the dung-heap with that
of the different kinds of litter collected in a day, little difference
is observed; the larger quantity of saline and earthy matters dis-
covered in the fermented manure is readily explained from the
additions of ashes incorporated with it, and also by the acci-
dental admixture of earthy matters proceeding from the sweep-
ings of the court, the earth adhering to the roots consumed as
food, &c.-refuse of every kind, the residue after cleansing the
various kinds of fodder for the stable and stall, &c., all goes
to the dung-heap. Lastly, and with reference to the elements
that are liable to be dissipated in the state of gas, or which may
be changed into water, the azote is perceptibly in larger quan-
tity in the prepared manure than in the unfermented litter and
excretions. This is at once seen on comparing the composition
of these two products after the saline and earthy matters have
been deducted.
VALUE OF AZOTISED PRINCIPLES.
353
Hydrogen.
5.8
6.1
Carbon.
The composition of fresh litter, is. 49.3
That of dung
52.8
Oxygen.
42.7
33.1
Azote.
2
3.0
Dung is, therefore, somewhat richer in carbon than litter, and
it contains less oxygen. It is the property of lignine under-
going decomposition, that it yields a product which relatively
abounds more in carbon than the original matter, in spite of the
carbonic acid which is formed and thrown off during the altera-
tions undergone; this is owing to the elements of water being
thrown off in relatively still larger quantity at the same time.
Fermented dung contains less oxygen than that which comes
from the stable; it ought also to contain less hydrogen: but
this, analysis does not proclaim. It must be observed, how-
ever, that the quantity of oxygen (4.6), the loss of which ap-
pears would require no more than 0.57 of hydrogen to constitute
water; and this is a quantity which it is impossible to answer
for in experiments made upon such substances without excessive
delicacy of manipulation. This much may be certainly con-
cluded, viz., that manure which has undergone preparation
contains a larger relative proportion of azote than the substances
which have concurred in its production; and for this reason, it is
very probable that upon the whole a very trifling loss of this ele-
ment is experienced if the fermentation has been carefully managed,
and the manure has been carried out and distributed upon the land
before its decomposition is too far advanced. This conclusion,
which I am particularly anxious to establish, is partly explained
by the interesting researches of Mr. Hermann, which go to prove
that woody fibre in rotting attracts and fixes a quantity of the
atmospheric air.
Azote is in fact the element which it is of highest importance
to augment and to preserve in dung. The organic substances
which are the most advantageous in producing manures are pre-
cisely those which give origin by their decomposition to the
largest proportion of azotised matters soluble or volatile. I say by
their decomposition, because the mere presence of azote in
matters of organic origin does not suffice to constitute them
Coal, for example, contains azote in very appreciable
quantity; and yet its ameliorating influence upon the soil is
manure.
A A
354
DURABILITY OF MANURES.
absolutely null; this happens from coal resisting the action of
those atmospheric agencies which determine that putrid fermen-
tation, the ultimate result of which is always the production of
ammoniacal salts, or other azotised compounds favourable to the
growth of vegetables. Whilst we admit the high importance,
indeed the absolute necessity of azotic principles in manures,
then, we must not therefore conclude that these principles are the
only ones which contribute to fertilize the earth.
It is unquestionable that the alkaline and earthy salts are
farther indispensable to the accomplishment of the phenomena
of vegetation; and it is far from being sufficiently shown that the
organic principles void of azote play a merely passive part when
added to the soil. But with few exceptions, the fixed salts,
water or its elements, and carbon superabound in manure. The
element which exists there in smallest proportion is azote, which
is the one also that is most apt to be dissipated during the al-
teration of the bodies that contain it. For these reasons azote
is really the element whose presence it is of highest moment to
ascertain; its proportion is that in fact which fixes the compa-
rative value of different manures.
Since it is by undergoing modification in the course of their
decomposition by putrefaction that those azotised substances
which are favourable to vegetation are developed in quaternary
compounds, it will be readily understood that all things else
being equal, a manure which is completely decompoundable into
soluble or gaseous products in the course of a single season,
will exert in virtue of this alone the whole of its useful influence
upon the first crop. It is entirely different if the manure de-
composes more slowly; its action upon the first crop will be less
obvious, but its influence will continue longer. There are ma-
nures which act, it may be said, at the moment they are put
into the ground; there are others, the action of which continues.
during several years. Nevertheless two manures, although act-
ing within periods so different in point of extent, will produce
the same final result if they severally contain the same dose of
azotic clements, if they are of the same intrinsic value.
The durability of manures, the length of time during which
they will continue to exert their influence, is a matter of great
STRAW, STEMS, &C.
355
importance. It often depends on their state of cohesion, or on
their insolubility, though climate and the nature of the soil have
also a marked influence on their decomposition and consequent
effects. It is not easy in the present state of knowledge to pre-
dict with certainty how long the beneficial effects of a given
manure will continue to be felt; but we know well enough what
will hasten the decomposition of manure, and what will retard
this final result, and so apportion as it were the fertilizing prin-
ciples among the different crops in the rotation. Aware of the
importance of azote in manures, M. Payen and I undertook an
extensive series of analyses, with a view to ascertain the propor-
tion of this principle in the various matters and mixtures made
use of in the improvement of the soil. This labour enabled us
to class manures, and assuming farm-dung as the standard, to
refer each to its place in a comparative scale, I shall give
the conclusions to which we came in the tabular form; but be-
fore doing this, I think it necessary to premise a few observations
upon the several manures, or substances usually employed in pre-
paring manures.
Straw, woody stems, haum, leaves and weeds. The straw of
corn, the haum and stalks of various plants of farm growth,
weeds of all kinds, and leaves collected in the woods, all contri-
bute to increase the supply of manure.
Straw is the article that is generally employed for litter; its
hollow tubular structure which makes it apt to imbibe urine,
renders it peculiarly valuable for this purpose; and it at the same
time supplies a soft and warm bed for the cattle. The weight
of the straw used as litter may be doubled by the absorption of
urine and admixture with excrements; but it is by its very na-
ture and of itself a manure which is not to be slighted, since it
contains from 2 to 6 thousandths of azote.
pa
The stems of leguminous plants-bean and pea straw-are
much more highly azotised than the straw of corn; it is cer-
tainly best to consume this article as forage when it is not too
woody and hard. As litter it is often unfit to form a good bed
for cattle, and should therefore not be so employed alone; but it
presents the twofold advantage of adding to the manure a large
proportion of azotised principles, and at the same time of effect-
A A 2
356
LEAVES-BEAN-STRAW.
ing a saving of straw. At Bechelbronn we have found it very
advantageous to mix a certain quantity of the dried stems of
the Madia sativa (gold of pleasure) with both our cow-house
and stable litter.
In forest districts, the leaves of trees are frequently used as
litter; they perhaps absorb urine in smaller quantities than
straw does, but as they are much more highly azotised, they
greatly improve the quality of the dung. It is desirable that
the materials used for litter should be capable of imbibing a
large quantity of liquid; and these same materials are by so
much the more advantageous as the proportion of azote which
enters into their composition is high. The leaves of trees combine
both of these conditions, and are therefore an immense resource
in districts where they can be procured in abundance. Where
the woods are strictly preserved, the removal of the leaves is
generally prohibited; and it is doubtless injurious to deprive the
soil of them in young plantations; but where the timber is
farther advanced, the objections to their removal are infinitely
less, and it is therefore generally permitted to carry them away
within certain limits. And when it is seen that from natural
causes a great part of the leaves is actually lost to the soil of
the forest, the wind sweeping them into the ravines, whence
they are carried away by the rains, it is evidently far better to
allow the poorer cultivators to profit by them. The benefit ob-
tained appears the greater, as the time and labour bestowed in
collecting the leaves is not taken into the reckoning.
Bean straw and other stalks of a very hard and thready na-
ture make but indifferent litter, they are often so hard that
they hurt cattle, and then their cuticle being impermeable they
absorb little or no urine. It has been proposed to crush them
in the mill or to cut them in pieces, but either of these pro-
cesses is attended with expense. The best thing to do would
sometimes be to place them where they would get crushed under
the wheels of the farm carts. The use of woody stems of every
description would be attended with unquestionable saving in the
useful article of straw, and it must never be forgotten that to
economise straw as litter, is to increase the quantity of available
forage. If, for example, it were possible to reduce to the state
GREEN LEAVES.
357
of litter the woody stems of the Jerusalem artichoke in places.
where this vegetable is grown to any extent, the advantages
would be very decided; the quantity of these stalks collected
from an acre may amount to from four to five tons; the pith
of which they are almost entirely composed is of a very spongy
nature and well fitted to absorb fluids. These stalks are light,
and properly bruised, would probably replace an equal weight of
straw, first as litter and then as an element of the dunghill, in-
stead of being burned as at present to heat the oven or to boil
the copper, which seems of all methods the worst to derive any
advantage from the woody haum, whether of the Jerusalem arti-
choke, the potato, rape, &c. These substances contain about
4 per 1000 of azote, and are most profitably transformed into
manure. We have found that by placing them at the bottom
of the dung-heaps, they end by undergoing decomposition; even
the most woody stems of vegetables, indeed, decompose pretty
rapidly when they are impregnated with urine and mixed with
the droppings of animals. Mere moisture without other addi-
tion does not suffice, they then rot with extreme slowness.
·
The green parts of vegetables buried in the ground with the
water they contain, undergo decomposition rapidly; the best plan
of using them as manure would therefore be to plough them in
at once, were there not certain objections to this. In the first
place it cannot always be done, on account of the season and the
crops upon the ground; and then it might be imprudent to
return to the earth the noxious weeds which had just been
pulled up, frequently full of seeds which would not fail to make
their existence known before long. It is besides often impossible
to bring loads of weeds to the farmstead; the best thing that
can then be done is to change them rapidly into manure in a
corner of one of the fields which has produced them. This is
readily accomplished by means of lime; a bed is first made of
the weeds about 14 inches thick, this is then covered with a
thin layer of quick lime, from half an inch to an inch in thick-
ness; another layer of weeds is laid on, and then another layer
of quick lime, and so on in succession. After a few hours the
action between the dry lime and the moist herbage begins, and
:
it
may be so intense as even to go the length of burning, to
358
GREEN MANURES.
prevent which the pile must be covered with earth or with turf,
and every means used to prevent the access of air. The pro-
cess is generally complete within twenty-four hours, and the heap
may then be spread as manure. Before proceeding to such an
operation, however, it would be highly proper to calculate its
All depends on the price of the lime and the labour; and
all things considered, I myself much doubt whether the plan
could be followed with advantage.
cost.
Green manures. Under this title, I include the green parts of
vegetables which form part of our crops, such as the haum of
potatoes, the outer leaves of carrots, cabbages, beet, turnips, &c.
These articles are at once forage and manure, and it is for the
husbandman to decide in conformity with his position and par-
ticular resources whether he ought to bury them at once, or
to use them first as food for cattle.
From my own experience I should say that the leaves of
beet and of turnips, and potato haum were articles which
ought only to be given to cattle in cases of necessity. It is
generally much better to bury them in the ground immediately
after the crop is gathered; if they be very indifferent food, they
are on the contrary excellent manure, superior in quality even to
the best farm dung. From the experiments I have made on this
subject, I find that the potato tops from an acre of ground may be
equal to 6 or 7 hundred weight of that manure presumed to be dry;
and the leaves of the beet from the same extent of surface are equal
to more than 21 hundred weight of the same manure, also in a
state of dryness. It is among green manures that we are to class
the sea-weed or marine plants which in many places are em-
ployed for improving the soil. These cryptogamic plants which
abound in azote, have a fertilising power superior to that of com-
mon dung, a fact which explains the great store which is set in
Brittany by the sea-weed that is collected on its coasts. Sea-
weed is employed either fresh and as it comes from the sea, or
half dried, or macerated, or roasted and even partially burned.
It appears to act at once in virtue of the azotised organic mat-
ters which it contains, of the hygrometric properties which it
possesses, and of the saline substances which enter into its com-
position. The agriculturists of Brittany have employed sea-weed
GREEN MANURES--SEA-WEED.
359
as manure from time immemorial; and so have the people of
Scotland and Ireland. In Brittany, the sea-weed is gathered at
periods fixed by law. The first gathering, as well as that which
has been cast up by the waves, is given up to the poor. The
gatherings then take place at regular intervals by means of a
kind of cutting rake. The sea-weed cut from the rocks is piled
upon rafts or thrown into barges and carried to the shore; and
there is a trade carried on in the article all along the shores of the
channel between Genest and Cape La Hogue, from the Chansey
Isles, and from the coast of Calrados.
When sea-weed is employed in the fresh state, it is ploughed
in as speedily as possible. For those kinds of crops which re-
quire made manures, the sea-weed is stratified with dung and so
left to ferment. In some places the sea-weed is roasted or im-
perfectly burned, by which, while a large proportion of the vege-
table tissue is destroyed, an azotised product is still left behind.
Before burning the sea-weed, it is exposed for a time to the air
and the rain, and it is then dried being frequently turned. In
this state, it is even used as fuel in places where wood is scarce.
One great advantage in sea-weed which has been particularly in-
dicated, is its total freedom from the seeds of noxious weeds.
Aquatic plants which grow in fresh water may also be em-
ployed as manure; the common reed cut and buried green, de-
composes rapidly. And here I may mention that to destroy
reeds, which are often a cause of great annoyance in ponds,
Schwertz recommends lowering the water about 16 inches, cut-
ting the plant, and then raising the water to its old level; the
water enters the interior of the stems and they all die in a very
short space of time.
Crops which are buried green, for the improvement of the
soil, are also to be ranked in the list of the manures which now
engage us. The plan of burying green crops dates from the most
remote antiquity; it was greatly recommended by the Romans,
and is followed in Italy at the present day. The plants usually
grown for the purpose of being burned green are colza or cole-
wort, rape, buckwheat, tares, trefoil, &c. The preference, how-
ever, is given to one or other of the leguminous plants, such as
tares, lupins, &c., plants which appear to have the highest power
by
360
OIL-CAKE MANURE.
of extracting azotised principles from the atmosphere; and indeed
the value of the whole process is founded upon this fact, for other-
wise it would be impossible to give any reason for this long ac-
credited mode of improving the soil. This, too, is one of the
ways in which fallowing becomes useful; it is not merely the
rest which the land thus obtains, it is also benefitted by the ve-
getables which grow upon it spontaneously which come to ma-
turity and die, leaving in this way in the ground all they had
attracted from the atmosphere, or fixed from the water with
which they had been supplied.
Seeds, Oil-cake. It is in the seed that by far the largest
proportion of the azotised matter assimilated by vegetables
during their growth is finally concentrated at the period of their
maturity. Seeds are consequently very powerful manures, and
great advantage is taken of them. In Tuscany, lupin seed is
sold as manure; it contains 34 per cent of azote. It is employed
after its germinating power has been destroyed by boiling or
roasting. The cultivation of the lupin is carried on in districts,
the situation of which is such that difficulty would be expe-
rienced in exporting more bulky crops. Grains from the brew-
ery would also make excellent manure were it not generally
found more advantageous to use them as food for cattle. In
some places, however, where there is no adequate demand for
them in this direction, they are dried upon a kiln, and are then
equal to twice and a half their weight of farm dung; in some
places they are actually sold at a proportionate price. The state
of division of grains admits of their being regularly spread. In
some parts of England, grains are used in the proportion of
from 40 to 50 bushels per acre for wheat or barley.*
The refuse of the grape in wine countries contains a large
quantity of azotised matter. The decomposition of the grape
stones being slow, this refuse answers admirably as a manure for
vines.
Oleaginous seeds after the extraction of the oil leave a residue
which is an article of commerce, and is familiarly known under
the name of cake. Oil contains no appreciable quantity of azote;
this principle is contained entirely in the cake, which becomes
* Sinclair, Agriculture, vol. 1.
OIL-CAKE MANURE.
361
through this alone most excellent manure. The proportion of
azote which cake contains, varies from 3 to 9 per cent. Oil-
cake, from its mode of preparation, contains but very little
moisture, and consequently offers great facilities in the way of
carriage; it may be taken without difficulty to situations whither
a load of dung could scarcely be carried.
Cake is applied in two modes: 1st. In powder, and by sow-
ing upon the field, sometimes mixed with the seed. 2nd. Mixed
in water or in the drainings of the dung-hill, in which case
the liquid containing the products of the decomposition of the
cake is distributed over the land. By putrefaction under water,
cake yields a matter of extreme fetor, comparable both in point of
smell and of effects on vegetation to human excrement obtained
from privies.
-
Although cake, from the large proportion of albumen
and legumen which it contains, be an excellent food for
cattle, it is still found more advantageous in many districts to
use it as manure than for feeding. England imports oil-cake
from all parts of the continent. France alone, from 1836 to
1840, exported more than 117,860 tons of the article. Oil-
cake has been particularly recommended as manure for light
sandy soils. When the soil is clayey and cold, Schwertz recom-
mends a mixture of one part of lime and 6 parts of powdered
cake. To me, however, the addition of lime has always ap-
peared a questionable auxiliary in such manures as give rise
readily to ammoniacal products, as is the case with oil-cake.
For clayey lands, it would perhaps be advisable to employ oil-
cake in a state of decomposition and diffused in water; its
effects, I imagine, would not be doubtful.
Gr
Oil-cake, as a manure, is employed at very different scasons,
according to the nature of the husbandry. It is always well to
employ it in rainy weather. Its effect is always certain, if it
comes on to rain two or three weeks after it has been put into
the ground. Drought suspends its action; it frequently hap-
pens, indeed, that the first crop shows none of its good effects;
but these never fail to appear in subsequent crops. Schwertz
remarks very properly, that this circumstance has led many
farmers to overlook the real advantages that belong to this ma-
-
362
REFUSE OF BEET AS MANURE.
nure. Cake, in fact, according to the dryness or moistness of
the season, may act as a manure either of difficult or of easy de-
composition, and so produce more immediate or more remote
effects. In England about 800 weight of oil-cake per acre are
commonly applied. Mr. Coke, of Holkham, ploughed in the pow-
dered cake about six weeks before sowing turnips, but it is held
more economical and more advantageous to strew it in fine
powder along the furrow with the seed. The latter view, how-
ever, must not be too confidently acted on by farmers; the
general recommendation to sow the fields with powdered cake,
either some weeks before or some weeks after putting in the
seed, and when the plants have already sprung appears to be the
right one. We have various observations made by one of our
most experienced practical farmers which prove that oil-cake
used dry and without mixture often produces the most injurious
effects upon germination. In September, 1824, M. Vilmorin,
desiring to make a comparative trial of different pulverulent
manures, strewed a quantity of powdered colewort-cake upon a
piece of red clover. Upon all the parts of the field which had
received other manures, applied in the same way, the clover
sprung perfectly; but that which had received the oil-cake con-
tinued absolutely naked; the cake had been employed in the
proportion of about 800 weight per acre. The same result was
also obtained in a trial made with vetches and grey winter peas. *
Duhamel, referring to similar facts, recommends the cake to be
applied ten or twelve days before sowing. In Flanders, from
6 to 7 cwt. per acre is the quantity generally employed for wheat
crops, and it is scattered over the surface before winter sets in,
when the grain is already above the ground.
The pulp of the beet-root which has been employed in the
sugar manufactories of France and Flanders, is an article which
as food for cattle is known not to be inferior to the root before
it has undergone expression, and it contains nearly the same
proportions of sugar, albumen, &c. It is, therefore, always used
as food to as great an extent as possible. But the article is kept
with difficulty, and the production at times far exceeds the
powers of consumption, so that it has to be made into manure,
* Vilmorin, in Maison Rustique, vol. 1, p. 204.
REFUSE OF THE SUGAR HOUSE.
363
for which it answers excellently. The skimmings and dregs
which are collected in the process of sugar making, are also avail-
able as manure. They contain about the same amount of azote
or azotised matter as farm dung, and are therefore of similar
value. The animal charcoal of the sugar refinery, after it has
served its office there, is an admirable manure. It is, in fact,
bone or ivory-black, mixed with the coagulated blood which has
been employed to clarify the syrup by entangling impurities, and
a very small quantity of sugar. This mixture, so rich in azotised
principles, used actually to be turned into the sewers until the
year 1824, when M. Payen showed its value as manure, since
which time nearly 10,000 tons have been annually employed in
ameliorating the soil, to the great advantage of practical agricul-
ture. The importance of the trade in this residue of the sugar
house, and complaints of the occasional indifferent quality of the
article, attracted the attention of the department of the Inferior-
Loire in 1838, and led to the appointment of an inspector of
the manure shipped from the port of Nantz. I may here ob-
serve, that in testing a manure it is by no means enough to
limit attention to the quantity of organic matter which it con-
tains. The only sure means is to determine the amount of azote;
it is not organic matter, but the amount of azotised organic
matter upon which almost alone depends the value of the
manure.
The residue of the sugar refinery is another of those articles
which presents an occasional anomaly in its application, and
which must not be left unnoticed. Its effect upon the ground
has not only been extremely variable, but it has sometimes hap-
pened that this manure, laid on very soon after coming from the
manufactory, has been found decidedly injurious to vegetation.
Kept for some time, for a month or two, in a heap before
being applied, its effect has not only been found more cer-
tain but also uniformly favourable.
It is not difficult to explain these divers and opposite in-
fluences: the sugar contained in the refuse undergoing fermenta-
tion yields first alcohol, and then acetic and lactic acids.
Employed in this state, the substance must necessarily prove
injurious to vegetation. It is only after it has lain for a suffi-
364
REFUSE OF POTATOES, APPLES, &C.
cient length of time exposed to the air, to have had the animal
matter it contains changed into ammonia, and the organic acids.
engendered saturated with this base, that it becomes truly useful
to vegetation. The heap indeed then shows alkaline, not acid
re-action.*
The residue of the starch manufacturer, the fetid water
which is obtained in such quantity in the process of making
starch from grain is a powerful manure, and ought not to be
suffered to run to waste.
The pulp or residue of the potato which is now produced in
considerable quantity in the potato starch manufactories, is known
to be an excellent article of food for hogs and cattle. Towards
the end of the season, however, it is apt to be of very indiffe-
rent quality, and green food having by this time come in abun-
dantly, it often goes to the dung-hill. In the dry state, it is worth
its own weight of farm dung; wet, 100 of the pulp may be equal
to about 131 of farm-yard dung. The water which has served
for washing out the starch from the pulp, as in the case of wheat
and other grain, contains an organic substance which when
dried constitutes pulverulent manure that is equal to about half
its weight of the dry manure prepared from night soil, which
the French call poudrette. M. Dailly made a comparative trial
of these two kinds of manure, and from actual experiment found
that 200 parts of the deposit from the starch manufactory might
be used for 100 of poudrette. Even the water that is used in
the manufacture, and from which the substance in question is
deposited, is an excellent manure when thrown upon the ground,
a circumstance which is by so much the more fortunate that
this water by standing putrifies and throws off most offensive
exhalations. By using the liquor to his fields, at once, M. Dailly
prevents every kind of annoyance to himself and his neighbours,
and moreover from his great starch manufactory he realises in
this way an additional profit which he estimates at upwards of
£60 per annum. Analysis has shown that 100 of this water
from the potato starch manufactory represents 17 of moist farm-
yard dung.
In cyder countries, the pulp of the apples that have been
* Payen and Boussingault, Ann. de Chimie, v. III, p. 95, 3e série.
ANIMAL REMAINS.
365
pressed is always thrown upon the land as manure. At Bechel-
bronn we reserve it for our Jerusalem artichokes; in Normandy it
is thought excellent for meadows and young orchards. Analysis
of the pulp of apples grown in Alsace shows that when dry it
contains a quantity of azote, which places it on the same footing
as farm-yard dung. Sinclair informs us that in Herefordshire
the pulp of the cyder press is made into good manure by being
mixed with quick lime and turned two or three times in the
course of the following summer. Doubtless the addition of
lime will hasten the decomposition of the woody matter of the
pulp; but it strikes me that this will take place rapidly enough
of itself in the ground without contriving any means of accele-
rating the process.
nure.
Animal remains. The remains of dead animals and the
animal matters obtained from the slaughter house are powerful
manures, which are much sought after in places where their
value is properly appreciated. Scraps and the refuse of skin,
hair, horn, tendons, bones, feathers, &c., all form invaluable ma-
The flesh of animals which die, and so much of that of
horses that are slaughtered which cannot be used as food for ani-
mals, may be dried after having been previously boiled, and then
reduced to powder and applied as manure. The blood of
slaughtered animals is less proper as food for hogs, although it
is often used in this way, than muscular flesh; it even occasion-
ally gives rise to serious diseases among these animals. It is
most easily prepared as manure, however, for which it answers
admirably; it is enough to coagulate it by exposure to heat, and
then having broken it down, to dry it in the air or in the stove.
Liquid blood has been employed as manure, but decomposition
then takes place so rapidly, that the products are exhaled with-
out producing much effect. This objection may be remedied by
two means, either by diluting the blood in a large quantity of
water, with which the land is then irrigated, or by mixing it
with a considerable mass of vegetable earth, which is then ap-
plied like ordinary manure. There is even a pulverulent manure
of which blood forms the basis, prepared in special establish-
ments in the vicinity of various large towns. The large quan-
tity of azote contained in these manures shows how their value
366
BONES.
may be such as to permit of their being advantageously ex-
ported to great distances beyond seas.
Bones are employed in agriculture after having had the fat
which they contained extracted from them by boiling. They are
crushed by being passed between the teeth or grooves of a
couple of cast-iron rollers. They must be regarded as a manure,
the action of which is of long duration, because the animal mat-
ter contained in them decomposes slowly, protected as it is
by the earthy casing which surrounds it. In England from 50
to 60 bushels of bruised bones per acre are usually put upon
land prepared for turnips.
The employment of bones as manure has given rise to the
most various and contradictory observations. In certain circum-
stances their effect upon vegetation has been almost null; in
others their action has been decisive and most favourable. M.
Payen has given a solution of these anomalies which is perfectly
satisfactory. According to my learned colleague, bones in their
interstices, contain a quantity of fat of various consistency,
which may be removed by long boiling in water; the average
quantity of grease obtained from fresh bones is about 10 per
cent. It has been observed that this fatty matter diminishes
gradually in bones that dry by long exposure; it even dis-
appears almost entirely when they are dried at a high tempe-
rature. This happens from the water which is disengaged from
the bony tissue by the effect of evaporation, being replaced by
fat melted by the heat. The consequence of this is, that the
organic tissue of bone, which was already sufficiently rebellious
to decomposition, becomes still less alterable when it is im-
pregnated with grease. The grease, in fact, by reacting
upon the carbonate of lime of the bone, has formed an earthy
soap which long resists atmospherical influences and change
under ground.
It will readily be understood that bones in this condition can
have little or no action upon vegetation, unless indeed they be
reduced to very fine power. This alone will explain how it may
happen that some bones, after having remained four years in the
ground, have been found to have lost no more than 8 per cent of
their weight, whilst those, the grease of which has been removed
GRAVES WOOLLEN RAGS.
367
by boiling water, have lost in the same space of time from 25
to 30 per cent. of their weight.*
These observations of M. Payen show how completely
Schwertz was mistaken when he ascribed the indifferent quality
of the manure prepared from old bones, or from bones that had
been boiled, to the absence of fat, which he regards, I know not
on what authority, as a substance extremely favourable to vege-
tation. It is not very obvious how fatty substances should act
as manures. I myself ascertained from experiments made some
years ago with a view to test the conclusions of an agriculturist
who ascribed the good effects of cake to the fatty matters which
it contained, that rape-oil had no kind of favourable influence
upon the growth of wheat. I have said nothing here upon the
importance of the earthy matter of bones, particularly of the
calcareous phosphate which they contain, but which is neverthe-
less acknowledged to be of great importance.
The refuse from the glue maker's, washed and pressed, con-
tains all the animal matters which have resisted the action of
boiling water, such as portions of tendinous and skinny substance,
hair, pieces of bone, of horn, and of flesh, a calcareous soap,
and earthy matters. This mixture putrifies rapidly; but dried
it may be preserved for a great length of time. Analysed dry,
it yields about 4 per cent. of azote. From 4 to 5 cwt. per acre
are employed, but it is necessary to manure every year.
The refuse of the tallow melter, graves, as it is called, a
residue consisting in great part of the membranes which have
enveloped the fat of our domestic animals, mixed with a little
blood, some flesh and bony matter, and grease, has hitherto been
employed almost exclusively as food for dogs. Of late, how-
ever, graves have been used as manure, and analysis shows that
this substance must be estimated as equal to about 31, farm
dung being fixed at one. Used in this proportion, graves produce
a marked effect. The action of graves, which may be thrown
on in fragments and dry, or after having been steeped in hot
water, and reduced to the state of a pulp, will continue for three
or four years.
Shreds of woollen rags form a good manure for vines and
* Payen, Maison Rustique, v. 1. p. 194.
368
HORN-HAIR-FEATHERS.
olive-trees especially, though they are also available in husbandry
of every description. The large proportion of azote and the
small quantity of water contained in woollen rags, constitute
them not only one of the richest manures, but also one of those
that is most easily transported; 25 cwts. per acre of woollen
rags, the cost of which in France may be about £3., have been
found sufficient as manure for three years. The slowness with
which wool decomposes, indeed, causes its action to be continued
during six or eight years. Twenty-five cwt. of woollen rags may
be held equivalent to upwards of 40 tons of farm dung, which
at the price of 5s. 10d. per ton would cost £12. 16s. At the
end of three years, M. Delonchamps, an excellent practical far-
mer, gives his land a dressing of farm-dung for three years.
more, when he returns to the wool. Before spreading rags they
must be cut into pieces, which is effected either by a machine
or by a piece of scythe blade fixed in a block of wood. In
England, the quantity of woollen rags allowed to the acre is ge-
nerally about 13 cwt. Sinclair says that they are best suited
for dry and sandy or chalky soils, and this because they attract
moisture. I have not found the fact to be so. In the very dry
soil of a vineyard manured with this article, I have found the
pieces to decompose with extreme slowness, and up to this time
the effect upon the vines has been scarcely perceptible.
The raspings and shavings of horn form a manure of great
power that seems applicable to every variety of soil. In England
about 40 bushels per acre are usually allowed.
Tendons, trimmings of hides, hair, feathers, &c., are ma-
nures very analogous to the last, and of which the value may be
estimated from the quantity of azote which they severally con-
tain. This value once determined, every farmer knows the
quantity which he must lay upon his land; and he thus pro-
ceeds upon a much more rational foundation than when he takes
for his guide one or other of those vague and arbitrary indica-
tions that have been given. Sinclair, for example, would have
us lay on 9 bushels of feather rubbish to the acre, and Schwertz
recommends from four to five times as much more. Nothing,
in fact, is more arbitrary and uncertain than to estimate such
materials by the bulk; it must be obvious that the weight of a
SHELLS, MUD.
369
bushel of hide trimmings, of horn shavings, and of feather rub-
bish, must differ very widely, not only with reference to one
another, but also according to the state of division in which
each is measured. As a general rule, it is by weight, and weight
alone, that the quantity of manure must be estimated.
Shells and mud from the sea-shore and the bottoms of rivers
are matters that are often not very highly azotised; neverthe-
less, they may contain an equivalent of the all important element,
azote, which may bring them near to wet farm-yard dung in
point of value. The abundance of such matters in certain situa-
tions makes them extremely useful. The alkaline and earthy
salts, which they generally contain in considerable quantity, also
add to their fertilising properties. The sea-sand which is em-
ployed in Brittany under the name of marl (merl) consists in
great part of the remains of corallines, madrepores and shells,
mixed with a few hundredths of highly azotised organic matter.
This marine marl is found in great abundance at the mouths of
the river of Morlaix, where there is a considerable traffic carried
on in the article. It is said to be reproduced, new banks of it
being met with from time to time. It is obtained by dredging
from barges, and the process is only allowed to go on from the
15th of May to the 15th of October, when the quays of the
town of Morlaix are seen covered with the produce. It is
carted to a distance of five leagues inland. A barge load weighing
7 tons, sells at from 6s. 6d. to 8s. This same species of marl
is now obtained upon the coast of Plancourtrez and in the roads of
Brest. It has also been discovered near the mouth of the River
Quimpert. It appears finally that the shell sand so much em-
ployed by the farmers of Devonshire and Cornwall is of the
same essential nature.
In the neighbourhood of Morlaix, from 5 to 6 tons per acrc
of this calcareous sand are employed upon light dry soils; from
11 to 12 tons are given to clayey lands. This quantity would
probably be too great for porous and damp soils, inasmuch as
sea marl belongs to the class of warm manures; that is to say,
it undergoes speedy decomposition. There can be no doubt
that sea-marl acts farther, in virtue of the calcareous matter
which it contains, and also of its mercly mechanical properties
BB
370
SHELL, MARL.
upon the strong argillaceous lands of Brittany, for which sand
alone is an excellent improver. It is also to the carbonate of
lime which it contains that its good effects upon lands that show
an inflorescence of iron pyrites must be ascribed. It is well to
lay this shell marl upon the land shortly after it is taken from
the sea; by long exposure to the air, it suffers disaggregation
and loses a portion of its good qualities.
There is another kind of sea-sand called Trez, which forms
banks in the neighbourhood of Morlaix, and which is known
under the name of Tanque on the northern shores of France,
which is favourable to vegetation, particularly after it has been
washed and freed from the greater part of the salt which it con-
tains. It is thrown upon the land in larger quantity than the
marl. The small quantity of animal matter which it contains
putrifies and is lost when it remains exposed to the air for any
length of time, so that a distinction has been made between
fresh or live Trez; and old or dead Trez, the one being the
article as it comes from the sea, the other after it has been ex-
posed some time on the shore; the article which has been
exposed undoubtedly contains a smaller quantity of organic
matter than that which is quite fresh. This variety of sea-sand
is particularly available upon close and clayey lands, which some-
times receive as many as 16 tons per acre with advantage;
lighter lands, of course, require much less.
Shells, sand, slime, and sea-weed, are not the only useful
materials supplied to agriculture by the sea; fish or their offal
is frequently employed as manure. The practice of manuring
with fish is very old, and is universal wherever it can be had
recourse to. I have already had occasion to say, that at the
period of the conquest of America, the Spaniards found it es-
tablished among the Indians, on the shores of the Pacific ocean.
The lands are occasionally manured with fish along the sea-board
of Great Britain and Ireland, and the low lands of Lincolnshire,
Cambridgeshire and Norfolk, also receive occasional supplies of
the same powerful manure. The offal of the herring fishery,
of cod, of skate, and of the pilchard in Cornwall, the dog-fish
entire, and other kinds that are either less esteemed or that
are caught in quantities greater than can be consumed as food,
SLUDGE, SOOT.
371
are all admirable manures. We have been recommended to mix
the fish or fish offal with quick lime; but, unless in certain cir-
cumstances, the practice is very questionable; the addition is
probably only proper where the materials are exceedingly oily,
as is the case with pilchards, herrings, &c.: an earthy soap is
then formed which prevents the injurious effects upon vegetation
which wholly oleaginous matters scarcely fail to produce. One
analysis of cod-fish which I made along with M. Payen, gave us
a proportion of azote of nearly 7 per cent. This of itself is
enough to explain wherefore the flesh, the cartilages, and the
bones of fishes should be found such energetic manures.
The slime deposited by rivers also yields manure which may
be employed to much advantage. The Nile which periodically
inundates the plains of Lower Egypt, owes its fertilising action
to the slime which it contains, and which it deposits before it
again recedes into its bed. On the banks of the Durance, the
mud or slime deposited by the river is carefully collected for dis-
tribution over the fields in its vicinity. The waters of this river are
frequently turbid and improper for irrigation, until they have depo-
sited the slime which they hold in suspension; the waters are there-
fore turned into canals for the purpose of deposition before they
are let upon the land; and such is the quantity of slime that is
precipitated, that two or three gatherings of it are made in the
course of the year. It is dug out and thrown upon the banks
to dry; reduced to powder, it is fit to be laid upon the land; and
such is its fertilising power, that a field which yielded but four
for one, has been brought to yield twelve for one by its
means.*
Wood and coal soot, and Picardy ashes. Soot has been
known for a long period as a useful manure. M. Braconnot, in
the soot of a chimney where wood had been the fuel, found the
following ingredients:
* Belleval in Annals of French Agriculture, 2nd series, vol. xiv, p. 261.
The beds of many of the cozy-bottomed rivers in England near the sea are
inexhaustible sources of the most valuable manure. The bed of the
Tham es, between London Bridge and Putney Bridge at low water, is a true
gold mine if it were but rightly used.-ENG. ED.
B B 2
372
SOOT.
Ulmic acid
Azotic matter, soluble in water
Insoluble carbonated matter
Silica
Carbonate of lime
Carbonate of magnesia (traces of)
Sulphate of lime
Ferruginous phosphate of lime
Chloride of potassium
Acetate of potash
Acetate of lime
Acetate of magnesia
Acetate of iron (traces of)
Acetate of ammonia
An acrid and bitter element
Water
·
30.0
20.0
3.9
1.0
14.7
0.5
1.5
0.4
4.1
5.7
0.5
0.2
0.5
12.5
100.0
The analysis which M. Payen and I made of wood and coal
soot, confirms the presence of the azotised principle detected by
M. Braconnot. A considerable trade is carried on in soot for
agricultural purposes in large towns; it is thrown upon clovers
and young wheats, in the proportion of about 20 bushels to the
acre. Some have recommended that it should be mixed with
lime; but as soot always contains salts having a base of am-
monia, the practice is evidently objectionable, unless indeed the
object be to get rid of that which is most useful in the article,
which will be effectually accomplished by adding lime to it. The
proper procedure is to employ the soot without admixture during
calm or wet weather. In Flanders, the colewort beds destined
for transplanting are very generally manured with soot, which is
believed to have the property of preserving the young plants
from the attacks of insects. In the neighbourhood of Lisle,
they give from 55 to 60 bushels of soot per acre. Schwertz
appeals to many facts which go far to satisfy us that the effects
of soot upon clovers are particularly advantageous; he says,
moreover, that coal soot is preferable to wood soot.
rior properties of coal soot are evidently due to two causes:
first, it is more dense than wood soot, and in a given bulk ac-
tually contains a larger quantity of matter; secondly, I have
The supe-
PICARDY ASHES.
373
found that, for equal weights, coal soot contains the larger quan-
tity of azote.
Picardy ashes are prepared by the slow and imperfect com-
bustion of the pyritic turf which is dug up in the department
of the Aisne for the manufacture of sulphate of iron and of
alum. This turf piled up, heats, and finally takes fire; the com-
bustion continues for about a month, abundance of sulphureous
vapours being disengaged. The residue is a grey ash, still con-
taining a quantity of carbonaceous matter, which is found very ad-
vantageous in the way of top-dressing for meadows. It might be
maintained that the utility of such ashes depends solely on the
sulphate of lime which they contain; but it is ascertained that
they are much more active as manure than this substance
employed by itself; analysis, in fact, explains in some degree the
fertilising powers of these ashes, by showing that they contain
more than per cent of azote, to say nothing of the saline
matters of which vegetables are so greedy. It is extremely pro-
bable that during the slow incineration of the turf, there is a
quantity of sulphate of ammonia produced.
The ashes which remain after the lixiviation of the pyritic
and aluminous lignites which are mined for the purpose of
making green vitriol, are analogous to Picardy ashes, and are
employed with equal success in agriculture. At Forges-les-
Eaux, the pyritic earths after lixiviation are mixed with a quarter
of their weight of turf ashes, and form an active manure which
is employed very extensively in the country around the town of
Bray in France: it is equally adapted to meadows and to land
under roots, such as potatoes or turnips, green crops or corn.
Analysis shows these ashes to have the following composition:
Soluble organic matter
Insoluble humus
Sulphate of protoxide and of peroxide of iron
Fine sand
Sulphuret of iron
Peroxide of iron
2.7
49.8
1.8
39.0
6.7
100.0
The vitriolic ashes of Forges-les-Eaux are more highly azotised
than those of Picardy; they contain 2.72 per cent of azote.
374
PARING AND BURNING.
The effect of the imperfect combustion of these pyritic turfs,
the product which results from it, explains to a certain extent the
beneficial effects of the practice of paring and burning, an im-
portant and widely spread practice, the utility of which it would
be difficult to understand, were it not connected in some way
with the production of ammoniacal ashes.
The useful effects of paring and burning, are, in all proba-
bility, connected with the destruction of organic matter, very
poor in azotised principles; in the transformation of the surface
of the soil into a porous, carbonaceous earth, made apt to
condense and retain the ammoniacal vapours disengaged during
the combustion; lastly, by the production of alkaline and earthy
salts, which are familiarly known to exert a most beneficial
influence upon vegetation. These conditions seem so entirely
those, the object of which it is to realise by paring and burning,
that in order to make the operation favourable to the soil which
undergoes it, the vegetable matter which it has produced, must
of necessity be transformed into black ashes; when it goes
beyond this, as Mr. Hoblyn has well observed, when the
incineration is complete, and the residue presents itself as a
red ash, the soil may be struck with perfect barrenness for the
future. The burning, therefore, that was not properly managed,
that led to the complete incineration of all the organic matter,
would, for the same reason, have a very bad effect in the
preparation of the Picardy ashes; which might indeed act in
the same way as turf ashes from the hearth and oven, but
which deprived of all azotised principles, would not ameliorate
the ground in the manner of organic manures.
I have frequently seen the process of burning performed
in the steppes of southern America. Fire is set to the pastures
after the grass which covers them has become dry and woody;
the flame spreads with inconceivable rapidity, and to immense
distances. The earth becomes charred and black; the com-
bustion of those parts that are nearest to the surface, however,
is never complete; and a few days after the passage of the
flame, a fresh and vigorous vegetation is seen sprouting through
the blackened soil, so that in a few weeks the scene of the deso-
lation by fire, becomes changed into a rich and verdant meadow.
MANURES.
375
ANIMAL EXCREMENTS.
Horse dung. The composition of horse dung would lead
us to infer that its action must be more energetic than that of
cow dung. Nevertheless, agriculturists frequently consider it
as of inferior quality. This opinion is, even to a certain extent,
well founded. Thus although it be acknowledged that horse
dung covered in before it has fermented, yields a very powerful
manure, it is known that in general the same substance, after
its decomposition, affords a manure that is really less useful
than that of the cow house. This comes entirely from the fact
that the droppings of the stable by reason of the small quantity
of moisture they contain, present greater difficulties in the way
of proper treatment than those from the cow house. Mixed with
litter and thrown loosely upon the dung hill, horse dung heats
rapidly, dries, and perishes: unless the mass be supplied with a
sufficient quantity of water to keep down the fermentation, and
the access of the air be prevented by proper treading, there is
always, without the least doubt, a considerable loss of principles,
which it is of the highest importance to preserve. I can give
a striking instance of this fact in the changes that happen in
the conversion of horse dung into manure in the last stage of
decomposition: fresh horse dung in the dry state contains 2.7
per cent of azote. The same dung laid in a thick stratum and
left to undergo entire decomposition, gave a humus or mould,
from which, reduced to dryness, no more than one per cent of
azote was obtained. I add that by this fermentation or decom-
position, the dung had lost nine tenths of its weight. From
these numbers every one may judge how great had been the
loss of azotised principles. In practice, however, little care is
bestowed on the preparation of horse dung; the fermentation
is rarely, if ever, pushed to this extreme point indeed; but it
is not the less true that it is constantly approached in a greater
or less degree; and that the consequences, although not alto-
gether so unfavourable as those which I have particularly signa-
lised, are nevertheless extremely destructive. All enlightened
agriculturists have, therefore, long been aware of the attention
necessary to the management of horse dung, which requires a
376
HORSE DUNG.
degree of care, that may be perfectly well dispensed with when
the business is to convert the dejections of horned cattle into
manure. To obtain the best results in the management of
horse dung, it appears to be absolutely necessary to give it a
much larger quantity of moisture than it can ever receive from
the urine of the animal; if it be not watered it necessarily
heats, dries, and loses both in weight and quality; whilst by
being kept properly moist, it produces a manure, which half
rotted, is of quality superior, or at all events equal to the same
weight of cow-dung.
M. Schattenmann who has the produce of stables containing
two hundred horses to manage, follows a process of the most
commendable description in the preparation of his manure, and
which is attended with the very best results. His dunghill
stance, of no great depth, is about 440 yards square in super-
ficies, and divided into two equal portions. The bottom of this
stance is so arranged as to present two inclined planes, which
bring all the liquids that drain from it to the middle, where
there is an ample tank for their reception, furnished with a pump
for their redistribution to the dunghill. There is also another
spring-water pump destined to supply the water that is neces-
sary to preserve the dung heap in an adequate state of moistness.
The latter auxiliary is quite indispensable; the quantity of water
necessary is so considerable when masses of such magnitude
are to be treated, that we cannot trust to any casual source of
supply. The two portions of the area are alternately piled with
the dung as it comes from the stables; it is heaped to the
height of 10, 12, or 14 feet; it is trodden down carefully, as
it is evenly spread, and plentifully watered from the spring-water
pump. Due consolidation, and a state of constant humidity,
are the two conditions that are the most indispensable to the
successful preparation of horse dung. M. Schattenmann is in the
habit of adding to the liquid, saturated with the soluble matters of
the dung hill, a quantity of sulphate of iron in solution, or of sul-
phate of lime (gypsum) in powder; he also throws the same salts
upon the surface of his heap; the object of this is evidently to
transform into sulphate, the volatile carbonate of ammonia formed
in the course of the decomposition, and so to prevent its escape
HORSE DUNG.
377
and loss. By these means a pasty manure, as rich as that which is
yielded by horned cattle, and of a quality, the excellence of which
is proclaimed by the remarkable crops that cover the lands which
receive it, is produced in the course of two or three months.*
It is almost useless to add, that great care must be taken not to
introduce too large a quantity of sulphate of iron, which might
have a prejudicial influence upon vegetation, into the dunghill or
the drainings from it. In making use of sulphate of lime
there is nothing to fear on this score; this salt in excess would
be rather favourable than hurtful; in general gypsum is cer-
tainly the preferable substance, both on account of its never
doing mischief, and of its greatly inferior price.t
Farmers generally advise horse dung to be reserved for
argillaceous, deep and moist soils; this recommendation is given
in connexion with the manure that is obtained by the usual
imperfect process of preparation. With regard to the horse
dung, prepared in the manner which I have just described, and
as practised by M. Schattenmann, it is adapted to soils of all
kinds; and if it differs from the dung of the cow-house, it is
only by its superior quality. This last fact is at once explained
by the elementary analysis of the excrements of a horse fed
upon hay and oats.
100 parts of the urine of the animal so fed, yielded 12.4 of
dry extract, the composition of which was as follows:
Carbon
Hydrogen
Oxygen
Azote
Salts
Water
•
In the state of extract. In the liquid state.
36.0
4.46
3.8
0.47
11.3
1.40
12.5
1.55
36.4
4.51
87.61
100.00
د.
100.0
The droppings of the same horse after drying, gave 24.7 of
fixed matter, the analysis of which indicated :
* Schattenmann, Annales de Chimie, 3e série, vol. iv. p. 117.
† Every farmer who should have something like a cart or waggon-load
of gypsum brought to the farm every year would find his profit from the
practice.-ENG. ED,
378
CATTLE STALL DUNG.
Carbon
Hydrogen
Oxygen
Azote
Salts
Water
Dry excrement.
38.7
5.1
37.7
2.2
16.3
Carbon
Hydrogen
Oxygen
Azote
Salts
Water
در
100.0
The dung of horned cattle is often extremely watery; it is
especially so when furnished by animals kept upon green food;
this extreme humidity renders its preparation easy. Its equiva-
lent number is higher than that of horse dung; it is, in fact,
less highly azotised, and consequently less active. If the food
have a great effect upon the quality of the manure, it is quite
certain that the circumstances or states of the cattle have
an effect which is scarcely less remarkable. Milch cows and
cows in calf always furnish a manure that is less highly azo-
tised, than stall-fed and labouring oxen; and this is readily
understood: the azotised principles of the food are diverted to
secretions, which concur in the development of a new being in
the one case, in the production of milk in the other; for the
same reason the dejections of young animals, all things else
being equal, furnish a manure of less power and value than
those of adult animals. I shall have occasion to recur to this
important subject, which has never yet been sufficiently studied.
The urine and excrements of a milch cow, which is giving
about 12 pints of milk per diem, have shown upon analysis,
the following quantities of elements: 100 of the urine contained
11.7 of dry extract, and had this composition :
Moist excrement.
9.56
1.26
9.31
0.54
4.02
75.31
100.00
Urine dry.
27.2
2.6
26.4
3.8
40.0
0.0
100.0
Urine liquid.
3.18
0.30
3.09
0.44
4.68
88.31
100.00
100 of fresh excrement left on drying 9.4 of dry substance,
and in each state contained:
HOG'S DUNG-PIGEON'S DUNG.
379
Excrement dry.
42.8
5.2
37.7
2.3
12.0
0.0
100.0
Carbon
Hydrogen
Oxygen
Azote
Salts
Water
Excrement moist.
4.02
0.49
3.54
0.22
1.13
90.60
100.00
Hog's dung. From all I have seen, I conclude that hogs
well kept and put up to fatten, yield dejections which are
highly azotised, and which must consequently furnish a manure
of excellent quality. Schwertz has, indeed, ascertained that this
manure acts more powerfully than cow dung.
Sheep dung is one of the most active of manures, fact
which is confirmed by analysis; for it is by no means watery,
and in the usual state contains upwards of one per cent of azote.
The mode of managing sheep generally implies that they manure
the ground immediately. Schwertz calculates that in the course
of a night, a sheep will manure something more than a square
yard of surface; at Bechelbronn we have found the quantity
manured to be about 4 square feet. The following are the
details of one experiment:
Two hundred sheep were folded for a fortnight upon a rye-
stubble, of an extent which gave as nearly as possible four square
feet of surface per sheep. The manuring thus effected was
found toproduce a maximum effect upon the crop of turnips
which followed the rye.
Pigeon's dung is known as a hot manure, and of such
activity that it must be used with discretion. Pigeon's dung
is available for crops of every description; Schwertz has made
use of it for a long time, and always with the greatest success,
mixed with coal ashes upon clovers. The Flemish farmers
procure pigeon's dung from the department of the Pas de
Calais, where there are a great number of dove-cotes, one of
which, containing from six hundred to six hundred and fifty
pigeons, will let for the sum of about £4 per annum, merely for
the sake of the dung; the quantity yielded in this time may
be about a waggon-load. In the neighbourhood of Lisle, this
manure is applied particularly in the cultivation of flax and
380
GUANO.
tobacco. According to M. Cordier, the dung of between seven
hundred and eight hundred pigeons is sufficient to manure
nearly 2 acres of ground. The dung of three hundred and
twelve pigeons, therefore, would suffice for an acre. The value
of pigeon's dung may be estimated from the large proportion of
azote which it contains; that which I analysed from Bechelbronn
gave 83 per cent of this principle, a result which ought not to
excite surprise when it is known that the white matter that
appears in the excrements of birds, consists of nearly pure uric
acid. The manure of the hen-house is nearly or quite as good
as pigeon's dung.
Guano is a manure of the same nature as pigeon's dung,
and the use of which, long familiar on the coasts of Peru,
has lately extended to these countries, the article being now
imported in large quantities, both from the South American
and African coasts. Guano appears to be the result of the
accumulation for ages of the excrements of the sea-fowl,
which live and nestle in the islets, in the neighbourhood of
the great southern continents of the new and old world.
The mass in many places forms beds of between 60 and
70 feet in thickness. The principal places whence guano
is obtained, are the Chinche islands near Pisco; but other
deposits of the substance are known to exist more to the
south, in the islets of Iza and Ilo, at Arica, and in the
neighbourhood of Payta, as I had an opportunity of ascer-
taining during my stay in that port. The inhabitants of
Chinche are the principal traders in guano; and a class of
small vessels, called Guaneros, are constantly engaged in car-
rying the manure.
*
Fourcroy and Vauquelin were the first who fixed attention on
the nature of guano. The specimen which they examined was
brought to Europe by M. de Humboldt, and contained: Uric
acid (0.25), oxalate of ammonia, chlorhydrate of ammonia,
oxalate of potash, phosphates of potash and of lime, chloride of
potassium, fatty matter, and sand.
Since this time Dr. Fownes has again analysed guano. The
* Humboldt, Annales de Chimie, vol. LVI, p. 258.
GUANO.
381
sample upon which he operated was of a light brown colour and
extremely offensive smell; it yielded :
Oxalate of ammonia
Uric acid
Traces of carbonate of ammonia and organic matter
Phosphates of lime and of magnesia
Phosphates and alkaline chlorides, and traces of sulphates
66.2
29.2
4.6
100.0
Another sample, deeper in colour and without smell, con-
tained: Pure oxalate of ammonia, 44.6; earthy phosphates,
41.2; alkaline phosphates, sulphates, and chlorides, 14.2 100.
The composition of guano would confirm, were there any oc-
casion for confirmation, the opinion that has been formed as to
its origin. The islets which supply it are still tenanted, espe-
cially during the night, by a multitude of sea-fowl. Neverthe-
less, from the calculations of M. de Humboldt, the excrements
of these birds in the course of three centuries, would not form
a layer of guano of more than one third of an inch in thickness;
-imagination stops short, startled, in presence of the vast
lapse of time which must have been necessary to accumulate
such beds of the substance as now exist, or rather, as lately ex-
isted in many places; for it is rapidly disappearing since it has
become a subject of the commercial enterprise of mankind.*
The average composition of guano must by no means be in-
ferred from the preceding analyses of picked samples: earthy
matters are usually present in much larger proportion than they
are here stated. The guano generally imported into England and
France yields a proportion of azote very far short of that which
the 25 per cent of uric acid which has sometimes been stated to
___________________
* Dr. John Davy, all whose scientific researches equal in accuracy the
brilliant investigations of his illustrious brother, has lately turned his at-
tention to this subject: he finds that we have collections of guano in Great
Britain that are really not to be despised in some cases. The surface
of the ground under old cstablished rookeries is a true guano
bed;
and re-
moved and used as manure in the open field, produces most excellent
effects. See Dr. Davy's paper in Ed. Lond. and Dub. Philos. Mag. Oct. 1,
1844.-ENG. Ed.
382
NIGHT-SOIL.
exist in this substance would yield. In three trials the azote
found was 0.14, 0.05, and 0.05; the mean would therefore be
0.08, which represents the quantity of azote in pigeon's dung.
The litter and excrement of the silkworm is used as manure
in the south. Analysis indicates 3 per cent of azote in its
constitution.
Human excrements are regarded as one of the most active
manures that can be employed. In countries where agriculture
has made real progress, this article is highly prized, and no
pains are spared to obtain so powerful a manure. In Flanders,
feculent matters form the staple of an active traffic; and in the
neighbourhood of large towns, they form an invaluable material
for the amelioration of the soil. The Chinese collect human ex-
crements with the greatest solicitude, vessels being placed for
the purpose at regular distances along the most frequented ways.
Old men, women and children, are engaged in mixing them
with water, which is applied in the neighbourhood of the plants
in cultivation.* The fresh excrement is occasionally worked up
with clay, and formed into bricks, which are pulverized when
dry, and the powder is applied as a top-dressing. One of the
advantages resulting from the almost exclusive use of this ma-
nure in China is this, that the fields seem to grow nothing but
the plant which is the object of solicitude with the farmer; it is
there extremely difficult to meet with a weed. The quality of
feculent matter as a manure depends much on the nature and
abundance of the food consumed by those who furnish it. M.
d'Arcet relates a curious anecdote in connexion with this fact:
a farmer had purchased the produce of the cabinet of one of the
most celebrated restaurateurs or taverns of the Palais Royal ;
encouraged by the success he obtained in employing this manure,
and desirous of obtaining a larger supply of the article, he rented
the produce of several of the barracks of Paris.
The manure
which he now obtained, however, he found to produce an effect
greatly less than he had anticipated, so that he lost money by
his bargain. Berzelius found the following substances in human
excrements:
* Julien, Annales de Chimie, vol. 1, p. 65, 3rd series.
NIGHT-SOIL.
383
Remains of food
Bile
Albumen
A peculiar extractive matter
Indeterminate animal matter, viscous matter,
resin, and an insoluble residuum
Salts
Water`.
The salts had the composition following:
Carbonate of soda
Chloride of sodium
Sulphate of soda
Ammoniaco-magnesian phosphate
Phosphate of lime.
Urea
Uric acid
•
Indeterminate animal matter
Lactic acid, and lactate of ammonia
Mucus of the bladder
Sulphate of potash
Sulphate of soda
Phosphate of soda
Chloride of sodium
Silica
Water
Phosphate of ammonia
Chlorhydrate of ammonia
Phosphate of lime and of magnesia
•
Human urine is one of the most powerful of all manures.
Left to itself it speedily undergoes putrefaction, and devolves an
abundance of ammoniacal salts as all the world knows.
composition, according to Berzelius, is the following:
Its
7.0
0.9
0.9
2.7
14.0
1.2
73.3
100.0
29.4
23.5
11.8
11.8
23.5
100.0
3.01
0.10
1.71
0.03
0.37
0.32
0.29
0.45
0.17
0.15
0.10
traces
. 93.30
100.00
The phosphates of lime and magnesia which it contains are
extremely insoluble salts, and have been supposed to be held in
solution by phosphoric acid, lactic acid, and very recently by
Professor Liebig, by hippuric acid, which he now states to be a
regular constituent of healthy human urine.
384
NIGHT-SOIL.
From the interesting inquiries upon urine made by M. Lecanu,
it
appears that a man passes nearly half an ounce of azote with
his urine in the course of twenty-four hours. A quantity of
urine taken from a public urine pail of Paris, yielded 7 per 1000
of azote. The dry extract of the same urine yielded nearly 17
per cent.
Human soil as commonly obtained consists of a mixture of
feculent matters and urine. It may be applied immediately
to the ground as it comes from the privy. In some parts of
Tuscany it is mixed with three times its bulk of water, and so
applied to the surface. I have myself seen night-soil as it was
obtained, and without preparation, spread upon a field of wheat
without any ill effect: so that the Tuscan preparation may be
regarded as a simple means of spreading a limited quantity of
manure over a given extent of ground.
It is in French Flanders, however, that human soil is collected
with especial care; it ought to be so collected everywhere. The
reservoir for its preservation ought to be one of the essential arti-
cles in every farming establishment, as it is in Flanders, where
there is always a cistern or cess-pool in masonry, with an arch
turned over it for the purpose of collecting this invaluable ma-
nure. The bottom is cemented and paved. Two openings are left:
one in the middle of the turned arch for the introduction of the
material; the other, smaller and made on the north side, is for
the admission of the air, which is requisite for the fermentation.
The Flemish reservoir may be of the dimensions of about
35 cubical yards. Whenever the necessary operations of the
farm will permit, the carts are sent off to the neighbouring town.
to purchase night-soil, which is then discharged into the reser-
voir, where it usually remains for several months before being
carried out upon the land.
This favourite Flemish manure is applied in the liquid state
(mixed in water) before or after the seed is in the ground, or to
transplanted crops after they have been dibbled in. Its action
is prompt and energetic. The sowing completed, and the land
dressed up with all the pains which the Flemish farmer appears
to take a pleasure in bestowing upon it, a charge of the manure
is carried out at night in tubs or barrels. At the side or corner
FLEMISH MANURE.
385
of the field there is a vat that will hold from 50 to 60 gallons,
into which the load is discharged, and from which a workman,
armed with a scoop at the end of a handle a dozen feet in length
or more, proceeds to lade it out all around him. The vat
emptied in one place is removed farther on, and the same pro-
cess is repeated until the whole field is watered.*
The purchase, the carriage, and the application of this
Flemish manure cannot be otherwise than costly; we therefore
see it given particularly to crops which, when luxuriant and suc-
cessful, are of the highest market value-such as flax, rape, and
tobacco.
This manure, the sample of it, at least, which M. Payen and I ex-
amined, is of a yellowish green colour, and with reference to smell
cannot be compared to anything better than a weak solution
of hydrosulphate of ammonia. This salt is undoubtedly pre-
sent; but exposure to the air converts it rapidly into the sulphate
of the same base. According to M. Kuhlmann, the quality of
the liquid Flemish manure is to be judged of by its smell, its
vicidity and its saline and sharp taste. By the fermentation
which takes place in the cess-pools, which are never emptied
completely, the feculent matter, kept for some time there, does
in fact acquire a slight vicidity. When solid excrementitious
matter predominates in the fermented mass, its effect upon
vegetation is of longer continuance; but when it is derived en-
tirely from urine, it acts almost immediately after its application.
In either case, the effect of Flemish manure does not extend
beyond the season; like all the other organic substances which
have undergone complete putrid fermentation, it is a true annual
manure.
Occasionally, a quantity of powdered oil-cake is thrown into
the reservoir. This is either when the manure is supposed to be
too dilute, or when there is little night-soil at command. The fol-
lowing, according to Professor Kuhlmann, is an example of the
employment of the Flemish manure in a rotation which is com-
mon in the neighbourhood of Lisle, and in the course of which
the crops are colza or colewort, wheat and oats.
First year. In October or November, the land is manured
* Cordier, Agriculture of French Flanders, p. 240.
C C
386
FLEMISH MANURE.
with farm-dung, which is ploughed in, in the usual way. At
this time a dose of the liquid manure, amounting to about 5000
gallons per acre, is applied: a second ploughing is given, and the
colewort is planted.
Second year. The colza is gathered, the ground is ploughed
for autumn sowing; from 1000 to 1300 gallons or so of
liquid manure are distributed and the wheat is sown.
Third year. The wheat stubble is ploughed down at the end
of the autumn, and about 1000 or 1100 gallons of the liquid
manure per acre are distributed; the oats are sown in the
spring. If circumstances should prevent the application of the
liquid manure in autumn, it is laid on in March, and then it has
been found that one fifth less will suffice; but its application at
this season is avoided as much as possible on account of the
havoc that is made by the passage of horses, carts, and men
over the surface of the soft ploughed land. It is with a view
to avoid this disturbance of the surface that in many places oil-
cake in powder is applied to the fields under colza when the
manuring has to be performed after the crop is in the ground.
For beet, the dose of Flemish manure is carried the length
of from 1300 to 1400 gallons per acre; but when the root is
intended for the manufacture of sugar, liquid manure is sedu-
lously avoided, experience having shown that it has the very
worst effect upon the production of sugar, a circumstance which
is very easily explained upon grounds that have already been
given.
The price of Flemish manure at Lisle is 24d. for a measure
containing 22 gallons. In Flanders, it is held that this quantity,
which will weigh hard upon 2 cwt., is equal to about 5 cwt.
of farm-yard dung. The liquid manure which I analysed
yielded 2 per 1000 of azote. Farm-yard dung in its usual state
contains as much as 4 per 1000; it follows, therefore, that the
real equivalent number of Flemish manure is 182, that of farm
dung being 100; in other words it would require 182 of Flemish
manure to replace 100 of farm-yard manure; a conclusion that
differs widely from that which is usually acted upon. But it must
be observed that from its nature, the Flemish manure produces its
maximum influence in the course of the season in which it is
FLEMISH MANURE.
387
applied. It seems to have no effect on the crop of the succeed-
ing year. Farm-yard dung, on the contrary, only exerts a por-
tion of the whole amount of its beneficial influence in the
course of the year in which it is laid on; it has still something,
often much, in reserve for succeeding years. To compare liquid
manure with farm-yard dung, with reference to an annual crop
is to compare this manure to the unknown fraction of the farm-
yard dung which comes into play in the course of the first year,
and from such a contrast no possible inference can be drawn in
regard to the relative value of the two kinds of dung. I have
insisted upon this circumstance, because it is often involved
in the estimates that are made of the relative values of the dif
ferent species of manure; and because, from losing sight of it,
unfavourable conclusions are frequently come to in regard to
manures that undergo decomposition very slowly; these ma-
nures, nevertheless, acting for a great length of time, produce
both a greater amount and a more durable kind of amelioration
of the soil. Rapidity of action, in a manure, is undoubtedly a
quality that is highly valuable in many cases; and Flemish ma-
nure possesses this quality in the highest degree. Nevertheless
it is also an advantage to possess a manure which elaborates
gradually and accordingly to the exigencies of vegetables, those
principles that contribute to their growth, and which suspend in
a great measure this elaboration in the course of the winter-
which remain during the cold and rainy season in an almost inert
condition, when any fecundating matter produced would merely
be washed away and lost. These advantages, to which must be
added that of breaking up and lightening the soil are all pos-
sessed by good farm-yard manure. They are such, in fact, that
this manure even in Flanders, is still indispensal le; the liquid
manures of that country are nothing more than annual auxi-
liaries.
The method followed in Flanders of using night soil is cer-
tainly highly rational; it is the same as that which is adopted
in Alsace in the neighbourhood of towns, with this difference
that our farmers collect no store of the material; they go in
quest of it at the moment it is wanted. It is applied as in
Flanders, or it is incorporated with absorbent substances, such
C C 2
388
POUDRETTE.
as straw, or with other more consistent manures. The night-
soil of Paris, which in the course of the year amounts to an
immense quantity, is treated in a totally different manner, which
appears to be in opposition to the simplest notions of science,
of economy, and of all that is conducive to health. I allude to
the mode of preparing poudrette.
In the neighbourhood of Paris there are places appropriated
to the reception of the night-soil: it is thrown into reservoirs of
no great depth in comparison with their superficial extent, and
of an aggregate capacity which is such that they will contain the
whole of the products collected by the night-man in the course
of six months. These reservoirs are arranged in stages, one
above another. Into the upper one are discharged the matters
collected in the course of the night. The upper resevoir full, a
sluice is opened by being pushed partially down, which allows
the more liquid matters to escape into the second reservoir
placed under it. Repeated drainings are effected in this way,
and when the second basin is also full, there is a deposition of
solid matter as in the first; the more liquid particles are then
let off from the second into the third reservoir, and so on in
succession until the last and lowest is attained, from which the
liquid used to be turned into a watercourse; but of late thesc
contaminated liquids have been got rid of by means of what
may be called absorbing artesian shafts-deep holes pierced in
a dry and porous soil.
When the deposit in the first reservoir is held to be suffi-
ciently consistent, it is drained by lowering the sluice more and
and more; no fresh matter is added, the new charges being de-
posited in another system of reservoirs. The deposit once
drained is in the pasty condition; it is then taken out with the
spade, and spread upon an earthern floor which slopes off on
either side, and the mass is turned from time to time to favour
the drying; this process, in fact, is continued until the material
has become pulverulent. It is then stored under sheds, or
thrown up into pyramidal heaps, the sides of which are well beaten
in order to enable them to throw off the wet.
Poudrette is of a brown colour, and weighs nearly 150lbs.
per sack. Put into a retort, and distilled with a heat of from
COMPOSTS.
389
424° to 930° Fal. it yields 52.6 of ammoniacal fluid, and
47.3 of dry matter, in which we encounter fixed ammoniacal
salts, such as the sulphates, phosphates, hydrochlorates, &c. M.
Jacquemart finds that in 100 parts of poudrette there is 1.26
of ammonia, the greater part in the state of carbonate; but it
contains a quantity of animal matter besides, which by dry dis-
tillation yields a nearly equal amount of the same substance;
whence it follows that poudrette contains nearly 2 per cent. of
volatile alkali, or 2 of azote. By direct analysis, I obtained 1.6
of azote.
Poudrette is spread upon the land at the time of ploughing,
from 26 to 34 bushels per acre being allowed. On meadow
lands, it produces very good effects in the dose of about 25
bushels per acre. The disgusting smell of night-soil is to a
certain extent an obstacle to its general use. This obstacle,
however, is only felt in places where agricultural industry, and
the manufactures connected with it are still in a backward state.
One remarkable circumstance is, that the disgust which naturally
arises from the manipulation of such articles has been more es-
pecially got over in countries that are justly celebrated for their
extreme attention to cleanliness, and the easy position of their in-
habitants-I quote Flanders and Alsace in proof of the fact. It
has been said, moreover, that certain articles produced in soils
manured with human excrement contract a smell and taste
which give rather unpleasant information of the nature of the
manure that has been employed to favour their growth. In the
limited circle of my own experience on this subject, I can say
that I have observed nothing which favours such a statement.
However this may be, Mr. Salmon has succeeded in disinfecting
night-soil completely by mixing it with a kind of animal char-
coal obtained by calcining in close vessels a porous earth im-
pregnated with organic substances. This is the article which is
sold under the name of animalised black. Its quality as a ma-
nure must depend especially, I might even say entirely, on the
quantity of azotised organic matter which enters into its com-
position.
Composts. A great deal has been written, and much has
been said on the advantages of composts or mixtures con-
trived with a view to the amelioration of the soil. The receipts
390
COMPOSTS.
for these composts are very numerous; they prove that the dis-
covery of a compost is an easy matter and requires but a small
amount of ingenuity. To unite different matters in such a way
as to obtain a compound that shall act advantageously, it is only
necessary to make it up of substances which of themselves and
isolatedly are good manures. But that it is possible to supply
the scarcity of manure, to create it in some sort by means of
composts is a subject of dispute. In fact, when we look atten-
tively at the numerous mixtures which have been indicated as
leading to this end, we always perceive that the proposal amounts
to an extension or dilution of some powerful manure with a
substance that is either inert or has little activity. This mode
of proceeding may have its advantages; it enables us to make
a more equal distribution of the manure we have at our disposal,
but it actually supplies us with nonc.
Earthy substances almost always figure in composts. Turf
ashes, wood ashes, marl, and particularly lime, are constant in-
gredients. Marl may suit certain soils; lime is a substance of
great activity, and which for this reason must be admitted into
composts with caution; it may act in the disintegration of woody
parts of stalks and stems, and leaves; but we must be very careful
not to follow the recommendation of Schwertz, who would have
us throw quick lime into our privies with a view to bringing the
matters there contained into a consistent and readily pulverisable
state. By doing so we should infallibly lose the greater part of
the principles that are truly useful in the soil. Much mischief
and great destruction of manure, indeed, have been the conse-
quence of the insensate and indiscriminate use of quick lime
under all circumstances; the business is much rather to preserve
than to destroy the substances that are used as manures, the
purpose is to fix, not to dissipate the volatile elements which
they contain. One great objection to the extensive employment
of composts is the amount of labour they require in the re-
peated turnings which are held necessary in their preparation,
and in the large quantity of matter which has to be transported.
The following table will be found useful as giving a compre-
hensive view of the proportion of azote contained in the various
kinds of manures which have been particularly examined, and
of their equivalents referred to farm-yard dung as the standard.
MANURES.
391
TABLE OF THE COMPARATIVE VALUE OF MANURES
KIND OF dung.
deduced fROM ANALYSES MADE BY MESSRS. PAYEN AND BOUSSINGAULT.


Idem
Idem
•
•
Farm-yard dung
79.3 1.95
Dung from an inn yard 60.6 2.08
Dung water
99.6 1.54 0.06
19.3
Wheat straw
Idem
0.30 0.24
5.3 0.53 0.49
Rye straw
Idem.
Oat straw
Barley straw
Wheat chaff
Pea straw
Millet straw
Buckwheat straw
Lentil straw
*
Dried potato tops
Withered madia stalks
Idem turned under
whilst green
Dried broom
•
Withered leaves of beet-
root
·
•
•
Ditto of potatoes
Ditto of carrots
Leaves of heather
Ditto of pear- trees
Ditto of oak
•
Ditto of poplar
Ditto of beech
Ditto of acacia
Box-tree
Burred clover roots
Fucus digitatus
Idem.
Fucus saccharinus
Idera
•
Burnt sea weed
Oyster shells
Sea shells
•
•
•
•
Fir saw-dust
Idem
Oak saw-dust .
•
•
•
•
White lupine seed
Malt grains
Grape husks
•
Oil-cake of linseed
Ditto of colewort
Ditto of arachis
Ditto of madia
Ditto of sesame
•
•
•
•
•
•
•
Mud of the Morlaix ri-
ver
•
Trez of Roscoff roads
Sea-side marl
•
Salt cod fish
Cod fish washed and
pressed
•
•
·
►
•
•
•
•
•
·
·
·
Water per 100.
Azote in
100 of matter.
Dry. Wet.
Wet.
5.3 0.43 0.41
9.4 1.42 1.33
39.3
53.6
59.3
70.6 1.53
0.45
10.4 1.37 1.22
Quality ac-
cording to
State.
9.7
1.77
39.2 1.41
40.0 1.58
40.0
2.29
75.5
Dry.
Dry. Wet.
0.41 100 100
0.79 107 107
78
12.2 0.20 0.17
12.6 0.50 0.42
21.0 0.36 0.28
11.0 0.26 0.23 13
7.6 0.94 0.85
8.5 1.95 1.79 100
19.0 0.96 0.78
11.6 0.54 0.48
92 1.12 1.01
12.9 0.43
14.3 0.66
0.37
0.57
3.8 0.40
17.9
0.40
0.05
OEREN 22 28224895bN8 RR
88.9 4.50
76.0 2.30
70.9 2.94 0.85 150
7.0 1.90
1.74 97
73
14.5
1.59 1.36
81.5
80
25.0 1.57
1.18
51.1 1.17 0.54 66
1.18 78
1.91
1.56
2.89
0.72 80
1.17 147
1.61
90
0.86 72
0.95
1.38 117
0 54
0.38
0.32
0.03
web: Exi
10.0 18.74 16.86 961
24.0 0.22 0.16 11
24.0 0.31 0.28 15
26.0 0.72 0.54 36
10.5 4.35
6.0 4.90
48.2 3.31
13.4 6.00
10.5 5,50
6.6 8.89
11.1
6.5 5.93
100 100
94
51
127
68
2
60 650
122.5 367
167
82
102.5
332.5
3.49 223
4.51 251
1.71 169
5.20 307
4.92 282
8.33 655
5.70 5.06 202
5.52 304
195
120
250
113
305
0.50 230 125
43
0.55 117 137.5 85
212.5 66
425
103
340
293
134
Equivalent
according to
State.
42.5 975
105
390
542
750
70
57.5
212.5 207
447.5 100
203
361
174
92.5 453
142.5 295
Dry. Wet.
3.7 0.42 0.40 21 100
0.5 0.14 0.13 7 32.5
1.0 0.52 0.51
26.5 128
38.0 10.86
6.70 557 1675
S
453
137
126
142
127
125
167
294
102
125
180
293
63
402.51 110
215 139
237.5 123
85
345
135
95
80
13 3750
488
488
464
1393
377
18
4215 10
40 986
57.5 629
135 256
872.5 45
1127.5 40
427.5 57
1300
1230
2082.5
1265
1378
33
35
83778
21
34
33
8
98
83 OR!
235
95
143
174
47 Of Alsace.
22
51
83
40
108
70
89
After seeding.
Before seeding.
33 Stalk and leaves.
80
73
47
23
29
34
74
34
56
34
25
46
42
29
74
105
125
769
REMARKS.
Average of Bechelbronn.
From south of France.
Washed by the rain.
Fresh, of Alsace, 1838.
Old from environs of Pa-
ris.
150 TH
Ditto stubble.
Ditto upper part, ear in-
cluded.
Of Alsace.
Environs of Paris, 1841.
74
Of mangel wurzel,
Withered top and leaves.
Dried in the air.
Leaves fallen in autumn.
Fresh.
Branches and leaves.
Dried in the air.
Dried in the air.
100
308} Sea sand.
78
6
Dried sea shells of Dun-
kirk.
2 Dried in the air.
250
174
74
Dried in the air.
111 Tuscan-boiled and dried.
9
23
8
392
MANURES.

