Glass. 
 Book. 
 
 . \Hr 
 
3V V4^W 
 
 THE SOIL, 
 
 CONSIDERED A8 A 
 
 SEPARATE AND DISTINCT DEPARTMENT OF NATURE, 
 
 ROBERT. SERRELL.WOOD, 
 
 Corresponding Member of the National Institut: 
 
 WASHINGTON, MARCH, 1850. 
 
 The most palpable source of nutrition to all created beings was sup- 
 posed by the ancients to possess the attributes of vitality; it was there- 
 fore an amiable weakness on their part to personify the Earfh, and to 
 hold her in peculiar veneration. Modern science has banished this beau- 
 tiful sentiment from its stern philosophy, but it can never invalidate the 
 fact that there are certain ingredients of the soil (whatever be their 
 origin) which claim intermediate rank between matter in such states of 
 comoi nation as the chemist can produce by synthesis, and the lowest 
 specimens of vege'able organisms : neither has it yet successfully proved 
 that the same elements in other shape than the organic salts of humus 
 contribute with equal efficiency to the luxuriance of vegetation, although 
 there is evidence in volcanic and other localities to show, that an excess 
 of either free carbonic acid gas, or ammonia, or water, even when the 
 other minerals present suffice for the wants of plants, is injurious to the 
 highest degree. A greater proportion than at present of those gases and 
 vapours in the atmosphere, and consequently in the soil, may have favored 
 the earliest denizens of our globe : those tribes have now nearly passed 
 awa)% or their constitution has been modified with modifications of cli- 
 mate, &c. 
 
 A just appreciation of fossil organic remains has elicited a probable 
 truth, that function and organization proceed through both kingdoms of 
 nature by parallel lines of advancement, observable since the difl^erent 
 periods of the world at which they respectively commenced their fxist- 
 ence. It would seem as if some general law, harmonizing with the 
 earth's progress in its physical capacity, governed the succession of these 
 products, an idea which is further supported by their gradujj,l develop- 
 ment at the present day from the germinal to a perfect state. We should 
 also bear in mind the remarkable fact, that animals and vegetables are 
 blended together so as to render any attempt to define their distinguish- 
 
ing properties utterly futile. Vegeto-animals have been fully recognised 
 by naturalists ; and we are next led to inquire whether the soil, forming 
 a connection between organized and unorganized matter, partakes of a 
 ve^eJo-minerdl character in the highest acceptation of the term. 
 
 The animal department, although indebted for its growth and prime 
 condition to azotized aliment approximating more or less in its nature 
 the tissues themselves, borrows, from vegetables especially, hydro-car- 
 bonaceous substances of a less complex composition, a portion of which 
 is converted into fat, another portion is directly oxidized and excreted, 
 while a third is presumed, in the case of the lowest animals, to be con- 
 vertible by means of ammonia into gelatine, &c., their integuments cor- 
 responding with those of plants as surfaces ab-;orbent of nourishment, 
 sufficiently at least to establish a close relation between both races in 
 this lespect as well as in their both inhaling oxygen.* Again, the vege- 
 table department in its highest range, although dependant upon rich 
 mould or organic manures for its most efficient support, (as man and 
 some other animals are upon flesh,) draws from the atmosphere elements 
 convertible into cellulose, &c., indicating the claims of animals upon 
 vegetables, of vegetables upon the soil, and, as I shall endeavor to show, 
 the ultimate dependance of the soil upon the atmosphere. Nature evi- 
 dently proposes more than one resource for the maintenance of her crea- 
 tures ; and unity of design, which pervades the works of creation, would 
 suggest that, although the soil receives its most unequivocal accessions 
 from the debris of plants, it nevertheless allows the crude materials of 
 air to circulate within its pores, and to form more notable combinations. 
 Animals, vegetables, and the soil are constituted in large proportion of 
 particles, which have possessed, but which no longer retain, the usual 
 characteristics of life— particles, be it observed, which threaten to resolve 
 themselves into simpler forms, unless the tendency to disintegration be 
 
