Book .'__ K 1^ J^ 
 
AN ESSAY . r^^ ^0 ^ 
 
 ^i 
 
 '^r 
 
 ON 
 
 CALCAEEOUS MANUEES; 
 
 BY 
 
 EDMUND EUFFIN. 
 
 A PRACTICAL FARMER OP VIRGINIA FROM 1812 ; FOUNDER AND SOLE EDITOR 
 OF THE farmers' REGISTER; MEMBER AND SECRETARY OP TIlE FORMER 
 STATE BOARD OP AGRICULTURE: FORMERLY AGRICULTURAL SUR- 
 VEYOR OF THE STATE OP SOUTH CAROLINA ; AND PRESIDENT 
 OF THE VIRGINIA STATE AGRICULTURAL SOCIETY. 
 
 FIFTH EDITION: 
 
 AMENDED AND ENLARGED. 
 
 J. W. RANDOLPH, 
 
 121, Main Street, Richmond, Va. 
 
 1852. 
 
\ssz. 
 
 Entered according to Act of Congress in the year 1852, 
 
 BY J. W. RANDOLPH. 
 
 In the Clerk's Office of the District Court in and for the Eastern Dist. of Virginia. 
 
 JUL 1 2 1933 
 
 PRINTED BY C. U. WYNNE, RICHMOND. 
 
 f\. 
 
PKEFACE TO THE FIFTH EDITION. 
 
 The publication of another edition of this Essay was not 
 designed to be made during the life of the author, until recent 
 circumstances served to induce a change of purpose. When 
 closing my publication of the " Farmers' Register" — -to which 
 service I had devoted and (in reference to my own interest) sacri- 
 ficed the ten best years of my life — I had withdrawn from all 
 connexion with the public, and had no thought of again leaving 
 the quiet seclusion which I had sought and found. But though 
 not expecting again to appear in print during my life, it was 
 nevertheless my practice to make corrections of this Essay, and to 
 prepare materials for future emendations and additions, as new 
 lights were afforded by extended observation and investigation, or 
 by my still extending practical experience. This labour was due 
 to my own reputation. Further, I trusted that, when the results 
 should finally be offered to my countrymen, this and also other 
 previous services might be the more justly appreciated, because 
 the author would then be beyond the reach of applause or recom- 
 pense. Thus, at difi"erent and irregular times, separated by long 
 intervals of cessation of this particular labour, this edition was 
 prepared for posthumous publication. And though the publication 
 is now advanced in time, the before-designed form and manner 
 are not changed, except in the making of still later additions and 
 corrections. 
 
 Under all the existing circumstances, I trust it will not be 
 deemed improper, or offensively egotistical, for me, at this time 
 and in plain words, to assert my just claim to the most important 
 of the truths which were first announced in the earliest and also 
 in every subsequent edition of this Essay; and which truthSj 
 though having formerly no other support than my obscure name, 
 are now so generally accepted and recognised, that they may seem 
 to have been long established and undisputed. Among these 
 opinions, or facts, which I was the first to distinctly assert, and to 
 maintain at length by proof and argument, were the following : — 
 
 1. The capacity of impoverished soils for receiving improve- 
 ment from putrescent manures, being in proportion to their origi- 
 nal or natural measures of fertility ; and that soils naturally poor 
 (especially in this country) could not be enriched by these manures, 
 durably or profitably, above their natural degree of productive- 
 ness. 
 
 2. The almost universal and total absence of carhonate of lime 
 in the soils of the Atlantic slope of Virginia, and (by inference) 
 of most others of the United States — and even in most lime-stone 
 
iv PREFACE TO THE EIFTn EDITION. 
 
 soils — while, from all existing testimony of preceding writers on 
 agriculture, the very general, if not universal prevalence of carbo- 
 nate of lime would have been inferred by every reader. 
 
 3. The general presence of some vegetable acid in all our natu- 
 rally poor soils, and this acid acting as a cause of sterility. 
 
 4. The application of carbonate of lime to soils deficient in that 
 necessary element, serving to neutralize the acid — and, by that and 
 other stated and important operations or effects, serving to tit the 
 before poor and unimprovable soils for speedy and profitable 
 improvement. 
 
 These positions were assumed and maintained in all tbe different 
 editions of this essay, from 1821 to 1842.^ For my own practice 
 they served, as soon as impressed on my mind, to direct and 
 enjoin, as indispensable for any important and remunerating im- 
 provement of poor soils, the application of calcareous manures ; 
 and especially of the cheapest and most abundant resources in this 
 region, the beds of fossil-shells (or marl), then scarcely noticed, 
 and not used in any known practice. 
 
 My just claim to the actual introduction in this country of this 
 now wide-spread and most beneficial means for fertilization, and 
 my making generally known the value, and inducing the later 
 numerous and extensive applications by many other farmers, has 
 not been openly disputed. Detractors in wish and intention have 
 indeed thought that they had plucked from me some borrowed 
 plumes, when stating that numerous older writers (in Europe) had 
 recommended marling — that thousands of farmers in Europe had 
 thus improved land — and that, even in this country, some few 
 persons had tried disintegrated fossil shells as manure, and, in still 
 fewer cases, with success. Such facts, as to European opinions 
 and practice, have been long and well known to all reading 
 farmers ; and it would have been impossible, if I had desired it, 
 to shut out this information. The trials in America were so 
 limited, and so little known (and of which but one case had then 
 appeared in print, and that later than my earliest practice, in 1818), 
 that not one of them had reached me until after my opinions had 
 been formed and uttered, and my practice, founded thereupon, had 
 been commenced and was in progress. And when these cases were 
 subsequently heard of, I industriously sought to gather the facts ; 
 and have published them all, at length, in the former editions of this 
 work. But, in truth, none of these prior practices, or opinions 
 
 * The principal and more important of these opinions had been asserted 
 as early as 1818, in a communication to the Prince George Agricultui-al 
 Society. ]5ut as that communication (whicli was the first concise sketch, 
 since enlarged to this Essay) was not then printed, perliaps I may Lave no 
 right to cite it as showing so early a date for my claims of discovery. Au 
 extract from that communication will be embraced iu one of the pieces in 
 the .Appendix. 
 
 hf?" 
 
PREFACE TO THR FIFTH EDITION. V 
 
 connected therewith, had any bearing on my claim — which is of 
 showing why, and under what circumstances, calcareous manures 
 are especially and generally necessary in this country, and of in- 
 ducing the extensive use of the particular material above named, 
 of which the existence had before attracted the notice of but few 
 persons, and of which any value was suspected by still fewer — and 
 the few earlier trials of which had been altogether empirical, and 
 made without any knowledge of the mode of operation — and which 
 therefore had generally ended in supposed failure and certain dis- 
 appointment, and speedy abandonment of all further effort. 
 
 As to the opinions above enumerated, which served to direct 
 my practice from the beginning of 1818, they had either no sup- 
 port from previous authority, or, if asserted by any, had been 
 denied by higher authority and by general understanding. This 
 latter case, of feeble assertion and stronger denial, covers only the 
 doctrine of acid in soils. The other important positions had not 
 been asserted by any known authority, previous to my declaration. 
 Yet all these doctrines are now received either generally or uni- 
 versally, and so appear in recent publications on scientific agricul- 
 ture. And in regard to the existence of acid in soil, the actual 
 discovery was truly made in Europe, later, indeed, than my first 
 annunciation of the doctrine, by men of high scientific attainments, 
 who most probably had never even heard of the opinions of so 
 remote and obscure a writer as myself. 
 
 Under these circumstances, when these now generally received 
 opinions are seen stated in any of my former editions (and still more 
 if in a subsequent edition), such appearance would not necessarily 
 imply the originality of such opinions. For it might well bo 
 inferred by the (otherwise well-informed) readei', that these doc- 
 trines had been introduced in the later editions, after they had 
 been discovered and published by other authorities. For it is the 
 general and proper usage of authors of scientific and didactic 
 works, to add to each successive edition any new lights on the 
 subject, up to the latest time of publication. Hence, when dates 
 and authorities are omitted (in regard to doctrines long established 
 and received), it is left doubtful which of the positions of an 
 author's latest edition had also been maintained in his earliest ; 
 and also, whether such doctrines were original with the author 
 then stating them, or belonged to some other discoverer not then 
 cited. It is especially designed, in this last edition, to avoid every 
 such source of error. For this purpose, the Chapters (from II. to 
 VIII. inclusive) which will set forth all these theoretical doctrines, 
 will exhibit an exact reprint of the edition of lSo2. No altera- 
 tions of the original test v/ill be made, other than merely verbal 
 and immaterial corrections. Any new matter, or extension of 
 remark or illustration, will be designated in every case; and, 
 1* 
 
vi PREFACE TO THE EDITION OF 1832. 
 
 however since amplified in expression or varied in form, these 
 same positions, more concisely worded, were all embraced in the 
 earlier edition of 1821 (in the "American Farmer"), and, as was 
 before stated, the main points of these opinions were also set forth 
 in the earlier communication of 1818. E. il. 
 
 Marlbourne, II.'iNOVER, Va., August, 1852. 
 
 PREFACE TO THE EDITION OF 1832. 
 
 The object of this Essay is to investigate tlie peculiar features and 
 qualities of the soils of our tide-water district, to show the causes of their 
 general unproductiveness, and to point out means, as yet but little used, 
 for their eflectual and profitable improvement. My observations are par- 
 ticularly addressed to the cultivators of that part of Virginia which lies 
 between the sea coast and the falls of the rivers, and are generally in- 
 tended to be applied only within those limits. By thus confining the appli- 
 cation of the opinions which will be maintained, it is not intended to deny 
 the propriety of their being farther extended. On the contrary, I do not 
 doubt that they may correctly apply to all similar soils, under similar cir- 
 cumstances ; for the operations of Nature are directed by uniform laws, 
 and like causes must everywhere produce like effects. But as I shall rely 
 for proofs on such facts as are either sufdciently well known already, or 
 may easily be tested by any inquirer, I do not choose to extend my ground 
 BO far as to be opposed by the assertion of other facts, the truth of which 
 can neither be established nor overthrown by any available or sufficient 
 testimony. 
 
 The peculiar qualities of our soils have been little noticed, and the causes 
 of those p-^culiarities have never been sought ; and though new and valua- 
 ble truths may await the first explorers of this opening for agricultural 
 research, yet they can scarcely avoid mistakes sufficiently numerous to 
 moderate the triumph of success. I am not blind to the difficulties of the 
 investigation, nor to my own unfitness to overcome them ; nor should I 
 Lave hazarded the attempt, but for the belief that such an investigation is 
 all-important for the improvement of our soil and agriculture, and that it 
 was in vain to hope that it would be undertaken by those who were better 
 qualified to do justice to the subject. I ask a deliberate hearing, and a 
 Bti-ict scrutiny of my opinions, from those most interested in their truth. 
 If a change, in most of our lands, from hopeless sterility to a high state 
 of productiveness, is a vain fancy, it will be easy to discover and expose 
 the fallacy of my views ; but if these views are well founded, none deserve 
 better the attention of farmers, and nothing can more seriously affect the 
 future agricultural prosperity of our country. No where ouglit such im- 
 provements to be more highly valued, or more eagerly sought, than among 
 us, where so many causes have concurred to reduce our products, and the 
 prices of our lands, to the lowest state, and are yearly extending want, and 
 its consequence, ignorance, among the cultivators and proprietors. 
 
 In pursuing this inquiry, it will be necessary to show the truth of vari- 
 ous facts and opinions which as yet are iinsupportcd by authority, and 
 most of which have scarcely boon noticed by agricultural writers, \uiless to 
 be denied. Tlie number of proofs that will be required, and the discursive 
 course through which they must be reached, may probably render more 
 
PREFACE TO THE EDITION OP 1832. vii 
 
 obscure the reasoning of an unpractised writer. Treatises on agriculture 
 ought to be so written as to be clearly understood, though it should be at 
 the expense of some other requisites of good wi-iting ; and, in this respect, 
 I shall be satisfied if I succeed in making my opinions intelligible to every 
 reader, though many might well dispense with such particular explanations. 
 Agricultui'al works are seldom considered as requii-ing very close attention ; 
 and therefore, to be made useful, they should be put in a shape suited to 
 cursory and irregular reading. A truth may be clearly established — but 
 if its important consequences cannot be regularly deduced for many pages 
 afterwards, the premises will then probably have been forgotten, so that a 
 very particular reference to them may be required. These considerations 
 must serve as my apology for some' repetitions — and for minute explana- 
 tions and details, which some readers may deem unnecessary. 
 
 The theoretical opinions supported in this Essay, together with my earliest 
 experiments with calcareous manures, were published in the "American Far- 
 mer" (vol. iii. page 313), in 1821. No reason has since induced me to retract 
 any of the important positions then assumed. But the many imperfections 
 in that publication, which grew out of my want of experience, made it my 
 duty, at some future time, to correct its errors, and supply the deficiencies 
 of proof, from the fruits of subsequent practice and observation. With 
 these views, this Essay was commenced and finished in 1826. But the 
 work had so grown on my hands, that instead of being of a size suitable 
 for insertion in an agricultural journal, it would have filled a volume. The 
 unwillingness to assume so conspicuous a position as the publication in 
 that form would have required, and the fear that my work would be more 
 likely to meet with neglect or censure than applause, induced me to lay it 
 aside, and to give up all intention of publication. Since that time, the use 
 of fossil shells as manure has greatly increased, in my own neighbourhood 
 and elsewhere, and has been attended generally with all the improvement 
 and profit that was expected. But from paying no regard to the theory of 
 the operation of this manure, and from not taking warning from the 
 errors and losses of myself as well as others, most persons have opei-ated in- 
 judiciously, and have damaged more or loss of their lands. So many dis- 
 asters of this kind seemed likely to restrain the use of this valuable ma- 
 nure, and even to destroy its reputation, just as it was beginning rapidly 
 to be extended. This additional consideration has at last induced me to 
 risk the publication of this Essay. The experience of five more years, 
 eince it was written, has not contradicted anj' of the opinions then ad- 
 vanced — and no change has been made in the work, except in form, and by 
 continuing the reports of experiments to the present time. 
 
 It should be remembered that my attempt to convey instruction is con- 
 fined to a single means of improving our lands, and increasing our profits ; 
 and though many other operations are, from necessity, incidentally noticed, 
 my opinions or practices on such subjects are not referred to as furnishing 
 rules for good husbandry. In using calcareous manure for the improve- 
 ment of poor soils, my labours have been highly successful ; but that suc- 
 cess is not necessarily accompanied by general good management and 
 economy. To those who know me intimately, it would be unnecessary to 
 confess the small pretensions that I have to the character of a good farmer ; 
 but to others it may be required, for the pui-pose of explaining why other 
 improvements and practices of good husbandry have not more aided, and 
 kept pace with, the efi'ects of my use of calcareous manures. E. R 
 
 Prince George county, Virginia, January 20iA, 1832. 
 
Viii PREFACE TO THE EDITION OP 1835. 
 
 EXTRACTS FROM THE 
 PREFACE TO THE EDITION OF 1835. 
 
 When the preceding edition of this Essay was published, it met with a re- 
 ception far more favourable, and a demand from purchasers much greater, 
 than the" author's anticipations had reached ; and it is merely in accordance 
 with the concurrent testimony of the many agriculturists who have since 
 expressed and published opinions on the subject, to say that the publication 
 has already had great and valuable effects in directing attention, and in- 
 ducing successful efforts, to the improvement of land by calcareous ma- 
 nures. Experimental knowledge on this head has probably been more than 
 doubled within the last two years; and the narrow limits of the region 
 •within which marling had previously been confined, have been enlarged to 
 perhaps ten-fold their former extent. Still, the circumstances now existing, 
 however changed for the better, present a mere beginning of the immense 
 and valuable improvements of soil, and increase of profits, that must here- 
 after grow out of the use of calcareous manures, if their operation is pro- 
 perly understood hy those who apply them. But if used without that know- 
 ledge, their great value will certainly not be found ; and indeed, they will 
 often cause more loss than profit. It is therefore not so important to the 
 farmers of our country at large to be convinced of the general and great 
 value of calcareous manures — and to those in the great Atlantic tide-water 
 region to know the newly established truth, that their beds of fossil shells 
 furnish the best and cheapest of manures — as it is, that all should know 
 in what manner, and by what general laws, these manures operate — how 
 they produce benefit, and when they may be either worthless or injurious. 
 And this more important end, the author regrets to believe has as yet 
 scarcely been even partially attained, by the dissemination and proper un- 
 derstanding of correct views of the subject. Of course it is not to be sup- 
 posed that this Essay has been read (if even heard of) by one in ten of the 
 many who have been prompted by verbal information to attempt the prac- 
 tice it recommends ; and of those who have read, and who have even ex- 
 pressed warm approbation of the work, it has seldom been found that their 
 praise was discriminating, or founded upon a thorough examination of its 
 reasoning and theoretical views, on which principally rests whatever value 
 it may possess. For all persons who are so easily convinced, it may truly 
 be said, that the volume embraced nothing more, and was worth no more, 
 than would be stated in these few words — "the application of calcareous 
 manures will be found highly improving and profitable." It is not there- 
 fore at all strange that the attentive reading of a volume, to obtain this 
 truth, was generally deemed unnecessary. 
 
 Though the previous edition of this work has been nearly exhausted, the 
 circulation has as yet been almost confined to that small portion of the 
 state of Virginia alone in which the mode of improvement recommended had 
 previously been successfully commenced, or had at least attracted much at- 
 tention. But this district is not better fitted to be thus improved than the 
 remainder of the great tide-water region stretching from Long Island to 
 Mobile — and to a great part of which calcareous manures may be cheaply 
 applied. It is only in parts of jNIaryland and Virginia that many extensive 
 and highly profitable applications of fossil shells, or marl, have been yet 
 made. In North Carolina the value of the manure has been but lately tried ; 
 in South Carolina and Georgia, no notice of it has yet been taken, or at 
 least has yet been made kno'mi ; and in Florida and Alabama (parts of 
 which are peculiarly suited to receive these benefits), it is most erroneously 
 thought that such improvements are only profitable for long settled and 
 iinpoverisUed countries. * * * * -x- tk 
 
PREFACE TO THE EDlTlOxV OP 1842. IX 
 
 But though the circulation of this work -will be most useful through the 
 great tide-water region, which is so generally supplied with underlying 
 beds of fossil shells, and so much of the soil of which especially needs 
 such manure, still the assertion may be ventured that there is no part of 
 the country where the views presented, if true, are not important to be 
 known ; and, if known, would not be highly useful to aid the improvement 
 of soils. It is to the general theory of the constitution of fertile and 
 barren soils, that the attention and severe scrutiny of both scientific and 
 practical agriculturists are invited ; and to the several minor points there 
 presented, which are either altogether new, or not established by autho- 
 rity — such as the doctrine of acidity in soils — of the incapacity of iioor 
 and acid soils to be enriched — and of the entire absence of carbonate of 
 lime in most of the soils of this country. 
 
 Aprdl, 1835. 
 
 EXTRACTS FROM THE 
 PREFACE TO THE EDITION OF 1842. 
 
 In the few years which have passed since the issue of the preceding 
 edition, it is believed that the use of marl and lime, in lower Virginia, has 
 been extended over thrice as much land as had been previously thus im- 
 proved ; and the previous clear income of the farmers thus fertilizing their 
 lands has probably been already thereby increased in amount by several 
 hundi'eds of thousands of dollars, and the intrinsic value of the lands 
 raised by as many millions. These great augmentations of annual profits 
 and of the true value of landed capital, from this single source, if they 
 could be accurately estimated, would be seen to have produced an important 
 item of additional revenue to the treasui-y of the commonwealth. And 
 these additions of wealth to individuals and to the state, would be obvious 
 as well as real, but for the existence of other circumstances which have 
 operated to counteract or to disguise the proper results. The most im- 
 portant of such influences will be merely referred to here in the cursory 
 manner only that the occasion permits. 
 
 In the first place — besides the deservedly very low appreciation of all 
 lands in Virginia, founded on the smallness of their products, the market 
 prices were formerly still more reduced by the almost universal urgent de- 
 sire of proprietors to sell, that they might be enabled then to emigrate to 
 the new and rich lands of the west. The impossibility of selling, even at 
 the lowest valuation price, was the only thing which prevented the actual 
 flood of emigration being so much more swelled as to leave half our lands 
 unoccupied and waste. If purchasers had but presented themselves, fully 
 half the farms in Prince George county (and it is presumed of many other 
 counties) might have been bought up at a considerable deduction from the 
 lowest estimated value ; and all the sellers would have removed, with all 
 their capital, to the western wilderness. To the then actual and regular 
 flow of emigration from the now marling district, an effectual barrier has 
 been opposed by the introduction of that mode of improvement. All emi- 
 gration has ceased wherever by trial of this means the cultivators of the 
 land found their labours to be richly repaid. Thus, in estimating the gains 
 of individuals and of the state, on this score, the comparison should be 
 made, not with the value of property and population which remained 
 twenty years ago, but with what would have remained now, if the then 
 existing inducements to emigration had continued to go on and to increase, 
 as they would have done, with time. 
 
 Next — the actual increase of intrinsic value of marled lands is far from 
 being even yet fully appreciated, because of the generally prevailing and 
 
X PREFACE TO THE EDITION OF 1842. 
 
 very erroneous mode of estimating the values of the increase of permanent 
 net income from land, (as will be made manifest in a part of this Essay—) 
 and but few even of those persons who have obtained such values by marl- 
 ing their lands, would estimate them at one-fourth of their true amount. 
 The source of any jiermaiient net increase of only $G of annual income from 
 land, adds $100 to the intrinsic value of the land. And this proposition 
 is not the less true, and to the full extent asserted, even though the esti- 
 mate of private purchasers and sellers, and of public assessors of lands, 
 may all count for the market price but a small proportion of the increased 
 real value. 
 
 Next — even whatever of new appreciation the foregoing influences might 
 have permitted to be exhibited in the increased marliet price of lands, and 
 still more their new real value, have been disguised, or altogether concealed, 
 by the great and frequent fluctuations of all market prices of praperty, 
 and by the general misdirections of capital and industry, all caused by the 
 universal individual and national gambling (whether voluntary or compul- 
 sory), at the maddening and ruinous game of paper-money banking — to 
 which system of delusion and fraud this otherwise most blessed country 
 and fortunate people are indebted for so much of disaster, loss, and, still 
 worse, of wide-spread corruption of habits and morals. The enormous 
 apparent and illusory profits promised by this system, and by the stock- 
 jol)bers who alone have fattened upon the facilities it offered for fraud and 
 plunder, served powerfully to depress the market price of lands, and to 
 discourage agricultural investments and pursuits. For, whatever actual 
 pi-ofits the improvement and cultivation of the soil miglit oflTer to reward 
 the care and labour of the proprietor, the stocks of various corporations, 
 falsely appreciated by means of a bloated paper currency, and by the arts 
 of stockjobbers, promised much higher profits, without requiring either 
 care, labour, or risk. Thus, the higher that fictitious dividends of profits 
 or the false values of stocks rose, and the stronger became the induce- 
 ments to make stock investments, the more the prices of lands sank (com- 
 paratively) below their true value, because of the general disposition to 
 convert landed capital to stock capital. But the real and solid increase of 
 income and of wealth to individuals and to the commonwealth, caused by 
 the permanent improvement of the soil, is not the less certain, or the less 
 profitable, because fictitious appreciations of values, caused by the fraudu- 
 lent banking system, and the consequent speculations and madness of its 
 votaries and victims, have been both so much higher and lower, at diiFer- 
 cnt times, as to make the amount of actual improved values appear small 
 in comparison, even if they were not thereby entirely concealed. But 
 these delusive and ruinous causes of fluctuating prices and values are now 
 fast showing their emptiness, and vanishing from view ; and whenever the 
 fraudulent paper system shall be completely exposed and entirely exploded, 
 then both lands and the paper-money system will be estimated at their true 
 value. May the consummation be speedy, complete, ami final I 
 
 But even though, if properly and accurately estimated, the true value 
 of the lands already marled and limed in Virginia has been increased to 
 the amount of millions of dollars, the gain is very small compared to that 
 which yet remains ready to be obtained. Marling has not yet been 
 extended over the hundredth part of the surface to which it may be pro- 
 fitably applied ; and liming, not to the ten-thousandth part of the lands 
 of the state to which lime may be brought. And elsewhere, with the 
 exception of a small part of Maryland, the beginnings of marling only 
 have as yet been made. Nevertheless, these beginnings are the widely- 
 Bcattered seeds which will spring up and spread, and horeafter yield 
 abundant harvests. 
 
 December, 1842. 
 
CONTENTS. 
 
 Preface to fifth edition iii 
 
 Preface to earlier editions vi 
 
 Chapter I. — Introductory. General description of agricultural eartlis 
 and soils. Physical and chemical constituents of soils. 
 
 Difficulties of defining eartlis and soils, 17, 18. Cliemists' definitions unsuitable for agricul- 
 ture, 18. Agricultural earths, 19. Siliceous earth, 19. Aluminous, 20. Calcareous, 20; 
 different definitions thereof by authors, 22. Chalk, 23. Magnesiau earth, 2-t. H\imu8, 
 25. Soils and sub-soils, 25. Constituents of soils, 26, and of sub-soils, 27. Physical and 
 chemical constituents, 28, 29, 30. Nomenclature and definitions of soils, 31, 32, 33. 
 
 Chap. II. — On the soils and state of agriculture of the Tide-water Dis- 
 trict of Virginia. 
 
 General features of the district and its soils, 34, 36. Ridges, 35. Slopes, 35, 36. River mar- 
 gins and alluvial lands, 36. Exhausting tillage and small products, 36. Decreasing popu- 
 lation, 38. Hopeless of improvement under existing circumstances, 39. 
 
 Chap. III. — The different capacities of soils for improvement. 
 
 Five principal propositions stated for discussion, 39. Natural fertility defined, 40. Perma- 
 nency of either fertile or sterile character of different countries and soils, 41. Land natu- 
 rally poor not capable of being enriched by putrescent manures, 41, 42. Opposing opinions 
 and authorities, 43, 45. Facts in support, 44. The degree of original fertility the limit of 
 profitable improvement by putrescent manures, 46, 47. 
 
 Chap. IV. — Effects of the presence of calcareous earth. 
 
 Calcareous earth not found in our poor soils, 48. Its presence indicating great fertility, 48. 
 Natural grovrths on shelly and on poor soils, 49. All authority supports the general pre- 
 sence of carbonate of lime in soils, 50 to 53, SoUs rarely calcareous in Virginia, 54. Re- 
 cent confirming testimony (note), 54, 55. 
 
 Chap. V. — Results of chemical examinations of various soils. 
 
 Methods for testing the presence or absence of carbonate of lime in soils, 56 to 59. Various 
 soils tested — calcareoas, 59 to 61. All known calcareous soils rich, and no poor soU calcar 
 roous, 61. 
 
 Chap. VI. — Chemical examination of rich soils containing no calcareous 
 
 earth. 
 
 Rich river lands. 62 — and also mountain lime-stone soils, 63 to 65. Prairie soils of Alabama 
 generally highly calcai'cous, or super-calcareous, 66, 67. 
 
 Chap. VII. — Proofs of the existence of acid and neutral soils. 
 
 Lime in some form present in ever3' soil, 68. Acid not considered an ingredient of soil by 
 any writers of authority, and denied by others, 69, 70. Proofs of acidity in soil, 70. 
 Growth of acid plants, 71. Nourished best by dead acid plants, 71, 72. By other putres- 
 cent manures, 72. Acid poi.sonoua to cultivated plants, 73. Disappearance of carlioiiate of 
 lime in cultivated soils, 75 to 80. Wood ashes contain lime, 81, 82. Scientific confirmation 
 of acid in soil, 82 to 88. Discovery of humic acid, 83 ; its properties, 86. Successive natu- 
 ral changes of chemical character in soils, 88, 89, 90. Testimony of Loudon of originality 
 of doctrine (note), 91. 
 
 Chap.^VIII. — The mode of operation by which calcareous earth increases 
 the fertility and j^roductivcncss of soils. 
 
 gilicious and aluminous earths have no chemical power to retain putrcpcent manure, 92, 
 93. 94. Calcarcona earth has such power, and how, 94. 95. Examples of combining operas 
 tions, 95. Power of fixing fertilizing matters in soils, 96. Power of neutralizing injurious 
 acids, 97, 93. Pox or of altering and improving texture of both sandy and clayey soils, 98, 
 
 (11) 
 
xii CONTENTS. 
 
 09 and of lessoniii'' evils of too much tlrynoss tincl moishwe, 09. Lime a necessary food 
 for plants, but ouly within narrow limitation, 100, 101. Proportions of limo in ashes of 
 various jjiantg, 102. 
 
 Chap. IX. — Action of caustic lime as manure. 
 
 Da^T's theory of limin- stated, 103. AppUed to practice, 104. Action of caustic Hmc gen^ 
 rally to le avoided, 104. Lime acts generally as carbonate, 105. lorm of classification of 
 manures, 10(5. 
 
 Chap. X.— Introductory and general observations on marl and lime. 
 
 Fossil shells, improperly called marl, 107. Incorrect use of terms in England, lOS-9. Dif- 
 ferent and general misapplications of the name of •' marl" (note), 109, and of " marling' 
 (note). 110. "Limius," in practice, equivalent to marling, 110 to 113. Preliminary 
 remarks on experiments, 114. Oldest applications of marl in A'irginia, 114. 
 
 Chap. XL — Experiments with, and effects of, calcareous manures on acid 
 sancli/ soils, newly cleared. 
 
 Experiments stated, and earliest and later results on light and acid loam, recently brought 
 under cultivation, 116 to 122. Errors in the mode of experimenting stated, 122-i. 
 
 Chap. XII. ^-Effects of calcareous manures on acid clay {or stiff) soils 
 
 recently clcai'ecl. 
 Description of the peculiar soil operated on, 124. Experiments and results stated, 125 to 
 129. Ilemarkable effects ou clover and grain crops, 127 to 129. 
 
 Chap. XIII. — The effects of calcareous mamires on acid soils reduced by 
 
 cultivation. 
 
 Marling always effective on such soils, 130. Experiments stated, and early good results, 130 
 to 136. Diseased crops of grain caused by excessive marling, 133. Effects of marl witli 
 putrescent manure, 137, 13S. 
 
 Chap. XIV. — Effects of calcareous manures on "free light land." 
 
 Character of such soil, 139. Experiments, 139, 140. 
 
 Chap. XV. — Effects of calcareous manures onexliausted acid soils, under 
 
 ilieir second growth of trees. 
 Experiments of this kind, 141, 142. 
 
 Chap. XYI.— -Effects of calcaremis mamires alone, or icitli gypsum, on 
 
 calcareous and neutral soils. 
 Inefficiency of marl on such soils, 143. Gypseous marl, 141. Experiments, 145 to 147. 
 
 Chap. XVII. — Digression to the theory of the action of gypsum as ma- 
 nure. Supposed cause of its ivant ofjwivcr and value on acid soils. 
 
 General inefficiency of gypsum on Atlantic coast, and mistaken views as to the cause, 14T. 
 Exceptions on neutral soils, 148. And the true cause of usual inefHcicucy, 149. Theory 
 of this ineificieucy, and its removal, 151 to 154. 
 
 Chap. XVIII. — The damage caused by too heavy dressings of calcareous 
 manure, and the remedy. 
 
 Earliest effects observed, and symptoms described, 155. Means for preventing or of curing 
 the injury, 150-7. The disease found only on soils naturally acid, 157; and not caused 
 merely by excess of calcareous earth, 158, and probably by humate of lime, 159. 
 
 Chap. XIX. — Recapitulation and more full staloncnts of the effects of 
 calcareous mamires. 
 
 The results of marling have conformed to previous theoretical views, 159. Exceptions above 
 the granite range, and causes, 161. Hazel loam, 161. Effects of calcareous manure pro- 
 portioned to the organic matter in soil, 162. Marl on " palls," 163. I'revents the watching 
 effects by rains, and the moving of sandy soils by winds, 164. Quantities of marl to 1» 
 applied, 160. Effects in preserving vegetable matter from waste, 167. " Free light laud," 
 and its sjieedy exhaustion, IPS. Marling deepens soils, 1G9. Gives peculiar value to sandy 
 sub-soils, 170. Hastens maturing of crops — cotton — wlieat, 170. Strengtbinis straw of 
 wheat, 171. Peculiar benefits to leguminous idiin's, and especially to clover, 172, and to 
 some bad weeds, 17 3. Eailures of clover on marled lands, 173. Effect of calxiug iu eradicat- 
 ing acid plants, 174r-5. 
 
CONTENTS. XUl 
 
 Chap. XX. — Directions for the use of marl in connexion witJi otlier 
 fanning operations. 
 
 Usual difficulties of lieginners ■witlinut reason, 175. The labours to lie regular nnd continu- 
 ous, 170. Keces^ity tbr intermixing marl regularly with the soil, 17G-7. Manner of drop- 
 ping and spreading heaps, 177. Organic manure an essential accompaniment, 177,178; 
 supplied by vegetable growth of the fields, 178. Ordinary farm-made manures, 179; other 
 materials, 180. 
 
 Chap. XXI. — Actual improvements and rbsidts of marling. Peculiar 
 value of sandy soils. 
 
 Cause's of dcfectiye results of earliest marling labours, 181-2. Actual results on Coggins 
 Point farm, to 1842, 183. Crops from 181.3 to 1851, 18-t. Remarks and notes on same, 
 185-6. Culture and crops on Blarlbourne, 187-8. Causes of neglect of marling, and small 
 effects, 189. Value of sandy .foils, 190. Poor soils of lower Virginia also very shallow, 191. 
 Rates of increase of products from marling, on different lands, 192. 
 
 Chap. XXII. — The extent of duration of the effects of calcareous manures. 
 
 Duration of effects known by experience, 192-4. Ke-marlings, why required, 195. Question 
 of duration of calxing, 196. Practice and opiuions in Britain, 197, 198. AUegcd reasons 
 for waste of lime in soils, and answers thereto, 199 to 211. Sinking of lime in soil, 211, 
 212. Kffect of organic (or putrescent) manures made permanent by combination with cal- 
 careous, 214 to 216. Apparent exceptions, 217. Actual duration of effects, 218. Antici- 
 pated progress of improvement, and fixing of organic matter by calxing, 219 — and of steri- 
 lity caused, xjnder reverse circumstances, 220. 
 
 Chap. XXIII. — General observations on the valuations of lands and their 
 improvements, and the expenses and profits of marling. 
 
 Usual estimates altogether erroneous, 221. True mode of estimating values, 222 to 225. 
 Supply and demand regulate selling prices of lauds, 227. Injiidicious marling labours, 
 228. General profits, 229. 
 
 Chap. XXIV. — Other fertilizing potoers and effects of calcareous earth. 
 
 Soils of ancient alluvial formation (or latter drift), 230. Effects of calxing thereon, 231 to 
 233. Action of calx by solvent power, 2.34. Sterility, when caused by calxing, and how, 
 235 to 237. Benefit of lenient cropping, 2.37, and supplying vegetable matter, 238. Erro- 
 neous practice in South Carolina, 239 to 241. Organic matter in plants, 242; how consti- 
 tuted, 243. Proportions of carbon, hydrogen, oxygen, and azote in plants, 244. Whence 
 derived, 246 to 248. Supply of carbon from the atmosphere increased on calcareous soil, 
 248 to 250. Dr. Wight's experiments thereupon, 250 to 252. Other proofs, 253. Ai«5t6 
 supplied from the atmosphere through leguminous plants, 253 to 257. Their peculiar ma- 
 nuring effects thus caused, 258. Residue of roots of clover, &c., 259. Value of the south- 
 ern field pea (or bean), 261. Recapitulation, 262. Effect of lime in soils and compost 
 heaps to produce nitrates, 263. This explains some ijractical results before not understood, 
 266, 267. Effect of lime in promoting the healthy constitution aud vigorous giowth of 
 plants, 207, 268, and the better quality of products, 268. 
 
 Chap. XXV. — The use of calcareous earth recommended to preserve 
 putrescent manures, and to promote cleanliness and health. 
 
 Effects of calcareous earth in preventing waste of products of animal matter, 209, 270. Cases 
 for use of this power, 271 to 274. Unfitness of quick-lime for this purpose, 274. Benefit in 
 preventing disease, 275, 270. How the burning of towns benefits health, 277. Benefits to 
 health of calcareous soU in Alabama, 278 — iu Virginia, 279 to 281 — in I'rance, 281, 2S3 — 
 in England, 283. 
 
 CuAP. XXVI. — The excavation of marl-pits, and carrying oid and ap- 
 plying marl. 
 
 Dry and high-lying marl, 284. Wet marl in hilly lands, 285. Method of opening and work- 
 ing pits of such marl, 286 to 289. Draining the excavation, 289, 290. Deep pitting, 290. 
 Blachiiies for raising marl, 291 to 295. Making roads, 295. Implements and carts for 
 marling, 297. Spreading, 298. Marling tables and estuuates, 299 to 302. Importance of 
 marling labours being continuous, 303. 
 
 Chap. XXVII. — Directions for the searching for and testing of marl. 
 
 ■ Searcliiu" for marl, 304. Use of the auger, 305. Exposures of marl, 306-7. Extended 
 labours anticipated, .307. Usual appearances of mnrl, 308-9. Po "ition and character of the 
 strata, 309-10. Directions fur aualyziug, 310 to 313. Dislunt transportation of marl, 313 
 to 317. 
 
 O 
 
Xiv CONTENTS. 
 
 Chap. XXVIII. — Estimates of the cost of labour applied to marllny. 
 
 The proper grounds for e?liuiat.es, 318. Cost of the labour of a negro man, 319 — of boy, 
 woman, and girl, 320 ; of working horse and mule, 320 ; costs of carts and implements, 
 321. These estimates applied to particular operations of marling, 322 to 326. 
 
 Chap. XXIX. — Details of actual and extensive marling labours. 
 
 Actual labours on low-lying and wet marl, 327. Marl and accomp.anying beds described, 
 328-9. Excavation in "small perpendicular pits, 329. Horizontal plan of diggings, 330-31. 
 Beginning and progress of labour, 329, 333. Work of a single mule, 33-1 to 339. Esti- 
 mated cost of the work, and remarks, 336 to 341. Excavating marl in large graduated 
 pits, 342 to 350. Savings of expense before incurred, 351-52. Expenses at various dis- 
 tances, and rule for estimating, 353. Hazard of large excavations, 354. Quantity of marl 
 removed, 355. 
 
 Chap. XXX. — The progress of marling in Virginia. 
 
 Usual obstacles to the progress of all new improvements in agriculture, 356. The beginning 
 and progress of marling in Virginia, and general condition (in 1842), 357 to 360. Liming, 
 S60. General effects of the use of calcareous manures in Virginia (to 1850), on values of 
 lauds and products of taxation, general wealth, and population, 300 to 363. 
 
 APPENDIX. 
 
 Introductorg rcmarJcs 363 
 
 Note I. — Additional proof, offered in the production and existence of 
 
 black waters, of the action of lime in combining vegetable matters with 
 
 soil. 
 Black waters of certain streams and ponds, and absence of colouring matter in others, 303 to 
 
 365. Causes, 365. Proofs and illustrations, 366. Clearness of lime-stone water, 367. Facts 
 
 and causes of black waters, 368 to 371. 
 
 Note II. — The statements of British authors on "marl," and their 
 applications of the name generally incorrect, and often contradictory. 
 
 Subject stated, 371-2. Correct definitions of marl, 373. Clay and shell marl, 374. "Marls" 
 not calcareous, 375-6. Old authors. Marls not known to be calcareous by their describers, 
 377 to 380. American opinions deduced from English books, 380. Other manures not 
 valued for their known calcareous parts, 381. Errors of modern writers, 382; Arthur 
 Young, 382 to 385; Lord Kames and Sir John Sinclair, 386. Cases of English marling not 
 serving to make .soil calcareous, 387-8. Sir John Sinclair confounding the operations of 
 carbonate, phosphate, and sulphate of lime, 389. Marling of Norfolk, 390. Clays of New 
 York calcareous, 391. Jlarshall's notices of marl and niarling, 391 to 394. Errors of 
 Farmers' Journal, 395. Fossil sea-shell beds (or marl of Virginia) in Europe, 395. Falu>is 
 andfulunage of Frano«, 397-8. Oldest and English views of the marl (now so called) of 
 Vh-ginia, 399. Deductions, 399, 400. Marl and marling of the ancients — notices by Varro 
 and Pliny, 401-2. 
 
 Note III. — The earliest known successful applications of fossil shells as 
 
 manure. 
 
 Oldest applications unsuccessful, 403-4. First successful use in Virginia. 405, and in Mary- 
 land, 405. John Taylor's slighting opinion, 406. Marling of John Singleton, 406 to 408. 
 
 Note IV. — First views which led to marling in Prince George county. 
 
 The author's early lessons and opinions, and errors in farming, 410-11. Former couditioTi 
 of his land, and sources of opinions, 412. Taylor's and Davy's doctrines, 413. Acid in 
 soils supposed, 414-15. First effort in marling, 416, and first results, 417. Earliest opinions 
 of constitution of soils, 418 to 420. English views and writings opposing the use of our 
 marl, 421. '• Kuflin's Folly" and first operation of example, 422-3. Succeeding labours, 
 423-4. Damage caused by marling, 424 to 426. 
 
 Note V. — Description and account of the different kinds of marl, and 
 oftJie gypseous earth of the tide-water region of Virginia. 
 
 Need for the information to bo offered, 427. Character, constitution, and formation of true 
 marl, 428 to 430. Classification of marls, 431. Chalk and rotten lime-stone, 432. Travertin, 
 
CONTENTS. X7 
 
 433. ArKillo-calcaroous, or true marl, 433. Shell-sand, 434. Shell marl, ns understood in 
 Britain, 434-5. Tertiary fossil shell marl (in Virginia), 435-6. Miocene marl, 437 to 440. 
 Varieties, 441 to 448. Crj'stallization in marl, 443-4. Loss of calcareous parts of marl, 448. 
 Comparative values, 449. Eocene marl, 450 ; of Coggins Point, 450-1. Kxteutof same kind, 
 452. Qualities, 4.53. Other eocene marls, 454. Gypseous earth, 454. Gypseous earth of Jamea 
 river, 455 to 475. Green-sand, 458. Use of gypseous earth as manure, 459. Sulphuret of iron 
 (and gypsum) contained, 460. The Tarious strata at Evergreen, 462 to 464. At Coggins 
 Point, 465 to 467. Harrison's Bar of gypseous earth, 467. Green-sand of New Jersey, 468. 
 Analyses of green-sands of Europe and America, 469-70. Analyses of gypseous earth of 
 Coggins Point, 471 to 473. Gypsum the main operating ingredient, 474. Eocene green- 
 sand (or gypseous) marl of Pamunkey, 475 to 482. Different layers described, 476 to 479. 
 Olive earth, 479-80. Gypseous earth of Pamunkey, 4S1-2. All appreciable effects due, not 
 to green-sand, but to gypsum, 482. Po.sition and order of succession of the different layers 
 of the Pamunkey eocene, 483 to 485. Sulphuret of iron in gypseous earth and some marls, 
 486-7. Alleged existence of green-sand, in quantity, in ordinary raiocene marls, 4S7-8. 
 The assertion disproved, 489 to 491. Peculiar miocene. of Hampstead bed only, known to 
 contain green-sand in considerable proportion, 491 to 493. 
 
AN ESSAY 
 
 CALCAREOUS MANURES. 
 
 CHAPTER I.— Introductory. 
 
 GENERAL DESCRIPTION OF AGRICULTURAL EARTHS AND SOILS. 
 
 PHYSICAL AND CHEMICAL CONSTITUENTS OF SOILS. 
 
 In discussions or instructions upon the fertilization of land, it 
 is an important requisite that we should correctly distinguish be- 
 tween earths and soils, and the many varieties of the latter com- 
 pound bodies. Yet the terms used for this purpose, are generally 
 misapplied ; and even among writers of high reputation and autho- 
 rity, no two agree in their definitions of soils, or modes of classifi- 
 cation. That such differences of definition, and contradiction of 
 terms, should exist, will appear the less strange, and the resulting 
 errors the more excusable, to those readers who have most care- 
 fully studied this branch of agricultural science, and who, therefore, 
 can best appreciate the difficulties of the required classification. 
 Each writer on soils is compelled to use terms in senses different 
 from the greater number of his many predecessors ; because but 
 few of them have concurred in even the most important definitions. 
 Where such great differences exist, and where no one known plan 
 of nomenclature is so free from material imperfections as to bo 
 referred to as a standard of authority, it becomes necessary for 
 every one who treats on soils to define for himself ; though perhaps 
 he may thereby add still more to the general mass of confusion 
 previously existing. This necessity must serve to excuse the writer 
 for whatever is new, unauthorized, or confessedly defective in the 
 definitions and terms which will be here adopted, and used as 
 required hereafter through this treatise. It would be inferred by 
 most readers, from the general heading alone, that this introductory 
 chapter must consist mainly of definitions and explanations already 
 established by scientific authority, and generally received by and 
 known to well-informed agriculturists. This inference would be 
 correct to a considerable extent ; nevertheless, there will be many 
 2 * (17) 
 
18 DIFFICULTY OF DEFINING EARTHS AND SOILS. 
 
 of the views wliicli are either new and unsupported, or entirely 
 opposed to all existing authority ; and which will require to be 
 understood and borne in mind by all who desire to study with pro- 
 per advantage the theory of fertilization which will be presented 
 and maintained in this essay. 
 
 Previous to the recent attention of chemists directed to agricul- 
 ture, which may be said to have begun with the publication of 
 Davy's admirable and very valuable (though necessarily very im- 
 perfect) work on the '^ Elements of Agricultural Chemistry," 
 agricultural writers had defined and described soils by their cjuali- 
 ties obvious to the senses, and without much, if any, regard to 
 their chemical, or even their physical constitution. Of course 
 they were often in error ; as the sensible qualities, or textures of 
 soils, do not always quadrate with, or conform to the proportions 
 or kinds of their materials. For example : an open and light soil, 
 is most generally made so by an excess of silicious sand ; but occa- 
 sionally soils owe their possessing this texture to an excess of 
 humus or vegetable matter, or of chalk ', and which soils may be 
 greatly deficient in sand, and would be rendered even more com- 
 pact by an addition of this earth. Again : the closeness and in- 
 tractability of a soil is generally owing to the excess of clay; but 
 a soil superaboundiug in clay, with large intermixture of vegetable 
 and calcareous earths, may be much more friable and light than 
 another with much less clay, and much more of silicious sand in a 
 very finely divided state. 
 
 More recently, when many men of science took their present 
 ground as co-labourers in agricultural investigation, they brought 
 to bear, on this branch of the science, terms and definitions exact 
 and precise enough indeed, they being those recognised in chemis- 
 try ; but altogether inapplicable to agriculture, because referring 
 to conditions of purity, and simplicity of composition, having no 
 existence in nature, nor even subject to the observation and senses 
 of the agriculturist. Hence, when chemists, using their scientific 
 nomenclature, attempt to instruct farmers of the composition of 
 soils, and refer to their contents of the chemical earths proper, 
 alumina, lime, magnesia, &c., they are speaking of things which 
 have no existence in nature, nor even in agricultural art; and they 
 might as well go farther back in search of scientific strictness, and 
 treat of the elementary parts of these several earths — that is, oxy- 
 gen, with the metals aluminum, calcium, and magnesium, respect- 
 ively ; which elements arc rarely produced or preserved separate, 
 and never except in the chemist's laboratory. The substances 
 known in chemistry as earths, are, indeed, defined with precision, 
 and their distinguishing properties are well understood by those 
 who are even slightly acquainted with that science. But of the 
 nine earths known to chemists, one only, silica, exists naturally in 
 
AGRICULTURAL EARTHS. 19 
 
 a state of purity, or uncompounded ; and in this state of purity (as 
 rock-crystal, or pure quartz-rock), it can have no action whatever 
 as an agricultural earth. Two other chemical earths, alumina and 
 lime, are only found combined with other bodies ; and, as thus 
 combined, exhibiting very different properties from the pure earths, 
 which can be produced only by chemical decomposition. A fourth 
 earth, magnesia, likewise is never found uncombined, and rarely 
 in other than very minute proportions, and always intermixed 
 with other earths, so as to be imperceptible by the senses. The 
 other chemical earths (barytes, strontian, zircon, &c.) are so rarely 
 found, and still more rarely in soil, and most of them only in such 
 minute quantities that, as to any influence on agriculture, they may 
 be deemed as non-existent.* 
 
 These few preliminary remarks will serve to expose something 
 of the difiiculty of distinguishing and clearly defining the earths of 
 agriculture. That the attempt which will here be made will but 
 imperfectly reach the desired object, will not be more evident to 
 other persons than to the writer. 
 
 The agricultural earths will here be understood as bodies natu- 
 rally existing, and, when separate, as jiure as ever presented by 
 nature ; and of which, each one, except humus, is composed princi- 
 pally of some one chemical earth. They are five in number — silicious, 
 aluminous, calcareous, magnesian, and vegetable or humus. These 
 agricultural earths, variously intermixed, serve to compose the 
 superficial layer of the globe. This layer, more or less productive 
 of vegetable growth, is soil; and however varying in different 
 places, all soils, for almost their entire bulk, are composed of one 
 or more of the three principal agricultural earths — the silicious, 
 aluminous, and calcareous, with more or less of humus, or vegetable 
 mould. It is convenient, though still a farther departure from 
 scientific strictness of definition, to include humus among the earths 
 of agriculture. 
 
 1. Silicious earth is presented in the cleanest, most crystalline, 
 
 * Tlic chemical earths are combinations of different metals (which are 
 known only in these combinations) with oxygen. Before Davy's splendid 
 discovery of these metals, and their combinations with oxygen, the earths 
 were supposed to be simple bodies, or incapable of being decomposed. A 
 single combination of one of these very rare chemical earths, the sulpliate 
 of barytes, has been recently found to be a very effective manure, acting 
 on clover with the remarkable power of sulphate of lime (gypsum). Pro- 
 fessor Armstrong, of Washington College, has fully tested it by the practi- 
 cal use of the earth as maniu-e. He also informed me that the sulpliate 
 of barytes was found in some parts of that mountain region in sufficient 
 quantity to be used for manuring, in the small proportions required for its 
 effects. These interesting facts do not contradict the remarks in the text 
 above, which referred to barytes and the other scarcer earths only as cou- 
 etituents of soils. 
 
20 SILICIOUS AND ALUMINOUS EARTHS. 
 
 whitest, and purest sancl, as washed and deposited by rapid streams, 
 or other water in motion. This, the very abundant agricultural 
 or natural earth, often approaches nearly in purity to the chemical 
 earth silica. Silicious earth generally appears as sand ; that is, 
 in separate and loose grains of small size, which are rugged and 
 irregular in shape, usually with sharp angles, rough to the touch, 
 and'hard enough to scratch glass. This earth is not soluble in any 
 acid except the fluoric, and cannot be made coherent by any mix- 
 ture with water. The solidity of the particles of sand renders each 
 one impenetrable by water ; and their loose and open arrangement 
 permits water to pass easily through the mass. The same condi- 
 tions of impenetrable grains and loose and open texture cause silicious 
 earth to be incapable of absorbing moisture from the air, or of re- 
 taining, with any force, either moisture or any aerial or gaseous 
 fluid with which it may have been in any manner supplied. Sili- 
 cious earth is also quickly and strongly heated by the sun, which 
 increases thd rapidity with which it loses moisture. 
 
 2. Aluminous earth, or argil, or purest clay, as it may also be 
 called for convenience, is composed, for a largo part, of the chemical 
 earth alumina, from which this and all other less pure clays derive 
 their peculiar and well-known qualities. Still, this purest of clays, 
 naturally existing (or " pipe clay," as termed by some agricultural 
 chemists), contains no more than 3G to 40 per cent, of aluminth, 
 chemically combined with 52 to 60 per cent, of silica, and 3 or 4 
 per cent, of oxide of iron.* Thus even the juirest natural clay, or 
 aluminous earth, does not approach the purity of the chemical earth 
 alumina within some GO to 64 per cent. And all ordinarj^ and less 
 pure clays, of course, have much more of silicious sand, the additional 
 cpantity being in the state of mechanical mixture. Aluminous 
 earth and all clays, in proportion to their purity, when dry, absorb 
 water abundantly; and when wet, form tough and ductile paste, 
 smooth and soapy to the touch. By burning, the mass becomes 
 brick, hard like stone, and is no longer capable of being softened 
 by water. When drying from a previous wet and softened condi- 
 tion, aluminous earth and all clays shrink greatly, and, separating 
 by numerous cracks and fissures, the mass is broken into hard 
 lumps. 
 
 3. Calcareous eavtli, carbonate of limc,'\ or calx, is the next 
 
 * Prof. J. F. W. .Jolinston's "Lectures on the Applications of Chemistry 
 and Geology to Agriculture," p. 230, et seq. First Am. edition of Wiley 
 and Putnam, New York, 1814. 
 
 •|- Carhonaie of lime is the chemical name for the substance formed by 
 the combination of carbonic acid with liinr. The names of all the thousands 
 of different substances (neutral salts) which are formed by the combination 
 of each of the many acids with each of the various earths, alkalies, and 
 metals, are formed by one uniform rule, which is as simple and easy to be 
 
CALCAREOUS EARTH. 21 
 
 raost abundant agricultural earth. It is a combination of the che- 
 mical earth lime with carbonic acid, in the constant proportions 
 (in whole numbers) of 5G parts lime to 44 of carbonic acid. It is 
 converted to pure or quicli-lime by red heat, which drives off tlie 
 carbonic acid; and quick-lime, by exposure, and attracting carbonic 
 acid from the atmosphere, soon reverts to its original condition of 
 carbonate, or calcareous earth. It forms marble, limestone, chalk, 
 and shells, with very small admixtures of other materials. Thus 
 the term calcareous earth will not be vised here to include cither 
 lime in its pure state, or any of the numerous combinations which 
 lime forms with the various acids," except the one combination 
 (carbonate of lime) which is beyond comparison the most abundant 
 throughout the world, and most important as an ingredient of soils. 
 Pure lime attracts all acids so powerfully, that it is never presented 
 by nature except in combination with some one of them, and generally 
 with the carbonic acid. When this compound is thrown into any 
 stronger acid, as the muriatic, nitric, or even common vinegar, the 
 lime, being more powerfully attracted, unites with and is dissolved 
 by the stronger acid, and lets go the carbonic, which escapes with 
 effervescence in the form of air. In this manner, the carbonate of 
 lime, or calcareous earth, may not only be easily distinguished 
 from silicious and aluminous earth, but also from all other com- 
 binations of lime. 
 
 Theforegoing definition of calcareous earth, which confines that 
 term to the carbonate of lime, is certainly liable to objections, but 
 less so than any other designation. It may at first seem improper 
 and even absurd to consider as one of the principal earths which 
 compose soils, one only of the many combinations of lime, rather 
 than either pure lime alone, or lime in all its combinations. One 
 or the other of these significations is adopted by the highest autho- 
 I'ities, when the calcareous ingredients of soils are described ; and 
 in either sense, the use of this term is more conformable with 
 scientific arrangement than mine. Yet much inconvenience is 
 caused by thus applying the term calcareous earth. If applied to 
 
 understood and remembered as it is useful. To avoid repeated explana- 
 tions in tlie course of this essay, tlie rule will now be stated by which these 
 compounds are named. The termination of the name of the acid is changed 
 to the syllable ate, and then prefixed to the particular earth, alkali, or 
 metal with which the acid is united. With this explanation, any reader 
 can at once understand what is meant by each of some thousands of terms, 
 none of which might have been heard of before, and which (without this 
 manner of being named) would be too numerous to be fixed in the most 
 retentive memory. Thus, it will be readily understood that the carbonate 
 of magnesia is a compound of the carbonic acid and magnesia— the sulphate 
 of lime a compound of sulphuric acid and lime — the sulphate of iron a com- 
 pound of sulphuric acid and iron — and in like manner for all other terms 
 50 formed. ="^ 
 
22 CALCAREOUS EARTH. 
 
 lime, it is to a substance wliicli is never found existing naturally, 
 and which will always be considered by most persons as the artifi- 
 cial product of the process of calcination, and as having no more 
 part in the corapoyition of natural soils-than the manures obtained 
 from oil-cake or pounded bones. It is crjually improper to include 
 under the same general term all the combinations of lime with the 
 fifty or sixty various acids. Two of these compounds, the sulphate 
 and the phosphate of lime, arc known as valuable manures; but 
 they exist naturally in soils in such minute quantities, as not to 
 deserve to be considered as important physical ingredients. Many 
 other salts of lime are known to chemists; but their several quali- 
 tiesj as affecting soils, are entirely unknown — and their cpiantities 
 are too small, and Iheir presence too rare, to require consideration. . 
 If all the numerous different combinations of lime, having perhaps 
 as many various and unknown properties, had not been excluded 
 by my definition of calcareous earth, continual exceptions would 
 have been necessary to avoid stating what was not meant. The 
 carhonate of lime, to which I have confined that term, though only 
 one of many existing combinations, yet in c{uantity and in import- 
 rmce, as an ingredient of soils, as well as a part of the known por- 
 tion of the globe, very far surpasses all the others. 
 
 But even if calcareous earth, as thus defined and limited, is ad- 
 mitted to be the substance which it is proper to consider as one of 
 the important earths of agriculture, still there are objections^ to its 
 name which I would gladly avoid. However strictly defined, many 
 readers will attach to terms such meanings as they had previously 
 understood : and the word calcareous has been so loosely and so 
 differently applied in common language, and in agriculture, that 
 much confusion may attend its use. Anything " partaking of the 
 nature of lime" is "calcareous," according to Walker's Dictionary ; 
 Lord Kames limits the term to pure Ivms ;* Davyf and Sinclair^ 
 include under it pure lime and all its combinations; and Kirwan,l| 
 Rozier,^ and Young, § whose example I have followed, confine the 
 name calcareous earth to the carbonate of lime. Nor can an}' other 
 term be substitutTjd without producing other difficulties. Carbon- 
 ate of lime would be precise; but there are insuperable objections 
 to the frequent use of chemical names in a work addressed to ordi- 
 nary readers, and this one would be especially awkward and incon- 
 venient for such use. Chalk, or shells, or mild lime (or what had 
 been quick-lime, but which, from exposure to the air, had ngaiu 
 
 * Gentleman Farmer, page 264 (2d Edin. ed.) 
 
 f Agr. Chcm., page 223 (Phil. ed. of 1821.) 
 
 X Code of Agricultm-c, page 184 (Hartford ed. 1818.) 
 
 ij Kirwan on Manures, chap. 1. 
 
 ^ " Tcrrcs" — Cours Complet d'Agricnlturc rrntiquc. 
 
 ^ Young's Essay on Manures, chap. o. 
 
CALCAllEOUS EAEin. 23 
 
 become carbonated), all tbese arc the same chemical substance ; but 
 none of these names would serve, because each would be supposed to 
 refer to such certain form or appearance of calcareous earth as they 
 usually express. If I could hope to revive an obsolete term, and, 
 with some modification, establish its use for this purpose, I would 
 call this earth calx — and from it derive calxing, to signify the 
 application of calcareous earth, in any form, as manure. A general 
 and definite term for this operation is much wanting. Liming, 
 marling, applying drawn ashes, or the rubbish of old buildings, 
 chalk, or limestone gravel, all these operations are in part, and 
 some of them entirely, that manuring which I would thus call 
 calxing. But because their names are different, so are their effects 
 generally considered — not only in those respects where difi'erences 
 really exist, but in those where they are precisely alike. 
 
 Calcareous earth, in the agricultural sense here assumed (calx, 
 or carbonate of lime), has almost no existence as an ingTcdieut of 
 soil throughout all the great Atlantic slope of the United States 
 north of Florida. Nor has it any existence, separate from soil, 
 unless as lime-stone rock and travertine in the mountain region, 
 and subterranean beds of fossil shells in the tide-water lands. In 
 England, France, and some other parts of Europe, this earth occurs 
 as chalk, in beds of great thickness and vast extent of surface. The 
 whiteness of chalk repels the rays of the sun, and its open texture 
 permits water to sink through almost as easily as through sand. 
 Thus calcareous earth alone, or when constitviting the bulk of a 
 soil, is remarkable for possessing some of the worst qualities of 
 both sand and clay. 
 
 But though the true chalk, which is so widely spread in Europe, 
 does not exist in North America, there are very extensive regions 
 of this continent of which the soils are composed in part, and their 
 subsoils mainly, of calcareous earth, and which may be considered 
 as chalk soils and subsoils in an agricultural, though not a geo- 
 logical sense. Such are most of the '^ prairie" lands of Alabama, 
 Mississippi, and Arkansas ; and (as I infer from analogy) of Texas, 
 and of the vast prairie region west of the Mississippi River. The 
 " everglades" of Florida, as I infer, and the nearest sea islands 
 also, are of like constitution. The subsoil and inferior layers, 
 known in many cases to be several hundred feet thick, are like an 
 impure chalk, composed principally of carbonate of lime (of which 
 there is a proportion from 70 to more than 80 per cent.), inter- 
 mixed intimately, or combined, with fine clay, which constitutes the 
 small remaining part. This great formation of impure calcareous 
 earth maybe considered as either a very rich marl, or a poor chalk; 
 and similar to true chalk in every relation to agriculture, except (in 
 consequence of its argillaceous admixture) in being, in most cases, 
 as much impervious to M^ater as true chalk is the reverse. 
 
24 MAGNESIAN EARTH. 
 
 4. It seems doubtful whether magnesia, in any form or condition, 
 should be counted among the earths of agriculture, or physical 
 constituents of soils. Though very generally diffused through soils, 
 it is usually in extremely small proportions. In this country, so 
 far as my personal observation or other information has extended, 
 no soil is known to contain magnesia, in any form, as a physical 
 or considerable constituent ; and even as a chemical or manuring 
 agent, the quantities present in soil have been so small, and, more- 
 over, so associated with larger proportions of the kindred earth 
 lime, that the effects of the magnesia alone could not be appre- 
 ciated. Nor are the chemical effects of magnesia much better 
 known in Europe, where they are more obvious to observation, and 
 have been more or less remarked upon by all agricultural chemists. 
 They have been considered by most writers as injurious to the fer- 
 tility and productiveness of soils. But, though without any 
 evidence of facts, I would infer the reverse operation of magnesia 
 in small proportions. The grounds of this inference are presented 
 in the general similarity of chemical character of magnesia to lime 
 — and also the very general diffusion of magnesia, in some form of 
 combination (though not often as carbonate), in soils, and espe- 
 cially the richest soils.* 
 
 In other parts of the world, however, magnesia ia much more 
 abundant. It is present in large and (as there supposed) injurious 
 quantity in the Gatinais (between the rivers Seine and Yonne), in 
 France, f and also in Cornwall, in England. | 
 
 Magnesia very much resembles lime in most of their known 
 Cjualities, and especially in their respective chemical affmities to 
 other bodies. The resemblance is perfect in this important respect, 
 that the pure chemical earth magnesia has no natural existence, 
 because of its strong attraction for acids. If made pure by art, it 
 is then the " calcined magnesia" of druggists. In that artificial 
 state, and in which only the pure chemical earth ever exists at all, 
 if exposed to the atmosphere, it soon attracts carbonic acid, and so 
 
 * In a specimen of the celebrated rich alluvial soil of Kcd Eiver, 
 Louisiana, I found from 1 to 2 per cent, of carbonate of magnesia ; and 
 something less in the equally rich deposit of the Mississippi River, on the 
 Arkansas shore. The rich mud of the Nile contains 4 per cent, of this 
 earth. (Regnault, quoted by Boussingault), Ptural Economy, &c., p. 338, 
 (1st Am. ed., 1845.) 
 
 I These peculiar soils were described at length in the "AmiaJcs d'Agri- 
 culti/re Frangaise," by M. Puvis, 'whose article was translated for and pub- 
 lished in the Farmer's Register, vol. iv., p. 212, accompanied by my reasons 
 for doubting the conclusions of the author as to the magnesia being the 
 cause of sterility. 
 
 X The Lizard Downs. (Davy.) This soil is formed in part by the disen- 
 tcgration of the underlying serpentine, a magnesian rock. (J. F. W. 
 luhnston.) 
 
HUMUS; OR VEGETABLE EARTH. 25 
 
 becomes the carbonate of maguesia, wbicli is the ordinary mild 
 substance used as medicine. This is a combination of 48 j^arts of 
 magnesia with 52 of carbonic acid. It is to this compound only, 
 the carhonate of magnesia, I affix the term of magnesian earth, 
 and not to any other form of combination with other earths or with 
 acids, nor to the pure chemical earth magnesia, which has no exist- 
 ence in nature, and, of course, can have no natural influence on 
 soils or on agriculture. 
 
 5. Humus is the partially decomposed remains of dead vegetablo 
 growth, reduced by time to nearly an earthy texture, pulverulent 
 when dry, and soft and slimy, and almost semi-fluid when full of 
 water. This vegetable earth, as peat, and in its pvirest state, is 
 very abundant in Great Britain and other cool and moist countries. 
 But in Eastern Virginia, it has scarcely any existence, separate or 
 alone, except in the Great Dismal Swamp, and in marshes covered 
 by the tides. In these places, and also in the still larger swamps 
 of North Carolina, the continual wetness and dense shade serve to 
 prevent the complete decomposition of vegetable matter, as is done 
 in Europe by the prevalence of cloudy and damp air, and low 
 average temperature ; and under such conditions only, in our hotter 
 and dryer climates, does humus occur alone, or even as forming 
 the principal material of any soil. The peat soil of Europe is com- 
 posed of pure vegetable matter, for GO per cent, or more of its dry 
 weight. (Johnston.) The peat used for fuel is probably still more 
 of vegetable constitution. Of four specimens of soil of the Dismal 
 Swamp, selected and examined by myself, the vegetable parts were, 
 respectively, 75, 90, and, in the other two, 96 per cent, of the 
 bulk of the soil. Different specimens of soils, from both salt and 
 fresh-water tide marshes, bordering on Powhatan (or James) 
 Kiver, lost full 50 per cent, of their dry weight by being burnt 
 thoroughly ; showing tliat half their weight, and probably five-sixths 
 of their bulk, is pure vegetable matter. These soils are, per- 
 haps, as near to pure humus as any in our climate. 
 
 As a small, or chemical ingredient of soil, intermixed or com- 
 bined with other earths and far more abundant materials, humus 
 is present universally, serving as aliment to be drawn up by the 
 roots of growing plants, and without which no healthy or luxuriant 
 growth could be produced. Humus gives colour and value to the 
 black rich mould of old garden ground, and to the richest forest or 
 alluvial soils, before they are reduced in fertility by tillage. 
 
 Soils and Suh-soils in General. 
 
 All the agricultural earths, including humus as one, when sepa- 
 rated pure, or as nearly pure as ever presented by nature, are 
 nearly or entirely barren. This might be inferred from the mere 
 3 
 
26 SOILS AND THEIR COMPOSITION. 
 
 doscription of tlieir respective qualities. Further— the too large 
 proportion of any one earth, in the mixture of several, is injurious 
 to fertility in proportion to such excess. But the quantity which 
 would thus be hurtful by excess would be very different in the dif- 
 ferent earths, and also as to each one, as modified by attendant 
 circumstances. Thus, as a supposition, or, at best, a mere ap- 
 proximation to truth, we may suppose the following named pro- 
 portions to be as large as can be present, respectively, in different 
 soils, and under ordinary circumstances, without being injurious 
 to production : — 
 
 Silicious earth (as pure sand), in a particular soil, 
 will be injurious by its excess, if more in propor- 
 tion to the soil than - - - - 85 per cent. 
 
 Or aluminous earth (argil, or purest clay), in ano- 
 ther soil, - - - - - 25 " 
 
 Or calcareous earth (carbonate of lime, or calx), iu 
 
 another, - - - - - 5 ? " 
 
 Or magnesian earth (carbonate of magnesia), in 
 
 another, 2? « 
 
 Or humus (nearly pure vegetable matter), in another, 12 ? " 
 
 In such large proportion as indicated by the above quantities, 
 the greater part of each earth could act only physicalli/ or mechan- 
 ically. If considered merely as chemical or manuring constituents, 
 and embraced in one soil, perhaps one per cent, of calx, a mere 
 trace of magnesian earth, and five per cent, of humus, would be 
 enough 5 while nearly all the remainder of the hundred parts would 
 be of silicious earth mainly, and aluminous earth, serving merely as 
 physical constituents, for nearly their whole quantities. 
 
 But whatever may be the most suitable proportions, and however 
 much the action and power of each one may be in some cases 
 modified by other ingredients, or by attendant circumstances, still 
 the admixture, in due proportions, of the different earths will serve 
 to correct the defects of all, and thus to form soils of every charac- 
 ter and variety. And various as are the soils naturally formed by 
 mixtures of some or all of the different earths, and greatly defective 
 as most of them are, there are but few which do not more or less 
 fulfil their purpose of serving to sustain the growth of useful plants ; 
 in which they may extend their roots freely, yet be firmly sustained 
 in their erect position ; and obtain the necessary supplies of air, 
 moisture, warmth, and food, without being too much oppressed by 
 the excess of either. Such are the soils, though of various pro- 
 portions and values, on all the surface of the globe wherever fit 
 for culture. And though the qualities and values of soils are as 
 various as the proportions of their ingredients are innumerable, 
 yet they arc mostly so constituted that uo one earthy ingredient is 
 
SOILS AND SUB-SOILS. ^ 27 
 
 SO albundant but that tlae texture* of tlie soil is rQeclianically suited 
 to some one valuable crop; as some plants require a degree of 
 closeness, and others of openness iu the soil, which would cause 
 other plants to decline or perish. 
 
 The dept4i of soil seldom extends more than a few inches below 
 the surftice, as on the surface only are received those natural suji- 
 plies of vegetable and animal matters, which are necessary to con- 
 stitute soil. Valleys subject to inundation have washings of soils 
 brought from higher lands and deposited by the water, and there- 
 fore are of much greater depth. 
 
 Below the soil is the sub-soil, of uncertain depth, and which need 
 not be considered as extending deeper than its texture or condition 
 may affect the production of the soil above, whether beneficially or 
 injuriously. It is, however, most common that the sub-soil is ap- 
 parently nearly of the same constitution with the subjacent mass for 
 several or many feet deeper. The sub-soil is usually a mixture of 
 two or more earths, and the same as may predominate in the soil 
 above. But the sub-soil is much more deficient in calcareous earth 
 (except under chalky soils), and lime in every state, and also in 
 humus; and, indeed, nearly all sub-soils in lower Virginia are 
 totally deficient in all those ingredients essential to vegetable pro- 
 duction. Even where such absolute deficiency may not exist, the 
 usual great excess of either sand or clay in sub-soils would alone 
 serve to render them nearly barren ; and, consequently, their mix- 
 ture with the better soil lying above would be injurious rather than 
 beneficial to its improvement. 
 
 The qualities and value of soils depend on the proportions of 
 their ingredients. "We can easily comprehend in what manner 
 silicious and aluminous earths, by their mixture, serve to cure the 
 defects of each other ; the open, loose, thirsty, and hot nature of 
 sand being corrected by, and correcting in turn, the close, adhesive, 
 and water-holding qualities of aluminous earth. This curative 
 operation is merely mechanical ; and in that manner it seems likely 
 that calcareous earth, when in large proportions, and serving as a 
 mechanical constituent, also acts, and aids the corrective powers of 
 both the other earths. This, however, is only supposition, as I 
 have met with scarcely any such natural soil. 
 
 But besides the mechanical effects of calcareous earth (which 
 are weaker than those' of the other two), that earth has chemical 
 powers far more effectual in altering the texture of soils, and for 
 which a comparatively small quantity is amply sufficient. The 
 chemical action of calcareous earth, as an ingredient of soils, wiU 
 be fully treated of hereafter ; it is only mentioned in this place to 
 
 * The texture of a soil means tlie disposition of its parts, wliicli produces 
 i^cli sensible qualities as being close, adhesive, open, friable, i'cc. 
 
28 niYSICAL AND CHEMICAL CONSTITUENTS OF SOILS. 
 
 avoid tlie apparent contradiction which might be inferred, if, in a 
 general description of calcareous earth, I had omitted all allusion 
 to qualities that will afterwards be brought forward as all-important. 
 
 Physical (or MccJianical) and Chemical Constituents of Soils. 
 
 In the discussion of this general subject, we should always bear 
 in mind the dificrent actions of the earths as the j'hi/sical, or me- 
 chanical, and the chemical ingredients of soils. These different 
 actions have already been incidentally referred to ; but they require 
 more particular notice. 
 
 Any of the earths which may serve as large materials in the 
 composition of a soil, must act, for much their greater proportion, 
 merely mechanically in the relation of the soil to the growth of 
 plants. Thus, the various mixtures of silicious and aluminous 
 earths existing in all ordinary soils — and these more rarely with 
 large proportions of either calcareous or magnesian earth, or humus 
 ' — serve, for much the larger proportions of each and all, to furnish 
 merely that mechanical position and support for growing plants 
 which is necessary for them to draw freely the available supplies 
 of water, air, and food. The conditions necessary for this purpose 
 are, that the soil shall have enough sand to be sufficiently permeable 
 by moisture, and for the extension of the rootlets ; that there shall 
 be enough clay to give firm support to the plant in its upright 
 position, and sufficiently to close the too great openness of the sand. 
 -These necessary physical conditions of the soil, in relation to its 
 texture and powers of receiving, retaining, and transmitting moist- 
 ure, are further improved, and opposite evils either modified or 
 prevented, by additional admixtures of calcareous (and perhaps 
 magnesian) earth, and humus. But so far the action of each and 
 all these materials, in large quantities, (and for much the larger 
 proportion being always understood), act only by their physical 
 qualities, and exert such powers in proportion to cjuantities. Any 
 one of these materials, for much its greater part, might be Substi- 
 tuted by some other, if offering like physical qualities, though 
 totally different in chemical character and constitution. Thus, 
 when chalk greatly predominates in soil disposed to dampness, 
 from position or climate, its physical qualities serve to increase the 
 evil, as would clay ; and the soil is both colder and wetter than if 
 there were no physical action of the calcareous earth. On the 
 other hand, in a soil disposed to suffer by dryness, the like chalky 
 constitution would increase that evil, as would sand, by its open 
 texture permitting the too rapid escape of moisture. Humus, in 
 large proportion, acting mechanically like clay, serves to close the 
 too open pores of sandy soils; and, by its remarkable absorbent 
 power, to make them more retentive of moisture wherever excess 
 
THYSICAL AND CHEMICAL CONSTITUENTS OP SOILS. 29 
 
 of moisture exists. Yet in a soil largely composed of clay, and as 
 much deficient in sand, a very lai'ge natural supply of humus will 
 prevent the tenacity and intractability which the clay otherwise 
 would have induced; and cause the soil, when dry, to be friable, 
 loose, and permeable. In wet seasons, however, the same soil will 
 be again too close and adhesive. 
 
 Further — if we can conceive that other materials could be sub- 
 stituted, having entirely different chemical characters, they might 
 serve as well for physical constituents of soils, as the earths of 
 which they took the place. Thus the purest clay, or even pure 
 alumina, if calcined to the state of brick, and then reduced to fine 
 grains, would serve the same physical purposes in soil as silicious 
 sand. And if an artificial soil were thus composed, it might have 
 all the physical qualities of the most sandy soil, while its chemical 
 composition would be more aluminous than ever exists in nature. 
 
 The physical or mechanical action of earths has been kept gene- 
 rally in view through the foregoing pages, inasmuch as the earths 
 have been considered as forming large ingredients of soils. But 
 besides this more obvious action of the agricultural earths, all of 
 them, as well as many other different liodies, act also by chemical 
 power. For the fullest exercise of this power by each, compara- 
 tively very small proportions of each ingredient are required. In 
 a soil composed of any proportion whatever of silicious, aluminous, 
 calcareous, magnesian, and vegetable earths, perhaps the quantity 
 of each acting chemically, might not exceed the hundredth, if the 
 thousandth, part of the whole mass of soil — all the remainders of 
 each earth, whether great or small, having, for the time, no other 
 than mechanical action. 
 
 But the magnitude and importance, and value to the farmer, of 
 the mechanical and chemical ingredients of soils are not at all in 
 proportion to the quantities reqiiired to exert the different powers. 
 The chemical action is much the more valuable in effect and benefit 
 produced; and also because the producing agents, from the small 
 quantities required, are more or less under the control of man ; 
 while the great quantity alone of any material required for physical 
 effect, would generally place it entirely beyond control. 
 
 All cliemical ingredients of soils, whether of the agricultural 
 earths which also make the universal mechanical materials, or of 
 any other bodies so far as they operate in soils by chemical action, 
 are ma mires, which serve directly or indirectly, immediately or 
 remotely, to give food to and promote the growth and production 
 of plants. 
 
 Thus, according to my views, and in the sense in which I use 
 
 the terms, the pliyucal or vieclianiccd constituents of soils, and the 
 
 agricnltural earths, when serving as earths, are the same ; and 
 
 also, that so much of these earths as act clicinicalbj, or as chemical 
 
 3* 
 
30 PHYSICAL AND CHEMICAL CONSTITUENTS OF SOILS. 
 
 coni^tituents of soils, are manures. The same substance (whether 
 silicious sand, clay, chalk, or humus) which, when in quantity, and 
 for the much larger proportion of such quantity, is a mere earth, 
 or mere physical material, also, for a very small proportion, in the 
 same or other soil, acts chemically and as a manure. And these 
 different operations of the same substance may even oppose each 
 other ; and then it will depend on other circumstances whether the 
 manuring action of a minute proportion of the si;bstance will do 
 more good than is produced of injury by the excess of the same 
 substance as an agricultural earth and physical material of the 
 soil. 
 
 If I have succeeded in clearly showing the distinction of me- 
 chanical and chemical action in soils of even the same substances, 
 it will serve to remove much of the obscurity and mystery which 
 have attended the general subject. When the application of cal- 
 careous matter as manure is new, or but beginning in any country 
 (as in Virginia thirty years ago), it has been deemed (by many par- 
 tially informed persons) a sufficient objection to the promised 
 benefit of a small application, that much larger natural proportions 
 elsewhere did not always «iake rich lands. It seemed incradible 
 that a proportion of calcareous earth less than 1 per cent, of the 
 soil could much promote its fertilization and productiveness, when 
 other soils had 5, 10, or 50 per cent, of that material, and were 
 not always rich, and in some cases were extremely barren. But, 
 in such cases, 1 per cent, (or less), perhaps, was as large a pro- 
 portion of carbonate of lime as could act chemically and as a ma- 
 nure. All beyond that proportion would be mere physical material ; 
 and if in excess even for its mechanical operation, would be injuri- 
 ous in proportion to its excess. Thus (as will be shown hereafter) 
 a very small proportion of this earth serves to lessen the evil effects 
 to soils of both too much wetness and too much di-yness, and the 
 opposite evils of too much heat and also of low temperature. But 
 in a chalky soil, where this ingredient is in great cjuantity, the 
 mechanical action predominates and overpowers the chemical ; and 
 such constitution o£ soil serves to aggravate all the opposite evils 
 of dryness and moisture, heat and cold, which the chemical action, 
 if alone, would greatly mitigate. 
 
 The perplexity and erroneous deductions which have prevailed 
 have been much increased by some writers of scientific celebrity. 
 From analyzing specimens of remarkably fertile soils, and finding 
 in most cases very large proportions of carbonate of lime, they have 
 absurdly inferred that these were the most proper proportions. 
 Hence, different chemists have indicated as the most suitable for 
 the highest fertility of soil, proportions of this earth varpng from 
 2 to 30 per cent, of the whole mass of soil. They who advocated 
 the larger quantities were ignorant that perhaps nine-tenths of the 
 
CLASSIFICATION OF SOILS, ol 
 
 lime was either inert earth, or positively hurtful by its peculiar 
 mechanical action ; and that" such soils, when highly fertile (as the 
 mud of the Nile, with its 25 per cent.), were so by aid of their 
 other useful ingredients, which enabled the soil to withstand the 
 evil operation of the greater portion of its lime. 
 
 It is scarcely necessary to state that neither of the agricultural 
 earths applied to soil can serve as a manure (i. e., have any chemi- 
 cal action), when there is already enough of the same earth present 
 to have any mechanical action. And however useful each of the 
 earths may be if applied where its chemical action is deficient, it 
 would bo as absurd in reasoning as useless in practice, to apply 
 sand to sandy, and clay to clayey soils, or lime to the chalky, or 
 vegetable matters to peaty soils. 
 
 The foregoing definitions and explanations ofi"er some materials, 
 or ground-work, for the classification of soils. But, greatly as that 
 is needed, it is not designed here to attempt the construction of a 
 proper general classification or nomenclature — which would serve to 
 add another failure to those of all preceding writers on soils. But 
 as it is impossible to discuss the subjects to be presented for con- 
 sideration in this essay without the use and aid of some definite 
 terms, I will adopt, for present and provisional use, the following 
 general terms for soils, deduced from their respective predominant 
 or most operative •pliyslcal ingredients, and which will have rela- 
 tion only to mechanical constitution, and such qualities and cha- 
 racters of soils as are generally indicated by their texture, and are 
 evident to the senses. 
 
 In reference, then, to physical predominating ingredients only, 
 each of the agricultural earths above described, by its quantity, • 
 serves to make a different general character of soil — which, accord- 
 ing to the predominant physical constituent earth, belongs to some 
 one of the following five classes or general divisions of soils : — 
 
 1. A siUcious or sandy soil contains so large a proportion of 
 silicious earth, in the state of sand, as by its excess to give more 
 or less of the peculiar texture and mechanical qualities of that earth 
 to the soil. Thus, a silicious or sandy soil will show most strongly 
 such qualities as openness, looseness, want of adhesiveness when 
 wet, permeability, rapidity in drying, &c., such as are still more 
 strongly shown by pure silicious sand. 
 
 2. An aluminous, argillaceous, or clayey soil contains such ox- 
 cess of aluminous earth, or purest clay, as will give to the soil the 
 cjualitics of adhesiveness and plasticity when wet, more or less of 
 obstruction to the passage or sinking of rain-water, great tendency 
 to shrink in drying, and to hardness when dry, &c. 
 
 3. A chaUcy, or snjyer-calcareons soil, whether made so by true 
 chalk, or by any other form of calx or carbonate of lime, from any • 
 
 .other source, contains an excess of that agricultural earth large 
 
32 CLASSIFICATION OF SOILS. 
 
 enough to be injurious, in any of the modes indicated to the phy- 
 sical properties above stated of that earth. No such soil exists in 
 all Virginia, nor in any other of the Atlantic States north of 
 Florida. 
 
 As these general divisions of soils are determined according to 
 their predominating or most operative physical ingredient only, 
 the term calcareous soil (of which such frequent use will be made 
 in this essay) has been designedly omitted above. But to prevent 
 misapprehension, it will be merely mentioned, in anticipation, that 
 calcareous soil will be hereafter used as a still more comprehensive 
 term, embracing not only all the super-calcareous soils, but all 
 others that contain even the smallest appreciable proportion of car- 
 bonate of lime. Generally, however, the term calcareous will be 
 that applied to soils in reference to their contents of small and 
 harmless proportions of carbonate of lime (acting as a chemical 
 constituent only or mainly) ; while those having larger and hurtful 
 proportions will always be contra-distinguished as the chalky or 
 super-calcai'cous.* 
 
 4. A magnesian soil would be one in which magnesian earth 
 is in sufficient excess to make its physical qualities predominate 
 over the other earths serving as ingredients. Such soils are of 
 doubtful existence; certainly of extremely rare occurrence. 
 
 5. Khumicj peati/, or vegctahle so;7, has so large a proportion 
 of humus that it is either injurious to production, or otherwise 
 serves to counteract and overbalance the opposite injurious qualities 
 of some other ingredient. Thus, a soil which by its aluminous 
 constitution alone would have been very clayey, or another which 
 would otherwise have been chalky, might have either of such de- 
 fects of texture, &Cy counteracted, and partially remedied, by a 
 greater predominance of humus ; and thereby be made a humic 
 instead of either a clayey or chalky soil. 
 
 For an earth to be predomina7it and excessive in a soil, as un- 
 derstood above, and so to convey its qualities and its name, it is 
 not necessary that it shall be the ingredient greatest in quantity — 
 
 * The previous difficulties of definition and of imderstanding on this 
 head, would be greatly increased by admitting the strange nomenclature of 
 the latest vri-iter, Professor J. F. W. Johnston, Tvhose authority stands so 
 high, and is so generally worthy of respect. He confines the term "cal- 
 careous soil" (by express definition) to such as contain more than 20 per 
 cent, of carbonate of lime ! Those containing from 5 to 10 pei' cent, he 
 terms " marly soils ;" and all containing less than 5 per cent, are left 
 ■without any distinguishing term or character in regard to their calcareous 
 constitution. (Johnston's Lectures, p. 233.) According to these designa- 
 tions, there would not be an acre of natural " calcareous soil," or even 
 of "marly soil," in all Virginia; nor will there be, after all that shall be 
 judiciously done by tlie industry of man in supplying calcareous manure 
 to tlic soils deficient in that ingredient. 
 
DEFINITIONS OF BOILS. 33 
 
 which only is always the ease as to silicious earth. Of this, in its 
 pure and uncombined state, as sand (capable of being separated by 
 washing in water), it requires a very large proportion, say not less 
 than 80 per cent, of the whole mass, to constitute a sandy soil. 
 But, in other soils, though consisting for much more than half their 
 mass of uncombined silicious sand, a much smaller proportion of 
 cither one of the other earths would serve to make the latter the 
 predominant ingredient, and properly to give character and name 
 to the soil. Thus, from 35 to 40 per cent, of " purest clay" (which 
 itself contains about 60 per cent, of silica), or 30 per cent, of calx, 
 or 25 per cent, of humus, or peidiaps less of each, under ordinary 
 conditions, would serve to constitute, respectively, either a clayey, 
 a chalky, or a humic soil; though, in each case, the other and 
 much larger ingTedients would be other earthy materials than the 
 one so predominating. 
 
 I3ut even in soils having some one physical ingredient sufficiently 
 predominant and distinguished to indicate their general character and 
 name, there also are usually apparent the manifest though weaker 
 indications of the presence of some other influential ingredient. 
 For such compound qualities, terms may be compounded of the 
 foregoing, which will sufficiently express the characters referred to. 
 For this purpose, there will be found a convenience in using also 
 the term loam for all soils approaching to a medium texture and 
 composition of the two usually most abundant, ingredients, silicious 
 sand and clay — or soils in which the opposite qualities of silicious 
 and aluminous earths serve in great measure to correct each other, 
 leaving no great or injurious excess of either. Such a medium 
 texture, or soil approaching nearly to such, would be simply a loam. 
 If still more sandy, it might be termed a sandy loam ; or a clayey or 
 chalky, or peaty loam, under other conditions of physical constitu- 
 tion. Besides all these and other such compounded terms, others 
 may be used for other physical and accidental qualities of soils, as 
 stony, gravelly, ferruginous, &c., any of which may apply to any 
 soil of diffijrent predominant character, and diiferent general de- 
 signation.* 
 
 * The convenient and very common term loam is defined above (it is pre- 
 sumed) with enough precision and correctness ; and also in accordance with 
 common understanding. Yet this term offers (next, perhaps, to "marl") 
 one of the strongest examples of the conflict of definitions and confusion 
 which jn-evail among agricultural writers. This term is so common that it 
 is ijped by every one who writes of soils— and which, in some one or other 
 sense, each writer probably considered as forming a very large, if not the 
 greatest proportion of the cultivated soils of his country, and of the world. 
 Some of various and contradictory and erroneous definitions will be here 
 quoted : — 
 
 liii'wan sajs — "Loam denotes any soil moderately cohesive, and more so 
 
CHAPTER II * 
 
 ON THE SOILS AND STATE OF AGRICULTURE OP THE TIDE- 
 WATER DISTRICT OP VIRGINIA. 
 
 -"During several days of our journey, no spot was seen that 
 
 was not covered with a luxuriant growth of large and beautiful 
 forest trees, except where they had been destroyed by the natives 
 for the purpose of cultivation. The least fertile of their fields, 
 when left untilled and without seeding, are soon covered with grass 
 several feet in height ; and unless prevented by subsequent culti- 
 vation, a second growth of trees rapidly springs up, which, without 
 care or attention, attain their giant size in half the time that would 
 be expected on the best lands in England." 
 
 than loose chalk. By tlic author of the ' Body of Agriculture,' it is said 
 to be a clay mixed with sand." (Essay on Manures, ch. 1.) 
 
 ^^ Loam, or that species of artificial soil into Avhich the others are gene- 
 rally brought by the course of long cultivation." — " AVhere a soil is mode- 
 rately cohesive, less tenacious than clay, and more so than sand, it is known 
 by the name of loam. F?ora its frequency, there is reason to suppose that 
 in some cases it mighU be called an ^original soil.'" [^Sinclair's Code of 
 Agriculture — chap. 1.] 
 
 "The word loam should be limited to soils containing at least one-third 
 of impalpable earthy matter, cojiioushj effervescing icith acids." [Dain/'s 
 Agricidtural Chemistry — Lecture 4.] According to this definition by the 
 most scientific writer and highest authority in chemical agi-iculture, if we 
 except the small portion of shelly land, there is certainly not an acre of 
 natural loam between the sea-coast of Virginia and the Blue Ridge Moun- 
 tains — and very few even in the limestone region. 
 
 " By loam is meant any of the earths combined tcilh decayed animal or 
 vegetable matter." [Appendix to Agr. Chem. by George Sinclair.'] 
 
 "Loam — fat unctuous earth — marl." [Johnson's Dictionary, 8vo. ed., 
 and also Walker's.] 
 
 "Loam may be considered a clay of loose or friable consistency, mixed 
 with mica or isinglass, and iron ochre." [Editor of American Farmery 
 (old series) val. Hi., page 320.] 
 
 [* In this and the next following seven chapters (II. to IX. inclusive), 
 in which are set forth my peculiar views of the qualities of our soils, the 
 general absence and want of calcareous earth, the mode of action of cal- 
 careous manures, and, in general, the theory of fertilization, the entire 
 matter of the edition of 1832 has been scrupulously retained, without aljira- 
 tic'n, other than in a few transpositions of matter and merely verbal cor- 
 rections, which have not at all altered the purport. AVhatevcr else has 
 been added, in later editions and the present, whether to the text or as 
 notes, will be designated by being enclosed in brackets, and will also, in 
 most cases, be marked with the date of (he edition, or the writing, in which 
 such additional passages first appeared.— 1852.] 
 
 (34) 
 
TIDE-WATER DISTRICT OE VIRGINIA. 35 
 
 If the foregoing description was met with in a ' Jouraey through 
 Cabul/ or some equally unknown region, no European reader woidd 
 doubt that such lands were fertile in the highest degree — and many 
 even of ourselves would receive the same impression. Yet it is no 
 exaggerated account of the poorest natural soils, in our own gene- 
 rally poor country, which are as remarkable for their producing 
 luxuriant growths of pines, and broom-grass, as for their unpro- 
 ductiveness in every cultivated or valuable crop. We are so ac- 
 customed to these facts, that we scarcely think of their strangeness ; 
 or of the impropriety of calling any land barren, which will pro- 
 duce a rapid or heavy growth of any one plant. Indeed, by the 
 rapidity of that growth (or the fitness of the soil for its production), 
 we have in some measure formed a standard of the poverty of the 
 soil. 
 
 With some exceptions to every general character, the tide-water 
 district of Virginia may be described as generally level, sandy, 
 poor, and free from any fixed rock, or any other than stones rounded 
 apparently by the attrition of water. On much the greater part 
 of the lands, no stone of any kind is to be found of larger size than 
 gravel. Pines of difierent kinds form the greater part of a. heavy 
 cover to the silicious soils in their virgin state, and mix consider- 
 ably with oaks and other growth of clay land. Both these kinds 
 of soil, after being exhausted of their little fertility by cultivation, 
 and '• turned out" to recruit, are soon covered by young pines which 
 grow with vigour and luxuriance. This general description applies 
 more particularly to the ridges which separate the slopes on differ- 
 ent streams. The ridge lands are always level, and very poor — 
 sometimes clayey, more generally sandy, but stiifer than would be 
 inferred from the proportion of silicious earth they contain, which 
 is caused by the fineness of its particles. Whortleberry bus'aes, as 
 well as pines, are abundant on ridge lands — and numerous shallow 
 basins are found, which are ponds of rain water in winter, but dry 
 in summer. None o^ this large proportion of our lands has paid 
 the expense of clearing and cultivation, and much the greater part 
 still remains under its native growth. Enough, however, has been 
 cleared and cultivated in every neighbourhood to prove its utter 
 worthlessness under common management. The soils of ridge 
 lands vary between sandy loam and clayey loam. It is difficult "to 
 estimate their general product under cultivation; but judging from 
 my own experience of such soils, the product may be from five 
 bushels of corn, or as much of wheat, to the acre on the most clayey 
 soils, to twelve bushels of corn, and less than three of wheat, on 
 the most sandy — if wheat were there attempted to be made. 
 
 The slojjes extend from the ridges to the streams, or to the allu- 
 vial bottoms, and include the whole interval between neighbouring 
 branches of the same stream. This class of soils forms another 
 
36 TIDE-WATER DISTRICT OP VIRGINIA. 
 
 great body of lands, of a higher grade of fertility, though still far 
 from valuable. It is generally more sandy than the poorer ridgo 
 land, and when long cultivated, is more or less deprived of its soil, 
 by the washing of rains, on every slight declivity. The washing 
 away of three or four inches in depth exposes a sterile subsoil (or 
 forms a ''gall"), which continues thenceforth bare of all vegetation. 
 A greater declivity of the surface serves to form gullies several feet 
 in depth, the earth carried from which covers and injures the ad- 
 jacent lower land. Most of this kind of land has been cleared 
 and greatly exhausted. Its virgin growth is often more of oak, 
 hickory, and dogwood, than pine ; but when turned out of cultiva- 
 tion, an unmixed growth of pine follows. Laud of this kind in 
 general has very little durability. Its best usual product of corn 
 may be, for a few crops, eighteen or twenty bushels — and even as 
 much as twenty -five bushels, from the highest grade. Wheat is 
 seldom a productive or profitable crop on the slopes, the soil being 
 generally too sandy. When such soils as these are called rich or 
 valuable (as most persons would describe them), those terms must 
 be considered as only comparative ; and such an application of them- 
 proves that truly fertile and valuable soils are very scarce in lower 
 Virginia. 
 
 Almost the only very rich and durable soils below the falls of 
 our rivers are narrow strips of high-land along their banks, and the 
 low-lands formed by the alluvion of the numerous smaller streams 
 which water our country. These alluvial bottoms, though highly 
 productive, are lessened in value by being generally too sandy, and 
 by the domage they suficr from being often inundated by floods of 
 rain. The best high -land soils seldom extend more than half a 
 mile from the river's edge — sometimes not fifty yards. These ir- 
 regular margins are composed of loams of various qualities, but all 
 highly valuable; and the best soils are scarcely to be surpassed in 
 their original fertility, and durability under severe tillage. Their 
 nature and peculiarities will be again adverted to, and more fully 
 described hereafter. 
 
 The simple statement of the general course of tillage to which 
 this -part of the country has been subjected, is sufficient to prove 
 that great impoverishment of the soil has been the inevitable con- 
 sequence. The small portion of rich river margin was soon all 
 cleared, and was tilled without cessation for many years. The 
 clearing of the slopes was next commenced, and is not yet entirely 
 completed. On these soils, the succession of crops was less rapid, 
 or, from necessity, tillage was sooner suspended. If not rich 
 enough for tobacco when first cleared (or as soon as it ceased to be 
 so), land of this kind was planted in corn two or three years in 
 succession, and afterwards every second year. The intermediate 
 year between the crops of corn, the field was " rested" under a 
 
BARRENNESS OF TIDE-WATER DISTRICT, 37 
 
 crop of wlioat, if it would produce four or five bushels to the acre. 
 If the saudiness, or exhausted condition of the soil, denied even 
 this small product of wheat, that crop was probably not attempted ; 
 and, instead of it, or oats, the field was exposed to close grazing, 
 from the time of gathering one crop of corn to that of preparing 
 to plant another. No manure was applied, except on the tobacco 
 lots ; and this succession of a grain crop every year, and afterwards 
 every second year, was kept up as long as the field would produce 
 five bushels of corn to the acre. When reduced below that pro- 
 duct, and to still more below the necessary expense of cultivation, 
 the land was turned out to recover under a new growth of pines. 
 After twenty or thirty years, according to the convenience of the 
 owner, the same land would be again cleared, and put under similar 
 scourging tillage, which, however, would then much sooner end, 
 as before, in exhaustion. Such a general system is not yet every- 
 where abandoned ; and many years have not passed since such was 
 the usual course on almost every farm. 
 
 How much our country has been impoverished during the last 
 fifty years, cannot be determined by any satisfactory testimony. 
 But, however we may difier on this head, there are but few who 
 will not concur in the opinion, that [up to 1831] our system of 
 cultivation has been every year lessening the productive power of 
 our lands in general — and that no one county, no neighbourhood, 
 and but few particular farms, have been at all enriched since their 
 .first settlement and cultivation. Yet many of our farming opera- 
 tions have been much improved and made more productive. Driven 
 by necessity, proprietors direct more personal attention to their 
 farms — better implements of husbandry are used — every process 
 is more perfectly performed — and, whether well or ill directed, a 
 spirit of inquiry and enterprise has been awakened, which before 
 had no existence. 
 
 Throughout the country below the falls of the rivers, and perhaps 
 thirty miles above, if the best land be excluded, say one-tenth, the 
 remaining nine-tenths will not yield an average product of ten 
 bushels of corn to the acre ; though that grain is best suited to our 
 soils in general, and far exceeds in quantity all other kinds raised. 
 Of course, the product of a large proportion of the land would fall 
 below this average. Such crops, in very many cases, cannot re- 
 munerate the cultivator. If our remaining wood-land could be at 
 once brought into cultivation, the gross product of the country 
 woixld be greatly increased ; but the nett product very probably 
 diminished ; as the general poverty of these lands would cause more 
 expense than profit to accompany their cultivation under the usual 
 system. Yet every year we are using all our exertions to clear 
 wood-land, and in fact seldom increase either nett or gross products 
 — because nearly as much old exhausted land is turned out of cul- 
 4 
 
38 LOW PROFITS OP TIDE-WATER DISTRICT. 
 
 tivation as is substituted by tlie newly cleared. Sound calculations 
 of profit and loss would induce us even greatly to reduce the extent 
 of our present cultivation, in lower Virginia, by turning out and 
 leaving waste (if not to be improved), every acre that yields less 
 than the total cost of its tillage."^ 
 
 No political truth is better established than that the population 
 of every country will increase, or diminish, according to its regular 
 supply of food. We know from the census of 1830, compared with 
 those of 1820 and 1810, that ovir population is nearly stationary, 
 and, in some counties, is actually lessening; and therefore it is 
 certain that [to 1830] our agriculture in general is not increasing 
 the amount of foocb or the means of purchasing food — with all the 
 assistance of the new land annually brought under culture. In 
 these circumstances, a surplus population, with all its de2)lorable 
 consequences, is only prevented by the great current of emigration 
 which is continually flowing westward. No matter who emigrates, 
 or with what motive — the enterprising or wealthy citizen who 
 leaves us to seek richer lands and greater profits, and the slave sold 
 and carried away on account of his owner's poverty — all concur in 
 producing the same result, though with very diff"erent degrees of 
 benefit to those who remain. If this great and continued drain 
 from our j^opulation was stopped, and our agriculture was not im- 
 proved, want and misery would work to produce the same results. 
 Births would diminish, and deaths would increase ; and hunger and 
 disease, operating here as in other countries, would keep down 
 population to that number that the average products of our agri- 
 cultural and other productive labour can feed, and supply with the 
 other necessary means for living. 
 
 A stranger to our situation and habits might well oppose to my 
 statements the very reasonable objection, that no man would, or 
 could, long pursue a system of cultivation of which the returns fell 
 short of his expenses, including rent of land, hire of labour, interest 
 on the necessary capital, &e. Very true; if he had to pay those 
 expenses out of his profits, he would soon be driven from his farm 
 to a jail. But we own our land, our labourers, and stock; and 
 though the calculation of nett profit, or of loss, is precisely the same, 
 yet we are not ruined by making only two per cent, on our capital, 
 
 [* The foregoing description was written in 1826, and first published in 
 ■ 1831, and particular exceptions to the general correctness of the applica- 
 tion had been even then recently exhibited; and, ■with the j^assage of every 
 year since, these exceptions have been becoming more numerous and more 
 important, and in a rapidly increasing ratio. These recent facts of im- 
 proved lands and increased production, as well as their peculiar causes, 
 will be treated of siibsoqucntly. The observations and deductions presented 
 in the remainder of this chapter Avcrc also of the same date as the forego- 
 ing statements, on which they are founded. (18J;2.) ] 
 
FIVE GENEBAL PROPOSITIONS. 39 
 
 provided we can manage to live on that income. If we live on 
 still less, we are actually growing richer (by laying up a part of 
 our two per cent.), notwithstanding the most clearly-proved regular 
 loss on our farming. 
 
 Our condition has been so gradually growing worse, that we are 
 either not aware of the extent of the evil, or are in a great measure 
 reconciled by custom to profitless labour. No hope for a better 
 state of things can be entertained, until we shake off this apathy — 
 this excess of contentment, which makes no effort to avoid existing 
 evils. I have endeavoured to expose what is worst in our situation 
 as farmers; if it should have the effect of arousing any of my 
 countrymen to a sense of the absolute necessity of some improve- 
 ment, to avoid ultimate ruin, I hope also to point out to some of 
 their number, if not to all, that the means for certain and highly 
 profitable improvements are completely within their reach. 
 
 CHAPTER III. 
 
 THE DJFPERENT CAPACITIES OF SOILS FOR RECEIVINQ 
 IMPROVEMENT. 
 
 As far as the nature of the subjects permitted, the foregoing 
 chapters have been merely explanatoi'y and descriptive. The same 
 subjects will be resumed and more fully treated in the course of 
 the following general argument, the premises of which are the facts 
 and circumstances that have been detailed. The object of this 
 essay will now be entered upon ; and what is desired to be proved 
 will be stated in a series of propositions, which will now be pre- 
 sented at one view, and afterwards separately discussed in their 
 proper order. 
 
 Proj)odtion 1. Soils naturally poor, and rich soils reduced to 
 poverty by cultivation, are essentially different in their powers of 
 retaining putrescent (or alimentary) manures ; and, under like 
 circumstances, the fitness of any soil to be enriched by these ma- 
 nures is in proportion to the degree of its natural fertility. 
 
 2d. The natural sterility of the soils of lower Virginia is caused 
 by such soils being destitute of calcareous earth, and their being 
 injured by the presence and effects of vegetable acid. 
 
 3d. The fertilizing effects of calcareous earth are chiefly pro- 
 duced by its power of neutralizing acids, and of combining putres- 
 
40 NATURAL FERTILITY. 
 
 cent manures with soils, between wliich there would otlierwiso be 
 but little if any chemical attraction.* 
 
 4th. Poor and acid soils cannot be improved durably, or profit- 
 ably, by putrescent manures, without previously maldng such soils 
 calcareous, and thereby correcting the natiu'al defect in their con- 
 stitution. 
 
 5th. Calcareous manures will give to our worst soils a power of 
 retaining putrescent manures, equal to that of the best — and will 
 cause more productiveness, and yield more profit, than any other 
 improvement practicable in lower Virginia. 
 
 Dismissing from consideration, for the present, all the others, I 
 shall proceed to maintain the 
 
 First PRorosiTlON. — Soils naturally poor, and ricJi soils reduced 
 to 'poverty hy cidtivation, are essentially different in tlicir poiccrs 
 of retaininr/ putrescent (or alimentary^ manures; and, under 
 like circumstances, the fitness of any soil to he enrieJicd hy these 
 manures is in pi'oportion to the degree of its natural fcrt'dify. 
 The naturcd fertility of a soil is not intended to be estimated by 
 the amount of its earliest product, when first brought under cultiva- 
 tion, because several temporary causes then operate either to keep 
 down or to augment the product. If land be cultivated immediately 
 after the trees are cut down, the crop is greatly lessened by the nu- 
 merous living roots, and consequent bad tillage — by the excess of 
 unrotted- vegetable matter — and the coldness of the soil, from 
 which the rays of the sun had been so long excluded. On the 
 other hand, if cultivation is delayed one or two years, the leaves 
 and other vegetable matters are rotted, and in the best state to sup- 
 ply food to plants, and are so abundant, that a far better crop will 
 be raised than could have been obtained before, or perhaps can be 
 again, without manure. For these reasons, the degree of natural 
 fertility of any soil should be measured by its products after these 
 
 * When any substance is mentioned as comliining 'witli one or more other 
 substances, as different manures with each other, or with soil, I mean that 
 a union is formed by chemical attraction, and not by simple mixture. Mix- 
 tures are made by mechanical means, and may be separated in like manner; 
 but comhinations are chemical, and require some stronger chemical attrac- 
 tion, to take away cither of the bodies so united. 
 
 When two substances combine, they both lose their previous peculiar 
 qualities, or ncutrdJize them for each other, and form a third substance 
 different from both. Thus, if certain known proportions of ninriatic acid 
 and pure or caustic soda be brought together, their strong attraction will 
 cause them to coml«ne immediately. The strong corrosive acid quality 
 of the one, and the equally peculiar alkaline taste and powers of the other, 
 will neutralize or entirely destroy each othei' — and the compound formed is 
 eommon table salt, the qualities of which are as strongly marked, but 
 totally dilicrcut from those of cither of its constituent parts. 
 
SOILS NATURALLY RICH OR POOR. 41 
 
 temporary causes liave ceased to act, wliicli will generally take place 
 before the third or fourth crop is obtained. According, then, to 
 this definition, a certain degree of permmiency in its early produc- 
 tiveness is necessary to entitle a soil to be termed naturally fertile. 
 It is in this sense that I deny to any poor lands, except such as 
 were naturally fertile, the capacity of being made rich by putres- 
 cent manures only. 
 
 The foregoing proposition would by many persons be so readily 
 admitted as true, that attempting to prove it would be deemed 
 entirely superfluous. But many others will as strongly deny its 
 truth, and can support their opposition by high agricultural 
 authorities. 
 
 General readers, who may have no connexion with farming, must 
 have gathered from the incidental notices in various literary and 
 descriptive works, that ,some countries or districts that were noted 
 for their uncommon fertility or barrenness as far back as any 
 accounts of them have been recorded, still retain the same general 
 character, through every change of culture, government, and even 
 of races of inhabitants. They know that, for some centuries at 
 least, there has been no change in the strong contrast between the 
 barrenness of Norway, Brandenburg, and the Highlands of Scot- 
 laud, and the fertility of Flanders, Lombardy, and Valencia. Sicily, 
 notwithstanding its government is calculated to discourage in 
 dustry, and production of every profitable kind, still exhibits that 
 fertility for which it was celebrated two thousand years ago. It 
 seems a necessary inference from the many statements of which 
 these are examples, that the labours of man have been but of little 
 avail in altering, generally or permanently, or in any marked de- 
 gree, the characters and qualities given to soils by nature. 
 
 Most of our experienced practical cultivators, through a difi"erent 
 course, have arrived at the same conclusion. Their practice has 
 taught them the truth of this proposition ; and the opinions thus 
 formed have profit«,bly directed their most important operations. 
 They are accustomed to estimate the worth of land by its natural 
 degree of fertility; and by the same rule they are directed on what 
 soils to bestow their scanty stock of manure, and where to expect 
 exhausted fiqlds to recover by rest, and their own unassisted powers. 
 Bat, content with knowing the fact, this useful class of farmers 
 have never inquired for its cause ; and even their opinions on this, 
 as on most other subjects, have not been communicated so as to 
 benefit other cultivators. 
 
 But if all literary men, who are not farmers, and all practical 
 
 cultivators, who seldom read, admitted the truth of my proposition, 
 
 it would avail but little for improving our agricultural operations; 
 
 and the only prospect of its being usefully disseminated is through 
 
 that class of farmers who have received their first opinions of im- 
 4=i= 
 
42 ERRONEOUS DOCTRINES OF WRITERS. 
 
 proving soils from books, and whose subsequent plans and practices 
 ' have gi'own out of those opinions. If poor natural soils cannot be 
 durably or profitably improved by putrescent manures, this truth 
 should not only be known, but be kept constantly in view, by 
 every farmer who can hope to improve with success. Yet it is a 
 remarkable fact, that the difference in the capacities of soils for 
 receiving improvement has not attracted the attention of scientific 
 farmers ; and the doctrine has no dii'cct and positive support from 
 the author of any treatise on agriculture, European or American, 
 that I have been able to consult. On the contrary, it seems to be 
 considered by all of them, that to collect and apply as much 
 vegetable and animal manure as possible, is sufiicient to insure 
 profit to every farmer, and fertility to every soil. They do not tell 
 us that numerous exceptions to that rule will be found, and that 
 many soils of apparently good texture, if not incapable of being 
 enriched from the barn-yard, would at least cause more loss than 
 clear profit, by being improved from that source. 
 
 When it is assumed that the silence of every distinguished author 
 as to certain soils being incapable of being profitably enriched, 
 amounts to ignoi'auce of the fact, or a tacit denial of its truth — it 
 may be objected that the exception was not omitted from either of 
 these causes, but because it was established and undoubted. This 
 is barely possible ; but even if such were the case, their silence has 
 had all the ill consequences that could have grown out of a positive 
 denial of any exceptions to the propriety of manuring poor soils. 
 Every zealous young farmer, who draws most of his knowledge and 
 opinions from books, adopts precisely the same idea of their di- 
 rections—and if he owns barren soils he probably throws away his 
 labour and manure for their improvement, for years, before experience 
 compels him to abandon his hopes, and acknowledge that his guides 
 have led him only to failure and loss. Such farmers as I allude 
 to, by their enthusiasm and spirit of enterprise, are capable of 
 rendering the most important benefits to agric^ulture. Whatever 
 may be their impelling motives, the public derives nearly all the 
 benefit of their successful plans ; and their far more numerous mis- 
 directed labours, and consecjuent disappointments, are productive of 
 national, still more than individual loss. The occurrence of only 
 a few such mistakes, made by reading farmers, will seVve to acquit 
 me of combating a shadow — and there are few of us who cannot 
 recollect some such examples. 
 
 But if the foregoing objection has any weight in justifying Euro- 
 pean authors in not naming this exception, it can have none for 
 those of our own country. If it be admitted that soils naturally 
 poor are incapable of being enriched with profit, that admission 
 must cover three-fourths of all the high laud in the tide-water dis- 
 trict. Surely no one will contend that so sweeping an exception 
 
DOCTRINE OF "ARATOR." _ 43 
 
 was silently understood by the author of ' Arator' as qualifying his 
 exhortations to improve our lands; and if no such exception were 
 intended to be made, then will his directions for enriching soils and 
 his promises of reward be found equally fallacious, for the greater 
 portion of the country which his work was especially intended to 
 benefit. The omission of any such exception, by the writers of the 
 United States, is the more remarkable, as the land has been so 
 recently brought under cultivation, that the original degree of 
 fertility of almost every farm may be known to its owner, and com- 
 pared with the after progress of exhaustion or improvement. 
 
 Many authorities might be adduced to prove that I have correctly 
 stated what is the fair and only inference to be drawn from agricul- 
 tural books, respecting the caj^acity of poor soils to receive improve- 
 ment. But a few of the most strongly marked passages in ' Arator' 
 will be fully sufficfent for this purpose. The venerated author of that 
 work was too well acquainted with the writings of European agricul- 
 turists, to have mistaken their doctrines in this important particular. 
 A large portion of his useful life was devoted to the successful 
 improvement of exhausted, but originally fertile lands. His instruc- 
 tions for producing similar improvements are expressly addressed 
 to the cultivators of the eastern parts of Virginia and North Caro- 
 lina, and are given as applicable to all our soils, without exception. 
 Considering all these circumstances, the conclusions which are 
 evidently and unavoidably deduced from his work, may be fairly 
 considered, not only as supported by his own experience, but as 
 concurring with the general doctrine of improving poor soils, main- 
 tained by previous writers. 
 
 At page 54, third edition of ' Arator,' "enclosing" (i. e. leaving 
 fields to receive their own vegetable cover, for their improvement, 
 during the years of rest) is said to be " the most powerful means 
 of fertilizing the earth" — and the process is declared to be rapid, 
 the returns near, and the gain great. 
 
 At page (31 are the following passages : " If these few means of 
 fertilizing the country (corn-stalks, straw, and animal dung) were 
 skilfully used, they would of themselves suffice to change its state 
 from sterility to fruitfulness." — " By the litter of Indian corn, and 
 of small grain, and of penning cattle, managed with only an inferior 
 degree of skill, in union with enclosing, I will venture to affirm that 
 a farm may in ten years be made to double its produce^ and in 
 twenty to quadruple it.'' 
 
 No opinions could be more strongly or unconditionally expressed 
 than these. No reservation or exception is made. I may safely 
 appeal to each of the many hundreds who have attempted to obey 
 these instructions, to declare whether any one considered his own 
 naturally poor soils excluded from the benefit of these promises — or 
 
44 EVIDENCE OF FACTS. 
 
 wlictlier a tithe of the promised benefit was realized upon trial on 
 any farm having generally such soils. 
 
 In a field of mine that has been secured from grazing since 1814, 
 and cultivated on the mild four-sliift rotation, the produce of a 
 marked spot has been measured every fourth year (when in corn) 
 since 1820. The difference of product has been such as the dif- 
 ferences of season might have caused — and the last crop (in 1828) 
 was worse than those of either of the two preceding courses. 
 There is no reason to believe that even the smallest increase of 
 productive power had taken j)lace in all the preceding fourteen 
 years. [Nor has there been, to 1841, in the apparent products of 
 this ground, any manifestation that there has been any more of 
 subsequent than of previous improvement, from the vegetable 
 manuriugs furnished by its growth. 1842.] 
 
 [A still more striking proof, because of the much larger scale, as 
 well as long continuance of the experiment, has been very recently 
 (in 1842), as well as in former times, mentioned to me, as confirm- 
 ation of my views in tjlis respect. Col. Gleorge Blow, of Sussex, 
 a highly respectable gentleman and intelligent and observant 
 farmer, had adhered for nearly thirty years to Taylor's " enclosing 
 system," and with a very mild rotation, on a farm of 600 arable 
 acres, of sandy soil, and originally poor; and had taken but one 
 crop (corn) in every three years. A few spots only of better 
 quality (the sites of old buildings, &c.) were put in wheat or oats 
 after the corn; the great body of the land having had regularly 
 two years in three to rest, and to manure itself by its volunteer 
 growth of weeds and grass. Very little grazing, and that but 
 rarely, was permitted. There could have been no material mistake 
 as to the general products and results ; and the proprietor is confi- 
 dent that the land has not improved in production in all this long 
 time. Yet, on soil differently constituted, Col. Blow has improved 
 and increased the products, rapidly and profitably. These two 
 facts, though observed more particularly and for longer time than 
 any others known, agree with, and are but confirmatory of others 
 presented to some extent on almost every farm 'in the tide-water 
 region of Virginia. 1842.] 
 
 It is far from my intention, by these remarks, and statements of 
 facts, to deny the propriety, or to question the highly beneficial 
 results, of applying the system of improvement recommended by 
 * Arator,' to soils originally fertile. On the contrary, it is as much 
 my object to maintain the facility of restoring to worn lands their 
 natural degree of fertility, by vegetable applications, as it is to 
 deny the power of exceeding that degree, however low it may have 
 been. 
 
 One more quotation will be offered, because its recent date and 
 the source whence it is derived furnish the best proof that it is still 
 
OPPOSING DOCTRINE. 45 
 
 the received opinion, among agricultural writers, that all soils may 
 be profitably improved by putrescent manures. An article in the 
 ' American Fanner,' of October 14th, 1881, on " manuring large 
 farms," by the editor (Gr. B. Smith), contains the following ex- 
 l^i'essions. ''By proper exertions, every farm in the United States 
 can be manured with less expense than the surplus profits arising 
 from the manure would come to. This we sincerely believe, and 
 we have arrived at this conclusion from long and attentive obsei'va- 
 tion. We never yet saw a farm that we could not point to means 
 of manuring, and bring into a state of high and profitable cultiva- 
 tion at an expense altogether inconsidei-able when contrasted with 
 the advantages to be derived from it." The remainder of the 
 article shows that putrescent manures are principally relied on to 
 produce these effects; marsh and swamp mud are the only kinds 
 referred to that are not entirely putrescent in their action ; and mud 
 certainly cannot be used to manure every farm. Mr. Smith having 
 been long the conductor of a valuable agricultural journal, as a 
 matter of course, is extensively acquainted with the works and 
 opinions of the best writers on agiiculture ; and therefore, his 
 advancing the foregoing opinions, as certain and undoubted, is as 
 much a proof' of the general concurrence therein of preceding 
 writers, as if the same had been given as a digest of their pre- 
 cepts.* 
 
 Some persons will readily admit the great difference in the capa- 
 cities of soils for improvement, but consider a deficiency of clay 
 only to cause the want of power to retain manures. The general 
 excess of sand in our poor lands might warrant this belief in a 
 superficial and limited observer. But though clay soils are more 
 rarely met with, they present, in proportion to their extent, full as 
 much poor land. The most barren and worthless soils in the 
 county of Prince George arc also the stiffest. A poor clay soil will 
 retain manure longer than a poor sandy soil — bu^t it will not the 
 less certainly lose its acquired fertility at a somewhat later period. 
 When it is considered that a much greater quantity of manure is 
 required by clay soils, it may well be doubted whether the tem- 
 
 [* Thougli not then known to me, and probably to few if any others in 
 Amei'ica, there was then in print the expression of the ojiinion which I 
 have announced and maintained above. This exception I subsequently met 
 ■with, and republished the article in the Farmer's Register (Vol. iv. p. 335.) 
 It was a communication from the excellent practical farmer, William Daw- 
 son, of Scotland, to the Farmer's Magazine, published in Edinburgh. In 
 this communication, the writer, and, so far as I know, he only, before 
 myself, asserts opinions which approach very nearly to the doctrine above 
 maintained, of the incapacity of naturally poor soils for being profitably 
 or dural)ly improved by putrescent manures alone — and also their newly 
 ac(|uircd fitness for being enriched after having been limed.] 
 
46 LIMIT TO IMPROVEMENT OP SOILS. 
 
 porary improvement of the sandy soils would not be attended ■with 
 more profit — or, more properly speaking, with less actual loss. 
 
 It is true that the capacity of a soil for improvement is greatly 
 affected by its texture, shape of the surface, and its supply of 
 moisture. Dry, level, or clay soils, will retain manure longer than 
 the sandy, hilly, or wet: But however important these circum- 
 stances may be, neither the presence nor absence of any of them 
 can cause the essential differences of capacity for improvement. 
 There are some rich and valuable soils with either one or more of 
 all these faults — and there are other soils the least capable of re- 
 ceiving improvement, free from objections as to their texture, 
 degree of moisture, or inclination of their surface. Indeed the 
 great body of our poor ridge lands are more free from faults of this 
 kind, than soils of far greater productiveness usually are. Unless 
 then some other and far more powerful obstacle to improvement 
 exists, why should not all our wood-land be highly enriched, by the 
 thousands of crops of leaves which have successively fallen and 
 rotted there ? Notwithstanding this vegetable manuring, which 
 infinitely exceeds all that the industry and patience of man can 
 possibly equal, most of our wood-land remains poor ; and this one 
 fact (which at least is indisputable) ought to satisfy all of the 
 impossibility of enriching such soils by putrescent manures only. 
 Some few acres may be highly improved, by receiving all the 
 manure derived from the offal of the whole farm — and entire farms, 
 in the neighbourhood of towns, may be kept rich by continually 
 applying large quantities of purchased manures. But no where can 
 a farm be found, which has been improved beyond its original 
 fertility, by means of the vegetable resources of its own arable 
 fields. If this opinion is erroneous, nothing is easier than to prove 
 my mistake, by adducing undoubted examples of such improve- 
 ments having been made. 
 
 But a few remarks will suflace on the capacity for improvement 
 of worn lands, which were originally fertile. With regard to these 
 soils, I have only to concur in the received opinion of their fitness 
 for durable and profitable improvement by putrescent manures. 
 After being exhausted by cultivation, they will recover their pro- 
 ductive power, by merely being left to rest for a suf&cient time, 
 and receiving the manure made by nature, of the weeds and other 
 plants that grow and die upon the land. Even if robbed of the 
 greater part of that supply, by the grazing of animals, a still longer 
 time will serve to obtain the same result. The better a soil was at 
 first, the sooner it will recover by these means, or by artificial 
 manuring. On soils of this kind, the labours of the improving 
 farmer meet with certain success and full reward ; and whenever 
 we hear of remarkable improvements of poor lands by putrescent 
 
morER MODE OF INVESTIGATION. ' 47 
 
 manures, furtlier inquiry will sbow us that these poor lands had 
 once been rich. 
 
 The continued fertility of certain countries, for hundreds or even 
 thousands of years, does not prove that the land could not be, or 
 had not been, exhausted by cultivation; but only that it was slow 
 to exhaust and rapid in recovering ; so that whatever repeated 
 changes may have occurred in each particular tract, the whole 
 country taken together always retained a high degree of productive- 
 ness. Still the same rule will ajjply to the richest and the poorest 
 soils — to wit, that each exerts strongly a force to retain as much 
 fertility as nature gave to it — and that when worn and reduced, 
 each kind may easily be restored to its original state, but cannot be 
 raised higher, with either durability or profit, by putrescent ma- 
 nures, whether applied by the bounty of nature, or the industry 
 of man. 
 
 CHAPTER IV. 
 
 EFFECTS OF THE PRESENCE OF CALCAREOUS EARTH IN SOILS. 
 
 Propositj:on 2. — The natural sterility of the soils of lower Virginia 
 is caused hy such soils being destitute of calcareous earth, and 
 their heing injured hy the presence and effects of vegetahle acid. 
 
 The means which would appear the most likely to lead to the 
 causes of the different capacities of soils for impi-ovement is to 
 inquire whether any known ingredient or quality is always to be 
 found belonging to improvable soils, and never to the unim- 
 provable — or which always accompanies the latter, and never the 
 former kind. If either of these results can be obtained, we will 
 have good ground for supposing that we have discovered the general 
 cause of fertility, in the one case, or of barrenness, in the other; 
 and it will follow that, if we can supply to barren soils the deficient 
 beneficial ingredient — or can destroy that which is injurious to 
 them — their incapacity for receiving improvement will be removed. 
 All the common ingredients of soils, as sand, clay, or gravel — and 
 such qualities as moisture or dryness — a level, or a hilly surface — 
 however they may affect the value of soils, are each sometimes 
 found exhibited, in a remarkable degree, in both the fertile and the 
 sterile. The abundance of putrescent vegetable matter might well 
 be considered the cause of fertility, by one who judged only from 
 lands long under cultivation. But though vegetable matter in 
 sufficient quantity is essential to the existence of fertility, yet will 
 
48 FERTILITY OF SHELLY SOILS. 
 
 tliis substance also be found inadequate for the cause. Vegetable 
 matter abounds in all rich land, it is admitted ; but it has also been 
 furnished by nature, in quantities exceeding all computation, to the 
 most barren soils known. 
 
 But there is one ingredient of which not the smallest jjroportion 
 can be found in any of our poor soils, and which, wherever found, 
 (and not in great excess), indicates a soil remarkable for natural 
 and durable fertility. This is calcareous earth, or carbonate of 
 lime. These facts alone, if sustainetl, will go far to prove that this 
 earth is the cause of fertility, and the cure for barrenness. 
 
 On some part of most farms touching tide-water, either mussel 
 or oyster shells are found mixed with the soil. Oyster shells are 
 confined to the lands on salt water, where they are very abundant, 
 and sometimes extend through large fields. Higher up the rivers, 
 mussel shells only are to be seen thus deposited by nature, or by 
 the aboriginal inhabitants, and they decrease as we approach the 
 falls of the rivers. The proportion of shelly land in the counties 
 highest on tide-water is very small ; but the small extent of these 
 spots does not prevent, but rather aids, the exhibition of the pecu- 
 liar cjualities of such soils. Spots of shelly land, not exceeding a 
 few acres in extent, could not well have been cultivated differently 
 from the balance of the fields of which they formed parts — and 
 therefore they can be better compared with the worse soils under 
 like treatment. Every acre of shelly land is, or has been, remark- 
 able for its richness, and still more for its durability. There arc 
 few farmers among us who have not heard described tracts of shelly 
 soil on Nansemond and York rivers, which are celebrated for their 
 long resistance of the most exhausting course of tillage, and which 
 still remain fertile, notwithstanding all the injury which they must 
 have sustained from their severe treatment. We are told that on 
 some of these lands, corn has been raised every successive year, 
 without any help from manure, for a longer time than the owners 
 could remember, or could be informed of correctly. But without 
 relying on any such remarkable cases, there can bo no doubt that 
 every acre of our shelly land has been at least as much tilled, and 
 as little manured, as any in the country; and that it is still the 
 richest and most valuable of all our old cleared lands. 
 
 The fertile but narrow strips, along the banks of our rivers 
 (which form the small portion of our high-land of first-rate quality), 
 seldom extend far without exhibiting spots in which shells arc 
 visible, so that the eye alone is suflicient to prove the soil of such 
 places to be calcareous. The similarity of natural growth, and of 
 all other marks of character, are such, that the observer might very 
 naturally infer that the former presence of shells had given the 
 same valuable qualities to all these soils — but that they had so 
 generally rotted, and been incorporated with the other earths, that 
 
NATURAL GROWTHS OF DIFFERENT SOILS. ** 49 
 
 tliey remained visible only in a few places, where they had been 
 most abundant. The accuracy of this inference will hereafter be 
 examined. 
 
 The natural growth of the shelly soils (and of those adjacent of 
 similar value) is entirely different from that of the great body of 
 our lands. Whatever tree thrives well on the one, is seldom found 
 on the other class of soils — or, if found, it shows plainly, by its 
 imperfect and stunted condition, on how unfi'iendly a soil it is 
 placed. To the rich river margins are almost entirely confined the 
 black or wild locust, hackberry or sugar-nut tree, and papaw. The 
 locust is with great difficulty eradicated, or the newer growth of it 
 kept under on cultivated lands; and from the remarkable rapidity 
 with which it springs up and increases in size, it forms a serious 
 obstacle to the cultivation of laud on the river banks. Yet on the 
 wood-land only a mile or two from the river, not a locust is to be 
 seen. On shelly soils, pines and broom-grass \^A7idro2)0(/on scopa- 
 rius\ cannot thrive, and are rarely able to maintain even the most 
 sickly growth. 
 
 Some may say that these striking differences of growth do not 
 so much show a difference in the constitution of the soils, as in 
 their state of fertility ; or that one class of the plants above named 
 delights in rich, and the other in poor land. No plant prefers poor 
 to rich soil — or can thrive better on a scarcity of food, than with 
 an abundant supply. Pine, broom-grass, and sheep-sorrel, delight 
 in a class of soils that are generally unproductive — but not on 
 account of their poverty; for all these plants show, by the greater 
 or less vigour of their growth, the abundance or scarcity of vegetable 
 matter in the soil. But on this class of soils, no quantity of 
 vegetable manure could make locusts flourish, though they will 
 grow rapidly on a calcareous hill-side, from which all the soil 
 capable of supporting other ordinary plants has been washed away. 
 
 In thus describing and distinguishing soils by their growth, let 
 me not be understood as extending these rules, without exception, 
 to other soils and climates than our own. It is well established 
 that changes of kind in successive growths of timber have occurred 
 in other places, without any known cause; and a difference of 
 climate may elsewhere produce effects, which here would indicate 
 a change of soil. 
 
 Some rare apparent exceptions to the general fertility of shelly 
 lands are found where the proportion of calcareous earth is in great 
 excess. Too much of this ingredient causes even a greater degree 
 of sterility than its total absence. This cause of barrenness is 
 very common in France and England (on chalk soils), and very 
 extensive tracts are not worth the expense of cultivation, or im- 
 provement. The few small spots that are rendered barren here are 
 seldom (if ever) so affected by the excess of oyster or mussel shells 
 
50 ERRONEOUS VIEWS OF AUTHORS. 
 
 in the soil. These effects generally are caused by hods of fossil 
 sea-shells, which in some places reach the surfoce, and arc thus 
 exposed to the plough. These spots (which are the only super- 
 calcareous or chalky soils of this region) are not often more than 
 thirty feet across, and their nature is generally evident to the eye ; 
 and if not, is so easily determined by chemical tests, as to leave no 
 reason for confounding the injurious and beneficial eifects of cal- 
 careous earth. This exception to the general fertilizing effect of 
 this ingredient of our soils would scarcely require naming, but to 
 raark what might be deemed an apparent contradiction. But this 
 exception, and its cause, must be kept in mind, and considered as 
 always understood and admitted throughout all my remarks, and 
 which therefore it is not necessary to name specially, when the 
 general qualities of calcareous earth are spoken of. [After all, this 
 exception is only in appearance, as it is found only in mper-cal- 
 carcous soils, and never in any soil in which calcareous earth is not 
 so abundant as to form a physical material. — 1849.] 
 
 In the beginning of this chapter, I advanced the important fact 
 that none of our poor soils contain naturally the least particle of cal- 
 careous earth. So far, this is supported merely by my assertion — and 
 all those who have studied agriculture in books will require strong 
 proof before they can give credit to the existence of a fact, which 
 is either unsupported, or indirectly denied, by all written authority. 
 Others, who have not attended to such descriptions of soils in 
 general, may be too ready to admit the truth of my assertion — • 
 because, not knowing the opinions on this subject heretofore re- 
 ceived and undoubted, they would not be aware of the importance 
 of their admission. 
 