KIND OF dung.
Oil-cake of hempseed
Ditto of poppy
Ditto of beech mast
Ditto of walnuts.
Ditto of cotton seed
Ditto from refiner's
Ditto ditto
Cyder apple refuse
Refuse of hops
Beetroot refuse
Idem.
Squeezed beetroot
Potato refuse
Potato juice
Water of the starch
manufactory
Deposit from the water
of ditto
Idem
Solid cow dung
Urine of cows.
Mixed cow dung
Solid horse dung.
Horse urine
•
•
•
Mixed horse dung
Pig dung
Sheep dung
Goat dung
•
•
•
Liquid Flemish manure
Idem
•
·
Poudrette of Belloni
Ditto of Montfaucon
Urine of the public vats
Idem .
Animalised black
Idem from the neigh-
bourhood of Paris
Idem, called Dutch ma-
nure
Animalised seaweed
Pigeon's dung.
Guano imported into
into
England.
Idem
Ditto imported into
France
Silk worm litter
Idem
•
·
Chrysalis of silk worm
Cockchafers
Dried muscular flesh
Soluble dried blood.
Liquid blood
Idem
Blood coagulated and
pressed
Insoluble dried blood
Dregs from Prussian
blue manufactory.
Melter's bones
Fresh bones
•
•
•
•
Fat bones, not heated.
Dregs of bone glue
Glue dregs
Graves
Animal black of the su-
gar refiners
•
•
•
•
•
•
•
•
Water per 100.
Azote in
100 of matter.
Quality ac-
cording to
state.
Dry. Wet. Dry. Wet. Dry. Wet.
5.0 4.78 4.21 245 1052
6.0 5.70 5.36
1340
292
6.2 3.53 3.31 181
6.0 5.59 5.24 287
11.0 4.52 4.02 231
10.0 3.92 3.54 201
828
1310
1000
885
110
75.4 3.02 0.74 154
81.4 3.37 0.63 172
63.0
2.99 1.11 153
46.0 3.93 2.16 201
0.19
0 22
12.5 4.40
41.4 2.67
96. 17.56
96.9 23.11 0.72 1133 179
44.6 1.96 1.09
3.85 225
1.56 137
16.83 900
55
962
390
4213
100.5 272
42.0 2.96 1.24
127 340
44.1 2.48 1.36
12.1 2.73
2.40 140 600
9.6
9.02
8.30 462
2075
19.6
6.20 5.00 323 1247
7.05 5.40 361 1349
23.4
Equivalent
according to
state.
185
157.5
277 5
540.
47.5
FI9888 888 8
7.7
6.4
73.0
2.23
1.26
9.3
··
0.58 0.54 30 135
0.63 0.59 32 147
0.56 114 140
1.14 64 285
70.0
0.38 64 85
94.5 1.76 0.01 90 2
73.0 1.95 0.53 100
95.4 8.28 0.38 425
8.28 0.07 425
131.5
94
99.2
17.5
90. 108
384.5
80. 1.81 0.36 92
15. 1.81 1.54 92
85.9 2.30 0.32 117
83.3 3.80 0.44 194
80.
84.3 2.59 0.41 132
75.3 2.21 0.55 113
79.1 12.50 2.61 641
41
15.7313.95 807 3487
11.3
14.3 3.48 3.29
11.4 3.71 3.29
78.5 8.99 1.95
485
77.0
801
8.5 14.25 13.04 730 3260
21.4 15.50 12.18 795 30-45
81.0
2.95 795 736
2.71 795 580
178.7 827
190 822
461
13.93 3.20 714
82.5
34
73.5
17.00 4.51 871 1128
12.5 17.00 14.88 871 3719
55
35
265
32
50
332
309
155
111
100
102.5 75
23
137.5 88
••
652.5 15
84
12200 88883
51
66
58
65
50
:1220* = 2r
44
73
151.6 310.5 66
11
98
79
214
314
28
53
214
14
13
12호
​114
114
53.4 2.80 1.31 144 526
7.5 7.58 7.02 388 1754
30.0
5.31
6.22
1326
1554
8.0
42.0 0.91 0.53 47
133 214
33.6 5.63 3.73 288.4 933.5 35
8.2 12.93
11.88 663
296953
15
131
47.7 2.04
1.06
104
96
972
4242
काका
7
94
36
18
210
182
10 Dried in the air.
25
2
83 56
26
76
12
7
10
114
75
68
67
35
106
4137
76
106
571
111
24
125
91
7 16
98
73
15
54
63
12 28
56
37
32
29
21 122 12
REMARKS.
Recent fat by means of
poplar sawdust.
Fish oil by ditto ditto.
Dried in the air.
30
6
Dried in the air.
Fresh from the press.
Process of Dombasle,
Settled and decanted.
From washing in 4 vo-
lumes of water.
33
Drainings from the heap.
Dried in the air.
38
The horse drank but lit-
tle; the urine was thick.
5 Of Bechelbronn.
In the normal state.
Dried in the stove.
Thin, ammoniacal.
Prepared for 11 months.
Recently made.
Made at Lyons.
Dried in stove (From
Marseilles).
13
3
34 As sold.
13
15
In the ordinary state.
Sifted.
Fifth age.
Sixth age.
9 Just out of the press.
23 Dried in the manufactory
Dried in the air.
From the slaughterhouses
From worn out horses
74 As sold by the melters.
64 Including 0.10 of fat.
76
11
As sold by the makers.
Animalised with blood.
Dried in the air.
As sent out.
KIND OF DUNG.
Sugar refiner's black
Scum from the sugar
refinery
English black
Feathers
Cow hair flock
Woollen rags
Horn shavings
Coal soot
Wood soot.
.
Picardy ashes.
Vegetable mould from
humus dung (terreau)
Water per 100.
MANURES.
Azote in
100 of matter.
Dry. Wet.
Quality ac
cording to
state.
Equivalent
according to
state.
Dry. Wet. | Dry.
27.7 19.01 | 13.75
974
3437
134
0.54
1.58
81
67.0
6.95
13.5 8.02
411.4 1738
903 3835
12.917.61 15.34
8.9 15.12 13.78 775
3415
4495
11.3 20.26 17.98 1039
809
9.0 15.78 14.36
3590
15.6 1.59
81
1.35
5.6 1.31 1.15 67
9.2 0.71 0.65 36
1.03
53
103
127
24
11
13
91
25$-- Popu
125
337.5
122
287.5 | 149
162.5 275
189
Wet.
223
28
75
of'mma mê
33
REMARKS.
393

From Paris.
From the sugar bakery of
Vigneux.
Blood, lime, soot.
Dried in the store.
It is almost unnecessary to give any explanation of the uses
that may be made of the preceding table, I shall, however,
give a few illustrations from instances which have actually oc-
curred in my experience.
Oil-cake is cheap at this time (1842); and the question
is, whether it could be advantageously employed in connexion
with the cultivation of wheat. The presumption is, that wheat
obtains the whole of its azote in the soil, that it acquires
none from the atmosphere; and again, I assume that the
whole of the azote putinto the ground would be used up
by the crop.
Under the most favourable circumstances of
heat and moisture, this would probably be the case; were
it not so to the letter, the active matter which remained
in the ground would operate advantageously in succeeding
years.
The following, then, are
question :
the elements of the
an
1st. In the wheat grown at Bechelbronn there is on
2nd. In the straw of 1841, I
average 0.025 of azote.
have just found 0.003 of azote. 3rd. The oil-cake which
I propose to employ contains 0.055 of azote, and its
4th. The
actual price, crushing included, is 3s. 4d. per cwt.
relation in point of weight of the grain to the straw is as
47: 100.
A sheaf or bundle of wheat, 220 lbs. in weight, consists
of :
394
EXPORTATION OF MANURES.
Wheat 70.4 lbs., containing 1.760 of azote, and is worth 4s. 8d.
Straw 149.6 lbs.
0.415
1s. 8d.
Total of azote
>>
""
2.175 Total value
Difference of value
To grow which, 39 lbs. of oil-cake would be required, of
the value of
6s. 4d.
5s. 4d.
1s. 2d.
So that 39lbs. of oil-cake, converted into a sheaf of wheat,
would be increased in intrinsic value to the extent of 5s. 2d.
Supposing that but one-half or one-third of this amount as in-
dicated by theory is realized in practice, it is obvious that the
addition of the oil-cake might be made with advantage; and
that no means should be neglected to insure the success of its
application as a manure.*
The production of oil-cake in France, the Netherlands, and
other countries of Europe, is very considerable; in round num-
bers, 100 of oleaginous seeds yield 60 of cake; but it has been
calculated with rare ability, and from authentic documents by M.
Leroy de Béthune, that not only is the whole of the oil-cake
which is the produce of the soil of France exported, but that like-
wise of the oleaginous seeds which she imports from other coun-
tries. This M. de Béthune looks upon as a very lamentable agri-
cultural fact. I have shown, indeed, from the example which
I have quoted, that every pound of cake represents a primary
material, which properly treated may be transformed into nearly
6 pounds weight of wheat-grain and straw, having a value infi-
nitely greater than that of the oil-cake originally employed.
Whilst I agree with M. de Béthunc, that it is generally wise
to encourage exportation, I also admit with him that there are
substances in reference to which it would be prudent to dis-
courage exportation: oil-cake, this powerful means of giving
fertility to the soil, might be placed in the foremost rank of such
substances. I am far from adopting all the principles of econo-
mists, which appear to me to be frequently far too absolute. In
my opinion, any exportation, the consequence of which is the
impoverishment of the soil, ought to be prohibited. I should,
•
* Our author has of course left many other elements very necessary to
be included out of his calculation here, such as labour, seed, rent charge,
interest on capital, &c.-ENG. Ed.
CALCULATION OF THE VALUE OF MANURES.
395
for instance, oppose the exportation of arable soil; and, in the
same way, to allow an active manure to pass into the hands of
strangers, is in my eyes tantamount to exporting the vegetable
soil of our fields, to lessening their productiveness, to raising the
price of the food of the poor; for as much labour is required,
as much care and capital must be expended upon an
grateful soil to obtain a little, as upon a fertile soil to procure an
ample return. To permit the exportation of oil-cake is to hinder
the husbandman from taking advantage of all the circumstances.
with which nature presents him; it is as if a chill were to be
brought over the genial climate of France.*
un-
I have shown the advantages of the application of oil-cake in
the growth of wheat. I shall now inquire whether or not it is
equally useful in connexion with hay and potato crops; the
price of the article being presumed to be the same as before.
Upland meadows, when they have not been soiled, yield miser-
able returns, and their situation renders them difficult of access to
carts: oil-cake in such circumstances comes powerfully to our aid.
Taking the price of hay at 5s. per 220lbs. which is about its
present price in France, and taking into account the composition
of the after-math, we may reckon the azote contained in the hay
of natural meadows at 0.015.
220 lbs. of hay, containing 3lbs. of azote will be worth. 5s. Od.
To produce which 56lbs. of cake (azote 3.3lbs.) worth. 1s. Sd.
would be required.
Difference in value between the cost and the crop
3s. 4d.
* I own I am surprised at this passage in my esteemed author. There
is nothing parallel in the instances he quotes. Did not the French hus-
bandmen and oil-pressers profit by the exportation of oil-cake they would
keep it at home; and the profit of the farmer and manufacturer is the
profit of the whole community. To export the soil would indeed be mad-
ness: it would obviously be killing the goose that lays the golden eggs;
but to export that which the soil produces in abundance year after year
is a totally different affair. M. Boussingault's reasoning would lead the
wine-growers of Bordeaux and Burgundy to refuse us a hogshead of their
smallest growth: they cannot send it to us without impoverishing their soil,
any more than they can let us have a pound of their oil-cake. But one half
of the vegetables that grow, at least, are at work accumulating the ma-
terials from the atmosphere and water, out of which the other half are
supplied, and so the process of waste and supply, of destruction and repro-
duction goes on without limits, and without end.—ExG. ED.
396
USE OF THE PRECEDING TABLE.
Upon this showing, oil-cake may be advantageously employed
in the amelioration of upland meadows. Besides the cost of the
manure, however, there are the very necessary additions to be
made of the price of labour and rent.
From the observations which I made at Bechelbronn in 1839,
I find that the relation between the weight of potatoes as they
come from the ground, and that of the tops or haum, supposed
to be dry, is as 100 is to 6.4.
The tubers contain :
Azote 0.0036 per 10000 parts; and 220lbs. contain
0.729 of a lb. of azote, and are worth
The tops or haum dry contain ;
Azote 0.0230 per 10000 parts; and 14lbs. contain
0.330 of a lb. of azote.
Total of azote 1.122.
Now 20.4 lbs. of cake which would be required to pro-
duce 220 lbs. of potatoes, contain 1.1lb. of azote, and
are worth
1s. 8d.
. Os. 7 d.
Difference
1s. Old.
The oil-cake at the price of 3s. 2d. per cwt. may therefore
be advantageously used for the production of potatoes: rent,
labour, seed, &c. considered as before. At the price of 7s. 6d. or
8s. 6d. per cwt., however, to which oil-cake occasionally rises,
it would not be possible to employ it profitably in this way.
The cost of the manure would then amount to nearly as much
as the value of the crop.
The equivalent numbers in the table express the relative
values of different manures; they proclaim the proportions in
which one substance must be substituted for another, and when
purchases are to be made, they will show at a glance which is
the article that is really, and in fact, the cheapest. The equiva-
lent number of one variety of oil-cake, for instance, is 7.25;
that of farm-yard dung is 100; which is as much as to say
that in reference to mere fertilizing elements, 100 parts—lbs.
cwts. or tons, of farm-yard dung may be replaced by 74 parts—
lbs. cwts. or tons of oil-cake ;—2 cwt. of farm-dung, for instance,
by 14 lbs.of cake. The 2 cwt. of farm-dung is valued in the table.
at 6d., or about 5s. per ton; the 144lbs. of cake would cost 5d.
It is obvious, therefore, that even at the above low price of oil-
1
VALUE OF DIFFERENT MANURES.
397
cake, there would be no real advantage in substituting it generally
for farm-yard dung; in situations, however, remote from large
towns, where it is almost impossible to procure dung, or where
the carriage of large masses of dung would be both difficult and
expensive, there would then be advantage in the substitution.
Woollen rags at the price of about 2s. 10d. per cwt. are more
profitable than farm-yard dung at 3d. per cwt. The equivalent
of the rags is 2.22, and this quantity (2.22lbs. avoird.) of rags is
worth about ad; by the substitution of the rags for farm-yard
manure, therefore, a saving is effected of about 21d. on every
cwt. of the latter that must have been employed. In good
farming, however, it is less with reference to the money advan-
tage of substituting one manure for another, that calculations
are made, than with reference to the possibility of procuring
either one manure or another at a moderate price. The estimated
value of the dung in one of the columns of the table gives
us at once the price that may be paid for it; for this purpose it
is enough to know the value of standard dung: let this be as it
usually is, 3d. per cwt.; if we would now know what may be
paid for a hundred weight of bones simply dried in the air, the
number designating these being 1554, we have only to make a
simple equation in the following terms:-100: 3d::1554:x
to have the solution: -3s. 10d.
The most careful consideration of the relative value of different
manures under the guidance of the analytical elements which
I have indicated, justifies the preference which is given in
practice to one kind over another, which on simple examination.
appears to offer greater advantages. Thus by diffusing oil-cake
through water, and leaving the mixture to ferment, a manure is
obtained which presents all the characters, which possesses all
the properties of human soil that has undergone fermentation in
privies or cess-pools. And it is to this mixture of putrid oil-
cake that the husbandmen of French Flanders have recourse,
as we have seen, when their supply of night-soil runs short.
When oil-cake is low in price, say about 3s. 3d. or 3s. 4d. per
cwt., it might seem advantageous to manufacture Flemish
manure with it; expensive carriage and time would be saved;
for night soil has generally to be fetched from a distance, and con-
398
VALUE OF DIFFERENT MANURES.
taining but 0.002 (ths) of azote, it is bulky and its equivalent
is in the same proportion high. Cameline oil-cake contains 0.055
(55ths) of azote; to make Flemish manure that should contain
0.002 of azote, it would be requisite to add to every 100 parts
of cake 2,650 parts of water; the cwt. of this manure would
then come to 1½d., whilst Flemish manure prepared with night
soil, would cost the farmer but 1d. I have here taken the
cake at a low price; were it 7s. 6d. per cwt. instead of 3s. 9d.
which is perhaps much nearer its usual average cost, it is
obvious that the cwt. of manure prepared from it, would cost
twice as much more.
The proportion of azote, the value, and the equivalents of the
several manures are given in the table, both for the substances
absolutely dry, and for the condition in which they are com-
monly employed. This distinction is one of great importance.
The water, the quantity of which is indicated in the first column,
is a most variable constituent; its presence, of course, depreciates
the manure in the precise ratio in which it occurs. The
reference of all the elements of each particular manure to that
manure in a state of absolute dryness, is a very important
feature in the table. In purchasing manures, the precaution of
drying them chemically must never be neglected, more especially
in connexion with articles, which by their nature are capable of
absorbing water in considerable, and often in very different,
quantities.
MANURES.
399
CHAPTER VI.
OF MINERAL MANURES OR STIMULANTS.
ALL the organic manures, when burned, leave ashes com-
posed of earthy and saline substances. The action of these
substances upon vegetation is quite unquestionable, and it is
certain that an organic manure, were it ever so rich in azotised
principles, and ever so assimilable, would still be imperfect did
it not further contain the truly mineral matters which plants
require to meet with in the soil, in order to complete their
growth and bring their seeds to maturity. The most active
organic manures are always abundantly provided with inorganic
principles. Farm dung (dry), contains about one-fourth of its
weight of such substances, and the water which is used for
irrigation invariably holds saline matter in solution.
Nevertheless, repeated cropping will often end by depriving
the soil of the mineral substances which plants require; the
salts contained in the manure supplied are sometimes inadequate
to meet the demands of successive crops, and then the return
falls off. It is consequently necessary in certain cases to furnish
the soil anew with saline matters, in order to supply the con-
tinued drain that is made upon it, or to meet the exigencies
of particular crops which are known to require an unusually
large quantity of salts for their successful cultivation. It is in
this way that clover, lucern, and sainfoin require plaster (gyp-
sum); the cereals, silica and certain calcareous salts; the vine,
potash, &c.
Practice got the start of science in the application of mineral
manures or stimulants. If their useful influence cannot be
denied, as it cannot, if the circumstances in which it is advan-
tageous to administer them, if the conditions and the doses
in which they ought to be given to the ground have been the
subject of long and careful observation with farmers, it must
400
LIMEING.
still be admitted that we are far from understanding exactly
in what way they act; this is another motive for continuing to
study them with perseverance.
CALCAREOUS MANURES.
In certain soils we have said that the calcareous element
is either wanting, or present in very small and inadequate
quantity; other soils, again, abound in calcareous matter, and
observation appears to prove that the presence of carbonate
of lime in a soil adds unequivocally to its fertility.
jority of the good wheat lands hitherto examined have been
found to contain a notable quantity of this earth or earthy
The ma-
salt.
It is usual to put lime into the ground in the state of caustic
or quick lime; this is limeing, properly so called. But it is
also applied in the state of carbonate, as when we make use of
chalk or marl, or shell-sand from the sea-shore.
The lime-stone that is used for burning is seldom pure; it
frequently contains clay, quartzy sand, metallic oxides, and occa-
sionally carbonaceous matter; frequently too it is so largely
mixed with magnesia that it acquires peculiar characters; this
is the magnesian lime-stone or dolomite. The purest carbonate
of lime by exposure for some time to a white heat, loses 43.7 of
carbonic acid, and consequently contains 56.3 of caustic lime.
Limestone is one of the most common of rocks; in the crys-
talline and saccharoid state, or of closer and finer grain, it
often constitutes mountain masses, and is met with in every
part of the geological series; it meets us as chalk in beds of
enormous thickness, filling up extensive basins in the tertiary
series; such are the chalk beds of the south and west coasts
of England, extending through the counties of Kent and Sus-
sex, &c.
The only mineral substance with which chalk, limestone, or
carbonate of lime is likely to be confounded, is gypsum or sul-
phate of lime. But it is easy to distinguish either of these salts
from the other: carbonate of lime dissolves with effervescence
in dilute hydrochloric acid; sulphate of lime is insoluble in this
liquid. Carbonate of lime is quite insoluble in water; sulphate
LIMEING.
401
of lime is very sensibly soluble, and a copious precipitate falls
on the addition of a solution of oxalic acid or of oxalate of am-
monia. Gypsum is always so soft that it can be scratched
with the nail; limestone, save in the state of chalk, is generally
so hard that it resists the nail.
The burning of lime for agricultural uses is carried on in the
same way as for building and other economical purposes. Burnt
or quick lime is a very different article from chalk or limestone;
it is powerfully caustic or destructive of the organic tissue, and
instead of being altogether insoluble, it is now soluble in about
630 parts of cold water. All the world knows how lime from
the kiln, when watered, rises in temperature, breaks first into
larger and then into smaller pieces, and finally falls down into
fine powder; but every one is not aware that there is a true
chemical union of water with the earth, and that the resulting
powder is in chemical language a hydrate of lime, a substance
which is much less caustic than pure lime, but still distinctly
alkaline in its reaction.
It is generally admitted that the soil which is without a cer-
tain, and that a considerable proportion of the calcareous
element, never possesses a high degree of fertility. This in
particular is the opinion of English agriculturists who apply
lime with a kind of profusion; and the great improvement it
frequently produces on the crops of grain, leaves no doubt as
to the advantages of the procedure. Still it is now generally
recognised that limeing ceases to be useful upon lands that are
already sufficiently calcareous, or that rest on a sub-soil of chalk.
It is, therefore, by supplying the calcareous element which land
requires to constitute it a soil adapted to the growth of corn,
that the application of lime becomes useful; limeing, in fact,
enables us to make this necessary addition at least cost. Like
other mineral manures, lime of itself produces little or no effect;
it is in concurrence with organic manures that it becomes
truly useful; it is nowise, and never can become a substitute
for these.
The geological constitution of a country is perhaps the best
guide to the necessity or advantages of limeing. Soils that
are derived from plutonic or igneous rocks, in which felspar,
D D
402
LIMEING.
mica, or quartz predominate, are on the face of things likely to
be improved by the introduction of lime. Direct analysis would
of course give more decisive information on the fact.
In any
case, the measure recommended by prudence is to make a few
preliminary trials upon the small scale; the experimental method
is the only safe one in agriculture, when the question is in
regard to the adoption of new plans. In England it is cus-
tomary in limeing clayey lands to allow from 230 to 300 or
310 bushels of stimulant per acre; on lighter soils the dose
may vary from about 150 to 200 bushels, according to their
character. In France the quantity usually employed is greatly
less, from about 60 to 70 bushels, being all that is gene-
rally thonght advisable, and this at intervals of seven or eight
years. In the neighbourhood of Lisle little use is made of lime,
although there the land is generally anything but calcareous;
perhaps the want of lime is not felt in consequence of the
universal practice of employing the Flemish manure, which,
as we have seen, contains ammoniacal salts (and both human
urine and excrement contain a large quantity of phosphate of
lime and phosphate of magnesia in addition, the very salts that
the generality of vegetables crave). In the vicinity of Dunkirk,
however, lime is frequently applied in the dose of between 40
and 50 bushels per acre, and with effects that are said to con-
tinue for ten or twelve years.
The dose of lime introduced into the soil in different coun-
tries, is moreover in a certain relation with the time during
which the action of the earth is believed to continue; as the
quantity administered at once is small, the dose must be re-
peated more frequently. Near Dunkirk they use from 40 to
50 bushels per acre every 10 or 12 years; in the department
of La Sarthe, according to M. Puvis, they scatter on some
9 or 10 bushels only; but they do so every three years. This
would lead us to conclude that soils which really wanted lime
should receive a dose in the proportion of about 3 bushels
per acre annually. But the crops gathered from the ground
every year, certainly do not abstract anything like this quantity
of calcareous matter; which would induce us to infer, that
after a certain time the land will contain such a quantity of
LIMEING.
403
lime as to make any farther addition of it unnecessary, or at
all events, unnecessary save at rare and distant intervals.
One of the great advantages which lime has over all the
other forms or kinds of calcareous stimulants employed, is
unquestionably the state of extreme sub-division which it ac-
quires in the quenching. In the course of falling down into
this extremely fine powder, lime, as has been said, combines
with a large quantity of water. But the change experienced
does not stop short here; the air always contains some 10,000ths
of carbonic acid gas, for which the hydrate of lime has a
powerful affinity, so that it absorbs this gas greedily, aban-
doning at the same time its constitutional water, by which in
due season, the hydrate of lime becomes changed into the
anhydrous carbonate of lime. This process is always slow;
more rapid at first, when the interchange between the carbonic
acid and water takes place freely, it becomes gradually slower
and slower as there is less and less water left in the particles;
the affinity of the lime for the water seems to increase con-
tinually in the ratio of the smallness of the quantity which
it still contains. It must, therefore, constantly happen that in
incorporating lime in powder and partially carbonated with the
soil, we also introduce lime that has preserved its causticity
in some measure; it must be observed, however, that once
intimately mixed with the soil, this lime must speedily pass
into the state of carbonate, because the soil and the water with
which it is moistened always contain a considerable quantity
of carbonic acid. Though
Though we commence operations with quick
lime, consequently, it is carbonate of lime that is definitively
introduced into the ground. I have thought this a point of
sufficient importance to engage our attention for a short time,
inasmuch as it simplifies the view of the end that is to be sought
in applying lime; this, as M. Puvis has most satisfactorily
established, is neither more nor less than the introduction into the
ground of that proportion of the calcareous element which it
either wanted originally or which it has lost in the course of
repeated cropping, in order to enable it to produce abundantly.
Quick lime incorporated with the soil, must pass, as I have
DD 2
404
LIMEING.
shown, very rapidly into the state of carbonate; but before
attaining to this state, it may unquestionably re-act upon the
organic substances it encounters, disorganize them, favour their
decomposition, in a word, behave as it does when used in com-
posts. On the other hand, in causing the destruction of organic
particles already in a state of decomposition, it must produce an
unfavourable influence.
Lime, previously quenched and cold, is generally spread by
being raked out from the cart upon the field, in little heaps,
from five to six or seven yards apart, each containing from half
to two-thirds of a bushel. It is or ought then to be spread
immediately as evenly as possible over the surface. There is
only the disadvantage attending this mode of proceeding, that
slaked lime is twice the bulk of lime in the shell or lump, and
that by slaking, it takes up at least one-fifth of its original weight
of water. There is saving of labour, therefore, in distributing
the lime unslaked in heaps, and waiting the slow process of
extinction and pulverization by the moisture of the atmosphere.
The lime is often laid in a corner of the field and covered lightly
over with vegetable earth to undergo pulverization, and this
plan answers very well. Sometimes the lime before being
laid on is worked up into a kind of compost with vegetable
mould and other matters; this is all matter of calculation as to
cost. If our object be to supply the soil with the calcareous
element it wants, the proper procedure is quite obvious.
The mode of using lime with reference to other improvers of
the soil varies in different places. In one place it is usual to
lime and to dung alternately; in others, the two operations are
done together, or very close upon one another. There are some
lands so fertile that they produce abundantly under the influence
of lime alone. In laying on lime, one general rule is, that the
weather should be dry, and the ground well drained; the end of
summer is probably the most favourable season. To say nothing
of the difficulty of spreading the lime in wet weather; if it is at
all fresh, its caustic qualities are brought into immediate play
by the moisture, and it destroys the roots of living vegetables,
and the organic elements of the soil; and, again, it is quite certain
MARL.
405
that lime produces very little effect upon undrained and wet
lands. In England lime is very commonly used upon fallows,
in the course of the summer, and before sowing the wheat for
which fallowing is always a preparation. When it is given to
land destined for beet or potatoes, it is led out in the spring and
spread before the young beet is transplanted in the one case,
the seed-potatoes deposited in the other.
It is always matter of great moment to have lime spread
evenly; a thorough harrowing and a double superficial plough-
ing incorporate it sufficiently. According to M. Puvis, who has
made a particular study of the subject of limeing, as practised
in the department of the Ain, a quantity of lime, amounting to
8250 bushels, spread upon seventy-seven acres of land in the
course of nine years, produced so decided an improvement that
the returns from winter grain crops became the double of what
they had been before.
Marl. Marl, in a general way, may be regarded as a mixture
of carbonate of lime and clay in very variable proportions.
Occasionally the clay is replaced by sand; whence the titles,
sandy marl, argillaceous marl. The article, in short, contains
from 15 to as many as 90 per cent. of carbonate of lime. It
presents numerous shades of colour. Geologically speaking,
it is usually met with in fresh water formations of the latest
date, the upper strata of the Jura limestone are frequently
covered with deposits of argillaceous marls, and we see its for-
mation going on at the bottoms of lakes and ponds at the
present day.
The distinguishing property of a calcareous marl, whatever
admixture of other matters it contains, is that of crumbling
to pieces under exposure to atmospherical influences. Every
limestone rock that has this property may be considered, and
employed as a marl. The grand purpose of putting marl upon
land is to supply it with the calcareous element it wants. Το
marl land, is therefore tantamount to limeing it; the effect is
the same.
The value of the article is indeed so well known,
that considerable expense is constantly incurred to get at the
beds of it that form strata in the crust of the earth or that lie
406
MARL.
at the bottoms of lakes. It appears to have been employed from
the remotest antiquity.
The reason why marl and marly lime-stones fall so com-
pletely into powder is obvious. If the mass, when wet, form a
pasty mass, it shrinks as it dries, and cracks in all directions;
if more consistent it is still always porous, and having imbibed
a large quantity of rain in the autumn, this congeals during the
frosts of the succeeding winter, and the ice expanding with
almost irresistable force separates the particles, which cohere
indeed so long as the frost continues, but fall away from one
another on the first thaw, by which the solid rock of the autumn
and winter becomes a heap of dust in the spring. In the same
way we see chalk exposed to the wet and the frost, fall down to
powder, and in virtue of this property and its constitution as car-
bonate of lime, employed with perfect success in lieu of lime and
marl. Wherever there is a bed of chalk at hand, it is needless to
go farther in search of marl and quick lime, in so far at least as
the calcareous principle is concerned.
Argillaceous marl and sandy marl, must, of course, act in two
different ways upon the soil: in virtue of the calcareous element
in either case, and in virtue of the argillaceous principle in the one,
of the sandy principle in the other; and the kind of soil for
which they are severally adapted can be conceived before hand.
To a stiff clayey soil we would naturally add the sandy marl;
to a light sandy soil we would supply the argillaceous product,
and thus effect improvement by a kind of double tide. It is
therefore very important to distinguish between these two
effects produced by marl :-one mechanical, connected with the
presence of clay or sand; the other chemical, and depending on
the presence of carbonate of lime. It is to these two effects
separately and combined, that all the influence of marl is usually
ascribed by practical agriculturists. From certain inquiries
common to M. Payen and me, however, it appears that marl
must act in yet another way; our analyses show that it always
contains a certain, though variable proportion of azotised matter.
And there is nothing extraordinary in the discovery of this
fact; it is no more than might have been anticipated from the
MARL.
407
geological circumstances attending its production. Marls are,
as has been said, always connected with the most recent forma-
tions of the tertiary series; they are constantly accompanied by
remains, which attest the presence of organic beings, and
frequently they consist of little else than shells, and the disinte-
grated dwellings and bodies of molluscas, and madrepores, and
corallines, and other inferior forms of things that once had life.
It is by no means astonishing, therefore, that deposits which
have had such an original should still contain evidences of the
presence of the softer and more decompoundable, as well as of
the harder and more rebellious constituents of the beings to
whose existence they are due. One sample of marl which we
analysed, gave 0.002 of azote; another from the Lower Rhine,
gave rather more than 0.001 of the same element. It were,
therefore, very proper in analysing marls, chalks, &c. to have an
eye to their organic or azotic, as well as to their mineral con-
stituents; there can be very little question of the azotised
elements being at the bottom of the really wonderful fertilizing
influences of the marls of certain districts.
Marl ought, like lime, to be spread very evenly over the
land; it is generally laid on in the same way as lime-in little
heaps at regular distances, and then scattered abroad. It appears
to be a very general opinion that it is not advisable to cover it
immediately, or very shortly after it is dug from the bed that
supplies it; the practice where its employment is most general
and probably best understood, is to let it lie exposed through
the summer or winter, or even the whole year before laying it
on the land. It is also held not to be proper to cover it in
marl deeply. Marl is advantageously laid out in heaps
upon stubbles in the autumn; and in the carly spring when it
has been pulverized by the frost, it is spread with the shovel.
When it is to be used with winter wheat or rye, it is laid on in
the summer, and spread at the time of ploughing; the latter
plan of procceding, however, as Schwertz observes, can only be
followed with marl that pulverizes readily. In England it is
also laid down as a kind of principle that marl ought to be
exposed for as long a time as possible to the influences of the
atmosphere; that it ought to have a summer's heat and a
408
MARL.
winter's cold before it is applied. And that, in fact, which is
at all consistent, and has not been exposed to the frost,
scarcely pulverizes sufficiently to be readily miscible with the
soil even under the influence of repeated ploughings; moreover,
it produces very little obvious effect upon the crop with which it
is first used. After spreading, a rough harrow is passed over
the surface of the ground, which is then ploughed superficially
two or three times, the harrow being again had recourse to
repeatedly to break lumps, and so bring out the effect of the
marl.
The quantity of marl that may be advantageously given,
varies according to the circumstances of the district. Marl, it
may fairly be said, is frequently abused. In an excellent paper
on the subject, M. Puvis lays it down as a principle that the
first element in the calculation of the proper dose of marl, is the
quantity of calcareous matter that is wanting in the soil. He
says that every soil which contains more than 9 or 10 per cent.
of carbonate of lime can dispense with marl; and that soils
in which the lime falls short of this quantity, may advantageously
receive a dose or successive doses of the substance that will
bring them up to the point. The proper dose, consequently,
depends first on the proportion of carbonate of lime contained
in the soil, and then on that which the marl itself includes.
:
Considered from the rational point of view which M. Puvis
has taken, marling is no longer an arbitrary process, but one
that may be conducted on determinate principles. The extra-
vagant quantities that are often laid on without other assignable
reason than blind custom, are shown to be, if not injurious, yet
uscless the quantity of marl to be incorporated is determined
by the quality of the substance which is at our disposal, and by
the depth of the layer of vegetable earth taken in connexion
with its chemical constitution. To facilitate the calculation of
the proper dose, M. Puvis has drawn up a table, which, as it
may be found useful in practice, I append. It shows at a glance
the quantity of marl in cubic feet that ought to be put upon
an acre of ground, the depth of the arable soil being considered
in connexion with the composition of the marl at command:
MARL.
409
Table of the Number of Cubic feet of Marl applicable upon an Acre of
Land ploughed to the depth of:
310
inches.
333
1661
111
8310
66,13
551
4710
41
37
3310
4130
inches.
444
222
148
111
88+0
74
63
55+%
49+%
44³o
5+%
inches.
554
277
1847%
1387
110,
σ
921
79+0
69%
614/1
55
610
inches.
666
333
222
1661%
1331'6
111
9510
831%
74
66+%
740
inches.
776
388
258 To
194
155
1
10
1291%
11013
97
8610
77,1%
87%
inches.
888
444
296
222
1771
148
1260
111
98+
881
When 100
parts of marl
contain of
carbonate of
lime.

10
20
30
40
50
60
70
80
90
100
M. Puvis does not by any means give the doses in this table
as those that should be invariably employed; the table is one of
averages, deduced from practical results, and tested by expe-
rience as most truly useful. But special cases may occur that
would make departure from these conclusions not only advisable,
but advantageous.*
The use of marl produces an unquestionable effect on the
productive properties of the soil. According to M. Puvis, the
application of the proper dose of a sandy marl, containing from
0.30 to 0.60 per cent of carbonate of lime, doubled the produce
of a piece of parched land in the department of the Isère. Before
the application of the marl nothing but dwarfish crops of rye were
gathered, yielding at most three for one of the seed; at present,
eight for one of seed, and that wheat, are obtained; and the
good effects are found to continue for ten and even twelve years.
The action of marl is not unlimited any more than that of
lime, as the last sentence will give the reader reason to conclude.
With every harvest, a certain proportion of it is carried off, and
the land is finally left with an inadequate quantity of the calca-
reous element, which then requires to be restored. The nature
of the crop, however, has the most marked influence on the
quantity of lime that is taken up and carried away from the soil;
allowing the broadest margin, and judging from the composition
of the ashes of the plants that form the subjects of our ordi-
* Puvis, in Annals of French Agriculture, vol. xxvIII, p. 328, 2nd
series.
DD 3
410
WOOD ASHES AND LYE ASHES.
nary crops, we can see that the quantity of 34 bushels of marl
of the usual composition per acre, which is assumed as the
average quantity to be laid on, is vastly more than can be abso-
lutely necessary.
Wood ashes contribute to improve the soil. They contain,
besides silica, both phosphate and carbonate of lime and alkaline
sulphates, phosphates and carbonates. In a general way, every-
thing derived from plants that have lived must be useful to
plants that are about to live, or that are actually living. Al-
though the utility of wood ashes, then, is generally admitted,
the numerous purposes to which they are applied in the arts,
and their high price, which is the consequence of this, enable the
husbandman to employ them but rarely on his land; they are
almost always lixiviated in order to procure the carbonate of po-
tash they contain. In countries which are thickly wooded, indeed,
the trees are actually cut down and burned for the sake of their
ashes, just as oxen are run down and slaughtered in the vast
plains of South America for the sake of their hides.
The good effects of wood ashes upon vegetation is known to
communities the least advanced in civilization. The Indians of
South America burn the stems and leaves of the maize in order
to improve the soil. The same practice occurs among the na-
tives of Africa: on the banks of the river Zaire, according to
Tuckey, the ground is prepared by having little piles of dried
herbs placed upon it, to which fire is set; and upon the spots
where the ashes are collected, they sow peas and Indian corn;
these ashes are in fact the only manure that is employed. In
England, wood ashes are esteemed as particularly useful upon
gravelly soils; about forty bushels per acre are applied in the
spring where the article can be obtained.
The lye-ashes from the soap-boiler contain a small quan-
tity of soluble saline matter which has escaped the lixiviation,
mixed with a large proportion of lime, partly in the state
of carbonate, the lime having been added to bring the carbonate
of potash employed in the manufacture of soap into the caustic
state. This ash or refuse is much sought after, and is ad-
ministered in quantities that vary from 45 to 70 bushels per
acre, a dose in which its action is felt for ten years or more.
PEAT ASHES.
411
In wooded districts, where there is a good deal of potash pre-
pared, ash of this kind is obtained in large quantity; it is there
employed alternately with organic manures. Ashes are applied
in the same way as lime, with this difference, that it is held
better not to plough them in until they have received a little
rain. There are places where the ashes that remain in the
lixiviating tub are thrown on in the dose of 170 bushels per
acre.
Turf or peat ashes. Peat is the result of a peculiar spon-
taneous change that takes place in vegetables. It is produced
in bogs or swamps, and in connexion with stagnant waters;
turfy deposits are also encountered on the banks of rivers, in
valleys, at the bottoms of former lakes, and at the mouths of
rivers. Peat is met with from the level of the sea to the
elevated platforms of the Vosges and Alps; it lies in horizontal
beds, frequently divided by strata of gravel, sand, or clay. It is
always a product of comparatively recent formation, a fact which
is attested by the thin layers of vegetable soil that lie over it in
many places, and the animal remains, and products of human
industry that are frequently encountered in it.
The state of decomposition of the vegetables that form turf
or peat is seldom so far advanced as to make the remains of the
plants which compose it doubtful. It is of different kinds:
hard or woody, and soft or herbaceous peat. Some of it is
extremely compact, black, and like vegetable mould in appear-
ance; generally speaking it is light, spongy, and of a lighter or
deeper shade of brown. When quite dry, it is often extremely
light; a cubic metre, which is about one eleventh more than a
cubic yard, will weigh from 5 to 6 cwt.
The circumstances in which turf has been found lead us to
infer that it must contain the elementary insoluble elements
of the plants that produced it. It appears, however, to contain
a somewhat larger proportion of azote than the average quantity
met with in herbaceous vegetables, supposed dry; but we have
seen that in the slow alteration of ligninc, azote becomes
concentrated, as it were, in the residue; and that, in fine, mould
contains a larger quantity of azote than the wood from which it
proceeds. It appears farther from some experiments very
412
PEAT ASHES.
lately performed by Mr. Hermann, that during the putrefaction
of the woody principle, azote is actually taken from the air
to concur in the formation of certain products that are perfectly
definite. Mr. Hermann quotes the following experiment:
Twenty-eight parts of wood taken from a log already attacked
with rot, and in which, indeed, there were several points already
decayed, were moistened and enclosed in a jar containing
atmospherical air over mercury. The bulk of the atmosphere
contained in the bell-glass was 262 volumes. The wood was
kept there for ten days at a temperature of 75.2° Fahr. The
apparent volume of the air continued unaltered to the end of the
experiment; but a large quantity of carbonic acid had been
formed:
RESULTS ON THE INCLUDED AIR:
Before
207 vols.
Oxygen 55
262
The air contained: Azote
After.
194 vols.
Carbonic acid. 40
28
262
در
The moist wood in its decomposition during ten days had
consequently caused thirteen volumes of azote and twenty-seven
volumes of oxygen to disappear. And Mr. Hermann found that
it now contained principles analogous to those of humus, one of
which, nitrolin, is highly azotised, and by the ulterior action of
air and moisture, gives rise to ulmate of ammonia. These
experiments of Mr. Hermann are new, and the conclusions to
which they lead are both interesting and important.*
Turf or peat is virtually the woody principle in the last stage
of modification by atmospherical influences; but it appears still
to contain, although modified, the usual principles which enter
into the constitution of herbaceous vegetables also. M. Payen
detected a quantity of fatty matter in it, analogous to that which
exists in leaves, and M. Reinsch found it to contain tannin.
One sample of turf (from the neighbourhood of Moscow by the
way) examined by Mr. Hermann, yielded of carbonaceous matter,
nitrolin and vegetable remains 77.5; of ulmic acid 17.0; extract
* Vide his paper in Journ. für prakt. Chemie, B. XXIII. §. 379.
PEAT ASHES.
413
of humus 4.0; ammonia 0.25; and ash 1.25-100.0. The
elementary composition of these varieties of turf, analysed by M.
Regnault, gave from 57 to 58 of carbon; 5.1 to 5.6 hydrogen;
30.8 to 31.8 oxygen and azote; and 4.6 to 5.6 ashes.
Turf or peat has consequently a certain resemblance to mould
or humus; it differs, however, in the absence of substances
soluble in water; and it is easy to imagine that, produced as
it is in connexion with water, continually soaked in moisture,
soluble matters ought not to be expected in it in appreciable
quantity. Peat might, in fact, be likened to the insoluble part
of humus left after lixiviation. And there is this farther resem-
blance that peat, like the humus which has been thoroughly
lixiviated, if exposed to the air, by and by acquires a quantity
of soluble material, the evolution of which is also hastened by
the contact of the alkalies. The employment of turf as manure,
in some countries, confirms the propriety of this mode of viewing
its nature and constitution; and then it is well known that bogs
consisting of pure turf, when drained and limed, become tolerably
fertile lands, yielding magnificent crops of oats and turnips
especially.
The ashes of turf we might expect to contain the mineral
substances usually found in the ashes of plants, and farther a
certain quantity of additional earthy matter. But this is not
the case several alkaline salts, indeed, have been discovered in
very small proportion; but no chemist, to my knowledge, has
ever even suspected the presence of any of the phosphates; a
special search which was made for them in my laboratory failed
to discover them. This is a fact, which I own, amazed me;
some coal ash, and another ash produced from lignite, gave a
result equally negative. We might imagine the disappearance
of the soluble salts; but how the earthy phosphates should
disappear; how the ashes of coal should come to be without a
trace of phosphoric acid, when we see that the iron ore, in
connexion with the coal fields, is always more or less phospho-
rigerous,* is surprising.
Turf or peat ashes are valuable improvers of the soil, and are
* Our author might have added the fact, that the common bog iron ore
of this country is a phosphate of iron.-ENG. Ed.
414
PEAT ASHES.
in great request among intelligent farmers. Analysis, in fact,
indicates several substances in their composition as calculated to
assist vegetation; carbonate of lime, in a state of extreme sub-
division, occasionally sulphate of lime (gypsum); calcined clay
whose action upon strong and retentive lands is always bene-
ficial; silica in a favourable state for assimilation; finally, alka-
line "salts, chlorides, sulphates, carbonates, and, perhaps, in spite
of the negative given by chemical analysis, traces of the phos-
phates.
The peat of the bogs of Sceaux, near Château-Landon, leaves
19 per cent. of ashes, composed, according to M. Berthier, of:
Caustic and carbonated lime
Clay
Gelatinous silica
Alumina
Oxide of iron
Carbonate of potash
Silica
Alumina
Oxide of iron
Lime
The peat of Voitsumra, dug upon the frontiers of Bavaria and
Bohemia, contains the remains of trees; it leaves 1.7 per cent.
of ashes, composed, according to M. Fikenscher, of:
•
Magnesia
Sulphate of lime
Chloride of calcium
Carbonaceous matter not incinerated
Carbonic acid and sulphur
Lime
63.0
7.5
13.0
7.0
9.0
0.5
100.0
Magnesia
Alumina and oxide of iron
Clay and silica
The brown herbaceous peat of the neighbourhood of Troyes,
leaves 11 per cent. of residue; it contains:
36.5
17.3
33.0
2.0
3.5
4.5
0.5
2.7
100.0
23.0
23.0
14.0
14.0
26.0
100,0
PEAT ASHES.
415
The peat of Vassy is compact, and of a brown colour; it is
mixed with fragments of chalk. On incineration, it leaves 7.2
of residue per cent., containing:
Clay
Carbonate of lime
Sulphate of lime
Oxide of iron
The peat of Champ-du-Feu, near Framont (Vosges), leaves
per cent. of ashes, which consist of:
3
Silica.
Alumina and oxide of iron
Lime
11.0
51.4
26.0
11.5
100.0
Silica and sand
Alumina
Lime
Magnesia
Oxide of iron
The peat of the environs of Haguenau (Lower Rhine), pro-
duces 12.5 per cent. of ashes, which, according to the analysis
made in my laboratory, contain:
Potash and soda
Sulphuric acid
Chlorine
40.0
30.0
30.0
100.0
65.5
16.2
6.0
0.6
3.7
2.3
5.4
0.3
100.0
Supposing the whole of the sulphuric acid found to have been
in combination with lime, this peat could only have contained
4.1 per cent. of gypsum.
These analyses will show that the composition of peat or turf
is very various. The varying and dissimilar effects produced
by turf ashes may probably be owing to this variety of composi-
tion. Turf ashes in a general way may be used as a substitute
for gypsum; but this is upon the presumption that they con-
tain lime, either in the state of carbonate or of sulphate. The
Vassy turf ashes, for example, may be employed for gypsing
416
PEAT ASHES.
meadows, inasmuch as they contain a quarter of their weight of
sulphate of lime.
The ashes from pyritic turf ought not to be used without
great circumspection; they usually contain a quantity of iron
pyrites which has not been destroyed in the burning, and which
exposed to the action of the air, gives rise to the formation of
green vitriol or sulphate of iron, which may prove prejudicial to
vegetation. These ashes are generally of a red colour, and
very heavy in consequence of containing a quantity of the oxide
of iron. Good turf ashes ought to be white and light; the
sack ought to weigh something less than a hundred weight.
Schwertz recommends us to keep them from the wet; but at
Bechelbronn, where we use large quantities of peat ashes, we find
no ill effects from leaving them exposed to the rain; frequently,
indeed, we moisten them with water from the dunghill, in order
to add to their properties as a mineral manure, those that be-
long to organic manures. On the whole, however, it is certainly
better for many reasons to keep them dry; they are more easily
carried, and they are more easily spread.
Turf ashes of a good quality, that is to say, which include in
their composition a large proportion of calcareous and alkaline salts,
are adapted to crops of every description; but it is upon clover
especially that their influence is truly surprising. This fact is
well established in Flanders; but one must have employed them
oneself to have any adequate idea of the improvement they pro-
duce. There is no risk of giving too large a quantity. In
winter, when we have peat ashes at our disposal, we give as many
as 60 bushels per acre to our clovers; we scatter them even
upon the surface of the snow, and distribute them by means of
the rake in the spring. The Dutch use these ashes in still
larger quantity, applying at two different times from 100 to
160 bushels per acre to their clover fields. According to Sin-
clair, the Dutch also make use of an ash procured from a turf
which during winter is in contact with brackish water, a circum-
stance which renders this ash particularly rich in alkaline salts.
It is sowed by hand in the spring upon clover, and the following
year an abundant crop of wheat is obtained. The same material
is also used in the cultivation of the hop; and it is said, that
ALKALINE SALTS.
417
administered in small quantity to the roots of the bine, they pre-
serve the plant from the attacks of destructive insects.
Coal ashes. Coal, like the two last combustible materials, is
the product of vegetables, which however have undergone such
a change as to have lost almost every trace of organization. Coal
of different kinds contains from 1.4 to about 2.3 per cent of
ashes, and about two per cent of azote. The ash of a variety
of coal of very excellent quality gave of:
Argillaceous matter (silica ?) not soluble in acids
Alumina
Lime
•
Magnesia
Oxide of manganese
Oxide and sulphuret of iron
Coal ash also contains very minute quantities of alkaline salts
which usually escape analysis when they are not especially in-
quired after. One specimen analysed in my laboratory gave
nearly 00.1 of alkali. Coal ash is particularly useful on
clayey soils; it acts by lessening the tenacity of the soil; and
farther, doubtless, by the introduction of certain useful princi-
ples, such as lime and alkaline salts.
OF ALKALINE SALTS.
62
5
6
8
3
16
100
It is impossible to doubt that salts having potash and soda
for their base are useful in agriculture. The influence of wood
ashes, and of paring and burning, is unquestionable; and they are
so, in some considerable degree at least, in consequence of the salts
of these bases which they supply, and which always enter into
the constitution of vegetables. There are even certain crops
which, in order to thrive, require a particular alkali; the vine,
for example, the fruit of which contains bitartrate of potash, and
sorrel, which contains the binoxalate of the same base, must
needs have supplies of potash. The plants which are grown for
the production of soda, the Salsola, &c., from which barilla is
made, must come in a soil that naturally contains a salt of
soda, such as that of the sea-shore.
E E
418
MANURES- -NITRE.
It would appear, however, that the salts of soda or potash,
must not exceed a very small proportion in the soil. All the
experiments that have yet been undertaken with a view to ascer-
tain the action of different saline substances on growing vege-
tables, have led to no very certain conclusion but this, that they
must be used very sparingly. M. Lecoq has published an ac-
count of some experiments, made apparently with great care,
which go to prove that common salt in the dose of from 1 to
24 cwts. per acre, favoured the growth of barley, wheat, lucern and
flax. Chloride of calcium and sulphate of soda, he also found
to have the same good effects. M. de Dombasle, however,
came to conclusions totally opposed to them, with reference es-
pecially to common salt, which, applied in the doses advised by
M. Lecoq was not found to produce any sensible effect. M.
Puvis also obtained results that were equally negative. It would
perhaps have been well had M. Lecoq begun by determining the
proportion of alkaline salts which existed previously in the soil
on which he conducted his experiments. If he operated on
a soil that was either destitute of these salts, or that contained
them only in minimum proportion, very probably he did good
by adding them.
Nitrate of potash has been repeatedly recommended as an
agent useful in agriculture. The conclusions that have been
In the
come to however from its use, are far from accordant.
processes or modes of using nitre to the soil, it is not uncom-
mon to find it associated with soot, or with vegetable mould,
substances which required no assistance of any kind to constitute
them powerful manures, and the addition of which is there-
fore calculated to raise strong doubts of the advantageous
qualities ascribed to nitre alone. Were the advantages of ni-
trate of potash much less questioned than they are, however, the
high price of the salt would probably always oppose insuperable
obstacles to its employment. This is the reason in all likelihood
that has turned the attention of English agriculturists for several
years past to nitrate of soda, a salt that is imported in quantity from
Peru, and of which the price per cwt. may be about 40 shillings;
a price which, were it found really useful, would permit of its
being used. Admitting the accuracy of the experiments that
NITRATE OF SODA.
419
have been made, indeed, we cannot doubt the efficacy of nitrate
of soda on soil already furnished with organic manure. The
quantity that has been recommended is about 1 cwt. per acre.
Mr. Barclay made a few experiments after having heard much
of the nitrate of soda from his neighbours, of the results of
which the following examples will suffice to give a comparative
estimate:
Without nitrate.
With nitrate.
Wheat. 31 bush. 2 pecks.
31 bush. 2 pecks. 35 bush. 3 pecks.
20cwt. Oqrs. 19lbs. 23cwt. 2qrs. 26lbs.
Straw
Difference in favour of
the nitrates.
4 bush. 1 peck.
3cwt. 2qrs. 7lbs.
The produce of the land treated with nitrate, however, did not
fetch so high a price at market as that grown without it; and
every item of expense taken into the reckoning, the use of the
nitrate was attended with no commercial benefit. Still this
does not militate against the fact, that the production of vege-
table matter was increased upon land treated with the nitrate of
soda. And indeed much of the information which M. de Gourcy
collected in England, is of a kind that tends to confirm the
favourable influence of this salt on vegetation. Wheat, clover,
and Swedish turnips are particularly specified as benefitting from
its use.
These facts admitted, we may ask how does the
nitrate of soda act? The chemical constitution of the nitrates
is such, that we might conceive their acting at once as mineral
and as organic manures. The important point for solution was
to ascertain whether the azote of the nitrate contributed in any
way to the formation of the azotised principles of plants. Davy,
in taking with much distrust the report of Sir Kenelm Digby's
experiments on the influence of nitre in the cultivation of barley,
shows no disinclination to believe that the azote of the salt may
concur in the production of albumen and gluten.* This, how-
ever, is a point in physiology which may be put to the proof by
experiment, and seems peculiarly worthy of being tested in this
way. I have admitted it as extremely probable, that the azote
of the azotised principles of plants has its source either in the
ammonia, which is the special ultimate product of the organic
manure we employ, or in the azote of the atmosphere in both
* Agricultural Chemistry.
EE 2
420
MANURE-GYPSUM.
simultaneously; but the opinion which should maintain that the
ammonia derived from the organic constituents of the soil, passes
into the state of nitric acid before penetrating the tissues of
plants, would find support nearly in the same facts which I have
quoted as favouring the former view. We have seen, moreover,
in our general considerations on nitrification, with what facility
the azote of ammonia undergoes acidification in certain circum-
stances, a fact from which an argument of much potency for the
nitric acid theory naturally flows. I shall here add an observa-
tion to which I have, up to this time perhaps, attached too little
importance. When M. Rivero and I examined the highly irri-
tating and poisonous milky sap of the hura crepitans, we had
occasion to leave a considerable quantity of the water derived
from the sap, after separating the caseum, to itself; by the spon-
taneous evaporation of this water, we collected really a conside-
rable quantity of nitrate of potash. Since this time, I have had
occasion to note the same salt in the sap of several trees of the
tropics. In the leaves and fruit, however, I have never found
more than very minute quantities.
Gypsum, sulphate of lime, or plaster of Paris, is a com-
pound of 41.5 lime with 58.5 sulphuric acid; gypsum generally
contains a quantity of constitutional water, in which case it con-
sists of 79.2 sulphate of lime, and 20.8 water 100. This
hydrate of sulphate of lime is one of the abundant minerals on
the surface of the earth; it is met with in the crystalline state,
and in granular and fibrous matters in the strata of most recent
formation. It has no sensible taste, but is slightly soluble in
water, this fluid dissolving of its weight of the salt. Ex-
posed for some time to a white heat, it loses its water of consti-
tution, and passes into the state in which when ground it is
known under the name of plaster of Paris.
1
ठण
Gypsum is one of the most commonly employed of the
mineral manures. Its virtues appear not to have been unknown
to the ancients; but until lately its employment was limited to
a few circumscribed districts. It was only about the middle of
the eighteenth century that the Protestant pastor, Mayer, took
up the study of gypsum in the principality of Hohenlohe, pro-
ceeding upon certain information which he had obtained from
GYPSUM.
421
Hehlen of Hanover, in the neighbourhood of which, it was
employed as an improver.
By extending a knowledge of the virtues of gypsum, both by
his example and his writings, Mayer did great service to agri-
culture. Experiments were soon instituted in all quarters.
Tschiffeli in Switzerland, Schubart in Germany, and Franklin
in America, wrote on its effects, or practically demonstrated
them to the satisfaction of all. But it appears to be the fate of
all useful discoveries, of all happy applications of principles, to be
opposed at first and only to be admitted after having been
vainly disputed. The use of gypsum soon aroused formidable
opposition; and there is a curious episode in the history of the
paper war that was long carried on upon the subject which I
think worth noting. Among the most strenuous enemies of
the use of gypsum, were the proprietors of the salt-pans. They
declared that gypsum was not only incompetent to replace
schlot or the refuse of their pans, as had been proposed, but that
it was injurious; schlot was the only real improver, the stimulant
of stimulants, for which there was no substitute. But it turned
out by and by that the schlot of the salt pan was found to be
neither more nor less than sulphate of lime, than gypsum—the
article that was not only inefficient, but injurious. These
gentlemen were afraid that the use of gypsum extending, they
would want a market for their refuse.
The use of gypsum once introduced, extended rapidly in
France, particularly around Paris, whence it crossed the Atlantic,
and the fields of North America were actually manured with the
produce of the quarries of Montmartre. The lately cleared
lands of America abound in humus, and the plants indigenous
there, were most beneficially acted on by gypsum, which really
produced remarkable effects; in both the new and the old world
its power, as one of the most useful auxiliaries of vegetation,
soon appeared to be established.
We must not blind ourselves to the fact, however, that the
partisans of gypsum were guilty of exaggeration. They spoke
of the substance as an universal manure, capable of supplying
the place of every other, as advantageous for every description
of crop, as applicable to every variety of soil. Experience soon
set bounds to such indiscriminate laudation; it was found that
422
GYPSUM.
gypsum alone was inadequate to produce fertility, that it always
required the concurrence of organic manures, if the soil did not
contain them of itself; that it only acted beneficially on a
certain, and that a very small number of plants; lastly, that it
was upon artificial meadows, constituted by clover, lucern, and
sainfoin, that it produced its best effects; its action, on the con-
trary, being scarcely perceptible upon natural meadows, doubtful
in connexion with hoed crops and null with the cereals. These
negative results cannot be called in question; they were come
to by parties who were every way interested in having the
decision otherwise.
The best season for spreading gypsum is the spring, and
when the clover, sainfoin, or lucern, has already made a certain
degree of progress; calm and moist weather is the best for
laying it on. Opinion was long divided as to whether it should
be applied in its natural state, and simply ground, or first burned
and then ground. But it is now generally admitted that
burning adds nothing to the qualities of gypsum. Although
the usual practice is to sow or powder the meadows with the
ground gypsum, it is still acknowledged that good effects are
obtained from incorporating the substance with the soil. The
advantage of the practice of scattering it on in powder, so as to
adhere to the wet leaves of the growing plants, I find explained
in the equality of distribution which is by this means effected.
In some places, the number and extent of which are by no
means inconsiderable, no good effect whatever has attended the
application of gypsum, although it has been administered in
favourable conditions and in connexion with crops that else-
where derive the highest amount of advantage from its use.
This anomaly has been explained by assuming, without proving
experimentally, however, that the fact is so, that the soil in these
districts naturally contains a sufficient dose of gypsum. It
has also been said that gypsum produces no effect on low-lying
and damp soils.
The quantity of gypsum employed in different places, varies
greatly; from 1 to 16 cwts. per acre have been recommended.
The quality of the article employed has a great influence on this
question, to say nothing of the price, which in many places, is high.
The opinions of practical men, with regard to the advantages
GYPSUM
423
and propriety of applying gypsum, although they agreed in certain
determinate circumstances, were still far from being unanimous
upon every point. A particular inquiry into the subject was
therefore held worthy of its attention by the French government,
and a comprehensive report on all the information collected, was
made by M. Bosc to the Royal Central Agricultural Society of
France. This report shows in a striking manner the advantage
that may be derived from the lights of practical men; in a single
line or sentence we frequently find a summary of twenty or thirty
years of experience. It is, however, indispensable to go to these
gentlemen for their information; the agriculturists who devote
themselves to cultivation, it is notorious, write very little, and
those who spend very little time in this way, on the contrary write
a great deal. It may be that the reason for the silence of the
one, is that also for the eloquence of the other.
The following series of questions and answers I believe to
embrace most of the points connected with the employment of
gypsum, that are of interest.
Of
1st. Does plaster act favourably on artificial meadows?
43 opinions given, 40 are in the affirmative; 3 in the negative.
2nd. Does it act favourably on artificial meadows, the soil of
which is very damp? Unanimously, no. Ten opinions given.
3rd. Will it supply the place of organic manure, or of vegetable
mould? i. e. will a barren soil be converted into a fertile one
by the use of plaster? No, unanimously. Seven opinions given.
4th. Does gypsing sensibly increase the crops of the
cereals? Of 32 opinions, 30 negative, 2 affirmative.
The information thus obtained, valuable as it is, cannot yet be
held to embrace everything that seems desirable. Happily all
that was wanting has been supplied by the individual inquiries
of Mr. Smith in England, and of M. de Villèle in France.
The soil upon which Mr. Smith made his experiments was
light, with a substrate of chalk; the vegetable earth was a yard
in depth at the top of the field, and lessened gradually, in such
a way that at the bottom it was but three inches thick. Every
precaution was taken that the respective breadths contrasted
should be as nearly as possible in the same circumstances.
The following table shows the results:
424
GROWTH OF SAINFOIN UPON SOILS GYPSED AND UNGYPSED IN
1792, 1793, and 1794.
experiment.
Number of
1
2
3
GYPSUM.

Remarks.
Crop on the deeper ungyp-
sed soil
Crop upon the contiguous.
breadth, which had re-
ceived about 15 bushels
of gypsum in April 1794
-
Difference in favour of the
gypsed breadth
Crop upon the same soil,
of less depth, and not
gypsed
Crop on contiguous soil,
dressed with about 15
bushels of gypsum in
April 1792
Difference in favour of the
gypsed breadth
Crop on the same soil, 3
inches deep, and not
gypsed
Crop on contiguous soil,
dressed with about 15
bushels of gypsum, 17th
May, 1794.
Difference in favour of the
gypsed piece
4 Crop on the contiguous soil
of experiment, No. 3,
gypsed with the same
dose in May, 1792
Difference in favour of the
crop gypsed twice, at
an interval of two years
Dry herb
per acre.
lbs.
3357
5462
2105
2766
4381
1615
2068
4879
4310
Seed
per
acre.
2242
lbs.
419
582
163
245
379
134
2811 145
Weight
of total
crop.
lbs.
3776 100:12.5
6044 100: 10.7
2268
Proportion
of stalk to
seed.
3011100:8.9
4760 100: 8.7
1749
66 2134 100: 3.2
211 5090 100: 4.3
2956
205 4515 100: 4.8
139 2381
GYPSUM.
425
cwts.
5
These results show to what extent gypsum is favourable to
the production of sainfoin. The crop from the unplastered
breadth being taken as 100, that upon the plastered breadth is
231; it is more than doubled. The influence of gypsum was
also found by Smith to extend to grain; assuming the grain
crops on the ungypsed land at 100, those on the gypsed
soil were 192; they were nearly doubled.
On comparing the weight of the herbaceous portion of the
sainfoin to that of the seed produced, widely different relations
are apparent. These Mr. Smith attributed to the different
In
depths of the vegetable soil in different parts of the field.
the first experiment, where the relative proportion of seed is
highest, the arable soil was three feet in thickness: the other
crops were taken from parts where the depth of vegetable mould
was considerably less. Thus the gypsed soil produced at the
rate per acre :
In the first experiment of
In the second experiment of 3
In the third experiment of
qrs. lbs.
0 22 the depth of soil being 3
1 15
1
0
1 3 15
feet. in.
3
7/1/20
4
With this interesting fact before him, Mr. Smith imagined
that soils of little depth wanted some principle essential to fruc-
tification, which gypsum, in spite of the unquestionable assistance.
it gives, is yet incompetent to supply. This principle is in all
probability organic matter, which is naturally more abundant in
the layer of true vegetable mould which is deepest.
Mr. Smith's observations on white clover were quite as de-
cisive in favour of gypsum as those on sainfoin, and are con-
firmatory of the conclusions of the generality of farmers on the
subject. The gypsum in connexion with this crop was applied
in the dose of six bushels per acre, on the 22nd of May, a date
at which the clover looked pale and seemed to want sap. A
fortnight afterwards, the effects of the gypsum were obvious;
although no rain had fallen in the interval, the clover had become
vigorous, and soon formed a covering thick enough to protect
the ground from the scorching rays of the sun, which burned up
all the parts that had not been gypsed.
E E 3
426
GYPSUM.
COMPARATIVE GROWTHS OF WHITE CLOVER, GYPSED AND UNGYPSED,
BY MR. SMITH.
A. Gypsed
A. Not gypsed
Difference.
EXPERIMENTS.
B. Gypsed.
B. Not gypsed
Difference.
KIND OF
Light, dry, ex-
posed to the
south, 6 to 9
inches deep,
and on chalk.
Stony clayey,
moist, about
16 inches deep
on a stiff clay.
•
Number of
experiments.
Crop.
Gypsum
per acre.
Herb or
stalk per
acre.
The mean of these two experiments shows that the crop of
white clover on the ungypsed land being 100, that on the
gypsed is 225,-twice as much and a quarter.
The experiments of M. de Villèle may be viewed as supple-
mentary or complementary to those of Mr. Smith. They were
performed in the south of France, in accordance with the routine
that is generally followed, viz.: clover-hay, or sainfoin, previous
to grain, upon soils of considerably different nature, and with
doses of gypsum that varied from 8 to 3 on the same extent of
surface. His conclusions or crops are stated in the
following
table:
NO
lbs.
2226
839
1387
2270
500
1770
1 Clover 4 0 10
Seed
per acre.
Dry crop in
the gypsed
ground per
acre.
lbs.
316
56
260
174
61
113
Total weight|
of the crop.
Ibs.
2542
895
1647
2462 100: 7.6
1478 100: 7.0
984
Dry crop on
meadow not
gypsed
per acre.
cwts. qrs. lbs. cwts. qrs. lbs. cwts. qrs. lbs. cwts.
1 Sanfoin 6 2
2 16 18 0 1 10
2 1
2 Sanfoin
2 27 16 1 13 16
3 Sanfoin 4 3
0 3 17 0 21 9
5 28
23
32
18 27
13
22328293
Proportion
of herb to
seed.
Excess of the
crop gypsed
over the
crop not gyp-
sed.
223
40
3 19 20
23 33 10 4
2 Clover 5 2 20 32 2 27 19 2 16 13 0 11 21 86
100 :4.3
100: 6.7


20
10
Money value of
the excess of
forage.
Cost of the
gypsum em-
ployed.
Profit from the
use of the gyp-
sum.

qrs. lbs. s. d. s.
2
15 18
13 27
06
9 2
1
3 8 16 85
d. s.
d.
910 10
8 25 0
211 2
4/30
011
The unquestionable fact of a mineral salt stimulating the
growth of certain plants in so remarkable a manner as to double
4
7
GYPSUM.
427
and even to triple the usual quantities grown per acre, naturally
aroused the curiosity of mankind to inquire into and endeavour to
discover the cause. Explanations in abundance have been pro-
posed; but so little satisfactory in general, that I do not think
myself bound to mention them all. I shall limit myself, indeed,
to two; one proposed by Davy some time ago, and one advo-
cated by Liebig very lately.
Davy assumes that the plants of artificial meadows simply
absorb sulphate of lime. He assures us that he had found a
large proportion of this salt in the ashes of vegetables grown in
soil which had been treated with turf ashes abounding in the
substance. He believed that the gypsum entered particularly
into the constitution of the woody fibre. And it is not unin-
teresting to observe, that the plants which gypsum certainly
favours in the highest degree, are of very rapid growth; and
that in all probability they would find it difficult to obtain the
whole of the sulphate of lime they require from ordinary or
ungypsed soils within the period of their growth. Let it
not be forgotten, however, that if it be true that saline substances
are indispensable to the organization of plants, it is also true that
these substances can only be absorbed within certain limits; a
salt the best calculated by its nature to aid vegetation, would
become injurious by its excessive proportion did the water
which moistened the general soil contain too large a proportion
of it in solution: if a plant languishes when it has not enough
of one or other of its natural saline constituents, it also dies
when furnished with the same substance in excess.
Let us now remember that salts can only act on vegetables in
the state of solution, and we shall understand how those only
which are but sparingly soluble, can ever be advantageously
employed in agriculture. Water, in fact, having the power to
dissolve only a very limited quantity of the mineral manure,
will present it to the growing plant nearly in a constant quantity,
so long as the soil contains any fair proportion of the substance.
It is in this way precisely that gypsum appears to gain its su-
periority over the generality of mineral or saline manures; water
does not take up more thanth part of its weight before it
becomes saturated; a certain proportion of the moisture of the
428
GYPSUM.
earth being dissipated by evaporation, there is forthwith a pre-
cipitation, of sulphate of lime; but the moisture that remains
is nevertheless charged as before, neither more nor less, and
in the fittest state, as it seems, to administer to the wants of
the growing plant. If instead of sulphate of lime we suppose
some salt that is much more soluble, sulphate of soda for
example, we have nothing of the same state of equilibrium
between the quantity of moisture and its charge of saline
ingredients maintained. Supposing the moisture of the ground
to holdth of sulphate of soda in solution, and this quantity
calculated to produce good effects upon growing vegetables;
suppose now that a drought sets in, which by dissipating one
half of the moisture, increases the charge of saline matter
toth of its bulk, it may very well happen that this propor-
tion, instead of proving beneficial, will be felt as injurious to
vegetation.
The hypothesis of Davy, supported by these ingenious views
of M. Chaptal, would therefore lead us to regard gypsum as
behaving to plants in the same general way as the insoluble salts
which usually form an element of the soil or of manures, the
phosphate and carbonate of lime, in particular, salts which are
made apt to enter the tissues of plants by the carbonic acid
which is found in all the water that falls from the clouds and
that moistens the soil, and which has the property of dissolving
small quantities of them. But whilst the strength of these
solutions, weak at all times, is liable, through atmospherical
vicissitudes to vary, when the mere traces of saline matter which
at best they offer at any time are inadequate to meet the de-
mands of a crop disposed to grow rapidly and luxuriantly, such
as clover, sainfoin and lucern, the solution of sulphate of lime,
of the same strength at all times and under all circumstances,
is ready to supply the plants with the mineral substance they
require, however rapid and vigorous their growth.
The theory of the action of gypsum proposed by Professor
Liebig is extremely ingenious. He admits, with M. de Saus-
sure, the presence of carbonate of ammonia in the atmosphere,
and consequently in rain water. This fact established, and it
appears undeniable, the influence of gypsum would consist in its
GYPSUM.
429
faculty of fixing the infinitely small quantity of carbonate of
ammonia which is brought down by the rain and the dew,
and so preventing its dissipation on the return of drought and
sunshine. Carbonate of ammonia, in fact, as we have already
seen, when speaking of manures, in contact with the sulphate
of lime decomposes this salt, carbonate of lime and sulphate of
ammonia being formed. I shall by and by inquire whether the
reaction that takes place is of the precise nature of that here
stated; but admitting, for the present, that it is, it would still
be competent for us to ask if the quantity of ammonia condensed
in this way was likely to suffice for the production of such de-
cided effects as we frequently witness in connexion with the
crops that are assisted by gypsum.
Professor Liebig observes that a pound of sulphate of lime
once converted into sulphate of ammonia, would introduce
into the soil a quantity of ammonia equivalent to that which
would be afforded it by 6.250 lbs. of horse's urine; a showing
upon which it would be easy to demonstrate, taking the compo-
sition of sainfoin to be as I have shown it, that a pound of plaster
fertilizing the ground to this extent, would be adequate to in-
crease one hundred-fold the quantity of dry fodder produced.
According to my manner of viewing this question, it must be
examined on a totally different basis. It is certain, for instance,
that gypsum has no effect upon natural meadows; positive ex-
perience has satisfied me of the absolute inutility of the substance
here; so that upon my natural meadows at Bechelbronn, I now
never employ a particle of it. But let us review Professor
Liebig's theory in connexion with the production of sainfoin and
clover, which in a general way derive an advantage from gypsum,
which no one disputes.
Our harvest of clover, taken as dry, amounts on an average
from strongly gypsed land, to 2 tons 1 cwt. very nearly per
acre; and this quantity agrees pretty well with that which ap-
pears common in Germany. It is generally allowed that by
gypsing we double the produce. It would follow from this,
that an acre which had not been gypsed, would yield no more
than 20 cwts. of dry clover; in my opinion the reduction
would be still greater. Dry clover hay, made from the plant
430
GYPSUM.
cut when in flower, contains about 2 per cent of azote. The
20 cwts. of forage gained by the intervention of the gypsum
would consequently contain 110lbs. of ammonia, equivalent to
134.2lbs. carbonate of ammonia. This consequently is the
quantity of carbonate of ammonia which the gypsum ought to
have been the means of procuring from the rain which falls upon
an acre of land during the time that clover is upon the ground,
in order to furnish the azote contained in the increased quantity
of the crop.
1
Now in Alsace, from the time of gypsing in April, to the
time of mowing in July, there falls on an average 3.92, nearly
4 inches of rain, which would amount in round numbers to
982 tons per acre. Were the azote of what may be spoken of
as the surplus produce, derived from the rain in fact, all the
water that falls ought to contain 17000 of its weight of carbonate
of ammonia. It is very questionable, however, whether any such
proportion of ammoniacal salts exist in rain-water; yet the pro-
portion ought to be very much greater, inasmuch as we have
supposed the whole of the rain that fell to penetrate the ground,
none of it to run off; but the truth is, that a very considerable
proportion of the rain that falls never sinks into the soil; once
the surface is thoroughly soaked, much that falls drains off,
passes away by the ditches, and is lost with all it may contain
that would prove beneficial to vegetation. It is in fact alto-
gether impossible to make any approximation, even of the
roughest kind in regard to the quantity of rain-water that soaks
into and that runs off the ground; and thus no kind of estimate
can be formed of the relation between the moisture absorbed by
plants, and that which escapes direct by the evaporation, without
passing through them at all.
But even in admitting that it was really the ammonia con-
tained in the rain-water, to which the very considerable increase
of the crop of clover, lucern, and sainfoin was owing, it would
still be left for us to explain wherefore, meteorological and other
circumstances remaining the same, the same relative effects were
not produced upon natural meadows covered with grasses, upon
hoed crops, such as beet and turnips, and upon wheat; finally,
the most serious objection that can be urged against this theory
GYPSUM.
431
is founded upon the fact, that gypsum has no truly beneficial
effect upon artificial meadows, save and except when the soil to
which it is applied contains an adequate proportion of azotised
organic manure. In a moderately manured soil, gypsum, as all
the world knows, produces no sensible improvement: and as
M. Crud, one of those men whom long experience has placed
at the head of practical farming, said: It is to throw away both
money and trouble to put gypsum upon an unkindly and im-
poverished bottom. It would seem, however, that if gypsum
really fixes ammonia in the soil, in consequence of its action
upon the rain-water that falls, converting its carbonate into sul-
phate of ammonia, the ammoniacal salt once introduced into
the soil, ought to act independently and without the concur-
rence of another manure. That it really does act isolatedly, and
of its own proper force when it exists, has been proved by the
experiments of M. Schattenmann, who demonstrated on the
large scale the beneficial effects of the sulphate of ammonia
directly applied to natural meadows. It is obvious, that if the
theory which I discuss be true, the great number of practical
observations which I have quoted must necessarily be false; or
on the contrary, these observations being accurate, the theory
must be erroneous.
G
I have given reasons for maintaining the accuracy of the prac-
tical results; nevertheless, the better to establish this conviction,
I have thought it advisable to add a few facts to the many that
are already extant. I was, therefore, induced to undertake a
series of experiments with a view to study, independently of all
hypothetical idea, the action of gypsum upon certain hoed crops
and cereals.
These experiments were made upon patches of land of 480
square yards each. Every precaution was taken to render the
experiments strictly comparable one with another. Thus the
ground appropriated to each particular crop was divided into
three equal contiguous zones. The first zone, A, always received
gypsum in the ratio of 4 bushels per acre. The second zone,
/1/1/0
B, and the third zone, C, were not gypsed. Each zone was
sowed with the same quantity of sced, or planted with an equal
number of beet plants or potatoes. A and C were the surfaces
EE 4
432
MANURE-GYPSUM.
which I proposed to myself to contrast; the intermediate zone,
B, was a kind of neutral ground employed merely to prevent
the immediate contact of the gypsed with the ungypsed
I may here remark, that it would be well always to take
such a precaution in making experiments on the effects of diffe-
zone.
rent manures.
In 1842 I tried the effect of gypsum upon wheat coming
after three different crops. 1st. After clover ploughed in. 2nd.
After beet-root. 3rd. After potatoes.
The gypsum was applied the 19th of May, at which time the
wheat looked extremely well. The crop was cut between the
21st and 26th of July, and the following are the results ob-
tained :
Crops.
Wheat after clover
Wheat after mangel wurzel
Wheat after potatoes
Average of the three experiments
Year 1843.
Rye with gypsum
Rye without
Weight of grain, corn, and straw.
A. piece gypsed. B. not gypsed. C. not gypsed.
319lbs. 323lbs. 327lbs.
176,,
158,
195
235
250,,
Oats with gypsum
Oats without
Sheaves.
lbs.
517
473
Wheat with gypsum . 463
Wheat without
510
Wheat without
453
The year 1842 having been unfavourable to wheat in conse-
quence of the long drought, the experiment required to be re-
peated. This was done in 1843; and it must be allowed,
that an experiment could scarcely be conducted under circum-
stances of weather more favourable to the cultivation of grain;
the results here are given for equal spaces of three French
acres, equal to 360 square yards. The gypsed zones had
been treated with 72lbs. of sulphate of lime each :
"
330
368
در
137
127
248,
147
156
143
""
112
113
158
264
250
Grain. Straw, chaff, and waste.
lbs.
lbs.
379
345
""
315
354
310
""
217
255
GYPSUM.
433
From these numbers it is obvious that gypsum produces no
appreciable effect upon wheat, oats, and rye, conclusions that
agree with those come to in the previous year.
EXPERIMENT WITH FIELD-BEET OR MANGEL-WURZEL, OPENING THE ROTA-
TION WITH MANURED SOIL, 1842.
The plants were transplanted and watered, and the gypsum
was applied at the time of earthing up; a good deal of rain fell,
and shortly after having been laid on, the gypsum had become
incorporated with the ground. The crop was gathered on the
8th of October, three months after the gypsing, and from two
equal surfaces, each of 242 square yards in extent, weighed as
follows:
From the gypsed ground
From the ungypsed
•
13 cwt. 2 qrs. 6 lbs.
3
12
2
>>
The gypsum would therefore appear to have had no beneficial
effect; for the difference in favour of the gypsed piece is so
trifling, that it cannot be reasonably ascribed to the mineral ma-
nure: in fact, the quantity obtained from the gypsed surface
does not exceed that which we constantly take from fields in the
ordinary course of cultivation, and which have received no
gypsum.
The action of gypsum, limited as it is to certain crops, will
not allow us to admit that it produces its effect by fixing in the
ground the carbonate of ammonia contained in rain-water; were
it connected with any fixation of ammonia, it would be mani-
fested generally, and not in particular instances only. Davy's
theory therefore appears the more plausible, and requires discus-
sion. Did the ashes of the clover grown in gypsed soils ac-
tually contain a large proportion of sulphate of lime, as affirmed
by the illustrious English chemist, the action of gypsum would
be readily understood. The whole question, therefore, seems to
turn upon the composition of the ashes.
I have analysed the ashes of clover grown at Bechelbronn,
without and with the concurrence of gypsum. I shall here give
the conclusions come to in 1841, a year remarkable for the heavy
crops of clover, and those also for the year 1842, when the clover
F F
434
GYPSUM.
crop was but indifferent. The first table contains the results
in the order in which they were registered; the second contains
those obtained after the deduction of the carbonic acid and car-
bon which had remained in the ashes examined :
Carbon and carbonic acid
included.
Carbonic acid
Chlorine .
Phosphoric acid
Sulphuric acid
Lime
•
Magnesia
Oxide of iron, man-
ganese; alumina
Potash
Soda
Silica
Loss and charcoal.
Chlorine
Phosphoric acid
Sulphuric acid
Lime.
•
Potash
Soda
Silica
•
Magnesia
Oxide of iron, man-
ganese; alumina
Extraordinary Crop of 1841.
Ashes of Clover.
Ungypsed.
14.2
3.4
8.0
3.2
23.7
6.3
1.0
19.6
1.0
16.8
2.8
100.0
4.1
9.7
3.9
28.5
7.6
1.2
23.6
1.2
20.2
100.0
Gypsed.
22.1
2.9
6.9
2.6
22.4
5.1
Carbonic Acid and Loss deducted:
0.6
27.8
0.7
7.9
1.0
100.0
3.8
9.0
3.4
29.4
6.7
1.0
35.4
0.9
10.4
100.0
Unfavourable Crop of 1842.
Ashes of Clover.