 •The oxidation of the hydrocarburets is generally believed lo liberate caloric in living bodies as 
 a primaty result, but I respectfullv maintaii-i that it, in the first instance, cause, the surrender of 
 electricity which was previously combined ; heat cou^equen.ly becomes a sec.mdary effect, ol an : 
 altered consistency or composition m sohds or fluids, whereby ,l,eir specfic capacity for cal.r.c ( 
 is affected. The temperature of animals is exaggerated by physical exenion, whieh cau-es the . 
 contract on of muscles and a more rapid circulation of the blood. A large portion of the.r food .3 
 already combined with oxygen in the propor.ion to form water ; no heat is theref„re evolved from 
 this source, ind the separation oFfree water from their surfaces m the shape of vapour produces a 
 reduction (if temperature perhaps equivalent to the heat generated by the conversion ot venou. into 
 arterial blood. The slow reactions between highly constituted substances may be identical in a 
 chemical point of view with ordinary cases of combustion, but the results very different ; the 
 amount of heat liberated being proportionate to the gr-ater or less competency of cotiductmg 
 media to carry off the electricity set free, or of ether contiguous molecules in the circulation or 
 elsewhere to appropriate that imponderable by forming new combinauons. And here I may be 
 permitted to add, that if the solution of a simple metal in the voltaic apparatus liberates a force 
 which, on being conducted by a special arrangement of wire around an enclosed bar of iron mag- 
 netizes it, a Ionian the resolution of more complex particles, such as those contained in the ani- 
 mal circulation, might be supposed capable of contracting (magnetizing) a muscle enclosed with- 
 in a network of conducting ne.vous filaments. A ganglion is the voltaic apparatus, certain con- 
 stituents of the blood electrolytes, the motor and sensitive nerves conducting media, and the mns- 
 cie, which is insulated by cellular matter and ligament, a magnet. 1 he contraction of a muscle 
 or a congeries of muscles would not necessarily diminish the volume of their mass, because their re- 
 duction of size only tends to enlarge the capacity of the surrounding cellular pubstance ; tree m- 
 grees is therefore aliowc d to the blood between the fibres, and coneequently greater efficiency 
 produced in the parts. 
 
3 
 
 counteracted by a force of an opposite kind. The soil possesses no evi- 
 dence of organization either in mass or in detail ; but organization may 
 mark grades of development without being indispensable to characterize 
 living matter. Nothing can be more indefinite than even the essential 
 properties of life. Can physiologists determine at wliat precise moment 
 the vital principle is surrendered by a piece of muscle cut from the leg 
 of a healthy animal 1 The separation of a part merely shortens its term 
 of existence by destroying perhaps the faculty of self-preservation or re- 
 production. Where then shall we find the first link in the self-supporting 
 chain of vital products? Are we to consider the vesicles or cells which 
 the microscope discovers almost everywhere on the earth's surface as ex- 
 hibiting the simplest manil'estations of life, or may we refer its rudiments 
 to the corpuscles of blood, or to certain constituents of sap ? 
 
 I propose to regard the soil as a creature sui generis, sustaining 
 living bodies whilst it is itself sustained by them. Its proportions are 
 limited by the means of increment placed at its disposal. If the 
 natural history of soil be studied, we find that although it may in- 
 crease enormously under certain conditions, and although its term of 
 maturity may be prolonged to an apparently indefinite extent, its ulti- 
 mate dissolution, in whole or in part, is a matter of as much certainty 
 as the lapse of ages. Organized bodies, however, display their power 
 of increase more particularly in their progeny, which represent the pa- 
 rent in an enlarged individuality. The soil, likewise constituted, as I 
 shall presently endeavor to show, of many individuals of different char- 
 acter, is' capable of propagating \\s kind by a quasi-fissiparous process — 
 that is to say, a portion of veritable mould being isolated from the main 
 body and placed in a favorable situation, exerts a quickening influence 
 upon surrounding matter of elemental identity: mould, consequently, 
 either enlarges in bulk itself, or gives bulk to vegetables, just as vegeta- 
 bles, daring their growth, either enlarge in bulk themselvs, or give bulk 
 to animals which leed upon them. It maybe further urged, as a gene- 
 ral proposition, that animals, plants, and the soil, increase and multiply 
 in co-ordinate ratios, and that, with the continued addition of light, a 
 much greater mass of matter will be engaged in the enjoyment of more 
 exalted faculties, either in an organized or semi-organized shape. 
 