 It is true that no author has said expressly that every soil con- 
 tains calcareous earth. Neither perhaps has any one stated that 
 every soil contains some silicious or aluminous earth. But the 
 manner in which each one has treated of soils and their constituent 
 parts, would cause their readers to infer that neither of these three 
 earths is ever entirely wanting — or at least that the entire absence 
 of the calcareous is as rare as the absence of silicious or aluminous 
 earth. Nor are we left to gather this opinion solely from indirect 
 testimony, as the following examples, from the highest authorities, 
 will prove. Davy says, ''four earths generally abound in soils, the 
 aluminous, the silicious, the calcareous, and the magnesian ;'^* and 
 the soils of which he states the constituent parts, obtained by 
 chemical analysis, as well as those reported by Kirwan, and by 
 Young, all contain some proportion (and generally a large propor- 
 tion) of calcareous earth. f Kirwan states the component parts of 
 
 * Davy's Agr. Chern., Lecture 1. 
 
 f Agr. Chem., Lect. 4. — Kirwan on Manures — and Young's Prize Essay 
 on Miiuiu'cs. 
 
ASSERTIONS OF CALX IN SOIL BEING USUAL. 51 
 
 a soil wliich contained thirty-one per cent, of calcareous earth, and 
 he supposes that proportion neither too little nor too much.* 
 Young mentions soils of extraordinary fertility containing seventeen 
 and twenty per cent., besides others with smaller proportions of 
 calcareous earth — and says that Bergman found thirty per cent. 
 in the best soil he examined. f Rozier speaks still more strongly 
 for the general diffusion and large proportions of this ingredient 
 of soils. In his general description of earths and soils, he gives 
 examples of the supposed composition of the three grades of soils 
 which he designates by the terms rich, good, and viiddliiig soils; to 
 the first class he assigns a proportion of one-tenth, to the second, 
 one-fourth, and to the last, one-half of its amount of calcareous 
 earth. The fair interpretation of the passage is that the author 
 considered these large proportions as general, in France — and he 
 gives no intimation of any soil entirely without calcareous earth. J 
 
 The position assumed above, of the general or universal concur- 
 rence of former European authors in the supposed general presence 
 of calcareous earth in soils, could be placed beyond dispute by ex- 
 tracts from their publications. But this would require many and 
 long extracts, too bulky to include here, and which cannot be fairly 
 abridged, or exhibited by a few examples. No author says directly, 
 indeed, that calcareous earth is present in all soils; but its being 
 always named as one of the ingredients of soils in general, and no 
 cases of its absolute deficiency in tilled lands being directly stated, 
 amount to the declaration that calcareous earth is very rarely, if 
 ever, entirely wanting in any soil. We may find enough directions 
 to apply calcareous manures to soils that are deficient in that in- 
 gredient ; but that deficiency seems to be not spoken of as absolute, 
 but relative to other soils more abundantly supplied. In the same 
 manner, Avriters on agriculture direct clay, or sand, to be used as 
 manure for soils very deficient in one or the other of those earths; 
 but without meaning that any soil under cultivation can be found 
 entirely destitute of sand or of clay. My proofs from general 
 treatises would therefore be generally indirect; and the quotations 
 
 * Kirwan on Manures, article " Clayey Loam." 
 
 f Young's Essay on Manures. 
 
 J "Composition of soils. Examples of the various composition of soils: 
 Eich soil ; silicious earth, 2 parts; aluminous, 6; calcareous, 1 ; vegeta- 
 ble earth, [humus'] 1 ; in all, 10 parts. Good soil — silicious, 3 parts ; 
 aluminous, 4; calcareous, 2^; vegetable earth, ^ of 1 part; in all, 10 
 parts. Middling soil [sol mediocre ;] silicious, 4 parts; aluminous, 1; cal- 
 careous, 5 parts, less by some atoms of vegetable earth ; in all, 10 parts. 
 We see that it is the largest proportion of aluminous earth that constitutes 
 the greatest excellence of soils ; and we know that independently of their 
 harmony of composition, they require a sufficiency of depth." — Translated 
 from the article " Tcrrrs," in the " Cours Complct d'Agi'iculture Pratique, 
 etc. par I'Abbe Rozier," 1815. 
 
52 CONCURRING AMERICAN AUTHORITIES. 
 
 necessary to exhibit them would show what had not been said, 
 rather than what had — and that they did not assert the absence of 
 calcareous earth, instead of directly asserting its universal presence. 
 Extracts for this purpose, however satisfactory, would necessarily 
 be too voluminous, and it is well that they can be dispensed with. 
 Better proof, because it is direct, and more concise, will be furnished 
 by quoting the opinions of a few agriculturists of our own country, 
 who were extensively acquainted with European authors, and have 
 evidently drawn their opinions from those sources. These quota- 
 tions will not only show conclusively that their authors consider 
 the received European doctrine to be that all soils are more or less 
 calcareous — but also, that they apply the same general character to 
 the soils of the United States, without expressing a doubt or naming 
 an exception. These writers, as all who have heretofore written 
 of soils in this country, have uttered but the echoes of preceding 
 English general descriptions of soils. They seem not to have sus- 
 pected that any very important difference existed in this respect 
 between the soils of England and of this country ; and certainly not 
 one had made the slightest investigation by any attempt at chemical 
 analysis, to sustain the false character thus given to our soils. 
 
 1. From a "Treatise on Agriculture" (ascribed to General 
 Armstrong), published in the American Farmer. \Vol. i. page 
 153.] 
 
 "Of six or eight substances, wliicli chemists have denominated earths, 
 four are ividely and abundantly diffused, and form the crust of our globe. 
 ■ These are silica, alumina, lime, and magnesia." — " In a pure or isolated 
 state, these earths are wholly unproductive ; but when decomposed and 
 mixed, and to this mixture is added the residuum of dead animal or vege- 
 table matter, they become fertile, and take the general name of soils, and 
 are again denominated after the earth that most abounds in their composi- 
 tion respectively." 
 
 2. Address of R. H. Rose to the Agricultural Society of Susque- 
 hanna. [Am. Far. Vol. ii. p. 101.] 
 
 " Geologists suppose our earth to have been masses of rock of various 
 kinds, but principally silicious, aluminous, calcareous, and magnesian — 
 from the gradual attrition, decay, and inixture of which, together with an 
 addition of vegetable and animal matter, is formed the soil ; and this is 
 called sandy, clayey, calcareous, or magnesian, according as the particular 
 primitive material preponderates in its formation." 
 
 3. Address of Robert -Smith to the Maryland Agricultural So- 
 ciety. [Am. Far. Vol. iii. p. 228.] 
 
 " The soils of our country are in general clay, sand, gravel, clayey 
 
 loam, sandy loam, and gravelly loam. Clay, sand, and gravel, need no 
 description, &c." — '■'■Clayey loam is a compound soil, consisting of clay 
 and sand or gravel, with a mixture of calcareous matter, and in which clay 
 is predominant. Sandy or gravelly loom is a compound soil, consisting of 
 sand or gravel and clay with a mixture of calcareous matter, and in which 
 sand or gravel is predominant." 
 
CALCAREOUS SOILS SUPPOSED COMMON. 53 
 
 The first two extracts merely state tlie geological theory of the 
 formatiou of soils, which is received as correct by the most eminent 
 agriculturists of Europe. How far it may be supported or opposed 
 by the actual constitution and number of ingredients of European 
 soils, is not for me to decide, nor is the consideration necessary to 
 my subject. But the adoption of this general theory by American 
 writers, without excepting American soils, is an indirect, but com- 
 plete application to them of the same character and composition. 
 The writer last quoted states positively, that the various loams 
 (which comprise at least nineteen twentieths of our soils, and I pre- 
 sume also of the soils *of Maryland) contain calcareous matter. 
 The expression of this opinion by Mr. Smith is sufficient to prove 
 that such was the fair and plain deduction from his general reading 
 on agriculture, from which source only could his opinions have been 
 derived. If the soils of Maryland are not very unlike those of 
 Virginia, I will venture to assert, that not one in a thousand of all 
 the clayey, sandy, and gravelly loams, contains the smallest propor- 
 tion of carbonate of lime — and that not a single specimen of cal- 
 careous soil can be found, between the falls of the rivers and the 
 most eastern body of limestone. 
 
 But though the direct testimony of European authors, as cited 
 in a foregoing page, concurs with the indirect proofs referred to 
 since, to induce the belief that soils are very rarely destitute of cal- 
 careous earth, yet statements may be found of some particular soils 
 being considered of that character. These statements, even if 
 presented by the authors of general treatises, would only seem to 
 present exceptions to their general rule of the almost universal 
 diffusion of calcareous earth in soils. But, so far as I know, no 
 such exceptions are named in the descriptions of soils in any general 
 treatise, and therefore have not the slightest influence in contradict- 
 ing or modifying their testimony on this subject. It is in the 
 description of soils of particular farms, or districts, that some such 
 statements are made ; and even if no such examples had been men- 
 tioned, they would not have been needed to prove the existence, in 
 Europe, of some soils, like most of ours, destitute of calcareous 
 earth. These facts do not oppose my argument. I have not 
 asserted (nor believed, since endeavouring to investigate this sub- 
 ject), that there were not soils in Europe, and perhaps many exten- 
 sive districts, containing no calcareous earth. My argument merely 
 maintains, that -these facts would not be inferred, but the contrary, 
 ^y ^iiy general and cursory reader of the agricultural treatises of 
 Europe with which we are best acquainted. It has not been my 
 purpose to inquire as to the existence, or extent, of soils of this 
 kind in Europe. But judging from the indirect testimony furnished 
 by accounts of the mineral and vegetable productions, in general 
 descriptions of different countries, I would infer that soils having 
 5* 
 
51: VIRGINIAN SOILS NOT CALCAREOUS. 
 
 no calcareous earth were often found in Scotland and the northern 
 p:irt of Grcrmauy, and that they were comparatively rare in England 
 and France. 
 
 With my early impressions of the nature and composition of 
 soils, derived in like manner from the general descriptions given in 
 books, it was with surprise, and some distrust, that, when first 
 attempting to analyze soils, in 1817, 1 found most of the specimens 
 entirely destitute of calcareous earth. The trials were repeated 
 with care and accuracy, on soils from various places, until I felt 
 authorized to assert, without fear of contradiction, that no naturally 
 poor soil, below the falls of the rivers, contains the smallest propor- 
 tion of calcareous earth. Nor do I believe that any exception to 
 this peculiarity of constitution can be found in any poor soil above 
 the falls ; but though these soils are far more extensive and im- 
 portant in other respects, they are beyond the district within the 
 limits of which I propose to confine my investigation. 
 
 These results are highly important, whether considered merely 
 as serving to establish my proposition, or as showing a radical 
 difference between most of our soils, and those of the best cultivated 
 parts of Europe. Putting aside my argument to establish a par- 
 ticular theory of improvement, the ascertained fact of the universal 
 absence of calcareous earth in o\ir poor soils leads to this conclusion, 
 that profitable as calcareous Inanures have been found to be in 
 countries where the scftls are generally calcareous in some degree, 
 they must be far more so on our soils that are quite destitute of 
 that necessary earth.* 
 
 [* Since the first and even the last edition (1842) containing the above 
 deductions, the later agricultural chemists have removed much of the ob- 
 scurity before resting uj)on the calcareous character of European soils. 
 Two recent European works have been republished in the United States, 
 which, on soils and calcareous manures especially, are more full and satis- 
 factory than any which had previously reached me. One is Boussingault's 
 "Rural Economy, in its relations with Chemistry, &c.,&c." This volume 
 was first published in this country in 1845 (by Appleton, & Co., N. Y.), from 
 the English translation and first edition. Ther6 is no date given to show 
 the time of publication of the original work in French, nor of the English 
 translation. But both were manifestly very recent; and probably neither 
 had been introduced or was accessible in this country before the American 
 edition appeared. As there is contained a reference to analyses of all the 
 crops made in 1841 on the author's farm, in which "long and tedious 
 labour" he "spent nearly a whole year," the original work could not have 
 been printed before the close of 1842, even if so early. ' The author, be- 
 sides being one of the most profound and able of modern chemists, and 
 who has directed much research to agricultural chemistry, was also a prac- 
 tical farmer, on a scale of operations sufficient to inform him how to pro- 
 perly direct his scientific investigations. Therefore, many of his subjects 
 and reported results are full of instruction, and doubtless are to be relied 
 on as among the latest and most certain lights aud truths yet derived from 
 a^'plyiug chemistry to agriculture. The other work referred to above is 
 
CHAPTEK V. 
 
 RESULTS OF THE CHEMICAL EXAMINATIONS OP VARIOUS SOILS. 
 
 Proposition 2 — continued. 
 
 The certainty of any results of cliemical analysis would bo 
 doubted by most persons who have paid no attention to the meana 
 employed for such operations ; and their incredulity will be the 
 more excusable, when such results are reported by one knowing 
 very little of the science of chemistry, and whose limited knov,-- 
 ledge was gained without aid or instruction, and was sought solely 
 with the view of pursiiing this investigation. Appearing under 
 such disadvantages, it is therefore the more incumbent on me to 
 show my claim to accuracy, or to so explain my method as to ena- 
 
 JoLnston's " Lectures on the Applications of Chemistry and Geology to 
 Agriculture," which -nms first published, complete in four parts, in London 
 in 1844. But as the earlier parts had been published in succession, I had 
 been able to see the first three at the close of 1843. The third part con- 
 tains the author's views and compilation of facts, chemical and agricultural, 
 of lime, as a constituent of soils and as manure. On these subjects, he is 
 more full of information than any or all preceding authors, because able to 
 draw from, compare, and decide upon the views of all his predecessors, 
 with the aid of the latest information as to European scientific i-esearcli 
 and agricultural practices and results — and which advantages seem to have 
 been used generally with ability and discretion. 
 
 It appears from both Boussingault's and Johnston's works, that the new 
 and still very defective science of agricultural chemistry no longer labours 
 under some of the grossest defects and errors which were indirectly and 
 justly charged in my remarks above ; or is liable to the formerly just 
 censure there indicated, as will appear in the course of this essay. It is not 
 now left to be inferred, as before, that all or nearly all soils of England 
 and France contain carbonate of lime; and the errors of the process of 
 analyzing soils, used by Davy, and all other chemists, previous to a very 
 recent time, are pointed out, which errors led to the erroneous conclusion 
 that carbonate of lime is almost universally present in soils. These two 
 authors state many particular soils, as well as classes of SQJls by inference, 
 which contain not a trace of lime in the state of carbonate, as 1 had before 
 declared, in opposition to all the then existing authority, to be the case 
 with nearly all the soils of our Atlantic states. But still, after removing 
 this obscurity, it appears manifest from the many reported contents of 
 soils given by Boussiugault, Johnston, and Liebig, that soils containing 
 carbonate of lime, and usually in large jiroportions, are very general in 
 Europe, so far as investigation has gone ; in this respect confirming my 
 own previous inferences, as stated above. 
 
 Some of the statements of tlicse latest and ablest authorities, which now 
 offer confirmatory testimony for my formerly unsupported and novel 
 opinions, will be quoted iu notes, or otherwise, on proper occasions. — 184.11.] 
 
 (55) 
 
56 MODE OF TESTING THE PRESENCE OF CALX. 
 
 ble others to detect its errors, if any exist. To analyze a specimen 
 of soil completely, requires an amoimt of scientific acquirement 
 and practical skill to which I make no pretension. But merely to 
 ascertain the absence of calcareous earth (or carbonate of lime), 
 or, if present, to find its quantity, requires but little skill, and less 
 science. 
 
 The methods recommended by different agricultural chemists for 
 ascertaining the proportion of calcareous earth in all soils, agree in 
 all material points. Their process will be described, and made as 
 plain as possible. A specimen of soil of convenient size is dried, 
 pounded, and weighed, and then thrown into muriatic acid diluted 
 with three or four times its quantity of water. The acid combines with, 
 and dissolves the Uriie of the calcareous earth, and its other ingre- 
 dient, the carhonic acid, being disengaged, rises through the liquid 
 in the form of gas, or air, and escapes with effervescence. After 
 the mixture has been well stirred, and has stood until all effer- 
 vescence is over (the fluid still being somewhat acid to the taste, to 
 prove that enough acid had been used, by some excess being left), 
 the whole is poured into a piece of blotting paper, folded so as to 
 fit within a glass funnel. The fluid containing the dissolved lime 
 passes through the paper, leaving behind the clay and silicious 
 Band, and any other solid matter ; over which, pure water is poured 
 and passed off several times, so as to wash off all remains of the 
 dissolved lime. These filtered washings are added to the solution, 
 to all of which is then poui*ed a solution of carbonate of j^otash. 
 The two dissolved salts thus thrown together {muriate of lime, 
 composed of muriatic acid and lime, and carbonate ofj^oianh, com- 
 posed of carbonic acid and potash), immediately decompose each 
 other, and form two new combinations. The muriatic acid leaves 
 the lime, and combines with the potash, for which it has a stronger 
 attraction — and the muriate of potash thus formed, being a soluble 
 salt, remains dissolved and invisible in the water. The lime and 
 carbonic acid being in contact, when let loose by their former part- 
 ners, instantly unite, and form carbonate of lime, or calcareous 
 earth, which, being insoluble, falls to the bottom. This precipitate 
 is then separated by filtering paper, is washed, dried and weighed, 
 and thus shows the proportion of carbonate of lime contained in 
 the soil.* 
 
 In this process, the carbonic acid which first composed part of 
 the calcareous earth, escapes into the air, and another supply is 
 afterwards furnished from the decomposition of the carbonate of 
 potash. But this change of one of its ingredients does not alter 
 the quantity of the calcareous earth, which is always composed of 
 
 * More full directions for the analysis of soils may be found in Kirwan'.s 
 Essay on Jlanures, Ptozier's Cours Complet, &c., and Davy's Agricultural 
 Chemistry. 
 
TESTING THE PRESENCE OF CALX. 57 
 
 certain invariable proportions of its two component parts ; and 
 when all the lime has been precipitated as above directed, it will 
 necessarily be combined with precisely its first quantity of carbonic 
 acid. 
 
 This operation is so simple, and the means for conducting it so 
 easy to obtain, that it will generally be the most convenient mode 
 for finding the proportion of calcareous earth in those manures 
 that are known to contain it abundantly, and where an error of a 
 few grains cannot be very material. But if a very accurate result 
 is necessary, this method will not serve, on account of several 
 causes of error which always occur. Should no calcareous earth be 
 present in a soil thus analyzed, the muriatic acid will take up a 
 small quantity of aluminoas earth, which will be precipitated by 
 the carbonate of potash, and without further investigation, would 
 be considered as so much calcareous earth. And if any compounds 
 of lime and vegetable acids are present (which, for reasons hereafter 
 to be stated, I believe to be not uncommon in soils), some portion 
 of these may be dissolved, and appear in the result as carbonate of 
 lime, though not an atom of that substance was in the soil. Thus, 
 every soil examined by this method of solution and precipitation 
 will yield some small result of what would appear as carbonate of 
 lime, though actually destitute of that ingredient. The inaccura- 
 cies of this method were no doubt known (though passed over 
 without notice) by Davy, and other men of science who have 
 recommended its use; but as they considered calcareous earth 
 merely as one of the earthy ingredients of soil, operating me- 
 chanically (as do sand and clay), on the texture of the soil, they 
 would scarcely suppose that a difference of a grain or two could 
 materially aflect .the practical value of an analysis, or the character 
 of the soil under examination.* 
 
 The pneumatic apparatus proposed by Davy, as another means 
 for showing the proportion of calcareous earth in soils, is liable to 
 none of these objections; and when some other causes of error, 
 peculiar to this method, are known and guarded against, its accu- 
 racy is almost perfect, in ascertaining the quantity of calcareous 
 earth — to which substance alone its use is limited . 
 
 * "Chalks, calcareous marls, or powdered limestone, act merely by form- 
 ing a uspful earthy ingredient iri the mil, and their efiBcacy is proportioned 
 to the deficiency of calcareous matter, which in larger or smaller quantities 
 'seems to be an essential ingredient of all fertile soils ; necessary perhaps to 
 their proper texture, and as an ingredient in the organs of plants." [Da- 
 vy's Agr. Chem. page 21— and further on he says] "Chalk and marl or 
 carbonate of lime only improve the texture of a soil, or its relation to absorp- 
 tion ; it acts merely as one of its earthy ingredients." [It is evident, from these 
 expres-sions, that Davy considered calcareous earth important only as a 
 physical constituent of soils ; and it does not appear that he had any con- 
 ception of its far more important and useful ser-\nce, in very minute pro- 
 portions, as a chemical agent, essential to fertilization.] 
 
58 
 
 BY PNEUMATIC APPAEATUS. 
 
 The following representation and description ivill make the ope- 
 ration quite clear : 
 
 *' A, B, C, D, E, represent tlie different parts of this apparatus. A repre- 
 sents the bottle for receiving the soil. B the bottle containing the acid, 
 furnished with a stop-cock. C the tube connected with a flaccid bladder. 
 D the graduated measiu'e. E the bottle for containing the bladder. When 
 thi.-j instrument is used, a given quantity of soil is introduced into A. B 
 is filled with muriatic acid diluted with an eqx^al quantity of water ; and 
 the stop-LOck being closed, is connected with the upper orifice of A, which 
 is ground to receive it. The tube C is introduced into the lower orifice of 
 A, and the bladder connected with it placed in its flaccid state into E, 
 which is filled with water. The graduated measure is placed under the 
 tube of E. When the stop-cock of B is turned, the acid flows into A, and 
 acts upon the soil ; the elastic fluid generated passes thi-ough C, into the 
 bladder, and displaces a quantity of water in E equal to it in bulk, and 
 this water flows through the tube into the graduated measure ; and gives 
 by its volume the indication of the proportion of carbonic acid disengaged 
 from the soil ; for every ounce measure of which two grains of carbonate 
 of lime may be estimated." — Davy's Agr. Chem. 
 
 The correctness of this mode of analysis depends on two well- 
 established facts in chemistry : 1st, That the component parts of 
 calcareous earth always bear the same proportion to each other, and 
 these proportions are as 43.7 parts (by weight) of carbonic acid, to 
 5(5.3 of lime ; and, '2d, That the carbonic acid gas which two grains 
 of calcareous earth will yield, is equal in bulk to one ounce of fresh 
 water. The process, with the aid of this apparatus, disengages, 
 confines, and measures the gas evolved; and for every measure 
 equal to the bulk of an ounce of water, the operator has but to 
 allow two grains of calcareous earth in the soil acted on. It is 
 evident that the result can indicate the presence of lime in no other 
 combination except that which forms calcai'eous earth ] nor of any 
 
CALCAREOUS SOILS. 69 
 
 other earth, except carbonate of magnesia, which, if present, might 
 be mistaken for calcareous earth, but which is too rare, and occurs 
 in proportions too small, to cause any material error in ordinary 
 cases, and in soils of this region. 
 
 But if it be only desired to know whether calcareous earth is 
 entirely wanting in any soil — or to test the truth of my assertion 
 that so great a proportion of our soils are destitute of that earth 
 — it may be done with far more ease than by either of the forego- 
 ing methods, and without apparatus of any kind. Let a handful 
 of the soil (without drying or weighing) be thrown into a large 
 drinking-glass, containing enough of pure water to cover the soil 
 about two inches. Stir it until all the lumps have disappeared, 
 and the water has certainly taken the place of all the atmospheric 
 air which the soil had enclosed. Remove any vegetable fibres, or 
 froth, from the surface of the liquid, so as to have it clear. Then 
 pour in gently about a table spoonful of undiluted muriatic acid, 
 which by its greater weight will sink, and penetrate the soil, with- 
 out any agitation being necessary for that purpose. If any calca- 
 rcoiis earth is present, it will quickly begin to combine with the 
 acid, throwing off its carbonic acid in gas, which cannot fail to be 
 observed as it escapes, as the gas that eight grains only of calca- 
 reous earth would throw out, would be equal in bulk to a gill 
 measure. Indeed, the product of a single grain only of calcareous 
 earth would be abundantly plain to the eye of the careful operator, 
 though it might be the whole amount of gas from two thousand 
 grains of soil. If no effervescence is seen even after adding more 
 acid and gently stirring the mixture, then it is absolutely certain 
 that the soil contained not the smallest portion of carbonate of 
 lime ; nor of carbonate of magnesia, the only other substance which 
 could possibly be mistaken for it. 
 
 The examinations of all the soils that will be here mentioned were 
 made in this pneumatic apparatus, except some of those which evi- 
 dently evolved no gas, and when no other result was required. As 
 calcai-eous earth is plainly visible to the eye in all shelly soils, they 
 only need examination to ascertain its proportion. A few examples 
 will show what proportions we may find, and how greatly they 
 vary, even in soils apparently of equal value. 
 
 1. Soil, a black clayey loam, from the top of the high knoll at 
 the end of Coggins Point [then my own farm], on James River, con- 
 taining fragments of mussel shells throughout. Never manured, 
 and supposed to have been under scourging cultivation and close 
 grazing from the first settlement of the country; then (1818) ca- 
 pable of producing twenty-five or thirty bushels of corn — and the 
 soil well suited to wheat. One thousand grains, cleared by a fine 
 sieve of all coarse shelly matter (as none can act on the soil until 
 minutely divided), yielded "sisteeu ounce measures of carbonic acid 
 
60 CALCAREOUS SOILS. 
 
 gas, wliich showed the finely divided calcareous earth to be thirty- 
 two gi-ains. 
 
 2. One thousand grains of similar soil from another part of the 
 same field, treated in the same manner, gave twenty-four grains of 
 finely divided calcareous earth. 
 
 3. From the east end of a small island, at the end of Coggina 
 Point, surrounded by the river and tide marsh. Soil, dark brown 
 loam, much lighter than the preceding specimens, though not 
 sandy — under like exhausting cultivation — then capable of bring- 
 ing thirty to thirty-five bushels of corn — not a good wheat soil, 
 ten or twelve bushels being probably a full crop. One thousand 
 grains yielded eight grains of coarse shelly matter, and eighty-two 
 of finely divided calcareous earth. 
 
 4. From a small spot of sandy soil, almost bare of vegetation, 
 and incapable of producing any grain, though in the midst of very 
 rich land, and cleared but a few years. Some small fragments of 
 fossil sea-shells being visible, proved this barren spot to be calca- 
 reous, which induced its examination. Four hundred grains yielded 
 eighty-seven of calcareous earth — nearly twenty-two per cent. 
 This super-calcareous soil was afterwards dug and carried out as 
 manure. [It is, in fact, the upper layer of a bed of fossil-shell 
 earth, the shells there being entirely disintegrated and invisible.] 
 
 5. Black friable loam, from Indian Fields, on York River. The 
 soil was a specimen of a field of considerable extent, mixed through- 
 out with oyster shells. Though light and mellow, the soil did not 
 appear to be sandy. Rich, durable, and long under exhausting 
 cultivation. 
 
 1260 grains of soil yielded 
 1G8 — of coarse shelly matter, separated mechanically, 
 8 — finely divided calcareous earth. 
 The remaining solid matter, carefully separated (by agitation and 
 settling in water), consisted of 
 130 grains of fine clay, black with putrescent matter, and which 
 lost more than one-fourth of its weight by being ex- 
 posed to a red heat, 
 875 — white sand, moderately fine, 
 20 — very fine sand, 
 30 — lost in the process. 
 
 ioGi 
 
 6. Oyster shell soil, of the best quality, from the farm of Wills 
 Cowper, Es^., on Nansemond River — never manured, and supposed 
 to have been cultivated in corn as often as three years in four, since 
 the first settlement of the country — now yields (by actual nica- 
 Buremcnt) thirty bushels of corn to the acre — but is very unproduc- 
 
ALL POOR SOILS NOT CALCAREOUS. 61 
 
 tive in wlieat. A specimen taken from the surface, to tlie depth, 
 of six inches, weighed altogether 
 242 dwt., which consisted of 
 
 126 — of shells and their fragments, separated by the sieve, 
 116 — remaining finely divided soil. 
 Of the finely divided part, 500 grains consisted of 
 
 18 grains of carbonate of lime, 
 330 — silicious sand — none very coarse, 
 
 9-4 — impalpable aluminous and silicious earth, 
 
 35 — putrescent vegetable matter — none coarse or unrottcd, 
 
 23 — loss. 
 
 500 
 
 It is unnecessary to cite any particular trials of ou.r poor soils, 
 as it has been stated, in the preceding chapter, that all are entirely 
 destitute of calcareous earth — -excluding the rare, but well marked 
 exceptions of its great excess, of which an example has been given 
 in the soil marked 4, in the foregoing examinations. 
 
 Unless then I am mistaken in supposing that these facts are 
 universally true, the certain results of chemical analysis, as well 
 as more extended general observation, completely establish these 
 general rules — viz. : 
 
 1st. That all calcareous soils are naturally fertile and durahle 
 in a very high degree — and, 
 
 2d. That all soils naturally j^oor are entirely destitute of calca- 
 reous earth. 
 
 It then can scarcely be denied that calcareous earth must be the 
 cause of the fertility of the one class of soils, and that the want 
 of it produces the poverty of the other. Qualities that always 
 thus accompany each other cannot be otherwise than cause and ejfect. 
 If further proof is wanting, it can be safely promised to be fur- 
 nished when the practical application of calcareous manures to 
 poor soils will be treated of, and the effects stated. 
 
 These deductions are then established as to all calcareous soils, 
 and all poor soils — which two classes comprise nine-tenths of all. 
 This alone would open a wide field for the practical exercise of the 
 truths we have reached. But still there remain strong-objections 
 and stubborn facts opposed to the complete proof and universal 
 application of the proposition now under consideration, and conse- 
 quently to the theory which that proposition is intended to support. 
 The whole difficulty will be apparent at once when I now proceed 
 to state that nearly all of our best soils, such as are very little if 
 at all inferior in value to the small portion of shelly lands, are as 
 destitute of calcareous earth (carhonate of lime) as the poorest. So 
 far as I have examined, this deficiency is no less general in the 
 6 
 
62 MANY IIICU SOILS NOT CALCAREOUS. 
 
 richest alluvial lands of the upper country — and, what will be 
 deemed by some as incredible, by far the greater part of the rich 
 limestone soils between the Blue Ridge and Alleghany Mountains 
 are equally destitute of calcareous earth. These facts were not 
 named before, to avoid embarrassing the discussion of other points 
 — nor can they now be explained, and reconciled with my proposi- 
 tion, except through a circuitous and apparently digressive course 
 of reasoning. They have not been kept out of view, nor slurred 
 over, to weaken their force, and are now presented in all their 
 strength. These difficulties will be considered, and removed, in 
 the following chapters. 
 
 CPIAPTER VI. 
 
 CHEMICAL EXAMINATION OF RICH SOILS CONTAINING NO CALCA- 
 REOUS EARTH. 
 
 Proposition 2 — continued. 
 
 Under common circumstances, when any disputant admits facts 
 that seem to contradict his own reasoning, such admission is 
 deemed abundant evidence of their existence. But though now 
 placed exactly in this situation, the facts admitted by me are so 
 opposed to all that scientific agriculturists have taught us to expect, 
 that it is necessary for me to show the grounds on which my ad- 
 mission rests. Few would have believed in the absence of calca- 
 reous earth in all our poor soils, forming as they do the much 
 larger part of all this region — and far more strange is it that the 
 same deficiency should extend to such rich soils as some that will 
 be here cited. 
 
 The following specimens, taken from well known and very fertile 
 soils, were found to contain no calcareous earth. Many trials of 
 other rich soils have yielded like results — and, indeed, I have 
 never found calcareous earth in any soil below the falls of the 
 rivers, in which, or near which, some particles of shells were not 
 visible. 
 
 1. Soil from Eppcs' Island, which lies in Powhatan, or James- 
 river, near City Point ; light and friable (but not sandy) brown 
 loam, rich and durable. The surface is not many feet above the 
 highest tides, and, like most of the best river lands, this tract 
 seems to have been formed by alluvion many ages ago, but which 
 may be termed recent, when compared to the general formation of 
 the tide-water district. 
 
RICH RIVER AND LIME-STONE SOILS. 63 
 
 2. Black silicious loam from the celebrated lands on Back river, 
 near Hampton. 
 
 3. Soil from rich land on Pocoson-river, York county. 
 
 4. Black clay vegetable soil, from a fresh-water tide marsh on 
 James river — formed by recent alluvion. 
 
 5. Alluvial soil of first-rate fertility above the falls of James 
 river — dark brown clay loam, from the valuable and extensive 
 body of bottom land belonging to General J. H. Cocke, of Flu- 
 vanna. 
 
 The most remarkable facts of the absence of calcareous earth 
 are to be found in the lime-stone soils, between the Blue Kidge 
 and Alleghany Mountains. Of these, I will report all that I have 
 examined ; and none contained any calcareous earth, unless when 
 the contrary will be stated. 
 
 Before the first of these trials was made, I supposed (as proba- 
 bly most other persons do) that limestone soil was necessarily 
 calcareous, and in a high degree. It is difficult to get rid of this 
 impression entirely — and it may seem a contradiction in terms to 
 say that a lime-stone soil is not calcareous. This I cannot avoid. 
 I must take the term lime-stone soil as custom has already fixed it. 
 But it should not be extended to any soils except those which are 
 so near to lime-stone rock, as in some measure to be thereby afi'ected 
 in their qualities and value. 
 
 1 to 6. Lime-stone soils selected in the neighbourhood of Lex- 
 ington, Virginia, by Professor Grraham, with the view of enabling 
 me to investigate this subject. All the specimens were from first- 
 rate soils, except one, which was from land of inferior value. One 
 of the specimens, Mr. Graham's description stated to be " taken 
 from a piece of land so rocky [with lime-stone] as to be unfit for 
 cultivation, at least with the plough. I could scarcely select a 
 specimen which I would expect to be more strongly impregnated 
 with calcareous earth." This specimen, by two separate trials, 
 yielded only one grain of calcareous earth, from one thousand of 
 soil. The other five soils contained none. The same result was 
 obtained from 
 
 7. A specimen of alluvial land on North river, near Lexington. 
 
 8. Brown loam from the Sweet Spring valley, remarkable for its 
 extraordinary productiveness and durability. It is of alluvial for- 
 mation, and before it was drained, must have been often covered 
 and saturated by the Sweet Spring and other mineral waters, which 
 hold lime in solution. [The carbonate of lime dissolved in these 
 watei's is so abundant, and so readily parted with, that it is depo- 
 sited on every twig that is exposed therein, forming rapidly grow- 
 ing incrustations.] The surrounding high land is of lime-stono 
 soil. Of this specimen, taken from about two hundred yards be- 
 low the Sweet Spring, from land long cultivated every year, threo 
 
64 LIME-STONE SOILS. 
 
 hundred and sixty grains yielded not a particle of calcareous earth. 
 It contained an unusually large proportion of oxide of iron, though 
 my imperfect means enabled me to separate and collect only eight 
 grains, the process evidently wasting several more. 
 
 About a mile lovrer down, drains were then making (in 1826) to 
 reclaim more of this rich valley from the overflowing waters. 
 Another specimen was taken from the bottom of a ditch just 
 opened, eighteen inches below the surface. It was a black loam, 
 and exhibited to the eye some very diminutive fresh-water spiral 
 shells, about one-tenth of an inch in length, and many of their 
 broken fragments. This gave, from two hundred grains, seventy-four 
 of calcareous earth. But this cannot fairly be placed on the same 
 footing with the other soils, as it had obviously been once the bot- 
 tom of a stream, or lake, and the collection and deposit of so large 
 and unusual a proportion of calcareous matter seemed to be of ani- 
 mal formation. Both these specimens were selected at my request 
 by one of our best farmers, and who also furnished a written 
 description of the soils, and their situation. 
 
 9. Wood-land, west of Union, Monroe county. Soil, a black 
 clay loam, lying on, but not intermixed at the surface with lime- 
 stone rock. Sub-soil, yellowish clay. The rock at this place, a 
 foot below the sur&ce. Principal growth, sugar maple, white wal- 
 nut, and oak. This and the next specimen are from one of the 
 richest tracts of high land that I have seen. 
 
 10. Soil similar to the last, and about two hundred yards distant. 
 Here the lime-stone showed above the surface, and the specimen 
 was taken from between two large masses of fixed rock, and about 
 a foot distant from each. 
 
 11. Black rich soil, from wood-land between the Hot and Warm 
 Springs, in Bath county. The specimen was part of what wf^s in 
 contact with a mass of lime-stone. 
 
 12. Soil from the western foot of the Warm Spring mountain, 
 on a gentle slope between the court-house and the road, and about 
 one hundred and fifty yards from the Warm Bath. Ilich brown 
 loam, containing many small pieces of lime-stone, but no finely 
 divided calcareous earth. 
 
 13. A specimen taken two or three hundred yards from the last, 
 and also at the foot of the mountain. Soil, a rich black loam, full 
 of small fragments of lime-stone of different sizes, between that 
 of a nutmeg and small shot. The land had never been broken up 
 for cultivation. One thousand grains contained two hundred and 
 forty grains of small stone or gravel, mostly lime-stone, separated 
 mechanically, and sixty-nine grains of finely divided calcareous 
 earth. 
 
 14. Black loamy clay, from the excellent wheat soil adjoining 
 the town of Bedford, in Pennsylvania : the specimen taken from 
 
LIME-STONE AND ALLUVIAL SOILS. 65 
 
 bencatli and in contact with lime-stone. One thousand grains 
 yielded less than one grain of calcareous earth. 
 
 15. A specimen from within a few yards of the last, but not in 
 contact with lime-stone, contained no calcareous earth ; neither did 
 the red clay sub-soil, six inches below the surface. 
 
 16. Very similar soil, but much deeper, adjoining the principal 
 street of Bedford — the specimen taken from eighteen inches below 
 the surface, and adjoining a mass of lime-stone. A very small 
 disengagement of gas indicated the presence of calcareous earth — 
 but certainly less than one grain in one thousand, and perhaps not 
 half that quantity. 
 
 17. Alluvial soil on the Juniata, adjoining Bedford. 
 
 18. Alluvial vegetable soil near the stream flowing from all the 
 Saratoga Mineral Springs, and necessarily often covered and soaked 
 by those waters, and 
 
 19. Soil taken from the bed of the same stream — neither con- 
 tained any portion of carbonate of lime. 
 
 Thus it appears that of these nineteen specimens of soils, only 
 four contained calcareous earth, and three of these four in exceed- 
 ingly small proportions. It should be remarked that all these 
 were selected from situations which, from their proximity to calca- 
 reous Yocli, or exposiire to calcareous waters, were supposed most 
 likely to present highly calcareous soils. If five hundred speci- 
 mens had been taken, without choice, even from what are commonly 
 called lime-stone soils (merely because they are not very distant 
 from lime-stone rock, or springs of lime-stone water), the analysis 
 of that whole number would be less likely to vshow calcareous 
 earth, than the foregoing short list. I therefore feel justified, from 
 my own few examinations, and unsujiported by any other authority, 
 to pronounce that calcareous earth will very rarely be found in any 
 soils between the falls of our rivers and the navigable western 
 waters.* In a few specimens of some of the best soils from the 
 borders of the Mississippi and its tributary rivers, I have since 
 found calcareous earth present in all — but in very small propor- 
 tions, and in no case exceeding two per cent. 
 
 [When the total deficiency of carbonate of lime, in nearly all the 
 soils of Virginia, was first asserted, as above, in the earliest publi- 
 cation of this essay (1821, in Amcrlccui Farmer, vol. iii.), the 
 
 [* Recent Confirmatory Testimony. — Still more strange cases of the total 
 absence of (carbonate of) lime have been stated recently in Johnston's 
 Agricultural ■Chemistry: " It is a fact which will strike you as not a little 
 remarkable that soils ■which rest upon chalk, as well as upon other 
 lime-stono rocks, even at the depth of a few inches only, are often, and 
 especially when in a state of nature, so destitute of lime, that not a parti- 
 cle cau be detected iu them." (p. 377.) The author of course meant the 
 carbonate of lime. — 1849.] 
 
 6* 
 
63 PRAIRIE SOILS CALCAREOUS. 
 
 proposition was so entirely new, and so opposed to all inferences 
 from authority then existing, that it was indispensably necessary to 
 adduce my facts, as is done above, to sustain the otherwise unsus- 
 tained doctrine. And such support, for the same reason, continued 
 to be wanting through the two nest editions. Now (in 1842) the 
 case is altogether different. The fact of the absence of carbonate 
 of lime, as generally as I had assumed, through the eastern or 
 seaward slope of the United States, and especially in New England, 
 has been confirmed by all the analyses of soils which have been 
 since made by Professor Hitchcock and other accurate scientific 
 investigators ; and the proposition, however untenable or incredible 
 it might have been deemed before, is now universally admitted, and 
 indeed is placed beyond question or doubt, as an important feature 
 in the chemical constitution of soils. — 1842.] 
 
 [The only soils of considerable extent of surface which, from the 
 specimens that I have examined, appear to be highly calcareous, 
 and to agree in that respect with many European soils, are from 
 the prairies, those lands of the south-west which, whether rich or 
 poor, are remarkable for being destitute of trees, and covered v/ith. 
 grass, so as to form natural meadows. The examinations were 
 made but recently (in 1834), and are reported because presenting 
 striking exceptions to the general constitution of soils in this 
 country. 
 
 20. Prairie soil of the most productive kind in Alabama; a 
 black clay, with very little sand, yet so far from being stiff, that it 
 becomes too light by cultivation. This kind of land is stated by 
 the friend to whom I am indebted for the specimens, to " produce 
 corn and oats most luxuriantly — and also cotton for two or three 
 years ; but after that time cotton is subject to the rust, probably 
 from the then open state of the soil, which by cultivation has by 
 that time become as light and as soft as a bank of ashes." One 
 hundred grains of the specimen contained eight of carbonate of 
 lime. All this prairie land in Alabama lies on a substratum of 
 what is there called "rotten lime-stone" (specimens of which con- 
 tained seventy-two to eighty-two per cent, of lime), and which 
 rises to the surftice sometimes, forming the ''bald prairies," a sam- 
 ple of the soil of which (21) contained fifty-nine per cent, of car- 
 bonate of lime. This was described as " comparatively poor — 
 neither trees nor bushes grow there, and only grass and weeds be- 
 fore cultivation — corn does not grow well — small grain better — 
 and cotton soon becomes subject to the rust." The excessive pro- 
 portion of calcareous earth is evidently the cause of its barrenness. 
 The substratum called lime-stone is soft enough to be cut easily 
 and smoothly with a knife, and some of it is in appearance and 
 texture moi'c like the chalk of Europe, than any other earth that 
 I have seen in this country. 
 
PRAIRIE SOILS. 67 
 
 22. A specimen of the very rich " cane brake" lands in Marengo 
 county, Ah\baTna, contained sixteen per cent, of carbonate of lime. 
 This is a kind of prairie, of a wetter nature, from the winter rains 
 not being able to run oif from the level surface, nor to sink through 
 the tenacious clay soil, and the- solid stratum of lime-stone below. 
 
 23. A specimen from the very extensive "Choctaw Prairie" in 
 Mississippi, of celebrated fertility, yielded thirteen per cent, of 
 carbonate of lime. 
 
 Several other specimens of different, but all of very fertile soils 
 from southern Alabama, and all lying over the substratum of soft 
 lime-stone, were found to be neutral^ containing not a particle of 
 lime in the form of cai-honate. These specimens were as follows : 
 
 24. One from the valley cane lan*l — " very wet through the 
 winter, bat always dry in summer — and after being ditched is dry 
 enough to be cultivated in cotton, which will grow from eight to 
 twelve feet high." 
 
 25. Another from what is called the best "post-oak land," on 
 which trees of that kind grow to the size of from two to four feet 
 in diameter — having but little underwood, and no cane growth — 
 " thought to be nearly as rich as the best cane land, and will pro- 
 duce 1500 lbs., or more, of seed cotton, or fifty bushels of corn to 
 the acre." 
 
 26. Another from what is termed " palmetto land, having on it 
 that plant as well as a heavy cover of large trees growing luxuri- 
 antly. It is a cold and wet soil before being brought into good 
 tilth ; but afterwards is soft and easy to till, and produces corn and 
 cotton finely. The cane on it is generally small — the soil from 
 four to ten feet deep." 
 
 One more prairie soil only will be adduced, from many analyses 
 which have furnished general results like the foregoing (20 to 26) ; 
 and this one is given because it serves as a fair specimen of a very 
 large class of the prairie lands. It was selected by Dr. R. W. 
 Withers, in 1835, and described by him as follows : (^Farmers' 
 Register, vol. iii. p. 498.) 
 
 27. Soil of Greene county, Alabama, " from our open ov hold 
 prairie, \i. e., totally without trees,] which has been cultivated for 
 seven or eight years — produces corn very well — nearly fifty bushels to 
 the acre are now standing on the ground ; but cotton does not pro- 
 duce so well on it as on poor sandy soil. I feel very confident that 
 this specimen is highly calcareous, as there are many fragments of 
 shells mixed with the soil, and the rock is not two feet from the 
 surfiice. Of all the specimens hitherto sent, this is the one which 
 will give the nearest approach to the general character of our open 
 prairie land in this part of the country." — This specimen was 
 found to contain 33 per cent, of carbonate of lime. — 1835.] 
 
 The foregoing details, respecting limc-stonc lands, may perhaps 
 
68 LIME ESSENTIAL TO FERTILE SOIL. 
 
 lie considered an unnecessary digression, in a treatise on the soils 
 of the tide-water district. But the analysis of lime-stone soils 
 furnishes the strongest evidence of the remarkable and novel fact 
 of the general absence of calcareous earth — and the information 
 thence derived will be used to sustain the following steps of my 
 argument. ^ 
 
 All the examinations of soils in this chapter concur in opposing 
 the general application of the proposition that the deficiency of 
 calcareous earth is the cause of the sterility of our soili^ And 
 having stated the objection in all its force, I shall now proceed to 
 inquire into its causes, and endeavour to dispel its apparent opposi- 
 tion to my doctrine. 
 
 CHAPTER VII. 
 
 PROOFS OF THE EXISTENCE OF ACID AND NEUTRAL SOILS. 
 
 Proposition 2 — continued. 
 
 Sufficient evidence has been adduced to prove that many of our 
 most fertile and valuable soils are destitute of calcareous earth. 
 But it does not necessarily follow that such has always been their 
 composition ; or that they may not now contain enough lime com- 
 bined with some other acid than the carbonic. That this is really 
 the case, I shall now offer proofs to establish; and not only main- 
 tain this position with regard to those valuable soils, but shall con- 
 tend, that lime, in some projioriion, comLined icith vegetahle acid, 
 is present in every soil capable of supporting vegetation. 
 
 But, while I shall endeavour to maintain these positions, without 
 asking or even admitting any exception, let me not be understood 
 as asserting that the degree of natural fertility of a calcareous soil 
 is in proportion to the amount of calcareous earth contained ; or, 
 that the knowledge of the proportion of calcareous earth, or of lime 
 in any form, contained, would serve to measure the capacity of the 
 soil for production or for fertilization. On the contrary, chalky 
 and calcareous soils, not differing materially in agricultural qualities 
 or fertility, sometimes exhibit remal-kable differences in their pro- 
 portions of calcareous earth ; so that one soil, having less than one 
 per cent., may seem as well constituted and as valuable as another 
 having ten per cent., or more. [The reason is, that a very small 
 proportion is enough for the full chemical action ; and that any 
 surplus, even if not hurtful by its amount, will have no other than 
 the comparatively feeble mechanical action — which may even be 
 injurious, and iu opposition to, and counteracted by the chemical 
 action.] 
 
ACID AND NEUTRAL SOILS DEFINED. 60 
 
 Tn all naturally poor soils, producing freely pine and whortlG- 
 berry in their virgin state, and sheep-sorrel after cultivation, I sup- 
 pose to have been formed some vegetable acid, which, after taking 
 up, and combining with whatever small quantity of lime miglit 
 have been present, still remains in excess in the soil, and nourishes 
 in the highest degree the plants named above, but is a poison to all 
 useful crops 3 and effectually prevents such acid soils from becom- 
 ing rich, by either natural or artificial applications of putrescent 
 manures. 
 
 In a neutral soil, I suppose calcareous earth to have been suffi- 
 ciently abundant at some former time to induce a high degree of 
 fertility — but that it has been decomposed, and the lime taken up, 
 by the gradual formation of vegetable acid, until the lime and the 
 acid neutralize and balance each other, leaving no considerable ex- 
 cess of either ; and that such are all our fertile soils which are not 
 now calcareous. 
 
 Both these suppositions remain to be proved, in all their parts. 
 
 No opinion has been yet advanced that is less supported by good 
 authority, or to which more general oppT)sition may be expected, than 
 that which supposes the existence of acid soils. The term sour soil 
 is indeed frequently used by. farmers, but in so loose a manner as 
 to deserve no consideration. It has been thus applied to any moist, 
 cold, and ungrateful land, without intending that the term should 
 be literally understood, and perhaps without attaching to its use 
 any precise meaning whatever. Dundonald only, of all those 
 who have applied chemistry to agriculture, has asserted the exist- 
 ence of vegetable acid in soils :* but he has offered no analysis 
 of soils in proof, nor any other evidence to establish the fact 3 and 
 his opinion has received no confirmation, nor even the slightest no- 
 tice, from later and more able investigators of the chemical cha- 
 racters of soils. Kirwan and Davy profess to enumerate all the 
 common ingredients of soils; and it is not intimated by either 
 that vegetable acid is one of them. Even this tacit denial by 
 Davy more strongly opposes the existence of vegetable acid, than it 
 is supported by the opinion of Dundonald, or any early writers on 
 agriculture, if there be any who may have admitted its existence. 
 [For it cannot be supposed that so able and profound an investiga- 
 tor would have omitted all reference to an ingredient of soils so 
 general, and therefore so important, as is here asserted, even if its 
 presence had been even suspected by him, much less if fully known.] 
 (xriscuthwaite, a late writer on agricultural chemistry, and who has 
 theP advantage of knowing the discoveries, and comparing the 
 opinions, of all his predecessors, expressly denies the possibility of 
 any acid existing in soils. His JVew ' Theory of Agriculture ■\ con- 
 
 * Dundonald' s Connexion of Chemistry and Agriculture. 
 I Republished in Ameiican Farmer, (old) vol. ii. 
 
70 CHEMICAL AUTHORITY OPPOSED TO ACID SOIL. 
 
 tains the following passage : " Chalk has been recommended as a 
 substance calculated to correct the sourness of land. It would 
 surely have been a wise practice to have previously ascertained this 
 existence of acid, and to have determined its nature, in order that 
 it might be effectually removed. The fact really is, that no soil 
 was ever yet found to contain any notable quantity of .acid. The 
 acetic and the carbonic are the only two that are likely to be gene- 
 rated by any spontaneous decomposition of animal or vegetable 
 bodies, and neither of them have any fixity when exposed to the 
 air." Thus, then, my doctrine is deprived of even the feeble sup- 
 port it might have had from Duudonald's mere opinion, if that 
 opinion had not -been contradicted by later and better authority ; 
 and the only support to be looked for, will be in the facts and argu- 
 ments that I shall be able to adduce. 
 
 I am not prepared to question what G-risenthwaite states as a 
 chemical fact, "that no soil was ever yet found to contain any 
 notable quantity of acid." No soil examined by me for this pur- 
 pose, with such poor means as I could apply, gave any evidence of 
 the presence of uncombined acid. Still, however, the term acid 
 may be applied with propriety to soils in which growing vegetables 
 continually receive acid from the decomposition of others (for which 
 no " fixity" is requisite), or in which acid is present, not free, but 
 combined with some base, by which it is readily yielded, to promote, 
 or retard, the growth of plants in contact with it. It will be suifi- 
 cient for my purpose to show that certain soils contain some sub- 
 stance, or possess some quality, which promotes almost exclusively 
 the growth of acid plants— that this power is strengthened by 
 adding known vegetable acids to the soil — and is totally removed 
 by the application of calcareous manures, which would necessarily 
 destroy any acid, if it were present. Leaving it to chemists to 
 determine the nature and properties of this substance, I merely 
 contend for its existence and effects; and the cause of these effects, 
 whatever it may be, for the want of a better name, I shall call 
 acid it I/. 
 
 The proofs now to be offered in support of the existence of acid 
 and neutral soils, however weak each may be when considered alone, 
 yet, when taken in connexion, will together form a body of evidence 
 not easily to be resisted. 
 
 First proof . — Pines and common sorrel \_rumcx acctocclla] have 
 leaves well known to be acid to the taste ; and their growth is fa- 
 voured by such soils as are here supposed to be acid, to an extent 
 which would be thought remarkable in other plants on the richest 
 soils. Except wild locust on the best of our river land, no growth 
 can compare in rapidity with pines on soils naturally poor, and 
 even when greatly reduced by long cultivation. Pines iisually 
 stand so thick, on old exhausted fields, that the increase of size in 
 
PROOFS OF ACID SOILS. 71 
 
 eacli plant is greatly retarded ; but if the wliole growth of an acre 
 were estimated, it wouhl probably exceed in quantity the diflerent 
 growth of the richest soils, of the same age and on an equal space. 
 Every cultivator of corn on poor light soil knows how rapidly 
 sorrel* will cover his otherwise naked field, unless kept in check by 
 continual tillage — and that to root it out, so as to prevent the like 
 future labour, cannot be eifected by any mode of cultivation what- 
 ever. This weed too is considered far more hurtful to growing 
 crops, than any other of equal size. Yet neither of these acid 
 plants can thrive on the best lands. Sorrel cannot even live on a 
 calcareous soil; and if a pine is sometimes found there, it has 
 nothing of its usual elegant form, but seems as stunted and ill- 
 shaped as if it had always suifered for want of nourishment. In- 
 numerable facts, of which these are examples, prove that these acid 
 plants must derive from their favourite' soil some kind of food pe- 
 cidiarly suited to their growth, and quite useless, if not hurtful, to 
 cultivated crops. 
 
 2d. Dead acid plants are the most effectual in promoting the 
 growth of living ones. When pine leaves are applied to a soil, 
 whatever acid they contain is of course given to that soil, for such 
 time as circumstances permit it to retain its form, or peculiar pro- 
 perties. Such an application is often made on a large scale, by 
 cutting down the second growth of pines, on land once under till- 
 age, and suffering them to lie a year before clearing and cultivating 
 the land. The invariable consequence of this course is a growth 
 of sorrel, for one or two years, so abundant and so injurious to the 
 crops, as to more than balance any benefit derived by the soil from 
 the vegetable matter having been allowed to rot. From the gene- 
 ral experience of this eifect, most persons put pine land under 
 tillage as soon as cut down, after carefully burning (to destroy) the 
 whole of the heavy cover of leaves, both green and dry. Until 
 within a few years, it was generally supposed that the leaves of 
 pine were worthless, if not hurtful, in all applications to cultivated 
 land — which opinion doubtless was founded on such facts as have 
 been just stated. But if they are used as litter for cattle, and 
 heaped to ferment, the injurious quality of pine leaves is destroyed, 
 and they become a valuable manure. This practice is but of recent 
 origin — but is highly approved, and rapidly extending. [Still 
 later it has been found that when these leaves are applied unrotted, 
 as raked up in woodland, to calcareous land, they produce only and 
 
 * Sheep sorrel, or Rumex acetocella. The ■wood sorrel {Oxalis acetocella) 
 is of a very different character. The latter prefers rich and even calcareous 
 soils, and I have seen it growing well on spots calcai'eous to excess. It 
 would seem, therefore, that wood sorrel forms its acid from the atmosphere, 
 aneVioes not draw it from the soil, as I suppose to be the case with common 
 sorrel. [The wood sorrel is a trefoil, and pod-bearing or leguminous 
 plant,] 
 
72 TEOOFS OF ACID SOILS. 
 
 always beneficial results ; and that this is the best as well as cheap- 
 est naode of their application.] 
 
 On one of the washed and barren declivities (or galls) which are 
 so numerous on all our farms, I had the small gullies packed full 
 of green pine bushes, and then covered with the earth drawn from 
 the equally barren intervening ridges, so as nearly to smooth the 
 whole surface. The whole piece hud borne nothing previously ex- 
 cept a few scattered tufts of poverty grass (ciristlda gracilis) and 
 dwarfish sorrel, all of which did not prevent the spot seeming quite 
 bare at mid-summer, if viewed at some distance. This operation 
 was performed in February or March. The land was not culti- 
 vated, nor again observed, until the second summer afterwards. At 
 that time, the piece remained as bare as formerly, escept along the 
 filled gullies, which, throughout the whole of their crooked courses, 
 were covered by a thick and uncommonly tall growth of sorrel, re- 
 markably luxuriant for any situation, and which, being bounded 
 exactly by the width of the narrow gullies, had the appearance of 
 some vegetable sown thickly in drills, and kept clean by tillage. 
 So great an eifect of this kind has not been produced within my 
 knowledge — though facts of like nature, and leading to the same 
 conclusion, are of frequent occurrence. If small pines standing 
 thinly over a broom-grass old-field are cut down and left to lie, un- 
 der every top will be found a patch of sorrel, before the leaves have 
 all rotted. 
 
 3d. The growth of sorrel is not only peculiarly favoured by the 
 application of vegetables containing acids already formed, but also 
 by such matters as will form acid in the course of their decomposi- 
 tion. Farm-yard manure, and all other putrescent animal and 
 vegetable substances, form acetic acid as their decomposition pro- 
 ceeds.* If heaps of rotting manure are left without being spread, 
 in a field but very slightly subject to produce sorrel, a few weeks 
 of growing weather will bring out that plant close around every 
 heap ; and for some time the sorrel will continue to show more 
 benefit from that rank manuring than any other grass. For several 
 years my winter-made manure was spread and ploughed in on land 
 not cultivated until the next autumn, or the spring after. This 
 practice was founded on the mistaken opinion, that it would prevent 
 much of the usual exposure to evaporation and waste of the manure. 
 One of the reasons which alone would have compelled me to aban- 
 don this absurd practice was, that a crop of sorrel always followed, 
 (even on neutral or good soils that before barely permitted a scanty 
 growth of it to live), which so injured the next grain crop as 
 greatly to lessen the benefit from the manure. Sorrel unnaturally 
 produced by such applications does not infest the land longer than 
 
 * Agr. Chem. p. 187. (Phil, cd.) 
 
PROOFS OP ACID SOILS. 73 
 
 until we may suppose the recent supply of acid to have been re- 
 moved by cultivation and other, causes. 
 
 It may be objected that, even if fully admitted, my authorities 
 prove only the formation of a single vegetable acid in soil, the acetic 
 — that my facts show only the production of a single acid plant, 
 sorrel — and that the acid which sorrel contains is not the acetic, 
 but the oxalic* In reply to such objections, it may be said, that 
 from the application of acids to recently ploughed land, no acid 
 plant except sorrel is made to grow, because that one only can 
 spring up speedily enough to arrest the the fleeting nutriment. Po- 
 verty grass (^Arktida gracilis or A. dichotomd) grows only on the 
 same kinds of soil, and generally covers them after tl^iey have been 
 a year free from a crop, but does not show sooner ; and pines re- 
 quire two years before their seeds will produce plants. But when 
 pines begin to spread over the land, they soon put an end to the 
 growth of all other plants, and are abundantly supplied with their 
 acid food, from the dropping of their own leaves. Thus they may 
 be first supplied with the vegetable acid ready formed in the 
 leaves, and afterwards with the acetic acid, formed by their sub- 
 sequent slow decomposition. It does not weaken my argument, 
 that the product of a plant is a vegetable acid different from the 
 one supposed to have nourished its growth. All vegetable acids 
 (except the prussic), however different in their properties, are com- 
 posed of the same three elementary bodies, differing only in their 
 proportionsf — and consequently are all convertible into each other. 
 A little more, or a little less of one or the other of these ingre- 
 dients, may change the acetic to the oxalic acid, and that to any 
 other. We cannot doubt but that such simple changes may be 
 produced by the chemical powers of vegetation, when others are 
 effected far more difficult for us to comprehend. The most tender 
 and feeble organs, and the mildest juices, aided by the power of 
 animal or vegetable life, are able to produce decompositions and 
 combinations which the chemist cannot explain, and which he would 
 in vain attempt to imitate. 
 
 4th. This ingredient of soils, which nourishes acid plants, also 
 poisons cultivated crops. Plants have not the power of rejecting 
 noxious fluids, but take up by their roots everything presented in a 
 soluble form.j Thus the acid also enters the sap-vessels of culti- 
 vated plants, stints their growth, and makes it impossible for them 
 to attain that size and perfection which their proper f lod would 
 insure, if it were presented to them without its poisonous accom- 
 paniment. When the poorest virgin wood-land is cut down, it is 
 
 * Agr. Chem. Lecture .S. 
 
 I Carbon, oxygen, and liydrogen. Agr. Cbem. Lecture ?, p. 78. 
 
 X Agr. Cliem. Lecture t>, page 180. 
 
 7 
 
74 PROOFS OP NEUTRAL AND ACID SOILS. 
 
 covered aud filled to excess with leaves and other rotted and rotting 
 vegetable matters. Can a heavier vegetable manuring be desired? 
 And as this completely rots during cultivation, must it not oifcr to 
 the growing plants as abundant a supply of food as they can re- 
 quire ? Yet the best product obtained may be from ten to fifteen 
 bushels of corn, or five or six of wheat, soon to come down to half 
 those quantities. If the noxious quality which causes such injury 
 is an acid, it is as certain as any chemical truth whatever, that it 
 will be neutralized, and its powers destroyed, by applying enough 
 of calcareous earth to the soil ; and precisely such effects are found 
 wherever that remedy is tried. On land thus relieved of this un- 
 ceasing au'Qoyance, the young plants of corn no longer appear of a 
 pale and sickly green, approaching to yellow, but take immediately 
 a deep healthy colour, by which they may readily be distinguished 
 from any on adjoining ground, left in its former state, before there 
 is any perceptible difference in the size of the plants. The crop 
 will produce fifty to one hundred per cent, more, the first year, be- 
 fore its supply of food can possibly have been increased^ and the 
 soil is soon found not only clear of sorrel, but absolutely incapable 
 of producing it. I have anticipated these effects of calcareous ma- 
 nures, before furnishing the evidence ; but they will hereafter be 
 established by facts beyond contradiction. 
 
 The truth of the existence of either acid or neutral soils depends 
 on the existence of the other ; and to prove either, will necessarily 
 establish both. If acid exists in soils, then whenever it meets with 
 calcareous earth, the two substances must combine with and neu- 
 tralize each other, so far as their proportions are properly adjusted. 
 On the other hand, if I can show that compounds of lime and vege- 
 table acid are present in most soils, it follows inevitably that nature 
 has provided means by which soils can generally obtain this acid j 
 and if the amount formed can balance the lime, the operation of 
 the same causes can exceed that quantity, and leave an excess of 
 free acid. From these premises will be deduced the following 
 proofs. 
 
 5th. It has been stated (page 57) that the process recommended 
 by chemists for finding the calcareous earth in soils was unfit for 
 that purpose, because some precipitate was always obtained, even 
 when no calcareous earth or carbonate of lime was present. Fre- 
 quent trials have shown me that this precipitate is considerably 
 more abundant from good soils than bad. The substance thus ob- 
 tained from rich soils by solution and precipitation, in every case 
 that I have tried, contains «ome carbonate of lime, although the 
 soil from which it was derived had none. The alkaline liquor from 
 which the precipitate has been separated, we are told by Davy, will, 
 after boiling, let fall the carbonate of magnesia, if any had been in 
 tho soil ; but when any notable deposit is thus obtained, it will 
 
DISAPPEARANCE OP CARBONATE OP LIME IN SOILS. 75 
 
 often bo found to consist more of carbonate of lime, than of mag- 
 nesia. The following are examples of such ijrocliicts : 
 
 One thousand grains of tide-marsh soil (page 03, No. 4), acted 
 on by muriatic acid in the pneumatic apparatus, gave out no car- 
 bonic acid gas, and therefore could have contained no carbonate of 
 lime. The precipitate obtained from the same weighed sixteen 
 grains ; which being again acted on by sulphuric acid, evolved as 
 much gas as showed that three grains had become carbonate of 
 lime, in the previous part of the process. 
 
 Two hundred grains of alluvial soil from Saratoga Springs (page 
 G5, No. 18), containing no carbonate of lime, yielded a precipitate 
 of twelve grains, of which three was carbonate of lime — and a 
 deposit from the alkaline solution weighing six grains, four of 
 which was carbonate of lime. 
 
 Seven hundred grains of limestone soil from Bedford, Pennsyl- 
 vania (part of the specimen marked 14, page 64), contained about 
 two-thirds of a grain of carbonate lime — and its precipitate of 
 twenty-eight grains, only yielded two grains : but the alkaline 
 solution deposited eleven grains of 'the carbonates of lime and 
 magnesia, of which at least five was of the former, as there 
 remained seven and a half of solid matter, after the action of sul- 
 phuric acid.* 
 
 [Eleven hundred and fifty grains of the rich alluvial earth depo- 
 sited by the Mississippi river, in Arkansas, yielded, in the pneu- 
 matic apparatus, 9^^ ounce measures of carbonic acid gas, and 
 of course could not have contained more than nineteen grains of 
 carbonate of lime, — or, so far as the carbonate was of magnesia, 
 something less in proportion. But by adding carbonate of potash 
 to the acid solution, fifty-two grains were precipitated, all of which, 
 according to Davy, should have been carbonate of lime ; and from 
 the alkaline solution thus made, by standing and boiling, 201 
 grains more of solid matter was precipitated, which, according to 
 Davy, should have been carbonate of magnesia ; and making of 
 
 * The measurement of the carbonic acid gas evolved was relied on to 
 show the whole amount of carbonates present — and sulphuric acid was used 
 to distinguish between lime and magnesia, in the deposit from the alkaline 
 solution. If any alumina or magnesia had made part of the solid matter 
 exposed to diluted sulphuric acid, the combinations formed would have 
 been soluble salts, which would of course have remained dissolved and in- 
 visible in the fluid. Lime only, of the four chemical earths, forms with 
 sulphuric acid a substance but slightly soluble, and which therefore can be 
 mostly separated in a solid foiTa. The whole of this substance (sulphate 
 *of lime) cannot be obtained in this manner, as a part is always dissolved ; 
 but whatever is obtained, proves that at least two-thirds of that quantity 
 of carbonate of lime had been present ; as that quantity of lime which will 
 combine with enough carbonic acid to make 100 parts (by weight) of car- 
 bonate of lime, will combine with so much more of sulphuric acid, as to form 
 about 150 parts of the sulphate of lime, or gypsum. 
 
76 NEUTRAL SOILS. 
 
 botli precipitates (52 + 202==) 722- grains of carbonates of lime 
 and magnesia, for the quantity in the original specimen of soil. 
 Yet the first operation clearly proved there could have been no more 
 than nineteen. Subsequent information and experience showed 
 tlyit Davy's mode for sGf)arating the results of lime and magnesia 
 was as little to be relied on, as that for ascertaining the quantity 
 of carbonate of lime alone.] 
 
 From these processes, there can be no doubt butihat the soils con- 
 tained a proportion of some salt of lime (or lime combined with some 
 kind of acid), which being decomposed by and combined with the 
 muriatic acid, was then precipitated, not in its first form, but in 
 that of carbonate of lime — it being supplied with carbonic acid 
 from the carbonate of potash used to produce the precipitation. 
 The proportions obtained in these cases were small ; but it does not 
 follow that the whole quantity of lime contained in the soil was 
 found. However, to the extent of this small proportion of lime, ia 
 proved clearly the presence of enough of some acid (and that not 
 the carbonic) to combine with it. Neither could it have been the 
 sulphuric, or the phosphoric acid ; for though both the sulphate and 
 phosphate of lime are in some soils, yet neither of these salts can 
 be decomposed by muriatic acid. 
 
 Q)th. The strongest objection to the doctrine of neutral soils is, 
 that, if true, the salt formed by the combination of the lime and 
 acid must often be present in such considerable proportions, that it 
 is scarcely credible that its presence and nature should not have 
 been discovered by any of the able chemists who have analyzed 
 soils.* This difficulty I cannot remove, but it may be met (or 
 
 * This difficulty, founded on my then profound and often misplaced re- 
 spect for all scientific authorities, "would have Ireen less, if my own acquaint- 
 ance with chemistry and chemists had been greater. Boussingault says 
 fhat any substance in minute quantity, not appearing among the results of 
 analyses by chemists, is by no means evidence that such substances might 
 not have been present, and even easily detected in the original body ana- 
 lyzed. Thus, he adds, "iodine and bromine for along time escaped notice 
 in all the analyses of sea-water. Chemists, in fact, only discover readily 
 the bodies which exist in some very appreciable qiiantities in the com- 
 pounds they examine. The substances whose presence is not foreseen, 
 those which only enter in extremely small quantity in a mineral, are apt to 
 pass the eyes unperceived, of even the most skilful and conscientious." 
 Rur. Econ. <J-c., jt7.'205. 
 
 Stephens, in his late "Book of the Farm," in reference to his reports 
 of analyses of soils, says : "I regret that I must refer to foreign works to 
 furnish these analyses • but the truth is, we have not one single published 
 analysis of British soil by a British chemist which is worth reading. Sir" 
 Humphry Davy just analyzed soil to determine the amount of the first four 
 substances mentioned [silica, alumina, oxide of iron, and oxide of man- 
 ganese], and one or two others, and failed to detect five or six of the most ' 
 important ingredients." (P. 22-4, of republication in Skinner's Farmer's 
 Library. ) 
 
'' NEUTRAL SOILS. 77 
 
 neutralized, to borrow a figure from my subject), by sbowing that 
 an equal diificulty awaits those who may support the other side of 
 the argument. 
 
 The theory of geologists of the formation of soils, from the de- 
 composition or disintegration of rocks, is received as true by all 
 scientific agriculturists. The soils thus supposed to be formed, re- 
 ceive admixtures from each other, by means of different operations 
 of nature, and after being more or less enriched by the decay of 
 their own vegetable products, make the endless variety of existing 
 soils.* But where a soil, lying on and thus supposed to have been 
 formed from any particular kind of rock, is so situated that it could 
 not have been moved, nor received considerable accessions from 
 torrents or other agents, then, according to this theory, the rock 
 and the soil should be composed of the same materials; and such 
 soils as the specimens, marked 11 and 16 (page 64), would be, like 
 the rock they touched, nearly pure calcareous earth, instead of be- 
 ing (as they were in truth) destitute, or nearly so, of that ingre- 
 dient. Such are the doctrines received and taught by Davy, or the 
 unavoidable deductions from them. But, without contendiug for 
 the full extent of this theory of the formation of soils, every one 
 must admit that soils thus situated must have received, in the lapse 
 of ages, some accessions to their bulk, from the effects of frost, 
 rain, sun, and air, on the lime-stone iu contact with them. All 
 lime-stone soils, properly so called, exhibit certain marked and pe- 
 culiar characters of colour, texture, and products, which can only 
 be derived from receiving into their composition more or less of the 
 rock which lies beneath, or rises above their surface. This mixture 
 will not be denied by any one who has observed lime-stone soils, 
 and reasons fairly, whether his investigation begins with the causes, 
 or their effects. If then all this accession of carbonate of lime re- 
 mains in the soil, why is it that none, or almost none, is discovered 
 by accurate chemical analysis ? Or, if it be supposed not present, 
 nor yet changed in its chemical character, in what ]3ossible manner 
 could a ponderous and insoluble earth have made its escape from 
 the soil ? To remove this obstacle, without admitting the opera- 
 tion of acid in making such soils neutral, will be attended with at 
 least as much difficulty, as any arising from that admission being made. 
 
 "ith. But we are not left entirely to conjecture- that soils were 
 once more calcareous than they now are, if chemical tests can be 
 relied on to furnish proof. Acid soils that have received large 
 quantities of calcareous earth as manure, after some time, will yield 
 very little when analyzed. To a soil of this kind, full of vegetable 
 matter, I applied, in 1818 and 1821, fossil shells at such a known 
 
 * Agr. Chein. p. 1.31. Also Treatise on Agriculture (by General Arm- 
 strong), quoted iu a preceding page (53) of this essay. 
 
 7* 
 
78 DISAPPEARANCE OP CARBONATE OF LIME IN SOIL. 
 
 and heavy rate as would have given to the soil (by calculation) at 
 least three per cent, of calcareous earth, for the depth of iive 
 inches. Only a small portion of the shelly matter was very finely 
 divided when applied. Since the application of the greater part 
 of this dressing (only one-fourth having been laid on in 1818), no 
 more than six years had passed before the following examinations 
 were made (at end of 1826) ; and the cultivation of five crops in 
 that time, three of which were horse-hoed, must have well mixed 
 the calcareous earth with the soil. Three careful examinations 
 gave the following results : 
 
 No. 1. — 100 grains yielded 7 2 of coarse calcareous earth (fragments 
 of shells), 
 
 And less than i of finely divided. 
 
 No. 2. — 1000 grains yielded 5 of coarse, 
 
 2 finely divided, 
 
 No. 3. — 1500 grains yielded 15 of coarse, 
 
 2 J finely divided. 
 
 17J 
 
 The specimens, No. 1 and No. 2, were obtained by taking hand- 
 fuls of soil from several places (four in one case, and twelve in tlie 
 other), mixing them well together, and then taking the samples 
 for trial from the two parcels. On such land, when not recently 
 ploughed, there will always be an over-proportion of the pieces of 
 shells on the surface, as the rains have settled the fine soil, and 
 left exposed the coarser matters. On this account, in making 
 these two selections, the upper half-inch was fiirst thrown aside, and 
 the handful dug from below. No. 3 was taken from a spot show- 
 ing a full average quantity of small fragments of shells, and in- 
 cluded the surface. I considered the three trials made as fairly as 
 possible, to give a general average. Small as is the proportion of 
 finely divided calcareous earth exhibited, it must have been in- 
 creased by rubbing some particles from the coarser fragments, in 
 the operation of separating them by a fine sieve. Indeed it may 
 be doubted whether any propoi-tion remained very finely divided — 
 or in other words, whether it had not been combined with acid, as 
 ffist as it was so reduced. But without the benefit of this supposi- 
 tion, the finely divided calcareous earth in the three specimens 
 averaged only one and one-fourth grains to the thousand, which is 
 one twenty-fourth of the quantity laid on ; aud the total quantity 
 
DISAPPEARANCE OF CARBONATE OF LIME FROM SOIL. 79^ 
 
 ol)tamccl, of coarse and fine, is eiglit grains in one thousand, or 
 about one-fourth of the original proportion. All the remainder 
 had changed its form, or otherwise disappeared, in the few years 
 that had passed since the application.* 
 
 1^ Another similar trial of this soil from the same ground was re- 
 peated in July, 1842, which showed that the finely divided carho- 
 nate of lime, then remaining, was in quantity so small as to be 
 barely perceptible and appreciable. The land had then remained 
 undisturbed by tillage for nine months ; and some scattered frag- 
 ments of shells were exposed to view on the surface generally. 
 For the obvious reasons stated in the preceding paragraph, there 
 will always appear an over-proportion of such fragments, upon the 
 surface of land not recently ploughed ; for this reason, as on two 
 of the three former trials, the upper half-inch of surface soil was 
 thrown aside, and the sample for examination taken immediately 
 below. Of this, 2400 grains yielded two grains only of small 
 fragments of shells, and less than one grain of finely divided car- 
 bonate of lime; whereas seventy-two grains had been the original 
 quantity furnished to the soil. This result, with those of the 
 earlier trials, agree precisely with what would be expected from the 
 action of acid in soil, and cannot be satisfactorily explained by 
 any other doctriae.f — 1842.] 
 
 [* An experiment conducted by LamjDadius, and quoted by Johnston in 
 his recent work, is very like the above, and shows like results. "He 
 mingled [tlie carbonate of] lime with the soil of a piece of ground till it 
 was in the proportion of 1.1',) per cent, of the whole, and he determined 
 subsequently by analj'sis, the quantity of lime it contained in each of the 
 three succeeding years. 
 
 1st 3^ear it contained 1.19 per cent, of carbonate of lime. 
 
 2d year . . 0.89 " " 
 
 3d year . .0.52 " " 
 
 4th year . . 0.24 " " 
 
 But from these premises, so similar to mine, it must be admitted that 
 Prof. Johnston arrives at a very different conclusion. He takes the gradual 
 lessening of the carbonate, as proving the entire removal from the soil of so 
 mucli lime; while I considered it as showing merely the change from the 
 carbonate to some other salts of lime. — 1819.] 
 
 [f Even of this very small amount of fragments of shells found (2 grains), 
 more than half was of the very hard gray shells (oyster and scallop), 
 which seem almost indestructible in soil. They must contain some chemi- 
 cal ingredient which enables them to withstand the acid or other corroding 
 action of soil, to which all the white fossil shefiS, whether hard or soft, so 
 readily yield in the course of time. I recently observed a most striking 
 proof of this well known general fact of the long durability of these gray 
 shells, and consequently their comparative worthlessness as a mantire. On 
 like soil to the sulject of the above trials, and near the same spot, I 
 recently (1842) found a small and thin but well-marked oyster-shell [Osirea 
 Virginiana), apparently as perfect and as well preserved as when it was 
 dug up, and which was a good characteristic specimen of the kind, and, as 
 
80 PROOFS OF NEUTRAL SOILS. 
 
 The very small proportions of finely clivided calearoons earth 
 compared to the coarse, in some shelly soils, furnish still stronger 
 evidence of this kind. Of the York river soil (described page 60 
 No. 5), 
 
 1260 grains, yielded of coarse calcareous parts, - 168 grains. 
 And of finely divided, . - - . 8 
 
 1044 of the rich Nansemond soil (No. 6), - - 544 coarse. 
 
 - 18 fine. 
 
 As many of the shells and their fragiTients in these soils are in a 
 mouldering state, it is incredible that the whole quantity of finely 
 divided particles derived from them should have amounted to no 
 more than these small proportions. Independent of the action of 
 natural causes, the plough alone, in a few years, must have pulver- 
 ized at least as much of the shells as was found. 
 
 8th. In other cases, where the operations of nature have been 
 applying calcareous earth for ages, none now remains in the soil ; 
 and the proof thence derived is more striking than any obtained 
 from artificial aj)plications of only a few years' standing. Valleys, 
 subject to be frequently flooded and saturated by the water of lime- 
 stone streams, must necessarily retain a new supply of calcareous 
 earth from every such soaking and drying. Lime-stone water con- 
 tains the super-carhonatc of lime, which is soluble; but this loses 
 its excess of carbonic acid when left dry by evaporation, and be- 
 comes the carbonate of lime, which not being soluble, is in no 
 danger of being removed by subsequent floods. Thus, accessions 
 are slowly but continually made, through many centuries. Yet 
 such soils are found containing no calcareous earth — of which a 
 remarkable example is presented in the soil of the cultivated part 
 of the Sweet Spring Valley (No. 8, page 63.) 
 
 [The excess of carbonic acid, which unites with lime and renders 
 the compound soluble in water, is lost by exposure of the calcare- 
 ous water to the air, as well as by evaporation to dryness. \^Ac- 
 cum's Chemistrij — Lime.'] The masses of soft calcareous rock 
 which are deposited in the rapids of lime-stone streams are exam- 
 ples of the loss of carbonic acid from exposure to the air ; and the 
 stalactites in caves, the deposit of the slow-dropping water holding 
 in solution the super-carbonate of lime, are examples of the same 
 efiect produced by evaporation. A similar deposit of insoluble 
 carbonate of lime, from both these causes, is necessarily mafte ou 
 all land subject to be flooded by lime-stone waters.] 
 
 sucb, has been placed in my cabinet. This shell was part of the dressing 
 spread upon the field for the crop of 1821, and had been since exposed to 
 all the vicissitudes of tillage and of weather for nearly tweuty-two years. 
 .—1842.] 
 
LIME IN WOOD ASHES. 
 
 81 
 
 9 til. All loood ashes contain salts of lime (and most kinds in 
 large proportions), which could have been deriA'ed from no other 
 source than the soils on which the trees grew. The lime thus ob- 
 tained from ashes is principally combined with carbonic acid, and 
 partly with the phosphoric, forming phosphate of lime. The 
 table of Saussure's analyses of the ashes of numerous plants,* is 
 sufficient to show that these products are general, if not, universal/ 
 The following examples of some of my own few examinations indi- 
 cate that ashes yield calcareous earth in proportions suitable to 
 their kind, although the wood grew on soils destitute of that in- 
 gredient — as was ascertained with regard to each of these soils. 
 
 * Quoted m 'Da.yj's Agr. Chem. Lecture 3. 
 
 f [In the first sketch and earliest .publication of this essay in the 
 "American Farmer," of 1821, the statement of the calcareous contents of 
 a'fehes, similar to the above, was followed by the following remark: "The 
 results of the few examinations I have made do not confirm the opinion 
 [or results] of De Saussure, that ashes yield quantities of calcareous earth 
 somewhat proportioned to the quantities contained in the soils from which 
 they were taken. But they show, in diiferent plants, quantities suited to 
 the soil which each prefers. Thus, of three kinds of ashes from the same 
 soil, those of pine gave 5J, of whortleberry 4, and of locust 51 per cent, 
 of carbonate of lime, and [somewhat] similar proportions of other salts 
 of lime." {Am. Far. iii,, p. 316.) In all the succeeding separate editions 
 of the essay, this remark was suppressed, being deemed too presumptuous 
 for me to use. But I may now dare to reassume the position, since .John- 
 ston denies the accuracy of De Saussure's and also of Berthier's analyses, 
 which coacui- in the conclusions referred to, and also the correctness of these 
 
82 LIME IN WOOD ASHES. 
 
 It must be evident and unquestionable that all the carbonate of 
 lime yielded by the ashes had been necessarily furnished in some 
 form by the soil on which the plants grew; and when the soil 
 itself contained no carbonate, as in all these cases, some other 
 compound of lime must have been pi'esent, to enable us to account 
 for these certain and invariable results. The presence of a com- 
 bination of lime with some vegetable acid, and none other, would 
 serve to produce such effects. According to established chemical 
 laws, if any such combination had been taken up into the sap- 
 vessels of the tree, it would be decomposed by the heat necessary 
 to convert the wood to ashes; the acid would be reduced to its 
 elementary principles, and the lime would immediately unite with 
 the carbonic acid (which is produced abundantly by the process 
 of combustion), and thus present a product of carltonate of lime 
 newly formed from the materials of the other substances decom- 
 posed.* 
 
 On the foregoing facts and deductions, I am content to rest the 
 truth of the existence of acid and neuti'al soils. 
 
 NOTE. 
 
 Scientific Co/firmation of the doctrine of Acid in Soils. 
 
 [1835. I have chosen to leave all the preceding part of this 
 chapter ('with the exception of a few merely verbal corrections and 
 alterations) precisely as it appeared in the previous edition of this 
 
 conclusions. He adds the following words, which, in connexion with his 
 context, show that his opinion concurs with my position, that (supposing 
 enough lime to Ije present) the proportion in the ashes of plants is accord- 
 ing to the nature and demand for lime, of the particular plant; and not to 
 the great abundance or scarcity of lime in the soil producing the plant. 
 He says — "the ash of the same plant, if ripe and healthy, is nearly the 
 same in kind and quality in whatever circumstances (if favourable) of soil 
 or climate it may grow." (p. 244.) That chemists now generally adniit 
 De Saussure's conclusions to be erroneous may also be safely inferred 
 from this: the many ixjsults of the ashes of plants which have appeared 
 in recent works, are rarely (if ever) accompanied by any report of the 
 contents of the soil whence derived; thus showing that the calcareous or 
 other ingredients are inferred to be according to the kind of plant, and 
 not dependent on the character of the soil. — 1849,] 
 
 * The reasoning on the presence of the carbonate of lime found in 
 ashes from acid soils, does not apply to the phosphate of lime which is also 
 always present. Tlie latter salt is not decomposed by any known degree 
 of heat [Art. CViCMj.s/ry, in Ediii. Ency.'], and therefore might possibly have 
 remained unchanged, in passiqg from tlio soil to the tree, and thence to the 
 ashes. 
 
HUMIC ACID, » 83 
 
 essay, (January 1832.)* But since that time T have first heard of 
 a discovery, and of consequent investigations by men of science, 
 which seem to furnish direct proof of what I have been contending 
 for, viz. the existence of a vcgetahlc acid substance in soils and 
 manures, generally diffused, and often in large projwrtions, and 
 2/et which had not been knoion or susjjected by chemists j^reviously. 
 ^The first intimation of this discovery which reached me was in an 
 extract in a newspaper from the " Aljjhabct of Scientific Gar- 
 dening," by Professor Rennie, published in Loudon in 1833, from 
 which the part relative to this subject will be quoted below. 
 Since, I have seen the French version of the late work of Berze- 
 lius, in which his views of humic acid (or, as he names it, the geic 
 acid) are given more at length."}" The facts respecting humic 
 acid, as concisely stated in the following quotation from Professor 
 Rennie, furnish strong confirmation of some of the opinions which 
 I have endeavoured to maintain. It will however be left, without 
 farther comment, for the reader to observe the accordance, and to 
 make the application. 
 
 *^ Humic acid and humin. — In most chemical books the i^Yms iilmic acid 
 and ulmin arc used, from iibmts, elm ; but, as its substance occurs in most, 
 if not all plants, the name is bad. I prefer Spreugel's terms, from humus, 
 soil. 
 
 "This important substance was first discovered by Klaproth, in a sort 
 of gum from an elm ; but it has since been found by Berzelius in all barks ; 
 by M. Braconnot in saw-dust, starch, and sugar; and, what is still more 
 interesting for our present purpose, it has been found by Sprengel and M. 
 Polydore Boullay to constitute a leading principle in soils and manures. 
 Humin appears to be formed of carbon and hydrogen, and the humic acid 
 of humin and oxygen. Pure humin is of a deep blackish brown, without 
 taste or smell, and water dissolves it with great difficulty and in small 
 quantities ; consequently it cannot, when pure, be available as food for 
 plants. 
 
 "Humic acid, however, which, I may remark, is not sour to the taste, 
 readily combines with many of the substances found in soils and manures, 
 and not only renders them, but itself also, easy to be dissolved in water, 
 which in their separate state could not take place. In this way humic acid 
 wilt combine with lime, potass, and ammonia, in the form of humates, and the 
 smallest portion of these icill render it soluble in ivater and fit to be taken up by 
 the spongelets of the root fibres. 
 
 ' ' It appears to have been from ignorance of the important action of the 
 humic acid in thus helping to dissolve earthy matters, that the older 
 writers were so puzzled to discover how lime and potass got into plants; 
 and it seems also to be this, chiefly, which is so vaguely treated of in the 
 
 * The general positions and views taken as to acid and neutral soils are 
 also, in substance and purport, just as they appeared in my first publica- 
 tion on this subject, in 1821. 
 
 •{• A long extract from Berzelius' " Traite de Chimie," embracing these 
 
 views, was translated for and published in the two preceding editions of 
 
 this essay, and also iu the Farmei-'s Register. It is omitted now as un- 
 necessary. — 1849. 
 
84 • HUMIC ACID. 
 
 older books, under the names of extractive, vegetable extract, mucilaginous 
 matter, and the like. Saussure, for instance, filled a vessel with turf, and 
 moistened it thoroughly with pure water, when by putting ten thousand 
 parts of it by weight under a heavy press, and filtering and evaporating 
 the fluid, he obtained twenty-six parts of what he termed extract; from 
 ten thousand parts of well dunged and rich kitchen garden mould, he ob- 
 tained ten parts of extract ; and from ten thousand parts of good corn field 
 mould, he obtained four parts of extract. 
 
 "M. Polydore BouUay found that the liquid manure, drained from *■ 
 dunghills, contains a large jsroportion of humic acid, which accounts for 
 its fertilizing properties so well known in China and on the continent; and 
 he found it also in peat earth, and in varying proportions in all sorts jjf 
 turf. It appears probable, from Gay-Lussac having found a similar acid 
 (technically azumic acid), on decomposing the prussic acid (technically 
 hydro-cyanic acid), that the humic acid may be found in animal blood, and 
 if so, it will account for its utility as a manure for vines, &c. Dobereiner 
 found the gallic acid convertible into the humic." 
 
 [When the second edition of this essay was published (in 1835), 
 the above annunciation had but just before -been made, showing 
 that there was indeed high scientific authority for the very general 
 existence of a vegetable acid in soils. And since that time, the 
 fact has been admitted by almost all scientific writers, and has - 
 been treated of at length in sundry chemical works and reports of 
 geological surveys in this country. The doctrine of the existence 
 of an acid of soil, of vegetable origin, which before had scarcely 
 any other authority for its support than mine, humble and obscure 
 as that was, is now of universal acceptation. Still, notwithstand- 
 ing all that has been written on the subject, very little light has 
 been thrown on it by the chemists who have treated of it. Being 
 myself too little informed to be able to properly digest these 
 difi"erent speculations and to balance authorities, and to separate 
 the true and valuable from the erroneous or worthless of what has 
 been lately published, I deem it best still to rely on my own pre- 
 viously published views and proofs only, as presented in the fore- 
 going pages. Therefore, leaving it to chemists to settle their 
 present differences of opinion in regard to the qualities^ and even 
 identity, as well as name of the acid of soil, and to clear away the 
 existing confusion and obscurity of their views, I will, for the 
 present, adopt nothing on their authority in this respect. Still, I 
 earnestly hope that their subsequent investigations may be success- 
 ful in eliciting and determining what is true of this acid — and also 
 in applying the truths ascertained to advance the knowledge of the 
 composition and improvement of soils. For the same reason, I 
 shall also decline adopting any of the various terms which have 
 been successively applied by different, and even the same chemists, 
 to designate the acid of soil; as humic, geic, crenic, and apocrenic 
 aciil, &c.— 1842.] 
 
 [Long after the publication of the latest of the passages of the 
 foregoing chapter, I first learned the existence of good and sufficient 
 
thaer's publication of views. 85 
 
 aiitliorlty, in a work of deservedly high reputation, for my doctrino 
 of acid soils. This is Thaer's ''Principles of Agriculture," of 
 which the English translation was first published in the United 
 States in 1846, (in Skinner's "Farmers' Library,") and which 
 permitted my earliest access to the work. The portion on humus 
 testifies positively and fully to the existence of acid soils, and also 
 to such results therefrom as I have maintained. At what time 
 these particular and important views of Thaer were first published, 
 does not appear; though it may be inferred, as almost certain, that 
 it was subsequent to the discovery and early observations of humic 
 acid of Sprengel and Boullay, as stated above in the article quoted 
 from Rennie's publication of 1833. The prefiice to the translation 
 of Thaer's work states that the original was first published in Ger- 
 many, in successive numbers, from 1810 to 1812. But a work of 
 this kind, in every succeeding edition, would undoubtedly receive 
 from its author such additions and alterations as would keep pace 
 with the progress of agricultural and chemical science. In pre- 
 senting the doctrine of acid in soil, Thaer does not claim the im- 
 portant discovery as his own, nor has he ever been quoted as the 
 first discoverer, or even as one among the earlier investigators. 
 Neither does he refer to other names, as authorities (as Rennie 
 has done above), which would naturally have been done if it was 
 then a discovery so recent as to require such authentication. These 
 would be enough reasons for inferring that Thaer's statements 
 on this subject are of date much later than his first edition. There 
 is another strong reason for this position. If he had announced 
 the existence of acid in soils in his earliest edition, it would have 
 been prior to the earliest elaborate and very able works on agri- 
 cultural chemistry, by Davy and Chaptal. It is incredible that 
 both these distinguished investigators should have passed over such 
 evidence, if in existence, and upon such high agricultural authority 
 as Thaer's, without the slightest notice, and (as before stated) 
 without making any allusion to the existence of humic or any 
 other vegetable acid as a very general ingredient of soils. Indeed 
 there is direct proof that Thaer's work was a later publication than 
 Chaptal's, as the latter is quoted from in the former, in the portion 
 entitled "Theory of Soils." For each and all these reasons, it is 
 impossible that Thaer's notice of humic acid could have been as 
 early as his first edition; and very improbable that it should have 
 been as early as Professor Rennie's statement copied above. 
 
 But whatever was their date, the following passages from Thaer 
 offer confirmation of my views of acid soils more full and complete 
 than to be seen in any other author within my observation, and 
 which, therefore, are doubly welcome, as the testimony of so pro- 
 found and distinguished an investigator, 
 8 
 
80 THAER ON IIUMIC ACID IN SOIL. 
 
 " Humus" is the term used by this author for the decomposed 
 vegetable and other organic matter which is more or less mixed 
 with all surface soil, and which gives to soil all its fertility, and 
 furnishes all the food of plants. He continues : — 
 
 "It is the resichic of animal and vegetable putrefaction, and is a black 
 body; wbcn dry it is pulverulent, and -when wet lias a soft, greasy feel." — 
 "It is the produce of organic jxiwcr — a conq30und of carbon, hydrogen, 
 nitrogen, and oxygen, such as cannot he chenucally composed," &c. jj. 534. 
 
 " When humus remains constantly damp, Tcithout, however, being covered 
 with water, it forms a very unpleasant smelling acid, which is more parti- 
 cularly characterized by the property which it possesses of colouring blue 
 litmus paper into red. This circumstance has long been known, and it is 
 the reason that land and meadows which are not properly drained, and 
 which exhibit these phenomena, are called sour. We have carefully exa- 
 mined these facts, and have endeavoured to discover the peculiar constitu- 
 tion of this acid. At first, we were inclined to regard it as being of a dis- 
 tinct nature, and having carbon for its base ; but we have since become 
 convinced that it is generally composeil of acetic acid, and occasionally 
 contains a portion of the phosphoric. This latter always adheres so firmly 
 to the humus that it cannot be separated from it either by boiling or wash- 
 ing. The liquid in which the humus is boiled certainly acquires a slight 
 acid flavour, but the greater part of the acid remains attached to the lui- 
 mus."— 7-" This acid or sour humus is not at all of a fertilizing nature ; on the 
 contrary, it is prcjuclicial to vegetation.* Where it is very strong and per- 
 vades the whole of the humus, the soil only produces reeds, rushes, sedge, 
 and other useless, unpalatable plants; and whenever these abound, it may 
 be inferred that the soil contains a great deal of sour or acid humus."-}- — 
 "There are various means of getting rid of this baneful property, and 
 rendering the humus fertile." — "It is well known that with the aid of al- 
 kalies, ashes, lime, and marl, humus may be def)rived of its acidity, and 
 rendered easily soluble." — "Heaths do not thrive whei-e this [acid] humus 
 does not exist, and when they have established themselves in one particular 
 spot, they sufi^er few other plants to appear. This humus may be changed 
 by a dressing composed of marl, lime, or ammonia ; and where this has 
 been mixed with the soil, the heaths, &c., speedily perish." (p. 538-9.) 
 
 " In the greater number of cases, peat is very much like acid or sour 
 humus ; indeed, it sometimes resembles it so strikingly that it is impossible 
 to distinguish these substances apai't." (p. 5-10.) 
 
 "In both the kinds of land we have been considering [i. e., classes of 
 very fertile soil, rich in humus], we have supposed the humus to be mild, or 
 exempt from acidify. % Sour or acid humus totally destroys the fertility of a 
 soil; sometimes, however, the soil contains so very small a portion of acid- 
 ity that its fertility is very slightly diminished, and only with regard to 
 some few plants. Barley crops become more and more scanty in propor- 
 tion as the acidity is increased ; but oats do not appear to be at all affected 
 by it. Rye grown on such land is peculiarly lialjle to rust, and is easily 
 laid or lodged. The grains of all the cereals become larger, but contain 
 
 * Even to this day, Von Thaer is the only agricultural chemist known, 
 who affirms, with me, this important evil quality of the acid of soil. — E. R. 
 
 •j- These, of course, arc like our broom-grass, sorrel, poverty grass, pine, 
 &c., of the general class of what I called acid plants. Ilcath is another, 
 and the most abundant in Europe, though not existing in America. — E. R. 
 
 J AVhich, according to my views and language, would be expressed by the 
 acid of the soil having been neutralized by lime. — E. R. 
 
DEDUCTIONS FROM FOREUOIiNG DOCTRINES. 87 
 
 less farina. Grass -which grows on these spots is, both in species and taste, 
 less agreeable, and less suitable for cattle, than any other, although it yields ' 
 a very considerable produce in hay. In fact, in exact proportion with the 
 increase of acidity, is the decrease of the value of the soil," &c. 
 
 [If the foregoing examinations of sqils, and the arguments which fol- 
 low, remain unquestioned, these two remarkable and important facts 
 may be considered as thereby established beyond dispute or doubt : 
 
 1st. That calcareous earth, calx, or carbonate of lime, is in gene- 
 ral as entirely deficient in the soils of Virginia, as that ingredient 
 had heretofore been supposed, by agricultural writers, to be com- 
 mon in all soils ; and, 
 
 2d, That, notwithstanding this total absence of the carbonate of 
 lime, lime in some other form of combination, and in greater or less 
 quantity, is an ingredient of every soil capable of producing vegetation. 
 
 Nor do these facts come in conflict with each other ; nor either 
 of them with the position which has been contended for, that calca- 
 reous matter in proper proportions is necessary to cause fertility in 
 soils. Should some other person, who may be aided by sufficient 
 scientific light, undertake the investigation, he may supply all that 
 is wanting for the direct proof of this theory of the cause of fer- 
 tility, and perhaps show that the productive value of a soil (under 
 equal circumstances) is in proportion to the quantity of the vege-^ 
 table salts of lime present in the soil. The direct and positive 
 proof of this doctrine, I confidently anticipate will hereafter be ob- 
 tained from more full examinations of the humic acid, and its com- 
 pounds in various soils, and from correct and minute reports of the 
 ciuantities and kinds of those ingredients, in connexion with the 
 degree of the natural fertility of each soil. As yet, however in- 
 teresting the recent discovery of humic acid may be to chemists, it 
 does not seem that they have suspected it to have anything like 
 the important bearing on the fertilization of soil which I had attri- 
 buted to the supposed acid principle or ingredient of soils. Ber- 
 zelius seems scarcely to have bestowed a thought on this most im- 
 portant application of his investigation of the properties of geine 
 and geic acid. — 1842.] [Other authors deem not only huniin but 
 also humic acid as directly fertilizing to soils, and beneficial to 
 plants ; which, as to this, or any other uncombincd acid, is altogether 
 opposed to my views.* — 1849.] 
 
 * Confirmatory testimony. — After treating extensively of difFerent acids 
 of soils (humic, ulmic, crenic, apocrenic, and medusous), Johnston adds: 
 " Besides these acids, it is known that the malic and acetic are occasionally 
 produced in the soil during the slow decay of vegetable matter of different 
 kinds. It is probable that many other analogous compounds are likewise 
 formed — which are more or less soluble in water, and more or less fitted to 
 aid in the nourishncnt of 2>lants:' (p. 280.) The last words of the passage 
 
88 FORMATION OP ACID IN SOIL. 
 
 Supposing the doctrine to be sufficiently established by my own 
 proofs offered above, it may be useful to trace the formation and 
 increase of acidity in different soils, according to the views which 
 have been presented, and to display the promise which that quality 
 holds out for improving those soils which it has heretofore rendered 
 barren and worthless. * 
 
 Every neutral soil at some former time must have contained cal- 
 careous earth in sufficient quantity to produce the uniform effect 
 of that ingredient of storing up and fixing fertility. [It was then 
 ?i calcareous soil, however small might have been the proportion of 
 free carbonate of lime contained.] The decomposition of the suc- 
 cessive growths of plants, left to rot on the rich soil, continually 
 formed vegetable acid, which, as fast as formed, united with the 
 lime in the soil. At last these two principles balanced each other, 
 and the soil was no longer calcareous, but neutral. Instead of its 
 former ingredient, cai-bonate of lime, it was now supplied with a 
 vegetable salt of lime. This change of soil does not affect the na- 
 tural growth, which remains the same, and thrives as well as when 
 the soil was calcareous ; and when brought into cultivation, the 
 soil is equally productive under all crops suited to calcareous soils. 
 If the supi)lies of vegetable matter continue, the soil may even be- 
 come acid in some measure, as may be evidenced by the growth of 
 sorrel — ^but without losing any of its fertility before acquired. The 
 tlegree of acidity in any one soil frequently varies ; it is increased 
 by the growth of such plants as delight to feed on it, and by the 
 decomposition of all vegetable matters. Hence the longer a poor 
 field remains at rest, and not grazed, the more acid it becomes ; and 
 this evil keeping pace with the benefits derived, is the cause why so 
 little improvement, or increased product, is obtained from putting 
 acid soils under that mild treatment. Cultivation not only pre- 
 vents new supplies, but also diminishes the acidity already present 
 
 of course I oppose ; deeming all acid products of soil, alone, as injurious to 
 fertility and productiveness of tlie land for useful crops. 
 
 Besides the state of carbonate, Johnston says that lime exists in fertile 
 soils as chloride of calcium (muriate of lime), as sulpliate, pliosphatc, 
 silicate, or humate of lime. "In combination with humic acid, lime exists 
 most frequently in soils wliich abound in vegetable matter — in peaty soils, 
 for example, to which lime or marl have been added. * * * Few in- 
 vestigations have as yet been made in regard to the proportion of lime 
 which exists in the soil in the state of humate. It has generally been taken 
 for granted, either that a soil teas destiiute of lime, if it exhibited no sensible 
 eifervescence with dilute muriatic acid, or, when further research was 
 made, and the quantity of lime rigorously detei'mincd, that the whole of this 
 lime must have existed in the state of carbonate. That this is not necessarily 
 the case, however, appears to be proved by some recent examinations of 
 certain soils in Normandy, which contain as much as 14 to 15 per cent, 
 of lime, and yet exhibit no eifervescence, and contain no carbonate. The 
 whole of the lime is said to Ik; in the state of humate. (p. 230-1. — 1819,] 
 
LIME PRESENT IN ALL SOILS, NOT BARREN. 89 
 
 in- excess, by exposing it to the atmosphere ; and therefore the 
 more a soil is exhausted of its fertility, the more will also be less- 
 ened its acidity, [in absolute quantity ; though not relatively to its 
 degree of fertility, which will be lessened still more.] 
 
 We have seen from the proof furnished by the analysis of wood 
 ashes, that even poor acid soils contain a little salt of lime, and 
 therefore must have been slightly calcareous at some former time. 
 But such small proportions of calcareou.s earth were soon equalled, 
 and then exceeded, by the formation of vegetable acid, before 
 much productiveness was caused. The soil being thus changed, 
 the plants suitable to calcareous soils died off, and gave place to 
 others which produce, as well as feed and thi-ive on, acidity. Still, 
 however, even these plants furnish abundant supplies of vegetable 
 matter, sufficient to enrich the land in the highest degree ; but the 
 antiseptic power of the acid prevents the leaves from rotting for 
 years, and even then the soil has no power to profit by their pro- 
 ducts. Though continually wasted, the vegetable matter is continually 
 again forming, and always present in abundance ; but must remain 
 almost useless to the soil, until the accompanying acidity shall be 
 destroyed. 
 
 [It may well be doubted whether any soil destitute of lime in 
 every form would not necessarily be a perfect barren, incapable of 
 producing a spire of grass. No soil thus destitute is known, as the 
 plants of all soils show in their ashes the presence of some lime. 
 But it is probable that our sub-soils, which, when left naked by the 
 washing away of the soil, are so generally and totally barren, are 
 made so by their being entirely destitute of lime in any form. 
 There is a natural process regularly and at all times working to de- 
 prive the sub-soil of all lime, unless the soil is abundantly supplied. 
 What constitutes soil, and makes the strong and plain mark of 
 separation and distinction between the more or less fertile soil and 
 the absolutely sterile sub-soil beneath ? The most obvious cause 
 for this difference which might be stated, is the dropping of the 
 dead vegetable matter on the surface ; but this is not sufficient 
 alone to produce the effects, though it may be so when aided by 
 another cause of more power. When the most barren surface 
 earth was formed or deposited by any of the natural agents to 
 which such effects are atti'ibuted by geologists, it seems reasonable 
 to suppose that the surface was no richer than any lower part of 
 the whole upper stratum so deposited. If, then, a very minute 
 proportion of lime had been equally distributed through the body 
 of poor earth to any depth that the roots of trees could penetrate, 
 it would follow that the roots would, in the course of time, take up 
 all the lime, as all of it would be wanting for the support of the 
 trees ; and their death and decay woukf afterwards leave all this 
 former ingredient of the soil, in general, on the surface. This 
 8* 
 
90 DORMANT FERTILITY OF UNrRODUCTIVE LANDS. 
 
 process must have the eifect, in the course of time, of fixing on 
 and near the surface the whole of a scanty supply of lime, and of 
 leaving the subsoil without any. But if there is within the reach 
 of the roots more lime than any one crop or growth of plants 
 needs, then the superfluous lime will be permitted to remain in the 
 sub-soil, which sub-soil will then be improvable by vegetable sub- 
 stances, and readily convertible to productive soil. The manner 
 in which lime thus operates will be explained in the next chapter. 
 —1835.] 
 
 Nearly all the woodland now remaining in lower Virginia, and 
 also much of the laud which has long been arable, is rendered un- 
 productive by acidity; and successive generations have toiled on 
 such land, almost without remuneration, and without suspecting 
 that their worst virgin land was then richer than their manux'ed 
 lots appeared to be. The cultivator of such soil, who knows not 
 its peculiar disease, has no other prospect than a gradual decrease 
 of his always scanty crops. But if the evil is once understood, 
 and the means of its removal are within his reach, he has reason 
 to rejoice that his soil was so constituted as to be preserved from 
 the effects of the improvidence of his forefathers, who would have 
 worn out any land not almost indestructible. The presence of 
 acid, by restraining the productive powers of the soil, has in a 
 great measure saved it from exhaustion ; and after a course of 
 cropping which would have utterly ruined soils much better con- 
 stituted, the powers of our acid land remain not greatly impaired, 
 though dormant, and ready to be called into action by merely being 
 relieved of its acid quality. A few crops will reduce a new acid 
 field to so low a rate of product, that it scarcely will pay for its 
 cultivation ; but no great change is afterwards caused, by continu- 
 ing scourging tillage and grazing, for fifty years longer. Thus our 
 acid soils have two remarkable and opposite qualities, both pro- 
 ceeding from the same cause : they can neither be enriched by ma- 
 nure, uor impoverished by cultivation, to any great extent. Quali- 
 ties so remarkable deserve all our powers of investigation ; yet 
 their very frequency seems to have caused them to be overlooked ; 
 and our writers on agriculture have continued to urge those who 
 seek improvement to apply precepts drawn from English authors, 
 to soils which arc totally different from all those for which their 
 instructions were intended.* 
 
 [* Confirmalory fcslimoni/. — Professor Johnston affirms tliat lime is indis- 
 pensable to the fertility of soils, as I have done. But he goes still farther 
 than what is true, at least as to America, in the following passage: " The 
 results of all the analyses hitherto made of soils naturally fertile, show 
 that lime is universally presgnt. The percentage of lime in a soil may be 
 very small, yet it can always be detected when valuable and healthy crops 
 will grow upon it. Thus the fertile soil of the 
 
TESTIMONY OP J. C. LOUDON, 91 
 
 IVrarsli lands of Holstein contains 0.2 per cent, of carbonate of iimc. 
 
 Salt marsh iu East Frieslaud . O.G " " 
 
 Rich pasture near Durham . 1.31 " " > 
 
 But though the percentage of lime in these cases appears small, the ab- 
 solute quantity of lime present in the land is still large. Thus, suppose 
 the first of these soils, which contains the least, to be only six inches deep, 
 and each cubic foot to weigh only 80 lbs.— it would contain about 3500 lbs. 
 of carbonate of lime to every acre." — Though the author at first speaks of 
 "lime" as universally present in very fertile soils, it is clear, from the con- 
 text, that he meant carbonate of lime. In succeeding passages he claims 
 the presence of lime in all producing soils, upon the same grounds that I 
 did, viz. : the presence of lime in all ashes of j)iants. [Johnston^ s Lectures, 
 pp. 378-9.) 
 
 It is interesting to compare this recent admission of Johnston, of even 
 more than I claimed (or would admit), and the now general acceptation of 
 the true doctrine, with the following expressions of the late J. C. Loudon, 
 perhaps then the highest agricultural authority in England, if not in all 
 Europe. IJoth the passages were editorial, in his "Gardener's Magazine" 
 for 1836. The first is part of a short notice of the first edition of this 
 essay (of 1832), which had been "jDirated," garbled, and disguised by the 
 editor of the "British Farmer's Magazine," and so published, as if a com- 
 munication to that periodical. In this notice Mr. Loudon copies the heads 
 of my five propositions, and says — " These propositions contain the mar- 
 row of the Essay, which is closely reasoned, and in several particulars 
 original. Mr. Ruffin has the merit of first pointing out that tlicre can be 
 no such thing as naturally fertile soil without the presence of calcareous 
 earth ; but where this earth is present, the soil, lioAvcver exhausted it may 
 have been by culture, will, when left to itself, after a time regain its origi- 
 nal fertility ; that soils which contain no calcareous earth are never found 
 naturally fertile, .... and that all that art can do to them, exclusive of 
 adding calcareous earth, is to force crops by putrescent manures ; but that 
 when these manures are withheld, the soil Avill speedily revert to its oi-igi- 
 nal sterility. Mr. Ruffin observes that no agi'icultural or chemical writer 
 ever denied these facts; but, he 'asserts, and we think loith truth, that by 
 not one of them have they ever been distinctly stated. AVe are not quite 
 certain as to Grisenthwaite, but we are so as to Ivirwan, Dundonald, Davy, 
 Chaptal, and other agricultural chemists of the continent. ... It is due to 
 Mr. llufiin to state it as our opinion, that he has performed a very important 
 service to the scientific agriculturist iu this counti-y, as well as in America." 
 
 And again, in a subsequent long editorial article, noticing all the im- 
 portant and valuable discoveries or new improvements in agriculture during 
 the preceding ycai% iMr. Loudon says — 
 
 "In agricultural science, the only point that we can recollect worthy of 
 notice, that has occm-red during the past year, is the advancement of the 
 principle by the American agricultural writer, Mr. Ruffin, that no soil 
 whatever will continue fertile for any length of time that does not contain 
 calcareous matter. This we believe was never distinctly stated as a prin- 
 ciple by Kirwan, Chaptal, Davy, or any other European chemist or agri- 
 culturist. "—1 819. ] 
 
CHAPTER VIII. 
 
 THE MODE OF OPERATION BY WHICn CALCAREOUS EARTH IN- 
 CREASES THE FERTILITY AND PRODUCTIVENESS OF SOILS. 
 
 Proposition 3. — The fertilizing effects of calcareous earth are 
 chiefly 'produced hy its power of neutralizing acids, and of com- 
 hining putrescent manures loith soils, between xvhich there would 
 otherwise he hut little, if any, chemical attraction. 
 
 Proposition 4. — Poor and acid soils cannot he improved durahly, 
 or profitahly, hy putrescent manures, without previously making 
 them calcareous^ and therehy correcting the defect in their con- 
 stitution. 
 
 It has already been made evident that the presence of calcareous 
 earth [in small proportion, or not in too great escess], in a natural 
 soil, causes great and durable fertility. But it still remains to be 
 determined, to what properties of this earth its peculiar fertilizing 
 effects are to be attributed. 
 
 Chemistry has taught that silicious earth, in any state of divi- 
 sion, attracts but slightly, if at all, any of the parts of putrescent 
 animal and vegetable matters.* But even if any slight attraction 
 really exists when this earth is minutely divided for esperiment in 
 the laboratory of the chemist, it cannot be exerted by silicious 
 sand in the usual form in which nature gives it to soils ; that is, 
 in particles comparatively coarse, loose, and open, and jet each 
 particle impenetrable to any liquid, or gaseous fluid, that might be 
 passing through the vacancies. Hence, silicious earth can have 
 no power, chemical or mechanical, either to attract enriching 
 manures, or to preserve them when actually placed in contact and 
 intermixed with them ; and soils in which the qualities of this 
 earth greatly predominate, must give out freely all enriching mat- 
 ters which they may have deceived, not only to a growing crop, but 
 to the sun, air, and water, so as soon to lose the whole. No por- 
 tion of putrescent matter can remain longer than the completion 
 of its decomposition ; and if not arrested during this process, by 
 the roots of living plants, all will escape in the form of gas (the 
 latest products of decomposition), into the air, without leaving a 
 trace of lasting improvement. With a knowledge of these pro- 
 perties, we need not resort to the common opinion that manure is 
 
 * Davy's Agr. Chem, page 129. 
 
 (92) 
 
SINKING OF MANURES, THROUGH SOILS AND SUB-SOILS. 93 
 
 lost by sinking throngli sandy soils, to account for its usiially rapid 
 and total disappearance* 
 
 Aluminous earth, by its closeness, mechanically excludes those 
 agents of decomposition, heat, air, and moisture, which sand so 
 freely admits; and therefore clay soils, in which this earth pre- 
 dominates, give out manure much more slowly than sand, whether 
 for waste or for use. The practical effect of this is universally 
 understood — that clay soils retain manure much longer than sand, 
 but require much heavier applications to show as much effect early, 
 or at once. But as this means of retaining manure is altogether 
 mechanical, it serves only to delay both its use and its waste. 
 
 * Except the very small proportions of earthy, saline, and metallic mat- 
 ters that may be in animal and vegetable manures, the whole remainder of 
 their bulk (and the whole of whatever can feed plants) is composed of 
 different elements which are known only in the forms of r/ascs — into which 
 manures must be finally resolved, after going through all the various stages 
 of fermentation and decomposition. So far from sinking in the earth, if in 
 quantity, these final results could not be possibly confined there, but must 
 escape into tlie atmosphere as soon as they take a gaseous form, unless 
 immediately taken up by the organs of growing plants, [or unless held by 
 the soil's absorbing chemical power.] It is probable, however, that but a 
 small portion of any dressing of manure remains long enough in the soil 
 to make this final change ; and that nearly all of it is used by growing 
 plants, during previous changes, or carried off by air an^water. [During 
 the progress of the many changes caused by fermentation and decomposi- 
 tion, every portion of the manui'e fit for use, becomes soluble. When in 
 the soluble state only, it is ready for the use of i^lants ; and if not then so 
 used, is as ready to be wasted, if the soil has not enough of attracting and 
 combining power to hold the soluble products. I infer that it depends 
 mainly, if not eiatirely, on the presence or absence of such chemical power 
 in a sandy soil, with also a sandy or other pervious sub-soil, whether the 
 soluble products of putrescent manures are lost by sinking. If there is 
 not enough such power in the soil — (that is, if it contains very little lime 
 in any state) — and there is too much manure in a soluble state for the roots 
 of growing plants to take up immediately, then the remainder will be dis- 
 solved in the first rain, and follow the course of the excess of water, 
 wlicther to flow off the surface, or to sink deep into the sub-soil. Of so 
 much as thus sinks, the further decomposition and final conversion to gases 
 must be retarded by the greater seclusion from heat and air. In the mean 
 time, the substance continues to be soluble, and liable to be again cai-ried 
 deeper, by successive heavier rains, until, with their excess of water, pene- 
 trating to the sources of springs, either temporary or permanent, and thug 
 passing into the streams. We know that springs are thus supplied by the 
 rains, and that their waters are in many cases polluted by organic as well 
 as miuernl soluble matters. This waste by sinking, even of the fertile 
 parts of natural or uumanured soil, is manifest on tilled land of which the 
 pervious sub-soil needs and has failed to receive drainage. In such cases, 
 the water below is oozing away after every wet spell ; and sometimes the 
 soil disappears as if washed away, though having nearly a level surface. 
 The dark-coloured organic and alimentary parts only have been thus re- 
 moved, leaving that which had been soil as poor as its sub-soil. — 18-19.] 
 
9-1 RELATIONS OF CLAY AND CALX TO PUTRESCENT MANURES. 
 
 Aluminous earth also exerts some cliemical power in attracting 
 and combining with putrescent manures, but too feebly to enable 
 a clay soil to become rich by natural means. [For though clays 
 are able to exert more force than sands in holding manures, their 
 closeness also acts to deny admittance beneath the surface to the 
 enriching matters furnished by the growth and decay of plants. 
 And therefore, before being brought into cultivation, a poor clay 
 soil would derive scarcely any beuetit from its small power of com- 
 bining chemically with putrescent matters. If then it is con- 
 sidered how small is the power of both silicious and aluminous 
 earths to receive and retain putrescent manures, it will cease to 
 cause surprise that such soils cannot bo thus enriched, with profit, 
 if at all. It would indeed be strange and unaccountable, if earths 
 and soils thus constituted could he enriched by putrescent manures 
 alone.— 1835.] 
 
 Davy states that both aluminous and calcareous earth will combine 
 with any vegetable extract, so as to render it less soluble (and con- 
 sequently not subject to the waste that would otherwise take place), 
 and hence '' that the soils which contain most alumina and carbo- 
 nate of lime, are those which act with the greatest chemical energy 
 in preserving manures." Here is high authority for calcareous 
 earth possessing the power which my argument demands, but not 
 in so great a degree as I think it deserves. Davy apparently places 
 both earths in this respect on the same footing, and allows to 
 aluminous soils retentive powers equal to the calcareous. But 
 though he gives evidence (from chemical experiments) of this 
 power in both earths, he does not seem to have investigated the 
 difference of their forces. Nor could he deem it very important, 
 holding the opinion which he elsewhere expresses, that calcareous 
 earth acts '' merely by forming a useful earthy ingredient in the 
 soil," and consequently attributing to it no remarkable chemical 
 effects as a manure. I shall offer some reasons for believing that 
 the powers of attracting and retaining manure, possessed by these 
 two earths, differ greatly in their degrees of force. 
 
 The aluminous and calcareous soils of this country, through the 
 whole of their virgin state, have had equal means of receiving 
 vegetable matter ; and if their powers for retaining it were nearly 
 equal, so would be their acquired fertility. Instead of this, while 
 the calcareous soils have been raised to the highest condition, many 
 of the tracts of clay soil remain the poorest and most worthless. 
 It is true that the one laboured under acidity from which the other 
 was free. But if we suppose nine-tenths of the vegetable matter 
 to have been rendered useless by that poisonous quality, the re- 
 maining tenth, applied for so long a time, would have made fertile 
 any soil that had the power to retain the enriching matter. 
 
 [Many kinds of shells arc partly composed of gelatinous animal 
 
MODE OP OPERATION OF CALX AS MANURE. 95 
 
 matter, wliich, I suppose, must be cliemically combined vv'itb tbo 
 calcareous eartb, and by that means only is preserved from the 
 putrefaction and waste that would otherwise certainly and speedily 
 take place- Indeed, the large proportion of animal matter which 
 thus helps to constitute some kinds of shells, instead of making 
 tliem more perishable, serves to increase their firmness and solidity. 
 When long exposure, as in fossil shells, has destroyed all animal 
 matter, the texture of the calcareous substance is greatly weakened. 
 A simple experiment will serve to separate, and make manifest to 
 the eye, the animal matter which is thus combined with and pre- 
 served by the calcareous earth. If a fresh-water mussel-shell is 
 kept for some days immersed in a weak mixture of «»nuriatic acid 
 and water, all the calcareous part will be gradually dissolved, 
 leaving the animal matter so entire, as to appear still to be a whole 
 shell — but which, when lifted from the fluid which supj^rts it, 
 will prove to be entirely a flaccid, gelatinous, and putrescent sub- 
 stance, without a particle of calcareous matter being left. Yet 
 this substance, which is so highly putrescent when alone, would 
 have been preserved in combination with calcareous matter, in the 
 shell, for many years, if exposed to the usual changes of air and 
 moisture ; and if secured from such changes, would be almost im- 
 perishable. — 1835.] 
 
 Calcareous earth has power to preserve those animal matters 
 which are most liable to waste, and which give to the sense of 
 smell full evidence when they are escaping. Of this, a striking 
 example is furnished by an experiment which was made with care 
 and attention. The carcase of a cow, that was killed by accident 
 in May, was laid on the surface of the earth, and covered with 
 about seventy bushels of finely divided fossil shells and earth 
 (mostly silicious), their proportions being as thirty-six of calcare- 
 ous, to sixty-four of silicious earth. After the rains had settled 
 the heap, it was only six inches thick over the highest part of the 
 carcass. The process of putrefaction was so slow, that several 
 weeks passed before it was over ; nor was it ever so violent as to 
 throw off any efiluvia that the calcareous earth did not intercept 
 in its escape, so that no offensive smell was ever perceived. In 
 October, the whole heap was carried out and applied to one-sixth 
 of an acre of wheat — and the effect produced far exceeded that of 
 the like calcareous manure alone, which was applied at the same 
 rate on the surrounding land. No such power as this ex-periment 
 indicated (and which I have since repeated in various modes, and 
 always with like results), will be obtained, or expected, from using 
 clay as the covering earth. 
 
 Quick-lime is used to prevent the escape of offensive efiluvia 
 from animal matter ; but its operation is entirely different from 
 that of calcareous earth. The former effects its object by " eating" 
 
96 TRESERVING AND FIXING MANURES. 
 
 or decomposing the animal substance (and nearly destroying it as 
 manure), before putrefaction begins. The operation of calcareous 
 earth is to moderate and retard, but not to prevent putrefaction ; 
 not to destroy the animal matter, but to preserve it effectually, by 
 forming new combinations with the products of putrefaction. This 
 important operation will be treated of more fully in a subsequent 
 chapter. 
 
 The power of calcareous earth to combine with and retain putres- 
 cent manure, implies the power of fixing them in any soil to 
 which both are applied. ■ The same power will be equally exerted 
 if the putrescent manure is applied to a soil which had previously 
 been made calcareous, whether by nature, or by art. When a 
 chemical combination is formed between the two kinds of manure, 
 the one is necessarily as much fixed in the soil as the other. 
 Neither air, sun or rain, can then waste the putrescent manure, be- 
 cause neither can take it from the calcareous earth, with which it 
 is chemically combined. Nothing can effect the separation of the 
 parts of this compound manure, except the attractive power of 
 growing plants — which, as all experience shows, will draw their 
 food from this combination as fast as they require it, and as easily 
 as from sand. The means then by which calcareous earth acts as 
 an improving manure are, comj>lcteljj preserving putrescent manures 
 from waste, and yielding them freely for use. These particular 
 benefits, however great they may be, cannot be seen very quickly 
 jafter a soil is made calcareous, but will increase with time, and, 
 with the means for obtaining vegetable matters, until their accu- 
 mulation is equal to the soil's power of retention. The kind, or 
 the source, of enriching manure, does not alter the process de- 
 scribed. The natural growth or the soil, left to die and rot, or 
 other putrescent manui'es collected and applied, would alike be 
 seized by the calcareous earth, and fixed in the soil. 
 
 This, the most important and valuable operation of calcareous 
 earth, then gives nothing to the soil ; but only secures other ma- 
 nures, and gives them wholly to the soil. In this respect, the 
 action of calcareous earth in fixing manures in soils, is precisely 
 like that of mordants in '^setting" or fixing colours on cloth. 
 When alum, for example, is used by the dyer for this purpose, it 
 adds not the slightest tint of itself — but it holds to the cloth, and 
 also to the otherwise fleeting dye, and thus fixes them permanently 
 together. " Witlii)ut the mordant, the colour might have been 
 equally vivid, but would be lost by the first wetting of the cloth. 
 
 [Thus, reasoning a priori from that chemical poAvcr possessed 
 by calcareous earth, which is wanting to both sandy and clayey 
 earths, would load to the conclusion that calcareous earth serves to 
 combine putrescent matters with the soil in general ; and the 
 known results of fertility being therein so fixed, might serve for 
 
NEUTRALIZING ACIDS IN SOILS. 97 
 
 tlie like proof, even -without tlie other course of reasoning. There 
 is still another proof of this combination being formed, which is ob- 
 tained by a chemical process, but which is so simple that no chemi- 
 cal science is requisite to make the trial. 
 
 If a specimen of any naturally poor soil, after being dried and 
 reduced to powder, be agitated in a vessel of water (as a common 
 drinking glass), and then allowed to stand still, the coarser sili- 
 cious sand will subside first, the finer sand next, and last the clay. 
 In this manner, and by pouring oif the ligliter parts, before their 
 subsidence, it is very easy to separate with suificient accuracy the 
 sand from the clay. But if a specimen of a good rich ncxdral soil 
 be tried in that manner, it will be found that the finest sand and 
 the clay and putrescent matter hold together so closely that they 
 cannot be separated by mere agitation in water. Then take another 
 sample of the same soil, and pour to it a small quantity of diluted 
 muriatic acid ; and though no effervescence is produced (the lime 
 not being in the form of carbonate), the acid will take away the 
 lime, or destroy its combination with the other earths, so that the 
 sand and the clay may then be separated by agitation in water, as 
 perfectly and easily as in the case of the poorest soils. This dif- 
 ference between good and bad soils (whether light or stiff), or those 
 naturally rich and those naturally poor, cannot escape the observa- 
 tion of the young experimenter; and the cause can be no other 
 than what I have supposed. This then serves as the third mode 
 of proof of the important position, that calcareous earth (or lime 
 in some other form) not only combines with vegetable and animal 
 matters, but also serves (as a connecting link) to combine these 
 matters with the sand and clay of the soil. — 1842.] 
 
 The next most valuable property of calcareous manures for the 
 improvement of soil is their poicer of neutralizing acids, which 
 has already been incidentally brought forward in the preceding 
 chapter. According to the views already presented, even our 
 poorest cultivated soils contain more vegetable matter than they 
 can beneficially use ; and when first cleared, they have it in great 
 excess. So antiseptic is the acid quality of poor woodland, that 
 before the crop of leaves of one year can entirely rot, two or three 
 others will have fallen ; and there are always enough, at any one 
 time, to greatly enrich the soil, if the leaves could be rotted and 
 fixed in it at once. 
 
 [This alleged antiseptic effect of vegetable acid in our soils re- 
 ceives strong support from the facts established with regard to j^eat 
 soils, in which vegetable acids have been discovered by chemical 
 analysis ; and though the peat or moss soils of Britain differ 
 entirely from any soils in eastern Virginia (except that of the 
 great Bisuial Swamp, the only extensive peat bog known), still some 
 facts relating to the former class may throw light on the properties 
 9 
 
98 ALTERING TEXTURE ANB ABSORBENCY OP SOILS. 
 
 of our own soils, different as they may be. Not only does vegeta- 
 ble matter remain without putrefaction in peat soils and bogs, and 
 serve to increase their depth by regular accretions from the succes- 
 sive annual growths, but even the bodies of beasts and men have 
 been found unchanged under peat, many years after they had been 
 covered.* It is well known that the leaves of trees rot very 
 quickly on the rich lime-stone soils of the Western States (neutral 
 soils), while the successive crops of several years' growth, in the 
 different stages of their slow decomposition, may be always found 
 on the acid woodland of lower Virginia. 
 
 The presence of acid in soils, by preventing or retarding putre- 
 faction, keeps the vegetable matter inert, and even hurtful on cul- 
 tivated land; and the crops are still further injured by taking up 
 this poisonous acid with their nutriment. A sufficient quantity 
 of calcareous earth, mixed with such a soil, will immediately 
 neutralize the acid, and destroy its powers; and the soil, released 
 from this baneful influence, will be rendered capable, for the first 
 time, of using the fertility which it really possessed. The benefiti 
 thus produced is almost immediate ; but though the soil will show 
 a new vigour in its earliest vegetation, and may even double its first 
 crop, yet no part of that increased product is due to the direct 
 operation of the calcareous manure, but merely to the removal of 
 acidity. The calcareous earth, in such a case, has not made the 
 soil richer in the slightest degree, but has merely permitted it to 
 bring into use the enriching principles it had before, and which 
 were concealed by the acid character of the soil. It will be a 
 dangerous error for the farmer to suppose that calcareous earth can 
 enrich soil by direct means. It destroys the worst foe of produc- 
 tiveness, and uses to the greatest advantage the fertilizing powers 
 of other manures ; but of itself it gives no fertility to soils, nor 
 does it furnish the least food to growing plants. f 
 
 These two kinds of action are by far the most powerful of the 
 means possessed by calcareous earth for fertilizing soils. It has 
 another however of great importance — or rather two others, which 
 may be best described together as the j)oiver of altering the texture 
 and ahsorhency of soils. 
 
 At first it may seem impossible that the same manure can pro- 
 duce such opposite effects on soils as to lessen the faults of being 
 either too sandy or too clayey — and the evils occasioned by both 
 the want and the excess of moisture. Contradictory as this may 
 
 * See Aiton's Essay on Moss Earth, republished in Farmers' Register, 
 vol. v., p. 462. 
 
 [•}■ Confirmation. — Lime "neutralizes acid substances, ■which arc naturally 
 formed in the soil, and decomposes or renders harmless other noxious com- 
 pounds which are not unfrequently within reach of the roots of plants."' 
 Johnston's A jr. Chem. p. 400.] 
 
ALTERING TEXTURE AND ABSORBENCY OF SOILS. 99 
 
 appear, it is strictly true as to calcareous earth. In common with 
 clay, calcareous earth possesses the power of making sandy soils 
 more close and firm — and in common with sand, the power of 
 making clay soils lighter, or more open and mellow. When sand 
 and clay thus alter the textures of soils, their operation is alto- 
 gether mechanical ; but calcareous earth must exert chemical 
 action in producing such efiects, as its power is very far greater 
 than that of either sand or clay. A very great quantity of clay 
 would be required to stiffen a sandy soil perceptibly, and still more 
 sand would be necessary to make a clay soil much lighter — so that 
 the cost of such improvement would genei'ally exceed the benefit 
 obtained. Far greater effects on the texture of soils are derived 
 from much less quantities of calcareous earth, besides obtaining 
 the more valuable operation of its other powers.* 
 
 Every substance that is open enough for air to enter, and the 
 particles of which ^ are not absolutely impenetrable, must absorb 
 moisture from the atmosphere. Aluminous earth, reduced to an 
 impalpable powder, has strong absorbing powers. But this is not 
 the form in which such soils can act — and a close and solid clay 
 will scarcely admit the passage of air or water, and therefore can- 
 not absorb much moisture except by its surface. Through sandy 
 soils, the air passes freely ; but most of its particles are impene- 
 trable by moisture, and therefore these soils are also extremely 
 deficient in absorbent power. Calcareous earth, by rendering clay 
 more open to the entrance of air, and closing partially the too 
 open pores of sandy soils, increases the absorbent powers of both. 
 To increase that power in any soil, is to enable it to draw supplies 
 of moisture from the air, in the drycst weather, and to resist more 
 strongly the waste by evaporation of light rains. A calcareous 
 soil will so quickly absorb a hasty shower of rain as to appear to 
 have received less than adjoining land of different character; and 
 yet if observed in summer, when under tillage, some days after a 
 rain, and when other adjacent land appears dry on the surface, the 
 part made calcareous will still show the moisture to be yet remain- 
 ing, by its darker colour. All the effects from this power of calca- 
 reous manures may be observed within a few years after their ap- 
 plication — though none of them so strongly marked, as they are 
 on lands made calcareous by nature, and in which time has aided 
 and perfected the operation. These soils present great variety in 
 their proportions of sand and clay ; yet the most clayey is friable 
 enough, and the most sandy firm and close enough, to be considered 
 soils of good texture; and they resist the extffemes of both wet 
 
 [* Trofessor Johnston confirms this remarkable power of calcareous 
 manures to make clay soils lighter, and light soils more close ; but (strangely 
 enough), ascribes these opposite operations to the physical or vKchankal 
 action of lime. (P. 400, Agr. Chem.)— 184'J.] 
 