Ungypsed.
21.5
2.5
5.4
2.4
25.4
5.6
0.5
22.5
2.2
10.0
2.0
100.0
3.3
7.1
3.1
332
7.3
0.6
29.4
2.9
13.1
100.0
Gypsed.
26.8
2.2
5.8
2.3
26.7
7.4
traces.
25.3
0.2
2.7
0.6
100.0
3.0
8.2
3.2
36.7
10.2
traces.
34.7
0.3
3.7
100.0
The analyses here do not indicate the modes in which the
various substances found were combined in the ashes; but sup-
posing that the whole of the sulphuric acid existed in combina-
tion with lime, which it most probably did, the preceding results
would meet us in the following shape: the ashes of the clover
GYPSUM.
435
grown upon soil without gypsum contain 6.0 per cent of sul-
phate of lime; those of clover grown upon a soil with gypsum,
5.7 per cent.
As it is impossible to answer for so small a difference as
3100 parts in researches of this kind, we must presume that the
two ashes contained the same proportions of sulphate of lime.
Here, however, as in all other agricultural questions, isolated
analyses throw but little light on the subject of inquiry. In
order that they may enable us to arrive at any definite con-
clusion, two new elements must be taken into the discussion:
1st. The proportion of ash furnished by a given weight of the
forage gathered; 2nd. The quantity of forage yielded by a
given surface before and after the use of gypsum.
I have taken from my own observations the quantity of dry
forage yielded by the two cuttings of 2nd year's clover after
gypsum, as amounting to 41 cwt. per acre. The same surface
in the 1st year, and before the use of gypsum, would have pro-
duced but 9 cwt. 100 of dry clover gave:
Clover ungypsed
Idem
Clover gypsed
Idem
Year 1841.
Fallow ungypsed
Ditto gypsed
•
Year 1842.
Fallow ungypsed
Fallow gypsed
•
•
•
MINERAL SUBSTANCES IN THE CROP FROM 21 ACRES.
Ο
Chlorine.
Phosphoric acid.
Year.
Ashes.
1841
12.0
1842 11.2
1841
7.0
1812
7.7
Sulphuric acid.
lbs.
lbs.
lbs.
10.1 24.2 96
22.6 53.2 20.2
Lime.
lbs.
70.8
174.6
6.6 15.4 6.6 708
184 50.3 19.8226.1
Ashes freed from
carbonic acid
per cent.
10.3
8.8
5.4
5.6
Magnesia.
lbs.
189
39 8
Oxide of iron, man-
ganese, alumina.
Per acre.
Potash.
103 lbs.
89
248
257
Soda.
>>
>>

Silica.
Ashes freed from
carbonic acid.
lbs.
Jbs.
lbs.
lbs. lbs.
3.0 58.7 3.0 48.9. 248
5.9 210.3 5.2 61.8 594
15.6 1.3 62.9 6.1 27.9 234
62.7
213.8 1.7 22.8 616
It is therefore obvious, that in the course of the three months
which followed the application of the gypsum, the soil must have
FF 2
436
supplied the plant with very considerable quantities of mineral
substance; the crops taken from the gypsed soils contained
in fact two or even three times the quantity of these substances
which those grown previously to the gypsing contained. Repre-
senting, for example, by unity the quantity of the several bases and
acids of the crop grown without gypsum, we should have the
quantities of the same principles contained in the crops produced
upon the gypsed soils represented by the following numbers:
Chlorine.
1841 2.2
1842
2.8
Phosphoric
acid.
2.2
3.3
GYPSUM.
Sulphuric
acid.
2.1
3.1
""
Lime.
2.5
3.1
1841, Sulphuric acid 4.8
1842,
6.0
Magnesia and Potash and
metallic oxide.
soda.
3.5
3.2
Silica appears to form the only exception here, which would lead
us to conclude that this earth was only absorbed by clover in the
first period of its growth. Potash and lime are the bases which
enter in largest proportion into the mineral constitution of clover;
and there is another fact made evident which deserves particularly
to fix attention: it is that the lime assimilated subsequently to
the gypsing, bears no kind of relation to the quantity of sulphuric
acid fixed during the same space of time. The excess of acid
and of lime obtained from the ash of the gypsed clover over that
of the ungypsed, is for:
""
2.1
3.7
Lime 47.2
70.6
"
Supposing further, that the sulphuric acid assimilated subse-
quently to the gypsing was taken up in the state of sulphate of
lime, we find that:
In 1841 the gypsed crop absorbed 18 lbs. of this salt.
In 1842
22 lbs.
Silica.
1.0
1.0
"
These quantities are so small as to lead us to suppose that the
utility of gypsing consists in furnishing the plant with the large
proportion of lime which it seems to require. Gypsing would
then be equivalent to the application of lime; and in fact, ac-
cording to Schwertz, Paris plaster is replaced in Flanders by
slacked lime, by the lyc-washed ashes of wood, and by peat-ash,
with decided advantage.* Some peat-ash contains sulphate of
lime, others none at all. What is employed successfully, most
likely presents sulphuric acid in the state of an alkaline sulphate.
* Schwertz, Culture des Plantes fourragères, p.72.
GYPSUM.
437
Wood-ash, which is certainly the best manure for artificial
meadows, may contain upon an average one per cent of sul-
phuric acid, and when lye-washed, the proportion ought to
be much less; if perfectly washed, it ought to be null; at all
events, there is no sulphate of lime present to fix the ammonia
of the rain water. Independently of earthy phosphates, so
useful to all plants, lye-washed ashes frequently yield more than
80 per cent of chalk. We thus perceive in a general way, that
the manures which stimulate the vegetation of clover, are
always calcareous, the lime being either in the state of sulphate
or carbonate, which exists abundantly in the crops, combined
with organic acids and freed consequently of nearly the whole
of the inorganic acid with which it was originally associated.
Assuming that gypsum acts like chalk, it may be conceived that
when the former is incorporated with the indispensable manure,
it is decomposed, and carbonate of lime, in a state of minute
division, and for that reason easily absorbed, is the result.
is only upon this supposition that I can understand the elimina-
tion of the sulphuric acid of the gypsum; for if the lime really
entered the vegetable in the state of sulphate, the ashes ought
to be much richer in that acid than analysis shows. This same
difficulty occurs in the hypothesis of Liebig. If the 56 lbs. of
ammonia derived from the atmosphere penetrated the plant in
the form of sulphate, there must enter at the same time 130 lbs.
of sulphuric acid, and which ought to be recovered in the ashes
of the crop from one acre. Now, the ashes of 41 cwts. of gyp-
sed clover, abstracting the carbonic acid, weigh 2 cwts. 8 lbs.
containing in the 100, 3 of sulphuric acid. But the amount of
ash, were the acid of the ammoniacal sulphate fixed in the crop,
would rise to 3 cwt. 1 qr. 20 lbs., and the ash would then con-
tain 70 per cent of sulphuric acid.
It
-
Before promulgating this last objection against received
theories, I thought it right to ascertain whether the ashes con-
tain in the state of sulphate, the whole of the sulphur pre-
existing in the incinerated plant. For it was not impossible
that at the high temperature employed, the silica might re-act
upon the sulphates so as to expel a portion of the sulphuric
438
GYPSUM.
acid. However improbable this expulsion, owing to the great
excess of potash always present in clover ash, it seemed expe-
dient to determine the fact.
After having made out as exactly as possible the quantity of
ash left by the hay, and also the sulphuric acid, I took a cer-
tain weight of the same hay, burned it in a platina crucible along
with a mixture of chlorate and carbonate of potash, and then
sought for the sulphuric acid in the product of the ignition.
1000 parts of the plant furnished directly 3 of sulphuric acid,
and by analysis of the ash, 2.8.
Thus, the alkaline ashes retain all the sulphur pre-existing
in the plant which produced them.
I have laid stress upon the small proportion of sulphuric acid
in a crop of clover, because there yet remains for consideration
a third theory of gypsing, which I have helped to propagate,
although doubtful concerning the author. This is founded upon
the assumption that the proportion of sulphur is much greater
in the leguminous than in the cereal tribe. Now, as gypsum is
generally adapted to the manurement of leguminous plants, the
origin of the sulphur has been ascribed to sulphate of lime
incorporated with the soil. This view appeared the more
plausible to M. Dumas and myself, inasmuch as in accordance
with it, plants operated as reducing agents. It is, besides, very
probable that sulphur as an immediate constituent principle
of vegetables, is derived from sulphates; but do leguminous
plants really contain more than the cereals? This seems doubt-
ful, since careful investigation of the azotised principles of plants
has shown gluten, cascine and legumine to be nearly identical
in composition. I moreover find upon analysis of the ashes, that
clover, haricots, and beans, do not sensibly contain more sulphur
than rye, wheat, oats, and potatoes. There appears to be no
doubt, therefore, that the sulphur required by plants is supplied
abundantly by the soil enriched with ordinary manure, as happens
in the culture of the cereals, roots and tubers.
In a word, it may be presumed that Paris-plaster acts usefully
on artificial meadows by introducing lime into the soil. This is
consistent both with the analysis of the ashes of the crops pro-
AMMONIACAL SALTS.
439
duced and of the soil; for according to the researches of M.
Rigaud de l'Isle, gypsum operates only upon soils which do not
contain a sufficient dose of lime in the state of carbonate.*
OF AMMONIACAL SALTS.
The last products of the putrefaction of azotised matters being
ammoniacal combinations, it necessarily follows that salts having
ammonia for their base, must act usefully in vegetation. This
is confirmed by the employment of guano, and by experiments
in which ammoniacal compounds have been directly applied as
I have already pointed attention to the observations
of Davy relative to the favourable effect of carbonate of ammo-
nia upon the development of plants, and shall now detail some
recent trials made by M. Schattenmann with the sulphate and
muriate of the same base.
manure.
These salts were introduced into the soil as a solution mark-
ing one degree of Beaumé's areometer, and in the dose of
102 bushels per acre. In 1843, the effects produced upon
wheat by muriate and sulphate of ammonia were most distinct;
as was also the case with natural meadows, which yielded under
the influence of this liquid manure 82 cwts. of hay per acre,
precisely double the crop afforded by the same meadow land
without the salts of ammonia; but another important fact, and
which M. Schattenmann announces with confidence as having
been proved by repeated trials, is this; that solution of sulphate
of ammonia employed in the same dose, and at the same degree
of concentration, causes no appreciable melioration upon trefoil
and lucerne. The result of a solution of sal-ammoniac was
equally negative.
These observations agree in certain points with those formerly
made by Rigaud de l'Isle, and more lately by M. Lecoq. But
they are in direct opposition with the experiments of several
physiologists who have studied the action of ammoniacal salts
presented separately to vegetables, a circumstance very different
from that wherein ammoniacal solutions are incorporated with
arable land. Thus, M. Bouchardat has stated that young
* Mémoires de la Société d'Agriculture, année 1844.
↑ Bouchardat, Comptes rendus de l'Académie des Sciences, tom. xvi.
440
AMMONIACAL SALTS.
plants of mentha aquatica and sylvestris, and of mimosa pudica
die very soon, when made to vegetate with the roots plunged in
very weak solutions of muriate, nitrate, and sulphate of ammonia.
In offering, some years back, divers considerations upon guano,
I promulgated the opinion that ammoniacal salts, in order to
serve as azotised manure, must always contain organic acids
or carbonic acid. Perhaps the term useful salt may be now
restricted to the carbonate alone. At least, having watered
young plants of trefoil, grown in silicious sand, with solution of
oxalate of ammonia at th, I observed them die after the lapse
of eight or ten days. Plants of the same size, sown under like
conditions, but irrigated with distilled water, continued to grow,
and flowered.
1
600
In treating of gypsing, I have assigned my reasons against
admitting that the azote fixed during the culture of trefoil, pro-
ceeds from the sulphate or muriate of ammonia naturally ab-
sorbed. I again assert, that it is materially impossible that
ammoniacal salts combined with inorganic acids, other than the
carbonic, can be useful as manure to plants, when administered
separately; they can only become advantageous when their
composition has undergone modification.
Two cwt. (220 lbs.) of wheat-sheaves, (straw and grain), con-
tain upon an average 2 lbs. 1 oz. 14 dwts. of azote, and leave
after ignition, 11 lbs. 3 oz. 16 dwts. of ash, into which enter
1 oz. 7 dwts. of sulphuric acid, and 14 dwts. of chlorine.
In the ammoniacal salts:
100 of azote corresponds to 283 of sulphuric acid.
257 of chlorine.
""
Let us now consider sulphate of ammonia, which according
to the experiments of M. Schattenmann, supplied an excellent
manure for wheat. If the 2 lbs. 1 oz. 14 dwts. of azote con-
tained in the 2 cwt. of sheaves be derived from the sulphate
absorbed by the cereal, the sulphuric acid of the sulphate ought
to be recovered in its ashes; and according to the above
standard, these ashes ought to contain 6 lbs. 16 dwts. of sul-
phuric acid. They afforded by analysis only 1 oz. 7 dwts.
Applying the same reasoning to muriate of ammonia, we
AMMONIACAL SALTS.
441
find, supposing the azote of the 2 cwt. of sheaves to emanate
from this salt, that the ashes should contain 5 lbs. 6 oz. 2 dwts.
of chlorine; whereas they really contain but 14 dwts.
Without doubt, the nitrogenous principles of the cereal can-
not be referred solely to the ammoniacal salts in the trials of
M. Schattenmann; the manure given to the soil, and the at-
mosphere must have contributed a share. The appreciation of the
value of ammoniacal salts becomes more precise when the results
obtained on meadow land are estimated. There the produce
was doubled, and of every 2 cwt. of hay gathered, 1 cwt. may be
ascribed to the action of the salt.
Two cwt. of hay, containing 4 lbs. 16 dwts. of azote, leave
16 lbs. 2 oz. of ash.
If the half (2 lbs. 8 dwts.) of the azote of the fodder comes
from the ammoniacal salts, the ashes will contain :
lbs. Oz. dwts.
5
8
5
2
4 of sulphuric acid, if the sulphate has been used.
0
if the muriate has been used.
>>
})
Now, the ashes of the hay yielded by analysis
oz. dwts.
5
5
9 of sulphuric acid.
4 of chlorine.
:
It is then very probable that if the ammoniacal salts afford azote
to the plants, they enter not as muriate, sulphate, or phosphate,
because there is no reason to believe that acids united with an
alkali are eliminated almost in totality during the act of vegetation.
It necessarily follows, that the ammonia of these salts, in order to
yield to vegetables its constituent azote, must reach their organs
in the form of carbonate, inasmuch as that is the sole ammo-
niacal salt which seems to exercise a direct and favourable agency.
However, if such be the case, how comes it to pass, that am-
moniacal salts as the muriate, phosphate, and sulphate, are con-
verted into carbonate when once incorporated in the soil? Good
arable land almost always contains, it is true, carbonate of lime ;
but there is no ground for admitting an acid interchange be-
twixt the calcareous and ammoniacal salts. We know, on the
442
AMMONIACAL SALTS.
contrary, that carbonate of ammonia re-acts instantaneously upon
muriate and sulphate of lime, the products of this re-action
being on the one hand muriate and sulphate of ammonia, on the
other, carbonate of lime. The gypsum theory of Liebig is based
upon the fact of this double decomposition, whereby the ammo-
niacal carbonate of rain water is fixed in the state of sulphate
at the cost of the sulphate of lime put on the ground as manure.
This reaction of sulphate of lime upon carbonate of ammo-
nia is incontestible as a laboratory experiment; but in well
tilled grounds containing just the proper quantity of moisture,
the reaction takes place in the inverse sense. The carbonate of
lime reacts upon the sulphate of ammonia, and there result
carbonate of ammonia and sulphate of lime.
This fact, however singular at first sight, is explained upon
principles established by Berthollet in his chemical statics:
When two saline solutions are mixed together, and from
the mixture an insoluble salt results, the insoluble com-
pound is formed and precipitated. This is what happens on
pouring a solution of carbonate of ammonia into one of sul-
phate of lime. But, if instead of bringing the two salts to-
gether dissolved, they are mixed in a pulverulent state, and just
sufficient water is added to promote the reaction without dis-
solving the products, a volatile compound forms and is evolved,
namely carbonate of ammonia.
The experimental proof is easy, and not without interest.
chalk previously washed be intimately mixed with crystallized
sulphate of ammonia, no change ensues, provided the powders.
are very dry. Let moist sand be introduced so as to impart to
the mixture the consistence of light arable land of the usual hu-
midity; at the very instant vapours of carbonate of ammonia,
cognizable by their action on vegetable colours and their odour,
are developed. When water is added in excess, the disengage-
ment of ammoniacal vapour immediately ceases. The carbonate of
ammonia not yet volatilized, dissolves and acts upon the ready
formed gypsum so as to constitute sulphate of ammonia and
carbonate of lime. The ordinary reaction is restored. Fi-
nally, this watery mixture being exposed to the air, furnishes
If
AMMONIACAL SALTS.
443
anew ammoniacal vapours in proportion as the water vaporizes,
and the volatile salt is progressively evolved until the mass is
quite dry. In maintaining a similar mixture in a fit and con-
stant state of moisture we may in two or three days, under the
influence of a temperature of from 68° to 80° F., dissipate the
greater portion of the ammonia of the sulphate, and obtain a
quantity of sulphate of lime indicating the progress of the re-
action.
It is almost needless to remark that sulphate of lime, placed
in a condition of moisture analogous to that of the chalk, un-
dergoes no alteration from the carbonate of ammonia. Thus,
in the ordinary circumstances of humidity of cultivated land, it
is at least doubtful whether the plaster diffused through it de-
finitively retains the ammonia of the rain water in the state of
sulphate.
To estimate the sulphate of lime produced by the reaction be-
tween the sulphate of ammonia and carbonate of lime, the
mixture after having been entirely dried in the air is to be
treated with cold water. The lime of the sulphate dissolved is
next thrown down by oxalate of ammonia, and computed in the
state of carbonate.
In order to ascertain the presence of sulphate of ammonia
the mixture is to be digested in dilute alcohol, which dissolves
this salt without taking up sulphate of lime.
Muriate, phosphate and oxalate of ammonia comport them-
selves as the sulphate. Carbonate of lime decomposes them
under the same circumstances, giving rise to equivalent pro-
ducts.*
1. 15.4 grains of crystallized sulphate of ammonia incorporated with
five or six times its weight of chalk, gave after two days' exposure of the
moist mixture in the open air, 12.3 grs. of sulphate of lime. In another
experiment 16.0 grs. of sulphate of ammonia were obtained from 13.1 grs.
of calcareous sulphate. Now according to the proportions of ammoniacal
salt there ought to have been obtained 13 grs. and 14 grs. of sulphate of
lime. Thus about ths of the ammonia contained in the sulphate sub-
mitted to experiment had been converted into carbonate.
2. 16.9 grs. of sulphate of ammonia were mixed with 123.2 grs. of
chalk, and from 924 to 1071 grs. of silicious sand. The mixture was kept
444
AMMONIACAL SALTS.
The preceding facts may perhaps tend to reconcile the con-
tradictory results obtained in the application of ammoniacal salts.
as manure. When muriate, phosphate or sulphate of ammonia
is presented to plants, these salts produce no useful effect; they
are absorbed in limited quantity, like the majority of soluble
substances. But if instead of administering them separately
dissolved in water, as was done in the physiological experiments,
they are incorporated with a loose and humid soil, these salts
react upon the calcareous matter almost always existing in the
ground, and are transformed into carbonate of ammonia, which
exerts undeniably a favourable influence upon vegetation. From
these facts it may be presumed that the introduction of lime, and
marl, is not merely to supply the defective calcareous element,
but likewise a principle, carbonate of lime, which produces a
particular action upon the manure, changing, through double
decomposition the unassimilable ammoniacal salts there present
into a carbonate capable of being assimilated, which transmits
to the plant the azote of the organic matter of the dung and
the carbon contained in the calcareous rocks.
These reactions which go on between soluble salts and one that
moist and exposed to the air during four days, the temperature ranging
from 68° to 80° F. The substance, after being dried by the action of the
air, was set to digest in weak alcohol; the alcoholic liquor yielded only an
insignificant trace of sulphate of ammonia. There was about 18.5 grs. of
sulphate of lime.
3. A very simple means of determining the reaction in question consists
in plunging a fragment of chalk into a solution of sulphate of ammonia;
the fragment so imbued on being exposed to the air emits during several
days fumes of carbonate of ammonia. Several bits of chalk moistened in
the solution, and exposed by the aid of an aspirator to a continuous current
of air, afterwards washed in muriatic acid, disengaged enough of ammo-
niacal vapour to form in the acid nearly 15 grs. of sal-ammoniac.
4. With a slightly moistened silicious sand were incorporated 30.8 grs.
of gypsum; the mixture then watered with a solution containing 30.8 grs.
of carbonate of ammonia, was allowed to remain in the air during eight
days, having always the consistence and humidity of arable land. At the
end of this time it was dried, then treated with weak alcohol; the alco-
holic fluid evaporated left no sulphate of ammonia.
5. Phosphate of ammonia, mixed with chalk, and kept in a moist state
for some days, comported itself exactly as the sulphate in the same circum-
WATER.
445
is insoluble under the peculiar conditions united in arable land,
show that we must not always conclude as to what passes in the
ground from phenomena observed in the laboratory of the chemist;
and it is probable that by extending the study of these singular
reactions to alkaline salts generally, we shall better understand the
mode of action and utility of saline substances in agriculture.
Thus, for example, the operation of common salt as a fertilizer is
still very obscure. Many skilful husbandmen question its efficacy;
nevertheless, when moderately employed it seems to do good.
In plants growing on the sea coast soda is found in a great
measure combined with organic acids, and the chlorine deduced
by analysis from their ashes is nowise proportional to the alkali
they contain. The whole sodium does not enter the vegetable as
a chloride, but very likely as carbonate of soda, and that in
virtue of a reaction analogous to the one which calcareous matter
has upon ammoniacal salts.
It is quite certain that chloride of sodium in solution is
not affected by carbonate of lime; but then it was proved by
Clouet that if into sand moistened with this same solution
powdered chalk be put, and the mixture left in contact with air,
an efflorescence of sesquicarbonate of soda ere long makes its
appearance. Thus by the conjoint effect of capillarity and the
carbonic acid of the atmosphere, common salt in the conditions
above mentioned undergoes by contact with chalk a partial de-
composition, of which the result is carbonate of soda, a salt,
like carbonate of potash, most favourable to the growth of
plants. Accordingly, in furnishing sea-salt to a soil sufficiently
calcareous, we really enrich it with carbonate of soda.
We
moreover perceive that the same salt diffused through land
devoid of carbonate of lime may not produce any fertilizing
effect.
ΤΟ
stances; ths of the ammoniacal phosphate were converted into phosphate
of lime.
6. The reaction of oxalate of ammonia upon chalk is visible even when
the mixture is well watered; this is explained indeed by the powerful
affinity of oxalic acid for lime. The totality of the alkaline oxalate is
promptly changed into oxalate of lime and carbonate of ammonia.
446
WATER.
OF WATER.
Water is not only indispensable to the life of plants, but like-
wise promotes vegetation after the manner of a manure, on
account of the saline or organic substances it generally holds in
solution. Rain is the source of the soft waters which flow in
rivers, spring from the soil, or constitute lakes. Rain water
although nearly pure is not absolutely exempt from extraneous
matters. The air, especially after continued drought, always
holds dust in suspension; this yields to the rain by which it
is precipitated, whatever soluble matter it may contain.
It is further ascertained by the experiments of Cavendish
and Séguin, that whenever the electric spark traverses a humid
mixture of oxygen and azote, nitric acid and nitrate of am-
monia are produced. Now this frequently happens; and ac-
cording to Professor Liebig storm-rain always contains nitric
acid associated with lime or ammonia. Common rain seldom
contains nitrates, merely faint traces of common salt.*
In river and spring-water there necessarily exists a larger
amount of dissolved substances derived from the strata they pass
through, varying in nature according to the geological structure
of the locality. From old crystalline rocks, like granite, water
issues sometimes so little impregnated with salts, as to be almost
identical with distilled water; that, on the contrary, which rises
from a calcareous or gypseous bed is always contaminated with
salts of lime. Notwithstanding the minute quantity of saline
or earthy ingredients in spring and river-waters, they are drink-
able, and considered good when they are limpid, without odour,
capable of dissolving soap, and fitted for vegetable cookery. These
two last characters are essential, inasmuch as proving that the
waters contain only infinitesimal quantities of soluble salts of lime.
The action of tests readily indicates the nature of the dissolved
salts.
Water contains: sulphates or carbonates, if nitrate of barytes
causes a precipitate; a sulphate when the precipitate is not re-
dissolved by the addition of nitric acid;
* Annales de Chimie, t. xxxv, 2e série.
WATER.
447
Chlorides, if it give with nitrate of silver a curdy precipitate,
insoluble upon addition of nitric acid;
Lime, when rendered turbid by oxalate of ammonia ;
Magnesia, if when mixed with pure ammonia, and preserved
in a closely stoppered phial, a white flocculent deposit ensues.
This test, however, is only applicable to water that has been
boiled sufficiently long to expel all the carbonic acid in solution,
and which would tend to hold any carbonate of lime dissolved.
Carbonate of lime is separated from water by ammonia,
after some hours, in the form of granular crystals, which adhere
to the sides of the vessel.
In order to render the operation of tests more sensible, the
bulk of the water may be reduced to a half or a fourth by evapo-
ration.
Besides fixed salts, river-water always contains those of am-
monia, particularly the carbonate; this fact was first ascertained,
relative to the Seine water, by M. Chevreul.* Subsequently,
Professor Liebig has discovered the same ammoniacal salt in
rain-water; and M. Hunefeld has proved, that spring-water like-
wise contains it. Lastly, M. Hermann has even determined quan
titatively, carbonate of ammonia in the ferruginous waters of
a turf-pit. The water of the Nile is not exempt from it, judging
at least from the analysis of its mud. According to Regnault,
100 parts of this mud dried in the air contain: ‡
Chloride of sodium, sulphate of soda, and
carbonate of ammonia
Organic matter
Water
Oxide of iron
Silica
•
Alumina
Carbonate of lime
Carbonate of magnesia
* Chevreul, Annales de Chimie, t. LXXXII, p. 56.
† Liebig, Traité de Chimie, Introduction, p. cii.
Description de l'Egypte, t. 11, p. 406.
1
9
10
6
4
48
18
4
100
448
WATER.
The beautiful synthetic experiments of M. Dumas demonstrate
that water is formed of:
Oxygen
Hydrogen
88.89
11.11
When pure it boils at a temperature of 212° F. under
a ba-
rometric pressure of 30 (29.921) inches. It congeals at 32° F.
All natural bodies dilate, augment in volume, by the action
of heat, and contract under diminution of temperature. Water
is amenable to this law between rather wide limits; it deviates,
however, and presents an anomaly as it approaches congelation.
As with all liquids, the density of water gradually increases in
proportion as it cools, until its temperature is 39°.38 F. Set-
ting out from this point the density diminishes, the liquid dilates
more and more, so that at 32° it occupies nearly the same.
volume that it did at 49°. From this remarkable property, it
results that during the most intense cold the stagnant water
which covers the meadows rarely attains a lower temperature
than 39º, whereby the organs of plants suffer no damage.
Let us suppose, in fact, that at the beginning of winter a
sheet of stagnant water has a temperature about 54°; in pro-
portion as the liquid at the surface cools, it becomes denser,
descends, and is immediately replaced by inferior layers, which
rise in the ratio of their less density; but these new superior
layers, subjected to the same refrigerating cause, contract and
descend alternately. There is then established in the fluid
molecules, movements of ascension and descent, of which the
result is the cooling of the entire mass. Let us now admit
that in virtue of this continued mingling of the cooled superior
layers with those below, the temperature of the sheet of water is
lowered to 39º.38; at this degree of the thermometer, the water
acquires its maximum density; in parting with its heat it not
only contracts no more, but becomes lighter. If then a body of
stagnant water at a temperature of 39° is exposed to the chilling
action of the atmosphere, the superior layer, far colder than the
inferior, will no longer descend, since it will become lighter as
its temperature diminishes. Thus it is that the water of a pond
WATER.
449
or lake freezes at the surface, while it preserves beneath a tem-
perature some degrees above 32º. In a situation where the tem-
perature of the air was 29°, Davy found the thermometer
indicate 43º in the herbage of an inundated meadow completely
covered with ice.*
Water is always impregnated with atmospheric air, and a
minute quantity of carbonic acid. Deprived of air, it is not
agreeable to drink; it is even said when long continued, to prove
unwholesome if the dissolved gases are expelled by ebullition.
River water usually contains th in volume of air, and th car-
bonic acid. In spring water, the amount of the latter is some-
times far more considerable.
The quantity and nature of saline ingredients in drinkable water
vary much: in an agricultural point of view, the study of the con-
tained salts would certainly be useful. The waters which serve
as drink to the cattle of a farm, introduce into the dung-heap
all the matters which are dissolved or held in suspension. At
Bechelbronn, for example, I find that more than 2 cwts. of alka-
line salts get into the dung in this way every year.
When a
farmer has the choice of several waters for giving his cattle or
irrigating his meadows, he will do well to select that which is
richest in alkaline salts, and still good to drink. In the steppes
of America, it is astonishing with what discernment the cattle
choose waters for allaying their thirst, containing minute
quantities of sulphate of soda or common salt.
I close these considerations with a tabular view of the most
recent analyses. The quantities of salts put down have been
deduced from 100,000 parts of water for drinking.
* Davy, Agricultural Chemistry, p. 352.
G G
450
WATER.
SOURCE OF THE waters.
Of the Seine above Paris
Marne
•
Ourcq at St. Denis
Yonne at Avallon
Benvronne
Thérouenne
Gergogne.
Bièvre near Paris
Arcueil
Spring of Roye (Lyons)
Fountain Spring (Lyons)
Rhone at Lyons (July).
Ditto ditto (February).
Spring of the garden of plants
at Lyons
Of Lake Geneva
Of the Arve (in August)
Ditto in February
Loire near Orleans
Loiret
Carbonate of
lime.
Carbonate of
magnesia.
Silica.
traces
idem
idem
Sulphate of
lime.
11.3 0.4
0.5
3.6 0.6
10.5 0.9 0.6 3.1 1.2
17.5 2.0
2.0
15.3 7.0
4.3
1.9
25.7
26.2
18.0
13.6
16.9
23.8
23.4
10.0
15.0
27.0
7.2 0.7 0.1
5.2 0.4 0.1
8.3 1.2 0.2
1.7
11.9
traces
20.3
2.0
1.5
25.1
16.9
Sulphate of
magnesia.
1.4
1.7
0.6 traces
2.0 0.7
25.2
2.6 3.1
3.2 2.9
6.5 6.2
3.8
Sulphate of
soda.
Chloride of
calcium.
•
1.0 0.8
1.7
4.0 traces
idem
1.5
8.5
3.6
1.5
Chloride of
magnesium.
10.9
11.0
Chloride of
sodium (marine
salt).
0.9
1.2
1.9
1.2
1.3 traces
0.2
traces idem traces
0.7
5.1
10.2
16.8 1.6 12.6
0.9
0.7
1.5
traces
2.5
Nitrates.
Organic matter.
traces traces
idem
Total weight of
matter.
18.2
Bouchardat
18.0
Ditto
47.8 Ditto
7.7 Ditto
54.5 Colin
31.8 Ditto
21.9 Ditto
50.8 Ditto
46.7 Ditto
idem
idem
oflime idem
traces traces 26.4 Boussingault
26.6 Dupasquier
10.6 Boussingault
18.4 Dupasquier
idem
idem
AUTHORS OF THE
ANALYSES.
strong
7.6 traces 90.8 Ditto
0.6 15.2 Tingry
0.3 12.8 Ditto
0.4 24.3 Ditto
6.8 Guindant
28.4 Ditto

WATER.
451
The water of the Artesian well at Grenelle, near Paris,
according to the analysis of M. Payen, contains, in 100,000
parts:
Carbonate of lime
Carbonate of magnesia
Bicarbonate of potash
Sulphate of potash
Chloride of potassium
Silica
•
Yellow matter, not defined
Organic azotised matter
6.80
1.42
2.96
1.20
1.09
0.57
0.02
0.24
14.30
GG 2
452
CHAPTER VII.
OF THE ROTATION OF CROPS.
§ 1. OF THE ORGANIC MATTER OF MANURE AND OF CROps.
It is known that the atmosphere and the organic matters
diffused through the earth concur simultaneously to maintain
the life of plants; but how far each contributes is undetermined.
We shall now study the theory of the exhaustion of the soil by
culture, and the rotation of crops.
When a succession of crops is grown upon fertile land with-
out renewal of manure, the produce gradually diminishes; and
after a certain period, if it be grain, the quantity which at the
outset was eight or nine times the amount of the seed, will be
reduced to three times or even to twice the seed.
Thus crops
impair the fertility of the soil, and eventually exhaust it.
It has been long admitted that different species of plants
manifest great diversity in their powers of exhaustion. Certain
kinds, indeed, as trefoil and lucerne, far from exhausting it,
communicate new vigour. As a general rule, however, every
plant may be said to impoverish the soil in which it grows. This
impoverishment is always manifest when the plant after maturity
is completely removed, but is less sensible when much rubbish
is left. Thus, for example, clover, after yielding two crops,
which are generally cut as fodder, might still yield a third; this
last, however, is generally ploughed into the ground as manure,
being buried along with a considerable quantity of roots. This
plan of meliorating the soil by the cultivation of trefoil is what
is called manuring by smothering; a method practised from a
remote period in the south of Europe, and which offers decided
advantages in those districts where there is abundance of pas-
ture land. Hence, in smothering trefoil, the soil is amended at
the expense of the nutritive matter it contains.
ROTATION.
453
Thaer, who endeavoured to make theory and practice mutu-
ally agree, laid it down as a rule, that the exhaustion occasioned
by cropping is proportioned to the amount of nutriment in the
crops, estimating the nutritive value according to Einhof's deter-
mination. But the above deduction is founded upon error.
In fact, to adopt the above principle is tacitly admitting that
the whole organic matter of plants originally comes from the
soil. This, no doubt, contributes in a certain proportion to the
development of plants, but so also do air and water. On the
other hand, physiologists, in opposition to the ideas of the school
of Thaer, have perhaps exaggerated the material withdrawn
from the air. Thus, M. de Saussure reckons that a sun-flower
derives from the ground during its growth not more than th of
its weight, supposing the plant dry. The reasoning upon which
he formed his conclusion is based, on the one hand, upon a
knowledge of the extractive matter of garden-mould; on the
other, upon the quantity of water a plant like sun-flower may
absorb in a given time, to return it again to the air by
transpiration.*
Little objection could be urged against the above conclusion,
did not the experiments of M. Gazzeri tend to prove that roots
virtually exercise, by their contact with solid organic matter, an
incontestable absorbent action in imparting solubility. I might
refer to an observation of M. de Saussure, in which he states
that plants grown in garden-mould deprived of its soluble com-
ponents by repeated washing, reached, nevertheless, perfect
maturity, although the produce in seed was less abundant than it
might have been. It is most probable that both parties have
promulgated extreme opinions. Plants possibly draw from the
atmosphere more than agriculturists commonly suppose, and the
soil furnishes, independently of saline and earthy substances, a
proportion of organic matter larger than certain physiologists
admit. There is every reason to believe, from what I could
learn respecting guano during my sojourn on the coast of Peru,
* Saussure, Recherches Chimiques sur la Végétation, p. 268.
† Annales de l'Agriculture française, No. 1, p. 57.
Saussure, Recherches Chimiques, p. 171.
454
that the greater part of the azotised principles of plants originates
in the ammoniacal salts which exist or are formed in manure.*
ROTATION.
In discussing the advantage of one course of crops over
another, the question always hinges upon that of exhaustion.
Wherever an unlimited supply of dung and of handywork can
be procured, there is no absolute necessity for following any
regular system of rotation. Under such favourable circum-
stances, it is expedient to ascertain what kind of cultivation is,
commercially speaking, best suited to the climate and the soil.
There is little to fear that by a continued succession of similar
crops, the fields will get infested with noxious weeds, because this
inconvenience may be obviated by labour. Nor is impoverish-
ment of the soil to be dreaded, since that can be remedied
by the purchase of manure. The whole craft of agriculture
is reducible to comparison of the probable value of the crop
with the cost of manure, labour, &c. Farming of this sort
excludes the keep and propagation of cattle, and may be strictly
regarded more as gardening than as agriculture.
But where manure cannot be had from without, things must
be reduced to a system; and the amount of produce which it is
possible to export each year is fixed within bounds, which can-
not be exceeded with impunity.
When by judicious cultivation land is rendered fertile, it is
necessary towards securing its fertility, to supply after every
succession of crops equal quantities of manure. In considering
this in a purely chemical point of view, it may be said that the
produce which can be taken away without damaging the fer-
tility of the land, is the organic matter contained in the crops,
abstraction made of that present in the manure. Indeed, this
latter substance must in some form or other return to the
soil to fecundate it anew. It is capital placed in the ground, the
interest of which is represented by the commercial value of
the produce of all the other agricultural operations.
Where lands are extensive, population scattered, and means
of communication difficult, there is less necessity for being tied
down to systematic cultivation. There is always enough for a
Annales de Chimie, t. LXV, année 1837.
13
ROTATION.
455
scanty population. A field yields grain, and after the harvest is
converted for a series of years into meadow-land; such is the
pastoral system in all its simplicity. To this primitive state of
husbandry may be referred those plantations on cleared land in
countries covered with forests. When the trees are felled and
burned upon the spot, the soil yields for long and without
manure, crops of maize and of wheat of surprising quality, at
the cost of the fecundity acquired during ages of repose.
But when from increased population the land becomes more
valuable, a larger amount of produce is demanded. Imperfect
culture would prove inadequate. Accordingly a triennial rotation
of crops was very anciently adopted in the north of Europe,
consisting as is well known of fallow land frequently ploughed
during summer, followed by two years of grain. The fallow-
land received a certain quantity of manure to repair the ex-
haustion occasioned by the two crops of grain; hence when this
mode of rotation is adopted there should be always sufficient
meadow-land to supply manure.
Leaving waste one third of the surface has always been held
a grave objection against triennial rotation. Hence various at-
tempts have been made to get rid of the summer fallow. Some
encouragement was given to these attempts from what occurs in
horticulture, where the ground is rendered continually produc-
tive. In certain countries, moreover, tillage is only interrupted
by severe weather.
On the other hand it has been long remarked that it is not
always beneficial to grow grain during several consecutive years in
the same ground, even when it is fertile and manure is abundant,
owing to the almost insurmountable difficulty of destroying
weeds. The fallow was justly considered the most efficient and
economic means of getting rid of these.
For this purpose
fallow-crops, as they were called, were introduced. Peas, beans,
vetches, were at first the only plants used as fallow-crops.
However, it was soon perceived that the fallow-crops occa-
sioned a very sensible diminution in the produce of corn; to
counteract this inconvenience recourse was had to a surcharge of
manure; but as this cannot always be obtained it was necessary
* Thaer, Agriculture raisonnée.
456
ROTATION.
either to reduce the cultivated surface or to appropriate a
certain amount of meadow. Still the fallow-crops had this ad-
vantage, that they enabled the farmer to derive from land a
greater amount of produce in a given time without prejudice to
the raising of corn. Hence the plan of turning the fallow to
account was soon generally adopted.
The introduction of clover so modified the system of fallow-
crops as at one time to induce the belief that the point of per-
fection had been attained in agriculture.* This was when it was
ascertained that trefoil, which had hitherto been only cultivated in
small enclosures, might be sown in spring upon corn land, and
occupy next year the place of the fallow in the triennial rotation.
Trefoil so far from exhausting the soil was found to give it new
fertility, and the succeeding corn crop yielded a plentiful harvest.
It may be easily conceived what advantages were expected in
substituting for the unproductive fallow the cultivation of a plant
which did not impoverish the land, and furnished a quantity of ex-
cellent fodder that served as food for an additional number of
cattle. It was even alleged that this plant cleared the fields of
weeds.
A few years' experience sufficed to show that trefoil did not
possess all the advantages attributed to it. On renewing the
clover every third year on the same piece of ground it some-
times failed. Schubarth, the most zealous and enlightened ad-
vocate for its use, limited the renewal of the artificial meadow
at first to the sixth, and eventually to the ninth year; and find-
ing that it did not completely destroy the weeds in corn, he had
recourse to hoed-crops for that purpose.
The introduction of trefoil has gradually led to the system of
alternate rotation of crops generally adopted at present; and
moreover, contrary to the anticipations of Schubarth, it may be
renewed every four or five years on the same parcel of land.
The impossibility of substituting trefoil for the fallow of the
triennial rotation was offered as a fresh proof of the principle
maintained from time immemorial by agriculturists, namely,
that different species of plants should be cultivated in succes-
sion on the same land, and that the same species should not
* Thaer, Agriculture raisonnée.
ROTATION.
457
recur except at considerable intervals; the earth yielding much
finer crops when the same species do not follow in immediate
sequence.*
Attempts have been made at various times to explain this
phenomenon. It was at first thought that different species of
vegetables required a particular nutriment; but it was soon per-
ceived to be otherwise, and that the organs of each plant de-
rived the necessary juices from substances which concur in the
nutrition of vegetables generally. In effect, plants the most
opposite in botanical character and properties, alimentary as well
as poisonous, will live and flourish on the same mound of earth,
and with the same manure. Moreover these plants reciprocally
withdraw nourishment from one another, which could not occur
did each species need different elements of nutrition.†
When it was taken for granted that the organs of plants ela-
borate a common nourishment derived from the manure, then
vegetables of diverse organizations were supposed endued with
the faculty of searching at different depths for the nutritive
matter contained in the soil, by reason of a more or less con-
siderable extension and development of their roots. This
served to explain how a plant with long and perpendicular roots
could, as a sequel to corn, derive benefit from manure situate in
the undermost layers of ploughed land. It is possible that an
action of this kind may take place under certain circumstances,
but the explanation can never be generally received.
Another explanation of the necessity for alternate crops is
based upon properties assigned to the excretions of the roots, as
compared to animal excrements.
The excretion of roots, first observed by Brugman in the
Viola arvensis,‡ has been confirmed by the recent observations of
M. Macaire. This physiologist obtained the matter exuded
from certain plants by keeping their roots in water; but strange
to say could not discover it in silicious sand in which certain
vegetables had been grown. I myself likewise failed in detect-
* Thaer, Agriculture raisonnée.
† De Candolle t. 1. p. 248.
‡ Ibid, t. 11. p. 1497.
§ Ibid, t. 1. p. 1474.
458
ROTATION.
ing sensible traces of organic matter in sand which had served
as soil during several months to wheat and clover; a result
which renders the fact of radicular excretion doubtful. The ex-
cretion consequent upon immersion in water is perhaps the effect
of disease.
Be that as it may, upon the assumption of the excretion from
roots, Messrs. von Humboldt and Plenck have explained the
cause of the attractions and repulsions of certain plants.*
More recently M. de Candolle has reproduced this idea as the
basis of a theory of rotation of crops. If it be supposed, in
fact, that the excretion from the roots represents vegetable ex-
crements, it may be easily imagined that these excretions once
deposited in the soil may be as prejudicial to the plant which
produced them as would be the excrement of an animal presented
to it as food. On the other hand, by change of species, the plant
newly implanted may profit by the excretions of the preceding
crop, absorbing them as nourishment. This ingenious hypo-
thesis is deficient in the groundwork, inasmuch as the fact of ra-
dicular excretion is not sufficiently established. Again, admitting
the excretion, several facts concur to demonstrate that plants may
thrive in soil charged with their own excrements.
The culture of corn, for example, may proceed uninterrup-
tedly, as we find in the triennial rotation. I have seen in the table-
lands of the Andes wheat fields, which had yielded excellent crops
annually for more than two centuries. Maize may likewise be con-
tinually reproduced upon the same ground without inconvenience;
this fact is well known in the south of Europe; and the greater
portion of the coast of Peru has produced nothing else, from a
date long anterior to the discovery of America. Further, potatoes
may come again and again upon the same soil; they are inces-
santly cultivated at Santa-Fé and Quito, and nowhere are they of
better quality. Indigo, sugar-cane may be brought under the same
category. In Europe the Jerusalem artichoke produces con-
stantly in the same place. It must be conceded, that if all
* De Candolle, t. 1. p. 1474.
↑ To this list might be added, according to the recent researches of M.
Braconnot, the bay-rose with double flowers, and Papaver somniferum.
That distinguished chemist terminates his memoir as follows: My ex-
-
**
ROTATION.
459
these plants excrete from their roots, their excretions are not of
such a nature as to interfere with the progress of vegetation of
the species producing them.
But the capital objection to the hypothesis of de Candolle is
this, that it would be very remarkable indeed did any soluble
organic matter, like such secretions, not putrify when lying in
the ground. In a word, it is difficult to understand how it should
resist for years, as is pretended, the decomposing influence of
heat and moisture together.
That there is no absolute necessity for alternation of crops
when dung and labour can be readily procured, is undeniable.
Nevertheless, there are certain plants which cannot be repro-
duced upon the same soil advantageously except at intervals
more or less remote. The cause of this exigence on the part
of certain vegetables is still obscure, and the hypotheses pro-
pounded for clearing it up far from satisfactory.
One of the marked advantages of alternate cultures, is the
periodic cultivation of plants which improve the soil. In this
way a sort of compensation is made for exhaustion. The main
thing to be secured in rotation of crops is such a system as
shall enable the husbandman to obtain the greatest amount of
vegetable produce with the least manure, and in the shortest
possible time. This system can be alone realized by employing
in the course of rotation those plants which draw largely upon
the atmosphere.
The best plan of rotation in theory, is that in which the
quantity of organic matter obtained most exceeds the quantity of
organic matter introduced into the soil in the shape of manure.
This does not hold quite in practice. It is less the surplus
amount of organic matter over that contained in the manure,
than the value of this same matter which concerns the agricul-
turist. The excess required, and the form in which it should
be produced, must vary widely according to locality, commercial
periments are unfavourable, as may be perceived, to the theory of rotation
of crops based on the excretions of the roots. These excretions if really
occurring in the normal state are so obscure and little known as to lead to
the inference that the general system of rotations must be referred to some
other source.” (Recherches sur l'influence des plantes sur le sol, Annales
de Chimie, t. LXXII. p. 27.
460
ROTATION.
demand, and the habits of people, considerations wholly apart
from theoretical provisions. One point in theory that should agree
with practice is this, that in no case is it possible to export more
organic matter, and particularly more azotized organic matter,
than the excess of the same matter contained in the manure
which is consumed in the course of the rotation. By acting upon
another presumption the productiveness of the soil would be
infallibly lessened.
This irrefragable condition as to the term of exportation from
a farm suggests some critical remarks upon sundry notions
lately promulgated. The manufacture of beet-root sugar is an
instance. European agriculture may probably derive certain ad-
vantages from this modern branch of industry, although these
have been much overrated by certain speculators, who contend that
sugar may thus be obtained through rotation of crops without
lessening the other produce of the domain; so that the sugar
constitutes an additional source of income. This seems to me
erroneous.
If an estate yields annually 100 tons of beet-root for the sup-
port of cattle, their number must be diminished if the root is to
be used for making sugar. The organic matter of the sugar
extracted therefrom, is just so much nourishment withheld from
the cattle. To assert the contrary would be equivalent to say-
ing that potatoes grown upon a couple of acres of land, and
submitted to the process of distillation before being employed as
fodder, would feed as many animals as if eaten directly: as-
suredly, the organic principles of the potato converted into alco-
hol are lost as regards nutrition.
This does not imply that the manufacture of indigenous
sugar, and of potato spirit, is less productive than breeding and
fattening cattle. My sole object is to show that only a limited
quantity of organic matter can be advantageously exported from
an agricultural establishment. It must depend upon local and
commercial circumstances whether this is to be exported in the
form of sugar, corn, spirit, or butcher-meat.
The above statement is in apparent contradiction with gene-
rally received notions. Many persons believe that the manu-
facture of sugar, instead of injuring, is favourable to the breed-
ing of cattle. It appears, from a Parliamentary return on this
ROTATION.
461
subject, in 1836, that in certain estates where sugar was made,
the number of animals was increased; the numerical results are
no doubt exact, but this augmentation in cattle is rather to be
ascribed to an improved mode of farming than to the manufac-
ture of sugar. In establishments where the triennial rotation
with fallow was pursued, a rotation of four or five years with
clover and weed-destroying plants has been introduced; so that
it is by no means to be wondered at, that independently of beet-
root, there should have been a considerable increase in other
things. The introduction of this root, where it was not formerly
grown, is of itself an important melioration. But in highly culti-
vated countries, where the most productive rotations have been
long followed, the extraction of sugar would not effect such advan-
tageous changes as those announced in the above return.
If at
Bechelbronn a time should ever come, and at present it seems far
distant, when it would be deemed expedient to make sugar from
the beet there grown, it would certainly be requisite to diminish
the number of cattle, or else to annex more meadow land. It is
only indirectly, therefore, that the manufacture of home-sugar
can promote the breeding of cattle, and so prove serviceable to
agriculture.
From the definition given by me of the most advantageous.
course of crops, theoretically considered, it may be inferred how
closely the study of rotations is connected with that of the exhaus-
tion of the soil. Hence, to discuss the value of divers rotations,
we must, in consonance with theory, compare the quantity of
organic matter in a sequence of crops, with that in the manure
expended upon them.
From a well-managed farm, where for a series of years an in-
variable system of culture has been steadily pursued, we must
look for data. This I have done, as regards Bechelbronn, de-
termining by analysis the composition of the manures and crops,
and also of the more ordinary kinds of fodder or food. For a
long time, a five years' rotation has been there adopted in the
following order:
1st year.
2nd year.
Potatoes or beet-root manured.
Wheat sown the autumn of the first year; clover interposed
in the spring.
462
ROTATION.
3rd year. Trefoil (clover) two crops; the third crop ploughed in or
smothered.
4th year. Wheat on the clover-break turnips after the wheat.
5th year.
Oats.
The crop of oats which ends the rotation is generally scanty.
The soil is then brought back to the point of fertility which
it had before being dunged; and it is known by experience that
it will not now yield a crop of any value.
I now proceed to detail the analyses of the different sub-
stances which enter into the rotation, indicating at the same
time the average produce per acre.
POTATOES.
In the rather strong soil of Bechelbronn one acre produces
upon an average about 105 cwts. of potatoes. This is below the
ordinary rate of Alsace, where the crop amounts to from 155
to 165 cwts. per acre.
The leaves and stems are left upon
the ground.
A potato was cut in two, in order to subject it to analysis with
a proportional part of the peel. The half weighed 335.2 grs.
Stove-dried and reduced to flour, it weighed 289.3 grs. By abso-
lute desiccation in vacuo, at a temperature of 230° F. it was
found that one of moist tuber became 0.241; 15.4 grs. left of
ash 0.039.
Carbon
Hydrogen
Oxygen
Azote
Ash.
The average quantity of azote is 1.2. In 1836, I found 1.8
of azote. This notable difference, perhaps, depends on the ana-
lysis not having been made immediately after the harvest; or it
may be partly due to meteorological influences. To convince
myself that it did not depend upon any error of analysis, I ex-
amined anew the potatoe of 1836, preserved in the farinaceous
state: it yielded 1.8 of azote. I shall, therefore, reckon the
azote at 1.5:
I.
43.72
6.00
44.88
1.50
3.90
II.
43.40
5.60
45.60
1.50
3.90
ELEMENTS OF A FIVE YEARS' COURSE.
463
Carbon
Hydrogen
Oxygen
Azote
Ash
WHEAT.
I analysed the grain gathered in 1837: one of wheat, dried
in vacuo at 230° F. was reduced to 0.885; one of dry wheat
left of ash 0.0243:
The mean produce in wheat at Bechelbronn varies from 201
to 22 bushels per acre; this variation depends on the drill crop
which commences the rotation. After potatoes the average crop
is 19 bushels; after beet-root, 17 bushels; on clover breaks it
is 24 bushels. The average weight of the grain is 63lbs. per
bushel.
WHEAT-STRAW.
Carbon .
Hydrogen
Oxygen
Azote
Ash
46.10
5.80
43.40
2.29
2.43
100.00
I estimate the proportion of the produce in grain to that in
straw, as 44 to 100.
One of straw completely dried in vacuo at 231.8° F. becomes
0.740; one of dry straw leaves 0.0697 of ash:
I.
48.48
5.41
38.79
0.35
6.97
100.00
RED CLOVER.
II.
48.38
5.21
39.09
0.35
6.97
100.00
Clover delights in clayey soils; it thrives generally in good
wheat lands; in light and sandy ground it gets bare and frosted.
During its growth, it always requires the shelter of some other
plant. For this reason, in spring, it is generally sown among
wheat, which is put in the preceding autumn, or barley sown the
same spring. We generally give from 11 to 14lbs. of seed
GG 3
464
ROTATION.
per acre.
Clover is mowed the second year, as it is coming into
flower; but when it is not to be consumed as green fodder, the
mowing may take place before the flowering; this is required from
the difficulty of making it into hay. In fact, in the process of dry-
ing clover, there is great risk of losing part both of the leaves and
flower; besides, the drying always requires a considerable time,
during which the clover runs the chance of being damaged by
rain, and clover hay-making is almost impracticable in wet weather.
Schwertz proposed to dry the clover on a sort of parrot-perches
stuck into the ground. These supports are about eight feet high,
and capable of bearing a load of 2 cwt. of green fodder, mowed
twenty-four hours, and already withered. This method, as I
have seen it practised in the Duchy of Baden, answers well, but
there is considerable cost for manual labour, and in the first
instance for perches. Schwertz reckons that 2 cwts. of green
clover yield 48lbs. of hay. The relation of green to dry fodder
varies with the age of the plant, and the meteorological circum-
stances under which it has grown. Subjoined is the result of
some experiments which I performed on the making of clover
hay:
1 ton of clover in flower, 2nd year (1841) afforded in hay 19cts. 2qrs. 16lbs.
1 ton of clover
1st year (1842)
19cts. 2qrs. 16lbs.
The average produce of this fodder reduced to hay at Bechel-
bronn is 41 cwts. 3 qrs. per acre.
One of clover hay, after complete desiccation, weighed 0.790;
one of dry hay left 0.078 of ash :
I.
Carbon . 47.53
4.69
37.96
2.06
7.76
100.00
Hydrogen
Oxygen
Azote
Ash
""
TURNIPS.
II.
47.19
5.33
37.66
2.06
7.76
100.00
When turnips are cultivated as a second crop, as after rye or
wheat, the produce is very uncertain. Attempts are occasion-
ELEMENTS OF CROPS.
465
ally made to raise them after wheat which has followed
clover.
When cultivated on fresh manured soil, the produce is consi-
derable; in some places it amounts to from 28 to 33 tons per
acre; but as a second crop, we only obtain upon an average 7½
tons per acre. This crop is only counted as a half crop in the
general produce of the rotation.
Turnip is the most watery root I have examined. A slice
weighing 2 oz. 17 dwts. dried in the stove, was reduced to
4 dwts. After thorough desiccation, one of turnip weighed
0.075; consequently the root contains 92.5 per cent of water;
one of dried turnip incinerated, left 0.0758 of ash :
Carbon
Hydrogen
Oxygen
Azote
Ash
I.
42.80
Carbon
Hydrogen
Oxygen
Azote
Ash.
5.54
42.40
1.68
7.58
100.00
OATS.
As this grain closes the rotation, the produce is not great.
The average crop is 37 bushels per acre, at the weight of
33 lbs. per bushel ;* one of oats completely dried weighs
0.792; one of dried oats leaves 0.0398 of ash:
I.
50.32
6.32
37.14
2.24
3.98
100.00
II.
42.93
5.61
42.20
1.68
7.58
100.00
OAT STRAW.
II.
51.09
6.44
36.25
2.24
3.98
100.00
Oat straw is estimated at about 15 cwts. per acre; one part
becomes, when dried in vacuo, 0.713; one part burned leaves
0.0509 of ash.
* This is but a light weight for a bushel of oats.-ENG. ED.
H H
466
ELEMENTS OF CROPS.
*
Carbon
Hydrogen.
Oxygen
Azote
Ash.
49.93
5.32
39.28
0.38
5.09
100.00
FIELD BEET OR MANGEL WURZEL.
On a freshly manured soil, the average produce of beet at
Bechelbronn is 10 tons, 15 cwts. 1 qr. per acre.
The worst
crops do not fall below 5 tons, 2 cwts. 14 lbs., and the
best do not exceed 16 tons, 7 cwts. 1 qr. 14lbs., results which
I took occasion to observe varied sensibly from those obtained
in different places. I stated that Schwertz and Thaer make the
average 14 tons, 14 cwts. 2 qrs. 18lbs. Moelinger, after taking
the mean of ten years, adopts 11 tons, 1 cwt. 3 qrs. 6lb. At
Roville, M. de Dombasle speaks of 7 tons, 3 cwts. 26lbs. as
the mean of seven years.
Carbon
Hydrogen
Oxygen
Azote
Ash.
50.25
5.48
38.80
0.38
5.09
100.00
At Bechelbronn, the leaves of the beet are not given to
cattle; they are left upon the ground. A piece of beet-root
weighing 1 oz. 16 dwts. was reduced to 4%, say 5 dwts. after
being stove dried. After complete desiccation, at 230° F. one
part of root became 0.122; one part of root left upon incinera-
tion 0.0624 of residuum:
42.75
5.77
43.58
1.66
6.24
100.00
RYE.
42.93
5.94
43.53
1.66
6.24
100.00
Rye is seldom introduced into the rotation at Bechelbronn.
They reckon its produce at 26 bushels per acre, when it has had
a supplementary dose of manure. The bushel weighs fully
58lbs. I have taken the proportion of grain to straw as 45 is
to 100. One part of rye, dried at 230° F. weighed 0.834; one
part incinerated left 0.0237 of ash:
ELEMENTS OF CROPS.
467
Carbon
Hydrogen
Oxygen
Azote
Ash.
Carbon .
Hydrogen
Oxygen.
Azote
Ash
I.
46.35
5.38
44.21
1.69
2.37
100.00
RYE STRAW.
One part of straw, completely dried, weighed 0.813; one part
of which, incinerated, left 0.0368 of ash:
Carbon
Hydrogen
Oxygen
Azote
Ash.
II.
III.
45.72
46.38
5.70
5.74
44.52
43.82
1.69
1.69
2.37
2.37
100.00 100.00
Carbon.
Hydrogen
Oxygen.
Azote
Ash
WHITE PEAS.
Raised on manured land yielded 16 bushels per acre, weighing
fully 62lbs. per bushel.
bushel. One part of peas, after complete desic-
cation, weighed 0.914; one part of dried peas left of ash
0.0314:
49.88
5.58
40.56
0.30
3.68
100.00
I.
46.06
6.09
40.53
4.18
3.14
100.00
II.
46.94
6.24
39.50
4.18
3.14
100.00
PEA STRAW.`
One acre of peas produces about 22 or 23 cwts. of straw;
one part of the straw after desiccation weighed 0.882; one part
after incineration 0.1132:
45.80
5.00
35.57
2.31
11.32
100.00
HH 2
468
ELEMENTS OF CROPS.
JERUSALEM POTATO OR ARTICHOKE.
In Alsace, Jerusalem artichokes are always grown on one and
the same piece of land, which is manured every two years. At
Bechelbronn, on a somewhat shallow soil, the produce per acre
amounts to:
Tubers
Dry stems
Carbon
Hydrogen.
Oxygen
Azote
Ash
Carbon
Hydrogen
Oxygen.
Azote
Ash
C
•
tons.
10
•
""
I.
43.02
5.91
43.56
1.57
59.4
100.00
A tuber which weighed on being taken from the ground 1 oz.
15 dwts., weighed 74dwts. after it was dried in the stove. After
absolute desiccation, one part was reduced to 0.208; one por-
tion of the dry tuber left 0.0594 after incineration :
•
cwts.
16
11
•
qrs.
pend Q
DRIED STEMS OF JERUSALEM ARTICHOKES.
1
2
These stems had stood through the winter where they grew,
and were almost wholly composed of pith. One part after de-
siccation weighed 0.871; one part left of ash 0.0276.
II.
43.62
5.80
43.07
1.57
59.4
100.00
lbs.
26
9
45.66
5.43
45.72
0.43
2.76
100.00
I fear that in this analysis the carbon and azote are rated too
low.
I have collected in two tables the results of the analyses as
detailed above. The first exhibits the quantity of dry matter
and moisture contained in each specimen; the other the elemen-
tary composition. On careful examination of the numbers
given in the second table, certain substances will be found very
ELEMENTS OF CROPS.
469
analogous in composition. If the ashes be deducted, the
analogy becomes complete; for many substances differing widely
both in character and properties, nevertheless appear to possess
the same composition; a fact which I do not undertake to ex-
plain.
TABLE OF THE PROPORTIONS OF WATER CONTAINED IN DIFFERENT
Wheat
Rye
Oats.
SUBSTANCES.
Wheat
Rye
Oats
Substances.
Wheat-straw
Rye-straw
Oat-straw
Potato
Field-beet
Turnip
Jerusalem potato
Peas
Pea-straw
Clover-hay
Jerusalem potato-stems
SUBSTANCES.
COMPOSITION OF THE SAME SUBSTANCES DRIED IN VACUO AT 2300 FAHR.
Pea-straw
Clover-hay.
Jerusalem potato-
stems
Carbon.
Ashes included.
Hydrogen.
Oxygen.
Dry matter,
0.855
0.834
0.792
0.740
0.813
0.713
0.241
0.122
0.075
0.208
0.914
0.882
0.790
0.871
Azote.
Water.
0.145
0.166
0.208
0.260
0.187
0.287
0.759
0.878
0.925
0.792
0.086
0.118
0.210
0.129

Ash.
Wheat-straw
46.105.8 43.4 02.302.4 47.206.0 44.4,02.4
46.205.6 44.2 01.702.3 47.305.7 45.3.01.7
50.7 06.4 36.7 02.204.0 52.9 06.6 38.202.3
48.4 05.3 38.9 00.4 07.0 52.105.7 41.800.4
49.9 05.6 40.600.303.6 51.805.8 42.100.3
50.105.4 39.000.405.152.805.7 41.100.4
44.005.8 44.701.5 04.0 45.9 06.146.4 01.6
42.805.8 43.401.7 06.3 45.7 06.2 46.3 01.8
42.9 05.5 42.3 01.707.6 46.3 06.045.901.8
Jerusalem potato .43.305.8 43.301.6 06.046.0 06.2 46.1 01.7
Peas
Rye-straw.
Oat-straw
Potato
Field-beet
Turnip
46.5 06.2 40.0 04.203.1 48.0 06.4 41.3 04.3
45.805.0 35.602.3 11.351.505.6 40.3 02.6
47.405.0 37.8 02.107.7 51.305.4 41.1 02.2
45.7 05.4 45.700.4 02.8 47.005.6 47.000.4
Ashes deducted.
470
ELEMENTS OF MANURE.
RELATIONS OF MANURES TO CROPS.
The manure employed at Bechelbronn is what is commonly
called farm-yard dung, a compost made up of the excrements of
horses, oxen, and straw litter impregnated with urine. The dung
of fowls and pigeons, and the sweepings of the yard, are some-
times applied to special purposes. The animals whose excrements
form the dung which I have examined were horses, oxen and swine.
The manure is put upon the ground when it has undergone
fermentation in the heap; it is manure half-made: the straw
litter is not entirely decomposed, but is soft and filamentous; in
this state manure retains a great deal of moisture.
DESICCATION OF HALF-MADE OR HALF-DECAYED MANURE.
EXPERIMENT I.
A quantity of manure prepared during the winter 1837-1838,
which in the state in which it was being put on the ground,
weighed 257 lbs, after it had been dried so as to be easily
reduced to powder, weighed 57 lbs. The loss of water was there-
fore about 77.3 in 100. This number comes very near the esti-
mate of several German agriculturists, who reckon the moisture
in farm-yard dung at 75 per cent. Still this loss does not re-
present the whole of the water; for after desiccation at 212° F.
the 57 lbs. weighed 54 lbs. In fine, after desiccation in vacuo,
at 230° F. it was found that one part of stove-dried manure
lost 0.039. Thus the manure parted in totality with 79.62 per
cent of water, and contained in consequence 20.4 of dry sub-
stance.
EXPERIMENT II.
Of the manure prepared in the winter 1838-1839, 220 lbs.
after being chopped and dried weighed 56 lbs. One part of this
manure was reduced in dry vacuo at a temperature of 230° F.
to 0.872. The 220 lbs. would therefore have weighed when dry
48 lbs.
EXPERIMENT III.
Of the manure prepared during the summer of 1839,
660 lbs. weighed after desiccation 151 lbs.; of this dry manure
reduced to powder, one part lost by desiccation in vacuo at
230° F. 0.1461.
ELEMENTS OF MANURE.
471
The 151lbs. would therefore have lost 22 lbs. ; consequently
the 660 lbs. of manure contained 129 lbs. of dry matter, that is,
19.64 per cent.
Subjoined is a summary of the per centage of dry matter:
First experiment
Second
Third
Average
Moisture (average)
I.
II.
III.
IV.
V.
VI.
J
">
ANALYSES OF HALF-MADE MANURES.
I. Manure prepared during the winter of 1837-1838:
Matter 0.5595, gave carbonic acid 0.528, water 0.157: C. 32.4, H. 3.8,
Azote 1.7-1.0 gave ashes 0.462.
"
II. Manure prepared during the winter 1837-1838:
Matter 0.575, gave carbonic acid 0.676, water 0.212: C. 32.5. H. 4.1,
Azote 1.69.-1.000 gave ashes 0.357.
III. Manure prepared during the winter 1837-1838:
Matter 0.567, gave carbonic acid 0.791, water 0.232: C. 38.7, H. 4.5,
Azote 1.73.—1.000 gave ashes 0.264.
Carbon.
32.4
•
IV. Manure prepared during the spring of 1838:
Matter 0.586, gave carbonic acid 0.759, water 0.208: C. 36.4, H. 4.0,
Azote 2.4.-1.000 gave ashes 0.381.
32.5
38.7
36.4
40.0
34.5
35.8
V. Manure prepared during the spring of 1839:
Matter 0.445, gave carbonic acid 0.643, water 0.171: C. 40.0, H. 4.3,
Azote 2.4.-1.000 gave ashes 0.257.
VI.
Matter 0.427, gave carbonic acid 0.543, water 0.150: C. 34.7, H. 3.9.
0.427,
0.530,
0.127: 34.3, 4.8,
Azote 2.0.-1.000 gave ashes 0.315.
"
COMPOSITION OF THE MANURES ANALYSED:
Azote.
Hydrogen.
3.8
1.7
4.1
26.0
1.7
4.5
28.7
1.7
4.0
19.1
2.4
4.3
27.6
2.4
4.3
27.7
2.0
Mean
4.2
25.8
2.0
In all these analyses, the combustion was promoted by the
addition of chlorate of potash; some oxide of antimony was
20.4
22.2
19.6
20.7
79.3
..
Oxygen.
25.8
""
"
>>
Salts & earths.
36.5
35.7
26.4
38.1
25.7
31.5
32.2
HH 3
472
RELATIONS OF ELEMENTS
likewise added. The carbonic acid of the ash was determined
and struck off.
The measure of dung in use at Bechelbronn is the waggon
drawn by four horses. After repeated weighings it was found
that this measure contains nearly 1 ton, 15 cwts. 2 qrs. 23 lbs.
of moist material, or 7 cwts. 1 qr. 15 lbs. if that be computed
dry. The first course of the rotation receives 27 loads of this
manure, weighing 48 tons, 4 cwts. 21 lbs. equivalent to 9 tons.
19 cwts. 2 qrs. 10 lbs. of dry manure.
*
The preceding analyses show that this charge of manure,
which is to fertilize the soil during the course of the rotation
(five years) contains:
Carbon
Hydrogen
Oxygen
Azote
Salts and earth
·
8002 lbs.
938
5767
447
7198
22352
Such are the principles which together form the organic
matter that is to be consumed and in major part assimilated by
the crops grown. I say partly, because I do not believe that
the whole organic matter necessarily enters into the con-
stitution of the plants which spring up during the rotation;
no doubt a considerable portion of the manure is lost through
spontaneous decomposition, or is carried away by the rain; and
another portion may remain a long time dormant in the soil, to
act as a fertilizer at a more or less distant period; just as in the
present rotation the manure formerly introduced co-operates
with that recently added. One thing is certain, viz., that the
proportion of manure indicated is essential for average crops ;
by diminishing it the produce is necessarily lessened. Lastly,
it is proved that after the rotation the crops have consumed the
manure, and the earth will not yield its increase unless a fresh
quantity be added.
* I presume that the quantity above specified is that which is laid on
the French hectare, equal to 2.4 acres English. To get at the quantity
laid on per acre, it would therefore be necessary to divide by 2%. Thus
48 tons, 4 cwts. 21 lbs. per hectare will be equal to 20 tons, 1 cwt. 3 qrs.
per English acre.-ENG. ED.
IN CROPS AND MANURE.
473
I now proceed to consider the relation subsisting between the
quantity of organic matter buried in the soil as manure, and
what is recovered in the crops. In this way the respective
proportions of elementary matter which various crops derive
from the air and the soil, may be determined approximately,
and a knowledge obtained of those rotations which least exhaust
the land, or in other words, which obtain from the atmosphere
the largest amount of organic matter.
The rotations set down in Tables I and II, are those de-
finitively adopted at Bechelbronn, and throughout the greater part
of Alsace. These two rotations, which differ only in the hoed
crop introduced, potatoes in one, beet-root in the other, are al-
most identical; nearly the same quantity of dry matter being
produced per acre and nearly the same quantity of organic ma-
terial withdrawn from the atmosphere.
The rotation No. 3 was introduced by Schwertz at Hohenheim,
theoretically, it is one of the most advantageous; it was tried at
Bechelbronn but abandoned, because, from meteorological causes,
peas and vetches fail frequently.
Table No. 4 shows the triennial rotation with manured fallow;
this is disadvantageous in point of theory. The organic consti-
tuents of the crop exceed but little those of the manure. Sup-
posing that even the whole of the straw were converted into ma-
nure, the farmer would still be compelled to procure manure
from abroad, in compensation for the out-going of wheat. It is
thus obvious why triennial rotation always requires a great deal
of meadow land.
In table No. 5, the result of the continuous cultivation of
Jerusalem artichokes is given. At Bechelbronn these are
dressed every two years with about ten loads of dung per acre.
Upon an average 21 tons, 12 cwt. 13 qrs. 5lbs. of tubers and
about 1 ton, 3 cwt. 19 lbs. of woody stems are gathered in the
course of two years. It will be perceived from perusal of this
table, that the culture of Jerusalem artichokes presents, theo-
retically, considerable advantages. The organic matter of the
crop greatly exceeds that of the manure. Moreover, in Alsace,
where it is very common, it is held to be most productive. Still,
HH 4
474
RELATIONS OF ELEMENTS
the organic matter of the stems must be taken into account,
which, practically speaking, are nearly worthless.
a
Table No. 6 comprises the data relative to a quadrennial ro-
tation, adopted by M. Crud, and in which are grown successively:
1st. Potatoes or beet-root. 2nd. Wheat. 3rd. Red clover.
4th. Wheat. The first sowing is dressed with about 18 tons
of half-wasted farm-yard dung. The gain in organic matter ob-
tained by this rotation surpasses that of the preceding; but as
the clover crops are not very sure when repeated every four
years, M. Crud, for reasons which may be called in question,
follows this rotation with one of lucern, which gets a fresh sup-
ply of manure. It cannot be denied that lucern furnishes
great mass of fodder, and in this respect the fertility of the land
ought to be vastly enhanced, were this consumed on the spot;
but I can discover no objection to the renewal of clover, if the
lucern succeeds so well as M. Crud says it does. From too fre-
quent repetition, farmers have gone into the opposite exteme of
cultivating clover only every five or six years. This subject.
offers an important field for research. It is not impossible that
the ill-success depends often on premature mowing of the clover
during the first year and before its roots have acquired sufficient
vigour. This practice has been abandoned with us for some
years, and there is now everything to assure us that the second
year's crop is thereby secured.
Years.
1st
2nd
3rd
4th
5th
Substances.
Potatoes
Wheat
•
Wheat-straw
Clover-hay
Wheat
•
Wheat-straw
Turnips (2nd crop)
Oats
Oat-straw
Total
Manure employed
Difference
•
ROTATION COURSE No. 1.



Crops
per acre.
lbs.
11733
1231
2798
4675
1521
3456
8754
1232
1650
37050
44995
Crops
dry.
lbs.
2828
1052
2070
3693
1300
2557
656
975
1176
16307
9314
6993
Hydro-
Carbon.
gen.
lbs.
1244
485
1002
1750
599
1237
282
494
589
7682
3426
4256
lbs.
164
61
110
185
75
135
36
62
63
Salts
Oxygen.
Oxygen. Azote. and
earths.
891
391
500
lbs.
1264
457
805
1396
564
995
278
358
458
6575
2403
4172
lbs.
42
24
8
78
30
10
11
21
5
229
185
44
lbs.
113
25
145
284
31
179
50
39
60
926
2999
2073
IN CROPS AND MANURE.
475
Years.
1st
2nd
3rd
4th
5th
Years.
1st
2nd
3rd
4th
5th
6th
Years.
Substances.
Mangel wurzel
Wheat.
Wheat-straw
Clover-hay
Wheat.
Wheat-straw
Turnips
Oats
Oat-straw
·
Total
Manure employed
Difference
Potatoes
Wheat
Substances.
·
Wheat-straw
Clover-hay
Wheat
•
•
•
Wheat-straw
Rye
Rye-straw
1st
2nd & 3rd. Wheat
Straw
Turnips
Peas (dunged)
Pea-straw
•
Total
Manures employed
Difference
Substances.
•
lbs.
23833
1
lbs.
2907
928
1827
1086
2468
4675
3693
O
1521
3456
1300
2557
•
8754
1232
1650
656
975
1176
48675 16019
44995
9314
6705
Dunged fallow
Total
Manure employed
Difference
ROTATION COURSE No. 2.

Crops
per acre.
Crops Crops
dry.
per acre.
Crops
dry.
lbs.
11733
42686
56618
1231
2798
4675 3693
1521
3456
8754
1001
2558
1539
3420
ROTATION COURSE No. 3.
lbs.
2828
1052
2070
lbs.
3041
6875
1300
2558
656
915
2256
1273
2780
Carbon.
lbs.
1244
428
883
1750
599
1237
281
495
589
lbs.
7506
3426
4080
··
2600
5080
Carbon.
21386 10035
11176
4000
10200
6035
lbs.
1244
485
1002
1750
599
1238
282
425
1033
590
1387
ROTATION COURSE No. 4.
lbs.
Hydro-
gen.
··
951
2462
lbs.
163
9916 7680 3413
18330
3795
1358
8414
3885
2055
53
98
185
75
135
36
62
63
Crops Crops Carbon. Hydro-
per acre.
dry.
gen.
875
391
481
Hydro-
gen.
lbs.
164
61
110
185
75
135
36
56
112
71
155
1160
470
690
lbs.
150
270
420
159
261
Salts
Oxygen. Azote. and
earths.
lbs.
1262
403
710
1396
564
995
277
358
458
6423
2403
4020
Ibs.
1264
457
805
1396
564
995
278
366
803
565
1129
8622
2883
5739
Oxygen. Azote.
lbs.
1128
1979
3107
979
2128
lbs. lbs.
49
182
21
22
128
284
31
179
50
39
60
7
77
30
10
11
21
5
231
185
46
Oxygen. Azote.
lbs.
42
24
8
78
30
10
11
38
52
22
8
323
223
100
lbs.
60
20
80
76
4
975
2999
2024

Salts
and
earths.
lbs.
113
25
145
284
31
179
50
28
255
30
100
1240
3599
2359

Salts
and
earths.
lbs.
*02
356
413
1222
804
HH 5
476
RELATIONS OF ELEMENTS.
Years.
1st & 2nd Potatoes
Stalks
Years.
Rotations.
No. 1.
No. 2
No. 3.
No. 4
No. 5.
No. 6.
Substances.
•
No. 5, CONTINUOUS POTATO CROP.