 Aboriginal soil, then, may be attributed to the rays of the sun co-ope- 
 rating with physical changes of certain universally diflused substances, 
 which I shall presently mention — changes of form, consistency, and po- 
 sition, capable of impressing the heterogeneous residue with new affini- 
 ties. We, however, regard, as chiejii/ rnstrnmental, at the present day, 
 in the generation ol" humus de nouo from carbonic acid and water, the 
 forces liberated by already existing humus, or by materials of higher 
 ^rade in the act of decomposition — forces identical with those emitted 
 from the luminous worlds around us. 
 
 Commencing with the lowest grade of progressive developments, we 
 submit for consideration : first, whether ulmin and other semi-organized 
 subst mces were not originally, and are not still, produced from carbonic 
 acid and water at the expense of ammonia which becomes decom- 
 posed in the ground by means of oxygen, nitrogen being liberated upon 
 the same terms which vegetables prescribe for themselves during an an- 
 
alogous process of transformation.* Secondly, whether the disintegra- 
 tion of those hydrocarburets which are formed in vegetables from ulmin, 
 such as starch, gums, oils, &c., does not promote the ibrmation of various 
 azotized proximate principles, when ammonia, sulphur, phosphorus, and 
 some few other minerals, are present. Lastly, whether the dissolution 
 of these proteine and allied compounds into less complex forms, or into 
 their ultimate elements, does not generate cellulose, &c. The idea on 
 which we particularly insist is, the reluctance on the part of bodies, 
 whether organized or unorganized, to allow their constitutional forces to 
 exhaust themselves by their component materials becoming resolved 
 into simpler combinations, as long as contiguous matter evinces the dis- 
 position of assuming an identical character or an equivalent complexi- 
 ty of constitution. For this reason, the snme forces which enter into 
 the constitution of vegetables are apparently transmitted from one gene- 
 ration to another. But, on the other hand, it must be confessed that, 
 were it not for the incessant appropriations of the luminous element by 
 the surface materials of our globe, no iurther progress in the quantity 
 or quality of chemico-vital phenomena could be anticipated. 
 
 It would likewise be unreasonable to expect the occurrence of these 
 spontaneous formations of soil, where the want of indi>pensable f)re- 
 requisites prohibits what would be an ordinary train of events in more 
 favored regions. The fixed alkalies and alknloi cls, in moderate quantity, 
 might expedite the process, and yet the same bases, or ammonia, or 
 water, in excess, effectually prevent it. To consider them as tending 
 to break up, under all circumstances, rather than to superinduce more 
 complex relations of matter, would be to adopt an error equivalent with 
 considering oxygen an element of universal destruction. 
 
 Viewed solely as an accumulation of dead or etiete materials, the 
 ground presents a melancholy picture of desolation, l)ut as a thing of 
 life it offers eminent support to the doctrine of development. As soon 
 as a fit habitation was prepared for land-animals and plants, they each 
 in the fulness of time entered on their career. There is an aptitude in 
 this arrangement, and no less probable is it that the first and simplest 
 forms of living matter derived their forces from existing substances of 
 lower degree in complexity, and that the light of heaven co-operated 
 then, as it dees now, in the glorious consummation. Water-plants flour- 
 ished long before dry land appeared ; these must have subsisted upon 
 gases and salts dissolved in the ocean, and their debris became the source 
 of much primeval soil. This admission by no means militates against 
 the proposition that semi-organized compounds, constituting humus, may 
 also be formed in Nature's laboratory by a direct union of the elements 
 concerned, the most obvious cause of a primary character being the 
 reduction of ammonia, or its transtbrmation, into water and nitrogen, 
 by means of oxygen. Whether other compounds be formed in the soil, 
 such as nitrates, which are due to progressive as well as retrograde re- 
 
 • It niny be oliserved that the gaseous effluvia (excretions proper) respired by the leaves of 
 planis, are (or the most part simple elements, as oxyuen and nitrosren, which, on assuming the 
 Oeritoiin condition, ijivt up the electiiciiy previously binding them with solids in tie closest chemi- 
 cal relations ; their loss of this force redounds to the benefit of plants by the consequent fixation 
 of cerhor? 
 
actions, must depend upon dynamic contingencies. Holding these pre- 
 mises in mind, we are led to inquire whether the decomposition of semi- 
 organized compounds did not liberate the necessary forces and introduce 
 the lowest types of vegetable organisms, under conditions of the world 
 more favorable than at present, and which we can scarcely now appre- 
 ciate.* These in turn becoming decomposed, and surrendering their 
 forces, may have forwarded new combinations of vegetable matter, until 
 we reach a period of the earth's history teeming with vital phenomena 
 familiar to us. 
 