100 LIME AS POOD FOR TLANTS. 
 
 and dry seasons, Ibettev than any other soils whatever. Time, and 
 the increase of vegetable matter, will bring those qualities to the 
 same perfection in soils made calcareous by artificial means, as 
 they are in soils made calcareous by nature. 
 
 The subsequent gradual accumulation of vegetable or other 
 putrescent matter in the soil, by the combining or fixing power 
 of calcareous earth, must have yet another beneficial ciiect on 
 vegetation. The soil is thereby made darker in colour, and it con- 
 sequently is made warmer, by more freely absorbing the rays of 
 the sun. [This must cause earlier ripening of all the vegetable 
 growths.] 
 
 [There is another power or function of lime in soil, indispensa- 
 ble to the perfection, healthy growth, and perhaps even to the ex- 
 istence of every plant ; and which has already been considered as 
 a proof of neutral soils. This is to supply, through the roots, to 
 every growing plant some lime in soluble state which will remain 
 fixed in the plant. This quantity varies with the kind of plant, 
 and its wants in different stages of growth ; and however varying 
 in difl^ercnt kinds of plants, even when most abundant, it is always 
 very small in proportion to the other (organic) matters taken up 
 by and retained in the substance of plants. By reducing the plant 
 to ashes only can the lime taken up by the roots be found, and the 
 proportion to the ashes and to the former vegetable substance be 
 known. 
 
 It may be perhaps deemed a contradiction, or drawing a distinc- 
 tion where there is no real difi'erence, to affirm the absolute necessity 
 of every plant receiving through its roots, a certain proportion of 
 lime, however minute, and yet denying that lime serves as food for 
 plants. I admit the difficulty of clearly discriminating by defini- 
 tion between the two functions. Still, there is great difference 
 between the manner and results of the supply of lime to plants, 
 and of the aliment which they draw from putrescent manures, 
 humus, or other soluble organic matter. According to the quantity 
 of soluble putrescent manure supplied to or naturally in a soil 
 (unless so enormous as to be hurtful), so will be the quantity of 
 the earliest vegetable growth thereon. But if a soil has been so 
 moderately supplied with lime, as to be barely rendered neutral, 
 the subsequent addition of any greater quantity of lime will add 
 nothing directly, or speedily, to the production of grain or other 
 ordinary crops — nor to the quantity of lime taken up by the whole 
 of such succeeding growth. If a soil so destitute of organic mat- 
 ter — such as is recognised by all as furnishing food to plantS' — as 
 to be nearly barren, is supplied properly and profusely with putres- 
 cent manures, the next growth of vegetables may be remarkable 
 for luxuriance and heavy product. But if this rich supply of food 
 had been entirely withheld, and lime or calcareous earth given 
 
SPECIFIC MANURE FOR CERTAIN KINDS OP PLANTS. 101 
 
 instead, in any quantity, either a very slight increase of productive 
 power, or none at all, would be shown in the next immediately 
 succeeding attempt to produce a crop thereon. Whether then it be 
 correct to consider lime as food for plants, or not, it is all-important 
 tliat farmers should act, in applying calcareous manures, as if they 
 thereby furnished no food whatever to plants in the direct manner 
 that is done by dung. And great as is this error of the opposite 
 opinion, it has had extensive influence and very injurious conse- 
 quences. In the greater number of cases, where ignorant farmers 
 have just arrived at the before unknown truth that calcareous ma- 
 nures are of benefit to crops and land, they proceed immediately 
 to the false conclusion that they will produce benefit in the same 
 manner as putrescent manures ; and they apply them by the same 
 rules and to similar soils, in the vain expectation of in like manner 
 supplying food to the crops. Such course can result only in dis- 
 appointment and loss of means, if not injury to the land. 
 
 As has been stated, all known plants, not excepting the acid 
 kinds, contain some lime, and therefore it may safely be assumed 
 that some lime is indispensable to the growth of every plant, and 
 to even the lowest productive power of every soil. But, for the 
 greater number of plants, the quantity of lime required is so ex- 
 ceedingly small, that they readily obtain their needed supplies from 
 soils the least supplied by nature with lime. And many plants 
 (like pines and sorrel) prefer the soils having such scant supply 
 of lime as to permit an excess of acid. Other plants require com- 
 paratively large supplies, such as clover, and all other of the legu- 
 minous or pea tribe. The ashes of these plants contain compara- 
 tively very large proportions of lime. Ked clover, lucerne, and 
 still more sainfoin, cannot thrive well, except on soils largely sup- 
 plied with lime in some state ; though, for most of such plants, 
 perhaps a rich neutral soil will offer the requisite supplies of lime 
 as well as if calcareous, or containing carbonate of lime. Among 
 trees, locust, papaw, and hackberry (or sugar nut), are also plants 
 to which lime in considerable quantity in the soil is essential. For 
 all such plants, lime is a specific manure; that is, it improves 
 their growth in a peculiar and remarkable degree, though none of 
 them can- take up into their bodies more than a very small amount 
 of lime. 
 
 The following list, showing the proportions of lime in many 
 cultivated plants, is extracted and abridged from the late publica- 
 tion of Johnston, who copied the analyses of Sprengel. The 
 quantities of pure lime are here understood, without reference to 
 the acid (or its kind) with which the lime was combined. 1000 
 parts in each case of the dry vegetable matters are supposed to bo 
 burnt to ashes, and the weights of ashes, and of the pure lime 
 
 they contain, are only stated. 
 (J* - 
 
102 
 
 LIME IN ASHES OF VARIOUS PLANTS. 
 
 1000 lbs. of 
 
 Grain of wheat 
 
 Straw of wheat 
 
 Grain of barley 
 
 Straw of barley 
 
 Grain of oats 
 
 Straw of oats 
 
 Grain of rye 
 
 Straw of rye 
 
 Field bean seed 
 
 Do. straw 
 
 Field peas (English) 
 
 Do. straw 
 
 Common vetch seed {vicia sativa) [our part- "I 
 
 ridge pea?] J 
 
 Straw of same 
 
 Rye grass 
 
 Red clover 
 
 White clover 
 
 Lucerne 
 
 Sainfoin . . . . ' 
 
 Gives total of 
 
 Of which there 
 
 ashes. 
 
 is limu (pure). 
 
 11.77 
 
 0.96 
 
 35.19 
 
 2.40 
 
 23.49 
 
 1.06 
 
 52.42 
 
 5.54 
 
 26. 
 
 0.86 
 
 57.-5 
 
 1.52 
 
 10.5 
 
 1.22 
 
 28. 
 
 1.78 
 
 21. 3G 
 
 1.65 
 
 31.21 
 
 6.24 
 
 24.64 
 
 0.58 
 
 49.71 
 
 27.30 
 
 29.9 
 
 1.60 
 
 51.1 
 
 19.55 
 
 52.86 
 
 7.34 
 
 74.78 ' 
 
 27.80 
 
 91.82 
 
 23.48 
 
 95.53 
 
 48.31 
 
 69.. 57 
 
 21.95 
 
 —1849.] 
 
 Additional and practical proofs of all these powers of calcareous 
 earth will be furnished, when its use and effects as manure will be 
 stated. I am persuaded, however, that enough has already been 
 said both to establish and account for the different capacities of 
 soils for improvement by putrescent manures. If the power of 
 fixing manures in soils has been correctly ascribed to calcareous 
 earth, that alone is enough to show that soils containing that in- 
 gredient, in proper quantities, must become rich; and that alumi- 
 nous and silicious earths mixed in any proportions, and even with 
 vegetable or other putrescent matter added, can never form other 
 than a sterile soil.* 
 
 [* The several peculiar or stronger powers for increasing fertility and 
 production ascribed above to calcareous earth in soil, are those whicli were 
 presented to my mind cither in advance of all practical applications of the 
 earth as manure, or otherwise were the results of actual observation 
 within a few years after the commencement. The chemical laws and 
 agencies were of course gathered from books. The confirmatory facts 
 were mostly found in my observation of the characters of natural soils, and 
 in the earliest results of my calcareous manurings. It is not necessary 
 here, and would scarcely bo proper, to adduce other powers of calcareous 
 manures, learned from mvich later practical results, or which have since 
 been presented by later and much more scientific investigators. Sundry 
 other useful and some very important agencies of calcareous earth in soils 
 may be seen in the "Lectures on the Applications of Chemistry and 
 Geology to Agriculture," by J. F. AV. Johnston. It is gratifying to me, 
 that this author in most respects sustains my doctrine ; though in some 
 points we are entirely opposed. These diiiereuccs, as well as the most im- 
 
CHAPTER IX. 
 
 ACTION OF CAUSTIC LIME AS MANURE. 
 
 The object of this essay is to treat only of calcareous eartt (as 
 before defiaed) as a manure, and not of pure caustic lime, nor of 
 manures in general. Still the nature of that which is properly my 
 subject is so intimately connected with some other kinds of manures, 
 and is so liable to be confounded with others which act very dif- 
 ferently, that frequent references to both classes have been and 
 will be again necessary. To make such references more plain and 
 useful, some general remarks and opinions will now be submitted, 
 as to the peculiar modes of the operation of various manures, and 
 particularly of lime. 
 
 Until now I have been careful to say as little as possible of j^ure 
 or quick-lime, for fear of my meaning being mistaken, from the 
 usual practice of confounding it with calcareous earth ; or of con- 
 sidering both its first and later operations as belonging to one and 
 the same manure. The connexion between the manures is so inti- 
 mate, and yet their actions so distinct, that it is necessary to mark 
 the points of resemblance as well as those of difference. 
 
 Mjt own use of quick or caustic lime as a manure has not ex- 
 tended beyond a few acres ; and I do not pretend to know any- 
 thing from experience of its first or caustic effects. But Davy's 
 simple and beautiful theory of its operation carries conviction with 
 it, and in accordance with his opinions Fsliall state the theory, and 
 thence attempt to deduce its proper practical use. 
 
 By a sufficient degree of heat, the carbonic acid is driven off 
 from shells, lime-stone, or chalk, and the remainder is pure or 
 caustic lime. In this state it has a powerful decomposing power 
 on all putrescent animal and vegetable matters, which it exerts on 
 every such substance in the soils to which it is applied as manure. 
 If the lime thus meets with solid and inert vegetable matters, it 
 hastens their decomposition, renders' them soluble, and brings them 
 into use and action as manure. But such vegetable and animal 
 matters as were already decomposed, and fit to support growing 
 plants, are injured by the addition of lime; as the chemical action 
 
 portant of other operations and values of calcareous manui*es wliich he pre- 
 sents, will be brought in view, and considered, at a later part of this 
 essay. Other passages confirming my opinions previously advanced, havo 
 been or will be quoted in notes. — 1849.] 
 
 (103) 
 
104 QUICK-LIME AS MANURE. 
 
 ■wliich takes place between these bodies forms different compounds, 
 which are always less valuable than the putrid or soluble matters 
 were, before being acted on by the lime.* 
 
 This theory will direct us to expect profit from applying caustic 
 lime to all soils containing much unrotted and inert vegetable 
 matter, as our acid wood-land when first cleared, and perhaps worn 
 fields, covered with broomgrass ; and to avoid the application of 
 lime, or (what is the same thing) to destroy previously its caustic 
 quality by exposure to the air, for all good soils containing soluble 
 vegetable or animal matters, and on all poor soils deficient in inert, 
 as well as in active nourishment for plants. The warmth of our 
 climate so much aids the fermentation of all putrescent matters in 
 soils, that it can seldom be required to hasten it by artificial means. 
 To check its rapidity is much more necessary, to avoid the waste 
 of manures in our lands. But in England, and still more in Scot- 
 land, the case is very difi"erent. There, the coldness and moisture 
 of the climate greatly retard the fermentation of the vegetable 
 matter that falls on the land ; so much so that, in certain situa- 
 tions, the most favourable to such results, the vegetable cover is 
 increased by the deposit of every successive year, and forms those 
 vegetable soils which are called moor, jicaf, and bo(/ lands. Vege- 
 table matter abounds in these soils, and sometimes it even forms 
 the greater bulk for many feet in depth ; but it is inert, insoluble, 
 and useless, and the soil is unable to bring any useful crop, though 
 containing vegetable matter in such great excess. Many millions 
 of acres in Britain are of the different grades of peat soils, of 
 which almost none exist in the eastern half of Virginia. Upon 
 this ground of the difference of climate, and its effects on ferment- 
 ation, I deduce the opinion that caustic lime would be serviceable 
 much more generally in Britain than here ; and indeed that there 
 are very few cases in which the caustic quality would not do our 
 arable lands more harm than good. This is no contradiction to 
 the great improvements which have been made on many farms by 
 applying lime ; for its caustic quality was seldom allowed to act at 
 all. Lime is continually changing to the carbonate of lime ; and, 
 in practice, no exact line of scpai-ation can be drawn between the 
 transient effects of the one, and the later, but dui-able improve- 
 ment from the other. Lime powerfully attracts the carbonic acid 
 of which it was deprived by heat, and that acid is universally dif- 
 fused through the atmosphere (though in a very small proportion), 
 and is produced by every decomposing putrescent substance. Con- 
 sequently, caustic lime, when on land, is continually absorbing 
 and combining with this acid ; and, with more or less rapidity, 
 according to the manner of its application, is returning to its for- 
 
 * Davy's Agr. CLem. Lect. vii. 
 
QUICK-LIME SOON CAIIBONATED. 105 
 
 mcr state of mild calcareous earth. If spread as a top-dressing 
 on grass lands — or on ploughed land, and superficially mixed with 
 the soil by harrowing — or used in composts with fermenting vege- 
 table matter — the lime is probably completely carbonated, before 
 its causticity can act on the soil. In no case can lime, applied 
 properly as manure, long remain caustic in the soil. Thus most 
 applications of lime are, in effect, and even from the beginning of 
 the manuring action, simply applications of calcareous earth; but 
 acting with greater energy and power at first, in proportion to the 
 quantity, because more finely divided, and more equally distributed. 
 
 [Whether lime, or carbonate of lime, or calcareous earth, may 
 be the term used in reference to any such manure used, or recom- 
 mended, the general, most important, and all effects other than 
 some of the earliest and least certain to occur, are the same in 
 practice of all. The operation in every case is that of calxing. In 
 presenting the theory, and in reasoning, and instruction, it is im- 
 portant to maintain the precise line of separation and distinction 
 between the artificial product, quick or caustic lime, and the 
 naturally existing calcareous earth, or carbonate of lime. But in 
 practical effects they are the same, excepting those only which 
 may be due to the different early conditions of the different sub- 
 stances. Therefore, (always allowing for those early and transient 
 and minor differences), whatever I may say of the operation of 
 calcai-eous earth as manure, would as well be produced by the pro- 
 per use of lime ; and whatever other writers on lime as manure 
 have correctly stated, even though perhaps designed by them to be 
 confined to quick-lime, would, as to all abiding and important 
 effects and operations, apply as well to mild and naturally existing 
 calcareous earth, in any of its various forms. 
 
 Further — even when the first chemical characters of both caustic 
 lime and carbonate of lime have been altered in the soil, and they 
 may have become changed to other salts of lime, by combining 
 with diff"erent afcids of soils, still, judging from all experienced and 
 abiding effects, the general and beneficial operations of the original 
 manures still continue. The only known exception is, and which 
 is abundantly obvious, that the power to neutralize acids has then 
 been fully used, and cannot again be exercised by the same lime 
 on any subsequently produced acids. — 1849.]* 
 
 [* Recent Confirmation. — .Johnston says — " The eifects of pure lime upon 
 the land, and upon vegetation, are ultimately the same, -whether it be laid ou 
 
 in a state of hydrate [or newly slaked], or of carbonate." 
 
 " In general, however, the chemical action of the marls and calcareous 
 sands is precisely the same in kind as that of lime in the burneJ and slaked 
 state, and so far the effects which we have already seen to be produced by 
 marls, represent also the general effects of lime in any form." — Lectures, 
 p. 390. And further — "You may safely proceed on the priuoiplc that the 
 iime iu the maiis, &c., will ultimately produce precisely the same effects 
 
lOG 
 
 FORM OF CLASSIFICATION OF MANURES. 
 
 upon your land, as the lime from the kiln, provided you lay on an equal 
 quantity, and in an equally minute state of division. The effect will only 
 be a little more slow," &c.— lb. p. 387. — 1849.] 
 
 [By adopting the views which have been presented of the action of cal- 
 careous earth and of lime as manures, and those which are generally re- 
 ceived as to the modes of operation of other manures, the following table 
 has been constructed, which may be found useful, though necessarily imper- 
 fect, and in part founded only on conjecture. The various particular kinds 
 of manures are arranged in the supposed order of their power, under the 
 several heads or characters to which they belong ; and when one manure 
 possesses several different modes of action, the comparative force of each is 
 represented by the letters annexed — the letter a designating its strongest 
 or most valuable agency, b tlie next strongest, and so on as to c and d. 
 
 Pr-OrOSED CLASSIFICATION OF MANURES. 
 
 ^ Feathers, hair, woollen rags, 
 I Pounded bones, [h) 
 All putrescent animal and vegetable 
 substances, as dung, 
 \ Stable and farm-yard manures, (a) 
 Straw, (a) 
 
 Green crops ploughed in, and dead 
 grass and weeds left on the sur- 
 f^xce. («) 
 'Quick-lime, [a) 
 Potash and soap He, [a) 
 ' Wood ashes not drawn, [d) 
 Paring and bui-ning the surface of the 
 soil, (a) 
 '' Calcareous earth, including 
 Lime become mild by exposure, {a) 
 Chalk, (a) 
 
 Lime-stone gravel, (a) 
 Wood ashes, (6) 
 Fossil shells (or shell marl), (a) 
 Marl (a calcareous clay), («) 
 Old mortar and lime cements. 
 All calcareous manures, (6) 
 Quick-lime, {b) 
 Potash and soap lie, {b) 
 Wood ashes, (c) 
 Clay, 
 Sand, 
 J Clay marl, {h) 
 Fermenting vegetable manures, (5) 
 Green manures, (i) 
 L'nfcrmented litter, {b) 
 ' Sulphate of lime, or gypsum (for clo- 
 ver). 
 Gypseous earth (or gi-een-sand earth), 
 for clover, 
 - Calcareous manures (for clover) 
 Phosphate of lime (for wheat) in 
 Bones, (a) and 
 Drawn ashes, (a) 
 Salt, for asparagus, (a). — 1835.} 
 
 Alimentary, or servin 
 food for plants — as 
 
 Solvent of alimentary ma- 
 mures — as 
 
 Fixers, or 3Iordants — 
 serving to combine with or 
 set other manures in soils 
 — as 
 
 Neutralizing acids — as 
 
 Mechanical, or improving 
 by altering the texture of 
 soil — as 
 
 Specific, or furnishing in- 
 gredients necessary for par- 
 ticular plants — as 
 
CHAPTER X. 
 
 INTRODUCTORY AND GENERAL OBSERVATIONS ON MARL 
 AND LIME.* 
 
 Proposition 5. — Calcareous manures will give to our worst soils 
 a power of retaining putrescent manures, equal to that of the 
 best — and loill cause more productiveness, and yield more profit, 
 than any other improvement practicahle in lower Virginia. 
 
 The theory of the constitution of fertile and barren soils, has 
 now been regularly discussed. It remains to show its practical 
 application, in the use of calcareous earth as a manure. If the 
 opinions which have been maintained are unsound, the attempt to 
 reduce them to practice will surely expose their futility ; and if 
 they pass through that trial, agreeing with and confirmed by facts, 
 their truth and value must stand on impregnable ground. The 
 belief in the most important of these opinions (the incapacity 
 of poor soils for improvement, and its cause) first directed the 
 commencement of my use of calcareous manures; and the manner 
 of my practice has also been directed entirely by the views which 
 have been exhibited. Yet in every respect the results of practice 
 have sustained the theory of the action of calcareous manures; 
 unless indeed there be claimed as exceptions the injuries which 
 have been caused by applying too heavy dressings to poor and acid 
 lands ; and also the beneficial efi'ects of proper practice being found 
 to exceed in degree what the theory seemed to promise. 
 
 My use of calcareous earth as manure has been almost entirely 
 confined to that form of it which is so abundant in the neighbour- 
 hood of our tide-waters — the beds oi fossil shells, together with the 
 matrix, or earth with which they are found mixed. The shells 
 are in various states — in some beds generally whole, and in others 
 
 [* My views of the theory of fertilization have been presented in the pre- 
 ceding pages, (chapters ii. to ix. inclusive), precisely as they appeared in 
 1832 (and, in substance, at a still earlier time), the later additions being 
 all distinctly marked as such. This was deemed necessary to the main- 
 tenance of my claim of priority or of originality of opinions, some of 
 which, though then novel and unsupported by other authority, have since 
 been recognised as true, and are now generally if not universally received 
 by writers on agricultural chemistry. The like necessity will not apply to 
 the remainder of this work ; and therefore the distinguishing of l*ter 
 additions to or alterations of the edition of 1832, will not be regularly 
 marked for distinction. Still it will be done whenever it may be required 
 for more clear exposition, or where the later dates of additions are deemed 
 of any importance to their purport. — 1852.] 
 
108 FOSSIL SHELLS AND MARL. 
 
 reduced nearly to a coarse powder. The earth which fills their 
 vacancies, and serves to make the whole a compact mass, in most 
 cases is principally silicious sand, and usually contains no putres- 
 cent or valuable matter, other than the calcareous.* The same 
 effects, in the main, might he expected from calcareous earth in 
 any other form, whether chalk, lime-stone gravel, wood ashes, or 
 lime — though the two last have other qualities besides the calca- 
 reous. During the short time that lime can remain quick or caustic, 
 after being applied as manure, it exerts (as before stated) a solvent 
 power, sometimes beneficial and at others hurtful, which has no 
 connexion with its subsequent and permanent action as calcareous 
 earth. 
 
 These natural deposits of fossil shells are commonly, but very 
 improperly, called marl. This misapplied term is particularly ob- 
 jectionable, because it induces erroneous views of this manure. 
 Other earthy manures have long been used in Europe under the 
 name of marl, and numerous publications have described their 
 general effects, and recommended their use. When the same name 
 is given here to a different manure, many persons will consider 
 both operations as similar, and perhaps may refer to English 
 authorities for the purpose of testing the truth of my opinions, 
 and the results of my pi-aetice. But no two operations called by 
 the same name can well differ more. The process which it is my 
 object to recommend, is calxing, or simply the aj^pUcation of calca- 
 reous earth in any form ichatever, to soils ivanting that ingredient, 
 and generally being quite destitute of it ; and the propriety of the 
 application depends entirely on the knowing that the manure con- 
 tains calcareous earth, and what proportion, and that the soil con- 
 tains none. In England, the most scientific agriculturists apply 
 the term onarl correctly to a calcareous clay of peculiar texture. 
 But many authors, as well as the illiterate cultivators, have used 
 that name for any smooth soapy clay, which may or may not have 
 contained, so far as they knew, any proportion whatever of calca- 
 reous matter. Indeed, in most cases, they have seemed uncon- 
 scious of the presence as well as of the importance of that ingre- 
 dient, by their not alluding to it when attempting most carefully to 
 point out the distinguishing characters by which marl maybe known. 
 Still less have they inquired into the deficiency of calcareous earth 
 in soils proposed to be marled — but applied any earth which either 
 science or ignorance may have called marl, to any soils within a 
 
 [* From later observation I have formed the opinion that the colouring 
 matter of blue marls is vegetable extract, chemically combined with the 
 calcareous matter, of which opinion the grounds will be stated hereafter. 
 But still the amount of this vegetable admixture is too small to have much 
 appreciable eifect as food for plants; and, for all practical use, the general 
 position assumed above may yet bo considered as altogether true. — 1812.J 
 
MAUL AND MARLING IN ENGLAND. 109 
 
 convenient distance — and relied upon the subsequent effects to 
 direct whether the operation should be continued or abandoned. 
 These remarks more especially apply to the older writers ; but 
 even the later authors, of the highest character (as Sinclair and 
 Young, for example), when telling of the practical use and valua- 
 ble effects of marl, omit giving the strength of the manure, and 
 generally even its nature — and in no instance have I found the in- 
 gredients of the soil stated, so that the reader might learn what 
 kind of operation really was described, or be enabled to form a 
 judgment of its propriety. From all this, it follows that though 
 what is called marlimj in England may sometimes be (though 
 very rarely, as I infer) the same chemical operation on the soil 
 that I am recommending, yet it may also be either applying clay 
 to sand, or clay to chalk, or true marl to either of those soils, or 
 to some other soil still more calcareous than the earth applied ; 
 and the reader will generally be left to guess, in every separate 
 case, which of all these operations is meant by the term maiiinrj. 
 For these reasons, the practical knowledge to be gathered from all 
 this mass of written instruction on marling will be far less abund- 
 ant than the errors and mistakes of the authors, and the consequent 
 inevitable false deductions by their readers. The recommenda- 
 tions of marl by English authors, induced me very early to look 
 to what was here called by the same name, as a means for improve- 
 ment. But their descriptions of the manure convinced me that 
 our marl was nothing like theirs, and thus actually deterred me 
 from using it, until other and original and more correct views in- 
 structed me that its value did not depend on its having " a soapy 
 feel," or on any admixture of clay whatever.* 
 
 [* The remarks above were written in 1820, and are much less applica- 
 ble to authors of hiter date. How well justified my expressions then were, 
 will fully appear in the Appendix, in the testimony furnished by quotations 
 of the language and opinions of many authors. 
 
 There is no want of precision and clearness in the definitions of marl 
 given by modern scientific writers. Though even with some of them, there 
 are still very remarkable misapplications of the terms ; as incorrect, in- 
 deed, as could be expected from the most ignorant cultivators. Thus the 
 former geological surveyor of New Jersey habitually applies the name of 
 marl to the " green-sand" of tliat country ; which remarkable earth is a 
 soft incoherent crumbly mass of separate grains, neither clayey nor marly 
 in texture or compactness, nor in the least calcareous in its chemical com- 
 position. Still more strange than this, is an example found as late as 
 18-19, in the " Second Visit to the United States" of the distinguished 
 geologist Sir Charles Lyell. This author says, when passing from New 
 y^ork to Philadelphia, " In New Jersey we passed over a gently undulating 
 surface of counti-y, formed of red marl and sand-stone, resembling in appear- 
 ance, and of about the same geological age as the new red sand-stone 
 (trias) of England." Vol. i. p. 191. This error was not caused by 
 merely the careless use of an incorrect provincial term ; for the "new red 
 
 10 
 
110 THE KAME OF MAUL MISAPl'LIEl). 
 
 [Nevertlielcss, much valuable information may be obtained from 
 these same English works, on calcareous manure, or on marl (in the 
 
 sand-stone" formation of England is largely composed of a true (calcare- 
 ous) "red marl." The soil in question was probably a red clay, but, as I 
 should suppose, containing not a particle of calcareous earth — and cer- 
 tainly having no quality in common with any marl, true or false, or agree- 
 ing with any of the difl'erent understandings of what marl is, in texture or 
 composition. 
 
 According to scientific definition, marl is composed of carbonate of lime 
 and fine clay. When taken moist from its bed, such marl is not ductile or 
 plastic, like ordinary clay ; and is broken more easily tlian bent. It is 
 cut by a knife to a smooth surface, having an unctuous or soapy feel. When 
 a lump has been dried, and is then put into water, it speedily crumbles to 
 powder, or into thin laminae. Puvis (in his " Essai sur la Marnc'''), con- 
 siders the clay and carbonateof lime in marl to be chemically combined — 
 which opinion seems well founded. lie also supposes marl to be generally, 
 if not universally, of fresh-water formation — as shown by the shells con- 
 tained. 
 
 The term mai'l may be considered as xanderstood in four principal signi- 
 fications, and two of these running into numerous provincial varieties. 
 With all the precision and care in defining that can be used, it will not be 
 possible for me to avoid using the term sometimes in the dilfcrent senses in 
 which it is used by other authorities to whom I may refer, or whose opinions 
 may be quoted. Therefore, it will serve for better understanding and 
 greater clearness, to state, in general terms, all the different meanings ap- 
 plied to the term marl, by different classes. 
 
 1. The definition of marl by mineralogists, and men of science, is tho 
 most exact and most restricted in application — a calcareous clay of pecu- 
 liar texture and physical qualities, as described more at full above, and 
 elsewhere in this work. 
 
 2. The most extended sense — in which I shall iisc it in reference to its 
 fertilizing operation, (calxing), to embrace every kind of substance of earthy 
 texture, containing carbonate of lime in useful quantity to serve as manure, 
 and that being the principal manuring ingredient. 
 
 3. The sense in which it is understood by modern British agricultural 
 authors — which is the mineralogical marl, but also embraces other earths 
 used for the calcareous contents. 
 
 4. All the provincial applications of the term in different regions — as to 
 fine clay (in England) — fossil shells, in lower Virginia — calcareous tiifa, 
 or travertine, in our mountain region — and non-calcareous green-sand, 
 in New Jersey, &c. : In short, to any kind of earth that experience has 
 proved, or that ignorance has supposed, to be useful as manure. 
 
 The operation called "marling" in England is even less like what is 
 known by the same name here, than are the different substances used un- 
 der that name. That which I have done, and advise, and call marling (in 
 conformity to our provincial and incorj'ect name given to the substance 
 used), is, as above stated, the application of calcareous earth of any kind, 
 or from any source, to soils deficient in that ingredient — and also, in quan- 
 tities no greater than will serve to produce the desired chemical change in 
 each particular soil. This required proi:)ortion of carbonate of lime is 
 rarely more than will make one per cent, of the soil for its ploughed depth ; 
 and generally less than half that quantity is enough for profit and for 
 safety. Hence, according to the strength of the manure and the condi- 
 tion of the soil, the usual applications lie between the extremes of 100 and 
 
MiUlLINa IN ENGLAND. Ill 
 
 sense in which that term is used among us) — but under a different 
 head, viz., lime. This manure is generally treated of with as little 
 
 500 bushels to the acre — and more generally between 200 and 300. In 
 England, (even where we know that the manure is truly marl, or is calca- 
 reous), the quantities applied are enormous, and must act mechanically for 
 much the greater part, even if^acting chemically at all. For there can 
 be no chemical action, if the soil was calcareous in the slightest degree 
 before the application. The expense there is great, because of the heavy 
 applications; and liming, though that also is there very much heavier and 
 therefore more expensive than with us, is always deemed cheaper labour, 
 and is substituted for marling whenever water-borne lime can be obtained. 
 The case here is reversed — marling being always nracli cheaper than the 
 cheapest liming, if the marl is dug ou or near to the farm to which it is 
 applied. 
 
 I will cite a few facts and authorities to show the enormous quantities 
 in which marl is applied in Britain. Arthur Young (in his Farmer's 
 Calendar, 10th London collection, p. 40), describes and commends the 
 labours- of Mr. Rodwell, who put 140,000 loads of marl (efl'ervescing with 
 acids), to 120 acres of leased land, with great profit. The size of the load 
 not stated. But if 20 bushels, this would be (171 loads of 20 bush.) 3420 
 bushels to the acre. Sir John Sinclair says the red marl (which is calca- 
 reous, certainly, as I learn from the Agricultural Report of Lancashire) 
 is the great sovirce of fertilization in Lancashire and 'Cheshire. " Tlie 
 quantity used is enormous ; in many cases 300 middling cart-loads to the 
 acre, and the fields are sometimes so thickly covered as to have the ap- 
 pearance of a red-soiled fallow, fresh ploughed." (Code of Agriculture.) 
 Counting these loads at 20 bushels, makes GOOO bushels to the acre. The 
 Lancashire Report, made by order of the Board of Agriculture, says that 
 the carts for marling are usually drawn by 3 horses, and carry about 15 
 cwt. (1680 lbs.) This is a very light load, for short distances and level 
 ground. This Report gives sundi-y facts concurring with the foregoing. 
 A few only will be here quoted. " The qxiantity [of marl] laid on is from 
 2 to 3 J cubic roods of 64 [cubic] yards to the statute acre; the expense 
 of which is, according to the distance cari-ied, if within 60 rods [330 
 yards] on the average, about £8 [or nearly $40] the acre." — " A cubic 
 rood of marl, of 64 [cubic] yards to the rood, adds nearly half an inch to 
 the staple of the soil to a statute acre of land." — Consequently, the usual 
 dressing, of 2 to o\ such "cubic" roods, must give a coat of from nearly 
 1 inch to nearly 1| inches to the soil. A particular piece of 9 acres of "a 
 wretched black sandy waste" (which however was bought for £83 6s. Qd. 
 per acre), was afterwards marled "at nearly 12 roods, of 64 cubic yards 
 to the acre of 8 rods." [This is a provincial measure, equal to 2 acres, and 
 18| perches, statute measure.] This was equal to 20,730 cubic feet to the 
 [large] acre — and more than as many heaped bushels, if the cubic measure 
 of the marl was made in its bed. The cost of this marling was £27 los. 
 6c?. per [large] acre — [or about $135, or not quite half this quantity and 
 price, per statute acre]. In this same report, particular estimates are 
 made of the expenses of marling, at stated rates and distances, which of 
 course we must suppose ordinary cases. 1. A field of 30 rods square 
 (about 6 statute acres), marled from a pit in the centre, at 6 cubic roods, 
 would cost for cartage per rood, 18*., or £82 8s. for the 6 acres. 2. If a like 
 square, adjoining the first, be marled from the same pit, the previous 
 average distance of 15 rods will be increased by 30, or to 45 rods ( X 5^ 
 yards = 247 yds.), the increased expense will be 12s. the acre, or £54 ia 
 
112 MAllLUNG IN ENGLAND. LIMING. 
 
 clearness or correctness, as is done "with marl; but the reader at ! 
 least cannot bo mistaken in this, that the ultimate effect of every i 
 application of lime must be to make the soil more calcareous ; and 
 to that cause solely are to be imputed all the long-continued bene- I 
 ficial consequences, and great profits, which have been derived | 
 from liming. But excepting this one point, in which we cannot ] 
 be misled by ignorance or want of precision, the mass of writings 1 
 on lime, as well as on calcareous manures in general, will need I 
 much sifting to yield instruction. • The opinions published on the 
 mode of operation of lime are so many, so various, and so contra- i 
 dictory, that it seems as if each author had hazarded a guess, and 
 added it to a compilation of those of all who had preceded him. , 
 For a reader of these publications to be able to reject all that is J 
 erroneous in reasoning, and in statements of facts — or inapplicable 
 on account of difference of soil, or other circumstances — and thus 
 
 all for marling the 6 acres. 3. Another 6 acres, adjoining the last, at 75 ; 
 
 rods average distance from the pit, would cost £79 4s. So that at this very | 
 
 small distance of 412 yards only, and on even, firm, and level ground, the : 
 
 cost of ordinary marling is about $35 the English statute acre. Of coiirse, j 
 
 for one or more miles, the expense would he intolerable. 1 
 
 Neither is this marl (or even the poorer "clay" as there termed) in 
 
 Lancashire wanting in calcareous matter. Of 4 specimens stated, the ) 
 
 calcareous proportions were between 19J and 22 per cent. I infer, from j 
 
 general notices, that others are much richer. There is no intimation in j 
 
 the report as to whether the soils are or are not calcareous before being 1 
 
 marled. But there is other and better authority for supposing that the i 
 soils are naturally calcareous. The red marl of Lancashire is of the 
 
 " new red sand-stone" geological formation, and so I presume is the i 
 
 over-lying soil (Morton on Soils, p. G7). If so, this would remove all i 
 
 chemical action from the very heavy dressings of calcareous marl in ! 
 Lancashire. At p. 70, the same author speaks of the great improvement 
 
 made by luiiing "on the red marl" in Somerset and Devonshire. The de- . 
 
 Bervedly high authority of this writer is enough to establish these facts : 
 
 of improvement which he asserts. But it requires no argument to prove ; 
 
 that vi'hen lime is found a beneficial application to a "red marl" soil, or i 
 
 any soil befoi'e calcareous, that it must be by some other mode than that ] 
 
 chemical action which I call marling or calxing, and which always consists j 
 
 in rendering a soil calcareous, which was not so before. We might safely i 
 
 infer that the farmers of Lancashire do not incur the enormous expense ! 
 of their marlings merely to put the calcareous ingredient on their lands. 
 
 But the author of the "Report" leaves no doubt on that point. He says: j 
 
 " Undoubtedly the calcareous matter contained in either marl [the clay or \ 
 
 the richer marl] is of the highest importance ; hut ohviaiing the natural de- j 
 
 ficicncies of the soil, bg adding sand to dag, or dag to sand, is of more conse- , 
 
 quence than the mere calcareous stimulus, which might be obtained at a much ' 
 
 lighter expense" — [i. e. by using lime instead.] ] 
 
 In the appendix there will be presented many more facts in confirmation, i 
 
 But these alone Avill go far to prove that the marling of England is still \ 
 
 more diiferent from the "marling" or calxing which I have recommended 1 
 
 and practised, than is our "marl" from the substances so called in Eui-ope. I 
 
 —1851.] 1 
 
LIMING. 113 
 
 obtain only what is true, and useful — it would be necessary for bim 
 first to understand the subject better than most of those whose 
 opinions he was studying. Indeed it was not possible for them to 
 be correct, when treating (as most writers do) of lime as one kind 
 of manure, and every different form of the carhonate of lime as so 
 many others. Only one distinction of this kind (as to mode of 
 operation and effects) should be made, and never lost sight of — ■ 
 and that is one of substance, still more than of name. Pure or 
 quick-lime, and carbonate of lime, are manures entirely different in 
 their powers and effects. But it should be remembered that the 
 substance that was jmre lime when just burned, often becomes 
 carhonate of lime before it is used (by absoi'biug carbonic acid 
 from the atmosphere) ; still more frequently before a crop is 
 planted ; and probably always before the first crop ripens. Thus, 
 it should be borne in mind that the manure spoken of as lime is 
 often at first, and always at a later period, neither more nor less 
 than calcareous earth ; that lime, which at different periods is two 
 distinct kinds of manure, is considered in agricultural treatises as 
 only one ; and to calcareous earth are given as many different 
 names, all considered to have different values and effects, as there 
 arc different forms and mixtures of the substance presented by 
 nature. — 1835.] 
 
 But, however incorrect and inconvenient the term marl may be, 
 custom has too strongly fixed its application for any proposed 
 change to be adopted. Therefore, I must submit to use the word 
 marl to mean beds of fossil shells, notwithstanding my protest 
 against the property of its being so applied.* 
 
 [* The geological character of this tide-water region renders impossible 
 the existence of true marl beds, which can only be sought for with hope, 
 if anywhere in Virginia, in the valleys of our mountain lime-stone 
 region — where it would be as much in vain to seek for the fossil shells, so 
 abundant elsewhere. The latter deposit is the product of the ancient 
 ocean (during the tertiary formations), of which the bottom, witli its beds 
 of shells, has been subsequently "up-lieaved" to the jDositiou of dry land. 
 True marl, when found in considerable quantity, is usually, if not always, a 
 fresh-Avater formation ; being produced from the earth torn ujj and borne 
 along by rapid rivers and mountain streams, flowing over a chalky or 
 other highly calcareous countiy. By such suspension and intermingling, 
 the heavier sand is first dropped, and the still floating calcareous and 
 aluminous earths mix and then combine chemically in suitable proportions ; 
 and when the susjicnding water becomes nearly still, by reaching a lake 
 or estuary, the lightest earthy matter is deposited and forms marl. This 
 natural process continues until the receptacle is filled, and the deposit is 
 raised above the water. However much it may appear like fine clay in 
 some respects, true marl is very diiferent in others. It is not in the least 
 plastic. If laid in water after drying, it speedily crumbles to smair frag- 
 ments, showing a laminated structure, the result of the manner of its de- 
 position. Some clays, however, destitute of lime, exhibit this mechanical 
 
 10* 
 
114 REMARKS ON EXPERIMENTS. j 
 
 The following experiments are reported, either on account of 
 having been accurately made and carefully observed, or as pre- 
 senting such results as have been generally obtained on similar ; 
 soils, from applications of fossil shells to nearly six hundred acres 
 of Coggius Point fiirm (made before 1830). It had been my i 
 habit to make written memoranda of such things ; and the mate- ' 
 rial circumstances of these experiments were put in writing at the 
 time they occurred, or not long after. Some of the experiments 
 were, from their commencement, designed to be permanent, and 
 their results to be measured as long as circumstances might per- 
 mit. These were made with the utmost care. But generally, . 
 when precise amounts are not stated, the experiments were less 
 carefully made, and their results reported by guess. Every ^ 
 measurement stated, of land or of crop, was made in my presence. 
 The average strength of the difi'erent marls used was ascertained 
 by a sufficient number of analyses; and the quantity applied ] 
 was known by measuring some of the loads, and having them i 
 dropped at regular distances. At the risk of being tedious, I shall j 
 state every circumstance supposed to affect the results of the ex- i 
 periments ; and the manner of description, and of reference, , 
 necessary to use, will require a degree of attention that few readers , 
 may be disposed to give, to enable them to derive the full benefit 
 of these details. But, however disagreeable it may be to give to j 
 them the necessary attention, I will presume to say that these ex- '■ 
 periments deserve it. They will present practical proofs of what \ 
 otherwise would be but uncertain theory — and give to this essay ; 
 its principal claim to be considered truly instructive and useful. | 
 
 When these operations were commenced, I had heard of no j 
 other experiments having been made with fossil shells, except two, j 
 which had been tried long before, and were considered as proving j 
 the manure to be too worthless to be resorted to again. ; 
 
 The earliest of these old experiments was made at Spring Gar- ; 
 den, in Surry, about 1775, by Mr. Wm. Short, proprietor of that j 
 estate. The extent marled was eight or ten acres, on poor sandy , 
 land. Nothing is now known of the effects for the first twenty- 
 five or thirty years, except that they were too inconsiderable to ^ 
 induce a repetition of the experiment. The system of cultivation . 
 was doubtless as exhausting as usual at that time. Since 1812, I 
 the farm lias been under mild and improving management gene- • 
 rally. No care has been taken to observe the progress either of 
 improvement or exhaustion on the marled piece ; but there is no ^j 
 doubt that the product has continued for the last fifteen years 
 
 stiucture and cliai'actcr in as marked manner as any true marl. Such 
 clays, in former times, were not distinguished by farmers, or even agri- 
 cultural writers, from marl. — 1849.] 
 
EARLIEST TRIALS OF MARL IN VIRGINIA. 115 
 
 better than that of the adjacent land. Mr. Francis Euffiri, the 
 present owner of the farm, believed that the product was not much 
 increased in f;ivourable seasons ; but when the other land suffered 
 either from too much wet or dry weather, the crop on the marled 
 land was comparatively but slightly injured. The loose reports 
 that have been obtained respecting this experiment are at least 
 conclusive in showing the long duration of the effects produced. 
 
 The other old experiment referred to was made at Aberdeen, 
 Prince George county, in 1803, by Mr. Thomas Cocke. Three 
 small spots (neither exceeding thirty yards square) of poor land, 
 kept before "and since generally under exhausting culture, were 
 covered with this manure. He found a very inconsiderable early 
 improvement, which he thought altogether an inadequate reward 
 for the labour of applying the marl. The experiment, being 
 deemed of no value, was but little noticed until after the com- 
 mencement of my use of the same manure. On examination, the 
 improvement appeared to have increased greatly on two of the 
 pieces, but the third was evidently the worse for the application. 
 Ji'or a number of years after making this experiment, Mr. Cocke 
 Lad considered it as giving full proof of the worthlessness of the 
 manure. But more correct views of its mode of operation, caused 
 by my experiments and reasoning, induced him to recommence its 
 use; and no one has met with more success, or produced more 
 valuable early improvement. 
 
 Inexperience, and the total want of any practical guide, caused 
 my applications, for the first few years, to be frequently injudicious, 
 particularly as to the quantities laid on. For this reason, these 
 experiments will show what was actually done, and the effects 
 thence derived, and not what better information would have directed 
 as the most profitable course. 
 
 The measurements of corn that will be reported were all made 
 at the time and place of gathering. The measure used for all ex- 
 cept very small quantities was a barrel, holding five bushels when 
 filled level, and which being filled twice with ears of corn, well 
 shaken to settle them, and heaped, was estimated to make five 
 bushels of grain ; and the products will be reported in grain, ac- 
 cording to this estimate. This mode of measurement will best 
 serve for comparing results; but in most cases it is far from giving 
 correctly the actual quantity of dry and sound grain, for the fol- 
 lowing reasons. The common large soft-grained white corn was 
 the kind cultivated, which was always cut down for sowing wheat 
 before the best matured was dry enough to grind, or even to be 
 stored in the ear for keeping ; and when the cars from the poorest 
 land were in a state to lose considerably more by shrinking. Yet, 
 for fear of some mistake, or mixture of the difterent quantities, 
 occurring if measurements were delayed until the crop was gathered 
 
116 EXPERIMENTS IN MARLING. _ 
 
 these experiments were measured when the hxnd was ploughed for 
 v/hcat in October. The subsequent loss from shrinking would of 
 course be greatest on the corn from the poorest and most backward 
 land, as tlie most defective and unripe ears would always be there 
 found. Besides, every ear, however imperfect or rotten, was in- 
 cluded in the measurement. For these several reasons, the actual 
 increase of product on the marled land was always greater than 
 will appear from the comparison of quantities measured ; and from 
 the statements of all such early measurements, there ought to be 
 allowed a deduction, varying from 10 or 15 per cent, on the best 
 and most forward corn, to 30 or 35 per cent, on the latest and 
 most defective. Having stated the grounds of this estimate, 
 practical men can draw such conclusions as their experience may 
 direct, from the dates and amounts of the actual measurements 
 that will be reported. Some careful trials of the amount of shrink- 
 age in particular experiments will be hereafter stated. 
 
 No grazing had been permitted on any land from which experi- 
 ments will be reported, since 1814 (or since being cleared, if in 
 forest at that time), unless the contrary shall be specially stated. 
 The cropping had also been mild, during that time, though previ- 
 ously it was the usual exhausting three-shift and grazing course. 
 
 CHAPTER XL 
 
 EXPERIMENTS WITH ANB EFFECTS OF CALCxVREOUS MANURES ON 
 ACID SANDY SOILS, NEWLY CLEARED. 
 
 Proposition 5 — continued. 
 
 As most of the experiments on new land were made on a single 
 piece of twenty-six acres, a general description or plan of the 
 whole will enable me to be better understood, as well as to be more 
 concise, by references being made to the annexed figure. It forms 
 part of the ridge or high table land lying between James River 
 and the nearest stream running into Powell's creek. The surface 
 is nearly level, but slightly undulating. The soil in its natural 
 state very similar throughout, but the part next to the line B C 
 somewhat more sandy, and more productive in corn, than the part 
 next to A D ; and, in like manner, it is lighter along A c, than 
 nearer to D/". The whole soil, a gray sandy acid loam, not more 
 than two inches deep at first, resting on a yellowish sandy subsoil, 
 from one to two feet deep, when it changes to clay. Natural 
 
- ON NEWLY CLEARED AND ACID LANDS. 
 
 117 
 
 A. V o 
 
 growth mostly pine — next in quantity, oaks of different kinds — a 
 little of dogwood and cliinquepin — whortleberry bushes throughout 
 in plenty. The quality of the soil better than the average of ridge 
 Jauds in general, but yet quite poor. Judging from experience 
 of adjoining grounds and similar soil, this land would have pro- 
 duced as its early and best crop, ajad under the best treatment, 
 about 12 bushels of corn to the acre, well ripened and fully shrunk. 
 And if thereafter kept under ordinary culture and management, 
 the products would have gradually and speedily sunk to 5 bushels 
 to the acre. Being still less suitable to wheat, that crop would 
 have been scarcely worth being sown on the land in its best natural 
 state (when the product might be 6 bushels), and certainly not at 
 all after a few years of the usual downward progress. The effects 
 of putrescent manures were very transient, as on all such poor lands. 
 
 Experiment 1. 
 
 The part B C (/ 7t, about 11 acres, grubbed and the trees cut 
 down in the winter of 1814-15 — suffered to lie three years with 
 most of the wood and brush on it. February, 1818, my earliest 
 application of marl was made on the smaller part B C m I, about 
 2^ acres. Marl, containing 33 per cent.' of pure calcareous earth, 
 and the balance silicious sand, except a very small proportion of 
 clay J the shelly matter finely divided. Quantity of marl to the 
 acre, one hundred and twenty-five to two hundred heaped bushels. 
 The whole space B C </ 7t couitered, and planted in its first crop of 
 corn in 1818. This was my earliest experiment of calcareous 
 manures. 
 
 Results. 1818. The corn on the marled land evidently much 
 better — supposed difference, forty per cent. 
 
 1819. In wheat. The difference as great, perhaps more so — 
 particularly to be remarked from the commencement to the end 
 of the winter, by the marled part preserving a green colour; while 
 
118 ON NEWLY CLEARED ACID LANDS. 
 
 the reraaiuder was seldom visible from a short distance, and in tlie 
 spring stood much thinner, from the greater number of plants 
 killed during the winter. The line of separation very perceptible 
 throughout both crops. 
 
 1820. At rest. During the summer marled B C g h, at the rate 
 of five hundred bushels, without excepting the space before covered, 
 and a small part of that made as heavy as one thousand bushels, 
 counting both dressings. The shells now generally coarse — average 
 strength of the marl, 37 per cent, of calcareous earth. In the 
 winter after, ploughed three inches deep only, as nearly as could 
 be ; which however, shallow as it was, made the whole new surface 
 yellow, by bringing the barren sub-soil of yellow sand to the top. 
 One of ray neighbours, an intelligent and experienced farmer, who 
 saw the land when in this state, pronounced that I ''had ruined 
 the land for ever, by ploughing and turning the soil too deep." 
 
 Hesuhs continued, 1821. In corn. The whole a remarkable 
 growth for such a soil. The oldest (and heaviest) marled piece 
 better than the other, but not enough so to show the dividing line. 
 The average product of the whole supposed to have been fully 
 twenty-five bushels of ripe and»good corn to the acre. 
 
 1822. In wheat — and red clover sowed on all the old marling, 
 and one or two acres adjoining. A severe drought in June killed 
 the greater part of the clover, but left it much the thickest on the 
 oldest marled piece, so as again to show the dividing line, and to 
 yield, in 1823, two middling crops to the scythe — the first that I 
 had known obtained from any acid soil, without high improvement 
 from putrescent manures. 
 
 1823. At rest — nothing taken ofi", except the clover on B C m I. 
 
 1824. In corn — product seemed as before, and its rate may be 
 inferred from the actual measurements on other parts, which will 
 be stated in the next experiment, the whole twenty-six acres being 
 now cleared, and brought under like cultivation. 
 
 Exj^eriment 2. 
 
 The part efn o, cleai'ed and cultivated in corn at the same 
 times as the preceding — but treated diiferently in some other 
 respects. This had been deprived "of nearly all its wood, and the 
 brush burnt, at the time of cutting down — and its first crop of 
 corn (1818) being very inferior, was not followed by wheat in 
 1819, because promising too little product to pay for the cost of 
 the crop. This gave two years of rest before the crop of 1821 — 
 and five years rest out of six, since the piece had been cut down. 
 As before stated, the soil rather lighter on the side next to o e, 
 than n f. 
 
 ]\Iarch, 1821. A measured acre near the middle, covered with 
 six hundred bushels of calcareous saud, containing 20 per cent. 
 
ON NEWLY CLEARED ACID LANDS. 119 
 
 of calcareous earth, the upper layer of another body of fossil 
 shells. 
 
 Eesulfs. 1821. In corn. October — the four adjoining quarter 
 acres, marked 1, 2, 3, 4, extending nearly across the i>iece, two 
 of them within, and two without the marled part, measured as 
 follows : 
 
 Not marled. No. 1, Ql) , ,, ooi t, i, i j? 
 
 Do No 4 51. r fiverage to the acre 22 J bushels of gram. 
 
 Marled, No. 2' 8 J) o^i ^ 1 i 
 
 Do. No. 3' 8M ^^®^'^S^ 5^^ bushels. 
 
 The remainder of this piece was marled before sowing wheat in 
 1821. 
 
 1823. At rest. 
 
 1824. In corn — distance 5 J by o]- feet, making 2436 stalks to 
 the acre. October 11th, measui'cd two quarter acres very nearly, 
 if not precisely, coinciding with Nos. 2 and 3 in the last measure- 
 ment. The products now were as follows : 
 
 No. 2 brought 7 bushels 3 J pecks, ") 
 
 or per acre, .... 31.1 [• average 31. 2'K 
 No. 3 brought 8 bushels, . . 32 ) 
 
 Average in 1821, 33.1 
 
 Experiment 3. 
 
 The parte/ (7 h was cut down in January, 1821, and the land 
 planted in corn the same year. The coultering and afler-tillage 
 very badly executed, on account of the number of whortleberry 
 and other roots. As much as was convenient was marled at sis 
 hundred bushels, 37 per cent, and the dressing limited by a straight 
 line. Distance of corn 5j by 3j feet — 2202 stalks to the acre. 
 
 Results. 1821. October — on each side of the dividing line, a 
 piece of twenty-eight by twenty-one corn hills measured as follows : 
 
 No. 1, 588 stalks, not marled, 2 bushels, equal to 7 bushels 3 
 pecks the acre. 
 
 No. 2, 588 stalks, marled, 4^ bushels^ equal to 16 bushels 2} 
 pecks the acre. 
 
 1822. In wheat, the remainder having been previously marled. 
 
 1823. At rest. During the following winter it was covered with 
 a second dressing of marl at 250 bushels, 45 per cent., making 
 850 bushels to the aci'e altogether. 
 
 1824. In corn. Two quarter acres, chosen as nearly as possible 
 on the same spaces that were measured in 1821, produced as follows : 
 
 No. 1 made 8 bushels, 2 pecks, or to the acre, 34 bushels. 
 The same in 1821, before marling, . . 7.3 J- 
 
 Increase, 26. Of 
 
120 ON NEW AND ACID LAND. 
 
 No. 2 made 7 bushels, 2 J pecks, or to tlio acre, 30.2 
 The same ia 1821, after marling, , . 1G.2J 
 
 Increase average, ..... 13.3 J 
 
 The second dressing of marl, or the larger quantity, had hut 
 little effect iu making the increase of crops greater than in 1821. 
 The diiference was caused mainly by the greater length of time 
 since the clearing of the land. 
 
 1825. The whole twenty-six acres, including the subjects of all 
 these experiments and observations, were in wheat. The first 
 marled piece, in Exp. 1, was decidedly the best — and a gradual 
 decline was to be seen to the latest. I have never measured the 
 product of wheat from any experiment, on account of the great 
 trouble and difficulty that would be encountered. Even if the 
 wheat from small measured spaces could be reaped and secured 
 separately, during the urgent labours of harvest, it would be 
 scarcely possible afterwards to carry the different parcels through 
 all the operations necessary to show exactly the clean grain derived 
 from each. But without any separate measurement, all my obser- 
 vations convince me that the increase of wheat, from marling, was 
 at least equal to that of corn, during the first two years, and cer- 
 tainly greater afterwards, in comparison to the product before using 
 marl. 
 
 It was from the heaviest marled part of Exp. 1, that soil was 
 analyzed to find how much calcareous earth remained in 1826 
 i(page 78.) Before that time the marl and soil had been well 
 mixed by ploughing to the depth of five inches. One of the 
 specimens of this soil then examined consisted of the following 
 parts — half an inch of the surface, and consequently the undecom- 
 posed weeds upon it, being excluded. 
 1000 grains of soil yielded 
 
 769 grains of silicious sand moderately fine, 
 15 finer sand, 
 
 784 
 
 8 calcareous earth, from the manure applied, 
 108 finely divided gray clay, vegetable matter, &c. 
 28 lost in the process. 
 
 1000 
 
 This part, it has been already stated, was originally somev>-hat 
 lighter than the general texture of the remainder of the land. 
 
 Experiment 4. 
 The four acres marked A D n o were cleared iu the winter of 
 
ON NEW AND ACID LAND. 121 
 
 1823-4. The lines ^:) q and r s divide the piece nearly into quar- 
 ters. The end nearest A j? o is lighter, and best for corn, and was 
 still better for the first croj), owing to nearly all that half having 
 been accidentally burnt over. After twice coultcring, marl and 
 putrescent manures were applied as follows; and the products 
 measured, October 11th, the same year. 
 
 s q not marled nor manured — produced on a quarter acre (No. 
 4), of soft and badly filled corn, 
 
 Bush. r. 
 
 3 bushels, or per acre 12. 
 
 q r and r 2:>, marled 800 bushels (45 per cent.) by three 
 measurements of diff"erent pieces — 
 
 Quarter acre (No. 1) 5 bushels, very nearly, or per acre 19.3 J 
 Eighth (No. 2) 2.3i ("average) . . . 22.2 
 
 Eighth (No. 8) 3.1} | 24.1 i | . . .27. 
 
 s t manured at 900 to 1100 bushels to the acre, of which, 
 Quarter acre (No. 5) with rotted corn stalks, from a 
 
 winter cow-pen, gave 5. 2 J . . . . . 22.2 
 Eighth (No. 6) with stable manure, 4. If . . 35.2 
 
 Eighth (No. 7) covered with the same heavy dress- 
 
 ings of stable manure, and of marl also, gave 4.2 . 36. 
 p w, marled at 450 bushels, brought not so good a crop 
 
 as the adjoining r p at 800. 
 The distance was 5 J by 3} feet. Two of the quarter acres were 
 measured by a surveyor's chain (as were four other of the experi- 
 ments of 1824), and found to vary so little from the distance 
 counted by corn rows, that the difference was not worth notice. 
 
 1325. In wheat, the different marked pieces seemed to yield in 
 comparison to each other, proportions not perceptibly different from 
 those of the preceding crop — but the best not equal to any of the 
 land marled before 1822, as stated in the 1st, 2d, and 3d experi- 
 ments. 
 
 1827. Wheat on a very rough and imperfect summer fallow. 
 This was too exhausting a course, (being three grain crops in the 
 four-shift rotation), but was considered necessary to check the 
 growth of bushes that had sprung from the roots still living. The 
 crop was small, as might have been expected from its bad pre- 
 paration. 
 
 1828. Corn — in rows five feet apart, and about three feet of 
 -distance along the rows', the seed being dropped by the step. 
 Owing to unfavourable weather, and to insects and other vermin, 
 not more than half of the first planting of this field lived ; and so 
 much replanting of course caused its product to be much less ma- 
 tured than usual, on the weaker land. All the part not marled 
 (and more particularly that manured) was so covered by sorrel, as 
 to require ten times as much labour in weeding as the marled parts, 
 
 11 
 
122 
 
 ON NEW AND ACID LAND. 
 
 which, as in every other such case, bore bo sorrel. October 15th^ 
 gathered and measured the corn from the several spaces, which 
 were laid off (by the chain) as nearly as could be, on the same 
 land as in 1824. The products so obtained, together with those 
 of the previous and subsequent courses of tillage, will be presented 
 below in a tabular form, for the purpose of being more readily 
 compared. 
 
 [On the wheat succeeding this crop, clover seed was sown, but 
 very thinly, and irregularly. On the parts not marled, only a few 
 yards width received seed, which the nest year showed the ex- 
 pected result of scarcely any living clover, and that very mean. 
 On the marled portions, the growth of clover was of middling 
 quality. Was not m.owed or grazed, but seed gathered by hand 
 both in 1830 and 1831.] 
 
 1832. Again in corn. It was soon evident that much injury was 
 caused to the marled half q p o n, by the too great quantity ap- 
 plied. A considerable proportion of the stalks, during their growth, 
 showed strongly the marks of disease from that cause, and some 
 were rendered entirely barren. A few stalks only had appeared 
 hurt by the quantity of marl in 1828. On the lightly marled 
 piece, w p, and also on w t, where the heaviest marling was accom- 
 panied by stable manure, there appeared no sign of injury. The 
 products of the [three] successive crops were as follows: 
 
 s 
 
 DEscraPTio:*. 
 
 PRODUOTS OF G^^AIN PER ACBE. 
 
 1st course. 
 
 2d course. 
 
 [3d course. 
 
 03 
 
 
 1824. 
 
 1828. 
 
 1832. 
 
 
 
 October 11. 
 
 October 15. 
 
 October 26. 
 
 
 
 Bush, pecks. 
 
 Bush, pecks. 
 
 Bush, pecks. 
 
 s q 
 
 Not marled or manured. 
 
 12 
 
 21 1 
 
 17 3i 
 
 qr 1 
 
 Marled at 800 bushels, 
 
 19 3J 
 
 28 \l 
 
 28 
 
 rp 2 
 rp 3 
 
 The same. 
 The same. 
 
 22 2 ) 
 
 27 / 
 
 31 0} 
 
 27 3 
 
 s t 5 
 
 Cow-pen manure only, 900 
 
 
 
 
 
 to 1100 bushels, 
 
 22 2 
 
 25 2 
 
 more than s q 
 
 s t 6 
 
 Stable manure only, 900 
 
 
 
 
 
 to 1100 bushels, 
 
 35 2 
 
 29 
 
 28 1 
 
 IV t 7 
 
 Marl and stable manure, 
 
 
 
 
 
 both as above. 
 
 3fi 
 
 38 2 
 
 37 Z\ 
 
 10 p 
 
 Marled at 450 bushels. 
 
 Less than r \ 
 P (800) / 
 
 
 
 
 
 Equal to r p 
 
 31 3 
 
 An accidental omission prevented the measurement oi s tb, in 1832.] 
 
 [This experiment has been made with much trouble, and every 
 care bestowed to insure accuracv. Still several causes have ope- 
 rated to affect the correctness of the results, and to prevent the 
 comparative products showing the true rate of improvement, 
 
ERRORS OP THE EXPEEIMENTS. 123 
 
 citliev from the marl or the putrescent ma.itiire. These oaascs will 
 be briefly stated. 
 
 1st. The quantity of marl (800 bushels) m q r and r p ip nearly 
 double the amount that ought to have bef^n used; and this error 
 has not only increased the expense uselessly but has served ';o pre- 
 vent the increase of product that would otherwi.se have takoL place. 
 This loss is proved by the gradual increase, aa-i at *ast the greater 
 product of w p, marled at only 450 bushels. 
 
 2d. The comparative superiority of all the marled ground to s 
 q, not marled, is lessened by this circumstance : most of the large 
 logs, as well as all the small branches, were burnt upon the land, 
 when it was cleared in 1824, before the experiment was com- 
 menced ; and the ashes have durably improved a spot where each 
 of these large fires was made on s q, but have done no good, and 
 perhaps have been injurious, to the marled pieces that were made 
 sufficiently calcareous without the addition of ashes. At least, the 
 good effect of ashes, on spots, is very evident in s q, and has helped 
 somewhat to increase all its measured products, and no such benefit 
 has been visible on the marled parts. 
 
 3d. The quantity of putrescent manure applied to s t (900 to 
 1100 bushels) was much too great both for fiur experiment and 
 profit; and the excess of quantity, together with the imperfectly 
 rotted state of the stable manure, has given more durability to the 
 effect, than is to be expected from a more judicious and economical 
 rate of manuring on such land when not marled. For these several 
 seasons, it is evident that far more satisfactory results than even 
 these would have been obtained, especially in the amounts of oictt 
 products, if only half as much of either marl or manure had been 
 applied. 
 
 There are other circumstances to be considered, which, if not 
 attended to, will cause the comparative increase or decrease of pro- 
 duct in this experiment to be misunderstood. It is well known 
 that poor land put under tillage immediately after being cleared, 
 as this was in 1824, will not yield near as much as on the next 
 succeeding course of crops. This increase, which depends merely 
 on the effects of time, operates independently of all other means 
 for improvement that the land may possess ; and its rate, in this 
 experiment, may be fairly estimated by the increase on the piece 
 s q from 1824 to 1828. The increase here, where time only acted, 
 was from 12 to 21^- bushels. But as the corn gathered here was 
 always much the most imperfectly ripened, and would therefore 
 lose the most by shinking, I will suppose eight bushels to be the 
 rate of increase from time, and that so much of the product of all 
 the pieces should be attributed to that cause. Then, to estimate 
 alone the increased or diminished effects of marl or manure on the 
 
124 
 
 ERRORS or THE EXPERIMENTS. 
 
 other pieces, eight bushels should be deducted from all the dif- 
 ferent applications, and the estimate will stand thus : 
 
 1824. 
 
 1828. 
 
 gr 1 
 
 rp 2 
 rp 3 
 s t 5 
 St 6 
 
 p. 
 
 y- 
 
 4 U 
 
 35 2 
 
 U 
 
 31 
 
 29 
 
 B. P. 
 
 2 
 
 1 IJ 
 5 2 
 14 2 
 
 From 800 bushels of marl. 
 800 " of marl. 
 
 1000 
 1000 
 
 cow-pen manure, 
 stable manure. 
 
 Even the piece covered with both marl and stable manure (to t) 
 shows according to this estimate a diminished effect equal to lOj 
 bushels ; which was owing to the marl not being able to combine 
 with, and fix, so great a quantity of manure, in addition to the 
 vegetable matter left by its natural growth of wood. The piece 
 w p, marled at 450 bushels alone, has shown a steady increase of 
 product at each return of tillage, and thereby has given evidence 
 of its being the only improvement made in such manner as both 
 judgment and economy would have directed. 
 
 [After the crop and measurement of 1832, it was inferred that 
 the separate products of such small spaces could no longer be relied 
 on, owing to the mixture of the surfaces of adjacent parts, necessa- 
 rily caused by tillage. Therefore the previously omitted parts were 
 marled before the next course of crops came round. — 1842.] 
 
 CHAPTER XII. " 
 
 EFFECTS OF CALCAREOUS MANURE ON ACID CLAY (OR STIFF) SOILS, 
 RECENTLY CLEARED. 
 
 Proposition 5 — continued. 
 
 The two next experiments were made on another field of thirty 
 acres of very uniform quality, marled and cleared in 1826 and the 
 succeeding years. The soil is very stiff, close, and intractable un- 
 der cultivation — seems to contain scarcely any sand — but, in fiict, 
 about one half of it is composed of silicious sand, which is so fine, 
 when separated, as to feel like the finest flour. Only a small pro- 
 portion of the sand is coarser than this state of impalpable powder. 
 Clayey earth of a dirty pale yellow colour forms nearly all of 
 its remaining ingredients. Before being cleared of the forest 
 growth, and ploughed, the soil is not an inch deep; and all below, 
 
EXPERIMENTS ON NEW AND ACID CLAY LANDS. 125 
 
 * 
 
 for many feet, is apparenily composed of the like parts of clay 
 and fine sand. This is decidedly the most worthless kind of soil, 
 in its natural state, that our district furnishes. It is better for 
 wheat than for corn, though its product is contemptible in every- 
 tliing. It is difficult to be made wet, or dry — and therefore suffei's 
 more than other soils from both dry and wet seasons, but espe- 
 cially from the former. It is almost always either too wet or too 
 dry for ploughing ; and sometimes it will pass through both states 
 in two or three clear and warm days. If broken up early in win- 
 ter, the soil, instead of being pulverized by frost, like most clay 
 lands, runs together again by freezing and thawing ; and by March, 
 will l>ave a sleek (though not a very even) crust upon the surface, 
 quite too hard to plant on without a second ploughing. The 
 natural growth is principally white and red oaks, a smaller proportion 
 of pinc^ and an under-growth of whortleberry bushes throughout. 
 
 Experiment 5. 
 
 On one side of this field a marked spot of thirty-five yards 
 square was left out, when the adjoining land was marled at the 
 rate of five hundred to six hundred bushels {37 per cent.) to the 
 acre. Paths for the carts were opened through the trees, and the 
 marl dropped and spread in January, 182G, and the land cleared the 
 following winter. Most of the wood was carried off for fuel ; the 
 remaining logs and brush burnt on the ground, as usual, at such 
 irregular distances as were convenient to the labourers. This part 
 was perhaps the poorer, because wood had previously been cut here 
 for fuel ; though only a few trees had been taken, here and there, 
 each winter, for a long time past. 
 
 Results, 1827. Planted in corn the whole recent clearing of 
 fifteen acres — all marled, except the spot left out for experiment : 
 broken up late and badly, and worse tilled, as the land was gene- 
 rally too hard, until the season was too far advanced to save the 
 crop. The whole crop so small, that it was useless to attempt 
 to measure the products. The diff"erence would have been only 
 between a few imperfect ears on the marled ground, and still less 
 ' — indeed almost nothing — on that not marled. 
 
 1828. Again in corn — as well broken and cultivated as usual 
 for such land. October 8th — cut down four rows of corn running 
 through the land not marled, and eight others, alongside on the 
 marled — all fifty feet in length. The rows had been laid off for 
 five and a half feet — but were found to vary a few inches — for 
 which the proper allowance was made, by calculation. The spaces 
 taken for measurement were caused to be thus small by a part of 
 the corn having been inadvertently cut down and shocked, just 
 before. The ears were shelled when gathered ; and the products, 
 • 11* 
 
12G 
 
 ON NEW AND AMD CLAY LANDS. 
 
 measured in a vessel which held (by^ trial) l-80th of a bushel, 
 were as follows : 
 
 On land not marled, 
 
 4 rows, average 5 feet, and 50 in length (500 square feet) 13^ 
 measures, or to the acre 7i bushels. 
 
 On adjoining marled land, 
 
 4 rows, average 5 feet 1 J inches by 50 feet= 512 square feet, 
 25| measures, or to the acre 13 ^ bushels. 
 
 4 nest rows, 5 feet 4 J inches by 50 = 537 square feet, 271 mea- 
 sures, or to the acre 14 bushels. 
 
 1829. In wheat. 
 
 1830. At rest — the weeds, a scanty cover. 
 
 1831. In corn. October 20th — measured by the chain equal 
 spaces, and gathered and measured their products. The corn not 
 marled was so imperfectly filled, that it was necessary to shell it, 
 for fairly measuring the quantity. The marled parcels, being of 
 good ears generally, were measured as usual, by allowing two 
 heaped measures of ears, for one of grain. 
 
 On land not marled, 
 303 square yards made ..... 3 gallons, 
 
 or to the acre, ...... 5 bushels. 
 
 On marled land, close adjoining on one side, 
 363 square yards made rather more than 6 gallons — to the acre, 
 10 bushels. 363 square yards on another side, made not quite 8 
 gallons, or to the acre, 12 bushels. 
 
 The piece not marled coincided with that measured in 1828, as 
 nearly as their difference of size and shape permitted — as did the 
 last named marled piece, with the two of 1828. The last crop 
 was greatly injured by the wettest summer that I have ever known, 
 which has caused the decrease of product exhibited in this experi- 
 ment — which will be best seen in this form : 
 
 Product of grain to the acre. 
 1828— October 18. 1831— October 20. 
 
 Not marled. 
 Marled (average). 
 
 7 bushels 1 peck. 
 18 « 3 " 
 
 5 bushels. 
 11 " 
 
 Experiment 6. 
 
 e 
 
 D 
 
 
 |c 
 
 A 
 
 E 
 
 r^ 
 
 
 
 
 B 
 
 
 / 
 
 
 
MARLING ON ACID CLAY SOIL. 127 
 
 The remainder of the thirty acres was grubbed during the win- 
 ter of 1826-27 ; marled the next summer at five hundred to six 
 hundred bushels the acre — marl 40 per cent. A rectangle (A) 
 11 by 13 poles, was laid off by the chain and compass, and left 
 without marl. All the surrounding laud supposed to be equal in 
 quality with A — and all level, except on the sides E and B, which 
 were partly sloping, but not otherwise different. The soil suited to 
 the general description given before ; no material difference known 
 or suspected between the lajid on which 5th experiment was made 
 and this, except that the latter had not been robbed of any wood 
 for fuel, before clearing. The large trees (or all more than ten 
 inches through) were belted, and the smaller cut down in the be- 
 ginning of 1828, and all the land west of the line c J\ was planted 
 in corn. As usual, the tillage bad, and the crop very small. The 
 remainder lying east of e f, was coultered once ; but, as more labour 
 could not be spared, nothing more was done with it until the latter 
 part of the winter, 1820, when it was broken by two-horse ploughs, 
 oats sown and covered by trowel ploughs ; then clover sown, and a 
 wooden-tooth harrow passed over to cover the seed, and to smooth 
 down, in some measure, the masses of roots and clods. 
 
 Results, 1829. The oats produced badly ; but yielded more for 
 the labour required than corn would have done. The young clover 
 on the marled land was remarkably good, and covered the surface 
 completely. In the unmarled part, A, only two casts through had 
 been sown, for comparison, as I knew it would be a waste of seed. 
 This looked as badly as had been expected. 
 
 1830. The crop of clover would have been considered excellent 
 even on good land, and was most remarkable for so poor a soil as 
 this. The strips sown through A, had but little left alive, and 
 that scarcely of a size to be observed, except one or two small 
 tufts, where I supposed some marl had been deposited by the 
 cleaning of a plough, or that ashes had been left, from burning 
 the brush. The growth of clover was left undisturbed until after 
 midsummer, when it was grazed by my small stock of cattle, but 
 not closel3^ 
 
 1831. Corn on the whole field. October 20th, measured care- 
 fully half an acre (10 by 8 poles) in A, the same in D, and half 
 as much (10 by 4) in E. No more space could be taken on this 
 side, for fear of getting within the injuriovis influence of the con- 
 tiguous woods. No measurement was made on the side B, because 
 a large oak, which the belting had not killed, affected its product 
 considerably. Another accidental circumstance prevented my 
 being able to know the product of the side C, which however was 
 evidently and greatly inferior to all the marled land on which oats 
 and clover had been raised. This side had been in corn, followed 
 by wheat, and next (1830) under its spontaneous growth of weeds. 
 
128 EFFECTS ON ACID CLAY SOIL. 
 
 The corn on eacli of the measured spaces was cnt down, and put 
 in separate shocks — and on Nov. 25th, when well dried, the parcels 
 were shucked and measured, before being moved. We had then 
 been gathering and storing the crop for more than fifteen days; 
 and therefore these measurements may be considered as showing 
 the amount of dry and firm gTain, without any unusual deduction 
 being required for shrinkage. 
 
 Bush. Pks. 
 A (half acre) made 7i bush, of ears, or of grain to the acre, 7 1 
 
 D (half acre) 16| 16 3 
 
 E (quarter acre) 11 22 
 
 The sloping surface of the side E, prevented water from lying 
 on it, and therefore it suffered less, perhaps not at all, from the 
 extreme wetness of the summer, which evidently injured the growth 
 on A and D, as well as of all the other level parts of the field. 
 
 [1832. The field in wheat. 
 
 1833. In clover, which was grazed, though not closely, after it 
 had reached its full growth. 
 
 ' 1834. Corn, a year earlier than would have been permitted by 
 the four-shift rotation. The tillage was insufficient, and made still 
 worse by the commencement of severe drought before the last 
 ploughing was completed, which was thereby rendered very labori- 
 ous, and imperfect withal. The drought continued through all 
 August, and greatly injured the whole crop of corn. 
 
 Jicstdts continued. October 22d. Marked ofi" by a chain half 
 an acre within the space A (8 by 10 poles) as much in D, and a 
 quarter acre (10 by 4 poles) in each of the other three sides C, B, 
 and E, having each of the last four spaces as near as could be to 
 the outlines of the space A. The products carefully measured (in 
 the ears) yielded as follows : 
 
 A, not marled, yielded 6 bush. Of peck of grain, to the acre. 
 
 D, marled, " 19 " 3 J " " 
 
 E, do. " 20 " 1 " « 
 C, do. " 20 " 2 " « 
 
 B, do. " 20 " 1* " • " 
 
 In comparing these products with those of the same land in 
 1831, stated above, it should be remembered that the corn formerly 
 measured was dry, while that of the last measurement had yet to 
 lose greatly by shnnking. As, after early gathering, the corn from 
 the poorest land of course will lose most by drying, and as the 
 ears on A were generally very defective and badly filled, if the 
 measurement had been made in the sound and well dried grain of 
 each parcel, the product of A could not have exceeded one-fourth 
 of that of the surrounding marled land, and probably was less. 
 
 But though these differences of product present the improvement 
 caused by marling in a striking point of view, this close and stub- 
 
EFFECTS. ON ACID CLAY SOIL. 129 
 
 born soil at best is very unfit fof the corn crop ; and its highest 
 value is found under clover, and in wheat on clover, of which some 
 proofs will be found in the next experiment. The first crop of 
 clover, however, after marling, has not since been equalled. — 1835.] 
 [My subsequent distant residence prevented my observing this 
 field when under any matured crop, until in 1842, when in wheat. 
 The then growth on the unmarled space was certainly not more than 
 one-fourth as much as that of the surrounding ground. — 1842.] 
 
 Experiment 7. 
 
 Another piece of land of twenty-five acres, of soil and qualities 
 similar to the last described (Exp. 5 and 6), was cleared in 1818, 
 and about 6 acres marled in 1819, at about three hundred and fifty 
 bushels. The course of cultivation was as follows : 
 
 1820. Corn — benefit from marl very unequal — supposed to vary 
 between twenty-five and eighty per cent. 
 
 1821. Wheat — the benefit derived great'Cr. 
 
 1822. At rest. 
 
 1823. Ploughed early for corn, but not planted. The whole 
 marled at the rate of six hundred bushels (40 per cent.), again 
 ploughed in August, and sown in wheat in October. The old 
 marled space more lightly covered, so as to make the whole nearly 
 equal, 
 
 1824. The wheat much improved. 
 1825 and 1826, at rest. 
 
 1827. Corn. 
 
 1828. . In wheat, and sown in clover. 
 
 1829. The crop of clover was heavier than any I had ever seen 
 in this part of the country, except in some very rare cases of rich 
 natural soil, where gypsum was used and acted well. The growth 
 was thick, but unequal in height (owing probably to unequal 
 spreading of the marl), standing from fifteen to twenty-four inches 
 high. The first growth was mowed for hay, and the second left to 
 manure the land. 
 
 1830. The clover not mowed. Fallowed in August, and sowed 
 wheat in October, after a second ploughing. 
 
 1881. The wheat was excellent, almost heavy enough to be in 
 danger of lodging. I supposed the product to be certainly twenty 
 bushels, perhaps twenty-five, to the acre. 
 
 As it had not been designed to make any experiment on this 
 land, the progress of improvement was not observed with mxich 
 eare. But whatever were the intermediate steps, it is certain that 
 the land, at first, was as poor as that forming the subjects of the two 
 preceding experiments in the unimproved state (the measured pro- 
 ducts of which have been given), and that its last crop was at least 
 'four times as great as could have been obtained, if marl had not 
 
130 EFFECTS ON IMPOVERISHED ACID SOILS. 
 
 been applied. The peculiar fitness of this kind of soil for clover 
 after marling, and the supposed cause of the remarkable heavy first 
 crop of clover, will require further remarks, and will be again 
 referred to hereafter. 
 
 CHAPTER XIII. 
 
 THE EFFECTS OF CALCAREOUS IMANURES ON ACID SOILS REDUCED 
 BY CULTIVATION. 
 
 Proposition 5 — continued. 
 
 My use of marl has been more extensive on impoverished acid 
 soils than on all other kinds, and has never failed there to produce 
 striking improvement. Yet it has unfortunately happened that the 
 two experiments made on such land with most care, and on which 
 I relied mainly for evidence of the durable and increasing benefit 
 from this manure, have had their beneficial eifects almost destroyed 
 by the applications having been made too heavy. These experi- 
 ments, like the 4th and 6th, already reported, were designed to re- 
 main without any subsequent alteration, so that the measurement 
 of their products, once in every succeeding course of crops, might 
 exhibit the progress of improvement under all the different circum- 
 stances. As no danger was then feared from such a course, marl 
 was applied heavily, that no future addition might be required ; 
 and for this reason, I have to report my greatest disappointments 
 exactly in those cases where the most evident success and increas- 
 ing benefits had been expected. However, these failures will be 
 stated fairly, and as fully as the most successful results ] and they 
 may at least serve to v.'arn from the danger of error, though not to 
 show, as was designed, the greatest profits of judicious marling. 
 
 [It should be observed that the general rotation of crops pur- 
 sued on the farm, on all land not recently cleared, was that of four 
 shifts (corn, wheat, and then the land two years at rest and not 
 gi-azed), though some exceptions to this course may be remarked 
 in some of the experiments to be stated.] 
 
 Experiment 8. 
 
 Of a poor sandy acid loam, seven acres were marled at the rate 
 of only ninety bushels (37 per cent.) to the acre ; laid on and 
 spread early in 1819. 
 
 Resitltii, 1819. In corn — the benefit too small to be generally 
 perceptible, but could be plainly distinguished along part of the 
 outline, by comparing with the part not marled. 
 
EFFECTS ON IMPOVERISHED ACID SOILS. 131 
 
 1820. Wheat — the effect something better ; and continued to be 
 visible on the weeds following, until the whole was more heavily 
 marled in 1823. 
 
 Experiment 9. 
 
 In the same field, on soil as poor and more sandy than the last 
 described, four acres were marled at one hundred and eighty 
 bushels (37 per cent.), March 1818. A part of the same was also 
 covered heavily with rotted barn-yard manure, which also extended 
 through similar land not marled. This furnished for observation, 
 land marled only — manured only — marled and manured — and some 
 without either. The whole space, and more adjoining, had been 
 heavily manured five or six years before by summer cowpens, and 
 stable litter — of which no appearance remained after two years. 
 
 Remits, 1819. In corn. The improvement from marl very evi- 
 dent; but not to be distinguished on the part covered also by ma- 
 nure, the effect of the latter so far exceeding that of the marl as 
 to conceal it. 
 
 1820. In wheat. In 1821 and 1822, at rest. 
 
 1823. In corn — 5| by 3^ feet. The following measurements 
 were made on adjoining spaces on October 10th. The shape of the 
 ground did not admit of larger pieces, equal in all respects, being 
 measured, as no comparison of products had been contemplated at 
 first, otherwise than by the eye. 
 
 Bush. Quarts. 
 From the part not marled, 414 corn-hills made 75 quarts — 
 
 or per acre, 13 26 
 
 Marled only, 414 . . . . 100 . 18 12 
 Manured only, 490 . . . . 105 . 15 5 
 Marled and manured, 490 . . . 130 . 20 20 
 
 The growth on the part both marled and manured was evidently 
 inferior to that of 1819. This was to be expected, as the small 
 quantity of calcareous earth was not enough to fix half so much 
 putrescent manure ; and, of course, the excess was as liable to 
 waste as if no marl had been used. 
 
 Experiment 10. 
 
 Twenty acres of sandy loam, on a sandy sub-soil, covered in 1819 
 with marl of about 30 per cent, average proportion of calcareous 
 earth, and the remainder silicious sand — at 800 bushels to the acre. 
 This land had been long cleared, and much exhausted by cultiva- 
 tion ; since 1814 not grazed, and had been in corn only once in 
 four years ; and, as it was not worth sowing in wheat, had three 
 years in each rotation to rest and improve by receiving all its scanty 
 growth of weeds. The same course has been continued from 1819 
 to 1832, except that wheat has regularly followed t^e crops of 
 
132 
 
 EFFECTS ON ACID AND SANDY BOILS. 
 
 corn, leaving two years of rest in four. This soil was lighter than 
 the subject of any preceding experiment, except the 9th. On a 
 high level part, surrounded by land apparently equal, a square of 
 about an acre (A) was staked off, and left without marl — which 
 that year's work brought to two sides of the square (C, D, and E). 
 
 c 
 
 
 1 
 
 ...A 
 
 2 
 
 d' 
 
 B 
 
 E 
 
 Results, 1820. In corn. October 13th, three half acres of marled 
 laud were measured, and as many on that not marled, and close ad- 
 joining, and produced as follows : 
 
 Not marled. 
 Bush. 
 Half acre in A, 7 
 The same in A, 7 
 Half acre in B, 7 
 
 Marled. 
 Pecks. Bush. Pecks. 
 
 1 adjoining in C, 12 3 
 1 " D, 13 31 
 
 21 " E, 15 0^ 
 
 The average increase being 12 J bushels of grain to the acre, 
 nearly 100 per cent, as measured, and more than 100 if the defect- 
 ive filling, and less matured state of the corn not marled, be con- 
 sidered. The whole would have lost more by shrinkage than is 
 usual from equal products. 
 
 1821. The whole in wheat ; much hurt by the wetness of the 
 season. The marled part more than twice as good as that left out. 
 1822 and 1823. At rest. A good cover of carrot weeds and 
 other kinds had succeeded the former growth of poverty grass and 
 sorrel, and every appearance promised additional increase to the 
 next cultivated crop. November, 1823, when the next ploughing 
 was commenced, the soil was found to be evidently deeper, of a 
 darker colour, and firmer, yet more friable. The two-horse ploughs 
 with difficulty (increased by the cover of weeds) could cut the re- 
 quired depth of five inches, and the slice crumbled as it fell from 
 the mould-board. But as the furrows passed into the part not 
 marled, an immediate change was seen, and even felt by the 
 ploughman, as the cutting was so much more easy, that care was 
 necessary to prevent the plough running too deep ; and the slices 
 turned over in flakes, smooth and sleek from the mould-board, like 
 land too wet for ploughing, which however was not the case. The 
 marling of the field was completed at the same rate (800 bushels), 
 
DISEASE OF CllOrS FROM OVEII-MAHLING. 
 
 133 
 
 which closed a third side (B) of the marked square. The fourth 
 side was my neighbour's field. 
 
 1824. lu corn. The newly marled (on B) showed as early and 
 as great benefit as was found in 1820 on C and D; but yet was 
 very inferior to the old^ until the latter was 10 or 12 inches high, 
 when it began to give the first known evidence of the very injviri- 
 ous efi"ccts of using this manure too heavily. The disease thus 
 produced became worse and worse, until many of the plants had 
 been killed, and still more were so stunted as to leave no hope of 
 their being otherwise than barren. The effects will be known from 
 the measurements which were made as nearly as could be on the 
 same ground as the corresponding marks in 1820, and will be ex- 
 hibited in the table, together with the products of the succeeding 
 rotations. Besides the general injury suffered here in 1824, there 
 were one hundred and three corn-hills in one of the measured 
 quarter acres (in C), or more than one-sixth, entirely barren, and 
 eighty-nine corn-hills in another quarter acre (D). In counting 
 these, none of the missing hills were included, as these plants 
 might have perished from other causes. [This unlocked for disaster 
 diminished the previous increase gained by marling, by nearly one- 
 half; and the damage has since been still greater, at each succes- 
 sive return of cultivation until some years after 1832. 
 
 Just before planting the crops of 1832, straw and chafi" very 
 imperfectly rotted by exposure, and which contained no admixture 
 of animal manure, were applied at the rate of 800 bushels the 
 acre to half the square without marl (A, 1), and to the adjacent 
 parts of the marled land. The vegetable manure showed but slight 
 benefit, until after all the worst effects of excessive marling had 
 been produced; and the later operation of the manure served 
 barely to prevent a still farther diminution being exhibited by the 
 land injured by marl. 
 
 > 
 
 f3 
 
 DESCRIPTION. 
 
 PRODUCT IN SHELLED CORN PER ACRE. 
 
 1st course 
 
 2d course 
 
 Sd course 
 
 4th course 
 
 P^ 
 
 
 1S20. 
 
 182-4. 
 
 1828. 
 
 1832. 
 
 
 
 October 13. 
 
 October 16. 
 
 October 13. 
 
 October 19. 
 
 
 
 Cush. pk. 
 
 Bush. pk. 
 
 Busb. pk. 
 
 Bush. pk. 
 
 A 
 
 N^ot marled, 
 
 14 2 
 
 16 1 
 
 11 3J 
 
 9 3 
 
 Al 
 
 After manuring, 
 
 
 
 
 16 3 
 not mea- 
 
 1". 
 
 Xot marled until 1823, 
 
 15 1 
 
 28 
 
 19 2 
 
 sured. 
 
 K 1 
 
 Marled in 1819 — manured 
 with cliaff, &c., in 1832, 
 
 (-25 
 
 \ 27 3J 
 
 (30 1" 
 
 19 2 
 20 
 not mea- 
 
 15 
 19 
 not mea- 
 
 18 . 
 
 19 i 
 not mea- 
 
 
 
 
 sured. 
 
 sured. 
 
 sured. 
 
 12 
 
134 EFFECTS CONTINUED. 
 
 The crops of wheat were throughout less injured by the excess 
 of marl than the corn. 
 
 For the crop of 1828, ploughed with three mules to each plough, 
 from six to seven inches deep — seldom turning up any sub-soil 
 (which was formerly within three inches of* the surface), and the 
 soil appearing still darker and richer than Avhen preparing for the 
 crops of 1824:. The ploughing of the square not marled (A) no- 
 where exceeded six inches; yet that depth must have injured the 
 land, as I can impute to no other cause the remarkable diminution 
 of product, through four courses of the mild four-shift rotation. 
 It was evident that a still greater depth of furrow was not hurtful 
 to the marled land. A strip across the field, in another place, was 
 in 1828 ploughed eight inches deep for experiment, by the side of 
 another of four inches, and the corn on the deepest ploughing was 
 the best. Another strip was trench-ploughed twelve inches deep, 
 without showing any perceptible diiference, either of product or in 
 the effects of damage from the excess of marl. 
 
 This square left without marl was the land previously referred to 
 (page 41) as showing a diminished product through three succes- 
 sive courses of the rotation recommended by the author of ' Arator' 
 as enriching. Since, another crop has been made and measured, 
 and found to be still smaller than any previous. To whatever 
 cause this continued falling of, for 16 years, may be attributed, it 
 is at least a remarkable contradiction to the doctrine of vegetable 
 matter serving alone to make poor land rich. 
 
 Much trouble has been encountered in attending to this experi- 
 ment, and much loss of product submitted to, since its commence- 
 ment, for the purpose of knowing the progress and extent of the 
 evil caused by the excess of marl. Eut another portion of the 
 field, marled as heavily in 1824, and whore equal damage was ex- 
 pected to ensue, has been entirely relieved by intermitting the corn 
 crop of 1828, sowing clover, which (by manuring with gypseous 
 earth, or green-sand earth, at 20 bushels to the acre) produced 
 well, and which was left to fall and rot on the land. The next 
 growth of corn on this part of the field (1832) was free from dis- 
 ease, and though irregular, seemed to the eye to amount to full 
 twenty-five bushels to the acre. — 1835.] 
 
 [After 1836, the rotation and management of this field ceased 
 to be regular or uniform, as previously ; and also, by cross plough- 
 in"', &c., during so many years, marl had necessarily become 
 slightly diffused over the space designed to remain without marl. 
 Therefore no more measurements were made, as they could no 
 longer be relied on for accurate comparison. The unmarled part, 
 even with its slight accidental gain of marl from the surrounding 
 ground, and half the piece having also been dressed with putres- 
 cent manure in 1832 (as stated above), is but very little improved 
 
EFFECTS ON ACID SIANDY SOILS. 135 
 
 since 1820. This and other spots, at first omitted for comparison, 
 when no longer fit for that purpose, were subsequently marled. — 
 1849.] 
 
 Experiment 11. 
 The ground on which this experiment was made was in the 
 midst of nineteen or twenty acres of soil apparently similar in all 
 respects — level, gray sandy loam, cleared about thirty years before, 
 and reduced as low by cultivation as such soil could well be. The 
 land that was marled and measured was about two hundred yards 
 distant from experiment 2, and both places are supposed to have 
 been originally similar in all respects. This land had not been culti- 
 vated since 1815, when it was in corn — but had been once ploughed 
 since, November 1817, which had prevented broom-grass from 
 taking possession. The ploughing then was four inches deep, and 
 in five and a half feet beds, as recommended in 'Arator.' The 
 growth in the year 1820 presented little except poverty grass 
 (Aristida gracilis), running blackberry briers, and sorrel — and the 
 land seemed very little if at all improved by its five successive 
 years of rest. A small part of this land was covered with calca- 
 reous sand (20 per cent.), quantity not observed particularly, but 
 probably about 600 bushels. 
 
 C 
 
 Results. 1821. Ploughed level, and planted in corn — distance 
 5 J by 3i feet. The measurement of spaces nearly adjoining, 
 made in October, was as follows : 
 23 by 25 corn-hills, not marled (in A) made 2 J bushels,") 
 
 or per acre, .... . Og ^ „„„,.!„ 
 
 23 by 25 corn-hills, marled (on the side B) 5f . 22 i ) "^''^^J^' 
 '1822. At rest. Marled the whole, - except a marked square of 
 fifty yards, containing the space measured the preceding year. 
 Marl 45 per cent, and finely divided — 350 bushels to the acre — • 
 from the same bed as that used for experiment 4. In August, 
 ploughed the land, and sowed wheat early in October. 
 
 1823. Much injury sustained by the wheat from Hessian fly, 
 and the growth was not only mean, but very irregular ; but it was 
 supposed that the first marled place (on the side B) was from 50 
 to 100 per cent, better than the last marled, and the last superior 
 to the included square not marled (A), in as great a proportion. 
 
 1824. Airain in corn, The effects of disease from marling were 
 
136 EFFECTS ON ACID SANUY SOILS. 
 
 as injurious here, both on the new and old part, as those described 
 in experiment 10. No measurement of products made, owing to 
 my being from home when the corn was cut down for sowing wheat. 
 
 1825. The injury from disease less on the wheat than on the 
 corn of the last year on the latest marling, and none perceptible 
 on the oldest application. This scourging rotation of three grain 
 crops in four years was particularly improper on marled land, and 
 the more so on account of its poverty. 
 
 1826. White clover had been sown thickly over forty-five acres, 
 including this part, on the wheat, in January, 1825. In the spring 
 of 1826, it formed a beautiful green though low cover on even the 
 poorest of the marled land. Marked spots, which were so diseased 
 by over-marling as not to produce a grain of corn or wheat, pro- 
 duced clover at least as good as other places not injured by that 
 cause. The square, which had been sown in the same manner, and 
 on which the plants came up well, had no clover remaining by 
 April, 1826, except on a few small spots, all of which together 
 would not have made three feet square. The piece not marled, 
 white with poverty grass, might be seen, and its outlines traced, at 
 some distance, by its strong contrast with the surrounding dark 
 weeds in winter, or the verdant turf of white clover the spring 
 before. 
 
 1827. Still at rest. No grazing allowed on the white clover. 
 
 1828. In corn — the land broken in January, five inches deep. 
 October 14th, made the following measurements : 
 
 In the square not marled (A), 105 by 104 j feet (thirty-six square 
 yards more than a quarter of an acre), made one barrel of ears — ' 
 
 Bushels. Pecks. 
 Or of grain to the acre . . . . 9 If 
 The same in 1821 8 IJ 
 
 Gain, 1 Oi 
 
 Old marling (in B)— 105 by 104J feet— 2i barrels, 22 2 
 The same in 1821 22 0^ 
 
 Gain, 1^ 
 
 New marling, 105 by 104 J feet, on the side that seemed to be the 
 most diseased (D), li barrels — or nearly 12 bushels to the acre. 
 
 [1832. Again in corn. Since 1826, the mild four-shift rotation 
 had been regularly adhered to. Ploughed early in winter five 
 inches deep, and again with two-horse ploughs just before planting, 
 and after manuring the land above the dotted line D x. The ma- 
 nure was from the stable yard, the vegetable part of it composed 
 of straw, corn-stalks, corn-cobs, and leaves raked from wood-land, 
 had been heaped in a wet state a short time before, and was still 
 
EFFECTS WITH PUTRESCENT MANURE. 
 
 137 
 
 Lot from its fermentation when carrying to the field. It was then 
 about half rotted. The rate at which it was applied was about 
 807 heaped bushels to the acre, which was too heavy for the best 
 nett profit. The corn on the oldest marling (B) showed scarcely a 
 trace of remaining damage, while that on J) 2 (not manured) was 
 again much injured. On the manured part, D 1, and C, the 
 symptoms of disease began also to show early; but were so soon 
 checked by the operation of the putrescent manure, that very little 
 (if any) loss could have been sustained from that cause. The 
 following table exhibits all the measured products for comparison : 
 
 > 
 
 DESCRIPTION. 
 
 PKODUCT IN GRAIN, PER ACRE. 
 
 1st course 
 
 2d course 
 
 Sd course 
 
 4th course 
 
 W 
 
 
 1821 
 
 
 1824. 
 
 1828. 
 
 1832. 
 
 
 
 
 October 
 
 - 
 
 
 October 14. 
 
 October 20. 
 
 
 Bush. 
 
 pk. 
 
 None measur- 
 
 Bush. pk. 
 
 Bush. pk. 
 
 A 
 
 r Not marled, "| 
 
 8 
 
 1^ 
 
 ed, but the 
 
 9 1| 
 
 9 2n 
 
 Al 
 
 \ Not marled & ma- l 
 
 
 
 product of B 
 
 
 
 
 ( nured in 1832, j 
 
 
 
 much reduced 
 
 the same 
 
 23 3 J 
 
 C 
 
 Marled in 1822, and 
 manured in 1832, 
 
 
 
 by excess of 
 marl, and D 
 
 
 31 IJ 
 
 B 
 
 Marled in 1821 (lightly) 
 
 22 
 
 oj 
 
 and C equally 
 
 22 2 
 
 25 
 
 D ] 
 
 Marled in 1822 (more 
 
 
 
 injured from 
 
 
 
 
 heavily) 
 
 
 
 the same 
 
 12 
 
 17 3 ^ 
 
 Dl[ 
 
 The same — and manur- 
 
 
 
 cause. 
 
 
 \ 
 
 J 
 
 ed in 1832, 
 
 
 
 
 the same 
 
 34 3 j 
 
 The products of the spaces A and B, in 1828, were not only 
 estimated as usual from the measurement of the corn in ears (which 
 estimated quantities are those in the table), but they were also 
 shelled on the day when gathered, and the grain then measured, 
 and again some months after, when it had become thoroughly dry. 
 Care was taken that there should be no waste of the corn, or other 
 cause of inaccuracy. The result showed nearly double the loss 
 from shrinking in the corn not marled, and of course a proportional 
 greater comparative increase of product in that marled, besides the 
 increase which appears from the early measurement exhibited in 
 the table. The grain of A, not marled, when first shelled, mea- 
 sured a very little more than the quantity fixed by estimate — made 
 as usual by measurement of the ears, and lost by shrinking 30 per 
 cent. The marled grain, from B, measured at first above 4 per 
 cent, more than the estimate, and after shrinking, fell below it so 
 much as to show the loss to be 16 per cent. The loss from shrink- 
 ing in this case was greater than usual in both, from the poverty 
 and consequent backwardness of the part not marled, and the un- 
 commonly large proportion of replanted and of course late corn on 
 the whole. 
 12* 
 
138 EFFECTS "WITH PUTRESCENT MANURE. J 
 
 I 
 The two last experiments, as well as tlie 4th, were especially de- I 
 signed to test the amount of increased product to be obtained from 1 
 marling, and to show the regular addition to the first increase, \ 
 which the theory promised at each renewal of tillage. As to the i 
 main objects, all the three experiments have proved failures — and ] 
 from the same error, that of marling too heavily. Although, for 
 this reason, the results have shown so much of the injurious 
 cifects, still, taken altogether, the experiments prove, clearly, not 
 only the great immediate benefit of applying marl, but also its con- 
 tinued and increasing good eifects when applied in proper quantities. 
 —1835.] 
 
 Exioeriment 12. 
 On 9 acres of sandy loam, marled in 1819 at 400 bushels (25. 
 per cent.), nearly an acre was manured during the same summer, 
 by penning cattle. With the expectation of preserving the ma- \ 
 nure, double the quantity of marl, or 800 bushels in all, was laid 
 on that part. The field in corn in 1820 ; in wheat, 1821 ; and at i 
 rest 1822 and 1823. ^ | 
 
 Results, 1824. In corn, the second rotation aftef marling. The i 
 effects of the dung have not much diminished, and that part shows 
 no damage from the cjuantity of marl, though the surrounding 
 corn, marled only half as thickly, gave signs of general, though 
 very slight injury from that cause. 
 
 Experiment 13. 
 
 Nearly two acres of loamy sand were covered with barn-yard 
 manure, and marl (45 per cent.), at the same time, in the spring i 
 of 1822, and the field put in corn the same year, followed by wheat. < 
 The quantity of marl not remembered — but it must have been ; 
 heavy (say not less than six hundred bushels to the acre), as it was \ 
 put on to fix and retain the manure, and I had then no fear of ! 
 damage from heavy dressings. 
 
 Result, 1825. Again in corn; and except on a small spot of 
 sand almost pure (nearly a " blowing sand," or liable to be drifted 
 by high wunds in dry weather), no signs of disease from over- 
 marling were seen, then or afterwards. I 
 
CHx\PTER XIV. 
 
 EFFECTS OP CALCAREOUS MANURES ON " FREE LIGHT LAND." 
 
 Proposition 5 — contimied. 
 
 The soil known in this part of the country by the name of " free 
 light land" has so peculiar a character that it deserves a particular 
 notice. It belongs to the slopes and undulating lands, between the 
 highest ridges and the water-courses, but has nothing of the dura- 
 bility which slopes of medium fertility sometimes possess. In its 
 wood-land state it would be called rich, and may remain productive 
 for a few crops after being cleared ; but it is rapidly exhausted, 
 and, when poor, seems as unimprovable by vegetable manures as 
 the poorest ridge lands. In its virgin state, this soil might be sup- 
 posed to deserve the name of neutral ; but its productive power is 
 so fleeting, and acid growths and qualities so surely follow its ex- 
 haustion, that it must be inferred that it is truly an acid soil. 
 
 Experiment 14. 
 The subject of this experiment presents soil of this kind with 
 its peculiar characters unusually well marked. It is a loamy sandy 
 soil (the sand coarse), on a similar sub-soil of considerable depth. 
 The surfiice waving, almost hilly in some parts. The original 
 growth principally red-oak, hickory, and dogwood, not many pines, 
 and very little whortleberry. Cut down in 1816, and put in corn 
 the next year. The crop Avas supposed to be twenty -five bushels to 
 the acre. Wheat succeeded, and was still a better crop for so 
 sandy a soil ; making twelve to fifteen bushels, as it appeared 
 standing. After 18 months of rest, and not grazed, the next corn 
 crop, of 1820, was evidently and considerably inferior to the first; 
 and the wheat of 1821 (which however was a very bad crop, from 
 too wet a season) could not have been more than five bushels to 
 the acre. In January, 1820, a piece of 1^ acres was limed, at 100 
 bushels the acre. The lime, being caught by rain before it was 
 spread, formed small lumps of mortar on the land, and produced 
 no benefit on the corn of that year, but could be seen slightly in 
 the wheat of 1821. The land again at rest in 1822 and '23, when 
 it was marled, at 600 bushels (.37 per cent.), without omitting the 
 limed piece ; and all sowed in wheat that fall. In 1824, the wheat 
 was found to be improved by the marl, but neither that, nor the 
 next crop of 1828, was equal to its earliest product of wheat. The 
 limed part showed injury in 1824, from the quantity of manure, 
 but none since. The field was now under the regular four-shift 
 
 (139) 
 
140 EFFECTS ON " FREE LIGHT LAND." \ 
 
 rotation, and continued to recover ; but did not surpass its first i 
 crop until 1831, when it brought rather more than thirty bushels ^ 
 of corn to the acre (estimated by the eye) — being five or six j 
 bushels more than its supposed first crop. I 
 
 Experiment 15. I 
 
 Adjoining this piece, six acres of similar soil were grubbed and | 
 the trees belted in August, 1826— marl at 600 to 700 bushels (37 j 
 per cent.), spread just before. But few of the trees died until the i 
 summer of 1827. In 1828, planted in corn ; the crop did not ap- I 
 pear heavier than would have been expected if no marl had been i 
 applied; but no part had been left without, for comparison. 1829, ■ 
 wheat. 1830, at rest. 1831, in corn, and the product supposed to 
 be near or quite thirty -five bushels, or an increase of thirty-five or' 
 forty per cent, on the first crop. No measurement was made ; but 
 the product was estimated by comparison with an adjacent piece, i 
 which measured thirty-one bushels, and which seemed to be inferior 
 to this piece. \ 
 
 The operation of marl on this kind of soil seems to add to the i 
 previous product very slowly, compared with other soils ; but it ia j 
 not the less effectual and profitable in fixing and retaining the vege- , 
 table matter accumulated by nature, which otherwise would be j 
 quickly dissipated by cultivation, and lost for ever. 
 
 The remarkable sand}^ and open texture of the soil on which the last ; 
 two experiments were tried, will be evident from the following state- 
 ment of the quantity and coarseness of the silicious sand contained. ; 
 1000 grains of this soil, taken in 1826 from the part that had been' 
 both limed and marled, was found to consist of 
 811 of silicious sand moderately coarse, mixed with a few grains; 
 of coarse shelly matter (the remains of the marl). I 
 
 158 finely divided 'earthy matter, part fine sand, as well as clay, 
 and organic matter. i 
 
 81 loss. ! 
 
 1000 i 
 
 At the same time, from the edge of the adjoining wood-land; 
 which formed the next described experiment, 15, and which had| 
 not then been marled, a specimen of soil was taken from between^ 
 the depths of one and three inches — and found to consist of the! 
 following proportions. This spot was believed to be rather lighter 
 than the other in its natural state. 
 
 865 grains of silicious sand, principally coarse, 
 
 107 finely divided earthy matter (partly fine sand), &c. ! 
 
 28 loss. 
 
 1000 
 
CHAPTER XV. 
 
 EFFECTS OF CALCAREOUS MANURES ON EXHAUSTED ACID SOILS, 
 UNDER THEIR SECOND GROWTH OF TREES. 
 
 Proposition 5 — continued. 
 
 Not having owned much land under a second gi'owth of pines, I 
 can only refer to two experiments of this kind. The improvement 
 in both these cases has been so remarkable, as to induce the belief 
 that the '■' old fields" to be found on every farm, which have been 
 exhausted and turned out of cultivation thirty or forty years, offer 
 the most profitable subjects for the application of calcareous manures. 
 
 ' Experiment 16. 
 
 May 1826. Marled about eight acres of land under its second 
 growth, by opening paths for the carts ten yards apart. Marl 40 
 per cent. ; put 500 to 600 bushels to the acre — and spread in the 
 course of the summer. In August, belted slightly all the pines 
 that were as much as eight inches through, and cut down or grub- 
 bed the smaller growth, of which there was very little. The pines 
 (which Avere the only trees) stood thick, and were mostly from 
 eight to twelve inches in diameter — eighteen inches where standing 
 thin. The land joined experiment 15 on one side ; but this is 
 level, and on the other side joins ridge wood-land, which soon be- 
 comes like soil of experiment 1. This piece, in its virgin state, 
 was probably of a nature between those two soils ; but less like 
 the ridge soil than the " free light land.'^ No information has been 
 obtained as to the state of this land when its cultivation was 
 formerly abandoned. The soil (that is, the depth which has since 
 been turned by the plough) a whitish loamy sand, on a sub-soil of 
 the same; in fact, all was .s?t5-so<7,. before the ploughing, except 
 half an inch or three quarters, on the top, which was principally 
 composed of rotted pine leaves. Above this thin layer were the 
 later dropped and unrotted leaves, lying loosely several inches thick. 
 The pines showed no symptoms of being killed, until the autumn 
 of 1827, when their leaves began to have a tinge of yellow. To 
 suit the cultivation with the surrounding land, this piece was laid 
 down in wheat for its first crop, in October, 1827. For this pur- 
 pose, the few logs, the boughs, and grubbed bushes were heaped, 
 but not burnt ; the seed then sowed on the coat of pine leaves, and 
 ploughed in by two-horse i^loughs, in as slovenly a manner as may 
 be supposed from the condition of the laiad : and a wooden-tooth 
 
 (141) 
 
142 ON LAND or SECOND GROWTII. i 
 
 barrow then passed over, to pull down the heaps of leaves, andi 
 roughest furrows. ! 
 
 liesults. The wheat was thin, hut otherwise looked well while, 
 young. The surface was very soon again covered by the leaves { 
 dropping from the then dying trees. On April 2d, 1828, most of ] 
 the trees were nearly dead, though but few of them entii-ely. Tho^ 
 wheat was then taller than any in my crop, and, when ripe, was aj 
 surprising growth for such land, and such imperfect tillage. • j 
 
 1829 and 1830. At rest. Late in the spring of 1830 an acci- j 
 dental fire passed over the land ; but the then growing vegetation ; 
 prevented all of the older cover being burnt, though some waa, 
 destroyed everywhere. ] 
 
 1831. In corn. The growth excited the admiration of all whoj 
 saw it, and no one estimated the product so low as it actually . 
 proved to be. A square of four (two-pole) chains, or four-tenths^ 
 of an acre, measured on November 25th, yielded at the rate of j 
 thirty-one and three-eighths bushels of grain to the acre. ■ 
 
 Exjjeriment 17. . ] 
 
 In a field of acid sandy loam, long under the usual cultivation, tj 
 a piece of five or six acres was covered by a second growth of pinea 
 thirty -nine years old, as supposed from that number of rings being 
 counted on some of the stumps. The largest trees were eighteen \ 
 or twenty inches through. This ground was altogether on the 
 side of a slope, steep enough to lose soil by washing, and more ! 
 than one old shallow gully remained to confirm the belief of the j 
 injury that had been formerly sustained from that cause. These 
 circumstances, added to all the surrounding land having been con- | 
 tinned under cultivation, made it evident that this piece had been \ 
 turned out of cultivation because greatly injured by tillage. It ; 
 was again cut down in the winter of 1824-5. Many of the trees 
 furnished fence-rails and fuel, and the remaining bodies were 
 heaped and burnt some mouths after, as well as the large brush. ' 
 In August it was marled, supposed at 600 bushels (37 per cent.), 
 twice coiiltered in August and September, and sowed in wheat— 
 the seed covered by trowel ploughs. The leaves and much of the , 
 smaller brush, left on the ground, made the ploughing troublesome 
 and imperfect. The crop (1826) was remarkably good; and still 
 better were the crops of corn and wheat in the ensuing rotation, ' 
 after two years of rest. On the last crop of wheat (1830) clover 
 was sown — and mowed for hay in 1831. The growth stood about ■ 
 eighteen inches high, and never have I seen so heavy a crop on | 
 sandy and acid soil, even from the heaviest dunging, the utmost ; 
 care, and the most favourable season. The clover grew well in the | 
 bottoms of the old gullies, which were still plainly to be seen, and | 
 which no means had been used to improve, except such as all the \ 
 
MARL ON CALCziREOUS AND NEUTRAL SOILS. 143 
 
 land liad received. Within two feet of the surface the sub-soil of 
 this land is of red clay, which probably helped its growth of clover. 
 
 CHAPTER XVI. 
 
 EFFECTS OE CALCAREOUS MANURES ALONE, OR WITH GYPSUM, ON 
 CALCAREOUS AND NEUTRAL SOILS, 
 
 Proposition 5 — continued. 
 
 Reason had taught that applications of calcareous earth alone 
 to calcareous soils were so manifestly useless, that no more than two 
 experiments of that kind have been made by me, of which, as ex- 
 pected, neither had any improving effect that could be noticed, in 
 the twelve ensuing years during which the experiments were ob- 
 served. 
 
 When calcareous manures have been applied to neutral soils, 
 whether new or worn, no perceptible and manifest benefit has been 
 obtained on the first crop. The subsequent improvement has gra- 
 dually increased, as would be expected from the power of fixing 
 manures ascribed to calcareous earth. But however satisfactory 
 these general results were to myself, they are not such as could be 
 reported in detail, with any advantage to other persons. It is 
 sufficiently difficult to make fiiir and accurate experiments where 
 early and remarkable results are expected- But no cultivator of a 
 farm can bestow enough care, and patient observation, to obtain 
 true results from experiments that scarcely will show their first 
 feeble effects in several years after the commencement. On a mere 
 experimental farm, such things may be possible; but not where the 
 main object of the farmer is to reap profit from his general and 
 varied operations. The effects of changes of season, of crops, of 
 the mode of tillage — the auxiliary efi"ects of other manures, and 
 many other circumstances — would serve to defeat any observations 
 of the progress of a slow improvement, though the ultimate result 
 of the general practice might be abundantly evident. 
 
 Another cause for being unable to state with any precision the 
 practical benefit of marling neutral soils, arises from the circum- 
 stance that nearly all the calcareous manure thus applied by me 
 has been accompanied by a natural admixture of gypsum ; and 
 though I feel confident in ascribing some effects to one, and some 
 to the other of these two kinds of manure, yet this division of 
 operation must rest merely on opinion, and cannot be received as 
 certain by any other than him who makes and carefully observes 
 
144 GYPSEOUS MAUL OP COGGINS TOINT. 
 
 the experiments. Some of these applications will be described, 
 that other persons may draw their own conclusions from them. 
 
 The cause of these manures being applied in conjunction was 
 this. A singular bed of marl lying under Coggius Point, and the 
 only one within a convenient distance to most of the neutral soil 
 of that farm, contains a very small proportion (perhaps about one 
 per cent.) of gypsum, scattered irregularly through the mass, 
 seldom visible, though sometimes and very rarely to be met with 
 in small crystals. The calcareous ingredient, on a general average 
 carefully made, was found to be 62 per cent. If this manure had 
 been xxsed before its (jyi^^eous quality was discovered, all its effects 
 would have been ascribed to calcareous earth alone, and the most 
 erroneous opinions might thence have been formed of its mode of 
 operation. 
 
 What led me to suspect the presence of gypsum, in this bed of 
 fossil shells, was the circumstance that throughout its whole extent, 
 of near a mile along the river bank, this bed lies on another earth, 
 of peculiar character and appearance, and which, in maiiy places, 
 exhibits gypsum in cr3'stals of various sizes. This earth has evi- 
 dently once been a bed of fossil shells, lilic that which still remains 
 above ; but nothing now is left of the shells, except numerous im- 
 pressions of their forms. Not the smallest proportion of calcare- 
 ous earth can be found, and the gypsum into which it must have 
 been changed (by meeting with sulphuric acid, or sulphuret of 
 iron) has also disappeared in most places ; and in others, it remains 
 only in small quantities — say from the smallest perceptible proj^or- 
 tion, to fifteen or twenty per cent, of the mixed mass. In some 
 rare cases, this gypseous earth is sufficiently abundant to be used 
 profitably as manure, as has been done, by Mr. Thomas Cocke, of 
 Tarbay, as well as myself. It is found in the greatest quantity, 
 and also the richest in gypsum, at Evergreen, two miles below City 
 Point. There the gypsum frequently forms large crystals of varied 
 and beautiful forms. The distance that this bed of gypseous earth 
 extends is about seven miles, interrupted only by some bodies of 
 lower land, apparently of a more recent formation by alluvion. 
 
 In the bed of gypseous marl above described, there are regular 
 layers of a calcareous rock, which was too hard to use profitably for 
 manure, and which caused the greatest impediment to obtaining 
 the softer part. This rock contains between eighty -five and ninety 
 per cent, of pure calclireous earth, besides a little gypsum and 
 iron. It makes excellent lime for cement, mixed with twice its 
 bulk of sand, and has been used for part of the brick-work, and all 
 the plastering of my present dwelling-house (at Shellbauks), and 
 for several of my neighbours' houses. The whole body of marl 
 also contains a minute proportion of some soluble salts, which pes- 
 
GYPSEOUS MARL. 145 
 
 sibly may have some influence on the operation of the substance, 
 as manure or cement. 
 
 Thus, from the examination of a single body of marl, there have 
 been obtained not only a rich calcareous manure, but also gypsum, 
 and a valuable cement. Similar formations may perhaps be 
 abundant elsewhere, and their value unsuspected, and likely to re- 
 main useless. This particular body of marl has no outward ap- 
 pearance of possessing even its calcareous character. It would be 
 considered, on slight inspection, as a mass of gritty clay, of no 
 worth whatever. 
 
 [The last preceding paragraphs present, as in the previous edi- 
 tions, my earliest views of this particular bed of marl. Further 
 information has taught that it is of the eocene, or more ancient 
 formation; and that the underlying stratum (which is usually not 
 at all calcareous), which I formerly named and treated of as '* gyp- 
 seous earth," is what geologists call " green-sand," a term still less 
 descriptive, and not at all more accurate. A full account of both 
 of these bodies will be given in the Appendix. — 1842.] 
 
 This gypseous marl has been used only on sixty acres, most of 
 which was neutral soil, and generally, if not universally, with 
 early as well as permanent benefits. The following experiments 
 show results more striking than have been usually obtained ; but 
 all agree in their general character. 
 
 Experiment 18. 
 
 1819. Across the shelly island numbered 3 in the examinations 
 of soils (page 60), but where the land was less calcareous, a sti-ip 
 of three-quarters of an acre was covered with mussel-shell marl, a 
 deposit on parts of the river banks supposed to have been made by 
 the aboriginal inhabitants. Adjoining this, through its whole 
 length, another strip was covered with gypseous marl, 53 per cent., 
 at the rate of 250 bushels. 
 
 Results. 1819. In corn. No perceptible effect from the mussel- 
 shells. The gypseous marling considerably better than on either 
 side of it. 
 
 1820. Wheat — less difference. 
 
 1821. Grrazed. Natural growth of white clover thickly set on 
 the gypseous marling, much thinner on the mussel-shells, and still 
 less of it where no marl had been applied. 
 
 The whole field afterwards was put in wheat on summer fallow 
 every second year, and grazed closely the intervening year : a 
 course very unfavourable for observing, or permitting to take place, 
 any effects of gypsum. Nothing more was noted of this experi- 
 ment until 1825, when cattle were not turned in until the clover 
 reached its full size. The strip covered with gypseous marl 
 showed a remarkable superiority over the other marled piece, as 
 13 
 
146 GYPSEOUS MARL ON NEUTRAL SOILS, 
 
 well as over tlie land wLicli was still more calearcous by nature, 
 and which had produced better in 1820. In several places, the 
 white clover stood thickly a foot in height- 
 
 Experiment 19. 
 
 A strip of a quarter acre passing through rich black neutral 
 loam, covered with gypseous marl at 250 bushels. 
 
 Results. 1818. In corn. By July, the marled part seemed, the 
 best by 50 per cent., but afterwards the other land gained on it, 
 and little or no difference was apparent when the crop was matured. 
 
 1819. Wheat — no difference seen. 
 
 1820 and 1821. At rest. In the last summer the marled strip 
 could again be easily traced, by the entire absence of sorrel (which 
 had been gradually increasing on this land since it had been 
 secured from grazing), and still more by its very lusuriaut gi-owth 
 of bird-foot clover, which was thrice as good as that on the adjoin- 
 ing ground. 
 
 Experiment 20. 
 
 1822. On a body of neutral soil which had been reduced quite 
 low, but was well manured in 1819 when last cultivated, gypseous 
 marl was spread on nine acres, at the rate of 300 bushels. This 
 terminated on one side at a strip of mussel-shell marl ten yards 
 wide — its rate not remembered, but it was certainly thicker, in pro- 
 portion to the calcareous earth contained, than the other, which I 
 always avoided laying on heavily, from a mistaken fear of causing 
 injury by too much gypsum. The line of division between the 
 two marls was through a clay loam. The sub-soil was a retentive 
 clay, which caused the rain water to keep the land very wet through 
 the winter, and early part of spring. 
 
 Results. 1822. In corn, followed by wheat in 1823 — not particu- 
 larly noticed, but the benefits must have been very inconsiderable. 
 All the mussel-shell marling, and four acres of the gypseous, 
 sowed in red clover, which stood well; but was severely checked, 
 and much of it killed, by a drought in June, when the sheltering 
 wheat was reaped. During the next winter (by neglect) my 
 horses had frequent access to this piece, and by their trampling in 
 its wet state must have injured both land and clover. From these 
 disasters the clover recovered surprisingly; and in 1824, two mow- 
 ings were obtained, which, though not very heavy, were better than 
 from any of my previous attempts to raise this grass. In 1825, 
 the growth was still better, and yielded more to the scythe. This 
 was the first time that I had seen clover worth mowing on the 
 third year after sowing ; and had never heard of its being com- 
 parable to the second year's growth anywhere in the lower country. 
 The growth on the mussel-shell marling was very inferior to the 
 
CAUSE OP THE NON-ACTION OP GYPSUM. 147 
 
 other, and was not mowed at all the last year, being thin and low, 
 and almost eaten out by wire-grass (^Cijnodon dacf>//on). 
 
 1826. In corn — and it was remarkable that the diiFerence shown 
 the last year was reversed, the mussel-shell marling now having 
 much the best crop. 
 
 In these and other applications to neutral soils, I ascribe tho 
 earliest effects entirely to gypsum, as well as the peculiar benefit 
 shown to clover, throughout. The later effects, and especially on 
 grain, are due to the calcareous earth in the manure. 
 
 CHAPTER XVII. 
 
 DIGRESSION TO THE THEORY OF THE ACTION OF GYPSUM AS MA- 
 NURE. SUPPOSED CAUSE OP ITS WANT OP POWER AND VALUE 
 ON ACID SOILS. 
 
 Proposition 5 — contmued. 
 
 Another opinion was formed from the effects of gypseous marl, 
 as stated in the foregoing chapter, which may lead to profits much 
 more important than any to be derived from the limited use of this, 
 'or any similar mineral compound — viz. : that gypsum may he pro- 
 Jitahly used after calcareous manures, on soils on which it teas 
 totally inefficient before. I do not present this as a fact fully esta- 
 blished, or, even if established, of universal application ; for the 
 results of some of my own experiments are directly in opposition. 
 But, however it may be opposed by some facts, the greater weight 
 of evidence, furnished by my experiments and observations, de- 
 cidedly suppoi'ts this opinion. If correct, its importance to our 
 low country is inferior only to the value of calcareous manures 
 alone — which value may be almost doubled, if the land is thereby 
 fitted to receive the wonderful benefits of gypsum on clover. 
 
 It is well known that gypsum has failed entirely as a manure ""on 
 nearly all the land on which it has been tried in our tide-water 
 district; and we may learn from various publications, that as little 
 general success has been met with along the Atlantic coast, as far 
 north as Long Island. To account for this general failure of a 
 manure so efficacious elsewhere, some one offered a reason, which 
 was received without examination, and which is still considered by 
 many as sufficient, viz. : that the influence of salt vapours destroyed 
 the power of g3'psum on and near the sea-coast. But the same 
 general worthlessness of that manure extends one hundred miles 
 higher than the salt water of the rivers, and the lands where it is 
 
148 NON-ACTION OP GYPSUM ON ACID SOILS. I 
 
 i 
 
 profitably used are much more exposed to sea air. Such are th^ 
 rich neutral soils of Curie's Neck, Shirley, Berkley, Westoverj, 
 Brandon, and Sandy Point, on James river, on all which gypsum 
 on clover has been extensively and profitably used, in advance of 
 marling or liming. On acid soils, I have never heard of enough 
 benefit being obtained from gypsum to induce the cultivator to ex- 
 tend its use further than making a few small experiments. When 
 any efi"ect has been produced on an acid soil (so far as known from 
 my own experience, or the information of others), it has been 
 caused by applying to small spaces comparatively large c^uantities J 
 and even then, the effects were neither considerable, durable, nor 
 profitable. Such have been the results of many small experiments 
 made on my own acid soils — and very rarely was the least percepti- 
 ble efi"ect produced. Yet on some of the same soils, after marling, 
 the most evident benefits have been obtained from gypsum on 
 clover. The soils on which the 1st and 10th experiments were 
 made (at some distance from these experiments) had both been 
 tried with gypsum, and at difi"ereut rates of thickness, before marl- 
 ing, without the least eff"ect. Several years after both had been 
 marled, gypseous earth (from the bed referred to, page 144) was 
 spread at twenty bushels the acre (which gave four bushels of pure 
 gypsum*) on clover, and produced in some parts a growth 1 have 
 never seen surpassed. It is proper to state that such results have 
 been produced only by heavy dressings. Mr. Thomas Cocke, of 
 Tarbay, in the spring of 1831 sowed nearly four tons of Nova 
 Scotia gypsum on clover on marled land, the field being a continua- 
 tion of the same ridge that my 1st, 2d, 3d, and 4th experiments 
 were made on, and very similar soil. His dressing, at a bushel t(D 
 the acre, before the summer had passed, produced evident benefit, 
 where it is absolutely certain, from abundant previous experience, 
 that none could have been obtained before marling. 
 
 On soils naturally calcareous, I have in some experiments greatly 
 promoted the growth of corn by gypsum, and have doubled the 
 growth of clover on my best land of that kind. When the marl 
 containing gypsum was applied, benefit from that ingredient was 
 almost certain to be obtained. 
 
 All these facts, if presented alone, would seem to prove clearly 
 the correctness of the opinion, that the acidity of most of our soils 
 caused the inefiicacy of gypsum, and that the application of calca- 
 reous earth, which will remove the acid, will also serve to bring 
 gypsum into useful operation. But this most desirable conclusion 
 is opposed by the results of other experiments, which, though 
 fewer in number, are as strong as any of the facts which favour that 
 
 * There wa.s very little of the gypseous earth so rich as this limited 
 layer — which was soou all removed for use. 
 
NON-ACTION OF GYrSUM ON ACID SOILS. 149 
 
 conclusion. If the subject were properly investigated, these facts, 
 apparently in opposition, might be explained so as no longer to 
 contradict this opinion, or perhaps might help to confirm it. Good 
 reasons, deduced from established chemical truths, may be oifered 
 to explain why the acidity of our soils should prevent the operation 
 of gypsum ; though it may be deemed premature to attempt the 
 explanation of any supposed fact, before every doubt of the 
 existence of the fact itself has been first removed. 
 
 One of the circumstances will be mentioned, which appears at 
 first glance most strongly opposed to the opinion which has been 
 advanced. On the poor acid clay soil, of such peculiar and base 
 qualities, which forms the subject of the 5th, 6th, and 7th experi- 
 ments, gypsum has been sufliciently tried, and has not produced 
 the least benefit, either before marling, or afterwards. Yet the 
 first growth of clover on this land after marling is fully equal to 
 what might be expected from the best operation of gypsum. Now 
 if it could be ascertained that a very small proportion of either 
 sulphuric acid, or of the suJpliate of iron, exists in this soil, it 
 would completely explain away this opposing fact, and even make 
 it the strongest support of my position. The sulphate of iron has 
 sometimes been found in arable soil,* and sulphuric acid has been 
 detected in certain clays. "j" I have seen, on the same farm, a bed 
 of clay of very similar appearance to this soil, which certainly had 
 once contained one of these substances, as was proved by the form- 
 ation of crystallized sulphate of lime, where the clay came in con- 
 tact with a bed of marl. The sulphate of lime was found in the 
 small fissures of the clay, extending sometimes one or two feet in 
 perpendicular height from the calcareous earth below. Precisely 
 the same chemical change would take place in a soil containing 
 sulphuric acid, or sulphate of iron, as soon as marl is applied. The 
 sulphuric acid (whether free or combined with iron) would imme- 
 diately unite with the lime presented, and form gypsum (sulphate 
 of lime). Proportions of these substances, too small perhaps to be 
 detected by analysis, would be sufficient to form three or four 
 bushels of gypsum to the acre — more than enough to produce the 
 greatest known effect on clover — and to prevent any benefit being 
 derived from a subsequent application of gypsum; because there 
 being already in the soil more gypsum than could act, no additional 
 quantity could be of the slightest benefit. J 
 
 * Davy's Agi-. Chem. p. 141. f Kirwan on Manures. 
 
 [J Confirmatory testimony. — Johnston has since fully sustained this rea- 
 soning, liy chemical facts. Besides the sulphate of iron, he names the siil- 
 phates of alumina and magnesia as occasionally present in soils, and liable 
 to be hurtful to plants. He adds: "When soils which contain any of the 
 three salts I have named, have ouce been limed or marled, it is in vain to 
 
 13* 
 
150 GYPSUM MADE ACTIVE ON MARLED LAND. '< 
 
 [Since fhe publication of the foregoing part of this chapter, in i 
 the edition of 1832, my use of gypsum, on land formerly acid, has | 
 been more extended, and the results have been such as to give ad- | 
 ditional confidence in the practice, and, indeed, an assurance of 
 good profit, on the average of such applications. But still, as be-| 
 fore, disappointments, either total or nearly so, in the effect of such • 
 applications, have sometimes occurred, and without there being' 
 any known or apparent cause to which to attribute such disappoint- 
 ment in the results. < 
 
 In 1832, nine acres of the same body of ridge land above re- ' 
 ferred to, adjoining the piece on which the 1st, 2d, 3d, and 4th : 
 experiments were made, and more lately cleared, were sown in : 
 clover in the early part of 1831, on wheat. The next spring. 
 French gypsum was sown at the rate of a bushel to the acre, ex-' 
 cept on four marked adjoining squares, each about one-third of an 
 acre, one of which was left without gypsum, and the others received 
 it at the several rates of 2, 3, and 4 bushels to the acre. The ; 
 whole brought a middling crop, and was mowed for hay, except the'j 
 square left without gypsum, which did not produce more than half | 
 as much as the adjoining land where gypsum was applied at one! 
 bushel the acre. The products of the other pieces were slightly ' 
 increased by each addition to the gypsum, but by no means in - 
 proportion to the increased quantity used; nor was the effect of the- 
 four bushels near equal to that formerly obtained, in several cases, j 
 from 20 bushels of gypseous earth taken fi'om the river bank.! 
 Hence it seems that it was not merely the unusual quantity of i 
 gypsum applied in this earth, which produced such remarkable! 
 benefit; and we must infer that it contains some other quality orj 
 ingredient capable of giving additional improvement to clover. I 
 —1835.] j 
 
 [Since the first publication of the foregoing passage (in 1835),] 
 and in accordance with the views there presented, more than 10' 
 tons of good French gypsum has been used, in different years and' 
 with less effect, in general, than formerly, in the first few yeara' 
 after the marling. This general diminution, and more frequent' 
 total failures, may be owing to the longer time that the land has! 
 been marled, and, by the increase of its vegetable supplies serving^ 
 as putrescent manure, the land being thereby changed from calca^i 
 rcous to neutral, and perhaps in some cases even approaching againi 
 to being acid. If this supposition be well founded, then a repetition! 
 of the marling would not only be profitable in other respects, but^ 
 
 apply gypsum for favouring the clover crop, since the lime, in decomposing 
 the sulphates, has alread}' formed an abundant supply of this compound 
 for all the purposes of vcgctatiou." Lectures on Agr. Chcm. — p. 414.] 
 