Total
Manure employed
Difference
Ist
Half acre of potatoes
Ditto of beet-roots
2nd & 4th Wheat, 153 bushels
Wheat-straw
3rd
Clover, three cuttings
lbs.
1862
1862
1862
1247
3710
2087
Crops grown.
Total
Manure consumed
Difference
•
•
lbs.
37
37
37
23
86
42
·
Dry manure
expended upon tained in the
Azote con-
one acre in
one year.
manure.
•
•
Crops
per acre.
lbs.
48473
25850
74323 32580
41663
Crops
per acre.
No. 6, QUATRENNIAL ROTATION, ADOPTED BY M. CRUD.
lbs.
9167
18333
3331
7333
7333
45497
40333
Crops
dry.
lbs.
lbs.
10083 4366
22497 10289
14655
8624 3087
23956
11568
Crops
dry.
18329
8349
9980
lbs.
3261
3204
3564
Carbon. Hydro-
gen.
lbs.
2209
2237
2847
5243
5793
2567
16299
4582
Dry produce
obtained in
one year upon
one acre.
SUMMARY.
lbs.
972
957
1312
2537
2746
8524
2989
5535
lbs.
585
1215
lbs.
46
46
54
26
125
70
Azote con-
tained in the
produce.
14655
1800
362
2225
1438 12430
Carbon. Hydro- Oxygen. Azote.
gen.
Oxygen. Azote.
lbs.
lbs.
4366
10289
ELEMENTARY INGREDIENTS OF THE CROP.
128
130
165
278
290
991
350
641
lbs.
987
970
1235
2040
2190
7422
2154
5268
lbs.
Gain in
organic matter
in one year
upon one
acre.
161
90
lbs.
1996
1746
2513
251
172
79
1565
12758
2889
lbs.
33
38
65
21
121
278
167
111
Salts
and
earths.
lbs.
ဆောက
605
630
1235
2777
1542
Salts
and
earths.
17
lbs.
Ibs.
88
Gain in
azote in one
year upon one
acre.
141
68
367
446
1110
2688
1578
From all that precedes, it is obvious that rotations which
include clover, red clover, lucerne, and sainfoin, are those that
afford considerably the largest proportion of organic matter;
a fact, indeed, which if not legitimately established, has still
been long acted on in that system of cropping which embraces
forage plants as an element. Lucernes, too, when they have
taken kindly, yield an extraordinary quantity of forage, as every
IN CROPS AND MANURE.
477
one may see by turning to the produce of the piece under that
crop which in the system of M. Crud succeeds the quatrennial
rotation. At the end of his rotation, M. Crud always lays on
manure in the ratio of 18 tons per acre, which lasts for six
years, and may be said to suffice for the succession of crops in
the appended table :
Lucern dry,
Wheat,
Straw
""
>>
""
Crops.
""
1st year
2nd year
3rd year
4th year
5th year
6th year
Produce per acre. Contents in azote.
30S0lbs.
72lbs.
9240
11458
9240
7333
1448
3645
Dung employed
Total gain in azote
Gain in azote per annum and per acre
40233
215
269
213
172
28
11
980
205
775
130
In glancing at these tables, it is obvious that the azote of the
crop always exceeds the azote of the manure. Generally speak-
ing, I admit that this excess of azote is derived from the
atmosphere; but I do not pretend to say in what precise man-
ner the assimilation takes place. I shall only quote the con-
clusion of a paper which I published on the subject in the year
1837.* Azote may enter immediately into the constitution of
vegetables, provided their green parts have the power of fixing
it; azote may also enter vegetables dissolved in the water which
bathes their roots, and which always contains it in a certain
proportion. Lastly, it is possible that the air may contain
an infinitely minute quantity of ammoniacal vapour, as some
natural philosophers† have maintained, and that this assimilated,
decomposed, and recomposed anew by the plant, is the source of
its azotised constituents.
2. OF THE RESIDUES OF DIFFERENT CROPS.
The vegetable matter which is produced in the course of
* Annales de Chimie, t. LXIX, p. 366.
† Saussure, Recherches Chimiques. and Liebig, Agricultural Chemistry.
...
478
RELATIONS OF ELEMENTS
a season is never found entirely in the crop. A certain quantity
of it, for instance, always remains in the ground. It is, there-
fore, a point of interest to ascertain what quantity of elementary
matter is left in the soil after each kind of crop in the rotation;
precise knowledge of this description may even be important
in calculating rotations, for it is obvious that the remains of the
crop now on the ground must influence that which is to follow,
and in the course of a rotation the sum of the residuary matters
must be regarded as a supplement or addition to the manure put
into the ground at its commencement.
In the systems of rotation very generally followed at the
present time, the influence of these residuary matters is manifest,
and it is partly by their means that we can explain how a
quantity of manure, frequently very moderate, should suffice for
the whole of the crops in a productive rotation. The remark-
able effect of clover has not failed to arrest attention even from
the most unobserving. The wheat crop which comes after our
drill crop in Alsace, beet or potatoes, averages from 18 to 20
bushels per acre; but the wheat crop that succeeds our clover
averages from 23 to 24 bushels per acre.
The improvement of the soil, so obvious in connexion with
clover, in all probability also occurs in connexion with the
residues of other crops; but as in most instances the residue
merely compensates the loss, or lessens its extent, the effect
produced is less remarkable, and is less, indeed, in amount.
All the world acknowledge, then, that the residues of the crops.
that enter into a rotation compensate in greater or less degree
for what is carried away in the shape of harvest, and that in
some cases they even add to the fertility of the soil; for in
growing crops that leave a large quantity of residue, it is pre-
cisely as if a smaller quantity were taken from a given extent of
surface. But what is the amount of residue or refuse which
is returned to the soil by such and such a crop? What, in a
word, is the value of this residuary matter considered as
manure? This is a point upon which only the most vague and
indefinite ideas are generally entertained; and it was with the
purpose of substituting positive facts for mere guesses that I
determined on weighing and analysing the vegetable residue of
IN CROPS AND MANURE.
479
the several crops that enter as elements into our more usual
rotations.
My experiments were made upon breadths of land which
varied from 120 to 500 square yards in extent. The clover
roots and stubble were taken up with the spade, and before
being dried, were freed from adhering earth by washing. The
beet-leaves and potato-tops were dried at once in the oven;
and it was from each the general mass reduced to powder that
samples were taken for ultimate analysis, before proceeding
to which, they were carefully dried in vacuo at 230° F.
It is not likely that any accurate mean result should have
been come to from an examination of the produce of a single
season. I should even say that the year in which these in-
quiries were undertaken was little favourable to them, inasmuch
as the crops were generally bad; but it is obvious that they
form a nucleus, around or by the side of which the results of
other seasons may be arranged, and an average from larger pre-
mises come to.
POTATO TOPS OR HAUM.
A piece of land measuring 120 square yards, marked off
from a spot that had suffered from drought, yielded 47.0 lbs. of
green tops, which were reduced by drying to 18.4 lbs. A similar
extent of surface, selected from a part of the field that looked well,
gave green tops 79 lbs. which dried in the air were reduced to
16 lbs. We should thus have 234 cwts. of green, and 64 cwts.
of dry tops per acre. The crop of potatoes in 1839 yielded at the
rate of 101 cwts. per acre. One hundred grammes, or 3 oz.
4 dwts. 8 grs. troy, of the top dried in the air, lost 12 grammes
or 7 dwts. 17 grs. by thorough drying at 230° F. The weight
of the tops yielded per acre, taken as dry, consequently amounts
to 5 cwts. 2 qrs. 14 lbs. and by elementary analysis they were
found to have the following composition:
Carbon
Hydrogen
Oxygen
Azote
Salts and earths
44.8
5.1
30.5
2.3
17.8
100.0
480
RELATIONS OF ELEMENTS
LEAVES OF FIELD-BEET, OR MANGEL-WURZEL.
Upon a surface of 500 square yards, 976lbs. of leaves were
gathered, the weight being taken two days after the roots were
pulled up.
55 lbs. of leaves reducible to powder by drying in an oven,
were brought to 6.6 lbs.
3 oz. 4 dwts. of leaves dried and pulverized, lost by desicca-
tion at 230° F. 3 dwts. of moisture. The 6.6 lbs. brought to
that state of dryness would have weighed 6.1 lbs. With these
data it is found that the 976 lbs. of green leaves gathered upon
500 square yards would have weighed when dry 108.9 lbs. ; and
that the acre produced 85 cwts. of green and 92 cwts. of dry
leaves. The crop of roots which answers to that quantity of
leaves, was in 1839 but 6 tons, 2 cwts., that is to say, little
more than half a crop; for our average is about 10 tons.
COMPOSITION OF DRY LEAVES
Carbon
Hydrogen
Oxygen
Azote
Salts and earth
WHEAT STUBBLE.
38.1
5.1
30.8
4.5
21.5
100.0
From 120 square yards of ground we have obtained 13 lbs.
of stubble dried in the air. The same surface in another field
produced 17lbs.
Thus we have 5 cwts. of stubble per acre; but as wheat re-
curs twice in the rotation, the residues must be doubled; say,
114 cwts. Stubble loses 0.26 of moisture when dried completely
at 230°.
In 1839, the wheat after the drilled crop, or after clover, was
only 17 bushels per acre.
I have assigned to stubble the same composition as that of
straw.
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ORGANIC ELEMENTS OF MANURES AND CROPS. 487
CLOVER ROOTS.
A surface of 120 square yards gave 44 lbs. of roots, weighed
after being thoroughly dried in the sun; when pulverized after
drying in the stove, the weight was reduced to 37 lbs.
3 oz. 4 dwts. of powdered roots lost by drying, at a temperature
of 230° F. 5 dwts. of moisture. Thus the 44 lbs of roots dried in
the stove would have weighed 34 lbs., and one acre would
have furnished 12 cwts. of residue perfectly dry.
In 1839, the clover crop when reduced to hay was far below
the average.
COMPOSITION OF THE ROOTS.
Carbon
Hydrogen
Oxygen
Azote
Salts and earth.
OAT-STUBBLE.
43.4
5.3
36.9
1.8
12.6
100.0
The residue of the oat crop, which concludes the rotation
course, does not act upon the present, but on the next rotation;
in the same way as the organic remains left in the ground by the
oats which terminated the antecedent course, exerted their influ-
ence upon the present one. In 1839, the oat crop was above
the average; it was as high as 16 cwts. 2 qrs. 18 lbs. per acre.
One French are of the land, equal to 120 square yards Eng-
lish, yielded 20 lbs. of stubble dried in the air, or at the rate in
round numbers of 8 cwts. per acre.
In the following table I have given a summary of the results
above stated, combining therewith the quantity and the compo-
sition of the manure expended in the rotation.
J I
488
ORGANIC ELEMENTS OF MANURES AND CROPS.
Nature of
the crop.
•
Produce per
acre in
1839.
•
SUMMARY OF THE FOREGOING RESULTS.
lbs.
lbs.
Potatoes 11367 2739
Beetroots. 13678 1668
Wheat
2150 1837
Clover-hay 2292 1810
Oats
1862 1474
Total
31349 9527
Manure
employed 44995
Produce dried
at 212 de-
grees F.
Nature of the residues
buried in the soil.
•
Residues ob-
tained upon
one acre.
•
Residues dried
at 230° F.
Elementary matter of the residues.

Carbon.
Hydro-
gen.
Oxygen.
lbs.
Potatoe tops
14
48
Beetroot leaves
Stubble
lbs. lbs. lbs. lbs. lbs.
2632 630
232 32
189
9599 1070 410 55
1283
460
950
50
Roots dried in the sun 1833 1418 615
75
Stubble
836 596 299 32
4
•
523
26
232
2
16182, 4664 2066 244 1643
Azote.
330
369
94
Salts
and
earths.
lbs.
112
236
67
178
30
617
9314 3335 391 2403 186 2995
It, therefore, appears that the refuse or residue of the several
crops of a rotation represent both in quantity and nature some-
what less than one half of the manure originally put into the
ground; I say somewhat less, because it must be remembered
that in the sum of these residuary matters, the beetroot leaves
and potato tops must not be allowed to stand together, the one
crop naturally excluding the other, or at all events the two hoed or
drill crops not entering in this proportion into the same rotation.
The large quantity of organic matter restored to the soil by
several of the crops in the series, consequently explains how the
rotation may be closed without its being found indispensable to
supply any additional manure in its course. It seems indubit-
able that without this addition of elementary matter, the fertility
of the soil would decline much more rapidly than it does; the
residue of each crop is nothing more than a portion of the crop
itself restored to the ground; it is as if we only carried off one
portion, the larger portion of the crop, and buried another por-
tion green.
In the five years' rotation, it may be observed that there are
two crops, the hoed crop and the forage crop, which yield sub-
stances to the ground that are both abundant in quantity and
rich in azotised matter, and it is unquestionable that these crops
act favourably on the cereals which succeed them. But data
are wanting for the appreciation of their specific utility in the
general rotation. We see, for instance, that despite the large
proportion of residuary matter left by the bect or mangel-wurzel,
ORGANIC ELEMENTS OF MANURES AND CROPS. 489
this plant lessens considerably the produce of the wheat crop
that comes after it. The potato, though it leaves much less re-
fuse than the beet, seems nevertheless to act less unfavourably
than this vegetable. Clover leaves more residue than the po-
tato, and on this ground, alone, ought to favour the cereal that
follows it; but it has a favourable influence out of all propor-
tion with its quantity, contrasting this with the residue of either
of the hoed crops; a fact from which we learn that the visible
appreciable influence of the residuary matters of preceding crops
upon the luxuriance of succeeding crops, does not result solely
from their mass, even supposing each to be possessed of equal
qualities; this other, this additional effect, depends especially on
an influence exerted on the soil by the crops which leave them.
Had these crops been powerfully exhausting, we should expect that
their refuse or residue, however considerable in quantity, could
do no more than lessen the amount of exhaustion produced; in
which case, its useful influence, however real, would pass unno-
ticed, were it estimated by the produce of the succeeding crop.
If, on the contrary, a crop has been but slightly scourging,
whether in consequence of the smallness of its quantity, or be-
cause it may have derived from the air the major part of its
constituent elements, the useful influence of the residue will not
fail to be conspicuous. When the relative value of different
systems of rotation are discussed in the way we have done, we
in fact estimate the value of the elementary matter derived from
the atmosphere by an aggregate of crops; but the procedure
generally followed is silent when the question is to assign to each
crop in particular the special share which it has had in the total
profit. To reply to this question, of which a knowledge of the
various residues is one of the elements, we must first ascertain
the quantity of elementary matter supplied by the soil and the
atmosphere, with reference to each of the crops which enter into
the rotation; in other words, the same investigations must be
undertaken in reference to each plant considered by itself, that
have been made in reference to the series collectively. There is
unquestionable room, in this direction, for an important series of
experiments.
II 2
490 INORGANIC ELEMENTS OF MANURES AND CROPS.
§ 3. OF THE INORGANIC SUBSTANCES OF MANURES AND CROPS.
We have but just considered the organic matter developed in
a series of successive harvests. To complete the study of rota-
tions, to the extent at least that this can be done in the present
state of science, we have still to examine the relations that may
exist between the mineral substances which enter into the con-
stitution of the produce, and those that make part of the ma-
nure given.
We have already shown in a general way that certain mineral
salts, certain saline matters or salifiable bases are essential to the
constitution of vegetables. To the best of my knowledge no
seed has yet been met with that is without a phosphate; and it
is now known that the alkaline salts powerfully promote vegeta-
tion.
Such is their ascertained influence, indeed, that tobacco, barley,
and buckwheat sown in soils absolutely without organic matter,
but containing saline substances, and only moistened with dis-
tilled water, produced perfect plants, which flowered and fruited,
and yielded ripe seeds.* Whence it follows, that the presence
of saline matter favours remarkably the assimilation of the azote
of the atmosphere during the act of vegetation.
The importance of considering rotations in connexion with
the inorganic substances that are assimilated by plants was per-
fectly well known to Davy. "The exportation of grain from a
country which receives nothing in exchange that can be turned
into manure, must exhaust the soil in the long run," says the
illustrious chemist; who ascribed to this cause the present
sterility of various parts of Northern Africa and of Asia Minor,
as well as of Sicily, which for a long succession of years was the
granary of Italy. Rome unquestionably contains in its cata-
combs quantities of phosphorus from all the countries of the
earth.
Professor Liebig in insisting with the greatest propriety on the
useful part played by alkaline bases and saline matters in vege-
tation, has shown the necessity of taking inorganic substances
into serious consideration in discussing rotations. It is long since
* Liebig in Journ. de Pharmacie, vol. iv, 3rd series, p. 94.
INORGANIC ELEMENTS OF MANURES AND CROPS. 491
I came to the same conclusion myself; but it strikes me, that
to be truly profitable, such a discussion must necessarily repose
on analyses of the ashes of plants which have grown in the
same soil, and been manured with the same dung, the contents of
which in mineral elements were already known. There is in
fact a kind of account current to be established between the in-
organic matter of the crop and that of the manure. Although
I give every credit to the fidelity of the analyses of vegetable
ashes that have been published up to the present time, I have
not felt myself at liberty to make use of any of them in the direc-
tion which I now indicate. I have not thought that it would be
fair or reasonable to contrast such heterogeneous compounds, as
the ashes of plants grown at Geneva and Paris, under such dis-
similar circumstances, with those of vegetables produced on a
farm of Alsace, where the point to be explained, through the re-
sults of this contrast, had reference to a particular series of
agricultural phenomena. And then my business was not merely
with the scientific question; the manufacturing or commercial
element in the consideration also touched me. I had to ascer-
tain how I was likely to stand at some future time, did I pre-
sume to act upon the conclusions to which I came.
There was
nothing for me therefore but to analyse the ashes of the several
vegetables which entered as elements into the rotation followed
at Bechelbronn, but confining my inquiries to that portion of
the vegetable which is looked upon particularly as the crop, so
much of the plant as remains on the ground and is turned in
again, of course taking nothing from it.
The ashes examined were almost all from the crops of 1841,
two analyses having generally been made of each substance:
and here I ought to say, that in this long and tedious labour, in
which I spent nearly a whole year, I was most ably seconded by
Mr. Letellier. By way of preface, I should say that in these ana-
lyses, losses will frequently be apparent, which for the most part
exceed the limits that in the present day are tolerated in the more
careful operations of the laboratory. These deficiencies, which
puzzled me a good deal at first, I by and by discovered to pro-
ceed from the difficulty of incinerating certain vegetable sub-
stances completely. When they abound in alkaline salts, they
492
INORGANIC ELEMENTS OF MANURES AND CROPS.
leave ashes that melt so readily, that it becomes difficult to pre-
vent their agglutination, and the charcoal that is not consumed
is then effectually protected against any further action of the
fire. There is nothing for it in such cases but to incinerate at
the lowest temperature possible, and then a little moisture is apt
to be left; the charcoal, however, is the substance that occasions
the main difficulty, and the more important loss. To quote one
of the instances, that of wheat, where the loss or deficiency is as
high as 2.4 per cent. I may say that a direct inquiry after charcoal
brought it out equal to 2, by which the actual deficiency is re-
duced to 0.4. I have not, however, introduced any correction.
for carbon, but present the reader with the results as they ac-
tually presented themselves to me. Among the number of the
products of the analyses, alumina figures beside the oxide
of iron. Alumina is an earth which I have always met
with in minimum quantity in the ashes of plants, and is
perhaps accidental; it may proceed from the earth which ad-
heres to all herbaceous plants, and from which it is so difficult
to free them completely.
COMPOSITION OF THE ASHES PROCEEDING FROM THE PLANTS GROWN
AT BECHELBRONN.
Substances which
yielded the ashes.
Potatoes.
Mangel-wurzel
Turnips
Potato tops.
Wheat
Wheat-straw
Oats
Oat- straw
Clover
Peas
·
French beans
Horse beans
•
Car-
bonic.
Acids.
Sul-
phuric.
Phos-
phoric. j
Chlorine.
Lime.
Magnesia.
13.4 7.1 11.3 2.7 1.8 5.4
16.1 1.6 61 5.2 7.0
140 10.9 6.0 29 10.9
11.0 2.2 10.8 1.6 2.3
470 traces 2.9
0.0 1.0
1.0 3.I 0.6
8.5
3.7
3.2
25.0
0.0
1.7 1.0 14.9 0.5
4.1 3.0 4.7 8.3
6.3 2.6 24.6
30.1 1.1 10.1
26.8 0.1 5.8
0.5
2.5
4.7
3.3 1.3
1.0
Potash.
Soda.
Silica.
1.6 34.2 0.7 5.1 8.6 45.2 0.0
·
0.7
51.5 traces 5.6
4.4 39.0 60 80
4.2
5.5
7.6
24
4.3 33.7 4.1 6.4 1.2
1.8 44.5 traces 13.0 5.2
15.9 29.5 traces 1.3 0.0
5.0 9.2 0.3 67.6 1.0 3.7
7.7 12.9 0.0 53.3 13 3.0
2.8 245 4.4 40.0 2.1 2.9
6.3 26.6 0.5 5.3 0.3 0.0
11.9 35.3 2.5
1.5 traces 2.3
11.5 49.1 0.0 1.0 traces 1.1
0.5 traces 3.1
Oxide of iron,
alumina, &c.
loss.
Charcoal,
moisture and
O2-
05
55
2.5
If these analytical results be now applied to the produce of an
acre of ground, we should have the precise quantities of mineral
substances abstracted from the soil by each of the several crops
that enter into the rotation. Here they are in a table:
INORGANIC ELEMENTS OF MANURES AND CROPS.
493
MINERAL SUBSTANCES TAKEN UP FROM THE SOIL BY THE VARIOUS CROPS
GROWN AT BECHELBRONN UPON ONE ACRE.



Crop.
Potatoes.
Beetroots
•
Half crop of turnips,
consumed off the
ground
Potato tops
Wheat
Wheat-straw
•
·
•
Oats
Oat-straw
Clover
Manured Peas
French beans
Horse beans
•
•
•
Dry crop.
Ashes per cent.
Quantity of
ashes per
acre.
lbs. lbs.
3085 4.0
3172 6.3
716
7,6
5500
6.0
1148
2.4
2790
7.0
1064
4.0
1283 5.1
4029 7.7
993 3.1
1580 3.5
2121 3.0
Acids.
Phos-
phoric.
phuric.
Sul-
Chlorine.
I
Lime.
Magnesia.
Potash & soda.
Silica.
lbs. lbs. lbs.
6.7 63.5
8.8 89.9
6.9
16.0
2.3
20.6
3.5
5.9 146.8
42.9
4.4
8.1
0.4
9.8
18.6
3.3
5.5
1.8
18.9
84.1
Oxide of iron,|
alumina, &c.
lbs. lbs. lbs. lbs. lbs.
8.8
123.4 13.9
199.8 12.0 3.2
3.3
2.2
10.4
14.0
54.4 3.3
5.9
1.6
5.9
330.0 35.6
5.3
7.6
27.5 12.9
0.0 0.8
16.6
1.2
132.0
1.6
22.7
7.3
0.3
195.3 6.0 2.0
42.6 6.4 0.4 0.2
65.4 1.9 2.7 3.1
310.2 19.5
7.7
8.1 76.3 19.5
16.4 0.9
30.9 9.3 1.5 0.3 3.1 3.7
0.5 traces
55.3 14.8
0.7
0.1 3.2 6.4 27.1 0.6 traces
63.6 21.8 1.0 0.5 3.2 5.5 28.7 0.3 traces
5.4
26.2
11.7
lbs.
18.6
5.0
0.7
17.2
"
2.0
0.6
1.4
On looking at this table we perceive that a medium crop of
wheat takes from one acre of ground about 12lbs. and a crop
of beans about 20lbs. of phosphoric acid; a crop of beet takes
11lbs. of the same acid, and farther, a very large quantity of
potash and soda. It is obvious that such a process tends con-
tinually to exhaust arable land of the mineral substances useful
to vegetation which it contains; and that a term must come
when, without supplies of such mineral matters, the land would
become unproductive from their abstraction. In bottoms of
great fertility, such as those that are brought under tillage amidst
the virgin forests of the New World at the present day, it may
be imagined that any exhaustion of saline matters will remain
unperceived for a long succession of years; for a succession of
ages almost. And in South America, where the usual prelimi-
nary to cultivation is to burn the forest that stands on the
ground, by which the saline and earthy constituents of millions
of cubic feet of timber are added to the quantities that were al-
ready contained in the soil, I have already had occasion to
speak of the ample returns which the husbandman receives for
very small pains.* Under circumstances, in the neighbour-
* The first breaks of the early English settlers in North America, are
now either very indifferent soils, or they have only been restored to some
portion of their original fertility by manuring; so that the supply of ferti-
lising elements is not inexhaustible.-ENG. En.
II 3
494
INORGANIC ELEMENTS OF MANURES AND CROPS.
hood of large and populous towns for instance, where the interest
of the farmer and market-gardener is to send the largest possible
quantity of produce to market, consuming the least possible
quantity on the spot, the want of saline principles in the soil
would very soon be felt, were it not that for every waggon-load
of greens and carrots, fruit and potatoes, corn and straw, that
finds its way into the city, a waggon-load of dung containing
each and every one of the principles locked up in the several
crops, is returned to the land, and proves enough, and often
more than enough, to replace all that has been carried away
from it. The same principle holds good in regard to inorganic
matters, which we have already established with reference to
organic substances.
The most interesting case for consideration is that of an iso-
lated farming establishment -a rural domain, so situated that it
can obtain nothing from without, but exporting a certain pro-
portion of its produce every year, has still to depend on itself for
all it requires in the shape of manure. I have already shown
with sufficient clearness, I apprehend, how it is that lands in cul-
tivation derive from the atmosphere the azotised principles neces-
sary to replace the azotised products of the farm, which are con-
tinually carried away in the shape of grain, cattle, &c. I have
now to show how the various saline substances, the alkalies, the
phosphates, &c., which are also exported incessantly, are replaced.
I believe that I shall be able, with the assistance of chemical
analysis, to throw light on one of the most interesting points in
the nature and history of cropping, and succeed in practically
illustrating the theory of rotations. In what is to follow imme-
diately, I shall always reason on the practical data collected at
Bechelbronn, and which have already served for the illustration
of other particulars. My farm, I may say by way of preliminary,
is an ordinary establishment; the lands which have been
brought by a system of rational treatment to a very satisfactory
state of fertility are not rich at bottom and originally, and they
fall off rapidly if they have not the dose of manure at regular
intervals which is requisite to maintain them in their state
of productiveness.
My first business was to determine the nature and the quan-
INORGANIC ELEMENTS OF MANURES AND CROPS.
495
tity of the mineral substances contained in my manure; and
with a view to arrive at this information, I burned considerable
quantities of dung at different periods of the year, mixed the
ashes of the several incinerations, and from the mixture took
a sample for ultimate analysis. The mean results are repre-
sented by .
Acids
Carbonic
Phosphoric
Sulphuric
Chlorine .
Silica, sand
Lime
Magnesia
Oxide of iron, alumina
Potash and soda
Silica
Alumina
Lime
But our farm-yard dung is not the only article we are in the
habit of giving to our land; it farther receives a good dose of
peat-ashes and gypsum.
I here recall to the reader's mind that
the mean composition of peat-ashes is this:
Magnesia
Oxide of iron
Potash and soda
Sulphuric acid
Chlorine
2.0
3.0
1.9
0.6
66.4
8.6
3.6
6.1
7.8
100.0
•
65.5
16.2
6.0
0.6
3.7
2.3
5.4
0.3
100.0
In the system followed at Bechelbronn, the farm-yard dung
laid upon an acre contains 26 cwts. 3 qrs. of ashes.
On our
clover leas we spread the first year 2 yards, 19 feet, 988 inches,
of turf-ashes; and in the beginning of spring of the second year,
we lay on as much more, in all, weighing about 2 tons. I do
not take the 8 cwts. of gypsum which, in conformity with usage,
the second year's clover generally receives, because I believe this
addition to be perfectly useless after the very sufficient dose of
peat-ash which we employ.
The whole of the mineral substances given to the land in the
course of five years per acre is as follows, viz.: Ashes contained
496
INORGANIC ELEMENTS OF MANURES AND CROPS.
in the manure and in the peat-ashes, 7624 lbs. ; consisting of
phosphoric acid 250 lbs., sulphuric acid 160 lbs., chlorine 50lbs.,
lime 652.5 lbs., magnesia 300 lbs., potash and soda 680 lbs.
silica and sand 4680 lbs., oxide of iron, &c. 500 lbs.
It is therefore easy to perceive, from the preceding data, that
what with the manure and the ashes it receives, the land is more
than supplied with all the mineral substances required by the
several crops it produces in the course of the rotation. Let us
cast a glance over these with reference to their mineral or inor-
ganic constituents, as we have already done in so far as the
organic matters are concerned; let us compare, in a word, the
quantity and the nature of the mineral substances removed in
the course of five successive years in contrast with the quantity
and the nature of the same substances supplied at the commence-
ment of the series, and we shall find that the sums of the phos-
phoric acid, sulphuric acid, and chlorine, and of the alkaline and
earthy bases of the crops, are always smaller than the quantities
of the same substances which exist in, and are supplied to the
arable soil.
I shall institute the comparison with the rotation No. 1, which
begins with potatoes; and farther with a continuous crop which,
as the one which is most common and convenient, shall be Jeru-
salem artichokes. I have not thought it advisable to discuss
the rotation No. 2, in which beet replaces the potato, because the
ashes of these two crops are so much alike, that it may be as-
sumed to be matter of indifference which of the two enters as
the drill-crop element into the series. With reference to the
Jerusalem artichoke, I shall only remind the reader that the
piece of land where it grows receives a dose of manure every
two years, in the proportion of 41245lbs. per acre, which manure
contains 2776lbs. of mineral constituent. Farther, in the course
of each winter peat ashes, in the ratio of 2700 lbs. pcr acre are
laid on the land: and that the stems are generally incinerated on
the spot, and the ashes they contain returned directly to the soil.
INORGANIC ELEMENTS OF MANURES AND CROPS.
497
TABLE OF THE MINERAL MATTERS OF THE
Average crop per acre.
ROTATION No. 1.
Potatoes
2nd and 4th years: wheat
Ditto wheat-straw.
3rd year clover
5th year: oats.
Ditto oat-straw
2nd crop turnips; half crop
•
Sum of mineral substances
Mineral substances of the manure
COURSE OF A ROTATION.
•
•
Excess over the mineral matters of
the crops
INCESSANT PRODUCTION OF THE
JERUSALEM POTATO.
1st and 2nd years: mineral matters
of the tubers.
Mineral matters of dung
Ditto of turf asbes
Whole mineral matters of manures
Difference in favour of the manures
Mineral
substances
in the
crops.
lbs.
123.4
55.0
390.6
310.2
42.6
65.4
54.4
1010.9
8272.0
660.0
3029.0
5000.0
:
Acids.
ཡིན་
Phos- Sul-
phoric phuric
CROPS AND MANURES IN THE

lbs. lbs.
13.9 8.8
25.8 0.6
12.0 4.0
19.5 7.7
6.4 0.4
1.9 2.7
3.3 5.9
82.8 30.1
98.0 1332 0
15.2 301.9
••
Chloride
•
2.4
8.1
0.2
3.0
1.6
18.6
35.0
Lime.
lbs. lbs. lbs. lbs. lbs
3.3
6.7 63.5 6.9
8.8 16.2 0.8
19.6 37.2 264.0
19.5
2.2
1.6
84.1 16.4
3.3 5.5 22.7
1.8 18.9 26.2
2.3 20.6
3.5
33 2
76.3
1.6
5.4
5.9
126.2
581.0
16.4 454.8
71.2❘ 14.6 10.6 15.2
91.0 57.6
270.0
91.0 327.6
19.8 313.0
•
Mag-
nesia.
Potash
and
Soda.
Silica.

62.0 246.0 340.5
148 0 370.0 5508.0
11.8293.6 85.8
18.2 260.5 109.0236.3 2011.0
15.0 300.0 30.0 115.0 3275.0
33.2 560.5 139.0 351.3 5286.0
22.6 545.3 127.2 57.7 5200.2
86.0124.0 5167.5
It was at one time asserted, that in order to ensure to a crop
of wheat the necessary quantity of phosphates, its cultivation
was preceded by one of roots or tubers or leguminous plants, which
were supposed to contain a much less proportion of these salts.
By reference, however, to the table of mineral substances removed
from the soil by different crops, the absurdity of such reasoning
becomes evident. For example, beans and haricots take 20 and
13.7lbs. of phosphoric acid from every acre of land; potatoes
and beet-root from the same surface take but 11 and 12.8lbs.
of that acid, exactly what is found in a crop of wheat. Clover is
equally rich in phosphates with the sheaves of corn which
have gone before it, and this large dose of phosphoric acid
withdrawn from the soil, will nowise diminish the amount which
will enter into the wheat that will by and by succeed the arti-
ficial meadow. It may be readily understood, that if the ground
contains more than the quantity of mineral substances necessary
for the total series of crops in a rotation, it is a matter of
indifference whether the crops draw upon the soil in any par-
II 4
498
INORGANIC ELEMENTS OF MANURES AND CROPS.
ticular order, and these succeed according to rules generally
adopted for quite different reasons.
It suits well, for instance, to
begin a rotation with a drill crop sown in spring, and which
consequently follows in our system the oats which closed the
preceding rotation; it is a great advantage to be able to collect and
cart out the manure during winter. Besides, the order is quite
at the farmer's discretion, and there are places where from par-
ticular reasons, quite another course is pursued. One part of
the produce returns, as has been shown, to manure, after having
served as fodder for the animals belonging to the farm. The
inorganic matters are restored to the earth from which they
came, deducting the fraction assimilated in the bodies of the
cattle. Lastly, the whole of the wheat and a certain amount of
flesh will be exported, and with these a notable quantity of
inorganic matter. Thus, in the above described rotation of five
years, the minimum exportation of saline substances which
must be removed from every acre of land, may be represented
by 27 lbs. of phosphoric acid and from 36 to 45lbs. of alkali;
this is just so much lost for the manure; and as there is defini-
tively found at the end of the rotation a quantity of manure equal
and nearly similar to that disposed of at the commencement, it is
essential that the loss of mineral substance be made up from
without, unless it be naturally contained in the soil.
In my first researches on the rotation of crops,* I stated
that wherever there are exportable products, it becomes indis-
pensable to keep a large proportion of meadow land, quoting
as an extreme case, the triennial rotation with manured sum-
mer fallow. It is, in fact, the meadow which restores to the
arable land the principles which have been carried off. This
point, advanced upon analogy, is amply confirmed by the results
of analysis.
I have examined, in reference to this question, the ashes of
the hay of our meadows of Durrenbach, irrigated by the Sauer.
The analysis were made with ashes furnished by the crops of
1841 and 1842.
* Memoir communicated to the Académie des Sciences, in 1838.
INORGANIC ELEMENTS OF MANURES AND CROPS.
499
I.
Carbonic .9.0
Phosphoric 5.3
Sulphuric 2.4
2.3
20.4
. 6.0
16.1
Soda
1.2
Silica
33.7
Oxide of iron, &c. .1.5
Loss
2.1
Acids
Chlorine
Lime
Magnesia
Potash
در
•
100.0
100.0
No. 1 yielded 6.0 per cent of ash.
No. 2
6.2 idem.
Acids
Chlorine
Lime
11.
5.5
5.3
2.9
2.8
15.4
8.3
27.3
2.3
29.2
0.6
0.4
Carbonic
Phosphoric
Sulphuric
III.
Magnesia
Potash and soda
Silica
Oxide of iron, and loss
"
5.5
""
""
21
""
"
در
0.5
""
In admitting as the average yearly return of our irrigated
meadows, 3666 lbs. of hay and after-grass for the acre, it ap-
pears that we obtain from a corresponding surface of land
223.6 lbs. of ash, containing:
Average.
7.3
5.4
2.7
2.6
17.9
7.2
21.7
1.8
31.5
0.9
1.0
100.0
16.3
12.1
6.0
5.7
39.1
16.1
52.0
70.4
4.2
221.9*
In reckoning, as I have done, the lowest annual exportation
of mineral substance from one acre of arable land at 5.5 lbs. of
phosphoric acid and 8.2 lbs. of alkali (potash and soda), there
must, in order to make up for loss, arrive each year at the
farm a quantity of hay corresponding to about 1800 lbs. for
every acre of ploughed land, which would establish between
the arable and meadow land, a relation somewhat less than 1 to
In practice, the relation in question is sensibly less than that
deduced from analysis; in some farms the meadow land only oc-
cupies a fourth or fifth of the whole surface. When rye replaces
wheat, the extent in meadow-land may be still more limited. It
deserves notice, that I have supposed the arable land as destitute
of proper inorganic matter, and that all came from the manure
* The sum is only too small here from the number of places of decimals
not having been carried out far enough.-ENG. ED.
500
INORGANIC ELEMENTS OF MANURES AND CROPS.
ashes and lime laid on, which is not rigorously true. There are
soils containing traces of phosphates, and it is difficult to find clay
or marl exempt from potash. Nevertheless, many clear-headed
practical men begin to suspect that meadow has been too much
sacrificed to arable land. In localities placed in similar con-
ditions to those in which we are, removed from every source of
organic manures, which, as I have shown in concert with
M. Payen, are always furnished with saline principles, an
attempt has been made to imitate what is done in more fa-
voured districts, where it is possible, for example, to add
animal remains to the manure. The corn crops felt this new
procedure; nor could it be otherwise. But now there is a reaction
in the opposite sense, and I could name most thriving establish-
ments, where one half of the farm is in meadow. The ever-
increasing demand for butcher-meat will further this movement,
to the great advantage of the soil. In consequence of our pecu-
liar position at Bechelbronn, nearly half our land is meadow,
which allows of a large exportation of the produce of the arable
land. In applying the results of the preceding analyses, I find
that each year, provided there is no loss, the hay ought to bring
at least :
1254 lbs. of phosphoric acid
627
sulphuric acid
chlorine
602
lime
magnesia
potash and soda
silica
4155
1672
5456
7312
>>
""
"
>>
""
"
This large amount of mineral substances is supplied by the
meadows, which have no other manure than the water and mud
thereby deposited, after flowing over the Vosges' freestone; they
receive no manure from the farm, but are merely earthed with the
sludge and mire borne down by the stream; these are real
sources of saline impregnation. Meadows without running
water ought not to be ranged in the same category, they only
give the principles naturally contained in them; hence, they must
be always manured every three or four years, and indeed, if not
situate upon a naturally rich soil are, according to my experience,
very far from profitable.
The excess of mineral matters introduced into the ground
INORGANIC ELEMENTS OF MANURES AND CROPS. 501
over those that issue with the crops, an excess that ought always
to be secured by judicious management, enriches the soil in
saline and alkaline principles which accumulate in the lapse of
years, just as vegetable remains and azotised organic principles
accumulate under a good system of rotation. By this, even in
localities the most disadvantageously situate for the purchase of
manure, temporary recurrence may be had to the introduction
of such crops as flax, rape, &c. which being almost wholly
exported, leave little organic residuum in the earth, and at the
same time carry off a considerable quantity of mineral substance;
circumstances which determine, as may be easily conceived, the
maximum of exhaustion, and for that reason, tend to reduce
a soil becoming over-rich to what may be called the standard
fertility.
In reviewing the chief points examined, it will be seen, that
as far as regards organic matter, the systems of culture which
in borrowing most from the atmosphere, leave the most abun-
dant residues in the land, are those that constitute the most pro-
ductive rotations. In respect to inorganic matter, the rotation
to be advantageous, to have an enduring success, ought to be so
managed that the crops exported should not leave the dung-hill
with less than that constant quantity of mineral substance which
it ought to contain. A crop which abstracts from the ground.
a notable proportion of one of its mineral elements, should not
be repeatedly introduced in the course of a rotation, which de-
pends on a given dose of manure, unless by the effect of time
mineral element has been accumulated in the land. A clover
crop takes up, for example, 77 lbs. of alkali per acre. If the
fodder is consumed on the spot, the greater portion of the
potash and soda will return to the manure after passing through
the cattle, and the land eventually recover nearly the whole of
the alkali. It will be quite otherwise if the fodder is taken to
market; and it is to these repeated exportations of the produce
of artificial meadows that the failure of trefoil now observed
in soils which have long yielded abundantly, is undoubtedly due.
Accordingly, a means has been proposed of restoring to these
lands their reproductive power, by applying alkaline manure. *
If under such circumstances carbonate of soda would act as
* Information communicated by M. Schattenmann.
502 INORGANIC ELEMENTS OF MANURES AND CROPS.
favourably as carbonate of potash or wood-ashes, the soda salt,
in spite of its commercial value, might prove serviceable, and
deserves a trial.
The lime manures naturally promote the growth of plants of
which calcareous salts form a constituent; but here a capital
distinction must be made. A soil may contain from 15 to 20
in the 100 of lime, and still be unable to dispense with calcareous
manure; because the lime is in some other state than as it exists.
in chalk, as in the rubbish of pyroxene, mica, serpentine, and
the like. A soil of this kind, although replete with lime,
might still require gypsum for artificial meadow, and chalk for
wheat and oats. It is from the carbonate that plants of rapid
growth derive the lime essential to them, as was established by
the researches of Rigaud de Lille, researches which have been
censured by agricultural writers to whom they were unintel-
ligible. I advocate the opinion of Rigaud, because in the Andes.
of Riobamba, I have seen lucerne growing in augitic rubbish,
very rich in calcareous matter, and yet greatly benefited by
limeing.
The operation of gypsum is to introduce calcareous matter
into plants. This I have endeavoured to demonstrate from the
analysis of the ash on the one hand, and on the other, from the
consideration that finely divided carbonate of lime, as it exists in
wood-ashes, acts with equal efficacy upon artificial meadows.
By what means gypsum, if it does not enter the vegetable as
a sulphate, parts with its sulphuric acid, is at present conjec-
tural. It appears highly probable that calcareous matter is
chiefly beneficial from the particular action it exercises on the
fixed ammoniacal salts of the manure, transforming these suc-
cessively, slowly, and as they may be wanted, into carbonate of
ammonia. In the most favourable condition, the earth is only
moist, not soaked with water, but permeable to the air. New
researches will perhaps illustrate the utility of ammoniacal
vapours thus developed in a confined atmosphere, where the
roots are in operation. At least, it would be difficult to assign
any other office to chalk in the marling or limeing of land
intended for corn, when we know how little lime corn absorbs. If,
indeed, gypsum promotes the vegetation of trefoil, lucern, saint-
foin, &c. by furnishing the needful calcareous element, it could not
INORGANIC ELEMENTS OF MANURES AND CROPS. 503
fail to exercise an equally favourable agency upon wheat and oats,
did they require it. The experiments adduced prove it not to be
so, and their results are in some measure corroborated by analysis.
Thus, if we compare the different quantities of lime withdrawn
from the soil by trefoil and corn, we find them as follows:
The clover crop takes from 1 acre of ground nearly 70 lbs. of lime
Wheat
16
6.4
Oat
در
""
در
"
""
>>
2)
K K
د.
With this comparison before us, it seems evident that if the
marling and limeing of corn lands had no other object than
the introduction of the minute portion of lime which is encoun-
tered in the crops, it would be difficult to justify the enormous
expenditure of calcareous carbonate which is proved by daily
experience to be advantageous.
It may be inferred from the foregoing, that in the most fre-
quent case, namely, that of arable lands not sufficiently rich to
do without manure, there can be no continuous cultivation
without annexation of meadow; in a word, one part of the farm
must yield crops without consuming manure, so as to replace the
alkaline and earthy salts that are constantly withdrawn by succes-
sive harvests from another part. Lands enriched by rivers alone
permit of a total and continued export of their produce without ex-
haustion. Such are the fields fertilized by the inundations of the
Nile; and it is difficult to form an idea of the prodigious quantities
of phosphoric acid, magnesia and potash, which in a succession of
ages have passed out of Egypt with her incessant exports of corn.
W
Irrigation is, without doubt, the most economical and efficient
means of increasing the fertility of the soil, out of the abundant
forage which it produces, and the resulting manure. Plants take
up and concentrate in their organs the mineral and organic
elements contained in the water, sometimes in proportions so
minute as to escape analysis; just as they absorb and condense,
in modified forms, the aeriform principles which constitute but
some 10,000th parts in the composition of the atmosphere. It
is thus that vegetables collect and organize the elements which are
dissolved in water, and disseminated through the earth and the
air, as a preparative to their being assimilated by animals.
504
CHAPTER VIII.
OF THE FEEDING OF THE ANIMALS BELONGING TO A FARM ;
AND OF THE IMMEDIATE PRINCIPLES OF ANIMAL ORIGIN.
§ 1. ORIGIN OF ANIMAL PRINCIPLES.
Ir is now generally admitted that the food of animals must
necessarily contain azote; and this circumstance has led to the
inference, that the herbivorous tribes obtain from their food the
azote which enters into the constitution of their bodies.
In a general way, the individual consuming a certain portion
of food every day, nevertheless does not increase in his average
weight. This is what occurs with animals upon the quantity of
food which is known to be sufficient for their keep; and it has
been found that the human subject, living very regularly, returns
at a certain hour, or at certain hours of the day, to a certain
mean weight. Grooms, farm-servants, &c., are perfectly well
aware of the fact, that with a certain allowance of hay and corn,
a horse will be kept in the condition necessary to do the work
required of him without either gaining or losing in flesh.
Under such circumstances, the whole of the elementary matter
contained in the food consumed, ought to be found in the dejec-
tions, the excretions, and the products of the act of respiration.
And assuming that this is so, it might then be maintained that
none of the elements is assimilated, assimilation being taken in
the sense of an addition of principles introduced with the food
to the principles already present in the body. Yet is there
unquestionably assimilation, in the sense that the alimentary
matters of the food become fixed in the system, having there
undergone modification or change; and that they replace, or
come instead of other elements of the same kind, which are
daily thrown off by the vital acts of the economy.
During the nutrition of a young animal, and also in the
process of fattening an adult, things go on differently; here
there is unquestionably definitive fixation of a portion of the
matter contained in the food: there is no longer balance between
the waste and the supply; an animal then increases in weight
notably and rapidly.
Looking at the question of feeding in the most general way,
then, I admit that an adult animal, upon the daily allowance,
ORIGIN OF ANIMAL PRINCIPLES.
505
voids a quantity of matter in its various excretions precisely
equal to the quantity which it receives in its food:* all the
elements, the same in nature and in quantity, which are con-
tained in the food, are also contained in the excrements, vapours
and gases, which pass off from the living body; carbon and
azote, hydrogen and oxygen, phosphorus, sulphur and chlorine,
calcium, magnesium, sodium, potassium and iron, as they are
all encountered in the food, so are they all encountered in the
body, and also in the excretions of an animal; and it seems
certain, that no one of these primary or simple substances can
be wanting in the nutriment without the body very speedily
feeling the ill effects of its absence. Iron, for example, is a
constant principle in the colouring matter of the blood; it also
exists in large quantity in the hair; and he who should live on
food that contained no trace of it, would certainly, and before
long, become disordered in his health.
In what has just been said, I take it for granted that animals
do not absorb or assimilate any of the azote which forms so
large a constituent in the air they breathe; and I am warranted
in this by the researches of every physiologist of any name or
distinction. Not only do animals obtain no azote from the
atmosphere, but they actually exhale it incessantly, as was proved
by M. Despretz in the course of his numerous experiments, and
as I myself also demonstrated in the inquiries I undertook to
ascertain whether herbivorous animals obtained azote from the
air or not. The azote exhaled, it was discovered, proceeded
entirely from the food consumed by the animal; a fact, which
already of great importance in a physiological point of view and in
reference to general physics, bears at the same time so imme-
diately upon one of the most important questions of agriculture,
that I think it well to give the particulars of one of the proce-
dures by which it has been established.
The experiments in this case were performed on a milch-cow
and a full-grown horse, which were placed in stalls so contrived
that the droppings and the urine could be collected without
loss. Before being made the subjects of experiment, the animals
were ballasted or fed for a month with the same ration that was
furnished to them during the three days and three nights
*Boussingault, Annales de Chimie, 2e série, t. LXXI, p. 113.
Į KK 2
506
ELEMENTS OF FOOD AND OF EXCRETIONS.
which they passed in the experimental stalls. During the
month, the weight of the animals did not vary sensibly, a cir-
cumstance which happily enables us to assume that neither did
the weight vary during the seventy-two hours when they were
under especial observation.
The cow was foddered with after-math hay and potatoes;
the horse with the same hay and oats. The quantities of
forage were accurately weighed, and their precise degree of
moistness and their composition were determined from average
samples. The water drunk was measured, its saline and earthy
constituents having been previously ascertained.
The excre-
mentitious matters passed were of course collected with the
greatest care; the excrements, the urine, and the milk were
weighed, and the constitution of the whole estimated from
elementary analyses of average specimens of each. The results
of the two experiments are given in this table:
FORAGE.
Hay
Oats
Water
Total
·
•
•
•
•
Weight
in the wet in the dry
Weight
state.
state.
FOOD CONSUMED BY THE HORSE IN 24 HOURS.
Elementary matter in the food.
lbs.
20
6
43
69
Urine
Excrements
nts 38 2
lbs. Oz.
17 4
5 2
With the hay
With the oats
•
Taken as drink .
Total consumed
22
Weight Weight
PRODUCTS. in the wet in the dry
state.
state.
6
Total
Total mat-
ter of the
food
Difference. 27 3 312 3 0
Carbon.
lbs.
•
lbs. oz. dwts. lbs. oz. dwts. lbs. oz. dwts
3 6 15 0 9 14 0 3 10
2 9 5 6 3 7 17
41 8 17
0
3 11 7
10 3
22 6 0
69 0 0
10 6 0
·
oz.
7 11
2
7
10 6
Carbon.
WATER CONSUMED BY THE HORSE
IN 24 HOUrs.
PRODUCTS VOIDED BY THE HORSE IN 24 HOURS.
Elementary matter in the products.
lbs. oz.
2
3
0
14
35 3
4
388
Hydrogen.
Oxygen.
lbs. oz. dwts. lbs. cz. dwts lbs. oz. dwts. lbs. oz. dwts.
0 10 7
3
1 6 14
0 3 18
14
0 3 2
0 1 7
0 2 10
0 0 8
1 9 12
•
1 2 5
6 6 131 08 3
68
1 10
8 7
Water exhaled by pulmonary and cutaneous transpiration
2
With the urine
With the excrements
Azote.
Total voided
Water consumed
0 4
Hydrogen.
Oxygen.
lbs. oz. dwts. lbs. oz. dwis. lbs. oz. dwts. lbs. oz. dwts.
0 0 7
0 3 10
0 5 15
1 6 10
0 1 2
3 6 14
3 7 16
1 10 0
0 6 2
1 2
5
8 7 2
1 9 12
•
Azote.
4 11 600 15
•
9
0 1 4
0 2 10
0 3 14
0 4 9
WATER VOIDED BY THE HORSE
IN 24 HOurs.
Salts and
earths.

·
Salts and
ea ths.
0 0
lbs.
2 6
23
8
28565
8
03.
ska jakna
14
4
38
12 6
ELEMENTS OF FOOD AND OF EXCRETIONS.
507
FODDER.
•
•
•
FOOD CONSUMED BY THE COW IN TWENTY-FOUR HOURS.
Elementary matter of the food.

Weight
in the wet
state.
Hydrogen. Oxygen.
0 1 12
lbs. oz. dwts. lbs. oz. dwts. lbs. oz. dwts. lbs. oz. dwts. lbs. oz. dwts lbs. oz. dwts. lbs. oz. dwts.
Potatoes 40 2 5 11 2 1 4 11 2 0 7 15 ! 4 10 17
0 G 13
After math
hay
Water. 160 0
20 1 2
7 11 11
0 11
7
5 10 17
0
Total
1220 3
7
•
Weight
PRODUCTS. in the wet
state.
<
Weight
in the dry
state.
With the potatoes
With the hay
Taken as drink
Total consumed
•
16 11 0
•
28 1 1
Weight
in the dry
state.
Carbon.
12 10 13
11 8 12
PRODUCTS VOIDED BY THE COW IN TWENTY-FOUR HOURS.
Carbon.
WATER CONSUMED BY THE COW IN
TWENTY-FOUR HOURS.
5 11 3
lbs.
23 12
2
132
153
oz.
I 7 2
ဘဝ
Hydrogen.
Oxygen.
4 0 9
lbs. oz. dwts. lbs. oz. dwts. lbs. oz. dwts. lbs. oz dwts. lbs. oz. dwts. lbs. oz. dwts. lbs. oz. dwts
Excrements 76 1 9 10 8 12 4 7 0 0 6 13
Urine
21 11 12
0 8 7 0 0
22 10 10
1 8
0 3
1 3 8
1 0 6
2 6
17
16
0 8
0 2 19
0 1 3
0 1 9
3
Milk.
3
1
0
3
3
0 10
6
0 1 1G
120 11 11
16 4
9
6 11 10
0 10 12
5 6 18
Total
Total mat-
ter of the 220 3 7
food
0 5 11
06 9
2 5 10
2 4 11
28 1
1
12 10 13
1 7
10 9 14
Difference 99 3 16
5
10 9 14
2
0 8 10 5 2 16
Elementary matter in the products.
With the potatoes
With the urine
With the milk
Water passed off by pulmonary and cutaneous transpiration
Total voided
Water consumed
Azote.
•
0 4 17
··
•
06 9
•
Azote.
Salts and
earths.
0 0 13
WATER VOIDED BY THE COW IN
TWENTY-FOUR HOURS.
6
1 8
0 1 12
2 4 11
Salts and
earths.
0 0 19
lbs.
53
15
16
02.
10
14
3
$5 11
158 5
72 10
From these sums it appears that the azote of the excrements is
less by from 339.6 to 455.0 grains than that of the forage
consumed. It appears also that the whole quantity of elementary
matter contained in the excrements is less than that which
had been taken as food; the difference is of course due to the
quantities which were lost by respiration and the cutaneous
exhalation.
The oxygen and hydrogen that are not accounted for in the
sum of the products, have not disappeared in the precise pro-
portions requisite to form water; the excess of hydrogen
amounts to as many as from 13 to 15 dwts. It is probable
that this hydrogen of the food became changed into water by
combining during respiration with the oxygen of the air.
508
COMBUSTION OF CARBON.
The loss of carbon which is very considerable, seeing that in
the two experiments it amounts to nearly 12 lbs. must have
gone to form the carbonic acid, which is known to be so large
and important a constituent in the expired air, and which is also
exhaled from the general surface of the body. Neglecting the lat-
ter, it appears that each of the animals produced in the course of
twenty-four hours, upwards of 13 cubic feet of carbonic acid
gas, the thermometer supposed at 32° F., the barometer at
30 inches.*
During respiration, then, or as a consequence of respiration,
the carbon and hydrogen of the food have disappeared and given
rise, by the concurrence of the oxygen of the air, to carbonic
acid and water, precisely as if they had been burned. And an
animal may, in fact, be regarded as an apparatus or system,
in which a slow combustion is incessantly going on: there is
perpetual disengagement of carbonic acid gas and of the vapour
of water, just as there is from a stove in which any organic
substance, wood, for example, is burning. In either case there
is evolution of heat; all animals have a temperature above that
of the medium which surrounds them, and the excess of the
elevation is in some sort relative to the activity of the respi-
ratory process, or in other words, to the intensity of the com-
bustion.
Under the influence of the oxygen that is taken into the
body, the soluble principles of the blood pass through a series of
modifications, the last of which is carbonic acid, which is exhaled
and dissipated in the air; and it is in this way that a portion of
the carbon of the food is returned to the atmosphere, after having
accomplished the important function of supplying the animal
with the heat that is necessary to its existence. Far from
deriving anything from the air, consequently, animals on the
* The large quantity of carbonic acid shows the necessity for large and
well ventilated stables and cow-houses. A cow, it appears, will vitiate
66 cubic feet of air in a day. It will be observed in the table that the
saline and earthy matters of the ejecta exceed those of the ingesta in both
instances. This is from error in observation, and is owing to the difficulty
of determining exactly the quantities of these substances. The error is
less in the case of the horse than in that of the cow.
509
contrary, are continually pouring carbon into it. The food is,
therefore, the only source whence animals derive the matter that
enters into their constitution; and as the primary food of animals
is obtained from vegetables, herbivorous creatures must neces-
sarily find in the plants they consume, all the elements they
assimilate. It might be expected from this, that the material
constitution of animals should approach, and sometimes even be
identical with that of vegetables; and it is found, in fact, that a
considerable number of ternary or quarternary organic compounds
of either kingdom present the greatest analogy to one another;
their identity, in some cases, is even complete. Some fatty
substances of animal origin do not differ in any way from
vegetable fats; the margaric acid which is obtained from hog's
lard has the precise characters of the margaric acid which is
furnished by olive oil, and the same identity is preserved
through the entire series of quarternary azotised principles, as a
glance at the following table, which contains the results of the
analyses performed by Messrs. Dumas and Cahours, will show.
IDENTITY OF ANIMAL AND VEGETABLE PRINCIPLES.

Carbon
Hydrogen
Oxygen
Azote
•
FIBRINE.
ALBUMEN.
CASEINE.

Animal. Vegetable.
Animal. Vegetable. Animal. Vegetable.
52.8
53.2
53.5
53.7
53.5
53.5
7.0
7.0
7.1
7.1
7.0
7.1
23.7
23.4
23.6
23.5
23.7
23.4
16.5
16.4
15.8
15.7
15.8
16.0
100.0 100.0 100.0 100.0
100.0 100.0