 Germs, like nuclei of lesser note, may be identical, or nearly so, in 
 their ultimate or proximate elements, and yet differ in the proportions 
 of their combined imponderables. On this hypothesis the variety of 
 vegetables and even animals is divested somewhat of mystery ; the ele- 
 ments of nutrition being the same, the congenital forces which direct 
 the earliest vital movements in each particular genus or species deter- 
 mine their subsequent figure and organization. 
 
 Af er making due allowance for climate and the immediate effects of 
 solar irradiation upon the digestive powers of plants, we attach no little 
 importance to the shape in which their food is presented to the roots. It 
 is asserted by the modern school of Agricultural Chemists, that the or- 
 ganic food of plants is exclusively carbonic acid and ammonia dissolved 
 in water, and, of course, the force of life is esteemed the chief cause of 
 all organic changes of a progressive character. With us, on the con- 
 trary, it is contended, that the substances aforesaid could not possibly be 
 melamorphosed into higher compounds except by the addition of light, 
 or of forces identical with light, derived from organized and semi-orga- 
 nized materiel in the act of decomposition. It is well known, that no 
 manure is more acceptable to vegetables than their own decaying leaves, 
 or the debris of a higher class of plants; the explanatioh now offered 
 for this fact by authoi's entitled to our utmost respect, is, as stated above, 
 very simjjle ; but unfortunately it leaves the solution of ulterior pheno- 
 mena hopeless. To attribute the more abstruse transmutations to a force 
 of life is tantamount to an abandonment of principles applicable to all 
 
 * These conditions have reference to tbrmer bipolar movements of our e inh, not of an extra- 
 vagant, but of an exaggerated iiind. I intend, on some future occasi m, to submit reasons for the 
 belief th;it the sun is the immeciate cause of the dmrnal rotation of planets within the solar sys- 
 tem, and of their annual changes of position and presentation. To be more explicit: if solar 
 rays be compounded, ;is I shall araue, of repellent and attractive forces neutralized by their com- 
 bination ill light, and ihey be decomposed on the surfacte of the ear h, (this surlace being a mixed 
 one of solids, liquids, and aeriform tiuids ) we can understand how more of the calorific rays tnay 
 be detained on the peripheral or outer portion of oui planet, and exert an influence there, while 
 the electric rays, for the most pan, pass on to ihe innermost surface ot ihe solid crust, causing ad- 
 ditional layers to be precipitated from the central fluid mass. A tempo ary loss of equilibrium 
 llnis occasioned bt'lween the opposite sides of the ^^phere, produces a centrifugal tendency in the 
 comparatively enlarged proximal surface, and a centripetal tendency in the d'stal surface, which 
 becomes, each section of it for the instant, comparaiively smaller than its antipod. We further 
 surmii-e that the earth has reached its present rate of movement and extfnt of bipolar oscillation 
 after considerable diminution of intensity in the North and Soutii hemispheres respectively, at 
 difl^erent epochs; that the approaches to a more perlect equiiibrium^and consequent alleraii(uis of 
 climate from this cause, have been so gradual within the historic period as to liave escaped the no- 
 tice of observers in this field of science. I am notacquainted with any more plausible explanation 
 of the undoubted changes of level in the ocean since the commencement of the tertiary era, as evi- 
 denced by phenomena of universal extent. 
 
6 
 
 physical changes for the production of which chemists are unable to con- 
 trol or concentrate the usual forces of matter. 
 
 Practical agriculturists will ke^iiai^ij0f<S^?3ai3i^L^^eaia3aiie.ififfi««fewt 
 that proximate principles must be, and in all cases are, reduced 
 before they can be absorbed by the roots. Because analytical chemists 
 are unable to dissolve by artificial means divers ingredients of humus, 
 it does not follow that a force derived from the voltaic movements of 
 contiguous living tissues is incompetent to do so; neither does it follow 
 that the constituents of the ascending sap vessels, or of animal chylife- 
 rous ducts, represent matter in its identical form as appropriated from 
 the primse viae, or the soil, because the organic portions of food may 
 become attached to the presenting superficial tissues, before the force of 
 absorpiion separates and reduces ihem to other soluble compounds as 
 found in the ^sap and chylous lymph. Although 1 have contended that 
 the precipitation of the solids in living bodies is mainly due to forces 
 derived fi-om analogous materials, yet accretions to the roots of plants 
 probably occur at all seasons ; during spring and summer, however, the 
 foliage enjoys the privilege of appropriating aeriform tbod by means of 
 light, in addition to the forces borrowed from chemical and mechanical 
 reactions. 
 