THEORY OP THE NON-ACXION OF GYPSUM. 151 
 
 would increase or restore tlie capacity of the soil to receive benefit 
 from gypsum. — 1842.] 
 
 1832. — The following are my views of the general causes of the 
 inertness and worthlessness of gypsum as manure, on all acid soils, 
 and for the different and valuable results from gypsum, after the 
 soils have been made calcareous. 
 
 I do not pretend to explain the mode of operation by which 
 gypsum produces its almost magical benefits ; it would be equally 
 hopeless and ridiculous for one having so little knowledge of the 
 successful practice to attempt an explanation, in which so many 
 good chemists and agriculturists, both scientific and practical, have 
 completely failed. There is no operation of nature heretofore less 
 understood, or of which the cause, or agent, seems so totally dispro- 
 portioned to the efi"ect, as the enormous increase of vegetable 
 growth from a very small quantity of gypsum, in circumstances 
 favourable to its action. All other known manures, whatever may 
 be the nature of their action, require to be applied in quantities very 
 far exceeding any bulk of crop expected from their use. But one 
 bushel of gypsum spread over an acre of land fit for its action, may 
 add more than twenty times its own weight to a single crop 
 of clover hay. 
 
 But without pretending to account for the wonderful action of 
 gypsum as manure, and without entertaining any confidence in any 
 of the numerous theories heretofore presented, [not excepting the 
 latest set forth, by Professor Liebig], I concur in the general 
 opinion expressed by Davy. This accurate investigator, who took 
 nothing upon trust which could be subjected to the test of rigid 
 experiment, pursued that mode to obtain light on this obscure sub- 
 ject. He found by chemical analysis, that gypsum was always 
 present in the ashes of red clover, and in quantity, in a good crop, 
 amounting to three or four bushels to the acre. He inferred that 
 gypsum, thus always forming a portion of the clover plant, was 
 essential to its healthy existence ; and that it is necessary to the 
 structure of the woody fibre of clover and other grasses. But it is 
 enough if Davy was correct in the main opinion, that a certain 
 though very small proportion of gypsum is an essential component 
 part of certain plants, of which the clover tribe furnishes the most 
 noted examples. If this be so, no matter what may be the ofiice 
 or function of the gypsum, the small amount necessary for the de- 
 mands of the plants must he jiresenl in the soil^ or otherwise the 
 plants needing it cannot live, or inaintain a healthy growth. It will 
 follow, further, that on soils well adapted for clover in other 
 respects, but almost totally deficient in gypsum, the application 
 of so small a dressing as one bushel of that substance to the acre 
 may enable a full crop of clover to grow, and twice or thrice as 
 much as the land could have brought without this small application. 
 
152 THEORY OF GYPSUM ON ACID SOILS. 
 
 Sucli I suppose to be the circumstances of those lands of this 
 country on which gypsum exerts the greatest power. But in Eng- 
 land, though clover culture is universally extended, gypsum has 
 shown scarcely any benefit as manure, and though extensively 
 experimented with, has not been found suificiently operative to be 
 brought iuto ordinary practice on any one farm in the kingdom. 
 This may be accounted for by supposing the soils generally tojse 
 supplied by nature abundantly with gypsum, so that no more is re^ 
 quired. Davy found gypsum in the soil itself of four farms, 
 examined with this view, and in one of them the very large propor- 
 tion of nearly one per cent. (^Agricultural Chemistry, Lecture vii.) 
 But there is another and numerous class of cases in which gypsum 
 cannot be supposed to be jH'csent, and yet when applied shows no 
 benefit. These are the poor acid soils of lower Virginia (and else- 
 where), and the cause of which it seems to me not difficult to 
 explain. 
 
 However wonderful and inscratable the fertilizing power of this 
 manure may be, and admitting its cause as yet to be hidden, and 
 entirely beyond our reach, still it is possible to show reasons why 
 gypsum cannot act in many situations, where all experience has 
 proved it to be worthless. If this only can be satisfactorily ex- 
 plained, it will remove much of the uncertainty as to the effects to 
 be expected ; and the farmer may thence leam on which soils he 
 may hope for benefit for this manure, on which it will certainly 
 be thrown away, and by what means the circumstances adverse to 
 its action may be removed, and its efUcacy thereby secured. This 
 is the explanation that I shall attempt. 
 
 If the vegetable acid, which I suppose to exist in what I have 
 called acid soils, is not in part the oxalic (which is the particular 
 acid in sorrel), at least, every vegetable acid, being composed of 
 different proportions of the same three elements, may easily change 
 to any other, and all to the oxalic acid. This, of all bodies known 
 by chemists,' has the strongest attraction for lime, and will take it 
 from any other acid which was before combined with it; and for 
 that purpose, the oxalic acid will let go any other earth or metal, 
 which it had before held in combination. Let us then observe 
 what would be the effect of the known chemical action of these 
 substances, on their meeting in soils. If oxalic acid were produced 
 in any soil, its immediate effect would be to unite with its proper 
 proportion of lime, if enough were in the soil in any combination 
 whatever. If the lime were in such small quantity as to leave an 
 excess of oxalic acid, that excess would seize on the other substances 
 in the soil, in the order of their mutual attractive forces ; and one 
 or more of such substances are always present, as magnesia, or, more 
 certainly, iron and alumina. The soil then would not only contain 
 some proportion of the oxalate of lime, but also the oxalate of cither 
 
GYPSUM ON ACID SOILS. 153 
 
 one or more of the other substances named. Let us now suppose 
 gypsum to be applied to this soil. The substance (sulphate of lime) 
 is composed of sulphuric acid and lime. It is applied in a finely 
 pulverized state, and in quantities from half a bushel to two bushels 
 the acre — generally not more than one bushel. As soon as the 
 earth is made wet enough for any chemical decomposition to take 
 place, the oxalic acid must let go its hase of iron or alumina, and 
 seize upon and combioe with the lime that formed an ingredient 
 of the gypsum. The sulphuric acid left free, will combine with 
 the iron, or the alumina of the soil, forming copperas in the one 
 case, and alum in the other. The gi/ps^um no longer exists — 
 and surely no more satisfactory reason can be given why no effect 
 from gypsum should follovr. The decomposition of the gypsum has 
 served to form two or perhaps three other substances. One of them, 
 oxalate of lime, like all salts of lime, is probable valuable as manure; 
 but the vei-y small quantity that could be formed out of one or even 
 two bushels of gypsum, might have no more visible effect on a 
 whole aci'e, than that small quantity of calcareous earth, or farm- 
 yard manure. The other substance certainly formed, copperas, is 
 known to be a poison to soil and to plants — and alum, of Avhich the 
 formation would be doubtful, I believe is also hurtful. In such 
 small quantities, however, the poison would be as little perceptible 
 as the manure ; and no apparent effect whatever could follow such 
 an application of gypsum to an acid soil. So small a proportion of 
 oxalic axid, or any oxalate other than of lime, would suffice to de- 
 compose and destroy the gypsum, that it would not amount to one 
 part in twenty thousand of the soil. 
 
 Why gypsum sometimes acts as a manure on acid soils when 
 applied in large quantities for the space, is equally well explained 
 by the same theory. If a handful, or even a spoonful of gypsum 
 is put on a space of six inches square, it would so much exceed in 
 proportion all the oxalic or other vegetable acid that could speedily 
 come in contact with it, that all would not be decomposed, and the 
 part that continued to be gypsum would show its peculiar powers 
 perhaps long enough to improve one crop. But as tillage served 
 to scatter these little collections more equally over the whole space 
 — or even as repeated soaking rains allowed the extension of the 
 attractive powers — applications like these would also be destroyed, 
 after a very short-lived, limited, and rarely profitable action. 
 
 Soils that are naturally calcareous, or even neutral, cannot con- 
 tain oxalic acid combined with any other base than lime. Hence, 
 gypsuia applied there continues to he gi/ps^im, and exerts its great 
 fertilizing power, as in the counties of Loudoun and Frederick. 
 But even on these most suitable soils, this manure is said not to 
 be certain and uniform in its effects ; and, of course, more certain 
 results arc not to be looked for with us. I have not undertaken 
 
154 GIYI'SUM ON ACID SOILS. 
 
 to explain its occasional failures any more than its general success, 
 on the lands where it is profitably used in general — but only why 
 it cannot act at all, on lands of a different kind. 
 
 The same chemical action being supposed, explains why the 
 power of profiting by gypsum should be immediately awakened on 
 acid soils after making them calcareous ; and v/hy that manure 
 should seldom fail, Avhen applied mixed with much larger quantitiea 
 of calcareous earth. 
 
 [When the foregoing attempt to explain the cause of the non- 
 action of gypsum on acid soils was written, and first published in 1832 
 (as it here appears distinguished from the later additions), the dis- 
 covery of humic acid by European chemists was not known to me, 
 and its very general existence in soils, now universally recognised, 
 was scarcely known to any. Without pretending to identify the 
 acid of soil whose existence I maintained, as early as 1818, to be 
 almost universally present and injurious in this country, it is now 
 clear and unquestioned that the humic acid is thus plentifully and 
 generally diffused. The effects ascribed above to the supposed 
 oxalic acid, of decomposing and destroying sulphate of lime when 
 applied as manure, may be as much produced by the actually pre- 
 sent humic acid. For, not only is the latter convertible to the 
 former, as above argued of all vegetable acids, but, without the 
 need of such conversion, the humic acid is now understood to have 
 the like power of decomposing sulphate of lime. This is stated 
 fully and distinctly in a very recent publication (Browne's Ame- 
 rican Muck Book, 1852), as follows: '^Gypsum is decomposed by 
 carbonate and muriate of barytes, the carbonates of strontia, 
 potash, soda, and ammonia, as well as by oxalic and humic acich^ 
 and where any of the four last named occur naturally in the soil, 
 or are applied by artificial means, new combinations take place, 
 which are attended in some cases with beneficial results. 
 If, however, it [the soil] contains too much free humic acid, it iviU 
 decompose the gypsum, so that humate of lime will be formed, and 
 the sulphuric acid set free, which may then act as a corrosive on the 
 roots of jilants" (p. 71.) Nothing is wanting to the fullest and 
 clearest establishment of my doctrine as stated above, except that 
 the humic acid, like the oxalic, has stronger affinity for lime than 
 the sulphuric, and therefore will decompose sulphate of lime 
 (gypsum), and form instead humate of lime, of which the effect 
 as manure is altogether different. And that humic acid (or what- 
 ever may be the acid of soil) really has this stronger affinity for 
 lime, is sustained by enough agricultural facts within my personal 
 observation, even if the proposition had no support whatever froia 
 chemical science. — ^1852.1 
 
CHAPTER XVIII. 
 
 THE DAMAGE CAUSED BY TOO HEAVY DRESSINGS OE CALCAREOUS 
 MANURE, AND THE REMEDY. 
 
 Proposition 5 — continued. 
 
 The injury or disease in grain crops produced by marling has 
 BO lately been presented to our notice, that the collection and com- 
 parison of many additional facts will be required before its cause 
 can be satisfactorily explained. But the facts already ascertained 
 will at least show how to avoid the danger of such injury in future, 
 and to find remedies for the evils already inflicted by the injudi- 
 cious use of calcareous manures. 
 
 The earliest effect of this kind observed was in May, 1824, on 
 the field containing esperiment 10. The corn on the land marled 
 four 3^ears before sprang up and grew with all the vigour and luxu- 
 riance that was expected from the appearance of increased fertility 
 exhibited by the soil, as before described (page 133.) About the 
 20th of May the change commenced, and the worst symptoms of 
 the disease were seen by the 11th of June. From having as deep 
 a colour as young corn shows on the richest and best soils, it be- 
 came of a pale sickly green. The leaves, when closely examined, 
 seemed almost transparent, afterwards were marked through their 
 whole length by streaks of rusty red, separated very regularly by 
 other streaks of what was then more of yellow than green ; and 
 next they began to shrivel and die downwards from their extremi- 
 ties. The growth of many of the plants was nearly stopped. 
 Still some few showed no sign of injury, and maintained the 
 vigorous growth which they began withj so as by contrast more 
 strongly to mark the general loss sustained. The appearance of 
 the field was such, that a stranger would have supposed that he 
 saw the crop on a rich soil exposed to the worst ravages of some 
 destructive kind of insects; but neither on the roots or stalks of 
 the corn could any thing be found to support that opinion. Before 
 the first of August this gloomy prospect had somewhat improved. 
 Most of the plants seemed to have been relieved of the infliction, 
 and to grow again with renewed vigour. But before that time 
 many were dead, and it was impossible that the others could so 
 fully recover as to produce anything approaching a full crop for 
 the land. It has been shown in the report of the products of Exp. 
 10, what diminution of crop was then sustained, and that the evil 
 was not abated in the three succeeding courses of cultivation. 
 
 (155) 
 
156 I>ISEASED CROPS CAUSED BY MARLING. 
 
 Still, neither of the diseased measured pieces has fallen quite aa 
 low as its product before marling; nor do I think that such has 
 been the result on any one acre together on my farm, though many 
 smaller spots have been rendered incapable of yielding even so 
 much as a grain of corn or wheat. 
 
 The injury caused to wheat by marling is not so easy to describe, 
 though abundantly evident to the observer. Its earliest growth, 
 like that of corn, is not affected. About the time for heading, the 
 plants most diseased appear as if they were scorched, and when 
 ripe will be found very deficient in grain. On very poor spots, 
 from which nearly all the soil has been washed, sometimes fifty 
 heads of wheat, taken together, would not furnish as many grains 
 of wheat. This crop, however, suffers less than corn on the same 
 land ; perhaps because its growth is nearly completed by the time 
 that the warm season begins, to which the ill effects of calcareous 
 manures seem confined. The injury to corn is also greater in a 
 wet than a drier summer. 
 
 When these unpleasant discoveries were first made, two hundred 
 and fifty acres had already been marled so heavily that the same 
 evil was to be expected to visit the whole. My labours, thus be- 
 stowed for years, had been greatly and unnecessarily increased ; 
 and the excess, worse than being thrown away, had served to take 
 away that increase of crop which lighter marling would have 
 insured. But though much and general injury was afterwards 
 sustained from the previous work, yet it was lessened in extent and 
 degree, and sometimes entirely avoided, by the remedial measures 
 which were adopted. My observation and comparison of all the 
 facts presented, led to the following conclusions, and pointed out 
 the course by which to avoid the recurrence of the evil, and the 
 means to lessen or remove it, where it had already been inflicted. 
 
 1st. No injury has been sustained on any soil of my farm by 
 marling not more heavily than two hundred and fifty heaped 
 bushels to the acre, with marl of strength not exceeding 40 per 
 cent, of calcareous earth. 
 
 2d. Dressings twice as heavy seldom produce damage to the first 
 crop on any soil ; and never even on the after crops on any calca- 
 reous, or good neutral soil; nor on any acid soil supplied plenti- 
 fully with vegetable matter. 
 
 3d. On acid soils marled too heavily, the injury is in proportion 
 to the extent of one or all these circumstances of the soil — poverty, 
 sandiness, and severe cropping and grazing, whether inflicted pre- 
 viously or subsequently. 
 
 4th. Clover, both red and white, will live and flourish on the 
 spots most injured for grain crops by marling too heavily. Thus, 
 in the case before cited of laud adjacent to the pieces measured in 
 experiment 10, and equally over-marled, very heavy red clover was 
 
DISEASED CROPS CAUSED BY MARLING. 157 
 
 raised in 1830, by adding gypseous earth, and wliich was succeeded 
 by a good growth of corn, free from every mark of disease, in 1832. 
 
 5th. A good dressing of putrescent manure removes the disease 
 completely (see Exp. 11, 12, 13). All kinds of marl (or fossil 
 shells) have sometimes been injurious ; but such effects have been 
 more generally experienced from the dry yellow marl, than from 
 the blue and wet. 
 
 The inferences to be drawn from these fiicts are obvious. They 
 direct us to avoid injury by applying marl lightly at first, and to be 
 still more cautious according to the existence of the circumstances 
 stated as increasing the tendency of marl to do harm. Next, if 
 the over-dose has already been given, we should forbid grazing 
 entirely, and furnish putrescent manure as far as possible ; or omit 
 one or two grain crops, so as to allow more vegetable matter to be 
 fixed in the land — apply putrescent manures — and sow clover as 
 soon as circumstances permit. One or more of these remedies 
 have been used on most of my too heavily marled land ; and with 
 considerable, though not always with entire success, because the 
 means for the cure could not always be furnished at once in suffi- 
 cient abundance. Other persons, who permitted close grazing, and 
 adopted a more scourging rotation of crops, have suffered more 
 damage, from much lighter dressings of marl than those of mine 
 which Avere injurious. 
 
 But though the unlooked-for damage sustained from this-^ause 
 produced much loss and disappointment, and has greatly retarded 
 the progress of my improvements, it did not suspend my marling, 
 nor abate my estimate of the value of the manure. If a cover of 
 500 or 600 bushels was so strong as to injure land of certain 
 qualities, it seemed to be a fair deduction, that the benefit expected 
 from so heavy a dressing, might have been obtained from half the 
 quantity; if not on the first crop, at least on every one after- 
 wards. That surely is nothing to be lamented. It also afforded 
 some consolation for the evil of the too heavy marlings already 
 applied, that the soil was thereby fitted to seize upon and retain a 
 greater quantity of vegetable matter, and would thereby ultimately 
 reach a higher grade of fertility. 
 
 The cause of this disease is less apparent than its remedies. It 
 is certain that it is not produced merely by the quantity of calca- 
 reous earth in the soil. If it were so, similar effects, shown in 
 diseased crops, would always be found on soils containing far 
 greater proportions of that earth. These injurious effects have not 
 been known, to any extent, except on soils formerly acid, and made 
 calcareous artificially ; and not on neither neutral or calcareous 
 soils, even by the addition of a great excess of marl. The small 
 spots of land that nature has made excessively calcareous, by marl 
 beds cropping out at the surface of cultivated fields (as the speci- 
 14 
 
158 DISEASED CEOrS CAUSED BY MARLING. 
 
 men 4, page 60), produce indeed a pale feeble gro^vtli of corn, 
 such as might be expected from poor gravelly soils ; but whether 
 the plants yield grain, or are barren, they show none of those pecu- 
 liar and strongly marked symptoms of disease which have been 
 described. Some such places on my farm, from which great quan- 
 tities of poor sandy marl had been removed for manure, and where 
 the remainder still was of unknown depth, have been afterwards 
 cultivated with the surrounding land ; and with no more aid than 
 the portion of the adjacent soil carried thereto necessarily by the 
 plough, these places have gradually improved to a product equal to 
 12 or 15 bushels of corn per acre, and have never exhibited any 
 mark of the marl disease. 
 
 By calculation, it appears that the heaviest dressing causing in- 
 jurious consequences, if mixed to the depth of five inches, has not 
 given to the soil a proportion of calcareous earth equal to two per 
 cent. This proportion is greatly exceeded in our best shelly land, 
 and no such disease is found there, even when the rich mould is 
 nearly all washed away, and the shells mostly left. [Soils of re- 
 markable fertility from the prairies of Alabama and Mississippi 
 have been shown (page 66) to contain from 8 to 16 per cent, of 
 calcareous earth, all of which proportions were in the state of most 
 minute division, and therefore most ready to produce this disease, 
 if it could have been produced by the quantity of this ingredient, 
 A specimen of soil remarkable for its great fertility, and maintaining 
 it under 40 years of successive corn culture, in Scioto valley, Ohio, 
 was sent me by Dr. Thomas Massie. It contained 10 per cent, of 
 carbonate of lime and magnesia. The soil of the borders of the 
 Nile, celebrated for its exuberant fertility through thousands of 
 successive crops, contains about 25 per cent, of carbonate of lime. 
 {LyelVs Geoh'jy.y] Very fertile soils in France and England 
 sometimes contain 20 or 30 per cent. Among the soils of remarka- 
 ble good qualities analyzed by Davy, one is stated to contain about 
 28 per cent., and another, which was eight-ninths of silicious sand, 
 contained nearly 10 per cent, of calcareous earth. Nor does he 
 intimate that such proportions are very rare. Similar results have 
 been stated, from analyses reported by Kirwan, Young, Bergman, 
 and llozier (page 51) ; and from all the same deduction is inevita- 
 ble, that much larger natural proportions of calcareous earth, than 
 our diseased lands have received, are very common in France and 
 England, without any such effect being produced. 
 
 From, the numerous facts of which these are examples, it is cer- 
 tain that calcareous earth acting alone, or directly, has not caused 
 this injury ; and it seems most probable that the cause is some new 
 combination of lime formed in acid soils only; and that this new 
 combination is hurtful to grain under certain circumstances; which 
 
RECAPITULATION. 159 
 
 we may avoid, and is liigbly l3eneficial to every kind of clover. 
 Pcrliaj^s it is the [hamate, or some other vegetable] salt of lime, 
 formed by the calcareous manure combining with the acid of the 
 soil, which, not meeting with enough vegetable matter to combine 
 with and fix in the soil; causes, by its excess, all these injurioua 
 eflfects. 
 
 CHAPTER XIX. 
 
 EECAPITULATION AND MORE FULL STATEMENTS OF THE EFFECTS 
 OF CALCAREOUS MANURES. 
 
 Proposition 5 — contimied. 
 
 From the foregoing experiments may be gathered most of the 
 effects, both injurious and beneficial, to be expected from calcareous 
 manures, on the several kinds of soils there described. Information 
 obtained from statements in detail of agricultural experiments is 
 far more satisfactory, to the attentive and laborious inquirer, than 
 a mere report of the general opinions of the experimenter, derived 
 from the results. But however conclusive may be this mode of re- 
 porting facts, it is necessarily deficient in method, clearness, and 
 conciseness. It may therefore be useful to bring together the 
 general results of these experiments in a somewhat digested form, 
 to serve as rules for practice. Other effects of calcareous manures 
 will also be stated, which are likewise established by experience, 
 but which did not belong to any one accurately observed experiment. 
 
 The results that have been reported confirm in almost every 
 particular the chemical powers before attributed to calcareous ma- 
 nures, by the theory of their action. It is admitted that causes 
 and effects were not always proportioned, and that sometimes 
 trivial apparent contradictions were presented. But this is inevi« 
 table, even with regard to the best established doctrines, and the 
 most perfect processes in agriculture. There are many practices 
 universally admitted to be beneficial • yet there are none of these 
 which are not found sometimes useless, or hurtful, on account of 
 some other attendant circumstance, which was not expected, and 
 perhaps not discovered. Every application of calcareous earth to 
 a deficient soil is a chemical operation on a great scale. Decompo- 
 sitions and new combinations are produced, and in a manner gene- 
 rally conforming to the operator's expectations. But other and 
 unknown agents may sometimes have a share in the process, and 
 thus cause unlooked-for results. Such differences between jiractice 
 and theory have sometimes occurred in my use of calcareous ma- 
 
160 RESULTS HAVE CONFOKMEL* TO TIlEUiiY. 
 
 nurcs (as may be observed in some of the reported experiments), 
 but they have neither been frequent, uniform, nor important. 
 
 [But in nearly all such cases of disproportion between causes 
 and eflfects in the use of marl, the manner of variation has been 
 in the effects surpassing the anticipated power of the causes (as 
 previously inferred from reasoning and in advance of any practice), 
 and in very few, if indeed any cases, of the contrary operation, of 
 the results falling short of what might have been inferred from the 
 theory of the action of calcareous manures. For such variation as 
 this, it may be that no reader will require either excuse or explana- 
 tion ; nevertheless it is as much due to truth that it should be 
 stated, as if the opposite kind of difference existed. 
 
 Before my earliest trials, or practical knowledge, of the effects 
 of marl, I was well assured, by my theoi'etical reasoning, that this 
 manure would correct the acidity of poor soil, and enable it to be 
 enriched by putrescent manures. But I was still totally at a loss 
 to know, or to guess, how much calcareous earth would be required 
 for that result, or how much time might be required for the suffi- 
 cient quantity to produce its full effect ; and there were grounds to 
 fear that the quantity of the manure and time for its operation, 
 and consequently the cost compared to profit, would be much 
 greater than after-experience has shown. If 1000 bushels of ordi- 
 nary marl had been required for an acre, and 10 years' time for that 
 application to raise the product to double its previous rate, the 
 theory of the action of calcareous manures would have been sus- 
 tained. But in fact, as great effect as this has been usually pro- 
 duced (in judicious and proper practice), by measures of marl and 
 of time less by three-fourths than those just stated. And thus, 
 while effects have almost universally exceeded in measure the sup- 
 posed power of their causes, I may safely assert that in not a sin- 
 ■ gle case, in the tide-water region, of a judicious application of 
 marl or lime, has it been known that the effect fell short of what 
 would be indicated by my theory of the action of calcareous earth 
 as manure. 
 
 But there is still another exception to admit, if it be one, or of 
 apparent want of accordance between theory and practice; and 
 unluckily, this case is of the effects falling short of the supposed 
 power of causes. There has as yet been made but little use of 
 lime in the region immediately above the granite ridge which forms 
 the lower falls of our eastern rivers. But almost all the failures 
 of lime to act that have been heard of, or of effects falling much 
 short of what were expected and are usual, are among the few ex- 
 periments which have been made within fifty miles above the 
 granite ridge. While truth requires that the fact of these failures 
 should be stated, I pretend not to account for them. It may be 
 the case, and probably is, that there is a general difference of 
 
DIFFERENCE OF LANDS. 161 
 
 cliemieal constitution between lands even of like apparent texture 
 and qualities, above and below the falls, as there certainly was a 
 great difference of geological formation.* 
 
 Of the poor lands above the falls, my knowledge is but slight, 
 and founded only on general and slight personal observation, or the 
 report and better information of resident cultivators. But judg- 
 ing from such uncertain lights, I would infer that the lands above 
 the falls were much less acid than those below, even when as poor. 
 The growth of pine and of sorrel is more scarce on lands above the 
 falls ; and gypsum often acts there on natural soils, and lime (in 
 some known trials) has produced but slight benefit. On the con- 
 trary, gypsum is scarcely ever operative on any natural soil below 
 the falls (that is, on any of the great body of acid soil), and lime 
 never fails to act well on these same lands. 
 
 The most important observation to be made on the disproportion 
 of causes and effects, in the tide-water region, is in regard to good 
 neutral soils, and especially as to that best class known by the 
 common name of "chocolate" or "mulatto land," or "hazel loam," 
 as designated more properly in England. On such soils, which 
 constitute the chief value of the best farms of James river, the 
 applications of lime have been the most extensive, and always 
 highly effective. 
 
 * The falls of the rivers of eastern Virginia mark the eastern and lower 
 outline of the primitive region. The soils of that region have been formed 
 more inimediately or recently from the disintegration of rocks ; and this 
 natural process is still going on, in the gradual continued disintegration of 
 the still remaining rocks, and even of gravel and sand. For, however much 
 the materials of the soils have been intermixed by natural causes, and the 
 soils thereby made more of uniform character, still each remaining stone, 
 and even each grain of sand, is a fragment and sample of the original com- 
 pound rock from which it crumbled down. Most of the different rocks 
 contain, chemically combined, several, if not all the important chemical 
 earths; though, as in poor soils, silica and alumina are usually most 
 abundant, and lime and magnesia are in very minute proportions. Still, 
 in the intermixture of fragments of all the ordinary rocks of that region, 
 and by their continued gradual disintegration, there are still furnished to 
 every soil so formed new supplies of all the necessary earths, and of potash 
 also. Small as may be the amount of lime and potash, there is some of 
 each furnished every year to evei'y such soil, by the disintegration of its re- 
 maining fragments of rocks. 
 
 On the other hand, the soils and sub-soils of the region below the falls 
 are composed of a much earlier disintegration of rocks. Except some 
 rarely found hard pebbles, and gravel (mostly of quartz), all rounded 
 by being water-rolled, everything in these soils has been reduced to the 
 minutest particles. Even if these soils had been originally produced from 
 the same kinds of rocks, as those above the falls, still there must be a 
 great difference between the soils in which the process of disintegration 
 and decomposition is yet in continual progress, and those in which it has 
 been completed and has Ceased for countless ages. 
 
 14* 
 
162 CALCAREOUS "WITH VEGETABLE MATTER. ' 
 
 The fact tliat the effects of calcareous manures so generally ex- 
 ceed in measure the supposed power and operation of the causes, 
 and more especially in regard to neutral soils, seemed to indicate 
 that calcareous manures possessed other fertilizing powers, be- 
 sides those set forth in Chapter VIII. This, which formerly was 
 stated as a probability, may now be considered as certain. Evi- 
 dence of such effects, and of the supposed auxiliary and lately 
 known causes, will hereafter be presented. Dismissing them from 
 consideration for the present, I will return to stating the results of 
 applying marl as they have occurred almost without exception in 
 my own earlier practice, and which are confirmed by the con- 
 currence of all known and certain testimony in regard to practical 
 operations in the marl region of Virginia.] 
 
 Under like circumstances in other respects, the benefit dei'ived 
 from marling will be in proportion to the quantity of vegetable or 
 other putrescent matter given to the soil. It is essential that the 
 cultivation should be mild, and that little or no grazing be per- 
 mitted on poor lands under regular tillage, and which have no 
 supply of putrescent manure, except the grass and weeds growing 
 on them while at rest. AVherever farm-yard manure is used, the 
 land should be mai-led heavily ; and if the marl is applied first, so 
 much the better. The marl cannot act by fixing the other manure, 
 except so far as they are in contact, and when both are well mixed 
 with the soil. 
 
 [When I first asserted the agency and force of calcareous ma- 
 nures in fixing alimentary manures in soils, and maintained the 
 great and indispensable necessity of that operation, the proposition 
 was founded almost exclusively on reasoning, and on observation 
 of natural soils, and not at all on practical effects then experienced 
 from applications of marl or lime. From the very nature of the 
 case, such effects as these, however important and valuable, could 
 not be seen at first, nor fully even in a very few years after begin- 
 ning to marl, nor their extent be understood and appreciated. 
 ]\Ioreover, my earlier experience had shown so fully the incapacity 
 of my acid or naturally poor soils to retain alimentary manures, 
 and my labours and expenditures to apply them had been so very 
 unprofitable, that I was not myself prepared for the full extent of 
 the contrary operation, after marl had been applied. And though 
 the views and estimation of such new operation have been yearly 
 enlarging, from the experience of practical results, still my esti- 
 mate of the fi-ic!n(j value of marl fell short of what is now confi- 
 dently believed, and which is every season manifest, of the greater 
 effect and permanency, and far greater profit of alimentary ma- 
 nures, caused solely by the presence of calcareous earth in the 
 same soils. Notwithstanding that the theory of the action of cal- 
 careous manures, as set forth in this essay, 'and published as early 
 
CALCAREOUS WITH VEGETABLE MATTER, 163 
 
 as 1821, made this fixing operation the first of the two most im- 
 portant agencies, and though that theoretical view guided my prac- 
 tice from the beginning, still it was not u.ntil after a long time, that 
 gradually and slowly I fully and truly estimated the full value and 
 profit of this operation. My early and zealous eiforts (before be- 
 ginning to marl) to improve naturally poor lands by the vegetable 
 and animal manures of the farm, had been so much disappointed, 
 and the effects had been so inconsiderable as well as so fleeting, 
 that it was long before I arrived at the conviction of the full ex- 
 tent of the opposite and new condition of the soil. But during 
 latter years, the certain and j^rofitable operation, and durable ope- 
 ration, of every kind of vegetable or alimentary manure, no mat- 
 ter how or when applied, has been made obvious ; and now my 
 estimate of value would be, that if marling had no other operartion 
 whatever than this one of making other manures much more active 
 and durable, the profit from this one source alone would amply re- 
 ward all the usual labours and expenses of the operation.*] 
 
 On "galled" spots, from which all the soil has been washed, and 
 where no plant can live, the application of mai'l alone is utterly 
 useless ; at least, until time and accident shall furnish some addi- 
 tion of vegetable matter also. Putrescent manures alone would 
 there have but little efiect, unless in great quantity, and would 
 soon be all lost. But marl and putrescent matter together serve to 
 form a new soil, and thus both are brought into useful action ; the 
 marl is made active, and the putrescent manure permanent. The 
 only parfect cures that I have been able to make, at one operation, 
 of galls produced upon a barren sub-soil, were by applying heavy 
 dressings of both calcareous and putrescent manures together ; and 
 this method may be relied on as certainly efi"ectual. But though 
 a fertile soil may thus be created, and fixed durably on galls othei*- 
 wise irreclaimable, the cost will generally exceed the vakie of the 
 land recovered, from the great quantity of putrescent matter re- 
 quired. Much of our acid hilly land has been deprived, by wash- 
 ing, of a considerable portion of its natural soil, though not yet 
 made entirely barren. The foregoing remarks equally apply to 
 this kind of land, to the extent that its soil has been carried off. 
 It will be profitable to apply marl to such land ; but its effect will 
 be diminished', in proportion to the previous removal of the soil. 
 Calcareous soils, from the difference of texture, are much less apt 
 to wash than other kinds. Within a few years after marling a hilly 
 
 [* Confirmatory testimony. — Liming "increases tlie effect of a given ap- 
 plication of [putrescent] manui'e ; calls into action that which, having been 
 previously added, appears to lie dormant ; and though manure must be 
 plentifully laid upon tlie land after it has been well limed, yet the same 
 degree of productiveness can still be maintained at a less cost of manure 
 than where no lime has been applied." Johnston's Lectures, p. S91.] 
 
164: MARLING PREVENTS WASHING EFFECTS OF RAINS. 
 
 field that has been injured by washing, many of the old gulleys 
 will begin to produce vegetation, and show that a soil is gradually 
 forming from the dead vegetables brought there by winds and 
 rains, although no means bad been used to aid this operation. 
 
 [This newly acquired ability to resist the washing power of rains, 
 is one of the most beneficial effects of marling on hilly lands. 
 And this effect is no less certain, than it is conformable to the 
 theory of the action of marl and to reason. On soils containing 
 very little lime (or almost none, as in naked sub-soils), whether 
 they be sandy or clayey, there is nothing to combine the vegetable 
 matter with the soil, nor the different ingredients of the soil with 
 each other. Consequently they have no cohesion, and whenever 
 made very soft, or semi-fluid by rains, and there is any declivity, 
 there is nothing to prevent the soil, or upper surface, being washed 
 off by excessive rain, though falling gently. Of course, torrents 
 of rain produce the same injurious eflects much more rapidly and 
 effectually. But when such soils have been made calcareous, a 
 chemical combination and bond of union and coherence is formed 
 between the lime and the putrescent or organic matter, and of both 
 with the silicious and argillaceous parts of the soil ; which combi- 
 nation is able to resist any but an unusual force of the washing 
 action of rains.* Moreover, by the increase of productive power 
 thus given, grass grows more kindly and rapidly, and by its decay 
 the vegetable mould is continually augmented, and thereby the 
 power of resisting washing is still more inci'eased as the fertility 
 of the soil is increased. This is but another aspect and operation 
 of the power of calcareous manure in soils to fix and retain 
 manures. 
 
 The tendency of some very sandy soils to be moved, and in part 
 blown away, by high winds, is also produced by the want of cohe- 
 sion of the particles. The wind operates on the soil in its dry 
 state in the same way, and for the same defect of its constitution, 
 as does water in rain torrents. The same remedy, calcareous ma- 
 nure, is even more effectual to prevent the wasting operations of 
 wind than of water. The absorbent power given to the before 
 loose and more rapidly drying particles of sandy soils serves to 
 preserve more moisture at the surface. This alone would tend 
 much to prevent the moving effect of the wind, which can take 
 place only on earth nearly or quite dry and pulverulent. Further, 
 both directly and indirectly (by combining the organic with the 
 earthy parts), the calcareous manure, when thoroughly diffused, 
 interposes some cohesive particles between the particles of sand. 
 
 * Confirmation. — Johnston speaks of organic (or putrescent) matter be- 
 ing presented to the action of lime "in the state of chemical combination 
 with eartliy substances — with the alumina, for example, and with lime and 
 magnesia — already existing in the soil." p. 402. 
 
AND THE BLOWING AWAY OP SANDS BY WIND. 165 
 
 The effect in practice is most striking. Fields and farms, which 
 before were noted for the dense and enormous clouds of dust pass- 
 ing away from them in every high and drying wind, become free 
 from such loss in a short time after being marled or well limed.*] 
 
 The effect of marling will be much lessened by the soil being 
 kept under exhausting cultivation. Such were the circumstances 
 under which we may suppose that marl was tried and abandoned 
 many years ago, in the case referred to in page 114. Proceeding 
 upon the false supposition that marl was to enrich by direct action, 
 like dung, it is most probable that it was applied to some of the 
 poorest and most exhausted land, for the purpose of giving the 
 manure what is called a '' fair trial. '^ The disappointment of such 
 ill-founded expectations was a sufficient reason for the experiment 
 not being repeated, or being scarcely ever referred to again, unless 
 as evidence of the worthless^ness of marl. Yet with proper views 
 of the action of this manure, this experiment might at first have 
 as well proved the early efficacy and value of marl, as it now does 
 its durability. ■{- 
 
 When acid lands are equally poor, the increase of the first crop 
 from marling will be greater on sandy, than on clay soils ', though 
 the latter, by heavier dressings and longer time, may ultimately 
 
 * I have heard (but do not know from my own personal observation), 
 that the well-known and valuable farm of Lower Wj^auoke, the property of 
 the late Fielding Lewis, presented a remai'kable example of the frequent 
 loss of soil by winds, before the liming, and of the cessation afterwards. 
 
 On March 1st, 1850, a few days before the writing of these lines, I saw 
 from the eminence on which my present dwelling stands, a very remarka- 
 ble exhibition of this conservative power of marl. The night before, there 
 had fallen a heavy shower ; and also some drizzle after day-break, suc- 
 ceeded by bright sunshine and a furious wind. Though the rain-water had 
 stood in puddles in the ruts and low spots of hard roads in the morning, 
 by 11 o'clock, a. m., dense clouds of dust, rising as high as the tops of the 
 forest trees on the higher lands, were seen drivQU off from the light fields 
 of three different and detached neighbouring farms, and which had not been 
 marled. A miich broader space of surface, intermediate or adjoining, was 
 also in view, much of which was equally sandy, and fully as much exposed 
 to the wind. All this land (except one small field, which was both stiff, and 
 low-lying, and of course not then dry) had been well marled ; and from 
 none of it was any dust seen to rise. Of the several thousand acres of 
 arable land in sight, and mostly of sandy soil, all the farms and fields not 
 marled (and not of clay or wet soil) might have been designated by the 
 clouds of dust then rising and passing off from them. 
 
 f Confirmation. — "One thing, however, must be borne in mind by those 
 who, in adopting the best system of [successive] liming, do not wish both 
 to injure their land and to meet with ultimate disappointment. Organic 
 matter — in the form of farm-yard manure, or green crops ploughed imdcr, 
 &c. &c., must be abundantly and systematically added, if at the end of 20 
 or 40 years the land in which the full supply of lime is kept up is to retain 
 its original fertility. . . . Otherwise present fertility and gain will be 
 followed by future barrenness and loss." Johnston's Lectures, p. 386. 
 
166 QUANTITIES OF MARL REQUIRED. 
 
 become the best land, at least for wbeat and for grass.* The moro 
 acid the growth of any soil is, or would be, if suffered to remain, 
 the more increase of crop may be expected from marl; which is 
 directly the reverse of the effects of putrescent manures. The in- 
 crease of the first crop on my worn acid land, I h-ave never known 
 under fifty per cent., and more often it is as much as one hundred; 
 and the improvement continues to increase, under mild tillage, to 
 three or four times the original product of the land. (See Exp. 
 11, page 185, and Exp. 4 and 6.) In this, and other general state- 
 ments of effects, I suppose the land to bear not more than two 
 grain crops in four years, and not to be subjected to grazing during 
 the other two ; and that a suflicient cover of marl has been laid on 
 for use, and not enough to cause disease. It is true, that it is 
 difficult, if not impossible, to fix that proper medium, varying as it 
 may on every change of soil, of cropping, and of the kind of marl. 
 But whatever error may be made in the proportion of marl applied, 
 let it be on the side of light dressing (except where putrescent 
 manures are also laid on, or designed to be laid on before the next 
 course of crops begins) ; and if less increase of crop is gained to 
 the acre, the cost and labour of marling will be lessened in a still 
 greater proportion. If, when tillage has served to mix the marl 
 well with the soil, sorrel should still show to any extent, it will 
 sufficiently indicate that not enough marl had been applied, and 
 that it may be added to, safely and profitably. If the nature of the 
 soil, its condition and treatment, and the strength of the marl, all 
 were known, it would be easy to direct the amount of a suitable 
 dressing ; but without knowing these circumstances, it will be 
 safest to give not more than 200 or 2.50 bushels of marl, of say 40 
 per cent, to the acre of worn acid soils. Twice or thrice as much 
 might be given, safely and profitably, to newly cleared wood-land, 
 or well manured land. Or, I would advise that the first dressing 
 should not exceed the quantity which would furnish one per cent. 
 of carbonate of lime to the soil, for its ploughed depth. If only 
 3 inches deep, 218 bushels of marl, of 40 per cent., would furnish 
 1 per cent, to the soil. Besides avoiding danger, it is more profita- 
 ble to marl lightly at first on weak lands. If a farmer can carry 
 out only ten thousand bushels of marl in a year, he will derive 
 more product, and confer a greater amount of improvement, by 
 spreading it over forty acres of the land intended for his next 
 crop, than on twenty ; though the increase to the acre would pro- 
 bably be greatest in the latter case. By the lighter dressing, the 
 land of the whole farm will be marled, and be storing up vegetable 
 matter for its progressive improvement, in half the time that it 
 could be marled at double the rate. 
 
 * Confirmation. — "On clay lands more lime is necessary than on light 
 and sandy soils." Johnston's Lectures, p. 382. 
 
PRESERVING OF VEGETABLE MATTER, 1G7 
 
 The greater part of the calcareous earth applied at one time 
 cannot begin to act as manure before several years have passeJ, 
 owing to the coarse state of many of the shells, and the want of 
 thoroughly mixing them with the soil. Therefore, if enough marl 
 is applied to obtain its full eifcct on the first course of crops, there 
 will certainly be too much afterwards. 
 
 Perhaps the greatest profit to be derived from marling, though 
 not the most apparent in the first few years, is on such soils as are 
 full of wasting vegetable matter. Here the efiect is mostly pre- 
 servative, and the benefit and profit may be great, even though the 
 increase of crop may be very inconsiderable. Putrescent manure 
 laid on any acid soil, or the natural vegetable cover of those newly 
 cleared, without marl, would soon be lost, and the crops reduced to 
 one-half or less. But when marl is previously applied, this waste 
 of fertility is prevented ; and the estimate of benefit should not 
 only include the actual increase of crop caused by marling, but as 
 much more as the amount of the diminution which would otherwise 
 have followed. Every intended clearing of wood-land, and espe- 
 cially of those under a second growth of pines, ought to be marled 
 before cutting down ; and it will be still better if it can be done 
 several j'cars before. If the application is delayed until the new 
 land is brought under cultivation, though much putrescent matter 
 will be saved, still more must be wasted. By using marl some 
 years before obtaining a crop from it, as many more successive 
 growths of leaves will be converted to useful manure, and fixed in 
 the soil; and the increased fertility will more than compensate for 
 the delay. By such an operation, the fanner makes a loan to the 
 soil, at a distant time for payment, but on ample security, and at a 
 high i-ate of compound interest. 
 
 Some experienced (though certainly not land-improving) culti- 
 vators have believed that the most profitable way to manage pine 
 old fields, when cleared of their second growth, was to cultivate 
 them every year, until worn out — because, as they said, such land 
 would not last much longer, no matter how mildly treated. This 
 opinion, which would seem at first so absurd, and in opposition to 
 all the received rules for good husbandry, is considerably supported 
 by the properties which are here ascribed to such soils. When 
 these lands are first cut down, an immense quantity of vegetable 
 matter is accumulated on the surface, which, notwithstanding its 
 accompanying acid quality, is capable of making two or three crops 
 nearly as good as the land was ever before able to bring. But as 
 the soil has no power to retain this vegetable matter, it will begin 
 rapidly to decompose and waste, as soon as exposed to the sun ; 
 and will be lost, except so much as is caught, while escaping, by 
 the roots of growing crops. The previous application of marl^ 
 
1G8 ErFECTs ON "free light land." 
 
 however, would make it profitable in these, as well as other cases, 
 to adopt a mild and meliorating course of tillage. 
 
 Less improvement will be obtained by marling worn soils of the 
 kind called " free light land/' than other acid soils which originally 
 produced much more sparingly. The early productiveness of this 
 kind of soil, and its rapid exhaustion by cultivation, at first view 
 seem to contradict the opinion that durability and the ease of im- 
 proving by putrescent manures are proportioned to the natural 
 fertility of the soil. But a full consideration of the circumstances 
 will show that no such contradiction exists. 
 
 In defining the term natural fertility, it was stated that it should 
 not be measured by the earliest products of new land, which might 
 be either much reduced, or increased, by temporary causes. The 
 early fertility of free light land is so rapidly destroyed, as to take 
 away all ground for considering it as fixed in, and belonging to the 
 soil. It is like the effect of dung on the same land afterwards, 
 which throws out all its benefit in the course of one or at most two 
 years, and leaves the land as poor as before. But still it needs 
 explanation why so much pi'oductiveness can at first be exerted by 
 any acid soil, as in those described in the 14th experiment. The 
 causes may be found in the following statement. These soils, and 
 also their sub-soils, are principally composed of coarse sand, which 
 makes them of more open texture than best suits pine, and (when 
 rich enough) more flivourable to other trees, the leaves of which 
 have no natural acid, and therefore decompose more readily. As 
 fast as the fiillen leaves rot, they are of course exposed to waste ; 
 but the rains convey much of their finer parts down into the open 
 soil, where the less degree of heat retards their final decomposition. 
 Still this enriching matter is liable to be further decomposed, and 
 to final waste ; but though continually wasting, it is also continu- 
 ally added to by the rotting leaves above. The shelter of the 
 upper coat of unrotted leaves, and the shade of the trees, cause 
 the first as well as the last stages of decomposition to proceed 
 slowly, and to favour the mechanical process of the products being 
 mixed with the soil. But there is no chemical union of the vege- 
 table matter with the soil. When the land is cleared, and opened 
 by the plough, the decomposition of all the accumulated vegetable 
 matter is hastened by the increased action of sun and air, and in 
 a short time everything is converted to food for plants. This 
 abundant supply suffices to produce two or three fine crops. But 
 now, the most fruitful source of vegetable matter has been cut ofl"; 
 and the soil is kept so heated (by its open texture) as to be unable 
 to hold enriching matters, even if they were furnished. The land 
 soon becomes poor, and must remain so, as long as these causes 
 operate, even though cultivated under the mildest rotation. When 
 the transient fertility of such a soil is gone, its acid qualities 
 
OPERATION OP DEEPENING SOIL. 169 
 
 (which ■wore before concealed in sonic measure by so mixcli enrich- 
 ing matter) become evident. Sorrel and broom-grass cover tho 
 land, and if allowed to stand, pines will then take complete pos- 
 session, because the poverty of the soil leaves them no rival to 
 contend with. 
 
 Marling deepens cultivated sandy soils, even lower than the 
 plough may have peueti'ated. This was an unexpected result, and 
 when first observed seemed scarcely credible. But this effect also 
 i.s a consequence of the power of calcareous earth to fix manui'cs. 
 As stated in the foregoing paragraph, the soluble and finely divided 
 particles of rotted vegetable matters are carried by the rains below 
 the soil ; but as there is no calcareous earth there to fix them, they 
 must again rise in a gaseous form, after their last decomposition, 
 unless previously taken up by growing plants ; [or descending still 
 lower in the sub-soil, dissolved in rain-water, may go ofi" into the 
 sources of springs, and so be lost to the land.] But after the soil 
 is marled, calcareous as well as putrescent matter is carried down 
 by the rains as far as the soil is open enough for it to pass. This 
 will always be as deep as the ploughing has been, and somewhat 
 deeper in loose earth; and the chemical union formed betweea 
 these different substances serves to fix both, and thus increases the 
 depth of the soil. This effect is very different from the deepening 
 of a soil by letting the plough run into the barren sub-soil. If, 
 by this mechanical process, a soil of only three inches is increased, 
 to six, as much as it gains in depth, it loses in richness. But when 
 a marled soil is deepened gradually, its dark colour and apparent 
 richness are increased, as well as its depth. Formerly, single-horse 
 ploughs were used to break all my acid soils, and even these would 
 often turn up sub-soil. The average depth of soil on old land did 
 not exceed three inches, nor two on the newly cleared. Even be- 
 fore marling was commenced, my ploughing had generally sunk 
 into the sub-soil — and since 1825, most of this originally thin soil 
 has required three mules, or two good horses to a plough, to break 
 the necessary depth. The soil is now fxom six to eight inches 
 deep generally, from the joint operation of marling and deepening 
 the ploughing a little in the beginning of every course of crops ; 
 [and to that depth, or very nearly, the land is now ploughed when- 
 ever preparing for corn, or for wheat on clover. The summer 
 ploughing of clover land requires four mules to a plough. 
 
 Since marling was begun, the deepening of the soil has much 
 more generally preceded than followed the deepening of the plough- 
 ing. How destructive to the power of soil this present depth of 
 ploughing would have been, without marling, may be inferred from 
 the continued decrease of the crop, through four successive courses 
 of a very mild rotation, on the spot kept without marl iir experi- 
 ment 10. Yet the depth of ploughing there did not exceed sis 
 15 
 
170 HASTENING MATURITY OF CROPS. 
 
 inclies, and depths of nine and even twelve inches were tried; with- 
 out injury, on parts of the adjacent marled land. — 18o5.] 
 
 [This remarkable and valuable effect of aiarling, in deepening 
 the soil, is increased in action by the sub-soil being sandi/, which 
 is commonly deemed the worst kind of sub-soil. Land having a 
 clay sub-soil, which is known in common parlance as land with "a 
 good foundation," is almost universally prized ; and that impervi- 
 ous sub-soil is supposed necessary to prevent the manure and the 
 rains from sinking, and being lost. And such, indeed, may be 
 among the disadvantages, before marling, of poor land having a 
 Bandy sub-soil. But not so after marling. While the open texture 
 of such a sub-soil permits so much of the water as is superfluous 
 and injurious to sink and disappear, and the combined manures to 
 sink enough to deepen the soil (by converting barren sub-soil to 
 productive soil), the attractive force of the calcareous earth, for both 
 putrescent matter and moisture, will much more effectually prevent 
 either from being lost to the soil, than would the mechanical ob- 
 struction of a clay sub-soil. Great as are the objections enter- 
 tained by most farmers to sandy sub-soils, or to what they call 
 " land without any foundation," I would decidedly prefer such to 
 lands having an impervious clay sub-soil — supposing both to be 
 ef[ually barren. The subjects of all my experiments stated as 
 : mtidc on acid sandy loams, had also sub-soils of yellow and barren 
 sand ; and on such lands have been made my greatest and most 
 profitable improvements by marling. However, a sub-soil (and 
 also a soil) more of medium texture, would no doubt have been as 
 much better than the very sandy, as the latter was better than the 
 very stiff and impervious clay sub-soils. — 1842.] 
 
 [Besides the general benefit which marling causes equally to all 
 crops, by making the soils they grow on richer and more productive, 
 there are other particular benefits which affect some plants more 
 than others. For example, marling serves to make soils warmer, 
 and thereby hastens the ripening of every crop, more than would 
 take place on the like soils, if made equally productive by other 
 than calcareous manures.* This quality of marled land is highly 
 important to cotton, as our summers are not long enough to mature 
 the later pods. 
 
 Wheat also derives especial benefit from the warmth thus added 
 to the soil. It is enabled better to withstand the severe cold of 
 winter ; and even the short time by which its ripening is forwarded 
 by marling, serves very much to lessen the danger of that crop 
 
 * Conjirmaiion. — '^Liming hastens the maturity of the crop. — It is true of 
 
 all our cultivated crops, but especially those of com [wheat] that their 
 
 ^ growth is attained more speedily when the land is limed, and that they are 
 
 ready for the harvest from 10 to 14 days earlier." Johnston's Lectures, 
 
 p. 302. 
 
PECULIAR BENEFITS TO WHEAT, ETC. 171 
 
 from rust, tlie most frequent and destructive of all its diseases. 
 This, much more than any other grain crop, seems to be especially 
 favoured by calcareous earth in the soil. The product is not only 
 always much increased, but other accessary effects are produced, 
 for want of which on the lands most highly manured, but still defi- 
 cient in lime, the wheat crop is made feeble, and in danger of great 
 loss or destruction from different disasters. Thus, if a heavy 
 growth of wheat is produced by putrescent manures only, the straw 
 is weak, and the crop is almost sure to be laid by its own weight 
 before ripening, even without stormy weather, and is very much 
 reduced in value. On limed or calcareous land, the crop is far 
 safer ; and is seldom laid, even when very heavy, unless by violent ' 
 storms, which is owing to the greater strength of the straw.* The 
 opening of the texture of close clay soils by the operation of cal- 
 careous manures, by permitting the better percolation of surplus 
 water, serves in some measure as drainage, and especially enables 
 wheat better to withstand the always redundant wet of winter on 
 such soils, which is much more the cause of '' winter-killed" wheat, 
 than the severity of cold, or altoi'ations of temperature. Wheat 
 also profits by the absorbent power of marled land (by which sands 
 acquire, to some extent, the best qualities of clays), though less 
 so than clover and other grasses that flourish best in a moist^^ 
 climate. 
 
 Indian corn does not need more time for maturing than our sum- 
 mers afford (except on the poorest land), and can sustain much 
 drought without injury, and therefore is less aided by these quali- 
 ties of marled land. Most (if not all) the different plants of the 
 leguminous or pod-bearing tribe, including all the varieties of clo- 
 ver, peas, and beans, derived such peculiar benefit from marling, 
 that it indicated some peculiar operation on these plants. "What 
 this is, has recently been made clear by the researches of chemists. 
 The analyses of the ashes of leguminous plants show that they 
 contain very large proportions of lime, and far exceeding those of 
 any other cultivated plants. Of course, they need a larger and 
 ready supply of lime in the soil ; and they profit in proportion to 
 their wants, by such supply being furnished. — 1845.] 
 
 On acid soils, without heavy manuring, it is scarcely possible to 
 raise red clover ; and even with every aid from putrescent manure, 
 the crop will be both uncertain and unprofitable. The recommenda- 
 tion of this grass, as part of a general system of cultivation and 
 improvement, by the author of ' Arator,' is sufficient to prove that 
 his improvements were made on soils far better than such as are 
 common. Almost every zealous cultivator and improver (in prospect) 
 of acid soil has been induced to attempt clover culture, either by 
 
 * Tliib effect is also affirmed by Johnston, p. 392. 
 
172 TECULIAR, BENEFIT TO CLOVER. 
 
 the recommendations of wi'iters on this grass, or by tlie succesa 
 witnessed on better constituted soils elsewhere. The utmost that ] 
 has been gained, by any of these numerous efforts, has been some- j 
 times to obtain one, or at most two mowings, of middling clover, j 
 on some very rich lot, which had been prepared in the most perfect I 
 manner by the pi-evious cultivation of tobacco. Even in such ; 
 situations, this degree of success could only be obtained by the 
 concurrence of the most favourable seasons. Severe cold, and 
 sudden alternations of temperature in winter and spring, and the 
 spells of hot and dry weather which we usually have in summer, j 
 were alike fatal to the growth of clover, on so unfriendly a soil. 
 The few examples of partial success never served to pay for the 
 "more frequent failures and losses ; and a few years' trial would ( 
 convince the most ardent, or the most obstinate advocate for the 
 clover husbandry, that its introduction on the ordinary poor soils 
 of lower Virginia was absolutely impossible ; and scarcely pi'acti- 
 cable, even partially, on such lands when very highly manured. , 
 Still the general failure was, by common consent, attributed to any- ' 
 thing but the true cause. There was always some reason offered 
 for each particular failure, sufficient to cause it, and but for which ; 
 (it was supposed) a crop might have been raised. Either the I 
 young plants were killed by freezing soon after first springing from j 
 the seed — or a drought occurred when the crop was most exposed i 
 to the sun, by reaping the sheltering crop of wheat — or native and i 
 hardy weeds, aided by very favourable weather, overran the crop ; * 
 and all such disasters were supposed to be increased in force, and ' 
 rendered generally fatal, by our sandy soil, and hot and dry sum- 
 mers. But after the true evil, the acid nature of the soil, is re- j 
 moved by marling, clover ceases to be a feeble exotic. If with- j 
 standing the early dangers of frost on the newly sprouted plants, j 
 and of drought soon after, clover is then naturalized on our soil, . 
 and is able to contend with rival plants, and to undergo every . 
 severity and change of season, as safely as our crops of corn and 
 wheat — and offers to our acceptance the fruition of those hopes of , 
 profit and improvement from this grass, with which previously we ,j 
 had only been deluded. 
 
 After much waste of seed and labour, and years of disappointed 
 efforts, I had abandoned clover as utterly hopeless. But after 
 marling the fields on which the raising of clover had been vainly 
 attempted, there arose from its scattered and feeble remains, a 
 growth which served to prove that its cultivation would then be 
 safe and profitable. It has since been gradually extended over all 
 the fields. It will stand well, and maintain a healthy growth on 
 the poorest marled land ; but the crop is too scanty for mowing, or 
 perhaps for profit of any kiud, on most poor sandy soils, unless 
 aided by gypsum. Newly cleared lands yield better clover than 
 
THE BAD WEEDS PRODUCED BY CALXING. 173 
 
 tlio old, tliougli the latter may produce as heavy grain crops. The 
 remarkable crops of clover raised on some-very poor clay soils, after 
 marling, have been already described. This grass, even without 
 gypsum, and still more if aided by that manure, will add greatly 
 to the improving power of marl ; but it may do as much harm as 
 service, if we greedily take from the soil all of the supply of 
 putrescent matter which it affords.* 
 
 Some other plants, less welcome than clover, are equally favoured 
 by marling. Unless both the tillage and the rotation of crops be 
 good, greensward (^poa pratensis), blue grass (^j^oa comjrrcssa), 
 wire-grass (cynodon dactylo'ii), and the vetch, or partridge pea 
 (yicia sativa), will soon increase so as to be not less impediments 
 to tillage, or to the grain crops, than manifest evidences of an 
 entire change in the character and power of the soil. 
 
 [The power of calcareous manures is still more strongly shown 
 in the eradication of certain plants, as has been before incidentally 
 
 [* Tliere is great difficulty, and frequent failure of securing a "stand" 
 of the young clover plants, even when the subsequent growth of those 
 which escape early destruction is ever so vigorous. This is not owing to 
 any defect of soil (after calxing), but to our climate. It is necessary to 
 BOW clover seed before the close of winter, to avoid, by its early growth, 
 the greater evils of the following summer's di-ought, which most afl'ects the 
 youngest plants. The time of sowing is usually not later than February. 
 It almost always happens that a succeeding warm spell causes most of the 
 seeds to sprout, and then a severe frost kills them, while in their most 
 tender state. Sometimes, the wliole young growth is thus killed by late 
 frosts. The danger from drought, and the hot sun, after reaping the 
 shading cover of wheat, is scarcely less than from frosts at the earlier 
 period. One or both of these disasters liave occurred for four of the first 
 five seasons for ray sowing clover on Marlbourue ; so that but one good 
 "stand" of plants, and of course but one sufficiently thick crop was ob- 
 tained. The loss was the greater, because no clover had previously been 
 on the land, and, of course, there was no volunteer growth, which other- 
 wise and usually furnishes as many plants as the new seed. Indeed, after 
 a field has once been well covered with clover, and the ripe seeds ploughed 
 under, there is not half the danger at any time afterwards of failing to 
 secure a stand of plants. 
 
 But a greater evil has been found than this, since the publication (in 
 1842) of the passages above reporting so favourably of the growth and 
 hardiness of clover. On the Coggius farm, and elsewhere, on the formerly 
 acid soils marled more than twenty years ago, the clover crops have recently 
 been much more apt to fail, as above, and are much inferior in product, 
 even when not failing to stand, than previously ; and this where the land 
 certainly has not lost anything of its richness, and where other crops than 
 clover show no diminution. It is not certain whether this change is owing 
 to the land being "clover-sick," (a common result in England, but not 
 known here, before), or that the acid of the soil (or sub-soil) is increasing 
 and overbalancing the qiiantity and effects of the calcareous earth. Some 
 facts sustain this'latter supposition. Eemarlings, at lighter than the earlier 
 rate, have been found, in some cases, to restore the before reduced power 
 of the land to produce clover.— 1849.] 
 15* 
 
174 ACID PLANTS ERADICATED. 
 
 mentioned. Sorrel (rumex acetocella) is the most plentiful and 
 injurious weed on the cultivated acid soils of lower Virginia; an 
 unmixed growth of poverty grass (aristida gracilis) is spread over 
 all such lands, a year after being left at rest; at a somewhat later 
 time broom-grass (^aiid i-oj^ioffon) of diflerent kinds covers them 
 completely ; and if suffered to remain unbroken a few years longer, 
 a thick growth of young pines will succeed. But as soon as such 
 land is sufficiently and properly marled, there remains no longer 
 the peculiar disposition or even power of the soil to produce these 
 plants. Sorrel is totally removed, and poverty grass no more is to 
 be found, where both in their turn before had entire possession. 
 The appearance of a single tuft of either of these plants is enough 
 to prove that the acid quality of the soil on that spot still remains, 
 and that either more marl, or more complete intermixture, is still 
 wanting. Thus, the presence of either of these plants is the most 
 unerring as well as most convenient and ready indication of a soil 
 wanting calcareous manure. The most laborious analyses, by the 
 most able chemists, directed to ascertain the different characters 
 of soils in this respect, are not to be compared for accuracy to the 
 tests furnished by either the appearance or total absence of sorrel 
 or poverty grass. In regard to broom-grass and pines, the change 
 is not so sudden, or complete ; but still the soil will have been 
 made manifestly unfriendly to both. Some striking apparent ex- 
 ceptions to these rules have caused some persons to doubt of their 
 correctness, when full examination of the circumstances would 
 have confirmed my positions. I have known a mere top-dressing 
 of marl, left for some years on a worn-out old field, to eradicate 
 the before general growth of broom-grass, and substitute a cover 
 of annual weeds. Yet on other tillage land, after marling and one 
 crop of wheat on fallow, I have seen 'the growth of broom-grass 
 return, and seemingly with greater than its former vigour. But 
 this return and vigour were but temporary, and the land is now 
 comparatively free from this injurious weed. When soil, already 
 filled with its seeds, is very imperfectly mixed with marl by plough- 
 ing, there is nothing to prevent the broom-grass springing from all 
 the spots not touched by the marl, whether these spots be above 
 or below or between unmixed masses of marl. And the growth 
 being thin and scattered, and not covering the surface completely 
 as formerly, will cause the separate tufts of broom-grass to be 
 much more luxuriant, and greater impediments to tillage, than 
 previously. But the next course of tillage will serve to mix the 
 marl and soil completely, and remove all this appearance of marl 
 being favourable, instead of destructive to broom-grass. Sorrel 
 may often be seen growing out of the heaps of pure marl, dropped 
 from the carts on acid laud, and the heaps left thus, unsprcad, 
 through a summer. But this apparent and very striking exception 
 
DIFFICULTIES WITHOUT CAUSE. 175 
 
 may bo fully exjjlained. The heaps of marl, thus left, had not as 
 yet by any intermixture affected the original composition of the 
 soil below ; and the seeds or roots of sorrel therein were therefore 
 free to spring and grow ; and the great hardiness and remarkable 
 vital power of that plant enabled it to rise through the (to it) dead 
 matter and great obstruction of several inches thickness of pure 
 marl above. On examining the roots of sorrel thus growing out 
 of marl, it will be seen clearly, and invariably, that they drew all 
 their support from the still acid soil below, and merely passed 
 through the marl^ without drawing anything therefrom.*] 
 
 CHAPTER XX. 
 
 DIRECTIONS FOR THE USE OF MARL IN CONNEXION WITH OTHER 
 FARMING OPERATIONS. 
 
 Proposition 5 — continued. 
 
 From the foregoing reasoning and statements, the general course 
 most proper to pursue in using calcareous manures, aud for cultiva- 
 tion in connexion with them, may be well enough deduced. But 
 as I have found that, notwithstanding all such aids, many persons 
 still require aud apply for more special directions to guide their 
 operations, the following suggestions and remarks will be offered, 
 at the risk of their being deemed superfluous. These directions, 
 like all the foregoing reasoning, may apply generally, if not en- 
 tirely, to the use of all kinds of calcareous manures, and to soils 
 of every region. But to avoid too wide a range, I shall consider 
 them as applying more especially to the lands of the tide-water 
 region ; and as addressed to farmers who have just begun the im- 
 provement of such lands, by means of the fossil shells or marl of 
 the same region. 
 
 jMauy persons, at first, attach much importance to some of the 
 conditions of marling which I deem scarcely worth consideration. 
 Numerous inquiries have been addressed to me for the purpose of 
 
 * In Engl.ind the effect of lime in preventing the gTowtli of sour plants 
 is stated by Johnston, though most of the plants are different from ours 
 of that character. Elsewhere he speaks doubtfully, and upon report only, 
 of calcareous manure eradicating sorrel. He says, liming ••kills- heath, 
 moss, aud sour and benty {agrostvs) grasses, and brings up a sweet herbage, 
 mixed with red and white clovers." "All fodder, whether natural or arti- 
 ficial, is said to be sounder and more nourishing when grown upon land to 
 ■which lime has been applied abundantly. On benty grass the richest 
 animal manure often produces little improvement, until a di-essing of limo 
 haa been laid on." p. 391. 
 
176 PROPER PROCEDURE OF BEGINNERS. ] 
 
 I 
 
 learning, in the case of each particular applicant for directions, at ! 
 what time and in what manner to apply marl, and which of different | 
 kinds of marl to prefer for different soils. There would be hut i 
 small danger of misleading any one, if to all such inquiries this ' 
 one general answer were given : '■'■ Put on the most accessible marl, ' 
 over as much land as possible, and speedily, without regard to any ] 
 attendant circumstances whatever." If the soil requires marling ; 
 (and there are scarcely any exceptions in lower Virginia), and the i 
 available bed is truly and sufficiently calcareous, there can be no 
 important error made in applying it, except by too heavy dressings, ': 
 or by very unequal spreading. If merely avoiding these two 
 errors, I should deem that procedui-e the best by which the new 
 beginner can put on his fields the greatest quantity of calcareous 
 earth in the shortest time. 
 
 But though comparatively of little importance, still there are 
 advantages and disadvantages to bo found in the circumstances to 
 which so much undue importance has been attached. These I will 
 proceed to remark upon. 
 
 To marl extensively or economically, it is essential (as has been 
 before stated) to devote to this business a certain labouring force, 
 either for the whole year, or for such certain parts of the year as 
 may be deemed more proper ; and for the time this force ghall be \ 
 so directed, the proprietor must not allow the labour to be diverted i 
 to any other object. If he draws upon the marling force whenever' 
 he or his overseer thinks the labour is needed to forward other farm | 
 operations, it will soon be found that the marling will be generally • 
 suspended; and yet, in all probability, the other labours be not thej 
 better performed because of this always ready resource for extraj 
 aid. \ 
 
 Then supposing that the marling is going on throughout thei 
 year, or through different designated portions of the year, it isj 
 obvious that the marl cannot be always applied to any one condition 
 of the land. In the beginning, the new marler should aim to cover] 
 as much land as possible for his next corn or other tillage crop. ] 
 After that crop shall have been planted, the marling can proceed 
 no farther on that field ; and the operation will be then eommcncedl 
 on the field for corn tillage the following year. It is much better' 
 that marling should be followed first by some tilled crop ; so that' 
 the dift'ercnt ploughings and harrowings shall well mix the marl; 
 and soil throughout, to the depth of the ploughing. This mixingi 
 is best and most certainly effected, when the marl has been spread; 
 over the ploughed surface. The subsequent shallow tillage, by! 
 small ploughs, cultivators, harrows, and hand-hoes, at every move^, 
 ment continually stirs and mixes the marl with the soil. j 
 
 But if the subsequent tillage processes should be such as tOj 
 effect the object of mixing tho marl and soil intimately, I would, 
 
INTERMIXTUllE OF MANUUE AND SOIL. 177 
 
 prefer spreading tlie marl before ploughing, on the vegetable cover 
 of the land. When thus placed in contact with the putrescent 
 mattei', it has seemed to me that the marl acted more speedily and 
 better. But, if marl be thus applied on the grass and ploughed 
 under, the first ploughing should not be deeper than will be at 
 least one thorough ploughing for the subsequent tillage of the first 
 crop. Otherwise, the maid will not be mixed with the soil above, 
 and-will remain unchanged and inert in the masses, whether soft 
 ^d loose, or lumpy, as turned under by the plough. In such 
 cases, the marl can have but little eifect, until brought up again by 
 as deep a ploughing, perhaps some years after. 
 
 Each of these modes of applying marl then has difi'ercnt ad- 
 vantages ; and may have also disadvantages, if they be not 
 guarded against. But in either mode, by proper care, the important 
 condition of sufficient mixture of the marl and soil may be secured. 
 When marl must be ploughed under (for a corn crop), it is import- 
 ant that the first ploughing should be as shallow as consistent with 
 good culture, and that the tillage, in part, shall be fully as deep. 
 If it be preferred to spread marl on the ploughed surface, that 
 may be done, for the greater part of the land, even after dropping 
 the marl, throughout the previous summer, on the grassy surface. 
 For this purpose, the marl heaps must be dropped accurately along 
 the middles of beds, if the land was then in beds designed to 
 be reversed; or along parallel lines, marked by the plough, if 
 not in beds. The spreading must be postponed until after the in- 
 tervals of land between the rows of marl shall have been ploughed 
 for the next crop, leaving merely the narrow strips on which the 
 heaps lie. In this manner, from two-thirds to three-fourths of the 
 whole surface is ploughed before the spreading of the marl. This 
 is next done, over the whole surface, after which the before omitted 
 strips are ploughed. 
 
 After the first year, generally, the farmer may be able to marl 
 fast enough to keep ahead of his cultivation ; and even should he 
 (to cff"ect that end) reduce the extent of his previous tillage one- 
 half, it will be best for him not to put an acre under crop which 
 has not been first marled. Fifty acres can^ in most eases, be both 
 marled and tilled at least as cheajDly as one hundred can be tilled 
 without marling ; and the fifty with marl will usually (if on soil 
 before acid), produce as much in the first course of crops as the 
 hundred without, and much more afterwards. 
 
 The most important auxiliaiy to marl, is to supply vegetable 
 matter (or any putrescent matter) to the land. The cheapest and 
 most efficient means, and especially for poor lands having no foreign 
 sources of supply, will be found in the non-grazing system, by 
 which the land, when not under cultivation, manures itself, by the 
 growth, and death, and decay of its own weeds and grass. Poor 
 
178 VEGETABLE MATTER ESSENTIAL. 
 
 and scanty as may be sucli products and sucli manuring of poon 
 lands, they very much exceed any substituted supplies ; and more-< 
 over cost nothing.* i 
 
 That rotation of crops which gives most vegetable matter to the" 
 soil, is best to aid the effects of marl recently applied. The four-; 
 shift rotation is convenient in this respect, because two or thre^ 
 years of rest may be given in each course of the rotation at first,^ 
 upon the poorest land ; and the number of exhausting crops mayj 
 be inci-eascd, first to two, then to three in the rotation, as the so^< 
 advances to higher states of productiveness. But it is only whila 
 land is poor that I would advise the four-shift rotation, with aSj 
 much as two years rest in the course; or the entire exclusion of, 
 grazing under any rotation. Both tend to make the fields foul withj 
 both weeds and insects; and when the land has been under such 
 treatment for some 8 or 10 years, and has been made riehcr as welt 
 as fouler thereby, it will be expedient to graze moderately and- 
 judiciously, and to adopt a different and better rotation. ;' 
 
 After marling, clover should be sown, and gypsum on the clover. ■ 
 On poor, though marled land, of course only a poor growth of i 
 clover can be expected ; but wherever other manures are given,J 
 and especially if gypsum is found to act well, the crop of cloverj 
 becomes a most important aid to the improvement by marling.. 
 
 * If there is one of the requisitions or acoompaniments of marlingi 
 more insisted on than all others — and both by my theoretical views ancli 
 practical instructions — in all my writing on this subject — it is the necessity! 
 for providing oi"ganic (or putrescent) mauur-c for all land in full proportiou; 
 to the calcareous earth supplied. Without this being done, not only willj 
 the early effects of the calxing be small, but, in the end, the land will b©] 
 more completely exhausted of its actual organic ingredient, and conse-: 
 qiiently and ultimately of its fertility, than if it had not been calxed. It j 
 is not necessary, however, that all the required organic manure shall be| 
 furnished from the stable and stock-pens — or shall even be what is ordina-' 
 rily termed manure. As much of this as may be available should be ob- ! 
 tained from these sources. But a much larger supply, and far mora^ 
 cheaply, will be furnished by the fields themselves, in their vegetable < 
 cover, whether of clover or weeds, suffered to grow and to die and rot oq ■ 
 or under the soil. This is the natural and the greatest source of supply ■ 
 of organic manm-e to the calxing farmer — and which he can increase to ; 
 any desired extent, by merely giving more time for the land to rest from, 
 tillage, and to produce more of alimentary or manuring growths. 
 
 Bat as often and as strongly as I have urged the indispensable necessityii 
 for this course, scarcely any of my disciples have obeyed the injunction '; 
 fully and properly. Nine out of ten of all the farmers who have viseclJ! 
 marl, and to great profit, still have drawn too heavily from their land, and'' 
 are lessening, instead of continuing to increase, the fund of productive 
 power in the soil, which calxing had made active. But with this important 
 truth they cannot be im.pressed. They cannot be persuaded that tliey are I 
 operating to exhaust their fields, while they still continue to deri\ei IX'OW 
 them crops three-fold greater than formerly could be gx'owu. 
 
ORGANIC MANURES. " 179 
 
 Without clover, and without returning the greater jiart of the early 
 product to the soil, the greatest value of marling will not be seen. 
 A small proportion of the clover may be used for mowing and 
 grazing ; and in a few years even this small share will far exceed 
 all the grass that the fields furnished before marling and the limit- 
 ation of grazing. This limitation, which is at first objected to as 
 lessening the food of grazing stock, and their products, within a 
 few years becomes the source of a far more abundant supply of 
 both. 
 
 During the first few years of marling, but little attention can 
 (or indeed ought to) be given to making putrescent manures, be- 
 cause the soil much more needs calcareous manure ; and three or 
 four acres may generally be supplied with the latter, as cheaply as 
 cue with the former. But putrescent manures cannot anywhere be 
 used to so much advantage as upon land after being made calcare- 
 ous ; and no farmer can make and apply vegetable matter as ma- 
 nure to greater profit than he who has marled his poor fields, and 
 can then withdraw his labour from applying the more to the less 
 valuable manure. After the farm has been marled over at the 
 light rate recommended at first (say 200 to 300 bushels), every 
 efi"ort should be made to accumulate and apply vegetable manures j 
 and with their gradual extension over the fields, a second applica- 
 tion of marl may be made, making the whole quantity, in both the 
 first and second marling, 500 or 600 bushels to the acre, or even 
 more ; which quantity might have been hurtful if given at first, 
 but which will now be not only harmless, but necessary to fix and 
 retain so much putrescent and nutritive matter in the soil. 
 
 The above injunction, that " every efibrt should be made to ac- 
 cumulate and apply vegetable manures," should not be limited, as 
 most new improvers would be apt to do, to the mere economical use 
 of the vegetable materials for manure furnished by the crops, and 
 those only as prepared by being first used as litter for animals. 
 Not only these, but every other vegetable and putrescent material 
 that is accessible should be saved and applied, and even without 
 any intermediate process of preparation, and at any time of the 
 year, and state of the fields, provided no growing or commencing 
 crop be thereby molested. Surplus straw, not needed for food or 
 litter, is most valuable and cheaply applied as top-dressing to clover 
 or other grass ; though it is an inconvenient and troublesome ma- 
 nure if soon after to be ploughed under. Leaves from the woods 
 of the farm may be used most profitably in the same manner, to 
 the full extent of the resources offered. And though the manuring 
 operations on the Coggins Point farm have not yet been extended 
 beyond the last-named putrescent material (and of that, not to 
 much extent), it is believed that other and abundant sources yet 
 remain untried and unproductive on that and most other farms, and 
 
180 RESOURCES EOR ORGANIC MANURES. 
 
 to use wliich would be but a waste of labour or money, if in ad- 
 vance of marling. Among the most abundant of sucli materials, 
 may be mentioned marsh grasses and marsh or pond mud, espe- 
 cially if used in compost ; and also the purchase of rich alimentary 
 manures from towns, to be carried by land or by water carriage to 
 much greater distances than has yet been done, or can be afforded 
 to be done, on other lands. Even saw-dust and spent tanner's 
 bark, which, because of their insolubility, are generally deemed of 
 no value as manures, would form important and valuable materials 
 for fertilization, in situations where they can be obtained cheaply 
 and in great quantity. Mixing these or other insoluble vegetable 
 substances with rich putrescent matters, and still more if with 
 some alkaline matter also, would render them soluble, and convert 
 them to food for plants. These inert substances would be most 
 pi'ofitably used as litter for stables and cattle pens in summer, where 
 the ordinary more decomposable materials are too quickly rotted, 
 and subject to great loss thereby. 
 
 But putting aside the consideration of all such unusual or un- 
 tried resources and operations for additional fertilization, and limit- 
 ing the present view merely to the ordinary materials furnished by 
 the fields of every farm, the progress and profit of improvement 
 by such means only, after marling, will be greater than will be at 
 first believed by most cultivators of acid soils, not yet marled or 
 limed. If, on such soils, the general course above advised be pur- 
 sued (and using merely the resources of the farm after marling), 
 the products of crops on all the marled land usually will be doubled 
 in the first course of the rotation — often in the first crop immedi- 
 ately following the marling; and the original product may be 
 expected to be tripled by the third return of the rotation. And 
 this may be from merely applying marl in sufficient (and not ex- 
 cessive) quantities, and giving the land two years' rest in four 
 without grazing.' But on the parts having the aid of farm-yard 
 and other putrescent manures, and of clover, still greater returns 
 may be obtained. 
 
CHAPTER XXL 
 
 ACTUAL IMPROVEMENTS AND RESULTS OE MARLING. PECULIAR 
 VALUE OF SANDY SOILS. 
 
 Proposition 5 — continued. 
 
 When sucli promises of improvement and of profit from marling 
 are stated as in the preceding chapter, there will naturally occur to 
 the mind of every inexperienced reader the questions, " Has the 
 writer himself met with so much success — and what have been the 
 actual results of his labours in the mode of improvement which he 
 so strongly recommends ?" From these questions the writer has 
 no excuse for shrinking ; though to answer them there must neces- 
 sarily be obtruded much egotism, and references made to many 
 trivial details, which are certainly not worth being offered to public 
 notice, except as explanatory and in support of the more general 
 and important foots asserted in this essay. 
 
 In answer, then, to these supposed questions, I have to admit 
 that, in my earlier: marling labours, the progress of fertilization 
 was not so rapid, in general, and the average profits therefrom not 
 so great, as might be expected from the general views and antici- 
 pations stated in the last preceding chapter ; though, more recently, 
 the benefits have been much greater, and full as j)rofitable as were 
 anticipated, or could be counted upon, from the foregoing views 
 applied to the existing circumstances of the lands under the opera- 
 tions. Among the sufficient causes of the stated slower improve- 
 ment, and lower profits of my earlier labours, were the following : 
 
 1st. The greater part of my land, on the Coggins Point farm in 
 Prince George county, was not of either such surface or soil as is 
 adapted for the greatest improvement by calxing : some having 
 been naturally calcareous, and therefore not needing marl ; and a 
 large part of the farm, where hilly or even of undulating surface, 
 having lost more or less of its soil — and on very many slopes, all 
 the soil — by the washing rains acting on bad tillage. 
 
 2d. Having at first everything to learn in regard to the practice, 
 and to prove by actual trial, without any light from either expe- 
 rience, or the prior or coteniporary operations of other farmers, 
 anuch of my labour was lost uselessly in wrong procedure , or was 
 worse spent in excessive applications of marl, which subsequently 
 proved to be injurious. 
 
 3d. The fitness given to the before acid soil, by marling, to pro- 
 duce clover, was not found out, until several years after tb.at best 
 auxiliary to the fii'st improvement ought to have been in full use, 
 16 (181) 
 
182 CAUSE OJF DEFECTIVE RESULTS. 
 
 4tli. Because of tlie want of enough labour to use properly both 
 calcareous and putrescent mauures, the collecting and applying of 
 the latter were greatly neglected as long as there was full employ- 
 ment in and need for marling. 
 
 5th. The adoption of cotton culture, for five years, occupied for 
 that crop and for that time the best land of the farm, and some- 
 times the whole of the very gooi land, and took all the prepared 
 putrescent manure, to the great diminution of other crops ; while 
 .this culture caused (by its clean and continual tillage) more wast- 
 ing of soil, and more detriment to general fertilization, than grain 
 and clover husbandry. 
 
 6th. The general bad practical management, and want of economy 
 in details, which, I have to confess, have attended all my business, 
 and throughout my life, of course injuriously affected this import- 
 ant branch of my farming ; though in a less degree, because it was, 
 as much as possible, kept under my personal and close attention. 
 
 7th. In 1827, my residence was removed from my farm, and my 
 personal attention much decreased ; and some years later was en- 
 tirely withdrawn. 
 
 To what extent all these drawbacks to full success operated, as 
 well as the actual degree of success achieved, may be inferred from 
 the tabular statement of the crops made, both before and since 
 marling, and from 1813 to 1851. The much greater increase of 
 production obtained in later years on the Coggins Point farm was 
 mainly owing to the adoption of a better rotation of crops, includ- 
 ing clover-f\illow for wheat, and to the residence, and personal and 
 judicious direction of my eldest son, who since the beginning of 
 1839 has been the occupant of the farm (and more lately the sole 
 proprietor), and, throughout this time, the sole director of its cul- 
 tivation and general management. Until this change of direction 
 occurred, the actual measure of productive power in the land, 
 which had been created by the marling, was not known. A large 
 share of this power, before dormant and concealed, was now brought 
 for the first time into action, and made ajjparent. The like condi- 
 tions of residence, attentive supervision, and a better system of 
 rotation, in my own case, also greatly hastened and increased the 
 success of my later marling labours (resumed after a long diversion 
 of my efforts to different objects), in a new locality, and under 
 very difficult and also very different circumstances from those of 
 my earlier farming. These recent labours, and the results, will 
 again be brought forward. 
 
 The following general statement of the then condition of the 
 farm was published in 1842. The still later and much greater 
 productiveness will appear in the annexed table of crops, which 
 will be now extended so as to include the latest obtained. 
 
 The many and extensive old galled parts of sloping land, 
 
ACTUAL RESULTS ON COGGINS PARxM. 183 
 
 wlicrcvcr dressed witli marl, and even without the further help of 
 barn-yard manure, arc now nearly all skinned over by a newly 
 formed soil ; and though such soil is still both poor and thin, and 
 may yet long remain so, the 7cJwk of its present productive power 
 is due to marling; as such galled land was before naked, entirely 
 barren, and irreclaimable by other manures. Where much or rich 
 putrescent matter has been also applied to galls, with or after marl, 
 both rich and durable soil has been formed, though at great cost. 
 
 The more level parts of the old and greatly exhausted fields, and 
 the newly cleared wood-land (both kinds being naturally poor, thin, 
 and acid soils), are the only lands which have enjoyed anything 
 like the full beneficial efiects of marling. These have been in- 
 creased in product from 5 and 10 bushels of corn per acre (which 
 may be considered the usual minimum and maximum rates), to at 
 least 20, and in some cases to 30 bushels, even without the aid of 
 barn-yard manure. Where putrescent manures have been also 
 applied, they have raised the products much higher; and these 
 manures are now as durable and as profitable as formerly they were 
 fleeting and pi-ofitless in effect. 
 
 The before poor and light soil which formed the greater part of 
 the old arable lands, and which was not above three inches in depth 
 (and scarcely tv.'o inches when in its natural forest state), is now 
 seven inches or more, and requires three-horse ploughs to break it 
 to proper depth, where the one-horse ploughs formerly would fre- 
 quently I'each and bring up the barren sub-soil. 
 
 The fertilizing operation of marl has increased with time, even 
 where the effects were also the most speedy, and most profitable on 
 the first crop after the application. 
 
 The soil, which before was totally unable to support red clover, 
 is now (except on the most sandy spots) well adapted to the growth, 
 and capable, according to the grade of fertility, of receiving the 
 great benefit which is offered by that most valuable of improving 
 crops. 
 
 And generally — notwithstanding all the many and great errors 
 committed in my marling (for want of experience), and of still worse 
 general farm management — and though a considerable proportion 
 of the old land was either but little or not at all fit to be improved 
 by marling — and though the land added since by new clearings was 
 all very poor, and worthless for its natural producing power — still, 
 the general annual grain products of the farm have been increased 
 from three to four-fold, and the net profit of cultivation and tlie 
 intrinsic value of the land have been increased in a still greater 
 proportion.— [1842.] , 
 
184 
 
 INCREASE OF CROPS FROM MARLING, 
 
 Statement of marlinxj and crops, on Coggins Point (iioxo Beech' 
 toood) Farm.^-^ 
 
 
 Acres marled. 
 
 WHEAT. 1 
 
 CORN. 1 
 
 
 
 1^ 
 
 ^ 
 
 ii 
 ^5 
 
 a> 
 
 < 
 
 
 . 
 
 to 
 ci t-t 
 
 1813 
 
 
 
 145 
 
 810 
 
 5.58 
 
 125 
 
 2250 
 
 18. 
 
 1814 
 
 
 
 110 
 
 550 
 
 5. 
 
 163 
 
 1340 
 
 8.18 
 
 
 
 1815 
 
 
 
 78 
 
 520 
 
 6.07 
 
 136 
 
 1955 
 
 14.38 
 
 
 
 1816 
 
 
 
 104 
 
 896 
 
 8.61 
 
 144 
 
 2300 
 
 10.90 
 
 
 
 1817 
 
 
 
 79 
 
 595 
 
 7.52 
 
 188 
 
 2050 
 
 10.90 
 
 
 
 1818 
 
 fl5 
 
 63 
 
 450 
 
 7.14 
 
 ^IGO 
 
 *2670 
 
 16.68 
 
 
 
 1819 
 1820 
 
 02 
 25 
 
 132 
 119 
 
 1015 
 1020 
 
 7.69 
 8.57 
 
 M37 
 =^164 
 
 *2000 
 *2780 
 
 14.59 
 17. 
 
 
 
 S A 
 
 tw . 
 
 1821 
 
 80 
 
 160 
 
 1049 
 
 6.56 
 
 ^77 
 
 §1775 
 
 23. 
 
 
 H 
 
 " 2. 
 
 1822 
 
 93 
 
 154 
 
 1627 
 
 10.56 
 
 -114 
 
 *2250 
 
 19.73 
 
 
 
 0) q2 
 
 1823 
 
 100 
 
 139 
 
 1475 
 
 10.61 
 
 158 
 
 *3000 
 
 19. 
 
 ^^ 
 
 1824 
 
 1825 
 
 80 
 50 
 
 194 
 195 
 
 1850 
 1452 
 
 9.54 
 
 7.45 
 
 156 
 70 
 
 * 8405 
 
 21.80 
 17.9] 
 
 
 
 1254 
 
 48 
 
 
 182(3 
 
 24 
 
 170 
 
 1390 
 
 8.17 
 
 138 
 
 *2275 
 
 16.48 
 
 70 
 
 
 1827 
 
 «?27 
 
 151 
 
 1366 
 
 9.01 
 
 104 
 
 *1665 
 
 16. 
 
 76 
 
 3711 
 
 1828 
 
 .0 
 
 153 
 
 936 
 
 6.12 
 
 112 
 
 1750 
 
 15.62 
 
 90J 
 
 55 
 
 1829 
 
 .0 
 
 134 
 
 908 
 
 6.78 
 
 133 
 
 2300 
 
 17.37 
 
 96" 
 
 
 f830 
 1831 
 1832 
 
 50 
 
 
 
 
 
 
 
 
 
 501 
 
 38 
 
 
 2160 
 
 
 
 
 
 0" 
 
 
 — 
 
 126 
 
 2830 
 
 22.46 
 
 
 
 
 
 
 — 
 
 
 — 
 
 — 
 
 
 
 
 a 
 
 .3 to" 
 
 1835 
 
 
 
 
 
 
 
 
 
 4000 
 
 
 CO 
 
 a5 cs 
 
 2 'K 
 
 183G 
 
 10 
 
 184 
 
 e394 
 
 2.17 
 
 
 4415 
 
 
 SO 
 
 CO 
 
 *^ ,:; 
 
 1837 
 
 
 
 147 
 
 2056 
 
 13.98 
 
 
 2()20 
 
 
 < 
 
 S 
 
 1838 
 
 
 
 150 
 
 2117 
 
 14.1] 
 
 
 + 2070 
 
 
 
 
 
 
 1839 
 
 2 
 
 107 
 
 tl252 
 
 7.49 
 
 190 
 
 4500 
 
 23.68 
 
 80 
 
 
 1840 
 
 cl2 
 
 228 
 
 1942 
 
 8.6] 
 
 143 
 
 8540 
 
 24.40 
 
 50 
 
 5e 
 
 1841 
 
 c32 
 
 212 
 
 2475 
 
 11.62 
 
 146 
 
 3800 
 
 25.33 
 
 10 
 
 10 e 
 
 1842 
 
 30 
 
 250 
 
 8377 
 
 18.50 
 
 155 
 
 
 
 50 
 
 10 e 
 
 1843 
 
 { «13} 
 sl5 
 
 807 
 
 4725 
 
 15.89 
 
 166 
 
 8380 
 
 20.36 
 
 
 
 1844 
 
 270 
 
 4600 
 
 17.01 
 
 100 
 
 2500 
 
 25. 
 
 
 
 1845 
 1840 
 
 s70 
 
 270 
 
 290 
 
 8000 
 3000 
 
 13.33 
 1 10.31 
 
 100 
 140 
 
 1600 
 8115 
 
 vl6. 
 22.25 
 
 
 
 1847 
 
 s90 
 
 234 
 
 2571 
 
 u 10.99 
 
 144 
 
 5070 
 
 35'. 20 
 
 
 
 1848 
 
 s5 
 
 274 
 
 3544 
 
 12.93 
 
 150 
 
 4625 
 
 30.83 
 
 
 
 1849 
 
 6 40 
 
 225 
 
 2600 
 
 X 11.55 
 
 170 
 
 5010 
 
 29.47 
 
 
 
 1850 
 
 s90 
 
 321 
 
 4112 
 
 12.81 
 
 110 
 
 3150 
 
 28.64 
 
 
 
 1851 
 
 { S25} 
 
 2G3 
 
 4420 
 
 10.81 
 
 118 
 
 8750 
 
 32.61 
 
 
 
 ** After 1827, I ceased to keep a regular farm journal, as had been done 
 before. Hence the blanks in the table -which appear afterwards to 1836. 
 The occupancy and direction of the present proprietor, Edmund Ruffin, 
 jr., began with the year 1839. 
 
CROPS OP COGGINS POINT FARM. 185 
 
 Explanatoi-y Remarks on the Land and its Management. 
 
 Quantity of land for cultivation (exclusive of ■waste parts), at first 472 
 acres ; increased by new clearings to 602 by 1826; to 652 in 1832 ; and no 
 more in 1842, though 30 more acres have since been cleared and tilled, be- 
 cause as much in 1836 converted to a permanent pasture. All the new 
 land added by clearing was poor, and very few acres of it would have pro- 
 duced more than 10 bushels of corn, or 5 of wheat (without the marling), 
 after the 3 or 4 first crops. Of course the new land added served to reduce 
 instead of increasing the general average product per acre. 
 
 Rotation at first of three-shifts, viz. : 1 corn, 2 wheat on the richer half, 
 3 at rest, and after 1814 not grazed. This changed gradually to 4 shifts 
 (by 1823) of 1 corn, 2 wheat, 3 and 4 at rest. 1820, began to fallow for 
 wlieat, in part and only in some years. In 1826 or 1827 began to sow the 
 ■wheat fields -generally in clover, and about 1835, to fallow a part (say one- 
 fourth to one-third) of each clover field for wheat the year preceding the 
 crop of corn. This changed in 1840 to a five-shift rotation, one-fifth of the 
 arable land being in corn, two-fifths in wheat (and oats), and two-fifths in 
 clover (or weeds), or other green or manuring crops. 
 
 The crops of wheat for first six years (1813 to 1818) raised on the richer 
 parts of each shift, making not much more than one-half the land only; 
 the remainder being then much too poor to be sown. As these poorest parts 
 were marled, all were sown in wheat, in their turn. Therefore, the earlier 
 average products of wheat per acre as stated, were for the richer part of 
 the land, while since 1822 the average is for the worst as well as the best 
 laud of each shift. 
 
 Grazing the clover fields commenced partially about 1830, and increased 
 since. Latterly about 20 head of cattle and 100 of hogs on the clover 
 during the grazing season. 
 
 The crops of hay, corn-foddei*, &c., being all consumed on the farm, 
 their products have not been estimated. 
 
 Notes on Particular Crops, ^c. 
 
 a 1818 to 1822, inclusive, 27 acres of rich embanked marsh in corn every 
 year, which served to increase these crops, and their average — which land 
 sunk too low after 1823 for corn, and has since been under the tide. 
 
 fin 1818, the first marling. 
 
 1828, oats on 17 acres. 
 
 1826 to 1830, a succession of bad seasons for wheat, or of crops — made 
 much worse (as I afterwards believed), by the laud having been so long 
 kept from being grazed and trodden by cattle. 
 
 * These crops not actually measured, but amoimts otherwise estimated. 
 All other quantities measured, unless stated otherwise. 
 
 § The richer half of the shift only cultivated in corn this year (1821). 
 
 ?? Marling nearly extended over all the cleared arable land requiring it, 
 and injurious where too thick. 
 
 From 1825 to 1830 inclusive, the richest land of the farm kept under 
 cotton, which served greatly to lessen the general products, and still more 
 the average product per acre of the wheat crops, during that time. Also, 
 fallowing for wheat had ceased (the sidtable land being occupied by cotton), 
 and this had served still more to reduce the crops of wheat. The largest 
 crops of wheat raised previously (1819 to 1825) were partly owing to the 
 crop being in part raised on summer fallow. And though this was in ad- 
 vance of having the all-important aid of clover, as green manure, still 
 ■wheat on fallow always produced much better than would the same land if 
 iu wheat after corn, as usual. My first largely increased crop of wheat 
 IG* 
 
188 CROPS OP COGGINS POINT FARM. 
 
 (in 1822), vras in part owing to the fallow process on a large space. But 
 as the same land had been then marled, and this was its first wheat crop 
 after the marling, I incorrectly ascribed all the great improvement of produc- 
 tion to the new fertility caused by marling. In after time, when the same 
 field yielded a much lighter crop of wheat, following corn, there was great 
 disappointment, for the supposed diminished fertility. In truth, there was 
 great improvement of fertility at first, from marling, and no diminution 
 afterwards. But a still greater measure of temporary production was 
 superadded at first by the fallow prepai'ation — which increase ceased when 
 this kind of preparation was not used. So generally now is known this 
 superiority of the yield of fallow wheat, that no farmer could be deceived 
 in this respect. Nevertheless, not only was I so deceived formerly, in the 
 beginning and partial use of summer fallow, but most other persons were 
 as ill-informed. For nearly all other improving farmers, in addition to 
 whatever means of fertilization they employed, soon also began to fallow 
 for wheat, and on clover, if the land had been enabled to bring clover. 
 The first and all succeeding crops so prepared for, would be more than 
 double any made previously on the saxue land, in the formerly universal 
 course, after corn. And this more than doubled production of the next 
 succeeding crop, when published, was supposed by all to be the result of a 
 doubled degree of fertility so quickly induced. Several such reports ap- 
 peared from diflFerent and excellent improving farmers in the "Farmers' 
 llegister;" and great as were the actual measures of new fertility in all 
 these cases, it is certain that the writers of these reports, as well as the 
 readers, wei-e deceived by the then new and little known peculiar benefits 
 of the summer fallow preparation for wheat — and consequently ascribing 
 less benefit to the mode of tillage, and more to the newly created fertility 
 of the field, than was proper. It was not until about 1835 that fallow pre- 
 paration had become my annual procedure, even to small extent ; nor un- 
 til 1839 that it was made a regular part of the rotation, extending to one- 
 fifth of the fai-m each year. Afterwards, as will be seen, the crops of wheat 
 ■were greatly and permanently increased over the general former products ; 
 they then having nil the before produced fertility, caused by marling, to- 
 gether with the surface under wheat being extended to two-fifths of the 
 land, and half of that quantity of fallow preparation, and with clover, so 
 far as this manuring crop could be made to grow. 
 
 1113,027 lbs, of cotton, net weight as sold, or 170 lbs. to the acre. 
 
 e 1836, the wheat crop nearly destroyed by rust, as was general through 
 eastern Virginia. 
 
 t Corn crop of 1838 and wheat crop of 1839 very much lessened by the 
 ravages of the chinch-bug. 
 
 c c On 26 of these acres the marling was a second application. 
 
 e The root crops (turnips and beets), and pumpkins and cymlings, occu- 
 pied part of the most highly enriched land — all consumed on the farm, and 
 products not estimated. 
 
 s 3 s Second dressings of marl, at about 250 bushels the acre ; applied 
 where first dressings had been lightest, or where moi*e seemed to be wanting. 
 
 V Severe drought in 1845 cut short the corn crop. 
 
 t Remarkable wet time for harvest in 1846, and much loss of wheat. 
 
 u In 1847, much Hessian fly in wheat. 
 
 ^ In 1849, three freezing nights in April cut down all the forward wheat. 
 
 In 1844, my residence and labours were removed to the farm, 
 
 Marlbourne, iu Hanover, wbicli bad been recently bought, and 
 
FARMING ON MARLBOURNE. ' 187 
 
 which I then began to marl, and to cultivate. I here brought to 
 bear much experience, and also judgment, both of which had been 
 wanting to my first marling labours, and therefore I now had more 
 speedy and complete success. Still there were important counter- 
 vailing obstacles, in the great existing differences of the soil and 
 level of my new farm, from the hilly lands on which my earlier 
 labours had been bestowed.. Owing to my want of knowing the 
 peculiar requisitions for land entirely new to me, each field had 
 to pass once at least through its course of culture, before I learned, 
 from my errors, what should be its proper tillage and management. 
 The arable land of Marlbourne, about 750 acres, was nearly all of 
 Pamunkey flats of high level, or "second low-grounds." The 
 surface generally is so level and also so much of it in shallow 
 basin-shaped depressions, as to need much labour and judgment in 
 draining; the soils of all shades of texture between very sandy 
 and light, and very stiff and intractable, under tillage. The origi- 
 nal qualities had varied between rich and less than medium fertility. 
 The cultivation had been very exhausting ; all the land (not too 
 wet to cultivate), had been greatly reduced ', and much of it was 
 extremely poor. About 80 acres, in many separated spots, of 
 cleared land, had been the bottoms of formerly existing ponds. 
 These "black-lands" only still were rich, and also of very stiff soil. 
 Most of the other clay lands were the poorest of the farm, and 
 extremely poor. The sandy soils all bore sorrel, thus giving evi- 
 dence of their then acid condition. About 60 acres had been 
 marled, but quite insufficiently, and required full as much more marl 
 as had been laid on. All the remaining land had to be marled for 
 th'e first time. Of the procedure and the results, this occasion per- 
 mits only the general statement which will follow, of the quantities 
 of marl carried out (obtained from an adjacent farm), and the crops 
 made. It is understood that no previous crop of wheat, made on 
 the farm for many years before my occupancy, had reached the 
 amount of 1000 bushels ; and even my first crop (reaped in the 
 second year) was increased by being partly on laud I had marled, 
 and also by having an over-proportion of the richest ground, taken 
 in detached spots. 
 
18S 
 
 CROPS OF MARLBOURNE. 
 
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PROFITS OF MARLING. 189 
 
 [1832.] With all the increase of products tliat I have ascribed 
 to marling, the heaviest amounts stated may appear inconsiderable 
 to farmers who till soils more favoured by natui-e. Corn yielding 
 twenty -five or thirty bushels to the acre, is doubled by many natural 
 soils in the western states ; and ten or twelve bushels of wheat 
 (following corn) will still less compare with the product of the 
 best lime-stone clay laud. The cultivators of our poor region, how- 
 ever, know that such products, without any future increase, would 
 be a prodigious addition to their present gains. Still it is doubtful 
 whether these rewards are sufficiently high to tempt many of my 
 countrymen speedily to accept them. The opinions of many 
 farmers have been so long fixed, and their habits are so uniform 
 and unvarying, that it is difficult to excite them to adopt any new 
 plan of improvement, except by promises of profits so great that an 
 uncommon share of credulity would be necessary to expect their 
 fulfilment. The net profits of marling, if estimated at twenty or 
 even fifty per cent, per annum, on the expense, for ever — or the 
 assurance, by good evidence, of doubling the crops of a farm in ten 
 years or less — will scarcely attract the attention of those who would 
 embrace, without any scrutiny, the most absurd plan that promised 
 five times as much. Hall's scheme for cultivating corn was a 
 stimulus exactly suited to their lethargic state ; and that impudent 
 Irish impostor found many steady old-fashioned farmers who had 
 always eschewed experiments, and held "book-firming" in utter con- 
 tempt, willing to pay for his pretended patent-right and directions 
 for making five hundred barrels of corn without ploughing, and with 
 the hand labour of two men only. 
 
 The products and profits derived from the use of marl, as pre- 
 sented in the preceding pages, considerable as they are, have been 
 kept down, or lessened in amount, by my then want of experience, 
 and ignorance of the danger of injudicious applications. My errors 
 may at least enable others to avoid similar losses, and thereby to 
 reach eqiial profits with half the expense of time and labour. But 
 are we to consider even the greatest known increase of product that 
 has been yet gained, in a few yeai's after marling, as showing the 
 full amount of improvement and profit to be derived ? Certainly 
 not; and if we may venture to leave the sure ground of practical 
 experience, and look forward to what is promised by the theory of 
 the operation of calcareous manures, we must anticipate future 
 crops far exceeding what have yet been obtained. To this, the ready 
 objection may be opposed, that the sandiness of the greater part of 
 our lands will always prevent their being raised to a high state of 
 productiveness — and, particularly, that no care or improvement 
 can make heavy crops of wheat on such soils. This very general 
 opinion is far from being correct ; and as the error is important, it 
 
190 VALUE OF SANDY SOILS. 
 
 may be useful to offer some evidence in support of the gi'eat value 
 to which sandy soils may arrive. 
 
 We are so accustomed to find sandy soils poor, that it is diiEcult 
 for us to connect with them the idea of fertility, and still less of 
 durability. Yet British agriculturists, who were acquainted with 
 clays and clay loams of as great value, and as well managed under 
 tillage, as aii}^ in the world, speak in still higher terms of certain 
 soils which are even more sandy than most of otrrs. For example 
 — " Kich sandy soils, however," says Sir John kSinclair, " such as 
 those of Frodsham in Cheshire, are invaluable. They are cultivated 
 at a moderate expense ; and at all times have a dry soundness, 
 accompanied by moisture, which secures exellent crops, even in the 
 driest summers."* Robert Brown (one of the very few who have 
 deserved the character of being both able writers and successful 
 practical cultivators) says — "Perhaps a true sandy loam, incumbent 
 on a sound sub-soil, is the most valuable of all soils. "f Arthur 
 Young, when describing the soils of France, in his agricultural 
 survey of that country, in several places speaks in the highest 
 terms of different bodies of light or sandy soils, of which the 
 following example, of the extensive district which he calls the plain 
 of the Garonne, will be enough to quote : " It is entered about 
 Creisensac, and improves all the way to Montauban and Toulouse, 
 where it is one of the finest bodies of fertile soil that can anj^where 
 
 be seen." " Through all this plain, wherever the soil is found 
 
 excellent, it consists usually of a deep mellow friable sandy loam, 
 with moisture sufficient for anything; much of it is calcareous. "j 
 The soil of Belgium, so celebrated for its high improvement and 
 remarkable productiveness, is mostly sandy. "The author last 
 quoted, in another work describes a body of land in the county of 
 Norfolk, as " one of the finest tracts that is anywhere to be 
 
 seen" " a fine, deep, mellow, putrid sandy loam, adhesive _ 
 
 enough to fear no drought, and friable enough to strain off super- 
 fluous moisture, so that all seasons suit it; from textu.re free to 
 work, and from chemical qualities sure to produce in luxuriance 
 whatever the industry of man commits to its friendly bosom. "§ 
 Mr. Coke, the great Norfolk farmer, made on the average 24 bushels 
 of wheat to the acre, on an estate of as sandy soil as our South- 
 ampton (where probably a general average of two bushels could 
 not be obtained, if general wheat culture were attempted) — and 
 many other farms in Norfolk yielded much better wheat than Mr. 
 Coke's in 1804, when Young's survey was made. Several farms 
 
 * Code of Agriculture, p. 12. 
 
 f Brown's Treatise on Agriculture, p. 218, of "Agriculture" in Edin. 
 Ency. 
 
 X Young's Tour in France. 
 
 ^ Young's Survey of Norfolk, p. d. 
 
SHALLOW AND TOOK SOILS. 191 
 
 averager! 36 bushels, and one of 40 is stated ; and the general ave- 
 rage of the county was 24 bushels.* Yet the county of Norfolk waa 
 formerly pronounced by Charles II. to be only fit " to cut up into 
 strips, to make roads of for. the remainder of the kingdom" — and 
 that sportive description expressed strongly the sandy nature of the 
 soil, as well as its then state of poverty and utter worthlcssness. 
 
 Because certain qualities of poor clay soils (particularly their 
 absorbent power) make them better than poor sands for producing 
 wheat, we most strangely attach a value to the stiifuess and in- 
 tractability of the former. Yet if all the absorbent quality and 
 productive power of clay could bo given to sand, surely the latter 
 would be the more valuable in proportion to its being friable and 
 easy to cultivate. The causes of all the valuable qualities and pro- 
 ductive power of the rich sands that have been referred to, are 
 only calcareous and putrescent manures, and depth of soil ; and if 
 the same means can be used, our now poor sands may also be made 
 as prodiTCtive and valuable. I do not mean to assert that the most 
 highly improved sandy soils can produce as much wheat as the best 
 clay soils ; but they will not fall so far short as to prevent their 
 being the more valuable lands, for wheat as well as other crops, on 
 account of their being more easily cultivated, and less liable to suffer 
 from bad seasons, or bad management. 
 
 The greatest objection to the poor sandy lands of lower Virginia, as 
 subjects for improvement by calcareous manures, is not their excess 
 of sand, nor yet their poverty — great as may be both these dis- 
 advantages — but it is the shalloioness of the poor and sandy soil. 
 The natural soil of a large portion of these lands, before cultivation, 
 is not more than from one to two inches deep, lying on a barren 
 sub-soil of sand. Now suppose this very shallow soil to be doubled 
 or even tripled in fertility by marling, or a productive power of 6 
 or 9 bushels of corn be raised to IS bushels, still it would be but 
 mean land. And a long succession of annual vegetable covers to 
 be left on the land, or a great quantity of prepared putrescent 
 manure furnished at once, would be required to make such soil both 
 rich and deep. If the original soil had been ten inches deep, the 
 fertility before marling might have been but little more than on the 
 shallowest soil. But heavy marling and deep and good tillage 
 would have served speedily to make a rich and productive soil, 
 approaching in value to those rich sands of Europe mentioned 
 above. 
 
 Another large class of the poor lands of lower Virginia are the 
 close stiff clays, of which the soil is still more shallow than the 
 sands. Such land was described at page 124 and formed the sub- 
 jects of experiments 5, 6, and 7. This is the very worst soil known 
 
 * Young's Survey of Norfolk, p. 300 to 304. 
 
102 RATES OP INCREASE OF MARLED CROI'S. 
 
 before being marled, and also the most worthless of all known 
 marled soils. And yet a three-fold product has been usually ob- 
 tained on these lands by marling alone, within four or at most eight 
 years after the application of marl. Still, this land, as well as the 
 most sandy, wants only greater depth of soil and abundance of 
 vegetable matter, to become fertile and valuable. 
 
 While then calcareous manures may be counted on to produce 
 great improvement on all soils not naturally provided with them — • 
 and to show a greater percentage of increase on the worst than on 
 better soils, and a remunerating profit on all ( — except those few 
 already calcareous — ) still, it will be far more profitable to marl 
 some soils than others. Dung, or other alimentary manure in the 
 best condition for use, increases vegetation nearly in proportion to 
 the quantity of the manure, and without regard or proportion to the 
 previous product of the soil. Thus, a wasteful application of dung 
 might, in a single year, increase the production of an acre of very 
 poor laud, from 5 bushels to 50 bushels of corn. But calcareous 
 manures improve production somewhat in proportion to the previous 
 power of the soil ; and if the original j^roduct was very low, the 
 addition thereto of 100 or even 200 per cent., made on the first 
 crops after marling, will show still but a poor product. These re- 
 remarks and illustrations arc designed for the instruction of those 
 beginners who deem it important to learn on what kinds of soil to 
 apply their marl. In more general terms I would answer, "apply 
 it to all soils not already calcareous ;" for however different may be 
 the measure of profit, I have never known marl applied unprofitably 
 in regard to place, if applied judiciously in manner. Of course I 
 refer to soils having some previous productive power and some 
 tenacity; and not to such naked sands, drifting with the winds, 
 as are seen in parts of North Carolina, South Carolina, and Georgia. 
 
 CHAPTER XXir. 
 
 TUE EXTENT OF DURATION OF THE EFFECTS OF CALCAREOUS 
 MANURES. 
 
 Proposition 5 — continued. 
 
 In advance of the discussion of the general question of the per- 
 manency of calcareous manures, I will here state the facts in regard 
 to duration of effects observed and known of my own oldest prac- 
 tice. Thiti extent of experience is indeed much too short to be 
 considered as the slightest evidence of such permanency of effect as 
 
CONTINUED EFFECTS OP MARL. 193 
 
 I ascribe to, and shall claim for, calcareous manures; nor are these 
 facts presented for that purpose. Still, even this comparatively short 
 experience shows an undiminished duration of benefit from calx- 
 ing, which is long compared to that of any other manuring. And, 
 therefore, for practical instruction, these and other like facts, if 
 brought from other sources, may be of more use than any reason- 
 ing upon theoretical grounds, though going to prove a degree of 
 duration of calcareous manures immeasurably greater than any ex- 
 perience of man. 
 
 At this time of my writing (1852), thirty-four years have 
 passed since my first application of marl (in January 1818), and 
 which was the beginning of regular and continued labours in the 
 same way. The dressings given in 1818, and also in 1819, were 
 all very light ; and were soon inferred to be insufficient, even for 
 the immediate wants of the land. Therefore, more marl was added 
 to all these places, with the next succeeding tillage crop. This 
 early repetition prevented any observation of the oldest dressings, 
 as to their separate and continued effects. In 1820, my error as 
 to quantity was in the opposite extreme, the marl being then laid 
 on so heavily as to produce injury to the crops, after some years. 
 For these different reasons, the marling for the corn of 1821 is the 
 oldest of my applications which was both heavy enough, and not 
 so excessive as to cause any subsequent abatement (by disease) of 
 the increase of crops produced in the first few years. No second 
 marling has there been given. The crops were increased always 
 in the first year after the marling ; and continued to show more and 
 more increase for ten or more years afterwards. Nor has there 
 been any known diminution of the highest productive power thus 
 obtained, to this time, in thirty-one years of tillage and rest, ac- 
 cording to the rotations in use, since the first marling. These re- 
 mai'ks apply especially and strictly to the eleven acres of newly 
 cleared (and then poor and acid) land, forming the subject of ex- 
 periment 1 (page 117 of this edition) ; and the like results, 
 though for different shorter times, have been experienced on the 
 adjoining and similar land, subsequently cleared and marled, 
 to the amount of eighty or ninety acres. Of nearly all the other 
 lands, also marled, on Coggins farm, for crops of 1821, or soon 
 after, of different soils and conditions, the same statements should 
 be made, in respect to there having been no known abatement of 
 the early increase of crops. To this general rule there are two 
 limited exceptions, apparent or real. The first has just been ad- 
 verted to, and was before described at length (p. 155). This injury, 
 by disease, however great, was not at all a diminution of effect of 
 the marl, but the result of excess of quantity, and of improper 
 effect. "With time, and siipplying vegetable matter in proportion, 
 17 
 
104 CONTINUED EFFECTS OF MART.. | 
 
 tliis excess of marl has been moderated in effect ; and those appli- i 
 cations now, as the others, show continuing good effects only. The 
 other exception, though not yet well understood, seems more real. - 
 It applies only to some small spaces of land, sometimes slightly! 
 oozy, on clay sub-soil. The surface of these spots is generally slop- 1 
 ing, though, in some cases, too level to lose much soil by washing 
 rains. The soil is shallow, and receives the excess of filtrating rain-] 
 water from the more level and higher land, in wet seasons, and! 
 which is discharged over its surface, when most abundant; or other- j 
 wise beneath the shallow soil, to the lower grounds, or to streams. ; 
 Such spots, being too wet only in winter and spring, and of small j 
 extent, were either not drained at all, or, where covered drains had, 
 been made and had failed, they were not renewed. In land of ■ 
 this kind, it seems as if the oozing water dissolves and carries off^ 
 the organic and nutritive ingredients of the soil. All soil of this 
 character, on the farm named, together makes but some ten ori 
 twelve acres, in many small, irregular-shaped spots, and always of j 
 small value for tillage, which circumstances caused their being neg- 1 
 lected. In all such cases, and even after being marled, and anj 
 early improvement being thereby produced, these spots have become i 
 more poor, and the soil itself seeming to diminish in quantity, asj 
 if lost by being washed away, which, however, is not the case. ! 
 Previous and proper drainage would, no doubt, have prevented the 1 
 existence of this only known real exception to the continued andi 
 unabated good effect of marling. It is stated here thus particularly, j 
 not only as due to truth, but also because the facts will be agaia i 
 referred to, in another connexion. ■ 
 
 It should be observed, as to my general practice, and in regard! 
 to all land referred to on which no repetition of the first marling 
 of early date has been made, or has been needed — and where no 
 abatement of the highest productive power has occurred — that the ; 
 following conditions existed, and were (as I suppose) essential for \ 
 the results stated: The marling had been heavy (perhaps furnish- 1 
 ing I2 to 2 per cent, of carbonate of lime to the tilled layer of soil), ; 
 and the land subsequently kept under sufficiently mild cropping 
 and treatment, which allowed it to be supplied, through its own j 
 growth of grass, and by help of atmospheric influences, with more! 
 organic or nutritive matter than the cultivated crops took away. 
 On some marled land, on other farms, where the general course of 
 cultivation was exhausting, and not compensated by enough of 
 natural or other supplies of vegetable and alimentary matter, the : 
 early increase of product has been subsequently lowered. In some I 
 such cases, within my observation, of most scourging tillage, in 
 eight or ten years after marling, and after excellent early effects, ■ 
 the land was reduced to as low a state as before beinsr marled. 
 
RE-MARLINGS. 195 
 
 Such I'csults, to this extent, have occurred only where the temporary 
 occupants of the land thought they had no interest in preserving 
 fertility for future use, or otherwise were grossly ignorant or neg- 
 lectful of their own interests. 
 
 But though the first dressing of marl being heavy, and not sub- 
 sequently repeated, are conditions best suited for showing the long 
 duration of elfects, that course is not economical or proper in any 
 other respect. When a heavy dressing is applied at once, perhaps 
 half the amount (even if not afterwards hurtful by its excess) is 
 superfluous, and lies useless and as dead capital for ten or twenty 
 years. It would be far cheaper, and more conformable to the 
 theoretical views of the action of calcareous manures, if half the 
 quantity of such heavy first applications had been withheld until 
 the addition was required by the increased store of organic matter 
 in the soil, and by the prospective continued supply, which would 
 call for more calcareous matter, for the purpose of combining with 
 what otherwise would be a useless and wasting excess of vegetable 
 or other organic matter. 
 
 Except where the first dressing was very light, and therefore was 
 very soon after added to, there were no re-marliugs on the Coggins 
 farm until about 1843. The want of more calcareous matter then 
 seemed to be indicated on parts of the farm, which either had at 
 first been the least heavily covered, or otherwise had since received 
 the most putrescent manure from the stock pens, or other supplies 
 of vegetable matter. These indications were understood when, 
 after a long time, scattering plants of sorrel began to reappear ; 
 when there was evidence of great increase of organic matter in the 
 soil shown by the larger products of grain ; and never by any de- 
 crease of production, except of clover alone. Believing that it was 
 time for re-marling to be beneficial, that operation was then begun, 
 and has been continued annually since on the parts of the land 
 supposed to raquire it, on each field, preceding its next corn crop. 
 The soils so re-marled, of course, were neutral before (from the 
 first marling) ; or, at most, had very little excess of newly-formed 
 acid ; and, of course, no perceptible or- manifest benefit from the 
 re-marling was expected, or has been found, in the next succeeding 
 grain crops. 
 
 In these cases, the want of additional calcareous matter was not 
 caused by the waste or disappearance of the first supply ; but be- 
 cause the first supply, still remaining with very slight diminution 
 of quantity, and none of effect, had served so to increase the organic 
 matter of the soil, that a larger quantity of calcareous matter could 
 be put to use and profit. This is altogether different from the 
 supposed exhaustion, by use and by waste, of the first supply of 
 calcareous matter, as occurs of putrescent manure, and the conse- 
 quent necessity for replacing it by a new supply. And this latter 
 
196 QUESTION OF DURATION OP CALXING. 
 
 is the cause requiring second and repeated applications of lime or 
 marl, as generally and erroneously supposed to operate, not only 
 by the ignorant, but by the scientific authorities whose opinions I 
 shall presently notice, and endeavour to controvert. 
 
 So far, I have merely aimed to show, by facts and from experi- 
 ence, that the increased productiveness of soils, induced by calca- 
 reous manures, has not ceased, nor, in general, been at all diminished 
 within such short time of experience as belongs to the agriculture 
 of this country, and of which only we can know and estimate all 
 the conditions and circumstances. But, however important may 
 be the value of these evidences of durable effect, bearing on the 
 question of the profit of practical operations, they go but little way 
 towards fixing the limit of duration, and of the undiminished ope- 
 ration of calcareous manures. 
 
 In the first sketch of this essay, published in 1821, as well as in 
 all the subsequent editions, I asserted and argued for the absolute 
 permanency of calcareous earth, acting as manure in soil ; and the 
 remaining in the soil of the lime, with but very little appreciable 
 diminution of its quantity, through all its chemical changes and 
 different successive combinations. In this opinion I have found 
 myself opposed to nearly if not quite all known authorities, whether 
 of scientific writers, or the practical European cultivators whose 
 reported practices and results have been quoted as evidence. Under 
 such circumstances, it was proper that my grounds should be care- 
 fully reconsidered, in connexion with the opposing reasoning. This 
 has been done ; and while deeming it proper to yield something of 
 the breadth of my previous position to newer and better information, 
 and while ready to admit the previous errors, and their recent cor- 
 rection, I have still to maintain my former opinion in "its most 
 important points. And, without exception, I deny the counter 
 opinions, either asserted by authors of high reputation, or neces- 
 sary deductions from their assertions, viz. : tltat calcareous manures, 
 though long continuing iii soils, still are liable to be nearly exhausted 
 by waste and use in terms of say twenty or thirty years ; and that 
 they then require being replaced, and may be so repeated, profitably, 
 and without limitation of the number. 
 
 No calcareous manurings made by man can possibly be old enough, 
 or capable of being clearly enough traced through their actual pro- 
 gress, to afford evidence of even very long duration, much less en- 
 tire permanency of effect. But, however weak for this purpose, 
 such facts, of long abiding effects, will at least serve to rebut the 
 assertions of the much earlier and necessary cessation of all the 
 effects of lime. For such opposition even my own experience of un- 
 abated effects, from applications not repeated, now extends to thirty- 
 one years. Another much older application (stated at page 114), 
 after long neglect, and under the worst treatment for its operation, 
 
BRITISH OPINIONS OP LIxMING. 197 
 
 sliowed visible cifects at the end of sixty years. Lord Kamcs men- 
 tions a particular case of the continued beneficial effects of an ap- 
 plication of calcareous manure for one hundred and twenty years 
 (Gentleman Farmer, p. 266, Edin. Ed.), and even Professor John- 
 ston, whose reasoning I shall have mainly to oppose, quotes, with 
 apparent assent, the opinion of "an intelligent and experienced 
 farmer," that certain lands in Scotland "would never forget an 
 application of forty to sixty bushels of lime to the acre." 
 
 I shall take from the Lectures of Professor Johnston, the argu- 
 ment in support of the temporary continuance and operation of 
 lime in soils, and its final entire loss and disappearance. No more 
 able advocate of the opinions I shall oppose, nor one of higher au- 
 thority, could be presented. His observations on lime as manure 
 are the most recent, and fullest of any known ; and in most of the 
 points, his opinions command my approval. In regard to this 
 branch of the subject, his views are as follows : — 
 
 "A certain proportion of lime," says this author, "is indispensable 
 in our climate to the production of the greatest possible fertility. 
 Let us suppose a soil to be wholly destitute of lime — the first step 
 of the improver would be to add this indispensable proportion. 
 This would necessarily be a large quantity ; and therefore, to land 
 limed for the first time, theory indicates the propriety of giving a 
 large dose. Every year, however, a certain variable proportion of 
 the lime is removed from the soil by natural causes. The effect of 
 the removal in a few years becomes sensibly apparent in the di- 
 minished productiveness of the land. After a lapse of five or six 
 years, during which it has been gradually mixing with the soil, 
 the beneficial effects of the lime are generally the most striking ) 
 after this, they gradually lessen, till, at the end of a longer or short- 
 er period, the land reverts to its original condition." (j). 383, 384.) 
 He states the usage in Roxburgh (Scotland), where most lands 
 are leased for nineteen or twenty-one years. On entering upon a 
 farm, the new tenant begins with applying 240 to 300 bushels of 
 [unslaked] quick-lime to the acre, and continues equal progress 
 "with his rotation of tillage, until all the farm is limed, within the 
 time of four or five years. He then continues to crop without more 
 liming for fourteen or sixteen years ; when, if he is sure of remain- 
 ing on his farm for another lease, he begins to lime again, at the 
 same rate as before. The author speaks of no limit to these re- 
 peated heavy limings ; and therefore it may be fairly inferred, that 
 he considers the repetitions, and the alternations of full supply and 
 disappearance of the lime, to be indefinite, or that at no future time 
 will such repetitions of liming ceasG to be required. Indeed, such 
 inference is unavoidable, if his previous statement be correct, that 
 land " reverts to its original condition," of being " wholly destitute 
 of lime." In such case, the land certainly would as much needi^ 
 17* 
 
198 RE-LIiMING IN BRITAIN. 
 
 lime again, as if it bad never been applied before. Elsewhere this 
 author speaks of twenty years as the ordinary duration of heavy 
 limings ; and that in some cases, on grass land, the effect lasted 
 thirty years, (p. 396.) '' A heavy marling or chalking in the south- 
 ern and midland counties of England is said to last for thirty years, 
 and the same period is assigned for the sensible effects of the ordi- 
 nary doses of lime-sand in Ireland, and of shell-sands and marls in 
 several parts of France." (p. 396, 397.) 
 
 There is no subject of practical agriculture on whicb it is more 
 difficult to gather truth from the evidence of alleged facts than in 
 regai'd to applications of calcareous manures, made by persons hav- 
 ing no knowledge or conception of their true action. The " facts," 
 as understood and reported by the most truthful men, may be de- 
 ceptions, and lead to false conclusions. There is a general accord- 
 ance in the practices of the re-limings, as above described, and the 
 repetitions of my own early marlings — yet how different in the 
 causes supposed in the two cases ! The British re-limings are re- 
 quired because the first dose was supposed to be either nearly or 
 entirely gone, " and the land had reverted to its original condition, 
 destitute of lime." In the other case, the lime certainly still re- 
 mained in quantity, and was believed to be not appreciably lessened ; 
 but more was required to balance and combine with the increased 
 organic matter. Besides these two causes, supposed and real, for 
 land needing re-liming, it may be wanting, and more than one re- 
 petition, because the previous dose was much too small for the 
 then wants of the soil. And in numerous cases, when no need 
 truly exists for more lime, and when indeed the land has been 
 already limed too heavily for its condition, but is exhausted of its 
 organic matter, and thereby impoverished by severe tillage, still 
 more lime is sometimes ignorantly added, and uselessly for its 
 resuscitation, if not injuriously. Yet all these different cases of 
 proper and improper applications, would be confounded by ordi- 
 nary report. And all that we can be sure of from such facta 
 reported to and published by Prof. Johnston, is that re-limings, at 
 intervals of twenty or more years, are common in Britain ; and 
 that sometimes, or generally, they have done good, and sometimes 
 harm. The statements of experience rarely extend so far as to 
 include the third or fourth application. When these shall be 
 known, I predict that there will be found many cases in which the 
 last application is in excess, and will do more harm than good. 
 Yet, strictly in accordance with the views of Prof. Johnston, the 
 fourth or the hundredth application, after proper intervals, would 
 be as much needed, and therefore should be as beneficial as the 
 first. 
 
 So much for the facts, and the very imperfect knowledge we can 
 
SUPPOSED REMOVAL OP LIME FROM SOILS. 
 
 199 
 
 liavc of thczn. I proceed to quote the author's explanations of the 
 manner iu which he infers that the lime is lost to the land. 
 
 1. '^ A considerahle quantity of lime," he says, "is annually 
 removed from the soil by the crops reaped from it. We have 
 already seen (Lecture X., § 4, p. 221) that in a four-years' rota- 
 tion of alternate green and corn crops, the quantity of lime contained 
 in the average produce of good land amounts to 119 lbs.* This is 
 equal to 37.5 lbs. of quick-lime, or 67 lbs. of carbonate of lime, 
 [per acre] for each year. The whole, however, is not usually lost 
 to the land. Part, at least, is restored in the manure, into which 
 a large portion of the produce is usually converted. Yet a con- 
 siderable portion is always lost — escaping chiefly in the liquid 
 manure and drainings of dung-heaps." (p. 399.) 
 
 Answer. — To some extent, the loss of lime to soil, by being ta- 
 ken up into the crops, is certain ; and I always before admitted it 
 expressly. But, on the author's own showing, the quantity lost in 
 this manner is very much smaller than would appear from the 
 above statement, if received without examination. The table 
 given previously in the " Lectures," and referred to above, of the 
 amounts of various inorganic matters absti-actcd from the soil by 
 all the crops of the ordinary Norfolk rotation, in four years, shows 
 the following amounts of lime so lost per acre : — 
 
 1st Year, Turnips (25 tons of roots), contains )^ 
 iu roots and leaves j 
 f Barley (38 bushels), grain, 
 \ Straw of same. 
 
 2d Year, 
 3(1 Year, 
 4tli Year, 
 
 ( Clover, 1 ton of hay, 
 
 \ Eye gi-ass, 1 ton, 
 
 ( Wheat, (2-5 bushels), grain, 
 
 (.Straw of same, 
 
 lbs. Lime. Lime. Total 
 
 45.8 
 
 12.9 
 03. 
 1G.5 
 
 2.1 
 
 1.5 
 
 lbs. 145.4 -t-3.C =149 
 
 By my thus presenting separately the respective quantities of 
 lime taken up by the grain alone, barley and wheat, which may be 
 supposed to be mostly sold and removed from the farm, and of the 
 turnips, hay, and straw, which mostly are consumed on the farm, 
 and the lime in them again returned to the fields somewhere in 
 the manure, it appears that the total loss of pure lime per acre, in 
 four years, by removal from the farm in the grain crops, is only 
 3.6 lbs. ; and annually, the average (0.9 lbs.) less than 1 lb. per 
 
 * This is stated as 248 lbs., and the numbers following in proportion. 
 But it is manifestly by mistake, as is seen by the table referred to (in 
 Lcct. X.). and by which I have corrected the sums above. The difference, 
 however, docs not materially affect the argument or conclusion. E. R. 
 