These principles, to which must be added gelatine, the fats
and several earthy and alkaline salts constitute the frame-work of
the animal tissues, or the fluids which penetrate them; it is
therefore necessary for us to examine each of them shortly.
Gelatine is met with in almost all the solid parts, in the
bones, tendons, cartilages, skin, cellular tissue, muscular flesh,—
all contain it. It is readily soluble in boiling water; cold water
only takes up a small quantity of it. Two or three parts of
gelatine dissolved in 100 parts of hot water, suffice to turn the
fluid into a tremulous jelly when it has become cold. Tannin,
or infusion of gall-nuts precipitates gelatine completely from its
510
FIBRINE, ALBUMEN.
solution, the precipitate being very bulky and perfectly insoluble
in water; and it is this chemical combination or principle which
lies at the bottom of the art of tanning.
Gelatine is extensively used in the arts under the familiar
name of glue. Isinglass consists of gelatine nearly pure, and
according to Mulder contains:
Carbon
Hydrogen
Azote
Oxygen
•
50.8
6 6
18.3
24.3
100.0
Fibrine occurs in a state of colution in the blood, and forms
the principal ingredient in muscular flesh. It is readily ob-
tained by whipping a quantity of blood just taken from the
veins of a living animal; the white stringy masses that adhere to
the rod are fibrine, which by gentle kneading under water be-
come colourless. Fibrine, when moist, is a highly elastic and
flexible substance; dried, it loses about 30 per cent of water
and becomes brittle, horny, semi-transparent. Thrown into
water, it gradually imbibes all it had lost by drying, and regains
its former properties. Burned and incinerated, fibrine leaves
a quantity of ash which consists, for the major part of phos-
phate of lime, with which is mixed a small quantity of phos-
phate of magnesia and of oxide of iron.
Albumen exists in large quantity dissolved in the water or
serum of the blood, and in the white of the egg; it is also
found in almost all the animal fluids that are not excretions or
destined to be thrown off as useless to the system. Albumen,
as familiarly known, has the remarkable property of coagulating
or setting into a soft solid, at a certain temperature,—158° F.
Caseum or caseine is the distinguishing principle of milk.
By combining with acids it forms an insoluble compound; and it
undergoes a remarkable coagulation, as all the world knows, in
contact with a piece of the inner membrane of the stomach of a
young animal: from a fluid it sets into a soft solid, which by
degrees separates into two portions, whey and curd. The curd,
or caseum, always contains fat, and when burned, leaves a
considerable quantity of ash.
FLESH, BONES.
511
Physiologists distinguish three principal tissues in the bodies
of animals; the muscular, the nervous, and the cellular.
The muscular tissue consists of an assemblage of contractile
fibres, here disseminated through the masses of organs, there
collected into bundles and constituting the flesh. This is the in-
strument by which animals perform all their voluntary motions,
and it is that also by which all the active but involuntary move-
ments of the body are excited. Muscular flesh is always a com-
pound substance, however; it consists of fibrine, the contractile
or proper element, albumen, fat, gelatine, an odorous extractive
matter, lactic acid, different salts and the colouring principle
of the blood.
Put into cold water, so long as the temperature is below from
130° to 140° F., little effect is produced beyond the solution of
the soluble salts which it may contain, and of a portion of its
extractive matter and albumen. At from 175° to 195º, the
albumen which had been dissolved coagulates and rises to the
top as scum, and the fat melts and floats on the surface. The
fibrinous element of the meat, however, preserves its characters
even after the action of boiling water continued for some time.
The nervous tissue constitutes the brain, spinal marrow, and
nerves distributed to all parts of the body. Brain in its compo-
sition contains a large quantity of water,-80 per cent, certain
fatty matters, albumen, osmazome, phosphorus in combination
with fat, sulphur, and phosphates of potash, lime and magnesia.
The composition of the brain of animals, the dog, the sheep,
the ox, appears to be very analogous to that of the human sub-
ject.
Cellular tissue is the general connecting medium throughout
the animal body, and is not only met with, it may be said every-
where, but forms a main element in many of the textures of the
body, such as the serous and mucous membranes, the cartilages,
the bones themselves, which are in fact only cellular tissue im-
pregnated with calcareous salts. Tendons may be viewed as
condensed ropes of cellular tissue; by long boiling in water they
melt entirely into gelatine.
Bones consist of cellular tissue, as stated, resolvable into ge-
latine, and of a large proportion of saline earthy matter, con-
512
BONES, BLOOD.
sisting principally of phosphate of lime. The presence of this
phosphate is not extraordinary, inasmuch as we have found that
it forms an element in all the vegetables upon which animals
are supported. By boiling bones even reduced to powder under
the usual pressure of the atmosphere, but a small quantity of
their gelatine is obtained; but by putting them into a Papin's
digester, and subjecting them to a considerably higher tempera-
ture than that of boiling-water, we can dissolve the whole, or
nearly the whole of the animal matter, and leave the earthy parts
unchanged; or by proceeding in another way, by soaking bones
for a time in dilute muriatic acid, we can dissolve out the earthy
matter, and leave the bone, having its original form indeed, but
as an elastic, pliant gristle.
The relations between the earthy and organic matter of bone,
vary with the species, but especially with the age of the animal.
In early life the cellular element predominates; in adult age the
salts predominate. We have three analyses of bone, which I
shall here present:
Man'
Cartilage susceptible of change into gelatine 33.3
Sub-phosphate of lime
53.0
Carbonate of lime
11.8
Phosphate of magnesia
Soda, and a trace of common salt
•
1.2
1.2
Ox.
33.3
57.4
3.9
2.0
3.4
Ox.
50.0
37.0
10.0
1.2
>>
100.0 100.0 98.3
Hair has a very complex composition, no fewer than nine
different principles or substances having been detected in its con-
stitution; among the number, mucus, various oily matters, sul-
phur and iron; wool, fur, and horn, are all similar in their com-
position to hair.
Blood, in all the higher animals, is a sluggish fluid, of a deep
red colour; in many of the inferior tribes, however, such as in-
sects, crustaceans and shell-fish, it is limpid, and generally colour-
less. Under the microscope, red blood is seen to consist of two
distinct portions, a serum or whey, in which float a multitude of
minute, solid, opaque, corpuscles-the globules of the blood of
physiologists, particles which have different characters in different
classes of animals.
BLOOD.
513
Blood is a very heterogeneous compound. Left to itself,
after being drawn from a vein, it sets or coagulates into a soft
gelatinous solid, which by and by begins to separate into two
portions, one watery, of a yellowish colour, and opalescent, the
water, whey or serum; another solid, of a deep red or reddish
brown colour, the clot or coagulum. The watery portion contains
a large quantity of albumen in solution. M. Lecanu, in his
analysis of the blood speaks of as many as twenty-five different
substances as entering into its composition :
Water
Oxygen, azote, free carbonic acid
Iron
Hydrochlorates of soda, potash, ammonia
Sulphates of potash and of soda
Subcarbonate of lime and magnesia
Phosphates of soda, lime, and magnesia
Lactate of soda
A soap, having soda and fixed fat acids for its elements
An odorous, volatile salt, a fat acid
A fatty substance, containing phosphorus
Cholesterine
Seroline
Albumen dissolved in the water
Globules and fibrine
790.4
11.0
67.8
130.8
1000.0
The blood globules consist principally of albumen combined
with a little fibrine and red colouring matter. Any differ-
ence observed between one sample of blood and another, is con-
nected especially, almost exclusively, with the relative proportions
of the liquid part or serum, and the solid part or clot. The
solids are in larger proportion in males than females, in grown-
up persons than in aged individuals and children, in subjects well
and abundantly fed than in those indifferently supplied with food.
No analysis that has yet been made has thrown any true light
on the cause of the difference of colour perceived between ar-
terial and venous blood; nevertheless, it is positively known that
it is by the concurrence of the oxygen of the atmosphere that
the arterial blood in the living body acquires the characters which
distinguish it, and that carbonic acid gas is evolved or thrown
off in the course of the action that takes place.
Ox blood thoroughly dried has been found to consist of:
514
MILK.
Milk.
Milk. This well-known fluid may be said to combine in
itself all the organic principles, and mineral substances which
enter into the constitution of organized beings. Caseum,
identical with fibrine and albumen, fatty matters, sugar of milk,
and different salts, among the number of which the phosphates
stand distinguished.
Of the cow
The caseum, the sugar, and a portion of the salts are in solu-
tion; the fatty matters are held in suspension in the milk in the
form of globules. The following table will be found useful, as
giving a comprehensive survey of the composition of different
kinds of milk.
Of the cow
Of the cow
Carbon
Hydrogen
Azote
Oxygen
Ash
men and insolu-
Caseun, albu-
ble salts.
3.6
4.5
3.8 3.5
5.6
5.1
Fatty matter.
4.0
1.7
Sugar of milk
and
soluble salts.
5.0
1.4
6.1
Water.
6.4
Of the cow
Of the cow
Of the ass
Of woman
3.1 3.4 4.3 89.2
Of woman 2.7 1.3 3.2 92.8
87.4
Dry matter
in
100 of milk.
3.1 5.4 87.0 13.0
3.6 4.0
86.8
87.3
3.0 4.6
52.0
7.2
15.1
21.3
4.4
100.0
90.5
Remarks.
86.6 13.4 Average of 6 an-Quevenne.
alyses in the en-
virons of Paris.
Idem.
12.6 Average of 12 Le Bel and
analyses at Be- Boussingault.
chelbronn.
Authors of the
analyses.
13.2
Idem.
12.7 An analysis,
Henriand Che-
valier.
Lecanu.
Giessen. Haidlen.
9.5 Average of 5 Péligot.
analysis.
10.8 Of good quality. Haidlen.
7.2 Ofmiddling qua. Haidlen.
lity.
Cow's milk always shows slight alkaline reaction; its density
is about 1.03. According to M. Haidlen it contains no salt
formed by an organic acid, no lactates, and the alkali is in com-
MILK.
515
bination with caseum, the solution of which it assists. It may
contain about a half per cent of ash, the several constituents of
which appear to be very stable, though their proportions vary
greatly. In 100 parts of milk, taken from two different cows,
Haidlen found the following salts:
Phosphate of lime
0.231
Phosphate of magnesia. 0.042
Phosphate of iron
0.007
Chloride of potassium. 0.144
0.024
Chloride of sodium
Soda
0.042
0.490
Carbon
Hydrogen
Oxygen
0.344
0.064
0.007
0.183
0.034
0.045
0.677
As cow's milk is that which is by far the most directly inte-
resting to agriculture, I shall enter somewhat particularly into
its history; having, however, already spoken of caseum, its dis-
tinguishing constituent, and albumen, I shall here confine myself
to the subject of the sugar and the oil or butter.
Sugar of milk is prepared for commercial purposes in coun-
tries or districts where cheese-making is carried on to a great
extent, and the quantity of whey at command is very large. In
some Cantons of Switzerland, sugar of milk is obtained by sim-
ply evaporating whey properly clarified, to the consistence of
syrup, which deposits the sugar in the crystalline form as it cools.
This first produce is brown, and contaminated with various im-
purities, from which it is freed by repeated solutions and crystalli-
zations. It then becomes colourless, transparent, and nearly
tasteless, feeling gritty between the teeth, and having only an
obscure sweet taste. It requires from 8 to 9 parts of cold water
to dissolve it; in hot water it is more soluble. According to
Proust it consists of:
40.0
6.7
53.3
100.0
Butter. To understand the preparation of butter thoroughly,
it is absolutely necessary to know the physical constitution of the
516
MILK.
milk from which it is obtained. Now the microscope shows us
that milk holds in suspension an infinity of globules of different
dimensions, which, by reason of their less specific gravity, tend
to rise to the surface of the liquid in which they float, where they
collect, and by and by form a film or layer of a different charac-
ter from the fluid beneath; the superficial layer is the cream,
and this removed, the subjacent liquid constitutes the skim-milk.
This separation appears to take place most completely in a cool
temperature from 54° to 60° F.
Allowed to stand for a time, which varies with the tempera-
ture, milk becomes sour, and by and by separates into three
strata or parts: cream, whey and curd, or coagulated caseum.
By suffering the milk to become acid before removing the cream,
it has been thought that a larger quantity of this, the most
valuable constituent of the milk, was obtained; and the fact is
probably so; but in districts where the subject of the dairy has
been most carefully studied, it has been found that it is better
to cream before the appearance of any signs of acidity have
appeared. When a knife can be pushed through the cream, and
withdrawn without any milk appearing, the cream ought to be
removed.*
Butter is obtained from cream by churning, as all the world
knows by the agitation. the fatty particles cohere and separate
from the watery portion, at first in smaller and then in larger
masses. The remaining fluid is butter-milk, a fluid slightly
acid, and of a very agreeable flavour, containing the larger por-
tion of the caseous element of the cream coagulated, and also a
certain portion of the fatty principle which has not been sepa-
rated.
The globules of milk appear, from the latest microscopical
observations,† to be formed essentially of fatty matter, sur-
rounded with a delicate, elastic, transparent pellicle. In the
course of the agitation or trituration of churning, these delicate
pellicles give way, and then the globules of oil or fatty matter
are left free to cohere, which they were prevented from doing
* Thaer, Principes, &c., t. IV. p. 341.
†M. Romanet, MSS.
MILK.
517
previously, by the interposition of the delicate film or covering
of the several globules. Were the butter simply suspended in
the state of emulsion in the milk, we should certainly expect
that it would separate on the application of heat; but this it
does not cream or milk may be brought to the boiling point,
and even boiled for some time without a particle of oil appearing.
Could M. Romanet show any of these pellicles, apart from the
oil-globules they inclose, it would be very satisfactory, and would
certainly enable us to explain the effect of churning.
Churning is a longer or shorter process, according to a va-
riety of circumstances; it succeeds best between 55° and 60° F.
So that, in summer, a cool place, and in winter a warm place, is
chosen for the operation. There is no absorption of oxygen
during the process of churning, as was once supposed; the ope-
ration succeeds performed in vacuo, and with the churn filled
with carbonic acid or hydrogen gas.
On being taken out of the churn, the butter is kneaded and
pressed, and even washed under fair water to free it as much as
possible from the butter-milk and curd which it always contains,
and to the presence of which must be ascribed the speedy alte-
ration which butter undergoes in warm weather. To preserve
fresh butter it is absolutely necessary to melt it, in order to get
rid of all moisture, and at the same time to separate the caseous
portion. This is the process employed to keep fresh butter in
all the warmer countries of the world. In some districts of the
continent, it is also had recourse to with the same view. The
butter is thrown into a clean cast-iron pot, and fire is applied.
By and by the melted mass enters into violent ebullition, which is
owing to the disengagement of watery vapour; it is stirred conti-
nually to favour the escape of the steam, and the fire is moderated.
When all ebullition has ceased, the fire is withdrawn, and the
melted butter is run upon a strainer, by which all the curd is re-
tained. M. Clouet has proposed to clarify butter by melting it at a
temperature between 120° and 140° F., and keeping it so long
melted as to dissipate the water and secure the deposition of the
cheesy matter, after which the clear melted butter would be de-
canted. I doubt whether by this means the water could be suf-
ficiently got rid of, a very important condition in connexion with
518
MILK.
the keeping of butter, though certainly all the caseum would be
deposited.
The moisture and curd contained in fresh butter may amount
together to about 18 per cent; at least we find that we lose
about 18 lbs. upon every 100 lbs. weight of butter which we
melt at Bechelbronn.
The information which we have on the produce in butter
and cheese from different samples of milk is very discordant,
so that I prefer giving the results of a single experiment made
under my own eyes.
From 100 lbs. weight of milk, we ob-
tained:
Cream
White curd cheese
Whey
15.60 lbs.
8.93 ""
75.47,,
100.00
The 15.60 lbs. of cream yielded by churning:
3.3 lbs. butter, or 21.2 per cent, and
12.27,, butter-milk.
Cheese
Butter
Butter-milk
Whey
The reckoning with reference to 100 lbs. of milk consc-
quently stands thus:
8.93
3.33
12.27
75.47
100.00
Taking the whole of the milk obtained and treated at diffe-
rent seasons of the year, I find that 36,000 lbs. of milk yielded
1080 lbs. of fresh butter, which is at the rate of 3 per cent.
From the statement of M. Baude, it appears that near Geneva
a proportion of butter so high as 3 per cent is never obtained,
probably because there a larger proportion of fatty matter is left
in the cheese. In the dairy of Cartigny, 2200 gallons of milk
gave:
FOOD AND FEEDING.
519
363 lbs. or about 1.6 per cent
Butter
Gruyère cheese
1515
6.9
5.2
Clot from the whey, obtained by boiling 1140
"
""
•
In the same neighbourhood, another dairy, that of Lullin,
gave from the same quantity of milk:
Butter
418 lbs. or 1.9 per cent
Cheese
1485
67.5
Clot from whey 968
4.4
">
*
OF THE FOOD OF ANIMALS AND Feeding.
"
The identity, in point of composition and properties, which
appears to obtain between certain substances derived from either
kingdom of nature, naturally led to the conclusion that animals
do not form or originate the substances which enter into their
organization, but that they find these ready formed in their food,
and merely appropriate them; whence we must conclude, that
herbivorous animals assimilate several of the proximate principles
of plants immediately, causing them to undergo but slight modi-
fications, and that the elements of the animal tissues and fluids
pre-exist in vegetables, which farther contain the earthy phos-
phate that forms the distinguishing characteristic in bone.†
The food of herbivorous animals must therefore always con-
tain, and in fact always contains, four essential principles, which
by their combination or re-union, constitute nutritious matter
properly so called: 1st. An azotised matter such as albumen,
caseine, gluten, substances which are probably the original of
flesh. 2nd. An oily or fatty matter, which approaches more or
less closely to fatty bodies in general. 3rd. A substance having a
ternary composition, sugar, gum, fecula. 4th. Certain salts,
particularly phosphates of lime, magnesia and iron. This mixed
constitution, which a forage plant must needs offer, justifies the
general ideas propounded by Dr. Prout on nutrition. This able
In all the dairy counties of England, the milk is never required like the
ground to give a double crop; it yields either butter or cheese, not both.
Hence the greater richness of English cheese in general.-ENG. Ed.
† Dumas and Boussingault. The chemical and physiological Balance
of organic Nature, post Svo. London. Baillière, 1843. [A delightful little
work.-ENG. ED.]
L L
520
FOOD AND FEEDING.
chemist has said, that milk was to be viewed as the standard
food, and that all alimentary matters must resemble it in compo-
sition, in greater or less degree; that is to say, besides phos-
phates, food must contain an azotised principle, a non-azotised
principle, and a fatty body, to stand in lieu of caseum, sugar and
butter.
The fundamental principle that animals find the several sub-
stances which make up their bodies, ready formed in the sub-
stances they consume, seems very well calculated to assist the
practical farmer in managing the food of the animals upon his
land; for if flesh, fat and bone exist all but ready formed in the
food, it is obvious that the best kind will be that precisely which
under the same weight contains the largest quantity of the various
matters of the organization.
It is by no means easy to ascertain precisely the amount of
the azotised constituents, gluten and albumen, contained in
plants; to do so requires both time and pains. But let it be
once admitted that the nutritive properties of forage increase in
he precise ratio of these matters, this is clearly as much as to
say that the value is in proportion to the quantity of azote con-
tained in the food, and that it becomes a matter of the highest
moment to have at hand a ready mode of determining the point.
I believe it infinitely better to get at the quantity of azote imme-
diately, which is easily done, than by any roundabout and labo-
rious process to ascertain the amount of albumen and gluten:
the quantity of azote ascertained, it is most easy to deduce the
quantity of albumen and gluten; in other words, of flesh con-
tained in each particular species of food examined; for, as a
general rule, vegetable food does not contain any other azotised
principle. It is true, indeed, that all the azotised principles of
vegetable origin cannot be considered as nutritious; some of
them, on the contrary, are virulent poisons or active medicines,
according to the dose in which they are administered. But
these poisonous substances are not met with in appreciable
quantity in the plants which are commonly grown for the food
either of man or beast. Still all the truly nutritious articles of
food contain an azotised principle. The experiments of M.
Magendie have shown that substances which contain no azote,
FOOD AND FEEDING.
521
such as sugar, starch, oil, will not support life; and, on the
other hand, it is ascertained that the quality of alimentary matter,
flour, for example, increases with the amount of gluten which it
contains. It is because the seeds of the leguminous vegetables
are richer in azotised principles, that is, in flesh, that they are
also more highly nutritious than the seeds of the cereals.
These several considerations, therefore, induce me to conclude,
that the nutritious principles of plants and their products re-
side in their azotised principles, and consequently that their
nutritious powers are in proportion to the quantity of azote
they contain. From what precedes, however, it is obvious that
I am far from regarding azotised principles alone as sufficient
for the nutrition of animals; but it is a fact, that every highly
azotised vegetable nutritive substance is generally accompanied
by the other organic and inorganic substances which concur in
nutrition.
In seeking to learn the precise quantity of azote contained in
a great number of articles used as food for cattle, I have had it
in view particularly to find a standard or fixed point for estimat-
ing their comparative nutritive properties. It is long since
more than one of the most distinguished farmers, both of Eng-
land and Germany, essayed to resolve this important problem in
rural economy. Thus Thaer and many others have given tables
of the quantities by weight in which one article of alimentation
might be substituted for another. These tables are in fact tables
of equivalents with reference to food. But it is unfortunate that
there should be considerable diversity of statement among their
authors. Yet, even up to the present time it could not well have
been otherwise, and these discrepancies will only surprise those
who are unacquainted with the difficulties of the subject. One
grand cause of difference probably exists in the degree of dry-
ness of the article subjected to experiment. The nature of the
soil, a very dry or very rainy season, the climate, &c., must all be
regarded as so many causes influencing the quantity of water
contained in plants, and in consequence their actual nutritive
qualities. The only sure mode of proceeding, in short, appears
to be, to reduce the several articles to a state of complete dry-
ness, and to make their quantity in this condition the first ele-
LL 2
522
FOOD AND FEEDING.
ment in the reckoning. I may state that the theoretical data
obtained by proceeding in this way have already been approved
by practical applications.
Hay may be assumed as the most common or universally used
of all kinds of fodder: it is in some sort the staple food of
the animals that are particularly attached to an agricultural con-
cern, and may therefore be appropriately made the standard of
comparison for all other kinds of food or forage. Hay itself,
however, varies greatly in point of quality; in assuming it as the
standard, I have therefore to state that meadow hay of good
quality is to be understood. The analyses which I have made
of this article at different times, satisfy me that in the state in
which it is commonly used, it contains from 1.0 to 1.5 of azote
per cent.
In choosing a specimen for analysis, it is of course
highly necessary that it be an average specimen; that it consist
of equal or rather relative proportions of the several elements
which enter into its constitution, such as stalks, leaves, flowers,
and seeds. Taking a sample of hay for instance, weighing
exactly 5 lbs. avoird., I found that it was made up of:
Hard woody stems
Bottoms of leaves and very fine stems
Flowers, leaves, and a few seeds
The ultimate analysis of which gave :
Of azote per cent.
Military contract hay of
Hay made in Alsace in
Hay made in Alsace in
1.19
1840 gave of azote per cent 1.21
1835
1.04
1837
1.15
1.15
""
2.393 lbs.
0.847
1.760
5.000
Average of azote per 100
,,
>>
Hay, as it is generally used, contains from 11 to 12 per cent
of water, which is got rid of by thorough drying. And as albu-
men, caseum, and vegetable gluten contain 16 per cent of azote,
we perceive that the azotised matter which is the representative
of flesh, in hay may be represented by the number 7.2 per cent.
Hay does not, indeed, always contain so much azote; that which
FOOD AND FEEDING,
523
is won from marshy lands contains much less; and again there
are samples that contain more. After-math, or second crop hay,
is certainly more nutritious than first crop hay, a fact which we
have ascertained repeatedly at Bechelbronn; but this hay is never-
theless held less suitable for horses, probably because being made
late in the season, it is commonly stacked more or less damp,
and suffers change in consequence:
After-math hay gave
A choice sample of the best hay
The flower or ear, containing little woody stem
2.0 per cent of azote
1.29
2.1
د.
""
These examples suffice to show, that when an animal is to be
put upon another kind of food than hay, it is very necessary to
take the quality of the latter article, which has been employed,
into the account. In the table which I shall immediately pre-
sent, I have assumed good meadow hay, containing 1.15 of azote
and 11 of water per cent for my standard. The importance of
a table of equivalents for forage has long been felt by farmers;
and they who have given their attention to the accumulation of
data for its construction, deserve our best thanks. The use of a
table of equivalents is extremely simple: the numbers placed
underneath the value of hay indicate the weights of the several
kinds of forage named in the first column, which may respec-
tively be substituted for 100 parts of hay by weight. Thus,
according to Block, 366 lbs. of carrots may be substituted for
100 lbs. of meadow hay. Pabst holds 60 lbs. of oats to be
equivalent to 100lbs. of hay. If the question be to replace
7.26 or 7 lbs. of oats in the ration of a horse by Jerusalem.
artichokes, we find in the table that 60 of oats are equivalent to
274 Jerusalem potatoes, and we therefore infer that 35.2, say
35 lbs. as the weight of the root to be substituted for that of
the oats.
Certain information on the nutritive value of the various ar-
ticles consumed by cattle as food, is really of high importance in
rural economy; it is obviously the only guide for the feeder in
the use or purchase of forage. Let us suppose, for example,
that a measure of potatoes (22 gallons) weighing 165 lbs. is
worth 10d. at market, and that hay is worth 2s. 6d. the cwt.;
524
FOOD AND FEEDING.
2 cwts. or rather 220 lbs. would cost 5s. Let us now admit on
theoretical grounds, that this quantity of hay is equivalent to
693 lbs. of potatoes; it plainly appears, on looking at the cost of
these equivalents, that there would be a positive advantage in using
potatoes, inasmuch as they are worth no more than 3s. 6d.
There would indeed be money to be made by selling hay, and
purchasing its equivalent in potatoes.
The equivalents which I have deduced from my elementary
analyses, agree on many occasions with the conclusions of prac-
tical men; in others, they differ notably from them; at the
same time it must be observed, that the practical equivalents
differ from one another in at least an equal degree. We see,
for instance, that Schnee and Thaer think 220 lbs. of hay will
be replaced by 1465 lbs. of wheat straw, whilst Flottow gives
429 lbs. as the equivalent number. According to Mayer, 630 lbs.
of turnip are equivalent to 220 lbs. of hay, whilst Middleton
gives 1760 as the equivalent number of turnips, a number which
coincides remarkably with that inferred from theory. Block
assigns 66 as the equivalent number of peas. Thaer makes it
more than twice as high, viz., 145. Mangel-wurzel, according
to Thaer, is represented by 1012; whilst Mayer and Pabst call
it but 550, and M. de Dombasle states it a little higher, viz.,
574. However highly we estimate the difficulties of coming to
accurate conclusions on the subject of alimentation or feeding, it
is not easy to account for such discrepancies among practical
men; and then, as to the astonishing similarity which their con-
clusions bear to one another upon many heads, it is impossible
to overlook the fact, that the resemblance is far more in appear-
ance than in fact; for it is notorious, that the generality of those
who have committed themselves to writing have generally copied
each other. Indeed, it is not always very obvious whether the
equivalent number which we find assumed, has been determined
by the farmer from his own observation or experience, or has
been adopted from some other observer. No one who is not a
total stranger to the art of making experiments, will ever be
brought to believe that eleven experimenters, operating sepa-
rately, could have fallen plump upon the number 90 as the
equivalent for lucern, or even that any five of them could have
FOOD AND FEEDING.
525
lighted upon 600, neither more nor less, as the equivalent
number for cabbage!
The method which I have myself pursued, that namely of in-
ferring the nutritious quality from the contents in azote, is far
from being free from objection; on the whole, it may be said to
place the equivalents somewhat too low, inasmuch as by the pro-
cess of elementary analysis, the quantity of azote is apt to come
out a little too high, some portion of it being derived from the
nitrates present in vegetables, which are certainly of no avail in
nutrition. This is the source to which I ascribe the anomaly
presented by the leaves of mangel-wurzel. And, then, it is not
to be forgotten that in dosing the azote we have regard but to
the flesh contained in the article of food, which although unques-
tionably the principle that is of highest value, and the one which
is apt to be most deficient is still not all. The neutral non-
azotised substances, starch, sugar, gum, oil, are indispensable as
auxiliaries in the alimentation of cattle; the three first undergo
changes in the course of the digestive process which fit them to
be absorbed immediately, and the oil is brought to the state of
an emulsion, and so is taken up and adds to the fat. The
woody fibre alone of vegetables appears to have no direct share
in the nutrition of animals; it is discovered almost or altogether
unchanged in the dejections.
C
It is therefore everything but matter of indifference whether a
particular article of forage contains a larger or a smaller propor-
tion of starch, sugar, &c., associated with a given quantity of
azotised or truly animalized matter. The potato and meadow
hay brought to the same state of dryness, contain as nearly as
possible the same proportions of azote; from 1.3 to 1.5 per
cent, in other words, about 8 per cent of albumen and gluten,
i. e., of flesh. But in the potato, almost the whole of the 911
per cent of the remainder consists of starch; whilst in hay it is
woody fibre, inert matter as we must presume it, that is present
in by far the largest proportion. And this explains the higher
value of the same weight of dry potato as an article of sustenance.
To give our theoretical equivalents all the precision that is really
desirable, it would be necessary to ascertain the quantity of or-
ganic matter which escaped digestion with reference to each par-
526
FOOD AND FEEDING.
ticular species of food. This is an inquiry which it is my pur-
pose to enter upon by and by. The labour completed, we should
then be in possession of tables in regard to the proportion of the
non-azotised as well as the azotised principles; and further, to
the quantity of inert matter which it would be proper to deduct
from the weight of the ration allowed in each case.
To have determined the azote in an article of food, then, is
not to have done all that is strictly necessary: still azote is the
scarce element in all kinds of vegetable food; starch, gum, sugar,
pectine, oil, are universally present, and generally in adequate
quantity. As articles, as unlike one another as possible, I have
mentioned potatoes and meadow hay. Now the theory indicates
300 of the root for 100 of the dried grass; and I can state
positively, from long and repeated observation, that it is not
advisable in practice to substitute less than 280 of potatoes for
100 of meadow hay.
The state of dryness of certain kinds of forage may have a
marked influence on their nutritious qualities. They may even
decline in nutritive value by the process of drying, so that ana-
lysis of itself may lead us into error in regard to the nutritive
value of dry articles of food. Breeders have in fact long sus-
pected that green fodder is more nutritious than dry fodder; that
grass, clover, &c., lose nutritious matter by being made into hay.
That the thing is so in fact, appears to have been demonstrated
by a skilful agriculturist, well acquainted with the art of experi-
menting,* who found that 9 lbs. of green lucern were quite
equal in foddering sheep to 3 lbs. of the same forage made into
hay, whilst he at the same time ascertained that 9 lbs. of green
lucern would not on an average yield more than 2.02 lbs. of hay.
In allowing each sheep 3 lbs. of lucern hay as its ration, con-
sequently, it was as if the animal had had 14.34 or more than
144 lbs. of the green vegetable for its allowance.
3
These practical facts are obviously of great importance; they
prove beyond a shadow of doubt that the belief of agriculturists
in general as to the immense advantages of consuming clover
and lucern as green meat is well founded. Nor is this all; it is
not merely the absolutely greater feeding value of the crop green
* M. Perrault de Jotemps, in Journ. d'Agricult. v. 111, p. 97.
FOOD AND FEEDING.
527
than of the crop dried and made into hay; there is farther, the
saving of expense in making the hay, and still farther, the cs-
cape of all risk from loss through bad weather during the pro-
cess, by which that which was valuable fodder but a few days
before, may become fit only for the dung-hill. Still, because
100 of green clover or lucern represent 23 of the same articles
dried, it does not follow that the feeding properties of the fodder
in each of the two states can be truly represented by the ratios
of these numbers to one another. Messrs. Perrault find from
their experiments that the true relation is 8 to 3. By assuming
71.5 lbs. as the quantity of dry forage obtained from 220 lbs.
of green clover or lucern, the quantity which is actually obtained
on an average, the ratio comes out 8 to 2.6, a number which
falls somewhat short of that which is assumed, but not much.
With regard to the difference in the feeding or nutritive value of
green and dried fodder, the loss may in a general way be as-
cribed to loss of the more substantial parts of the plants especially
experienced in the process of drying. This is the conclusion,
at all events, to which M. Crud came; I have myself, however,
found that clover hay, made in the field and ricked in the usual
way, had not the same nutritive value as a quantity of the same
crop carefully dried in the laboratory.
By way of pendant to the conclusions of Messrs. Perrault,
from their valuable observations, I shall here add the average of
some experiments that were made at Bechelbronn, in 1841, on
the conversion of clover into clover hay. The clover crops of
this season were magnificent; the plant in its second year grow-
ing to more than a yard in height. Green clover on the average
may be considered as consisting of:
Clover hay
Water
29.85
70.15
100.00
As extremes in our experiments of 1841, we add :
25.0
Clover hay
Water
76.0
100.0
35.7
64.3
100.0
528
FOOD AND FEEDING.
Analysis gave the number 75 as the nutritive equivalent
number of clover-hay. Assuming 76 to represent the moisture
lost during the drying, the equivalent becomes 311 for the
same fodder in the green state, meadow-hay, the standard,
being 100.
But practice is not here in harmony with theory; the value
of clover-hay, in point of nutritive power, is found not to differ
essentially from that of meadow-hay; and the equivalent of
green clover is generally placed between 425 and 500. And I
may say that daily experience in the stable tends to show that
the theoretical equivalent of clover-hay is too high, that its
nutritious properties are not so great as they are inferred to be.
From a mean of four weighings, I find that four cows upon
green clover consume 2499 lbs., or 6244 lbs. each per diem.
The usual allowance to one of our cows, however, is 33 lbs. of
hay of good quality; from which it would follow, that the
equivalent of green clover would be 445. But the animals on
the green fodder fattened apace, and every thing showed that
they were very differently nourished than they would have been
with their 33 lbs. of meadow-hay. According to theoretical
data, each cow in its 624 lbs. of green food per day, received
an equivalent of 47.3 lbs. of hay; and if it be considered that
during the season of green forage they have it almost at will,
it must be conceded that during this period the quantity of food
consumed is actually greater than when it is regularly doled out.
Additional experiments are therefore necessary to decide the ques-
tion as to whether forage eaten green is really more nutritious
than the same forage consumed when converted into hay. For
my own part, I should not be surprised, from what I have seen,
were it found that dry fodder, previously moistened and carefully
portioned out, was actually more nourishing than the same
food would have been had it been eaten green. Green forage,
of a very soft or watery nature, is notoriously possessed of pur-
gative properties, which must lessen its value as food; but my
observation leads me to say on the other hand, that animals
kept upon dry fodder require more care with regard to watering
than is generally bestowed upon them. The absolute necessity
FOOD AND FEEDING.
529
of a sufficient degree of moistness in the food, in order to secure
its due and easy digestion, greatly countenances the practice
which is beginning to be introduced in some places of steeping
hay for some time in water before giving it to cattle. This
necessity farther explains the great advantages in associating
with dried fodder other very watery articles, such as roots and
tubers, turnips and field-beet, potatoes and Jerusalem artichokes.
The oleaginous seeds contain a considerable proportion of
animalized matter, similar in composition and qualities to the
caseum of milk; and the cake which comes from the oil-mill
retains almost the whole of this substance. The proportion of
from 0.05 to 0.06 of azote, indicates nearly 42 per cent of the
representative of flesh in oil-cake. Theory, in fact, rates the
nutritious power of this substance so high, that 100 of hay may
be replaced by from 22 to 27 of cake.
The almost universal use of oil-cake in the feeding and fat-
tening of cattle, is of itself sufficient evidence of its highly nutri-
tive qualities. It has even been found possible to keep sheep
and oxen upon this food almost exclusively. M. Bouscaren
finding considerable difficulty in getting rid of his oil-cake,
thought of associating with his oil-mill an establishment for
feeding cattle; and he found that oxen put up to fatten throve
perfectly upon a mixture of the refuse of the wine-press and
oil-cake. Cows, upon a diet of this kind, give on an average
123 pints of milk per diem. The allowance per head is about
15 lbs. of oil-cake in three meals, given each time immediately
after the animals have been watered, and in the interval, each is
allowed about 12 lbs. of straw or chaff. The cake broken in
pieces is steeped in water, and worked up into a paste of the
consistency of dough. If the animals show any disinclination
to this food at first, they are brought to like it by having a ball
of it, the size of the fist, administered to them two or three
times.
Supposing that the cows fed in this way would be adequately
maintained upon 33 lbs. of hay, and that 13 lbs. of straw are
equivalent to 3 lbs. of hay, it appears that in the allowance
given, 15 lbs. of oil-cake will supply the place of 30 lbs. of hay ;
530
FOOD AND FEEDING.
the equivalent of the cake, therefore, 51.5, a number very dif
ferent from the 22 deduced from analysis. The equivalents
of those who have sought to appreciate the alimentary value of
oil-cake are, however, sufficiently at variance with one another.
It will be seen in the table, that the numbers assigned by dif
ferent authorities are 42, 57 and 108; and M. Perrault, from
direct experiment, found the equivalent number of colza-cake to
be 36, analysis giving 23 as the theoretical number. On the
whole, it may be said that in practice, the results, although
sufficiently different, still agree in ascribing to oil-cake a nutri-
tive value inferior to that indicated by theory.
I have thought it important to insist upon the discrepancy
which is here so conspicuous between the inferences from che-
mical analysis and those arrived at by experience, because it
appears to me to depend upon a particular circumstance which
frequently intervenes in the feeding of cattle, and which it is
very important to be aware of: I allude to the influence of the
bulk of the allowance of food.
Vegetable food of every description has nearly the same
specific gravity; it is but little above that of water; the bulk of
the allowance therefore depends upon its weight. Every one will
conceive that a ration of highly nutritious food, which for this rea-
son would occupy but little space, would be open to many objec-
tions. A cart-horse, of the ordinary size, from what I have myself
repeatedly observed, requires from 26 to 33 lbs. of solid food,
and about the same quantity of water in the twenty-four hours.
The bulk of this allowance, when masticated and brought to the
state in which it is swallowed, will be upwards of 9 cubic feet.
Now, if for the ordinary forage, one that is five times more
nutritious were substituted, oil-cake, for example, the dry ration,
according to the rule of equivalents, would be reduced to 6.6, or a
little more than 44 lbs, and its bulk would not surpass 5 cubic
feet. The animal would not feel satisfied with this allowance, it
would still feel hungry, or the food given in such a concentrated
shape would disagree with it. If, on the contrary, a forage that
is very little nutritious, were substituted, such as wheat-straw, the
equivalent of which is 500, the ration would then become too
FOOD AND FEEDING.
531
bulky to be eaten in the course of a day, it would amount to as
many as 165 lbs.
It is therefore absolutely necessary to take into
consideration the bulk of the food allowed: the belly must of
necessity be filled; whatever the nutritive value of any article, it
must be given in a certain quantity; and in the case of such a
substance as oil-cake, the consumption to fill the stomach would
cease to be in any kind of proportion to the nutritive equivalent.
It is extremely difficult to appreciate the precise limits be-
yond which an article of forage or a given ration ceases to be
nutritious. When any addition is made to an allowance known
and admitted to be sufficient, the effect of the extra quantity is
scarcely perceptible; so that in practice, we are apt to fall into
the error of estimating at too low a rate the nutritious powers of
food given in too large quantities. I have had proof of this in
a series of experiments on the maintenance of a number of
milch-kine. To a cow which was receiving the equivalent of
33 lbs. of meadow-hay in dry fodder and Jerusalem potatoes, an
addition was made of 64 lbs. of oil-cake, by which the allowance
of nourishment was doubled theoretically; the animal only ate
the half of the cake, however; still, the quality of the milk was
not improved. Experience here would compel us to set down
the 31 lbs. of cake consumed as nil; yet it is positively ascer-
tained that the article is one of the most substantial known.
The hard and husky grain which is given to cattle, fre-
quently escapes digestion, because it has escaped the teeth;
a circumstance which leads to the formation of an estimate of
its nutritious qualities inferior to those it actually possesses.
To prevent this loss, oats are now often bruised, as are beans
and peas also; or they are mixed with chopped hay or straw,
which the animals are compelled to chew thoroughly before they
can swallow it; or the corn is steamed or steeped in boiling
water before it is put into the manger. Some experiments that
were instituted by order of the French veterinary commission,
however, seemed to show that the loss of corn from passing
through the stomach and bowels unchanged was really so trifling,
that it might be safely left out of the account.
Tubers and roots are invaluable fodder for horned cattle, and
532
FOOD AND FEEDING.
in the course of the winter, come instead of hay to a consider-
able extent. Our experience at Bechelbronn also enables us to
say that horses are readily brought to a regimen of the same
description, which, judiciously instituted, becomes the means of
great economy in the maintenance of these animals.
Roots, turnips, and mangel-wurzel are frequently thrown down
whole before the animals. It is vastly better, nay, it is so much
better that it ought to be made an invariable rule never to give
them save cut into slices and mixed with cut straw or chaff. There
is always a great advantage in combining any very soft and watery
article of food with one that is dry and hard, to say nothing of
the chaff absorbing and rendering useful the juices that would
escape and be lost.
Mangel-wurzel, turnips, carrots, and Jerusalem potatoes are
always given raw. The potato is frequently steamed or boiled
first; yet I can say positively, that horned cattle do extremely
well upon raw potatoes; and at Bechelbronn, our cows never
have them otherwise than raw; they are never boiled save for
horses and hogs. The best mode of dealing with them is to
steam them; they need never be thoroughly boiled as when
they are to serve for the food of man. The steamed or boiled
potatoes are crushed between two rollers, or simply broken with
a wooden spade or dolly, and mixed with cut hay or straw or
chaff before being served out. It may not be unnecessary to
observe that by steaming, potatoes lose no weight; whence we
conclude, that the nutritive equivalent for the boiled is the same
as that for the raw tuber. Nevertheless, it is possible that the
amylaceous principle is rendered more readily assimilable by
boiling, and that by this means the tubers actually become more
nutritious. Some have proposed to roast potatoes in the oven;
and there can be little question, but that treated in this way,
they answer admirably for fattening hogs or even oxen. Done
in the oven, potatoes may be brought into a state in which they
may perfectly supply the place of corn in the foddering of horses
and other cattle. There is but the expense of the firing to be
taken into the account.
The only mode of ascertaining the favourable or unfavourable
FOOD AND FEEDING.
533
influence of any particular system of diet or regimen upon ani-
mals, is by weighing them. In regard to full-grown animals per-
forming regular work, such as cart and plough horses, and to
milch-kine, the allowance ought to be such as will maintain them
at the same or nearly the same weight. Anything like stinting is
immediately followed by loss of flesh and of weight, of strength,
and spirit in the animal. The allowance being continued the
same, similar effects will follow any increase of work, any exac-
tion of unusual effort on the part of the animal. An essential
condition, therefore, in all experiments on the due dieting or
feeding of animals, is that they be performed under precisely
similar conditions of labour. Young animals receiving a suf-
ficiency of wholesome food increase from day to day by a quan-
tity which we shall have occasion immediately to mention; and
all changes of regimen are followed at once by notable variations
in the ratio of the growth; if the new regimen be less nutri-
tious than that which went before it, the balance immediately
proclaims the fact.
Cattle put up to fatten are always supplied with a superfluity
of fodder; the excess may be regarded as an addition to the
quantity requisite to maintain them in health and strength.
The increase in the weight of an animal is often so great within
a given time, as to be very appreciable by weighings made even
at very close intervals; the balance also shows us that the rate
of increase varies at different periods of the interval during
which the fattening is going on. An animal put up to fatten
for the butcher is not the best subject for coming to conclusions
upon in regard to the nutritive value of different articles of
sustenance; still it is useful, in a practical point of view, to
determine the influence of this and of that course or regimen on
the production of fat. Any misapplication of nutritive equiva-
lents is speedily proclaimed by the animal's losing weight, in-
stead of maintaining or gaining upon the amount to which it
had attained.
When the quantity of fodder has been ascertained which an ani-
mal ought to have in the twenty-four hours to maintain it in full
health and vigour, or that may be necessary to enable it to lay
534
FOOD AND FEEDING.
on additional flesh and fat, it is to be weighed, and the article or
mixture of articles which it is the business of the experimentor
to try, is to be given in part or in whole. After the lapse of a
certain time, the animal is weighed again; and the weight upon
this occasion enables us to say whether the new or amended
ration is superior, equal, or inferior to that which had preceded
it. Such is the procedure generally followed; but in putting it
in practice myself, I saw that it was liable to lead to rather
serious mistakes, which I then used every effort to diminish or
to nullify in the experiments which I undertook on the keep of
horses, experiments which I think interesting enough to deserve
being particularly related.
In a considerable number of observations with which I had
become familiar, I saw that the course had not always been
continued for a sufficient length of time; so that changes which
were the effect of mere accident must frequently have been
ascribed to the effects of regimen. In a general way, it is
acknowledged that an adult animal upon the ration that is
known to be adequate for its maintenance, returns at the same
hour every day to the yesterday's weight; this, however, is only
strictly true in reference to a series of weighings continued
through a number of days to make any irregularity between one
weighing and another disappear.
With a view to discovering the amount of variation which an
animal experiences in point of weight when it is fed in the same
uniform manner, is foddered precisely at the same hours, &c.,
I weighed a horse and a mare, which were leading the most
regular and unvaried life possible, for they were both employed
in working an exhausting machine, for several days in succes-
sion, the weighings being performed at noon each day before
they were watered, and from four to five hours after their break-
fast. Here are the results in a tabular form:
MAINTENANCE OF ANIMALS.
535

25
27
28
29
30
31
Date of the weighings.
16 December, 1841
17
18
19
20
21.
22
23
24
Mean weights
Maxima
Minima
Greatest difference above the
mean
Greatest difference below the
mean
Difference between the extreme
weights
Weight of the horse.
lbs. avoird.
996.6
kil.
453.0
455.0
456.0
454.0
449.0 988.9
449.5
449.0
454.0
454.0
459.5
448.0
452.0
454.0
448.0
452.5
452.0
459.5
448.0
998.8
1010.9
985.6 490.5
994.4
496.0
491.0
484.0
491.0
16.5
994.4
491.8
1010.9 497.5
985.6
484.0
8.8
Weight of the mare.
kil.
494.0
497.0
497.0
497.5
487.0
487.5
492.0
496.5
484.5
7.7
lbs. avoird.
1086.8
1092.7
1065.9
1064.8
1081.9
1092.7
1064.8
10.8
17.1
6.3
Another horse (Old Fox) 12 years old, taken fasting, at four
o'clock in the morning of the 28th of April, 1842, weighed,
1051 lbs.; at the same hour of the 29th, he weighed 1060 lbs. ;
ditto on the 29th, 1038 lbs.
It is obvious, therefore, that a horse foddered most regularly
and weighed at the same hour, nevertheless presents differences
in his weight that may amount to nearly 30 lbs. ; and which,
without assurance of this fact, we should be disposed to ascribe
to the effect of our regimen. This is enough to satisfy us that
in all experiments upon feeding, it is absolutely necessary to
carry them on for some considerable time, in order to escape, or
at all events to lessen the errors that would be introduced into
the conclusions by these accidental differences of weight. They
may vary with reference to different animals; they are necessarily
smaller in amount among those that are young and small, such
as calves and sheep, than in adult oxen and horses; but they
M M
536
MAINTENANCE OF ANIMALS.
do not occur the less on that account, and must, therefore, oc-
casion errors of the same description. What, then, shall we
say of those small variations in the weight in a ewe or a ram,
amounting perhaps to 1 or 2 lbs., ascertained in the course of
an experiment carried over two or three days, though conducted
with the most scrupulous attention to accuracy in the world?
That they may very possibly have been purely accidental.
The first in every series of experiments on the maintenance of
animals, ought in fact to have it in view to ascertain the amount of
accidental variation in the weight of the creatures which are their
subjects; as this variation is now on this side now on that, there
is an obvious advantage in having a certain number upon trial
at a time; any error that occurs will thus be more apt to be cor-
rected; and the results may be held more worthy of confidence
in proportion as the numbers have been large from which
they have been deduced. Another cause of error which I had
occasion to discover in the course of my experiments appears to
be connected with the weight of the allowance. Equal in nu-
tritious value, different allowances may still have very different
weights; it is obvious, that a ration of hay and corn will weigh
much less than its equivalent in roots, tubers, or green meat.
Animals that have been kept for some time upon a dry diet, if
put on one that is very bulky and watery, will immediately in-
crease very considerably in weight; and their increase is both so
sudden and so great, that it is impossible to ascribe it to aug-
mented nutrition, to flesh and fat laid on. The animals are
simply distended, their paunch and bowels are filled with a larger
quantity of food than they were before; and the state of dis-
tension continues, though it suffers accidental variations, so long
as the new course of feeding is persisted in. In opposite cir-
cumstances, as when animals that have been long upon soft and
watery food, are suddenly put upon hard diet, they always drop
very considerably in weight. These sudden changes throw dis-
order and contradiction into the conclusions, and puzzled me
greatly until I discovered their cause. It is obvious that no
kind of reliance can be placed upon the conclusions which have
been come to from single weighings made at the end of each
particular course of alimentation. To get at results which shall be
MAINTENANCE OF ANIMALS.
537
worthy of any credit, the animals that are to be made the subjects.
of experiment must be fed for several days upon the particular
ration that is to be approved, in order to be brought to the state
of body which may be said to belong in particular to each system
of dieting, before being weighed; it is only when this is attained,
indeed, that the experiment can be held to be properly begun;
and then it is to be continued for a sufficient length of time to
lessen the influence of those accidental variations of weight, of
which I have spoken so particularly. It is perhaps needless to
observe, that any increase in weight and the maintenance of that
increase, are not always of themselves sufficient signs for affirm-
ing that the course then followed is superior or equal to the one
which preceded it. Various other circumstances of divers cha-
racter must be taken into the reckoning, and in particular the
state of the animals. It is very necessary to have an eye to the
state of the coat, to the spirit or liveliness of the animal, to the
nature of the dejections, the size of the belly, the disposition of
draught animals for their work, the quantity of milk given by
milch kine, &c. Nevertheless, and as a general proposition, it
may be said that a stationary condition, or a slight increase of
weight, is almost always in favour of the course along with which
it is gained or maintained, whilst any loss is almost always an
indication of an inadequate allowance or of deficient nutritive.
qualities in the ration, taken in connexion with the work required
or the milk obtained.
-
The experiments which I am about to detail were under-
taken to determine the nutritive value of a variety of forages
associated with the ordinary articles in keeping the horse. The
great dearth of forage that was felt in Alsace, in consequence of
the extraordinary droughts of 1840, led us to feel the full im-
portance of researches in this direction; for then we were com-
pelled to replace by potatoes a very large proportion of the hay
usually consumed in the stable. And, indeed, by assuming the
theoretical equivalent as the basis of this substitution, I found
that I saved money by the course, at the same time that the
health and strength of my draught cattle were maintained unim-
paired. Still as every question that bears upon the keep of the
animals attached to a farm is too important to be left to the de-
M M 2
538
MAINTENANCE OF ANIMALS.
cision of theory alone, I thought it imperative on me to control
the inferences of chemical analysis by the results of expe-
rience.
The best food for horses has long been admitted to be hay
and oats in combination; neither article alone would have the
same happy effect that the two together produce. A ration of
hay alone would be too bulky; one of oats alone would not be
bulky enough. But the horse is not particular in his food. Barley
in southern countries replaces oats, and answers equally well. I
have myself kept horses and mules for long periods of time on
maize and the tops of sugar canes exclusively; and on the ele-
vated table-lands of the Andes, and in the steppes of South
America, the horses, though they do much hard work, are kept
wholly on green meat. Much of course depends on the way in
which the animal has been brought up.
In the circumstances in which we are generally placed in this
country, I do not imagine that there would be any actual ad-
vantage in replacing the ordinary food of our horses by roots and
tubers; I doubt even whether the substitution would have good
effects. I know, indeed, that horses have been kept through
the winter upon potatoes and mangel-wurzel; but it is a different
matter to feed an animal and keep him standing quiet in the
stable without work, and to feed him at the same time that a
certain quantity of labour is required of him every day. A
horse in full work would scarcely get through the bulky ration,
which should consist of beetroot alone; his meal times are re-
stricted; if he has certain hours for his work, so has he certain
hours for his breakfast, dinner and supper also. This is one
reason why carrier's horses and post horses, horses in a word
which have long and severe work to perform, receive the larger
portion of their allowance in corn. The inconveniences of bulky
rations are much less felt in the cow-house than in the stable;
not to speak of their particular organization, which actually
enables them to take in a much larger quantity of food than
the horse, the steer and the cow have always a longer time
allowed them for their meals than are regularly given to the
horse.
The experience of nearly a whole year having satisfied me
MAINTENANCE OF ANIMALS.
539
that a cart-horse may have half his ration in roots or tubers,
I set out from this fact in the experiments which I instituted.
EXPERIMENTS ON THE MAINTENANCE OF HORSES WITH MIXED FOOD.
The usual allowance to a horse at Bechelbronn for the twenty-
four hours consists of:
Hay
Straw
Oats
With this ration the teams are kept in excellent condition.
Two teams were selected as subjects of experiment, each con-
sisting of four horses; these I shall distinguish by the titles,
Team No. 1, and Team No. 2. Each remained under the care
of the same servant throughout.
Team No. 1 was com-
posed of:
Braun, a mare
Schimmel, a horse 7
Hans,
do. 16
8
Gaty,
do.
Team No. 2 was composed of:
Old Fox, a mare
do.
Braun,
Nickel,
do.
Hengst, a horse
7 years old.
Hay
Straw
Oats
Potatoes
""
"9
""
16 years old.
5
14
5
"
22 lbs.
5+
71
در
EXPERIMENT I.
One half the allowance of hay was replaced by potatoes lightly
steamed; 280 of the tubers being assumed, according to theory,
as equivalent to 100 of hay. The ration, therefore, consisted of:
11lbs.
5
71
30,8%
The potatoes were broken down and mixed with chopped
straw, and never put into the mangers until cold.
540
MAINTENANCE OE ANIMALS.
From accidental circumstances, particularly bad weather during
the course of the autumnal labours, the teams were exposed to
very hard work, an event which of course throws uncertainty
over the results of this trial. After having been upon the
course of food indicated for a few days, the teams were weighed
once, and again after an interval of twenty-four hours:
First weighing
Second weighing
In 24 hours
loss
Team No. 1.
4617.8
4554.0
63.8
8
10ths
No. 2.
4461
4334
127
EXPERIMENT II.
Both teams.
9079.4
8888.0
191.4
The loss experienced here authorized me to conclude, that
the allowance under the circumstances was not sufficient. The
30.8 lbs. of steamed potatoes could not have adequately replaced
the 11 lbs. of hay; it would have been highly interesting to
have ascertained how horses kept on the standard and usual
allowance would have stood the same amount of fatigue. Un-
fortunately this comparison could not be made, all the horses
in the stable having been put on the potato regimen at the same
time. There is this much to be said for the particular course
tried, however, that the animals did their work with great spirit,
and continued in excellent health.
Hay
Straw
Oats
Jerusalem potatoes
Mean per horse
1134.9
1111.0
INTRODUCTION OF JERUSALEM POTATOES INTO THE RATION.
Jerusalem potatoes are held excellent food for the horse;
they are eaten greedily, and he thrives on them. In this second
slices were substi-
experiment, 30 lbs. of Jerusalems cut into
tuted for 11 lbs. of hay, the same theoretical equivalents being
assumed for them as for the common potato. The ration now
consisted of:
23.9
11 lbs.
5/1/
7금
​30.8
Having been accustomed to this regimen for some days, the
MAINTENANCE OF ANIMALS.
541
teams were weighed, and having gone on for 11 days, they were
weighed again:
First weighing
Second weighing
In 11 days
No. 2.
3245
Both teams. Means per horse
8901
1112.7
1113.6
3412
8923
gain
loss 33 gain 22
gain 0.9
A result which leads to the conclusion that the equivalent as-
sumed for the Jerusalem potato was correct; the animals had
done their work, and gained, one with another, ths of a pound
in weight.
Team No. 1.
4556
4611
First weighing
Second weighing
In 14 days gain
Hay
Potatoes
55
EXPERIMENT III.
RATION OF HAY AND POTATOES.
Eleven pounds of hay, in the usual allowance, were replaced
by 30.8 lbs. of potatoes; the whole of the oats and straw, by
15.4 lbs of hay. These substitutions were made upon the sup-
position that 100 of hay was equivalent to 280 of potatoes,
to 50 of oats, and to 520 of straw. The ration, then, was
composed as follows:
This was a ration which it was the more interesting to try,
from the circumstance of Professor Liebig* having come to the
conclusion, from certain theoretical views, that it must be im-
possible to keep horses in health and strength upon hay and
potatoes exclusively. The experiment was continued for a fort-
night:
Team of No. 1.
4620
4675
55
26.6 lbs.
30.8
No. 2.
4312
4697
385
The two teams. Mean wght. p. horse
8932
1116.5
1171.5
9372
440
55.0
In one fortnight, consequently, the weight of eight horses had
increased by an aggregate sum of 440 lbs., or 55 lbs. per head,
* Agricultural chemistry.
542
MAINTENANCE OF ANIMALS.
an increase at the rate of, as nearly as possible, 3.9 say 4 lbs.
per diem; and allowing the greatest latitude for error, it seems
that we cannot estimate the increase per head at less than 1.76,
say 1 lbs. per diem.
diem. The condition of the horses was most
satisfactory; the dejections were healthy in appearance; the only
inconvenience observed was, the considerable bulk of the allow-
ance, and the additional time which had to be given the teams
to their meals. This inconvenience was particularly obvious in
the case of the older horses. Besides the two experimental
lots, other twelve horses were put upon the same regimen, and
with the same good effects. The equivalents adopted in the
composition of the ration, in this third experiment, may there-
fore be regarded with perfect confidence as suitable. Experience
indeed would rather lead us to conclude that the nutritive power
of the potato had been estimated at somewhat too low a rate.
EXPERIMENT IV.
SUBSTITUTION OF OATS AND STRAW FOR A PORTION OF THE HAY.
The ration here consisted of:
Hay
Straw
Oats
First weighing
Second weighing.
In 11 days gain
The horses having been two days on this diet were weighed.
The experiment was continued for eleven days:
Team No. 1.
4584.8
4593.6
8.8
No. 2.
4348.3
4352.7
11 lbs.
11
12.1
4.4
Both teams.
8933.1
8946.3
13.2
Average per horse
1116.7
1118.2
1.5
Under this regimen, consequently, the weight of the teams
remained very nearly the same as it was before beginning the
experiment; still there was something gained.
In conducting this experiment, we had an opportunity of ob-
serving how important it is to habituate the animals to their
new regimen before weighing for the first time. Had this pre-
caution been neglected, the result would have come out against
MAINTENANCE OF ANIMALS.
543
the ration, for the animals were found when first entered on it,
to weigh together as many as 9372lbs., and two days after-
wards no more than 8933lbs., which would have indicated a
loss of 440lbs.; the difference being due, however, in great
part, or entirely, to the less bulky or weighty food employed.
EXPERIMENT V.
POTATOES SUBSTITUTED FOR A PORTION OF THE HAY.
The ration made use of in the first experiment looks so well
in reference to economy of hay, and indeed answered so well
under the peculiar circumstances in which it was tried, that I
thought it would be advisable to try it again when the horses
were doing ordinary work. The ration consisted of:
First weighing
Second weighing
In 63 days gain
11 lbs.
5.50
7.23
Steamed potatoes . 30.8
Hay
Sugar
Oats
The first weighing took place after the horses had been over
a week on the ration, and the experiment was continued for 63
days. In team No. 1, Braun, from indisposition, had been
replaced by Rapp, a horse nine years old, and weighing
1157lbs.:
Team No. 1.
4425
4501
76
No. 2.
4362
4428
66
Both teams. Aver. wght. p. horse.
8848
1106.1
8929
1116.2
81
10.1
In the course of two months, consequently, on a ration in
which 11lbs. of hay were replaced by 30.8lbs. of dressed po-
tatoes, the weight of the horses may be said to have been
more than maintained. This experiment seems to show satis-
factorily that the equivalent of the potato cannot be far from
the number 616.
EXPERIMENT VI.
JERUSALEM POTATO FOR A PORTION OF THE HAY.
The horses were brought back to the same conditions as in
the second experiment, 30.8lbs. of Jerusalems being substituted
M M 3
544
MAINTENANCE OF ANIMALS.
for 11lbs. of hay. The team No. 2 was alone subjected to
this experiment, being kept on it for 16 days, and first weighed
after having had it for some time :
First weighing.
Second weighing.
No. 2. 4395 lbs. Average weight per horse 1098.9
4396.7
1099.1
In 16 days gain
1.7
0.2
This result confirms that which was elicited by the second
experiment.
Hay
Straw.
Oats
Beet
">
INTRODUCTION OF FIELD-BEET OR MANGEL-WURZEL INTO THE RATION.
Horses readily get accustomed to field-beet. The root is
sliced and mixed with chaff (cut straw). For 11lbs. of hay
which I retrenched, I allowed 44lbs. of beet; i. e. I took 880
as the equivalent number of the root. The ration consisted as
under :
EXPERIMENT VII.
""
First weighing
Second weighing
In a fortnight
Hay
Beet
Straw
11 lbs.
5.50
7.23
A horse, after having been kept on this diet for some time
was weighed; and the regimen having been continued for a
fortnight, he was weighed again:
44.0
1014.0lbs.
1023.0
9
gain
This horse was all the while doing rather hard but very re-
gular work; for eight hours every day he was in the shafts of
a grinding mill. He did not alter in condition; the dejections
were healthy.
During the winter of 1841-42, our cows ate a considerable
proportion of our beet; and as a substitute for the 33lbs. of
meadow hay, which is their usual allowance, we give 724lbs of
beet. The ration then stood thus:
22 lbs.
72.6
4.4
MAINTENANCE OF ANIMALS.
545
Upon this regimen, the weight of the inmates of one of our
stables was:
On the 29th of January
On the 21st April
Increase due to births and to growth
24615lbs.
26488
1873
It thus appears that, in foddering kine, the quantity of beet
allowed with advantage may be large; but it is also obvious,
that the nutritive value of the root is not great. At Bechel-
bronn, at all events, we found it requisite to replace 19 or 22 of
hay by 88 of root. Our beet, it is true, contains but 26 per
220 of dry matter; in other places, where the proportion of dry
substance to the water is larger, it is possible that a smaller
proportion would be found to answer the end.
EXPERIMENT VIII.
INTRODUCTION OF THE SWEDISH TURNIP INTO THE RATION AND
REPLACING A PORTION OF THE HAY.
Hay
Straw
Oats
Swedes
Swedish turnip, combined with some dry forage, answers ex-
cellently with the horse. Analysis, indicating 616 as the equi-
valent of this article, two horses were put upon the following
ration, in which 11lbs. of the usual allowance of hay were re-
placed by Swedish turnip :
11 lbs.
5.50
7.23
30.8
It was obvious before the lapse of but a few days, that the
horses were falling off upon this regimen, that they were not
fed; and on weighing them, this plainly appeared:
First weighing
2283lbs. Aver. of each horse 1141.8
Second weighing, 9 days afterwards 2178,,
1089.0
52.8
Loss in 9 days
105
The equivalent for the Swedish turnip adopted, had therefore
been too high; the allowance was not sufficient. This led me
to analyse the article again; and I discovered that the true equi-
M M 4
546
MAINTENANCE OF ANIMALS.
valent of the sample with which I was operating, was at least
676lbs. and not 280lbs. as I had presumed before. Indeed, in
another experiment with the same pair of horses where the equi-
valent of Swedish turnip was assumed at 880lbs. I found that
though the animals kept up their weight at the point to which it
had fallen, they gained nothing; whence it may be safely inferred
that the 880lbs. was still too low, and that the new equivalent
676lbs. is nearer the truth.
EXPERIMENT IX.
INTRODUCTION OF CARROTS INTO THE RATION.
Horses are extremely fond of carrots; and there is no root
perhaps, the nutritious qualities of which have been more vaunted
or exaggerated. Yet, analysis appears to indicate that 770lbs. of
carrot are required to place 220lbs. of good meadow hay. On
one occasion, in the stable at Bechelbronn, when the potato in
one of our rations was replaced by an equal weight of carrots,
the effect was highly disadvantageous; and even in following
the theoretical equivalent of the carrot (770) we had still no
reason to be perfectly satisfied. I now believe, in fact, that as
many as 880lbs. of carrots may be found requisite to replace
220lbs. of good meadow hay.
The carrot crop of 1841 having been a failure, I had to limit
myself to observations made on a single horse, which was put
upon a ration in which 11lbs. of hay were replaced by 38.5lbs.
of carrots. The horse, habituated to this diet,
Weighed
A fortnight after
Loss in a fortnight
1025.2lbs.
1014.2
11.0
Nevertheless he remained in good condition, so that the equi-
valent 350 is probably not far from the truth.
I ought to say,
however, that the men think this number too low; an opinion
in which they would be borne out, could we but be certain that
the loss of weight of the horse just indicated was not acci-
dental.
MAINTENANCE OF ANIMALS.
547
BOILED RYE AS A SUBSTITUTE FOR ANIMALS.
EXPERIMENT X.
It has been stated, that rye boiled till the grain bursts may
be used as a substitute for an equal bulk of oats in the keep of
a horse. The experiment which I made on the point is very
far from bearing out anything of the kind. By preliminary
trials I had ascertained that rye of good quality swells to twice
the former bulk by boiling.
""
The two horses that were made the subjects of experiment
now, had been kept for some time on a ration formed of:
Hay
Oats
First weighing: Both horses
Second
Loss in 11 days
For the oats, the same quantity by measure, 8.8 pints of
boiled rye were substituted, containing 4.4 pints of raw grain,
weighing 4lbs. On the 11th day it was deemed prudent to
interrupt the experiment, of which the following are the
results :
2)
22lbs.
5.5 = 8.8 pints.
2010lbs. Average of each. 1004.5
1927
963.0
83
41.5
>>
In fact, with such a ration as this, in which water was made
to replace solid corn, no other result could reasonably be ex-
pected. In continuing it, the health of the horses would very
certainly have soon been seriously compromised. There is no
objection to rye in itself as an element in the food of a horse;
but then it must be substituted in the quantity indicated by the
table of equivalents, by adopting which, Mr. Dailly found that
he could keep the post horses of Paris in good heart, at a time
when the difference between the price of oats and rye made it
advantageous to substitute the latter for the former. The ex-
periments of Mr. Dailly on the subjects were so decisive and so
ably conducted, that I felt myself relieved from the necessity of
inquiring farther into it myself.
From these experiments, the particulars of which have now
been given, it may be concluded that the nutritive equivalents of
M M 5
548
the potato, beet, Jerusalem potato, and carrot, as they come out
upon analysis, or as they are inferred from the amount of azote
they contain, may be adopted without detriment to the health of
horses. If they err at all, it is that they assign equivalents
somewhat too high, which is the same as saying that their actual
nutritive power is rather less than these numbers give it; so
that a portion of the hay of the standard ration being substituted
for its equivalent of tuber or root, the diet will be improved.
MAINTENANCE OF ANIMALS.
Thus, 220 of good meadow hay may be taken, as ascertained
by experiment, to be equivalent to:
616 potatoes-by analysis, equal to
616 Jerusalems
880 Beet
880 Swede (too little)
880 Carrot
693
684
1205.6
1487
840
In the following table of nutritive equivalents, to the numbers
assigned by the theory, I have added those of the whole which I
find in the entire series of observations that have come to my
knowledge. I have also given the standard quantity of water,
and the quantity of azote, contained in each species of food.
When the theoretical equivalents do not differ too widely from
those supplied by direct observation, I believe that they ought to
be preferred. The details of my experiments, and the precau-
tions needful in entering on and carrying them through, must
have satisfied every one of the difficulties attending their con-
duct; yet all allow how little these have been attentively con-
templated, and what slender measures of precaution against
error have been taken. Our equivalent for field-beet is 880, in
introducing 44lbs. of the root into the ration, we should have
obtained 11,000, had we introducd 56lbs. of beet root in lieu of
11lbs. of hay; it is questionable whether the final result would
have been effected by this substitution. In my opinion, direct
observation or experiment is indispensable, but mainly, solely as
a means of checking within rather wide limits the results of
chemical analysis.
MAINTENANCE OF ANIMALS.
549
Ordinary natural meadow hay
Ditto, of fine quality
Ditto, select
Ditto, freed from woody stems
Lucern hay
Red clover-hay, 2nd year's growth
Red clover cut in flower, green, ditto
New wheat straw, crop 1841
Old wheat-straw
TABLE OF THE NUTRITIVE EQUIVALENTS OF DIFFERENT KINDS OF
OF FORAGE.
}}}·······
TITLE.
Acacia ditto (autumn)
Drum cabbage
Swedish turnip
Turnip
Field-beet (1838)
·
Ditto, ditto, lower parts of the stalk
Ditto, ditto, upper part of ditto and car
New rye-straw
Old ditto
Oat-straw
Barley ditto
Pea ditto
Millet ditto
Buck-wheat ditto
Lentil ditto
Vetches cut in flower and dried into hay
Potato tops
Field-beet leaves
Carrot ditto
Jerusalem potato stems
Lime-tree young shoots
Canada-poplar ditto
Oak ditto
·
Ditto, white Silesian
Carrots
Jerusalem potatoes (1839)
Ditto (1336)
·
11.0
14.0
18.8
14.0
16.6
10.1
76.0
26.0
85
5.3
9.4
18.7
12.6
21.0
11.0
8.5
19.0
11.6
92
11.0
76.0
88.9
70.9
86.4
55.0
62.5
57.4
53.6
92.3
91.0
92,5
87.8
85.6
87.6
79.2
75.5
1.34
1.50
2.40
2.44
1.66
1.70
0.36
0.53
0.43
1.42
0.30
0.50
0.36
0.30
1.95
0.96
0.54
1.18
1.16
2.30
4.50
2.94
2.70
3.25
2.20
2.16
1.56
3.70
1.83
1.70
1.70
1.43
2.40
1.60
2.20
1.15
1.30
2.00
2.10
55
1.38 83
1.54
0.64
0.27
0.49
0.24
0.42
0.30
0.25
1.79
0.41 280
1.33 86
0.13
0.21
0.18
0.30
0.33
0.42
:
|
| | | | | |
100 100 100 | 100 | 100 | 100 | 100 | 100 100 100 100 100 100 100 100 100 100 100 100 0
98
58 108 100
..
100
··
88:880
••
75 100
90100
90 100
311 430
450425 | 500 | 450
426 200 360 | 150 | 450| 300 | 175
235
··
··
..
..
•
··
479 200 500 150 666 35
··
..
..
•
250
..
0.78
|
383 200 200| 150 | 190 | 200|175
460 | 193 | 180 | 150 | 150 | 200 | 175
64 165| 200| 150 | 130 | 150 | 200
147
250
240
200
114 | 160 | 200
101
125
300
0.48
1.01
1.14
0.55
209
0.50
0.92
0.72
230 G00
0.85 135
0.37 311
1.45
79
73
0.86 134 67
125 83
160
411556 | 500|250|429| 600 | 600
676
300 300| 250
885 533 600 290 526 450 500
548366 400 | 250 | 460 | 250 | 300
669 | 366
382 205250225| 300) 250
..
..
0.28
0.17
··
348
274
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100
600
325
··
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..
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175
··
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Pohl.
Rieder.
Gemerhausen.
Crud.
..
..
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90
··
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850
525
··
..
..
90
··
...
••
500 500
..
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..
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90
··
:: 5:
··
•
660
190
150
··
·
··
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..
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•
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90 90
600
··
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··
90
90
··
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Weber.
::·ཙྩེཧྲཱིཿཧྥེ་ལྕེ::
..
90
··
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·.·
•
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150
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600 | 600 | 500 | 600
370 350
525 525 525 500
460255
··
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Dombasle.
··
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::8:
::
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90 90
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D
··
··
··
··
Krantz.
··
··
:: 8:
..
··
..
•
•
..
..
··
··
··
··
··
··
··
··
U B
..
··
U
..
Schwertz.
··
29:
..
··
100 90
100
..
..
•
··
··
•
··
261
220
266 | 270 | 266 | 260 | 266 | 307 | 266 | 270
··
··
··
··
400 182
400 154
143
··
··
••
··
··
Schnee.
··
200
450
333
··
••
500
··
..
666
..
191
90
··
··
•
..
••
··
··
Midleton.
Murre.
André.
Boussingault.
..
..
··
..
..
··
·
··
··
··
·
··
··
..
··
….
..
··
338
· Q
••
··
•
··
►
..
··
··
800 667
··
··
……
··
··
90
··
··
..
..
··
··
U
··
··
350
··
..
..
··
··
..
400
··
380
280
··


550
MAINTENANCE OF ANIMALS.

Potatoes (1838)
Ditto (1836)
Ditto after keeping in the pit
Cyder apple pulp dried in the air
Beet-root magma from the sugar mill
Vetches in seed
Field beans
White peas (dry)
White haricots
Lentils
New maize
Buck wheat
Barley (1836)
Barley-meal
Ditto
Oats (1838)
Ditto (1836)
Ditto (Parisian)
TITLE.
Rye (1836)
Ditto (1838)
Wheat (1836, Alsace)
Ditto (1838)
Ditto from highly manured soil
Recent bran
Wheat husks or chaff
Rice (Piedmont)
Gold of pleasure seed (Madia)
Ditto, cake
Linseed cake
Colza ditto
Madia ditto
Hemp ditto
Poppy ditto
Nut ditto
Beech mast ditto
Arachis (?) ditto
Dry acorns
Refuse of the wine press, air-dried
Standard water
per cent.
65.9
79.4
76.8
6.4
70.0
14.6
7.9
8.6
5.0
9.0
18.0
12.5
13.2
13.0
13.0
20.8
12.4
14.0
11.5
11.5
10.5
14.5
16.6
12.1
37.1
13.8
7.6
13.4
8.0
11.2
13.4
10.5
6.5
5.0
6.8
6.0
6.2
6.6
48.2
Azote per cent.
1.50
1.80
1.18
0.63
5.13
5.50
4.20
4.30
4 40
2.00
2.40
2.02
2.46
2.20
2.20
2.22
1.93
1.70
2.27
2.33
2.30
3.18
2.60
2.18
2.77
0.94
1.39
4.00
5.70
6.00
5.50
5.93
4.78
5.70
5.59
3.53
8.89
3.31
Azote per cent
in the article not
dried.
4.00
1.64
2.10
Theory.
Block.
0.36
0.37 311
0.30
0.59
0.38
4.37
5.11
3.84
4.58 25
29
70
55
1.76 65 33 61 53
383 400
195
303
26 30
23 30
2.14 54
KJ8O8N
3.31
8.33
0.80
1.71
319 216 200 150 200 200 250 200
1.90 61
1.74 68
1.92 60
1.70 68
2.00 58
::::8:
2.09 55 27
2.00 57
2.65 43
:: ~: &::
2.80
1.36
2.30
41
85 105
50
135160
96
0.85
1.20
3.67
31
5.06 23
5.20
4.92
5.51
4.21
5.36
5.24
2228238
::3333 :835 : :F: :3 :8:
::
:::
14
143
68
Petri.
27 30 54 43 66
..
··
··
1.50 77 33 55
··
..
54
54
39
52
64
71
52
··
··
22 42 108
23
21
..
..
··
..
• •
··
..
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Meyer.
..
2::
62
··
::83
::: 8:
51
Thaer.
·
40
50 73 40
40
••
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:::828
:
66
··
::::::::*:
71
46 64
76
86
··
··
··
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Pabst.
··
··
:
··
8::8::8
50
60
50
40
:
··
··
..
••
..
..
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::12
75
Flottow.
►
..
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··
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·
··
..
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Pohl.
..
..
··
44 38
··
::85:
50
47
•
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..
: 8:: 8:
50
··
•
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175
..
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..
DO
··
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..
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..
Rieder.
Gemerhausen.
Crud.
Weber.
..
2::5
55
52
··
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210
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57
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Dombasle.
187 227 220
··
..
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··
··
47
·
··
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..
•
..
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Krantz.
··
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→
··
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••
65
•
44
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··
..
..
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Schwertz.
··
··
··
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•
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Schnee.
··
•
•
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··
52
..
··
..
··
..
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..
··
..
..
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Midleton.
..
··
··
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Murre.
•
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André.
Boussingault.
..
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40
..
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··
··
··
••
··
280
• 4
:::*:::: 8:
59
50
•
MAINTENANCE OF ANIMALS.
551
To complete the preceding ample table, I shall still add the
equivalents of a few articles of forage that have not yet been
examined chemically.
100 of meadow hay are replaced by:
From 85 to 90 of sainfoin hay, according to Petri and Meyer.
Petri.
Pabst and Flottow.
Block and Petri.
Petri.
Petri.
Block.
By 90 of spurry hay
325 to 500 of green spurry
42 to 50 of chesnuts
By 50 of Indian chesnuts
62 of turnsole seeds
109 of rye bran
Wheat flour (good quality)
Wheat
Barley-meal
Barley
Rye.
Buck-wheat
Maize
Yellow peas
Horse-beans
White French beans
Rice
Lentils
In the list of substances there are some which are used al-
most exclusively for the food of man, and I have thought it
not uninteresting to contrast these different articles with refe-
rence particularly to the quantity of azote they contain. I have
composed the following table or list of equivalents on this basis;
having assumed wheaten flour as the standard and called it 100.
As all herbs, roots, leaves, &c., may be pulverized after drying,
I have spoken of these articles dry under the name of meal.
White-heart cabbage
Cabbage meal
Potatos
Potato meal
Carrots
Carrot meal
"
Turnips
Mealy bananas (Ficus Indica)
Manihot (casava plant) .
Name? (discorea sativa).
Apio? (arracacha).
"
>>
""
"
100
107
119
130
111
108
138
67
44
56
171
57
810
83
613
126
757
95
1335
700
700
300
1050
N N
552
MAINTENANCE OF ANIMALS.
▸
Judging from the equivalents, leguminous vegetables must be
possessed of a much higher nutritive value than wheat; and it
is known, indeed, that haricots, peas and beans, form in some
sort substitutes for animal food. The difference indicated is so
great, however, that it may surprise those who have never
thought of the subject that engages us. In a general way we
are all perhaps disposed to regard the articles that enter habi-
tually into our food as highly nutritious. The fact, however, is,
that tubers, roots, and even the seeds of the cereal grasses are
but very moderately nutritious. If we see herbivorous animals
getting fat upon such things it is only because their organization
enables them to consume them in large quantities. I doubt
very much whether a man doing hard work could support him-
self on bread exclusively. I am aware that countries are quoted
where the potato and where rice form the sole articles of food
of the inhabitants; but I believe also that these instances are
incomplete. In Alsace, for example, the peasantry always asso-
ciate their potato diet with a large quantity of sour or curdled
milk, in Ireland with buttermilk. The Indians of the Upper
Andes do not by any means live on potatoes alone, as some tra-
vellers have said they do; at Quito the daily food of the inha-
bitants is lorco, a compound of potatoes and a large quantity of
cheese. Rice is often cited as one of the most nourishing
articles of diet; I am satisfied, however, after having lived long
in countries where rice is largely consumed, that it is any-
thing but a substantial, or, for its bulk, nutritious article of
sustenance. This is an important question, inasmuch as in
some departments of the public service rice is sometimes served
out as a substitute for other articles of diet. In the French
navy, for example, 60 grammes, or about 20 dwts. of rice may
be substituted for 60 dwts, of split peas or haricots; but I
cannot hold such a substitution to be either fair or reasonable.
At a period when I had myself the charge of the rations for a
detachment of men, I found that the experience of the country
where I was assigned, 3lbs. of rice as the equivalent of 1 lb. of
haricot beans; and analysis confirms this practical conclusion.
Haricots, in fact, contain about 0.046 of azote; rice no more
than 0.014. And if the nutritious properties be really in pro-
INORGANIC ELEMENTS OF FOOD.
553
portion to the amount of azote, it is obvious that 3½ of rice
will be required in lieu of 1 of the leguminous seed.
We hear it constantly repeated that rice is the sole nutriment
of the nations of the whole of India. But the fact would ap-
pear not to be precisely so; and I may here quote M. Lequerri,
who during a long residence in India paid particular attention
to the manners and customs of the inhabitants of Pondicherri.
"The food," says M. L., "is almost entirely vegetable, and rice
is the staple; the inferior castes only ever eat meat. But all
eat kari, an article prepared with meat, fish, or vegetables, which
is mixed with the rice boiled in very little water. It is requisite
to have seen the Indians at their meals to have any idea of the
enormous quantity of rice they will put into their stomachs.
No European could cram so much at a time; and they very
commonly allow that rice alone will not nourish them. They
very generally still eat a quantity of bread.”*
§ II. OF THE INORGANIC CONSTITUENTS OF FOOD.
We discover in the bodies of animals the several mineral
substances, the existence of which we have ascertained in vege-
tables. The bones, as we have seen, contain a large quantity of
phosphate of lime; it is requisite therefore that the elements
of this salt, phosphoric acid and lime, should form part of the
ration or diet roll; this is a point upon which all physiologists
are agreed; but the point upon which there is nothing like uni-
formity yet attained has reference to the precise quantity of
mineral matter which must enter into the constitution of the
food. The analyses of ashes which I have given show that if
vegetable aliments all contain nearly the same inorganic prin-
ciples, they still contain them in very different proportions; thus
potatoes, wheat, oats, and beans, contain much less lime than
clover, straw and peas. The phosphoric and sulphuric acids
and the alkalies do not vary less; so that we are led to ask
whether a ration compounded of such and such an article or of
such and such articles, will furnish the animals to which it is
* The Irish peasantry who live so much on potatoes have buttermilk
with them at least, often salt herring; and a labouring man, it is said,
will consume 12 or 14lbs per diem!-ENG. ED.
NN 2
554
INORGANIC ELEMENTS OF FOOD.
supplied with the necessary dose of inorganic principles, which
must be assimilated daily, and which is quite indispensable to
maintain them in health and vigour.
It is easy to arrive at a knowledge of the mineral principles
which are necessary as elements of the diet, by ascertaining
their quantity in the ration, which long experience has shown
to be sufficient. Yet as there is reason to believe that in many
cases mineral substances are present in excess, I have thought that
it might be useful to determine by means of analysis the nature
and the proportion of the inorganic elements which are actually
assimilated by an individual, in order to have a minimum which
might serve as a basis for any reasonings or inferences on the
subject. My experiments were performed in two opposite cir-
cumstances in which I regard assimilation as most rapid and
most complete: videlicit, a calf in full growth, and a milch cow
in calf.
The calf was six months old, and weighed 369lbs. Some
days before being made the subject of experiment it was fed
with hay. During the two days when it had this fodder ad
libitum, it ate 19lbs.
In the course of the 1st. day the calf passed 21.49 lbs. of excrements.
2nd. day
20.39
41.88
"D
Of the hay
Of the dry excrements
Of the urinous extract
Which, dried, was reduced to 7.41 lbs.
In the course of the two days 5.584lbs. of urine were col-
lected, which evaporated, yielded 2933.2 grains of extract, the
animal having in the same interval drunk 45.7 pints of water.
Analysis discovered in 100:
Azote 1.6
2.1
4.0
""
""
>>
Ashes 7.6
12.7
40.0
""
"
Now if we inquire from these data in regard to the quan-
tity of azote and of mineral matters which were assumed with
the food in the course of two days we have:
INORGANIC ELEMENTS OF FOOD.
555
1
In the excrements
In the urine
azote
>>
""
Carbonic
Acids Phosphoric
Sulphuric
101.1 grs.
7.6
""
108.7
138.7
In the food, discarding fractions
Therefore, azote fixed or exhaled in 2 days 30, or per day 15 grs.
The composition of the ashes obtained from the hay and from
the excrements, show us approximately both the quantity and
the nature of the several inorganic substances which had been
assimilated. The composition of these ashes is as follows:
Of the hay.
9.0
5.3
2.4
2.3
Chlorine
20.4
Em
Lime
Magnesia
6.0
Potash and soda
Oxide of iron, alumina
17.3
1.5
33.7
2.1
Silesia
Loss
100.0
Of the excrements.
2.0
5.1
2.3
1.9
16.0
6.5
12.5
1.0
51.0
1.7
100.0
Of the urine.
17.3
0.2
7.0
9.9
0.9
6.0
57.3
* The exact quantity is 2392.8 grains troy.-ENG. ED.
>>
1.4
100.0
If the hay consumed contained 328 half-drachms of ash or
mineral matter, the excrements and urine 252 half-drachms of
the same matters; the difference between the two sums, 76 half-
drachms,* is the quantity of mineral matter fixed in the course
of two days, of which 200.6 grains were phosphoric acid, and
494.0 grains were lime. This quantity of lime, however, is
more than four times as much as is necessary to constitute a
subphosphate of lime such as exists in the bones. It is true in-
deed that there is always a quantity of carbonate of lime associ-
ated with the subphosphate in bones; 10 of carbonate for 38 of
phosphate, according to Fourcroy and Vauquelin, in those of
the ox.
Still the quantity of lime assimilated was vastly more.
than it ought to have been had it only gone to assist in the
formation of bone. If there was no error in the observations,
it is probable that the base in question enters into the constitu-
tion of the salts with organic acids which are encountered in all
parts of the animal body.
NN 3
556
INORGANIC ELEMENTS OF FOOD.
By a series of weighings, I ascertained that my calf, fed
simply upon hay, increased every day by a quantity equal to
9725.940 grains troy, in which were included 8583.52 grains
of mineral substances, the calcareous phosphate and carbonate
of the bones in this quantity being represented by 262.446
grains, or nearly 3 per cent of the entire weight acquired in the
course of twenty-four hours.
In the experiment with the milch-cow in calf, I limited my
inquiries to the phosphoric acid and the lime taken in and given
out. The animal, four years old, was 24 months gone with
calf, and weighed 1452.6lbs. She had the same allowance
during the experiment as she had had for several days before,
and which for twenty-four hours consisted of:
Hay
Cut wheat-straw
Beet
16.5lbs.
9.9
59.4
The experiment was continued for four days, during which
the excrements, the urine, and the milk were carefully collected
and weighed, and the ashes both of the food consumed and of
the products rendered, were determined by chemical analysis.
Suffice it to say, that representing the quantity of mineral mat-
ters assumed into the body in the course of the experiment by
849.9 half-drachms, the quantity voided amounted to no more
than 556 half-drachms. In the quantity assumed there were
100.2 half-drachms of phosphoric acid and 203.8 half-drachms of
lime; in the quantity voided there were but 68.2 half drachms of
phosphoric acid, and 116.8 half-drachms of lime; this is at the
rate of about 8 half-drachms of phosphoric acid, and 22 half
drachms of lime assimilated in the course of twenty-four hours.
Here, as in the case of the calf, the quantity of lime assimilated
is greatly superior to what it ought to be, in order, by combining
with the phosphoric acid, to constitute the phosphate of lime of
the bones.
From these inquirics into the nutrition of a calf and of a cow
in calf, it follows that there is a portion of the mineral sub-
stance taken in with the food which remains definitively fixed to
concur in the growth or in the evolution of the individual. In
INORGANIC ELEMENTS OF FOOD.
557
an adult animal it is to be presumed that no such definitive
fixation of inorganic principles takes place, or that it is much
less considerable; that in the dejections and several secretions.
ought to be found the whole of the phosphoric acid, of the
lime, &c., taken in with the food. And this presumption is
confirmed by experience; for on instituting an inquiry into the
matter upon a horse, it was found that the mineral matters
assumed were almost exactly balanced by those discharged.
Nevertheless, and granting this to be quite true, which it is,
it would be a grave mistake to suppose that an adult animal
could go on for even a very short period of time upon food
that contained no mineral matter. Precisely as in the case of
organic matter, it appears that a portion of inorganic matter is
also fixed in the living frame, where for a time it forms an
integral element in the wonderful structure; and a supply of the
latter kind is undoubtedly no less necessary than is the supply
of the former description recognized by all the world. Were
there an inadequate quantity of phosphoric acid, of lime, &c. in
the food, no question but that the body would speedily feel the
effects of the deficiency, and that disease and death would by
and bye put an end to life. So much, indeed, seems demon-
strated by the very interesting experiments of M. Chossat, in
which he kept granivorous animals upon a diet rich in azotised
principles and in starch, but deficient in lime. From some
previous inquiries, M. Chossat had observed that pigeons even
require to add a certain proportion of lime to their ordinary
food, the quantity naturally contained in which does not suffice
them. Wheat, as we have seen, though it contains a large
proportion of phosphate of magnesia, contains very little phos-
phate of lime; and pigeons put on this grain, though they do
perfectly well at first, and even get fat, begin by and bye to fall
off. In from two to three months, the birds appeared to suffer
from constant thirst; they drank frequently, the fœces became
soft and liquid, and the flesh wasted, and in from eight to ten
months the creatures died under the effects of a diarrhea,
which M. Chossat attributed to deficiency of the calcareous
element in the food. And it is neither uninteresting nor unim-
portant to observe that the same thing occasionally occurs in
558
INORGANIC ELEMENTS OF FOOD.
the human subject during the period when the process of ossifi-
cation is usually most active. But one of the most remarkable
features of M. Chossat's experiments was observed in the state
of the bones of the pigeons; they became so thin and weak that
they broke during the life of the birds with the slightest force.*
The conclusion from this fact is obvious. Supplies of all the
elements of all the parts of the body are indispensable to the
maintenance of health, to the continuance of life.
A pigeon will eat about 463.140 grains of wheat per diem,
containing 9.725 grains of ash, in which analysis discovers
4.569 grains of phosphoric acid and 0.277 of a grain of lime.
But this small quantity of lime is incompetent to maintain the
bones in their standard condition. I have thought it of mo-
ment to insist upon these facts, because I see that they may
sometimes come into play in practical rural economy.
No
breeder or feeder ought to be ignorant of the influence of mineral
substances on nutrition. It is not only indispensable that the
allowance of an animal in full growth be sufficient to support
and even to add to the soft textures, it must further contain
the elements requisite for the nutrition of the osseous system;
and it is not impossible but that in managing the feeding of
young cattle or young horses in such a way as to reduce to a
minimum or to give in excess certain of the inorganic elements
of the food, we may succeed in impressing one character or
another upon a race. It is even possible that the empirical
rules which are acted upon with a view to increase or diminish
the quantity of bone, the weight of flesh or of fat, &c. are all
connected with various proportions of phosphoric acid, of lime,
magnesia, &c., in the food. It will probably be discovered some
day that Bakewell's art is to be explained through the compo-
sition of the ashes of the food.
Wheat is not the only alimentary matter that contains an in-
sufficient quantity of lime; maize or Indian corn contains still
less; and if that which is grown in the tropics contains as little
as that which is produced in Europe, it would be difficult to ex-
plain how the grain should answer so well as it unquestionably
* Chossat, in Comptes Rendus, t. xiv, p. 451.
INORGANIC ELEMENTS OF FOOD.
559
does for food.*
It is true that it is seldom or never consumed
alone and without addition; and in South America where the
animals have it largely, I have observed that they frequently eat
earth. The habit which certain tribes of the natives have of
eating earth, too, which has been particularly remarked upon by
travellers and missionaries as an instance of depravation of taste,
presents itself to me in quite another light since I became ac-
quainted with the composition of the ashes of the ordinary
article of diet in the countries where it occurs.†
The calcareous and other salts necessary to nutrition, how-
ever, are not derived from the food exclusively; the water that
is generally consumed contains a quantity which is by no means
to be neglected. A horse or a cow, for instance, which drinks
from 15 to 45 quarts of water per diem, will even, if the water
be as pure as that of the Artesian well of Grenelle, take in from
35 to 108 grains of saline matter in which carbonate of lime
predominates; water that is less free from saline impregnation
would of course introduce a much larger proportion; some
waters in the quantities above specified will contain from 138
to upwards of 400 grains of saline matter one half of which
may be carbonate of lime. And I am here speaking of clear
or filtered water; that which is muddy or turbid contains a still
larger quantity of earthy matter in suspension than in solution.
In an experiment made for the purpose of getting at the amount
of earthy matter taken by a milch-cow from the watering-trough
in the course of the day, I found that it amounted to about
770 grains troy.
Notwithstanding these facts it is still doubtful whether the
lime contained in ordinary well water would prove sufficient to
supply a growing animal with the material requisite to the for-
mation of its bones; in adults, indeed, changes in the elements
of the bones appear to proceed so slowly that a very small
quantity of calcareous matter probably suffices to repair losses;
but it is otherwise with young and growing animals. I have
* An ash of maize, analysed in my laboratory by M. Letellier, contained
but 1.3 per cent. of lime to 50.1 of phosphoric acid and 17.0 of magnesia.
† I several times saw children chastised in Indian villages who had been
caught eating earth.
560
INORGANIC ELEMENTS OF FOOD.
shown that a calf six months old receives with its forage a
quantity of phosphoric acid which corresponds to 555.7 grains
of phosphate of lime. A calf a few weeks old, when it has
17 or 18 pints of milk per diem receives 802.7 grains of mi-
neral substances, into which sub-phosphate of lime or bone
earth enters in the proportion of 370.5 grains. It would be
interesting to ascertain what quantities of these substances were
assimilated by so young an animal, and at a period when the
growth is so rapid that the increase from day to day sometimes
exceeds 2 pounds.
The importance of the inorganic principles of the food once
recognised, it concerns us to take note of their nature and
quantity in the ration we allow to our domestic animals. It is
in fact this consideration which has led me to determine the
quantities of phosphoric acid and lime contained in the various
articles of food the ashes of which have been analysed. With
these data the proportion of bone earth contained in a given
ration is forthwith perceived.
One thousand parts of the forage gathered at Bechelbronn in
its ordinary state contained:


FORAGE.
Hay.
Potatoes
Beet
Turnip
Jerusalem potato
Wheat
Maize
Oats
Wheat-straw
Oat-straw
Clover-hay
Peas
Haricots
Beans
Mineral
substances.
Azote.
Phosphoric
acid.
Lime.
62.33
11.50
3.37 10.04
9.64
3.70
1.09
0.17
7.70
2.10
0.46
0.54
5.70
1.30
0.35
0.62
12.47
3.75
1.35
0.29
20.51
20.50
9.64
0.60
11.00 16.40
5.51
0.14
31.74 17.87
4.73
1.17
51.90
3.00
1.61
4.41
35.70
3.00
1.07
2.97
73.50
21.00
4.63
18 08
30.00
38.40
9.03
3.03
35.00
45.80
9.38
2.03
30.00 51.10 10.26
1.53
Bone
earth.
6.96
0.33
0.95
0.72
0.56
1.16
0.27
2.27
3.32
2.21
9.85
5.83
5.94
9.27
We seem here to observe a certain relation between the pro-
portion of azote and that of the phosphoric acid contained in
the food; the most highly azotised are also those that generally
INORGANIC ELEMENTS OF FOOD.
561
contain the largest quantity of the acid, a circumstance which
seems to indicate that in the vegetable kingdom the phosphates
are connected more especially with the azotised principles, and
that they accompany them in passing into the textures of ani-
mals. With the assistance of the above table it is easy to
ascertain the quantity of phosphate of lime which enters into a
given ration. Let us take that given to the horses in experi-
ment 3rd, in which the half of the hay was replaced by potatoes,
one of the articles that contains the smallest proportion of lime,
and we find in the
26.6lbs. of hay 632.9grs. phosphoric acid and 1867.9grs. of lime.
30.8lbs. potatoes 387.7
3.705
1020.6
1870.16
numbers which correspond with 1798 5 grains of bone earth,
and 978.7 grains of uncombined lime.
In his usual allowance a work horse at Bechelbronn receives:
Hay 22lbs. containing 524.8grs. phosph. acid, and 1543.8grs. of lime.
Straw 5.5
61.7
239.2
Oats 7.2
815.7
"
•
>>
•
>>
In other words 1735 grains of bone earth, and 864 grains of
free lime.
I have found that very young foals, growing rapidly and
weighing about 374lbs., consume per diem:
"
3)
Hay 19.8lbs. containing of phosph. acid 463grs.; lime 1389grs.
Oats
7.2
231
58.6
"}
**
**
which represent 95 of bone earth or subphosphate of limc. As
a consequence of the relation which appears to exist between the
azote and phosphoric acid of an article of sustenance, it comes
to pass that like nutritive equivalents also indicate like propor-
tions of phosphoric acid, so that by introducing a suitable quan-
tity of hay or clover, articles that abound in lime, into the
ration, we are always certain of having food favourable to the
development of the osseous system, whatever the nature and
quality of the other articles that enter into the constitution of
the allowance.
N N 4
562
FATTY ELEMENTS OF FOOD AND ON FATTENING.
The relation of the phosphoric acid to the azote approaches
the ratio of 3 to 10, in the more ordinary articles of forage;
but the same relation is no longer apparent in the cereals and
leguminose vegetables; in grain and in peas, beans, &c., the phos-
phoric acid amounts to about a fourth of the azote contained.
Thus we have:
Hay
Potatoes
Beet
Turnip
Jerusalems
Dry clover
Wheat straw
Oat straw
Oats
Maize
Wheat
Peas
Haricots
Beans
Theoretical
equivalent.
100
320
548
885
273
75
235
380
68
70
43
25
27
23
§ III. OF THE FATTY CONSTITUENTS OF FORAGE;
FATTENING.
Phosphoric acid in
the equivalent.
0.34
0.35
0.28
0.31
0.37
0.34
0.37
0.40
0.32
0.38
0.41
0.23
0.25
0.24
CONSIDERATIONS ON
When fat was observed accumulating in the tissues of the
animal body, and it was unknown that the presence of fatty
matters in plants is what may be termed a general fact, men
naturally conceived that the fat was produced from the food in
the act of digestion, that it was composed in the animal body
much in the same way as it is formed in the seed and leaf of
the living vegetable.
The inquiries which I am about to present, however, all tend
to make us conclude that fatty substances are only produced in
vegetables, and that they pass ready formed into the bodies of
animals, where they may either undergo combustion immediately,
so as to evolve the heat which the animal requires, or be stored
up in the tissues in order to serve as a magazine of combustible
matter.
This latter view appcars the most simple; but before discuss-
ing the experiments which bear it out, it seems necessary to pass.
FATTY ELEMENTS OF FOOD AND ON FATTENING.
563
in brief review the notions that have been entertained at different
times on the formation of fat. When the great burying-place
of the Innocents was emptied, for example, it was commonly
imagined that one of the effects of the putrefactive process was
to convert the flesh, the brain, the viscera, &c., into fat-adipocere,
as it was called; it was not, indeed, till after the researches of
Mr. Chevreul had been undertaken, and that it was discovered
adipocere contained the same acids as human fat, which had
in fact only been partially saponified by ammonia; until the
inquiries of Mr. Gay-Lussac were made public, that it was ac-
knowledged that muscular flesh or fibrine subjected to putrefac-
tion leaves no larger a quantity of fat than can be obtained from
it by proper solvents before it has undergone any change: the
effect of putrefaction is to destroy the fibrine, and so to expose
the fatty substance which it contained.
It may therefore be said, that all these fortuitous opinions
upon the supposed formation of fat by chemical processes, have
vanished as they have been successively subjected to careful
examination.
Let us now turn to the inferences come to by physiology.
The bodies of carnivorous animals are often loaded with fat;
and none can be detected in any of their excretions. It is
therefore in these animals that it must be most easy to ascertain
the source or origin, and mode of disappearance of fatty
matter.
When the progress of digestion is watched in a dog, it is soon
discovered that the chyle is far from being a fluid having uniformly
the same characters and qualities. That which is produced under
the influence of a vegetable diet, abounding in the starchy prin-
ciple and in sugar, or after a meal of perfectly lean meat, is
always and alike poor in molecules or globules. The chyle is
then nearly transparent, extremely serous, and yields very little fat
when washed with ether. But if the animal have a meal of
fat food, the chyle that results from it is opaque like cream, very
rich in particles, and, digested with ether, yields a large quantity
of fatty or oily matter to that solvent.
These facts, observed by M. Magendie, and confirmed with
more ample details by Messrs. Sandras and Bouchardat, show
564
FATTY ELEMENTS OF FOOD AND ON FATTENING.
that the fatty principles of our food minutely subdivided or made
into an emulsion by the act of digestion, pass without under-
going any essential change into the chyle, and from that into
the blood, whither they can in fact be followed, and in which
they can be shown to remain for a longer or a shorter time un-
altered, at the disposal of the economy, as it were. Such ob-
servations have naturally led physiologists to conclude that the
fatty principles of the food were the principal, if not the only
sources whence animals derive the fat which is met with stored
up in their tissues, or which appears in the butter of their
milk. And this view, so long as the carnivorous tribes alone
are considered, has not a single feature which makes it objec-
tionable. But when we would extend it to the herbivorous
tribes, two difficulties meet us on the threshold of the in-
quiry.
1st. Do vegetables actually contain such a quantity of fatty
matter in their structure as will explain the fattening of cattle
and the formation of milk?
2nd. Is it not more simple to suppose fat and butter the
product of certain transformations undergone by starch and
sugar in the animal economy ?
It appears at first sight most opposite to nature to suppose
that the feeding ox finds the whole of the fat he lays on ready
formed in the food he eats; it is only, in fact, after having made
repeated analyses of plants, and discovered fatty matters almost
everywhere, and in quantities generally superior to any that had
been suspected in the composition of plants, that the idea begins
to acquire likelihood; finally, the chemist becomes convinced that
it is so when he finds a regular association of neutral azotised
substances and fatty principles in all the articles usually em-
ployed as food for cattle,—in the grasses and cereals, in the leaves
and stems and seeds of plants.
Fatty substances appear to be principally formed in the leaves,
where they frequently show themselves under the form, and with
the properties of wax. Taken into the bodies of animals, mingled
with the blood, and exposed to the influence of the oxygen of the
inspired air, they will undergo an incipient oxidation, whence
will result the stearic or oleic acid that is found as a constituent
FATTY ELEMENTS OF FOOD AND ON FATTENING.
565
of suet. By undergoing a second elaboration in the bodies of
the carnivora, the same fatty substances, oxidated anew, would
produce the margaric acid which characterises their fat. These
divers principles, by a still further degree of oxidation, would
give rise to the fat volatile acids which make their appearance in
the blood and in the perspiration. Finally, did they suffer com-
plete oxidation, i. e. combustion, they would be changed into
carbonic acid and water, and be in this shape eliminated from the
economy.
Among the various properties possessed by fatty substances,
there is one which may play an important part in the phenomena
of fattening; this is the solvent power which they severally
possess in regard to one another; the property of mixing in all
imaginable proportions, still preserving the general features which
severally distinguish them. In the stomach, in the intestines,
in the chyle and in the blood, fatty substances of various kinds
may form homogeneous matters by their intimate admixture,
and become divided into globules of complex composition, but
everywhere the same.
Another property of fatty matters of every kind, which de-
serves particular attention, is that of insolubility in water. We
find, in fact, that when an animal eats a soluble substance, that
in general it is consumed by a true process of combustion, which
converts its carbon into carbonic acid, and its hydrogen into water;
or otherwise, it is simply eliminated without change in the urine.
Fatty matters may, indeed, disappear under the first form;
but so long as they escape remarkable modification, it is certain
that they do not pass off by the urine, and that the quantity
climinated by the perspiration is insignificant. Their insolu-
bility, therefore, retains them in the economy once they have en-
tered the blood or the tissues; and it is in virtue of this quality
that they constitute a kind of magazine of combustible matter
in the animal body. This is the principal reason wherefore in-
dividuals supplied with food in excess get fat, and that those
insufficiently fed fall lean; the fatty matter being deposited in
the interstices of the tissues in the former case, being taken up
from them and burned in the second.
This explanation is attractively simple; but in our attach-
566
FATTY ELEMENTS OF FOOD AND ON FATTENING.
ment to it we must not forget that other explanations have also
been given; and in particular it must be contrasted with a view
which has been formed upon certain inquiries undertaken by M.
Dumas. It is known, for instance, that sugar may be regarded
as a compound of carbonic acid, water and olefiant gas. Now
there is nothing to prevent olefiant gas, by becoming detached
and taking different states of condensation, to give rise to
bodies which by undergoing oxidation would produce fat acids
and consequently fats. Since it has been known that the oil of
potato spirit is also met with in the spirit obtained from the
refuse of the grape, and in the spirit procured from malt, and
from the molasses of beetroot sugar, the assurance that the oil
is a product of the fermentation of sugar appears to be com-
plete.
We ought even to be prepared to admit a phenomenon of
the same kind as taking place in plants when we see the sugar
of their stems disappearing in the same ratio as their seeds or
fruits become charged with oleaginous matter: all the palms
elaborate sugar before producing oil.
It is
upon chemical views of this kind that the second opinion
as to the source of fat in animals has been formed, and which
may
be said to stand in direct contrast with that which assumes
this substance as pre-existing in the food, which regards it as
produced in the blood itself, under the influences of the most
intimate forces of animal life. For my own part, I adopt the view
which supposes an animal to be supplied with fat already formed,
mainly because it presents itself to me as more in harmony with
the facts which I observe in our stables. Still I do not deny
that it may be possible for a certain quantity of fat to be elabo-
rated in the bodies of herbivorous animals, under the influence
of a special fermentation of the sugar which forms an element
in their food; although I feel satisfied, from practical facts, that
sugar plays no essential part in the fattening of cattle.
The formation theory, nevertheless, is not without data of a very
curious and important kind, which require notice. Huber had
found that bees fed upon honey, and even upon sugar, did not lose
the power of producing wax for a long period. And Messrs. Milne
Edwards and Dumas have lately confirmed the occasional accu-
FATTY ELEMENTS OF FOOD AND ON FATTENING.
567
racy at least of this conclusion. Their first experiments were
unfavourable to the conclusions of the celebrated bee-master of
Geneva. A swarm fed with lump-sugar yielded very insignifi-
cant quantities of wax; three other swarms, placed in glazed
hives, and fed on honey and water failed to produce any wax;
but a fourth swarm gave a totally different result.
The procedure by analysis was now instituted. The absolute
quantity of wax contained in the body of a bee, or in the bodies
of a certain number of bees, was first ascertained; second, the
quantity of wax in the combs constructed by the labourers was
determined; third, the quantity of wax contained in the honey
consumed was discovered. The final result of the inquiry was,
that a swarm of 2005 labourers, after having in the course of
a month consumed 12889.43 grs. of honey, had produced
2407 grs. of wax.*
Granting the accuracy of this conclusion, admitting that the
bee fed upon honey has the power of producing wax, I might still
ask whether it was therefore legitimate to conclude that the ox
was endowed with any faculty of the same kind? Still to the inte-
resting physiological fact above quoted, may be associated the
remarkable fact of the conversion of sugar into butyric acid,
observed by Messrs. Pelouze and Gélis, a conversion effected by
mixing a small quantity of caseum with a solution of sugar,
and adding a sufficiency of chalk to neutralize acid as it was
formed. This mixture, placed in a temperature of from 77° to
86º F., by and by passes through a series of changes, the last
term of which is the butyric fermentation.
This butyric acid is a volatile, colourless, and very limpid
fluid, having an odour that brings to mind at once that of
vinegar and rancid butter. Although it has a resemblance to
the acids which prevail in different kinds of fat, it nevertheless,
by uniting with glycerine, constitutes a fatty body, butyrine,
which forms about one hundreth part in the constitution of
butter, and must therefore be received as one of the elements
of the fats; and the observations of Arthur Young would even
incline us to presume that butyric acid exerts a favourable in-
fluence in the fattening of animals. Comparative experiments
* Vide Comptes rendus de l'Académie des Sciences, t. xvII, p. 131.
<
00
568
FATTY ELEMENTS OF FOOD AND ON FATTENING.
satisfied Young that hogs fattened more quickly on food that
had become sour, than on the same food before it had turned.
Now it is very probable that there was production of butyric
acid in the course of the fermentation.
The question in reference to the formation of fat is of much
more limited interest to the farmer than to the physiologist. The
agriculturist, in fact, cares little whether a couple of pounds of
honey consumed by a hive of bees will give origin to some
10 dwts. or so of wax; the matter that concerns him is, as to
the degree in which the roots or tubers that he grows are fatten-
ing; and whether or not he can advantageously substitute a
cheaper for a more costly article in his piggery or stalls? And
here, as in so many other places, practice got the start of theory;
and I own, with perfect humility, that I think its conclusions are
in general greatly to be preferred; the universal custom of
giving oil-cake and oleaginous seeds to our milch kine and fatting
oxen and sheep, appears to me to supply an argument of much
greater force than any that can be obtained from chemical re-
searches pursued in the laboratory.
Such articles as the potato and the banana, which answer
admirably for the keep of hogs after they are weaned, are not
adequate to fatten them for the butcher; they contain but very
small quantities of fatty matter, and though the animals will
grow rapidly upon them, and even attain to and maintain a cer-
tain condition, all that is required can only be secured by adding
some other article to the ration that is richer in oleaginous or
fatty principles. At Bechelbronn, whatever others have said on
the subject, we find that our hogs will not fatten on potatoes
alone; so that I agree with Schwertz when he says, that whilst
hogs will get into good flesh upon potatoes, and even seem to
fatten for a time, they soon cease from improving, and only
begin to advance again when they receive in addition an allow-
ance of barley or of split peas or beans.
A young pig will consume about 13 lbs. of potatoes per
diem, into which, as analysis of the ashes informs us, there
enters but about 17.2 grs. of lime. But this quantity is pro-
bably too small to meet the demand for bone earth in a young
animal in full growth, and hence the great advantage of the
FATTY ELEMENTS OF FOOD AND ON FATTENING.
569
whey or small quantity of skim milk which is so commonly added
to the potato ration. It ought to be laid down as a general
rule, that young creatures, as well as adults, ought to have a
ration which contains the earthy elements of the bony system,
the azotised elements of the flesh, and the fatty matter of the
fat. From a series of experiments which I undertook, in con-
cert with Messrs. Dumas and Payen, it appears that all the
articles acknowledged the most powerful as fatteners, are those
also that contain the largest proportions of fatty principles. The
following substances contain the numerical quantities of matter
soluble in ether in 100 parts:
Common maize.
Beaked Lombardy maize
Large white Parisian maize
Rice.
Oats
Ditto
Rye.
Rye flour
Hard Venezuela wheat
Hard African wheat
Wheat flour
•
Ditto
Fine bran.
Coarse bran
Dry clover
•
Dry lucern
Meadow hay
African wheat straw
8.8
7.8
8.1
0.8
Ditto Alsace
5.5
Ditto near Paris
3.3
Oat straw.
1.8 Bean meal.
3.5
Beans
2.6
Haricots
2.1
Peas.
2.1 Lentils
1.4 Potatoes
4.8 Mangel-wurzel
5.2 Carrots
4.0 Oil-cake
•
·
3.5
3.8
3.2
2.2
2.4
5.1
2.1
2.0
3.0
2.0
2.5
0.08
0.1
0.17
9.0
M. Payen found that oil was everywhere present in the seeds
of gramineous plants. The embryo contains much, the husk
less, the farinaceous portion still less. But maize and oil-cake
contain about 9 per cent, whence the universally admitted supe-
rior fattening power of these two articles.
If we now discuss particularly one or more of the rations or
allowances to oxen put up to fatten, or to milch cows, we shall
find that they uniformly contain a larger quantity of fatty mat-
ters than the secretions, excretions, and fat which have been
produced under their influence. Thus a cow, in good condi-
tion, that produces 72 pints of milk, containing 3.3 lbs.
of butter, whilst she eats 220 lbs. of meadow hay, will have
consumed more than 6.6 lbs. of matter soluble in ether-fatty
substances. The quantity of fat contained in the food, over
002
570
FATTY ELEMENTS OF FOOD AND ON FATTENING.
and above that which is discovered in the milk, has passed with
the excrements, which are never entirely free from substances
analogous to fatty matters.
With a view to comparing as accurately as is possible in in-
quiries of this kind, the quantity of fatty matter contained in
the forage consumed by a cow, with that found in the milk and
in the excrements, the following experiment was made. A cow,
Esmeralda, No. 6 in the stable at Bechelbronn, calved on the
26th of September, and she was put to the bull again on the
4th of November. Up to the 22nd of January (inclusive)
Esmeralda received the usual allowance, viz.:
1st to
2nd
3rd
4th
Aftermath hay
Oil-cake
5th
6th
7th
8th
9th
10th
11th
Turnips
Wheat chaff
and the milk she gave in the course of the month of January,
amounted on the:
Pints.
12.9
12.3
12.3
11.4
10.5
12.3
12.3
12.9
12.3
10.5
11.4
12th
13th
14th
15th
16th
17th
18th
19th
20th
21st
22nd
Hay.
Chopped wheat-straw
Beetroot
11 lbs.
22
66
22
The average quantity of milk, therefore, per day, in the course
of the week that preceded the experiment, was 10.287 pints.
From the 23rd of January, when the ration was altered to:
The quantity of milk yielded was :
January.
23rd
24th
25th
26th
27th
28th
29th
30th
16.5 lbs.
9.9
59.4
Pints.
12.3
11.4
11.4
12.3
10.5
11.4
10.5
11.4
11.4
11.4
11.4
Pints.
11.4
10.5
10.5
10.5
11.6
11.4
11.4
11.4
FATTY ELEMENTS OF FOOD AND ON FATTENING.
571
on an average 11.8 pints per diem; a little more than with
the former allowance.
The excrement passed by this cow was analysed during four
days, from the 24th to the 27th of January; the whole quantity
being weighed moist every day, and well mixed, a mean sample
of about 6 oz. in weight was taken for analysis. This being
stove-dried, the entire quantity of dry matter contained in the
moist excrement was readily ascertained :
Dates. Moist excrement.
Jan. 24 40.7 lbs.
25
41.8
26
62.1
27
43.4
188.0
Hay
Straw.
Dry excrement.
6.8 lbs.
7.3
9.0
7.1
30.2
Milk in piuts.
10.5
10.5
10.5
10.5
42.0
To ascertain the quantity of fatty or waxy substances con-
tained in the food, the several samples were first treated with
hot water, then with ether, and finally with a mixture of ether
and alcohol boiling. The fatty element of the butter was deter-
mined by Peligot's method.
Hay
Straw
Beet.
J 1st Experiment
2nd Ditto
1st Experiment
2nd Ditto
Milk in lbs.
13.5
13.5
13.5
13.5
54.0
{
[ 1st Experiment
2nd Ditto
Fatty Matters in the
Food per cent.
3.6
3.9
2.4
2.0
Fatty Matter in the
Excrements and
Milk per cent.
3.3
3.9
3.7
Excrements (dry) .
Milk
Let us say, that the proportion of fatty substance contained
per cent in the several articles consumed as food, was as
follows:
3.7
2.2
0.1
Dry Excrements
3.6
Milk.
3.7
and we shall have the results of the experiment in this shape:
572
FATTY ELEMENTS OF FOOD AND ON FATTENING.
FOOD CONSUMED IN FOUR DAYS.
Fatty matter.
Beet 237.6 lbs.
66.0
Hay
Straw.
39.6
•
Fatty matter in food 24956.8
The excretions
21813.8
•
1667.3 grs.
1776.1
6113.4
Fatty matter fixed
or burned
EXCREMENTS AND MILK IN FOUR DAYS.
Excrements
Milk
30.4 lbs.
54.3
Fatty matter in excre-
ments and milk
Fatty matter.
7688.1 grs.
14125.7
21813.8
3143.0
The natural conclusion from this experiment appears to be
this; that the cow extracts from her food almost the whole of
the fatty matter it contains, and that she converts this matter
into butter.
It would perhaps be possible to make the proportion of butter
contained in milk to vary within certain limits. It is well known.
that the butter of cows in the same district varies notably ac-
cording to the nature and abundance of the forage; the butter
of the same country-side, for example, has been ascer-
tained to contain 66 of margarine to 100 of oleine in summer,
and 186 of margarine to 100 of oleine in winter. In the first
case, the cows are grazing on the mountains (the Vosges); in
the second, they are eating dry fodder in the stall. I have be-
sides had an opportunity to make a direct experiment upon this
subject, which appears to me quite conclusive. Having substi-
tuted for one half the allowance of hay an equivalent quantity
of rape-cake, still very rich in oil, the cows were kept in excel-
lent condition; but the butter was extremely soft, and had the
taste of rape-seed oil to a degree that was perfectly intolerable.
I do not know a single instance in any of the systems fol-
lowed at Bechelbronn, in which a milch-cow does not receive in
her ration a quantity of matter analogous to fat, superior to that
which is contained in the milk she yields. Having upon a cer-
tain occasion put a cow exclusively upon beet, I anticipated an
unfavourable effect on her milk; and in fact a very sensible di-
minution in all its valuable elements occurred, and the animal
began to suffer. By simply adding a few pounds of straw which
had been taken away the milk resumed its standard quality.
The two rations thus composed may be contrasted under the two
points of view of contents in fat and contents in organic matter.
FATTY ELEMENTS OF FOOD AND ON FATTENING.
573
In the ration of beet and straw (beet 119 lbs. straw 7 lbs.)
there were 140 dwts. 20 grs. of fatty matter; in that composed
exclusively of beet (132 lbs.) there were but 38 dwts. 14 grs. of
fat. The ill effects of the beet-root ration could not be ascribed
to deficiency of inorganic elements, for the phosphate of lime it
contained amounted to 37 dwts. 7 grs.-amply sufficient for all
the purposes of the economy.
The information we have from M. Damoiseau, one of the
most careful of the observers who have investigated the subject
of the production of milk, confirms us in our views of the neces-
sity of fatty matters in the daily ration of the milch-cow. The
following are the elements of three of the rations for a cow in
M. Damoiseau's establishment.
No. 1.
Beet or mangel wurzel 88 lbs.
Bran
6.6
5.5
6.6
13.2
Pollard
Lucern
Oat straw
Salt
Quantity of milk
yielded
•
0.11
•
No. 2.
Carrots 74 lbs.
121.0
Maximum.
From 25 to 26 pts.
6.6lbs. of bran and 5.5 lbs. of
pollard at
6 6 lbs. lucern
13.2 lbs. oat straw
>>
"
"}
""
6.6
5.5
6.6
13.2
107.0
Medium.
16 to 18 pts.
0.11
"}
"
No. 3.
Potatoes 55 lbs.
""
>
>>
33
››
Let us now calculate the actual nutritive value of the dif-
ferent items in the above rations; or selecting one, let us take
that with the beet for particular consideration as among the
most usual.
6.6
5.5
6.6
13.2
5 per cent. 0.60 of fatty matter.
3
. 5
=0.33
=0.60
1.53
>>
0.11
>>
88.0
Minimum.
12 pts.
Whence it follows, that a cow here received upwards of 1 lbs.
of matter of a fatty nature with her food, a quantity more
than sufficient to produce not only 16 or 18, but the maximum
quantity of 25 or 26 pints of milk very rich in cream. Did
the cow receive an additional 40 lbs. of beet-root, she would
find something like 12 lbs. more of solid matter in this article,
composed especially of sugar, which she would burn to keep up
574 FATTY ELEMENTS OF FOOD AND ON FATTENING.
her temperature, and nearly 25 dwts. of oily matter which she
would transfer to her milk, to say nothing of new azotised prin-
ciples which would be converted into caseine.
If we now, by an easy transition pass to the phenomena of
fattening, we still find that the principles which have been laid
down can be most satisfactorily applied. Setting out from the
numbers obtained from the experiments of Mr. Riedesel, which
in many points agree with all I have seen myself, we arrive at
the following conclusions:
An ox weighing 1320 lbs. avoird. will keep up his weight
upon about 22 lbs. of good hay per diem. Put up to fatten,
the same animal would require about twice this quantity, say
44 lbs., upon which he would gain at the rate of about 2 lbs.
per day.
Now if we even take Mr. Riedesel's conclusions as a little too
favourable, as giving at least the maximum nutritive value to
the hay and its equivalents, we may still admit with him that
22 lbs. of hay will produce about 17 pints of milk, or about
2 lbs. avoirdupois of flesh, containing 0.55 lb. or rather more
than lb. of fat. Now 22 lbs. of hay contain nearly 12 oz.
12 dwts. of principles soluble in ether, i. e. of fatty or waxy
1
matter.
The fatting ox consequently fixes a certain proportion of
these principles in the same way as the cow. There is only this
difference that the cow returns with the milk she yields a con-
siderable quantity of the fat she finds in her food. There con-
sequently exists an obvious relation between the formation of
milk and fattening, a position which would gain support, did it
require any, from a note which I owe to the politeness of M.
Yvart, who in summing up a long array of facts concludes with
these words: "The secretion of milk appears to alternate with
that of fat. When a milch-cow fattens she loses her milk;"
and the converse of the proposition is no less true; when we
would fatten a cow we must let her go dry.
The breeds of kine admitted to be the best milkers remain
long lean after the calving. In some of the short horned Eng-
lish breeds the quantity of milk is often very considerable
shortly after the calving; but the animals are much disposed to
get fat, and getting fat, the secretion of milk neither continues.
FATTY ELEMENTS OF FOOD AND ON FATTENING.
575
so long, nor is it so plentiful as in some of the other less im-
proved kinds. English hogs, which become much fatter than
French hogs, appear not to be such good nurses. Now if we admit
that there is this intimate relation between the formation of
milk and that of fat, we are obviously very near the ad-
mission that articles of food containing fatty substances, indis-
pensable to the production of milk, are also indispensable to the
production of animal fat. And then has it ever yet happened
that animals have been fattened with food devoid of grease? I
have not for my own part met with a single fact which counte-
nances such a proposition. I have referred to the distinguished
agriculturist who attempted to fatten pigs upon potatoes, but
who only succeeded by adding a certain quantity of graves to
the food, an article which, as every one knows, contains a con-
siderable proportion of fat in its composition.
M. Payen has in fine made some experiments which appear
altogether conclusive, and from which it follows that two Hamp-
shire hogs, which having consumed 66 lbs. of gluten and upwards
of 30 lbs. of starch had only gained 17 lbs. ; whilst other two
animals of the same breed having been fed with 99 lbs. of the
flesh of sheep's heads, containing from 12 to 15 per cent. of
fat, had gained 35 lbs. Yet judging from elementary analysis
these two rations were almost identical; they contained the same
quantity of dry nutritious matter. The first ration contained
26.4 lbs. of dry gluten and 30.4 lbs. of starch; the second
contained 20.9 lbs. of dry flesh and 15.4 lbs. of fat. The
quantities of carbon and azote were therefore a little higher in
the vegetable than in the animal ration; but they differed
notably in this, that the latter contained an equivalent of fat for
the equivalent of starch contained in the former.
In a second experiment four hogs fed upon boiled potatoes,
carrots, and a little rye, gained 117.7 lbs., whilst other four
animals of the same age and in the same conditions, but fed
upon sheep's heads, gained as many as 226.6 lbs.
In the course of these experiments M. Payen was struck with
this circumstance, that the increase in weight of an animal that
is fattening being represented by 50 per cent of water, 33.3 of
fat, and 16.6 of azotised matter, the conviction is forced upon
576
FATTY ELEMENTS OF FOOD AND ON FATTENING.
us that he actually fixes the greater proportion of the fat of his
food in the cellular tissue of his body. The first hogs, for ex-
ample, had eaten 14.74 lbs. of fat, and had gained 11.44 lbs.
in weight; the four last referred to had had 18.48 of grease
and had increased 14.74 lbs. in weight.
It has now been the practice for several years in various
places to maintain hogs in considerable numbers upon muscular
flesh, horse-flesh; and it has been ascertained that the article, if
extremely lean, though it keeps the animals in good heart and
condition, though they grow and thrive on it, yet they will not
fatten. When they are to be got ready for the butcher they
must in addition be put upon a course that is known to be
proper to fatten them.
The scientific question of fattening having of late years at-
tracted very general attention, the opinions which have now been
announced have been very actively contested. Among other
arguments the general freedom from fat of the bodies of carni-
vorous animals, and the usual fat state of those of the her-
bivorous races has been cited. Whales have even mistakenly
been included in the list of fat vegetable feeders; but it is
known to all naturalists that the great majority of the whale
tribes, the whole of those that inhabit the northern seas, are
carnivorous. And indeed the mention of this fact leads me to
revert to one of the most curious problems in the physics of the
globe, that, to wit, presented by the vast amount of animal life
amidst the waters of the ocean, and its support by a quantity
of vegetables which to us appear altogether inadequate to such
an end. The beautiful researches of M. Morren, however, seem
calculated to throw some light on this interesting subject, that
inquirer having shown that certain animalcules possess the
faculty of decomposing carbonic acid in the same way as vege-
tables; and it is probably in virtue of this power that the enigma
is to be explained of the source whence the myriads that people
the deep derive their food.
G
But is it absolutely true that herbivorous animals only abound
in fat? Who has not seen fat dogs and cats? and in the Cor-
dilleras, where palm-trees abound, there is a particular species of
bear which lives in a great measure on the oily palm-nuts and
FATTY ELEMENTS OF FOOD AND ON FATTENING.
577
young shoots of the palm tree, which becomes remarkably fat
and proves a great attraction to the tigers of the country.
*
Before coming to a close with this discussion I think it right
to refer to the experiments of M. Magendie, who has so well
established the fact that the chyle of animals fed on fat food
contains a large quantity of fat; and that animals kept long on
such food frequently become affected with what is called the
fatty liver.t
To sum up then, experiment demonstrates that hay contains
a larger quantity of fatty matter than the milk and excretions.
which it forms; and that it is the same with all the other mix-
tures and varieties of food that are usually given to animals.
That oil-cake increases the production of butter, and that
like maize it owes the fattening properties it possesses to the
large quantity of oil it contains.
That there is the most perfect analogy between the production
of milk and the fattening of animals; that potatoes, beet,
carrot and turnip only fatten when they are conjoined with sub-
stances that contain fatty matters, such as straw, corn, bran and
oil-cake of various kinds.
That in equal weights gluten mixed with starch, and flesh
meat abounding in fat, have a fattening influence on the hog
which differs in the relation of 1 to 2.
Lastly, that fat food-food which will afford fat in the diges-
tive canal, appears to be the indispensable condition of fattening.
If it be necessary that the respiration be diminished or lessened
in extent, this is only that the fatty substances taken into the
stomach, and which have made their way into the blood, may
not be oxidated, may not be burned; not that their formation
may be favoured.
All these facts are in such perfect harmony with the simple
* These beasts evidently cease to be carnivorous whilst they live on palm-
nuts and leaves. For my own part, I do not think the point settled yet.
The fatty matter of the generality of vegetables is wax rather than grease.
And then some of the herbivorous tribes seem never to get fat.-ENG. ED.
† 1 may here state the contrary fact as announced to me by a physiological
friend in whose report I place great reliance, that the chyle of animals fed
with substances that give mere traces of waxy matter, contains fat or oil
that can be collected in large drops.-ENG. ED.
003
578
FATTY ELEMENTS OF FOOD AND ON FATTENING.
view of assumption and assimilation of fatty matters that it is
difficult to conceive on what foundation the opinion can repose
which would have them composed out of their elements in the
animal body. Nevertheless, I am myself the first to admit that
more extensive experience may lead to the modification or even
entire change of the opinion which I advocate. The facts on
which that opinion is based, despite their number, are not pro-
bably yet sufficient to constitute a perfectly satisfactory or con-
clusive theory. New researches are therefore indispensable; it
would be requisite to show that a cow kept on a regimen abun-
dant in point of quantity, but as poor as possible in matters
analogous to fat, will continue to maintain her condition and
yet yield milk abounding in cream; and that it is really possible
as some persons affirm, to fatten animals rapidly on roots and
tubers alone.
* Whoever would try experiments in this direction must be careful to
mix his food; one article alone never agrees. The Americans say a pig
will die upon pumpkins and upon apples alone; but he will live and fatten
on a mixture of the two. I have myself seen scores of oxen fattened
upon turnips with a moderate allowance of straw or bog hay; and have
seen pigs get into admirable condition for the butcher on little more than
potatoes.-ENG. ED.
579
CHAPTER IX.
OF THE ECONOMY OF THE ANIMALS ATTACHED TO A FARM.
OF STOCK IN GENERAL, AND ITS RELATIONS WITH THE
PRODUCTION OF MANURE.
AGRICULTURAL industry generally extends to the breeding
and fatting of cattle; the breeding or at all events the mainte-
nance of horses; the breeding and feeding of sheep and swine.
The circumstances indeed in which the tiller of the ground sees
himself spared the necessity of attending to these matters are
rare exceptions to the general rule, and in fact only occur where
it is easy to obtain abundant supplies of manure from without,
or in those few favoured spots where the fertility of the soil is
such that it continues to yield its increase without addition in
the shape of manure. In the vicinity of great centres of popu-
lation where dung can be bought cheap, or of guano islands,
where a cargo costs a trifle, and in some tropical countries, large
farming establishments may be found totally without stock in
the shape of sheep and horned cattle. But in a general way
the agriculturist is obliged to give himself up to the care of
flocks and herds of one description or another; and in fact we
now know that there is a certain and very indispensable relation
to be maintained between the extent of surface under crop and
the number of cattle to be provided for, variable as regards
farms differently situated and circumstanced; but invariable
when circumstances are the same, and the system of manage-
ment pursued is similar in its principal features.
The question as to whether the cultivation of grain or other
useful plants, or the rearing of cattle is more profitable? which
is often agitated, must receive a different solution in regard to
cach different locality. In one place it may be more advan-
tageous to breed cattle or horses; in another to rear or fatten
them; here the production of milk, butter, and cheese may be
580
ECONOMY OF FARM ANIMALS.
the best husbandry; there the growth of hay (as for miles
round London on the north and west;) and again wheat and
the other cereal grasses may be the staples of production. Even
supposing that the growth of grain is that which is most ad-
vantageous on the whole, it by no means follows that the farmer
shall give himself up to this exclusively; it is seldom that he
can do so, indeed; he must have manure, and this entails the
necessity of keeping cattle. If the latter, however, be the least
profitable item in the economy of a particular domain, it will of
course be kept within as narrow limits as possible.
In many places where the land is well adapted to the plough,
and where the production of grain is unquestionably profitable,
stock appears to offer few advantages; it sometimes happens,
indeed, that the balance as regards the stall and cow-house is on
the wrong side for the farmer when the actual value of the
forage that has been consumed is taken into the account. The
loss is only made up for by the manure, which is in fact the re-
turn. This is the view that M. Crud obviously takes when he
speaks of the stock upon a farm as a necessary evil.* I am far
from participating in his opinion; the cattle upon a farm are no
evil, though they may be very necessary. To be satisfied of
this it is enough in fact to recollect the principle which has been
established in treating of rotation courses, viz: That in no case
is it possible to export a larger quantity of organic matter,
and particularly of organic azotised matter from a farm than
is represented by the excess of the same description of matter
contained in the manure consumed in the course of the rota-
tion. By acting otherwise the standard fertility of the soil
would inevitably be diminished.
This principle recognised, and I believe that it cannot be dis-
puted, it is obvious that a portion of the produce of the fields
must be returned to them to fecundate them anew, and it is
precisely this portion of the forage crops destined to furnish
manure that must be consumed in the stable and cow-house.
Reasoning abstractly, the forage plants which it is not intended.
should quit the farm might be buried directly as manure without
being made to pass through the bodies of animals; their fer-
* Theoret. and Pract. Economy of Agricul. vol. 11. p. 235, (in French.)
ECONOMY OF FARM ANIMALS.
581
tilizing influence on the soil would come out sensibly the same,
and this is what is done in fact, so often as we manure by
smothering. But we have scarcely made the first step in the
rudiments of agriculture before we discover the immense ad-
vantages of following the usual custom, which first employs as
forage for cattle the crops that are grown with a view to the
production of manure. And we shall by and bye find, in fact,
that by adding to that portion of these crops a supplement of
forage plants which it would be legitimate to export, without
trenching upon the fundamental principle above laid down, we
obtain the same quantity of manure, and turn the whole of this
supplement into useful forces, or into animal products which
possess a market value greatly superior to that of the forage be-
fore its assimilation. It is only the price of this portion of the
forage, fixed or modified by the cattle on the farm, which can
fairly be set down to the debit account of wool grown, of power
created, and of flesh and dairy articles produced. As to the
forage plants which are immediately turned into manure, it
seems to me impossible to regard them as possessed of the
proper market value; the farmer could not have sold them at
this. In my mode of looking at the thing the cost of pro-
ducing the forage crop, and the value that it actually has, con-
stitute a circulating capital, the annual interes of which esti-
mated at a certain rate expresses the true cost-price or value of
the manure employed in the course of a rotation. In a word,
in my eyes the value of the manure which gives fertility to the
soil is represented by the price of the labour, the rent charge,
&c.-by the general outlay entailed by the growth of the forage
from which it is obtained.
I shall endeavour by and by to illustrate this topic by ex-
amples; but in order thoroughly to understand this mode of
estimating the price of manure there are several elements want-
ing, which I propose to assemble in this chapter. With this
view I shall first present the facts which I have been able to
collect, or which I have myself had an opportunity of observing
in reference to the economy of the domestic animals attached to
a farm; and I shall then make an attempt to deduce the rela-
582
HORNED CATTLE.
tion that exists between the consumption of forage and litter,
animal reproduction and increase, and the formation of manure.
SHORNED CATTLE.
It were foreign to the purpose of this work did I enter
into the natural history of the animals that are usually attached
to farming establishments; neither will I pretend to discuss the
relative merits of the different breeds of sheep and oxen, nor
speak of the best methods of improving them. I confine my-
self to the varieties which I have on my own farm, or which I
see on the farms of my neighbours, and upon which I have op-
portunity of making daily observations. It will be enough if I
give a brief summary in this place of the general principles ad-
mitted by practical men of the highest name and authority upon
these points.*
Between the external forms of animals and the internal or-
gans essential to life there is the most obvious and intimate
connection. A broad and deep chest is the sure indication of
ample lungs and a good general constitution. The pelvis or
bony cincture formed by the rump and haunches ought to be
spacious in the females. A small head is generally the indica-
tion of a good kind. Horns in our domestic animals must be
regarded as objectionable rather than useful, and by adopting
measures which tend to repress their growth we undoubtedly
favour both the production of flesh and wool. The strength of
animals depends far more on the degree in which their muscu-
lar system is developed than on the mass of their bones; it is,
besides, flesh, not bone, that has value in the butcher's eyes; so
that the farmer's business is by all means to strive after a delicate
but well covered skeleton. Animals which have been indiffe-
rently fed whilst young have often the bony system very dispro-
portionately developed.
Two modes are generally followed with a view to improving
the external shape of domestic animals. One of these consists
* Cline, in General Report of Scotland; Communication to the Board
of Agriculture; Spencer on the choice of male animals for breeding from;
Cully's Introduction, &c. on live stock, &c.
BREEDING.
583
in only breeding from animals of the most faultless forms of
the same race, and generally of close degrees of kindred; another
in crossing females with the males of a neighbouring race,
each possessing in the greatest degree the qualities which it is
held desirable to transmit to the future race. The former of
these plans is spoken of as the method of breeding in and in;
the second as the method by crossing.
Certain disadvantages have been stated as belonging to the
system of breeding in, by the side of several unquestionable and
more immediate advantages. Whilst the race acquires small
bones and shows a decided disposition to take on fat readily, it
is said after several generations to lose in constitution, to become
more subject to disease; the cows to give less milk, and the
males, in losing their characteristic masculine forms, to show
themselves less fit for propagation. The English breeders who
take this view of the subject are, therefore, in the habit of having
recourse to males of the same race, but bred at a distance from
themselves. I must for my own part say, that I have seen no
reason to admit any ill effects from propagation continued in
the same direct line. Our live stock at Bechelbronn has not
been otherwise renewed for a very long time and without the
race appearing to suffer in any way; our bulls on the contrary
have very much improved.
Mr. Cline insists greatly on the selection of females not only
of good shape, but so much above the mean height as to ap-
proach the standard of the males. When the bull is very much
larger than the cow, the progeny is apt to fall off instead of
improving; the reason for which Mr. Cline finds in the large
size of the fœtus, the issue of a large male, which a small female
can neither accommodate properly in her womb, send easily into
the world, nor suckle duly when it is born. Whatever we think
of this explanation, there can be no doubt of the propriety of
giving the principle pointed at the most careful consideration
in practice. Mr. Cline refers to the great improvement that
has been effected in the breed of English horses mainly through
crosses with small barbs and Arabian stallions; the introduction
of Flemish mares would upon the same principle have been
another means of still farther improving the race. The neglect
P P
584
BREEDING.
of this principle, Mr. Cline is of opinion lies at the bottom of
the numerous failures and disappointments that have been en-
countered in attempts to improve the breed of horses. A
striking illustration of it occurred some years back, when bay
horses of great height were in particular request; the Yorkshire
breeders had their mares covered by the tallest stallions that
could be found; but they immediately found that the progeny
was merely long legged, that it was narrow chested and without
either weight or bottom.
Spencer acknowledges with breeders in general that the bodily
and constitutional qualities are almost always those that pre-
ponderated in ancestors, and that the qualities of the father
predominate in the posterity, particularly as regards oxen and
sheep. This point settled, the choice of a good male is evidently
the first point of consequence in attempting to improve a breed.
As it is not possible, however, to find either a bull, or a tup, or
a stallion quite perfect, the one must be chosen that is most free
from defect, particularly the defect or defects which we have it
in view to correct in our breeding animals, our cows, ewes and
mares. Certainly no reasonable breeder would bring together
animals that presented similar deficiencies; on the contrary, he
will strive to have his female served by the male which shows
all the qualities in the very highest degree that are most wanting
in her. On the whole the association of animals of the same
race appears to me the best mode of continuing desirable qua-
lities, especially when this is conjoined with ample supplies of
good food to the young. The influence of feeding is immense ;
in my own neighbourhood I see that the progeny of the Bechel-
bronn bulls are often inferior both in stature and shape to those
that are brought up in our own stables.
Great size, however, is not always to be regarded as an im-
provement; height is by no means a constant indication of
vigour of constitution. Improvement in those particulars of
form and stature which are ascertained to be best suited to the
circumstances of the locality, the climate, the pasture, &c., are
the points to be especially attended to. It is above all indis-
pensable to breed animals of vigorous constitution: over-refine-
ment of original races has often led to indifferent conformation
MANAGEMENT OF CATTLE.
585
of body, and to undoubted delicacy of constitution, which has
rendered the herd or the flock much more obnoxious to attacks
of epizootic diseases.
The degree of refinement of an original stock is evidently
connected with the quantity and quality of the forage of the
district. In cold and mountainous districts, where the herbage
is scanty, it is necessary to restrain the ambition of having
highly improved stock within considerably narrow limits; in
such circumstances, the grand affair is to have a hardy race,
not over nice in its food, which through a considerable portion
of the year consists of but coarse grass.
The ox (bos taurus) has been reduced to domesticity from the
remotest ages, and nothing but conjecture can be offered with re-
gard to its original race. The animal accommodates himself with
wonderful facility to the most opposite climatic circumstances; he
multiplies with astonishing rapidity in the hottest regions of the
tropics; unknown at the period of the conquest, he has now overrun
the steppes of the vast basins of the Oronoco and the Amazons,
and is met with in vast herds on the highest and coldest table-
lands of the Andes, even up to the line of perpetual snow;
wherever there is food, he appears to thrive; the extremes
of temperature seem to have little or no influence upon him.
The buffalo (the bos bubulus of naturalists), is the only other
member of this family that has been domesticated. He is fond
of warmth, and is supposed to have been introduced into Italy
towards the sixth century, from Eastern Asia. The buffalo is
also found in Hungary and Greece; and wherever he is met
with, he is made serviceable as a beast of draught and burden,
and as food.
In breeding oxen, the great consideration is the bull. Accord-
ing to Thaer, the bull ought to have a short thick neck, the
head short and small, the forehead broad and curled, the eyes
black and sparkling, the ears long and well placed, the chest
broad and deep, the body long, the legs short and columnar in
shape.*
A well-made bull would serve seventy or eighty cows
were the season spread equally over the whole year; but as it is
*Principles of Agriculture, vol. iv, p. 296.
P P 2
586
MANAGEMENT OF CATTLE.
not so, Thaer thinks that twenty is as many as can properly be
given to the same animal; and this, in fact, is the number
which we adopt at Bechelbronn.
The cow gives more milk than any animal known. A great
variety of external signs of a good milker have been particu-
larized; but it may be said that there is none infallible. In a
general way, I think that race has much to do with the point;
the cow that is the offspring of a mother of a good kind and a
free milker, will herself be a good milker also. I will only add
that among the milch-kine which I have had an opportunity of
observing, those that showed little tendency to take on fat,
whilst they kept their appetite, have appeared to me to yield
milk in largest quantity, and for the longest time.
The age at which it is advisable to put heifers to the bull,
depends a good deal on the way in which they have been kept
and brought up, and also on their growth. Young animals of
a good kind, that have been well fed from the birth and received
all the care which contributes so powerfully to their development,
will be ready to receive the bull when they are between a year
and a half, and two years old. At Bechelbronn, we bull the
greater number of our heifers at the age of about eighteen
months. Whenever they enter into heat with anything like
force, whatever their age, they ought to be put to the bull, or
there is risk of the disposition to receive him dying away, and
never returning; the heifer then begins to lay on fat, and ever
after refuses the male. The rule, however, is not to allow the
young female to be leapt until she is nearly at her full growth;
this, in fact, is the season when the desire for the male usually
first shows itself.
If there be no new indication of heat in the course of three or
four weeks after the male has been admitted, there is reason to
believe that the animal is pregnant. The cow goes with calf
about forty weeks; the delivery generally takes place between
the 277th and the 299th day after the access of the bull; but
periods so short as 240 days, and others so long as 321 days
have been observed.*
* Teissier in Annals of French Agriculture, vol. ix, 2nd series.
REARING CALVES.
587
The calf that is brought up with proper care is generally
allowed to suck for five or six weeks; but it sometimes hap-
pens that even at three weeks old the quantity of milk supplied
by the mother is insufficient; an additional quantity of food is
therefore requisite. One of the best drinks for calves is made
by mixing a proper quantity of oil-cake with tepid water; the
large proportion of vegetable caseum, of oily matter, and of
phosphates which the substance contains, makes it peculiarly
appropriate food for calves; diffused in water, it in fact bears
a close resemblance to milk in point of chemical composition.
It is now, too, that the calf begins to play with a little hay, so
that it is always advisable to place some within its reach, the
finest and softest portions being picked out.
But it is by no means necessary that the calf should ever be
allowed to suck; it drinks without difficulty, or can be made to
drink, as every dairy man and woman knows, by putting a finger
or two into the animal's mouth under the surface of the drink.
A little warm water is added to the milk during the first few
days, in order to give it due warmth. Some begin from the
very first to measure the milk; but those who are best in-
formed upon the subject of breeding and rearing do nothing
of the kind. Crud allows his calves to drink as much milk as
they will take for the first week. After this time they have an
allowance of about seven pints of new milk mixed with the
same quantity of fresh whey. They are weaned at seven weeks.
From the age of between nine and ten weeks to a year, a calf
will consume about a fourth of the ration of a grown cow, say
6 lbs. of hay per diem. During the second year, the allowance
of hay may be estimated at about 13 lbs. or a little more; and
in the third year it will amount to between 19 and 20 lbs.
This is to be understood of cattle brought up carefully but
frugally.
In some of the best dairies of Switzerland, the procedure is
different. During the first six weeks the calves are allowed to
drink as much milk as they will take without a surfeit.
At a
month old they are served with chopped hay and roots, or better
still, if the season admits of it, with green clover or lucern,
which they have at discretion till they are seventy days old.
588
REARING CALVES.
Treated in this way, a calf is nearly twice as large and twice as
heavy as one that has been brought up economically. During
the remaining 295 days that make up the first year, the animal
is allowed from 8 to 9 lbs. of hay; and this quantity is doubled
during the second year. By proceeding in this way, a heifer
at two years old may herself be a mother and contributing to the
produce of the dairy.
Our procedure at Bechelbronn is calculated on the Swiss
plan. The calves suck till they are six or seven weeks old,
being put to the cows night and morning. Anything they
leave is milked off. After numerous trials by guaging and
weighing, I find that our calves take each during the forty-two
days they are allowed to suck, from 528 to 600 pints of milk;
in other words, from 14 to 18 pints per diem. The quantity
of milk which a calf takes immediately after its birth, does not
indeed amount to anything like even the smaller of these quan-
tities still it is considerable.
A calf which weighed at its birth on the 18th of May
108.9 lbs., after having sucked weighed 112.4 lbs. ; so that it
had taken 3.5 lbs. of milk to its meal; and as it had two of
these in the day, 7.0 lbs. in all. The same calf, thirteen days
afterwards, weighed 130.9 lbs. ; and after having sucked,
139.0 lbs.; it had therefore taken 8.1 lbs. to its meal, or
16.2 lbs. per day.
About the third week after birth, our calves have hay of the
best quality set before them; they take very little at first, but
they soon get accustomed to it, and at weaning time it com-
monly suffices for their support. It may happen, however, that
at this period they fall off a little, but they soon recover again;
still, if any of them appear delicate, it will be prudent to allow
about a couple of quarts of milk a day mixed with water, for
some little time, which is gradually withdrawn as the animal
becomes accustomed to its new food.
Calves grow with great rapidity during the suckling time.
The only experimental data with which I am acquainted in re-
gard to the increase of weight of calves during the first period
of their lives, are those of M. Perrault de Jotemps. These
observations I shall associate with those which I have myself
REARING CALVES.
589
the same Swiss race
The weight of three
to be:
made at Bechelbronn, where, by a happy coincidence, we have
of cattle as Messrs. Perrault at Feuillasse.
calves at birth was found by M. Perrault
No. 1.
No. 2.
No. 3.
Average
At Bechelbronn the weight of six calves at birth was:
No. 1, born in May
February
Ditto
April
June
May
A calf which at birth weighed
Weighed 13 days afterwards
Increase in 12 days
. 108.9 lbs.
139.0
30.1
70.4 lbs.
83.8
80.8
78.0
Average
M. Ernest Perrault found that a calf, No. 1, during the first
eighteen days of its life increased on an average 2.8 lbs. per
diem; No. 2 increased at the rate of 1.8 lbs. per day; and
No. 3 at the rate of 2.7 lbs. per day; average increase, 2.4 lbs.
per day.
Another calf, born at Feuillasse, which weighed
101.2 lbs., when nineteen days old weighed 151.2 lbs.; so
that it had gained 50 lbs., or at the rate of 2.6 lbs. per
diem.; a rate which corresponded precisely with what was
observed in the case of nine other calves fed for the butcher,
the average increase of which per diem was 2.7 lbs., during
which each has had about 19.3 pints of milk daily.
The conclusions come to at Bechelbronn bear a close resem-
blance to those of Feuillasse:
•
. 108.9 lbs.
88.0
90.2
100.1
88.8
101.2
96.2
•
Increase per day, 2.5 lbs.
A calf born 12th of Feb. weighed 88.0 lbs.
On the 30th of March it weighed
Increase in 46 days
171.6
83.6 Increase per day, 1.8
590
REARING CALVES.
The same calf, weaned the 21st
of April, weighed
Increase in 21 days
•
193.6 lbs.
22.0
Increase per day, 1.03
It is obvious, therefore, that from the time of weaning, the
growth ceases to be so rapid; the transition from the milk diet
to one of hard dry food, is often critical for young animals; and
I have already said that it is one at which they frequently lose
weight.
If we reckon the daily increase from birth, that is to say, for
69 days of mixed alimentation, we have 1.5 lb. for the quantity:
Crescent, born the 27th June, weighed
Eleven days later
Increase
At the age of 37 days he weighed
Increase in 26 days
Six days afterwards he weighed
Increase in 6 days
Another calf at birth weighed
At weaning, aged 41 days .
Increase
•
•
88.8
112.1 lbs.
23.3 per day, 2.1 lbs.
. 188.1
67.1
per day, 2.5
202.4
14.3 per day, 2.3
. 101.2
189.2
88.0 per day, 2.1
•
These various observations give about 2.2 lbs. for the average
daily increase of a calf in weight during the period it is sucking.
The data of M. Perrault make it a little higher, 2.7 lbs. So
that it may be assumed that a calf which is receiving from
15 to 19 pints of milk in the day, will be gaining 2.48, or
very nearly 2½ lbs. in weight per diem.
It will readily be understood that in places where milk is of
considerable value, as in the neighbourhood of cities, the farmer
may find his profit in selling that article directly rather than in
turning it into veal or beef, more especially if the usage of the
district be to give the calves milk till they are three or even
four months old. Nothing, in my eyes, can justify such a
needless expenditure of milk; especially since I have had an
opportunity of witnessing what I may call the natural course of
rearing cattle in the steppes of South America. There the
young animals only receive milk in anything like quantity for
REARING CALVES.
591
two or three weeks; they soon get accustomed to live on grass.
In the warmer countries of the earth, too, cows give much less
milk than they do in temperate latitudes, and the secretion also
dries up much sooner. The value of the milk and the high
price of butter and cheese are unquestionably at the bottom of
the immense slaughter that takes place in France among the
calves even at a very early age, when they are fat but do not
eigh more than from 110 to 112lbs. This circumstance
undoubtedly stands in the way of the production of meat in that
country, and causes the notorious scarcity of meat of the best
quality. Of the two millions of calves which it is calculated are
slaughtered in France, ths are killed before they are a month
old, and when they do not weigh one with another more than from
90 to 110lbs. But we have seen that at two months old
the weight will have increased to from 154 to 176lbs., more
than half as much again; so that by merely keeping the ani-
mals for one month more, the quantity of butcher-meat brought
to market would be increased by about 120,000,000lbs.
It does not by any means follow, however, as the excellent
authority I have quoted seems to think, that this increase of
butcher-meat would add to the actual amount of food produced
by the agricultural industry of the country. To produce 2lbs.
of veal, in fact, I have shown that something like 22lbs. of
milk must be consumed; but it is evident, that 1,200,000,000
of pounds of milk represent an amount of nutritive matter
superior in value to 120,000,000 of pounds of veal. Could
the production of the additional quantity of meat in the course
of the second month be effected by means of any other food
less costly than milk, which is itself a fluid of great value as
food,* with ordinary forage, for example, or linseed tea,
or oil-cake, &c., the state of the question would be changed,
and there would then be no doubt of the advantage to
the community of the additional supply of butcher meat.
This indeed is so well understood that all the efforts which
have been made to improve upon the ordinary and simply
natural mood of rearing young cattle have been directed with a
view to economizing milk. The interesting work of M. Ernest
* Perrault de Jotemps, in Journal d'Agriculture, t. v.
PP 3
592
Perrault, from which I am about to make several extracts, was
not written with any other purpose.
M. Perrault set out with the view of ascertaining experimen-
tally, 1st. whether the large quantity of milk generally allowed
to sucking calves is really indispensable, and whether it is pos-
sible to diminish it without detriment to the animals; 2nd.
whether a portion of the milk can be replaced by hay tea, an
article prepared by pouring 14 or 15 pints of boiling water upon
a pound of fine meadow hay, and infusing for a few hours.
The observations were made upon three calves taken after
weaning. A was kept for 94 days on the usual allowance to
calves at Feuillasse; B had a smaller quantity of milk, and from
the 42nd day after birth had an increasing allowance of solid
food; C in the course of the comparative experiment had 476
pints of hay tea, and as it is impossible to regard the infusion as
of higher nutritive value than the article from which it is pre-
pared, I shall set down this drink as equal to 284lbs. of hay.
The allowance of milk was stopped 48 days after the weaning.
A B and C were kept on their respective rations for 95 days.
The three were kept for the first 18 days on milk entirely,
during which it was calculated that each had had from the
mother 337 pints. Here are the rations in a tabular and com-
parative manner.
A.
On the usual allowance.
Food, 94 days..
Suckling, 18 days
Days 112
Milk in pints.
Hay or an equi-
valent.
REARING CALVES.
1411
348
1759
B.
On a reduced allowance of
milk.
Milk in pints.
lbs.
374 Food, 95 days 1520
Suckling, 18 days 435
374 Days 113
..
Hay or an equi-
valent.
lbs.
396
C.
On hay-tea.


Food, 95 days
Sucking, 18 days
1955 396 Days 113
………
Milk in pints.
290
435
725
Hay or an equi-
valent.
lbs.
591
591
It would have been desirable to have had these three calves
weighed immediately after the termination of the experiment;
as this was not done, the results have not the whole of the pre-
cision that seems desirable. Nevertheless, M. Perrault from his
observations concludes:
REARING CALVES.
593
1st. That A, kept on milk alone, weighed at birth
At the age of 452 days
Total increase
Increase per day
2nd. That B, on the reduced allowance of milk, weighed
at birth
At the age of 224 days
Total increase
Increase per day
3rd. That C, on hay-tea, weighed at birth.
At the age of 101 days
Total increase
Increase per day
•
•
">
A consumed in 112 days 1357lbs. of hay*
B
113
113
1137
906
с
"J
88lbs.
..
771.0
>>
683.0
1.5
83.6lbs.
404.2
320.6
1.4
88lbs.
M. Perrault's general reference is, that the calf which had the
hay-tea ration grew more rapidly than either of the other two
brought up either on pure or dilute milk. The differences,
however, are within the limits of the variations noted in animals.
that are reared on the same ration.
270
If we reduce the various articles consumed in these experi-
ments to food of the same nutritive value, to hay for example,
we find that:
182
16.7
The minimum ration for the maintenance of calves, to which
M. Perrault comes from his experiments, differs little from that
which we think amply sufficient at Bechelbronn ; and our animals
certainly are not inferior to those of Feuillasse. This fact may
* Milk must be regarded in the light of forage, so that its equivalent
should be stated. Assuming milk to consist of 27.7 dry matter and
192.2 water, I find by direct analysis that 100 of this dry matter contains
4.0 of azote; so that 100 of milk contains 0.50 azote. This shows that
230 of milk are required to replace 100 of good meadow hay containing
1035 g. azote.
PP 4
594
REARING CALVES.
be judged of by the following particulars, which I have selected as
affording the elements of contrast with M. Perrault's B. and C.
Sophy weighed at birth
At the age of 102 days
Total increase
Increase per day
In all
Rosa at birth weighed .
At the age of 239 days
Food consumed: Milk 528 pints, weighing 684lbs. hay 297lbs.
Hay
539
836
Total increase
Increase per day
100.1lbs.
279.4
•
179.3
1.76
96.8lbs
473.0
376.2
0.48
This calf consumed: Milk 528 pints weighing 684lbs. hay 297lbs.
Hay
1773
In all
2070
Without calling in the assistance of hay-tea, consequently,
by bringing up on milk for seven weeks, and giving forage as
soon as possible, it is obvious that we obtain results fully as good
as those of M. Perrault.
GRAN
I have said that it was during the period when calves are
sucking, or receiving a regular allowance of milk, that the in-
crease of weight was most rapid. As the animal approaches
the term of its complete development, the weight in an equal
interval of time increases at a progressively diminishing rate;
but from the data which I have collected, but which are
not very extensive, it appears that the increase is very regular
until the full growth is attained. From this period the animal
continues stationary, if he merely receives the ration of main-
tenance; any variation observed is purely accidental, and loss or
gain one day is compensated by gain or loss on another. The
adult animal, which does not lay on fat, thus acquires a stan-
dard weight which is preserved for a term of years unchanged,
until the period of decrepitude and decay arrives.
It is not unimportant to ascertain the progressive increase in
weight of cattle; the balance is a means which the breeder and
REARING CALVES.
595
feeder ought not to neglect; it is a powerful check upon his
servants, and a sure tell-tale in regard to the state of the stock at
any moment. A conscientious herdsman is a most precious person
on a farm; but the more I study breeding and feeding, the more I
am satisfied that the most trustworthy agent of all, is the balance.
Frequent weighings are necessary, in order to keep a regular ac-
count of the state of the cow-houses. I here append such
absolute observations as I have made on the increase of weight
in horned cattle, with an expression of regret that I have not
been able to present my reader with more numerous data :*


Names of Beasts.
Victoria
Ditto
Susan
Ditto
Gallop
Ditto
Ditto
Schwartz.
Sophy
Mignonne
Ditto
Margot
Ditto
Ditto
James
Ditto
Ditto
Petrel
Ditto
Ditto
Rosa
Stern
Ditto
Ditto
Chastel
Ditto
Eichaas
Ditto
Castor, 2nd bull
Castor, 1st bull
•
Weight at
Birth.
lbs.
82
""
80
در
88
"
:88:8080
90
91
90
در
""
88
,,
88
>>
28888888
90
در
>>
89
""
90
د.
100
98
Age when
weighed.
Days
56
156
168
168
82
164
264
83
102
103
203
108
190
290
119
201
301
147
229
329
239
275
357
436
465
547
730
811
796
1009
Weight at
this time.
lbs.
180
288
176
270
178
254
388
202
254
216
312
224
304
482
216
284
452
270
378
538
430
570
732
880
972
1080
976
1074
1740
1602
Increase
per diem.
lbs.
1.93
1.45
1.55
1.25
1.21
1.43
1.59
1.47
1.76
1.34
1.56
1.38
1.56
1.83
1.25
1.07
1.32
1.36
1.40
1.49
1.58
1.91
1.93
2.00
2.09
2.00
1.34
1.34
2.26
1.65
REMARKS.
Under a year old.
From 1 to 3 yrs. old.
Become fat, killed.
Ditto.
* As the weights were merely relative, I have neglected the fractions in
turning the French kilogramme into avoird. pounds. I have, however,
given the true increments of weight per diem.-ENG. ED.
596
INCREASE OF WEIGHT OF STOCK.
By way of pendant to these results, I give two series of
weighings, one of which has reference to the increase of weight
of a heifer, on which I made a number of consecutive observa-
tions; the other was undertaken with a view to ascertain the
variations which milch kine, aged more than three years, may
experience:
Dates
Heifer weighed.
Sept. 5
9
"
23
}}
Nov. 3
28
"
Jan. 29
Apl. 21
July 9
Aug. 3
Names.
Esmeralda
Orphan
Galatea.
Gitana
Weight.
lbs.
369.8
3740
393.8
429.0
469.4
550.0
678.4
884.4
950.4
•
Age.
. 3 1
3 2
6
6
7
7
г со со
Hannchen
Paysanne
Raffalea
Prima Donna.
Formosa
>>
Belle et Bonne 11 3
8
TABLE OF MILCH-KINE THREE YEARS OF AGE AND UPWARDS.
S
>>
9
""
""
33
در
Gain
between one
weighing and Time
another.
elapsed.
lbs.
¡Days.
3
در
42
19.8
14
35.2 41
40.4 25
S0.6 62
82
128.4
206.0 79
66.0 25
Increase
in 24 hours.
1st.
2nd.
Weighing Weighing
lbs. avoir. lbs. avoir.
1445 1555
1315
1434
1540
1394
1320
1386
1100 1236
1449
1540
1672 1727
1784 1654
1573 1601
1346 1287
1.40
1.41
0.85
1.21
1.32
1.50
2.48
2.64
Fed with hay and
roots.
110
119
146
66
136
91
55
130
28
59
Was fed on green
clover at discretion.
Interval between Differences
Difference, the weighings.
per day.
Days.
82
"
"
1.5
0.2
""
""
در
>>
Remarks.
""
"
},
During the period of suckling at the rate of 2.4lbs.
Under three years
Above three years
Taking the preceding numbers as the authority, and until we
have a larger number of weighings, I think we may conclude
that the living weight of cattle of the Swiss breed increases by
the following quantities per diem:
lbs. 4
+1.3
+1.5
-1.7
+0.8
+0.2
+1.1
+0.6
—1.5
+0.4
-0.6
ALLOWANCE OF PROVENDER.
597
The increase of weight of growing animals depends much on the
kind of food they have, and it is matter of great moment to know
the precise amount of fodder which neat-cattle require in order to
thrive. Those who have treated of it specially are as far from
being agreed as to the proper ration; and then many who have
specified the kind and quantity of the food have neglected the ages,
the absolute weights, the amount of labour required, and the
milk obtained from the animals. It is subject of simple obser-
vation that an animal of great size, all things else being equal,
will require a larger quantity of forage than another of less bulk.
Once the allowance of food is well established, it is greatly
to be desired that it be continued with the greatest regularity.
Nothing is more injurious to cattle than stinting. Still there is a
term in every year when the live stock, or some portion or them,
at least, are almost necessarily stinted in their food; in the depth
of winter the animals that are not put up to fatten consume
little or nothing but straw. At this season consequently the
stock fall off considerably in flesh, in strength, and in the milk
they give; and when the loss has been very great, the animals
are sometimes too far gone to recover when the spring has come
round. This state of things is greatly to be deplored, and in-
deed ought to be viewed as most prejudicial; it will be alto-
gether impossible to advance the economy of neat-cattle to the
point of perfection which it is fitted to attain until means are
taken to secure every portion of the stock at every period of the
year a sufficiency of properly nutritious food. Happily with
the progress of agriculture, this condition is becoming every year
more and more easy; the introduction of roots (turnips and
mangel wurzel,) and of tubers (potato,) into the routine of every
farm that is respectably managed, supplies a fodder through the
whole of the winter that is equivalent to the grass and other
green meats of spring and summer.
Thaer fixes at 13 lbs. the quantity of hay per diem which a
cow requires for her maintenance in perfect condition; and if
the animal be in milk he allows as many as from 22 to 33 lbs.
But the ration must vary, as I have said, with the weight of the
animal. M. Perrault states 27 lbs. as the allowance for a milch-
598
ALLOWANCE TO CATTLE.
cow weighing about 880 lbs. ; he having in his experience found
that an animal in milk required about 6 lbs. of hay for every
220 lbs. of living weight. Pabst, who paid great attention to the
feeding of cattle, admits that for the ordinary allowance of an
ox doing nothing, or of a cow which is dry, 3.85, or upwards
of 3 lbs. of hay are required for each 220 lbs. of carcass
weight; 4.4 or about 4 lbs. if the animal be a draught ox;
and 6.6 or upwards of 6 lbs. if it be a milch-cow.
The inquiries which I have made into this subject have led
me to conclusions somewhat different, from which I infer that
the relation between the weight of the living animal and the
necessary fodder is not an invariable quantity. A very large ox
or cow relatively to its weight requires less food than an animal
of smaller dimensions. And this circumstance is a grand argu-
ment with those breeders who are in favour of very large cattle;
they say that if a large ox consumes more food than a small one,
still the increase of consumption is by no means in the ratio of
the increase of weight.
The milch-cows at Bechelbronn have no more than 33 lbs. of
hay per head per diem, or the equivalent of this quantity of
forage. But the smallest creature on the farm at the time my
experiments were made did not weigh less than 1110 lbs.
(79 stone 4 lbs.); the relation of the living weight to the food
being therefore as 100 is to 2.73, say 2.4.
The largest cow, again, weighed 1784 lbs. (127 stone 4lbs.)
so that the relation is here as 100 is to 1.85 or 15ths. The
average relation, taking the whole of the cows in the stable
came out as 100 is to 2.25; in other words for every 100 lbs.
of carcass weight, 2 lbs. of meadow hay per day had to be al-
lowed.
It thus appears from these inquiries that growing animals re-
quire more food relatively to their weight than when they are
adult. The young animals upon which I made my observations
were from 5 to 20 months old; and for this age I found that
for every 100 of living weight 3.08 or upwards of 33 lbs. of
hay were required. The following table will give my conclusions.
at a glance.
FEEDING.ALLOWANCE.
599



Animals.
12345678
No.1
8929
12
3
4
10
9
3
4
1
10
11
12
13
14
Ages in days.
107
119
126
130
205
170
158
115
163
206
328
290
289
252
239
341
303
302
265
252
304
371
748
483
Weight of the
lots.
رد
lbs.
در
} 418
} 484
1247
2479
2536
•
} 2054
Hay consumed
per lot in 24
hours.
lbs. months. days.
3
26
4
6
14.3
14.7
36.0
11.0
9.3
66.0
62.7
22.0
19.1
62.7
Average age
of the several
animals.
5
VO CO
5
(Perrault)
6
9
9
10
13
20
For simple sustenance (Pabst)
When labouring (Pabst)
When in milk (Pabst)
9
22303
10
Growing rapidly (Boussingault)
LA
5
18
5
5
Average weight
of the several
animals.
lbs.
209
242
311.8
297.0
372.4
495.8
507.3
|
Average per cent of living weight
627.0
550.0
1027.0
Hay consumed
per head in 24
hours.
lbs.
7.15
7.41
9.0
11.0
9.39
13.0
12.5
22.0
19.14
31.35
•
Hay per cent of
living weight
consumed.
lbs.
3.42
3.06
2.89
3.70
2.53
2.66
2.47
3.50
3.48
3.05
3.08
رد
In the course of the experiments, the calves were kept on
good meadow hay allowed them at will according to our usual
custom. The hay that was put into the crib once a day was
weighed, and an account was kept and deducted of any that had
been left of the previous day's allowance. The length of time
during which each several experiment was continued, varied
from 2 to 13 days, and I have thought it right to indicate the
season of the year lest that should have any influence. To sum
up then, it may be said that for every 100 of living weight neat-
cattle require:
>>
>>
>>
REMARKS.
0.75 or lbs. meadow hay.
2.00
3.00
3.12
(Boussingault, large cows) 2.73
3.08
";
In February.
ditto.
July.
February.
September.
July.
ditto.
February.
ditto.
ditto.
The forage ought to be given to cattle with great regularity,
and care should be taken that they do not eat too hastily.
Generally speaking, they have their allowance three times a day,
constituting so many meals, which, however, are well divided,
Q Q
600
.
FEEDING
Papadaku.
-SALTthe whole quantity for each meal not being placed before the
animal at once. This precaution is particularly necessary when
the allowance consists of green fodder. The watering should
take place in the intervals between meals, the animals being
driven to the trough night and morning; though when the heat
is excessive, it is better to water them three times a day. The
water ought to be of good quality, though if it have no delete-
rious substance dissolved in it, cattle seem to make no objection
to that which is turbid, and which cannot we should think be
very palateable. Our cattle are watered during a part of the
year with water from a shaft pierced through a highly argilla-
ceous soil. Cattle seem to dislike excessively cold water, they
then drink as little as possible. The cattle in the great South
American plains drink water at a temperature of from 85° to
97° F. In Europe, the best water in point of temperature in
winter is that of a deep well.
Every one is familiar with the taste which herbivorous animals.
show for salt, and this is one of the articles which is advan-
tageously made to enter into the ration when its price is not
too high. In France it is absolutely necessary to use the article
with extreme parsimony, a circumstance which I much regret,
and which I cannot but view as prejudicial to rural economy;
[in England where the odious salt tax has been got rid of, salt of
the most beautiful quality is one of the cheapest of all manufac-
tured substances.] I know that many feeders do not think salt
indispensable; but their authority is opposed by that of some
of the highest names in Germany and England, and my own
mind has long been made in regard to the value-to the excel-
lent effects of this substance. I ascertained, for instance, that
milch-kine, though they would not do upon potatoes alone, throve
well when they had from two or two and a quarter ounces
of common salt added to the ration. A celebrated English
breeder, Mr. Curwen, recommends about 3 ounces of salt to
be given daily to cows and heifers in calf and to draught oxen,
and something less, (2 oz.) to fatting oxen, (1 oz.), young
and calves, (18 dwts.)
very
*
The high price of salt in France does not allow us to be so
* Sinclair, Agriculture.
MILCH-KINE.
601
liberal at Bechelbronn ; yet we make a distribution of the article
three times a week, and in quantities which bring the allowance
to something more than about an ounce and a half per day. By
way of eking out the allowance of saline matter we farther supply
from time to time a quantity of Glauber salt, which comes in all to
rather more than half an ounce per head per diem. The use of
this salt, sulphate of soda has long been common in Alsace, and
also on the other side of the Rhine, and its effect on the health
of horses and of sheep, as well as of horned cattle, has been
recognized as highly advantageous. In Wurtemburg, the horses
have very commonly 725 grains, neat-cattle 463 grains, sheep
305 grains, and swine 250 grains of Glauber's salt twice a
week.*
Salt appears to be more especially useful in hot weather and
in warm climates. In the steppes of South America it is held
by the llama keepers as an axiom that cattle cannot live without
salt. Wherever a flock thrives particularly well it may be
averred a priori that there is a salado there, a salt-lick of the
Northern Americans, or place where there is a salt spring. In
the Savannahs that are without saline springs, the herdsmen
make a distribution of salt every day. On the plateau or
table land of Nueva Granada, common salt is replaced with
Glauber salt, as in Alsace and Wurtemburg, and I may say that
it was matter of much interest to me to find the same custom
prevailing on the table lands of the Andes as upon the banks of
the Rhine.
II. MILCH-KINE.
I have already had occasion to say that the signs by which
the qualities of kine as milkers were sought to be appreciated
are somewhat deceitful. Still I am far from denying that prac-
tice and experience do not enable many persons to pronounce
with some certainty upon this particular. The power of doing
so, however, is in some sort the peculiar privilege of him who
possesses it; at least I have seen all the general rules that have
been laid down on the subject fail: I have seen cows of the
most opposite conformations equally productive. I have also
* Communicated by Mr. Schattenmann.
Q Q 2
602
MILCH-KINE.
said that race or descent had much to do with this quality; the
heifer that comes of a mother, a good milker, will be very likely
to turn out a good milker also. The legitimate way, therefore,
of obtaining a good race of milch-kine is to breed them from
a stock that is already noted in this respect. At the time of
my penning these lines there are two animals on the farm that
are remarkable as milch-kine: one is a tall unseemly animal,
the bones projecting, and altogether thin and miserable; the
other is a small cow with rounded outlines everywhere, the bony
frame but little conspicuous; her skin soft, her hair sleek and
fine. Nevertheless these two animals have one character in
common, the udder is of extraordinary size.
We ought not to be hasty in judging of the value of a milch-
cow after the first calf; age has great influence on the secretion
of milk. It is generally allowed that a cow does not attain to
her maximum capacity of yielding milk until she has passed her
sixth year.
With regard to the means we have of judging of the age of
a cow, they are principally derived from the horns. The teeth do
not afford us any indication as in the horse and sheep. In the
ox about the fifth year there is a ring formed about the root of
each horn; in the cow this ring makes its appearance after the
first calving, and from this epoch there is a new ring formed
each year which pushes on the former one. In aged animals
these rings have become faint and can scarcely be counted.
is also evident that the horns which in early life were thicker at
the base and tapered gradually towards the tips, about the ninth
or tenth year of the animal's life present an opposite conforma-
tion; they exhibit a kind of constriction at the roots. The de-
pression above the eye increases with age, and the false hooves
become long and often bent.
It
Thaer reckons that one with another, in well regulated esta-
blishments, cows will continue in milk for about 280 days, and
yield in all about 2265 pints, or 283 gallons. But it is certain
that the yielding of a cow varies greatly with circumstances,
race, age, climate and individual. The cows that graze at liberty
in Southern America do not give more than about three pints
of milk per diem, which as it is almost wholly used in bringing
MILCH-KINE.
603
up the calf, the dairy is there of very little importance. In es-
tablished farms a cow is reckoned to yield about 48 lbs. of
cheese per annum.
Mr. Curwen estimates the quantity of milk
at 6580 pints or 822 gallons per cow; M. Perrault states it at
but 2992 pints or 374 gallons, and Mr. Low gives the quantity
at 5994 pints, or 7494 gallons. The differences between these
several quantities are obviously enormous, and can scarcely be
reconciled with any conceivable diversity of circumstances. They
are probably connected with the method taken to ascertain the
quantities.
The following table comprises the whole of the statements
with which I am acquainted.