 The usual articles of food correspond more or less with the tissues 
 which prevail in living bodies; hence it happens that, when referring to 
 animals, practical as well as speculative agriculturists lay great stress 
 upon fibrin, albumen, phosphate of lime, &c.; when referring to plants 
 they formerly paid especial regard to the ordinary ingredients of humus^ 
 and while pursuing that natural system (apart from the use of highly 
 stimulating manures, both organic and inorganic) were not troubled 
 with the treatment or the discussion of modern vegetable diseases. We 
 now suspect that just as there are peculiar principles in vegetables which 
 produce constitutional eflects on animals, so there are in vegetable mould 
 of good quality combinations, not the result merely of deoom position, but 
 of direct union between the elem^-nts concerned,- nnd that these vegeto- 
 mineral varieties are of great importance, and define the nicer qualifi- 
 cations of soil and consequent character of plants cultivated therein. 
 The nervous matter of animals taken as food appears most likely to 
 sustain the nervous system and to promote the growth of neurine within 
 our own frames. No people feeding on vegetables exclusively has ever 
 attained eminence in the scale of nations ; not because neurine cannot 
 be formed from vegetable products, but because it cannot be so bounti- 
 fully formed. However much disposed the digestive apparatus may be 
 to reduce the ingesta to a homogeneous fluid, certain substances pass its 
 ordeal which may eventually give flavor, color, and other characteristics 
 to both animals and vegetables.* Public opinion has changed even in 
 respect to the elements which necessarily enter into the composition of 
 
 *A very general repugnance to truck raised upon night-soil exists, and I believe the objeclionB 
 are to a certain extent valid. When vegetables are supplied with but a moderate amount of such 
 offensive manure, the probability is, that the digestive powers of ihe roots will complett-jy alter the 
 character of such portions ol food as are not assimilated by the soil ; or even if any is direcily 
 absorbed into the vegetable system, it is very rapidly decomposed and passed away. l he case ia 
 different when plants are rendered rank and stmiulated by an exce.'S of sewage ; and it is from 
 such an unnatural and continuous process of forcing growth that we instinctively revolt. 
 
vegetables, but is still adverse to an acknowledgement of any advan* 
 tnge derivable from the direct absorption of compounds highly endowed. 
 We cannot detect any absolute contrast in kind, such as is alleged to 
 exist, between the materials constituting the food of animals and vege- 
 tables, but simply a difference in amount of semi-organized and mine- 
 ral nutriment appropriated by the races respectively, corresponding with 
 their functions and the complexity of their organisms. The fungous and 
 certain parasitic tribes establish this view of the subject almost conclu- 
 sively. Light is necessary to their health and welfare in difljerenr. de- 
 grees; its influence upon the functions of the human body being small, 
 there is the greater necessity for man's securing a full supply of protein- 
 ized aliment, and a moderate allowance of those vegetable stimulants 
 and beverages which administer to his gratification. It is in vain to 
 shut our eyes to what some may consider a humiliatory fact, that diet 
 essentially contributes to our physical and mental calibre. 
 