200 LIME TAKEN UP BY CROPS. 
 
 acre. And if the lime abstracted by the retained straw and other 
 home-consumed crops be added as lost, unfair and incorrect as 
 would be that assumption, the whole annual loss would be but 
 87.25 lbs. of lime, or say about one bushel of quick and slaked lime. 
 If then, 300 bushels of quick-lime had been applied, or as much 
 lime in marl, it would require the total removal of 300 successive 
 crops (and as heavy crops as those above stated) to take away 
 the lime applied. If considering only the loss of lime in the 
 grain, that annual waste, of less than a pound per acre, would re- 
 quire 11,175 successive and as heavy crops for the complete using 
 of the lime applied. In the one case or the other, these respect- 
 ive quantities of lime, annually resupplied to the land, would be 
 enough to compensate for the supposed waste. If the barn-yard 
 and other organic manures of the farm were all saved and applied 
 in time regularly to every part of the fields, then less than a pound 
 of lime added thereto for each acre, annually, would restore the 
 whole amount lost in the sold and removed crops. This is very 
 much less than I had before supposed, and admitted, from more 
 imperfect information than that now furnished by Prof. Johnston. 
 Boussingault reports, among other results of his many analyses, 
 the mineral, or inorganic parts composing the ashes of samples of 
 all the crops of his five-field rotation at Bechelbroun, which was 
 referred to above, for a different purpose. The amount of each 
 crop to the acre, throughout the rotation, had been ascertained. 
 And having, by analysis, determined the constituent elementary 
 parts of a certain quantity of each product, calculation correctly 
 showed the respective quantities of these constituent parts, in the 
 crops of each year, and for the whole rotation of five years. I 
 will extract below, from two of his tables, the statements of the 
 average crops and these inorganic parts, which were taken up, and may 
 be supposed were as much of these matters as the crops required. 
 There was an abundance of these matters in the soil ; for, besides 
 the natural original supply in the manure for the rotation, there 
 was furnished, of each inorganic matter, more than all that the 
 crops took up. Of the lime, this supply in the manure was more 
 than quadruple the quantity taken up. 
 
ALLEGED REMOVxlL OF LIME BY WATER. 
 
 201 
 
 
 
 
 Acids. 
 
 
 
 
 cS 
 
 
 
 
 3 ^ 
 
 
 
 -J 
 
 
 ^ 
 
 '^ 
 
 
 AVERAGE CROP PER ACRE, ON 
 
 
 • r-t 
 
 
 ' 
 
 
 6 
 
 a 
 
 
 o 
 'J2 
 
 c3 
 
 THE FIVE FIELDS OF THE 
 ROTATION. 
 
 Lbs. 
 
 inera' 
 ances 
 ops. 
 
 O -r^ 
 
 f^ 2 
 
 1 o 
 
 II 
 
 _3 
 5 
 
 
 
 ci 
 
 ^ 
 
 
 
 
 F^ to S 
 
 C 
 
 Ph 
 
 
 
 
 58 
 
 
 1. Potatoes, 
 
 11,733 
 
 lbs.113 
 
 13 
 
 8 
 
 3 
 
 2 
 
 6 
 
 G 
 
 2. Wheat, lbs. 1231, 1 
 4. Wheat, lbs. 1521, / 
 
 2,752 
 
 50 
 
 24 
 
 
 
 1 
 
 8 
 
 15 
 
 
 Wheat straw, of same, 1 
 2798, 3456, / 
 
 6,254 
 
 358 
 
 11 
 
 4 
 
 O 
 
 30 
 
 18 
 
 34 
 
 242 
 
 3. Clover hay, 
 
 4,675 
 
 284 
 
 18 
 
 7 
 
 T 
 
 70 
 
 18 
 
 77 
 
 15 
 
 5. Oats, 
 
 1,232 
 
 39 
 
 6 
 
 
 
 1 
 
 3 
 
 5 
 
 20 
 
 Oat straw of same, . 
 
 1,650 
 
 60 
 
 1| 
 
 2.7 
 
 3 
 
 5 
 
 n 
 
 17 
 
 24 
 
 Turnips, secondary crop, T 
 after wheat of 4th year, / 
 
 8,754 
 
 50 
 
 3 
 
 5 
 
 1 
 
 5 
 
 2 
 
 19 
 
 3 
 
 According to this statement, during the rotation of five years, 
 the total amount of pure lime taken up by the potato crop, and 
 three grain crops, was 4 lbs. The turnips, straw, and clover, took 
 up 120 lbs. The former quantity, equal to the yearly average of 
 0.8 lbs.; is all that may be supposed to be removed from the farm. 
 The latter, of 24 lbs. a year in the turnips, litter and hay, must bo 
 returned to the farm in manure. Both these quantities are still less 
 than by the foregoing estimate, quoted by Johnston. Both are so 
 minute as scarcely to bo appreciable; and all such loss would 
 scarce deserve consideration, as a practical matter, but for the fiilse 
 importance which has been given to this manner of abstraction of 
 lime from land. 
 
 The ordinary farm-made manures, with some purchased peat- 
 ashes, composed the manure applied by Boussingault, in each ro- 
 tation ; and which served to supply to the soil much more of all 
 the mineral parts than were taken up by the crops of all kinds. 
 Of course, there could have been no deficiency of supply of lime 
 for the use of the growing plants, nor any less taken up by them 
 than they required. 
 
 2. Another waste of lime alleged by Frof. Johnston is by solu- 
 tion in rain (or other) water. He says : " In the quick or caustio 
 state, lime is soluble in pure water, 750 lbs. of water serving to 
 dissolve 1 lb. of lime. The rains that fall cannot fail, as they sink 
 through the soil, to dissolve and carry away a portion of the lime 
 so long as it remains in the caustic state. Again, quick-lime, 
 mixed with the soil, speedily attracts carbonic acid, and in time 
 becomes the carbonate, which is nearly insoluble in pure water, 
 but is soluble in water impregnated with carbonic acid ; and as the 
 drops of rain in falling absorb this acid from the air, they become 
 capable, when they reach the soil, of dissolving an appreciable 
 quantity of the finely-divided carbonate of lime on cultivated fields. 
 
202 SUCH 'WASTE OF LIME DENIED. 
 
 Hence tlie water that flows from tlie drains upon such lands is 
 always impregnated with lime, and sometimes to so great a degree 
 as to form calcareous deposits in the interior of the drains them- 
 selves. . . The loss of lime from these causes cannot be 
 estimated, and must vary with the exposure to rains, and slope of 
 surface, &c. But the cause is universal and continually operating, 
 and would alone therefore render necessary, after the lapse of years, 
 the applications of new doses of lime." (p. 399.) 
 
 A71S10C1'. — These several chemical powers, &c., are fully admitted. 
 But their action, under usual and jiroj^er conditions of limed or 
 mai'led land, must be very limited, even when any such agency of 
 waste can be produced. Caustic lime, as stated above, may be 
 sparingly dissolved in pure water. But lime, applied as manure, 
 does not long remain caustic, and, after ceasing to be so, is no 
 longer the least exposed to this particular source of loss ; and marl, 
 or carbonated lime, is not at all so exposed. As carhonate of lime, 
 however, and while so remaining, another means of solution is 
 operating, in the carbonic acid of the air. But the quantity of 
 this acid is so small, and its tendency to be absorbed by water so 
 great, that a very light rain, or merely the beginning of a long or 
 heavy rain, must bring all the then floating carbonic acid to the 
 soil. This fluid would immediately sink into the pores of the earth, 
 with its dissolved carbonate of lime, if any ; and there be preserved, 
 either mechanically or chemically (by further and speedy combina- 
 tion with other matters of the soil), so as to be very little if at all 
 subject to removal in superfluous water before being saved and put 
 to use as manui'c in later-formed and more fixed chemical combina- 
 tions. This particular source of waste cannot apj)ly at all but to 
 lime in the form of carbonate. And, according to my previously 
 expressed views, that form is soon changed (with moderate and 
 proper dressings) to other salts of lime, or combinations with the 
 organic parts and the other earths of the soil. In such case, the 
 last considered outlet for waste is also closed ; but, possibly, and 
 as Prof. Johnston supposes certainly, others are opened, and will 
 operate, as thus : — 
 
 3. " During the decay of vegetable matter, and the decomposi- 
 tion of mineral compounds, which take place in the soil where lime 
 is present, -new comluuations are formed in variable quantities, 
 which are more soluble than the carbonate, and which therefore 
 hasten and facilitate this washing out of the lime by the action of 
 rains. Thus chloride of calcium, nitrate of lime, and gypsum, are 
 all produced — of which the two former are eminently soluble in 
 water — while organic acids [as humic, acetic, &c. &c.] also result 
 from the decay of the organic matter, with some of which the lime 
 forms readily soluble compounds (salts), easily removed by water/' 
 (p. 399.) 
 
OTHEE ALLEGED CAUSES OF WASTE. 203 
 
 Ansioer. — Admitted fully, as to the supposed chemical changes, 
 and the solubility of some of the now compounds. But these new 
 compounds are produced only so long as the lime remains either 
 caustic or carbonated in the soil, neither of which conditions ex- 
 tends beyond a few years, if dressings be not excessively heavy, 
 and if the material is finely divided and well diffused through the 
 soil ; and while in progress, the formation of these acid products, 
 and their resulting salts of lime, must be so extremely slow and 
 gradual, that probably nearly as fast as produced they are further 
 combined with other solid matters, and secured from the waste 
 which possibly might be caused by their solution in water. Of 
 course, it is impossible to estimate the measure of this supposed 
 saving process. The general effects are inferred from the known, 
 unquestionable, and grand results of thousands of years old, seen 
 in the still preserved constituents of lime and of fertilizing organic 
 matter in combination, in all the natural moderately calcareous and 
 rich neutral soils known. If we were to admit the full operation 
 of causes of waste of lime, as supposed by Professor Johnston, then 
 every natural and moderately calcareous soil must long ago have 
 lost nearly or all its lime, by one or all of the several preceding 
 operations of solution and removal. And if deprived of the lime, 
 it would be a certain consequence (according to my views) that the 
 soluble and useful organic matter, however abundant, under ordi- 
 nary circumstances of soils, would also be carried off, leaving the 
 uncultivated land throughout the world destitute of both lime and 
 organic matter, and therefore completely and hopelessly barren. 
 Such results, or even any approaching thereto, are unknown; and 
 their possible existence is as much opposed to all known facts of 
 natural soils, as they would be to our belief in final causes and the 
 all-benevolent care and protection of his works and creatures by 
 Almighty Grod. 
 
 But however strong may be these general reasons for denying 
 the wasting of lime and its resulting salts, there is a particular 
 chemical power asserted by recent authority, which, if true, covers 
 and sustains nearly my whole ground of objection. Professor 
 Gardner, in his late work, " The Farmer's Dictionary" (published 
 1846), in the article " Humus," refers to, as a known and undis- 
 puted chemical truth, that the humate of lime is nearly insoluble 
 in water.* Now, though the humic acid is but one of four or five 
 
 * Of the fact of the insolubility of humate of lime, the authority of Prof. 
 G.ardner, or of any recent chemical writer, must be sufficient. But I would 
 deny his deduction from that property, that therefore humate of lime can- 
 not directly act to feed plants. Vegetable life can exert dissolving and 
 decomposing powers that the chemist in his laboratory cannot imitate or ap- 
 proach. If the property of insolubility in pure water rendered any substance 
 necessarily useless as a direct manuring agent, we should be compelled 
 
204 CAUSES OF WASTE CONSIDERED. 
 
 acids of soil, of vegetable origin, wliicli chemists have recently 
 ascertained, the humic acid is by far the most frequent, abundant, 
 and important of all. Of course when lime is applied to an acid 
 soil (i. e., any one needing the chemical action of calcareous earth), 
 the most abundant resulting salt will be the humate of lime, which 
 being insoluble in water (or very nearly so), is entirely secured 
 from the waste to which a soluble salt might possibly be, but is 
 not necessarily liable. 
 
 4. "The ultimate resolution of all vegetable matter in the soil" 
 continues Professor Johnston, " into carbonic acid and water, like- 
 wise aids the removal of the lime. For if the soil be everywhere 
 impregnated with carbonic acid, the rain and spring waters that 
 flow through it will also become charged with this gas, and thus be 
 enabled to dissolve so much the larger portion of carbonate of lime. 
 Thus, theory indicates, what I believe experience confirms, that a 
 given quantity of lime will disappear the Sooner from a field, the 
 more abundant the animal and vegetable matter it contains." (p. 
 399, 400.) — Answer. — First, to the last incidental passage, I will 
 merely state unqualified dissent. So far from the quantity of vege- 
 table matter promoting the escape of the lime, it would tend to 
 prevent such waste, if otherwise likely to occur. According to 
 my theory of the action, the lime and vegetable matter in soils 
 combine with each other, and with other parts of the soil, each one 
 thus serving to retain the others, if otherwise liable to waste. 
 
 Whatever may occur in old manure heaps, or in the chemist's 
 laboratory, it is not likely that much, if any, vegetable matter in 
 soil (and when not in great excess), can pass through all the va- 
 rious stages of decomposition, to the last, that of being resolved into 
 carbonic acid and water. Previous changes would slowly render 
 the parts soluble, and fit to be drawn up by the roots of plants ; 
 and probably all would be so used, so that very little reaches the 
 gaseous state. But if carbonic acid should be formed, the pro- 
 duction would be very slow, so that the results would be all required 
 for, and taken up, by plants in aid of their support and growth, 
 almost as fast as they were produced. Thus, there would be but 
 little if any opportunity for the alleged waste of lime, in conse- 
 quence of the organic matters in the soil reaching the last stage 
 of decomposition, and being reduced to carbonic acid and water. 
 
 So far, the sundry particular reasons offered iu support of the 
 alleged transitory operation and existence of lime in soils have been 
 opposed by particular objections. But still stronger grounds of 
 objection may be assumed in general views, which will now be 
 brought forward. 
 
 to place in the same class both carbonate and phosphate of lime entirely ; 
 and also caustic lime, for much the greater part of the bulk of au ordinary 
 application as manure. 
 
DURATION OF EARTHY MANURES. 205 
 
 Most farmers are so accustomed to consider manures as being 
 fleeting in their ojDeration and existence in soil, as are the ordinary 
 putrescent manures, that it is difficult for them to have any con- 
 ception of any kind lasting and acting for ever. And this difficulty 
 of conception, stands much in the way of my argument. But, how- 
 ever little used by farmers, or even thought of, in this light, it is 
 obvious aud undeniable, that certain mineral manures will continue 
 in operation, and without abatement of effects, as long as the soil, 
 or the habitable globe itself, shall exist. Thus, clay is a manure 
 for sandy soil, serving to stiffen and compact its before too light, 
 loose, and open texture. Sand also is a manure for stiff clay soils, 
 serving to correct their tenacity when wet, and their obduracy when 
 dry, and make them more open, light, and permeable ; more easy 
 to cultivate, and more safe for production. And in either of these 
 manuring operations, it is self-evident, and not admitting of ques- 
 tion, that the continuance of these manures, and their good effects, 
 will be eternal. 
 
 Carbonate of lime in soil, whether supplied by nature or art, 
 like sand and clay, is a ponderous earth, and but to small extent 
 liable to waste or loss by any natural agency. It is insoluble by, 
 water, except so far as water may contain carbonic acid, which 
 renders water a solvent of carbonate of lime. But this impregna- 
 tion of water in soil is very limited. It can scarcely occur at all 
 except in the usual mode, by rain-water, when descending through 
 the atmosphere, absorbing and bringing to the earth the very small 
 and strictly limited quantity of carbonic acid in the lower atmos- 
 phere. Except in this respect, and for the still more minute and 
 scarcely appreciable quantity of lime taken up by growing plants, (as 
 stated above), carbonate of lime in soil would seem to be as inde- 
 structible, and as surely abiding through all future time, as the clay 
 or the sand which might also have been given as manure, or other- 
 wise held as natui'al ingredients of the same soil. As rain-water 
 always brings to the earth some carbonic acid, though in extremely 
 small quantity, still, to that small extent, the carbonate of lime in 
 the soil is liable to be dissolved; and when so dissolved, if there 
 were no counteracting agencies, some of the dissolved earth might 
 be lost (possibly) by filtration through the soil, or, less improbably, 
 by being floated off from the surface, in the flowing away of any 
 excess of rain-water. But there are counteracting agencies ope- 
 rating to prevent the loss of lime in this, and also in other soluble 
 forms. According to my own early (and then unsupported) views 
 of the formation of acid in soil, as well as according to the now 
 received general opinions on that subject, the carbonate of lime 
 would soon begin to be changed to other salts of lime, by combina- 
 tion with other acids in the soil. Some one or more of these newly 
 formed salts might be much more soluble in water than the carbo- 
 18 
 
206 DURATION OP SALTS OF LIME. 
 
 nate, and therefore more liable to be wasted by rain-water surcharg- 
 ing the soil. This result can neither be affirmed nor denied, from 
 any positive knowledge of such facts, or of the chemical changes 
 necessary for them. We do not know which of the vegetable acids, 
 nor how many of them, at once or successively, may combine with 
 the lime ; and therefore cannot know what other salts of lime will 
 be produced. The humate of lime, which, it may be presumed, 
 will be the most abundant of such products, is difficult of solution 
 by water. If osalate of lime should be formed (as is probable, 
 where sorrel was before an abundant growth), that is an insoluble 
 salt, and therefore safe from this manner of loss. The acetate of 
 lime, another probable result, is easily soluble in water ; and per- 
 haps other vegetable and soluble salts may be formed in soils, 
 though more rarely and in less quantity than the humate and oxa- 
 late of lime. Besides, there are other soluble salts of lime named 
 by Prof. Johnston, and quoted above. But, however little may 
 be known by chemists or others of thS kinds and quantities of these 
 salts into which carbonate of lime is gradually changed, by access of 
 different vegetable or other acids, it appears, from the general and 
 abiding effects on fertilization and production, that all these differ- 
 ent salts of lime continue to perform, and as fully, all the enduring 
 functions of carbonate of lime. For when a soil, after having been 
 made slightly calcareous, has in time become neutral (and of course 
 its carbonate of lime has been all converted to other salts of lime), 
 the soil thereby loses none of its so acquired fertility or value, 
 through any succeeding known time. This could not be the case 
 if the limo in its new condition was liable to certain and rapid, and 
 finally complete waste, by dissolving and escaping waters. In a 
 former chapter (pp. 96, 97,) I maintained that the serviceable and 
 acting lime in soil (for of course any quantity in excess is not so 
 considered) becomes chemically combined with the organic, or ali- 
 mentary manuring principles present, and all these with other earthy 
 parts of the soil. Judging from the abiding effects, and in regard 
 to neutral soils, it may be safely inferred that such combinations 
 occur not only with the carbonate, but with nearly all the later 
 produced salts of lime, resulting from the carbonate. And if so, 
 such combination with other insoluble and permanent matters of the 
 soil, would render as fixed and permanent even the salts most solu- 
 ble and liable to waste when alone. Of this, I will state an ex- 
 ample that will be familiar to every one. Sulphate of iron (copperas) 
 is easily soluble in water; and, if alone, would be soon removed 
 completely by the dissolving water passing away. The red juice 
 of fresh nut-galls would be nearly as easily taken up, and washed 
 off by water. But these two substances, if meeting together, would 
 chemically combine, making ordinarj' black ink ; which cannot be 
 washed away by water from any substance to which it is attached ; 
 
NATURAL CALCAREOUS .SOILS. 207 
 
 nor caa cither of the before soluble parts be thus taken from the 
 other. It is in this manner that lime, even in its soluble forms, 
 is fixed permanently in soils. And whether in this manner, or 
 otherwise, it is sufficiently manifest that such results are produced, 
 by reference to the great manuring operations of nature, unlimited 
 as to both space and time, and compared to which the largest ex- 
 perience and greatest labours of man are as nothing. To these great 
 operations I now appeal for proof of the long-abiding and unending 
 benefits of calcareous manures. 
 
 Soils naturally supplied with lime, in proper proportions, are a3 
 much cases of calcareous manuring, as if performed as early by 
 agricultural art and industry. All such naturally limed lands, 
 throughout the known world, have always been, and still continue 
 to be, among the most valuable and fertile. Such lands, in Europe 
 and Asia, remarkable for their productiveness thousands of years 
 ago, have lost nothing of that character to this day. In America, 
 our agriculture is comparatively new, and therefore our historical 
 proofs of such facts are comparatively limited. But even in this 
 new country, the rich soils of the valley of Virginia have continued 
 to bring fine crops for more than a century. And no one acquaint- 
 ed with these and other similar naturally fertile lands has ever 
 doubted that they will, under judicious culture, and equal circum- 
 stances, maintain their present superiority over other poorer lands, 
 through all time. Yet these fine lands owe their value and supe- 
 riority to their natural lime constitution ; and their continued fer- 
 tility, for a century, is but the efi'ect and evidence of the original 
 liming having operated as long. It is true that many such lands, 
 in this country, have already been greatly reduced in fertility by 
 long-continued exhausting cultivation, which has been used to take 
 as much from, and return as little as possible to the soil. But 
 though such exhausting tillage is capable of consuming and destroy- 
 ing most of the organic matter, and thereby inducing corapai-ative 
 barrenness for the time, yet it does not lessen the lime ingi-edient 
 and quality, nor the recuperative powers which the soil derived 
 from the lime ; and which, if left again to act, for sufficient time, 
 will restore the former condition of productiveness. Scourged aa 
 such soils have been in many cases, by continued exhausting til- 
 lage, they still show, in their most reduced and barren condition, 
 as much as ever before, the possession of the peculiar qualities de- 
 rived from their lime ingredient. When such soils, by time, or 
 cultivation, shall have lost their dark colour, their power of absorb- 
 ing and retaining moistui'e, and of retaining putrescent manures, 
 and their peculiar fitness for producing leguminous plants, then, 
 and not before, it may be asserted with some plausibility that the 
 salts of lime, which had formerly induced fertility, have been siu^^e 
 entirely lost by tho soil. 
 
208 ABSURDlTi' OP THE DOCTRINE OPPOSED. 
 
 If the lime in soil was indeed subject to waste and loss in the 
 manner and to the extent maintained by Prof. Johnston, the ill 
 consequences would necessarily be general, and so disastrous that 
 there could be no possible mistake of the operation and its results. 
 Upon his own premises, the actual (and always admitted) removal 
 of lime from the soil in its crops, though certain, is too small to 
 be appreciable. It is a theoretical truth, of which the practical 
 operation is imperceptible. And this imperceptible part of the 
 alleged loss of lime is all that is caused by tillage and the removal 
 of the crops. It is by the lime (either as quick-lime, carbonate, or 
 other salts) being dissolved in water, according to Prof. Johnston's 
 views, that the great loss is incurred, and that all, or nearly all, 
 the lime furnished for manure is finally lost, and within not very 
 long periods of time. This, the great cause of waste, is operating 
 (as asserted) by every considerable or excessive rain, on all soils 
 containing lime, and through all time. This operation, too, would 
 not be less sure on lime existing naturally in soils, than if supplied 
 as manure, and as thoroughly iucorpoi'ated as in a natural calcare- 
 ous or neutral soil. And if twenty or thirty years' operation of 
 the solvent power of rain-water suffices (as asserted) usually to re- 
 move either mostly or completely the lime before furnished to the 
 land as manure, then, surely, the same universally operating power 
 of rain-water must as completely remove and utterly waste any 
 barely sufficient natural ingredient of lime, say in 100 years. So, 
 all lands throughout the world, moderately and properly supplied 
 by nature with lime, would thus have lost the whole thousands of 
 years ago. And they would all have thenceforward remained thus 
 destitute of lime, until being re-supplied by man. This kind of 
 artificial manuring has never been used on but a very small pro- 
 portion of all the lands of the world under tillage ; and even on such 
 small proportion, for but a short portion of all the time in which 
 tillage has been in use. Of course, then, on all other lauds not 
 containing an excessive store of lime, the whole of this essential 
 ingredient, in every form of combination, should be entirely want- 
 ing ; and, therefore (according to my views of the absolute neces- 
 sity for, and the action of lime), much the greater portion of the 
 surface of the earth would have been thus rendered perfectly bar- 
 ren. For, without lime to combine with and fix organic matter, 
 there would be nothing to retain the latter; and the complete 
 waste of the lime would be necessarily followed by the waste of all the 
 enriching matter in the soil, and the inducing of complete sterility. 
 The known fact that no such eifects are produced, or any even ap- 
 proaching to them, is alone sufficient proof that the waste of lime 
 in soil cannot occur, as supposed by Prof. Johnston. 
 
 Enough has been said in opposition both to the alleged fact of 
 the natural waste of the acting and requisite lime in soil, and the 
 
OTHER SALTS IN SOILS. 209 
 
 Bupposcd manner of the waste being produced. But tliere is an- 
 other connected and similar subject which deserves notice. 
 
 The salts of lime are not all the salts, nor the only soluble mat- 
 ters, usually present in soils. The inorganic parts of plants, 
 forming their ashes, after their being burnt, consist mostly of 
 various salts, not only of lime, but also of other bases, as magnesia, 
 potash, soda, &c. These salts, of course, were drawn by the plants 
 from the soils on which they grew. From their being universally 
 present in plants (so far as known), modern chemists have inferred 
 that all these various salts are essential to the health, if not to the 
 existence of the plants, and, of course, essential to the productive- 
 ness of the soil for these plants. But most or all of these salts, of 
 magnesia, potash, soda, &c., are soluble in water, and some very 
 easily soluble. If, then, as Prof. Johnston argues as to lime, water 
 necessarily dissolves and removes whatever soluble salt or earth is 
 existing in soils, I would ask why have not all these other soluble 
 matters been removed from all soils ? These are present usually 
 in much smaller proportions than lime or its salts, and therefore 
 could be more easily dissolved and removed. That no such com- 
 plete loss of these other salts has been produced in any soil, so far 
 as known, is another sufficient reason for inferring that neither is 
 lime, nor its more soluble salts, likely to be taken away from the 
 soil, when acting usefully as fertilizing matters, by the solvent 
 action of water. This view of the case is still stronger in another 
 aspect. Liming in England and Scotland is usually renewed (as 
 stated above), or requires renewal, in twenty years or thereabout. 
 The farmers of Norfolk (England) also renew their heavy marlings 
 every eight years or sooner. Hence it is argued that the calcareous 
 manure is exhausted in some such limited times. But the other 
 salts, of magnesia, potash, soda, deemed by modern chemists as 
 essential to soils and to their production, are almost never replaced 
 by artificial applications, or by design, even under the highest and 
 best farming, and absolutely never (unless by rare accident) in 
 ruder culture. Hence it would seem legitimately deduced from 
 Prof. Johnston's reasoning as to the disappearance of lime, that 
 even in the highly-limed and cultivated lands of Britain, the other 
 elements of fertile soil, all deemed as essential to production as 
 lime, ought to have been exhausted long ago. On nearly all other 
 parts of the world, not only all these other substances, but also the 
 lime itself, ought to have been entirely removed, and every soil 
 rendered barren. This reduction to an absurd conclusion would 
 alone be enough to disprove the argument I oppose. 
 
 Prof. Johnston, in his attempt to prove the transitory existence 
 
 and operation of lime as manure, has committed an error to which 
 
 scientific men who treat on practical agriculture are extremely 
 
 prone. This is to suppose that matters in the soil act with and 
 
 18* 
 
210 THE MEASURE OP DURATION. 
 
 arc acted on by others present, as they woukl in the chemist's 
 hiboratory. In the soil, there are many other matters present, and 
 some, perhaps, whose presence is not suspected ; and very complex 
 and extensive and varying combinations may exist of various mat- 
 ters, whose characters and powers are certainly not vinderstood. 
 But while denying the correctness of his application to the soil of 
 correct and unquestioned chemical laws in regard to the Jcnown 
 matters and agencies under consideration, and while striving to 
 restrict his estimate of the extent of the operation of other agencies, 
 still I readily admit that valuable truth and good instruction are 
 to be gathered from his opinions on this branch of his subject. 
 He has enabled me to see errors in, or exceptions to the extent of 
 my own first opinion, as heretofore stated. That opinion, which 
 claimed absolute permanency for all the lime in soil (always ex- 
 cepting the minute portion taken up by plants), and Prof. 
 Johnston's opinion of the great waste and speedy removal of aU 
 the lime used as manure, were both carried to very erroneous ex- 
 tremes. 'The true doctrine will be found between those extremes ; 
 which I trust that I have now reached, and will endeavour to 
 indicate. 
 
 As strenuously as formerly, I still assert and maintain the per- 
 manency of lime in soil, for such amount of quantity as is at the 
 time acting chemically, or as manure. That quantity is very small, 
 compared to what is in some highly calcareous soils — perhaps not 
 usually more than 1 per cent, of the whole tilled layer. Yet this 
 small quantity performs all the useful manuring functions of lime j 
 and any excess of this earth, beyond that amount, has no manuring 
 or beneficial action. It is merely a mechanical earthy ingredient — 
 Avhich, if large, may do some good, or, as likely, some harm by its 
 presence and its mechanical bearing on the texture of the soil, but 
 is not in the least a fertilizing agent. Upon any such surplus 
 quantities of either lime or carbonate of lime in soil (and perhaps 
 also some other salts of lime not required by and combined with 
 the soil, and therefore in excess), the solvent power of rain-water 
 may act, and the lime bo gradually thereby removed, according to 
 the operation of chemical laws, in the manner stated by Prof. 
 Johnston. But with regard to the small quantity of lime required 
 as manure, it is (according to my original views before presented, 
 p. 96) combined chemically with the alimentary organic matter, 
 and both these, with the soil itself, and this state of combination, 
 is safe from solution or loss. The quantity of lime which may be 
 required and used as manure by a soil, varies at diiferent times 
 according to the changes of condition. The more putrescent matter 
 the soil receives, as manure, the more lime will be required to 
 combine with, preserve, and properly utilize the organic and ali- 
 mentary matter. Any excess of UmC; whether bestowed by uatui'C, 
 
USEFUL APPLICATIONS TO PRACTICE. 211 
 
 or as manure by man, beyond the present wants of the soil, is 
 only of value so far as being there ready for any future increased 
 demand of the soil, and so may supersede the necessity of another 
 supply being required as soon. Therefore, however active may be 
 the solvent power of water, and however rapid the consequent 
 waste of the excess of lime in the soil, the operation can detract 
 nothing from any manuring value, or quantity of the lime, pre- 
 viously and then existing. 
 
 The statements and reasoning of Prof. Johnston brought to prove 
 the waste and final disappearance of all lime used as manure, how-'' 
 ever inconclusive for his object, furnish important truths for 
 practical use. We may thence deduce additional reasons for the 
 impropriety of laying on at once too much marl or lime for the then 
 wants of the soil ; and also of the usual unequal diflusion, which 
 serves to make even a light dressing excessive in many spots, while 
 entirely wanting in others. Not only, as I had before urged, is all 
 such excess of quantity, whether general or pai-tial, a waste of 
 labour, a conversion of active to dead capital, and the causing 
 danger of actual injury to crops — but further, such excess of lime, 
 or carbonate of lime, is subject to more or less waste, by solution 
 and remov-al, so long as it remains superfluous, and not required 
 for immediate use by either the soil or growing plants. It is such 
 excess as this in soils, that furnished all the wasted lime found by 
 chemists in the waters discharged by drainage from limed lands. 
 Still more extensive natural operations of the same kind, and 
 stronger proofs, are to be seen in all lime-stone and highly cal- 
 careous regions. The rain-water filtrating through such rocks and 
 soils, becomes universally and highly charged with lime ; of which 
 a large portion is removed and lost to the place of its origin, by 
 flowing off into sources of springs and streams. Another portion, 
 by filtration, may sink deep into the earth. In limestone and chalk 
 regions, indications of the quantity of lime dissolved by rain-water, 
 from the rocks and soil, and carried off by springs, may be observed 
 not only in the lime-impregnation of spring-water, but also in the 
 deposition of travertine, or calcareous tufii, at the rapids of streams; 
 and of the loss by filtration in the stalactite deposits in every 
 cavern of the earth. 
 
 There remains to state one other manner of the loss of lime in 
 soil, which is mentioned by Prof. Johnston, and also other authors, 
 as being a common, if not a general result in England. This loss 
 is caused by the tendency of lime, which has been applied, to sink 
 below the upper soil. " It has long been familiar to practical men," 
 says Johnston, " that when grass lands, which have been Ijmed on 
 the sward, are after a time broken up, a white layer or band of 
 lime is seen at a greater or less depth beneath the surface, but 
 lodging generally, where it has attained its greatest depth between 
 
212 SINKING OF LIME. 
 
 the iipper, loose, and fertile, and the lower, more or less impervious 
 and unproductive soil. In arable lauds, the action of the plough 
 counteracts this tendency in some measure, bringing up the lime 
 again from beneath, and keeping it mixed with the surface mould. 
 Yet through ploughed land it sinks at length, especially where the 
 ploughing is shallow ; and even the industry of the gardener can 
 scarcely prevent it from descending beyond the reach of his spade." 
 (p. 397.) 
 
 Such results, frequent as they doubtless are in England, are cer- 
 tainly very rare, and of no material disadvantage in this country. 
 Indeed, until very lately (in 1851), I had never heard of any such 
 case. But then I learned from Mr. John A. Selden, that he has 
 observed this effect on his highly improved and well limed farm, 
 Westover. I had before inferred that this sinking of lime, in its 
 separate and pure state, could not occur except where it had been 
 applied in excess — as must be generally done in the usual heavy 
 applications in England j and that it was only the excess of lime, 
 vrhich the soil did not then need, and with which, therefoi-e, the 
 organic matter could not combine, that could thus continue sepa- 
 rate, and sink through the open soil. If such combination had 
 taken place (as I suppose of a barely sufficient application), of all 
 the lime with the organic matter, and of both with the other earthy 
 parts of the soil, then the lime could not separate from its combi- 
 nation, and of course could not sink alone. Neither could it carry 
 with it the other matters in combination. This sinking, it seems, 
 does not occur with marl, or other " impure calcareous manures," 
 but with the finely powdered burnt lime only. When breaking up 
 land for a second cultivation subsequent to its having been marled, 
 I have often seen the plough bring up marl, unchanged in appear- 
 ance, from the bottom of the furrow. But this had been before 
 turned under (when first spread) to that depth, and had not been 
 reached and intermixed by the after tillage. Caustic lime is applied . 
 in England very heavily — often as much as 300 bushels, or more, 
 unslaked, to the acre — and repeated at intervals of about twenty 
 years. And these, or lighter dressings, must often occur on soils 
 before calcareous, either naturally, or made so by previous liming. 
 In either of these cases, I would deem any addition of lime, how- 
 ever small, to be in excess, for the time ; and of course svich ex- 
 cessive quantity would remain uncombined, and therefore subject 
 to waste. In this country, all liming has been given in compara- 
 tively light dressings, and very rarely, if ever, to a calcareous soil ; 
 and therefore it was rare that any portion of the lime was in 
 excess, «.nd consequently remained separate and uncombined. And 
 it is because of these very difterent conditions that the sinking of 
 lime, an efiect so common and notorious in England, should be so 
 
RECAriTULATION. 213 
 
 uncommon, and not to he counted as a loss or disadvantage in 
 practice, in this country. 
 
 The foregoing reasoning, and the conclusions thereby reached, in 
 regard to the duration of calcareous manures, may be deemed a 
 continuation of the subject of Chap. VIII., " on the mode of ope- 
 ration by which calcareous earth increases the fertility and pro- 
 ductiveness of soils." It may be useful here to recapitulate, and 
 bring together in a small space, the main positions which I have 
 asserted and maintained. 
 
 1. Besides the chemical power and action of calcareous earth as 
 manure, to neutralize acids, to alter and improve the texture of 
 soils and their relation to moisture, and also other beneficial 
 agencies, before discussed at length, the principal and most import- 
 ant action of the carbonate and other subsequently resulting salts 
 of lime, in soils, is the combining with organic or alimentary ma- 
 nures, and also with other earthy parts of the soil. The several 
 matters, so combined, are rendered, by their combination, fixed in 
 the whole soil, and secure from waste — and from other diminu- 
 tion, except for the supply of alimentary matter to growing plants. 
 To this extent, then, and with the exceptions stated, the combined 
 matters would be permanent. For this purpose, and to the extent 
 required by growing plants, their vital forces can decompose the 
 combination of organic, calcareous, and other earthy constituents, 
 and take from it freely the parts which the plants require from the 
 soil for their support. The organic part of the compound is mainly 
 drawn upon, and diminished by growing plants ; the calcareous (or 
 other lime) part thus furnishes an extremely small amount only. 
 Putrescent matter, if again supplied to the soil, will replace in the 
 combination whatever organic matter had been withdrawn by grow- 
 ing plants. It the soil is not allowed to obtain the requisite sup- 
 ply of organic or putrescent matter, the fertility of the soil will 
 continue to be reduced by growing crops gradually exhausting the 
 previous supply; although the lime parts of the soii may not be 
 appreciably lessened. If, on the contrary, putrescent matter shall 
 be furnished to a calxed soil, or be permitted to accumulate in it 
 by natural means, in greater quantity than the lime parts can 
 combine with, more lime will be required. 
 
 2. If without such state of combination existing, owing to the 
 absence or insufiicient quantity of either part, the excess of the 
 other part would be subject to, and continually undergoing waste. 
 If the part in excess was the putrescent, or organic, it would 
 rapidly and entirely be removed by decomposition, solution, and 
 other natural modes of its waste. If the excessive matter was in 
 lime, whether caustic, or carbonated, or as any other soluble salts 
 of lime, this also would be gradually dissolved, and lost; and 
 though the progress of such waste would be very slow, yet in the 
 
214 DURATION OF ORGANIC MANURES. 
 
 course of long time it might be very considerable, or possibly (as 
 asserted by other authority) nearly complete. 
 
 3. According, then, to the condition of excess of either of the 
 parts necessary for the fertilizing combination above stated, either 
 the organic matter or the lime in soil might be wasting, and the 
 other part for the time remain fixed, and safe from diminution — 
 always excepting the portion, large or small, taken up by and re- 
 moved in the crops. 
 
 If I have succeeded in establishing the foregoing views of the 
 permanent operation of calcareous manures, it will involve the 
 strong probability, if not certainty, of another result, to which 
 assent would be still more difficult to obtain, without good reasons 
 being shown. 
 
 Tlaough probably all observing and practical formers would be 
 ready to admit the proposition, that the natural and peculiar quali- 
 ties of good soils, including their measure of productive power, are 
 permanent, (which is but stating, in other words, that the good effects 
 of calcareous manures are permanent), still perhaps few would 
 grant the possibility of permanency of effect to putrescent manures 
 also, when added thereafter. Yet this latter proposition is as legi- 
 timate a deduction from the former, as the former proposition is 
 from the theory which has lieen maintained of the action of calca- 
 reous manures. The attention of the reader is requested to the 
 argument which will now be offered to sustain this important de- 
 duction. 
 
 We have all been trained to consider farm-yard and stable-ma- 
 nures, dung, and all vegetable and other putrescent matters, when 
 applied to soils, as having temporary effects only ; and whether the 
 effects lasted for but the first crop, as on acid sandy soils, or for 
 four, six, or even eight years on well constituted natural soils, still 
 the effects were truly, as usually considered, only for a limited 
 time, and would at some period be totally lost; and the ground so 
 manured woftld return to the same state of less productiveness, as 
 of the surrounding land, previously equal, and which had received 
 no such manuring. Such views are almost universal ; and the ut- 
 most that would be claimed by the most zealous and sanguine ad.- 
 vocate for extending the effect of such manures, would be a protracted 
 though still limited and temporary duration of action. And the 
 actual results would always accord with these opinions, (and also 
 with my theory of the action of calcareous manures), both on good 
 and on bad soils, before making them more calcareous. All natural 
 soils (not excessively and injuriously calcareous) have secured by 
 their natural powers and facilities, and have had fixed in them, as 
 much alimentary or organic matter as their natural ingredient of 
 lime could combine with. If that ingredient had been very small, 
 the soil would be poor; if large, and not so large as to be hurtful. 
 
DURATION OP ORGANIC MANURES. 215 
 
 tlicD the soil would be rich. But in neitlier case woukl there bo 
 power in the soil to combine with an additional supply of aliment- 
 ary manure ; and if such were applied, it would be exhausted and 
 pass away, rapidly on the bad soil, and more slowly on the good; 
 but certainly, in the end, on both. 
 
 Again, suppose the soils to be more or less exhausted by scourg- 
 ing cultivation. Then their actual amount of alimentary matter 
 would have been reduced below what their respective shares of 
 lime could combine with and retain, under a state of nature, or of 
 mild tillage. Then, if alimentary manures were applied, so much 
 as was required for combination by the lime jircseut would be as 
 permanently fixed as if the original fertility had never been ab- 
 stracted ; and any additional quantity and excess of manure, not 
 being so combined and fixed, would be totally lost in more or less 
 time, as in the previously supposed case. 
 
 Lest these propositions may not appear, because of their novelty, 
 perfectly clear and unquestionable to every reader, an illustration 
 will be offered which can scarcely fail to induce their general and 
 ready admission. Suppose a cultivator to have two fields, one of 
 bad and poor soil naturally, and the other of the best natural qua- 
 lity — and both having been brought under cultivation together, 
 and kept under the same rotation of crops and other management. 
 Suppose further that the equal and uniform course of cropping 
 has been such (whether taking one or two or three grain crops to 
 one year of rest and resuscitation), that both fields have neither 
 been reduced nor increased in average product, since brought under 
 regular tillage ; and that such average product, when of corn, is 
 equal to 10 bushels per acre on the poor, and 60 bushels on the 
 rich soil. Now, these different products are derived from the dif- 
 ferent funds of alimentary and putrescent manure originally sup- 
 plied to the soil by nature, (which were just so much as the lime 
 of each soil could combine with) ; and, under the supposed degrees 
 of exaction and relief, counteracting each other under tillage, the 
 same rates of product may be obtained for ever. And the yielding 
 of 50 bushels by the one soil operates no more to reduce its after- 
 power of production, then the yield of the other of but one-fifth of 
 that amount of crop. The yield from each soil, at and for the time, 
 is certainly so much reduction of its productive power ; but the re- 
 cuperative power of each (to seize upon and retain new supplies for 
 fertilization, drawn from the atmosphere, and from the grass and 
 weeds grown and suffered to decay on the land,) is in proportion 
 to the yield ; and the vegetable growth serving for manure, and 
 atmospherical influences, during a year of rest, will continually 
 give to the good soil the renewed power of producing again its large 
 crop, as certainly as to the poor soil the power of still continuing 
 to produce it,s small crop. It is not that the natural alimentary 
 
21G DURATION OF ORGANIC MANURES. 
 
 manure in the soil is not taken away in part, by the growth and 
 removal of every crop, but that such waste is continually _compcn- 
 satcd by new acquisitions. And whether such new supplies of 
 alimentary matter be furnished in part during every day, or in 
 every year, or only during the one term of rest in the whole course 
 of crops, the practictiil result is the same, of the natural or original 
 amount of alimentary manure remaining finally undiminished. 
 
 So far as to the absolute permanency of putrescent or alimentary 
 manures supplied by nature. Next let us see whether the same 
 reasoning, and also experience, so far as yet obtained, do not in 
 like manner prove the permanency of putrescent manures applied 
 after calcareous manures. The poor soil just adduced for illustra- 
 tion, while having its natural alimentary ingredient and its natural 
 supply of lime thus balanced and proportioned to each other, was 
 supposed to produce at the rate of 10 bushels of corn to the acre, 
 and to remain at or near that rate of productive power. Suppose 
 then marl to be applied in such quantity as would give enough cal- 
 careous earth to combine with twice as much new alimentary mat- 
 ter as the soil before held. Suppose further, that the soil so marled 
 is not left to draw and store up this now needed stock of alimentary 
 manure by its newly increased power, (and as would be done in 
 sufficient time, if under favourable circumstances of tillage), but 
 that so much putrescent manure is applied to the soil, gradually 
 and judiciously, as can be combined with and held by the supply 
 of calcareous earth ; and that such addition of manure gives to the 
 soil a power to produce 30 bushels of corn. As soon as this com- 
 bination is completely made, the soil is in precisely the same con- 
 dition as to its newly increased rate of product of 30 bushels, as 
 before to that of 10 bushels ; and the new and larger supply of 
 putrescent manure must be as permanent as was the natural and 
 smaller supply. 
 
 But it is not contended that the mere application of vegetable 
 or other putrescent manure, under such circumstances, secures the 
 I)ermanency of effect of all thus applied, but only of so much as 
 can be and is combined with the calcareous earth. And many cir- 
 cumstances may and do usually obstrvict the immediate and com- 
 plete combination from taking place. To insure the perfect and 
 full result, the intermixture of the calcareous and the putrescent 
 matters, and in due proportions, must be perfect, and no excess of 
 the latter must remain anywhere in the soil ; the putrescent mat- 
 ter must also be in the particular state of decomposition (whatever 
 that may be) to enter into combination ; and moreover there must 
 be enough and equally diffused moisture, without which no chemi- 
 cal combination can take place. Now, as some and probably all 
 these conditions must necessarily be deficient in every case of ap- 
 plying putrescent matters to marled land, it must follow that much 
 
OEGANIC MANURES MADE PERMANENT. 217 
 
 of the manure must remain uncombined for some length of time ; 
 and during that time is as liable to be wasted and exhausted as if 
 in any other soil. And hence, and the more as the dressing is 
 lavish, farm-yard and stable manure so applied must be expected to 
 yield more for the first and second year, whiie the excess is wasting, 
 than afterwards. But after this first waste and exhaustion has 
 been suffered, whatever of the manure remains to the soil, say for 
 the next ensuing rotation at latest, must be fully combined with 
 and fixed in the soil, and will be permanent for all future time, 
 under proper, judicious, and also the most profitable course of 
 cropping. This first waste probably cannot be entirely prevented; 
 but it can be much lessened by care. And to this end, putrescent 
 manure should not be applied heavily at once, but lightly, and re- 
 peated subsequently, and should be well scattered and equally dif- 
 fused over the ground. Its subsequent decomposition being slow, 
 and the products being gradually, as well as surely, presented to 
 the lime diffused previovisly throughout the soil, will also tend to 
 remove as much as possible of the manure from the condition of 
 being fleeting and wasting, to that of being fixed and permanent. 
 
 Next let us see how far facts and experience sustain this reason- 
 ing. It is conceded that the time since marling was commenced in 
 Virginia, and since correct views of the action of calcareous ma- 
 nures were entertained and acted on" in any case, has been too short 
 to furnish decisive proofs. But so far as accurate facts can thus 
 be referred to, they fully sustain the foregoing doctrine, not only 
 of the permanency of calcareous manures, but also of putrescent 
 manui-es in combination therewith. Some of these facts will be 
 mentioned generally. 
 
 However much in accordance with the theory of the action of 
 calcareous manures, this absolute permanency of efiect given 
 thereby to putrescent manures was not at first counted on or ex- 
 pected, and was not known until it was forced on my observation 
 by long-continued results. My own practice is not only the oldest, 
 but is all that I can refer to for proofs. And until all my marling 
 was completed, and indeed for some time after, but little care was 
 used by me to make and apply putrescent manures. This culpa- 
 ble neglect was the resvilt of the habits caused by the disappoint- 
 ments and losses experienced in manviring long before. From the 
 same ignorance and carelessness in this respect, no experiments on 
 the durability of putrescent manures were made until long after, 
 and then injudiciously. Thus, in experiments 4, 9, and 11 (pp. 120, 
 131, 134), the putrescent manure applied was in quantity much too 
 great for the calcareou.s earth to combine with at once, even if the 
 recent and irregular scattering of both kinds of manure had not 
 prevented their meeting in proper proportions. For like reasons, of 
 all the putrescent manures applied on the farm, and since larger 
 19 
 
218 ACTUAL DURATION OF EFFECTS. 
 
 quantities have been used, there is much more of early than con- 
 tinued effect. Still, so fur as known and belieyed, there is always 
 more or less of abiding effect, and which I infer will be permanent. 
 
 But wider scope for observation has been afforded in the increas- 
 ing productiveness of aril the marled lands, kept under what was 
 deemed not too frequent tillage. Neither has the tillage been al- j 
 ways mild, nor the rotation uniform; and latterly the grain crops I 
 have been made more frequent than before, and much more grazing 1 
 permitted.* Still, even where no prepared putrescent manures I 
 have ever been applied, and putrescent matters have been furnished | 
 only from the growth of the land itself during its share of rest in i 
 each course of crops, there has been a regular increase of produc- ■ 
 tiveness of the grain crops, in eveiy successive rotation. — [1842.} J 
 In one connected clearing, of what I found as poor forest land^ 
 now making 85 acres, the marling was commenced in 1818, and has- ; 
 been continued, as the successive clearings extended, to 1841, j 
 The earliest effects of the applications were always satisfactory^ , 
 but they have regularly and largely increased with time. Thus^ 
 ■when imder the last crop of corn (in 1839), the crop on the last ! 
 finished marling, though perhaps thereby nearly doubled iij pro- 
 duct, was obviously and considerably less than that of four to six ■ 
 years earlier — that again as inferior to that of the marling of ten j 
 to fifteen years — and the crop on the marling of 1821 and earlier, 
 decidedly the best of all, under circumstances otherwise equal. For 
 the limited time of twenty-three years, and without any careful and 
 accurate experiment or observation having been made for this special 
 object, there could not well be stronger practical proof of the per- ; 
 manency of the vegetable manures stored up by the marl. \ 
 
 If we keep in mind the mode by which calcareous manure acts, ' 
 its effects may be anticipated for a much longer time than my ex- 
 perience extends. Let us trace the sujiposed effects, from the ] 
 causes, on an acid soil kept under meliorating culture. As soon \ 
 as applied, the calcareous earth combines with all the acid then \ 
 present, and to that extent is changed to the humate and other 
 vcgetahle salts of lime. The remaining calcareous earth continues j 
 to take up the after formations of acid, and (together with the ! 
 salts so produced) to fix putrescent manures, as fast as these sub- ] 
 stances are presented, until all the lime has been combined with 
 acid, and all their product is combined with i^utrescent matter, j 
 Both those actions then cease. Daring all the time necessary for . 
 those changes, the soil has been regularly increasing in productive- 
 ness; and it may be supposed that, before their completion, the - 
 
 * The land, however much improved in richness by being secured from , 
 grazing so long, had in consequence become too "pufiFy" for wheat, and j 
 also full of insects and bad weeds ; for all wliich grazing at some proper 
 time of the rotation is beneficial, and indeed essential. 
 
SUPrOSED PROGRESS OF ACTION. 219 
 
 product had risen from ten to thirty bushels of corn to the acre. 
 The soil has then become neutral. It can never lose its ability 
 (under the mild rotation suj^posed) of producing thirty bushels ; 
 but it has no power to rise above that product. Vegetable food 
 for plants continues to form, but is mostly wasted, because the 
 salts of lime are already combined with as much as they can act 
 on ; and whatever excess of vegetable matter reTnains in the soil, 
 is kept useless by acid also newly formed, and left free and noxious 
 as before the apjilication of calcareous earth. But though this 
 excess of acid may balance and keep useless the excess of vegeta- 
 ble matter, it cannot affect the previously fixed fertility, nor lessen 
 the power of the soil to yield its then maximum product of thirty 
 bushels. - In this state of things, sorrel may again begin to grow, 
 and its return may be taken as notice that a new marling is needed, 
 and will afford additional profit, in the same manner as before, by 
 destroying the last formed acid, and fixing the last supply of vege- 
 table matter. Thus perhaps five or ten bushels more may bo 
 added to the previous product, and a power given to the soil gra- 
 dually to increase as much more, before it will stop again for 
 similar reasons, at a second maximum product of forty or fifty 
 bushels. I pretend not to fix the time necessary for the completion 
 of one or more of these gradual changes ; but as the termination 
 of each, and the consequent additional marling, will add new pro- 
 fits, they ought to be desired by the farmer, instead of his wishing 
 that his first labour of marling each acre may also be the last re- 
 quired. Every permanent addition of five bushels of corn, to the 
 previous average crop, will more than repay the heaviest expenses 
 that have yet been encountered in marling. But whether a second 
 application of marl is made or not, I cannot imagine such a con- 
 secjuence, under judicious tillage, as the actual decrease of the 
 product once obtained. My earliest marled land has been severely 
 cropped, compared to the rotation supposed above, and yet has 
 continued to improve, though at a slow rate. The part first marled, 
 in 1818, had only four years of rest in the next fifteen; and 
 yielded nine crops of grain, one of cotton, and one year clover 
 twice mowed. This piece, however, besides being sown with 
 gypsum (with little benefit), once received a light cover of rotted 
 corn-stalk manure. The balance of the same piece of land (Exp. 
 1) was marled for the crop of 1821 — has borne the same treat- 
 ment since, and has had no other manure, except gypsum once 
 (given in the natural gypseous earth found on the farm),* in 1830, 
 which acted well. These periods of twelve and fifteen years (even 
 though now extended to and confirmed by nine years more of ex- 
 perience) are very short to serve as grounds to decide < n the 
 
 * See accounts of this bed of "gypseous earth" iu vol. 1 of Farmers' 
 Eegister, aud of its eflcctn, iu success and failure, in vol. 10. 
 
220 THE EXHAUSTION OF CALXED LAND, 
 
 eternal duration of a manure. But it can scarcely be believed 
 that the effect of any temporary manure, would not have been 
 somewhat abated by such a course of severe tillage. Under milder 
 treatment, there can be no doubt that there would have been much 
 greater improvement. — [1842.] 
 
 If subjected to a long course of the most severe cultivation, a 
 soil could not bj such course alone be deprived of its calcareous 
 ingredient, whether natural or artificial : but though still calcare- 
 ous, it would be, in the end, reduced to barrenness, by the exhaus- 
 tion of its vegetable matter. Under the usual system of exhaust- 
 ing cultivation, marl certainly improves the product of acid soils, 
 and may continue to add to the previous amount of crop, for a 
 considerable time ; yet the theory of its action instructs us, that 
 the ultimate result of marling, under such circumstances, must be 
 the more complete destruction of the land, by enabling it to yield 
 all its vegetable food to growing plants, which would have been 
 prevented by the continuance of its former acid state. An acid 
 soil yielding only five bushels of corn may contain enough food for 
 plants to bring fifteen bushels ; and its production will be raised 
 to that mark, as soon as marling sets free its dormant powers. But 
 a calcareous soil reduced to a product of five bushels, can furnish 
 food for no more ; and nothing but an expensive application of 
 putrescent manures can render it worth the labour of cultivation. 
 Thus it is, that soils, the improvement of which is the most hope- 
 less without calcareous manures, will be the most certainly im- 
 proved with profit by their use. 
 
 CHAPTER XXIII. 
 
 GENERAL OBSERVATIONS ON THE VALUATIONS OP LANDS AND < 
 THEIR IMPROVEMENTS, AND THE EXPENSES AND PROFITS OS j 
 MARLING. i| 
 
 Proposition 5 — concluded. 
 
 At this time there are but few persons among us who doubt the 
 great benefit to be derived from the use of marl; and many of 
 those who formerly deemed the early practice the result oi folly, 
 and a fit subject for ridicule, now give that manure credit for vir- 
 tues which it certainly docs not possess ; and, from their manner 
 of applying it, seem to believe it a universal cure for sterility. 
 Such erroneous views have been a principal cause of the many 
 injudicious and even injurious applications of marl. It Is aa 
 
ESTIMATING VALUES OP LAND. 221 
 
 necessary to moderate the ill-founded expectations wliicli many 
 entertain, as to excite the too feeble hopes of others.* 
 
 The great improvement of land and its products, to he caused by 
 marling, and its long duration, if not absolute permanency, have 
 been established, I trust, beyond question, by the foregoing argu- 
 ment and proofs. Still, any degree of improvement may be paid 
 for too dearly ; and the propriety of the practice must depend on 
 the amount of its clear profits, ascertained by fair estimates of the 
 expenses incurred. 
 
 With those who attempt any calculations of this kind, it is very 
 common to set out on the mistaken ground that the expense of 
 marling should bear some proportion to the selling price of the 
 land ; and without in the least underrating the effects of marl, 
 they conclude that the improvement cannot justify an expense of 
 sis dollars on an acre of land that would not previously sell for 
 four dollars. Such a conclusion would be correct if the land were 
 held as an article for sale, and intended to be disposed of as soon 
 as possible ; as the expense in that case might not be returned in 
 immediate profit, and certainly would not be added to the price of 
 the land by the purchaser, under present circumstances. But if 
 the land is held as a possession of any permanency, its previous 
 price, or its subsequent valuation, has no bearing whatever on the 
 amount which it may be profitable to expend for its improvement. 
 Land that sells at four dollars, is often too dear at as many cents, 
 because its product will not pay the expense of cultivation. But 
 if by laying out for the improvement ten dollars, or even one 
 hundred dollars to thfe acre, the average increased annual profit 
 would certainly and permanently be worth ten per cent, on that 
 cost of improvement, then the expenditure would be highly expe- 
 dient and profitable. We are so generally influenced by a rage for 
 extending our domain, that another farm is often bought, stocked, 
 and cultivated, when a liberal estimate of its expected products, 
 would not show an annual clear profit of three per cent. : and any 
 one would mortgage his estate to buy another thousand acres, that 
 was supposed fully capable of yielding ten per cent, on its price. 
 Yet the advantage would be precisely the same, if the principal 
 money was used to enrich the land already in possession (without 
 regard to its extent, or previous value), with equal assurance of its 
 yielding the same amount of profit. 
 
 Nothing is more general, or has had a worse influence on the 
 state of agriculture, than the desire to extend our cultivation and. 
 landed possessions. One of the consequences of this disposition 
 has been to give an artificial value to the poorest land, considered 
 
 * This introductory paraiiraph was prepared for and first appeared iu the 
 edition of 1832, to ■which time it was especially applicable. 
 19* 
 
222 TRUE MODE OP ESTIMATION. 
 
 merely as so mucli territory, while various causes have concurred 
 to depress the price of all good soils much below their real worth. 
 Whatever a farm will sell for, fixes its market value ; but by no 
 means is it a fair measure of its value as permanent farming 
 capital. 
 
 The true value of land, and also of any permanent improve- 
 ments to land, I Avould estimate in the following manner : Ascer- 
 tain as nearly as possible the average clear and permanent annual 
 income, and the land is worth as much money as would securely 
 yield that amount of income, in the form of interest — which may 
 be considered as worth six per cent. For example, if a field brings 
 ten dollars average value of crops to the acre, in the course of a 
 four-shift rotation, and the average expense of every kind neces- 
 sary to carry on the cultivation is also ten dollars, then the land 
 yields no clear profit, and is worth nothing. If the average clear 
 profit was but two dollars and forty cents in the term, or only sixty 
 cents a year, it would raise the value of the land to ten dollars ; 
 and if six dollars could be made annually, clear of .all expense, it 
 is equally certain that one hundred dollars would be the fair value 
 of the acre. Yet if lands of precisely these rates of profit were 
 ofi'ered for sale at this time, the poorest would probably sell for 
 four dollars, and the richest for less than twenty dollars. In like 
 manner, if any field, that paid the expense of cultivation before, 
 has its average annual net product increased six dollars for each 
 acre, by some permanent improvement, the value thereby added to 
 the field is one hundred dollars the acre, without regard to its for- 
 mer worth. Let the cost and value of mai-ling be compared by 
 this rule, and it will be found that the capital laid out in that mode 
 of improvement will seldom return an annual interest of less than 
 twenty per cent. — that it will more often reach to forty — and in 
 very many cases will exceed one hundred per cent, of annual and 
 permanent interest on the investment, or total cost of the marling. 
 The application of this rule for the valuation of such improve- 
 ments will raise them to so large an amount, that the magnitude 
 of the sum may be deemed a sufficient contradiction of my esti- 
 mates. But before this mode of estimating values is rejected, 
 merely for the supposed absurdity of an acid- soil being considered 
 as raised from one dollar, or nothing, to thirty dollars, or more, 
 per acre, by a single marling, let it at least be examined, and if 
 erroneous, its fallacy exposed. 
 
 If the reader will accompany me through some detailed estimates 
 of values, and arithmetical calculations, in regard to the grounds 
 of which we cannot differ, the truth of the results which I claim 
 will be made manifest, however startling and monstrous they may 
 appear to some persons at first glance. 
 
 Assuming as sound and unquestionable the grounds for cstimat- 
 
TRUE MODE OF ESTIMATION. 223 
 
 iTig tlie intrinsic value of lands, as stated generally above, let us 
 illustrate the position more particularly. The principle of valua- 
 tion is that the laud is worth to its proprietor and cultivator such 
 sum of money as would yield in annual interest the same amount 
 as the net annual product of the land, after paying for all labour, 
 attention, expenses, aud risks. Further, to simjilify the calculation, 
 and also to suit the course of culture to the more general practice 
 of the country, let us suppose the land in question to be cultivated 
 under the ordinary three-shift rotation, of 1st, corn, 2d, wheat (or 
 oats), od, at rest, with no grazing when the laud is poor, and with 
 but partial aud moderate grazing (or mowing of clover) when im- 
 proved or rich. 
 
 Then suppose a field of the poor and thin soil most common in 
 lower Virginia, under this treatment for some years previously, to 
 produce, on the general average, 10 bushels of corn to the acre, 
 and five bushels of wheat, or its equivalent value of oats ; and the 
 value of the corn, at the barn, to be 50 cents the bushel, aud of 
 the wheat SI. And let the joint and total expenses of preparation, 
 tillage, seed, harvesting, thrashing, &c., for market (or for home 
 use), and of superintendence aud care of both the corn and wheat 
 or oat crops, be counted as being over and above the value of the 
 ofi"al (stalks, straw, &c.) of the crops, by $10 for the two years. 
 Then the full stat-ement will be as follows : 
 
 First year, product in corn per acre, 10 bushels, at 50 cents . S5 
 Second year, wheat, 5 bushels, at $1 . . . . .5 
 
 Third year, no crop or money product, and no expense . . 
 
 Total product of the thi-ec years' rotation .... $10 
 CJost of cultivation, &c., of the crops . . . . .10 
 
 Net profit 00 
 
 However wi'etched may be the foregoing exhibition of products, 
 it will be admitted to be abundantly liberal by all persons ac- 
 quainted with lower and middle Virginia, for a very large propor- 
 tion of the cultivated lands. Yet such lands might sell at prices 
 varying from $3 to $6 the acre ; and that without a view to their 
 being improved, and even before calcareous manures were thought 
 of as means for improvement. Yet the conclusion is evident, that 
 such land, no matter what may be its then selling price, (or specu- 
 lative appreciation sometimes caused by the eifects of paper-money 
 and fraudulent bank issues), is worth not one cent for cultivation, 
 or for the benefit of the proprietor and cultivator. 
 
 Next, suppose the laud in question to be properly marled, and 
 at the xmusually heavy expense of $7 the acre. This rate is more 
 than double the usual expense for a full aud sullicicnt dressing, 
 when the marl is obtained on tbe farm where applied. Suppose 
 
224 ESTIMATED VALUES FROM CALXING. 
 
 also that the increase of products, as shown in the second course 
 of the rotation (beginning three years after the ai^plication), is 
 equal to 100 per cent, on the production previous to marling. This 
 estimate is quite low enough, as all experience has shown. Upon 
 such land, and so treated, this degree of increase may very often 
 be obtained upon the first crop of the first course ; and, even if no 
 auxiliary means of enriching be afterwards used, the rate of in- 
 crease will be more and more for each of sundry succeeding courses 
 of crops thereafter. Then let us test the value of the returns by 
 figures as before : 
 
 First year, product in corn per acre, 20 bushels, at 50 cents . $10 
 Second year, wheat, 10 bushels, at $1 . . . . .10 
 Third year, clover, most of it left as manure to the land, and 
 no present pecuniary profit counted here . . . .00 
 
 20 
 Total expenses of cultivation, &c., as before, in two years . 10 
 
 Net product, or clear profit of cultivation in the term of three 
 
 years $10 
 
 This is all so much increase of net annual product upon the pre- 
 vious rate; and the amount, $.3.33 yearly, is the interest (at 6 per 
 cent.) of something more than a capital of $55. And therefore, 
 according to these grounds of estimate, $55 per acre is the increase 
 of intrinsic value given to the land by marling alone, or $48 the 
 clear gain made by the operation, after deducting $7 paid for the 
 marling of the land ; and this without regard to what might have 
 been its previous intiinsic value, or its former or its more recent 
 market price. The more rigidly this mode of estimate is scruti- 
 nized, the more manifestly true will be found the results. The 
 premises assumed, in the supposed efiects and profits of marling, 
 will not be objected to (unless as being too low) by any person 
 who is well informed by practice and experience. 
 
 But there is one important apparent omission of a proper charge 
 in the last statement of expenses. This is the increase of labour 
 of tillage, harvesting, &c., caused by the crop being doubled in 
 quantity. This is certainly a fair ground of charge ; and, if esti- 
 mated alone, would serve to reduce considerably the statement of 
 increased net product, and consequently of increased value of land. 
 But there were also omitted sundry items of increased production, 
 which together would undoubtedly much more than compensate for 
 the increase of labour in tilling a deeper and richer soil, and in 
 harvesting, removing, and preparing for sale or use, a double quan- 
 tity of crops. These items of gain are, first, the additional offal, 
 in corn-stalks, fodder, and shucks, and wheat or oat straw and 
 chaff j second; the limited proportion of clover grazed or mowed } 
 
ESTIMATED VALUES OF LANDS. 225 
 
 and third, tbc further gradual increase of crops, in subsequent 
 time. Probably the first class of items alone would balance the 
 increased expense of labour; if not, the addition of the second 
 (the clover) certainly would be enough. And if that be doubted, 
 the subsequent annual increase upon the first doubling of the crops 
 (which only is estimated above) will not only furnish a fund to 
 meet any such deficiency, but also will greatly, and beyond any 
 calculation here attempted, augment the whole profit of marling, 
 and consequentl}'^ the intrinsic value of the land to the proprietor. 
 
 I admit the practical difiiculty of applying this rule for estimat- 
 ing the value of laud, or of its improvement, however certain may 
 be its theoretical truth. It is not possible to fix on the precise 
 clear annual profit of any farm to its owner and cultivator ; and 
 any error made in these premises is increased sixteen and two-third 
 times in the estimate of value founded on them. Still we may ap- 
 proximate the truth most nearly by using this guide. The early 
 increase of crops from marling will, in most cases, be a full equal 
 inci'ease of clear profit, (for the subsequent improvement and the 
 additional ofi"al will surely pay for the increase of labour) ; and it 
 is not very difficult to fix a value for that actual increase of crop, 
 and thereby to estimate the value of the improvement, as newly 
 created farming capital.* 
 
 This mode of valuing land, under a diff"erent form, is univer- 
 sally received as correct in England. Cultivation there is carried 
 on almost entirely by tenants ; and the annual rent which any 
 farm brings, on a long lease, fixes beyond question what is its an- 
 nual clear profit to the owner. The price, or value of land, is 
 generally estimated at so many " years' purchase," which means as 
 many years' rent as will return the purchaser's money. There, the 
 interest of money being lower, increases the value of land accord- 
 ing to this mode of estimation ; and it is generally sold as high as 
 twenty years' purchase. My estimate is less favourable for raising 
 the value of our lands, as it fixes them at sixteen and two-thirds 
 years' purchase, according to our higher rate of interest on money. 
 
 But though this rule for estimating the true value of land, and 
 of the improvements made by marling, may be unquestionable in 
 theory, still a practical objection will be presented by the well 
 known fact that the income and profits of farmers are not usually 
 increased in proportion to such supposed values of improvements, 
 nor is there found such avast disproportion, as this rule of estimat- 
 ing values would show, between the profits of the tillers of poor 
 and of rich lands. These positions are admitted to be generally 
 
 * No degree of uncertainty in the application, however, detracts from the 
 truth of this rule. For if the annual average net profit derived from marl- 
 ing he considered as an vnknown quan/i/j/, (.r), it is not therefore the less 
 certain that x X IGf = the increased intrinsic value of the land. 
 
22G VALUES or improved lands. 
 
 well foimdccl — but it is denied that thoy invalidate the previous 
 estimates. A farmer may, and generally does, obtain less gross 
 product from a large or a rich farm, than his more necessitous, and 
 therefore more attentive and economical neighbour gets from a 
 smaller or poorer farm, in proportion to the producing power of 
 each ; and even the same persons, when young and needy, have 
 ofteu made more profit according to their means, than afterwards 
 when relieved from want, and having lands increased to a double 
 power of production. These, and similar facts, however general, 
 are only examples of the obvious truth, that the profits of land 
 depend principally on the industry, economy, and good manage-^ 
 Dieut of the cultivator ; and that many a farmer, who can manage 
 well a small or poor farm, is more deficient in industry, economy, 
 or the increased degree of knowledge required, when possessed of 
 much moi'e abundant resources. In short, if these considerations 
 were to direct or influence our estimates, we should not be compar- 
 ing and estimating the value of lands, but the value of the care 
 and industry bestowed on their management by their proprietors. 
 
 Another objector may ask, "If any poor land is raised in 
 intrinsic value (according to this estimate) from one dollar to 
 thirty, by marling, would a purchaser make a judicious investment 
 of his capital, by buying this improved land at thirty dollars 't" I 
 would answer in the aflirmative, if the view was confined to this 
 particular means of investing farming capital. The purchaser 
 would get a clear interest of six per cent., which has always been 
 deemed a good return froin land, and is twice as much as all lower 
 Virginia now yields, on a general average of the unimproved lands. 
 But if such a purchase is compared with other means of acquiring 
 land so improved, it would be extremely injudicious; because 
 thirty dollars expended in purchasing and marling suitable land, 
 would serve both to acquire and improve, to as high a A^alue, five 
 or six acres. 
 
 The immense quantity of rich and low-priced land held for sale 
 by our government, and always in market, and the flood of emi- 
 gration thereby drawn from the old states, and especially from 
 Virginia, have served more than all other causes to depress the 
 selling prices of our lands, and to discourage their being improved. 
 So long as rich land can be bought in any quantity for $1.25 the 
 acre, though it may be under forest growth, and on the frontier of 
 civilization, there will be thousands of impi-ovident or adventurous 
 landholders in the old states always striving to sell their impover- 
 ished farms, and to buy new settlements in the west — rather than 
 resort to what they deem the slow and costly means for restoring 
 or increasing fertility. And though very many others now believe 
 that it is far more profitable to improve their own poor land than 
 to emigrate to new and rich — and act upon that belief iu buying 
 
CAUSE OP LOW PKICES OF LANDS. 227 
 
 to improve, as well as improving the land held previously — still 
 tlieir very limited numbers and action can go but little way to 
 lessen the excess of supply of land offered for sale, over the exist- 
 ing demand of purchasers. We all know that a great excess of 
 supply over demand of any commodity, no matter how essential 
 for the use or even existence of the consumers, is enough to reduce 
 the market price to almost any extent. Even in regard to corn, 
 which every man requires for sustaining life, and which will be 
 wanting by every one, in certain and known quantity, for the next 
 as well as the present year, still a great excess of supply may re- 
 duce the price of this most indispensable commodity to one-third, 
 or even one-tenth, of what it may command when the demand as 
 greatly exceeds the supply. The market price of Indian corn in 
 Virginia, where it is the principal grain consumed by both man 
 and beast, has frequently, within a few years' time, ranged from 
 40 to 100, cents the bushel, according to the preponderance of 
 supply and demand. Indeed, within my farming life, it has sold 
 as low as 20 cents ; and at another time, at 82 the bushel. No 
 matter what may be deemed the intrinsic value of any commodity, 
 no buyer will pay for it even half that rate, so long as eager or 
 necessitous sellers offer the like to him for a fourth, or for less. 
 So it is with our land. Such considerations, and the existing state 
 of our land market, may (and ought to) operate to prevent a buyer 
 from paying as much as ^10 for the laud which under different 
 circumstances of market price he would gladly buy at $50. Yet 
 ini both cases of prices so different, the intrinsic value of the land, 
 and also its net product, might be the same. 
 
 The excess of supply over demand not only serves to depress the 
 selling prices of both good and improvable lands greatly below 
 their true and productive value, but also it acts with much force to 
 repress the desire for and prevent the results of improving the 
 land in possession. For whatever may be the productive value of 
 any improvements of land, they must be estimated and depreciated 
 in market price by the same law of supply and demand as deter- 
 mines the selling prices of other lands of like value. Many par- 
 ticular farms in lower Virginia, by marling, have been doubled in 
 gross product, and thereby, perhaps, increased ten-fold in net pro- 
 duct and in true intrinsic value. And yet, when the death of the 
 proprietor, and the consequent division of his estate, or other causes, 
 have compelled the sale of such a farm, the additional price ob- 
 tained over the market estimation before marling, perhaps has not 
 paid even the small cost of that improvement. Hence arises a 
 great discouragement, at this time, to all improvement of land in 
 Virginia, which acts not only on those proj^rietors who look forward 
 to a future sale of their farms, but also on most other persons who 
 have no such expectations. 
 
228 INJUDICIOUS MARLING LABOURS. 
 
 But' the principal discouragement to the proper extension of 
 marling proceeds from the erroneous and exaggerated estimates of 
 the difficulty and cost. Estimates of the expenses required for 
 marling are commonly erected on as improper grounds, as those of 
 its profits. AVe never calculate the cost of any old practice. We 
 are content to clear wood-land that afterwards will not pay for the 
 expense of tillage ; to keep under the plough, land reduced to five 
 bushels of corn to the acre; to build and continue to repair miles 
 of useless and perishable fences ; to make farm-yard manure 
 (though not much of this feult), and apply it to acid soils ; with- 
 out once calculating whether we lose or gain by any of these opera- 
 tions. But let any new practice be proposed, and then every one 
 begins to count its cost ; and on such erroneous premises, that if 
 applied to every kind of farm labour, the estimate would prove • 
 that the most fertile land known could scarcely defray the expenses 
 of its cixltivation. 
 
 The usual injudicious modes of conducting marling operations 
 have served greatly to increase the actual cost. Some farmers, 
 even after some years of such work and experience, still waste 
 nearly or quite half their labour so employed. Many new begin- 
 liers, by their greater mismanagement and consequent loss, are so 
 discouraged as to be stopped almost at the very outset. Thus, a 
 little, but insufficient amount of experience in marling, is likely to 
 magnify the supposed difficulties. By such deficiency of judgment 
 and economy in directing and executing the labours, marling is 
 often made very costly. But so it would be, without information 
 or experitnce, with any other new farming operation. It is as easy 
 in this as in any other business to work judiciously and economi- 
 cally ; and if so conducted, marling (or liming), where properly 
 available, will be found the cheapest as well as the most productive 
 means for fertilization. 
 
 The expenses of particular operations of marling, or liming, 
 have been, and of others may be, easily and correctly ascertained. 
 So have been, and may be, the early products and pro- 
 bable abiding profits of particular applications. But these two 
 actual results cannot be fairly combined, so as to indicate in 
 general the balance of jirofit exceeding the expense. For th^ 
 measure of increased product is in proportion to the quantity of 
 marl applied, and the previous want of the land for the application ; 
 and not to the expense of that application. It may hajtpen that 
 the most expensive marling may be on land so little requiring that 
 improvement, or so little fitted to receive such improvement, that 
 but small benefit is produced. In other cases, where the expense 
 of marling is the least, because of great facilities, the benefit to the 
 land may be the greatest. In the former case, of maximum labour 
 and minimum increase of production^ the net profit of the marling 
 
COSTS or ACTUAL MARLINGS. 229 
 
 miglit not exceed 10 per cent, per annum, on the cost — (thougli^T 
 Lave never kuown so little, from anj proper application). In the 
 latter case, of minimum expense and maximum eifect of marling, 
 the net profit might be 200 per cent, per annum on the cost. Most 
 operations would be much within these extreme results. In much 
 the greater number of cases of my own labours, and of all others 
 which have come under my personal observation, and were con- 
 ducted and applied with ordinary judgment, the net profits have 
 not fallen short of 50 per cent, per annum on the expense, for the 
 whole time which has elapsed since the application. How long 
 such operation may continue, and whether increasing or decreasing, 
 I leave to be inferred from the preceding facts and reasoning, in 
 regard to the duration of the effects of calcareous manures. The 
 grounds of this belief have been already in jjart submitted, in 
 sundry statements of particular products, the results of particular 
 applications. The expenses of particular and large marling opera- 
 tions have been as carefully noted, and will hereafter be reported 
 in detail. But for the better understanding of these details, and 
 more methodical arrangement, they mvist be postponed until other 
 explanatory matters shall have been presented. I will therefore 
 here merely state the general results. In four extensive marling 
 operations, on three different farms, under difierent circumstances, 
 and nearly all of which were unusually difficult and laborious, the 
 total expenses were severally 142, 97 i, 86, and 94 cents for the 
 100 heaped bushels of marl, spread upon the fields. 
 
 Most of marling labours, under ordinary circumstances of facility 
 and difficulty, ought not to exceed in cost $1 for the 100 bushels 
 of marl applied ; while the ordinary profits thereon will well repay 
 an expenditure of $6, under existing circumstances ; or of twice or 
 tlirice as much, if lands and their permanent improvements in 
 Virginia were priced according to their producing and intrinsic 
 value, and not according to the excess of supply over demand in 
 the land market. 
 
 The argument in support of the several propositions which were 
 advanced, and have been discussed through so many chapters, is 
 now concluded. However unskilfully, I flatter myself that it has 
 been effectually urged ; and that the general deficiency in our soils 
 of calcareous earth, the necessity of supplying it, the profit by that 
 means to be derived, and the high importance of all these consider- 
 ations, have been established too §rmly to be shaken by either 
 arguments or facts. 
 
 There remain, however, and will be presented in order, other 
 important matters ; which though not necessary for the mainten- 
 ance of the series of propositions which have been argued, and 
 which were too long to have been properly included in that discuS' 
 Biou, are not the less deserving of consideration. 
 20 
 
CHAPTER XXIV. 
 
 OTHER rERTILIZING POWERS AND EFFECTS OF CALC^UIEOUS EARTU. 
 
 When stating the supposed powers, or modes of operation, of ' 
 calcareous earth, or of the salts of lime generally, as ingredients j 
 of soils, by which their presence caused fertility, and their absence ' 
 or great deficiency maintained barrenness (Chap. VIII.), no power < 
 or quality was named which had not been either inferred in ad- ' 
 vancc of any known results of calxing, or observed in natural 
 soils, or otherwise, soon after the commencement of my practical 
 applications. Also, subsequently, in Chap. XIX., when either re- ' 
 capitulating, or stating for the first time, tlie results of calxing,. | 
 none were named (unless incidentally and slightly), which had not i 
 been obtained from my own practice, or by personal observation of • 
 the practice of intelligent and trustworthy co-labourers in this^ 
 mode of improvement. There remain to be presented other or? 
 greater effects than had been anticipated, or known early from ex-^ 
 perience ; and also other auxiliary and important causes for such-^ 
 unexpected measure of benefit produced by calcareous manures. 
 
 My own early practice in calxing was mostly on acid soils. The ■ 
 much smaller surface of neutral soils, though also marled, was not 
 observed for the effects through a course of years — nor carefully, by 
 experiment, for less time, in but few cases. On such soils, my 
 theory promised no early perceptible benefits ; and late returns 
 could not well be known and estimated, except from large surfaces,, 
 as a whole field, or the greater part of a farm. 
 
 But though my high and hilly farm of Coggins had but a small j 
 proportion of neutral soil, most of the lower and level lands on the 1 
 tide-water of James river consisted principally of soil of that kind. 
 These best lauds of the lower James (as of all the other tide-waters ' 
 of Virginia) have evidently been formed by the deposit of alluvial 
 earth, subsequent to the general " upheaving" of the higher-lying j 
 and greater body of the surrounding lands from below the bottom ! 
 of the ancient ocean ; yet long before the present degree of eleva- 
 tion of the general surface had been completed, by the producing ] 
 geological causes. These ancient alluvial lands are always low, in j 
 comparison to the adjacent lands of difierent and earlier formation; i 
 yet so much elevated above the present greatest height of the ■. 
 river, that they have as little of the characteristic defects of "low- 
 ground," as if not of alluvial formation. The common geological ,, 
 origin of these lands, and their common sources of materials, have ^ 
 tjcrvcd to give to them a general uniformity of character and 
 
 (230) 
 
SOILS OP ANCIENT ALLUVIUM. 231 
 
 qualities, tliougli with considerable variations of texture and 
 fertility. Such were the natural soils, generally, of the farms of 
 Sandy Point, Brandon, Wyanoke, Westover, Eppes' Island, Jor- 
 dan's Point, Shirley, Curie's Neck, and smaller parts of many 
 other lands along James river. Some small portions, as on 
 Wyanoke, were so sandy as to suffer loss of soil from high winds, 
 before being improved by lime, which stopped the further progress 
 of that injury. Other parts are made objectionably stiff and in- 
 tractible, by containing too much clay. More generally, the 
 texture is of, or approaches to medium, or is between the extremes 
 of sandy loam and clayey loam. The surface is nearly level, but 
 generally is very slightly undulating, and exhibiting, in the direc- 
 tion of the depressions and elevations, the course and degree of 
 violence of the ancient flood of turbid water, which deposited the 
 soil, and also thus furrowed the surface. AH such lands were 
 originally rich, and of course neutral; but nearly all had been 
 much reduced in fertility by the exhausting and bad cultivation 
 formerly general in lower Virginia. A large proportion of these 
 lands were of that peculiar and best kind of soil known as " mu- 
 latto," or chocolate-coloured. They are reddish brown, showing by 
 this colour a considerable ingredient of red oxide of iron ; Mdiile the 
 darker tint, friable texture, and growth of these soils, would seem 
 to indicate a calcareous character and constitution formerly, though 
 none have been known to be more than neutral, before the artificial 
 calxing. Before this improvement on all the best of such soils, 
 clover would grow, and gypsum acted on clover. These "mulatto" 
 soils have before been incidentally mentioned in this essay ; and 
 more particular descriptions of several of the best tracts, and of 
 their recent improvement by calxing, were published in different 
 parts of the Farmers' Register.* 
 
 lleasoning from the modes of operation ascribed to calcareous 
 earth in Chap. VIII. , and in advance of all experience of the effects 
 of calcareous manures on these fine neutral soils, I had not sup- 
 posed them capable of deriving much benefit from that mode of 
 improvement. But very different have been the results. The 
 effects of calxing thereon, whether by marling or liming, are (as 
 was expected), scarcely, if at all, perceptible on the first crop ; 
 and even the earliest appreciable benefit is as nothing compared to 
 the speedy and wonderful effects on acid soils. Still, the improve- 
 ment is not long in becoming manifest; and within the first round 
 of the rotation of crops, and especially when clover becomes the 
 growth of the field, the benefit from the previous calxing is great, 
 and in the succeeding grain crops is amply remunerating, though 
 
 * As of Lowei- Wyanoke, Shirley, and Curie's Neck, in vol. i. ; AVestover, 
 in vol. i. ; Sandy Point, in vol. ix. ; Brandon, in vol. x. ; besides many 
 other slighter references to these or other similar lands. 
 
232 ANCIENT ALLUVIUM Oil LATEST LRlFr FOUMATION. 
 
 still falling mucli short of wliat it will reach some years later. All 
 these fine lands, on James river (owing to tlieir fresh-water allu- 
 vial formation), are destitute of the marl (of fossil sea-shells), 
 which is so generally abundant lying under the adjacent higher 
 lands. Still, nearly all have been covered either by marl water- 
 borne from other places, or by lime brought from Pennsylvania, or 
 burnt from purchased oyster-shells. The percentage of increase 
 in the crops, even after the full effect is produced by calxiug, is 
 much less on these lands, than of the poorest acid soils. But the 
 absolute increase of crop, and also the profit compared to the ex- 
 pense of the manuring, on these neutral and especially the hazel or 
 "mulatto" soils, after some years, arc as great as the absolute in- 
 crease of product, and the profit, on any acid or other poor soils. 
 The original production, and even the much reduced production of 
 these best soils, was so much higher than that of acid soils, that 
 an improvement of 50 per cent. in. the crops of the former may 
 well be a greater absolute increase and profit, than an increase of 
 100 or even 150 per cent, on much poorer lands. 
 
 On all the other tide-water rivers of Virginia, there are flat 
 lands of like geological formation, and having general resemblance 
 to those of James river 5 while all such, on each different river, 
 have still more of general similarity of character to each other, 
 and of general difference from such lands on other rivers. Such 
 results might be inferred, from the great sources and materials of 
 the ancient alluvium having been different on each of the rivers. 
 Such lands on the Pamunkey river are the most extensive, the 
 most elevated (being in most cases full 30 feet above the present 
 level of the river, and far above the highest freshes), and also the 
 most valuable. Not much of this land is as clayey or was as rich 
 originally as the smaller extent of best lands on the tide-water of 
 James river. But for ease of tillage, and cheapness of improve- 
 ment by marl, and for profit on the capital and labour employed, 
 no lands are superior. Since the beginning of 1814, I have been 
 a proprietor and cultivator of a fiirm of this description, bor<lcring 
 on the Pamunkey (Marlbourne) ; and within the next seven years, 
 applied marl to the amount of nearly 370,000 bushels. The in- 
 crease and profits therefrom have already much exceeded my pre- 
 vious expectations ; though both (from the lateness of the manur- 
 ings^are still much below the mark they will reach, when time 
 enough shall have passed to bring the manure into full operation. It 
 is proper, however, to state that the marl used on the Pamunkey flats 
 is the green-sa7id eocene — of peculiar character, and of more 
 than the beneficial operation of mere calx, or carbonate of lime. 
 It is indeed not rich in calcareous earth (having from 25 to 30, 
 and very rarely 35 to 40 per cent.); but, in addition, it contains 
 some gypsum, and a considerable proportion of green-sand. And, 
 
ANCIENT ALLUVIAL OR LATTER DRIFT SOILS. 233 
 
 judging from the effects as manure, it seems probable that some 
 phosphate of lime is also present. By these auxiliary ingredients, 
 added to the main source of fertility, the calx of the manuring 
 earth, the vigour and luxuriance of clover is peculiarly promoted — 
 beyond any effect of calsing alone known elsewhere — and the 
 succeeding wheat crop, is also increased in proportion to the clover- 
 manure grown and turned under to prepare for the wheat. 
 
 Some small portions of the Pamunkey fiats are of close and im- 
 permeable pale yellowish clay, and the value much the less for this 
 objectionable quality. But most of such lands are of light sandy 
 loam, and some very sandy. Some of the sands are of mulatto 
 soil, and some gray, and even approaching to acid character. No 
 red clay soil, or sub-soil, is there known. 
 
 It has been deemed proper to speak thus fully of these neutral 
 soils, and their improvement by calxing, because the circumstances 
 serve most clearly to establish the opinion stated formerly (in the 
 edition of 1842), that calcareous manures must possess some other 
 and important fertilizing action, besides the several kinds before 
 asserted (in Chap. "VIII.). Of these several powers, neutral soils 
 did not require, and therefore could not profit by that of neutraliz- 
 ing acids; nor of altering the texture, absorbency, &c., of the soil. 
 Such soil had already been provided by natural constitution with 
 enough lime for these purposes. Therefore, the only other fertiliz- 
 ing property there claimed, in advance of experience, for calcareous 
 earth, that of combining with, preserving, and fixing putrescent 
 manures in soils, was all that could be counted upon to improve 
 neuti'al soils. But this slow and merely conservative action, how- 
 ever valuable for improvement, could not possibly be the sole cause 
 of the great and progressively increasing production of neutral 
 soils, which was manifest within a few years after their being 
 calsed ; and other and important causes had evidently been operat- 
 ing. And although the circumstances of neutral soils led more 
 immediately to this conclusion, those of the acid soils also con- 
 curred. As was intimated in former editions, on all soils and crops 
 which were improved by calcareous manures, though the expe- 
 rienced efifects were strictly in accordance with the theory of their 
 operation, they seemed in measure and amount to surpass their 
 supposed causes. I will now proceed to set forth other auxiliary 
 causes of fertilizing action and power of calcareous earth, or lime 
 salts genei'ally, in soils ; which causes have been suggested by or 
 deduced from the more recent lights furnished by the progress of 
 the science of agricultural chemistry, and in part are the results 
 of my own later observations or experience. The most important 
 of these additional powers or operations of lime in soil arc the 
 following : 
 
 20* 
 
234 SOLVENT ACTION OF CALX. 
 
 I. Causing the more rapid decomposition and perfect solubility 
 of vegetable matters, otherwise iuert or insoluble. 
 
 II. Enabling either the soil, or the plants growing thereon, to 
 draw from the atmosphere greater supplies of manuring or aliment- 
 ary principles, viz. : 
 
 1. Carbon, to growing plants; 
 
 2. Azote (nitrogen), from the atmosphere, through the instru- 
 mentality of leguminous plants; 
 
 3. Nitric acid, and nitrates, to the soil, and thereby increasing 
 the supplies of azotic principles to growing plants. 
 
 III. Griving to all growing plants a more healthy constitution, 
 and more vigorous vital powers, and thereby more ability to with- 
 stand dangers and injuries of all kinds. 
 
 These several branches of the subject will be discussed in the 
 following pages ; and so far as they admit of separation, in the 
 order stated. 
 
 § I. Lime and Carbonate (and oilier Salts) of Lime render Vege- 
 table and Organic matters more soluble. 
 
 It is a well established chemical action of the fixed alkalies pro- 
 per (potash and soda), on vegetable or other organic matter, to render 
 it more soluble, and thereby more speedily and effectually to reduce 
 insoluble and inert organic manures to the state fit to be taken up 
 by the roots of plants ; and enable them to be more completely 
 consumed as food for plants. It may well be inferred, from the 
 general resemblance of chemical properties, that this solvent action 
 of the alkalies proper must also belong to the alkaline earths, lime 
 and magnesia, even though in combination with carbonic acid 
 That caustic or pure lime exerts this solvent power was stated 
 previously (page 103), when treating of its manuring action. Like 
 effects, as exhibited in the rapid disappearance of leaves, &e., on 
 calcareous and neutral soils, were also stated (page 98), from which 
 eftects it might be inferred that this solvent power attended lime in 
 all its ordinary combinations or conditions in soil ; though perhaps 
 then exerting this power more slowly than either caustic lime, or 
 carbonate of potash. These well-known effects on natural soils, 
 and also the quicker and better effects of vinrotted putrescent ma- 
 nures when applied to calxcd lands, I had ascribed altogether to the 
 indirect action of calcareous earth, in its having neutralized the 
 previously existing acid, which was antiseptic, and prevented or 
 retarded the rotting and solubility of the vegetable matters. But 
 besides this indirect action, there seems good reason to believe that 
 there is also a direct solvent power exerted by salts of lime, similar 
 to that of the alkalies proper, and their salts, or combinations with 
 acids. Ilcuuie and Thaer have expressly extended this known 
 chemical action of the alkalies proper to the alkaline earths, even 
 
ALLEGED IMPOVERISHMENT BY CALXING. 235 
 
 wlicn in tlic state of carbonates.* That such estension is correct 
 is further confinned by some of the eifects of calcareous manures, 
 as adduced by Prof. Johnston, and as understood by practical 
 limers in England. He says, of the action of lime, '' it changes 
 the inert vegetable matter in the soil, so as gradually to render it 
 useful to vegetation (p. 400) ; and further (p. 401), that '^ under 
 the influence of lime, the organic matter disappears more rapidly 
 than it would otherwise do; and that, after it has thus disappeared, 
 fresh additions of lime produce no further good effect." These 
 results, in substance, have been maintained in the preceding por- 
 tion of this essay ; but were ascribed there to other than the gene- 
 ral solvent action of calcareous earth — which I would now suppose 
 to be one of the important concurring causes. 
 
 According to the treatment of the land while this solvent action 
 of calx is proceeding, through a course of years, the general and 
 final results will be either injurious, in the removal and destruction 
 of the organic matter (as stated by Johnston), or beneficial, by its 
 being stored up and fixed in the soil, under reverse circumstances. 
 If the system of cropping be continually exhausting — taking as much 
 as possible from the land and returning nothing — then the lessen- 
 ing and disappearance of the organic matter, whether slowly or 
 speedily, will finally be complete ; and equally sure will be the so 
 induced and almost hopeless subsequent sterility of the soil. It was 
 upon such ignorant and destructive cropping as this that wag 
 founded the often quoted old proverb in England, that '' liming 
 makes rich fathers and poor sous." And this saying will be cer- 
 tainly true, if understood of liming (or of calxing in general), 
 followed by continued or generally exhausting tillage ; though en- 
 tirely false if followed by mild meliorating cultivation, and judi- 
 cious management. Doubtless there were formerly in England, in 
 times of ignorance and bad farming, numerous cases of the destruc- 
 tive results of calcareous manures ; and it is much to be feared, 
 that, from as ignorant practice, and at some time hence, there will 
 be many such results in this country. Some such have already 
 
 * Both passages have before been quoted, in reference to other subjects. 
 Rennie saj's of insoluble humic acid, that it "readily combines with many 
 of the substances found in soils and manures, and not only renders them, 
 but itself also, easy to be dissolved in xoaier, tvhich in their separate slate could 
 not take place. In this way humic acid will coiulnne with lime, potass, 
 ammonia, in the form of humates, and the smallest portion of these [alka- 
 line matters] will render it [the humic acid] soluble in water, and fit to be 
 taken up by the spongelets of the root fibres." — [Alphabet of Scientific Gar- 
 deninrj. ) 
 
 Thaer says — " It is well known that with the aid of alkalies, ashes, 
 lime, and marl, humus may be deprived of its acidity, and rendered easily 
 soluble," (p. 538.) 
 
236 MANNER OF CAUSING STERILITY. 
 
 I 
 been produced j and many more are in progress, in spite of all j 
 warnings of the danger. 
 
 Though Johnston uses the word "lime" alone in the above pas- 
 sages, or in immediate connexion with them, it is evident from his 
 context that he meant carbonate of lime, or such condition as lime 
 would be in some years after its having been applied as manure; and i 
 this condition would certainly not be that of caustic or pure lime. 
 If admitting to the fullest extent the solvent action claimed according 
 to his views, the extreme cases would stand thus : The unrotted 
 and then insoluble organic matter in a soil, which, without calxiug | 
 the land, might require (suppose) twenty years gradually and ' 
 slowly to become soluble and fit for use, and to be used by plants | 
 as becoming fit, might otherwise become soluble and as fit for feed- ' 
 ing plants in the course of ten years, if in soil made calcareous. |i 
 In the former case, the most relentless exhausting tillage could not ; 
 totally consume or remove all the organic matter in less than twenty : 
 years, because it could not be used or exhausted before becoming ■ 
 soluble. In the latter case it might be done (possibly) in ten ' 
 years, admitting the extreme deduction from Johnston's views; or ' 
 according to mine (if allowing for the preservative as well as the 
 solvent operation of calx), all the first existing organic matter 
 might be used, and the land made sterile, say in fifteen years. I 
 Supposing further, to be produced but an ordinary increase of crops ! 
 from the calxing, then the total products even in the ten and fif- 
 teen years respeetivelyj.'equired to reduce the land to a state of 
 unproductiveness would amount to twice or thrice the amount that , 
 could have been obtained in twenty years from the land if not 
 calxed. Thus, even in such extreme and similar circumstances of j 
 unmitigated exhausting tillage, the advantage in profit would still 
 be greatly in favour of the calxed land. i 
 
 But why should we waste argjiments or words on such supposed | 
 cases of absurd and destructive tillage, pushed to the extremity of j 
 reducing the land to barrenness ? Whether land be limed or not, 
 a continued exhausting course of tillage, even with some, but in- ' 
 sufiicient intermission, can only, sooner or later, lead to the same 
 result of the greatest possible exhaustion, and with certain eventual '. 
 loss to the proprietor. 
 
 Even if nothing be^ allowed for the important preservative action | 
 of calx (which in truth would hold and fix all the organic matters j 
 made soluble, until they were used by growing plants, however | 
 long that use might be deferred), still I would deny that the sol- 
 vent action of calcareous manures would be of itself destructive or ; 
 injurious to the future productive power of the land. It is indeed j 
 true, that the fertilizing elements thus offered so readily (by earlier 
 solution of inert vegetable matters) might be so much the more | 
 readily wasted and exhausted by an ignorant and improvident cul- ) 
 
BENEFIT OF LENIENT CROPriNG. 237 
 
 tivator. But on the otber hand they might as readily be used 
 profitably, in part reinvested, and increased by partial accumula- 
 tion, while still producing good profit, by judicious flirming. If a 
 mei'chant's capital, in ships, warehouses, and merchandise, could, at 
 any instant when desired, be converted, partly or wholly, to the value 
 in ready money, surely no one would deem that facility as other 
 than an immense advantage to his business and means for increas- 
 ing his wealth. Or suppose that the merchant's trade with remote 
 countries, usually requiring three years to return his ventures and 
 tlic profits, could, by some change, bring the like returns every 
 three months ; would any one contend that this more rapid " turn- 
 ing over his money" would be a loss to him ? Yet both facilities 
 would enable him, if so inclined, so much the sooner to spend his 
 income and his capital stock. Just so, and no more, is the farmer's 
 land necessarily to be exhausted, or his total income and capital 
 spent, because calxing has enabled him to obtain a certain amount 
 of income in half the time previously required; or even to draw out 
 his whole landed capital in annual income, and to waste the whole, 
 if he is so foolish a prodigal as to take that course. 
 
 In truth, if but a small proportion of the new products, or in- 
 crease created by calxing, be given back as manure to sustain the 
 productive powers of the land — whether in prepared putrescent 
 manures, or in green crops used as manure, or merely by giving 
 rest, and the natural growth during rest to be left on the land — so 
 that the draughts from the land will be less than the supplies fur- 
 nished to it from all sources, there will be no continued exhaustion 
 even in the slightest degree, no diminution of average products — 
 and the sons, no less than the fathers, may be made rich by the 
 operation of lime. 
 
 On all cultivated lands, whether rich or poor, calxed or not, 
 proper considerations of farming profit alone would require that the 
 crops should take no more of fertilizing principles from the land, 
 than are restored, and exceeded, if possible, in the returns made to 
 the soil. In making these returns, bountiful Nature adds three 
 and four-fold to all that the farmer can give in manure or other 
 improvement. The earth, water, and the air, are all continually 
 preparing and furnishing manuring principles to the soil and to the 
 crops. The richer and better constituted the soil, or the more it is 
 enriched by putrescent manures and rest, the more, and in a far 
 increased proportion, does Nature furnish in addition, other aids 
 to resuscitation or increase of fertility. Hence, the more that 
 the farmer gives to the land, the more, and in increased pro- 
 portion, will it return to him. Therefore, it is no certain course 
 of cropping, and of intermission or melioration, that can be stated 
 as alwa3's improving the fertility of land, or otherwise exhausting 
 it. The results of a certain rotation may bo improving to a good 
 
238 BENEFIT OF SUPPLYING VEGETABLE MATTER. 
 
 and ricli soil, and yet would be exhausting to a bad and poor one, 
 A good and rich soil may, in some cases, yield three crops of grain 
 in four years, and yet improve by the rest and self-manuring (by 
 its own vegetable growth) of the fourth year only — while very poor 
 land may not increase its scant products, though cropped but one 
 year in three. Yet the rule of resuscitation, and its working, are 
 alike in both cases. The one-fourth of the product of the best 
 soil serves to give it more manuring, even in proportion to all its 
 large crops removed, than two-thirds of the whole product of the 
 poorest soil, in j^roportion to its very small yield for consumption 
 and sale. This greater supply of fertilization to a good soil in 
 shorter time is not altogether in the mere quantity of vegetable 
 matter furnished. The greater part probably is due to the superior 
 power of a lime soil to fix and so retain the enriching products of 
 vegetable decomposition, which, on an acid soil, wanting this fixing 
 power, would be mostly wasted. This is another illustration of the 
 important economy of calxing all lands not abundantly supplied 
 with lime by nature. 
 
 The allowing to land, after having been marled or limed, a due 
 share of rest from tillage, so as to permit its being manured by its 
 own growth during the times of rest, even if not essential, would 
 be one of the most important of the accompanying benefits to the 
 farmer; for by such means of furnishing the necessary supply of 
 organic or putrescent matters to the soil, the same value of manui-- 
 ing is given at very far less expense than if by manures artificially 
 prepared in the stables and barn-yard. Highly valuable and im- 
 portant as are the latter, and more especially profitable to the 
 calxing farmer, still their amount is limited by the measure of both 
 the supply of materials and of labour to be given for preparing and 
 applying the manure. But to manure a field by its own growth, 
 requires very little more than to let it alone. If merely left a year 
 untilled and ungrazed, an important gain is secured without any 
 cost of labour or material. And if, as part of a proper rotation, 
 to the resting there is added the seeding of the land in clover, or 
 any suitable leguminous growth for green manuring, the additional 
 benefit will be much more than the additional expense. 
 
 This essential and also highly profitable accompaniment to 
 liming or marling is precisely the condition which is most gene- 
 rally objected to by those who wish to begin such impfovcments — 
 and the most frequently neglected by those who have already 
 limed or marled. In the reasoning of the one class, and the prac- 
 tice of the other, it seems to be required that calxing shall do 
 everything for fertilization and production, without aid, and be 
 proof against all powers of exhaustion and destruction by tillage. 
 And if such unreasonable demands be pronounced impossible to be 
 complied with^ it serves with many as sulEcient ground to deem 
 
ERRONEOUS TRACTICE IN SOUTH CAROLINA. 239 
 
 the use of calcareous manures unprofitable ; or if already used, to 
 charge to them the subsequent deterioration or exhaustion of 
 the land which had been allowed neither sufficient rest, nor returns 
 of putrescent matters. 
 
 In the year 1843, when acting as Agricultural Surveyor of South 
 Carolina, my most earnest elfort was to induce the planters to make 
 proper use of marl ; which is there more rich, more abundant, and 
 more easy of access through a large portion of that state than a 
 stranger can well conceive, and of which almost no use had then 
 been made. Gov. Hammond and a few others made the only ex- 
 ceptions to this general neglect ; which cases of exception were 
 stated in the " Report of the Agricultural Survey of South Caro- 
 lina." My failure then to persuade more than a few planters to 
 try this richest and also cheapest of means for fertilization, and 
 the neglect to use these means which still continues very generally 
 in South Carolina, were mainly owing to the required condition of 
 giving due rest and vegetable growth for manuring to the marled 
 lands. This condition I always and strongly urged as essential } 
 and it was so contrary to the general system of tillage there in 
 use, and therefore was deemed so objectionable, that but few persons 
 were willing to make the required change for any expected benefits 
 from marling. Nearly all who before or since have there tried 
 marling, have failed to add these necessary accompaniments ; and 
 of course their early returns have not been half what they would 
 otherwise have been, and the ultimate results will be still more 
 deficient. 
 
 The general usage in South Carolina was to take a crop for 
 market or consumption (generally either cotton or corn) every 
 year. As there was no other than tillage land (arable, and not 
 before worn out), if a planter were to spare a field, or any smaller 
 space from culture, it would be equivalent to losing just so much 
 of his usual crop and income, for that year. This was deemed a 
 sacrifice which very few were willing to make, and none to suffi- 
 cient extent. It is true that new clearings, where there was forest 
 land to clear, were added every year to the tilled land. But this 
 additional surface was required (as supposed) either to substitute 
 the older land utterly worn out, and turned out of culture, or 
 otherwise to serve for the planter's increased means for labour. 
 
 This very bad usage of continual tillage was indeed made the 
 less exhausting, and the more tolerable, by a system of collecting 
 and applying vegetable manures, admirable for the energy with 
 which it was pursued, and for the great extent to which it was 
 carried. I have never known so much of the labour of forms to 
 be devoted to making and applying putrescent manures, nor so 
 much of the tilled surface to be so manured, as in lower South 
 Carolina. For this purpose, large stocks of cattle are kept (in 
 
2-10 NEED FOR VEGETABLE MANURES. 
 
 very poor condition indeed), and vegetable matter in great 
 quantity is gathered in leaves from the wood-land, and sedge and 
 rushes and other growth of the tide-marshes, to be used as litter. 
 The manure is applied in the row or drill, so as to go as f;ir, and 
 act as quickly, as possible. This large but slight and poor manur- 
 ing required frequent renewal ; and by some planters it was re- 
 newed every year over their whole extent of cotton, which was 
 niuch the largest of all the tilled surface. All these efforts barely 
 served to keep up the manured land to its previous moderate rate 
 of production; aud if that could be done, the planter was content 
 to make no absolute or abiding increase of fertility by his continual 
 applications of wasting and fleeting manures. When urging on 
 such persons the use of marl or lime, I was frequently met by the 
 question " Will marling enable me to dispense with other ma- 
 nuring ?" and the negative to that question, always promptly given 
 in answer, was generally assumed as sufficient reason for failing to 
 use calcareous manures. Yet never was there a greater mistake, 
 or more false reasoning, than led to this conclusion. 
 
 Besides all other benefits to be gained by thus improving the 
 constitution of the soil, marling would have made half the usual 
 dose of putrescent manuring do more good than the whole. By 
 giving rest and its own self-manuring, say to one-third of the arable 
 surface, the other two-thirds would soon surpass the previous pro- 
 duction of the whole. And much more crop would be obtained 
 both from the land and the labour employed, than before marling 
 and resting, or than with marling and without resting, besides a 
 continued growing increase of fertility and production. 
 
 But the idea of even the present gain of a proprietor being made 
 the greater, or the early lessening of crops being avoided, by con- 
 tinual culture, is entirely fallacious. The renter of another's land, 
 for one or two years only, may indeed reap most crop and profit 
 by tilling the whole surface. But his successor will lose in pro- 
 portion to the previous excess of cropping. So the man who hires 
 a horse for a d:iy only may get from him the greatest quantity of 
 labour and at least expense, by working him the whole time, with- 
 out food or rest. But it is as true economy and profit to allow 
 food and rest to the land in an occupancy of but a few years, as to 
 the horse if employed but for a few days. In either case, the ex- 
 pense of such allowance is an investment which will return a 
 higher rate of profit than all that could be gained without such 
 expense. 
 
 Further : unless when the application of putrescent manures is 
 very frequently renewed, and therefore is very expensive, the 
 resting of the land is not the less certain to occur, and for as long 
 intervals, as if allowed by the most lenient rotation of crops. In 
 the latter case, perhaps the land (after being calxed) yields three 
 
PROFIT OF REST TO LAND. 241 
 
 grain or otter crops for market in a five-years rotation; tlie other 
 two years being given to rest, self-manuring by the vegetable 
 growth, remaining, or part of the land being in pasture. With 
 such respite, the three-fifths of the land will very soon surpass the 
 previous product of the whole, and continue long to increase still 
 more in product. In the other case, of continual annual cropping, 
 and even with much care given to applying prepared manures, the 
 land may perhaps bear such treatment for twenty, thirty, or in rare 
 cases forty years, before being so reduced as to be no longer worth 
 cultivating. It is then " turned out," and left useless and profit- 
 less for some thirty years, until, under a new growth of trees, it is 
 brought back partially to a state fit for a second and expensive 
 clearing, and renewed cultivation. Nature will not permit the soil 
 to be utterly robbed of its due claim for rest and resuscitation. 
 And if the cultivator will not of his own accord grant one or two 
 years in four or five, he will be compelled to lose a much larger 
 proportion of time, after longer delay. In the one case, the rest 
 is accompanied by increasing fertility ; in the other it is the result 
 of exhaustion, and is followed by long-continued and total unpro- 
 ductiveness. 
 
 The amount of rest for land required for its progressive improve- 
 ment after being marled, after all, is inconsiderable, and is, usually, 
 fully compensated in the greater product of the two next succeeding 
 crops of grain. In lower Virginia, the system of continual tillage 
 formerly was as prevalent as now in South Carolina. Yet there 
 are very few of even the most improvident and exhausting cultiva- 
 tors who do not now know that more grain and more profit are to 
 be obtained in a three-years course (for example), including one 
 year of rest, than if taking a crop every year. And on calxed and 
 well conducted farms, making regular advances in production, 
 three grain-crops and one of clover are taken off in a five-years' 
 rotation, leaving but one year of the term in which the land is un- 
 productive of profit for that time — though not unproductive in 
 preparing for future returns. 
 
 Whether the question be considered and tested by facts and ex- 
 perience, or by reasoning, there cannot be a shadow of reason or 
 excuse for the custom of continual tillage, except in a newly settled 
 and uncleared country, of great fertility, and where labour is very 
 costly, and land priced very low. Not one of these conditions now 
 exists in lower South Carolina to justify the general system of till- 
 age. And that so intelligent, well educated, and withal so indus- 
 trious a class as is found in the planters generally of that state, 
 sliould so strangely persist in such a system, and, for its preservation, 
 reject the means of doubling their products and their wealth by 
 marling, is not the result of the teachings cither of reasoning or 
 of experience, but of the supremacy of habits long established, 
 and in almost universal use. 
 21 
 
242 ELEMENTS OF PLANTS, 
 
 § II. Calcareous earth enables the soil, or the plants growing 
 thereon, to draw much more mttriment from the atmoi^phere. 
 
 Every plant, after being completely burned, leaves a small pro- 
 portion of its previous quantity in ashes. This portion, inde- 
 structible by burning, is distinguished by chemists (not with much 
 accuracy of signification) as the inorganic parts of plants ; and 
 these are found to consist of different salts, or chemical compounds 
 of different acids with alkalies proper, and alkaline or other earths, 
 and also some oxides of metals. All these matters, making the 
 whole residue in ashes, in any one plant, or part or product of any 
 plant, rarely amount to as much as one-tenth of the original dry 
 weight; and in more of other cases fall below the one-hundredth 
 part.* 
 
 The other and much larger portion of all vegetable matters^, 
 called by chemists the organic, or that which is destructible by 
 burning, is composed either of three or most generally all four of 
 these elements, carbon, hydrogen, oxygen, and nitrogen or azote. 
 
 The like division of products, destructible or indestructible by 
 burning, applies to all animal matters, and also the general consti- 
 tution of their different parts; but in very different proportions. 
 Excepting the solid bony or shelly parts of animal matters, the 
 portion indestructible by burning is extremely small. Of the des- 
 tructible parts of animal matter, azote (or nitrogen), always forms 
 a considerable proportion ; while in most vegetable products it is 
 in very small proportion, and in others entirely wanting. It is^ 
 however, always present either in some part, or element, or pro- 
 duct of every plant. It is the proportion of azote, small as it is, 
 which mainly determines the degree of richness and nutritive value 
 of any substance, whether as food for animals, or as manure for 
 growing plants. And according to the quantity of azote contained, 
 is the tendency of either vegetable or animal matter to putrescence, 
 and to give out offensive odours while putrefying. Thus, in a rough 
 way, common observation and experience, and the sense of smell, 
 may afford tolerably accurate tests of the amount of azotic prin- 
 ciples in materials of manures for plants, or food for animals. 
 
 It follows from the consideration of the questions of which the 
 general results only are here stated, that whatever serves to furnish 
 most azote to the soil, in manure, is most conducive to its immediate 
 fertility ; and whatever abstracts most azote from the soil, without 
 return, is the most exhausting of its immediate productive powers. 
 Ha;ving presented these general propositions (which seem to be 
 received by all authorities), let us proceed to inquire as to the 
 sourc;ps of the mode of supply of azote, and of the other much 
 more abundant constituents of plants. 
 
 * See tables of proportions for ashes from many vegetable products re- 
 ported by Ijuut-tiiiigault, p. G^, -1, Kural Ecouumy, Am. Ed. of Eiig. Ti'ans. 
 
ELEMENTS OP PLANTS. 243 
 
 Putting aside for tlac present the minute proportion of inorganic 
 elements (or ashes) of plants — or supposing their amount to be 
 always ascertained separately, or understood— the great remainder 
 of all plants, amounting from more than nine-tenths of the dry 
 weight of some products to more than ninety-nine-huudredths of 
 others, consists of elements which also constitute air and water, or 
 are always present in the atmosphere ; and which therefore are 
 always surrounding all growing plants, and in unlimited quantities. 
 But though so abundant and inexhaustible, these elements cannot 
 be taken up by growing plants escept under certain conditions j 
 and these conditions are but slightly under the control of cultiva- 
 tors, or even known to the present researches of science. 
 
 Of the four great elements of organic bodies, carbon only is 
 ever presented to our senses, alone and as a solid. Charcoal is 
 nearly pure carbon ; and the brilliant and precious diamond is pure 
 crystallized carbon. Of the three other great elements, oxygen, 
 hydrogen, and azote, each one in its separate state is only known 
 to us as gas, or air; and however different and potent their quali- 
 ties, they are all as little perceptible by our sight or touch, as the 
 atmosphei'e. Further : carbon, though existing nearly pure, and 
 visible and tangible, as charcoal, yet, when in that state, is incapa- 
 ble of affording any direct support to plants ; for which office it is 
 necessary that carbon shall be combined with oxygen ; which com- 
 bination also forms a gas (carbonic acid), in which state it is dif- 
 fused throughout the atmosphere, and in which only it is fit to be 
 received into plants, through their leaves, and thus to furnish to 
 them their essential element, carbon. 
 
 Thus, the materials of nearly the whole solid substance of all 
 plants and all animal bodies, are supplied wholly by four gases, or 
 different kinds of air. This proposition (than which none in agri- 
 cultural chemistry is better established), when first heard, may 
 well seem too mysterious for comprehension, and the results too 
 wonderful for belief. And after the proposition has been fully 
 assented to, there must occur to the mind of every student of this 
 interesting subject another question involving as much of mystery 
 and wonder, if not also of doubt. This question is, " If the 
 atmosphere always contains all the organic constituents of plants 
 in inexhaustible quantities — and if plants derive from the atmos- 
 phere nearly all of their constituent parts — why should they ever 
 suffer for want of a sufficient supply of nourishment, whether 
 growing on rich or poor soils V The answer is, that the laws of 
 nature forbid some of these gaseous bodies to be taken up directly 
 by growing plants — or, at least, only under certain conditions; 
 and these conditions are not dependent on the quantities of these 
 gases present in the surrounding atmosphere, and are but slightly 
 under the control of man, limited in knowledge as at present. 
 
244 
 
 ORGANIC AND INORGANIC PARTS 01 PLANTS. 
 
 Should the progress of science ever serve to place these conditiong 
 under man's control, then cxhaustless stores of the richest nourish- 
 ment to plants, and the sure means of universal and exuberant 
 productiveness from the poorest soils, will also be at his command. 
 Food for land and plants and brutes and men will be as unlimited 
 and almost as available as the air we breathe. But to indulge in 
 such speculations of the possible future, is now mere dreaming 
 anticipation. My object is more practical. It is to gather and 
 display such faint lights as now may be drawn from previous 
 scientific researches upon this dark and yet interesting subject of 
 inquiry. As little as has been discovered and established by agri- 
 cultural chemists, and still less put to j^ractical use, I believe that 
 new and very important and useful deductions may be derived from 
 the scattered and unconnected truths already ascertained in regard 
 to the nutrition of plants, and, through the medium of plants, the 
 nutrition and fertilization of soils. 
 
 The following table is given by Boussingaiilt as the results of 
 his investigations, showing the proportions of the constituent 
 elements of various ordinary vegetable products. 
 
 Substances— ariecl at 230° Falir. 
 
 
 
 
 
 .s 
 
 
 100 parts. 
 
 u 
 
 •u 
 w 
 
 S" 
 
 1 
 
 "S 
 
 
 6 
 
 a 
 
 O 
 
 ■^ 
 
 < 
 
 Wheat 
 
 46.1 
 
 05.8 
 
 43.4 
 
 02.3 
 
 02.4 
 
 llye 
 
 46.2 
 
 05.6 
 
 44.2 
 
 01.7 
 
 02.3 
 
 Oats 
 
 50.7 
 
 06.4 
 
 36.7 
 
 02.2 
 
 04. 
 
 Wheat straw .... 
 
 48.4 
 
 05.3 
 
 38.9 
 
 00,4 
 
 07. 
 
 Rye straw ..... 
 
 49.9 
 
 05.6 
 
 40.6 
 
 00.3 
 
 03.6 
 
 Oat straw ..... 
 
 50.1 
 
 05.4 
 
 39. 
 
 00.4 
 
 05.1 
 
 Potato ..... 
 
 44. 
 
 05.8 
 
 44.7 
 
 01.5 
 
 04. 
 
 Field beet 
 
 42.8 
 
 05.8 
 
 43.4 
 
 01.7 
 
 06.3 
 
 Taruip ..... 
 
 42.9 
 
 05.5 
 
 42.3 
 
 01.7 
 
 07.6 
 
 Jerusalem artichoke (or potato) . 
 
 43.3 
 
 05.8 
 
 43.3 
 
 01.6 
 
 06. 
 
 Peas ...... 
 
 46.5 
 
 06.2 
 
 40. 
 
 04.2 
 
 03.1 
 
 Pea-straw 
 
 45.8 
 
 05. 
 
 35.6 
 
 02.3 
 
 11.3 
 
 Clover hay ... 
 
 47.4 
 
 05. 
 
 37.8 
 
 02.1 
 
 07.7 
 
 Jerusalem artichoke stems . 
 
 45.7 
 
 05.4 
 
 45.7 
 
 00.4 
 
 02.8 
 
 From these propositions of the vegetable products stated, it 
 would appear that the per centage of each of its elements is be- 
 tween the following extremes : 
 
 {Carbon from 42.8 to 50.7 per cent. 
 Hydro";en 5. to 6.4 
 
 oiygeS 35.6 to 45.7 
 
 Azote 00.4 to 4.3 
 
 Inorganic parts — Ashes 2.4 to 11.3 
 
 Of the first-named four and great constituent parts, carbon 
 
OHGANIC PARTS OF PLANTS, 245 
 
 only is furnished by nature otherwise than in the greatest profu- 
 sion. Oxygen gas makes about one-fifth, and nitrogen or azote 
 about four-fifths of atmospheric air ; and pure water is a compound 
 of 8 parts of oxygen and 1 of hydrogen. Carbon in the form 
 of carbonic acid gas is universally present in the atmosphere, and in 
 variable proportions ; but usually (over land) making about -^L^ 
 only of the whole bulk. In weight, the proportion of carbonic'aeid 
 is jo'o °^ ^^*^ atmosphere. Small as is this proportion, still, as it 
 is present in the air surrounding and in contact with all growing 
 plants, their supply might be deemed inexhaustible, provided they 
 possessed the power of attracting and arresting it, and taking up 
 and assimilating the carbon of the gas. But this power seems to 
 be not fully exerted under ordinary circumstances. The other 
 great elements, oxygen, hydrogen, and azote are in unlimited 
 quantity surrounding plants, as constituents of the atmosphere, or 
 entering and filling the bodies of plants as the constituents of wa- 
 ter. And as the atmosphere always contains, in large proportion, 
 water dissolved by heat, that is, the water itself being in gaseous 
 form, therefore the ordinary atmosphere alone ofi"crs to plants all 
 the four great elements required to constitute nearly their whole 
 substance. If then we suppose that the very small proportions of 
 necessary salts, found in the ashes of plants, are already in the 
 soil (as is generally the case), or, if not naturally present, to be 
 supplied by art, it is manifest that all cultivated plants, on all 
 soils — and on the most barren not appreciably less than on the 
 richest — have at hand unlimited supplies of all materials required 
 for their sustenance and growth. But the power to seize upon 
 these materials is either wanting, or possessed but to a strictly 
 limited extent. And it is in proportion to the power to use them, 
 and not to the abundance of the resoui-ces present, that the sup- 
 port and growth of plants arc regulated. 
 
 The proportions of the atmospheric constituents of each particu- 
 lar vegetable product (as gluten, starch, sugar, wax, &c.) seem to 
 be uniform ; and of each of the more compound products of a par- 
 ticular plant (as its seeds, flowers and leaves, bark, wood, &c., of 
 like age and kind), the constituents seem to approach uniformity 
 of proportions ; so that it may be inferred that the differences are 
 caused by differences of conditions, of wants andrsupplies; and that, 
 under like conditions, the constituents, organic and inorganic, would 
 be in like propositions. But the quantities of the simpler pro- 
 ducts of plants of like kind (as gluten or starch in wheat, sugar 
 in beets, &c.) vary greatly, and of course cause variation in the 
 proportions of elementary constituents of the entire plant. Es- 
 pecially does the proportion of azote vary in like plants, under 
 different circumstances of supply, even when the other constituents 
 vary but little. Boussingault found the following proportions in 
 21* 
 
246 NITROGEN IN PLANTS. 
 
 wheat of tlio same variety, but of wliich one sample was taken 
 from garden ground, very rich, aud the other from the ordinary 
 soil of his field, and of course comparatively poor. The growths 
 were of the same year, and the same farm, and therefore the influ- 
 ences of weather the same. 
 
 "from the open field. from the gardex ground. 
 
 Carbon, . 46.10 .... 45.51 
 
 Hydrogen, . 5.80 5.G7 
 
 Oxygen, . 43.40 .... 43.00 
 
 Azote, . , 2.29 3.51 
 
 Ashes, . 2.41 .... 2.31 
 
 100.00 100.00 
 
 "In the produce of the garden ground there were 21.94 per 
 cent, of gluten and albumen [the products of wheat which only 
 contained azote] ; in that of the open field no more than 14.31 per 
 cent, of the same principles." — (Rural Economi/, &c., p. 176.) 
 
 The cursory reader would perhaps be struck only by the general 
 agi'ccment of the proportions of the constituents of these two 
 samples of wheat grown on such dificrent soils. But while there 
 is such near approach to equal proportions of the three larger con- 
 stituents, the azote, smallest in quantity, but the most important 
 for its quality, is shown to be increased in proportion more than 
 50 per cent, by the richer soil. 
 
 Thus the smallest but richest element, azote, would seem to be ob- 
 tained by plants principally or entirely through their roots, and from 
 the soil. Therefore, the supply to plants is in no degree increased by 
 the prodigious quantity of azote in the atmosphere. On the other 
 hand, the carbon, which constitutes about half the dry weight of 
 all plants, is supplied, for much the larger j^art, from the carbonic 
 acid gas of the atmosphere, through the leaves, and thus is fixed 
 in and assimilated to the plant. Carbon is the only one of the 
 four great elements found in air or water which is presented (by 
 the atmosphere) to plants in small quantity, aud apparently in in- 
 sufficient quantity for the supply of their leaves. Therefore, I 
 infer that to increase the nourishment and growth of plants it is 
 not only necessary to increase the supply of azotized manures 
 through the soil to their roots, but also (if possible), to increase 
 the sui)ply of carbonic acid to the leaves; or to increase their 
 power to take up the supply actually present in the surrounding 
 atmosphere.* As to the oxygen and hydrogen, they will be sup- 
 
 * Professor Liebig maintains that all the azote taken up by plants is 
 through their roots, and of course derived immediately from the soil. 
 Boussiugault infers, from some very interesting experiments, to wliich I 
 shall again advert, that some azote is also taken directly from the atmos- 
 phere, at least by leguminous plants. Tho latter author, agreeing with 
 
SUPPLY OF ORGANIC PARTS TO PLANTS. 247 
 
 plied from the air and water in any quantities required in propor- 
 tion to the amount of carbon and azote derived from all sources. 
 Chemists seem to concur in the opinion that plants exert the power 
 to decompose water received through their roots into their sap 
 vessels, and to assimilate the results of the decomposition, hydro- 
 gen and oxygen, in requisite proportions. Besides all other reasons 
 in support of this opinion, its truth may be inferred from the 
 established fact that in many vegetable substances the constituents 
 of hydrogen and oxygen are present in precisely the proportions 
 which serve to constitute water. 
 
 If then enough azote and carbon be furnished to growing plants, 
 enough of oxygen and hydrogen will be at the same time taken up 
 and assimilated, by the plant's own natural powers. 
 
 The foregoing views seem to ofi'er the only plausible explanation 
 of that great mystery of vegetable life, that plants on barren land 
 should pine or starve, when surrounded by unlimited supplies, in 
 air and water, of their necessary elements. 
 
 The supply of azote to the roots must be limited to the amount 
 of azotized matters already in the soil, and to such subsequent 
 additions as can be furnished in prepared putrescent manures, or 
 an the azotized green or dry products of the land left there to de- 
 cay. If we could also increase the supply of carbonic acid in the 
 atmosphere, the benefit to plants would be as great as the giving 
 of azote in manure. It has been proved by experiments, that of 
 different plants kept in confined artificially composed atmospheres, 
 those grew best, which had carbonic acid in much larger propor- 
 tion than is in the natural atmosphere. (Boussingault, p. 36.) 
 To increase the quantity of carbonic acid diffused through the 
 atmosphere, to any useful or even appreciable extent, is beyond the 
 power of man. But the desired results of such increase would be 
 reached in some measure by enabling plants to inhale and assimi- 
 late more than their share of the general supply of carbonic acid 
 in the whole atmosphere. This is partially effected for all vegeta- 
 ble growth by the winds, which continually renew the air in con- 
 
 most other late and high authorities, supposes the carbon of plants to be 
 derived principally from the atmosphere, and through the leaves, but also 
 ill part from the earth and through the roots. Liebig asserts that carbon 
 is furnished altogether through the leaves, except dui-ing germination ; and 
 none through tlife roots, after the opening of the earliest leaves from the 
 seed. This opinioa seems to involve the absui'd position that the carbona- 
 ceous (dark-coloured) part of manure, usually deemed evidence of richness 
 in manure and in soil, is of no use to plants through their roots ; nor 
 otherwise, except to furnish more carbonic acid to the atmosphere. In this 
 event, the manure, by its carbonaceous part, may possibly assist the 
 growtli (through the leaves) of the plants growing nearest. But if any 
 wind was blowing when the gas rose from the earth, the manure would bo 
 as likely to take effect on distant as on the nearest plants, even if not car- 
 ried out of reach, of all for the time being. 
 
248 SUPPLY OP CARBON TO PLANTS. 
 
 tact with plants, removing that which had given up its carbonie 
 acid, and bringing new supplies from the upper or lower air. It has 
 also been proved that plants grow faster in agitated than in still 
 air. (Boussingault, p. 42.) This effect of winds is general — ope- 
 rating with nearly equal benefit on all neighbouring localities ; and 
 this also of course is not within man's control, or even under his 
 partial direction. 
 
 There is still another mean, by which possibly the desired end 
 may be attained. Though we cannot increase the supply of car- 
 bonic acid, or bring more of the actually existing supply in con- 
 tact with the leaves of plants, yet if we can stimulate the plants to 
 attract, seize upon, and rapidly absorb the contiguous carbonic 
 acid, instead of the much greater part passing by and escaping from 
 the otherwise feebler attracting powers of plants, then the same 
 object would be effected as if by actual increase of the supply of 
 carbonic acid. There is good reason to believe that such greater 
 stimulation of the appetite of plants and increased power of taking 
 up carbonic acid is to be conferred by the application of various 
 manures; but more especially and in greater measure by the use 
 of calcareous manures ; as I shall endeavour to show. 
 
 Universal as is this function of growing plants of absorbing and 
 fixing the carbon of the atmosphere — essential as it is to their 
 existence — and largely as it is exercised to the extent of thereby 
 obtaining much the larger part of one-half the whole dry weights 
 of plants — still this power is strictly limited by, or only exerted 
 under, certain known conditions. It is by their green matter only 
 that plants absorb carbonic acid, and that under the stimulating 
 influence of liglit. Through all the day, and by all their leaves 
 and other green parts, plants are absorbing carbonic acid from the 
 air, and assimilating and fixing its carbon, and evolving the oxygen 
 gas, the other constituent element of the carbonic acid. But this 
 operation always ceases with the withdrawal of light ; and even a 
 reverse operation, to smaller extent, proceeds during the night, 
 when the leaves actually evolve some of the larger quantity of car- 
 bonic acid which had been absorbed during the previous daylight. 
 It is well known that any plant, or single branch of a plant, 
 secluded from light, does not acquire the usual green colour, but 
 remains white. In this state, the white leaves and stems exert 
 very little power, if any, in absorbing cai-bon. If the whole of 
 any plant is kept in tlie dark during its growing state, it must 
 soon die, for want of this essential source of sustenance. 
 
 1. Calcareous earth causes plants to draio more carbon from, the 
 atmosphere. 
 
 The vigorous growth of plants, and the intensity or depth of 
 their green colour, always go together and in proportion to each 
 
CALX INCREASING THE SUPPLY OP CARBON. 249 
 
 otiicr. We must correctly infer that the deeper the green colour, 
 from whatever cause it may proceed in part (as rich manuring, 
 -bright sunlight, or moist season), the greater must be the absorp- 
 tion of carbon by the leaves of the plant. Therefore, if in any 
 manner the intensity of the green colour of plants is increased, it 
 is equivalent to giving them the power of absorbing and assimilat- 
 ing^ more carbon, and with that (as before stated), the power of 
 taking up and assimilating the required proportional quantities of 
 oxygen and hj^drogen. 
 
 Now one of the earliest and most manifest effects produced by 
 adding calcareous earth to a soil before extremely needing that ma- 
 nure, is to give a deeper green colour to the plants. This effect is 
 so remarkable on young corn, growing on soil previously acid and 
 recently marled, that before the plants are four inches high, the 
 outlines of the spot made calcareous may be distinctly seen and 
 easily traced by any observer, merely by the strong contrast be- 
 tween the deep green colour of the plants on one side, and the 
 pale, yellowish, and sickly green of the other; and this before there 
 is any obvious difference of size of the plants. And this difference 
 of colour remains so strongly impressed, that a strip of corn thus 
 treated, when of more advanced growth, may be distinguished at 
 the distance of half a mile, if exposed to view so far. 
 
 This early and marked effect of calcareous manures, of giving a 
 deep green colour to plants, I had formerly ascribed solely to the 
 neutralizing of the noxious acid of the soil. And this is doubtless 
 the cause in part. But more extended observations, and the abid- 
 ing effects of this kind, induced me to believe that a direct, as 
 well as the supposed indirect action was produced. But from 
 whatever cause it proceeds, it is unquestionable that the increase 
 of green colour is accompanied by proportionate increase of sup- 
 plies of atmospheric food to the plants, and proportionate increased 
 products of the crops for the food of animals, and for food (or 
 manure) for the soil. 
 
 One other well-known agricultural fact will be cited in support 
 of this position. AVhen gypsum (sulphate of lime) is applied to 
 clover, on a neutral soil (where there is no injurious excess of acid 
 to affect the crop, or to be removed by lime), and the gypsum acts 
 well, one of the earliest and most striking evidences of its benefi- 
 cial action is seen in the deeper green colour of the clover dressed, 
 compared to any omitted portions. This effort, however produced 
 (as said before), is equivalent and proportioned to an increased ab- 
 sorption of carbon from the atmosphere ; and, as in the previous 
 case, must be ascribed to the increased power of absorption ^given 
 to the clover by the lime which is the base of the gypsum. 
 