France: La Feuillasse (Ain).
Places.
England.
Do.
Lompries (Ain)
Roville (Meurthe)
Lyonnais (montagnes).
Bechelbronn (Bas-Rhin)
•
Belgium; Antwerp
Do.
•
•
Holland: Low Countries
Do..
Campine
Saxony: Meissen
Altenburg
Austria: Carinthia
Prussia: Moeglin
Switzerland
*
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Authorities.
Schmalz.
Burger.
Thaer.
Neighbourhood of Berlin Thaer.
Hoffyll
•
Perraultde Jotemps
D'Angeville.
De Dombasle.
Grognier.
Le Bel and Bous-
singault.
Low.
Curwen.
Schwertz.
Schwertz.
Schwertz.
Aiton.
Schwertz.
Schweitzer.
D'Angevllle.
D'Angeville.
Weight of the
cows.
"
"
lbs. lbs pts. pts.
880 27.5 2992 8.2 Cows in the house.
605 13.8 1610 4.4 Do.
22.02492|| 5.9 Do.
1284 3.5, Cows ill fed in winter.
""
""
"
""
"
Hay consumed
per day.
Milk per annum.
Milk per day.
"
686
825
""
"
33.0
""
28.6 6580 17.8, Do.
27.2 4500 12.3 Do.
""
??
"1
5994 16.2. Do.
27.23967 10.9 At grass & in the house.
, 3400 9.2, In the house, winter.
|7066| 19.4|
931325.5
>>
""
567 19.82687 7.3 Kept in the house.
30.83432 9.21
2752 7.5. Well fed.
22.02648 7.2 Kept in the house.
27.53004 8.2
Observations.
"
""
1045 2992 8.2 Do.
|1320| 38.54685 12.8 Well fed.
At Bechelbronn we have seven cows whose allowance per head
is 33 lbs. of hay per diem. The milk is measured night and
morning, and the quantity given by each cow is particularly
noted. The herd consisted of Raffalea 8 years old, whose milk
failed the 21st of April, and reappeared the 18th of June without
her having calved; La Paysanne, 7 years old, whose milk
ceased the 21st of February and she calved the 29th of April;
Prima Donna, 8 years old; milk stopped February 19th, calved
December 5th; Formosa, 9 years old; ceased milking 1st
April, calved 2nd June; La Gitana, 6 years old, ceased milking
Q Q 3
604
MILCH-KINE.
30th September, calved 9th November; Galatea, 6 years old,
ceased milking 9th July, calved 2nd October; Belle et Bonne,
114 years old, ceased milking the 15th February, calved 3rd
April. These seven cows gave in the course of the year,
neglecting fractions, 30934 pints, or 3866 gallons of milk. In
the month of January in round numbers, 1870 pints; in Feb-
ruary 1335 pints; March 1335 pints; April 1658 pints; May,
2527 pints; June, 3726 pints; July, 4180 pints; August,
3661 pints; September, 3113 pints; October, 2623 pints;
November, 2530 pints; December, 2360 pints; having, one
with another, given, 552 gallons of milk, and milked on an
average 3021 days each; the entire herd having milked during
2118 days, and the average quantity yielded by each cow having
been 14.6, say 14 pints for every day she was in milk; the
quantity for each day of the year amounts to about 11.9, say
10 pints.
June, July, and August are obviously the months most
productive of milk, during which, the cows had scarcely any
other food than clover. The average quantity for these months
was undoubtedly raised from three of the cows having calved in
March, April, and May, so that these were severally giving their
largest measures during the three summer months.
It may be enough to state that the largest quantity of milk is
obtained in the course of the three first months after calving;
the produce then will amount to 18, 20, and even 24 pints per
day, whilst the mean quantity during the whole time of milking
will very little exceed 12 pints.
The observations for the year 1842, which I referred to some
short way back, showed a mean of 14.6, say 14 pints of milk
for each cow. But in the mode of reckoning pursued, there
were sources of error, which have been avoided in the estimates
just given. The only mode of securing accuracy of result is
to take the quantity of milk yielded by each cow between the
period of calving one year to the same event the following year.
This mode of reckoning gives the quantity 13 pints per day for
each cow, which I am disposed to adopt as the standard for the
Swiss breed, fed with 33lbs. of good meadow hay or an equiva-
lent in wholesome roots, &c. I am also disposed to look upon
MILCH-KINE.
605
310 as the mean number of days during which a cow will give
milk after calving.
We sometimes see quantities of milk mentioned as given by
particular cows that are truly surprizing, and that seem even
calculated to excite suspicion of the veracity of the reporters.
Some have spoken of cows that gave 44 and 524 pints of milk
a day for several months. Mr. Crud says that cows of great
size indeed have even given as many as 70.4 pints in twenty-four
hours, and Thaer goes still farther when he states that persons
worthy of every credit say they have seen cows in first-rate
pastures, which, at the height of their milking time produced as
many as from 74 to 824 pints of milk in the twenty-four hours.
Such a flux of milk can only be very temporary, and indeed
must occur but very rarely. The herdsmen at Bechelbronn
have often diverted me with tales of such marvels; but since I
have accurately gauged the dairy produce of the farm, I have met
with nothing which would lead me to credit their reality. We
have had cows indeed which have given 26, and even 31
pints a day for several weeks; but these are still very far from
the quantities which have been mentioned to me.
Good feeding is undoubtedly required in order that cows may
produce milk abundantly; but I believe that the influence of
particular kinds of forage on the production of milk is often
greatly exaggerated. Each breeder or feeder seems to have his
own favourite article, however, so that there is nothing like
uniformity among them; with one it is the carrot that is in the
ascendent; with another it is the beet that is supreme; there is
no root, in fact which has not alternately had its apologists and
detractors. The truth lies between the extremes here as it does
in so many other instances; and I am satisfied that cach and
all the roots and other articles of forage that are generally intro-
duced into the ration of milch-kine, are calculated to produce
abundance of good milk; it is only necessary that the substances
be allowed in ample quantity, that no mistake be committed
in regard to the nutritive equivalents of the several articles. I
do not hesitate to add that the opinions of the generality of
farmers and dairymen on the subject are based on observations
which are always more or less imperfect.
606
MILCH-KINE.
It is but a few years ago that a series of experiments were
undertaken at Bechelbronn with a view to ascertain whether the
particular nature of each of the several articles consumed by
milch-kine influenced the quantity or chemical constitution of
the milk in any appreciable manner. The purpose of these
inquiries being purely practical,-having been undertaken with a
special eye to the dairy and its produce, the inquiry was confined
to the articles that are usually given to cows with us. These
necessarily vary with the season, but I have already said that the
dole to each head is equivalent to 33lbs. of meadow hay, which
indeed always enters in considerable quantity into the ration,
whatever else be given,-unless, indeed, the animals are exclu-
sively upon green meat, when, of course, the use of everything
else is suspended. In winter the hay is allied with beet,
potatoes, turnips, or Jerusalems. In spring the hay is gradually
replaced by green fodder, which in the first instance is rye cut
green, and by and bye clover. The experiments which I shall
now detail were made upon a cow which had calved two hundred
days and was again pregnant.
1ST EXPERIMENT.
200 DAYS AFTER CALVING.
The cow fed on hay alone gave 65.42 pints of milk in the
course of seven days, or 9.34 pints per day. This milk con-
sisted of:
Caseum
Butter
Sugar of milk
Ash of caseum
Water.
3.0
4.5
4.7
0.1
87.7
100.0
Solids 12.4
2ND EXPERIMENT.
207 DAYS AFTER CALVING.
Fed with turnips and cut straw (the ration consisting of tur-
nips equal to 29.7 lbs., and straw equal to 3.3 lbs. of hay), the
same cow gave in the course of eight days 84.4 pints of milk,
or 10.5 pints per day. The composition of this milk was:
MILCH-KINE.
607
Caseum
Butter
Sugar of milk
Ash of caseum
Water.
The animal discussed her provender with good appetite, but
the ration was too large; about 11lbs. of the turnips being left
each day unconsumed.
3RD EXPERIMENT.
The ration here consisted of:
215 DAYS AFTER CALVING.
Caseum
Butter
Milk sugar
Ash of caseum
Water
Field-beet, an equivalent for 29.7 lbs. of hay.
Chopped straw
3.6
•
3.0
4.2
5.0
0.2
87.6
100.0
"
In the course of fourteen days the quantity of milk obtained
amounted to 137.6 pints, or 9.8 pints per diem, and was com-
posed as below:
The ration consisted of:
Solids 12.4
4TH EXPERIMENT.
Caseum
Butter
Milk sugar
Ash of caseum
Water
•
3.4
4.0
5.3
0.2
87.1
100.0
229 DAYS AFTER CALVING.
?
"
Raw potatoes equivalent to 29.7 lbs. of hay.
Chopped straw
3.6
Solids 12.9
3.4
4.0
5.9
0.2
86.5
In the course of eleven days the cow gave 96.1 pints of milk,
or at the rate of 8.7 pints per day, the fluid consisting of:
"
Solids 13.5
100.0
608
MILCH-KINE.
The cow did not do well upon this regimen; she became
heated, and refused one-half the straw. In a general way, we
do not give tubers to a greater extent than is equivalent to one-
half of the allowance of hay, in which proportion cows do very
well upon raw potatoes.
5TH EXPERIMENT.
240 DAYS AFTER CALVING.
The forage here consisted of the full allowance of hay, or
33 lbs. In the preceding experiment the milk, which had
hitherto kept up to from about 9 to 10 pints a day, fell sud-
denly to little more than 8 pints. To ascertain whether the
fall was owing to the potato regimen or not, the cow was re-
turned to the ration of hay under which in the 1st experiment.
the daily average of milk was 9.3 pints. In the course of
thirty days 188 pints of milk were collected, at the rate of
6.2 pints per day. The declension in the quantity secreted
consequently cannot be ascribed to the potatoes which were
given in the 4th experiment.
6TH EXPERIMENT.
270 DAYS AFTER CALVING.
The ration here was raw potatoes, with salt and straw-the
ration of the fourth experiment, with the addition of about
24 oz. of salt. The animal ate this salted ration with appetite;
she also made away with the whole of the chopped straw, and
it agreed well with her; nevertheless, the milk continued to
decrease in quantity; it had fallen off to 5.9, say 6 pints a-day.
7TH EXPERIMENT.
290 DAYS AFTER CALVING.
In this trial the ration consisted of Jerusalem potatoes equiva-
lent to 33 lbs. of hay, under which the milk may be said to
have remained stationary, though it was above rather than under
the 6 pints per diem, as in the 6th experiment. In composi-
tion it was as follows:
MILCH-KINE.
609
Caseum
Butter
Sugar of milk
Ash of caseum
Water
Caseum
Butter.
Sugar of milk
Ash of caseum
Water
The quantity of the milk had obviously decreased from the
first down to the two last experiments; but its chemical constitu-
tion does not appear to have varied during the entire course of the
trials; the varied regimen has had no influence on the proportions
in which its several ingredients are encountered. But there was
still one point to be ascertained, viz: whether the milk secreted
very shortly after the delivery differed from that which was formed
at a period remote from that epoch.
Caseum
Butter
Sugar of milk
Ash of caseum
Water
3.3
3.5
5.5
0.2
87.5
100.0
STH EXPERIMENT.
A cow which had calved twenty-four days before, and, upon a
mixed regimen of hay and green clover, was giving at the rate
of 18.6 pints of milk a-day, was brought under observation.
Analysis showed this milk to consist of:
•
Solids 12.5
3.0
3.5
4.5
0.2
88.8
100.0
•
Solids 11.2
9TH EXPERIMENT.
35 DAYS AFTER CALVING.
The same cow, upon green clover, was now producing 21.2
pints of milk a-day, and of the following composition:
3.1
5.6
4.2
03
86.8
100.0
This milk evidently presents a larger quantity of butter than
appears in any of the preceding analyses. But no hasty con-
Solids 13.2
610
MILCH-KINE.
clusion must be drawn from this; for the succeeding experi-
ments will exhibit a change equally sudden in the proportion of
the fatty element, but in a different way.
In a second series of experiments I set myself the task of
ascertaining whether green fodder had any such remarkable
influence on the production of milk, and especially of its fatty
element, or butter.
1ST EXPERIMENT.
BEGUN 176 DAYS AFTER THE CALVING.
The ration here consisted of articles of winter fodder :
Potatoes equivalent to 16.5 lbs. of hay.
Hay
16.5
"J
Caseum
Butter
Sugar of milk
Ash of Caseum
Water
Upon which the cow had long been kept, though the milk was
only measured during the last six days. The quantity was 16.3
pints a-day, and consisted of:
3.3
4.8
5.1
0.3
$6.5
100.0
>>
رد
Solids 13.5
2ND EXPERIMENT.
182 DAYS AFTER THE CALVING.
Mixed regimen: Green clover equivalent to 16.5 lbs. of hay.
16.5,,
Hay
Upon which the quantity of milk was at the rate of 17 pints
a-day.
3RD EXPERIMENT.
193 DAYS AFTER THE CALVING.
Green meat: Clover equivalent to 33 lbs. of hay.
Quantity of milk, 17.2 pints a-day, composed of:
MILCH-KINË.
611
Caseum
Butter
Sugar of milk
Ash of caseum
Water
4.01
2.2
4.7
0.3
89.7
100.0
Caseum
Butter
Sugar of milk
Ash of caseum
Water
Solids 11.2
The small quantity of butter here induced me to repeat the
analysis, but the result came out very nearly the same, the
quantity being still but 2.35 per 100.
4TH EXPERIMENT.
204 DAYS AFTER THE CALVING.
Green fodder: same quantity as before.
Milk per day 13.7 pints, composed of:
3.7
3.5
5.2
0.2
87.4
100.0
Solids 12.6
It would therefore appear that fresh-cut clover has no such
virtue as that of increasing the quantity of milk given by cows.
Under the winter fare, in fact, the milk produced in the course
of the twenty-four hours amounted to 16.7 pints; under green
clover it was but 14.9 pints. It would be a great mistake,
however, as I conceive, to ascribe the diminution here to the use
of the green forage; it is due, I apprehend, exclusively to the
greater length of time that has elapsed since the period of
calving.
The chemical composition of the milk varied little, as I have
already incidentally remarked in the course of these experi-
ments. The differences in respect of the caseum, by which let
me say I understand the whole of the azotised constituents,
the whole flesh of the milk, rarely exceed one-hundredth part.
The proportion of the fatty element varies suddenly, and as it
seems, independently of the various circumstances in which the
cows are placed.
The general inference from these experiments, then, is that
612
MILCH-KINE.
the nature of the food does not exert any marked influence on
the quantity and chemical constitution of the milk (I do not now
speak of the quality of the fluid) if the cows but receive the
proper nutritive equivalents of the several sorts of provender.
It is of great importance to insist on this point; for it is quite
certain, that if the weight of the several rations be not calculated
according to that of the equivalents, variations in the secretion
of milk would be forthwith conspicuous; but then these varia-
tions would have the increase or diminution of the provender
allowed as their cause.
When cows are kept through the winter upon straw alone,
they cease to give milk; but on the return of green forage, in
the spring, the secretion is restored. The re-appearance of the
milk in this case, however, is not connected with the coming in
of the fresh provender, but with the return of plenty; the ani-
mals are not only fed, from having been starved, but they are more
than fed; they have something to spare which their economy
turns partly into milk.
In well managed establishments, where a good system of
husbandry secures an abundant supply of good nutritive pro-
vender to the cattle during winter, the produce of the dairy
during this season differs much less from that of the summer
than is generally supposed. I am besides persuaded that we
estimate the nutritive powers of green forage at too low a rate,
and that when cattle are upon wet clover or lucern, they are in
fact much more effectually nourished than under ordinary cir-
cumstances.
If it be true, as it evidently is that the quantity of milk pro-
duced depends especially upon the absolute quantity of nutritive
food consumed, it is not so with the quality of the fluid. It is
undeniable, that the milk of spring and summer, formed upon
green and succulent food, is much more palatable than that of
the winter season; the butter is also much finer and better fla-
voured. The green herbs of our pastures undoubtedly contain
volatile principles which are dissipated and lost in the processes
of drying and fermentation which they undergo in their conver-
sion into hay. If chemistry be powerless in seizing such princi-
ples, it still informs us of the possibility of introducing a variety
FATTENING.
613
of articles into the food of cows which have the property of
communicating those qualities which we prize in milk. In all
grazing countries certain vegetables are pointed out as giving in
the vulgar opinion, a particular aroma to the flavour of milk.
§. FATTENING OF CATTLE.
Under a parity of circumstances, feeding cattle for the
butcher may occasionally be found more advantageous than the
dairy to the farmer. In feeding for the market there is, in the
first place, a quicker return for the outlay, than in keeping milch-
kine through the whole of the year. In the first operation, the
capital is realized at the end of four or five months; that which
is employed in producing milk, and butter, and cheese, is always
lying out, like a sum at interest.
The quantity of food requisite to bring cattle intended for the
butcher into condition, does not vary less than that which is re-
quired to secure a plentiful production of milk. Thus the
stature, the age, the race of the individual, and the relative pro-
portions of flesh and fat which we would have laid on, all imply
varied doles of various kinds of forage. The age in especial
has to be considered; for in putting up a young animal to fatten,
we have both flesh and fat to form. This is what always occurs
in the fatting of oxen of two years old, and of pigs of ten or
eleven months. The increase in living weight experienced at
various ages is not equally owing to accumulation of fat; this
indeed may be so in the case of beasts, the muscular system of
which has already attained complete development, but it is other-
wise with young and still growing animals.
Practice does much in enabling us to select the animals that
will fatten readily. In a general way it is well to choose young
animals that have a large chest, the body bulky and rounded,
the ribs finely arched, the bones small, the limbs short, the neck
thick for its length, the skin soft, pliant, velvety to the touch,
and moveable over the body, particularly over the ribs, the tail
should be scanty, the buttocks not deeply cleft, but fleshy—well
breeched, as the phrase runs in some districts. The look of the
animal should be sharp and bold; the horns slender, whitish,
614
FATTENING.
and rather transparent. The animal must have been cut whilst
he was still at the teat.
The celebrated English breeder, Robert Bakewell, succeeded,
after a long and troublesome course of experiments, in creating
a race of neat-cattle and of sheep which show themselves parti-
cularly disposed to take on fat. The fundamental principles
established by Bakewell, after all his experience, are these: that
smallness of bone, fineness of skin, and cylindrical shape of
body, are the surest indications in cattle of the disposition to lay
on fat readily, and upon the smallest quantity of provender.
The most striking features in the breed obtained by Bakewell,
commonly known as the Dishley breed, may be summed up in
the following terms:
1st. The animal low on his legs.
2nd. The back-bone straight.
3rd. The carcass rounded and almost cylindrical.
4th. The chest deep and large.
An ox is held to have grown rapidly and well, when at the
age of three years he weighs from 1016 to 1051, from 72 to
75 stone avoirdupois. The disposition to fatten young is also a
precious quality in the beast which it is intended to bring up for
the butcher; the feeder comes the sooner at his return. Sinclair
thinks, that independently of good constitution, which is indis-
pensable, this quality is derived especially from meekness of dis-
position, from good temper; and as docility is generally the
result of good treatment in early life, young animals ought always
to be treated with great gentleness and made perfectly familiar.
The different races do not all yield meat of the same quality,
and this quite independently of age. The best meat has a very
decided and characteristic flavour after it is dressed, which indif-
ferent meat wants, or which is replaced by a savour that is dis-
gusting rather than agreeable. The fat in the best meat, as well
as being laid on superficially, is distributed through the substance
of the muscles, so as to give the flesh a marbled appearance.
In fattening cattle, it is perhaps of more importance than in
general feeding, that the provender should be distributed regu-
larly; plenty of soft litter, and the greatest attention to cleanli-
ness aid materially in fattening. The cow-house ought to be
THE OX.-FATTENING.
615
dark, and quiet; in a word, all the conditions ought to be com-
bined which conduce to sleep, and secure freedom from disturb-
ance of every description.
The age at which cattle fatten most readily, is that of from
7 to 8 years.* Animals under this age, which have not yet come
to their full growth, will nevertheless get into excellent condition;
but they require both longer time and more food, for the reason
apparently that they are still forming both flesh and fat.
In fattening during winter which is done almost exclusively
with hay in some countries, an ox weighing 748lbs.
upon 40lbs.
of hay per diem, will increase by about 2lbs. daily. According
to Mr. Low, an ox weighing 770lbs. and consuming about
2223lbs. of turnips per week, if he thrive, will gain in the same
space of time nearly a stone in weight (a stone of 14lbs.) Ad-
mitting that the equivalent number for turnips is 676, I find
that the ration of hay for this allowance comes out 47.8lbs.,
having produced exactly 2lbs. of increase.
In the information obtained in the Rhenish Provinces by
M. Moll in regard to the fattening of cattle under the influence
of a regimen which would give 11lbs. of hay to every 220lbs.
of dead weight, the animal will increase one third in weight in
the course of three or four months.
To these general results I add a few particular facts, which are
indeed the only data in rural economy that can ever be received
as having much value.
In a series of experiments which he undertook, Mr. Robert
Stephenson proposed to compare the progress of the increase in
weight of oxen upon different alimentary regimens. Starting
with the principle which we have already established, that ani-
mals consume a quantity of food in proportion to their weight
or size, when they are under the same conditions, he had of course
to divide his stock into several lots, each made up of animals.
of as nearly as possible the same weight. Oxen of two years
old, brought up on the same farm, and kept in the same manner,
were the subjects of experiment. I shall select one experiment,
in which the observations were made upon three lots of six
* This is as in the original, and may be true; but in England and Scot-
land we have seldom an opportunity of proving it so.-ENG. Ed.
R R
616
beasts each. The weight of each lot was ascertained before and
after the experiment which was carried on for 119 days.
The first lot was put upon white turnips, linseed oil-cake,
beans, and oats; and for the last 24 days each beast had 20lbs
of potatoes every day in addition.
The second lot was fed like the first, with this difference, that
it had no cake, and that during the last 24 days the quantity of
potatoes allowed was but 10lbs. per diem.
The third lot had no other provender than turnips.
Here are the weights and the nature of the provender con-
sumed by the animals during the 119 days, with a column
added containing the equivalent in hay corresponding with each
of the articles consumed:
LOT I.
Provender.
White turnips
Swedes
Beans
Oilcake
Oats
Potatoes
•
Weight
in lbs.
1518
13336
THE OX.-FATTENING.
•
Equivalent
in hay
in lbs.
171.6
1973.4
358 1559.8
389
1768.8
173
279.4
479 151.8
LOT II.
Equivalent
in hay,
in lbs.
Weight
Weight
in lbs.
in lbs.
1628 184.8 1122
13384.8 1980 12012
358 1559.8
>>
173
239.8
""
279.4
77
4081
",
34.3
رد
در
LOT III,
در
Equivalent Equiva-
in hay
in lbs.
lent
assumed.
885
127.6
1777.6
676
23
22
62
315
""
>>
د.
Ration expressed in hay 5904.8
Hay consumed per
day per head
49.7
Hay per 100 of the
living weight.
[the]
4.01
3.03
2.0
It therefore plainly appears that the lot which had the largest
allowance of provender, the food which contained the greatest
quantity of azotised principles-of flesh in fact, produced the
largest amount of dead weight in a given time, and that the lot
which had the shortest allowance increased in the smallest
mcasure both in flesh and fat, results which might have been
readily foreseen. It is also apparent, from the table, that in
proportion to the nutritive value of the articles consumed by each
lot, the increase in carcase weight was greatest in that which
received its allowance in the least bulk. Thus reducing the
different rations to a standard forage, we find that in the first
lot, which was most plentifully supplied, 100 of hay gave
4.2 of increased weight, whilst the same allowance of hay pro-
duced 6 in the third lot which was fed most parsimoniously.
This fact is most readily explained: over a certain limit, the
JJ
1905.2
16.0
THE OX.-FATTENING.
617
more food an animal receives, the smaller is the fraction which is
assimilated and turned to use in the body. Breeders have conse-
quently discovered that it is by no means generally advantageous to
push animals beyond a certain point of fatness.
The excess of
weight which is obtained with the assistance of quantities of food,
exaggerated as it were, no longer compensates for the additional
expense incurred. This is a circumstance which Mr. Stephen-
son's experiments also illustrate, and indeed they led him to the
conclusion which has just been stated. Judging by the market
price of the several articles of provender employed by this dis-
tinguished breeder, the first lot appears to be that, the fattening
of which turned out the least advantageously: whilst each
pound weight of flesh produced here, cost about 5d, the price of
production in the second lot did not much exceed 4d. (4th) in
the third it was a little more (4ths).
With these observations of Mr. Stephenson we find the
following numbers to express the daily increase in weight of the
cattle during the period of fattening:-
Average weight of
the oxen before
fattening.
lbs.
1st lot. 1115
2nd
3rd,,
1016
794
"
•
·
>>
"
"
Hay consumed per
day and per head.
>>
lbs.
49.7
34.3
16.
Increase per head
in 119 days.
The weight of the several animals must also be taken into
account in seeking to estimate the increase realized upon every
100 lbs. of live weight during the fattening.
In the
1st lot. 100 of live weight in 119 days, gained, 22.2
2nd,
3rd
22.8
14.2
در
lbs.
247.5
231.6
112.6
Increase per day
and per head.
>>
lbs.
2.
1.9
0.9
(26 S
It is seldom that cattle are fattened in the house upon clover
or lucern in the green state; nevertheless animals will fatten
upon this forage with great rapidity. An ox will cat as much
as 1 cwt. of clover cut in flower in the course of the day. In
case the green food should relax the bowels too much, a fraction.
of the allowance may be given dried, and towards the end of the
RR 2
618
THE OX.-FATTENING.
fattening a little cake may be given. But these additions do
not appear to me indispensable; they are always attended with
additional cost, and I have frequently seen cows upon green
clover at discretion, acquire a remarkable degree of fatness,
although they had not ceased to be regularly milked.
In those countries, the nature of whose climate is favourable
to pasturage, the rearing of cattle presents immense advantages;
but the animals can only be fattened in those that are the most
fertile. The meadow that suffices for the growth and keep of a
bullock, will not always bring the animal into condition for the
butcher. Those countries where the climate is moist, but long
droughts rarely felt, where neither the summer heats nor the
winter colds are excessive, the conditions, in fact, which are met
with in the beautiful pasture lands of England, in especial, are
those that prove most favourable to the rearing and feeding of
cattle. The pasture lands of Normandy and Britanny in France,
of Switzerland, Holland, several of the provinces watered by the
Rhine, &c. are also remarkable for their luxuriant herbage. In
such situations and with such advantages the grand object with
the farmer is the production and fattening of cattle. Whenever
it has been possible to lay down extensive and productive
meadows, it is now beginning to be clearly understood that the
introduction of even the best system of rotation were to make
a false application of agricultural science. In my opinion, there
is no system of rotation, however well conceived and carried
out, which will stand comparison in point of productiveness.
with a natural meadow favourably situated and properly attended
to. The reason of this is obvious, and follows from the very
principles which we have laid down in treating of rotations.
The whole object in the best system of husbandry is to make
the earth produce the largest possible quantity of organic matter
in a given time. But in such a system we are limited by the
climate, inasmuch as we are obliged so to arrange matters that
our crops shall always attain to complete maturity; the conse-
quence of which is, that with all our pains the soil remains
unproductive during a certain number of weeks and months.
towards the end of autumn, in the early spring and through the
whole of the winter. But upon meadow lands vegetation is
THE OX.-FATTENING.
619
incessant; the winter even does not interrupt it completely; it
still revives and makes progress on the bright days; and in the
spring it proceeds when the mean temperature is but a few
degrees above the freezing point of water, and never ceases until
it is checked again by the severer cold of winter. It is therefore
easy to obtain conviction that a given surface of meadow land
must necessarily produce a larger quantity of forage than land
laid out in any other way. It is true that the forage thus
obtained will not, like the cereal grasses, answer immediately for
the support of man; but it nevertheless concurs powerfully in
this by producing milk, and butter, and cheese, and in breeding
and fattening cattle; let there be added to all these advantages
of what may be called a permanent vegetation, that the cost of
keeping it in order is infinitely less, and that there is no risk to
be run from failures of crops, and the vast advantages of meadow
or pasture land will meet us with all their force.
On the banks of the Elbe, in Holland, in the neighbourhood
of Arnheim, the meadows are depastured during one year, and
cut, and their produce made into hay the following year, and so
on alternately. The cattle are fed in the house with the hay
during the winter. They are driven out into the pastures in
May. In the Low Countries, it has been found that to fatten a
large ox a surface of meadow land of about 9960 square yards,
upon which he will pasture during five or six months, was neces-
sary. In the bottoms of greatest fertility near Dusseldorf it has
been calculated that to keep a cow an extent of surface equal to
about 1800 square yards was necessary.
In countries which possess rich pasture lands, oxen are put to
fatten immediately upon the richest of them. In the valley of
the Auge, in Normandy, these meadows are designated as
herbages. A meadow of this kind requires a rich damp soil,
capable of retaining moisture. It is, therefore, to a considerable
extent dependent upon its subsoil. In the district mentioned,
the soil of the pastures consists of a thick layer of vegetable
mould resting upon clay; it is therefore very rare that this
meadow land feels the effect of drought; it is indeed only in
the early spring that the pasture upon such lands sometimes
fails, in which case the stock must of course be assisted with
RR 3
620
THE OX.-FATTENING.
hay, the quantity being gradually diminished as the season ad-
vances.
M. Dubois finds that a lean ox weighing 473lbs., after fatten-
ing in the valley of the Auge, will weigh 763lbs., so that he
will have gained 290lbs.; the degree of fatness attained in this
district is often prodigious. M. Dubois mentions oxen which
weighed when fat 1760lbs., upwards of 125 stone, and he
speaks of one which attained the enormous weight of 2750lbs.,
upwards of 196 stone.
The height of the oxen fattened in the herbages of the Auge
varies from 3 ft. 9 in. to 5 ft. 3 in. measured at the haunch;
when thoroughly fat the four quarters will weigh from 550lbs.
to 990lbs., the hide will weigh from 70lbs. to 116lbs., and
they will yield from 100lbs. to 150lbs. of tallow.
It is calculated that on the meadows of greatest fertility, a
surface of 2811 square yards are required to fatten a large ox;
on meadows of medium fertility, a surface of 4684 square
yards are required to fatten an ox of medium size; on those
of the third quality, a surface of 3747 square yards is deemed
necessary to fatten a small ox.
M. Dubois calculates the quantity of green fodder consumed
by an ox during the eight months when he is fattening as equi-
valent to 6600lbs. in dry hay; this at least is the quantity that
the extent of meadow required to fatten one ox would produce.
The average ration of green forage per diem is, therefore, equiva-
lent to about 27lbs. of hay, a quantity which appears small, and
which would be so in effect, were not the oxen kept so long in
the meadows. M. Dubois indeed observes that in the stall, with
a ration composed of from 11lbs. to 13lbs. of linseed oil-cake
and 26lbs. of hay, an ox will become sufficiently fat for the
butcher in seventy days, and will acquire nearly the same weight
that he would have gained in the course of seven or eight months
in the meadows. There is nothing surprising in this fact inas-
much as the ration mentioned by M. Dubois in our mode of
viewing it, is equivalent in nutritive value to at least 81lbs.
weight of hay; the quantity of oil-cake alone is enough to
supply a good pound weight of fat per diem.
In Ost-Frise (Hanover) where the pastures are excellent, results are
THE OX.-FATTENING.
621
obtained which may be compared with those of the meadows in
the valley of the Auge; an ox of from 770 lbs. to 990 lbs.
weight will be pushed to a weight of from 1100 lbs. or 1650 lbs.
on a surface of meadow land between 3000 and 3600 square
yards in extent.
In the meadows of the Auge the fattening goes on even
during the winter; the oxen are received into the pastures be-
tween the 15th of September and the 15th of November, and
the animals pass the winter in the open field; but they receive
from 12 lbs. to 26 lbs. of hay per diem until the month of
April, when the grass has already grown sufficiently to suffice
for their keep. These oxen are generally fat and ready for mar-
ket in July.
In these observations of M. Dubois the fattening has refe-
rence to the neat weight of the carcass, sinking the offal, as it is
said, or estimating the weight by the quarter. The most es-
teemed quarters are the hind quarters, which are found to weigh
rather less than the forequarters, although the difference is less,
the higher the condition of the animal.
It is long since various means have been devised for ascer-
taining the neat weight of a living animal, or in other words
the weight which the carcass will have when it has been em-
bowelled, flayed, and the head and fat cut off. These various
parts compose what is called the offal. It is readily to be con-
ceived that one grand feature in the excellence of an ox must
consist in the great relative weight of the carcass properly so
called in comparison with the offal; but it may easily be ima-
gined also that the relations in the weight of these two different
portions of the living animal will vary according to the state of
fatness and also according to the breed and the age of the
beast.
Mr. Anderdon has found that an ox which is not absolutely
lean will give for every 100 lbs. of his absolute weight:
Of marketable meat
An ox somewhat fatter will yield
And one completely fat as many as .
Mr. Layton Coke's estimate is:
53½ lbs.
55
61.1%
"
**
622
THE OX.-FATTENING.
For a lean ox
For an ox in middling condition 65
And for a fat ox
73
60 per cent. of marketable meat.
These estimates appear to me exaggerated, and I much doubt
from the sales of cattle which we make ourselves, whether they
would readily be admitted by the buyers; they are in fact too
high as regards the available meat.
Butcher's meat per cent.
Tallow
The hide
The entrails and offal
From a great number of actual trials made with animals of
about two years old, and which were all as nearly as possible in
the same condition, Mr. Stephenson was enabled to determine
with great accuracy the actual weight of the butcher's meat in
contrast with the entire weight of the animal. Mr. Stephenson
comes to the following conclusions:
>>
The 2 fore quarters weighed
The 2 hind
">
>>
The precise quantities of marketable meat and of offal have
also been determined by Mr. Mallo in an ox of the Durham
breed which was slaughtered in his presence. The weight of
the animal on its feet was 1496 lbs.
The skin
The tallow
The blood
The head, fat and entrails
57.7
8.0
5.5
28.8
100.0
Ibs. Percentage of
live weight.
}
405.9
423.5
62.7
4.2
112.0
7.5
110.0 7.4
381.7 25.5
1496.0 100.0
55.4
These relations as to meat, tallow and skin agree in a very
considerable measure with the estimates of Mr. Stephenson.
Sir John Sinclair gives the following numbers as the results
obtained in connexion with an ox of the Devonshire breed
slaughtered at the age of 3 years and 10 months.
THE OX.-FATTENING.
623
,,
>>
Weight of the living animal, 1549.6 lbs.
lbs.
""
Butcher's meat, the four quarters
The skin
Tallow
Entrails and blood
>>
•
1549.4 100.0
The animal here was not in prime condition. On the whole,
the relations as stated by Mr. Stephenson may be taken as those
that will be found nearest the average truth, and as his numbers
are deduced from numerous actual experiments I feel disposed
to adopt them. M. Dubois has found that an ox which will
weigh 473 lbs. sinking the offal, will be brought by fattening to
the weight of 763 lbs. We have, therefore, for the weight of
an animal as it stands:
According to Thaer
Low
*
Head and tongue
Feet
Heart, liver and lungs
››
Before fattening
After fattening
Gain in weight
The fattening having been effected in eight months, the
absolute increase in weight per diem will amount to 2 lbs.; the
increase per cent. upon the weight is 61.4.
We have seen that during the fattening, the mean consump-
tion, reckoning the provender in hay, amounts to 6600 lbs. ;
the increase obtained being 508 lbs. gives 16.9 lbs. of living
solid for every 220 lbs. of hay consumed. Lastly the mean
ration being settled by M. Dubois at 26.4 lbs. of hay per head
and per diem, and the weight of the animal on being taken into
the meadow being 828.3 lbs. this ration corresponds to 7.1 lbs.
of hay for every 220 lbs. weight of the living animal.
To sum up from the fact just stated on the subject of fatten-
ing it appears that the increase per day is:
Per centage of
the live weight.
70.0
1083.5
84.9
5.5
143.2
9.2
163.6 10.5
>>
36.7
17.1
20.4
""
Dubois.
828 lbs.
1336
508
•
0.93 per cent. on the hay consumed.
0.91
Stephenson, 1st. lot
0.94
2nd.
20.89
3rd. . 0.45
0.95
}}
2.4
1.4
1.3
>>
در
در
"}
624
THE HORSE.
§ IV. OF HORses.
In what follows I shall limit myself to the consideration of
the horse in his relation to agricultural industry, and shall give
the result of certain experiments which I have made upon his
growth with a view of solving the question, much disputed in
various places at the present time, whether or not the general
farmer can breed horses with advantage to himself.
The horse employed in farm labour ought to be spirited and
strong; attention to external form is only to be given in so far
as it is an indication of the qualities that are required. He
ought therefore to be broad in the chest and in the haunches, and
his muscular system must in general be decidedly developed. A
horse of considerable size, if he be otherwise exempt from de-
fects, is generally preferable to a small animal; he is stronger,
takes longer steps, and does more for his keep than the other.
We are not to require in the draught horse the vivacity and
amount of spirit which we look for in the saddle horse, yet he
ought to have that liveliness which is almost always a sign of
health in animals.
Thaer does not approve of the practice commonly followed at
this time of mixing with good draught horses the blood of stal-
lions of elegant shape, but little adapted to stand hard work.
Although this remark is not without truth, it is still impossible
to deny that in many cases the employment of stallions of some
breeding has much improved the race of draught horses in various
districts. It is not, besides, unworthy of attention, that it is
really important for the farmer to have a breed which he can
readily dispose of to advantage, particularly in those countries
where horses for cavalry and artillery service are in request.
My own observations would lead me to say, that the breeds in
France are frequently improved by crossing with stallions of
the royal studs. The effect from this procedure has not perhaps
been so great as might reasonably have been expected, still
evident progress has been made.
The mare will take the stallion at about the age of three years;
but it is seldom that the animal is covered at so carly an age;
on the farm she will be at least five or six
years of agc before
this is allowed, especially if the animal is to be wrought during
THE HORSE.
625
the time she is with foal; and the same consideration leads us
to say, that a mare ought not to be covered oftener than once
in two years, although it is very possible to have a foal from her
every year, for she frequently comes into season towards the
eleventh day after foaling, and she goes with young for a term
which varies between 333 and 346 days.
A brood mare may be employed in ordinary work during the
first period of her pregnancy; but when the time is further
advanced, when she is in the tenth month, for example, every
possible precaution must be taken against accident. This is the
period at which we withdraw our brood mares from the common
stable, and put them into separate boxes. After she has foaled,
the mare receives in small quantities and frequently repeated,
warm drinks and bran mashes. Whilst she is giving suck, her
food ought to be of a more substantial or better kind than that
which is generally allowed.
The mare may be put to light work twenty days after she has
foaled; but it is requisite not to demand anything like exertion
from her within eight or ten weeks after this event; she then goes
out accompanied by her foal, which is generally suckled for about
one hundred days. Foals are frequently brought up in the
stable or in the loose box; this is our practice in Alsace; but it
is well, with a view to the growth and health of the young
animal, that it be taken out every day. On quitting the teat,
foals are fed upon choice hay; in the course of the second year a
portion of the hay should be replaced by an allowance of oats,
and in the season the use of green clover cannot be too highly
recommended.
According to Thaer, the daily allowance to a horse of middling
height, and doing ordinary work, may be regarded as good when
it consists of:
Hay
Oats
Hay
Ditto
Allowance reckoned in hay
8.2 lbs.
9.2
=
8.2 lbs.
14.2
22.4
In England the following allowance has been particularly
mentioned as that of certain well conducted stables.
626
THE HORSE.
Cut hay
Cut straw
Oats
Beans
Hay
Ditto
Ditto
16.9
Ditto.
4.7
Allowance reckoned in hay
33.2
According to M. Tassey, veterinary surgeon in the Munici-
pal Guard of Paris, the provender of the horses in this corps
in 1840 consisted of:
Hay
Oats
Hay
. 11 lbs.
Oats
8
Straw for litter 11
•
Hay
Oats
Straw
•
Hay
Oats
Straw
11.0 lbs.
2.2
11.0
1.1
Total allowance
16 lbs. Hay
17
. 11
For the cavalry of the line:
8.8 lbs.
7.5
For the light cavalry:
Hay
Oats
Straw.
Hay
Ditto
Ditto
The same authority reckons that horses employed in severe
draught receive or require:
11 lbs. Hay
8
Ditto
Ditto
Total allowance
. 11.
Hay
Ditto
Ditto
Total allowance
8.8 lbs.
Ditto.
=
•
Total allowance
Until very lately (previously to 1840,) the allowance of troop
horses in the French army consisted for the reserve cavalry of:
Hay
Ditto.
Ditto.
. 6.6
11
Total allowance
•
•
•
. 12
. 11.0 lbs.
0.55
·
11 lbs.
. 25
•
2 1/1/20
•
16 lbs.
26
42/
. 11 lbs.
. 12
2/1
25/1/
8.8 lbs.
C
. 11.5
2.7
23.0
8.8 lbs.
10.1
2.7
. 21.6
Influenced by the consideration of the frequent indifferent
THE HORSE.
627
quality of hay, and its injurious effect upon the health of the
horse, it was decided in 1841 to replace a portion of the hay
ration by a larger quantity of oats, an article much less liable to
be adulterated, or to be indifferent in quality. The allowance
now consisted for the reserve cavalry of:
Hay
Oats
Straw
Hay
Oats
Straw
For the light cavalry:
Hay
Oats
Straw
lbs.
8.8
9.2
11
For the cavalry of the line:
Total allowance
lbs.
6.6
8.8
=
lbs.
6.6
Hay
Ditto
Ditto
-
Hay
Ditto
Ditto
11
Total allowance
Hay
8.3 Ditto
11
Ditto
Total allowance
lbs.
8.8
14.2
2.7
25.7
lbs.
6.6
13.5
2.7
22.8
lbs.
6.6
12.8
2.7
. 22.1
From what precedes, it appears that the substitution of oats
for hay was made upon a calculation which squares well with the
theoretical inferences in regard to the relative nutritive powers of
these two articles.
The allowance to the horse ought to be distributed into three
portions, constituting as many meals, and put before him in the
morning before going to work, in the middle of the day, and in
the evening; he is generally watered at meal times. It is also
highly advantageous to the health of the horse, that he be made
to work with a certain regularity. Our horses at Bechelbronn,
upon an allowance equivalent to 33 lbs. of hay, work from 8 to
10 hours a day, having an hour's rest at mid-day.
There is of course a certain relation between the height, or,
if you will, the weight of the horse, and the quantity of provender
he requires. Some attention, as we have seen, has been given to
this point, in connexion with horned cattle; but with reference to
628
THE HORSE.
the horse I know of no data but such as I myself possess. Seven-
teen horses and mares, aged from 5 to 12 years, and having each
provender equivalent to 33 lbs. of meadow hay, weighed to-
gether 18,190 lbs. The mean weight of each horse being
represented by the number 1070 lbs., we perceive that for every
100 lbs. of live weight, 6.7 lbs. of meadow hay are required for
the daily ration, the horses working from 8 to 10 hours a day.
This relation differs very little from that which we have obtained
in reference to cattle.
I was anxious to ascertain the rate of growth of the horse;
and in connexion with our breed, which have a mean weight of
about 1100 lbs., I found that the foals weighed
as follows:

Names.
Filly of Chevreuil. 25 May, 1842
Filly of Hechler 12 June, 1842
Filly of Brunette 12 June, 1842
•
Date of birth.
•
Weight at birth.
lbs.
110
113
113
Date of weaning.
20 Aug. 1842,
7 Sept. 1842
7 Sept. 1842
Weight at weaning.
Number of days
suckled.
lbs.
294.8 87
286.
35-1.
87
87
days.
of weight
during the suckling.
Increase
lbs.
184.8
172
241
Increase of weight
per diem.
lbs.
2.1
1.9
2.7
The mean increase per day during the period of suckling in
the three cases quoted above, therefore, appears to have been
rather more than 2 and ths lbs. avoirdupois.
Immediately after weaning, young horses appear to experience
an arrest of their growth for some short time, an event which
indeed happens to animals generally. I found, for example,
that Chevreuil's filly, which on the day of weaning weighed
294 lbs., nine days afterwards weighed but 288 lbs., and had
consequently lost 6 lbs.
I shall add a few weighings of horses further advanced in age,
although still young :
Alexander, a colt, weighed at birth, 110 lbs.; at the age of
128 days, 337 lbs. ; increase 227 lbs., or about 1.8 per diem:
51 days afterwards, 490 lbs.: increase 105 lbs., or per day
1.4 lb.
Finette, a filly, weighed, when weaned at the age of 86 days,
THE HORSE.
629
295 lbs.; 83 days afterwards, 396 lbs.: increase 101 lbs.; per
day, 1.1 lb.
Hechler's filly weighed, when weaned at the age of 87 days,
286 lbs.; 65 days afterwards, 358 lbs.: increase 72 lbs. or per
day 1.10 lb.
From what precedes we may conclude:
1st. That foals, the issue of mares weighing from 960 to
1100 lbs., weigh at birth about 112 lbs.
2nd. That during suckling for three months, the weight
increases in the relation of 278 to 100, and that the increase
corresponds very nearly to 2 and lbs. avoirdupois for each in-
dividual per diem.
3rd. That the increase of weight per diem of foals, from the
end of the first to the end of the second year, is about 1lbs.
avoirdupois; and that towards the third year, the increase per
day falls something under 1 lb. avoirdupois. After three years
complete, the period at which the horse has very nearly attained
his growth and development, any increase becomes less and less
perceptible. These conclusions in regard to the horse, differ
very little from those which I have had occasion to draw in
connexion with horned cattle.
I have also made a few experiments with reference to the
quantity of provender consumed by foals in full growth, and
have found that Alexander, Finette, and Hechler's, filly, weigh-
ing together 1106 lbs., consume per day :
Hay
Oats
. 19.8
Hay
Ditto
.
7
Total allowance
Per head
=
19.8
11
30.8
10.22
The mean weight of these foals was 368.6 lbs., so that the hay
consumed for every 100 lbs. of live weight was 2.85 lbs., with
which allowance the daily increase amounted to about 1.2 lb.
Consequently, a mixed provender, equivalent to 100 lbs. of hay
had produced 12 lbs. of live weight. I must confess that this
result appears to be somewhat too favourable, but I can only
set down the numbers as they presented themselves to me.
The flesh of the horse is not generally used, or at least
630
THE HOG.
openly used, as food for man, though there are countries in
which it is exposed for sale and commonly eaten. At Paris,
indeed, in times of scarcity, horse-flesh has been consumed in
quantity. During the Revolution, a knacker exposed publicly
for sale, in the Place de Grève, joints from the horses which he
had killed, and the sale continued for three years without any ill
effect; in 1811, a scarcity obliged the Parisians to have re-
course to the same kind of food, and it is said, indeed, that the
traffic in horse-flesh as an article of human sustenance is still
continued to a very considerable extent in the French metro-
polis; at the present moment, a distinguished writer on Medical
Police, M. Parent-Duchatelet has even proposed to legalize the
sale of horse-flesh as food for man.
§ v. OF HOGS.
There is perhaps no farming establishment which does not
keep a certain number of hogs, a measure by which offal of all
kinds that would go directly to the dunghill, is turned to the
very best account. The dairy, the kitchen-garden, and the
kitchen, all yield their contingent of food to the pig-stye, which
is moreover an excellent means of using up certain portions of
the harvest. But the rearing and fattening of hogs, although
frequently looked upon as matters of course, and requiring very
little care, do in fact demand considerable attention and certain
conveniences in situation. The rearing of hogs, in a general
way, may be said to suit the small farmer better than the great
agriculturist.
Our common domestic hog appears to derive his origin from
the common wild hog of Europe. The breeds are extremely
numerous. The black hog, covered with rather fine hair, and
commonly found in Spain, is a native of Africa. This is the
race which has been carried to South America, where it has
multiplied in a truly surprising manner. It grows rapidly; and
if it has little to recommend it with reference to fattening, it is
nowise nice in the matter of food and general entertainment;
the flesh is excellent when the animal has been kept upon the
banana, and fattened off upon Indian corn.
The hogs of the east of Europe are remarkable for their size;
THE HOG.
631
they are of a deep grey colour, and have very long ears; they are
not very prolific, the brood swine having rarely more than four
or five at a birth. The Westphalian breed, on the contrary,
though they resemble the last, are highly prolific, the litter gene-
rally consisting of from ten to twelve. In Bavaria the hogs are
remarkable for the smallness of their bones and the readiness.
with which they take on fat. Lastly, the Chinese race, which is
common in England and begins to extend on the continent,
differs from those hitherto known, in having the back straight or
even hollow, and the belly large. This breed is also remarkable
for its quietness; the pork which it yields is of the very best
quality.
One of the great advantages connected with the hog being
its extreme fecundity, it is important to have a breed which is
distinguished in this respect. There are some brood swine
which have regularly borne ten to fifteen, and even eighteen
pigs at a litter; a more general number is eight or nine.
According to Thaer, the hog that is disposed to take on fat
is distinguished by length of body, long ears, and a pendulous
belly. The hog attains his growth at the end of about a year,
until which time the female ought not to be put to the boar.
One boar generally suffices for about ten females.
The hog, as all the world knows, is an animal the least
dainty in his food; he is omnivorous, nothing comes amiss to
him; but his food is by no means matter of indifference when
the quality of the flesh comes to be considered. Thaer seems
to think that maize is of all articles that which is the best for
feeding swine; and I have had occasion to verify the accuracy
of his conclusion in South America, where I may add it is found
that the oily fruit of the palm-tree contributes powerfully to the
fattening.
Husbandry, in regard to the hog, comprises two distinct
periods: the growth of the animal, and his fattening. It is
generally admitted that it is most advantageous not to fatten
swine for the butcher until they have completed or nearly com-
pleted their growth. A hog which has been well kept from the
period of its birth, may be put up to fatten at the age of about
a year.
The female shows signs of heat at the age of about five
SS
632
THE HOG.
or six months, and goes with young on an average 115 days,
and will produce regularly two litters per annum; when par-
ticularly well kept, she may have three litters in the course of
from thirteen to fourteen months.
The hogs which are destined to be fattened for the knife are
generally cut at the age of six weeks, particularly if they are to
be put up to fatten at the age of nine or ten months, as is often
done. Almost all the varieties of roots and grain produced
upon the farm are suitable for the maintenance of the hog; but
in Alsace, and I believe generally, the staple is the steamed
potato, with which are associated various articles in smaller
quantity, such as peas, and barley and rye meal, &c.
The farrow sow ought to have food by so much the more
abundant and nutritious as she is required to suckle a larger
number of pigs. Our allowance at Bechelbronn to the hog with
five young ones during the six weeks of suckling is as follows:
lbs.
7.8
4.0
6.2
18.0
After the fifth week when the animal is no longer giving suck
the ration consists of:
lbs.
24.75 hay
2.45
13.2
Total allowance
Steamed potatoes
Rye meal
Skim milk
Steamed potatoes
Rye meal
Skim milk (sour)
lbs.
. 12.1
1.0
6.5
P
"
lbs.
hay . 7.3
1.6
3.3
12.2
21
1
رد
Total allowance
This allowance is gradually reduced to the end of the second
month after the farrowing, when the animal is upon the mainte-
nance ration of the farm consisting of:
lbs.
lbs.
16.5= hay . 5.2
Steamed potatoes
The potatoes are mixed with dish washings, which certainly
contribute to improve their nutritive power, although I am alto-
gether at a loss to estimate the value of the article.
The young pigs begin to taste the food given to the mother at
the age of about a fortnight, but they never take to this kind of
THE HOG.
633
food freely until they are four or five weeks old and are weaned;
up to the time they have an allowance of skim milk and whey.
To five pigs at the time of weaning we allowed per day:
Steamed potatoes
Rye meal
Skim milk
lbs.
22.0
10
6.6
29.6
hay
"
""
7.3 per head 1.4
1.6
0.33
0.57
2.8
11.7
"
"
This allowance was modified by degrees; the quantities of
milk and rye meal were gradually abridged, and the proportion
of potatoes increased, so that about the third month the
allowance per head was from 11 to 13 lbs. of potatoes mixed with
greasy water. This is the regimen, equivalent to about 5 lbs. of
hay, upon which our store pigs are maintained until they are
put up to fatten. During the three months which follow the
weaning, therefore, we may reckon that each animal has con-
sumed 3.8 lbs. of meadow hay per day, and that from the third
month the consumption may be represented by 5.2 lbs. of the
same article.
We have attempted in vain to replace the potato by rape
or madia oil cake; the pigs refused it obstinately; but they
showed no objection to poppy seed, walnut and linseed cake;
during the season they will also eat clover, and are partly main-
tained upon this plant. In summer they are put entirely upon
green meat, animals from five to six months old consuming
about 19 lbs. of clover a-day, a quantity which represents very
nearly 5 lbs. of clover hay.
The hog may be fattened at any age; but as we have already
said, it is not generally advisable to fatten before he is ten
months or a year, some say fifteen months or a year and a half
old, at which period the animal is undoubtedly in flesh and at
its full growth. The other extreme limit appears to be about
five years; but it is only a brood sow that is ever kept to five
years of age. It is generally allowed that twelve weeks are
required to bring a hog into prime condition, when he ought to
have a layer of fat under the skin, upwards of an inch in thick-
Sixteen weeks may be required to obtain an animal really
fat; and twenty weeks to have him at the highest point that is
ness.
SS 2
634
THE HOG.
attainable. The hog requires to be fed regularly. After wean-
ing, pigs should have five or six meals in the course of the day;
the number of meals is diminished gradually, and towards the
end of two months they amount to but three in all.
I was curious to ascertain the weight of pigs at the moment
of their birth so as to determine their rate of increase during
the period of suckling. On the 5th of September a sow farrowed
a litter of five.
Ibs
No. 1 weighed 2.205
No. 2
3.025
No. 3
2.476
No. 4
2.750
No. 5
3.300
Weight of the litter
13.756
Average weight per head
2.751
On the 11th of October the weight of the litter was 86.9 lbs.,
or 17.3 lbs. per head, : increase in thirty-six days, 73.2 lbs. ; per
head, 14.6 lbs. ; per day, 0.409 lb. On the 15th of November
the weight was 177 lbs.: increase in thirty-five days, 90.2 lbs. ;
per head, 18 lbs. ; per day, 0.506. During the thirty-six days
of suckling consequently, 100 of live weight at birth had become
632.
"
>>
"
""
In another instance, I found that eight pigs which at the time
of weaning weighed 114 lbs. or 14.3 lbs. per head, at a year
old weighed 1320 lbs. or 165 lbs. per head: increase in eleven
months 1206 lbs. or 150 lbs. per head.
The increase per diem since the weaning had been 0.4,-not
quite half a pound; and as the food consumed may be repre-
sented by 5.2lbs. of hay per day and per head, it will follow
that 100 of forage had produced 8.58 of live weight. This
ratio is too high, however; for these pigs besides the regular
allowance had whey and various scraps of which no account was
kept; and we know that whey alone contains a considerable
quantity of the representatives both of flesh and fat.
Baxter came to some interesting conclusions on the growth
and fattening of young hogs. Four animals each of the age of
nine months weighed at the beginning of the experiment
THE HOG.
635
458.2 lbs. ; twenty-one days afterwards, 620.8 lbs.: increase of
weight 162.6 lbs. to obtain which there were consumed:
Barley
Beans
Malt grains
lbs.
151
140.8
440
JJ
lbs.
equivalent to hay, 250
611
367
1228
So that a quantity of nutritive matter represented by 100 lbs.
of hay produced 13.21 lbs. of live weight.
Assuming the weight of each pig of nine months old before
the fatting to have been 114 lbs. the increase per head was
40.6 lbs. in the course of twenty-one days, or at the rate of
1.9 lbs. each. Baxter reckoned the carcass weight, sinking offal,
at 74 per cent.
>>
One of the pigs between nine and ten months old weighing
159.5 lbs., at the end of twenty days weighed 198.8 lbs. ; in-
crease in twenty days, 39.3 lbs. ; increase per day, 1.9 lbs.
During these twenty days, the animal had consumed 188 lbs.
of barley, equivalent to 314 lbs. of hay. The increase would
consequently give for every 100 lbs. of hay consumed an increase
of live weight of 12.52, say 12 lbs.
Arthur Young, by keeping pigs of a year old on peas-meal
obtained the following results:
No. 1 weighed 99.0; 35 days afterwards, 157.5; gain, 58.5; per day 1.672
No. 2
53.7
91.7; 42
86.6; 63
145.4;
139.4;
1.276
0.836
No. 3
52.8
13
**
>>
""
3.
I shall here give two series of observations made at Bechel-
bronn on the fattening of hogs. September 6th, 1841, seven
hogs, aged fifteen months each, already in good condition, were
put up to fatten. They had hitherto had the usual hog's food-
sour milk and boiled potatoes after weaning; by and bye from
11 to 15 lbs. of potatoes, whey and dish washings. The seven
porkers weighed 1691.8 lbs.; or 241.670 lbs. each. The
increase had been at the rate of 0.528, rather better than half a
pound per day and per head, supposing them to have weighed
13.7 lbs. each, at the time of weaning.
ss 3
636
lbs.
After fattening, 20th December, the 7 swine weighed 2101.0
Before
6th September
1691.0
Hogs.
Increase in 104 days, 410 lbs; or per head 58.3
Increase per day and per head .
0.572
In the course of the 104 days, there were consumed:
1
2 3
>>
4
5
6
་
Barley
Peas
Potatoes
THE HOG.
Greasy water and whey-quantity not determined 8333.6
So that with the provender equivalent to 100 lbs. of hay, 4.91 lbs.
of live weight had been produced.
These seven porkers slaughtered, yielded:
Weight alive.
+
lbs.
323.0
259.0
283.0
316.0
264.0
259.6
393.8
2098.4
lbs.
lbs.
772 equivalent to hay 1144
1042.8
4171
9504
8296
lbs.
Weight after Weight of the
bleeding.
blood.
312
248
272
305
257.4
250.8
376.2
""
lbs.
11
11
11
11
"
6.6
8.8
17.6
""
"}
>>
Weight of the
porkers with-
out heads or
feet.
lbs.
268.0
231.0
209.0
264.0
220.0
213.4
321.2
1726.6
Weight of
heads and
offal.
lbs.
44.0
39.6
63.8
41.8
37.4
37.4
55.0
د.
It must be admitted that these animals had increased both
in flesh and in fat; but in spite of this, the experiment appears
to be unfavourable to the opinion that fat in animals is the effect
of direct assimilation of the substance. The whole increase of
weight in the seven porkers had been 409.2 lbs.; supposing
27
per cent of fat in this increase, its amount must have been
110.4 lbs. in all; but the food consumed did not contain more
than 57.4 lbs. It would therefore be necessary to admit that
the food which had not been taken into the account had con-
tained as many as 53.0 lbs. of fatty matter, which I own does
not appear to me probable. But no definitive conclusion can be
drawn from the circumstance, owing to the actual state of fat-
THE HOG.
637
ness of the animals when they were specially put up to fatten,
not having been ascertained; perhaps the absolute quantity of
fat already accumulated is greater at this time than is generally
supposed.
I find, for instance, that a young porker of 196.9 lbs., killed
at the time when he might have been put up to fatten specially,
yielded as many as 26.3 per cent of fat.
The following are the data afforded by the fattening of the
farm porkers for 1842:
Nine porkers, from thirteen to fifteen months old, and
already in good condition, were put upon the full fatting allow-
ance on the 1st of October, on which day they weighed :
Nov. 28th, after having been bled, they weighed
Increase in 58 days
>>
per head, 37.4 lbs.; per day 6 ounces.
In the course of fifty-eight days the hogs had consumed:
Rye
Peas
Potatoes
lbs.
770 equivalent to hay
1302
5896
"
""
lbs.
1940
2307.8
3678
lbs.
1141.8
5209
1861
Greasy water and whey undetermined
211.8
The nine animals gave 1746.8 lbs. of meat, fat and lean, or
75.7 per cent of their weight as they stood alive; besides which,
141.9, say 142 lbs. of lard were obtained from the internal
parts. Now supposing that in the increase of weight obtained
in the course of fifty-eight days, the fat were to be represented
by 29 per cent, the fat fixed would amount to 100.1 lbs. ; whilst
the whole of the fatty substances contained in the food consumed
would not amount to more than 59.6 lbs. It would therefore
be imperative on us, did we maintain that all the fat was
obtained ready formed from without, to suppose that the whey
and dish washings administered in indeterminate quantity, had
introduced 40.5 lbs of fat into the bodies of the animals. Some
experiments which are going on at Bechelbronn at this moment
will, I trust, settle the question definitively as to whether during
the fattening of hogs and other animals there is any formation of
fat at the cost of the starch and sugar of the food.
S S 4
638
THE HOG.
The observations which I have made on the fattening of hogs
may be summed up in these terms:
Provender expressed
in lbs. of hay.
lbs.
5.1
13.5
15.7
11.5
15.4
lbs.
138
145
160.5
184.8
lbs.
0.440
0.836
1.958
1.254
0.572
0.660
Increase per day.
he ate
>>
>>
>>
lbs.
11
13.2
15.4
17.6
Live weight obtained
from every 100 lbs. of
provender.
lbs.
8.58
13.21
12.52
ور
4.91
4.21
"}
Age of the animal
at the beginning of
experiment.
""
Months.
1
9
9/
equivalent in hay to
"}
12
15
14
The allowance to the hogs in the preceding observations was
always abundant. To determine the quantity of potatoes con-
sumed each day by a hog in full growth, and whose weight was
known, I had him weighed at intervals, as well as the potato
ration, placed before him at will, which he ate daily, and found
that when he weighed:
Duration of the experiment.
Months.
11
Total increase
Increase per day, per head
""
Two sheep six months old weighed together.
Sixteen days afterwards they weighed
""
>>
o
>>
""
lbs.
3.4
4.2
4.8
5.5
Days.
""
21
20
""
104
58
To these observations on the keep and fattening of horned
cattle, horses and hogs, I would gladly have added remarks of
like extent on the growth and fattening of sheep; unfortunately
I have only been able to obtain very imperfect information on
this branch of rural economy. I have, however, sought to as-
certain approximately the relations which exist between the
weight of a young animal, the food consumed, and the increase
in live weight by means of the following experiment:
Per 100 of the
live weight in hay.
2.52
2.89
3.01
3.02
134.3 lbs.
151.8
17.6
0.55
THE HOG.
639
In the sixteen days the two sheep ate :
Hay
Potatoes
44.0 Hay
53.3 = Hay
Or head in hay
per
Or per head per day
•
44.0
16.9
60.9
30.4
1.9
This would give us about 2.9 of hay provender per cent. of
the live weight, so that a ration which should be represented by
100 of hay would be followed by an increase on the weight of
a sheep of six months old of 27.7 per cent.
VI. OF THE PRODUCTION OF MANUre.
The forage consumed on the farm being the source of the
manure produced there, it would seem that it must be easy to
calculate the value of all that comes from the stables and cow-
houses day after day. I do not mean the mass or weight of
the dejections here, for it is certain that the more or less watery
nature of the food materially influences the weight of the dung
produced; and if a common mode of calculating the quantity
of dung by merely multiplying the weight of food consumed by
three be correct in some cases, it is very far from the truth in
others. The dung produced on the farm must be calculated
on different grounds from this; and without pretending to any
degree of accuracy which is really unattainable, it is still very
possible to get at the quantity of azote which is contained in
the litter and in the dejections, so as to be able to refer to a
standard the quantity of manure made.
Were not the azotised principles of the food partly exhaled
by animals, the whole quantity not appearing in the excretions,
it is obvious that it would suffice to have ascertained the quan-
tity of azote contained in the food to be in a condition to decide
on that contained in the dung added to the litter. But this
cannot be done: to be convinced of the fact, it is enough to
take the least complex case, that of a full-grown horse, receiving
as his allowance per day :
ss 5
640
Hay
Oats
Straw
Litter
33lbs. of hay contain
4.4
22lbs. containing 1775.3 grains of azote
11
1389.4
11
308.7
108.0
3581.4
8.8
THE HOG.
straw for litter contain
Azote
>>
>>
>>
Azote
Now assuming 2 per cent as the contents in azote of dry
farm-yard dung, we see that the food consumed by the horse,
speaking theoretically, might or should form 25.5lbs. of dry
manure. But we have seen that a horse or cow will exhale from
355.0 to 416.8 grs. of azote, which is all derived from the food,
and is consequently lost to the dung-heap. Now 385.9 grs. of
azote represent 2.75lbs. of dry manure; so that the dry dung
produced by the horse kept in the stable, will be reduced from
25.5lbs. to 22.6lbs. In the course of a year, upon this calcu-
lation, the azote exhaled will diminish the weight of dry dung
produced by one horse by a quantity equal to 1045lbs.
The azote of the food of a cow is still more considerable in
quantity, and the loss to the dung-hill proportionally larger; in-
asmuch as to the amount she exhales, must be added all that
goes to constitute the milk she gives. Practical men, without
pretending to get at the cause of the thing, have long been
aware of the fact, that a cow produces less dung than a horse;
and the truth of this is readily demonstrated on scientific
grounds. Suppose a cow, consuming the equivalent of 33lbs.
of hay, and giving about 17 pints of milk per day :
2670 grs. of azote
123
در
د.
""
But in the 24 hours, there have been of
Azote exhaled .
Azote in 17 pints, or 22.7lbs.
of milk carried off
>>
2793=19.8lbs. of dung supposed to
be dry.
385.9 grains, and of
802.7 grains
1188.6 8.8 of dry dung.
The 33lbs. of hay digested by the cow, consequently, the litter
added, have only produced 8.8 of dry dung. The azote of the
food, of which we find no account in the dejections, amounts
THE HOG.
641
per annum to nearly 30 cwts. (3300 lbs.) the deficiency in the
case of the horse amounting to no more than 1045 lbs. (9 cwts.
1 qr. 9 lbs.)
The estimation of the dung produced by growing animals,
presents several special difficulties, inasmuch, as besides the
azote exhaled from the lungs, there is the quantity that is fixed
in the living body.
In one of the experiments which I have related, it appears
that a calf six months old, consuming :
Hay 9.6 lbs. containing
Discharged by its dejections.
Azote fixed or exhaled in 24 hours
1069.8 azote
838.3
231.5
**
""
The azote lost to the manure by the fixing of azote is there-
fore very considerable, in the case of young animals as well as
of milch-kine. We find, for example, that for every 100 lbs.
weight of hay consumed:
در
"
A horse supplies the equivalent of 51 lbs. of dry standard dung
A milch-cow
32
A calf of six months.
40
>>
ور
To estimate with any rigour the quantity of azotised manure
which ought to result from the forage consumed on the farm, it
were necessary to know the proportion of azote contained in
the bodies of all the animals entertained upon it. Having the
increase of weight that occurred in the stable, cow-house, pig-
sty, and poultry-yard, we should then be in a condition to know
the precise quantity of dung which it would be necessary to
retrench from that which the forage ought to have produced,
had there been no production of animal matter, had the whole
of the azote of the food passed through the live stock to the
dung-hill. Unfortunately, we have no very precise data by which
we might calculate the quantity of azote contained in a living
animal. I shall nevertheless endeavour to apply such as we
possess.
From a few practical experiments, and the information at my
command, I admit that the following substances in their usual
state contain per cent:
642
THE HOG.
Beef-flesh
Veal
Blood
Skin
Hair
Horn
Beef bones (tibia)
An entire skeleton
Moisture.
77
77
80
60
9
9
30
36
Brain, intestines, &c.
81
Fat freed from skin 20
•
In horned cattle
In the horse
In the hog
In the sheep
Dry matter.
23
23
20
40
81
91
70
64
10
80
Average
Salts.
1.0
"
0.9
1.0
2.0
0.7
"
35.0
1.0
Azote.
3.5
These data applied to the various parts which enter into the
constitution of the animals which up to this point have engaged
our attention, we should have for the quantity of azote per cent
contained:
3.47
3.64
3.80
3.66
3.0
7.2
13.8
14.4
""
5.2
2.9
1.9
3.64
For every 100 lbs. of live weight produced on the farm, con-
sequently, we may, without probably being a great way from the
truth, presume that there has been 3.6 of azote fixed, azote ob-
tained from the forage, and which consequently cannot go to the
dung-heap; in other words, every 100 lbs. of live weight pro-
duced, deprive the establishment of 180 lbs. of dry standard
dung, or nearly 18 cwts. of moist farm-yard dung.*
We may be allowed, therefore, to entertain the hope that
we shall one day be able, from the quantity of forage consumed
upon a farm, to calculate the actual quantity of manure which
we shall have at our disposal. To arrive at this result, it would
indeed only be necessary to subtract the manure represented by
the azote exhaled from and fixed in the bodies of the stock,
from the amount of azotised manure represented by the whole
quantity of forage, were it to be used immediately. To obtain
results of any accuracy, however, it were necessary to possess
* This discussion will undoubtedly extend by and by to phosphoric acid.
I shall only say at this time, that from the results obtained in the case of a
pig, the phosphoric acid appears to be in the proportion of from 2 to 3 per
cent of the live weight.
THE HOG.
643
data both more numerous and more precise than any we have
at present. This perfection of co-efficients must be viewed as
an affair for the future; agricultural science has almost every
thing to create.
In estimating the quantity of manure from the forage con-
sumed, it has been supposed that there is no loss. With refe-
rence to the stall or cow-house, a careful husbandman may
approach this perfection, by doing almost the contrary of all that
is usually done now-a-days; i. e. by taking every precaution
against waste; but it is obvious that in so far as the stable is
concerned, there must always be a considerable and inevitable
loss; all that falls upon highways and byways is irretrievably
gone. It is, indeed, matter of ordinary calculation that in con-
sequence of their work out of doors, the horses upon a farm do
not afford more than about two-thirds of the dung which ought
to be obtained from the provender consumed.
Some experi-
ments made in the stables at Bechelbronn show that the loss in
this way may amount to one quarter of the whole amount of
dejections; still, as the animals are for the major part engaged
on the land of the farm, it is obvious that what falls there is by
no means lost. To supply my reader with definite sums from
a particular instance, upon which he may fix his mind, I shall
state for his information that in the course of 1840-41,* my
stock at Bechelbronn consisting of: sixteen head of cattle,
eleven calves, twenty-seven horses, and (?) hogs, consumed
733.653lbs. or 327 tons, 10 cwts. 1 qr., 17 lbs. of forage,
containing 6396lbs. of azote, and produced upon their original
weight 45.806lbs. of flesh, fat, and milk, containing with the
addition of a calculated quantity for loss from out of door prop-
pings, exhalation by the lungs, &c., 2631lbs. of azote. The
forage and the litter, from their contents in azote, ought to have
produced about 15356 cwt. of moist farm-yard dung; they,
however, produced no more than 9522 cwt.; and, in fact, we
see that there had been a consumption of azote by arrest within
the bodies of the stock, by exhalation from the lungs, and by
loss amounting to 2631lbs; by an equivalent quantity of dung,
therefore, had the absolute produce necessarily been diminished.
* Twelve months, I presume.-ENG. ED.
Ss6
644
THE HOG.
Thaer allows that articles of dry forage and litter double their
weight in becoming converted into dung. The statement which
I have just made agrees on the whole pretty well with this esti-
mate. In our cow-house ration, one-half only is generally hay,
the other half consists of roots and tubers. The dry forage and
litter consequently amount to 4660 cwt., which according to
Thaer, ought to become changed into 9320 cwt. of dung, a
number not very wide of that to which we have come. Sinclair
reckons the dung of the cow-house at four times the weight of
the litter, a view which neither accords with Thaer's estimate nor
with our experience.
I think it altogether unnecessary to insist on the importance
to the farmer of a fore-knowledge of the quantity of manure
which he may reasonably calculate on obtaining from a known
weight of forage consumed upon his premises. Of the various
methods proposed for arriving at this information, that which
I have employed, and which is based on ascertaining the amount
of azote, appears to me the best calculated to supply satisfactory
results, particularly when experience shall have corrected or con-
firmed the numbers which I have adopted as the elements of
my calculations.
I have already said that any supplementary forage, or forage
added to that which is indispensable to the production of ma-
nure, generally acquires by the fact of its conversion into power
or into exportable substances, a value superior to that which it
could have had of itself in the market-place. This additional
forage is that fraction of the provender, the azote of which
figures in the statements that have just been made as azote
exhaled or assimilated and fixed. We find, in fact, that in rc-
presenting this forage which is lost to the dung-heap, but gained
to power and exportable articles, that in the stall, 100lbs. of hay
yield 8.6lbs. of live weight, and 40.8lbs. of milk, and that in the
hog-stye, 100lbs. of hay yield 21 of living weight. In the
stable, again, the azote fixed, exhaled or lost amounts to nearly
1540lbs. represented by about 1218 cwts. of hay which have
yielded 1504lbs. of live weight, due in great part to the birth
and growth of foals, in addition to the force represented by
8370 days' work.
645
CHAPTER X.
METEOROLOGICAL CONSIDERATIONS.
I. TEMPERATURE.
THE phenomena of vegetation are always accomplished under
the influence of a certain temperature. If, in addition, the
concurrence of light, air, moisture, and various inorganic sub-
stances be required, it is still perfectly certain that all of these
agents only contribute to the development of a plant when they
are assisted by a due measure of heat, variable with reference to
the different vegetable species, and comprised within limits that
are rather far apart, but essential. Germination, for example,
takes place at a temperature a few degrees above the freezing point
of water, 38º or 39º, F. and at one indicated by 100° or 120° of
the same scale. The forests of tropical countries thrive in a hot,
moist atmosphere, which often marks upwards of 100° F., and I
met with a saxifrage upon the Andes at an elevation of 15,748
feet above the level of the sea, beyond the line of perpetual
snow, and very near the line of perpetual congelation.
Some families of plants require a temperature not only high,
but that never falls below a certain very limited degree; the
majority of the intertropical plants are in this predicament. There
are others which, imperatively requiring a high temperature for
their growth and perfection, nevertheless suspend their powers
during the winter, and bear without detriment degrees of cold
of great intensity; among the number may be cited the larch-pine,
which abounds in Siberia, and stands the utmost rigours of its
climate where the thermometer at mid-winter frequently falls to
35° and even 40° below zero, F. from observations made by
Mr. Erman, and such severe winters are followed by warm and
dry summers.*
The meteorological habitudes or dispositions of plants being
extremely various, it follows that the geographical distribution of
* Humboldt, Asie Centrale, v. 1. p. 52.
646
METEOROLOGY.-TEMPERATURE.
plants is a consequence of the distribution of heat over the sur-
face of the globe-of climate.
The earth we inhabit appears to have a heat proper to itself;
it is a heated body in progress of cooling. It is found in fact
that as the centre of the earth is approached, as mines penetrate
more deeply below its surface, that the temperature increases.
Below a very limited distance from the surface, the temperature
ceases to be affected by variations in the temperature of the
general atmosphere; from the point of invariable temperature
the subterranean heat increases uniformly at the rate of 1º cent.
(1.8° Fahr.) for every 101 feet of descent.
The depth at which the point of stratum of invariable tem-
perature is met with, varies in different places, and is mainly
affected by the extent of the thermometrical variations in the
superincumbent air in the course of the year. In the higher
latitudes, consequently, the depth is very considerable; at Paris
for example, M. Arago has found that a thermometer buried at
26 feet under the surface does not remain absolutely stationary.
In climates of greater constancy, as may be conceived, the
layer of invariable temperature will be found much nearer the
surface; were the temperature of the air invariable the layer of
invariable temperature would necessarily be found at the surface
of the ground. In countries under and close to the equator,
this in fact is found to be the case. From a series of observa-
tions which I made in South America between the 2nd parallel of
southern, and the 11th of northern latitude, I found that near
the line, the layer of invariable temperature is found nearly at
the surface; the thermometer placed in a hole about one foot
deep under the shade of an Indian cabin, or a shed, does not
vary by more than from one-tenth to two-tenths of a degree cent.
It was probably under the influence of the internal or proper
heat of the globe, according to M. de Humboldt, that the same
species of animals which are now confined to the torrid zone
inhabited in former and remote ages the northern hemisphere,
covered as it then was by arborescent ferns and stately palms.
It is easy to imagine how, as the surface of the earth cooled, the
distribution of climates became almost exclusively dependent on
the action of the solar rays, and how also those tribes of plants
and of animals, the organization of which required a higher tem-
METEOROLOGY.-TEMPERATURE.
647
perature and more equable climate, gradually died out and dis-
appeared.*
In the state of stability to which the surface of the globe
appears actually to have attained, the sun must be considered as
the agent which most directly influences the temperature of our
atmosphere. The length of the day, the number of hours
during which the sun is above the horizon, coupled with the
height to which he ascends, such is the cause with which the
temperature of each particular latitude is primarily connected; and
in looking at the subject practically it is found to be so precisely;
not only is the mean temperature of the year dependent on the
length of the days and the meridian altitude of the sun, but
the mean temperature of each month in the year is essentially
connected with the same circumstances. In the northern hemi-
sphere, the temperature rises from about the middle of January,
slowly at first, more rapidly in April and May, to reach its
maximum point in July and August, when it begins to fall again
until mid-January, when it is at its minimum.
The highest mean annual temperature is of course observed
in the neighbourhood of the equator; between 0° and 10° or
12° of latitude on either side, at the level of the sea, where,
besides the equality of day and night, the sun always ele-
vated, passes the zenith twice a year. The observations that
have been made up to this time, lead us to conclude that this
temperature oscillates between 26° and 29° cent.; 78.8° and
84.2° Fahr.
Did the earth present unvarying uniformity of surface, not
only with reference to clevation but to constitution, so that the
power of absorbing and of radiating heat should be everywhere
alike, the climate of a place would depend almost entirely on
its geographical position: the points of equal temperature would
be found on the same parallels of latitude, or to employ the happy
expression introduced by M. de Humboldt, the isothermal lines
would all be parallel with the equator. But the surface of our
planet is covered with undulations and asperities which cause its
outline to vary to infinity; and then the soil is dry, or swampy;
it is a moving desert of sand, or covered with umbrageous and
* Humboldt's Central Asia, v. III. p. 98.
T T
648
METEOROLOGY.-TEMPERATURE.
impenetrable forests; and all this causes corresponding varieties in
climate, for the surface becomes heated in different degrees as it
is in one or other of these conditions. Another very important
consideration is, that the surface is a continent, or an island in
the ocean: the climate of a country, or of a district, is vastly
influenced by its proximity to or distance from the sea. The
difficulty, the slowness with which such a mass of liquid as the
ocean becomes either heated or cooled, is the cause of the tem-
perate character both of the summers and winters of the shores
it bathes, and the islands of moderate dimensions it surrounds.
As we penetrate great continents from the sea-board, we find
that the temperature both of summer and winter becomes.
extreme, and the difference between the mean summer and
mean winter temperature is great; and again we find that
places which have considerably different latitudes have still very
nearly the same mean annual temperature. The mean tempe-
rature of Paris in latitude 48° 50m is about 51.4° F.; that of
London in lat. 51° 31m is 50.7° F.; that of Dublin in lat.
53° 23m is 49.1° F.; and that of Edinburgh in lat. 55° 57m is
47.4° F.
An island, a peninsula, and the sea-shore consequently enjoy a
more temperate and equable climate, the summers less sultry,
the winters more mild. On the shores of Glenarm in Ireland, in
latitude 55°, the myrtle vegetates throughout the year as in
Portugal; it rarely freezes in winter; but the heat of summer
does not suffice to ripen the grape. Under the very same
parallel, however, at Konigsberg in Prussia, they experience a
cold of 17° and 18° below zero of Fahrenheit's scale in the
winter. The ponds and little lakes of the Feroe Islands,
although situated in N. lat. 62°, never freeze, and the mean
winter temperature is very nearly 40° F. On the coasts of
Devonshire, in England, the winters are so mild, that the orange
tree as a standard will there carry fruit; and the agave has been
seen to flourish, after having lived both winter and summer, for
twenty-eight years in the open air uninjured.
One of the grand characteristics of what may be called a
maritime climate, is the less difference which occurs between
the temperature of summer and that of winter. At Edinburgh,
METEOROLOGY.-TEMPERATURE.
649
for instance, the difference only amounts to 19° F.; at Moscow,
which is nearly on the same parallel, the difference amounts to
50° F.; and at Kasan (lat. 56°) it is as much as 56.3° F.
The influence of extensive continents, or remoteness from the
sea-board, does not seem merely to render a climate extreme,
increasing at once the heat of summer and the cold of winter.
The collective observations on temperature, made in Europe and
in Asia, show that the mean annual temperature decreases
as we penetrate more into the interior of continents towards
the east. Humboldt ascribes this diminution of temperature
partly to the refrigerating action of the prevailing winds.
Whilst the mean annual temperature of Amsterdam (N. lat.
52° 22′) is 49.6° F., that of Berlin (N. lat. 52° 31) is
47.4° F.; that of Copenhagen (N. lat. 55° 41') is 46.7° F.;
and that of Kasan N. lat. 55° 48′) is but 35.9° F.
The highest temperature which has yet been registered as
occurring in the open air appears to have been observed by
Buckhardt in Upper Egypt; the thermometer indicated
47.5° cent., upwards of 117° F. The lowest was seen by
Captain Back in North America; when the thermometer fell to
-.56° cent., 68.8° F. below zero.
§ II.
DECREASE OF TEMPERATURE IN THE SUPERIOR STRATA OF
OF THE
ATMOSPHERE.
The temperature rises rapidly as we ascend in the atmosphere;
places among the mountains always possess a climate more severe
as they are higher above the level of the sea. Even under the
equator, height of position modifies the seasons so much, that
the hamlet of Antisana, which is within one degree of south
latitude, but which is upwards of 13,000 feet above the sea
level, has a mean temperature which does not differ much from
that of St. Petersburgh. Near it, but at a still greater height,
the summit of Cyambe, covered by an immense mass of ever-
lasting snow, is cut by the equinoctial line itself.
The cold which prevails among lofty mountains is ascribed
to the dilatation which the air of lower regions experiences in
its upward ascent, to a more rapid evaporation under diminished
pressure, and to the intensity of nocturnal radiation.
TT 2
650
METEOROLOGY.-TEMPERATURE.
Places which are situated upon the same mountain-chain,
nearly in the same latitude, and at the same height, have often
very different climates. The temperature which would be proper
to a place perfectly isolated, is necessarily modified by a consider-
able number of circumstances. Thus the radiation of heated plains
of considerable extent, the nature of the colour of the rocks,
the thickness of the forests, the moistness or dryness of the soil,
the vicinity of glaciers, the prevalence of particular winds,
hotter or colder, moister or dryer, the accumulation of clouds,
&c., are so many causes which tend to modify the meteorolo-
gical conditions of a country, whatever its mere geographical
position. The neighbourhood of volcanoes in a state of activity
docs not appear to affect the temperature sensibly; thus Puracé,
Pasto, Cumbal, which have flaming volcanoes towering over
them, have not warmer climates than Bogota, Santa Rosa, De
Osos, Le Param de Hervè, &c., situated on sandstone or
syenite.
From the whole series of observations which I had an oppor-
tunity of making on the Cordilleras, it appears that one degree of
temperature, cent., 1.8°F. corresponds to 195 metres or 649.4 feet
of ascent among the equatorial Andes. In Europe it has been
ascertained that the decrease of temperature in ascending moun-
tains is more rapid during the day than during the night, during
summer than during the winter; for example, between Geneva
and Mount St. Bernard, to have the Fahrenheit thermometer fall
one degree, it is necessary to ascend:
In spring.
In summer
In autumn
In winter.
326.1 feet
336.6
382.2
422.2
It sometimes happens, however, that in winter, in a zone of
no great elevation, the temperature increases with the elc-
vation, a fact which Messrs. Bravais and Lottin observed in the
70° of N. latitude, in calm weather; at an elevation between
1312 and 1640 feet, the rise amounted to as many as 6º centi-
grade, 10.8° Fahrenheit.
In no part of the globe is the diminution of temperature
occasioned by a rise above the level of the sea more remarkable
METEOROLOGY.-TEMPERATURE.
651
((
than among equatorial mountain ranges; and it is not without
astonishment that the European, leaving the burning districts
which produce the banana and cocoa tree, frequently reaches, in
the course of a few hours, the barren regions which are covered
with everlasting snow. Upon each particular rock of the rapid
slope of the Cordillera," says M. de Humboldt, "in the series
of climates superimposed in stages, we find inscribed the laws
of the decrease of caloric, and of the geographical distribution
of vegetable forms.*”
In the hottest countries of the earth, the summits of very
lofty mountains are constantly covered with snow; in the ele-
vated and cold strata of the atmosphere, the watery vapour is
condensed and falls in the state of hail and snow. In the
plain, hail melts almost immediately; the fusion is slower upon
the mountains; and for each latitude there is a certain elevation
where hail and snow no longer melt perceptibly. This elevation.
is the inferior limit of perpetual snow.
The accidental causes which tend to modify the temperature
of a climate, also act in raising or lowering the snow line. On
the southern slope of the Himalaya, for example, the snow line
does not descend so low as it does upon the northern slope; and
in Peru, from 14° to 16° of S. latitude, Mr. Pentland found
the perpetual snow line, at an elevation of 1312 feet higher
than it is under the equator.
Elevation above the level of the sea, consequently, has the
same effect upon climate as increase in latitude. Upon moun-
tain ranges, vegetation undergoes modification in its forms,
becomes decrepid, and disappears towards the line of perpetual
snow, precisely as it does within the polar circle, and for no
other than the same reason; viz., depression of temperature.
The constancy and the small extent of variation which occurs
in the temperature of the atmosphere under the equator,
enables us to indicate with some precision, the point of mean
temperature below which there is no longer any vegetation. In
ascending Chimborazo, I met with this point at the height of
15774.5 fect, where the mean temperature approached 35° F.,
and where consequently the saxifrages, which root among the
rocks, must still receive a temperature of from 41° to 43° F.
* Humboldt's Central Asia, vol. 1. p. 236.
652
METEOROLOGY.-TEMPERATURE.
during the day, inasmuch as far beyond the inferior snow line,
at an elevation of 19,685 feet above the sea-line, I saw a thermo-
meter suspended in the air, and in the shade mark 44.6° F.
In considering the extension of vegetation towards the polar
regions, we discover plants growing in very high latitudes.
in places which have a mean temperature much below that
which I believe to be the limit of vegetable life on the
mountains of equatorial region. In these rigorous climates.
vegetation is suspended by the severity of the cold during the
greater portion of the year; it is only during the brief and
passing heat of summer that the vegetable world wakes from
its long winter sleep. Nova Zembla, lat. 73° N., the mean
temperature of whose summer is between 34° and 35° F., is
perhaps, like the perpetual snow-line of the equator, the term of
vegetable existence. It is also to the very remarkable heat of
the summer in countries situated at the northern extremity of
the continent of Asia, remarkable if it be contrasted with the
intensity of the winter cold, that man succeeds in rearing a few
culinary vegetables in those dreadful climates. At Jakoustk, in
62º of N. lat., and where mercury is frozen during two
months of the year, the mean temperature of summer is very
nearly 64° F. We have here, as M. de Humboldt observes,
"a well characterized continental climate," examples of which
indeed are frequent in the north of America. At Jakoustk,
wheat and rye sometimes yield a return of 15 for 1, although
at the depth of a yard the soil which grows them is constantly
frozen.*
The limit of perpetual snow being much lower upon the
mountains of Europe than in tropical countries, agriculture
ceases at a much less elevation. At a height of 6560 feet
above the level of the sea, the vegetables of the plain have
almost entirely disappeared. In Northern Switzerland, the vine
does not grow at an elevation of more than 1800 feet above the
sea line; maize scarcely ripens at an elevation of 2850 feet,
whilst in the Andes, it still affords abundant harvests at an
elevation of 8260 feet. On the plateau or table land of Los
Pastos, fields of harley are seen at upwards of 10,000 feet above
*Humboldt's Central Asia, vol. 1, p. 49.
METEOROLOGY.-GROWTH OF PLANTS.
653
the level of the sea; but on the northern slope of Monte Rosa,
in Switzerland, barley fails at an elevation of about 4260
feet; on the southern slope, indeed, it reaches a height of about
6560 feet; and this great variation in the ultimate limit of
barley is frequently observed with reference to the same plant
grown upon opposite aspects of a mountain range. The dif
ference is ascribed to local influences; thus it is a well-ascer-
tained fact that on the mountains of the northern hemisphere,
vegetation reaches a much higher latitude upon southern than
upon northern exposures; but a general law, and one applicable
to every latitude, is that the higher we rise above the level of
the sea, the scantier does vegetation become, the later do har-
vests reach maturity; but as the heat of the atmosphere in-
creases with the elevation, it follows that there is an obvious.
relation between the time a crop is upon the ground and the
mean temperature of the place or season where it grows.
have still to examine this relationship.
We
§ III. METEOROLOGICAL CIRCUMSTANCES UNDER WHICH CERTAIN
PLANTS GROW IN DIFFERENT CLIMATES.
In discussing the conditions of temperature under which the
various plants that are common in our European agriculture
come to maturity, we are led to conclusions which are not
without interest. A knowledge of the mean temperature of a
place situated between the tropics suffices of itself to give us an
idea of the nature of its agriculture; in fact, the temperature of
each day differs little from that of the entire year, during which
vegetable life proceeds without interruption. It is altogether
different with regard to countries situated beyond the limits of
the torrid zone. The mean annual temperature is not then a
datum sufficient to enable us to appreciate the agricultural im-
portance of a country. In order to know what the earth will
produce, the temperature proper to the different seasons of
the year must be known; in a word, it is the mean tempera-
ture of the cycle in which vegetation begins and ends that it
imports us to ascertain, in order to learn what the useful plants
are which may be required of the soil.
In examining the question which now engages us, we first
654
METEOROLOGY.-GROWTH OF PLANTS.
inquire what time elapses between the sprouting of a plant and
its maturity, and then we determine the temperature of the
interval which separates these two extreme epochs in vegetable
life. In comparing these data with reference to the same spe-
cies of plant grown in Europe and America, we arrive at the
following curious result, that the number of days that elapse
between the commencement of vegetation and the period of
ripeness is by so much the greater as the mean temperature is
lower. The duration of the life of the vegetable would be the same,
however different the climate, were this temperature identical; it
will be longer or it will be shorter as the mean temperature of
the cycle itself is lower or higher. In other words, the duration
of the vegetation appears to be in the inverse ratio of the mean
temperature; so that if we multiply the number of days during
which a given plant grows in different climates, by the mean
temperature of each we obtain numbers that are very nearly
equal. This result is not only remarkable in so far as it seems
to indicate that upon every parallel of latitude, at all elevations
above the level of the sea, the same plant receives in the
course of its existence an equal quantity of heat, but it may
find its direct application by enabling us to foresee the possi-
bility of acclimating a vegetable in a country, the mean tem-
perature of the several months of which is known.
CULTIVATION OF WHEAT, ALSACE.
In 1835 we sowed our wheat on the 1st of November; the
cold set in shortly after the plant had sprung, and the harvest
took place the 16th of July, 1836. The vegetation during
the last days of autumn is so slow and irregular, that it
may be assumed without sensible error, that it really begins in
spring, when the frosts are no longer felt; from this period only
does it proceed without interruption. For Alsace, I regard this
period as beginning with the 1st of March.
The period of the growth was, therefore 137 days, the mean
temperature was 59° F. (8083° F.)
Tremois wheat, this same year, required 131 days to ripen
under a mean temperature of between 60° and 61° F. (7925º F.)
At Paris, setting out from the 31st of March, wheat generally
METEOROLOGY.-GROWTH OF PLANTS.
655
requires 160 days to attain maturity, the mean temperature
being about 56° F.(8960º F.)
At Alais the month of February having generally but few
days of heat it may be regarded as the epoch when the con-
tinued vegetation of autumn sown wheat commences. The
harvest taking place on the 27th of June the number of days
which it requires to ripen is 146, the mean temperature being
between 57° and 58° F. (8322° F.)
CULTIVATION OF WHEAT IN AMERICA.
At Kingston, New York, the wheat is sown in autumn; ve-
getation suspended through the winter resumes its activity in the
beginning of April, and the harvest takes place about the 1st
of August. The crop is therefore growing during about 122
days under the influence of a mean temperature of 63° F.
(7680º F.)
In the same place Tremois wheat is sown in the beginning of
May, and the harvest takes place towards the 15th of August,
so that it is 106 days on the ground under a mean temperature
of 68° F. (7208° F.)
At Cincinnati the wheat sown in the end of February is
harvested in the 2nd week in July, say the 15th day, the crop
is therefore 137 days on the ground under a mean temperature
of between 60° and 61° F. (8288º F.)
INTERTROPICAL REGION.
Wheat sown at the end of February was reaped on the 25th
of July at Zimijaca, plain of Bogota, having been 147 days on
the ground, the mean temperature being between 58° and
59° F. (8526° F.)
At Quinchuqui the vegetation of wheat begins in February
and ends in the month of July, say 181 days; and I found the
mean temperature to be between 57° and 58° F.
At Venezuela, according to M. Codazzi, wheat to ripen re-
quires 92 days at Turmero, mean temperature between 75.2º and
76° F.; (6918° F.) 100 days at Truxillo, mean temperature
72.1° F. (7210° F.)
CULTIVATION OF BARLEY.
Of all the cereals barley is that which succeeds in the most
diversified climates. It comes to maturity under the burning
656
i
METEOROLOGY.—GROWTH OF PLANTS.
heats of the tropics; and in regions where the mean and con-
stant temperature is scarcely 52° F. fields of barley of great
beauty are still encountered.
At Alsace (Bechelbronn) barley sown at the end of April was
harvested on the 1st. of August. It had remained 92 days on
the ground, the mean temperature having been between 66°
and 67° F.(6118° F.)
Winter barley sown on the 1st of November was cut on the
1st of July. Reckoning the period of active vegetation from
the 1st of March it was 122 days in coming to maturity, the
mean temperature having been between 58° and 59° F.
(7076° F.)
At Alais winter barley is harvested on the 18th of June. As-
suming that as in the case of wheat the 1st of February is the
date of commencing vegetation, it must have taken 137 days to
come to maturity under a mean temperature between 55° and
56° F.
In Egypt upon the banks of the Nile barley is sown in the
end of November, and the harvest takes place at the end of
February, at an interval therefore of 90 days, and the mean
temperature of the winter at Cairo is nearly 70° F. (6300° F.)
At Kingston, North America, the barley is sown in the begin-
ning of May, and the crop is cut towards the beginning of
August in about 92 days, therefore the mean temperature being
between 66° to 67° F.
At Cumbal under the line there is no fixed period for sowing
barley. It is generally put into the ground on the approach of
the rainy season about the 1st of June, and it is then reaped
about the middle of November; it therefore stands on the
ground for about 168 days, and the mean temperature is be-
tween 51° and 52° F.
At Santa Fé de Bogota they reckon about four months be-
tween the barley seed time and harvest, or about 122 days, the
mean temperature being between 58° and 59° F.
CULTIVATION OF MAIZE OR INDIAN CORN.
In the neighbourhood of Bechelbronn the maize which
sprouted on the 1st of June yielded an abundant harvest on the
1st of October, the mean temperature having been 68° F.
METEOROLOGY.—GROWTH OF PLANTS.
657
In South America maize comes to maturity in the course of
three months, say 92 days, the mean temperature being between
81° and 82° F.; but on the elevated plains, as that of Santa
Fé, maize will require six months to come to maturity, say 183
days, and there the mean temperature is 59° F.
CULTIVATION OF THE POTATO.
In 1836 our potatoes at Bechelbronn were put into the ground
on the 1st of May, and the crop was gathered on the 15th of
October, after 157 days therefore, the mean temperature having
been about 65º F.; but in ordinary years when the temperature
is less elevated than that of 1836 the potato crop is generally
gathered at the end of October, after 183 days, the mean tem-
perature having been as before nearly 59° F.
In the neighbourhood of Alais potatoes are planted at the
end of March and taken up about the 1st of September, after
five months or 153 days, the mean temperature of which has
been 70° F.
According to M. Codazzi potatoes are grown near the lake of
Valencia, (Venezuela) in 120 days, and the mean temperature
of Maracaibo near the lake is 78° F.
According to the same observer, the potato still yields good
crops at Merida in the Cordilleras, where the mean tempera-
ture is between 71º and 72° F., and the growth lasts about 4
months.
On the temperate levels of New Granada at Santa Fé I saw
potatoes set in the middle of December immediately after the
rainy season, and the harvest was gathered in the course of the
first week in June, the crop therefore was at least 200 days in
the ground, the mean temperature having been between 58°
and 59° F.
On the occasion of my ascent of the volcanic mountain,
Antisana, I ate on the 4th of August some potatoes which had
just been gathered, and which had been planted in the beginning
of November, so that the crop had been 276 days in the ground,
the mean temperature of the country being 52° Fahr.
superior limit to the cultivation of
They are still grown at Cambugan,
But this is not yet the
potatoes under the equator.
658
METEOROLOGY.-GROWTH OF PLANTS.
the mean temperature of which scarcely exceeds 49° Fahr. the
plant remaining nearly eleven months in the ground, and the
crop being frequently lost from frosts that occur at this great
elevation in the course of the months of November and January.
CULTIVATION OF THE INDIGO PLANT.
In Venezuela, in plantations very near the level of the sea,
the first crop is cut about eighty days after sowing. The mean
temperature is there between 81° and 82° Fahr. In other
countries where the mean temperature ranges between 72° and
74° Fahr. which must be regarded as the limits to the growth
of indigo, the first cutting takes place 3 months or 106 days
after the sowing. In India the first cutting seems generally to
occur about ninety days after the sowing, and the mean tempera-
turc of the two winter months and of the summer months
when the crop is on the round, at Bombay is about 76º Fahr.
I shall terminate this section by calling the attention of vegetable
physiologists to a fact which appears to have escaped them.
It is this: that plants in general, those of tropical countries very
obviously so, spring up, live, and flourish in temperatures that are
nearly the same. In Europe and in North America, an annual
plant is subjected to climateric influences of the greatest diversity.
The cereals, for example, germinate at from 43° to 47° or 48°;
they get through the winter alive, making no progress; but in
the spring they shoot up, and the ear attains maturity at a
season when the temperature which has risen gradually, is some-
what steady at from 74° to 78° Fahr.
In equinoxial countries things pass differently: the germina-
tion, growth and ripening of grain take place under degrees of
heat, which are nearly invariable. At Santa-Fe the thermometer
indicates 79° Fahr. at sccd, as at harvest time. In Europe the
potatoe is planted with the thermometer at from 50° to 54° Fahr.
and it does not ripen until it has had the heats of July and
August. But we have just seen that this plant grows, slowly
indeed, but regularly, in places where the temperature, nearly
invariable, does not rise above 48.2° or 50° Fahr.
Germination, and the evolution of those organs by which
METEOROLOGY.-GROWTH OF PLANTS.
659
vegetables perform their functions in the soil and in the air, take
place at temperatures that vary between 32° and 112° Fahr.;
but the most important epoch in their life, ripening, generally
happens within much smaller limits, and which indicate the
climate best adapted to their cultivation, if not always to their
growth; for the vine grows lustily in many places where its
fruit never ripens. To produce drinkable wine, a vineyard must
have not only a summer and an autumn sufficiently hot; it is
indispensable in addition that at a given period, that namely
which follows the appearance of the seeds, there be a month, the
mean temperature of which does not fall below 19° cent. or
about 661° Fahr., a fact of which conviction may be obtained
from the following table which I borrow from M. de Hum-
boldt:
0
Paris
Berlin
London
Cherbourg
Temperature of
summer
Bordeaux
Frankfort, A. M. 65°
Lausanne
65.2º
64.5°
63.2°
62.9°
61.9°
•
71° Fahr
Temperature
of autumn
58°
50°
49.7°
52.2°
48.0°
51.2º
54.4°
Sugar-cane
Cocoa-nut
Palm
The coco, or chocolate bean
Banana
Indigo
Temperature of
the hottest month.
73.3° F.
very
66.0°
65.8°
66.2º
64.4° Wine scarcely drinkable
63.8° Vine not cultivated.
63.20
In high latitudes the disappearance of vigorous vegetation in
plants may depend quite as much on intensity of winter colds
as on insufficiency of summer heat. The equable climate of
the equatorial regions are therefore much better adapted than
that of Europe to determine the extreme limits of temperature
between which vegetables species of different kinds will attain
to maturity. Thus it has been found that the vine between the
tropics is productive in temperatures that vary from 69° F. to
79° or 80º. I shall terminate with a list of the temperatures
favourable to the particular vegetables in the success of which
man is more especially interested.
Maximum
82° F.
"
>>
})
**
favourable.
•Y
>>
Minimum.
73° F.
64°
71°
71°
78°
78°
TT 3
660
METEOROLOGY.-NIGHT COOLING.
Tobacco
Manihot
Cotton-tree
Maize
Haricots
Orchil
Rice
Calebash
Carica papaya
Pine-apple
Melon
Vanilla
Guaduas
The vine
Coffee
Anis.
Wheat
Barley
Potatoes
Arachaca
•
Flax
Apple
Oak.
·
•
•
+
Maximum.
82° F.
>>
,,
"
"}
"
>>
""
))
""
"
> }
""
79°
79°
770
74°
74°
75° (?)
75°
74°
729
67°
Minimum.
65° F.
72º
67°
59°
59°
72º
75°
72º
66°
68°
67°
770
73°
740
66°
73°
59°
57°
49°
53°
59º
590
61°
IV. COOLING THROUGH THE NIGHT; DEW, RAIN.
When the sky is clear and calm during the night, vegetables cool
down and very soon show a temperature inferior to that of the air
which surrounds them. This property of cooling in such circum-
stances belongs to all bodies; but all do not possess it to the
same degree. Organic substances, for instance, such as wool or
cotton, feathers, &c., radiate powerfully and sink low; polished
metals on the contrary have a very weak emissive or radiating
power; and air and the gases in general radiate still more feebly.
Inasmuch as a body is continually emitting heat its tempera-
ture can only remain stationary so long as it receives from sur-
rounding objects at every instant a quantity of caloric precisely
equal in quantity to that which it loses from its surface.
-
From the moment that these incessant exchanges cease to be
in a state of perfect equality, the temperature of a body varies;
it may even experience a considerable degree of cooling if it is
exposed during a clear night in an open spot. In such circum-
stances, a body gives off towards all the visible parts of the
METEOROLOGY.-NIGHT COOLING.
661
heavens more heat than it receives; for the higher regions of the
atmosphere are excessively cold, a fact which is proved by the
rapid diminution of temperature experienced on ascending
mountains, or by rising into the air in balloons. The internal
temperature of the globe, the tendency of which would be to
compensate the loss experienced by the body which radiates, has
scarcely any effect in lessening the cooling, because it is propa-
gated with extreme slowness, in consequence of the indifferent
conducting powers of the earthy substances of which its crust is
composed. The air, lastly, which surrounds the radiating body,
does not warm it save in the most minute, inappreciable degree,
and rather by its contact than by transmitting to it rays of heat,
for the gases have only very limited emissive powers. It is even
in consequence of the small amount of this power that the
stratum of air in contact with the surface of the ground, does
not by any means sink in the same proportion as the surface
upon which it lies. Thus, in the circumstances which I have
indicated, a thermometer laid upon the ground always indicates
a temperature lower than that which is proclaimed by one sus-
pended in the air; and the difference is by so much the greater
as the radiating power of the bodies exposed is more decided or
as it may take place into a greater extent of the heavens. Every
cause which agitates the air, which disturbs its transparency,
which contracts the extent of the visible sphere, interferes with
nocturnal radiation, and therefore with cooling. A cloud, like
a screen, compensates either in whole or in part according to its
proper temperature, for the loss of heat which a body upon
the surface of the earth experiences in radiating into space.
Wind by continually renewing the air which is in contact with the
surface of bodies tending to cool by radiation, always diminishes
its effect to a certain extent. It is for this reason that a cloudless
sky and a calm atmosphere, when nocturnal radiation attains its
maximum, are most dangerous or injurious to our harvests.
In a night which combines all the conditions favourable to
radiation, a thermometer of small size laid upon the grass will
be found to mark from 10° to 14° or 15° Fahr. below the
temperature of the surrounding atmosphere. Thus in the
temperate zone in Europe as Mr. Daniell has observed, the
662
METEOROLOGY.-NIGHT FROSTS.
temperature of meadows and heaths is liable to fall during ten
months of the year by the mere effect of nocturnal radiation to a
temperature below the freezing point of water; this is particu-
larly apt to happen both in spring and autumn, when the des-
tructive effects of radiation are most to be apprehended, the
nocturnal radiations of those seasons frequently lowering the
temperature several degrees below the freezing point.
A few observations which I made upon nocturnal radiation
at different heights in the Cordilleras, seem to indicate that its
effects there are less decided than in Europe, in consequence
perhaps of the greater quantity of heat acquired by the ground
in the course of the day. It appears that in this mountain
range it rarely freezes at a height less than 6560 feet above the
level of the sea; although there are certain circumstances there
which favour nocturnal radiation so much that it is really im-
possible to indicate any very precise limits. In a general way
it may be said that the crops of those plains which are suf-
ficiently elevated to have a mean temperature of from 50° to 58°
Fahr. are exposed to suffer from frost; it frequently happens
that a crop of wheat, barley, maize, or potatoes, of the richest
appearance, is destroyed in a single night by the effect of radia-
tion. In Europe during the fine nights of April and May,
when the air is calm and the sky clear, buds, leaves, and young
shoots are frequently cut off, are frozen; in a word, although
a thermometer in the air indicates several degrees above the point
of congelation. Market gardeners and others who are much ex-
posed to loss from this cause, ascribe the effect to the light of the
moon of the months of April and May; and they ground their
opinion upon the fact that when the sky is clouded, the destruc-
tive effects of frost are not apparent, although the same tem-
perature of the atmosphere be indicated by the thermometer.
In the lower ranges of the Cordilleras, farmers also ascribe the
same injurious consequences to the light of the moon, with this
difference, that according to them the destructive influence con-
tinues throughout the year; and it is not unworthy of remark
that, in the neighbourhoods of Paris and of London, the mean
temperature of the months of April and May (from 50° to
57°, or 58° F.) represents exactly the invariable climate of those
METEOROLOGY-NIGHT FROSTS.
663
places among the Andes, where the effects of frost upon vege-
tation are particularly to be apprehended. M. Arago has shown,
that the cold ascribed to the light of the moon is nothing but
a consequence of the nocturnal radiation, at a season when the
thermometer in the air is frequently at from 40° to 43° F. and the
sky is clear and calm. At this temperature a plant, radiating into
space, readily falls below the point of congelation, and then the
hopes of the gardener and farmer are destroyed. The pheno-
menon takes place particularly in a bright night and if the
moon happen to be up when it occurs, the influence is as-
cribed by the vulgar to her light. Were the sky clouded, the
principal condition to radiation would be wanting; the tempera-
ture of objects on the surface of the ground would not fall below
that of the surrounding medium, and plants would not freeze
unless the air itself fell to 32º F.
The observation of gardeners, therefore, as M. Arago re-
marks, was not in itself false, it was only incomplete. If the
freezing of the soft and delicate parts of vegetables in circum-
stances when the air is several degrees above the freezing point,
be really due to the escape of caloric into planetary space, it
must happen that a screen placed above a radiating body, so as
to mask a portion of the heavens, will either prevent or at least
diminish the amount of the cooling. And that this takes place
in fact, appears from the beautiful experiments of Dr. Wells. A
thermometer, placed upon a plank of a certain thickness, and
raised about a yard above the ground, occasionally indicates in
clear and calm weather from 6° to 7º or 8° F. less than a second
thermometer attached to the lower surface of the plank. It is
in this way that we explain the use of mats, of layers of straw,
in a word, of all those slight coverings which gardeners are so
careful to supply during the night to delicate plants at certain
seasons of the year. Before men were aware that bodies on the
surface of the ground became colder than the air which sur-
rounds them during a clear night, the rationale of this practice
was not apparent; for it was altogether impossible to conceive
that coverings so slight could protect vegetables from a low tem-
perature of the air.
The means indicated, as simple as they are effectual in
pro-
U U
664
METEOROLOGY-NIGHT FROSTS.
tecting plants in the garden, are rarely applicable in farming,
where the surface to be preserved is always very extensive.
Nevertheless, in severe winters, the frost by penetrating the
ground would frequently destroy the fields sown in autumn, were
it not that in high latitudes the snow which covers the surface
becomes a powerful obstacle to excessive cooling, by acting at
one and the same time as a covering, and as a screen preventing
radiation. As a covering, because snow is one of the worst
of conductors, one of those substances which for a given thickness
opposes the passage of heat most effectually; it is therefore an
obstacle almost insurmountable to the earth beneath it getting
into equilibrium in point of temperature with the atmosphere.
As a screen, because in sheltering the ground it prevents it
from undergoing the cooling which it would not fail to expc-
rience in clear nights by radiation into the open firmament. It
is familiarly known in many parts of Europe, that the accidental
want of the usual covering of snow will cause the loss of the
autumn sown crops of grain.
It is on the surface of the snow
that the great depression of temperature takes place; and the
substance being a very bad conductor, the earth cools in a
much less degree. In the month of February, 1841, I made
some experiments, which show that the snow which covers the
ground acts in the manner of a screen. I had first a thermo-
meter upon the snow, the bulb of the instrument being covered,
by from 0.078 to 0.117 of an inch of snow in powder; second,
a thermometer, the bulb of which was situated completely under
the layer of snow in contact with the ground; third, a thermo-
meter in the open air, at about 37 or 38 feet above the surface,
on the north of a building. The layer of snow was about four
inches in thickness, and had covered a field sown with wheat for
a month. The sun shone brightly upon the field on those days
when my experiments were made.
Feb. 11. Five o'clock in the evening; the sun has been
hidden by the mountains for half an hour; the sky is unclouded,
the air very calm thermometer under the snow,
32° F.;
thermometer upon the snow, 29° F.; thermometer in the
air, 36.3° F.
:
Feb. 12. The night very fine, no clouds, the air calm. At
METEOROLOGY-NIGHT FROSTS.
665
seven o'clock in the morning the sun is not yet upon the field:
thermometer under the snow, 26.2° F.; thermometer upon the
snow, 10° F.; thermometer in the air, 26.3° F.
At half-past five in the evening, the sun behind the moun-
tains thermometer under the snow, 32° F.; thermometer upon
the snow, 29° F.; thermometer in the air, 37.5° F.
Feb. 13. At seven in the morning; the sky grey, the air
slightly in motion: thermometer under the snow, 28° F.; ther-
mometer upon the snow, 17° F.; thermometer in the air, 25° F.
At half-past five in the evening; the air calm, the sky cloud-
less, the sun already concealed for some time: thermometer
under the snow, 32° F.; thermometer upon the snow, 30° F.;
thermometer in the air, 40° F.
-
Feb. 14. Seven in the morning, wind W., a fine rain falling:
thermometer under the snow, 32° F.; thermometer upon the
snow, 32° F.; thermometer in the air, 35.7° F.
When we reflect upon the losses occasioned to farmers and
market gardeners by frosts that are entirely due to nocturnal
radiation at seasons of the year when vegetation has already
made considerable progress, we ask eagerly if there be no pos-
sible means of guarding against them. I shall here make known
a method imagined and successfully followed by South American
agriculturists with this view. The natives of the upper country
in Peru who inhabit the elevated plains of Cusco are perhaps
more than any other people accustomed to see their harvest de-
stroyed by the effects of nocturnal radiation. The Incas appear
to have ascertained the conditions under which frost during the
night was most to be apprehended. They had observed that it
only froze when the night was clear and the air calm: knowing
consequently that the presence of clouds prevented frost, they
contrived to make as it were artificial clouds to preserve their
fields against the cold. When the evening led them to appre-
hend a frost, that is to say when the stars shone with brilliancy,
and the air was still, the Indians set fire to a heap of wet straw
or dung, and by this means raised a cloud of smoke, and so de-
stroyed the transparency of the atmosphere from which they had
so much to apprehend. It is easy in fact to conceive that the
transparency of the air can readily be destroyed by raising a
UU 2
666
METEOROLOGY-DEW.
smoke in calm weather; it would be otherwise were there any
wind stirring; but then the precaution itself becomes unnecessary,
for with air in motion, with a breeze blowing there is no reason
to apprehend frost from nocturnal radiation.
The practice followed by the Indians just described is men-
tioned by the Inca Garcillaso de la Vega in his Royal Commen-
taries of Peru. Garcillaso in the imperial city of Cusca and
in his youth had frequently seen the Indians raise a smoke to
preserve the fields of maize from the frost.*
The cooling of bodies occasioned by nocturnal radiation
is always accompanied by a deposit of moisture upon their sur-
face under the form of minute globules: this is dew. The
ingenious experiments of Wells having demonstrated that the
appearance of dew always follows, never precedes the fall in tem-
perature of the bodies on which it is deposited, the phenomenon
cannot be attributed to anything more than a simple condensa-
tion of the watery vapour contained in the air, comparable in all
respects to that which takes place upon the surface of a vessel
containing a fluid that is colder than the air. The quantity
of moisture dissolved in the atmosphere is by so much the
greater as the temperature is higher. In very warm climates
the dew is so copious as to assist vegetation essentially, supplying
the place of rain during a great part of the year.
+
According to some meteorologists dew is most copious near
the sea board of a country; very little falls in the interior of
great continents, and indeed is said only to be apparent in
the vicinity of lakes and rivers. I cannot agree in any statement
of this kind made so absolutely. I have never had occasion
to see more copious dews than those which occasionally fall in
the steppes of San Martin to the east of the eastern Cordilleras,
and at a very great distance from the sea; the dew was so copious
that for several nights I found it impossible to employ an
artificial horizon of black glass in order to take the meridian
altitude of the stars; the moment the apparatus was ex-
* The good effects of smoke in preventing nocturnal congelation are
also signalized by Pliny the naturalist.
† Arago, Annuaire des Longitudes, Année 1837, p. 160.
‡ Kaemtz Meteorology, translated by W. Walker, London, 1844.
METEOROLOGY-Dew.
667
posed there was such a quantity of water deposited on the sur-
I found
face that it soon gathered into drops and trickled off.
it necessary to have recourse to mercury to reflect the star under
observation. During the clear, calm nights the turf of these
immense plains receives a considerable quantity of moisture in
the form of dew, which materially assists vegetation and by its
evaporation tempers the excessive heat of the ensuing day. In
tropical countries, the forests contribute to keep down the tem-
perature. In very hot countries it is rare to be out in a cleared
spot, when the night is favourable to radiation, without hearing
drops of water, produced by the copiousness of the dew, falling
continually from the surrounding trees, so that forests contribute
further to produce and to maintain springs by acting as con-
densers of the watery vapour dissolved in the air. I might cite
a number of observations upon this point which I made in the
forest of Cauca. In the bivouac between the 4th and 5th of July,
1827, the night was magnificent; nevertheless in the forest
which began at the distance of a few yards from our encamp-
ment, it rained abundantly; by the light of the unclouded moon
we could see the water running from the branches.
It is possible that the transpiration from the green parts of
the trees might have been added to the dew condensed, and so
increased the intensity of the phenomenon which I have described;
but I rather incline to believe that the cooling of the leaves by
way of radiation had by far the larger share in the production
of this dew rain. It is true that of all the leaves which form the
crown of a tree, those whose surface is exposed and radiate freely
into space intercept, as would a screen, the radiation of the leaves
and branches which are not so exposed; but as M. de Humboldt
has observed, if the leaves and branches which crown a tree cool
directly by emission, those which are situated immediately be-
neath them by radiating towards the lower parts of the leaves
which are already cooled a greater quantity of heat than they
receive, their temperature will also necessarily fall, and the cool-
ing will thus be propagated from above downwards until the
whole mass of the tree feels its effects. It is thus that the
ambient air circulating through the leaves becomes cooled
during bright nights, and to judge from the influence which
668
METEOROLOGY-RAIN.
forests exert in lowering the temperature of a country, it is
enough to recollect with M. de Humboldt that by reason of the
vast multiplicity of leaves, a tree, the crown of which does not
present a horizontal section of more than about 120 or 130
square feet, actually influences the cooling of the atmosphere by
an extent of surface several thousand times more extensive than
this section.
The proportion of watery vapour which a gas will retain in
solution is by so much the more as the temperature of the air
is higher. All the causes which cool air saturated with watery
vapour occasion, as we have already seen, the precipitation of a
certain quantity of moisture.
When this condensation takes place in the midst of a gaseous
mass the precipitated water collects into small floating vesicles,
which trouble the transparency of the medium that momenta-
rily hold them in suspensions. Mists, fogs and clouds are col-
lections of these vesicles; a fog, as a celebrated naturalist said, is
a cloud in which one is, and a cloud is a fog in which one is not.
The vesicles of clouds tend towards the earth, like all heavy
bodies, but by reason of their specific lightness the resistance of
the air which they displace lessens the rapidity of their descent.
When they are of larger size they coalesce and form drops of
water which fall with greater celerity. When these drops pass
through strata of very dry air they undergo partial evaporation,
and this is the reason wherefore there is sometimes less rain upon
plains than upon mountains. In opposite circumstances it is
the inverse phenomenon that is observed; the drops increase in
size in passing through the inferior strata of an atmosphere
saturated with moisture condensing vapour in their course.
This is what happens most generally.
In taking a survey of a large amount of observations, metco-
rologists have inferred that the annual quantity of rain varies.
with the latitude; that, greatest at the equator, it gradually
lessens as higher northern and southern latitudes are attained;
this is as much as saying that the quantity of rain is greater
as the temperature of the climate is higher. But to this rule
there are numerous exceptions; for instance, under the line at
Payta on the sea coast it only rains very rarely; a shower of
METEOROLOGY-RAIN.
669
rain is an event; and when I visited the country eighteen years
had elapsed since they had had anything of a fall of rain. Lo-
cal causes have the greatest influence upon the fall of rain, so
that countries on the same parallel of latitude are far from being
equally distinguished by dryness or humidity.
It is believed that in Europe it rains more heavily and more
frequently in the day than in the night. In the equinoxial regions,
at least in those parts that I have visited, it would seem that
the opposite rule held good. Every one in South America al-
lows that it rains principally during the night, and the observa-
tions which I made in the neighbourhood of Marmato enable
me to state that of 7.874 inches, of rain which fell in the
month of October, 1.336 inches fell in the day, 5.738 inches
in the night; of 8.881 inches which fell in the month of
November 0.707 inches came down in the day, 8.174 inches
in the night; of 5.934 inches which fell in December 0.786
inches fell in the day, 5.148 inches in the night.
Two series of observations taken in the same country at two
stations not far from one another, but situated at very different
elevations, seem to confirm in reference to the equatorial regions
the conclusions of European meteorologists as to the fact that the
annual quantity of rain which falls diminishes as the height
above the level of the sea increases. They also show that in
latitudes which do not differ materially, more rain falls where the
mean temperature is 68° F. than where it is 58° F.
Marmato lies in N. lat. 5° 27", and 75° 11" (?) W. long. at a
height of 4676 feet above the level of the sea; Santa Fé in
N. lat. 4º 36", W. long. 75° 6" at a height of 8692 feet above
the level of the sea. And whilst the quantity of rain at the
former place amounted according to my own observations for
1833 to 60 inches, according to Caldas in 1807 at the latter
there fell but 39.4 inches.
In temperate climates the quantity of rain that falls varies
with the seasons. Near the equator, where the temperature re-
mains constant throughout the year, the rainy season commences
precisely at the period when the sun approaches the zenith, and
whenever the latitude of a place in the torrid zone where it rains
is of the same denomination and equal to the declination of the
sun, storms occur. In such circumstances the sky in the morn-
670
METEOROLOGY -THUNDER STORMS.
ing is of remarkable purity, the air is calm, the heat of the sun
insupportable. Towards noon clouds begin to show them-
selves upon the horizon, the hygrometer does not advance to-
wards dryness as it usually does, it remains stationary, or even
falls towards extreme humidity. It is always after the sun has
passed the meridian that the thunder is heard, which being
preceded by a light wind is soon followed by a deluge of rain.
In my opinion the permanence or incessant renovation of storms
in the bosom of the atmosphere is a capital fact, and is connected
with one of the most important questions in the physics of our
globe, that of the fixation of the azote of the air by organized
beings.
The most recent inquiries show dry atmospherical air to con-
sist in volume of:
Oxygen
Azote
20.8
79.2
The air contains in addition from 2 to 5/10,000ths of car-
bonic acid gas, and quantities perhaps still smaller of carburetted
combustible gas. The experiments of M. Theodore de Saussure,
as well as those of Professor Liebig, have further demonstrated
in it traces of ammoniacal vapour.
I have already shown that animals do not directly assimilate
the azote of the atmosphere. Azote is nevertheless an element
essential to the constitution of every living being, and is met
with indifferently in either kingdom of nature. If we inquire
into the source of this principle in connexion with the herbivo-
rous tribes of animals, we find it as an element in the food which
sustains them. If we next inquire into the immediate origin of
the azote which enters into the constitution of vegetables, it is
discovered in the manure which proceeds more especially from
animal remains; for vegetables, to thrive, must receive azotised
aliment by their roots. We thus come to apprehend that plants
supply animals with their azote, and that these restore it to
plants when the term of their existence is accomplished; we are
led to discover, in a word, that living organic matter derives its
azote from dead organic matter.
This view leads us to conclude that the amount of living mat-
ter on the surface of the globe is restricted; that its limits are
METEOROLOGY-THUNDER STORMS.
671
in some sort determined by the quantity of azote in circulation
among organized beings; but the question must be viewed
from a loftier eminence, and we must ask what is the origin of
the azote which enters into the constitution of organic matter
considered as a whole?
If we now turn to the possible sources or magazines of azote,
we shall find, setting aside organized beings and their remains,
that there is in truth but one, the atmosphere. It is, therefore,
extremely probable that all living beings have previously ob-
tained their azote from the atmosphere, just as it seems very
certain that they have thence derived their carbon.*
The most reasonable supposition in the actual state of science,
is to consider the ammoniacal vapours diffused through the
atmosphere as the prime source of the azotised principles of
vegetables, and then through them of animals; a consequence
of which hypothesis would be to assume with Liebig, that car-
bonate of ammonia existed in the atmosphere before the appear-
ance of living things upon the face of the earth.
The phenomena and effects of thunder-storms appear to me
calculated to support this opinion. It is known, in fact, that so
often as a succession of electrical sparks passes through moist
air, there is formation and combination of nitric acid and ammo-
nia. Now nitrate of ammonia is one of the constant ingredients in
the rain of thunder-storms. But nitrate of ammonia being a
fixed salt, cannot exist in the atmosphere in the state of gas or
vapour; and then it is not the nitrate, but the carbonate of
ammonia that has been signalized in the air. In bringing to
mind the scries of reactions of which I have spoken, it is not
difficult to perceive how the nitrate of ammonia, precipitated in
thunder showers, and thus brought into contact with calcareous
rocks should suffer decomposition, pass into the state of car-
bonate on the return of fair weather, and become fitted to
undergo diffusion in the state of vapour through the atmosphere.
We should in this way be led to regard the electrical agency, the
flash of lightning, as the means by which the azote of the atmo-
sphere is made fit for assimilation by organized beings. In
Europe, where thunder-storms are rare, an office of so much
* Boussingault, Annales de Chimie, t. LXXI, 1839.
672
METEOROLOGY-RAIN.
importance will perhaps be accorded reluctantly to the electricity
of the clouds; but in tropical countries, no difficulty would
probably be felt on the matter. In the torrid zone, thunder-
storms happen in one place or another not only every day, but
every hour, and even every minute of every hour throughout the
year; so that an observer, placed at the equator, were he
endowed with organs of sufficient delicacy, would never lose the
roll of the thunder.
As the equator is quitted, the times at which rain falls
become less specific or periodical. Under the tropics, the rains
of thunder-storms, which are always the most copious, fall while
the sun is in the neighbourhood of the zenith. In the northern
hemisphere, the greatest quantity of rain falls during winter, and
at places somewhat far south on the temperate zone, the sum-
mer rain is altogether insignificant. In assuming the number
100 to express the whole annual quantity of rain we should
have in
Winter
Spring
Summer
Autumn
·
•
Winter
Spring
Summer
Autumn
In the west of
England
26
20
23
31
Less rain falls in the eastern parts of Europe than in the
western. The annual rain, too, is distributed very unequally
over the different seasons, as has been shown by Mr. Gasparin
in a remarkable paper. If we express by 100 the quantity of
rain gauged in a year, we should have for each season:
St. Petersburg.
Madeira.
51
16
3
30
West of
France.
23
13
25
34
Lisbon.
40
34
18
22
37
23
3
23
East of Germany
France.
20
23
29
28
14
18
37
30
The quantity of rain which falls in the course of a year varies
considerably according to the climate; to form an idea of the
extent of these variations, it is enough to notice the results
obtained at different observatories; but it is less the annual
quantity of rain that falls, than the way or quantities in which it
is distributed over the different months of the year which
INFLUENCE OF AGRICULTURE ON CLIMATE.
673
interests the farmer; upon this distribution in fact in many
districts, depends the productiveness and fertility of the soil. I
add a table of the mean quantities of rain in inches and 10ths,
that fall at London in the different months of the year:
in.
1.45
Jan. Feb. March. April. May. June. July. Aug. Sept. Oct. Nov. Dec.
in.
in.
in.
in.
in.
1.29
in.
1.61
ia.
in.
2.39 1.80 1.84 2.03 2.20 1.72
in.
1.25
in.
1.17
in.
1.72
Sv. ON THE INFLUENCE OF AGRICULTURAL LABOURS ON THE CLIMATE
OF A COUNTRY IN LESSENING STREAMS, ETC.
A question of great importance and that is frequently agitated
at this time is, as to whether the agricultural labours of man are
influential in modifying the climate of a country or not? Do
extensive clearings of woods, the draining and drying up of
great swamps, which certainly influence the distribution of heat
during the different seasons of the year, also exert an influence
on the quantity of running water of a country, whether by
lessening the quantity of rain which falls, or by promoting the
more speedy evaporation of that which has fallen?
In some districts it has been held that the streams which
had been used as moving powers, have very sensibly diminished.
In other places the rivers are said to have shrunk visibly; and
in others, springs that were formerly abundant, have almost dried
up. Observations to this effect appear to have been principally
made in valleys surmounted by mountains, and it is generally
asserted that the falling off in the springs and streams had fol-
lowed close upon the period at which the woods scattered over
the surface of the country were cleared away without any kind
of reserve.
These statements, which may be assumed as facts, seem to
indicate that where the woods have been filled, it rains less than
it did formerly; this, indeed, is the general opinion entertained
on the subject; and were it admitted without further examina-
tion, the natural inference from it would be that the extension of
agriculture diminishes the annual quantity of rain which falls in
a country. But at the same time that the facts as stated have
been observed it has further been noticed that since the clearing
of the surface from forests, the torrents and rivers which
seemed to have lost in amount of regular supply of water, had
674
INFLUENCE OF AGRICULTURE ON CLIMATE.
become subject to sudden and extraordinary risings which had
proved the cause of numerous and grave calamities. In the
same way, springs that are generally all but dry, have been seen
to burst forth again abundantly after violent storms. These
latter observations, as may readily be imagined, are of a kind
that should lead us not lightly to embrace the vulgar opinion,
which maintains that the cutting down of the woods has had
the effect of lessening the mean annual quantity of rain: it is
not only not impossible that this quantity has not varied, but it
may even happen that the mass of water which passes over the
bed of a stream, supposed shrunken, is actually the same as ever
it was; the only difference may be, that now the flow is much less
regular than it used to be in former times the bed was always,
and more moderately full; at present it is excessively full, at
intervals only. It is very possible, therefore, that here as else-
where, occasionally, the appearance of the fact has been taken
for the reality. It were very important to discover some natural
index to a solution of the question at issue: whether or not the
destruction of the forests that once covered the face of a district
of country had had the effect of lessening the mean annual
fall of rain?
The lakes which are met with in plains and at different levels
in mountain ranges, seem to me peculiarly well calculated to
throw light on this subject. Lakes may, in fact, be received as
natural gauges of the running waters of a country. If the mass
of the water contained in the lakes undergo change in one
direction or another, it is obvious that this change and the direc-
tion in which it has occurred will be proclaimed by the state of
mean level of the lake or lakes, which will differ for the same
reason that it does at different seasons of the year, viz.: as
drought or rain prevails. The mean level of the lake or lakes of
a district will therefore fall if the quantity of water which flows
through that district diminishes; the level, on the contrary,
will rise if its streams increase; and it will remain stationary if
the afflux and efflux of the lake continue unchanged. In the
following remarks I shall attach myself particularly to observa-
tions upon lakes which have no outlet, by reason of the facility
with which any even slight change in the level of these must be dis-
INFLUENCE OF AGRICULTURE ON CLIMATE.
675
covered. I shall not, however, neglect those lakes which have an
exit by a stream or canal, because I believe that the study of
these may also lead to accurate enough results; the only point
requiring preliminary remark is the sense in which the words,
change of level, are to be taken.
Geologists admit that the level of the waters upon the surface
of the globe has everywhere undergone great changes, whether at-
tention be directed to the shores of the sea or to those of great
inland lakes. This fact is universal, and is questioned by none,
but great diversity of opinion prevails in regard to the cause of
the phenomenon. Some pretend that in many cases the change of
level is only apparent, that the body of water has not sunk, but
that the shores have risen; others, again, maintain that there
has been a true diminution in the mass of fluid, a true drying
up, and that its level has actually sunk. I shall not in this
place enter upon the great geological question; the variations
which are there signalized are often of vast extent, and involve
the supposition of violent catastrophes, which, in a general way,
were long anterior to the historical epoch. I shall only refer
to changes of level observed in lakes by our ancestors or con-
temporaries; in a word, to facts which have taken place under
the eyes of men, inasmuch as it is the influence of their agricul-
tural labours upon the meteorological state of the atmosphere,
which I am seeking to appreciate. The facts upon which I
shall more particularly dwell were observed in South America;
but I shall show that what is true with regard to this continent,
is true also with reference to any other continent.
C
One of the most interesting portions of Venezuela is un-
doubtedly the valley d'Aragua. Situated at a short distance
from the seaboard, possessed of a warm climate, and of a soil
fertile beyond example, it combines within itself all the varieties
of agriculture that belong in particular to tropical regions; on the
hillocks which rise in the bottom of the valley are seen fields
which bring to mind the agriculture of Europe. Wheat suc-
ceeds pretty well upon the heights which surround La Vittoria.
Bounded on the north by a chain of hills which run parallel
with the seaboard, and to the south by the range which sepa-
rates it from Llanos, the Aragua Valley is limited on the east
676
INFLUENCE OF AGRICULTURE ON CLIMATE.
and west by a series of lesser elevations, which shut it in com-
pletely. In consequence of this peculiar configuration of
country, the rivers which rise in its interior have no outlet to the
ocean; their waters accumulate in the lowest part of the valley,
and form the beautiful lake Valentia. This lake, which M. de
Humboldt says exceeds the Lake Neufchâtel in size, is raised
about 1300 feet above the level of the sea; it is about ten leagues
in length, and about two leagues and a half where it is widest.
At the time when M. de Humboldt visited the Aragua Valley,
the inhabitants were struck with the gradual diminution which
had been going on in the waters of the lake during the last
thirty years. It was enough to compare the statements of older
writers with its condition at this time, to obtain conviction that
the waters had in fact very much diminished. Oviedo, for
instance, who visited the valley frequently towards the end of
the sixteenth century, says that the town of New Valencia was
founded in 1555, at the distance of half a league from the lake;
in 1800, M. de Humboldt ascertained that the lake was upwards
of 5749 yards, or, upwards of 34 miles instead of about 14 mile
from its banks.
The appearance of the surface also gives new proof of the
fact of the recession of the water; certain hillocks which rise in
the plain still preserve the title of islands, which undoubtedly
they formerly received with propriety, when they were sur-
rounded by water. The land which had been left by the retreat
of the lake soon became transformed into beautiful plantations of
cotton-trees, bananas, and sugar-canes. Buildings which had
been erected on the banks were left year after year farther and
farther from them. In 1796, new islets made their appearance.
An important military position, a fortress built in 1740, in the
Isle de la Cabrera, was then upon a peninsula. Finally, in two
islets of granite, M. de Humboldt discovered, several yards
above the level of the lake, a bed of fine sand, mixed with fresh
water shells. These facts, so certain, so unquestionable, did
not pass without numerous explanations from the wise men
of the country, who as if by common consent, fixed upon a sub-
terranean exit for the waters of the lake. M. de Humboldt,
after the most careful examination of all the circumstances, did
INFLUENCE OF AGRICULTURE ON CLIMATE.
677
not hesitate to ascribe the diminution of the waters of the Lake
Valencia to the extensive clearings which had been effected in
the course of half a century in the Aragua Valley. "In felling
the trees which covered the crowns and slopes of the moun-
tains," says this celebrated traveller, "men in all climates seem
to be bringing upon future generations two calamities at once,
a want of fuel and a scarcity of water.*
In the year 1800, the population of this favoured valley
where the cultivation of indigo, of cotton, of cocoa, and the cane
had made immense progress, was as dense as it was in the most
thickly populated districts of England or France, and every one
was delighted with the appearance of comfort that prevailed in
the numerous villages of this industrious country.
Twenty-five years after M. de Humboldt, I explored in my
turn the Valley d'Aragua, having fixed my residence in the
little town of Maracaibo. The inhabitants had now remarked.
that for several years not only had the lake ceased to diminish,
but that it had even risen very perceptibly. Some fields that were
formerly covere l with cotton plantations were now submerged.
The Isles de las Nuevas Aparacidas, which had risen from the
waters in 1796, had again become shoals dangerous to naviga-
tion; the tongue of earth, De la Cabrera, on the north side of
the valley had become so narrow, that the slightest rise in the
water of the lake covered it completely; a continuous N.E wind
was sufficient to flood the road which led from Maracaibo to
New Valencia; in short, the fears which the inhabitants of the
lake had entertained for so long a period had entirely changed
their nature; they were now no longer afraid of the lake drying
up; they saw with dismay that if the water continued to rise as
it had done lately, it would in no long space of time have
drowned some of the most valuable estates, &c. Those who
had explained the diminution of the lake by supposing subter-
raneous canals, now hastened to close them up in order to
find a cause for the rise in the level of the water.
In the course of the last twenty-two years, important political
events had transpired. Venezuela no longer belonged to Spain;
* Humboldt, vol. v, p. 173.
678
INFLUENCE OF AGRICULTURE ON CLIMATE.
the peaceful valley d'Aragua had been the theatre of many
a bloody contest; war to the knife had desolated this beautiful
country and decimated its inhabitants. On the first cry of inde-
pendence raised, a great number of slaves found freedom by
enlisting under the banners of the new republic; agricultural
operations of any extent were abandoned, and the forest, which
makes such rapid progress in the tropics, had soon regained
possession of the surface which man had won from it by
something like a century of sustained and painful toil. With
the increasing prosperity of the valley, many of the principal
tributaries to the lake had been turned aside to serve as means of
irrigation, so that the beds of some of the rivers were absolutely
dry for more than six months in the year. At the period which I
now refer to, the water was no longer used in this way, and the
beds of the rivers were full. Thus with the growth of agricul-
tural industry in the valley d'Aragua, when the extent of cleared
surface was continually on the increase, and when great farming
establishments were multiplied, the level of the water sunk; but
by and bye, during a period of disasters, happily passing in their
nature, the process of clearing is arrested, the lands formerly
won from the forest are in part restored to it, and then the
waters first cease to fall in their level, and by and by show an un-
equivocal disposition to rise.
I shall now, without however quitting America, carry my
readers into a district where the climate is analogous to that
of Europe, where the surface is occupied by immense fields,
covered with the cereals as with us. I speak of the table lands
of New Granada, of those valleys raised from 10,000 to 13,000
and 14,000 feet above the level of the sea, in which the mean
temperature throughout the year ranges from 58° to about 62°
Fahr. Lakes are frequent in the Cordilleras; and it would be
easy for me to describe a great number; I shall, however,
confine myself to those which became subjects of observation in
former times.
The village of Ubaté is now situated in the neighbourhood of
two lakes. Some seventy years ago these two lakes formed but
one; the old inhabitants saw the water shrinking and new fields
presenting themselves year after year. At this present time
INFLUENCE OF AGRICULTURE ON CLIMATE.
679
fields of wheat of extraordinary luxuriance occupy levels that
were completely inundated thirty years ago.
It is enough indeed to perambulate the neighbourhood of
Ubaté to consult the old sportsmen of the country, and to refer
to the annals of the various parishes, to be satisfied that exten-
sive forests have been cut down in the whole of the surround-
ing country; the clearing, in fact, still continues; and it is
certain that the recession of the waters, although much slower
than it was in former times, has not yet entirely ceased.
A lake, situated in the same valley, to the east of Ubaté,
deserves our particular attention. By means of barometric
measurements, made with extreme care, I found that this lake
had precisely the same level as that of Ubaté. Nearly two
centuries ago, it was visited by Piedrahita, Bishop of Panama,
an author of great accuracy, to whom we owe the history of the
conquest of New Grenada. He states this lake to be ten
leagues in length, by three leagues in breadth; but Dr. Roulin
having had occasion, a few years ago, to make a plan of the
lake, he found it a league and a half in length, by one league
in breadth; my own impression is, that at the time Piedrahita
wrote, there was but a single lake extending all the way from
Ubaté to Zimijaca, not two lakes as at present, a supposition
which would take away everything like exaggeration from the
statement of Piedrahita. But the fact of the retreat of the
waters of these lakes is unquestioned; the inhabitants of
Zimijaca all know that the village was founded close to the lake,
whereas, at the present time it is nearly a league from its banks.
Formerly, there was no difficulty in obtaining all the building
timber that was wanted; the mountains which rose from the
valley on either hand were covered up to a certain height with
the trees proper to these cold regions; the oak of the Andes
abounded; numerous myricas were also in existence, from which
abundance of wax was obtained: at the present time these
mountains are almost stripped of their trees, an event mainly
brought about by the eagerness to procure fuel in manufacturing
salt from the springs of Taosa and Enemocon.
To these authentic facts, which I could multiply and support
by many others of a similar kind, it may be replied, that the
X X
680
INFLUENCE OF AGRICULTURE ON CLIMATE.
diminution of the water, incontestible as it is, might perhaps
have taken place without the clearing away of the forests. It
may indeed be maintained, that the drying up of the waters is
owing to a totally different cause, altogether unknown to us;
that it must be ranked among the numerous phenomena, the
reality of which we perceive, but without being able to render
any account of their cause.
I cannot, in the instance last quoted, as in that of the Lake
of Valencia, refer to any increase of the lake connected with
the suspension of agriculture, or the re-appearance of the forest.
I might, however, adduce in favour of the opinion which I de-
fend, the slowness with which the decrease in the lakes of the
valley of Ubaté has lately gone on, and since the felling of trees
in the neighbourhood has almost entirely ceased. Extensive plots
of fertile ground are now no longer left dry and available to the
husbandman by the retreat of the lake; he already begins to think
of means for obtaining by artifice that which nature, assisted
by the clearing of the country, presented him with in former
times. In the year 1826 there was a speculation on foot for
draining the valley completely by cutting a canal and letting off
the water. Further proof of the fact which I am urging is ob-
tained in another way. It is not difficult to show, that lakes in
the immediate vicinity of those that have shrunk most remark-
ably, but around which no destruction of the forest has taken
place, have undergone no change in their level. The Lake of
Tota, situated at no great distance from the Valley of Ubaté, at
an elevation that must approach 13,000 feet above the level of
the sea, in a region where vegetation has almost entirely disap-
peared, has preserved its pristine level unaltered. The lake is
nearly circular; and Piedrahita, in 1542, gives it two leagues.
in breadth. It is subject to violent storms, which render its
navigation dangerous; and even travelling along its banks, from
the particular circumstances in which the road is situated, with
the lake on one hand and a perpendicular cliff upon the other,
is not without risk. In 1652, the road passed as it does at pre-
sent, the water laving the foot of the same rocks, and its level
having suffered no change, any more than the sterile country
which surrounds it.
INFLUENCE OF AGRICULTURE ON CLIMATE.
681
I shall conclude what I have to say on the lakes of South
America by speaking of that of Quilatoa, because it has been
made the subject of accurate observations sufficiently remote from
one another-1740 and 1831.
Living at Latacunga, a town situated at no great distance from
Cotopaxi, the traveller is sure to hear of the wonders of the La-
guna da Quilatoa. From time to time this lake, it is said, casts
forth flames which set fire to the shrubs and withered grass that
grow upon its banks, and frequent detonations are heard, the sound
of which extends to a great distance. M. de la Condamine, in
1738,visited this lake, which he found of a circular form, and about
1278 feet in diameter; on the 28th November, 1831, I also
visited the Lake of Quilatoa. It cannot be better compared to
anything than to the crater of a volcano filled with water; I found
it nearly 13,000 feet above the level of the sea, in the cold
region, therefore; and indeed it is surrounded with immense
pastures; but the information which I obtained from the shep-
herds in the neighbourhood of the Lake of Quilatoa, dissipated
all that was marvellous in its history; they had never seen any
flames issue from its bosom, they had never heard any detona-
tions; in short, I found the lake, as M. de la Condamine appears
to have found it, everything having remained for nearly a cen-
tury without change.
The study of the lakes, which are so common in Asia, would
probably supply conclusions similar to those deduced from obser-
vations made in South America, viz., that the waters which
irrigate a country diminish as the forests are cleared away, and
as agriculture extends. The recent labours of M. de Humboldt,
which have thrown so much new light upon this quarter of the
world, appear to leave no doubt upon the subject. After having
shown that the system of the Altai is about to lose itself by
a succession of slopes in the steppes of Kirgiz, and that con-
sequently the Ural chain is not connected with that of the Altai
as was generally believed, this celebrated geographer shows,
that precisely in the situation where the Alghinic mountains.
are usually set down, a remarkable region of lakes commences,
which extend into the plains that are traversed by the Ichim,
XX 2
682
INFLUENCE OF AGRICULTURE ON CLIMATE.
the Omsk, and the Obi.* It would appear that these numerous
lakes are remainders as it were of an immense sheet of water,
which formerly covered the whole of the country, and which
had become divided into so many particular lakes by the confi-
guration of the surface. In crossing the steppe of Baraba, in his
way from Tobolsk to Baraoul, M. de Humboldt perceived every-
where that the drying up of waters increases rapidly under the
influence of the cultivation of the soil.
Europe also possesses its lakes; and we have still to examine
them from the particular point of view which engages us. M. de
Saussure, in his first inquiries in regard to the temperature of
the lakes of Switzerland, examined those which are situated at
the foot of the first line of the Jura. The Lake of Neufchâtel is
eight leagues in length, and its greatest breadth does not exceed
two leagues. On visiting it, Saussure was struck with the ex-
tent which this lake must formerly have possessed; for, as he
says, the extensive level and marshy meadows which terminate
it on the south-west, had unquestionably been covered with
water at a former period.
The Lake of Bienne is three leagues long and one broad; it
is separated from the Lake of Neufchâtel by a succession of
plains that were probably inundated.
Lake Morat is also separated from the Lake of Neufchâtel by
low and level marshes, which beyond all question were formerly
submerged. Unquestionably, adds Saussure, the three great
lakes of Neufchâtel, Bienne, and Morat, were formerly con-
nected, and formed one great sheet of water.†
In Switzerland, as in America and Asia, the old lakes, those
that may be spoken of under the title of the primitive lakes,
and which occupied the bottoms of the valleys when the country
was uncultivated and wild, have become divided, and now form
a variable number of smaller and independent lakes. I shall
wind up the present subject by referring to the observations of
Saussure upon the Lake of Geneva, which may be looked upon
as the starting point of the admirable works of this distin-
guished philosopher.
* Humboldt, Fragmens Asiatiques, t. 1, p. 40-50.
Saussure, Voyage dans les Alpes, t. 11, chap. 6.
INFLUENCE OF AGRICULTURE ON CLIMATE.
683
Saussure admits, that at an epoch long anterior to the times
of history, the mountains which surround this lake were them-
selves submerged; a great catastrophe let off this immense
collection of water, and by and by the current possessed no more
than the bottom of the valley; the Lake of Geneva was
formed.
In merely considering the monuments left by man, it is im-
possible to doubt that within 1200 or 1300 years the waters of
the Lake of Geneva have gradually fallen in their level. It is
evidently upon the levels which have thus been left, that the
quarter de Rive, and the lower streets of the city of Geneva have
been built. This depression of the surface, continues Saussure,
is not merely the effect of any deepening of the bed of the Rhone,
by which the lake is discharged, it has also been produced by a
diminution in the quantity of water which flows into it.
The conclusions which it seems legitimate to draw from the
observations of Saussure are, that in the course of from 1200
to 1300 years the quantity of running water has sensibly
diminished in the districts around the Lake of Geneva. No
one will, I apprehend, deny that in this long period there have
not been extensive clearings of forest lands in Switzerland, and a
continual increase in the extent of cultivated field within this
beautiful country. Here consequently, as elsewhere, an attentive
examination of the levels of the lakes leads us to conclude, that
where extensive clearings from forest have been effected, where
agriculture has extended, that there has in all probability been
diminution of the running waters which irrigate the surface;
whilst in those districts where no change has been effected, the
amount of running stream does not appear to have undergone
any variation.
The effect of forests considered in this point of view would
therefore be to keep up the amount of the waters which are
destined for mills and canals; and next to prevent the rain-
water from collecting and flowing away with too great rapidity.
That a soil covered with trees is further less favourable to evapo-
ration than ground that has been cleared, is a truth that all will
probably admit without discussion. To be aware that it is so,
it is enough to have travelled, some short time after the rainy
684
INFLUENCE OF AGRICULTURE ON CLIMATE.
season, upon a road which traverses in succession a country
that is free from forests, and one that is thickly wooded.
Those
parts of the road that pass through the unencumbered country
are found hard and dry, whilst those that traverse the wooded
districts are wet, muddy, and often scarcely passable. In South
America, more perhaps than anywhere else, does the obstacle to
evaporation from a soil thickly shaded with forests strike the
traveller. In the forests the humidity is constant, it exists long
after the rainy season has passed; and the roads that are opened
through them, remain through the whole year deeply covered
with mire; the only means known of keeping forest ways dry, is
to give them a width of from 260 to 330 feet, that is to say,
to clear the country in their course.
If once the fact is admitted that running streams are
diminished in size by the effect of felling forests and the ex-
tension of agriculture, it imports us to examine whether this
diminution proceeds from a less quantity of rain, or from a
greater amount of evaporation, or whether perchance it may
owing to the practice of irrigation.
be
I set out with the principle that it must be next to impos-
sible to specify the precise share which each of these different
causes has in the general result; I shall, nevertheless, endeavour
to appreciate them in a summary way. The discussion will
have gained something if it be proved that there may be dimi-
nution of running streams in consequence of clearing off the
forests alone, without the whole of the causes being presumed
to act simultaneously.
With regard to irrigation, it is necessary to distinguish be-
tween that case in which an extensive farm has been substituted
for an impenetrable forest, and that in which an arid soil, which
never supported wood, has been rendered productive by the
industry of man. In the first case it is very probable that
irrigation will have contributed but little to the diminution in
the mass of running water; it may readily be imagined that the
quantity of water used up by a dense forest will equal at all
events, if not exceed that which will be required by any of the
In the
vegetables which human industry substitutes for it.
second case, that is to say where a great extent of waste country
INFLUENCE OF AGRICULTURE ON CLIMATE.
685
has been brought under cultivation, there will evidently be con-
sumption of water by the vegetation which has been fostered
upon the surface; agricultural industry will thus tend to dimi-
nish the quantity of water which irrigates a country. It is
extremely probable that it is to a circumstance of this kind that
we must ascribe the diminution of the lakes which receive so
large a proportion of the running streams of the north of Asia.
It is almost unnecessary to add, that in circumstances of this
kind the effect which is due to the simple evaporation of rain
water is not increased; the loss by this means must be rather
less, because from a surface covered with plants, evaporation
takes place more slowly than from one that is devoid of vege-
tation.
In the considerations which I have presented upon the lakes
of Venezuela, of New Grenada, and of Switzerland, the diminu-
tion may be directly ascribed to a less mean annual quantity
of rain; but it may with equal reason be maintained to be a
simple consequence of more rapid evaporation.
There are, in fact, a variety of circumstances, under the influ-
ence of which the diminution of running streams can be shown
to be connected with more active evaporation. I shall confine
myself to the mention of two particular instances, one no-
ticed by M. Desbassyns de Richemond, in the Island of Ascen-
sion, the other is from observations by myself, and is among the
number of facts which I registered during my residence for
several years at the mines of Marmato.
In the Island of Ascension there was an excellent spring,
situated at the foot of a mountain originally covered with wood;
this spring became scanty and dried up after the trees which
covered the mountain had been felled. The loss of the spring
was rightly ascribed to the cutting down of the timber. The
mountain was therefore planted anew, and a few years afterwards.
the spring reappeared by degrees, and by and by flowed with its
former abundance.
The metalliferous mountain of Marmato is situated in the pro-
vince of Popayan, in the midst of immense forests. The stream
along which the mining works are established is formed by the
686
INFLUENCE OF AGRICULTURE ON CLIMATE.
junction of several small rivulets which take their rise in the
table-land of San Jorge. The country which overlooks the
establishment is thickly wooded.
In 1826, when I visited the mines for the first time, Mar-
mato consisted of a few miserable cabins, inhabited by negro
slaves. In 1830, when I quitted the country, Marmato had the
most flourishing appearance; it was covered with workshops, it
had a foundry of gold, machinery for grinding and amalgam-
ating the ores, &c., and a free population of nearly three
thousand inhabitants. It may be readily imagined, that in the
course of these four years an immense quantity of timber had
been cut down, not only for the construction of machinery and
of houses, but as fuel, and for the manufacture of charcoal.
For facility of transport, the felling had principally gone on upon
the table-land of San Jorge. But the clearing had scarcely been
effected two years, before it was perceived that the quantity of
water for the supply of the machinery had notably diminished.
The volume of water had been measured by the work done by the
machinery, and actual gauging at different times showed the
progressive diminution of the water. The question assumed a
serious aspect, because at Marmato any diminution in the quan-
tity of the water, which is the moving power, would be of course
attended with a proportional diminution in the quantity of gold
produced. Now in the island of Ascension, and at Marmato,
it is highly improbable that any merely local and limited clearing
away of the forest should have had such an influence upon the
constitution of the atmosphere as to cause a variation in the
mean annual quantity of rain which falls in the country. More
than this, as soon as the diminution of the stream at Marmato
was ascertained, a pluviometer, or rain-gauge, was set up, and
in the course of the second year of observation a larger quantity
of rain was gauged than in the first year, although the clearing
had been continued; still there was no appreciable increase in
the size of the running stream.
A couple of years of observation are unquestionably insufficient
to show any definitive variation in the annual quantity of rain that
falls. But the observations made at Marmato still establish the fact,
INFLUENCE OF AGRICULTURE ON CLIMATE.
687
that the mass of running water had diminished in spite of the
larger quantity of rain which fell. It is therefore probable that
local clearings of forest land, even of very moderate extent, cause
springs and rivulets to shrink, and even to disappear, without
the effect being ascribable to any diminution in the amount of
rain that falls.
We have still to inquire whether extensive clearings of the
forest, clearings which embrace a whole country, cause any
diminution in the quantity of rain that falls. Unfortunately,
the observations which we have upon the quantity of rain which
falls in particular districts are only of sufficient antiquity and
accuracy in Europe to be worthy of any confidence, and there
the soil was cleared before observation, in the generality of
instances, began.
The United States of America, where the forests are disap-
pearing with such rapidity, will probably one day afford elements
for the complete and satisfactory solution of the question,
whether or not the cutting down of forests causes any diminu-
tion in the quantity of rain which falls in the course of the
year.
In studying the phenomena accompanying the fall of rain in
the tropics, I have come to a conclusion which I have already
made known to many observers. My own opinion is, that
the felling of forests over a large extent of country has
always the effect of lessening the mean annual quantity of
rain.
•
It has long been said, that in equinoctial countries the rainy
season returns each year with astonishing regularity. There can
be no doubt of the general accuracy of this observation, but
the meteorological fact must not be announced as universal and
admitting of no exception; the regular alternation of the dry
and rainy season is as perfect as possible in countries which pre-
sent an extreme variety of territory. Thus a country whose
surface is covered with forests, and rivers, and lakes, with moun-
tains, and plains, and table-lands, the periodical seasons are
quite distinct. But it is by no means so where the surface is
more uniform in its character. The return of the rainy season
688
INFLUENCE OF AGRICULTURE ON CLIMATE.
will be much less regular if the soil be in general dry and
naked; or if extensive agricultural operations take the place of
the primeval forest; if rivers are less common, and lakes less
frequent. The rains will then be less abundant; and such coun-
tries will be exposed from time to time to droughts of long
continuance. If, on the contrary, thick forests cover almost the
whole of the territory, if its rivulets and rivers be numerous, and
agriculture be limited in extent, irregularity in the seasons will
then take place, but in a different way,-the rains will prevail,
and in some seasons they will become as it were incessant.
The continent of America presents us, on the largest scale,
with two regions placed in the same conditions as to temperature,
but in which we successively encounter the circumstances which
are most favourable to the formation and fall of rain in one case,
to its absence in the other.
Setting out from Panama, and proceeding towards the south,
we encounter the Bay of Cupica, the provinces of San Bona-
ventura, Choco, and Esmeraldas; in this country, covered with
thick forests and intersected with a multitude of streams, the
rains are almost incessant; in the interior of Choco scarcely a
day passes without rain. Beyond Tumbez, towards Payta, an
order of things entirely different commences; the forests have
entirely disappeared, the soil is sandy, agriculture scarcely
exists, and here rain is almost unknown. When I was at
Payta, the inhabitants informed me that it had not rained
for seventeen years! The same want of rain is common in
the whole of the country which surrounds the desert of Sechura,
and extends to Lima; in these countries rain is as rare as
trees are.
In Choco, where the soil is thickly covered with trees, it
rains almost continually; and on the coasts of Peru, where the
soil is sandy, without trees and devoid of verdure, it never rains;
and this, as I have said, under a climate which enjoys the same
temperature, and whose general features and distance from the
mountains are nearly the same. Piura is not more remote from
the Andes of Assuay than are the moist plains of Choco from
the Western Cordillera.
INFLUENCE OF AGRICULTURE ON CLIMATE.
689
The facts which have now been laid before the reader seem to
authorise me to infer:
1st. That extensive destruction of forests lessens the quantity
of running water in a country.
2nd. That it is impossible to say precisely whether this dimi-
nution is due to a less mean annual quantity of rain, or to more
active evaporation, or to these two effects combined.
3rd. That the quantity of running water does not appear to
have suffered any diminution or change in countries which have
known nothing of agricultural improvement.
4th. That independently of preserving running streams, by
opposing an obstacle to evaporation, forests economize and regu-
late their flow.
5th. That agriculture established in a dry country, not covered
with forests, dissipates an additional portion of its running
water.
6th. That clearings of forest land of limited extent may
cause the disappearance of particular springs, without our being
therefore authorised to conclude that the mean annual quantity
of rain has been diminished.
7th and lastly. That in assuming the meteorological data col-
lected in inter-tropical countries, it may be presumed that clear-
ing off the forests does actually diminish the mean annual
quantity of rain which falls.*
* These meteorological observations are highly interesting, and worthy
of every consideration. That unforesting a country makes it absolutely
drier, seems unquestionable; but whether that be in consequence of less
rain falling, or of that which falls going farther, making more show, may still
be doubtful. It does not seem very legitimate to decide, that because a coun-
try is covered with wood, therefore it is wet: the converse of that propo-
sition appears much more probable; viz., because a country is wet, there-
fore it is covered with trees. There is one part of the ocean which is
called by mariners "The Rains;" because it rains there almost ceaselessly,
as it does in the province of Choco: but the Rains" has no forests to
account for its dripping sky. Did that region consist of dry land instead
of salt-water, then doubtless its surface would be covered as that of Choco
is with an impenetrable forest. The subject is adverted to here, however,
not to discuss the general question, but to throw out the suggestion that
under the hand of man the soil and even the climate of our immense
Co
690
INFLUENCE OF AGRICULTURE ON CLIMATE.
Australian possessions might possibly be improved. Drought is the
grand enemy of the Australian settler; and the country is generally barren
of wood.
Governors, district governments and farmers, and all who are interested
in the prosperity of the colony, surely ought to encourage, by every pos-
sible means, the growth of the taller trees and shrubs that are indigenous
to the country.
Expeditions might be made once or twice a year at the proper season
for scattering or planting the seeds of these trees or shrubs.
Could every
knoll within a hundred miles of Sydney be crowned with a thick screen
of leafy trees, there can be little doubt that the rain which falls would be
economised; and that the beds of the rivers, instead of being dry for
eight or nine months, would be occupied all the year round by at least a
moderate stream of water.-ENG. ED.
THE END.
LONDON:
Printed by Schulze and Co., 13, Poland Street,
Fage 193
199
341
362
366
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454
491
519
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633
668
line 6
27
17
23
35
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CORRECTIONS.
for employs its evenings
rages
definitively
800 weight
power
constitutional
magnificent
gypsing
constituted by
twice and a quarter
handy work
repose
delightful
allied
wrought
the
more
read employ their evenings
ranges
ultimately
800 cwt.
powder
constituent
good
gypsoming or plastering
cropped with
twice as much and a quarter
hand labour
rest
very useful
mixed
worked
this
greater

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