 From these miscellaneous data we infer that, although humus con- 
 sists mainly of well-known organic matter, it contains orher substances 
 which perform an otlice entirely overlooked by agriculturists, and ad- 
 monishes them to reconsider the necessity of frequent rotations in crops, 
 so far as permanent improvement of the soil, and not immediate profit 
 by overtaxing its every capability, is concerned. The staples of a coun- 
 try^ being ascertained by experience, may be encouraged by strictly res- 
 toring to the ground the refuse of those staples as specific manure. The 
 minute products referred to exhibit to my mind degrees of chemico-vital 
 complexity and corresponding differences in their physiological relations. 
 Not the least reason, perhaps, why the cerealia in particular are disin- 
 clined to extreme climates, or certain regions of country in even temperate 
 latitudes, is the same which prevented them from sooner gracing the bosom 
 of our earth, to wi', the want or insufficiency of appropriate semi-organ- 
 ized aliment. I may be told that grain has been successfully raised wilh- 
 out the least portion of humus, or any of this highly-extolled materia ali- 
 mentaria. We will join issue on this point, and await the verdict of good 
 and true men. who will we'gh the evidence of unexceptionable and long- 
 continued experiments; and if the cerealia do not degenerate or become 
 diseased, as potatoes have become, by the injudicious refinements of art, 
 I shall be agreeably disappointed. There cannot, I suspect, be too great a 
 supply of mould if there be also a proper proportion of mineral ingre- 
 dients, and silica in particular, to support the luxuriant stem. While 
 calculating the value of this class of plants we should be mindful not 
 to underrate the straw, whether as food, litter, or manure, for domestic 
 consumption. The tuber of potatoes has been perhaps over-stimulated 
 by unfermented organic manures not possessing a sufficiency of mineral 
 bases to ensure hardy germs; whereas, what seems to threaten wheat is 
 an excess of inorganic elements over the organic, so as to render 
 it eventually more grain than stem ; and thus by forcing year after year 
 exuberant seed and a precocious progeny, we endanger the permanent 
 welfare of the plant. It is true that the grain crops are not cultivated 
 for their leaves or roots, as cabbages or turnips are; but does not the 
 constitution of the germ depend upon the efficiency of the parent's whole 
 structure ? The evil is analegous to that of breeding in and in, whereby 
 
certain organs, peculiar products, and morbid tendencies are exaggera- 
 ted to the prejudice of tlie other parts and functions. Such a system 
 must terminate disastrously to animals and vegetables, as it operates 
 injuriously to the healthy condition and growth of humus, when by re- 
 peated over-doses of any one element, or by the total neglect of others, 
 or by allowing certain noxious elements to accumulate, we depress the 
 productive energies of the soil. 
 
 An argument is frequently raised in disparagement of mould, that an 
 excess of vegetable matter, as in swamps or heath-moors, is unfavor- 
 able to a wholesome vegetation : on the other hand, experiments have 
 proved that certain plants will thrive in pure charcoal — plants which do 
 not deserve to be styled useful except by indirection, transplanted from 
 rich garden earth, containing abundant resources in their systems, sup- 
 plied freely with water perhaps saturated wilh organic matter, in a 
 close atmosphere charged with concentrated nutriment, in a green-house 
 which collects the rays of the sun wilh great effect upon growth ; plants 
 such as these, many of which cannot survive a sudden change of tem- 
 perature, and die out or are forgotten in a few generations, are brought 
 in comparison with field crops, t e support of man and his fortunes ! 
 It may not be inappropriate, by way of comparison, to direct my readers 
 to those conditions of society in which a pampered aristocracy is found 
 in juxta-position with a degraded, ignorant, and vicious populace: the 
 former are the hot-house plants, the latter those noisome weeds which 
 from their very rankness are cumbersome to the ground. Happy is 
 that country in which neither class exists, but a population of intelligent 
 freemen, with such qualifications of mind and body as ennoble the race. 
 
 As far as plants administer to the food of men and domestic animals, 
 their importance may be graduated by the amount of their fecula., gum', 
 oils, &c., or of albumen, &c. In order to obtain these products tie plants 
 are generally destroyed, some of them in embryo as seeds and tubers, 
 some more advanced in life : but we never wait until these latter sponta- 
 neously cease to live, because at the period of their natural dissolution 
 their hydro-carbonaceous deposites have been converted into lignin. The 
 proteinized deposites in the cells and nitrogenous solutions in the sap 
 have also disappeared ; they have done their appropriate duty, which 
 partly corresponds with that performed by the adipose deposites in the 
 cellular substance of animals, or by the fatty matters of bile. A^egeta* 
 bles, with a view to their self-preservation, are known to use the hydro- 
 carbonaceous substances in their saptbr building up their structures, at the 
 same time borrowing, as I conceive, the necessary forces from the azotic 
 ingredients, until the germs divert the juices measurably from the stem 
 and branches. In consideration of the collateral uses ol'azotized matter in 
 vegetables we are too apt to regard it as 'forming an integral portion 
 of a plant per se. The vegetable and vegeto-mineral kingdoms economize 
 nitrogen, not for its own sake, but for the advantageous reactions which 
 it promotes: the vegeto-animal and animal kingdoms appropriate hydro- 
 carburets chiefly for that purpose. The same principle may be extended 
 to their modes of growth at the incipient stage of their existence ; phane- 
 rogamous flowering plants not being fecundated until the pollen reaches 
 the blossom, nor the animal ovum until the seftien masculinum quickens it. 
 