 It may perhaps be questioned that such great effect can be pro- 
 duced by the operation of so small a quantity of lime as is con- 
 
250 CALX INCREASING THE SUPPLY OP CARBON. 
 
 tained in a bushel of gypsum, the ordinary dressing for an acre. 
 But gypsum is easily soluble in enough pure water, and would 
 find enough in the earth furnished by rain for its speedy solution ; 
 v/hcreas carbonate of lime is insoluble in water, unless with the 
 addition of carbonic acid. Therefore it may follow, that even from 
 a bushel of the soluble gypsum, the crop may draw up lime more 
 readily and abundantly for the time, than from 100 bushels, or 
 more, of insoluble carbonate of lime. Boussingault ascribes the 
 great effect of gypsum to its easy solubility in water, and its thus 
 readily furnishing dissolved lime to the roots and to the body of 
 the phmt. Though this is not at all a satisfactory cause for all the 
 wonderful operation of gypsum on clover (and still less to exphun 
 its very frequent want of effect), there can be no doubt of the 
 authority for the fact that the gypsum (or its lime) may be easily 
 so received into the sap of the body of the clover. And, as analysis 
 Las shown that 1000 lbs. of dry clover hay contains 27 lbs. of 
 lime (Sprengel, quoted by Johnston, p. 220), and 100 lbs. of sul- 
 phate of lime freed from water contains 41.5 lbs. of lime, it fol- 
 lows that this quantity would suilice for the healthful constitution 
 of as much clover as would be converted to more than 1500 lbs. 
 of dry hay. 
 
 The chemical facts which have been cited are well established, 
 and the agricultural facts have been observed by very many prac- 
 tical cultivators ; and both would seem sufficient to establish the 
 position that lime gives to plants greatly increased power for ab- 
 sorbing carbon from the air. But, in addition to these, some very 
 interesting and apparently accurate experiments have furnished 
 more direct and certain proof of the results above mentioned. 
 These will now be reported. 
 
 When nearly all the sheets of the preceding edition of this 
 essay (1842) had been printed, embracing the whole except part 
 of the Appendix, I first heard of the discovery having been made 
 by Dr. Wm. L. Wight, of Goochland, of the important property of 
 calcareous earth now under consideration. Forthwith I sought 
 and obtained from him information of his experiments and deduc- 
 tions ; and with his permission, a concise report of their substance, 
 together with such introductory and explanatory remarks as I 
 deemed required, was published among the papers of the Appendix 
 which then remained to be printed. 
 
 Soon after my publication as above stated. Dr. Wight placed his 
 discovery before the public more at length in his " Observations 
 on Vegetable and Animal Physiology," printed in 1843; from 
 which publication will be here copied all that applies to this subject. 
 
 After referring to the previous edition of the " Essay on Calcare- 
 ous Manures" especially, and also to other confirmatory publications, 
 tending to establish both the fertilizing and health-preserving 
 
* CALX INCREASING THE SUPPLY OF CARBON. 251 
 
 actions of calcareous earth in soils, Dr. Wight proceeded to say 
 that in his consideration of the subject "it became a question of 
 deep interest to determine what was the peculiar influence of lime 
 in the process of vegetation; and for this purpose the followino- 
 experiments were instituted. Seeds of wheat, resting upon moist- 
 ened cotton, were first placed in glasses of water, and thus allowed* 
 to germinate. When two or more plants had put forth five roots, 
 which is their complement, or an equal number, taking especial 
 care that those experimented with should have an equal number 
 of roots, this being the test of their being equally healthy, they 
 were immediately transferred, half of them to vessels of pure rain- 
 water, the other half to vessels of rain-Avater in which a small portion 
 of the hydrate of lime [or slaked quick lime] had been dissolved. 
 
 ''As soon as the first leaf had attained sufficient length, they 
 were introduced under separate receivers, and supplied with car- 
 bonic acid. It was soon apparent, however, that the plants growing 
 in the pure rain-water threw off more oxygen than the others, 
 though the difference was slight. The experiment was repeated 
 with the other leaves, as they were successively unfolded, but with 
 no better success. 
 
 '' The carbonate of lime, or lime in the state it is found as a 
 natural production, was now substituted for the hydrate. Select- 
 ing the thin pellicle which collects upon lime-water, and reducing 
 it to a fine powder, as much was previously dissolved in the rain- 
 water in which half of the plants were to grow as could be, by 
 brisk agitation for a few minutes in a closed bottle. The plants to 
 be experimented with being always transferred from the glasses as 
 soon as it was perceived that they had an equal number of roots. 
 Previous to the period at which plants become dependent upon ct- 
 terior influences, the effect of the carbonate of lime was rather to 
 retard than to quicken the decomposing process ; but generally, by 
 the time the second leaf had fully unfolded itself, and always in 
 the case of the third, the greater resistance offered to the touch, 
 and the deeper and more polished tint of green, inspired anticipa- 
 tions of a successful result. When introduced under the receiver, 
 and supplied with carbonic acid, these anticipations were more than 
 fully realized — the plants growing in rain-water in which carbo- 
 nate of lime had been previously dissolved, giving off two, three, 
 and sometimes four volumes of oxygen to one disengaged by those 
 growing in pure rain-water; and for every volume of oxygen 
 emitted, an equal quantity of carbonic acid disappeared from the 
 jar containing it. These experiments were frequently and care- 
 fully repeated with the other plants cultivated in this latitude, 
 until it seemed to be fully ascertained that the influence of the 
 carbonate of lime in the process of vegetable nutrition consists in 
 increasing the action of plants upon the light— in so modifying 
 
252 CALX INCREASING THE SUPPLY OF CARBON. 
 
 tlicir constitution as to dispose tlicm to reflect, under the ordinary 
 defects of climate and season, their natural green ; and, by con- 
 necting this power with the other and well-known events in the 
 scries, viz. the more active decomposition of carbonic acid, where- 
 by more carbon, the basis of vegetable matter, is assimilated, and 
 luore oxygen returned to the atmosphere, we obtain, as is conceived, 
 a consistent explanation of the action of lime, both in the pro- 
 motion of the fertility of the soil, and in the restoration of the 
 air to its purity." Observations, &c., pp. 9, 10. 
 
 These interesting experiments have still later been repeated by 
 Dr. AVight, and always with the like results. There can be no ques- 
 tion of the care and accuracy with which they have been conducted ; 
 and very little ground to object to the conclusiveness of the posi- 
 tion which the results demand — that is, that the effect of carbonate 
 of lime, acting through the roots of the plants, enabled them to 
 absorb and to assimilate at least more than a doubled quantity of 
 carbon, and consequently to disengage more than a doubled quan- 
 tity of oxygen gas, formed by the decomposition of the carbonic acid 
 taken in by the plants. The only apparent defect in the process 
 is one which is unavoidable. This is, that the wheat (or other) 
 plants were made to grow with their roots in water, a situation 
 contrary to their nature and wants ; instead of in dry soil, con- 
 formable to both. But in naming this unavoidable defect, I do 
 not mean to convey that it can invalidate the results of the experi- 
 ments, or even reduce their measure in any very important extent. 
 
 But there is one deduction which Dr. Wight seems to have 
 made, to which it is scarcely necessary for me to announce my 
 dissent. "While I fully admit that he has first indicated, and at 
 Ifeast gone far to establish by his experiments, one of the very im- 
 j)ortant properties and powers of calcareous earth, as a fertilizing 
 manure (and also as a sanitary agent), still I do not agree that this 
 is its sole or even the most important mode of operating, for 
 either end. 
 
 The bearing of Dr. Wight's experiments on the effect of calca^- 
 rfcous manures in preserving health, will be referred to when that 
 subject shall come under consideration. All reference to this 
 branch of the subject in this chapter was incidental and in advance 
 of the designed and more appropriate place. 
 
 The power given by calcareous earth to plants to draw carbonic 
 acid much more copiously from the atmosphere, which Dr. Wight 
 go admirably deduced from actual experiments, might previously 
 have been inferred from the observations of alleged facts made by 
 practical cultivators. But the statement, hidden in the German 
 of the agricultural chemist Sprengel, probably first was disclosed 
 in this country in the recently published ''Lectures" of Johnston, 
 •whose words I will quote. This author, referring to Sprengel, 
 Bays : " lie states that it has very frequently been observed in 
 
GYrSUM INCREASING THE SUPPLY OF CARBON. 253 
 
 Ilolstein, that if, on an extent of level ground sown with corn, 
 some fields be marled and others left unmarled, the corn on the latter 
 portions will grow less luxtiriantlj/, and will yield a poorer crop 
 than if the whole had heen unmarled. Hence, he adds, if the 
 occupier of the unmarled field would not have a succession of poor 
 crops, he must marl his land also. 
 
 " Can it really be," continues Johnston, " that Nature thus re- 
 wards the diligent and the improver? Do the plants which grow 
 on a soil in higher condition take from the air more than their due 
 share of the carbonic acid or other vegetable food it may contain, 
 and leave to the tenants of the poorer soil a less proportion than 
 they might otherwise draw from it ?" (p. 101.) Like most other 
 readers, probably, I cannot venture to answer these questions 
 affirmatively. But if indeed calcareous earth in soil gives to plants 
 the power to seize upon and assimilate a much larger amount of 
 carbonic acid, it may well follow that other adjacent plants, not so 
 endowed, may in the contest fail to obtain their previously due 
 share of the always very small proportion of carbonic acid gas in 
 the atmosphere. 
 
 In connexion with these interesting statements, I will add an- 
 other, which is fully believed by many persons, and which I have 
 also heard asserted by one of the best practical farmers of Virginia, 
 and who is also an intelligent and judicious observer. The opinion 
 referred to is, that if a narrow strip of a clover-field be omitted, for 
 experiment and observation, when all the adjoining ground is 
 dressed with gypsum (sulphate of lime), and the manure acts well, 
 that the omitted strip will produce worse clover than it would have 
 done if no gypsum was near. The farmers who maintain this pro- 
 position, do so simply upon having observed (as they conceive) 
 such facts. They had no theoretical views to support by such a fact, 
 and indeed they did not pretend to oiler a supposed cause for such 
 an effect. For my own part, I have had no opportunity of observ- 
 ing any such facts, and will neither affirm nor deny such to have 
 been accurately observed by others. But such results seemed so 
 unsupported by reason, that at first I deemed the observations 
 mistaken, and the statements not worth any consideration. But by 
 applying the obvious deductions from Dr. Wight's experiments, 
 these before (supposed) irrational and incredible results may appear 
 well sustained, both in regard to their accuracy and their causation. 
 
 2. Lime in soil increases the effect of azotized manures^ and, 
 through leguminous plants, draws azote also from the atmo- 
 sp)here. 
 
 The quantity of carbon in plants, or in different products of 
 plants, amounts, in some subjects, to more than one-half of the 
 whole weight of the dry plant or product ; and in all other cases it 
 
254 AZOTE IN PLANTS. 
 
 fulls not mucli below tliat proportion. According to Professor 
 Liebig, the whole of tbe carbon in plants is derived, through their 
 leaves, from the atmosphere ; and Boussingault, whose authority I 
 respect much more highly, says : " From all we have seen up to 
 this time, we feel authorized to conclude that the greater proportion, 
 if not the whole, of the carbon which enters into the composition 
 of vegetables, is derived from the atmosphere." (p. 42.) All other 
 chemical authorities concur in maintaining that at least much the 
 larger part of the carbon received by and tised in plants, is taken 
 from the atmosphere through the leaves. How very great, then, 
 must be the proportion of vegetable nutriment and support, and of 
 materials for growth and increase, derived exclusively from the air ! 
 For it is not only that nearly half their quantity is thus obtained 
 in their carbon alone, and they also take vip from water, whether 
 in the air or in the soil, nearly as much as of carbon, in hydrogen 
 and oxygen; which, though always pi'esent in enormous super- 
 abundance, cannot be thus used by plants, except in strict propor- 
 tion to the carbon assimilated. All these quantities, then, which 
 the atmosphere supplies either exclusively, or may supply, as in 
 regard to water, probably amount always to full four-fifths of the 
 substance of all vegetable products; leaving but one-fifth, at most, 
 to be derived from the soil, or having any direct dependence on the 
 condition of fertility of the soil. 
 
 Further : of thig small proportion of vegetable growth and sub- 
 stance derived from and dependent on the contents of the soil — • 
 say one-fifth, at most, and generally not more than one-tenth part 
 ' — a quantity which varies much in different plants, but on an 
 average making more than half of this proportion derived from the 
 soil alone, consists of inorganic elements ; while the remainder, of 
 about 1 to 4 per cent, only of the whole plant, is of azote, which 
 is either wholly or principally a part of the matter derived from 
 the contents of the soil. (See Table on p. 244.) Yet is this very 
 small supply of azote all-important to the support and product of 
 plants ; and its being duly supplied in organic manures, or other- 
 wise, is the great and essential operation of all improvement of 
 crops through the improvement of soils. In considering, then, the 
 value of azote, we must take care not to measure its importance by 
 its always small quantity in soils, manures, or plants, but by tho 
 great and essential operation of this element, and which even in 
 this small quantity it produces. Azote is eminently the enriching 
 part of all putrescent manures, and of all vegetable products serv- 
 ing as food for animals. The most enriching of animal manures 
 abound most in azote; and, above all, the excrements of carnivorous 
 animals, whose food is also rich in azote. Next in order stand the 
 excrements of animals fed on the most highly azotized vegetable 
 food. Vegotablo matters, compared to animal, in general have but 
 
AZOTE IN PLANTS. 
 
 255 
 
 little azote ; and, as we all know, when used alone, make much 
 poorci" manure. But even among different vegetables forming 
 ordinary farm products, there are great differences in their propor- 
 tions of azote, and also in their sources of supply of this rich 
 ingredient ; and according to such differences are the respective 
 values of crops for food, and more especially their powers as im- 
 provers or exhausters of the soils on which they grow. The in- 
 vestigation and attempt at elucidation of this last branch of the 
 subject is the object of the next following pages. 
 
 Boussingault reports (from the results of analyses by himself and 
 Payen, in conjunction) the pro23ortions of azote contained in nume- 
 rous vegetable and animal substances (at p. 297, Rural Econom//\ 
 from which the following extracts of some ordinary manuring ma- 
 terials will serve as examples : — 
 
 Ordinary f;irm-yard manure, 100 parts, dry, contained of 
 azote ........ 
 
 Richer manure, from an inn-yard - . . . 
 Wheat-straw of Alsace [presumed from ordinary soil] 
 Do., from environs of Paris [presumed much richer soil] 
 Rye-straw of Alsace ...... 
 
 Do., environs of Paris ,..,.. 
 Oat-straw ........ 
 
 Barley-straw ....... 
 
 Wheat-chaff 
 
 Pea-straw [or vines, &c.] ..... 
 
 Clover roots ....... 
 
 Oilcake of flax-seed ...... 
 
 Do. cotton-seed ....... 
 
 Solid cow-dung ....... 
 
 Solid horse-dung ....... 
 
 Guano . . . . . ' . 
 
 Dried muscular flesh ...... 
 
 Woollen rags ....... 
 
 1.95 
 
 2.08 
 0.30 
 0.53 
 0.20 
 0.50 
 0.36 
 0.26 
 0.94 
 1.95 
 1.77 
 6.00 
 4.52 
 2.30 
 2.21 
 6.20 
 14.25 
 20.26 
 
 While I do not deem the azotic as the only fertilizing parts of 
 putrescent manures, nor concur in all that Boussingault seems to 
 claim for their preponderance of operation, still it cannot be denied 
 that the azote of all organic manures constitutes their principal and 
 greatest fertilizing quality. Hence, we may learn, that if by any 
 means, and from new or additional sources, there can be gi'^en to 
 plants an additional supply of azote, of which the absolute quantity 
 would be so small as to seem scarcely worth consideration, yet that 
 there would bo added relatively as much amount of manuring value 
 as a larger dressing of ordinary manure could supply. And a due 
 consideration of these premises will serve to increase the cstimatq 
 
25G SOURCES OP SUPPLY OF AZOTE. 
 
 of the importance of the sources of supplies of azote which will be 
 indicated.* 
 
 Azote is mostly derived by plants from the soil and through 
 their roots. This is made evident by the obvious effects of all 
 putrescent manures, and the superior effects of those known to be 
 richest in azote. But it seems from some delicate and careful ex- 
 periments of Boussingault's, that some particular plants, and, as 
 far as known, those belonging to the leguminous or pod-bearing 
 kind only, possess the power of also deriving azote from the atmo- 
 sphere. This power, if certain, would be enough to explain the 
 reason of the well known and peculiar value of leguminous plants 
 as manuring crops. 
 
 This eminent chemist and practical agriculturist sowed known 
 quantities of the seeds of different kinds of plants in artificial soils, 
 composed of either burnt clay or silicious sand, which had been 
 deprived of all azotic and other alimentary manuring principles by 
 sufficient exposure to a high degree of heat. In other cases, young 
 plants were removed from natural soils to such artificial soil, after 
 being completely cleared of all adhering earth. The vessels con- I 
 taining the soils and plants were protected from receiving dust, or 
 anything else from without, and the seeds and plants therein were 
 duly moistened with distilled water. The plants, in some cases, 
 stood until mature; in others, for shorter terms. Finally, the 
 several kinds were analyzed, as had been done of the like kinds of 
 seeds, or transplanted plants, from which they grew, and the differ- j 
 ences of contents noted (omitting the ashes, or inorganic parts), j 
 as shown in the following summary of the results : — : 
 
 ■ ■ i 
 
 * Ordinary barn-yard manure, whicli Las been heaped, partially fer- j 
 mented, and is half rotted, is the kind which M. Boussingault used on his j 
 farm and in his analyses. Such manure was considerably richer than ours, 
 made with fewer and worse-fed cattle, compared to the large proportion of 
 litter, and used without being heaped or fermented. His manure, also, in 
 a heap, would necessarily have less water. Yet he estimates the water alone | 
 at from 75 to 80 per cent, of his manure. Of course, when dried, as stated j 
 in the preceding table, 100 parts of such manure is equal to at least 400 
 parts in the heap ; and, therefore, these 400 parts in ordinary condition 'j 
 contain only 1.95 parts of azote — or less than the half of one per cent, 
 serving to constitute the principal enriching value of the manure. 
 
AZOTE SUPPLIED FROM THE ATR. 
 
 257 
 
 
 Weight (grains.) 
 
 
 g 
 ■en 
 
 a 
 
 to 
 
 O 
 
 ■^ 
 
 1st. Clover seed sown 
 
 riants at 3 months, from same 
 
 Gain by growth . 
 
 24.48 consiatiug of 
 63.38 
 
 12.44 
 32.141 
 
 1.466 
 4.183 
 
 8.815 
 2-1.155 
 
 1.7.59 
 2.408 
 
 38.90 
 
 +19.70 
 
 +2.717 
 
 +15.840 
 
 +0.649 
 
 2J. Peas sown .... 
 riants (with seeds ripe) from 
 same 
 
 Gain by growth . 
 
 16.549 .... 
 CS.5G0 .... 
 
 7.950 
 36.680 
 
 1.065 
 4.384 
 
 6.523 
 25.930 
 
 0.710 
 1.559 
 
 52.02 
 
 +28.73 
 
 +3.319 
 
 +19.11 
 
 +0.S49 
 
 3d. "Wheat seed sown 
 
 Plants from same, at 1-1 to 15 
 inches high 
 
 Gain by growth . 
 
 25.38 .... 
 45.65 .... 
 
 11.84 
 
 22.47 
 
 1.46 
 
 2.67 
 
 11.19 
 20.57 
 
 0.87 
 0.92 
 
 21.27 
 
 +10.G3 
 
 +1.21 
 
 +9.38 
 
 +0.05 
 
 4th. Young clover plants . 
 
 Same after 63 days' growth 
 
 Gain by growth . 
 
 13.64 .... 
 34.96 .... 
 
 5.92 
 18.52 
 
 0.74 
 2.23 
 
 6.46 
 13.32 
 
 0.50 
 0.864 
 
 21.32 
 
 +12.C0 
 
 +1.49 
 
 +6.S6 
 
 +0.35 
 
 5th. Young oat plants 
 
 Same after 48 days' growth 
 
 Gain and loss fai growth . 
 
 :::::; 
 
 12.907 
 23.157 
 
 1.6.36 
 2.979 
 
 8.770 
 21.180 
 
 0.910 
 0.818 
 
 +10.190 
 
 +1.343 
 
 +12.410 
 
 —0.062 
 
 The above table is an epitome of tlie results of the five experiments 
 which, with the full explanations, occupy about five pages of the 
 author's work. The analyses made of seeds and plants at the 
 earliest times, were, of course, of other samples, of like kind and 
 quantities of seeds to those sown, and, as nearly as could be, of the 
 plants, compared to those transplanted. The results show the 
 following facts : — 
 
 As the artificial soils were devoid of all organic or nutritive 
 matter, the gains made by the plants were derived entirely from 
 pure (distilled) water, and from the atmosphere. The increase in 
 azote, of course, could have been obtained from the atmosphere 
 only. _ ^ 
 
 Besides the large gains made during growth, by all the plants, 
 of carbon, hydrogen, and oxygen, the clover of 1st experiment 
 increased its azote by more than half the quantity contained in the 
 seeds ; in the clover of 4th experiment, the azote of the young 
 plants was nearly doubled ; and in 2d experiment, the azote of the 
 peas sown was more than doubled in the crop. 
 
 • In the growth of wheat, the gain of azote was scarcely appreci- 
 able (and, therefore, perhaps doubtful) ; and in the growth of oats, 
 there was an absolute loss of azote. 
 
 The results of these very interesting and apparently very accu- 
 rate experiments (as seen in the author's full details), exhibit, in 
 a striking manner, how largely all the kinds of plants possess them- 
 22* 
 
B5S BENEFIT OF CLOVER. 
 
 selves of and assimilate carbon, hydrogen, and oxygen, all drawn i 
 
 from water and the air only ; and also, that in addition to these ele- i 
 
 ments, the leguminous plants, and these only, drew azote from the air, ' 
 assimilated or fixed it in their bodies, and thus could give it to the 
 soil as manure. When other plants contain azote, and give it to 
 
 the soil as manure, they had derived the whole supply previously : 
 
 from the soil, and therefore there was no gain in regard to that i 
 
 richest element. But tho leguminous plants, deriving part of their ; 
 
 azote from the atmosphere, give so much to the soil, if used as ] 
 manure, more than the soil had before furnished. This peculiar 
 
 power of leguminous plants is an important cause of their well- ] 
 
 known peculiar value as manuring crops. ! 
 
 It has long been a received and unquestioned opinion among in- 
 telligent farmers, that the growth of clover, and other leguminous i 
 crops, drew away from the soil less of the fertilizing principles, and j 
 returned to it more, than any others. This opinion prevailed in 1 
 districts where most of the product of clover was usually removed 
 from the fields, as well as in other places where the clover was , 
 mostly left on the ground, to be ploughed under as manure. In i 
 Lower Virginia, wherever improvements by calcareous manures and 
 by clover have correctly gone together, and however the rotations 
 of crops may differ in other respects, there is one pai't of the courses ^ 
 of crops generally alike, viz., the succession of — 1st, Indian corn ; » 
 2d. wheat ; 3d, clover ; and 4th, wheat. On some farms (of best | 
 soil, which only can bear such severe cropping), this is the whole ' 
 course constituting a four-shift rotation. On others, and more ] 
 generally, a fifth year is added, of rest, or at most of pasturage i 
 only, and interposed between the fourth crop, wheat on clover, and i 
 the subsequent recurrence of the first crop in the series, Indian •■ 
 corn. In cither case, it is generally believed that the product of 1 
 the second crop of wheat, sown upon clover turned under as manure, 1 
 is usually about double that of the first crop of wheat following ^ 
 corn, though the immediately preceding corn crop had received all ; 
 the prepared putrescent manure given. This great difterence of ! 
 production, however, is not altogether due to the clover manure ■ 
 for the second, or " fallow" crop of wheat, but partly to the cir- , 
 cumstance of the first crof) of wheat having followed another grain j 
 crop, which is a vile succession, and must always lessen the second j 
 or immediately succeeding crop more than in proportion to the then | 
 actual productive powers of the land. In my own practice, as in I 
 general of others, there have been no separate measurements of * 
 these two nearest crops of wheat, or any parts thereof, from the i 
 same land. But the same estimate of difference has been made 
 upon merely general observation, viz., that the wheat after clover 
 was usually double as much as the previous wheat after corn on 
 the same field. My own putrescent manure; frcm stable and stock- 
 
BENEFIT OP CLOVER TO WHEAT SUCCEEDINa. 259 
 
 pens, bas iDcen given exclusively as top-dressing to the clover, -wliieh 
 is so niucli the more in favour of the succeeding wheat. 
 
 The scientific and practical farmer as well as able chemist, 
 Boussingault, has with great care ascertained the usual or average 
 quantities, and also the chemical contents, of the clover and all the 
 other crops of his rotation, so as to make certain the results which 
 with other persons would rest merely on supposition, or loose esti- 
 mates. On his farm, Bechelbronn in Alsace, he says — "For a 
 long time a five years' rotation has there been adopted in the fol- 
 lowing order : — 
 
 1st year, Potatoes, or beet-root, manured. 
 
 2d " Wheat, sown the autumn of the first year; clover in 
 the spring. 
 
 3d " Clover, two crops [mown]; the third ploughed in. 
 
 4th " Wheat on the clover break; turnips after the wheat. 
 
 5th " Oats. 
 
 It should be observed of this rotation that the first crop of wheat 
 was preceded by potatoes, a forerunner very favourable to the pro- 
 duct of the succeeding wheat; and still more so, as the potato 
 crop had all the manure of the farm. This crop of wheat, to the 
 acre, averaged 20 bushels and 31 lbs. of grain; and of both straw 
 and grain 4029 lbs. The clover following the next year yielded 
 2 crops of hay, making 4675 lbs. dry (or in state of hay), and a 
 third crop, ploughed in for manure. It is the usage in Alsace to 
 mow clover very young, when it is just beginning to get in blossom ; 
 hence the two mowings must have been removed so early, as to 
 allow the third growth to be as heavy as each of the two first. 
 Counting it tlffen as one-third of the whole, the year's product of 
 clover, if all had been made into hay, would have weighed (4675-(- 
 2337=) 7012 lbs. ; of which one-third only was left on the land 
 as manure. After all this abstraction from the land, and also the 
 prepared manure having been applied to the first crop of the rota- 
 tion, the wheat following the clover yielded the average of 25 bush. 
 21 lbs. of grain, and straw and grain together 4979 lbs. 
 
 This rotation is general in Alsace ; and speaking of general re- 
 sults, M. Boussingault says — '' The remarkable effect of clover [as 
 a manure crop] has not failed to arrest the attention of the most 
 unobserving. The wheat crop which comes after our drill crop in 
 Alsace, beets or potatoes, averages from 18 to 20 bushels per acre ; 
 but the wheat succeeding clover averages from 23 to 24 bushels." 
 (p. 360.) 
 
 There is another important subject for consideration and com- 
 parison of clover and other crops (not leguminous), in their relative 
 quantities of roots, stubble, or other residues, or ofial parts, left on 
 the land. In the same year (1839), when the season was not pro- 
 pitious to cither crop, the residues were taken by M. Boussingault 
 
260 CAUSE OF MANURING VALUE OP CLOVER. 
 
 from equal spaces, and after being perfectly cleared of the adhe- 
 ring earth, wei'e dried, weighed, and also portions of each analyzed. 
 Of the two crops of wheat of that year, averaged, he found the 
 whole residue of stubble and roots to be per acre : 
 
 (from grain, weighing, lbs. 1075) lbs. 644 
 Residue of clover 
 
 stubble and roots (from hay, lbs. 2292) " 183.S 
 
 Eesiduc of oat stubble and roots (from grain, lbs. 1862) " 836 
 
 The residues of wheat and oats each contained per acre 2 lbs. of 
 azote only; while the residue of the clover contained 26 lbs. Of 
 course the superiority of the latter in quantity, great as it was over 
 the other residues, was still greater in richness, or quality for 
 manuring. 
 
 While all persons have concurred in asserting the meliorating 
 eifects of clover and other leguminous crops, there has been as 
 general an erroneous agreement as to the cause of this quality. It 
 has been assumed by our scientific instructors, and their doctrine 
 was received without question, that plants with broad leaves ab- 
 sorbed more carbon from the air, and hence the superiority in this 
 respect of leguminous plants over all of the narrow-leaved tribes. 
 Never was there an opinion more generally admitted on a weaker 
 foundation, or more easy to overthrow. Several cultivated crops, 
 as tobacco, palma-christi, cabbage, turnip, pumpkin, and other like 
 vines, have much broader leaves than any of the legumes ; but 
 neither of these has ever been deemed to have any peculiar power 
 for manuring by its growth and decay on the land. Nearly all 
 forest trees also have very broad leaves, and they exhibit no su- 
 periority of manuring qualities on that account, whether compared 
 with narrow-leaved trees, or with leguminous crops. But is enough 
 to refer to the numerous analyses of plants reported by chemists, 
 all of which, like those in the table copied on a preceding page 
 (244) go to show that clover, beans, peas, vetches, &c., have iu 
 general no larger proportions of carbon than other and even the 
 most exhausting plants. Indeed, of this element there is a close ap- 
 proximation to equal proportions in all plants whose constituent 
 parts have been reported. The proportion usually varies between 
 45 and 50 per cent, of the whole dry weight of the plant. From all 
 these facts, it may be inferred as being nearly a correct rule, tliat in 
 general the plants or crops which yield the greatest quantity of total 
 product to the acre, in dry weight, will have taken up (from all 
 sources, and of course mostly from the atmosphere) the largest 
 amount of carbon ; and therefore will return more to the land if 
 left to act as manure. We must then look to other powers than 
 that of absorbing carbon for the cause of the superiority of clover 
 as manure — which, as Boussingault says, is out of all proportion 
 
VALUE OP THE SOUTHERN PEA. 261 
 
 to tlic quantity of the crop given to the soil. That cause, I presume, 
 will be found partly in the greater product and quantity of residue 
 to the acre than is left by most other crops ; but still more because 
 of the greater quantity of azote contained in the residue of roots 
 and stubble, as well as of the crops consumed as forage, or left to 
 be ploughed under, and in both cases, though in differentWays, 
 serving as manui-e to the land. 
 
 Of grain crops, or any others which take all their contents of 
 azote from the soil, and, if sold or removed from the farm, those 
 ■which have taken up and removed the most azote from the land, 
 must be the most exhausting of its fertilizing principles. And such 
 would be the leguminous crops, for beyond all others, if they came 
 under the conditions named, as they contain much the largest quan- 
 tities of azote. As they are known by observation to be among the 
 least exhausting, even when removed from the farm, that alone 
 would strongly indicate, what Boussingault's experiments have 
 proved, that these crops take a portion, and probably the larger 
 portion, of their azote from the atmosphere. Of course, when re- 
 turned to the earth as manure, the azote so drawn from the air is 
 so much of supply of the richest principle, in addition to all others 
 contained, in common with other vegetable substances. We can 
 supply barn-yard and other auimalized and azotized manures to our 
 farms only in limited and insufficient quantities. But by ploughing 
 in leguminous manuring crops, azote may be furnished to much 
 greater extent. 
 
 Field peas, such as are raised in England, and in our Northern 
 States, are varieties of and very like to the kinds we know here only 
 as garden vegetables. These field peas contain even more azote 
 than clover does. Lucerne is also superior to clover in that respect, 
 and European field beans not inferior. All these plants are un- 
 suited to our climate, or unprofitable for culture on extensive 
 spaces. 
 
 But we have a leguminous plant, in numerous varieties, native 
 to our country, and little known except in Virginia and the more 
 Southern States, which, as a green manure, and meliorating crop, 
 is scarcely inferior to clover — and for some qualities, and always in 
 more southern regions, is preferable to clover. This is our southern, 
 or " corn-field pea," as commonly called, from being most generally 
 raised as a secondary crop among corn. In truth it is not a pea, 
 but a iea;i.* Of this plant, I know of no chemical analysis. But 
 
 * Miller's Gardener's Dictionary states a sufficiently plain distinction 
 between beans and peas, by describing the seeds of the former as " kidney- 
 shaped," and the latter as "roundish." The only pea known to me as a 
 cultivated plant, other than our European garden peas, has very small and 
 "roundish" pale green seeds, in a black pod. Even this is more like the 
 vetch {vicia saiiva) or our bad weed the "partridge pea," as to seeds and 
 
262 AZOTE SUPPLIED THROUGH PEA CROPS. 
 
 it may be safely inferred, from its being a legume, from its luxuri- 
 ance of growth, and also from all of the little careful obsei'vation 
 that has been yet directed to it, that our native southern pea or 
 bean is a fertilizer of great value, and whose value in this respect is 
 just beginning to be understood. My own experience of this plant, 
 in tieiirculture, is but a few years old. But it has been so encourag- 
 ing in the results, that I have already extended this growth, so as to 
 make it occupy an entire field, and to make an important part of 
 my rotation. It is too soon yet to rely on such recent facts and 
 observations. But so far as tested by my experience, I have every 
 reason to value highly this as a manuring crop, and especially as a~~ 
 preparatory crop for wheat.* 
 
 If this plant was not an annual, and requiring (when sown sepa- 
 rately as a fallow or manure crop) to have the laiid ploughed for 
 its seeding, it would be more valuable than clover. This defect is 
 however in one aspect an advantage ; as we can raise the crop in 
 three or four months from the seeding, to the state of full growth 
 fit for ploughing under, with more certainty of success, both in the 
 standing and producing, than with clover in sixteen mouths from 
 the sowing, l^'arther south, the growth and production of the bean 
 crop becomes better, in ^^roportion as clover becomes more precari- 
 ous and generally unproductive. 
 
 In the preceding pages I have endeavoured to explain and to 
 establish these opinions : 
 
 1. That azote, the smallest but richest, and for its quantity by 
 far the most important element and ingredient of plants, is derived 
 by most plants exclusively from the soil ; 
 
 2. That plants of the leguminous tribe, and they alone, so far as 
 known, possess and exert the power also to draw azote directly from 
 the atmosphere, assimilate and fix in their bodies this richest ma- 
 terial, and to give it as manure to the soil on which they grow, and 
 are left to decay ; 
 
 3. That owing to this jjeculiar power, leguminous plants arc the 
 most highly enriching to soil, as manure. 
 
 pods, than to any known pea. But unlike the vetch, it is not a vine, but 
 a shrub. 
 
 * The varieties of these beans are innumerable. The most common and 
 best known as an excellent table vegetable, is the "black-eyed pea," of 
 ■which the seed is -white with a black spot around the eye or germ. This 
 name, made doubly incorrect, is extended in common parlance, and in lists 
 of prices-current, to all the varieties of this crop, and seeds of various 
 colours. All the white kinds are the least valuable for green manuring 
 crops, because producing least vine and leaf. The greatest "runners," or 
 producers of vines, and making the heaviest cover to the ground, are all late 
 peas, and either black, red, or pale bull' colour. There are many varieties, 
 •with differences of time and manner of growth, even of these colours ; and 
 the seeds of one colour not distintruialuvble from other kinds of like colour. 
 
LIME AIDING LEGUMINOUS PLANTS. 263 
 
 And that the important benefits thus to be derived are available 
 only through the aid of lime in soil, is the important deduction 
 from the foregoing positions, as premises, which I now design to 
 maintain. 
 
 It is not necessary to repeat the many statements, in the forego- 
 ing portion of this essay, of the peculiar and all-important aid-^aud 
 support which calcareous matter in soils furnishes for the grov.'th 
 and luxuriance of leguminous plants especially. In some small 
 proportion, lime in soil is essential to the life of all plants, and to 
 even the poorest product from all cultivated crops. In larger, 
 though it may still be but very small proportion, it further and 
 greatly improves the growth and production of all cultivated crops, 
 and all except acid plants. And lime in greater quantity still, in 
 amount serving to constitute truly calcareous soil, is especially 
 promotive of the vigour and luxuriance of growth of all leguminous 
 plants, and even essential to the existence of some of them. Saint- 
 foin, a valuable forage plant of highly calcareous lands in Europe, 
 cannot live in any natural (non-calcareous) soil of our Atlantic 
 slope. Lucerne, for the same reason, rarely thrives here, and never 
 except in the best artificial soils. Red clover, the chief of manuring 
 and forage plants, and which now serves as one of the principal and 
 essential elements of our present improving agricultural system, in 
 connexion with the use of calcareous manures, had no existence 
 and could not exist in field culture in the tide-water region before 
 the fitting the soils for its support, by the use of marl and lime. 
 
 To the next most important legume and manuring plant, our 
 field pea or boan, lime in quantity is as much conducive to its greatest 
 pi'oduction, as to clover; but it is not so essential for the existence, 
 and moderate productiveness, of this kind of bean. 
 
 3. Operation of calcareous earth to produce nitrates in soi'l^ 
 and compost heaps. 
 
 In sundry marginal notes to the foregoing pages, the recent 
 words or opinions of Prof. Johnston have been quoted, to show 
 their concurrence with my own earlier stated positions. It is highly 
 gratifying to me that such confirmation, having such authority, 
 may be adduced to support nearly every deduction of mine that 
 bears strongly upon, or would either direct or divert practical ope- 
 rations. Ills lecture '' on the use of lime as a manure,'' especially 
 ofi"ers a copious mass of information on this subject, both scientific 
 and practical, which is generally correct, and more instructive than 
 all that had been before published by preceding English chemists 
 and agriculturists. When so many points of agreement appear of 
 this scientific work with mine, which has so little pretension to 
 science, it is well that my priority of publication must secure me 
 from any possible charge of plagiarism. I am altogether uncjualified 
 
2Gi LIME INDUCING THE FORMINO OF NITRATES. 
 
 to judge of many of th3 chemical doctrines and facts presented by 
 JohustoQ; but infer that they are among the unquestioned results 
 of the latest and ablest chemical researches. As a matter of course, 
 the scicntilic author may be supposed to have no personal acquaint- 
 ance with practical farming. But his numerous agricultural facts, 
 though received from other persons, are not less the fruits of 
 practice and observation, and therefore are worthy of much respect, 
 even when not to be admitted as conclusive. Though knowing 
 nothing of this author, except from his book, and confessedly unfit 
 to decide on the correctness of many of its scientiiic positions, 
 still I accept this work as the latest and fullest embodimopt and 
 digest of the now received doctrines of agricultural chemistry in 
 Europe, and of agriculture in England ; and so esteeming the work, 
 it will be again referred to, as has been done before, whether for 
 support of my own i^ositions, as in many previous citations — or to 
 derive new lights and information, as now, — or to oppose or refute, 
 as has been attempted in other cases. 
 
 This section will present additional effects and valuable opera- 
 tions of calcareous manures, for which subjects, either wholly or 
 in part, I am indebted to Johnston, and to whom the credit due 
 "will be particularly as well as thus generally awarded. The most 
 interesting and important of such new or additional positions, is 
 the power of calcareous earth, in soil, or in compost heaps of 
 manure, to form nitrates from atmospheric supply of material. 
 
 The same two elements, oxygen and nitrogen, which when in- 
 termixed in gaseous form, and in certain uniform proportions, serve 
 to make atmospheric air, will, when chemically combined, consti- 
 tute nitric acid. Such combination is produced by electricity. " It 
 is known," says Boussingault, ''■ that so often as a succession of 
 electrical sparks passes through moist aii-, there is formation and 
 combination of nitric acid and ammonia. Now nitrate of ammonia 
 is one of the constant ingredients in the rain of thunder-storms." 
 (p. 494.) " The currents of electricity which in nature traverse 
 the atmosphere must produce the same effect [of forming nitric 
 acid], and the passage of each flash of lightning through the air 
 must be attended by the formation of some portion of this acid." 
 (Johnston, p. 160.) 
 
 Ammonia, the volatile or aeriform alkali, is a civomical compound 
 of nitrogen (azote), one of the two elements of avniospheric air, 
 and hydrogen, one of the two elements of water. IJence, of am- 
 monia, as of nitric acid, there are in the ordinal y moi.^-t air of the 
 atmosphere, the most abundant materials for both these compound 
 products. There is wanting only the agency for their f-'rmation, 
 vfhich is exercised by nature only (as by lightning), and t''at spa- 
 rino'ly, tliough incessantly, in some or other regions of the tmo- 
 i^phere. Both ammonia and the nitrates (the certain and jtf'me- 
 
CALCAREOUS COMrOSTS ARE NITRE-BEDS. 265 
 
 diatc products of nitric acid on the soil), are well known to bo 
 highly fertilizing. The foregoing passages show (besides other 
 known sources) that the air supplies both, and that the surface 
 of the earth, everywhere, is sure to be more or less supplied from. 
 the air, with ammonia and nitric acid. Nitrogen, which is one 
 of the two constituent parts of both these fertilizing compounds, is 
 also the richest and the most important element (for the small pro- 
 portion required), in the nutriment of plants, and the most power- 
 ful promoter of their luxuriance and perfection of growth. It may 
 be inferred, that it is by furnishing their element nitrogen to 
 plants, that both ammonia and the nitrates are such important aids 
 to vegetable growth, and to the fertilit}'- of soils. Ammonia is 
 produced and evolved in large quantity by the putrefaction of all 
 animal substances. Also, " during the decay of vegetable sub- 
 stances in moist air, ammonia is formed at the expense of the hy- 
 drogen of the water and of the nitrogen of the air. In conse- 
 quence of, or in connexion with, such decay, nitric acid is also 
 largely produced in nature." — (Johnston, p. 161.) 
 
 " The most familiar, as well as the most instructive examples of 
 this formation of nitric acid, is in the artificial nitre-beds of France 
 and the north of Europe. These are formed of earth [calcareous 
 in part], stable manure, or other animal and vegetable matters, the 
 mixture laid in ridges, occasionally watered with liquid manure, 
 and turned over, to expose fresh portions to the air. After a time, 
 perhaps once a year, the whole is washed, when the water which 
 comes off is found to contain a variable quantity of the nitrates of 
 potash, soda, lime, and magnesia, which are employed for the manu- 
 facture of saltpetre. In these nitre-beds, it has been observed that 
 the production of nitric acid either does not take place at all, or 
 only with extreme slowness, unless animal and vegetable matter be 
 present in considerable proportion. And yet the quantity of nitric 
 acid which is formed is much greater than could be produced by 
 the oxydation of the whole of the nitrogen contained in the organic 
 
 matters present in the mixture It appears, therefore, 
 
 that organic matters are, in our climate, necessary to cause the for- 
 mation of nitric acid to commence ; but that after it has begun, it 
 will proceed in the same heap for an indefinite period, and at the 
 expense apparently of the nitrogen of the air only. 
 
 '■'■ Compost heaps [of manure, formed of rich soil, animal manure, 
 and lime or calcareous earth] are in general only artificial nitre- 
 heJs, often unskilfully prepared, and badly managed, producing, 
 however, a certain quantity of nitrates, to the presence of which, 
 their effect on vegetation may not unfrequently be ascribed. . . . 
 The soils in the plains of India, and in other similar spots in the 
 tropical regions, may be regarded as nataral nitrc-heds, in which 
 the decay of organic matter being vastly more rapid than in our 
 23 
 
2G6 LI5IE IN COMrOST UEArS. 
 
 temperate regions, the production of nitric acid is rapid in propor- 
 tion." — (Johnston, p. 161.) 
 
 Thus, and in other modes, by the presence and agency of calca- 
 reous earth, it may be supposed that nitrogen (or azote), which Is 
 the essential element of all rich putrescent manures, is continually 
 produced from the atmosphere ; and that the results, in nitrates, 
 are given to growing plants, by which they obtain and assimilate 
 the necessary nitrogen, which could not be otherwise obtained, ex- 
 cept from large supplies of rich animal manures. 
 
 If these views are sound, they lead to most important conse- 
 quences, and suggest the existence of before unknown enriching 
 and fructifying agencies of lime, continually at work, in drawing 
 rich manure from the air, and giving the supplies to each successive 
 crop of growing plants, so long as the lime and organic matter re- 
 main together in the soil. 
 
 These views also serve to throw much light on some opinions 
 and facts in reference to the benefits of lime, which I formerly 
 brought before the public, because of their interest, but of which 
 the causes were then left in all their obscurity. One class of facts 
 were presented in the very light limings of La Sarthe, in France, 
 of about 11 bushels only to the acre (though repeated in every 
 round of four crops), and showing undoubted good effects. This 
 was stated in Puvis' "Essay on Lime,"* which I translated and 
 published in the third volume of the " Farmers' Register." The 
 other facts referred to, doubtless were produced by that publication. 
 Mr. Peter Mellett, of Sumpter, S. C, pursued a similar course of 
 liming, and even with still lighter though more frequent dressings, 
 giving bvxt 2^ bushels to the acre, annually, and yet with satisfac- 
 tory results, and manifest and progressively increasing improve- 
 ment of both land and crops. f The process in both cases was to 
 form compost heaps of alternate layers of earth, putrescent manures, 
 and lime in very small proportion. In both cases, the evidences of 
 the results seemed unquestionable. Yet to me, the reported effects 
 then seemed to exceed the operation of all the then known causes, 
 in enormous disproportion. But the difficulties of comprehension 
 will be removed by explanations suggested by the passages quoted 
 above. These compost heaps were in fact nitre-beds ; and the lime 
 acted much less by its quantity, and directly, as manure, than by 
 inducing the formation of nitrates, and thereby furnishing supplies 
 of nitrogen to the crops. Another circumstance strengthens this 
 conjecture. Puvis states of this practice, which was extensively 
 
 * *'/)t'.s differcns moi/ens cVamcnihr le sol" iu the ^' Annales d^ Agriculture 
 Frangaise," for 1835-6. 
 
 f These facts were more fully stateil in my "Report of the Agricultural 
 Sni-vey of South Carolina," made in 1813, under the order and appoint- 
 ment of the government of that State. 
 
LIME IN COMPOST HEArS. 267 
 
 in iiSG in Normandy, that the longer the compost heaps were kept 
 before being carried out as manure, and the more often they were 
 cut down, the parts mixed, and again heaped, the richer and more 
 efficient would be the manure. Now this seemed scarcely less 
 strange than the general result. For, after as many mixings and 
 turnings of the mass as would serve for thoroughly separating each 
 ingredient, and mingling the whole together, with enough of time 
 for the combining chemical action between the different elements, 
 there appeared no reason why the compound mass could gain more 
 in richness, and thcf putrescent parts would probably lose, by con- 
 tinued exposure and further decomposition. But even if such 
 were the case as to the original materials of the compost, yet doubt- 
 less the formation of nitrates continued, and their quantity was in- 
 creased with every new exposure of surface, and through the whole 
 course of time. 
 
 Under these impressions, I now deem much more valuable and 
 worthy of imitation the very light limings, in compost, of La 
 Sarthe ; and as especially suitable when a farm throughout has 
 once been well calxed, and it is yet too soon to repeat the applica- 
 tion in any considerable quantity. This plan, of very light lim- 
 ings, in compost, offers ample remuneration for vising lime as ma- 
 nure in localities so distant from the source of supply, that the 
 carriage of enough for ordinary dressings might be more expensive 
 than profitable.* 
 
 § III. Improving the lieaWi, and jjromoting the vigour and perfec- 
 tion of plants. 
 
 The beneficial efi^ects of calxing are not to be measured by the 
 mere increase of the bulk or quantity of products, and still less in 
 comparison with crops on similar land not yet calxed, in seasons 
 when both lands, according to their different qualities, yield well. 
 The addition of calcareous earth, when before greatly deficient, serves 
 to so improve the fitness of the land for vegetable production, that 
 
 * It may be of use to some readers, who Iiave no access to either of the 
 works above referred to, to state here concisely the mode of making this 
 compost in Normandy, and also in Belgium, as reported by Puvis. He' 
 says: — "There is first made a bed of earth, mould, or turf [peat], of a 
 foot or thereabout in thickness. The lumps are chopped doAvn, and then 
 is spread over a layer of unslaked lime, of a hectolitre [2| bushels] for 
 every 20 cubic feet of earth. Upon this lime is to be placed another layer 
 of earth [of like kind], equal in thickness to the first, then a second layer 
 of lime ; and then the heap is finished by a third layer of earth." As soon 
 as the lime is fully slaked, by the moisture of the earth, " the heap is cut 
 down, and well mixed ; and this operation is repeated afterwards, before 
 using the manure, which is postponed as long as possible, because the 
 power of the eft'ect on the soil is increased with the age of the compost, 
 and especially if it has been made with earth containing much vegetable 
 mould " 
 
2G8 LIME CAUSING HEALTHY GROWTH. 
 
 all plants grown thereon will be more healthy, more able to resist 
 all causes of disease and disaster, to bear up unhurt under injuries 
 of season, insects, &c., which would have either destroyed, or 
 greatly injured the feebler and diseased growth of a soil deficient 
 in lime. Plants thus receive that endowment which in regard to 
 animals is called a good j'Jii/sicaJ constitution. And the difference 
 between the possession of this good constitution and the want of it, 
 whether in animals or plants, in most times for comparison, would 
 be as the difference between perfect health and full ability on the 
 one side, and of disease or decay on the other. 
 
 In this aspect, the superiority of product from calxed land, how- 
 ever great it may be over the uncalxed, in any particular season 
 not disastrous to the growth of either, is of less account and value 
 than the ability of the former to maintain good products, under 
 circumstances of injury which would greatly reduce the production 
 of the latter. 
 
 In addition to this much greater certainty of calxed land pro- 
 ducing crops proportioned to its fertility, than of the un-calxed, in 
 proportion to its lesser rate there is the further advantage that the 
 growth of the former is in comparison more perfect and more valu- 
 able than would be indicated by mere quantities. The grain of 
 wheat is heavier to the measure, has a thinner skin, and yields 
 more flour, on calxed soils, or those naturally calcareous ; " while 
 this flour is said also to be richer in gluten," and of course will 
 make more and better bread. — (Johnston, p. 391.) These benefits 
 arc in addition to the greater quantity and also the greater cer- 
 tainty of production. Though the millers of this country have 
 been slow to learn these truths, still they are beginning to know 
 that the wheat produced on calxed lands is the most valuable. 
 Johnston says that liming "improves the quality of almost every 
 cultivated crop." — " All fodder [grass, &c.], whether natural or 
 artificial, is said to be sounder and more nourishing when grown 
 upon laud to which lime has been abundantly applied." — " Pota- 
 toes are made more mealy and palatable, especially on moist lauds 
 needing draining. Turnips, peas, and beans are also improved for 
 food, in addition to the increase of crops." 
 
CHAPTER XXV. 
 
 THE USE OF CALCAREOUS EARTH RECOMMENDED TO PRESERVE 
 PUTRESCENT MANURES, AND TO PROMOTE CLEANLINESS AND 
 HEALTH. 
 
 The operation of calcareous earth in enriching barren soils has 
 been, in a former part of this essay, ascribed mainly to the chemi- 
 cal power possessed by that earth of combining with putrescent 
 matters, or with the products of their decomposition ; and in that 
 manner preserving them from waste, for the use of the soil, and 
 for the food of growing plants. That power was exemplified by 
 the details of an experiment (page 95), in which the carcass of an 
 animal was so acted on, and its enriching properties secured. That 
 trial of the putrefaction of animal matter in contact with calcare- 
 ous earth, was commenced with a view to results very different 
 from those which were obtained. Darwin says that nitrous acid 
 is produced in the process of fermentation, and he supposes the 
 nitrate of litne to be vei'y serviceable to vegetation.* As the 
 nitrous acid is a gas, it must pass off into the air, under ordinary 
 circumstances, as fast as it is formed, and be entirely lost. But as 
 it is strongly attracted by lime, it was supposed that a cover of 
 calcareous earth would arrest it, and form a new combination, 
 which, if not precisely nitrate of lime, would at least be composed 
 of the same elements, though in different proportions. To ascertain 
 whether any such combination had taken place, when the maniire 
 was used, a handful of the marl was taken, which had been in im- 
 mediate contact with the carcass, and thrown into a glass of hot 
 water. After remaining half an hour, the fluid was poured off, 
 filtered, and evaporated, and left a considerable proportion of a 
 white soluble salt (supposed eight or ten grains). I could not 
 ascertain its kind; but it was not deliquescent, and therefore 
 could not have been the nitrate of lime. The spot on which the 
 carcass lay was so strongly impregnated by this salt, that it re- 
 mained bare of vegetation for several years, and until the field was 
 ploughed for cultivation. 
 
 But whatever were the products of decomposition saved by this 
 ex2:»eriment, the absence of all offensive effluvia throughout the 
 process sufflciently proved that little or nothing was lost, as every 
 atom must be, when flesh putrefies in the open air ; and I presume 
 that a cover of equal thickness of chj, or sand, or any mixture 
 of both, without calcareous earth, would have had very little effect 
 
 * Darwiu's riiytologia, pp. 210 and 224. Dublin edition. 
 23* (269) 
 
270 ANIMAL MATTER FIXED BY CALCAREOUS. i 
 
 in arresting and retaining the aeriform products of putrefaction. 
 All the circumstances of this experiment, and particularly the 
 good effect exhibited by the manure when put to use, proved the 
 propriety of extending a similar practice. In the neighbourhood i| 
 of towns, or wherever else the carcasses of animals, or any other ■ 
 animal substances subject to rapid and wasteful putrefaction, can ! 
 be obtained in great quantity, all their enriching powers might be j 
 secured, by depositing them between layers of marl, or calcareous 
 earth in any other form. It is said that on the borders of the \ 
 Chowan, herrings are often used as manure, when purchasers can- ,] 
 not take oif the quantities supplied by the seines. A herring is i 
 buried under each corn-hill, and fine crops are thus made as far as 
 this singular mode of manuring is extended. But whatever benefits * 
 have been thus derived, the sense of smelling, as well as the known '' 
 chemical products of the process of animal putrefaction, make it I 
 certain that nine-tenths of all this rich manure, when so applied, 
 must be wasted in the air. If those who fortunately possess this | 
 supply of animal manure would cause the fermentation to take I 
 place and be completely mixed with and enclosed by marl, in pits j 
 of suitable size, they would increase prodigiously both the amount | 
 and permanency of their acting animal manure, besides obtaining 1 
 the benefit of the calcareous earth mixed with it.* j 
 
 But without regarding such uncommon or abundant sources for i 
 supplying animal matter, every farmer may considerably increase 
 his stock of putrescent manure by using the preservative power of I 
 inarl ; and all the substances that might be so saved are not only j 
 now lost to the land, but serve to contaminate the air while putre- 
 fying, and perhaps to engender disease. The last consideration is 
 of most importance to towns, though worthy of attention every- , 
 where. "Whoever will make the trial will be surprised to find how ,' 
 much putrescent matter may be collected from the dwelling-house, 
 kitchen, and laundry of a family ; and which if accumulated | 
 (without mixture with calcareous earth), would soon become so 
 offensive as to show the necessity of putting an end to the practice. 
 Yet it must be admitted that when all such matters are scattered i 
 about (as is usual both in town and country), over an extended 1 
 surface, the same putrefaction must ensue, and the same noxious I 
 effluvia be evolved, though not enough concentrated to be very 
 offensive, or even always perceptible. The same amount is in- 
 
 * I have since heard that this mode of manuring, but Avith the garbage 
 of the herrings, is a general and very extensive practice on the borders of 
 Albemarle Sound. By the enormous seines there used, herrings are taken 
 in numbers that seem scarcely credible ; and all the fish arc trimmed and 
 salted at the fisheries. This great and regular supply of garbage used as 
 manure, is of great value, even with all the usual waste in the air ; but 
 would be of teu-fold value if treated as recommended above. 
 
FILTH OF TOWNS. 271 
 
 haled — but in a very diluted state, and in small thougli incessantly 
 repeated doses. But if mild calcareous earth in any form (and 
 fossil shells or marl present much the cheapest) is used to cover 
 and mix with the putrescent matters so collected, they will be pre- 
 vented from discharging offensive effluvia, and preserved to enrich 
 the soil. A malignant and ever acting enemy will be converted to 
 a friend and benefactor. 
 
 The usual dispersion and waste of such putrescent and escre- 
 mentitious matters about a farm-house, though a considerable loss 
 to agriculture, may take place without being very offensive to the 
 senses, or manifestly injurious to health. But the case is widely 
 different in towns. There, unless great care is continually used to 
 remove or destroy filth of every kind, it soon becomes offensive, if 
 not pestilential. During the summer of 1832, when that most 
 horrible scourge of the human race, the Asiatic cholera, was deso- 
 lating some of the towns of the United States, and all were es- 
 pected to be visited by its fatal ravages, great and unusual exertions 
 were eveiywhere used to remove and prevent the accumulation of 
 filth, which, if allowed to remain, it was supposed would invite the 
 approach, and aid the effects of the pestilence. The efforts made 
 for that purpose served to show what a vast amount of putrescent 
 matter existed in every town, and which was so rapidly reproduced, 
 that its complete riddance was impossible. Immense quantities of 
 the richest manures, or materials for them, were washed away into 
 the rivers — caustic lime was used to destroy them — and the chlo- 
 ride of linle to decompose the offensive products of their fermenta- 
 tion, when that process had already occurred. All this amount of 
 labour and expense was directed to the complete destruction of what 
 might have given fertility to many adjacent fields — ^and yet served 
 to cleanse the towns but imperfectly, and for a very short time. 
 Yet the object in view might have been better attained by the pre- 
 vious adoption of the proper means for preserving these putrescent 
 matters, than by destroying them. These means would be to mix 
 or cover all accumulations of such matters with rich marl (which 
 would be the better for the purpose if its shells were in small par- 
 ticles), and in such quantity as the effect would show to be suffi- 
 cient. But much the greater part of the filth of a town is not, and 
 cannot be accumulated ; and from being dispersed is the most diffi- 
 cult to remove, and is probably the most noxious in its usual course 
 of fermentation. This would be guarded against by covering 
 thickly with marl the floor of every cellar and stable, back-yard 
 and stable lot. Every other vacant space should be lightly covered. 
 The same course pursued on the gardens and other cultivated 
 grounds would be sufficiently compensated by their increased pro- 
 ducts that would be obtained. But independent of that considera- 
 tion, the manures there applied would be prevented from escaping 
 
272 MARL FOR CLEANSING- TOWNS. 
 
 into tlie air ; and being wholly retained hj the soil, much smaller 
 applications would serve. The level streets ought also to be sprin- 
 kled with marl, and as often as circumstances might require. The 
 various putrescent matters usually left in the streets of a town 
 alone serve to make the dirt scraped from them a valuable manure; 
 for the principal part of the bulk of street dirt is composed merely 
 of the barren clay brought in upon the wheels of wagons from the 
 country roads. Such a cover of calcareous earth would be the 
 most cifectual absorbent and preserver of putrescent matter, as well 
 as the cheapest mode of keeping a town always clean. There 
 would be less noxious or offensive effluvia than is generated in 
 spite of all the ordinary means of prevention ; and by scraping up 
 and removing the marl after it had combined with and secured 
 enough of putrescent matter, a compost would be obtained for the 
 use of the surrovinding country, so rich and so abundant, that its 
 use would repay a large part, if not the whole of the expense 
 incurred in its production. Probably one covering of marl for 
 each year would serve for most yards, cellars, &c. ; but if re- 
 quired ofteuer, it would only prove the necessity for the opera- 
 tion, and show the greater value in the results. The compost that 
 might be obtained from spaces equal to 500 acres, in a populous 
 town, would durably enrich thrice as many acres of the adjacent 
 country; and after twenty years of such a course, the surrounding 
 farms might be capable of returning to the town a ten-fold in- 
 creased surplus product. After the qualities and value of the 
 manure so formed were properly appreciated, it would be used for 
 fiirms that would be out of the reach of all other calcareous manures. 
 Carts bringing country produce to market might with profit carry 
 back loads of this compost eight or ten miles. The annual supply 
 that the country might be furnished with would produce very dif- 
 ferent effects from the putrescent and fleeting manure now obtained 
 from the town stables. Of the little durable benefit heretofore 
 derived from such means, the appearance of the country offers 
 sufficient testimony. At three miles distance from some of the 
 principal towns in Virginia, more than half the cultivated land is 
 too poor to yield any farming profit. The surplus grain sent to 
 market is very inconsiderable — and the coarse hay from the wet 
 natural meadows can only be sold to tavern-keepers, or those who 
 feed horses belonging to other persons — and to whom that hay is 
 the most desirable that is least likely to be eaten. 
 
 But even if the waste and destruction of manure in towns were 
 counted as nothing, and the preservation of health by keeping the 
 air pure were the only object sought, still calcareous earth, as pre- 
 sented by rich marl, would serve the purpose far better than 
 quick-lime. It is true that the latter substance acts powerfully in 
 decomposing putrescent animal matter^ and destroys its texture 
 
INCONVENIENCES OF LIME. 273 
 
 and qualities so completely, that the operation is commonly and 
 expressively called "burning" the substances acted on. But to 
 use a sufficient quantity of quick-lime to meet and decompose all 
 putrescent animal matters in a town would be intolerably expen- 
 sive, and still more objectionable in other respects. If a cover of j 
 dry quick-lime in powder was spread over all the surfaces requiring 
 it for this purpose, the town would be unfit to live in ; and the 
 nuisance would be scarcely less, when rain had changed the suffo- 
 catiug dust to an adhesive mortar. Woollen clothing, carpets, and 
 even living flesh, would be continually sustaining injury from the 
 contact. No such objections would attend the use of mild calca- 
 reous earth; and this could be obtained probably for less than one- 
 third of the cost of quick-lime, supposing an equal quantity of 
 pure calcareous matter to be obtained in each case. At this time 
 the richest marl on James river may be obtained at merely the cost 
 of digging, and its carriage by water, which, if undertaken on a 
 large scale, could not exceed, and probably would not equal, two 
 cents the bushel.* 
 
 The putrescent animal matters that would be preserved and ren- 
 dered innoxious by the general marling of the site of a town, would 
 be mostly such are so dispersed and imperceptible that they would 
 otherwise be entirely lost. But all such as are usually saved in 
 part would be doubled in quantity and value, and deprived of their 
 offensive and noxious qualities, by being kept mixed with calcareous 
 earth. The importance of this plan being adopted with the pro- 
 ducts of privies, &c., is still greater in town than country. The 
 various matters so collected and combined should never be applied 
 to the soil alone, as the salt derived from the kitchen, and the pot- 
 ash and soap from the laundry, might be injurious in so concAi- 
 trated a form. When the pit for receiving this compound is 
 emptied, the contents should be spread over other and weaker 
 manure before being applied to the field. 
 
 Towns might furnish many other kinds of rich manure, which 
 are now lost entirely. Some of these particularly require the aid 
 of calcareous earth to be secured from destruction by putrefaction, 
 and others, though not putrescent, are equally wasted. The blood 
 of slaughtered animals, and the waste and rejected articles of wool, 
 hair, feathers, skin, horn, and bones, all are manures of great rich- 
 ness. We not only give the flesh of dead animals to infect the 
 air, instead of using it to fertilize the land, but their bones, which 
 might be so easily saved, are as completely thrown away. Bones 
 arc composed of phosphate of lime and gelatinous animal matter, 
 
 * Such was tlie case in 1833 when this jjart was first published; but 
 now a half cent the bushel is the usual price charged for the best marl, as 
 it lies in the river banks. 
 
274 CALX BETTER THAN QUICK-LIME. 
 
 and, wlien crushed, form one of the richest and most convenient 
 manures in the world. They are shipped in quantities from the 
 continent of Europe, and latterly even from this country, to be sold 
 for manure in England. The fields of battle have been gleaned, 
 and their shallow graves emptied for this purpose : and the bones 
 of the ten thousand British heroes, who fell on the field of Water- 
 loo, are now performing the less glorious, but more useful purpose 
 of producing, as manure, broad for their brothers at home. 
 
 There prevails a vulgar but useful superstition, that there ia 
 •'bad luck" in throwing into the fire anything, however small may 
 be its amount or value, that can serve for the food of any living 
 animal. It is a pity that the same belief does not extend to every 
 thing that as manure can serve to feed growing plants — and that 
 even the parings of nails and clippings of beards are not saved (as 
 in China) for this purpose. However small each particular source 
 might be, the amount of all the manures that might be saved, and 
 which are now wasted, would add incalculably to the usual means 
 for fertilization. Human excrement, which is scarcely used at all 
 in this country, is stated to be even richer than that of birds ; and 
 if all the enriching matters were preserved that are derived not 
 only from the food, but from all the habits of man, there can be no 
 question but that a town of ten thousand inhabitants, from those 
 sources alone, might enrich more land than can be done from as 
 many cattle. 
 
 The opinions here presented are principally founded on the the- 
 ory of the operation of calcareous manures, as maintained in the 
 foregoing part of this Essay (Chap. YIII.), but they are also sus- 
 tained to considerable extent by facts and experience. The most 
 undeniable practical proof of one of my positions is the power of 
 a cover of marl to prevent the escape of all offensive effluvia from 
 the most putrescent animal matters. Of this power I have long 
 made use, and know it to be more effectual than quick-lime, even 
 if the destructive action of the latter were' not objectionable. 
 Quick-lime forms new combinations with putrescent substances, 
 and, in thus combining, throws ofi" effluvia, which, though difl"erent 
 from the products of putrescent matter alone, are still disagreeable 
 and offensive. Mild lime on the contrary absorbs and preserves 
 everything — or at least prevents the escape of any ofi'ensive odour 
 being perceived. Whether putrescent vegetable matter is acted on 
 in like manner by calcareous earth cannot be as well tested by our 
 senses, and therefore the proof is less satisfactory. But if it is 
 true that calcareous earth acts by combining putrescent matters 
 with the soil, and thus preventing their loss (as I have endeavoured 
 to prove in Chapter YIII.), it must follow that, to the extent of 
 fcuoh combination, the formation and escape of all volatile products 
 of putrefaction will also be prevented. 
 
EFFECTS OF CALXIXG ON HEALTH. 275 
 
 But it will be considered that the most important inquiry remains 
 to be answered, to wit : Has the application of calcareous manures 
 been found in practice decidedly beneficial to the health of the 
 residents on the land ? I answer, that long experience, and the 
 collection and comparison of numerous facts derived from various 
 sources, will be required to remove all doubts from this question ; 
 and it would be presumptuous in any individual to offer as sufficient 
 proof, the experience of only ten or twelve years on any one farm. 
 But while admitting the insufficiency of such testimony, I assert 
 that, so far [to 1S33], my experience decidedly supports my posi- 
 tion. My principal farm [Coggins], until within some four or five 
 years, was subject in a remarkable degree to the common mild 
 autumnal diseases of our low country. Whether it is owing to 
 marling, or other unknown causes, these bilious diseases have since 
 become comparatively very rare. Neither does my opinion in this 
 respect, nor the facts that have occurred on my farm, stand alone. 
 Many other persons are equally convinced of this change on other 
 land as well as on mine. But in most cases where I have made 
 inquiries as to such results, nothing decisive had then been ob- 
 served. The hope that other persons may be induced to observe 
 and report/ facts bearing on this important point, has in part caused 
 the first appearance of these crude and perhaps premature views. 
 
 Even if my opinions and reasonings should appear sound, I am 
 aware that the practical application is not to be looked for soon ; 
 and that the scheme of using marl in towns is more likely to be 
 met by ridicule, than to receive a serious and attentive examina- 
 tion. Xotwithstanding this anticipation, and however hopeless of 
 making converts, either of individuals or of corporate bodies, I will 
 offer a few concluding remarks on the most obvious objections to, 
 and benefits of the plan. The objections will all be resolved into 
 one — namely, the expense to be encountered. The expense certainly 
 would be considerable ; but it would be amply compensated by the 
 gains and benefits. In the first place, the general use of marl as 
 proposed, for towns, would serve to insure cleanliness, and purity 
 of the air, more than all the labours of their boards of health and 
 their scavengers, even when acting under the dread of approaching 
 pestilence. Secondly, the putrescent manures produced in towns, 
 by being merely preserved from waste, would be increased ten-fold 
 in quantity and value. Thirdly, all existing nuisances and abomi- 
 nations of filth would be at an end ; and the beautiful city of 
 Kichmond (for example) would not give offence to our nostrils, 
 almost as often as it offers gratification to our eyes. Lastly, the 
 marl (or mild lime), after being used until saturated with putres- 
 cent matter, would retain all its first value as calcareous earth, 
 and be well worth purchasing and removing to the adjacent farms, 
 independent of the enriching mamue with which it would be^ 
 
276 EFFECTS OF CALXING ON HEALTH. 
 
 loaded. If tlicso advantages can indeed be obtained, they would 
 be cheaply bought at any price necessary to be encountered for the 
 purpose. 
 
 The foregoing part of this chapter was first published in the 
 Farmers' Register (for July, 1833), as supplementary to the pre- 
 vious edition of this Essay. That publication drew some attention 
 from others to the subject, and served to elicit many important 
 facts, of which I had been before altogether ignorant, in support 
 of the operation of calcareous earth in arresting the effects of 
 malaria, and the usual autumnal diseases of the Southern States and 
 other similar regions. These facts, together with the result of my 
 own personal experience, extended through two more autumns (or 
 sickly seasons, as commonly called here and farther south), since 
 the first publication of these views, will now be submitted. Most 
 of the facts derived from other persons relate to one region, the 
 "rotten lime-stone lands" of southern Alabama; but that region is 
 extensive, is of remarkable and well known character and pecu- 
 liarities, and the evidence comes from various sources, and is full, 
 and consistent in purport. The facts will be here presented in an 
 abridged form. The several more full communications, from which 
 they are drawn, may be referred to in the Farmers' Register, vol. 
 I., pp. 152, 214, and 277. 
 
 The first fact brought out was that, in the town of Mobile, near 
 the Gulf of Mexico, the streets actually had been paved or covered 
 with shells — thus presenting precisely such a case as I recom- 
 mended, though not with any view to promoting cleanliness or 
 health. The shells had been used merely as a substitute for stones, 
 which could not be so cheaply obtained. Nor had the greatly im- 
 proved healthiness of -Mobile, since the streets were so covered 
 (of which there is the most ample and undoubted testimony), been 
 attributed to that cause, until the publication of the foregoing 
 opinions served to connect them as cause and eff"cct. This can 
 scarcely be doubted by those who will admit the theory of the 
 action of calcareous earth ; and the remarkable change from un- 
 hcalthiness in Mobile, to comparative healthiness, is a very strong 
 exemplification of the truth of the theory. But it is not strange, 
 when so many other causes might (and probably did) operate to 
 arrest disease, that none should have considered the chemical 
 operation of the shelly pavement as one of them, and still less as 
 the one by far the most important. The paving of streets (with 
 any material), draining and filling up wet places, substituting for 
 rotting wooden buildings new ones of brick and stone — and espe- 
 cially the operation of destructive and extensive fires — all, we 
 know, operate (and particularly the last) to improve the healthi- 
 ness of towns; and all these operated at Mobile, as well as shell- 
 ing the streets. Neither was the shelling so ordered as to produce 
 
EFFECTS OF BURNINGS IN TOWNS. 277 
 
 its best effect for health. The streets, alleys, and many yards and 
 small vacant lots were covered, and so far the formation and evolv- 
 ing of pestilential effluvia were lessened. But as this was not the 
 object in view, and indeed the chemical action of shells was not 
 thought of, the process was incomplete, and must necessarily have 
 been less effectual than it might have been made. The shelling 
 ought to have been extended to every open spot where filth could 
 accumulate — to every back-yard, in every cellar, and made the 
 material of the floor of every stable, and every other building of 
 which the floor would otherwise be of common earth. In addition, 
 after a suSicient lapse of time to saturate with putrescent matters 
 the upper part of the calcareous layer, and thus to make it a very 
 rich compound, there should have been a partial or total removal 
 of the mass, and a new coating of shells laid down. The value of 
 the old material, as manure, would probably go far towards paying 
 for this renewal. If it is not so renewed, the calcareous matter 
 cannot combine with more than a certain amount of putrescent 
 matters ; and, after being so saturated, can have no further effect 
 in saving such matters for use, or preventing them from having 
 their usual evil course. 
 
 The burning of towns is well known to bo a cause of the healthi- 
 ness of the places being greatly improved, and that such effect 
 continues after as many buildings, or more, have replaced those 
 destroyed by fire. Indeed this improvement is considered so per- 
 manent, as well as considerable, that ^e most sweeping and de- 
 structive conflagrations of some of our southern towns have been 
 afterwards acknowledged to have proved a gain and a blessing. 
 The principal and immediate mode of operation of this universally 
 acknowledged cause is usually supposed to be the total destruction, 
 -by the fire, of all filth and putrescent matters ; and in a less de- 
 gree, and more gradually, by afterwards substituting brick and 
 stone for wooden buildings, which are always in a more or less de- 
 cayed state. But though these reasons have served heretofore to 
 satisfy all, as to the beneficial consequences of fires, surely they 
 are altogether inadequate as causes for such great and durable 
 effects. The mere destruction of all putrescent matters in a town, 
 at any one time, would certainly leave a clear atmosphere, and give 
 strong assurance of health being improved for a short time after- 
 wards. But these matters would be replaced probably in the course 
 of a few months, by the residence of as many inhabitants, and the 
 continuance of the same general habits ; and most certainly this 
 cause would lose all its operation by the time the town was rebuilt. 
 But there is one operation produced by the burning of a town, 
 which is far more powerful — which in fact is indirectly the very 
 practice which has been advocated — and the effect of which, if 
 given its duo weight, furnishes proof of the theory set forth, by 
 24 
 
278 HEALTH ON THE CALCAREOUS PRAIRIES. 
 
 the experience of every iinliealtliy town wliieli has sufFercd much 
 from fire. If a fair estimate is made of tlie immense quantity of 
 mild calcareous earth which is contained in the plastering and 
 brick-work of even the wooden dwelling-houses of a town, and still 
 more of those built of masonry, it must be admitted that all tliat 
 material being separated, broken down (soon or late), and spread, by 
 the burning of the houses and pulling down their ruins, is enough 
 to give a very heavy cover of calcareous earth to the whole space 
 of land burnt over. It is to this operation, in a far greater degree 
 than to all others, that I attribute the beneficial effects to health 
 of the burning of towns. 
 
 I proceed to the fiicts derived from the extensive body of prairie 
 lands in Alabama which rest on a substratum of soft lime-stone, or 
 rich indurated clay marl. It was from these remarkable soils that 
 the specimens were obtained which were described at pp. 60, 67. 
 Some of these, indeed all that have been examined by chemical 
 tests, of the high and dry prairie lands, contain calcareous earth 
 in larger proportions than any soils of considerable extent in the 
 United States that I have seen or tested. The specimens not con- 
 taining free calcareous earth are of the class of neutral soils ; and 
 the calcareous earth, which doubtless they formerly contained, and 
 from which they derived their peculiar and valuable qualities, may 
 be supposed only to be concealed by the accumulation of vegetable 
 matter, according to the general views submitted in Chapter VII. 
 
 The more full descriptions of the soils of this remarkable and 
 extensive region before referred to render it unnecessary to enlarge 
 much here. It will be sufficient to sum up concisely the facts there 
 exhibited, and which agree with various other private accounts 
 which have been received from undoubted sources of information. 
 The deductions from these facts, and their accordance with the 
 theory of the operation of calcareous matter, are matters of rea- 
 soning, and, as such, are submitted to the consideration and judg- 
 ment of readers. 
 
 The soil of these prairie lands is very rich, except the spots 
 where the soft lime-stone rises to the surface, and makes the calca- 
 reous ingredient excessive. In the specimen formerly mentioned, 
 the pure calcareous matter formed 59 parts in the 100 of thia 
 '' bald prairie" land. The soil generally has so little of sand, that 
 nothing but the calcareous matter which enters so largely into its 
 composition prevents it being so stiff and intractable, that its tillage 
 would be almost impracticable. Yet it is friable and light when dry, 
 and easy to till. But the suj)erfluous rain-water cannot sink and 
 pass off, as in sandy or other pervious lands, but is held in thia 
 close and highly absorbent soil, which throughout winter is thereby 
 made a deep mire, unfit to prepare for tillage, and scarcely practi- 
 cable to travel over, This water-holding quality of the soil; and 
 
EFFECTS OP CxVLXING ON HEALTH. 279 
 
 the nearness to the surface of the hard and impervious marly sub- 
 stratum, deprive the country of natural springs and running 
 streams ; and before the important discovery was made that pure 
 water might be obtained by boring from 300 to ■ 700 feet through 
 the solid calcareous rock, the inhabitants used the stagnant rain- 
 water collected in pits, which was very far from being either pure 
 or palatable. Under all these circumstances, added to the rank 
 herbage of .millions of acres annually dying and decomposing un- 
 der a southern sun, it might have been counted on, as almost cer- 
 tain, that such a country would have proved very unhealthy. Yet 
 the reverse is the fact, and in a remarkable degree. The healthi- 
 ness of this region is so connected with and limited by the calca- 
 reous substratum and soil, that it could not escape observation ; 
 and they have been considered as cause and effect by those who 
 had no theory to support, and who did not spend a thought upon 
 the mode in which was produced the important result they so 
 readily admitted. Their testimony therefore is in this respect the 
 more valuable, because it cannot be suspected of having any such 
 bias. 
 
 To the time when this last publication is made (1842) there has 
 been no reason to doubt the actual facts of autumnal diseases (the 
 effects of malaria) being greatly lessened by even the partial use 
 of marling; nor the inference that they would almost cease to 
 occur (if no mill-ponds and undrained lands remained), if all the 
 surface of a considerable extent of counti-y were made calcareous, 
 and all rapidly putrescent and otherwise offensive matter were pre- 
 served and kept harmless by being combined with marl, applied 
 from time to time as required. But it should be remembered that, 
 as yet, rapid and extensive as has been the progress of marling in 
 A^irginia, there has been no instance of the greater part of any 
 whole neighbourhood of so much as a few miles in extent being 
 marled; nor even of all the surface of any one farm; and that, 
 therefore, we have no means of judging by experience of the full 
 measure of benefit to be derived from such a general change of the 
 character of the soil. The most that has yet been done anywhere is 
 the marling of all the cultivated and arable land ; leaving unmarled, 
 and as much as ever the abundant sources of vegetable decompo- 
 sition and of disease, all the wood-land, steep hill-sides, and the wet 
 bottoms. Now, as the remaining wood-lands are generally among 
 the poorest of our soils, that is, (according to the theory maintain- 
 ed), soils incapable of combining with and retaining the products 
 of decomposition — and as they are covered annually with leaves, 
 which in time all rot and their gaseous products finally pass oft' into 
 the air — it follows, that the lands so left must be among the most 
 fruitful of malaria. It is obvious that the remedy is but partially 
 and incfiiciently in operation, so long as from one-third to one-half 
 
280 EFFECTS OF CALXING' ON HEALTH. 
 
 of every farm is left unmarled, and as free as ever to evolve tlie 
 agent of disease. So sure does this opinion scera to me, that I 
 have commenced acting on it, by marling the wood-land that is not 
 designed to be cleared for cultivation — and shall continue, as more 
 necessary labours permit, to do so, until not an acre of the farm 
 is left without being changed in character by calcareous earth. 
 
 It is proper to add, as an opinion founded on but limited expe- 
 rience as yet, that though the cases of sickness on Coggins Point 
 farm have certainly diminished very greatly — there- not being one 
 case of late years of bilious disease, where there were twenty 
 formerly — still that the diseases seem to have changed in kind, 
 and to have increased in severity and danger. Formerly, there 
 was almost no sickness except from ague and fever (or, very rarely, 
 a case of mild bilious fever), from which, though few persons 
 escaped through the autumn, and some suffered several relapses, 
 the attacks were rarely dangerous, and required little skill, and 
 but a few days to cure, for that time. Bad as was this state of 
 things, it seemed that the ague and fever acted as a safety-valve 
 to the system, and while it seldom permitted the enjoyment of long- 
 continued robust health, it prevented the occurrence of more 
 dangerous or fatal diseases, such as are the most common among 
 the fewer diseases of what are deemed healthy regions. The fewer 
 diseases of my adult negroes for the last twelve or thirteen years 
 have been of a more inflammatory kind, and are not confined to 
 autumn ; and there have been certainly more severe and fatal dis- 
 eases, and more that required medical aid, than formerly, when 
 there was so much more of sickness of one kind, and confined to 
 one season. In short, it seems that the diseases are no longer (or 
 but in few cases) those of the low country and of a bilious climate, 
 but are more like those of the upper country, which, though 
 occurring but rarely, are generally of a more serious nature. The 
 facts on which this particular opinion has been formed, are still too 
 few, and of too short continuance, to attach to them much import- 
 ance ; and even if they were less doubtful, I have not the medical 
 knowledge to trace these new effects back to their causes. Still, it 
 is deemed due to candour, and to the desire for a fair and full in- 
 vestigation of the subject, even if making against my own views, 
 that these opinions should be stated. There is no other subject, 
 than this, taken in general, which more deserves and requires in- 
 vestigation ; and in the present inchoate state of the discussion, 
 the expression of even erroneous opinions will not be useless, if it 
 should serve to elicit more full or correct ones from other sources. 
 
 Nothing better than this one subject deserves investigation by 
 medical men, acting under the direction of government. The ma- 
 terials for information are now abundant, in the experience and 
 observation of the numerous farmers who have maiied or limed 
 
EFrECTS OP CALXING ON HEALTH. 281 
 
 their lands long enough to judge of the effects on health ; and 
 whether upon true or false grounds, the opinion among such per- 
 sons seems now (1842) almost universal (so far as I have heard 
 opinions expressed), that the prevalence of autumnal diseases, the 
 product of malaria, has been invariably and manifestly lessened 
 since the lands were in part marled or limed. My individual ex- 
 perience and observations on this point, now of nine years' more 
 extent than when the first fruits thereof were stated in a foregoing 
 part of this chapter, concur with the more general and loose 
 information derived from others, in confirming my position. It 
 sometimes happens that the very fact of an opinion being univer- 
 sally admitted prevents the obtaining such proofs of its truth as 
 would certainly have been ready, if the opinion had been questioned 
 and denied by many sceptics. And such is the state of the pro- 
 position now under consideration. Even in the few years which 
 have passed since I first advanced the opinion that the use of cal- 
 careous manures served to improve health, that opinion has become 
 so general, and is deemed so certain and unquestionable, by those 
 persons who have used those manures, that but few facts can be 
 learned of them sufiiciently exact to serve as proofs — because no 
 person has deemed it necessary to collect and preserve proofs of 
 what none doubted. When asking for such proofs, as I have often 
 done, of cultivators and residents in various parts of the marl 
 region, I have rarely obtained any, except new declarations, from 
 every person interrogated, of concurrence and entire faith in the 
 general opinion that marling or liming had served greatly to abate 
 the prevalence of autumnal diseases. Such general belief and con- 
 fidence in an opinion so recently promulgated, cannot be altogether 
 founded on error. (1842.) 
 
 When my opinions of the beneficial operation of calcareous earth 
 in soil, or mixed with putrescent matter, in destroying or disarming 
 the sources of disease, were first published, and until after the 
 second publication of the same in 1835, I had no knowledge that 
 similar grounds had been taken by any other person. But since, 
 in the recent publications of a French writer, M. Puvis, I have 
 found the same general opinion expressed, and many important 
 facts given in confirmation. However, while I gladly accept the 
 important aid of M. Puvis's facts, as proof, I do not admit the cor- 
 rectness of his reasoning thereupon. Some of the former will be 
 quoted in the following passages. For his full views, see the 
 translations of his essays " On Lime as Manure," and " On Marl," 
 both contained in vol. iii. of the Farmers' Register. 
 
 " The results of marling may be considered in a point of view 
 
 more elevated, and still more important than that of the fertility 
 
 which it gives to the soil; they may perhaps have much influence 
 
 on the healthiness of a country where it becomes a general practice. 
 
 24* 
 
282 EFFECTS OF CALX ON HEALTH IN FRANCE. 
 
 "Although it may not have been yet uttered by others, this 
 opinion appears founded on strong probabilities, on strong analogies 
 and precise facts, all of which appear to give it a sufficient cer- 
 tainty. 
 
 " It is known that the calcareous principle is one of the most 
 powerful agents to resist putrefaction. It is employed to make 
 healthy places inhabited by men and animals, in which sickness or 
 contagion is feared ; it serves to neutralize the emanations of dead 
 bodies undergoing putrefaction ; it destroys the deleterious exhala- 
 tions which escape from privies, and which sometimes cause the 
 death of those who are emj^loyed to cleanse them. 
 
 " It even seems that calcareous countries are unhealthy only 
 when they are interspersed with marshes, or when some causes, 
 foreign to the soil and climate, determine the unhealthiness, as in 
 countries on the borders of the sea, where the flowing of the tide 
 and the mingling of salt and fresh waters infect the air, by the dele- 
 terious emanations of their combination. This cause of unhealthi- 
 ness is regarded as a certain fact ; for salubrity is generally seen to 
 appear whenever this mixture of waters is prevented. 
 
 " In the valleys of rivers bordered by calcareous mountains, 
 which enclose unhealthy countries in their interior, insalubrity 
 commences there only as the calcareous soil, which is attached to 
 the mountain, gives place to silicious soil. In the same plain, 
 and far from a mountain, salubrity is seen to diminish in the same 
 proportion that the calcareous soil of the surface docs ; and the 
 communes of Bresse, which have an abundance of marly or calca- 
 reous soils, are much more remarkable for their salubrity than those 
 on the white lands (terrain llanc*). While the ponds of Dombe, 
 which are on the silicious soil, appear to be one of the greatest 
 causes of unhealthiuess, those of Bresse, which are on calcareous 
 lands, do not show such effects in the country where they are found; 
 so, likewise, the ponds of the country situated between the Veyle 
 and the lleyssouze, to the north-west of Bourg, which arc generally 
 on calcareous soil, do not appear to injure the healthiness of the 
 country in any manner. 
 
 " For the support of this system, we will also cite the ponds of 
 Berri on calcareous soil, whose emanations have nothing unhealthy ; 
 the laying dry of the ponds of Parra^ay, in the canton of Lignicres, 
 has added nothing to the healthiness of a calcareous country na- 
 
 * The reader of M. Puvis's essays on lime and marl, wliicli were inserted 
 in vol. iii. of Farmers' Register, may remember that this provincial term 
 and others {plateaux argiUo-silicieux, &c.) were there used to designate a 
 peculiar kind of soil, destitute of calcareous matter, stiff, intractable, and 
 poor — and which seems precisely of the character of the poor ridge lauds 
 of lower Virginia, to which calcareous manures are so peculiarly adapted. 
 — Trandaior. 
 
EFFECTS ON HEALTH IN FRANCE AND ENGLAND. 283 
 
 turallj healthy. And in the same canton, the pond of Villiers, 
 which is said to be seven leagues in circumference, does not cause 
 diseases on its borders. Besides, during the month of August, the 
 water of the ponds on calcareous soil does not become blackish, 
 as often happens in silicious ponds. The water would then be 
 made wholesome by the calcareous principle, in the same way as 
 their emanations. 
 
 " In fine, Dombe and Sologne, and a number of other countries, 
 are unhealthy, and subject to intermittent fevers, without being 
 marshy ; but their soil is likewise silicious, and the land moist. 
 Puisaye, and a part of Bresse, in similar land, which contain little 
 or no calcareous soil, have also many autumnal fevers." — Transla- 
 tion from " Essai sur la Marne."* 
 
 In addition to these opinions of Puvis, and his facts in regard to 
 France, I may add the later testimony of two other eminent agri- 
 cultural writers, whose information may be inferred to have been 
 derived from the experience of England and Scotland. In a small 
 pamphlet written by Sir John Sinclair, and dated 1833, on the 
 means for preventing the ill effects of malaria,'\ he names as 
 among the most important the use of calcareous manures. " The 
 eifect of burnt limestone," he adds, "in improving the quality of 
 the soil is hardly to be credited. It either absorbs any noxious 
 matter, or annihilates any deleterious properties it possesses ; and 
 it may be relied upon as an established fact ' that a soil full of 
 calcareotis onatter never produces an umcholesome atmosphere.'" 
 And again : " The introduction of immense quantities of calcareous 
 matter into the soil not only contributes to its improvement, but 
 is the best means of preventing malaria." 
 
 Professor Johnston, still more recently, speaks as follows : " The 
 liming of the land is the harbinger of health as well as of abun- 
 dance. It salubrifies no less than it enriches. . . . The lime 
 arrests the noxious effluvia which tend to rise more or less from 
 every soil at certain seasons of the year, decomposes them, or causes 
 their elements to assume new forms of chemical combination, in 
 which they no longer exert the same injurious influence on animal 
 life." — Lectures, &c., pp. 392-3. 
 
 Thus there is now good evidence and high authority for this 
 opinion, which I at first advanced with much hesitation and fear ; 
 and which then met with distrust or incredulity with almost all 
 
 * This -work was published in Paris in 1826. The first known (and pro- 
 bably still the only) copy brought to America, was in ISoO, by my order, 
 made soon after seeing M. Puvis's essays on lime and marl iu the "Annates 
 d^ Agriculture Fran^aise," both of which I translated and published in the 
 Farmers' Pvegister, vol. iii. 
 
 t This pamphlet was republished in the Farmers' Registci-, vol. i., p. 
 550. 
 
284 NATURAL CONDITIONS OF MARL BEDS. 
 
 who had not experience or information of the sanitary influence of 
 calcareous manures. 
 
 But however strong the conviction of these authors of such 
 effects of calcareous manures, they offer no satisfactory explanation 
 of the manner in which the effects are produced. But -whether 
 lime, in soil, exerts its health-preserving power by " arresting the 
 noxious effluvia which tend to rise from every soil," &c. — or by 
 absorbing noxious matter, or annihilating any deleterious properties 
 it possesses" — or, according to my previously expressed doctrine, 
 by the power of lime (calx) to combine with the first results of 
 putrefaction, and so fix them in the soil, there to serve only as food 
 for plants — the end is the same, of converting to the purpose of 
 fertilization and production what would otherwise escape into the 
 air in the form of pestilential gases. 
 
 The important facts, recently made known by Dr. "Wight, as 
 stated in a previous chapter, that the calxing of soil causes the 
 plants gi'own thereon to absorb from the atmosphere much in- 
 creased quantities of carbonic acid, and to evolve proportionately 
 increased quantities of oxygen gas, serve to add greatly to the be- 
 fore supposed sanitary operation 'of calxing land. Both the as- 
 serted actions, co-operating, are abundant and satisfactory causes for 
 the beneficial effects to health ; and of which effects there can be 
 no longer room to doubt, seeing the testimony adduced from France 
 and England, in addition to all that I had before offered. 
 
 CHAPTER XXVI. 
 
 THE EXCAVATION OF MARL PI1*S, AND CARRYING OUT AND APPLY- 
 ING OF MARL. 
 
 The natural features of marl beds, and their exposures, are dif- 
 ferent at almost every locality ; and therefore no one manner of 
 working will suit precisely for different diggings. Still, all the marl 
 beds of Virginia may be classed under three heads, in reference to 
 the excavation and removal of the marl. 
 
 I. The first class is of marl exposed (or " cropping out") high 
 up on hill-sides, with but little overlying earth to remove for large 
 excavations of the marl below — the marl and the adjacent ground 
 dry and free from springs — and the proper sites for roads, leading 
 to the fields, either descending, or nearly level, or with not much 
 ascent. Marl so lying is often of the richest kind, containing from 
 GO to more than 80 per cent, of pure shelly matter, and that mostly 
 
DRY AND WET MARL BEDS IN HILLY LANDS. 285 
 
 finely djvided. Many of these richest and also almost easily worked 
 bodies of marl are in the middle range across the rivers and the 
 marl region of Virginia; for example, in the counties of Nanse- 
 mond, Isle of Wight, Surry, James City, York, New Kent, and 
 the lower part of King AVilliara. Under these very favourable cir- 
 cumstances, special directions for working such marls would be 
 superfluous. The labours required are as simple, and almost as 
 cheap, as the digging and carting away of earth from a hill-side to 
 construct a mill-dam. 
 
 II. The second class of exposures and diggings is usually of much 
 poorer marl, and attended with much more difficulty and cost than 
 the preceding. In high lands, cut through by deep ravines, or 
 narrow valleys, the natural " out-croppings" of the marl are usually 
 low down the sides, or at the bottoms of steep hill-sides, the marl 
 often wet from springs oozing over the top, and also from water 
 percolating slowly through the mass of marl. The lower adjacent 
 ground is also wet, by springs or streams. The overlying earth is 
 very thick, and costly to remove ; and a steep or a long-ascending 
 road is required to draw the marl to the higher lands where it is to 
 be applied. 
 
 In hilly lands, the bed of marl usually "crops out" on the 
 swells, or couvex curves of the hill-sides, and thus is naturally ex- 
 posed to view. If this is at a considerable elevation above the bot- 
 tom of the ravine or narrow valley which is usually at the foot of 
 the hill, the marl will generally be dry. But its being dry will 
 depend on some one of the following conditions : 1st. "When the 
 overlying beds of earth have not enough extent of surface to allow 
 springs to be formed by infiltration of rain-water; or there is no 
 impervious bed, either of the marl or its overlay, on which spring 
 water can be borne, if it flows from distant sources : 2d. Or even 
 if there be any such impervious and water-bearing stratum, that its 
 " dip" is in a direction leading from- the " out-cropping" of the 
 marl; so that all spring-water, or infiltrated rain-water, must 
 necessarily flow in a direction leading from the exposure. In the 
 reversed circumstances, the marl will be wet, and proper drainage 
 of the pits will be necessary. Bodies of marl of this second class 
 are most common in the high and broken lands lying between the 
 localities named above, and the falls of the rivers. 
 
 III. The third class of marl generally belongs to the more level 
 lands, but in some cases to the low bottoms and ravines of the 
 higliest and most hilly. But in either case, the surface of the marl 
 is lower than that of all the surrounding land (unless perhaps of 
 the mere outlet for the water) ; and the excavations and the roads 
 all need careful and perfect drainage. 
 
 I will now return to the consideration, principally, of excavations 
 of the second class ; though they will in part suit also for the third 
 class. 
 
286 
 
 EXCAVATION Or WET MARL. 
 
 There is a general clip of the marl to the cast, Ibrougli lower 
 Virginia. But this so slight, and irregular withal, that it does not 
 always direct the course of the spring-water above according to the 
 general course of the dip. At each particular locality, the marl 
 stratum may be considered as nearly horizontal. The upper sur- 
 face of the dry marls is often very irregular in outline, owing to 
 the washing operation of ancient currents of the sea, or later floods^ 
 and whirpools, subsequent to the deposition of the beds of shells. 
 
 Unless very sandy and poor, and also oozy, all our marls are 
 sufficiently firm before being dug, for tlie sides of a pit to stand 
 secure when cut perpendicularly. The dry beds, of course, are 
 much easier to be worked than the wet. Where the bed is dry, 
 no directions are required for pit-work; except that the pit shall 
 be long enough to allow the carts to descend therein, and to rise 
 out, loaded, on a graduated and gently sloping road-way. This will 
 obviate the necessity existing when pits are short and steep, of 
 twice throwing the marl — first out of the pit, and afterwards into 
 the carts. No machine or contrivance yet known will serve as 
 well for cheapness to raise marl from the bottom of a pit, or dig- 
 ging, as a cart ; and no care or labour will be lost in draining and 
 enlarging the pit, and graduating the ascent out from it, if there- 
 by carts can easily and safely draw from the bottom. These re- 
 marks may apply to any excavation made by sinking pits below 
 the level of the general surface. 
 
 Profile, or cross-scciion of marl diggings, of class II. 
 
 Explanations, 
 b, a, Face of hill-side. 
 s, Stream, or bottom of Talley. 
 p, c, f, h, m, Bed of marl, out-cropping at c. 
 m, m, Bottom of workable marl. 
 o, d, ff. Overlying earth. 
 
 I will describe an ordinary case of hill-side cscaTation. 
 
EXCAVATION OP MARL IN HILLY LANDS. 287 
 
 Suppose the marl to "crop out," or otherwise to come near to 
 the surface near the foot of a high hill-side (as at c), a ravine and 
 stream being at the bottom (s), and table-land at the top of the 
 hill-side, over which the marl is to be carted to the fields, after 
 rising the hill-side by a graduated road. These are common natural 
 features of marl localities, in hilly lands (and of class II), The 
 out-crop, or natural exposure of the marl (c) is on a convex curve 
 of the hill-side. The first operation is to clear off the little over- 
 lay of earth, from above the out-crop (o), so as to uncover a sufil- 
 cieut space for digging and carting (o, c.) This space should be 
 (if practicable), 15 feet across, of horizontal width, to permit sin- 
 gle-carts to turn upon ; and as long (with the course of the stream) 
 as the gi'ound may permit, say 30 feet or more. This small amount 
 of overlying earth (o) is easily disposed of, by being thrown into 
 the ravine, or across the stream. The uncovering reaches to the 
 top of the marl stratum, which is supposed 12 feet thick ; of which, 
 8 feet are above and 4 below the level of the stream. A road is 
 nest laid off, graduated to best advantage, and constructed, de- 
 scending from the upper table land to the uncovered marl, the lower 
 end of the road being on a level about 1 foot higher than the 
 stream, and of course 5 feet above the bottom (m, m), of the marl 
 fit for use. (The lowest part is usually too poor, and sometimes 
 too much affected by water, to be worth being removed.) If springs 
 ooze out over the top of the marl, a little trench (y) of about 4 
 inches wide and as many deep, must be made along the back line 
 of the uncovering, to cut off and convey away the spring water. 
 The uncovered and drained marl (c, ^,) is then dug and carted out ; 
 the work being so conducted as to level the surface, and enable the 
 carts as soon as the surface is enough lowered, to pass over, tui-n 
 about, and be loaded upon the marl. When the whole space has 
 been dug down to the level of the lower end of the road (a, ^,) 
 then a perpendicular pit should be dug at the end of the area 
 fixrthest from the descending road, and across its whole width. 
 This pit (p 'p) will be 15 feet long, about 6 to 9 wide, as may 
 be most convenient, and 5 deep when finished to the bottom. The 
 carts turn on the area (a, t,) and are loaded at the edge of this 
 pit. When finished, another similar pit is dug alongside ; and 
 others in succession, until the whole area of the first uncovered 
 marl has been so pitted out. The overlay (d) is then dug and 
 thrown off from the next range or section of marl (/), so as to 
 uncover another width of 15 feet. The removed earth here (d), 
 •where highest, might have been more than 10 feet thick. But the 
 space excavated for the first range of marl (c p) has more than 
 room enough to receive all this earth. 
 
 The carts now have to be supplied from the second range of 
 marl (/). As this is throughout of the full thickness of the bed, 
 
288 REMOVING OVERLYING EARTH. 
 
 and rising 7 feet above the lower end of tlic road, it may be con- 
 venient to make a brancli to the road running on a level to the top 
 of the marl. This branch will be used until the lowering of the 
 upper marl, by its excavation, shall render the lower branch of the 
 road again more suitable. This range of the marl is drained, 
 worked out to the level of a f, and then the lower part (r, r,) ex- 
 cavated in successive perpendicular pits, in the same manner as the 
 previous range. Then a third range of overlay (//) is dug and 
 thrown off into the finished previous excavation (/, r, r) ; and by 
 its increased thickness perhaps fills it up as high as the top of the 
 marl stratum. But this does no serious harm. It will however 
 require the leaving a wall of marl (a:, x) when digging out the 
 marl belo^^ (li) to keep out the earth and water of this heap ; and 
 also cross walls for support, between the lower perpendicular pits. 
 
 It will now be much more laborious to uncover another range 
 (at z), still deeper in the hill-side ; and it will become a question 
 for the operator to decide, whether to proceed farther with this' 
 work here, or to begin another uncovering in some more favourable 
 situation. 
 
 For any extensive operation, it is much cheaper to take off a 
 cover of earth 20 feet thick, to obtain marl of equal depth, than 
 if both the covering earth and marl were only three feet each. 
 Whether the cover be thick or thin, two parts of the operation 
 are equally troublesome, viz. to take off the mat of roots, and per- 
 haps some large trees on the surface soil, and to clean off the sur- 
 fiico of the marl, which is sometimes very irregular. The greater part 
 of the thickest cover would be much easier to work. But the most im- 
 portant advantage in taking off earth of ten or more feet in thick- 
 ness, is saving digging by causing the earth to come down by its 
 own weight. If time can be allowed to aid this operation, the 
 drycst earth will mostly fall, by being repeatedly undermined a 
 little. But this is greatly facilitated by the oozing water, which 
 generally fills the earth lying immediately on beds of wet marl. In 
 uncovering a bed of this description, for one of my early operations, 
 where the marl was to be dug 14 feet, and 10 to 12 feet of earth 
 to remove, my labour was made ten-fold heavier by digging 
 altogether. The surface bore living trees, and was full of roots — 
 there was enough stone to keep the edges of the hoes battered — 
 and small springs and oozing water came out everywhere, after 
 digging a few feet deep. A considerable part of the earth was a 
 tough, adhesive clay, wet throughout, and which it was equally 
 difficult to get on the shovels, and to get rid of. Some years after, 
 another pit was uncovered on the same bed, and under like circum- 
 stances, except that the time was the last of summer, and there 
 was less water oozing through the earth. This digging was begun 
 at the lowest part of the earth, which was a layer of sand, kept 
 
DRAINING AND WASHING WKT MARL PITS. 289 
 
 quite wet and soft by the -water oozing tlirough it. Witli gravel 
 shovels, this was easily cut under from one to two feet along the 
 whole length of the old pit, and, as fast as was desirable, the upper 
 earth, thus undermined, fell into the old pit ; and afterwards, when 
 that did not take place of itself, the fallen earth was easily thrown 
 there by shovels. As the earth fell separated into small but com- 
 pact masses, it was not much affected by the water, even when it 
 remained through the night before being shoveled away. No dig- 
 ging was required, except this continued shoveling out of the 
 lowest sand stratum ; and whether clay, or stones, or roots, were 
 mixed with the falling earth, they were easy to throw off. The 
 numerous roots, which were so troublesome in tlie former operation, 
 were now an advantage ; as they supported the earth sufficiently to 
 let it fall only gradually and safely ; and before the roots fell, they 
 were almost clear of earth. The whole body of earth, notwith- 
 standing all its difficulties, was moved off as easily as the dryest 
 and softest could have been by digging altogether. The thicker 
 the overlying earth, the greater is the facility of undermining, and 
 causing it to fall by its own weight. 
 
 In working a pit of low-lying and wet marl, covei'ed and sur- 
 rounded by higher ground (class III.), nopains should be spared to 
 drain it as effectually as possible. Very few beds of marl are 
 penetrated by veins of running water which would deserve the 
 came of springs ; but water generally oozes very slowly through 
 every part of wet marl, and many small springs often burst out 
 immediately over its surface. After the form of the pit and situa- 
 tion of the road are determined, a ditch to receive and draw off all 
 the water should be commenced lower down the valley, as deep 
 as the bottom of the area where the carts are to stand is expected 
 to be made ; and the ditch opened up to the work, deepening as it 
 extends, so as to keep the bottom of the ditch on as low a level as 
 the bottom of the area. It may be cheaper, and will serve as well, 
 to deepen this ditch as the deepening of the pit proceeds. After 
 the surface of the marl is uncovered for the full size intended for 
 the area (which ought to be at least large enough for carts to turn 
 about on), a little drain of three or four inches wide, and as many 
 deep (or the size made by the grubbing-hoe used to cut it), should 
 be carried all around to intercept the surface or spring-water, and 
 conduct it to the main drain. The marl will now be dry enough 
 for the carts to be brought on and loaded. But as the digging 
 proceeds, oozing water will collect slowly ; and, aided by the wheels 
 of loaded carts, the surface of the firmest marl would soon be 
 rendered a puddle, and next a quagmire. This may easily be pre- 
 vented by the inclination of the surface. The first course dug off 
 should be much the deepest next the surface drain (leaving a mai-- 
 gin of a few inches of firm marl, as a bank to keep in the stream), 
 25 
 
290 WORKING WET MARL TITS. 
 
 SO that the digging shall be the lowest around the outside, and 
 gradually rise in level to the middle of the area ; or nest to the 
 old diggings, now heaped with the later removed overlay. What- 
 ever water may find its way Avithin the work, whether from oozing, 
 rain, or accidental bursting of the little surface drain, will run to 
 the outside, the dip of which should lead to the lower main drain. 
 After this form has once been given to the surface of the area, 
 very little attention is required to preserve it ; for if the successive 
 courses are dug of equal depth from side to side, the previous 
 shape will not be altered. The sides or walls of the pit should be 
 cut (in descending), something without the perpendicular, so that 
 the pit is made 12 or 15 inches wider at bottom than top. The usual 
 firm texture of marl will prevent any danger from this overhanging^ 
 shape, and several advantages will be gained from it. It gives more 
 space for work— ^prevents the wheels running on the lowest and 
 wettest parts — allows more earth to be disposed of, in opening for 
 the next pit — and prevents that earth from tumbling as easily into 
 the nest digging, when the separating wall of marl is afterwards 
 cut away. The upper and larger drain of the pit, which takes the 
 surface water, will hang over the small one below, kept for the 
 oozing water. The former remains unaltered throughout the job, 
 and may still convey the stream when six feet above the heads of 
 the labourers in the pit. The lower drain of course sinks with the 
 digging. Should the pit be dug deeper than the level of the main 
 receiving ditch can be sunk, a wall should be left between, and the 
 remainder of the oozing water must be conducted to a little basin 
 near the wall, and thence be bailed or pumped into the receiving 
 ditch. The passage for the carts to ascend from the pit should be 
 kept on a suitable slope ; and the marl forming that slope may be 
 cut out in small pits, after all the other digging has been completed. 
 
 If the marl is so situated that carts cannot be driven as low aS' 
 the bottom, either because of the danger of flooding, or that the 
 ascent would be too steep for sufficiently easy draught, then the 
 area must be cut out in small pits, as before stated, beginning at 
 the back part, and extending as they pi^oceed, towards the road 
 leading out of the pit. 
 
 It is the less required to extend directions for the mode of work- 
 ing low-lying marl, covered and sourrounded by higher land, and 
 by its springs, because large excavations under these difficulties^ 
 will be described in a later part of this work, and the whole course 
 of procedure minutely stated. 
 
 In some cases, either because of the great liability of the over- 
 lying, oozy earth to cave and fall in, and thus continually to choke 
 the surrounding marl drains, or of rain-fioods to fill and damage 
 the excavations, it is too hazardous to leave diggings unfinished for 
 any length of time ; and still more for the unfinished work to be 
 
CRANE FOR RAISING MARL BY HORSE POWER. 291 
 
 suspsnded through winter. In such casfes, it is better to bestow 
 more labour to obtain security. Under such circumstances perpen- 
 dicular pits should be sunk first through the over-lay and then the 
 marl. If not too great a height, the marl, as dug, should be 
 thrown to the top of the remaining firm earth, there to be thrown 
 into and removed by the carts. When the digging is carried so 
 low that the throwing exceeds 10 feet in perpendicular height, a 
 scaftbld should be made, or a shelf of marl left, at the side 
 of the pit nest to which the carts approach, and at a convenient 
 height for the remainder of the digging. The lower marl will be 
 thrown first upon the scaffold, thence to the surface of the ground 
 above, and then into the carts. Thus, the marl may be thrown up 
 from the bottom of the bed, if that be not more than 20 feet be- 
 low the surface, for loading. The length and breadth of such pits 
 should not be greater than to permit each pit to be finished in a 
 few days after its commencement. Then an adjoining like space 
 may be uncovered, the earth being thrown into the previous dig- 
 ging, and the marl excavated in like manner. Should a flood of 
 rain-water, or the caving in of wet earth fill such a pit, when the 
 digging had not been sunk but a few feet, the damage may be 
 remedied and the remaining marl saved. Or if but a few feet 
 thickness of marl be left, and is covered by earth or water in 
 too great quantity to be worth clearing out, then the loss of the 
 bottom marl will not be very important. 
 
 For such situations as these, in some cases lifting machines have 
 been used successfully. One used by Wm. Carmichael, Esq., of 
 Maryland, was described by him in a communication to the Far- 
 mers' Register, as follows : 
 
 "In your 'Essay on Calcareous Manures,' you give instructions 
 for digging and carting marl. This method I pursued for many 
 years, but found the labour hard on my handsf and tedious. Marl 
 here is generally found in deep ravines or in wet grounds. My 
 operations have been slow, from the difficulty of making firm and 
 lasting ways, and the labour of ascending steep hills. Last winter 
 I made a model, and this spring I built a machine for raising marl, 
 to be worked by a horse. I have been using it to advantage, and 
 now send you a draught of it, as it may be useful to those 
 who have wet marl pits like mine. By means of a pump to throw 
 off the water, pits may be worked at a considerable depth ; and 
 even if marl is dry, but lies deep, I think the crane might be used 
 to advantage. I use two boxes, and by means of hinges and a 
 latch the marl is discharged from the bottom. I have double 
 blocks; the rope passes through the swoop about eighteen inches 
 from the end, and runs down to the post which supports the swoop, 
 and passes through it on a small roller, and in like manner through 
 the next post to the cylinder, to which a reel is attached to increase 
 the motion. The post which holds the swoop and the cylinder, 
 
292 
 
 CRANE FOR RAISIxXO MAR,L BY HORSE POWER. 
 
 runs on iron pins let into thimbles. The lever is in two pieces, 
 one fastened in the cylinder with a groove at the end, into which 
 the other is let, and secured by a sliding iron clamp. When the 
 marl is discharged from the box, and the swoop swung round over 
 the pit, in nautical phrase, by unshipping the end of the lever, the 
 rope unwinds, and the box descends without moving the horse. 
 The circle in which the horee travels ought to be twenty-one feet in 
 diameter. The second and third posts are supported by side braces. 
 
 " The cost of the machine is small, though I cannot make an 
 exact estimate. The carpenter who did the work was hired by the 
 day on the farm, and was taken off with other jobs; but his bill 
 could not exceed eight dollars. The cost of the iron-work was 
 ten, and one hundred and sixty-five feet of inch rope, at eighteen 
 and a half cents a pound. The timber, taken from my own woods, 
 may be estimated at five dollars. The rope I find soon wears out, 
 and I intend to supply its place with a light iron chain. 
 
 " When the marl is uncovered, with one efficient hand in the pit 
 and a less efficient one to discharge the boxes and drive the horse, 
 five hundred bushels may be raised in a day. The work is not 
 oppressive to the labourers. The teams stand on high, dry ground; 
 no sloughs to plunge through, and no hill to climb. The swoop 
 is turned by a small rope over the carts, and the marl immediately 
 discharged into them. I work four carts, with two sets of oxen to 
 each. They came out of the winter lean and weak ; and now, with 
 green clover for their food, at the distance of a half to three-quarters 
 of a mile I draw out from four to five hundred bushels a day, and 
 my oxen have improved. My work goes on with ease and expedi- 
 tion, without stoppage to mend roads, or to clean ditches." 
 
 The machine which will be described below is used at Fortress 
 Monroe for raising sand from the fosse to fill the ramparts; and 
 has been found by experience to be the best contrivance of all 
 which have been tried for that operation, and for which an immense 
 amount of labour was necessary in constructing the defences of the 
 fortress. Precisely the same manner of operation is required for 
 raising marl from deep pits, and there can be no doubt of this 
 being a more effective machine for that purpose than any worked 
 by hand. The force applied is the weight of the labourerp, on 
 
MACHINE FOR HAND LABOUR. 
 
 293 
 
 tlie principle of the treacl-mill, which, though heavy labour, is the 
 most eiFective manner in which the power of men can be applied. 
 I am indebted for the suggestion of this machine for raising marl 
 to the observation and scientific knowledge of mechanics of my 
 friend Professor M. Tuomey, and also for the following description, 
 and the drawings for the engraved figures. Mr. Tuomey, when 
 making a transient visit to the fortress, had seen the machine at 
 work; and after reading in the foregoing part of this work the 
 remarks on the different modes of raising marl, and having wit- 
 nessed some of the usual modes in practice, this machine and what 
 he had seen of its power appeared greatly superior, wherever cir- 
 cumstances may require the use of machinery. Upon being thus 
 informed, I applied to Dr. Robert Archer, U. S. A. Surgeon at 
 Fortress Monroe, for a rough plan, and accurate statement of the 
 dimensions of the machine, both of which he kindly furnished; 
 and with the aid of these, Mr. Tuomey has been enabled to give 
 such particular description and correct delineation as will serve for 
 full instruction for the building and working of the machine. 
 
 Fig. 1. 
 
 " 1. Figiirc 1 is a side view, in perspective. 
 
 i, i. The base, consisting of 3 pieces of scantling, each 12 feet long, and 
 11 inches by 5, notched on to each other about 6 inches from the end, so 
 as to be flush on top, forming an equilateral triangle. 
 
 e, The principal post 8 feet, 8 by 6 inches, secured to the base, and braced 
 by the braces /. Near the top of this post 2 iron sheeves or pulleys are 
 placed, one on each side, and secured by pieces spiked over them. The 
 chains pass over these pulleys. 
 
 /. 2 braces 11 feet long, 4 inches by 6. 
 
 h, h, Two uprights, in which the gudgeons of the wheel turn; they are 
 bolted to the base and connected at the top by the piece g, 10 feet 6 
 inches long, 4.^^ by 6 inches, which also serves as a hand rail for the men 
 to steady by when working on the wheel. These uprights are further 
 secured by cross-pieces connected with the braces, and bearing in front 
 
294 
 
 MACHINE FOR HAND LABOUR. 
 
 and rear of the wlieel two steps on which the men stand as they go on or 
 off the wheel. 
 
 IV. The wheel 4 feet in diameter, the steps 3| feet long 8 inches wide, made 
 of 1^^ inch plank. The ends of the wheels are formed of two thicknesses 
 of inch plank placed crosswise, the inside being grooved to receive the 
 steps which are placed about 8 inches apart. The axle of the wheel is 
 10 feet G inches long and 8 inches in diameter, the portion round which 
 the rope winds is enlarged, so as to suit the force employed on the wheel, 
 or the weight to be raised, by nailing on strips of plank, over which a 
 few turns of old rope may be placed to prevent the slipping of tlie chain. 
 
 To prevent confusion, only one crane (or arm) is represented in this figure. 
 
 The crane post is represented as turning on two iron pivots in pieces s, s, 
 one bolted to the principal post e, and the other spiked to the base. The 
 crane post is 6 inches square. 
 
 a. The crane jib, 7 feet 6 inches long, 6 by Tijichcs. 
 
 b. The strut to the jib, 8 feet 6 inches long, 4 by G inches. Near the Ex- 
 tremity of the jib an iron sheeve is fixed over which the chain passes. 
 
 c. Is a three-quarter inch rod of iron secured to a by means of a staple, 
 and having a hook at the other end, which drops into a staple at i. This 
 rod serves the double purpose of a stay and a guide, by which (when 
 unhooked) the arm is drawn to one side for the purpose of landing the 
 box. When fixed as represented in the drawing, it serves to retain the 
 crane in its proper position. When the box is raised the rod is unhooked, 
 and by means of it the box is landed. 
 
 Figure 2 is a front view, showing the relative position of the cranes, which 
 are represented as turned aside. The chain is seen winding around the 
 axle. It is evident that the men must pass to the opposite side of the 
 wheel as each box is drawn up. 
 
 lleprcsents 2 views of the boxes, which are square and may be each 
 about 21 inches every way. They will then contain neaxly 6 cubic feet 
 each. They are suspended by two pins, placed a little below and to one 
 
 JJ 
 
ROAD-MAKING. 295 
 
 side of the centre so as to turn over and empty tliemselTes when a small 
 iron pin seen at /, figure 2, is withdrawn. Three men can be cmpkiyed 
 to advantage at the wheel, two remaining on, whilst the third gets off to 
 land the box. Should the box not be heavy enough, the diameter of the 
 axle can be enlarged, so as to make up in time what is lost in weight. 
 Should it be too heavy for the force employed, the diameter may be les- 
 sened." 
 
 The above dimensions of timbers were those of the particular 
 machine measured bj Dr. Archer; but they vary iu all the machines 
 of this kiud used at the fortress. The length of the arms of course 
 should be proportioned to the height to which the loaded buckets 
 are to be raised. For marl, any sized timbers on hand, or logs, 
 that are long enough, would serve for the base (i, t.) It is how- 
 ever desirable that the machine should be as light as is consistent 
 with strength, for the greater facility of moving it; and for strength 
 alone (as in all other machines) the large size of timbers is of less 
 importance than their being well put together. Two thick and 
 narrow planks, firmly spiked together, and with a space left be- 
 tween of proper size for the sheeve to play in at the upper end, 
 would be a cheaper substitute for the jib a. When carts are re- 
 moving the marl at the same time it is raised, there would be much 
 advantage gained in having the boxes of such size as to be emptied 
 into the carts, and the measure or load of a box, to be some aliquot 
 part of the loads for the carts. 
 
 Machines of this kind will be required, and will be most profita- 
 ble, whenever marl is to be taken from deep and wet pits, and in 
 extended operations. 
 
 Making Roads. 
 
 On high and hilly land, marl is genei*ally found near the bottom 
 of ravines, and separated from the field to which it is to be carried 
 by a high and steep hill-side. The difficulty of cutting roads in such 
 situations is much less than any inexperienced person would sup- 
 pose. We cannot get rid of any of the actual elevation — but the 
 ascent may be made as gradual as is desired, by a proper location 
 of the road. The intended course must be laid off by the eye, and 
 the upper side of the road marked. If it passes through woods, 
 it will be necessary to use grubbing hoes for the digging. With 
 these, the digging should be begun at the distance of four or five 
 feet below the marked line, and carried horizontally onward to it. 
 The earth so dug is to be pulled back with the broad hoes, and 
 laid over a width of three or four feet below the place from which 
 it was taken. Thus the upper side of the road is formed by cut- 
 ting down, r.nd the lower side by filling up with the earth taken 
 from above. 
 
296 ItOAD-MAKTNG. 
 
 a 
 
 The annexed figure will prevent tbese directions being misunder- 
 stood. The straight line from a to 6 represents the original slope 
 of the hill-side, of which the whole figure is a section. The upper 
 end of the dotted part of the line is in the mark for laying off the 
 upper side of the road. The upper triangle is a section of the 
 eai'th dug out of the hill-side, and the lower triangle of the part 
 filled up by its removal. The horizontal line is the level of the 
 road formed by cutting in on the upper, and filling up on the lower 
 side. After shaping the road roughly, the deficiencies will be seen, 
 and may be corrected in the finishing work, by deepening some 
 places and filling up others, so as to graduate the whole properly. 
 A width of ten feet of firm road will be sufiicient for carting marl 
 up a short hill. 
 
 If the land through which the road is to be cut is not very steep, 
 and is free from trees and roots, the operation may be made much 
 cheaper by using the plough. The first furrow should be run along 
 the line of the lower side of the intended road, and turned down 
 hill ; the plough then returns empty, to carry a second furrow by 
 the first. In this manner it proceeds, cutting deeply, and throwing 
 the slices far (both of which are easily done on a hill-side), until 
 rather more than the required width for the road is ploughed. 
 The ploughman then begins again over his first furrow, and ploughs 
 the whole over as at first, and this course is repeated perhaps once 
 or twice more, until enough earth is cut from the upper and put on 
 the lower side of the road. After the first ploughing, broad hoes 
 should aid and complete the work, by pulling down the earth from 
 the higher to the lower side, and particularly in those places where 
 the hill-side is steepest. After the proper shape is given, carts, at 
 first empty, and then with light loads, should be driven over every 
 part of the surface of the road until it is firm. If a heavy rain 
 should fall before it has been thus trodden, the road would be ren- 
 dered useless for a considerable time. 
 
IMPLEMENTS, CARTS AND TEAMS FOR MARL. 297 
 
 Implements and Means fur facilitating the LaLours — Application 
 
 of Marl. 
 
 These directions are mostly suited for greater difficulties than 
 usually occur, though they are such as attended most of my labours 
 in marling. In the great majority of cases, there will be less 
 labour, and care, and skill required, because there will not be en- 
 countered such obstacles as high and steep hills to ascend, thick 
 over-lying earth to remove, or wet pits and roads to keep drained. 
 
 In large operations and in dry and compact marl, much labour 
 of digging may be saved by slightly undermining the face of a per- 
 pendicular body of marl, and then splitting oif large masses, by 
 driving in a line of large wooden wedges on the upper surface. 
 
 For very hard marl, narrow and heavy pickaxes are the best dig- 
 ging implements. For softer marl, though still of close and com- 
 pact texture, heavy and narrow grubbing hoes are better. They 
 should weigh near or quite 7 lbs. when new, and have the cutting 
 edge 3 to 3 J inches. Gravel shovels (with rounded points and 
 long handles), of the best quality, are the cheapest and most effec- 
 tive tools for throwing out the marl, and loading the carts, as well 
 as for afterwards spreading the heaps in the field. 
 
 Tumbrel or tilting carts, drawn by one horse or mule, are the 
 most convenient for conveying marl very short distances ; and even 
 for longer distances, if on hilly roads and fields. Every part of 
 such cart^ should be as light as will serve for strength, and the 
 body should be so small as to hold only the load it is designed to 
 carry. This enables the drivers to measure every load; which 
 advantage, on trial, will be found very important. If carts of 
 common and much larger sizes are used, the careless labourers will 
 generally load too lightly, and yet will sometimes injure the horse 
 by too heavy loading. The small-sized cart-bodies prevent both these 
 faults. Their loads cannot be made much too heavy ; and if too 
 light, the deficiency is detected at a glance. When there is much 
 or steep ascent in the carriage way, 5 heaped bushels of ordinary 
 wet marl, or 6 of dry, will make a full load for a good mule, or 
 ordinary horse. The larger quantity may be put in by heaping 
 somewhat above the level of the cart. The greatest objection to 
 these carts is that they are too small to caiTy loads of anything but 
 marl. Ou roads nearly level, tumbrels drawn by two mules are 
 much preferable. There is the saving of another driver, and the 
 cost and weight of another cart ; and though the cart is large and 
 heavy, it is so much lighter than two small carts, that two mules 
 together in the former, will draw full as much weight as if separate 
 and with the latter. The larger carts should hold about 15 heaped 
 bushels of marl, when the load is level with the top of the body; 
 and which may be increased to 18 or 19 bushels (the proper load 
 
298 DROPPING AND SPREADINO MARL. 
 
 for two mules on level land and firm roads) by heaping. Two 
 mules together will draw this load, or about 1900 lbs. ; or one 
 mule, in a light cart, 9 bushels, as easily as the latter will draw 5 
 bushels on hilly land. But on hilly land, two-mule carts cannot 
 •well be used. For when drawing up a hill, if one mule ceases to 
 pull for ever so short a time, the whole load, and a doubled labour, 
 is put upon the other mule, which is thus over-strained, and taught 
 to balk, if not otherwise damaged. 
 
 Strong labourers are required for digging and shovelling marl. 
 Boys of 12 to 11 years old may drive single-mule carts. The 
 animals kept regularly at such hauling soon become so gentle and 
 tractable, that very little skill or strength is required in the driver. 
 But for a two-mule cart, an active and careful young man should 
 drive, because his strength is required at some times, and his judg- 
 ment and care always to load properly, and to make the mules draw 
 equally. 
 
 One of the most general and injurious errors in marling, is the 
 unequal and irregular spreading of the marl on the land. From 
 this cause it often happens that there is too much and too little 
 marl applied to the same quarter-acre; and sorrel still remaining 
 and growing, and " marl-burnt" corn, maybe seen not many yards 
 apart. The only effectual means which I have found to attain any- 
 thing like equal distribution, has been to measure by stepping, and 
 marking with a hoe, each distance for a heap to be dropped. This 
 has been done by myself for" much the greater quantity of all the 
 marl I have had carried out ; as I never could have the measuring 
 and marking of distances done with sufficient accuracy by the dri- 
 vers. If the field had been left in beds, or the rows of the last pre- 
 vious ploughing are visible, it will much facilitate the marking. 
 Otherwise, rows must be marked by the plough in one direction, 
 or measuring poles must be set up at each extremity of the rows 
 for marl, to mark the cross-distance as well as to guide the direction 
 of the rows. The thus placing the heaps at regular or average 
 distances is the best security for regular distribution of the marl 
 in spreading. But, nevertheless, the latter operation ought to be 
 carefully watched, and made as uniform as will serve for thorough 
 and equal diffusion through the soil, with the subsequent aid in 
 tillage, of ploughing and harrowing. 
 
 Some extensive marlers, before commencing on a field^ have it 
 marked off by a plough for the placing of the heaps of marl. If 
 the laud is in beds, cross-furrows only are needed. If the surface 
 is smooth, it must also be marked at right-angles. In either case, 
 the field is thus marked off into rectangular spaces, in each of which 
 a heap of marl is dropped, and over the whole of which space it is 
 afterwards to be spread. But I found this mode more objection- 
 able than the former. The drivers have so much latitude, that 
 
MARLING TABLES. 
 
 290 
 
 they are very careless as to wliere they drop their heaps within 
 each rectangle; and the spreaders have more labour to distribute 
 the marl equally, and therefore are more apt to neglect it. Besides, 
 it is often requisite to alter the distances of the heaps, either because 
 of change of soil, or because of change in the sizes of the loads, 
 owing to altered condition of the roads. 
 
 Marling Tables and Estimates. 
 
 The following tables may be useful in facilitating calculations, 
 and promoting the important object of applying marl in equal and 
 uniform quantities, according to the quality of the marl and the 
 wants of the soil ; which object, however, is generally so little re- 
 garded, that few persons attempt by calculation to reach any of the 
 results which these tables are designed to show by mere reference. 
 
 Table I. Showing the number of cubic feet of dug marl (as compressed by its 
 weight in the loaded carts), necessary to furnish one per cent, of carbonate 
 of lime to the acre of soil, for the ploughed depths stated : 
 
 Marl contain- 
 
 
 
 
 
 
 
 ina of carb. 
 
 3 inches. 
 
 i iaches. 
 
 5 inches. 
 
 6 inches. 
 
 7 inches. 
 
 8 inches. 
 
 lime. 
 
 
 
 
 
 
 
 per cent. 
 
 cubic feet. 
 
 cubic feet. 
 
 cubic feet. 
 
 cubic feet. 
 
 cubic feet. 
 
 cubic teet. 
 
 10 
 
 1089. 
 
 1452. 
 
 1815. 
 
 2178. 
 
 2541. 
 
 2904. 
 
 20 
 
 544.5 
 
 726. 
 
 907.5 
 
 1089. 
 
 1270.5 
 
 1452. 
 
 30 
 
 363. 
 
 484. 
 
 605. 
 
 726. 
 
 847. 
 
 968. 
 
 40 
 
 272.25 
 
 363. 
 
 453.75 
 
 544.5 
 
 635.25 
 
 726. 
 
 50 
 
 217.8 
 
 290.4 
 
 363. 
 
 - 435.6 
 
 508.2 
 
 580.8 
 
 60 
 
 181.5 
 
 242. 
 
 302.5 
 
 363. 
 
 423.5 
 
 480.66 
 
 70 
 
 155.57 
 
 207.43 
 
 259.28 
 
 211.14 
 
 363. 
 
 414.80 
 
 80 
 
 136.12 
 
 181.5 
 
 226.87 
 
 272.25 
 
 317.62 
 
 363. 
 
 90 
 
 121. 
 
 161.33 
 
 201.66 
 
 242. 
 
 282.33 
 
 322.06 
 
 100 
 
 108.9 
 
 145.2 
 
 181.5 
 
 217.8 
 
 254.1 
 
 290.4 
 
 Table II. Showing the number of even bushels of marl, as compressed by its 
 weight in the carts, necessary to furnish one per cent, of carbonate of lime to 
 the soil, for the tilled depths stated : 
 
 Marl cont'ing 
 
 
 
 
 
 
 
 per cent of 
 
 3 inches. 
 
 4 Inches. 
 
 5 inches. 
 
 6 inches. 
 
 7 inches. 
 
 8 inches. 
 
 ciirb. lime. 
 
 
 
 
 
 
 
 
 bushels. 
 
 bushels. 
 
 bushels. 
 
 bushels. 
 
 bushels. 
 
 bushels. 
 
 10 
 
 875.1 
 
 1166.8 
 
 1458.5 
 
 1750.2 
 
 2041.9 
 
 2333.6 
 
 20 
 
 437.55 
 
 .583.4 
 
 729.25 
 
 875.1 
 
 1020.95 
 
 1106.8 
 
 30 
 
 291.7 
 
 388.93 
 
 486.17 
 
 583.4 
 
 680.63 
 
 777.87 
 
 40 
 
 218.77 
 
 291.7 
 
 364.62 
 
 437.55 
 
 510.47 
 
 583.4 
 
 50 
 
 175.02 
 
 233.36 
 
 291.7 
 
 350.04 
 
 408.38 
 
 466.72 
 
 60 
 
 145.85 
 
 194.46 
 
 243.08 
 
 291.7 
 
 340.31 
 
 388.93 
 
 70 
 
 125.01 
 
 180.97 
 
 208.36 
 
 250.03 
 
 291.7 
 
 333.37 
 
 80 
 
 109.38 
 
 14.5.85 
 
 182.31 
 
 218.77 
 
 255.23 
 
 291.7 
 
 90 
 
 97.23 
 
 129.64 
 
 162.05 
 
 194.46 
 
 226.88 
 
 259.29 
 
 100 
 
 87.51 
 
 116.58 
 
 145.85 
 
 175.02 
 
 204.19 
 
 233.36 
 
300 
 
 MARLING TABLES. 
 
 Table III., showing the number of rectangular spaces, of various dimensione, 
 ■> in an acre of land. 
 
 
 
 Rectan- 
 
 Yards. 
 
 Sq. yds. 
 
 gular 
 Spaces. 
 
 15x15 
 
 =225 
 
 22 
 
 15x14 
 
 —210 
 
 23 
 
 15x13 
 
 195 
 
 25 
 
 15x12 
 
 180 
 
 27 
 
 15x11 
 
 165 
 
 29 
 
 15x10 
 
 150 
 
 32 
 
 15x 9 
 
 135 
 
 86 
 
 15x 8 
 
 120 
 
 40 
 
 14x14 
 
 190 
 
 24 
 
 14x13 
 
 182 
 
 26 
 
 14x12 
 
 168 
 
 29, 
 
 14x11 
 
 1.54 
 
 31 
 
 14x10 
 
 140 
 
 84 
 
 14x 9 
 
 126 
 
 38 
 
 14x 8 
 
 112 
 
 43 
 
 14x 7 
 
 98 
 
 49 
 
 13x13 
 
 169 
 
 28 
 
 13x12 
 
 15G 
 
 31 
 
 13x11 
 
 143 
 
 34 
 
 13x10 
 
 180 
 
 37 
 
 13x 9 
 
 117 
 
 41 
 
 13x 8 
 
 104 
 
 46 
 
 13x 7 
 
 91 
 
 53 
 
 12x12 
 
 144 
 
 33 
 
 12x11 
 
 132 
 
 36 
 
 
 
 Rectan- 
 
 Yards. 
 
 Sq. yds. 
 
 gular 
 
 
 
 Spaces. 
 
 12x10 
 
 =120 
 
 40 
 
 12x 9 
 
 =108 
 
 44 
 
 12x 8 
 
 96 
 
 50 
 
 12x 7 
 
 84 
 
 57 
 
 12x 6 
 
 72 
 
 67 
 
 11x11 
 
 121 
 
 40 
 
 11x10 
 
 110 
 
 44 
 
 llx 9 
 
 99 
 
 48 
 
 llx 8 
 
 88 
 
 54 
 
 llx 7 
 
 77 
 
 62 
 
 llx 6 
 
 66 
 
 73 
 
 10x10 
 
 100 
 
 48 
 
 lOx 9 
 
 90 
 
 53 
 
 lOx 8 
 
 80 
 
 60 
 
 lOx 7 
 
 70 
 
 69 
 
 lOx 6 
 
 60 
 
 80 
 
 lOx 5 
 
 .50 
 
 96 
 
 9x 9 
 
 81 
 
 59 
 
 9x 8 
 
 72 
 
 67 
 
 9x 7 
 
 63 
 
 76 
 
 8x 8 
 
 04 
 
 75 
 
 8x 7 
 
 56 
 
 86 
 
 7x 7 
 
 49 
 
 98 
 
 7x 6 
 
 42 
 
 114 
 
 6x 6 
 
 36 
 
 133 
 
 It is scarcely necessary to direct the application of these tables 
 to practical operations; and therefore a single example only will 
 be offered. Suppose a farmer's marl contains about 40 per cent, 
 of carbonate of lime, and he wishes to give 1 per cent, to his de- 
 signed tilled depth of 5 inches. He takes the number 40 per cent, 
 in the first column of Table II., and passes thence in the same 
 horizontal line across the table until reaching the column headed 
 " 5 inches." The number at the intersection is 364.62, the num- 
 ber of bushels of marl required. Next, to apportion this quantity 
 to the acre. The heaps he can most conveniently make, Av.e will 
 suppose, will be 8 bushels. Dividing 364.62 by eight, gives about 
 452- heaps required for the acre. Then referring to Table III., for 
 that number of spaces, or the nearest to that number, in an acre, 
 it is seen that the distances of 
 
 14 X 8 yards, will make 43 heaps. 
 
 13 X 8 " " 46 « 
 
 11 X 10 " " 44 " 
 
 Either of these quantities would be suitable enough ; and the 
 farmer would choose the distances which will best suit his width 
 
MARLING ESTIJIATES. 301 
 
 of ploughing. If desiring more perfect exactness, it could be easily 
 obtained by adding to or deducting from one of the dimensions the 
 necessary fraction of a yard. 
 
 Heaped bushels of loose marl, as measured separately, do not 
 vary much from the same number of even bushels, as compressed 
 in a cart body, by its own weight, and by the travel to the field. 
 I find reference to bushels more convenient than to cubic feet. But 
 if preferred, the same desired results may be reached by using 
 Table I., and cubic feet as the measure instead of bushels. 
 
 The measuring of marl, in a half-bushel measure, for the purpose 
 of determining larger quantities, is but a rough and uncertain 
 method, which is only to be relied on when the average is taken 
 of many such trials. The irregularity of the lumps of marl, when 
 first dug, and the uncertainty of the degree of heaping of the 
 measure, may make even the same kind and condition of marl 
 appear to vary in quantity and weight, by 6 or 8 pounds in the 
 bushel. Besides other smaller trials, at other times, I made the 
 following measurements and weighings of a single load of marl, of 
 which the report may be of use for comparison : — 
 
 A load of marl, just dug, was thrown into the cart, as usual, by 
 shovels. The heaping of the load rose 7 inches, in the middle, 
 above the top of the cart body. (Lumpy and moist marl may be 
 heaped much higher than dry and pulverized.) This was about 
 the ordinary degree of heaping, when the roads were in the firmest 
 state. The load was drawn to my barn, 2000 yards of the route to 
 the field, ^nd there measured by the half-bushel, heaped, and each 
 separate measure weighed. The weights varied from 49 to 56J 
 lbs. of the 39 half-bushel measures (19 J bushels) which the load 
 filled. The whole load weighed 2050 lbs., and the average weight 
 of the heaped bushel was 105.16 lbs. This marl was of the kind I 
 have altogether used at Marlbourne [to 1850] — compact clayey 
 marl, partly in lumps, moist naturally in its bed, but free from any 
 other water. 
 
 The inside dimensions of this two-mule cart body were these : 
 Average of length, inches, 60.87 
 " width, " 40 
 
 '( depth, " 15.16; 
 
 which make 21.36 cubic feet, or 17.12 even bushels of capacity. 
 (A bushel contains 2150.6 cubic inches.) But, it should be ob- 
 served, that the compression of the marl by its own weight, as 
 thrown into the cart, and still more by the settling during the tra- 
 vel to the field, permits and causes more bushels of marl (if pre- 
 viously measured) to be put into the body than would be indicated 
 by its cubic capacity. Thus, into the cart described above, at an- 
 other time, the marl was put in at the pit by a half-bushel measure, 
 heaped as usual — and which heaping certainly added as much as 
 26 
 
302 MARLING ESTIMATES. 
 
 20 per cent, to tlie even measure. Yet 16 bushels (the measure 
 being thus heaped), were required to fill the cart even. (If thrown 
 in, as usual, by shovels, still mard marl would have been put into 
 the same space, by its falling more heavily from the shovels than 
 from the half-bushel.) Upon this even filling of the cart (the 16 
 heaped bushels), more marl was added, to the amount of 5 bushels 
 of like heaping measurement, making 21 heaped bushels in all. 
 This raised the heaping of the cart higher than usual, though not 
 too much to be carried without waste. After being driven to the 
 field, rather more than IJ miles, the then heaping part of the load 
 alone was carefully taken ofi", and measured by even half-bushels; 
 but each filling being pressed into the measure moderately, which 
 was supposed to give a degree of compactness equal to the remain- 
 ing lower part of the load, caused by its weight and the travel. 
 This quantity made 3 2f of such even bushels; the difference be- 
 tween which and the 5 heaped bushels put on in heaping at the 
 pit, was owing to the settling of the whole load by its weight and 
 the travel. 
 
 The remaining even and compressed filling of the cart body, by 
 cubic measurement of its capacity, as stated above, was (21.36 
 cubic feet, or) 17.12 even bushels. Add to this the oh even and 
 compressed bushels of the heaping (after its being settled by the 
 travel), and the quantity of the whole load is (17.12 -\- 3.50=) 20.62 
 compressed and even bushels, equal to 21, loose and heaped, as 
 measured at the loading. Therefore it may be considered that a 
 heaped bushel of loose and moist marl is about equal, when com- 
 pressed, to the same measure even full. 
 
 From all these and other trials and observations, combined and 
 compared, I consider the following quantities as sufiiciently close 
 approximations to the truth : — 
 
 A heaped bushel of this and similar marl, loose, as dug, weighs 
 105.16 lbs. 
 
 An even bushel, compressed, weighs about the same. 
 
 The load of a proper two-mule cart, for roads in good order and 
 over firm land not varying much from level, is 18 to 19 heaped 
 bushels— or 1900 to 2000 lbs. 
 
 Weight of a cubic foot of this marl, in the bed, is 120i lbs. 
 (determined by trial of a smaller measured solid). By two differ- 
 ent trials, of pits measured by their cubic dimensions in the bed, 
 one of 1052 cubic feet yielded 1103 heaped bushels of marl, as dug, 
 and measured by the estimated cart-loads; and the other, of 1475 
 cubic feet in the bed, yielded 1675 heaped bushels. These esti- 
 mates would respectively make the cubic foot weigh about 111 and 
 119 lbs. Of course these were not esaet measurements, either in 
 the bed, of feet, or in the carts, of bushels. 
 
 10 cubic feet of marl, measured in the (^rt body, and as com- 
 
PROPER PROCEDURE FOR MAULIXO. 303 
 
 pact as made by its own pressure and tlie travel, are equal to 8.03 
 (say 8) even bushels, in the same state of compactness ; and may 
 be taken as equal to the same number (8) of heaped bushels, loose 
 as when dug. 
 
 In marls of equal degrees of moisture, the weight will be greater 
 in proportion to the quantity of silicious sand in each; and, in a 
 less degree, also to the soundness and compactness of any shells 
 contained. In marls similar in these respects, of course the weight 
 will be in proportion to the wetness. The lightest marl I ever 
 worked, which was as dry as any earth could naturally be, did not 
 weigli less than 100 lbs. to the heaped bushel. 
 
 Some or all the foregoing suggestions of facilities and expedients, 
 or perhaps some better plans, might perhaps occur to most persons 
 before they are long engaged in marling. Still these directions 
 may help to smooth away some of the obstructions in the way of 
 the inexperienced ; and they will not be entirely useless, if they 
 can serve to prevent even small losses of time and labour. 
 
 It is impossible to carry on marling to advantage, or with any- 
 thing like economy, unless it is made a regular business, to be con- 
 tinued throughout the year, or a specified portion of it, by a labour- 
 ing force devoted to that 'purpose, and not allowed to be withdrawn 
 for any other. Instead of proceeding on this plan, most persons 
 who have begun to marl, attempt it in the short intervals of leisure 
 aflforded between their difl'erent farming operations — and without 
 lessening, for this jiurpose, the extent of their usual cultivation. 
 Let us suppose that preparations have been made for such an at- 
 tempt, and on the first opportunity, a farmer commences marling 
 with zeal and spirit. Every new labour, however, is attended by 
 causes of difficulty and delay ; and a full share of these will be 
 found in the first few days of marling. The road is soft for want 
 of previous use, and, if the least wet, soon becomes miry. The 
 horses, unaccustomed to carting, balk at the hills, or carry only half 
 loads. Other difficulties occur from the awkwardness of the labour- 
 ers, and the inexperience of their master — and still more from the 
 usual unwillingness of the overseer to devote any labour to improve- 
 ments which are not expected to add to the crop of that year. 
 Before matters can get sti'aight, the leisure time is at an end. The 
 work is stopped, and the road and pit are left to get out of order, 
 before making another attempt some six months after, when all the 
 same vexatious difficulties are again to be encountered. It is there- 
 fore not at all surprising that many zealous beginners have been 
 discouraged by the bad management of their first operations ; and 
 have abandoned all eflfort to marl, until after years of delay, and 
 when again induced to resume, by the success and profit of others 
 who had not limited their marling labours to leisure times only. 
 
 If one horse or mule,'\)aly, is employed in drawing marl through' 
 
304 SEAHCIIIXG FOR MARL. 
 
 out the year, at tlie Bioclerate allowance of 200 working days, 
 and 100 bushels carried out for each day, the year's work will 
 amount to 20,000 bushels ; or enough for the first dressing of 80 
 acres, at 250 bushels. This alone would be creating a great value, 
 and obtaining a great profit upon the outlay of expense. But, be- 
 sides, this operation would allow the profitable employment of any 
 amount of additional and available force. When, at any time, 
 other teams and labourers could be spared to assist, even if but for 
 a day or two, everything would be ready for them to go immedi- 
 ately to work. The pit is well drained, the road is firm, the bridges 
 in good order, and the ground for the marl marked off and ready 
 to receive the loads. In this manner, much work may be obtained 
 in the course of the year, from teams which would otherwise be 
 idle, and labourers whose other employment would be but of little 
 importance. Also the spreading of marl on the field is a job that 
 will be always ready to oecuj^y spare labour (unless the marl is 
 clayey and also very wet) ; and the removing of earth to uncover 
 marl may be done when rain, snow, or severe freezing weather has 
 rendered the earth unfit for almost every other kind of work. 
 
 CHAPTER XXVII. 
 
 DIRECTIONS FOR THE SEARCniNG FOR AND TESTING OF MARL. 
 
 In the order of time and of operations, the searching for marl, 
 when required for any one locality, must precede the labours di- 
 rected or described in the foregoing chapter. Nevertheless, the 
 reverse order will be better for the clear understanding of directions 
 by those persons who are without an}' experience in this business. To 
 know how best to search for marl, it is essential to know the gene- 
 ral position, and other characters of the beds ; and the necessary 
 lights on these points were given in the preceding chapter as the 
 most suitable place. 
 
 It is not only on farms, or in larger spaces, where no marl has 
 been seen, that the search for it may be necessary. On large farms 
 where it is most abundant, and easily accessible, in some places, it 
 is usually very important to trace the bed to some other place, 
 where the working will be more useful or convenient. The being 
 thus enabled to bring the excavations a few hundred yards nearer 
 to the fields may save twice as many hundred dollars in the expense 
 of carting the marl within one or two years. 
 
 The farmer who has seen (and still better if he has worked) 
 marl in some one spot of his land, or his neighbourhood, has thereby 
 
SEARCHING FOR MARL. 305 
 
 obtained tliG best possible indications of the probable existence of 
 the same bod in a more desirable situation. As the beds usually 
 lie nearly horizontal, and are continuoiis for considerable distances, 
 the search should be extended upon nearly the same level. Natural 
 exposures may have been made by the courses of rivers or smaller 
 streams — or artificial, by the digging of ditches, wells, or other 
 excavations. If none of these serve to expose marl to view, the 
 next resort will be to boring. And in using the auger, the same 
 rule should be pursued of being guided by the supposed level of 
 the bed sought. Of course, any nearly horizontal lower bed will 
 have the least covering of upper earth where the surface is most de- 
 pressed. Thus, under swamps, or in deep bottoms or ravines, a hidden 
 bed of marl may be expected to be reached with less depth of boring 
 than on the higher land. But it will not do to rely upon borings 
 in these lowest depressions only. For in many cases, the marl 
 itself, or the upper part of the bed, has been washed away and re- 
 moved by the ancient action of running water, and the cavity sub- 
 sequently filled by other washings of earth, forming the present 
 surface soil and lower layers. Therefore, besides boring in the 
 lowest ground, the nearest rise of the adjacent slope of high land 
 should be tried. There the marl would have been left, even though 
 removed in the former lower channel of the ancient strong current 
 of water. 
 
 If marl reaches the surface, or is cut into anywhere by the wash- 
 ing of rapid streams, it may probably be found by examining the 
 deepest parts of these cuttings. Any of the smallest particles of 
 shells found in the lower part of the course of the stream will 
 clearly indicate that the water has cut into marl somewhere above; 
 and which place may be found by carefully examining the bed of 
 the stream above. 
 
 The auger most convenient for the ordinary searching for marl 
 is a very simple and cheap implement. It is made by welding a 
 straight cylindrical iron rod, five-eighths of an inch in diameter, 
 to the stem of a common screw auger of about one and a half 
 inches bore. If the auger has been so much worn in use as a car- 
 penter's tool, as to be unfit for that work, it will serve well enough 
 for boring in earth. A cross-piece for a handle, also of iron, and 
 14 inches long, should be fitted to slide along the stem (which 
 passes through a hole in the handle), and small indentations are 
 made, two feet apart, on the stem, at which the handle is fixed, at 
 any desired height, by a small thumb-screw, passing through one 
 side of the handle, and the point pressing into the indentation on 
 the stem. The lowest indentation should be 4 feet from the lower 
 end of the auger, and the others at every 2 feet above. An 
 auger of 12 feet length will serve for all ordinary operations, 
 and is not too unhandy^in use. But, it will be more convenient, 
 2G* 
 
306' BORING FOR MARL. 
 
 if much boring is to be clone, to have two augers, of equal bore j 
 (or the short one something tiie hirger), one of 8 feet length, and 
 the other 14. The shorter will be used first, and the longer only 
 •when more than the depth of 8 feet is required. The auger is not 
 only useful to find the upper surface of the bed of marl, but also 
 to pierce the bed deeply enough to know whether it is thick and 
 rich enough to be worth the labour of uncovering and excavating. 
 Not more than about 6 inches depth should be bored at one time, ; 
 when the auger should be drawn up, and the cutting part cleared 
 of the adhering earth. If more boring is done at once than the 
 auger can lift completely, the bored hole is soon obstructed by 
 loose earth, and the design of the boring is impeded by the greater - 
 haste of the labour. ,i 
 
 It is seldom that the shorter length of 8 feet will not be enough ^ 
 for these uses of a marl auger; and the greater length of 12, or i 
 at most 14 feet, will be ample. But, if for peculiar circumstances, \ 
 ■greater depth is required, additional pieces, of 4 feet each, may be j 
 attached to and so lengthen the stem of the auger. The working | 
 of so long an auger is' excessively inconvenient, when it has to be 3 
 drawn up so frequently. n 
 
 For the suggestion of this very useful tool, I was indebted to . 
 Dr. William J. Cocke, who first introduced it ; and who, by its aid, ^ 
 was enabled to find and to use extensively a very valuable bed of 
 marl under the low and level surface of his land (on Blackwater, j 
 in Sussex), where its presence had not been reached or suspected '\ 
 before. ^ 
 
 When it is desired to use an auger longer than 14 feet, by at- 
 taching one or more extra joints, the great inconvenience of lifting J 
 and returning the auger may be much lessened by a simple con- \ 
 trivauce introduced by Mr. Williams Carter, of Hanover. This is i 
 to have a bench of narrow and thin plank, 7 or 8 feet long, with 
 legs of 8 or 10 feet. A hole large enough for the auger to turn 
 in freely is in the middle of the bench. As soon as it is necessary 
 to attach another piece to the stem of the auger, the bench is set , 
 over the boring, ^ith the hole immediately above, through which ^ 
 the stem is passed. Thus, when the auger is lifted, it is supported | 
 in its perpendicular jjosition by the bench above. . 
 
 Such means as these, imperfect as they are, will be found more 
 convenient and efi"ective in use, and much cheaper, than the heavy 
 and complicated augers used to search for coal. 
 
 When I first began to apply marl, in Prince George county, it had 
 attracted so little observation, even as a matter of curiosity or singu- 
 larity, that the deposit was supposed by the few observers to be 
 limited to the few places where it was both exposed and also mani- 
 fest to the eye. These places were indeed very few in lower Vir- 
 ginia. For not only was the natural exposure of a sectiuu of the 
 
POSITION OF MARL BEDS. 307 
 
 beJ required, but also that the fossil shells should be sufficiently 
 preserved to be recognised as such at a glance. The most nume- 
 rous, most extensive, and also the richest beds, exposed to the eye, 
 in some of the steep and broken banks of the rivers, and vphich are 
 now known to the most ignorant labourer as marl, were then not 
 distinguished from other earth, because the shelly matter was so 
 reduced as not to be obvious to view. 
 
 But as soon as the value of these beds was made known, disco- 
 veries or observations of their presence and accessibility were rapidly 
 extended. And in advance of all scientific instruction (from which 
 the general extension of any such formations might have been in- 
 ferred), marl had been found on thousands of farms, where its pre- 
 sence had not been known or thought of, previous to ray earliest 
 publication on this subject. Even in Prince George, and after the 
 highest interest had been excited on this subject, for some years 
 the only known exposures of marl were in either the cliffs, or the 
 neighbouring sloping borders of James River, and in the ravines 
 of the hilly lands of some streams emptying therein. Since, besides 
 other places, under all or nearly all the level swampy borders of 
 the Blackwater and its many branches, marl has been found, at no 
 great depth, though concealed from view ; and numerous extensive 
 excavations have been made, and for great improvements. New 
 discoveries of marl are still continually made in localities where it 
 was not before known. There can be little question of the general 
 fact that marl underlies nearly all the lands between the se;j,,coast 
 and the falls of the rivers, and stretching from ]Maryland to liorida ; 
 and increasing in thickness, and generally in richness also, as pro- 
 ceeding southward. In Virginia, 'the workable thickness of marl 
 is not often more than 12 feet ; and if in some cases as much as 
 25 feet, it is much oftener less than 8 feet. In South Carolina, 
 I ascertained the extensive bed of very rich marl to be more than 
 300 feet in thickness. 
 
 But generally extended as are the marl deposits through lower 
 Virginia, the overlying earth is most generally too thick for the 
 economical working of the marl below. Under most lands, the 
 marl is more than thirty feet below the surface ; and even if reached 
 by digging, would be covered by spring-water, so as greatly to in- 
 crease the difficulty and expense of obtaining it from such depths. 
 Will these obstacles always debar the proprietors from the benefit 
 of this treasure, through more than half the great region under 
 wJiich it lies, now useless and concealed? I think not. Though 
 it would be ridiculous now to propose such undertakings, it will 
 at some future time be found profitable to descend to still greater 
 depths for good marl; and shafts will be sunk, and the water and 
 the marl will both be drawn up by machinery worked by horse- 
 power or steam engines, and the excavations conducted in the same 
 
o08 DEEP-LYING MARL. 
 
 mannei" as is now done in coal mines. When sucli means sliall be 
 resorted to, it is probable that there will be but a small proportion 
 of all the great tide-water region (or the region lying eastward of 
 the granite range), in which marl may not be found sufficiently 
 accessible for profitable use. For example : from a mile south of 
 Petersburg, along the line of the railway to the Roanoke, no marl 
 had been found either by the excavations for the road, or in tho 
 much deeper wells dug long before in the vicinity of the route. 
 The well for the water-station nine miles from Petersburg did not 
 at all times supply enough water for the engines, and it was deter- 
 mined to dig one deep enough for that purpose. Disregarding the 
 small veins of water usually reached at less than 20 feet, the 
 digging was sunk to 50 feet, when marl was reached. Its quality 
 at top was rather poor ; but it became more and more rich, as well ' 
 as of firmer consistence (though never very hard), until the well 
 had been sunk to 80 feet, without reaching the bottom of the 
 marl, or finding any other vein of water. The lower part of this 
 marl was from eighty to ninety per cent, of carbonate of lime, as I 
 found by several analyses. It would have served to make good 
 lime, by burning, for cement or for manure, to be transported to 
 a distance on the railway ; besides being of more value to be used 
 unprepared to enrich the nearer land. Though covered by fifty 
 feet of earth, and the excavation impeded by the water from above, 
 this marl might have been profitably raised eighty feet, or as much 
 lower"':!^ the bod may extend. And so firm was its texture, that 
 the excavation might have been safely enlarged gradually as it was 
 deepened, as is done in the chalk-pits of England, so that the 
 digging should form a hollow cone, communicating from its apex 
 by t!ie narrower cylindrical well through the fifty feet of earth 
 above to the surface. Thus, though the earth might have been 
 twice the thickness of the marl below, the greater diameter of ex- 
 cavation in the latter would have furnished much the greater quan- 
 tity of contents. Of this most valuable deposit, found in a region 
 before supposed destitute, and where its transportation to a long 
 line of destitute land was so convenient, no use has been made, 
 except of the quantity necessarily drawn up in digging this well. 
 And this means for enriching the undertaker, and fertilizing a vast 
 extent of surface of acid and poor land, will probably remain totally 
 neglected for the next fifty years. It is most probable that this 
 same thick and rich body of marl may be found at many miles' 
 distance on the line of railroad, and indeed wherever the surface 
 is in the same position relative to the granite range. (1842.) 
 
 After marl has been found, whether by natural exposure or by 
 boring, it may still be difficult to distinguish it by the eye. If 
 fossil sea-shells are intermixed, and enough preserved in form to be 
 distinguishable, that is certain proof that the object sought has 
 
MARLS NOT DISTINGUISHABLE BY SIGHT. 809 
 
 been found. But sometimes, and more usually in the richest marls, 
 the shells are so reduced as to be scarcely (if at all) distinguishable, 
 and the mass may appear to the eye either as a barren sand or as 
 barren clay sub-soil, according to its mechanical texture, of no 
 worth or interest whatever. The touch of muriatic, or other strong 
 add, to the earth, first moistened by water, is the only sure test. 
 If there is shelly matter (or carbonate of lime) present, the acid 
 will produce immediate effervescence and discharge of carbonic acid 
 gas. If there is no such action, the earth is not calcareous, and 
 of no value as marl (or for calxing~), whatever it may contain of 
 other fertilizing ingredients. 
 
 More than a hundred species of sea-shells are found in tho 
 beds of marl which I have worked. Generally the shells, 
 though very fragile, are entire, though much broken by the dig- 
 ging and after-operations. The white shells are rapidly reduced, 
 after being mixed with an acid soil ; but some gray kinds, as 
 the scallop (^pecteti) and the oyster, are so hard as to be very long 
 before they can act as manure. Some beds, and they are gene- 
 rally the richest, have scarcely any whole shells, but are formed 
 principally of small broken fragments. Of course the value 
 of marl as a manure depends in some measure on which kinds 
 of shells are most numerous, and their state of "division, as 
 well as upon the total amount of the calcareous earth contained. 
 The last is, however, by far the most important criterion of 
 value. The most experienced eye may be much deceived in the 
 strength of marl; and still more gross and dangerous errors 
 would be made by an inexperienced marler. The strength of a 
 body of marl often changes materially in sinking a foot in depth — 
 although the same changes may be expected to occur very regu- 
 larly, in every pit sunk through the same bed. The annexed 
 figure will serve better to illustrate both these changes in perpen- 
 dicular extension in a marl-bed, and the regularity of quality in 
 horizontal extension. 
 
 Such as this is no uncommon character of a bed of marl, and 
 such I have worked, and could recognise the identity of the 
 several layers, by their appearance, in different diggings, half a 
 mile or more apart. Thus, suppose the two ends of the section 
 
810 APPEARANCE AND TESTING OF SIARL, 
 
 to be at such considerable distance. The upper lajer, a (say, 
 for example, finely-rubbed-down fragments of shells, making 55 
 per cent, of the layer), may be 6 feet thick at one part, and only 1 
 foot or less at the other. The next layer, h (indurated or stony, 85 
 per cent, of carbonate of lime), may vary at the same two distant 
 places from 1 foot to 3. The nest, c (sandy and fine, 20 per 
 cent.), is 4 feet in one digging, and runs out to nothing before 
 reaching the other. The nest, d (firm, with entire shells, 40 per 
 cent.), is 7 feet in the one and but 3 in the other place. Now it 
 would require a careful analysis of each of these layers of diflPerent 
 qualities, and observation of their comparative thickness, to know 
 the average strength of the whole section of marl at one escava- 
 tion. But these same observations would usually serve for estimat- 
 ing nearly enough the averages of the like layers whenever they 
 were found and identified, by allowing for the changes in thickness 
 of each layer. 
 
 Whoever uses marl ought to know how to analyze it, which 
 a little care will enable any one to do with sufiicient accuracy. 
 The method described, at page 56, for ascertaining the propor- 
 tions of calcareous earth in soils, will of course serve for the 
 same purpose with marl. But as more particular and minute 
 directions may be necessary for many persons who will use this 
 manure, and who ought to be able to judge of its value, such 
 directions will be here given, and which any one can follow, 
 by merely applying sufiicient attention and care. To perform 
 this process will require no other chemical tests than muriatic 
 acid and carbonate of potash, and no apparatus, except correct 
 scales and weights, a glass funnel, and some blotting or very porous 
 printing paper — all of which may be bought at any apothecary's 
 shop. 
 
 Directions /or anali/?:ing Marl hy solution and precipitation. 
 
 1st. Take a lump of marl, fossil shells, &c., large enough 
 to furnish a fair sample of the particular body under considera- 
 tion — dry it perfectly near the fire — pound the whole to a coarse 
 powder (in a metal mortar), and mix the whole together. 
 Take from the mixture a small sample, which reduce to a finely- 
 divided state, and weigh of it a certain portion, say 50 grains, for 
 trial. 
 
 2d. To this known quantity, in a glass, pour slowly and at dif- 
 ferent times muriatic acid diluted with three or four times its bulk 
 of water (any except lime-stone, or hai-d water.) The acid will 
 dissolve all the lime in the calcareous earth, and let loose the car- 
 bonic acid, with which it was previously combined, in the form of 
 gas, or air, which causes the effervescence, which so plainly marks 
 
ANALYZING OP MARL. 311 
 
 the progress of such solution. The addition of the muriatic acid 
 must be continued as long as it produces eifervcscence ; and but 
 very little after that effect has ceased. The mixture should be 
 •well and often stirred, and should have enough excess of acid to be 
 sour after standing thirty or forty minutes. (So much of the acid 
 as the lime combines with loses its sour taste, as well as its other 
 peculiar qualities.) 
 
 The mixture now consists of: 1, the lime combined chemically 
 with muriatic acid, forming muriate of lime, which is a salt, and 
 which is dissolved in the water ; 2, a small excess of muriatic acid 
 mixed with the fluid ; and 3, the sand, clay, and any other insolu- 
 ble parts of the sample of marl. To separate the solid from the 
 fluid and soluble parts is the next step required. 
 
 3d. Take a piece of filtering or blotting paper, about sis or eight 
 inches square (some spongy and unsized newspapers serve well); 
 fold it so as to fit within a glass funnel, which will act better if its 
 inner surface is fluted. Pour water first into the filter, so as to see 
 whether \i is free from any hole or defect ; if the filtering paper 
 operates well, throw out the water, and pour into it the whole 
 mixture. The fluid will slowly pass through into a glass under the 
 funnel, leaving on the filter all the solid parts, on which water must 
 be poured once or twice, so as to wash out and convey to the solu- 
 tion every remaining particle of the dissolved lime. 
 
 4th. The solid matter left, after being thus washed, must be 
 taken out of the funnel on the paper, and carefully and thoroughly 
 dried — then scraped off the paper and weighed. The weight, say 
 27 grains, being deducted from the original quantity, 50, would 
 make the part dissolved (50 — 27 =23) 46 per cent, of the whole. 
 And such may be taken as very nearly the proportion of calcareous 
 earth (or carbonate of lime) in the earth examined. But as there 
 will necessarily be some loss in the process, and every grain taken 
 from the solid parts appears in the result as a grain added to the 
 carbonate of lime, it will be right in such partial trials to allow 
 about two per cent, for loss, which allowance will reduce the fore- 
 going statement to 44 per cent, of carbonate of lime. 
 
 5th. But it is not necessary to rely altogether on the estimate 
 obtained by subtraction, as it may be proved by comparison with 
 the next step of the process. Into the solution (and the washings) 
 which passed through the filter, pour gradually a solution of car- 
 bonate of potaah. The first effect of the alkaline substance, thus 
 added, will be to take up any excess of muriatic acid in the fluid — 
 and next, to precipitate the lime (now converted again to carbonate 
 of lime), in a thick curd-like form. When the precipitation is 
 ended, and the fluid retains a strong taste of the carbonate of 
 potash (showing it to remain in excess), the whole must be poured 
 on another filtering paper^ and (as before) the solid matter left 
 
312 ANALYZING OF IMABL. 
 
 tliereon repcatedlj waslicd by pouring on •R'ater, then dried, scraped 
 off, and weighed. This will be the actual proportion of the calca- 
 reous part of the sample, except, perhaps, a loss of one or two' 
 grains in the hundred. The loss, therefore, in this part of the pro- 
 cess apparently lessens, as the loss in the earlier part increases the 
 statement of the strength of the manure. The whole may be sup- 
 posed to stand then : 
 
 27 grains of sand and clay '\ 
 
 21 " of carbonate of lime V:=50. 
 
 2 " of loss 3 
 
 If the loss be divided between the carbonate of lime and the other 
 worthless parts of the manure, it will make the proportion 28 and 
 22, which will be probably near the actual proportions. 
 
 The foregoing method is not the most exact, but is sufficiently so 
 for practical use. All the errors to which it is liable will not much 
 affect the reported result — unless magnesia is present, and that is 
 not often in manures of this nature. I have never found carbo- 
 nate of magnesia in any of the deposits of fossil shells in Virginia, 
 though it was in many cases sought for.* If, however, any consi- 
 derable proportion of carbonate of magnesia should ever be present 
 in marl tried by the foregoing method, it may be suspected by the 
 effervescence being very slow compared to that of carbonate of 
 lime alone ; and the proportions of these two earths may be ascer- 
 tained as follows : Tlae magnesia as well as the lime would be dis- 
 solved by the muriatic acid (applied as above directed), but the 
 magnesia would not be precipitated with the carbonate of lime, but 
 would remain dissolved in the alkaline solution, last separated by 
 filtering. If this liquor is poured into a Florence flask and boiled 
 for a quarter of an hour, the carbonate of magnesia will fall to the 
 bottom, and may then be sej^arated by filtering and washing, and 
 its quantity ascertained by being dried and weighed. — (Davy.) 
 This part of the process may be added to the foregoing, but it will 
 very rarely be required. 
 
 If desired, the proportions of sand and clay (besides the calcare- 
 ous parts of each) may be ascertained with enough truth for prac- 
 tical purposes, by stirring well the remaining solid matter in a 
 
 * Carbonate of magnesia is known to me only in one case. This is of a 
 peculiar compound of carbonates of lime and magnesia witliotlier common 
 earths, found on Bear Creek Island in Hanover county, above the falls of 
 Pamunkey. 1 have seen it only in a specimen sent to me fifteen years ago, 
 and of which analyses were made both by Prof. W. B. Rogers and myself, 
 in 'different modes, with like results. I presume this earth must have been 
 found in very small quantity, as I have never heard of its being used as 
 manure, nor indeed anything else about it. 
 
 Prof. C. U. Shepherd reports magnesia found by him in some of the rich 
 eocene marls of South Carolina. I had before soiight for it in vain, ia_many 
 otlier specimens of the same general kind of marl. 
 
ANALYZING OF MARL. 313 
 
 glass of water, and, after letting it stand a minute, for the sand to 
 subside, pouring off the fluid, with the lighter and still floating clay, 
 into another glass. The sand will be left, and the clay will be 
 poured off with the water ; and each may be collected on filtering 
 paper, dried, and weighed separately. 
 
 The proportion of carbonate of lime in marl may also be conve- 
 niently and correctly determined by the diminution of weight from 
 the escape of the carbonic acid ; the quantity of which is always 
 in an invariable proportion to the lime with which it is combined. 
 For this purpose, weigh (in a thin and open-mouth vial) a certain 
 quantity (say 200 grains) of muriatic acid. Then of well dried 
 and powdered marl, weigh half as much (100 grains), and then add 
 the weighed marl, very slowly and gradually, to the acid. After 
 all effervescence has ceased, the whole will fall short of the original 
 weights (300 grains), by that of the carbonic acid evolved. This 
 bears the fixed proportion (very nearly) to the carbonate of lime, 
 of 45 parts in the 100. Therefore for every 4.5 grains weight 
 lost, estimate 10 grains of carbonate of lime in the marl tried. — 
 (Davy.) 
 
 For want of attention to the only safe guide, the chemical analy- 
 sis of marl, gross errors are often committed, and losses continually 
 sustained. By relying on the eye only, I have known marl, or 
 rather a calcareous sand, to be rejected as worthless, and thrown 
 off at considerable cost of labour, to uncover worse marl below, in 
 which whole shells were visible ; and on the contrary, earth has 
 been taken for marl, and used as such, which had no calcareous 
 ingredient whatever. The best marls for profitable use are gene- 
 rally such as show the fewest whole shells, or even large fragments, 
 and Avould be passed by unnoticed in some cases, or considered 
 only as barren sand, or equally worthless clay. But even if such 
 mistakes as these are avoided, every farmer using marl, without 
 analyzing specimens frequently and accurately, will incur much loss 
 by applying it in quantities either too great or too small. 
 
 Distant transportation of Marl. 
 
 An interesting question respecting the expense of this improve- 
 ment is, to what distance from the pit may marl be profitably 
 carried? If the amount of labour necessary to carry it half 
 a mile is known, it is easy to calculate how much more will be 
 required for two or three miles. The cost of teams and drivers is 
 in proportion to the distance travelled; but the pit and field labours 
 are not affected by that circumstance. At present, when so much 
 poor land, abundantly supplied with fossil shells, may be bought at 
 from two dollars to four dollars the acre, perhaps a farmer had bet- 
 ter buy and marl a new farm, than to move marl even three miles 
 27 
 
314 DISTANT TRANSPORTATION OF MARL. 
 
 to his land in possession.* But this would be merely declining one 
 considemble proiit, for the purpose of taking another much greater. 
 Whenever the value of marl shall be properly understood, and 
 our lands are priced according to their improvement, or their capa- 
 bility of being improved from that source, as must be the case here- 
 after, then this choice of advantages will no longer be offered. 
 Then rich marl will be profitably carted eight or more miles from the 
 pits, and perhaps conveyed by water as far as it may be needed. A 
 bushel of such marl as the bed on James river, described page 144, 
 containing 62 per cent, of carbonate of lime, is as rich in calca- 
 reous earth alone, as a bushel of slaked lime will be after it 
 becomes cai'bonated; and the greater weight of the first is a less dis- 
 advantage for water carriage, than the price of the latter. Many 
 marls, in other places, are much richer than this, and also dry, and 
 easy to work. Farmers on James river, who have used lime as 
 manure to great extent and advantage, might more cheaply have 
 moved rich marl forty miles by water, as it would cost nothing but 
 the labour of digging and transportation. (1882.) 
 
 Within the short time that has elapsed since the first publica- 
 tion of the foregoing passages in the previous edition of this essay, 
 the transportation of marl by water carriage has been commenced 
 on James river, and has been carried on with more facility and at 
 less expense than was anticipated. The farmers who may profit by 
 this new mode of using marl will be indebted to the enterprise of 
 C. H. Minge, Esq., of Charles City, for having made the first full 
 and satisfactory experiment of the business on a large scale, 
 (1835.) I induced this gentleman to undertake this operation, for 
 improving his farm in Charles City county (now known as Sher- 
 wood Forest, and the property and residence of President Tyler), 
 not only by advice, but by offering to him the gratuitous use of my 
 marl on Coggins Point. His operations were continued through 
 two years. His example was subsequently followed by some other 
 farmers to less extent, and at much greater cost, as they hired the 
 freighting, though obtaining the marl from me, in the bed, without 
 
 * This statement of prices, though correct when first published (in 1832), 
 IS no longer so. Some little land may yet be so low ; but, in general, the 
 prices of lands having maii have already advanced from 50 to 100 per cent, 
 ■within fifteen years (1842). The lowest of the above-named prices was much 
 above the former minimum rate. The various tracts of land in James City 
 county, belonging to Mrs. Paradise's large estate, when sold some 12 or 14 
 years ago, brought prices that averaged only about $1.25 the acre. Most 
 of the lands were poor, but easily improvable, and all having plenty of rich 
 marl. One of the tracts of that description, of 800 acres, was bought at 
 75 cents the acre ; and after being held for three or four years, without 
 being in any respect improved, was re-sold by the purchaser for $2.50 the 
 acre. Where marl has been actually applied, the increased intrinsic or 
 productive value of the land always considerably exceeds the increased 
 market price, eveu though the lutter may be ah-eady doubled or tripled. 
 
•VVATER-BORNE MABL. 313 
 
 charge. Since, the business has gi-eatly increased, and is now car- 
 ried on by many fiat-bottomed vessels (or lighters, decked and 
 rigged), from other places on James river, as a regular and con- 
 tinuous business. But still the business is badly conducted in 
 general, and /herefore is much more costly than it would be under 
 better and proper direction. Farmers are averse to being engaged 
 in the management of vessels, or any other business away from 
 their farms, and therefore they have always preferred to bity the 
 marl from vessels, even at higher prices, rather than to have it dug 
 by their own labourers and transported in their own vessels. And 
 this division of labour would be right in all respects, if the owners 
 of the river lighters were better managers of their business, and 
 their hands were industrious and sober. For rich marl thus ob- 
 tained and transported, the prices at the purchasers' landings have 
 usually been from 4 to 5 cents the heaped bushel. And at these 
 high prices, the lazy and worthless and ill provided navigators 
 have rarely realized any profit. The highest price charged for marl, 
 in beds on the river banks, is a half cent the bushel. Under ex- 
 isting circumstances, the cheapest and best mode of obtaining 
 water-borne marl is for the farmer to also carry on the digging and 
 the navigating. And if the several operations were j)roperly con- 
 ducted, the entire expense of water-borne marl, say 10 to 30 miles, 
 will rarely exceed 3 cents the bushel when landed, and under 
 favourable circumstances may fall short of 2 cents. Collier H. 
 Minge, Esq., and Gen. Corbin Braxton, of King William county, 
 who have carried on this business extensively, and for years in sue- 
 cession, for marling their own farms, have furnished me with careful 
 and detailed estimates of their expenses, which have been published 
 at length in the Farmer's Register (p. 5G7, vol. i., and p. 691, vol. 
 viii.). According to the estimate of Mr. Minge, the entire cost of 
 thus procuring marl, carried 15 miles on the broad water of James 
 river, amounted to less than 2 cents the heaped bushel when landed. 
 And Gen. Braxton's total expense, the transportion being for eight 
 miles on the narrow and smooth Pamunkey, was but little more 
 than half a cent the bushel, placed at his landing. No charge was 
 made for the marl in either case, but every other charge or expense 
 was included. The labour and difficulties on James river, both 
 of uncovering and digging the marl (at Coggins Point) and un- 
 loading (on a shallow creek) were unusually great ; and on the 
 Pamunkey these labours were very light. A vessel and also a 
 mode of loading, which would be safe in strong winds, were neces- 
 sary on James river ; while no such danger had to be feared, or 
 was guarded against, on the well-sheltered Pamunkey river. So 
 much of the business, in both these cases, as was conducted from 
 home, necessarily was wanting of proper superintendence ; and, no 
 doubt, both of these undertakings suflFered for that important de- 
 
310 WATEfif-BSos" ITm£' 
 
 ficicncy, as in all cases where labour is on a small scale of opera- 
 tions, and more especially when skive labour is employed.* 
 
 Another source for obtaining calcareous manures has been opened 
 to the farmers of lower Virginia, which they think cheaper than either 
 transporting marl or burning shells, and they are availing themselves 
 of it to great extent. This is northern stone-lime, which is brought 
 in bulk, ready slaked, and sold by the vessel-load at prices varying 
 from § to 10 cents the bushel. Slaked lime, even if pure, from 
 its extreme lightness, cannot be as much to the bushel as rich 
 marl contains of pure lime, even though the marl may have 30 
 per cent, of other earths. Therefore the lime is much the most 
 costly, as marl may be procured and transported at from 3 to 5 
 cents the bushel. Still, the lime is so much more readily obtained 
 in large quantities, and a farm can by that means be so much more 
 speedily covered, that the purchase of lime is often the more de- 
 sirable and also the more profitable operation of the two. (1842.) 
 
 In making this improvement, more than in any other business, 
 ''time is money.'' Marling is usually effected by the farmer's 
 labour, whereas the expense of liming is mostly in the purchase. 
 By the use of water-borne marl, few farmers could dress a fourth 
 of their tillage field in a year, whereas by purchasing lime the 
 whole field might be limed, and the whole farm covered in one- 
 fourth of the time required for marling. If then the lime were 
 even thrice the cost of marl (for equal quantities of pure lime), it 
 would still be the cheapest mode of improvement, because yielding 
 its products in one-fourth of the time required for marling. The 
 difference of amount of net product in the first crop, between au 
 acre marled or limed, and another acre not so improved, would 
 usually pay the cost of marling or liming the acre. Therefore, on 
 every acre cultivated by any farmer, and not marled or limed until 
 
 * Since 1843, the water-carriage of marl on James river has greatly in- 
 creased. About ten decked and rigged flat-bottomed vessels have generally 
 been employed in carrying marl from what may be considered one locality, 
 in the neighbourhood of my former residence, in Prince George county, 
 though on the close adjacent lands of three propiietors. Half a cent the 
 bushel is paid for the marl in its bed. For the labour and expense of 
 removing the overlay of earth, digging the marl and carrying it on board, 
 and convej'ing to distances from 15 to 40 miles, the carriers charge from 
 3J to 4 cents — making the total cost at the buyer's landing place from 4 to 
 4J cents. A still larger business has been at the same time carried on in 
 bringing slaked stone-lime, in sea vessels, to James river, from the kilns 
 on the Schuylkill and Hudson, and elsewhere in the Northern States. This 
 lime has latterly been sold as low as 7 cents the bushel, usually, and in some 
 cases still lower. The principal demand for and use of both the water- 
 borne marl and lime is on the lands of Charles City county, where marl is 
 not found on any of the river lands, and in but few cases near to the 
 river. (1849.) The Schuylkill lime contains about 05 per cent, of mag- 
 nesia. The New-Yoi-k lime contains much silex. 
 
MARL ON RAIL-ROADS. 317 
 
 after mating tlie crop, there is as mucli loss of crop suffered by 
 the dehay, as would have paid for makiug the improvement. 
 
 The objections to carrying marl unusual distances, admitted 
 aboVe, apply merely to improvements proposed for field culture. 
 But it would be profitable, even under existing circumstances, 
 for rich marl to be carried 10 miles by land, or 200 miles by 
 water, for the purpose of being applied to gardens, or other land 
 kept under perpetual tillage, and receiving frequent and heavy 
 coverings of putrescent manure. In such cases, independent of 
 the direct benefit which the calcareous earth might afford to the 
 crops, its power of combining with putrescent matters, and pre- 
 venting their waste, would be of the utmost importance. If the 
 soil is acid, the making it calcareous will enable half the usual 
 supplies of manure to be more effective and durable than the whole 
 had been. There are other uses for marl, about dwelling-houses 
 and in towns, which should induce its being carried much farther 
 than mere agricultural purposes would warrant. I allude to the 
 use of calcareous earth in pi-eserving putrescent matters, and 
 thereby promoting cleanliness and health ; which subject has been 
 already discussed. 
 
 Either lime or good marl may hereafter be profitably distributed 
 over a remote strip of poor land, by means of the railroad now 
 constructing from Petersburg to the Roanoke [18.31]; provided 
 the proprietors do not imitate the over greedy policy of the legis- 
 lature of Virginia in imposing tolls on manures passing through 
 the James River canal. If there were no object whatever in view 
 but to draw the greatest possible income from tolls on canals and 
 roads, true policy would direct that all manures should pass from 
 town to counti'y toll free. Every bushel of lime, marl, or gypsum 
 thus conveyed, would be the means of bringing back, in future 
 time, more than as much wheat or com ; and there would be an 
 actual gain in tolls, besides the twenty-fold greater increase to the 
 wealth of individuals and the state. 
 
 27 * * 
 
CHAPTER XXVin. 
 
 ESTIMATES OF THE COST OP LABOUR APPLIED TO MARLING. 
 
 Before we can estimate with any precision the expense of im- 
 proving land by marling, it is necessary to fix the fair cost of every 
 kind of labour necessary for the purpose, and for a length of time 
 not less than one year. We very often hear gncsscs of how much 
 a day's labour of a man, a horse, or a wagon and team, may be 
 worth ; and all are wide of the truth, because they are made on 
 wrong premises, or no premises whatever. The only correct method 
 is to reduce every kind of labour to its elements, and to fix the 
 cost of every particular necessary to furnish it. This I shall at- 
 tempt ; and if my estimates are erroneous in any particular, other 
 persons better informed may easily correct my calculation in that 
 respect, and make the necessary allowance on the final amount. 
 Thus, even my mistakes in the grounds of these estimates will not 
 prevent true and useful results being derived from them. 
 
 The following estimates of the cost of labour were first prepared 
 in 18'28, according to the actual prices of that year, and so appeared 
 in the three preceding editions of this essay. The lapse of time and 
 changes of average prices of some of the elements of cost required 
 correction of some of the particulars. The corrected estimates now 
 submitted are not (as before) of the actual prices of any one parti- 
 cular year, but the supposed average^ prices of a number of years, 
 to the end of the year 1846. In making the necessary corrections 
 for this purpose, some of the original charges were deemed too 
 high for the average statement desired, and others of larger amount 
 were too low. The dilFerence is small (making less than 3 per cent, 
 of general increase), but has so far served to raise, on the whole, the 
 estimated costs of marling. 
 
 But no such estimates (even if at any one time correct in the 
 premises of prices assumed) can more than approach to accuracy 
 for any average of extended time, and still less for any particular 
 subsequent year, owing to the great and irregular fluctuations of 
 prices. Therefore, neither these nor any other estimates of costs 
 can be relied on to show the expense of labour always, or even 
 generally. But these may at least supply a convenient form and 
 rule for the true mode of estimating such values; and every person 
 may easily change the particular charges as required to suit other 
 circumstances. Thus, even if other times and circumstances should 
 require changes of price of every element of labour, the form of 
 
 (318) 
 
COST OF LABOUR — HANDS. 319 
 
 these estimates will still serve greatly to facilitate sucli alterations 
 and new calculations, and serve better to secure the accuracy of 
 the general results.* 
 
 Average prices of different elements of labour, applied to Marling 
 operations. 
 For a negro man — 
 Hire for the year, payable at the end . . . ^50 00 
 
 Food — lOJ bushels of Indian corn, at 45 cents $8 77i 
 Add 10 per cent, for loss in keeping 88 
 
 130 lbs. bacon, at 7 cents . . 9 10 
 
 Interest on 818.752 for a year 
 
 Clothing — 6 yards of strong woollen cloth, at 
 50 cents .... 
 
 13 yards of cotton, for shirts and sum- 
 mer clothes, at 10 
 
 Woollen hat 50 cents, blanket $1.30, 
 each once in two years, is yearly 
 
 Shoes and mendins .... 
 
 $18 75J 
 
 1 
 
 12J 
 
 $3 
 
 00 
 
 1 
 
 30 
 
 
 90 
 
 2 
 
 00 
 
 19 88 
 
 7 20 
 
 Taxes — State, 47 cents, county and poor, 80, 
 labour on public road, suppose two 
 days, 68 cents, . . . . . 1 95 
 
 For nursing when sick (exclusive of medical aid and 
 medicines), and share of expenses for quarters, fuel, 
 and sending to mill ...... 6 00 
 
 Add to this amount, 10 per cent, for superintendence 8 50 
 
 Total expenses per year, .... $93 53 
 
 * As stated above, these estimates were designed to suit the average 
 prices of a series of years preceding and including 1846. But since they 
 were prepared, owing to temporary causes, tlie prices of both hand and 
 mule labour have greatly advanced. Therefore, if any person designed 
 to begin a job of marling now, and had to incur for that pvirpose the recent 
 and still continuing high prices of mules and of hire of hands, the actual 
 advances on each of these particular expenses only should be added to the 
 general costs as here estimated. But, in fact, very few of our farmers 
 Lave to buy or to hire more than a small proportion of the force, if any, that 
 they apply to marling. Most landholders own enough, or nearly enough 
 labouring force, and h.'id before kept it at less profitable employments, to 
 can-y on marling in addition. This is known to be the case with nine in ten 
 of such operations. And so far as a farmer had been before the owner of 
 the labouring force he will devote to mai-ling, aud would have kept it, 
 
820 COST OF LABOUR — HORSES. 
 
 Time lost — Sundays and usual holidays, 58 days. 
 
 Bad weather and half holidays, and 
 sickness, suppose - - 30 
 
 Making in all . . . . 88 
 
 Deducting 88 lost days from 365 leaves for working days 
 277, and makes the cost of each day (193.58^-277 =) 
 not quite, ....... cents 34 
 
 A hoy of 13 or 14 years, might hire for $25 00 
 
 Food and clothing, two-thirds as much as a man's 18 12 
 Taxes (county and poor only) 80c., nursing, fuel, 
 
 &c., &c., ^4 4 80 
 
 ^7 92 
 10 per cent, for superintendence . . 4 80 
 
 Total yearly expense ^52 72 
 
 And daily, for 277 working days, not quite, cents 19^ 
 
 Women and girls over 13 years, may be averaged at the same 
 expense, though worth less for labour. 
 
 According to the established custom, all the expenses of medical 
 attendance, and loss of time from the death of a slave occurring 
 when he is hired, are paid, or deducted from the hire, by the 
 owner, and therefore are omitted in this estimate. By supposing 
 the slave to be hired by his employer, instead of being owned, the 
 calculation is made more simple, and therefore more correct. Yet 
 it is well known that the labour of slaves owned by their employe? 
 is much more profitable, and therefore should be estimated as 
 cheaper, than the labour of actual hirelings. 
 A ivovk-liorse. First cost in buying, at five years old, say §75 — 
 
 supposed to last six years, makes the annual icear §12 50 
 
 Interest for one year on $75, and tax, 12 J cents 4 62 J 
 
 96 bushels of corn (2| gallons for working days, and 
 
 2 gallons when idle) at 45 cents, and 3500 lbs. of hay 
 
 or fodder at 50 cents the 100 lbs. - - 160 70 
 Add 10 per cent, for expense and loss in 
 
 keeping 07 
 
 66 77 
 
 Interest on $66 77 for one year - - - 4 00| 
 
 Total yearly cost, $87 89 
 
 ■whether going to marling or not, it is manifest that he is not affected by 
 any temporary fluctuations of prices of labour. The prices which will be 
 here stated as fair averages may fall or rise to any extent for a year or two, 
 •without lessening or increasing the expenses of a proprietor who neither 
 hired, bought, uor sold labouring force during that time (1852). 
 
MULES, CARTS, &C. 321 
 
 Lost time, suppose 98 clays, leaves 267 working days, at nearly 
 33 cents, cost for each. 
 
 A mule, young, and of better than ordinary or average ability, 
 usually may be bought for less price than a young horse. A mule 
 may be kept at work on much less grain than is necessary for a 
 horse, and with coarser and cheaper long forage. The mule is also 
 more long-lived. All these considerations will make tlie cost of a 
 mule's labour, less than that of a horse by at least one-fifth ; which 
 being deducted, leaves, (33 — 6.30 =) 26f cents for the cost of each 
 working day. 
 
 A li(j]it tiimhrd or tilting cart, for one horse or mule, may be 
 bought for S25. Suppose it to last at marling (and other uses) for 
 four years without repair ; or that at the end of that time it would 
 be worth as much only as all the previous cost of repairs. Then 
 the annual cost of " wear and tear" would be one-fourth of the first 
 cost ($6 25) and the interest on $25, or $1.50, or annually, 
 $7.75; and daily (say for 190 days) 4 cents. 
 
 A tumbrel for two mules will cost $34, and will last at least five 
 y«ars marling, with but slight repairs. Suppose the cart at that 
 time to be worth the previous cost of all repairs, the annual cost 
 will be one-fifth of $34, and of its interest $2.04, making ($34 -^- 
 5 = $6.80+$2.04 =) $8.84 for the yearly cost, and daily for 190 
 days, nearly 5 cents. 
 
 Harness for each horse or mule, annual average cost may be 
 supposed $4, and daily for 267 days in use, li cents. 
 
 Of the utensils used for uncovering, digging, loading, and spread- 
 ing marl, as a scraper (used very rarely), grubbing hoes, picks and 
 shovels, the cost of use and wear, supposed to be fully covered by 
 3 cents the 100 bushels of marl put out and spread. 
 
 In the estimate of the cost of horse labour, no charge is made 
 for attendance, because that is part of the labour of the driver, and 
 forms part of his expense. No charge is made for grazing, because 
 enough corn and hay are allowed for eveiy day in the year ; and 
 when grass is part of his food, more than as much in value is saved 
 in his dry food. No charge is made for stable or litter, as the ma- 
 nure made is supposed to compensate those expenses. 
 
 It may be supposed that the prices fixed for corn, and fodder or 
 bay, are too low for an average. Such is not my opinion. The 
 price is fixed at the beginning of the year, when it is always com- 
 paratively low, because it is too soon for purchasers to keep shelled 
 corn in bulk, and the market is glutted. Besides, the allowance 
 for waste during the year's use (10 per cent.) makes the actual 
 price, equal to 49 ^ cents the bushel for corn, and 55 cents the 
 hundred for hay on July 1st. The nominal country price of corn 
 in January is almost always on credit ; and small debts for corn 
 are the latest and worst paid of all. The farmer who can consume 
 
822 ESTIMATES OP COST OF MARLINGt. 
 
 any additional portion of his crop, in employing profitable labour, 
 becomes his own best customer. The corn supposed to be used, 
 by these estimates, is transferred on the 1st of January, without 
 even the trouble of shelling or measuring, from A. B. corn-seller, 
 to A. B. marler, and instantly paid for. Forty-five cents the 
 bushel, at that early time, and obtained with as little trouble, from 
 any purchaser, would be a better regular sale than the general 
 average of prices and payments. 
 
 Tlie estimates of labour ajJjjlied to particular marling operations. 
 
 According to such estimates as the foregoing of the elements of 
 labour, or as corrected in any particulars which may be deemed 
 wanting, the expenses of marling operations ought to be estimated. 
 And if conducted with proper attention and judgment, it will be 
 found that, in the majority of cases in lower Virginia, the total cost 
 of applying marl, on farms furnishing the marl, would not exceed 
 one cent the bushel. In many other eases, of very favourable cir- 
 cumstances, half a cent the bushel would cover all the expenses. 
 In but very few cases of any known actual operations, and of rare 
 and great diflSculties to encounter, ought the total cost to have 
 reached 2 cents. Yet even if amounting to 6 cents (for rich marl), 
 there would still be great profit on the outlay ; which is sufficiently 
 proved by the great and increasing recent use of water-borne marl, 
 which is sold at 4 and 5 cents the bushel, delivered at the buyer's 
 landing, and which is further increased, for the carting to and 
 spreading on the field. 
 
 In my own long-continued and extensive marling labours, over 
 nearly all the arable land of three several farms in succession, I 
 have but in few cases, and those of small extent, bad very easy 
 work. Nearly all my marling has been of more than ordinary 
 difficulty, owing to the natural features of the land, and the posi- 
 tion and character of the marl ; besides the other early and great 
 difficulties always attending the first beginnings of new operations, 
 "without experience or other guidance. Yet, throughout all my 
 marlings (now extended to some 1500 acres, at more than the 
 general average rate of 400 bushels), the average of the whole ex- 
 penses ought not (as I would now conduct such) to have exceeded 
 one cent the bushel, spread on the field. 
 
 Such general opinions and statements, however, will be much 
 less satisfactory than statements of actual labours and the actual 
 costs. I know of no such estimates of the easier and cheaper 
 marlings — ^which indeed are so easy and cheap that no one would 
 care to calculate the cost. None of my cheapest operations were 
 extensive enough to furnish subjects for fair estimates. For, unless 
 the labours, especially of the teams, are continued neai-ly regularly 
 for some months, the accuracy of the estimates of cost may well be 
 
COSTS OF MAELING. 323 
 
 doubted. It is necessary for the labours to be continued through 
 enough time to test the ability of the teams to perform them, and 
 still keep in good condition. 
 
 At diflFerent periods, and under varying difficulties and circum- 
 stances, I have carefully estimated the expenses of four considera- 
 ble jobs of marling, each of which was but a portion of the usual, 
 and as heavy labours of the teams, extending much beyond the 
 portions of time and labour particularly estimated. And all the 
 four operations, in greater or less degree, were attended with more 
 natural obstacles and difficulties than are generally to be encoun- 
 tered on other farms. I will describe in general the circumstances, 
 facilities, and difficulties of each of these jobs, and give the results 
 of the estimates of costs. The details of the operations, though 
 carefully noted, and some of the earlier of them before published, 
 in the preceding editions, will be omitted here, except as to a more 
 recent and much the largest operation, of which the facts were 
 observed so minutely, that they are deemed worth reporting in de- 
 tail ; and which will be so reported in a subsequent chapter. 
 
 The labours and expenses of marling come under the following 
 four diflFerent heads: 1. Removing the overlay of earth; 2. Dig- 
 ging the marl and shovelling it into carts; 3. The carting to 
 the field ; and 4. The spreading. It rarely happens that all these 
 different operations are very easy — which would constitute the 
 cheapest possible marling ; and if all were very difficult, the whole 
 would be (or at least so deemed by most persons) too costly to be 
 compensated by the eventual improvement. It usually happens 
 that the unusual facilities for some of these particular labours serve 
 to compensate in some measure the obstacles presented in others. 
 
 The first job estimated was attended with such uncommon dis- 
 advantages that it may be deemed a failure, or as mostly lost 
 labour, and therefore not a fair subject for estimating costs. But 
 as the operations had been carefully noted, and as this work imme- 
 diately preceded, without any intermission, the second job, I will 
 state the fii'st also. 
 
 The two operations were but a small part of the excavation and 
 removal of a very large quantity of marl from this locality, enough 
 perhaps for 200 acres ; of which the portions estimated were among 
 the latest executed ; and the most expensive, because of the then 
 much increased thickness of the overlying earth. 
 
 The marl " cropped out," or was exposed at the surface of a 
 steep hill-side (in large forest growth). The upper 6 feet of the 
 marl was dry and firm, but easy enough to dig ; the shelly portion 
 in small fragments, and amounting to 45 per cent, of the mass. 
 Below 6 feet, it was much poorer (not 20 per cent.), and was not 
 used, except for very short distances. 
 
 I. The excavations for the first job, as usual on hill-side expo- 
 
324 COSTS OF MARLING. 
 
 sures, wag carried on by first cutting down the exposed and nearly 
 naked marl, which required but little labour for uncovering. The 
 next succeeding stretch reaching higher up the hill, had perhaps 
 as much overlying earth as of good marl beneath. The next had 
 much more overlay ; and indeed it was not worth uncovering so 
 deeply, when other places could be more cheaply worked. This 
 last stretch formed the subject of the first estimate. In reference 
 to the four divisions of the labour and expenses — 
 
 1. The removing of the overlay of earth was here unusually 
 heavy, compared to the thickness of the marl, rising to IG feet 
 where thickest, and averaged 11 to 12. 2. The digging and load- 
 ing, and also the spreading, were very easy. 3. The cai-riage easy 
 as to distance (997 yards average from pit to field), but bad in 
 having a hill to rise of about 40 feet perpendicular height, and 
 also a valley to cross, of about 30 perpendicular depth. 
 
 One-fourth of the uncovered marl was lost by the falling in of 
 a large body of earth from above; so that only 4 J feet of marl 
 was actually carried out, thus increasing the before heavy cost of ■ 
 the uncovering, for the quantity of marl saved. 
 
 Under these circumstances, the total costs, obtained by noting 
 every day's work, and its elements, and at the foregoing prices 
 (omitting the details), were as follows : — 
 Expense of removing overlay of earth (11 to 12 feet thick 
 
 on an average) ....... $24 70 
 
 Digging, loading, and carting marl (3844 heaped bushels) 26 18 
 Spreading, at 50 cents the 500 bushels . . . . 3 84 
 
 Total, $54 72 
 
 "Which makes the cost per 100 bushels, $1.42 ; and per acre, as 
 applied, at 572 bushels, $8.12; or if for 300 bushels, $4.26. 
 
 The quantity actually applied was much too heavy; and by the 
 excess increased, by one-third, the otherwise heavy expense. The 
 thickness of the dressing, however, made the spreading cheaper 
 for the quantity, the heaps being so much the closer to each other. 
 II. The second job followed on immediately, but on the opposite 
 slope (across the narrow ravine), where the overlay was 8 2 to 9 
 feet average depth, and all the G feet of good marl was used. The 
 average distance from pit to field (over the same hilly road), was 
 887 yards. The marl being precisely as in the first job, the facili- 
 ties for digging, loading, and spreading were the same. But the 
 loads (for a single horse or mule-cart), which before were 5 J heaped 
 bushels, were now 5J — the marl weighing 101 lbs. 
 
 Removing overlay ...... $14 15 
 
 Digging and carting marl (4036 bushels) . . 20 75 
 
 Spreading, at 50 cents the 500 bushels . . . 4 30 
 
 Total, $39 26 
 
COSTS OF MARLING. 825 
 
 Which makes the cost, per hundred bushels, 97 J cents ; or, per 
 acre, as applied, at 598 bushels, $5.8l2-; or, if at oOO bushels, 
 which would have been an abundant first dressing, $2,911 per acre. 
 These two jobs extended, without interruption, except from bad 
 weather or accidents to carts, from April 20th to May 31st, 1824. 
 Two ordinary horses and a very good mule were worked in light sin- 
 gle carts. The best of the two horses was seventeen years old. The 
 two had been kept at hauling marl, whenever weather permitted, 
 from the beginning of the preceding November ; and, indeed, the 
 same two horses had carried out nearly all the marl on Coggins 
 farm, since the commencement in 1818. The day's ti-avel from pit 
 to field and back, for both the two jobs, varied from 22 to 23 J 
 miles, besides about IJ miles in all from and to the stable. For 
 the digging, loading, and carting, two men and two small boys were 
 employed. 
 
 III. The third estimated job was on Shellbanks farm, also in 
 Prince George county, over a much larger surface than the preced- 
 ing, but from sundry different pits, over different routes, and to 
 different fields. The overlay was mostly thinner than the marl 
 beneath, and both were dry in most cases ; the working of both 
 easier than usual ; the distances moderate, the average from pits 
 to fields being not more than half a mile ; though the land being 
 hilly, almost every load had to rise a hill from the pit, from 40 to 
 100 feet of perpendicular height. In 1828, soon after buying this 
 poor farm, I began the marling, and in about 4 months finished 
 120 i acres at rates between 230 and 280 bushels per acre. The 
 time taken up in this work was five days in January, and all Febru- 
 ary and March, with two single mule carts (and but ordinary 
 mules), and from August 5th to September 27th, with a much 
 stronger force. 
 
 Taking everything into consideration, I should suppose that the 
 labour and cost of this large job of marling will be equal to, if not 
 greater than the average of all that may be undertaken, and 
 judiciously executed, on farms having plenty of this means for im- 
 provement, at convenient distances. The whole cost of this large 
 job was as follows : — 
 
 Preparatory work, including uncovering marl, cutting 
 and repairing the necessary roads, and bringing corn 
 (from another farm) for the teams — digging, carrying 
 out, and spreading 6892 loads of marl (4 J heaped 
 bushels only, because of the steep hills, and sometimes 
 wet marl), 31,014 bushels on 120 J acres, - - $265 90 
 At the average rate of 57 i- loads, or 259 bushels per 
 
 acre, the average expense was to the acre, - - 2 28 
 
 Or $;2.58, if for 300 bushels to the acre. 
 And to the bushel, - - 86-lOOths of a cent. 
 28 
 
826 COSTS OF MARLING. 
 
 In this job, the quantity of labour of every kind employed, wag 
 accurately noted, and also the amount of marl carried out ; so that 
 the cost could be very exactly calculated. But owing to the great 
 and frequent variation of distances from the various pits opened, 
 there was no measurement of the travel made, and of course the 
 proportion of work performed to the force engaged was not known. 
 
 ly. The next job of marling estimated was in 1844, on Marl- 
 bourne, a farm on the Pamunkey river then recently bought, and 
 made my residence. This is the operation of which the facts in 
 detail will be given hereafter. Therefore it is enough to state here 
 that the total cost of 7803 bushels, carried to the average distance 
 of 1436 yards from pit to field, amounted to 94 cents for the 100 
 bushels of marl, spread on the land. 
 
 Thus, of these four considerable operations, performed at diffe- 
 rent periods, and under different circumstances, of which one only 
 can be deemed of ordinary facility and cheapness, and one other 
 was excessively laborious and expensive, the costs brought together 
 are as follows : — 
 
 1st, on Coggins Point farm, - - - 
 
 2d " li a ti _ _ . 
 
 3(J, " Shellbanks, . - - _ 
 
 4th, " Marlbourne, - _ . - 
 
 But not one of these operations was as judiciously and cheaply 
 executed as my more full experience would now direct; and if 
 either one were now to be done, I could save much of the labour 
 before expended. Nor does this rest on supposition, but has been 
 actually tested by further and large operations in the same locality 
 and circumstances as of the fourth in the above statement. By 
 improving the processes, or avoiding previous waste of means, 
 something has been saved in every branch of labour, as will here- 
 after be shown. 
 
 Cost per 100 
 
 Cost per aero if 
 
 ieape<i bushels. 
 
 at 300 bushels. 
 
 $1 42 
 
 $4 26 
 
 97^ 
 
 2 92 
 
 86' 
 
 2 58 
 
 94 
 
 2 82 
 
CHAPTER XXIX. 
 
 DETAILS OF ACTUAL AND EXTENSIVE MARLING LABOURS. 
 
 The largest known uncovering and excavation of marl is that 
 ■which was begun by me in 1844, soon after my resuming marling 
 labours in a new locality, and under new circumstances ; and which 
 work was in progress to 1850. This work is deemed worthy of 
 being particularly described, for the extent and the mode of opera- 
 tion ; and still more because some or all of the same general features 
 ' of the locality, and advantages and difficulties, belong to very many 
 other situations, of low-lying marl. It will not be my aim, in this 
 place, to describe the general character or to note differences of the 
 extensive marl formations of the Pamunkey river ; but to s^ate 
 minutely the particular conditions of this one locality, and the 
 labours there actually performed. 
 
 The place is on the Newcastle farn^ belonging to Carter Braxton, 
 Esq., and adjoining my own. The ground is part of a long and 
 narrow stretch of the lower and more sandy land of the broad 
 flats boi'dering the Pamunkey. The surface soil, covering the dig- 
 gings to be described, is nearly level, but gradually rises, and the 
 earth overlying the marl increases in thickness from 4 feet, in the 
 earlier work, to 6J at its greatest present enlargement. The sur- 
 face of the bed of marl is also very nearly horizontal ; and the vari- 
 ations from the level do not agree with those of the surface soil. 
 
 The marl originally was here exposed to view by being partly 
 cut through by a narrow gully conveying a small stream ; which 
 stream received all the drainage of the adjacent land, and thereby 
 was subject to be swollen by heavy rains. The stream, naturally, 
 was about 2 feet below the highest exposed marl, and about 4 feet 
 above the bottom of the bed at the same place. Except the con- 
 tinuation of this stream, and the narrow ravine conveying it, which 
 very gradually descended to the river, all the adjacent ground 
 was at least four feet higher than the upper surface of the marl. 
 The annexed figure will show the profile of the different layers, at 
 the distance of 40 to 60 feet from the stream. 
 
 (327) 
 
328 
 
 Overlay. 
 
 PAMUNKEY MARL. 
 FlGUKE 1. 
 
 'Saudy siu-facc soil, about 6 inches 
 
 Sandy sub-soil, dry and firm "1 
 Loose and dry sandy gravel J 
 
 Indurated ferniginous sandy "I 
 gravel, wet, 1 foot J 
 
 Feet. 
 
 w 
 
 Wet and adhesive green clay, ("olive earth") 1 foot 
 
 Marl. 
 
 ' Soft and pervious clay marl, 6 inches 
 Compact and impervious clay marl, 5 feet 
 
 Softer layer, 1 foot 
 
 Layer of stony lumps, 1 foot 
 
 Gypseous, or green-sand earth, with very little shelly mat- )^ 
 ter, of great and ujiknown thickness — at least 40 feet j 
 
 40 
 
 The soil of the overlying land is a rich black sandy loam (before 
 drained and cultivated), 6 or 8 inches deep, lying on a sandy 
 subsoil, firm and dry, and becoming more coarse and loose as de- 
 scending, until it is more of fine gravel than sand. All the above 
 layers, varying from 2 J to 4 feet in the successive uncoverings, are 
 dry and easy to dig and remove. Below these, the gravelly sand 
 is more or less cemented into a hard and almost stony bed, by the 
 percolation of ferruginous spring water. Under this layer, which 
 is full of veins, of springs, coming from beneath the higher ground, 
 there lies a very uniform layer, from 8 to 14 inches thick, of green 
 clay, which is the water-bearing stratum, and keeps the lower part 
 of the gravel above full of water. This green clay has a very pe- 
 culiar appearance and texture. Though very largely constituted 
 of pure clay, and extremely adhesive and close after being moved, 
 yet in its bed it is very soft and pervious to slowly-oozing water, 
 and, of course, is saturated by the numerous veins of springs above, 
 I think that this green clay was formerly the upper part of the 
 marl ; and has had all its former shelly matter decomposed and 
 carried oif by the constant access and passage of water containing 
 salts of iron. The upper 4 to G inches of the marl immediately 
 below this clay, seems as if in transition to the same state. It is 
 Boft, permeable by water, miry, and adhesive, all which are qualities 
 of the clay above, and entirely diflferent from the compact marl 
 
EXCAVATION OF SMALL PITS. 329 
 
 below. Although this lower marl also contains a large proportion 
 of clay, yet the carbonate of lime present, in finely-divided state, 
 not only preserves a very firm natural texture, but also prevents 
 adhesiveness in working; unless the marl is permitted to receive 
 water after being dug and finely reduced. Then, indeed, it is made 
 a sticky mass; and the labour of shovelling it is more than doubled. 
 
 The whole bed of marl at this place varies from 6 to 8 feet in 
 thickness, and generally is more than 7 feet, through the extent 
 of my work. The much larger part, of 4 to 6 feet thick, is per- 
 fectly impervious to the passage of water, though highly absorbent 
 of moisture, and always moist in its bed. This requires to be dug 
 by a heavy and narrow grubbing-hoe, which, in the hands of a good 
 pit-man, can be sunk barely 3 inches into this marl at a stroke. 
 Still lower, for a foot or more, the marl is softer, and the shells 
 are less reduced. And lowest, also for about a foot, the marl is in 
 large stony masses, lying so closely as to form a connected pavement. 
 The bi'eaking up of this stony layer requires heavy and strong 
 picks, and the work is laborious and slow. But these hard lumps 
 are much richer in lime than the marl above. The excavation is 
 carried no deeper than through this stony layer ; and even that 
 has often been omitted, on account of the greater labijur to dig, 
 and to throw it up from the greatest depth. 
 
 Next below this stony layer is the green-sand earth, of great and 
 unknown depth. Here, this contains only about 2 or 3 per cent, 
 of carbonate of lime, in a few widely dispersed shells, with the 
 usual and considerable proportion of green-sand. I do not use this 
 earth, nor deem it worth using as manure, where the upper marl 
 is to be obtained. Nevertheless, this lowest bed was formerly used 
 by the proprietor, and by others, in this neighbourhood, as "marl," 
 without discrimination; and it was then even preferred by most 
 persons to rich calcareous marl, if the latter were without green- 
 sand.* 
 
 Excavation of Marl in small perpendicular pits. 
 
 The first working was begun by digging and throwing off the 
 overlay adjoining a part of the narrow " out-crop" or exposed marl, 
 on the side of the natural gully through which the stream flowed, 
 so as to uncover a surface of marl 5 or 6 feet wide and 8 or 9 iu 
 length (marked 1, in fig. 2). So narrow was the gully, and so lit- 
 tle fall had the stream, that it was difficult to dispose of the earth 
 from even this small uncovering. The marl was then dug out, so 
 
 * The description of the strata is here generally confined to such features 
 as materially afiected the labours of excavation, and removal of the overlay 
 and marl, or the supposed manuring values of the lower beds. In a subse- 
 quent part, in connexion with the marls of Virginia in general, the Pa- 
 munkey beds will be more fully described. 
 
330 
 
 MANNER OF EXCAVATION. 
 
 FlO. II. 
 Eorizontal Plan of Marl Diggings. 
 
Explanations. Fia. II. 
 
 X, X — Stream, in a small natural ravine, on the sides of which some of tho 
 marl was exposed, at the out-cropping. 
 
 A, A — the first range of marl, successively uncovered and excavated in the 
 small perpendicular pits 1, 2, 3, 4, &c. 
 
 B, B, and C, C — second and third ranges of diggings, in like manner, but 
 increased in sizes of pits. 
 
 D, D, D — at first the natural siu'face of ground (5 feet above the marl), on 
 which the marl was thrown out of the pits of range C ; and next after, 
 D, D, D, was the first range of graduated digging. 
 
 c, d — the upper part of D, 96 feet long, the overlay but partly removed at 
 first, so as to form an inclined plane for the roadway. The same de- 
 scending grade continued in excavating the marl from d to e e. 
 
 c, d, e, e — narrow drain cut first down to, and afterwards into the marl, to 
 intercept spring water, and turn it into the stream z — and thus to drain 
 the space D D. 
 
 ff, g — farm road, on level, opposite ranges D, E, F, G, rising from 5 to 6^ 
 feet above the marl. 
 
 h, h, h, h — upper ends of roads successively used from the graduated dig- 
 gings. 
 
 0, — Slower onds of descending roadways in the marl. 
 
 E, F, G — successive ranges, uncovered and excavated in graduated diggings, 
 similar to D, but increased In extent. 
 
 H, H — range 36 feet wide, uncovered for next working — and less than half 
 the marl of which was excavated, when my operations at this place were 
 finally closed in December, 1850. 
 
 N. B. The Fig. II. is drawn on the scale of 80 feet to the inch, for tho 
 dimensions of ratfges, and the general outline and space. But small sizes, 
 and distances, as width of drains, &c., are necessarily irregular, and much 
 larger than the scale. 
 
 (331) 
 
332 EXCAVATION OF SMALL PITS. 
 
 as to form a pit with perpendicular sides, and thrown upon the 
 adjoining firm ground (on 3), whence the carts removed it nearly 
 or quite as fast as supplied from the digging. This small excava- 
 tion served to receive the removed overlay from the next adjoining 
 and larger uncovering (2), which, when pitted, in like manner, 
 received the overlay from a still larger space (3). In this manner, 
 successively digging out small pits with perpendicular sides, and 
 then filling each one with the earth removed to uncover adjoining 
 and enlarged spaces, the whole of the first irregular range (A A A) 
 was worked out, between the stream (^x) and the line a b, then the 
 lower limit of the firm overlying surface gi-ound, on which the marl 
 had been thi-own for the carts, from the previously dug range of 
 pits. So fgr, the work had been on the thinner out-running of the 
 strata, and the sloping overlay not any where more than 4 feet thick. 
 But thin as it was, and close to the places where thrown, the re- 
 moval was laborious, owing to the oozing spring-water, and the 
 adhesive clay, made much worse by the quantity of water. Of 
 course, for such small and frequent uncoverings the previous cutting 
 off of the access of springs was out of the question. This difiiculty, 
 caused by the water being necessarily worked up with the clay and 
 other earth, increased with the increased width of the uncoverings, 
 and the distances to throw off the earth. Each small uncovering 
 of marl, after all its overlay had been removed, was separately 
 drained, by a small trench being dug in the marl along its land 
 side, and catching and leading the intercepted oozing springs into 
 the previously made and still partly open excavations. As the 
 marl was thrown up across these draining trenches, they were fre- 
 quently choked by the marl, falling back. This was partially 
 guarded against by laying a thick plank over the trench. Walls 
 of marl, 15 to 20 inches thick, were left between each completed 
 pit and the next one begun, to keep out of the newer work the 
 mud and water which filled the older. But after each pit was 
 finished, more or less of the wall previously left was cut down, and 
 so much of the marl saved. Still, there was much loss of marl in 
 what was necessarily left of these walls. Besides, other losses were 
 sometimes caused by floods from heavy rains, or the breaking down 
 of walls, filling unfinished diggings with water or mud too ^eep to 
 be worth the cleaning out. 
 
 Along the first range of digging (A A A), the stream was higher 
 than the bottom of the pits, from 2 feet at the beginning (1), to 4 
 feet at the upper end («). Its water was kept out of the diggings 
 by leaving a narrow wall of marl alongside of the stream. This 
 served as a barrier until each pit was finished ; after which the en- 
 trance of water caused no serious inconvenience. As the pitting 
 was extended up the course of the stream, the thickness of the 
 marl stratum increased to 8 feet. The lowest stony layer, however, 
 
EXCAVATION OF S3IALL PITS. 833 
 
 was then generally left ; being not deemed worth the great labour 
 of throwing it up so high. The overlay being there 4 feet thick, 
 the extreme height to raise the marl was 12 feet from the bottom 
 of the marl to the surface of the ground where the carts were 
 loaded. 
 
 In this manner of working, were successively uncovered and 
 excavated the next ranges, B B and C C. But before either range of 
 marl was near being finished, the removal of the next succeeding 
 overlay had been begun and was extended at convenient times, and 
 especially when the wet or frozen condition of the land forbade 
 most other form labours. At such times, the worst previous 
 weather but slightly impedes the uncovering of marl ; and thus a 
 large proportion of this heavy labour has been performed whea 
 scarcely any other farm work could be done. This circumstance 
 greatly diminishes what would otherwise be the expense. 
 
 The digging of the first marl (1 in A) was begun on June 28th, 
 1844. The excavation of the third range of pits, CC, was finished 
 the following April. This last range was 250 feet long, 15 
 feet wide on an average ; and measured 25,800 cubic feet in the 
 bed (allowing a proper deduction for lost walls and bottoms), which 
 would expand to about 29,670 heaped bushels after being dug. 
 
 The separate pits of the wider and more regular range C C were 
 much longer, as well as much wider, than those of the earlier ranges. 
 They were the full width permitted by that of the uncovered marl, 
 clear of the narrow drain on the land-side, and the wall left on the 
 opposite .side — or about 13 feet. In length, they were 15 to 20 
 feet, or more, to suit the amount of labour engaged. In the 
 usually dry weather of summer and autumn, and even in winter 
 when "a strong force was employed, there was the less danger of 
 having unfinished work suspended by rain, and lost by overflow 
 of water, or caving earth ; and then larger diggings were opened. 
 By increasing the size of the pits, there was the less trouble in 
 constructing new drains, less loss in the dividing walls left, and 
 more space and convenience for the pit-men. Besides, there was 
 the benefit of equalizing the labour of throwing out the marl, by 
 keeping the digging on two different levels at the same time. 
 
 The still slightly increasing thickness of the overlying earth 
 made that of the next range (D) 5 feet ; to which height, of course, 
 the marl was thrown from the pits of C, making the perpendicular 
 height from the top of the marl 5 feet, and from the boitom, 13 
 feet, when all was dug ; or 12 feet when the stony bottom layer 
 was left, as was now usual. But to make sure of the thrown marl 
 not falling back into the pit, and especially when there was some 
 quantity of marl remaining in the pile in advance of the carting, 
 the height of the pit-man's cast was necessarily considerably more 
 than the mere depth of the then excavation. Added to this was 
 
834 LABOURS OP A SINGLE MULE. 
 
 all the lateral distance, which where greatest of the range C, and 
 from the outside of the pit across to the loading place, was usually 
 14 and in some wider parts 17 feet. This throwing of the marl 
 from the greatest depth and width of the pit was very heavy and 
 slow work. 
 
 It was after the usual steady work of my then regular marling 
 force, begun the 24th of the preceding January at another digging, 
 and continued whenever the state of the weather and roads per- 
 mitted, that the excavation and carting were begun at this digging 
 on June 28th, 1844. On April 29th, previously, I had begun to 
 measure and to note the quantity of marl carried every day by 
 each cart, and the distances travelled ; and of which the record 
 was carefully and accurately continued until Sept. 11th (with the 
 exception of a few days only, when the teams were at other work), 
 for every day when the weather and roads permitted marling. 
 Though noting thus the work of every separate cart and team, 
 whether regularly or rarely so employed, the trial was especially 
 designed for one particular mule, which was always kept at hauling 
 marl (when that work was going on), and which has continued to 
 be so employed to this time, in 1849. This mule is rather above 
 average size, and might have been sold for $65, according to the 
 prices usu^al in and before 1844. She had begun this labour 
 in January, when poor ; had improved while so employed ; and 
 was in excellent working condition when marling was suspended 
 in September, for the purpose of all the mules being used for the 
 heavier labours of fallow-ploughing for wheat, and afterwards har- 
 rowing in the seed. I could extend the statement of this mule's 
 daily work, as particularly, by embracing what had been previously 
 observed and noted from April 29th, and also of all the other 
 teams, irregularly employed. But it will be enough to present the 
 portion of work done by this one, and only from the beginning of 
 the excavations at this locality, of which the circumstances, and 
 for this purpose, have been so minutely stated above. It is only 
 by such careful observations, and actual measurements of quanti- 
 ties and distances, and these, moreover, continued for a considera- 
 ble extent of time, that any fair and unquestionable evidence can 
 be afforded of the amount and cost of any labour that can bo per- 
 formed in a certain time, by men or beasts, and especially of the 
 latter. For a few days, or perhaps for a few weeks, there might 
 be performed labours which the teams would sink under if con- 
 tinued much longer. But when a certain measure of work has 
 been done regularly for months together, without any apparent 
 difficulty or hardship to hands or teams, still more, when the teams 
 have improved in flesh while continuing and even increasing their 
 daily labour (as in this case) , there can remain no question as to 
 
DIRECTION OP LABOUR. 335 
 
 the ability of all to continue to perform the same amount of labour 
 for any length of time, under like circumstances. 
 
 From the commencement of my marling on my then newly-pur- 
 chased farm, Marlboume, two mules were assigned to this work, 
 to be regularly so employed in all time fit for hauling marl, except 
 during the greater pressure of certain other farm labours. These 
 times were to be during wheat harvest (when only for eight or ten 
 days all the mules usually would be idle, because all the drivers were 
 needed as harvest hands), when hauling out the stable and winter- 
 made manure — ha uling in and thrashing the wheat crop, and deliver- 
 ing the grain for market at the river landing — for the ploughing for 
 fallow wheat, and ploughing and harrowing when seeding — and to 
 plough the corn for a few days both before and after wheat harvest 
 — and sometimes when hauling in the corn ci'op, if hands could 
 not then be spared to dig marl. None of these labours, except 
 hauling in wheat and corn from the fields, are lighter than would 
 be the continuation of hauling marl ; and some of them (fallow- 
 ploughing, harrowing, and thrashing) are much heavier. All these 
 different operations usually kept the marling suspended for times 
 amounting to about half the working days of each year. But not 
 so much in 1844, as there was then no wheat crop to harvest or 
 thrash, and very little manure made to be carried out. All these 
 abstractions of the regular marling teams are much more than com- 
 pensated by the irregular employment, at marling, of the ploughing 
 teams at what would otherwise be their idle or leisure times. 
 There is much convenience and gain in having labour thus to be 
 exchanged. At the pressing seasons of harvesting, fallowing, for 
 seeding and thrashing wheat, the regular farm force is insufficient, 
 and no supply of extra force can be hired. Then the other force 
 kept for marling becomes an important aid, and is worth much 
 more than the cost, or than the marling labours thereby postponed. 
 On the other hand, the regular carrying on of marling operations 
 by an extra force so applied, enables the farmer to increase it at 
 any leisure time, by any surplus force, of hands or teams necessarily 
 kept for farm labour ; and whose surplus or spare time, for short 
 intervals, could not otherwise be put to any profitable use. In the 
 one case, force that would be cheaply hired at double of average 
 price of hires, is obtained for the lowest rates ; and in the other, 
 for no more than the cost of maintenance. Without both these 
 reciprocal aids thus exchanged, I am sure that my wheat crop would 
 necessarily be curtailed by one-sixth, and my marling by more 
 than one-half. 
 
 The statement to be here offered of a connected portion of the 
 marling labours of 1844, will be of what was actually done, under 
 the then existing circumstances, and with the then defective mode 
 of working — and not of what might have beea dono with better 
 
doO DETAILS OP OPERATIONS. 
 
 appliances and more experience, or with such improvements of 
 operations as I have since introduced. 
 
 The distances from tlie pit were accurately measured ; except 
 for inconsiderable and daily variations from, or extensions of known 
 distances, which were estimated by the less exact measure of my 
 stepping. For every new route, and every considerable alteration, 
 the measuring tape was used. The contents of the cart-bodies were 
 ascertained both by cubic measurement and by the heaped half- 
 bushels of marl which could be put in. After enough of such trials 
 had been made for fixing an average, each cart-load, accoi'd- 
 ing to its being filled even, or slightly heaped, or fully heaped 
 (which variations might be required by different conditions of 
 teams, marl, or roads), was respectively taken as the measure of a 
 stated number of bu.shels. 
 
 Single mule carts were used this year, which was one of the 
 errors afterwards abandoned. The loads of the 'one mule whose 
 work will be separately stated, was at first made 8 heaped bushels, 
 afterwards increased to 8|. Her driver was a boy of 15 years old. 
 Two other mules which were generally but not regularly hauling 
 marl during the same time, were driven, one by a boy, and the 
 other by a girl, neither driver exceeding 13 years old. Tasks were 
 assigned to each mule cart. Maiding is the only kind of farm 
 labour that I ever could have performed advantageously by task- 
 work. For this, tasks were found very advantageous ; and no 
 other work which has been under my direction has been executed 
 so faithfully, or with so little superintendence or difficulty. This 
 peculiar adaptation to task-work is owing to the uniformity of the 
 labours, when conducted on a regular plan of operations. 
 
 The marl was very generally free from all extraneous water. 
 Though moist in its bed, and when dug, it is as little so as any 
 highly absorbent earth could be, if in like manner covered by wet 
 and water-soaked clay. The marl, just after being dug, weighs 105 
 lbs. to the heaped bushel. If allowed to become wetter, its weight 
 is much increased. I found, by trial, that a bushel of this marl, 
 as moist as when dug, would absorb two gallons moi-e of water (16 
 lbs.), without being so surcharged that any would drip away. Yet 
 many of those persons who work marl having springs oozing out 
 above, allow so much water to have access, as to add much more 
 than 16 lbs. to the weight of the bushel of marl, and to increase 
 the labours of shovelling and loading in still greater proportion. 
 
 The degree of inclination of the surface of the land on which 
 marl is carted, and its being rough or smooth, soft or firm, all have 
 important influence on the labour of marling. The land to which 
 mine was then applied, as well as all over which the routes passed, 
 was part of the broad flats bordering on the Pamunkey. The very 
 gradual ascent from the margin of the pit (where the marl was 
 
CONDITIONS OF THE LABOURS. 837 
 
 thrown up, ready for filling the carts), was not more than 10 feet 
 of perpendicular height, to the highest summit ; after which, the 
 routes to all the different places of deposit pass over slight and 
 gradual undulations of surface, as much descending as ascending, 
 and which variations of level, in their extremes, scarcely exceed 6 
 feet. So level a way is of course a great advantage, and enables 
 me to carry much heavier loads than on the high and hilly lands 
 which I formerly marled elsewhere. But, on the other hand, this 
 almost level surface requires the land everywhere to be ridged; 
 and the water furrows (or deep alleys), and the many deeper 
 cross '' grips" (or very narrow and shallow ditches), together pre- 
 sent greater obstacles to the passage of carts over the fields, than 
 would be found with much more of ascent and inequality of sur- 
 face, but with smooth tillage. Another disadvantage, suffered then, 
 and generally for some years after on nearly all my land, was, that 
 as it had not been recently grazed and trodden by cattle, the soil 
 was not firm, but puffy and soft; and therefore, even when dry, and 
 still more when wet, this soft soil greatly increased the labour of 
 ■carting on the fields. ■ 
 
 The marl contains, on the average, 38 to 40 per cent, of carbo- 
 nate of lime. It was applied at about 350 bushels to the acre — in 
 heaps, 11 yards each way, of the whole load of a single mule, or 
 half the load of two mules, or two oxen. 
 
 After all these matters of preliminary explanation, I will now 
 present the particular statement designed, showing for an entire 
 job of 64 consecutive working days, the daily travel, and number 
 and amount of loads of a single mule ; and also the total quantity 
 of marl dug for and carried out by other and less regular teams, 
 whose work, though noted separately, it is not necessary to give 
 more particularly in this abstract from the fuller record in my 
 farm journal. The work stated in the following table comprised 
 all the marl of the ranges A and B, and a large part of the next 
 and wider range C. 
 
 29 
 
338 
 
 ACTUAL MARLING LABOURS, 
 
 
 IIAULIXG BY ONK IIULE. 
 
 1 Whole "Work. I 
 
 Days. 
 
 1 
 
 3 
 
 ■3 ^ 
 
 ivcrage dis- Additional i 
 to ice from . 
 
 Vliole day's journey, 
 iicludins distances to 
 ud from stable. 
 
 1 
 
 ^1 
 
 Miles. Yards. 
 
 Juue 28 
 
 12 
 
 of 8 
 
 1770 X 2 
 
 380 Xi 
 
 25. 
 
 2 
 
 310 
 
 " 29 
 
 12 
 
 " 
 
 
 " 
 
 25 
 
 " 
 
 308 
 
 Monday, 
 
 July 1 
 
 j. 11** 
 
 " 
 
 a 
 
 « 
 
 22.1740 
 
 " 
 
 302 
 
 " 2 
 
 12 
 
 " 
 
 " 
 
 u 
 
 25. 
 
 " 
 
 304 
 
 « 3 
 
 12 
 
 " 
 
 " 
 
 " 
 
 25. 
 
 " 
 
 310 
 
 " 4 
 
 12 
 
 u 
 
 " 
 
 " 
 
 25. 
 
 " 
 
 346 
 
 " 5 
 
 12 
 
 " 
 
 1S25 
 
 296 
 
 25. 984 
 
 " 
 
 346 
 
 " 6 
 
 11 
 
 " 
 
 1866 
 
 274 
 
 23.1576 
 
 " 
 
 316 
 
 M. " 8 
 
 11 
 
 " 
 
 1883 
 
 208 
 
 24. 18 
 
 " 
 
 316 
 
 " 9 
 
 10 
 
 " 
 
 2245 
 
 none. 
 
 25. 900 
 
 " 
 
 272 
 
 " 10 
 
 7*i 
 
 " 
 
 " 
 
 " 
 
 15.1510 
 
 " 
 
 154 
 
 " 11 
 
 13t 
 
 " 
 
 
 
 
 " 
 
 274 
 
 
 
 
 « 12 
 
 10 
 
 " 
 
 2245 
 
 none. 
 
 25. 900 
 
 
 246 
 
 « 13 
 
 2& 
 
 " 
 
 965 
 
 1005 
 
 24. 380 
 
 " 
 
 274 
 
 M. « 15 
 
 20 
 
 " 
 
 915 
 
 955 
 
 22.1600 
 
 " 
 
 274 
 
 « 16 
 
 20 
 
 " 
 
 '< 
 
 " 
 
 22.1600 
 
 " 
 
 274 
 
 « 17 
 
 20 
 
 " 
 
 939 
 
 " 
 
 23. 900 
 
 " 
 
 274 
 
 " 18 
 
 20 
 
 « 
 
 963 
 
 a 
 
 24. 100 
 
 3 
 
 354 
 
 " 19 
 
 20 
 
 (I 
 
 971 
 
 a 
 
 24. 420 
 
 " 
 
 402 
 
 « 20 
 
 12*4. 
 
 « 
 
 984 
 
 955X2 
 
 23. 2;;3 
 
 " 
 
 250 
 
 51. " 22 
 
 20 
 
 " 
 
 995 
 
 955 X-i 
 
 24.1300 
 
 " 
 
 330 
 
 " 23 
 
 17*t 
 
 « 
 
 « 
 
 « 
 
 20.1450 
 
 5 
 
 604 
 
 " 24 
 
 24 
 
 " 
 
 1012 
 
 855 
 
 26. 100 
 
 " 
 
 716 
 
 « 2.5 
 
 19 
 
 " 
 
 « 
 
 " 
 
 23.1396 
 
 " 
 
 746 
 
 " 26 
 
 " 27 
 M. " 29 
 
 13*ffl 
 
 u 
 
 1378 
 
 652 
 
 23.1156 
 
 " 
 
 532 
 
 15 
 
 « 
 
 1408 
 
 " 
 
 25. 848 
 
 2 
 
 324 
 
 " SO 
 
 15 
 
 " 
 
 " 
 
 " 
 
 25, 848 
 
 3 
 
 500 
 
 " 31 
 
 15 
 
 " 
 
 « 
 
 " 
 
 25. 848 
 
 " 
 
 514 
 
 Aug. 1 
 
 15 
 
 (( 
 
 « 
 
 « 
 
 25. 848 
 
 " 
 
 498 
 
 " 2 
 
 14*6 
 
 <( 
 
 1263 
 
 707 
 
 20. 164 
 
 " 
 
 606 
 
 " 3 
 
 16 
 
 " 
 
 « 
 
 " 
 
 24.1004 
 
 " 
 
 536 
 
 M. " 5 
 
 16 
 
 " 
 
 « 
 
 " 
 
 24.1004 
 
 " 
 
 500 
 
 " 6 
 
 16 
 
 " 
 
 1293 
 
 677 
 
 25. 184 
 
 " 
 
 500 
 
 « 7 
 
 18 
 
 " 
 
 1069 
 
 901 
 
 23.1608 
 
 " 
 
 530 
 
 « 8 
 
 16 
 
 " 
 
 1323 
 
 647 
 
 25. 924 
 
 a 
 
 529 
 
 « 9 
 
 16 
 
 " 
 
 " 
 
 " 
 
 25. 924 
 
 « 
 
 510 
 
 " 10 
 
 16 
 
 " 
 
 « 
 
 " 
 
 25. 924 
 
 " 
 
 450 
 
 :>i. " 12 
 
 16 
 
 (I 
 
 1363 
 
 607 
 
 26. 284 
 
 " 
 
 514 
 
 " 13 
 
 15 
 
 « 
 
 1374 
 
 596 
 
 24.1364 
 
 " 
 
 592 
 
 " 14 
 
 15 
 
 " 
 
 1395 
 
 575 
 
 25. 184 
 
 " 
 
 596 
 
 « 15 
 
 15 
 
 « 
 
 " 
 
 " 
 
 25. 184 
 
 " 
 
 596 
 
 « 16 
 
 19 
 
 « 
 
 1091 
 
 880 
 
 25. 978 
 
 « 
 
 585 
 
 " 17 
 
 19 
 
 " 
 
 " 
 
 " 
 
 25. 978 
 
 " 
 
 585 
 
 M. « 19 
 
 15 
 
 " 
 
 1428 
 
 522 
 
 25. 92» 
 
 " 
 
 543 
 
 " 20 
 
 15 
 
 " 
 
 " 
 
 " 
 
 25. 928 
 
 " 
 
 470 
 
 <' 21 
 
 19 
 
 " 
 
 1110 
 
 857 
 
 25.1608 
 
 2 
 
 253 
 
 " 22 
 
 19 
 
 " 
 
 1234 X 2 
 
 836X4 
 
 26. 676 
 
 ' 2 
 
 278 
 
 « 23 
 
 18 
 
 of 8K 
 
 1154 
 
 816 
 
 25. 808 
 
 " 
 
 271 
 
 « ai 
 
 18 
 
 of ?,\i 
 
 " 
 
 '< 
 
 25. 808 
 
 " 
 
 271 
 
 M. " 26 
 
 12 
 
 " 
 
 1805 
 
 none. 
 
 26. 760 
 
 3 
 
 530 
 
 « 27 
 
 18 
 
 " 
 
 11.54 
 
 816 
 
 25. 808 
 
 3 
 
 540 
 
 « 28 
 
 18 
 
 » 
 
 1176 
 
 794 
 
 25.1512 
 
 " 
 
 579 
 
 « 29 
 
 18 
 
 " 
 
 
 " 
 
 25.1512 
 
 " 
 
 555 
 
 « 30 
 
 18 
 
 " 
 
 1200 
 
 772 
 
 26. 628 
 
 " 
 
 489 
 
 " 81 
 
 10*0 
 
 of 81 2 
 
 " 
 
 " 
 
 15.1688 
 
 " 
 
 283 
 
 M. Sept. 2 
 
 17 
 
 of 83^ 
 
 1222 
 
 750 
 
 25. 448' 
 
 " 
 
 513 
 
 '' 3 
 
 12 
 
 " 
 
 1865 
 
 none. 
 
 25. 760 
 
 « 
 
 403 
 
 " ' 
 
 12 
 
 ft 
 
 " 
 
 » 
 
 25. 760 
 
 2V 
 2k 
 
 403 
 
 " 1 
 
 12 
 
 " 
 
 <( 
 
 u 
 
 25. 7C0 
 
 450 
 
 << 1 
 
 13 
 
 « 
 
 « 
 
 " 
 
 27. 970 
 
 2 
 
 428 
 
 11 ' 
 
 12 
 
 « 
 
 " 
 
 « 
 
 25. 760 
 
 2 
 
 283 
 
 M. " < 
 
 ) 12 
 
 " 
 
 « 
 
 « 
 
 25. 760 
 
 3 
 
 639 
 
 '■■■ 1( 
 
 ) 12 
 
 " 
 
 « 
 
 « 
 
 25. 760 
 
 4 
 
 672 
 
 " 1 
 
 I 10*. 
 
 Load.";. 
 
 a 
 
 
 21. 340 
 
 4 
 
 334 
 
 
 • ^ 
 
 1.547. i;70 
 
ESTIMATES OP MARLING LABOURS. S39 
 
 REMARKS. 
 
 * Tlic numbers marked thus (*) are short of full clay's work, for causes 
 to be stated. 
 
 ■** .July 1, one load, or one-twelfth of the task, lost by rain. 
 
 *f -July 10, rain prevented 3 loads, or three-tenths of the task. 
 
 f July 11, full but irregular work at another place, and distances not as- 
 certained — the ordinary road being too wet to use. 
 
 *.j. July 20, stopped at 12 o'clock for half holiday — 8-20ths of full day's 
 work wanting. 
 
 ■j-f July 23, I'ain caused loss of 3 loads, or 3-20ths of task. 
 
 4 July 24, a load too much, by mistake. 
 
 *« A good rain in afternoon — 2 loads (2-15ths) lost. Next day (27th) 
 earth too wet for marling, and the mules at the harder work of ploughing 
 for wheat. 
 
 *6 Aug. 2, rain caused loss of 2 loads, or 2-16ths of task. 
 
 *c Aug. 31, stopped at 12 o'clock for half holiday, 8 loads, or B-lBths 
 wanted of full day's work. 
 
 '''d Sept. 11, rain, after long drought, stopped all work at 4 P. M? Next 
 day more and heavy rain, and this mule, and all others fit, put to plough- 
 ing for wheat. For two weeks previous to these rains, the ground had 
 been excessively dry, so that the road, and tracks across the fields, which 
 were constantly travelled over, were so deep in fine dust that it was very 
 unpleasant, and even an impediment to the teams. 
 
 The foregoing table gives the following results : — 
 The mule, whose work is stated separately, in 65 consecutive 
 days, omitting the Sundays only, travelled in marling labour 1572 
 miles and 408 yards. Of these 65 days, 1 (July 27th), the teams 
 were at other labour. One other day (July 11), of full but not 
 measured marling labour, being estimated and added in at the 
 general average, and of 8 other days,* of which the work was bro- 
 ken by rains, the idle parts being deducted, leave 62 \ of full work- 
 ing days of hauling marl. This makes the daily average travel of 
 the mule 25 miles and 138 yards, including the distances from the 
 stable and back. 
 
 The whole number of loads actually carried out by the one mule 
 was 965; the average load, in heaped bushels, 8.095, weighing 105 
 lbs. to the bushel, and 850 lbs. the load. The average number of 
 loads daily (for full day's work), was 15.4 ; and the average travel 
 for each load, 2867.4 yards. 
 
 The quantity of marl carried out in 62 J full days' work, 7803 
 bushels; which makes the daily average quantity carried, 124.85 
 bushels. 
 
 And as to the general operations of all the force employed — 
 The whole quantity of marl dug, and carried out by all the 
 teams, in this time, 26,271 bushels. 
 
 * The parts of the 8J days lost by rain or otherwise, amounted in time 
 to much more than \\ days. But the loss in tvork was no more, because 
 in every such interruption, the hauling, or task-work for the day, was in 
 advance of the hour when operations were suspended. 
 
S40 ESTIMATES OP 7«L\IlITNCt LABOTTRS.' 
 
 The whole digging and throwing out of the marl, and assisting 
 the drivers generally to load (which assistance by one of the pit- 
 men was required always, but not always given to all of the extra 
 teams), was equal to 177 days' labour of a single pit-man; which 
 makes the average quantity of marl, dug, thrown out, and partly also 
 loaded, for each pit-man, 142.42 bushels. 
 
 So much for the labours actually performed. I shall now proceed 
 to estimate their cost. For this purpose, the different kinds of labour 
 will be charged at the prices stated in the previous chapter. 
 
 Estimate of the cost of 3Iarling. 
 
 CaHiiKj. — The mule per working day, cents, . . 26.75 
 
 Her driver, (boy of 15 years,) cents, 22 
 
 Cart and gear, suppose, cents, . . . 5.50 
 
 "For daily work, an average of 124.85 bushels, . 54.25 
 
 Or, for the 100 bushels, cents, 44.26 
 
 Diyging and assisting to load. — Pit-man, per day, 
 
 cents, 34 
 
 His share of tools, suppose, cents, 4.50* 
 
 For his average daily work, of 148.42 bushels, . 38.50 
 
 Or, for the 100 bushels, 26- 
 
 Throwing off overlay of earth to uncover marl (its 
 thickness compared to that of the marl about in 
 proportion of B to 5), supposed to be one-half the 
 labour of pit-work of the marl below ; or per 100 
 
 bushels of marl dug, 13. 
 
 Sjveading marl (340 bushels to the acre,) per 100 
 
 bushels, -flO. 
 
 Total cost of applying 100 bushels, " 93.26 
 
 * This charge includes all the use of tools for as much marl as one pit- 
 man supplies in a clay, not only for his own digging and throwing up, but 
 also for the loading and subsequent spreading of the same marl. 
 
 f The spreading of this marl requires very unequal labour according to 
 its condition. AVhen recently carried out, and still moist, and much of it 
 in firm lumps — or otherwise, after mouldering by exposure, and then being 
 saturated by rain-water — it is twice as difficult to spread as after being left 
 in heaps for some months of summer weather, or until dry after being fro- 
 zen. When in good order, a man can easily spread 60 heaps of 8 to 9 
 bushels, at 11 yards distance. AVhen but in tolerable order, and in winter 
 days, I have had 50 such heaps spread by good hands ; and when in bad 
 order, barely 40 heaps. Thinner di-essings, or more distant heaps, would 
 require more labour for spreading, in proportion to the quantity. The 
 charge above, a man (at 34 cents a day) is allowed to spread per day no 
 more than 40 heaps, of 8^- bushels to the acre. This is very light work, 
 unless the marl is in bad condition. 
 
SUMMER AND WINTER MARLING. 341 
 
 Small as is this cost for a durable manuring, it far exceeds what 
 woukl be required on most farms possessing marl-beds. In many 
 localities in Virginia marl may be uncovered, escavated, and car- 
 ried to the field for one-half of my expenses for the same; and in 
 some cases in Virginia, and in numerous situations in South Caro- 
 lina, the necessary expenses would scarcely be more than a fourth 
 of mine. The spreading is not included in this comparison, as its 
 cost has no relation to the greater or less cost of the other labours. 
 The obstacles to my operations were unusually great — in the soft 
 and adhesive overlying clay — the numerous small springs necessary 
 to be diverted — the liability of the loose sand above to be washed 
 down by rains — the low level of the marl compared to the sur- 
 rounding land — and the great distance from the pit to the field. 
 But whether the difficulties of other marlings be greater or less than 
 mine, their costs may be estimated by my rules and prices, with 
 due regard paid to difference of circumstances. Befoi'e, however, 
 making such application, regard should be paid to the improved 
 processes and reductions of expense in my subsequent operations, 
 which will presently be stated. 
 
 It may, perhaps, be objected to the foregoing statements and 
 estimates, that the work was done in the long days of summer, and 
 in dry weather, when there would be the least obstruction to, or 
 loss of labour from bad weather and bad roads. And I will admit 
 further, that the expense incurred was not increased by sickness of 
 any one of the regular marling hands, nor by any other important 
 loss in labour or materials. All these would be good grounds for 
 objection, if no allowances had been made for average losses on 
 these scores. But, in the general estimates of the cost of labour, 
 there were made the ample allowances of 30 days' labour of the 
 year lost on the average by each man and boy, by bad weather, 
 sickness, and half holidays (besides the 58 of Sundays and regular 
 holidays), and 40 days for each mule; and also enough for wear 
 and breakage of carts and utensils. Therefore the proper propor- 
 tion of these losses is in fact fully charged in the estimate, though 
 scarcely any of such losses occurred. 
 
 It is true that winter marling would be much more costly, owing 
 to the then generally muddy or slightly frozen and rough roads. 
 And therefore during that season, and when the earth is wet and 
 soft, it will be generally better to suspend marling labours, if the 
 teams can be employed at other, easier, and as necessary work. My 
 marling, however, was not thus suspended. For the extra expense 
 of the more disadvantageous and costly winter marling was deemed 
 of less amount than would be lost in the difference of productive 
 value of land marled, and the same if left unmarled. Thus it is 
 cheaper to pay $4 an acre, for marling a field before taking its crop 
 from it for that year, than to take the crop first, and afterwards 
 29* 
 
342 GRADUATED PITS. 
 
 marl it for §?"2. And, therefore, deeming the omUsiov, or delay of 
 inarlbifj to he hy far the moat expensive thing in regarJj to the 
 operation, I marled even in unsuitable seasons, so as to avoid the 
 necessity of ever again bearing the much heavier loss of cultivating 
 any unmarled ground. 
 
 Excavating Marl in large graduated pits 
 
 The excavation of the range of perpendicular pits C (Fig. II. j, 
 was finished in April, 1845. The marl carried out from that and 
 the two previously worked ranges, A and B, amounted to 71,541 
 heaped bushels — according to the number of loads counted on the 
 fields, and their estimated quantities. Previous to beginning to 
 work at this diggins, there had been carried out from anothor, not 
 far off, 26,600 bushels, from January 24th, 1844, to June 28th, 
 the time of beginning the second excavation. Of the earlier job, 
 it is enough to say that it was very laborious, owing to the overlay 
 to remove, of 7 to 8 feet, which was double the thickness of the 
 marl below. This, my first excavation here, was worked upon the 
 plan I had used elsewhere ; the carts descending by a gently graded 
 slope to the bottom of the marl. But every considerable rain caused 
 the loose sand and gravel to fall in and choke the small drain cut 
 around on the top of the marl, and then the spring and rain water 
 flooded the pit ; the bottom of the digging (when deep) being lower 
 than any outlet for the water. The many such disasters which 
 were suffered and repaired, and the consequent losses of time and 
 labour, induced me, for the next work, to pursue the more laborious, 
 but less hazardous plan of excavating by small perpendicular pits, 
 as described in the foregoing pages. But after thus working out 
 the ranges A, B, and C, I thought that with my then better expe- 
 rience, and by using better safeguards than before, I might venture 
 to return to the plan of graduated excavations. With this inten- 
 tion, the range D (Fig. II.), had been laid off, and cleared of its 
 overlay, during the winter and spring of 1845, at my leisure and 
 convenience, while the latter excavations of the range C were still 
 in progress. The same plan has been since continued, with im- 
 proveilients, for the successive and adjacent ranges, E, F, and Gr, 
 which last is not quite exhausted of its marl, at this time (October 
 1849), and another range, H, has nearly been cleared of its over- 
 lay, and made ready for its excavation to be begun. It will be 
 unnecessary to keep separate the incidents of these different large 
 workings, when referring to such processes as may be deemed worth 
 being mentioned. The natural features continued the same as to 
 the marl, and also of the overlay, excepting its increasing in thick- 
 ness, as the distance from the stream was extended. The different 
 means used for saving labour were mostly adopted in the working 
 
REMOVING OVERLAY. 343 
 
 of the first graduated range, D, in 1845; but some of them were 
 introduced more recently. 
 
 The range D (Fig. II.), when completely uncovered and ready for 
 the carts to descend into, and to be loaded on the surface of the 
 marl, was 20 feet wide, including the space for the narrow drain 
 along its land-side (c, (Z, e, e,) for the greater part of its length — 
 narrower at the angle (i) and then widened to 26 feet at lower end, 
 to give room for a wagon to turn. The whole length was 255 feet; 
 but of this, 96 at the upper end (c, d) had but half the overlay 
 removed at first ; the earth being left in an inclined plane, sloping- 
 downward from the road (gg) on the surface of tlie laud, to 
 the surface of the uncovered marl. The thickness of the overlay 
 here having been 5 feet, the graded road served to rise that height 
 in 96 feet of the slope. The same grade was not exceeded in ex- 
 cavating the marl ; and it would have served to descend, if required, 
 two feet lower than the usual level of the bottom of the marl, at 
 the lower end of the digging. The digging and removal of the 
 marl was begun at the lower end (/, e, x) and carried on in succes- 
 sive layers ; but always keeping the floor of the pit sloping down- 
 ward towards the lowest end (.x-), and also laterally towards the 
 land-side (e, e). At the lower end was a short, narrow ditch 
 (i", X,) serving as an outlet into the stream, which had been deep- 
 ened so as to be lower than the lowest designed digging. Thus, 
 whatever water might get into the digging, from rain-floods, or 
 from the side-drain being chokc^ by caving sand, and thereby turn- 
 ing in the spring-water, it would necessarily keep to the lower side, 
 and flow out at the lower end into the stream. The figures II., III., 
 aud IV., show severally the horizontal plan, and the longitudinal 
 and cross sections, or profiles of the work. 
 
 The first improved operation adopted was in removing the over- 
 lay, by using, where practicable and convenient, the plough to 
 loosen the earth, and the scraper (such as is used for road-making) 
 to move it into the finished ranges of pitting. The difference be- 
 tween these aud the former modes of hand-labour, with hoes, picks, 
 and shovels, was not accurately observed, nor could it be ; as these 
 large operations were extended through several months (and more 
 lately, through a whole year), at such irregular times as labour 
 could be best spared, and especially when previous rain, snow, or 
 freezing had put a stop to usual fiirming operations. Any farmer 
 can nearly enough estimate the superiority of ploughing over hoe- 
 ing to loosen earth. The hoeing would certainly cost four times, 
 and perhaps ten times as much as ploughing. The scraper is also 
 very fur cheaper than shovels, for removing earth to all distances 
 between 30 and 40 feet. For short distances, for which one throw 
 of the shovel is enough, the latter is the cheapest. The excavation 
 by plough and scraper was not only, as anticipated, much easier 
 
«lslri8*, Fig. in. 
 
 Longitudinal Section or Profile of Graduated Diggings (at 
 range D, in Fig. II.) Scale 40 feet to inch. 
 
 
 Explanations. 
 
 a, a, Surface of ground, and level of highest part of graded 
 roadway. 
 
 m, m, Overlying earth, 6 feet thick. 
 
 n, n, Marl, 7 to 8 feet thick. 
 
 s, s, Green-sand earth, of unknown thickness. 
 
 a, 0, r, Eoadway, descending 6 feet in 96, from surface of 
 land a, to bottom of marl, r. 
 
 V, V, V, Successive perpendicular excavations, beginning at r, 
 made after digging down'to the inclined plane, o, r. 
 
 n, 0, Marl either excavated like v, v, or subsequently by a re- 
 versed direction of descending grade. 
 
Fig. IV. 
 
 Cross Section or Profile of Graduated Diggings (aa 
 of range G, in Fig. II.) Scale 20 feet to inch. 
 
 ExPLAJlAilONS. 
 
 a, a, Surface of ground (and overlay of nest range 
 to be uncovered.) 
 
 d, d, Former extension of surface, now removed. 
 
 m, Overlying earth, here 7 feet thick. 
 
 n, Marl, 8 feet thick. 
 
 8, s, 5, Green-sand earth. 
 
 G, The bed of marl, here removed from its original 
 height, the dotted line next above G i, to the line 
 beloTV — and the lower part, w, t, stiU to be remo- 
 ved, to the bottom, at s. 
 
 i, Small drain, to intercept and lead off the springs 
 coming out of m. 
 
 t, Lowest graded side, or drain, to receive and dis- 
 charge accidental floods into the stream. 
 
 o, Wall of marl, left to be last dug out, to keep out 
 the water and earth from 
 
 g, p, k, Successive fillings of previous excavations, by 
 the overlay removed from the next uncovered. 
 
 (345) 
 
346 REMOVING OVERLAY. 
 
 wliere the overlay was dry and sandy, but also lower down in ttie 
 tvet springy gravel, often indurated by ferruginous cement ; and 
 even to some extent, iu the wet, miry, and sticky clay still lower. 
 Difficult as was this lowest part of the uncovering, in every mode, 
 the scraper took up the clay, and let it drop because of the weight 
 of the mass, much better than any hand utensils. In this, the 
 plough was not needed, nor could the scraper be used much, because 
 the feet of the horses sank through both the miry clay and the 
 upper thin layer of soft marl (Fig. I.), and would have worked up 
 both together. 
 
 But the plough and scrapct could not serve for all the overlay. 
 Not only for the miry clay layer, but for much of the other over- 
 lay, either because of its texture, or its place, it was still cheapest 
 to remove by hand implements, as previously; and especially for 
 giving the final shaping to the opening. If the job had been con- 
 tinuous and regular, and the labourers all able men, it would pro- 
 bably hav^e been cheaper to remove the whole overlay at once in 
 wheel-barrows, in the manner of excavating for canals and railroads. 
 As it was executed, the saving of labour in removing the overlay 
 was fully one-half of the former cost. 
 
 To return to my actual labours. As soon as the wet gravel 
 (Fig. I.) was laid naked, the land-side outline of the range was 
 marked off, and a nari'ow ditch (c, d, e, e, x, Fig. II.) dug along 
 it down to the marl, intercepting the numerous small springs, and 
 conveying the water into the stream (at e, x, Fig. II.). After re- 
 maining thus drained for some weeks, the clay, though still miry 
 and sticky, is worked much more easily ; and in later operations, 
 has been mostly removed in carts, which were drawn upon the then 
 partly excavated and firm marl. The scrapers' work had pre- 
 viously served to fill the sinks and pools in the older ranges, with 
 dry sand and gravel ; forming a drained, firm, aud nearly level sur- 
 face, on which the carts carried and dropped the remaining clay 
 overlay. 
 
 The design of the plan of operations was to have the carts to 
 descend upon the marl, and to draw loads ultimately from the 
 lowest digging. For this purpose, as has been stated, part of the 
 overlay had been left on the upper end of the range (a, m, o, Fig. 
 III.), forming a sloping roadway for 9G feet of length, aud rising 
 5 feet in that distance, frffm the marl to the road on the surface 
 of the land. A few yards of " poling" over the soft clay bottom 
 layer served to make a fii-m passage from the marl to the dry 
 fiandy earth. The marl, except its upper 6 inches, was at first 
 firm enough for the loaded carts; and soon became dryer and firmer 
 in drying. The slope, given by the digging and removal of the 
 marl, descending always to one side and to the lower end, where 
 there was a discharging outlet into the stream for all water. 
 
ADVANTAGES OP GRADUATED PITS. 347 
 
 served to keep the marl as dry as was possible for a naturally moist 
 and extremely absorbent bed. This preservation from all extra- 
 neous water, as well as losing some of its own by exposure, rendered 
 the marl easier to dig and to load, and something lighter of car- 
 riage. 
 
 Further — the digging was no longer impeded by the necessity 
 of having to leave, shape, and secure cross-walls, which had before 
 caused much trouble, and much loss of marl. Now there there was 
 but one wall to be left, which was along the whole length (o. Fig. 
 IV.), to keep out the earth and water which filled the old diggings ; 
 which wall was afterwards cut down, and mostly saved, in the 
 closing operations of each range, in succession. The unlimited 
 room for their work permitted the pit-men to dig the marl in much 
 larger masses, which saved much of the labour of digging, and 
 something in that of loading. For the earthy portion of this marl, 
 compact as it is, is composed of thin horizontal laminas, the result 
 of slow and uniform sedimentary deposition. In consequence, it 
 may be cleaved in the direction of its '' grain" much more easily 
 than cut or fractured in any other direction. This facility is best 
 availed of when a wide area is worked; and not in small pits, con- 
 fined by perpendicular sides. The shovelling was also much easier — 
 first, because the marl was more in large lumps, and less in a finely 
 reduced state than before ; and secondly and mainly, because the 
 height of the cart was the greatest extent to which it had to be 
 thrown, instead of double throwing, as before, and the throw out 
 of the pit, which at the maximum, was 13 feet in height, besides 
 the lateral distance. This change, taking away all the throwing 
 out of the pit, saved much more than one-half of the pit labour. 
 The average quantity of marl obtained before from each pit-man's 
 daily labour was 148.42 bushels. Now, one man only was usually 
 employed, who dug for the carts from 400 to 600 bushels a day. 
 It is true, that he was now relieved from assisting to load, which 
 work was put upon the drivers. In the closing operations of the 
 digging, when small pits still had to be sunk, and through the 
 bottom stony layer, and the marl from them thrown up on the 
 sloping roadway, and walls to cut down, the result of the pit-man's 
 work was much less. But even then, when the dilficulty was 
 greatest, the least amount of marl obtained was 160 bushels for 
 each man in the pit. It is certain, that throughout the whole ex- 
 cavation of the range, the pit-man's labour furnished on the ave- 
 rage more than twice the quantity of marl. This part of the cost 
 then also was reduced fully one-half. But this is in advance of 
 describing the later of the operations of which the cost was so re- 
 duced. 
 
 The digging down and removing the marl in the pit to the grade 
 of 5 to 6 feet depression in the 100 of length, served to reach tho 
 
348 MANNER OF EXCAVATION. 
 
 bottom green-earth, and leave it naked, for tbe extent of some 70 or 
 80 feet length of the lower end of the range (r, in Fig. III.). This 
 completing of the excavation throngh the lowest marl was begun 
 at the Ipwer end, where is the outlet for water from the pit. And 
 as soon as each successive few yards in length had been so deepened 
 to the bottom, the side-wall of marl was cut down, and its marl 
 mostly saved. Then, indeed, the earth, which this wall had been 
 left as a barrier to keep out, fell in, and more or less of the old con- 
 fined water beneath the earth flowed in also, from the old diggings. 
 But this now did no harm. The bottom (green-earth) where the 
 caving earth fell, and the water overflowed, was not needed ; and 
 the water, after rising a few inches thereupon, passed off" through 
 the outlet into the stream. The next few yards length of bottom 
 marl was then removed, and then its part of the side-wall taken 
 down in like manner, until the whole lower 70 or 80 feet (2, r, 
 in Fig. III.) had been taken out, including its adjoining side-wall. 
 Next, the lowest part of the sloping roadway of marl (c, ?•, Fig. 
 III.) was dug out, the carts turning and loading on the adjoining 
 space next above, which also was next dug out. Thus, the whole 
 slope of marl was dug out in the manner of successive perpendicu- 
 lar pits (w, V, V, &c.), each of the full width of the range, and 6 
 or 8 feet in the direction of the range. The first or lowest of these 
 perpendicular diggings was not a foot deep at the upper side. Each 
 increased in thickness, vmtil the last and highest (o. Fig. III.) at be- 
 ginning of the slope of the overlay forming the road, was 8 feet thick. 
 Btill, though this digging was according to the former mode, by 
 perpendicular pits, this operation was much less laborious ; as the 
 throwing up of the marl varied in height from less than one foot, 
 to at most but 8. As fast as each of these pits was finished to the 
 bottom, the adjoining part of the side-wall (o, Fig. IV.) was cut 
 down, and as much saved as was not prevented by the coming in 
 of earth and water. 
 
 The thinner part of the overlay forming the slope (jn, o, Fig. 
 III.) was next thrown, in successive uncoverings, into the last 
 finished pits, and the marl below in like manner dug out. But 
 when the thickness of this earth had reached some 3 feet, and about 
 50 feet of the length remained, this remnant was left to be taken 
 out with the next succeeding range of marl ; when carts, by having 
 a longer route, could descend on this part of the marl by a slope 
 made in a reverse direction (as space h o li, in ranges E and F, 
 Fig. II.) This postponement of the complete uncovering and the 
 digging out of the marl of the upper 50 feet of each range, for the 
 benefit of more easy access at a later time, has been since continued. 
 It is including all these more costly labours with the principal and 
 usual operation, that the excavation is deemed reduced in cost fully 
 one-half of that of the former mode. 
 
CARTS AND TEAMS. 349 
 
 The labours of tlie teams and their drivers were slightly increased 
 by the change of plan. The carts had to be drawn from the bot- 
 tom of the digging, and also, for a large part of the time, from the 
 bottom of the bed of marl. But the ascent was so gradual, and 
 the way so firm, that no greater effort was made necessary than 
 many of the obstructions on the nearly level ground, of roads or 
 field, encountered afterwards. The drivers also had now to put in 
 the whole of their loads, instead of being assisted by a pit-man, as 
 previously. But because of the greater distances in 1845, and 
 generally since, there were fewer trips, and of course fewer loads 
 to be put in and out, which kept the loading labours to the drivers 
 nearly the same in general. These circumstances then added no- 
 thing to the former cost of hauling and loading. 
 
 Another gain was made in increasing the loads (by heaping 
 higher in the carts), from the heaviest of the preceding year to 9 
 bushels for the single-mule cart, and 18 bushels for the two-mule 
 carts. Of the latter, one was now regularly worked, and two others 
 frequently, and found to be much preferable. For if carrying a 
 double quantity, a two-mule cart was much cheaper than double 
 the jirice of a single-mule cart; and also was cheaper in working, 
 than two small carts, in requiring one driver instead of two — 
 though a driver of more ability and value. The increase of loads 
 to 9 bushels to the mule (whether in single or double carts,) had 
 been made in April 1845, and has been maintained since, when- 
 ever the ground was firm, and the road good. Particularly, the 
 marling mules continued regularly to haul these loads through all 
 the time when so engaged that year, until in September, when 
 marling was suspended. They kept in excellent condition ; and 
 better than I have ever had the ploughing teams during summer. 
 The average day's travel, in hauling marl, had also been increased, 
 for weeks together, to as much as 26 miles; and from April to 
 September was not less than an average of 25 miles. Any greater 
 distance was not desired ; but could not be always avoided, when 
 the trips were very long. The increasing the sizes of loads made 
 a diminution of cost, nearly equal to one-ninth, certainly to full 
 one-tenth of the previous cost of transportation. 
 
 The values of the several diminutions of cost of labour stated 
 above will be more clearly exhibited by comparative statement of 
 the expenses in 1844, before presented, and those of 1845. 
 
 30 
 
550 
 
 COSTS OF ACTUAL MARLING LABOURS. 
 
 Total cost of appli/ing marl, per 100 Lushels, at the average dis- 
 tance of 14oo yards from j^it to field ; or tvith 25 miles and 
 138 ya/rds, of total daily travel. 
 
 In 1844. 
 
 In 1845. 
 
 
 Cts. 
 Labour of pit-man, 
 
 for lOU bushels . 2G.00 
 Carting . . . . 44.2G 
 Throwing off overlay 13.00 
 Spreading marl . . 10.00 
 
 Total expense, cents, 93.26 
 
 Reduced by 
 
 Half, or . 
 One-tenth 
 One-half . 
 
 13.00 
 4.42 
 6.50 
 0. 
 
 Leaves cost . . 
 
 Cents. 
 
 13.00 
 
 30.84 
 
 r, ^,(\ 1 
 
 Total expense, ctf 
 Former cost . 
 
 Reduction of ex. 
 
 10.00 
 
 . 69.34 
 93.26 
 
 23.92 
 
 From all these detailed premises the conclusion has been reached 
 that, under the circumstances stated, or others not of greater diffi- 
 culty, the total cost of applying marl is less than 70 cents for the 
 hundred bushels — (09.34). The circumstances, and the elements 
 of cost, of course must vary with every locality, and even frequently 
 at the same locality. Nevertheless, the foregoing estimates and 
 results may be applied to any other operations, with due allowances 
 for differences ; and thus may be facilitated the calculations of the 
 amounts and the costs of other marling operations. 
 
 From my large experience, not only of the years 1844 and 5, 
 but since to the present time, there can be no doubt of the ability 
 of carrying 1890 lbs. (18 bushels) of marl as the regular loading 
 of a two mule cart, on nearly level routes, and on firm ground and 
 good roads ; and that the regular and continued daily travel of 
 the carts, from pit to field loaded, and returning empty, may bo 
 25 miles and 138 yards each day. Upon these grounds, it will 
 be easy to calculate the cost of marling at any greater or less dis- 
 tances than the average of mine (2867 yards from pit to field and 
 back) in the particularly noted trial in 1844. The transportation 
 is usually the main expense of marling. This, alone, increases 
 with and is in proportion to the distance; the other expenses arc 
 not afiected by the distance of carriage, but remain in proportion 
 to the quantity of marl carried out, under like circumstances. 
 With the conditions last stated (for 1845, page 204), my expense 
 for carting alone of 100 bushels of marl, in trips to and fro of 
 2867 yards average distance, and making 25 miles and 138 yards 
 of total travel daily, amounted to 39.84 cents. All the other ex- 
 penses of applying the 100 bushels made 29.5 cents. These facts 
 furnish premises upon which to calculate what the total costs would 
 be for any other length of trips^ as follows ; 
 
COSTS AT DIFFERENT DISTANCES. 
 
 351 
 
 Bushels. 
 100 
 
 1 
 1 
 
 100 
 
 cost 
 
 Carting yards, 
 
 to and fro. 
 
 2867 
 
 2867 
 
 1760 (1 mile) 
 1760 
 
 Cents, for 
 carting. 
 
 39.84 
 0.8984 
 0.2446 
 
 24.46 
 
 Cents, for all 
 other labours. 
 
 and 29.5 
 
 +29.5 
 24.46 
 
 Total cost of 100 bushels, trips of 1 mile to and fro, 53.96 
 
 Upon these grounds the following table is constructed, showing 
 the cost of apj)lying 100 bushels, for trips to and fro of all lengths 
 from 1 mile to 25 ; or of distances from pit to field of half the ex- 
 tent, or from half a mile to 12 ^ miles; if there is no extra travel 
 to be included. 
 
 Length of 
 trip to aud 
 fro. 
 
 Cost of carting of 100 
 bushels. 
 