9 " 
 
 The very compound ammonia which under favorable circumstancef?, such 
 as an abundance of carbonaceous aliment, might forward the growth of 
 plants, under other circumstances becomes the means of disintegrating 
 their frame- work even unto utter debility and dealh. It is for tins reason I 
 deprecate an excessive use of, or an entire dependence upon, the iertiliziiig 
 salts now so prevalent, which will probably cause a more rapid ex- 
 haustion of the soil unless we keep our farms in good heart ; and then 
 we may lay on the minerals with a liberal hand. Thus are true econ- 
 omy and high tillage combined. Our interest demands that we foster the 
 carbonaceous elements of the soil on the Atlantic slope of this conti- 
 nent, in order to compete with the middle States of the West, notwith- 
 standing the diseases of new countries which affect both animals and 
 vegetables: nearly all of them will soon be avoided by scientific and 
 careful husbandry, more particularly by draining. The reluse of our 
 homesteads and green manures must be our chiei' resource, and in pro- 
 portion as we gain carbon by any available means, we should encourage 
 its still further accumulation by an equivalent admixture of mineral 
 bases, among which ammonia is pre-eminently serviceable, both as a 
 solvent or vehicle, and as a stimulant in the manner suggested. 
 
 In reply to those who consider the .atmosphere competent to supply a 
 full amount of carbon both to the leaves and roofs of our fiel'l and gar- 
 den crops, and who, conlbrmably with this doctrine, rely upon mineral 
 manures, I would ask why the ammonia which is furnished in the same 
 way does not suffice. Can the vapor of water dissolved in air, or even the 
 dew which is deposited at night, sustain under ordinary circumstances 
 the welfare of the higher class of vegetables for aseason, not to mention 
 a series of years ? it might as well be contended that no rain is needed 
 anywhere, because in Egypt the periodical overflow of the Nile ren- 
 ders it unnecessary there by soaking the adjacent plains to an extra- 
 ordinary depth, as that wheat can be raised on poor soil for many 
 successive years without the slightest artificial or natural additions of 
 carbon in some of its solid or liquid forms. 
 
 We do not propose adding compounds of nitrogen to worn-out soil 
 solely for the purpose of raising vegetable mould, ali hough the 
 improvement in the soil is the first step in the improvement of 
 our vegetables, and consequently of our animals. Whether our in- 
 crease of wealth consist of azotized food which has been acquired at 
 the expense of hydro-carbonaceous matter in vegetables, or whether it 
 consists of hydro-carbonaceous organizable matter in the soil which has 
 been acquired at the expense of ammoniacal ingredients, the chemical 
 process is identical ; and when the value of good mould is taken into 
 account, the difference between the market prices of the organized and 
 semi-organized products is not always in favor of the first. 
 
 During the decomposition of a manure heap or a compost bed, as long 
 as ammoniacal fumes escape, provided the air be allowed to percolate the 
 mass, and there be no deficiency of fixed alkalies and alkaline earths, I 
 fully believe that a positive addition of semi-organized substances results; 
 although the retention of ammonia is doubly desirable for direct ap- 
 propriation by growing plants, a desideratum, which may be in some 
 measure effected by artificial •mean'^. Were, however, the loss of am- 
 
10 
 
 monia complete, which it generally is not, the porous character of the 
 new-born mould would attract back again a certain proportion. Thus 
 it happens that as in the atmosphere, carbonic acid, ammonia, and vapor, 
 hold a proportionate i-elation to each other, so do they in the soil near 
 the surf'ace of the ground, and it is in consequence of ihe natural ina- 
 bility of the mineral bases to regulate their own movements satisfacto- 
 rily in reference to vegetation, ihat man is called upon to remedy any 
 defects or excesses. It is usually asserted by those who admit the 
 supply of carbonic acid and ammonia to the roots from decaying organ- 
 ic matter, that the atmosphere was the primeval source of those elements; 
 they therefore refer the origin of vegetables or vegetable growth to that 
 vast magazine, as amply empowered to sustain what it originated. We 
 admit the joint influence of gases, liquids, and solids on living bodies, and 
 this we hold to be suilicient to account for all the material phenomena 
 and reactions of life. 
 
 Whether this theory be right or wrong, no injury can accrue from the 
 adoption of a practice founded on its requirements. We should by no 
 means place our sole reliance upon the natui-al but slow formations of 
 soil as food for our cuMvated crops, any more than we should rely upon 
 the organic elements of the atmosphere, or of the same elements absorb- 
 ed by ground kej)t in fine tillh. For precisely sinjilar reasons we should 
 object to feeding our domestic animals upon food slightly azotized, if our 
 aim be to train tiesh and nerve. Under favorable condi' ions then, and 
 by the aid of light, the pulverized surface of worn-out soil becomes slow- 
 ly self-renovated, provided its texture be porous and yet sufficiently re- 
 tcn'ive; and this recuperation proceeds the more rapidly in proportion 
 to the amount of semi-organized substances already existing. A nucleus 
 assists, without being necessary to, formative action. We may not at 
 first, or at once, attain a pabulum adapted to sweet vegetation ; indeed 
 we might never succeed without slight extraneous additions. I therefore 
 do not recommend any purely natural system of agriculture for civi- 
 lized communities; but as a question of physiology, I contend, 'that 
 as a coarse vegetation precedes the development of nobler plants, 
 so the commonest earthy bases, in conjunction with water and the 
 elements of the atmosphere, serve to prepare poor land for future 
 usefulness, by a succession of higher and higher subterranean products; 
 and among the elements of air I include phosphorus, sulphur, and some 
 other minerals, either in solution or mechanically suspended. 
 
 It is, moreover, questionable, whether the organiic acids in combination 
 with mineral bases, or other still more abundant organic substances the con- 
 stituents proper of soil, are so unstable as generally sup[)osed ; a doubt 
 which may be extended to the constituents proper of living vegetables and 
 animals, as long aseasily-decomposable matters in the circulation or other- 
 wise favorably located are available for functional purposes; whether, 
 for instance, the exposure of those hydrocarburets to the atmosphere, by 
 repeated fallows, necessarily entails their speedy loss in the absence or 
 comparative paucity of growing plants ; the latter alternative, of course, 
 resulting in no necessary loss, provided the plants be allowed to rot on 
 the ground or within the furrow. My own impression is, that under the 
 circumstances stated, and as long as moisture is maintained, partial de- 
 
11 
 
 composition is adequately compensated by original nitrogenized forma- 
 tions, these again to be supplanted in natural order by original h^'drocar- 
 bonaceous deposites at the expense of the atmosphere. Uncropped land 
 which has been kept constantly worked for several successive seasons, 
 or which has been lying waste for five or ten years, may be gradually 
 accumulating vegeto-mineral products peculiar to the climate, to such 
 an extent that the application of a little guano alone will ensure a re- 
 munerating crop of grain. This is no argument in disproof of my main 
 position, for I have uniformly discovered that, where the ground was de- 
 cidedly worthless and bare, the whole class of mineral manures disap- 
 pointed me ; but where a scanty allowance of humus gave them a chance 
 of turning that pittance to immediate account, the crop spoke for itself, 
 if the season was favorable ; although, as I have before remarked, it 
 was tasking the ground to its utmost strength for the purpose of giving 
 the crop a good start. 
 
 The constitutional depravity of the middle regions in Maryland and 
 Virginia must be assigned to the exhaustion of available alkalies 
 and alkaline earths, and to the too rapid withdrawal of sulphur and 
 phosphorus. Let the proper mineral bases bear the right proportion in 
 a raw surface composed of rock lately disintegrated, and if the climate 
 be genial, there can be little doubt of a soil-formation, and subsequent 
 vegetation based upon it, even on a solitary island in the midst of the 
 Atlantic ocean. 
 
 The conclusion to which we arrive is, that animals, vegetables, and 
 the soil hold certain properties in common, alike affecting their growth 
 and the means of obtaining nutriment. When circumstances admit, 
 they all appropriate materials but little if at all removed in composition 
 from their own substance ; but they also are enabled to generate within 
 their system more or less compounds suitable to their immediate wants 
 from the same elements in simpler states of combination. The more 
 capital, therefore, we judicially invest in organic manures, or in mineral 
 manures with a view of fostering humus, the more deeply we plough 
 and pulverize the soil within prudential limits, the larger interest accrues, 
 not only by the increased weight and quality of produce above ground, 
 but also below the surface. 
 
 Mount Hermon, Washington County, Marc/t, 1850.