 (Cents.) 
 
 Cost of all other labours. 
 (Cents.) 
 
 Total cost of 100 
 bushels ajiplied 
 at such lengths 
 of travel . 
 (Cents.) 
 
 Miles 
 
 1 
 2 
 3 
 
 4 
 5 
 6 
 7 
 8 
 9 
 
 10 
 11 
 12 
 13 
 14 
 15 
 16 
 17 
 18 
 19 
 20 
 21 
 22 
 23 
 24 
 25 
 
 Uncove 
 Pit wo 
 Spread 
 
 ng 
 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X 24.46 
 X 24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 X 24.46 
 X24.46 
 X24.46 
 X24.46 
 X24.46 
 
 24.46 
 48.92 
 73.38 
 97.84 
 122.30 
 146.76 
 171.22 
 195.68 
 220.14 
 244.60 
 269.06 
 293.52 
 317.98 
 342.44 
 366.90 
 391.36 
 415.82 
 440 28 
 464.74 
 489.20 
 513.66 
 538.12 
 562.58 
 587.04 
 611.50 
 
 insc 
 
 . 6.5 
 . 13. 
 . 10. 
 
 +29^ 
 +29.5 
 +29.5 
 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 +29.5 
 
 53.96 
 78.43 
 102.88 
 127.34 
 151.80 
 176.26 
 201.72 
 225.18 
 249.64 
 274.10 
 298.56 
 323.02 
 347.48 
 371.94 
 396.40 
 420.86 
 445.32 
 469.78 
 494.24 
 518.70 
 543.16 
 567.62 
 592.08 
 616.54 
 641.00 
 
352 RISKS OP GRADUATED PITS. 
 
 Thus it appears, that if 100 bushels of marl had been carted to 
 12 J miles distance from the pit (making the trip to and fro 25 
 miles), the cost of carting would be 86.11 J, which added to the 
 other fixed expenses, 29.5 cents, shows the total cost to be §G.41 
 the 100 bushels. 
 
 Superior in general advantage as is the mode of working of marl 
 in large graduated excavations, it is very hazardous in wet situa- 
 tions, without much care. The liability to damage is especially 
 great when the work of an unfinished excavation is suspended 
 through winter. Then the caving in of the side-walls, both of 
 overlay and of the marl, caused by frequent rain floods, and still 
 more by the frequent alternate freezing and thawing of the exposed 
 marl, may operate first to choke the passage, and soon to crumble 
 down the entire side-drain The outlet of water from the pit is 
 thus obstructed, and the quantity dammed up in the pit converts 
 the caved earth and marl to a mire. The successive freezing aiid 
 thawing continue to throw down successive layers of the walls, 
 serving still more to raise the water, and filling the pit with mire. 
 It has happened in my much earlier labours, elsewhere, that the 
 unfinished bottom of large spaces of marl was thus so covered in 
 deep mire, as to be given up, because not worth the great labour 
 of being again uncovered. 
 
 The surest safeguard against such dangers is to complete the ex- 
 cavations of each such large digging before freezing weather; also 
 to throw in enough of the next overlying earth to cover the naked 
 upright wall of marl, and thus protect it from freezing. Then the 
 marl under the sloping roadways may be safely worked through 
 winter, in perpendicular pits, and each excavation, as soon as 
 finished, filled with earth, in uncovering another space of marl. 
 
 But when the extent of the range, or the insufficiency of the 
 force compels the large excavation to remain unfinished through a 
 winter, other means may be used, varying according to the features 
 of each locality, to prevent much loss, and which will be suggested 
 by the peculiar circumstances to the mind of every observing 
 marler. 
 
 In removing overlying earth, the excavation should not be 
 limited precisely to the laying naked a sufficient surface of marl, 
 and leaving the section of earth above nearly perpendicular. Even 
 if there is no likelihood of the earth so left caving down in masses, 
 and endangering the labourers below, the earth will be washed 
 down by every rain in small qantities ; and crumbled down by 
 alternate freezing and thawing, if in winter. The face of the over- 
 lying earth should be cut to a slope (as seen in Fig. IV.) Then 
 if a layer is crumbled by freezing, or by drying, the loose 
 earth is kept in its place by its gravity. It is even cheaper, or 
 
MARLING OPERATIONS AT MARLBOURNE. 
 
 353 
 
 more convenient, when removing the overlay by the plough and 
 scraper, to cut out as much beyond the outline of the designed un- 
 covering, as will give the slope of section recommended. 
 
 During 1846 and 1847, the next ranges, E and F (Fig. II.), 
 respectively of 22 and 25 feet width, and each increased in length, 
 were uncovered and excavated. The next range Gr was 33 feet 
 wide throughout, and 428 feet long. The excavation of the marl 
 of Gr was begun in January 1847, and was not entirely completed 
 by October 1849. At that time there had been uncovered another 
 still longer range, H, 36 feet wide and about 450 long, which was 
 nearly ready, and could be so as soon as required to begin the 
 excavation of the marl. This last uncovering had been in progress 
 more than a year, having been worked at when most convenient to 
 spare, or to apply the labour. In each of the ranges since D, the 
 upper end of the marl, for 50 feet in length, had been left to be 
 taken out with the next succeeding range, for greater facility in 
 carting. Therefore so much of the range G still remains in the bed. 
 [1849.] All the ranges excavated, omitting the unfinished part of 
 Gr (and all of H) and including the work at another earlier digging, 
 have furnished the following quantities of marl, as estimated by 
 the heaps counted on the fields. 
 
 Carried out 
 
 in 
 
 1844, 
 
 1845, 
 1846, 
 
 heaped bushels, 
 
 67,875 
 75,512 
 35,545 
 
 
 
 1847, 
 
 1848, 
 
 
 42,575 
 55,106 
 
 
 
 1849, 
 
 
 56,169 
 
 
 To Dec. 
 
 1850; 
 
 (parts of range H.) 
 
 34,684 
 
 Total 
 
 367,466 
 
 When my operations at this place ceased (December, 1850), there 
 then remained more than half of the marl of range H uncovered 
 and not excavated. 
 30* 
 
CHAPTER XXX. 
 
 THE PROGRESS OP MABLING IN VIRGINIA. 
 
 My designed task is at last completed. Whether I shall be able 
 to persuade my countrymen to prize the treasures, and seize the 
 protits which are within their reach, or whether my testimony and 
 arguments shall be fruitless, soon or late a time must arrive when 
 my expectations will be realized. The use of calcareous manures 
 is destined to change a large portion of the soil of lower Virginia 
 from barrenness to fertility ; which, added to the advantages we 
 already possess — our navigable waters and convenient markets, the 
 focility of tilling our lands, and the choice of crops offered by our 
 climate — will all concur to increase ten-fold the present Value of 
 our laud, and produce more farming profit than has been found 
 elsewhere on soils far more favoured by nature. Population, wealth 
 and learning, will keep pace with the improvement of the soil; and 
 we or our children will have reason to rejoice, not only as farmers, 
 but as Virginians, and as patriots. [1832.] 
 
 Such, as appear in the last paragraph, were the concluding words 
 of this essay, as published in 1832, and substantially as the work 
 had been prepared for the press six years before that jiublication 
 was made. Such was then the language of hope and anticipation. 
 It may now [1842] be both interesting and useful to examine to 
 what extent such hopes and sanguine anticipations have been so far 
 realized. 
 
 Every new and great improvement in agriculture has had to 
 work its way slowly and in opposition to every possible discourage- 
 ment and obstacle. It would seem that the agricultural classes are, 
 of all classes and professions, always the least ready to receive 
 benefit from instruction — the most distrustful of iustructers, and 
 the least thankful for their services — even after the benefit is the 
 most completely proved, and established by actual practice and un- 
 cjuestiouable facts. The novel improvement by marling has not 
 presented an exception to this universal rule. But still, it may 
 be confidently asserted, that no other agricultural improvement has 
 been so rapidlij extended, so icideJi/ and generally received in such 
 short time, or has been so generalli/ and greatly profitable to all 
 who have availed themselves of the benefits thereby offered to their 
 acceptance.. When my first trials were made in 1818, so far as I 
 then kneW; I had no forerunner in success. For the few and small 
 
 (354) 
 
EARLY OBSTACLES TO MARLING. 355 
 
 nnd long abandoned experiments, then known, and the opinions 
 deduced therefrom, stood as warnings against, and not in the least 
 as encouragements to repetition ; and the then actually proceeding 
 use of marl, silent and unknown, and to small extent but successful, 
 had not even been heard of. A few more years served to dispel 
 all doubts of those who had tried or could witness the results of the 
 applications of marl. Still, ignorance of the mode of operation has 
 not been dispelled by the knowledge of the gi-eat benefits of marl; 
 and therefore the grossest errors of practice accompanied and greatly 
 lessened the full advantages of the continually extending use of 
 marl. It required but little time for all to learn and assent to the 
 I^ropricty of the one main and simple instruction, " apply marl ;" 
 but few would consent to leai-n anything else ; or would believe that 
 there was anything else necessary to learn or to do, except merely 
 to " apply marl." They would not learn from anything but their 
 own dearly bought experience of error. And very many have thus 
 learned, and have paid the cost to their own pecuniary loss of thou- 
 sands of dollars in value — whether in delay by misapplied effort, or 
 in positive loss and injury sustained by wrong practice — which the 
 outlay of a few dimes, and tjie attentive reading for a few hours, 
 might have eifectually guarded them against. And so it still goes 
 on, and will go on, with all who are new beginners and learners, 
 and who have not yet paid each their hundreds or thousands of 
 dollars in loss, in preference to less than as many cents, in both 
 money and labour, in accj[uiring proper instruction, and security 
 from all such loss. 
 
 But with all such enormous drawbacks of loss, which if avoided 
 would have doubled the actually achieved benefits, the extension 
 of marling and liming, and the amount of benefit thence derived 
 and realized in lower Virginia, since 1818, have had no precedent 
 in the annals of agricultural improvement by any mode of manuring. 
 The following extract from a more general report, recently made by 
 the writer to the State Board of Agriculture (in 1842), will present 
 this branch of the subject in its proper aspect. 
 
 *' Marling, or manuring from beds of fossil shells. — This mode of fertiliza- 
 tion, now so general through all the marl region of lower Virginia, was not 
 practised except on three or four detached farms, and that to but small ex- 
 tent before 1820. Some few and small experimental applications of marl 
 had indeed been made by different individuals, from 15 to as far back as 
 45 years earlier ; but which applications, from total misconception of the 
 true mode of action of calcareous manures, had been deemed failures ; 
 and, without exception, had been abandoned by the experimenters as 
 worthless ; and the experiments had been almost forgotten, until again 
 brought to notice, after and in consequence of the much later and fully 
 successful introduction of the practice. 
 
 " Henley Taylor and Archer llankins, two plain and illiterate farmers, 
 aud near neighbours ia James City county, were the earliest successful ajid 
 
356 EARLIEST MARLING OPERATIONS. 
 
 continuing appliers of marl in Virginia. But at wliat time they began, and 
 ■which of them was the first, I have not been able to learn ; though visiting 
 ]Mr. Hankins' farm for that purpose, as well as to see his marling, and 
 making inquiries of him personally, in 1833. Mr. Taylor had then been 
 long dead, and his improvements said to be almost lost, by the exhausting 
 tillage of the then occupant of his land. Mr. Hankins was unable to say 
 when he and his neighbour began to try marl. He was only certain that it 
 was before 181G. Yet, though these farms are within 12 or 15 miles of 
 AVilliamsburg, to which place I had made visits once a year or oftener, yet 
 I never heard an intimation of their having begun such practice, until some 
 time after my own first trials in 1818. At that time, when led to the use, 
 as I was, altogether by theoretical views, and by reasoning (in advance) on 
 the sujDposed constitution of the soil, as well as the known constitution of 
 the manure, it would have been to me the most acceptable and beneficial 
 information to have heard that any other person had already proved prac- 
 tically the value of marling. The slow progress of the knowledge of the 
 mei-e fact of mai-1 having been successfully used before that time, was a 
 strong illustration of the then almost total want of communication among 
 farmers, as well as of their general apathy and ignorance in regard to the 
 means of improving their lands.* 
 
 " Much earlier than the commencement of marling in James City, the 
 practice had been commenced (in 1805), in Talbot county, ]\Iaryland, by 
 Mr. Singleton. His account of his practice is in the 4th volume of the 
 ' Memoirs of the Philadelphia Agricultural Society,' dated December 31, 
 1817, and first published some time in 1818. But successful as was his 
 practice, and also that of Mr. Taylor and Mr. Hankins in connexion with 
 much worse farming, it is certain that neither of these individuals had the 
 least idea of the true action of marl ; and they were indebted to their good 
 fortune, more than to any exercise of reasoning, that they received profit- 
 able returns, and did no injury by marling. They all three applied their 
 putrescent manures with the marl. But though this was the safest and 
 most beneficial plan, the thus uniting them prevented the separate action 
 and vakie of putrescent and calcareous manures being known, compared, 
 and duly appreciated. 
 
 " My own application of marl, on Coggins Point farm, Prince George 
 county, which in 1818 extended only to 15 acres (of which but 3 or 4 were 
 under the crop of that year), by 1821 had been increased to above 80 acres 
 a year, and so continued until nearly all the then arable land on that fai'm 
 requiring it (more than GOO acres), had been covered. In 1821, my earliest 
 publication on the subject was made. Though the facts and reasoning thus 
 made known by that time were beginning to attract much notice, and to 
 induce many persons to begin to marl, still it was some years later before 
 incredulity and ridicule had generally given place to full confiilence in the 
 value of the improvement. Even at this time, when nearly 25 years of my 
 own experience of marling and its benefits have passed, and the results are 
 open to public notice and scrutiny, lyilf the persons who could marl are 
 either not engaged at it, or are marling to but little pui-pose ; and of all 
 who are using marl, nineteen in twenty are proceeding injudiciously, with- 
 out regard to the mode of operation of the manure, and therefore are either 
 doing harm, or losing profit, almost as often, though in less degree, as 
 doing good. At this time, however, there are scarcely any persons, how- 
 ever negligent or mistaken in practice, who do not fully admit the great 
 value and certain profit of applying maxd, wherever it is available. 
 
 * See a more full account at page 108, vol. i., Farmers' Register. 
 
PROGRESS OF MARLING. 857 
 
 "But with all the existing neglect of using this means of fertilization, 
 and with all the still ■^vorse ignorance of or inattention to its manner of 
 025ei"ating, there never has been a new imiDroTcment in agriculture more 
 rapidly extended, or with such beneficial and profitable results. In Prince 
 George county there is not one farmer having marl on or near his land, 
 who has not applied it to greater or less extent, and always with more or 
 less profit — and, in most cases, largely as well as profitably. In James 
 City county there has been perhaps the next largest as well as the oldest 
 jiracticc. In York county, as in James City, some of the most valuable 
 aud profitable improvements by marling have been made. And some of 
 the farms of both counties, adjoining Williamsburg, and having the benefit 
 of jjutrescent town manures, show, more strikingly than any others known, 
 the remarkable power of calcareous manure to fix the putrescent in the 
 soil, aud make them more efficient and far more durable. In Surry, Isle 
 of Wight, Nansemond, Charles City, New Kent, Hanover, King William, 
 King aud Queen, Gloucester, and Jliddlesex counties, in the middle of the 
 marl region of Virginia, marl has been already extensively applied, and the 
 profits therefrom are annually increasing. And in other surrovinding coun- 
 ties, less abundantly supplied with marl, the practice has been carried on 
 in proportion to the facilities, and to the more scanty experience and degree 
 of information on the subject. It would be a most important statistical 
 fact, if it could be ascertained how much land in Virginia has already been 
 marled. The quantity however is very great ; and all the land marled has 
 been thereby increased in net product, on the general average, fully 8 
 bushels of corn or oats, or 4 bushels of wheat, if following corn, and the 
 land increased in intrinsic value fully 200 j^er cent, on its previous value 
 or market price. AVhere the marling has been judiciously conducted, these 
 rates of increase have been more than doubled. From these data, might 
 be calculated something like the ali-eady prodigiously increased values 
 and i3roducts due solely to marling, and which will be still more in- 
 creasing from year to year. If not already reached, the resvilt will soon be 
 reached, of new value to the amount of millions of dollars having been thus 
 created. * * * * * 
 
 " It required the improvement by marling, on originally poor and mid- 
 dling soils (or liming, which in final or general results is the same thing), 
 to render as generally available the best (and otherwise but rarely found) 
 benefits of the two kinds of vegetable manuring recommended by Taylor. 
 When such soils have been made calcareous, by marling or liming, then, 
 and not until then, all the benefits, present and futui*e, that his readers 
 might have been induced to expect, may be confidently'couuted upon. In 
 my own earlier practice — and Taylor had no greater admirer, or more im- 
 plicit follower — I found my farm-yard manurings on acid soils scarcely to 
 pay the expense of application, and to leave no trace of the effect after a, 
 very short "time. And land, allowed to receive for its support all its vege- 
 table growth (of weeds and natural grass) of two and a half years in every 
 four, and the products in corn having been measured and compared, showed 
 no certain increase in more than twenty years of such mild treatment. 
 Since, on the same fields, farm-yard manures, in every mode of prepara- 
 tion and application, always tell well, both in early efiect and in duration. 
 And even the leaves raked up on wood-land, spread immediately and with- 
 out any preparation as top-dressing on clover, always produce most mani- 
 fest improvement, and are believed to give more net profit than any appli- 
 cation of the much richer farm-yard manui-e, per acre, made on like land 
 before it is marled. This utilizing and fixing of other manures, aud the 
 fitting land to produce clover (and to receive benefit from gypsum on clo- 
 
358 PROGRESS or liming. 
 
 ver), wMch effects of marling are in addition to all the direct benefit pro- 
 duced, woxxld alone serve to give a new face to the agi-iculture of the 
 country. Whatever may be done by clover, and almost every thing that 
 can be done to profit by vegetable manures, on the much larger propor- 
 tion of the lauds of lower Virgina, will be due to the application of marl 
 or lime. 
 
 " Liming. — The kindred improvement by liming began to be extensively 
 praclised on some of the best James river lands, where no marl was found, 
 soon after the use of the latter began to extend. Who may have made 
 the earliest and small applications of lime is not known, nor is it at all im- 
 portant. The Earlier profitable use of lime in I'emisylvania, and the much 
 earlier and more extended use in Britain, were known to every well in- 
 formed or reading farmer. Such a one was Fielding Lewis, of Charles City, 
 as well as a most attentive, judicious, and successful practical cultivator 
 and improver. He is believed to have been the earliest considerable limer, 
 and the one who obtained the most manifest profits therefrom, and whose 
 example had most effect in spreading the practice. Some of his disciples 
 and followers have since, in greater rapidity and wider extent of opera- 
 tions, far surpassed their teacher and leader — to whom, however, they 
 award the highest meed of praise for bringing into use, and establishing, 
 this great benefit to the agriculture of lower Virginia. Nearly all the best 
 soils on James river are comparatively of low level, as if of ancient alluvial 
 formation, and have no marl, with which the neighbouring higher and 
 poorer lands ax-e mostly supplied. Of such rich lands are the farms of Wey- 
 anoke, Sandy Point, Westover, and Shirley, &c., in Charles City, and 
 Brandon (Upper and Lower), in Prince George — and on all these lauds, as 
 well as some others, lime has been largely applied. The use is extending 
 to the lands on and near to all the tide-waters of the state ; and it has re- 
 cently received a new impulse from the low price at which northern stone- 
 lime is now brought and sold. It is reacly slaked, and the vessels are 
 loaded in bulk. The lime is sold on James river at 10 cents the bushel, 
 and even may be contracted for at 8 cents, from vessels that come for car- 
 goes of wood, and would come empty but for bringing lime. The greater 
 Hghtuess and cheaper transportation of lime will enable it to be applied 
 where marl could not be carried with profit ; and with the two, there will 
 be but little of lower Virginia which may not be profitably improved by 
 calcareous manures."* 
 
 With all the caution proper to be used in a report made to a 
 Board of Agriculture, and through it to the government of the 
 commonwealth, the writer dared to predict, in 1842 (as quoted 
 above), of the increased value of lands caused by marling, that '' if 
 not already reached, the result ivill soon be reached, of new value 
 to the amount of millions of dollars having been thus created." 
 Because of the then deficiency of statistical and documentary 
 evidence (since partially and imperfectly supplied), he was not 
 then aware that this prediction had already been more than fulfilled. 
 
 * Extract from "Report to the State Board of Agi-iculturc, on the most 
 important improvements of agriculture in lower Virginia, and the most 
 important defects yet remaining." Published by order of the General 
 Assembly, as a state document, and also in Farmers' Register, p. 2o7, 
 vol. X. 
 
EFFECTS ON PUBLIC INTERESTS. 859 
 
 The message of the present Governor of Virginia to the legislature, 
 in January, 1852, stated, upon the evidence of official documents, 
 that the assessed values of lands in the tide-water district, had been 
 increased more than 17 millions of dollars in the twelve years pre- 
 ceding the last assessment of 1850. The governor properly ascribed 
 this increased value of lands of this region to the recent fertilization 
 of particular portions. With all well-informed residents, or those 
 acquainted generally with the past and present circumstances of 
 this region, there Will be no question as to the xvhule of the in- 
 creased value being due to the use of calcareous manures. For 
 before the introduction of this still recent practice, both the intrinsic 
 and the market values of lands had decreased — as they have con- 
 tinued since to decrease in the neighbouring counties in which 
 there has been very little or no use of marl or lime. All other 
 improvements of agricultural practices, great as they certainly have 
 been, have not sufficed to replace the productive power wasted by 
 the generally exhausting tillage. 
 
 But great as is this declared general increase of value of the 
 lands of this tide-water region alone — and, as I maintain, from the 
 eiFects of calsing alone — it is not near so much as can be truly 
 asserted, and satisfactorily proved from the public documents and 
 statistical tables, defective as they are for this course of investiga- 
 tion. This is not the place to offer in detail the authorities and 
 proofs of these important facts. But this shall be done in another 
 paper, which will be a communication to the State Agricultural 
 Society. In that paper I will maintain, and expect to establish, 
 the following propositions, of which the enunciation will be here 
 stated concisely, in advance of the proofs, and deductions therefrom, 
 which will hereafter appear : 
 
 1. The parts of lower Virginia, long settled and cultivated, and 
 also the neighbouring upper counties, had been decreasing in pro- 
 duction, in population, and especially in productive or labouring 
 population, in wealth generally, in the intrinsic or productive value, 
 and also the selling and assessed values of lands, for more or less 
 time, previous to the commencement of the improvement by marl- 
 ing; and such decrease has continued to this time, and is still pro- 
 ceeding, wherever there has been no marling or liming. 
 
 2. In the counties in which most land has been improved by 
 marling or liming, and only since these improvements were in pro- 
 gress, there has been a marked change from the former declining 
 condition, just stated, to increase of value of lands, of wealth gene- 
 rally, and of products of taxation — and as a later and as yet less 
 advanced effect, an increase of population also. 
 
 3. This change from decrease to increase of the values of lands, 
 though not indicated by official documents earlier than the assess- 
 ment of 1838, (there having been no previous assessment later than 
 
SCO EFFECTS ON PUBLIC INTERESTS. 
 
 tliat of 1819), had in fact begun about 1828, -when tliere existed a 
 much lower state of depression of production and of value; from 
 which lower rate, and earlier time, the selling value of lands, and 
 much more the productive or intrinsic value, had been increasing 
 for 22 years preceding the last assessment of 1850 — and (at least) 
 to the amount of nearly 30 millions of dollars; instead of 17i 
 millions increase in 12 years, as computed in the governor's mes- 
 sage. _ _ , , 
 
 4. All this stated increase of value of lands is much less than is 
 the actual increase ; and though stated as for the whole tide-water 
 district, in truth it has been achieved upon a very small proportion 
 of the surface of that district — the great remainder (more than 
 twenty times as much in quantity) — still being without any such 
 improvement, or increase of either assessed or productive value. 
 Even on the very small proportion marled or limed, the improve- 
 ments are of less than half the value which judicious procedure 
 would have effected, and earlier, at less cost, and also permanently. 
 Hence, the actual calsings may yet be doubled in effect and value, 
 and twenty times as much space may be raised to like increased 
 production and value. 
 
 5. Therefore, the admitted newly created value of land, of 17i 
 millions of dollars between the two latest assessments, and the as- 
 serted increase of nearly 30 millions from 1828, are both, bej'ond 
 comparison, far below the available increase for the whole of the 
 tide-water district alone-^to say nothing of the other parts of Vir- 
 ginia, improvable by like means. The whole available increase 
 of value on lands alone, and for the tide-water district alone, on the 
 premises stated, may reach to 500 millions of dollars — with pro- 
 portional increase of value of other farming capital and connected 
 movable property, and of population and products of taxation. 
 
 Enormous or incredible as these predicted results may appear, I 
 maintain that there is more ground now to expect the complete 
 fulfilment within the next 35 years, than there was, 35 years past, 
 in the then desperate condition of agriculture, to expect, not only 
 the now actual increase of values in lower Virginia, but even any 
 smaller general increase. The main thing needed to aid and hasten 
 the fulfilment should be a measure which heretofore has been en- 
 tirely neglected and scornfully refused, in this and in all other 
 relations to agriculture, viz. : that the government of Virginia 
 shall in proper manner induce investigation, and encourage the 
 diffusion of knowledge, in this and every other department of agri- 
 cultural research and labour. 
 
 In the report, part of which was quoted above, it was recom- 
 mended, and again more formally in the general report of the Board 
 of Agriculture to the legislature, that the amount of land marled 
 and limed should be obtained by the commissioners of the revenue, 
 
NEGLECT BY THE GOVERNMENT. oGl 
 
 and reported by the goTernment. This small and costless aid to 
 agricultural knowledge, and encouragement to further improvement 
 (as well as all aid of greater value), the legislature of Virginia denied. 
 If it had been granted, and thereby had been shown the real extent 
 of these improvements in every county, and even as it might be on 
 every form, these facts, in connexion with the values shown by the 
 diiferent assessments, would have exhibited clearly and fully the 
 results which can now only be inferred generally, loosely, and ac- 
 companied necessarily by many errors. Such important results, 
 so fully established, and made so obvious to all, would have operated 
 more strongly than any and all other existing incitements, to en- 
 courage the extension and the judicious procedure of improvements 
 by calcareous manures. It would then clearly appear which in- 
 dividuals had secured to themselves this 30 millions of dollars of 
 already increased value of property, and by what easy means. And 
 all other persons, who could follow the example, and secure their 
 shares of as rich rewards, would be imperatively called to use the 
 like procedure, and so obtain the like benefit for themselves and 
 for the commonwealth. It would have been to the before and still 
 listless and inert proprietors and cultivators of our poor and unim- 
 proved lands similar in efi'ect with the first announcement of the 
 gold of California being ready for every needy adventurer who 
 was able to go and dig for it. In the use of calj^areous manures, on 
 all the poor or exhausted land where their use is available, there 
 are offered rewards to all judicious adventurers far richer, and more 
 certainly and largely productive, than the golden products of Cali- 
 fornia — and the former would be as much conducive to public and 
 private weal, as the gold of California has been and will be in- 
 jurious to both. 
 
 31 
 
APPENDIX. 
 
 INTRODUCTORY REMARKS. 
 
 In the foregoing esposition of theory and practice, it has been 
 the object and eft'ort of the author to embrace whatever seemed 
 necessary for proof or for illustration ; and to omit everything else, 
 lest too much of amplification or digression should weaken rather 
 than strengthen the main positions. Thus* it is believed that the 
 foregoing chapters, as argument and proof, serve to establish the 
 Beries of propositions which were at first advanced and throughout 
 contended for. Still there remained many minor but "interesting 
 subjects, more or less intimately connected with the investigation, 
 or serving for more full proof, and which well deserved more ex- 
 tended discussion, and the consideration of those readers who should 
 desire to pursue farther the general object of this essay. These 
 subjects will be treated separately in the different articles of this 
 appendix ; which may be read, it is believed, with both interest and 
 benefit by the more inquiring class of readers; or may be passed 
 over, by the more cursory and careless, without much detriment to 
 the arguments and facts of the preceding portion and regular body 
 of the work. 
 
 NOTE I. — Extension op the subject op pages 92 — 97. 
 
 Additional proof, offered in the production and existence of hiack 
 waters, of the action of lime in combining vegetable matters with 
 soil. 
 
 Every person who has seen much of the different parts of lower 
 Virginia (to go no farther for examples), must have remarked the 
 dark permanent colour of the waters of many streams and mill- 
 ponds ; and that others, whether when clear or when turbid, are at 
 all times and entirely without any tinge of this peculiar colouring 
 matter. The waters thus coloured by vegetable matter are more 
 deeply tinted at some times than at others ; but are always strongly 
 
 363 
 
364 BLACK WATERS. 
 
 tlius marked. These waters, when several feet in depth, appear to the 
 eye quite blaclc or very dark brown. The same if viewed in a drink- 
 ing glass would appear of the colour of Sherry wine, and might 
 present some shade between the palest and deepest tints of such 
 wine. This colour has nothing of muddiness ; for these waters are 
 as clear from suspended clay or mud as any other waters not so 
 coloured in the slightest degree. In the county in which nearly 
 all my life has been passed, Prince G-eorge, these different kinds of 
 waters are to be seen in stronger contrast, because of their close 
 neighbourhood. All the streams which flow into Blackwater river, 
 as well as the main stream which that name so well describes, 
 from its head to its outlet, are coloured deeply, and it is believed 
 without exception. On the contrary, the sti-eams which flow into 
 James river are all without the least tint of colour, though they 
 often rise from sources very near to some of the others, the head- 
 springs being on opposite sides of the same dividing ridge of level 
 table land, and in lands precisely alike. Some of these lands are 
 of close and stiff soil, and some more sandy and quite light ; but 
 all are level, poor, and acid lands, and ai-e mostly still under forest 
 growth. 
 
 All persons, whether of the most or the least observant class, 
 would concur in the opinion that this colour proceeds from vegeta- 
 ble matter. This is obvious even in the waters of heavy rains, 
 which when more than the level ridge lands can absorb, flow off, 
 and are sometimes for a day or more thus passing in temporary 
 streams to the nearest valley, or other descent. These surplus 
 waters, while yet on the highest woodland, are coloured to a greater 
 or less depth of tint; and just as much in those which take their 
 course towards James river, as the others which flow in the opposite 
 direction to the Blackwater. The difference is that the former soon 
 lose all such colouring matter, and in no case carry it to or even 
 near James river, whilst the other waters increase in depth of 
 colour with the length of their course, or the duration of time they 
 remain in the mill-ponds they pass through, or in the sluggish Black- 
 water river. 
 
 The supply of colouring matter is principally furnished by the 
 dead and fallen leaves in the poor forest land, and is doubtless in- 
 creased afterwards, both by the partial evaporation of the water, 
 and by its dissolving still more of the soluble vegetable extract ia 
 the flat swampy grounds through which the streams flow into the 
 lilackwatcr. This might indeed satisfactorily account for these 
 waters being more deejAy coloured than those which pass by a more 
 rapid descent to James river. But these different circumstances 
 do not serve at all to explain why the latter waters should soon 
 lose, if they had it at first, the slightest trace of colour. 
 
 The like circumstances arc probably to be found to more or less 
 
BLACK WATERS. 365 
 
 extent in most of the counties on our tide-water rivers, as most of 
 thcni have poor forest lands and some swampy streams in the 
 interior. 
 
 As the opposite circumstances of the presence or absence of 
 colour in different waters is certainl}- not caused by such difference 
 in the sources of supply, they must be caused by some subsequent 
 action, which serves to clear the waters in one locality, by combin- 
 ing with and taking off the dissolved colouring matter, and which 
 action does not take place elsewhere, because there is no such 
 efficient agent present. That agent I take to be carbonate of lime, 
 or some other salt of lime in the soil in the one case, and v/hich is 
 present in quantity altogether insufficielit for such action in the 
 other case. According to the views which were presented (page 
 96) in regard to the power of calcareous earth to combine chemi- 
 cally with vegetable matter, if the coloured waters should flow over 
 soils furnished with calcareous matter, or into streams impregnated 
 with any salts of lime, it would follow that the suspended or dis- 
 solved vegetable extract would combine with the calcareous matter 
 of the soil in the water, and the new combination be precipitated, 
 and be given to the soil, as manure, either immediately or remotely. 
 This effect would be greatly aided if the streams swollen by rains 
 actually passed in contact with and washed away exposed banks of 
 marl. All I'cceut rain-water contains a small amount of carbonic 
 acid, and that impregnation enables water to dissolve a proportional 
 quantity of carbonate of lime, which is insoluble in water without 
 this addition of carbonic acid. Therefore, in such circumstances 
 the swollen streams and land floods would necessarily dissolve some 
 carbonate of lime, which would be thus placed immediately and 
 fully in mixture and perfect contact with the before dissolved vege- 
 table colouring matter, and next must take place the combination 
 of the two, and precipitation of the compound manure. The con- 
 sequence must be, that the lands thus overflowed must be more or 
 less enriched by every heavy rain ; while the lands overflowed by 
 the coloured waters receive, or retain, nothing of soluble vegetable 
 matter from this source, and may even lose part of what they had 
 before received from the decay of their own growth, or other 
 sources, by its being dissolved and carried off by such overflowing 
 waters. 
 
 Now let us see how the actual results agree with these different 
 causes, so far as the causes are known to exist. In the limited 
 region particularly referred to above, the low grounds, subject to 
 inundation by rains in a state of nature, and having beds of marl 
 which the stream cuts through, are of much richer soil than any 
 others, though the quantity of marl displaced by the stream (if in- 
 deed any such displacing be perceptible) would seem altogether too 
 small in amount to produce such extent of fertilization by direct 
 31* 
 
866 CLEARNESS OF LIME-STONE WATERS. 
 
 action. And it is believed, whether marl beds be so exposed or 
 not, that the low grounds on the streams of colourless water are 
 always much better soils, and of more durable fertility, than those 
 washed by coloured waters. The latter soils being often swampy, 
 are full of vegetable matter, and of course would be very productive 
 when first drained and cultivated. But these soils are far from 
 being among the most durable, and they are even at first, and when 
 in best condition, very inferior lands to most low grounds of prime 
 quality; and the latter are always penetrated by streams, or had 
 been sometimes covered by floods, which, however turbid at certain 
 times with suspended clay and mud, are never coloured by vegeta- 
 ble extractive or soluble matter alone. 
 
 If we go farther for examples, the effects will be found to be 
 still more striking. None of the lime-stone streams are ever 
 coloured ; and their remarkable transparency, very far surpassing 
 that of the most pure and limpid waters of the low country, show 
 that the dissolved lime, which the mountain streams contain, serves 
 to remove everything of colouring matter. These lime-stone wa- 
 ters, and land floods from rains which also necessarily carry dis- 
 solved carbonate of lime, form the principal supply of the upper 
 James river. But long before the waters reach the head of tide, 
 not a particle of lime remains. The dissolved lime had been con- 
 tinually uniting with the suspended or dissolved vegetable matter, 
 until no lime was left, and the precipitated compound had served 
 to add more manure to the extensive low-grounds along the whole 
 course of the upper James river, and which are so well known and 
 deservedly celebrated for their great and enduring fertility and 
 high value. 
 
 When a resident of the lower country first visits our mountain 
 and lime-stone region, he cannot avoid observing and being forcibly 
 impressed by the remarkable clearness of the waters. Pools and 
 basins in the streams containing sis feet depth of water, will ap- 
 pear to his unpractised eye as not deeper than two or three feet. 
 And it is only by comparison, and by becoming acquainted with 
 this really and perfectly clear lime-stone water, he learns that ho 
 had, in truth, never before seen a stream or pond of perfectly clear 
 water. Though the dissolved matters may be in too small quan- 
 tity to produce any appearance of colour, they serve to impair the 
 transparency of the water. And when any such colouring or 
 vegetable matters are received into and intermixed with lime-stone 
 streams, the vegetable matter is immediately combined with lime, 
 and the compound precipitated ; still leaving in the water a great 
 excess of dissolved lime, scarcely diminished by the loss of the 
 small part acting to clear the water of all colouring and vegetable 
 • impregnation. 
 
 From the large proportion of lime held in solution by limc-stono 
 
LIME-STONE WATERS, 367 
 
 springs, and the streams proceeding from them, and also by rain 
 floods passing over lime-stone soils, it must be inferred (according 
 to my views), tli^-t such waters must very quickly combine with 
 and precipitate all colouring matters, and, when not turbid with 
 earthy matter, be as transparent as water can possibly be. Hence, 
 "the well known and remarkable transparency of such water is not 
 directly caused (as commonly understood) by lime being contained 
 in them — but because of the other adulterations being totally re- 
 moved in combination with a part of that dissolved lime. Thus, 
 the water is not in the least made crystalline and transparent be- 
 cause of what it contains, but because of what it has been deprived 
 of. And, therefore, even after all the lime may have been pre- 
 cipitated, the water must retain its previous perfect transparency, 
 unless subsequently impregnated with other colouring matter. 
 
 The additional supply of carbonic acid to water, which alone 
 gives to it the power to dissolve or to retain in solution even the 
 smallest proportion of carbonate of lime, is not strongly held. It 
 is given off by the lime-stone water in its partial evaporation, and 
 to every contact of atmospheric air; and this operation is increased 
 by such agitation of the water as exposes a larger surface to the 
 air. Hence, at all rapids of lime-stone streams, there is a pecu- 
 liarly rapid and large deposition of carbonate of lime, let loose by 
 the water because of the loss of the proportion of carbonic acid 
 which before served to hold the lime dissolved in the water. This 
 precipitation and gradual accumulation of carbonate of lime, at the 
 rapids and cascades of streams, is the formation called calcareous 
 tufa or travertine, and vulgarly called "marl" in our mountain 
 region, and which is presented in great quantity, and sometimes in 
 enormous masses. 
 
 As lime-stone water so easily parts with the carbonic acid which 
 enables it to hold lime in solution, it can scarcely be supposed that 
 any of the acid remains after the water collects and remains long 
 ia the great reservoirs formed in lakes. But whether the water 
 remains impregnated with carbonic acid, and of course with lime, 
 or has lost both, the effect is the same, and is exhibited most 
 strongly in the remarkable transparency of lakes so formed. Of 
 such, I have never myself witnessed any but of Lake George, in 
 New York. And after the long lapse of time since my short visit 
 to this lake, I cannot remember to what extent the transparency 
 of its waters was asserted, or what my own personal observation 
 ascertained. I only remember certainly that the depth of water 
 through which very small objects were distinctly visible was very 
 great, and that no ground was left to doubt what is generally 
 asserted and received as true on that head. 
 
 To return to the lands and waters of Prince (leorge county. 
 The water left by heavy rains, standing in shallow pools on the 
 
368 . BLACK WATERS. 
 
 high level wood-laud, and flowing off in temporary rivulets, is seen 
 to be coloured by vegetable matter even within a mile of James 
 river, just as it is found on the other lands sloping towards the 
 Blackwater. But in either and every known case of such dis- | 
 coloration being caused, it is on poor and acid land. No such * 
 effect takes place on calcareous or even neutral soil, no matter how I 
 abundantly it is provided with dead leaves or other vegetable mat- 
 ter. Therefore it is manifest that it is not difi'erence of locality, 
 but difi'erence of soil, which causes the different effects of the 
 surplus rain-water becoming tinged, and remaining tinged with 
 vegetable extract, or otherwise remaining colourless. And also, 
 after the water has been so tinged, that it depends on the difference 
 of chemical composition in the soils over which it passes, or of the J 
 streams into which it is discharged, whether the colour remains or ^ 
 is quickly discharged. And, as already stated, this difference of 
 action and effect depends on the absence or presence of lime in the 
 soils or waters to which the coloured excess of rain-water flows. 
 
 It is only in the surplus quantity of rain-water, or that which is ■ 
 more than the soil can absorb, that this colouring matter is see7i. 
 But it is not the less certain that all of the much greater cjuantity 
 of water from more gentle and more frequent rains which soak 
 into the earth, must also be more or less tinged with the colouring 
 matter of the leaves and other dead vegetable matter through , 
 which the water passes, and must take up, in passing, all that is ' 
 then easily soluble, and not chemically combined with some other 
 body. Thus, every gentle and soaking rain probably carries into 
 the soil the greater part of all the then solulole vegetable matter, i 
 and that only which is soluble is all that is then completely ready < 
 to act as food for plants. The same rain, and the subsequent j 
 chediical action of air and warmth, cause the decomposition of the - j 
 before insoluble vegetable matter to recommence, and in a few ! 
 days there is a renewed supply of soluble or extractive matter ' 
 formed in the vegetable cover of the soil, ready to be dissolved aijd : 
 to be carried into the earth by the next succeeding rain. 
 
 Such is nature's process of furnishing alimentary manure, or 
 the food of plants, to soils. And the source of supply is unlimit- ] 
 ed ; for it is principally from the atmosphere and water, and by I 
 fixing their elements (oxygen, nitrogen, hydrogen, and carbon), that [ 
 the vegetable growths of soils, and consequently all alimentary 
 manures, are formed. 
 
 Enormous then as is the continual waste of vegetable ex- ; 
 tractive matter and manure that is caused by every heavy rain, and i 
 which is always evident to the eye in the black waters of so many . 
 ponds and streams, all this lost fertilizing matter must be in very 
 small proportion, compared to the greater quantity that is carried 
 more^radually and frequently into the earth. Much the greater '■. 
 
BLACK WATERS. 5(59 
 
 part of tbe wood-laud of lower Virginia is most freely and abund- 
 antly thus supplied, not only because of tbe abundant sources pre- 
 sented in a thick layer of fallen leaves, the growth of many 
 successive years, but also because of the very level surface of the 
 land, which obstructs the flowing off of the surplus rain-water, and 
 the general sandy and open textilre of the soil and sub-soil, which 
 operate to absorb quickly the water and its dissolved vegetable 
 matter. Yet it is more especially these lands that show the least 
 remaining and abiding store of this supply of vegetable manure. 
 The soil, or all of the upper part which shows any colour from 
 containing vegetable matter, is usually not more than two inches 
 thick on sandy soils, and still less on the stiffest ; and all the por- 
 tion below (though ueces'sarily manured by being often soaked to 
 a foot or more with rain-water conveying all its dissolved vegeta- 
 ble extract), is entirely barren and worthless. Such results would 
 be as inexplicable as they are wonderful, but for the reasons afford- 
 ed by the doctrine of the combining and fixing powers of carbonate 
 of lime and vegetable salts of lime; the absence of which ingre- 
 dients is the sole defect in these cases, and which, when present in 
 soils, show results of fertilization altogether the reverse of these. 
 Where lime is present in sufficient quantity, no colouring or ma- 
 nuring matter is lost to the soil in the flowing off of surplus water, 
 nor in the wasteful and profitless decomposition of the greater 
 quantity of colouring and alimentary matter soaked into the earth. 
 
 My observation was not attracted to the cause of the existence 
 of black waters, and this application of the facts, until nearly the 
 close of my residence in the country, and of my opportunities for 
 personal and accurate observation. And I am well aware, and 
 ready to admit, that previous observations, made by mere chance 
 and without object, are worth very little comparatively. I there- 
 fore would be glad to have the attention of other observers drawn 
 to this point, and any facts to be elicited that will either confirm 
 or disprove my positions. From inquiries made of persons who 
 have had ample opportunity to observe what waters were either 
 permanently black or without tinge of such vegetable stain, I have 
 heard the following general statement of facts, on which my com* 
 ments will be offered as the facts are presented. 
 
 Streams and ponds of black waters are rarely seen above the falls 
 of the rivers ; and are believed to be very rarely found even twenty 
 +iO thirty miles above. They are never seen in the still higher 
 lime-stone region. If this opinion be correct, thea these waters 
 are confined exclusively (as they certainly are mainly) to the region 
 of soil of the most acid quality. At the distance above the falls 
 where black waters are never found, the high laud was naturally lu 
 general of good quality, and the bottom or alluvial lands, on smnll 
 streams, invariably of good soil. Of course these qualities iudi- 
 
370 CONFINED TO ACID SOILS. 
 
 cate more of lime in the soil ; and, according to my views, also the 
 inability of water to become black, or at least to remain coloured.* 
 
 The waters of Blackwatcr river a.id its tributary streams and 
 swamps become darker in autumn, owing to the low level of the 
 surface at that season. This is according to sound reason ; as eva- 
 poration of the solvent fluid necessarily increases the strength of 
 the solution. But this cause is held by most persons as secondary 
 in force to another, viz. : the dropping of the leaves, and especially 
 of the numerous black -gum trees, and their berries, at that season, 
 on the swamps and in the streams. Of course such is the source 
 of the colouring matter ; but it would produce no notable or abid- 
 ing effect, but for tlie want of lime both in the soil and in the wa- 
 ter. The extensive tide swamps on the creeks of James river, are 
 covered with a dense growth of trees, of which a large proportion 
 are black-gums. Yet in the numerous rills trickling or oozing out 
 of these soils, after some days of Idw tides, I have never observed 
 the water to.be dark, or in the least discoloured. Yet the soil of 
 these tide swamps is as much of vegetable formation as any capa- 
 ble of bearing trees, and is believed to be more so than the swamp 
 lands of Blackwater river and its tributaries. Therefore it is not 
 the abundance of dead vegetable matter in a soil, nor the quantity or 
 kind of leaves furnished by the trees growing on it, which alone or 
 together produce coloured waters. The earthy portion of the soil 
 of these tide marshes and swamps, small as is its amount, is not 
 acid, but neutral, and the lime contained serves to prevent the wa- 
 ter remaining discoloured. 
 
 Yet this is not always the case on tide swamps. The waters of 
 Pocomoke river, flowing into the Chesapeake, are black, which I 
 presume is owing to the deficiency of lime in the water and in the 
 surface soil of the lauds from which the waters flow. 
 
 The great Dismal Swamp of Virginia and its lake, and the still 
 more extensive swamps and lakes of North Carolina, all present 
 black waters, and which may all be accounted for by the reasons 
 here given. 
 
 Neither is it necessary that marl beds should be wanting to pro- 
 duce the efl'ect of black waters. It is only necessary that the marl 
 (no matter how abundant) should be so far below the surface as 
 not to afi'ect the overflowing waters, and that the soil of the higher 
 lands should be generally of acid quality. Such are the lands on 
 Blackwater river and its tributaries. And though marl was scarcely 
 
 * The extract translated from M. Puvis' '^Ussai siir la Marne," and intro- 
 duced at page 150 of this essay, affords testimony that the facts in regard 
 to the existence and localities of black waters in France accord strictly 
 with the views presented in this article. This writer says that, " during the 
 mouth of August, the water of the ponds on calcareous soil does not be- 
 come blackish, as often happens in silicious ponds." 
 
MARL AND MARLING IN EUROPE. 371 
 
 known anywlicre. there twenty years ago, it is now known to be 
 abundant, and generally to be found, though almost always a few 
 feet below the surface of the low lands. 
 
 Many persons who would concur with me as to the premises and 
 results, would yet ascribe the colouring of certain watejs to the 
 more level surface of the land, and the more sluggish and stagnant 
 state of the waters; and would suppose the absence of colouring 
 matter in the waters of the upper country to be caused" by the 
 rapidity of the descent and of the passage of the streams. This 
 would be a correct view, if the matter in question were the degree 
 of intens'dij of colour, instead of the existence or entire absence of 
 colour. It is true, and obvious, that if the coloured waters which 
 now creep and stagnate over the level lands below the falls, had as 
 rapid a descent and free discharge as the mountain torrents, their 
 colour could not become darker, with time, by long infusion of the 
 leaves, nor by evaporation of still waters. But though the colour 
 would be much more pale, its existence would not be the less cer- 
 tain. The source of colouring matter, the soaking of dead leaves, 
 &c., in rain-water, is as abundant in the upper as in the lower 
 country ; and the more rapid discharge of the waters, if no other 
 cause of clearing them operated, would not prevent their becoming 
 and remaining coloured, as generally, and, however more pale in 
 tint, would be seen as obviously, as in the most level lands. But 
 this is not all. Though there is almost no level land, and therefore 
 no swamps in the hilly or still less in the mountain region, there 
 are mill-ponds in the lower hilly country, and natural lakes in the 
 mountain region. If there was the slightest tint of dissolved colour- 
 ing matter in the streams, the waters when collected in these deep 
 reservoirs could not fail to exhibit the colour much more deeply. 
 Yet no one such fact is known, or is believed to have existence. 
 
 NOTE II. — Extension of the subject of pages 108 — 113. 
 
 The statements of British authors on marl, and their applications 
 of the name, generally incorrect, and often contradictory. Both 
 the terms ^' marl" and ^^ maiding" have diffe7-ent significations 
 in Britain and in Virginia. 
 
 Custom has compelled me to apply improperly the name marl 
 to ouf deposits of fossil shells. But as I have defined the ma- 
 nuring by means of this substance, which is called marling (and 
 for which I suggested calxing as a much better and also more com- 
 prehensive name), to be simply rendering a soil ccdcareous — any 
 term used for that operation would serve, if its meaning was always 
 kept in view. But, unfortunately, this term (marling) is of old 
 
372 MARL AND MARLIXG IN EUROPE. 
 
 and frequent use in English books, with very different meanings. 
 The existence of these differences, and errors, has been stated 
 generally in a foregoing part of this Essay, and here will be adduced 
 the proofs, in quotations from maiiy authors. I maintain, and will 
 establish the following propositions : — 
 
 1. By nearly or quite all of the older (and even some of the 
 modern) British authors, the term marl was applied to clays (or 
 earths) containing no calcareous matter ; and even when calcareous 
 earth was known to be contained in marl, that ingredient was not 
 deemed (if indeed it was) the essential or the most valuable fertiliz- 
 ing quality of the manure. 
 
 2. The marls of Europe, whether as correctly defined or under- 
 stood by modern writers and scientific agriculturists, or as often 
 miscalled aud misunderstood by illiterate cultivators — are very dif- 
 ferent from the deposits of fossil shells, called marl in this 
 country. 
 
 3. Even when the chemical character, and the manuring action 
 (in like applications) of the marls of England and Virginia are 
 the same (that is, agreeing in being both calcareous) — still the ordi- 
 nary marlings of the former are quite a different manuring opera- 
 tion from the marling (or calxing) advised in this Essay — inasmuch 
 as the lands so manured in England were mostly calcareous before, 
 either by natural constitution, or by previous marling — and there- 
 fore were not onculc calcareous (or calxed) by the dressing in 
 question. 
 
 4. In many cases of published statements of, or references to 
 marling labours or improvements in England, the reader is left in 
 doubt whether the marl or the soil was calcareous — or which the 
 most so — and therefore, whether the "marling" served to increase 
 or to lessen, or had not materiallj' altered the proportion of the 
 previous calcareous contents of the soil. 
 
 5. The marling of England, especially, has been almost entirely 
 empirical — and riot directed by theory, reasoning, or by inferences 
 drawn from the known (or even surmised) chemical constitution 
 of either the soil or the earthy manure applied. 
 
 These assertions refer principally, but not exclusively, to the 
 writers on agriculture of former and less enlightened times than 
 the present or recent. Scarcely auy inception is known in works 
 much older than the institution of the British Board of Agricul- 
 ture, in 1795. Before that time, the errors which I shall adduce 
 prevailed almost universally, in books as well as in vulgar language 
 and opinion. And these older writers were, to much later times, 
 the unquestioned authorities of the earliest agricultural writers of 
 America, as well as of all our other readers and thinkers. And 
 the aid of all the more correct information as to the true character 
 of marl, afforded by the more recent British writers, it seems has 
 
COERECT DEFINITIONS OF MARL. 373 
 
 cleared away but little of the before general obscuration on this 
 subject in their own country. Of such i-cm;iining ignorance, or its 
 appearance, striking and recent examples will be presented. 
 
 The passages to be quoted will exhibit so fully the contradictions 
 and ignorance generally jjrevailing as to the nature of whatever 
 was called marl, and the operation of calcareous manures generally, 
 that it will not be required for me to express dissent in every case, 
 or to point out the errors of facts or of reasoning, which will appear 
 so manifestly and abundantly in some of the quotations. 
 
 But besidc-3 the errors and even absurdities of opinions and prac- 
 tices in regard to marl or lime, which some of these passages will 
 show, there will be presented in connexion some correct, precise, 
 and very interesting facts. Among these will be definitions and 
 descriptions by recent authors of marl proper, and also the varieties 
 known in Britaiu by the provincial names of " clay" or " clay 
 marl," and the ''shell marl" formed only in ancient lakes, since 
 changed to peat bogs. These passages, though some of them are 
 the very latest in the order of time, will be offered first — so that 
 what is sound and true may be kept in view, through all the mass 
 of error that will be afterwards presented. 
 
 1. "Compact limestone, by an increase of argillaceous matter, passes 
 into marl." " Marl is essentially composed of carbonate of lime and clay, 
 in various proportions." — Cleaveland's Mineralogy. 
 
 2. " Marl is a com.pound of carbonate of lime, argil [finest clay] and of 
 silicious sand. The sand appears to be only in a state of mixture, and 
 may be, when not very fine, separated easily. But the argil and carbo- 
 nate of lime in marl (like the alumina and silica in argil), seem to be a 
 ■[chemical] combination, and not a simple mixture." — Puvis — Essai «?<?• la 
 
 Marne. 
 
 "Marl seems to be, In most cases, a formation of fresh water." — Puvis — 
 Translation, Farmers' Register, vol. iii. p. 692. 
 
 3. "Marl is a combination of carbonate of lime and clay. These two 
 bodies are usually found in so complete a state of amalgamation, that it is 
 impossible to distinguish the particles of one from those of the other, either 
 with the naked eye, or with the aid of the microscope." " When water is 
 poured upon marl, that fluid penetrates, with greater or less facility, into 
 all its pores, destroys the cohesion of the parts, separates them from one 
 another, and reduces them to a fine powder. This is one of the essential 
 properties, which serves as the first distinction of marl," &c. 
 
 "It certainly cannot be admitted as a principle that any kind of earth 
 which loses its aggregation in water must necessarily be marl, since some 
 very poor clays are afiected in the same manner ; but if any kind of earth 
 is not spontaneously reduced to powder by the action of water, we may 
 feel convinced that it is not mai'l. Every kind of marl, even that which is 
 called 'stony,' becomes soft and pulverized in water." — Von Thacr's I'rin~ 
 cijiles of Agriculture. 
 
 It appears from different authors that the proportions of carbo- 
 nate of lime in marl usually vary from 20 to more than 60 per 
 32 
 
374 CLAY MARL AND SHELL MARL. 
 
 cent. "When niucTi richer, say near or quite 80 per cent., it becomes 
 of stony hardness, or passes into lime-stone. 
 
 In Britain the marls most abounding in clay are called "clay 
 marl," and vulgarly " clay" simply. This is the kind most gene- 
 rally used, and in enormous quantities. Stephens (in the latest 
 edition of his " Book of the Farm"), offers the first precise in- 
 formation that I have seen, as it is also the most recent of the 
 component parts of this marl, as follows : — from Johnston on the 
 Use of Lime. 
 
 4. " The following analysis may give a fair idea of the composition of a 
 clay marl." This specimen was found in Ayrshire. 
 
 Carbonate of lime . . . , 8.4 
 
 Oxide of iron and alumina 
 
 Organic matter 
 
 Clay, and silicious matter 
 
 Water 
 
 2.2 
 
 2.8 
 
 84.9 
 
 1.4 
 
 99.7 
 
 Every one who has observed what is called marl in lower Vir- 
 ginia will recognise its entire disagreement with the true marl 
 described in all the foregoing quotations, in every physical or 
 mechanical property, in texture, and in its manifest origin or for- 
 mation. 
 
 5. "Shell Marl. — In some parts of the country, as in Forfarshire [Scot- 
 land,] this substance is found in great quantities associated Tyith peat. 
 . . , . It is taken out of the bogs by means of a boat mounted with a 
 dredging apparatus. When of fine quality and in a dry state, it is as 
 white as lime, not crumbling down into powder like quick-lime, but cutting 
 
 something like cheese, with the spade It is applied at 40 to 
 
 50 bolls (8 cubic feet) to the acre. Vv'hen applied as lime, it is beneficial; 
 but, as is often the case, when applied solely as manure, in quantities of 35 
 to 4-5 cubic yai-ds to the acre, it never fails to be mischievous. It does not 
 easily injure new fresh land ; [Qu. the first time applied ?] but u-hcn re- 
 peated frequently, as a sole manuring, I have seen land reduced to such a 
 state of pulverization, that the foot, with a stamp, sank into the ground as 
 deep as the ankle. Applied to lands followed by severe cropping, it has 
 reduced them to a state of utter sterility, which they have not recovered 
 from to this day." — {Stephens' Book of the Farm, or Farmers' Guide, 1850; 
 Headrick's Survey of Forfarshire.) 
 
 This "shell marl" consists of 
 "Carbonate of lime 
 Oxide of iron and alumina . 
 Organic matter .... 
 Insoluble, chiefly silicious matters 
 
 100. 100. 
 
 This substance, according to its analysis above, is undoubtedly 
 the most valuable of all calcareous manures. But still it is not 
 
 Top of bed. 
 
 Bottom of bed 
 
 77.6 
 
 81.7 
 
 1.8 
 
 0.6 
 
 14.6 
 
 14.6 
 
 6.0 
 
 3.1 
 
"marls" not CALCAHJiOUS. 375 
 
 marl, either as understood by mineralogists and scientific "aoricul- 
 turists in Europe, or as marl is known in this country. This peculiar 
 formation (the deposit of the shells of fresh-water molluscs in what 
 had been ancient lakes, and which since became pcat-bogs), has 
 been referred to previously, and will be again, in another connexion. 
 So far, all the earths called marl have been calcareous. But all 
 are not so that are recognised under that name, even by modern 
 and well informed writers, who certainly knew the chemical cha- 
 racter (in this respect), of the earths referred to. In '' British 
 Husbandry,'^ a recent work of authority, prepared for and pub- 
 lished by the " Society for the Difiusion of Knowledge," in treating 
 of marl, the following passages occur : — 
 
 6. "A bluish marl much used iu some parts of Ireland, and long cele- 
 brated as a manure, makes no ebullition with acids ; neither do several of 
 the red marls ; yet many of them are known to be productive of great im- 
 provement to land." p. 265. "Out of 12 specimens of marl submitted to 
 Sir Humphrey Davy, 11 were found to contain calcareous earth; but the 
 result of many other trials of marls, from different parts of the country, 
 and found by farmers to produce an ameliorating effect on the land, yet 
 proves them to be, in many instances, wholly deficient in that substance." 
 See "Marl" in Holland's Report on Cheshire. ^ 
 
 Now whatever of fertilizing properties these earths contained, 
 they were not marl in the proper understanding of that term, nor 
 do they agree with our marl in any stated character, either chemi- 
 cal or physical. 
 
 An earlier, though yet a modern writer, Marshall, has also de- 
 scribed a valuable " marl" of Norfolk, England, which is almost 
 destitute of calcareous matter. 
 
 7. " The red earth which has been set upon the lands of this district, in 
 great abundance, as 'marl,' is much of it iu a manner destitute of calca- 
 reous matter ; and, of course, cannot, with propriety, be classed among 
 marls. Nevertheless, a red fossil is found, in some parts of the'' district, 
 which contains a proportion of calcareous matter. The marl of Croxall 
 (iu part of a stone-like, or slaty contexture, and of a light red colour) is 
 the richest iu calcareosity ; one hundred grains of it afford thirty grains of 
 calcareous matter ; and seventy grains of fine, impalpablo, red-bark-like 
 powder.* And a marl of Elford (in colour and contexture various, but re- 
 sembling those of the Croxall marl) affords near twenty grains. Yet the 
 
 * This marl is singularly tenacious of its calcareous matter ; dissolving 
 remarkably slowly. One hundred grains, roughly pounded, was twenty- 
 four hours in dissolving ; and another hundi-ed, though pulverized to mere 
 dust, continued to effervesce twelve hours ; notwithstanding it was first 
 saturated with water, and afterward shaken repeatedly. The Breedon stone, 
 roughly pounded, dissolved in half the time ; notwithstanding its extreme 
 hardness. [I strongly suspect that Marshall used nitric acid in this trial, 
 and was deceived by the slow solution of carbonate of iron, with some 
 ebullition, and that there was as little calcareous earth as in the other 
 casea. I have never experienced such slow solution of carbonate of lime, 
 in strong acid. E. R.] 
 
376 "marls" not calcareous. 
 
 marl of Barton, <3ti the opposite side of the Trent — though somewhat of a 
 simihxr contextmo, but of a darker, more dusky colour — is in a manner 
 destitute of calcareosity ! one hundred grains of it yielding little more thaia 
 one grain — not two grains of calcareous matter. Nevertheless, the pit, from 
 Avliich I took the specimens analyzed, is an immense excavation, out of 
 which many thousand loads have been taken. And the marls of this 
 neighbourhood (which mostly diifer in appearance from those described, 
 having generally that of a blood -red clay, interlay ered, and sometimes u\- 
 termingled with a white gritty substance) are equally poor in calcareosity. 
 One hundred grains of the marl of Stafford (which I b?lieve may be taken 
 as a fair specimen of the red clays of this quarter of the district) afford 
 little more than tivo grains of calcareous matter — lodged not in the sub- 
 stance of the clay, but in its natural cracks, or fissures. Yet this is said 
 to be 'famous marl;' and from the pits which now appear, has been laid 
 on in great abundance. 
 
 " I do not mean to intimate, that these clays are altogether destitute of 
 fertilizing properties, on their first application. It is not likely that the 
 large pits which abound in almost every part of the district, and which 
 must have been formed at a very great expense, should have been dug, 
 without their contents being productive of some evidently, or at least ap- 
 parently good effect, on the lands on which they have been spread. I con- 
 fess, however, that this is but conjecture ; and it may be, that the good 
 effect of the marls first described being experienced, the fashion was set ; 
 and the distinguishing quality being unknown, or not attended to, mai'ls 
 and clays were indiscriminately used." — Marshall's Midland Counties, vol. 
 i. p. 1-52. 
 
 8. "On the southern banks of the Anker, is found a gray marl; re- 
 sembling in general appearance the marl of Norfolk, or rather the fuller's 
 earth of Surrey. In contexture it is loose and friable. This earth is sin- 
 gularly prodigal of its calcareosity. The acid being dropped on its surface, 
 it flies into bubbles as the Norfolk marl. This circumstance, added to that 
 of a striking improvement, which I was shown as being effected by this 
 earth, led me to imagine that it was of quality similar to the marls of 
 Norfolk. But, from the results of two experiments — one of them made 
 with granules formed by the weather, and collected on the site of improve- 
 ment, th^other with a specimen taken from the pit, it appears that one 
 hundred grains of this earth contain no more than six grains of calcareous 
 matter ! the residuum a cream-coloured saponaceous clay, with a small 
 proportion of coarse sand." — Blarshall's Midland Counties, vol. i. p. 15.5. 
 
 In the latter quotations are presented separately the proofs from 
 authors fully competent to try and know the remarkable facts 
 stated of many well approved "marls," so called, being nearly or 
 entirely destitute of calcareous earth ! I will now go bi j 
 to older writers, who treat of marls without noticing that ingredient 
 as being present, or without seeming to be aware that its presence 
 would be useful. 
 
 The learned and also practical Miller thus defines and describes 
 marl, in the Abrulgmcnt of the Gardener' s Dictionari/, fifth Lon- 
 don edition, 17G3, at the article marl : 
 
 " Marl is a kind of clay which is become fatter and of a more enriching 
 quality, by a better fermentation, and by its having lain so deep in the 
 earth as not to have spent or weakened its fertilizing quality by any pro- 
 duct. 
 
MARL NOT KNOWN TO BE CALCAREOUS. 877 
 
 "Marls are of different qualities in different counties of England. There 
 are reckoned four kinds of marl in Susses, a gray, a blue, a yellow, and a 
 red ; of these the blue is accounted the best, the yellow the next, and the 
 gray the next to that ; and as for the red, that is the least valuable. 
 
 " In Cheshire they reckon six sorts of marl : 
 
 " 1. The cowshut marl, which is of a brownish colour, with blue veins in 
 it, and little lumps of chalk or limestone ; it is commonly found under clay, 
 or low black laffd, seven or eight feet deep, and is very hard to dig. 
 
 " 2. Stone, slate, or flag marl, which is a kind of soft stone, or rather 
 slate, of a blue or bluish colour, that will easily dissolve with frost or rain. 
 This is found near rivers, and the sides of hills, and is a very lasting sort 
 of marl. 
 
 "3. Peat marl, or delving marl, which is close, strong,* and very fat, 
 of a brown colour, and is found on the sides of hills, and in wet or 
 boggy grounds, which have a light sand in them about two feet or a yard 
 deep. 
 
 " 4. Clay marl ; this resembles clay, and is pretty near akin to it, but is 
 fatter, and sometimes mixed with chalk stones. 
 
 "5. Steel marl, which lies commonly in the bottom of pits that are dug, 
 and is of itself apt to break into cubical bits ; this is sometimes under 
 sandy land. 
 
 " G. Paper marl, which resembles leaves or pieces of brown paper, but 
 sometliing of a lighter colour; this lies near coals. 
 
 " The properties of any sorts of marls, by which the goodness of thera 
 may be best known, are better judged of by their purity and uncompound- 
 edness, than their colour : as if it will break in pieces like dice, or into thin 
 flakes, or is smooth like lead ore, and is without a mixture of gravel or sand ; 
 if it will slake like slate-stones and shatter after wet, or will tumble into 
 dust, when it has been exposed to the sun ; or will not hang and stick to- 
 gether when it is thoroughly dry, like tough clay ; but is fat and tender, 
 and will oijen the land it is laid on, and not bind; it may be taken for 
 granted that it will be beneficial to it." 
 
 In all these descriptions, so minutely stated, both general and 
 particular, and of ten diiferent varieties of marl, there is no indica- 
 tion that calcareous earth is an essential constituent part ; nor in- 
 deed does it appear that it was deemed a constituent part, proper, 
 even in the two varieties, in which bits of chalk are found. For 
 these are accidental admixtures, as would be any silicious sand, or 
 gravel, or land, or even river shells ; none of which, if found there- 
 in, would properly belong to true marl. 
 
 The well-deserved reputation of Miller is a sufiicient guaranty 
 that there was no more full or correct knowledge of marl, in his 
 time, than he possessed, and taught in the foregoing extracts. 
 
 9. Johnson's Dictionary (octavo edition) dehnes marl in pre- 
 cisely the words of the first sentence of Miller, as quoted above. 
 
 10. Walker's Dictionary (octavo edition) gives only the fol- 
 lowing definition — " Marl — a kind of clay much used for ma- 
 nure." 
 
 * ^^ Strong" applied to soil in England means stiff or clayey — and in this 
 sense I presume the word is used above. E. 11. 
 82* 
 
378 MARL NOT KXOWN TO BE CALCAREOUS. 
 
 11. Kirwan, on tlie autliority of Arthur Youug and tlie Bath 
 Memoirs [1783,] states that, 
 
 *' In some parts of England, where husbandry is successfully practised, 
 any loose clay is called marl ; in others, maH is called chalk, and in others, 
 clay is called loarn." — Kirwan on Manures, p. 4. 
 
 12. A Practical Treatise on HushancJry (second I^pndon edition, 
 4to. 17G2,) which professes to be principally compiled from the 
 writings of Duhamel, Evelyn, Home, and Miller, supplies the fol- 
 lowing quotations : 
 
 "But of all the manures for sandy soils, none is so good as marl. There 
 are many different kinds and colours of it, severally distinguished by many 
 •writei's ; but their virtue is the same ; they may be all used upon the same 
 ground, without the smallest difference in their effect. The colour is either 
 red, brown, yellow, gray, or mixed. It is to be known by its pure and un- 
 compounded nature. There are many marks to distinguish it by ; such as 
 its breaking into little square bits;, its falling easily into pieces, by the 
 force of a blow, or upon being exposed to the sun and the frost; its feeling 
 fat and oily, and shining when it is dry. But the viost unerring ivay to 
 judge of marl, and know it from any other substance, is to break a piece as 
 big as a nutmeg, and when it is quite dry, drop it into a glass of clear 
 water, where, if it be right, it will dissolve and crumble, as it were, to 
 dust, in a little time, shooting up sparkles to the surface of the water." — 
 p. 27. 
 
 Not the slightest hint is here of any calcareous ingredient being 
 necessary, or even serving in any manner to distinguish marl. But 
 afterwards, in another part of this work, when shell marl is slightly 
 noticed, it is said : 
 
 "This effervesces strongly with all acids, which is pdrhaps chiefly owing 
 to the shells. There are very good marls u'hich show nothing of this effervescence ; 
 and therefore the author of the New System of Agriculture judged right ia 
 making-its solution in water the distinguishing mark." — p. 29. 
 
 The last sentence declares, as clearly as any words could do, that, 
 in the opinion of the author, no calcareous ingredient is necessary, 
 either to constitute the character, or the value of marl. And 
 though it may be gathered from other parts of this work, that what 
 is called marl generally contains calcareous earth, yet no import- 
 ance seems attached to that quality, any more than to the particular 
 colour of the earth, or any other accidental or immaterial appearance 
 of some of the varieties described. 
 
 The "■ shell marl" alluded to above, without explanation might 
 be supposed to be similar to our beds of fossil shells, which are 
 called marl. The two manures are very different in form, appear- 
 ance, and value, though agreeing in both being calcareous. The 
 manure called shell marl by the work last quoted from, is described 
 there with sufficient precision, and more fully in several parts of the 
 Edinburgh Farmers' Magazine,* and in the Memoirs of the Phila- 
 
 * See Fai-mers' llegister, vol. i., p. 90. 
 
_ CALCAREOUS QUALITY NOT KNOWN. 379 
 
 delpliia Agricultural Society,* [and in the late edition of Stephens' 
 Book of the Farm, as quoted above]. It is still more unlike marl, 
 properly so called, than any of the substances described under that 
 name, in the foregoing quotations. This manure is almost a pure 
 calcareous earth, being formed of the remains of small fresh-water 
 shells deposited on what^were once the bottoms of lakes, but which 
 have since become covered with hog or peat soil. If I may judge 
 from our beds of mussel shells (to which this manure seems to bear 
 most resemblance), much putrescent animal matter is combined 
 with, and serves to give additional value to these bodies of shells. 
 This kind of manure is sold in Scotland by the bushel, at such 
 prices as show that it is very highly prized. It seems to be found 
 but in few situations, and though called a kind of marl, is never 
 meant when that term alone is used by British writers. 
 
 13. A much older work than either of these referred to fur- 
 nishes in part the definitions and even the words used above. This 
 is the " St/stema Agriculturce. the Mystery of Husbandry dis- 
 covered," published in 1G87 ; and the author or compiler of that 
 old work was probably indebted to others still older for his descrip- 
 tion of marl. For new books on agriculture, more especially, 
 have been most generally made by comj^iling and copying from 
 older ones. 
 
 " Marie is a very excellent thing, commended of all that either write or 
 practise any thing in husbandry. There are several kinds of it, some stont/, 
 Bome soft, while, gray, russet, yellow, blew, black, and some red : It is of a 
 cold nature and saddens land exceedingly ; and very heavy it is, and will 
 go downward, though not so much as lime doth. The goodness or badness 
 thereof is not known so much by the colour, as by the purity and uncora- 
 poundness of it ; for if it will break into bits like a dye, or smooth like lead 
 oar, without any composition of sand or gravel ; or if it will slake like slate- 
 stones, and slake or shatter after a shower of rain, or being exposed to the 
 sun or air, and shortly after turn to dust when it's thoroughly dry again, 
 and not congeal like tough clay, question not the fruitfulness of it, notwith- 
 standing the difference of colours, which are no certain signs of the good- 
 ness of the marie. As for the slipperiness, viscousness, fattiness, or oyliness 
 thereof, although it be commonly esteemed a sign of good marie, yet the 
 " best authors affirm the. contrary — viz. that there is very good viarle which 
 is not so, but lieth in the mine pure, dry and short, yet nevertheless if you 
 water it, you will find it slippery. But the best and truest rule to know 
 the richness and profit of j'our marie, is to try a load or two on your lands, 
 in several places and in different proportions. 
 
 " They usually lay the same on in small heaps, and disperse it over the 
 whole field, as they do their dung ; and this marie will keep the land 
 whereon it Is laid, in some places ten or fifteen, and in some j^laces thirty 
 years in heart: it is most profitable in dry, light, and barren lantlfe, such as 
 is most kind and natural for rye, as is evident by Mr. Blithe's experiment 
 in his chapter of marie. It also affordeth not its vertu«»or strength the first 
 year, so much as in the subsequent years. It yields a very great increase 
 
 * Vol. iii. p. 20G. 
 32* 
 
380 AMERICAN OPINIONS DERIVED FROM ENGLISH. 
 
 and advantage on high, sandy, gravelly, or mixed lands. Though never so 
 barren, strong clay ground is unsuitable to it; yet if it can be laid dry, 
 marie may be profitable on that also." 
 
 The author then proceeds to direct the mode of application more 
 particularly ; and if there were any doubt as to his total ignorance 
 (or otherwise denial) of calcareous earth being necessary to the 
 constitution of marl, that doubt would be removed by a subsequent 
 sentence. 
 
 "You shall observe (saith Markham,) that if you cannot get dry, per- 
 fect, and rich marie, if then you can get of that earth Avhich is called 
 fuller's earth (and where the one is not, commonly the otlier is), then you 
 may use it in the same manner as you should do marie, and it is found to 
 be very near as profitable." 
 
 14. Evelyn's Terra, or Plulosopldcal Discourse of Earths, 
 &c., delivered before the Royal Society in 1675, has the following 
 passage : 
 
 "Of marie (of a cold sad nature, a substance between clay and chalk),, 
 seldom have we such quantities in layers as we have of forementioned 
 earth ; but we commonly meet with it in places afl'ected to it, and it is 
 taken out of pits, at different depths, and of divers colours, red, white, 
 gray, blue, all of them unctuous, and of a slippery nature, and differing in 
 goodness ; for being pure and immixt, it sooner relents after a shower, and 
 when dryed again, slackens, and crumbles into dust, without induration, 
 and grooving hard again. They are profitable for barren grounds, as 
 abounding in nitre ; and sometimes there has been found in marie, del/s, a 
 vitriolic wood, which will kindle like coal." 
 
 The opinions expressed in the foregoing extracts, prove suffi- 
 ciently that it was not the ignorant cultivators only, who either did 
 not know of, or attached no importance to the calcareous ingredient 
 in marl; and it was impossible that, from any number of such 
 authors, an. American reader could learn that either the object or 
 the effect of marling was to render a soil more calcareous — or that 
 our bodies of fossil shells resembled marl in character, or in opera- 
 tion as a manure. Of this, the following quotation from a modern 
 and also an American agriculturist and author, Bordloy, will fur- 
 nish striking proof — and the more so as he refers frequently to the 
 works of Anderson, and of Young, who treated of marl and of cal- 
 careous manures, in a more scientific and correct manner than had 
 then been usual. This author cannot be justly charged with in- 
 atteutiou to the instruction to be gained from books; for his greatest 
 fault, as an agriculturist, is his fondness for applying the practices 
 of the most improved husbandry of England, to our lands and 
 situatio»ii, however different and unsuitable — which he carried to 
 an extent that is ridiculous as' theory, and would be ruinous to the 
 farmer who should so shape his general practice. 
 
 15. "I farmed in a country [the Eastern Shore of Maryland] where 
 habits are against a due attention to manures : but having read of the ap- 
 
• ■ CALCAREOUS PART NOT PRIZED. 381 
 
 plication of marl as a manure, I inquired where there was any in the penin- 
 sula of the Chesapeake in vain. My own farm had a grayish clay which to 
 the ej'C was marl : but because it did not effervesce with acids, it was 
 given up when it ought to have been tried on the land, especially as it ra- 
 pidly crumbled and fell to mud, in water, with some ajjpearance of eifer- 
 vescenee." — Bordlci/s Ilusbandry, 2d cd., p. 55. 
 
 That peninsula, through which Mr. Bordley in vain inquired for 
 marl, has immense quantities of the fossil shells which we impro- 
 perly call by that name. But as his search was directed to inarl 
 as described by English authors — and not to calcareous earth sim- 
 ply — it is not to be wondered at that he, well-read and intelligent 
 as he was, should neither find the former substance, nor attach 
 enough importance to the latter, to induce the slightest remark on 
 its probable use as manure. 
 
 16. The Practical Treatise on Husbandry/, among the directions 
 for improving clay land, has what follows : 
 
 " Sea sand and sea shells are used to great advantage as a manure, 
 chiefly for cold strong [i. e. clay] land, and loam inclining to clay. They 
 separate the parts ; and the salts which are contained in them are a vei-y 
 great improvement to the land. Coral, and such kind of stony plants 
 which grow on the rocks, are filled with salts, which are very beneficial to 
 laud. But as these bodies are hard, the improvement is not the first or 
 second year after they are laid on the ground, because they require time to 
 pulverize them, before their salts can mix with the earth to impregnate it. 
 The consequence of this is, that their manure is lasting. Sand, and the 
 smaller kind of sea weeds, will enrich land for six or seven years ; and 
 shells, coral, and other hard bodies, will continue many years longer. 
 
 " In some countries fossil shells have been used with success as manure ; 
 but they are not near so full of salts, as those shells which are taken 
 from the sea-shore ; and therefore the latter are always to be preferred. 
 Sea sand is much used as manure in Cornwall. The best is that which ia 
 intimately mixed with coral." — p. 21, 
 
 After stating tbe manner in which this " excellent manure" is 
 taken up from the bottom^^ in barges, its character is thus con- 
 tinued : 
 
 " It [i. e. the sea sand mixed with coral, as it may happen] gives the 
 teat of lime, and the fatness of oil, to the land it is laid upon. Bemg 
 more solid than shells, it conveys a gi-eater quantity of fermenting earth in 
 equal space. Besides, it does not dissolve in the ^ound so soon as shells, 
 but decaying more gradually, continues longer to impart its warmth to the 
 juices of the earth." 
 
 Here are described manures which are known to be calcareous, 
 which are strongly recommended — but solely for their supposed 
 mechanical effect in separating the parts of close clays, and on ac- 
 count of the salts derived from sea-water, which they contain. 
 Indeed, no allusion is made to any supposed value, or even to the 
 presence of calcareous earth, which forms so large a pi'oportion of 
 these manures ; and the fossil shells (in which that ingredient is 
 
382 ERRORS OF MODERN AUTHORS. 
 
 more abundant, more finely reducccl, and consequently more fit for 
 both immediate and durable efTects) are considered as less effica- 
 cious than solid sea shells, and inferior to sea sand. All these 
 substances, besides whatever service their salts may render, are pre- 
 cisely the same kind of calcareous manure, as our beds of fossil 
 shells furnish in a different form. Yet neither here nor elsewhere, 
 does the author intimate that these manures and marl have similar 
 powers for improving soils. 
 
 The foregoing quotations show what opinions have been expressed 
 by English writers of reputation, and what opinion would thence 
 necessarily be formed by a general reader of these and other agri- 
 cultural works, of the nature of what is called marl in England, as 
 well as what is so named in this part of our country. I do not 
 mean that other authors have not thought more correctly, and 
 sometimes expressed themselves with precision on this subject. 
 Mineralogists define viarl to be a calcareous clay ; and in this cor- 
 rect sense, the term is used by Davy, and other chemical agricul- 
 turists. Such authors as Young and Sinclair also could not have 
 been ignorant of the true composition of marl ; yet even they have 
 used so little precision or clearness, when speaking of the eifects of 
 marling, that their statements (however correct they may be in the 
 sense they intended them) convey no exact information, and have 
 not served to remove the erroneous imjDressions made by the great 
 body of their pi-edeeessors. Knowing as Young did [see above, 
 11] the confusion in which this subject was involved, it was the 
 more incumbent on him to be guarded in his use of terms so gene- 
 rally misapplied. Yet considering his practical and scientific 
 knowledge as an agriculturist, his extensive personal observations, 
 and the quantity of matter he has published on soils and calcareous 
 manures, his omissions are more remarkable than those of any 
 other writer. In such of his works as I have met with, though 
 full of strong recommendations of marling, in no case does he state 
 the composition of the soil (as respects its calcareous ingredient), 
 or the proportion added by the operation ; and generally notices 
 neither, as if he viewed marling just in the same loose and incor- 
 rect manner as most others have done. These charges are supported 
 by the following extracts and references. 
 
 17. Young's Fanner's Calendar, 10th London edition, page 
 40. — On marling. Through nearly four pages this practice is 
 strongly recommended — but the manures spoken of, are regularly 
 called " marl or clay," and their application, " marling or claying." 
 Mr. Rodwell's account of his practice (which I before referred to, 
 p. Ill,) is inserted at length. On leased land he " clayed or marled" 
 eight hundred and twenty acres with one hundred and forty thou- 
 sand loads, and at a cost of four thousand nine hundred and fifty- 
 eight pounds — and the business is stated to have been attended 
 
ERRORS OP ARTHUR YOUNG. 383 
 
 with great profit. At last, the author lets ua know that it is not 
 the same substance that he has been calling " marl or clay" — and 
 that the marl effervesces strongly with acids, and the clay slightly. 
 But we are told nothing more precise as to the amount of calcare- 
 ous ingredients, either in the manures, or the soil ; and even if we 
 were informed on those heads (without which we can know little or 
 nothing of what the operation really is), we are left ignorant of 
 how much was clayed, and how much marled. It is to be inferred, 
 however, that the clay was thought most serviceable, as Mr. Rod- 
 well says — 
 
 " Clay is much to be preferred to marl on those sandy soils, some of 
 which are loose, poor, and even a black sand." 
 
 18. Young's Survey of Norfolk (a large and closely printed oc- 
 tavo volume) has fourteen pages filled with a minute description of 
 the soils of that county ; but without any indication whatever of 
 the proportion, presence, or absence, of calcareous earth in that 
 extensive district of sandy soils, so celebrated for their improve- 
 ment by marling — nor in any other part of the county. The wastes 
 are very extensive : one of them (page 385) eighteen miles across, 
 quite a desert of sand, " yet highly improvable." Why it is im- 
 provable he does not say, as of this also, no information is given 
 as to its calcareous constitution. 
 
 19. The section on marl (page 402, of the same work) gives 
 concise statements of its application, with general notices of its 
 effects, on near fifty different parishes, neighbourhoods, or separate 
 farms. Among all these, the only statements from which the cal- 
 careous nature of the manure may be gathered, are (page 406), of 
 a marl that "ferments strongly' with acids" — another (page 409), 
 that marling at a particular place destroys sorrel — and (page 410) 
 that the marl is genei'ally calcareous, and tJiat tJiat containing the 
 most clay, and the least calcareous earth, is preferred by most per- 
 sons, but not by all. 
 
 20. Young's General View of the Agriculture of Suffolk (an 
 'octavo of 432 pages of close print), in the description of soils, 
 affords no information as to any of them being calcareous, or other- 
 wise; yet the author mentions (page 3) having analyzed some of 
 the soils, and reports their aluminous and silicious ingredients. 
 Nor can more be learned in this respect, in the long account after- 
 wards given of the " marl" which has been very extensively applied 
 also in the county of Suffolk. We may gather, kowever, from the 
 following extracts, that the " marl or clay" of Suffolk is generally 
 calcareous, but that this quality is not considered the principal 
 cause of its value ; and further, that crag, a much richer calcareous 
 manure (which seems to be the same with our richest beds of fossil 
 
384 ERRORS OF ARTHUR YOUNQ. 
 
 shells, or marl), is held to be injurious to the sandy soils, which 
 are so generally improved by what is there called marl. 
 
 "Claying — a term in Suffolk, -wlucli includes marling; and indeed the 
 earth carried under this term is very generally a clay marl ; though a pure, 
 or nearly a pure clay, is preferred for very loose sands." — Young's Suffolk, 
 p. 186. 
 
 After speaking of the great value of this manure on light lands, 
 he adds : 
 
 "But when the clay is not of a good sort, that is, when there is really 
 none, or scarcely any clay in it, but is an imperfect and even a hard chalk, 
 there are great doubts how far it answers and in some cases has been spread 
 to little profit." — p. 187. 
 
 "Part of the under stratum of the county is a singular body of 
 cockle and other shells, found in great masses in various parts of the 
 country, from Dunwich quite to the river Orwell, &c." — " I have seen pits 
 of it to the depth of fifteen or twenty feet, from which great quantities had 
 been taken for the purpose of improving the heaths. It is both red and 
 white, and the shells so broken as to resemble sand. On lands long in 
 tillage, the use is disconlinwd, as it is found to make the sands blow more." 
 [That is, to be moved by the winds.] — p. 5. 
 
 21. The Essay on Manures, by Arthur Young, for which the 
 author was honoured with the Bedford medal, speaks distinctly 
 enough of the value of marl being due to its calcareous ingredient 
 (as this author doubtless always knew, notwithstanding the loose- 
 ness of most of his remarks on this head) ; but at the same time 
 he furnishes some of the strongest examples of absurd inferences, 
 or of gross ignorance of the mode in which calcareous earth acts 
 as an ingredient of soil, and the proportion which soils ought to 
 contain. These are his statements, and his reasoning thereon : 
 
 "It is extremely difficult to discover, from the knowledge at present 
 possessed by the public, jrhat ought to be the quantity of calcareous earth 
 in a soil. The best specimen analyzed by Giobert had 6 per cent. ; by 
 Bergman, 30 per cent. ; by Dr. Fordyce, 2 per cent. ; a rich soil, quoted 
 by Mr. Davy, in his lecture at the Royal Institution, 11 per cent. This is 
 an inquiry, concerning which I have made many experiments, and on soils 
 of the most extraordinary fertility. In one, the proportion was equal to 
 9 per cent. ; in another 20 per cent. ; another, 3 per cent. ; and in a spe- 
 cimen of famous land, which I procured from Flanders, 17 per cent. But 
 the circumstance which much perplexes the inquiry is, that many poor 
 Boils possess the same or neai-ly the same proportions as these most 
 fertile ones. To attain the truth, in so important a point, induced me to 
 repeat many trials, and to compare every circumstance ; and I am disposed 
 to conclude, that i/ie necessity of there being a large proportion of calcareous 
 earth in a soil depends on the deficiency of organic [i. e. vegetable or animal] 
 matter ; of that organic matter which is [partly] convertible into hydi-ogen 
 gas. If the farmer finds, by experiment, that his soil has but a small 
 quantity of organic matter, or knows by his practice that it is poor, and 
 not worth more than 10s., 15s. or 20s. an acre, he may then conclude that there 
 ought to be 20 per cent, of calcareous earth in it ; but, if, on the contrary, it 
 abound with organic matter, and be worth in practice a much larger rent, 
 
ERRORS OF ARTHUR YOUNG. 385 
 
 in that case Lis marl cart ■will not be called for, though there be but 5 per 
 cent, or even less, of calcareous matter." — Young's Essay on Manuirs — • 
 Sect. 2. 
 
 It is scarcely necessary to state, that the opinion of calcareous 
 matter being needed in larger quantities in proportion to the drfi- 
 cicnci/ of the " organic" or putrescent matter, is directly opposed 
 to the reasoning of this essay. If a poor soil were made to contain 
 twenty per cent, of calcareous matter, by applying lime, chalk, or 
 marl, the quantity and the expense would be so enormous as not to be 
 justified by any possible return ; and besides, it would lessen rather 
 than increase the product of a poor soil. The fact named as strange 
 by Young, that some rich soils contain very small, and others very 
 large proportions of calcareous earth, is easily explained. If a na- 
 tural soil contains any excess of calcareous earth, even though but 
 one per cent., it shows that there is so much to spare, after its 
 having served every purpose of neutralizing acids and combining 
 with putrescent matter. If there were twenty per cent, more of 
 calcareous matter, it would be useless, and indeed probably hurtful, 
 until met by an additional supply of putrescent matter. Young's 
 statement that some poor soils agree precisely with other rich soils, 
 in their contents of calcareous earth, does not necessarily contra- 
 dict my doctrine that a proper proportion of calcareous earth will 
 enable any soil to become rich, either in a state of nature, or un- 
 der mild cultivation, and for the following reasons : 
 
 22. 1st. The correctness of Young's analyses of soils may be 
 well doubted; and if he used the then usual process for separating 
 calcareous earth, he was obliged to be incorrect on account of its 
 unavoidable imperfection, as has been already explained at page 
 57. 2d. It cannot be known positively what was the original state 
 of fertility of most cultivated soils in England, nor whether they 
 were subjected to exhausting or improving cultivation, for centuries 
 before our information from history begins. 3d. Lime has been 
 there used for a long time, and to great extent ; and chalk and 
 marl were applied as manures before the time of the Roman con- 
 quest, as stated by Pliny (or more than 1800 years ago); so that it 
 cannot be always known whether a soil has received its calcareous 
 ingredient from nature, or the industry of man. 4th. It is known 
 that severe cropping after liming, and also excessive doses of cal- 
 careous earth, have rendered land almost barren; of which the 
 following extracts oifer sufficient proof: — 
 
 "Before 1778 [in East Lothian], the out-field did not receive any dung 
 except wliat was left by the animals grazed upon it. In many cases, out- 
 field land was limed ; and often with singular advantage. The after man- 
 agement was uniformly bad ; it being customary to crop the limed out-field 
 with barley and oats successively, so long as the crop was worth cutting. 
 In this way numerous fields suffered so severely as to be rendered almost 
 sterile for "half a century afterwards." — Fanner's Magazine, p. 53, vol. xii. 
 
386 LORD KAMES AND SIR JOlIxNT SINCLAIR. 
 
 "An overdose of shell marl [that from nnrler peat, above describcrl], 
 laid perhaps an inch thick, produces for a time large crops. But at last it 
 renders the soil a caput mortimm, capable of bearing neither corn nor 
 grass ; of -which, there are too many examples in Scotland, &c. — Gentle- 
 man Farmer, p. 378. 
 
 23. Yet the last-quoted writer (Lord Kames) elsewhere states 
 (at page 379), that as much clay marl as contains 1500 bolls (or 
 9000 bushels), of pure calcareous earth to the acre, is not an over- 
 dose in Scotland. 
 
 The next following evidences have been referred to, and some 
 of them at greater length, in previous parts of this essay. They 
 will be again adduced here, because of their peculiar importance in 
 sustaining my positions. The particular opinions here to be quoted 
 are from writers of high character and authority, as scientific agri- 
 culturists, or chemists. The names of Sinclair, Davy, and Morton 
 (and also Young, before quoted), deservedly stand among the 
 highest. Moreover, they are all modern authorities. They seve- 
 rally had all the lights on calcareous manures which existed before 
 the last thirty years (or later) ; and certainly each of them well knew 
 what was true marl, its mineralogical and chemical character, and 
 also what was calcareous soil. Sir John Sinclair will be the firsfe 
 of these quoted. 
 
 24. " Marl. Of this substance, there are four sorts, rock — slate — clay — • 
 and shell marl. Tlie three former are of so heavy a nature that they are 
 seldom conveyed to any distance ; though usefnl ■when found below a lighter 
 soil, to which they can be applied without incurring much expense. But 
 shell marl is specifically lighter, and consists entirely of calcareous matter 
 (the broken and partially decayed shells of fish), which may be applied aa 
 a top-dressing to wheat and grass, when it would be less advantageous to 
 use quick-lime." [This is the kind of manure referred to in extract 12, and 
 there more particularly described.] "In Lancashire and Cheshire, clay, 
 or red marl, is the great source of fertilization, &c." — "The quantity 
 used is ehoraious ; in many cases about three hundred middling cart loads 
 per acre, and the fields are sometimes so thickly covered as to have the 
 appearance of a red soiled fallow, fresh ploughed". — Sinclair's Code of Ag- 
 riculture, Amer. ed. (Hartford) p. 138, and 5th London ed. 
 
 This account of the Lancashire improvements made by red clay 
 marl closes with the statement that "the effects are represented to 
 be beneficial in the highest degree," which is fully as exact an ac- 
 count of profit, or increased production, as we can obtain of any 
 other marling. Throughout, there is no hint as to the calcareous 
 constituents of the soil or the manure, or whether either rock, clay, 
 or slate marls, generally, are valuable for that or for other reasons; 
 nor indeed could we guess that they contained any calcareous earth, 
 but for their being classed with many other substances, under the 
 general head of calcareous manures. 
 
 But we may learn from other sources that the "red marl" of 
 Lancashire is calcareous, and that the soil to which it was applied 
 is also calcareous. This character of the marl is distinctly stated 
 
MARLING NOT TO MAKE SOIL CALCAREOUS. C87 
 
 by tlie Agricultural Surveyor of Lancashire, in his Report to the 
 Board of Agriculture (of which Sir John Sinclair was president), 
 and the calcareous character of the soil is inferred from its being 
 of the " new red sand-stone formation," which is highly calcareous, 
 and also from Morton's speaking of the " red marl" in some parts 
 forming the surface soil. 
 
 25. The Report of the Agricultural Survey of Lancashire (made 
 to and published by the Board of Agriculture) states the general 
 practice, and also particular cases of the enormous quantities and 
 consequent great cost of the marlings of that country. All the 
 marl (or " clay" as called in some cases) is calcareous. It lies 
 under the surface generally of every field, and at no great depth, 
 and sometimes forms the surface soil. Of course the access to 
 and working the marl could not well be cheaper. Yet so heavy 
 are the usual dressings, 3000 to more than 10,000 bushels to the 
 statute acre, that the improvement is very costly. Actual expendi- 
 tures are stated ranging from $35 to S65 the aci'c, for a single 
 marling, at short distances and with the other usual facilities of the 
 locality. We might safely infer that these great labours are not 
 necessary or even useful for the purpose of furnishing lime to the 
 soil ; and still less if to a soil already calcareous. And of the 
 correctness of this inference the author leaves no doubt in the fol- 
 lowing subsequent passage of his Report : — • 
 
 " Undoubtedly the calcareous matter contained in either marl [i. e. the 
 "richer marl" having 40 per cent, or more, or the "clay," of 20 or 22 
 per cent, of carbonate of lime], is of the highest importance; but obviat- 
 ing the natural deficiencies of the soil, by adding sand to clay, or clay to 
 sand, is of more consequence than the mere calcareous stimulus, which 
 might be obtained at a much lighter expense" [by liming]. 
 
 26. Of the agricultural character of the lands on the " new red 
 sand-stone formation" (which includes the red marl land of Lan- 
 cashire), Morton says — 
 
 " In Devon and Somersetshire, this is an unctuous friable clay, or red 
 marly soil of the first quality. It is friable enough for turnips, yet sufiii- 
 ciently tenacious for beans and wheat, and produces the richest and most 
 luxuriant crops of any soil in the kingdom ; and the only manure that seems 
 necessary is (he application of lime, with which it produces increased crops on 
 every repetition. The effects of lime on the red marl, are much greater Ik 
 Somerset and Devonshire than in any other portion of the soil of this 
 formation. 
 
 " AVherever the red marl comes to the surface, it forms a rich red fria- 
 ble loam," &c. — "The nature of the soil is clay, calcareous matter or marl, 
 elippery and greasy when wet, and of a soapy feel when dry," &c. {Mor- 
 ion on Soils, 4th London ed., pp. 70, 71.) 
 
 Now whatever may be the benefits, and however great, of apply- 
 ing lime to these already calcareous soils (if the so called " marl" 
 is indeed calcareous), the operation is most certainly not that of 
 calxiny, or the marling which I have recommended. 
 
888 MARLING NOT TO MAKE SOIL CALCAREOUS. 
 
 27. The marling of Norfolk county is the most celebrated in 
 England for the great extent of the operation, and the great im- 
 provements thereby made. Yet the following passage from the 
 same writer will clearly show that the ordinary operation called 
 " marling" in Norfolk is entirely different from the chemical action 
 I propose : 
 
 "So convinced" (says Morton, at p. 29), "are the farmers of Norfolk 
 and Suffolk of the value of the clay or chalk marl [both certainly calcare- 
 ous] as an alterative to their sandy surface, that they generally chalk or 
 clay their land once in eight years at least, and sometimes oftener; and by 
 allowing 100 cubic yards to the acre, incur an expense of 50s. [more than 
 $12] per acre, for digging, "wheeling, and spreading. It is solely by this 
 process, that the Norfolk sandy soil, which naturally was of the most 
 worthless kind, and produced nothing but heath and bent, for a few starv- 
 ing sheep, is now converted into good sandy loam, which yields large crops 
 of turnips, barley, and wheat." 
 
 Now the first application certainly included the chemical opera- 
 tion which I call marling (or calxing) the soil — if it was not before 
 calcareous. If calcareous by nature, even the first artificial appli- 
 cation would have no such chemical action. But much more than 
 half of even the first apiilication, and all of each of the subsequent 
 applications, made every eight years or oftener, in great quantity 
 and at great expense, was merely mechanical in its action, was not 
 rendering the soil calcareous (it being enough so before), and, in 
 short, was in no respect the chemical process which I have defined 
 and recommended, as marling. We may infer that in all these 
 later applications, the carbonate of lime in the marl produced no 
 chemical efi"ect, and acted only meclianically, if at all ; and that it 
 was the clay that acted most beneficially, and altogether mechani- 
 cally. 
 
 28. " In Hampshire and Berks, 2880 bushels per acre [of chalk, nearly 
 pure carbonate of lime] are applied with great advantage, at the expense 
 of 42s." {ilorton on Soils, p. 154.) 
 
 29. There can be no higher authority than Sir Humphrey Davy's, 
 for established scientific opinions, at the time he wrote, as to the 
 characters of soils and mineral manures. His "Lectures on Agri- 
 cultural Chemistry" contain the following passage — which with 
 others of similar import remained unaltered in his latest published 
 edition : — 
 
 " Chalk and marl, or carbonate of lime, tvill only improve the texture of a 
 soil, or its relation to ahsorjjtion ; it acts merely as one of its earthy ingre- 
 dients." {Agr. Chem. 4th London ed. of 1835, Lecture vii.) 
 
 Of course, neither this illustrious chemist, nor Professor John 
 Davy, who issued, with his notes, this edition of his then deceased 
 brother's great work, could have had any conception of the chemi- 
 cal action of carbonate of lime, when applied in such small quan- 
 
ERRORS OP SINCLAIR. 389 
 
 titles as merely to make its presence evident to tlic analyzer, in a 
 soil before entirely deficient. 
 
 30. The next following quotation ojffers the most remarkable 
 evidence of erroneous opinions of the chemical action of different 
 mineral manures, uttered by a modern author of the highest repu- 
 tation as a scientific agriculturist. Sir John Sinclair was a volu- 
 minous and able writer. Presiding over the British Board of Agri- 
 culture, he mainly directed its operations, and of course was fami- 
 liar with all the lights of British agriculture brought together in 
 the published reports of all the agricultural surveys of the counties 
 of Great Britain and Ireland. Moreover, the professed object of 
 his latest work, the " Code of Agriculture" was to present a 
 digest of all the valuable facts and instructions elicited by all those 
 voluminous surveys and reports, and tested and established by judi- 
 cious and authoritative approval. Yet in the 5th Loudon edition 
 of his " Code of Agriculture," as late as 1832, and with numerous 
 recent additions and improvements to the work, the following pas- 
 sages stand in an article with the title below : — 
 
 "On bones as a manure, and on the use of shells, shell-marl and coral 
 for the same beneficial purposes." 
 
 "Were the advantages of the discovery restricted to the use of bones 
 
 alone, as they might possibly be exhausted, or raised in price, it would be 
 less important ; but fortunately the shells of oysters, and other fish, are 
 found to be equally effectual. Shell marl also, ■which abounds in many parts 
 of the kingdom, may be applied to similar purposes ; and coral, the banks 
 of which are abundant even on our own coasts, is found to be equally use- 
 ful. In short, it is impossible to foresee what may be the ultimate results 
 of this neiv source of improvement, for by a small quantity [25 bushels to 
 the acre, as elsewhere directed] of pounded bones or shells, great crops of 
 turnips may be raised ; and with the manure which these turnips produce, 
 abundant crops of corn may be obtained even on the poorest soils, with the 
 aifl of a judicious rotation." (Code of Agr., 5th Lon. ed. p. 141, Appendix.) 
 * * * i»^\^s bones are likely to become a scarce article, it is a most fortu- 
 nate circumstance that the shells of oysters and other shell-fish, when properly 
 reduced in size, have been fovmd equally iiscful as a manure. Their utility 
 •would be much increased if they were sprinkled with sulphuric acid, by 
 the addition of which they would be converted into gypsum." (p. 14G.) 
 
 Thus, the distinguished author, as late as 1832, asserts that 
 substances whose manuring principles are almost exclusively com- 
 posed of carbonate of lime, will serve to substitute, and act alike 
 and as effectually, as those which are almost exclusively composed 
 of pJio.s.2)hate of lime (and of fatty and gelatinous animal matter, 
 if these remain) ; and then recommends, as still better, the con- 
 verting tho carbonate to the svJpliate of lime or gypsitm ! This 
 last-named manure, moreover, has not been found of benefit but in 
 few cases in England. It is unnecessary to expose, by further com- 
 ments, this confounding of the action and effects of three manur- 
 ing substances, all valuable in their places, yet each very different iu 
 action from the others. 
 33* 
 
390 MARLING OF NORFOLK, 
 
 31. The means of ameliorating tlie texture of clialhj soils, are either by 
 the application of clayey and sandy loams, pure clay, or marl." — "The 
 chalk stratum sometimes lies upon a thick vein of black tenacious marl, 
 of a rich quality, which ought to be dug up and mixed with the chalk." — 
 Code of Agriculture, p. 19. 
 
 32. Dickson's Farmer's Companion. — The author recommends 
 "argillaceous marF' for the improvement of cJudki/ soils; and for 
 sandy soils, "where the calcareous principle is in sufficient abund- 
 ance, argillaceous marl, and clayey loams," are recommended as 
 manures. 
 
 33. " Chalky loam. The best manure for this soil is clay, or argillaceous 
 marl, if clay cannot be had ; because this soil is defective principally in 
 the argillaceous ingredient," — Kir wan on Manures, p. 80. 
 
 The evident intention and effect of the marling recommended iu 
 all the three last extracts, is to diminish the proportion of calcare- 
 ous earth in the soil. 
 
 34. In a Traveller's Notes of an agricultural tour iq England, 
 in 1811, which is published in the third volume of the Edinburgh 
 Farmers' Magazine, the following passages relate to Mr. Coke's 
 estate, Holkham, and to Norfolk generally. 
 
 "Holkham. — The soil here is naturally very poor, being a mixture of 
 sand, chalk, and flint stones, with apparently little mixtui-e of argillaceous 
 earth — the sub-soil, chalk or lime-stone everyxchere." p. 486. " As the soil 
 of the territory [of Norfolk generally] through which I passed, seems to 
 have a sufficient mixture of calcareous earth naturally, I learn they do not of- 
 ten lime their lands ; but clay marl has been found to have the most bene- 
 ficial consequences on most of the Norfolk soils." p. 487. 
 
 35. "In Norfolk, they seem to value clay more tlian marl, ■^vo\)^\>\y \>&- 
 cause their sandy soils already contain calcareous parts." — Kirwan on 3Ia- 
 nures, p. 87. 
 
 From this and the preceding quotation it would follow, that the 
 great and celebrated improvements in Norfolk, made by marling, 
 had actually operated to lessen the calcareoiis proportion of the soil, 
 instead of increasing it. Or, otherwise (as may be deduced from 
 what will follow), if so scientific and diligent an inquirer as Kir- 
 wan was deceived on this very important point, it furnishes addi- 
 tional proof of the impossibility of drawing correct conclusions on 
 this subject from European books — when it is left doubtful, whether 
 the most extensive, the most profitable, and the most celebrated 
 improvements by " marling" in Europe, have in fact served to 
 make the soil more or less calcareous. 
 
 If the "clay marl" offered above (4) by Stephens as a fair 
 average, and which contained only 8.40 per cent, of carbonate of 
 lime, is indeed as rich as the "clay marls" or "clays" spoken of 
 in the latter extracts, it would convert the doubt to certainty, that 
 many soils in England were more calcareous than such marl ; and 
 that its application (though truly a calcareous manure), served often 
 
CALCAREOUS CLAYS OF NEW YORK. 391 
 
 to lessen rather than to increase the previous calcareous constitu- 
 tion of the soil. 
 
 36. In connexion with this statement of the poor "clay marls" of 
 Britain, it is worthy of notice that of six kinds of " clay" (not 
 "clay marls," but presented simply as clays), of New York, ana- 
 lyzed and reported by Professor Emmons (and quoted in Browne's 
 Muck Book), the calcareous proportion in five was either nearly as 
 large, or larger, than in the above stated British "clay marl." The 
 Bpccimcns reported by Professor Emmons were as follows: — 
 
 "Tci'tiavy or Albany clay, contains carbonate of lime per cent. . 8.00 
 
 Niagara clay .......... 14.62 
 
 Cayuga clay 16.48 
 
 Adonirach clay. ......... 0.94 
 
 Bricl{(?) clay, near Caldwell ' . 8.92 
 
 lleddish clay of Christian Hollow 8.29" 
 
 Browne's 3Iuck Book (1852). 
 
 All but one of these New York "clays" would be "clay marls" 
 in Britain, according to Stephens, the latest and a high British 
 authority. 
 
 ]Most of the extracts which I have presented, are from British 
 agriculturists of high character and authority. If such writers as 
 these, while giving long and (in some respects) minute statements 
 of marl and marling, omit to tell, or leave their readers to doubt, 
 whether the manure or the soil is the most calcareous — or what 
 proportion of calcareous earth, or whether any is present in 
 either — then have I fully established that the American reader 
 who may attempt to draw instruction from such sources, as to the 
 operation, effects, and profits of either marl or calcareous manures 
 in general, will be more apt to be deceived and misled than 
 enlightened. 
 
 I have now to refer to an author, whose works, well known as 
 they may be to others, had not coma under my view until after the 
 earliest publication of most of the foregoing extracts. Otherwise, 
 Marshall would have been stated as an exception to the general 
 silence of British authors as to the true and precise nature of what 
 they treated of as marl. But though he has not been, like others, 
 Bo faulty as to leave in doubt what was the character and value of 
 the marls of which he spoke, and the nature of their operation on 
 the soils to which they were applied, still no other writer furnishes 
 stronger proof of the general ignorance and disregard of the nature 
 of marls and calcareous manures, and of their mode of operation ; 
 and even the author himself is not fi-ee from the same charge, as 
 will be shown. I shall quote the more at length from Marshall, 
 because he presents the strongest opposition to what I have stated 
 as to the general purp(n-t of publications on marling ; and also, 
 because whatever may be their character, there is much to interest 
 the reader in his accounts of the opinions and practices of those 
 
392 Marshall's statements. 
 
 who have used calcareous manures longest and most extensively, 
 although without knowing what they were doing. 
 
 In his ''■ Rural Economy of Norfolk,' the "marls" and "clays" 
 most used in the celebrated improvements of that county are mi- 
 nutely described, and the chemical composition stated, showing that 
 both are highly calcareous. Of the "marls" or chalks, most used 
 for manure in Norfolk, he analyzed three specimens, and one of 
 clay, and found -the proportions of pure calcareous matter as 
 follows : — 
 
 Chalk marl of Thorp-market, contained, per cent. . . 85 
 Soft chalk of Thorp-next-Norwieh, .... 98 
 
 Hard chalk of SwaiFham, almost pure, — nearly . . 100 
 Clay marl of Hemsby ....... 43 
 
 87. Of these he spoke previously and in general terms, thus : 
 "The central and northern parts of the district abound, universally, with 
 a ■whitish-coloured chalk marl ; while the Fleg hundreds, and the eastern 
 coast, are equally fortunate in a gray-coloured clay marl. The first has, 
 in all probability, been in use as a manure many centuries ; there are oaks 
 of considerable size now going to decay in pits which have obviously been 
 heretofore in use, and which, perhaps, still remain in use, as marl-pits. 
 
 " The iise of clay marl, as a manure, seems to be a much later discovery; 
 even yet, there ai-e farmers who are blind to its good effect ; because it is 
 ■not marl, but "clay;" by which name it is universally known. Tha name, 
 however, would be a thing of no import, were it not indiscriminately ap- 
 plied to unctuous earths iu general, whether they contain, or not, any por- 
 tion of calcareous matter. Nothing is "marl" which is not white ; for, 
 notwithstanding the county has been so long and so largely indebted to its 
 fertilizing quality, her husbandmen, even in this enlightened age, remain 
 totally ignorant of its distinguishing properties ; through which want of 
 infoi'mation much labour and expense is frequently thrown away. One 
 man, seeing the good effect of the Fleg clay, for instance, concludes that 
 all clays are fertile, and finding a bed of strong brick earth upon his farm, 
 falls to work, at a great expense, to "claying" — while another, observing 
 this man's miscarriage, concludes that all clays are unprofitable ; and, in 
 consequence, is at an expense, equally ill applied, of fetching "marl" from 
 a great distance; while he has, perhaps, in his own farm, if judiciously 
 sought after, an earth of a quality equally fertilizing with that he is throw- 
 ing away his time and his money in fetching. — ilarshalVs N'orJ'olk, vol. i., 
 p. 16. 
 
 Yet it is remarkable, that Marshall should not have intimated 
 "whether the Norfolk soils were naturally calcareous (as the two 
 writers just before quoted declare) or not ; and therefore we are 
 still left to guess whether these manures served to increase the 
 calcareous quality of soils already possessing that quality in a high 
 degree, or to give it to soils devoid of it before. 
 
 Other passages v/ill now be quoted from the same, and from 
 other similar works of IMarshall's, to show the prevailing ignorance 
 of the ingredients and operation of the marls, sometimes prized 
 and sometimes contemned, with as little reason in the one case as 
 the other, by formers in various parts of England. 
 
, MARLS AND CLAYS OP NOKFULK. 398 
 
 38. " The principal part of bis estate, however, is of a much shallower 
 soil, not deeper than the plough goes ; and its present very amazing fer- 
 tility he ascribes in a great measure to his having clayed it. Indeed, to 
 this species of improvement the fertility of the Fleg Hundred is allowed to 
 be principally owing. 
 
 "iSIr. F. gave me an oppoi'tunity of examining his clay pit, which is very 
 commodious ; the uncallow [i. e. overlying earth] is trifling, and tlie depth 
 of the bed or jam he has not been able to ascei'tain. It is worked, at pre- 
 sent, about ten or twelve feet deep. The colour of the fossil, when moist, 
 is dark brown, interspersed with specks of white, and dries to a colour 
 lighter than tliat of fuller's earth ; on being exposed to the air, it breaks 
 into small die-like pieces. 
 
 " From Mr. F.'s account of the manner of its acting, and more particu- 
 larly from its appearance, I judged it to be a brown marl, rather than a 
 clay ; and, on trying it in acid, it proves to be strongly calcareous ; effer- 
 vescing, and hissing more violently than most of the white marls of this 
 neiglibourhood : and what is still more interesting, the Hemsby clay is 
 equally turbulent in acid as the Norwich marl, which is brought by water 
 forty miles into this country, at the excessive expense of four shillings a 
 load upon the staith ; besides the laud carriage. [The strength of this 
 Hemsby clay is stated above.] 
 
 " It is somewhat extraordinary that Mr. F., sensible and intelligent as 
 he is, should be entirely unacquainted with this quality of his clay ; a cir- 
 cumstance, however, the less to be wondered at, as the Norfolk farmers, in 
 general, are equally uninformed of the nature and properties of marl." — 
 Marshall's Norfolk, vol. ii., p. 192. 
 
 The following is a remarkable instance, ia a particular district, 
 of a clay very poor in calcareous matter, being considered and used 
 as valuable manure, and a very rich marl equally accessible, being 
 deemed inferior. 
 
 89. " The marl is either an adulterate chalk, found near the foot of the 
 chalky steeps of the West Downs, lying between the chalk rock and the 
 Maam soil, partaking of them both — in truth, a marl of the first quality — 
 or a sort of blue mud, or clay, dug out of the area of this district, par- 
 ticularly, I believe, on the south side of the river. This is said to have 
 been set on with good effect, while the former is spoken of as of less 
 value ; whereas, the white is more than three-fourths of it calcareous ; 
 while the blue does not contain ten grains, per cent., of calcareous mat- 
 ter. — Marshairs Southern Counties, p. 175. 
 
 There have before been given some extracts from this author, 
 showing that sundry other valued "marls" (so called) were 
 scarcely at all calcareous. Whatever manuring effects all these 
 have, must be owing to some other and unknown ingredient. 
 
 The first extracts from Marshall (just referred to) suggested a 
 remark, which ought to have been made earlier. When there is 
 BO much general ignorance prevailing among practical farmers as 
 to what they call marl, it cannot be expected that the most intelli- 
 gent writers can be correct, when attempting to record their prac- 
 tices. When Arthur Young, for example, reports the effects of 
 marl in fifty different localities, as known from the practice of 
 several hundreds of individuals, it must be inferred that he uses 
 
394 SEA SAND. 
 
 tlie term, generally, as they did from whom his information was 
 gathered, and in very few cases, if at all, as learned by his own 
 analyses. Therefore, it may well be doubted whether the uncertainty 
 as to the character of marl does not extend very generally to even 
 the most scientific writers on agriculture. 
 
 As some of the foregoing extracts exhibit the use of " marls" 
 (so called) destitute of calcareous earth, so the following shows, 
 under the name of sea sand, a manure which is in its chemical 
 qualities a rich marl (in our sense) or calcareous manure. 
 
 40. " Sea sand. This has been a, manure of the district, beyond memory 
 or tradition. There are two species still in use : the one bearing the ordi- 
 nary appearances of sea sand, as found at the mouths of rivers ; namely a 
 compound of the common sand and mud ; the other appears to the eye 
 clean fragments of broken shells without mixture ; resembling, in colour 
 and particles, clean-dressed bran of wheat. 
 
 " By analysis, one hundred grains of the former contain about thirty 
 grains of common silicious sea sand, with a few grains of fine silt or mud; 
 the rest is calcareous earth mixed with the animal matter of marine shells. 
 
 "One hundred grains of the latter contain eighty-five grains of the mat- 
 ter of shells, and fifteen grains of an earthy substance, which resembles, in 
 colour and particles, minute fragments of burnt clay or common red brick. 
 
 "These sands are raised in different parts of Plymouth Sound, or in the 
 harbour; and are cai'ried up the estuaries in barges; and from these on 
 horseback, perhaps five or six miles into the country ; of course at a very 
 great expense, yet without discrimination, by men in general, as to their 
 specific qualities. The shelly kind, no doubt, brought them into repute, 
 and induced landlords to bind their tenants to the use of them ; but with- 
 out specifying the sort — and the bargemen, of course, bring such as they 
 can raise and convey at the least labour and expense. It is probable that 
 the specimen first mentioned, is above par, as to quality : I have seen sand 
 of a much cleaner appeai*ance, travelling towards the fields of this quarter 
 of the country ; and near Beddiford, in North Devonshire, I collected a 
 specimen under the operation of " melling" with mould, which contains 
 eighty grains per cent, of clean silicious sand!" — Marshall's West of Eng- 
 land, vol. i., p. 154. 
 
 It might be inferred from all these proofs of Marshall's know- 
 ledge of calcareous earth constituting the real value of marls, that 
 he could scarcely miss the obvious corollary to that proposition, 
 that the valuable operation of calcareous manures is to render soils 
 calcareous, and that the knowledge of the nature of the manure 
 and the soil would sufficiently indicate when the application of the 
 one to the other is judicious or not. But the following expres- 
 sion of opinion (^MarshaW s Yorkshire, vol. i., p. 377) is not only 
 strongly opposed to those deductions, but to the general purport 
 of all his truths which I have before quoted. 
 
 41. "Nothing at present but comparative experiments can determine 
 the value of a given lime, to a given soil ; and no man can with common 
 prudence lime any land upon a large scale, until a moral certainty of im- 
 provement has been established by experience." 
 
 If this be true, then indeed is there no true or known theory, or 
 
LATEST ENGLISH ERRORS. 895 
 
 establisbed principles or precepts, for applying either lime or any 
 calcareous manure. It amounts to saying, that every new applica- 
 tion is a mere experiment^ the result of which cannot even be con- 
 jectured from any facts previously known of other soils and other 
 manures. 
 
 42. The next quotation, which is from an editorial article in the 
 Farmers' Journal of July 28, 1823, shows that the old opinion 
 still prevails, that marl is profitable only on sandy lands ; which 
 opinion carries with it the certain inference that it is the argillaceous 
 quality, rather than the calcareous, that operates. The editor is re- 
 marking on a new agricultural compilation by a Mr. Elkinson, and 
 ridiculing the author for his solemn annunciation of the truism 
 (in the editor's opinion)^ that " marling on sand is more useful than 
 on clay land." The reputation of Mr. Elkinson, says the editor, 
 
 " may remain undistui'bed among the farmers of Lincolnshire for a long 
 time, Trho may never have chanced to meet with the old proverb, or have 
 taken a journey into the sandy district of Norfolk. AVe really do not know 
 whether it be as old as Jarvais Markham or not : but we have seen tho 
 following lines in black letter: — 
 
 He that marls sand, may buy land ; 
 
 He that marls moss, shall have loss ; 
 
 He that marls clay, throws all away!" 
 
 The editor then passes to a subject on which his admitted igno- 
 rancc serves to prove that the improvement gained by marling 
 could not be simply the making a soil calcareous — for, upon that 
 ground, when marl has once been plentifully given, and the land 
 afterwards worked poor, there can be neither reason nor profit in a 
 second marling. Yet, as if the mode of operation was altogether 
 unknown, this passage follows : 
 
 "It was once asked of the editor by a very good practical Norfolk far- 
 mer, 'whether land which had been once marled and worn out would re- 
 ceive the same benefit from a second marling?' It was answered, that an 
 experiment made on one field, or on one acre, would decide the point, but 
 co7ijccture led to nothing conclusive. It has often been observed that loose 
 land, after having been marled and out-cropped, deposited its marl in the 
 Bub-soil, which therefore became more retentive [of water] ; and it has 
 been suggested, that deep ploughing ought to be tried, to bring this marl 
 again to the top. AVe hope that the point here in question has before now 
 been settled by practice in both ways ; though at the above period (about 
 1806), such facts had not reached the gentleman alluded to, although a 
 very intelligent man." 
 
 There are copious descriptions of marl, and accounts of its use 
 and operation in several modern French works which I have seen 
 only since the first publication of this essay.* In all of these, 
 marl is correctly described, as being composed of carbonate of lime 
 
 ' * "Cours Complet," &c., par l'Abb6 Rozier; "Maison Rustique, &c." 
 
 «'Essai sur la Marne," par M, Puvia. 
 
396 FOSSIL SHELL BEDS IN EUROPE. 
 
 and clay, or as what I have distinguislied as true marl. Neither 
 ill these very minute descriptions (nor in any others known to me), 
 are shells mentioned as forming either a universal or general con- 
 stituent part of ordinary marls; or as having furnished directly and 
 immediately the main supply of the carbonate of lime of ordinary 
 and true marls. It is true that shells, or their fragments, arc men- 
 tioned as being sometimes contained; but these may be presumed 
 to be accidental ingredients. They are either land shells (and 
 sometimes so described) swept from the surface of the calcareous 
 lands from which the es.sential materials of the marl were brought 
 in the floods of turbid water; or in other cases, shells of fresh- 
 water molluscs which lived in the ancient lakes under which the 
 marl was deposited, and of course, the shells of such dead animals 
 would be enveloped in the marl, though not necessarily or properly 
 belonging to it. 
 
 Again : " Shell marl" is mentioned by sundry authors, but this 
 is even a more different formation from true marl than it is from 
 our fossil shells. Its peculiar character was stated above (page 
 374). This is the " shell marl" to which Sir John Sinclair refers 
 above. 
 
 If any one can still suppose that these European writers, when 
 speaking of marl, could possibly mean to include such beds as ours, 
 or would so include them, if known there, I have a sufficient answer 
 ready in the fact that such beds of fossil shells as are here called 
 marl exist in Europe and in great extent — that they were known 
 to and were described by authors who wrote most extensively on 
 marl — and that in no case have they been termed or considered as 
 marl. 
 
 Many and extensive beds of fossil marine shells are known to 
 exist in Europe, which, in their general features, physical and 
 chemical, and fitness for agricultural uses, must be similar to ours. 
 Of these deposits, both in England and France, there have been 
 applications to the land, though to very limited extent compara- 
 tively, and the fertilizing value is recognised. Scientific observers, 
 of course, know that these beds agree with true marl in the im- 
 portant and main characteristic of being in part composed of car- 
 bonate of lime. Still, in the only three agricultural notices of these 
 beds of fossil shells which I have seen, and all are from scientific 
 agriculturists, this substance is not called marl ; and it is noticed 
 under a different head, and treated as if a different manure. The 
 practical cultivators who have applied it, doubtless deemed this 
 manure as different from marl in substance and qualities as in 
 name. 
 
 One of the notices referred to has already been quoted above, 
 (20, page 383), in the words of Arthur Young, concerning the 
 Suffolk '' crcuj," the name used for this deposit iu England. This 
 
FALUx\S AND FALUNAGE OF TOLRAINE. 397 
 
 scant notice is all that is taken of this kind of fossil manure, in that 
 author's voluminous Agricultural Survey of Suffolk, and of which 
 a large portion is devoted to marl and marling. It is manifest 
 from his expressions, that neither Young nor the Suffolk farmers 
 had any idea of this " crag" being marl. 
 
 The other and more full accounts are by French authors. The 
 latest is by M. Puvis, who has written so extensively on lime and 
 marl, and whose views of calcareous manures are worth more than 
 those of any other European writer, previous to the general digest 
 in the recent Lectures of Prof. Johnston. Puvis' remarks on this 
 subject, of which all will be translated and given below, follow his 
 Essay on Marl in the Annalcs, but as one of several different though 
 connected subjects — under the different divisions and titles of 
 '' Plairas, or remains of demolished buildings" — " Falunagp, or 
 use of shells as an improver" — " Grypsum" — and '' Wood-ashes." 
 Under the head of falunage the following remarks occur : 
 
 "43. Of Falunage, or the use of shells, as an improver of soil. 
 
 " The name fahms has been given to those beds of fossil shells which are 
 found, whether on the borders of the sea, or in the interior of the laud. In 
 certain places the faluii is used under the name of shell marl ;* but it is only 
 the falun of Touraiue [in France], of which the use in agriculture is well 
 known. Thefalunicre there forms a bed of three leagues in length, and of 
 variable width and thickness. The falun is taken out from many feet in 
 depth ; and as there is much water, it is obtained by the force of many 
 hands, of which some draw off the water while others get out i\xe falun. It 
 is put on the land at from 30 to GO wagon loads to the hectare [nearly 2 J 
 acres] according to the nature of the soil. Its action appears at least as 
 efficacious as that of marl ; and the effects last long. 
 
 " They use in England a much lighter di-essiug ; not more than one-half 
 of the lightest dressing in Touraiue. The particular qualities and fertilizing 
 forces may be different, as the beds are composed of very diff'erent families 
 of shells ; so that each region may be right in its practice. The duration 
 of a falunage in England is longer than that of marl ; and its energy is re- 
 newed by a compost of barn-yard manure and shells, as in regard to marl 
 and lime. The soil is greatly meliorated ; still more, as it seems, than by 
 lime or marl. It may well be true that these shell beds may in fact contain 
 some albuminous substances, some animal parts, which add to the effect 
 of the cai'bonate of lime, which forms the principal base of the manure. 
 
 " There are found in France these shelly beds in many places. They are 
 spoken of in the environs of Dax, of Grignon (Seine-et-Oise), of Courtag- 
 non (in Marne) ; but the conchologists seem to have made more use of them 
 than the agriculturists. Doubtless, they are to be found in many other 
 
 * It is manifest that the author, in reporting this provincial and particu- 
 lar application of the name "shell marl" does not adopt it, or approve it. 
 He never himself uses the words marl (?)iarne) or marling {marnage) applied 
 to this earth; but always falun for the substance, falunage for the applica- 
 tion of it as manure ; and faluniere for the bed, or deposit in its natural 
 place, or for the excavations therein, as understood in the next succeeding 
 article. E. E,. 
 
 34 
 
398 fALUNAGE IN FRANCE. 
 
 places. These deposits are one of our mineral treasures, from -wliich -wo 
 are far from deriving proper advantages. For if using tiie falun at tlie 
 rate of 100 hectolitres to the hectare, as in England, it might be trans- 
 ported to a distance, either by water or land carriage. And what further 
 recommends its use, at least as much, the falun is not accused of having 
 impoverished the soil. On the contrary it is found every whsre improved."* 
 — Annales d' Agriculture Frangaise, 1835. 
 
 The next passages are translated extracts of the article " Falun" 
 in the " Oours Complct," &c., which is a joint contributiun by 
 Rozier and Cadet-de-Vaux. 
 
 44. " This name is given to a great body of marine remains which 
 exist in Touraine, over an extent of about three leagues in length, and of 
 less breadth. Neither the exact limits nor the depth of this bed is known. 
 The excavations have not been sunk lower tlian 20 feet, because of the 
 water which oozes from all sides into these falunieres. What a deposit ! 
 "What immense quantity of shells ! We may also add, what a treasure ! for 
 these spoils of the ocean are an excellent improver of soil. 
 
 We will then merely consider the falun as an improver. 
 
 After being extracted from the pit, suffered to drain and become dry, it is 
 spread on the fields the same as marl ; and the proportion varies according 
 to the quality of the lands on which it is spread — in the same manner as 
 of marl. 
 
 " Here is the diiforence which exists between these two improvers: Marl 
 is a calcareous earth, of the same nature as the falun, but it is mixed with 
 sand and ai-gil ; so that the first thing to do when one marls a field is to 
 know well the [^degree of purity of the] marl. This knowledge is easy to 
 acquire by the most simple analysis. ....... 
 
 . . . . The falun is pure calcareous earth ; but which contains more 
 or less of the principles which were united to the calcareous earth in the 
 formation of the shells. Unless constantly soaked in water, it may not 
 have lost these principles. Then the falun can no longer be considered as 
 
 a pure calcareous earth, and destined to act only mechanically 
 
 We will observe that the falun has, in common with marl, no influence on 
 the fertility of the field which receives it until the second year ; and the 
 elfects of both these earths become enfeebled at length ; when it is neces- 
 sary to apply them again." 
 
 I have omitted of the last article as much as could be separated 
 of the superfluous, useless, and mistaken statements — and there is 
 not much else. But all is left that refers to what I designed to 
 show, i. e., that the authors had no thought that the falun was 
 marl. 
 
 This last description of the falun of Touraine goes to show that 
 the mass was of shells or their fragments alone, or without the 
 
 * This ground of superior value assumed for i\xQ falun, I take as indirect 
 evidence, in addition to the author's direct assertion, that this kind of 
 manure has been but little used, or that little is known of the effects. Tho 
 use of calcareous manures in Europe has been almost entirely empirical, 
 and not directed by any theory, or rational rules. Hence damage has often 
 been done by improper applications of both lime and marl ; and if ih<i falun 
 has been harmless, rich and abundant as it is, and easy to apply, it must 
 be because of its very limited use. E. R. 
 
/ OLD VIEWS OF MARL OP VIRGINIA. 399 
 
 iisual arlmisture of sand or clay. I have worked a particular layer 
 nearly as pure, and which hud the same disadvantage of water 
 pouring in through the very open texture of the broken shells. 
 There is an extensive bed of as pure and unmixed fossil shells, near 
 to the surface of the earth, and there quite dry, near the northern 
 limit of sea-coast of South Carolina.* 
 
 45. The next evidence is from a report of the Rev. John 
 Clayton, Rector of Crofton, in Yorkshire, to the Royal Society of 
 England, in 1688. The writer visited Virginia, and this was the 
 report of his personal and somewhat scientific examinations. It 
 was republished in the 4th vol. of Farmers' Register. The writer 
 saw, with astonishment, and describes the beds of fossil shells in 
 the river cliffs — and though with much looseness and inaccuracy, 
 still there is no doubt that he included in his observations not only 
 the actual beds of loose oyster shells, but the petrified oyster shells in 
 other places, and also the beds of other and various fossil sea shells, 
 which since have obtained in Virginia the provincial term of marl. 
 For though he calls all of them " oyster shells," it is manifest that 
 he also referred to the sea shells, as he particularly describes the 
 " shark's teeth" and large vertebrae which are so common in these 
 beds, and never known in the deposits of oyster shells alone. Now 
 this gentleman, from his residence, and his information, could not 
 possibly have been ignorant of marl in England. Yet in all his 
 remarks and speculations (some very wild), on these beds in Vir- 
 ginia, he does not call them marl, or refer to any similarity of these 
 beds to marl — nor even suppose any use for ours, other than that 
 before known, of burning the shells to make lime for cement. (See 
 Farmers' Register, vol. iv., pp. 642-3.) 
 
 From all the foregoing quotations and evidences, I claim that 
 the propositions enumerated in the beginning of this article, have 
 been sustained fully ; and that the following deductions must neces- 
 sarily be made : — 
 
 1. For centuries after marling had been recommended by Eng- 
 lish books on agriculture, and extensively practised by very many 
 farmers of England, it was not generally, if at all, understood by 
 either writers or farmers that calcareous earth was the all-important 
 or even an essential ingredient of marl, as a manuring agent ; and 
 many clays used for and as marl, certainly contained no carbonate 
 of lime. 
 
 2. Though more lately, English writers have taught correctly 
 that marl is calcareous, and also (generally) that the value of the 
 manure depends mainly on the lime contained, still the previous 
 
 * DG?crihed in the supplement to my E,eport of the Agricultural Survey 
 of South Carolina. The deposit is on and near Price's creek, in Horry — and 
 is of the pobt-pUoccne division. E. R. 
 
400 MAUL NOT VALUED FORMERLY. 
 
 ignorance continued to prevail among the more Illiterate farmers; 
 and even some writers of reputation, to recent times, have shown 
 in their expressions the influence remaining of the previous and 
 universal ignorance on this subject. Long after these more correct 
 views of the constitution and true source of value of marl had been 
 published by the then most enlightened writers, their readers did 
 not learn from them enough of their ti'uth to dispel the previously 
 long existing and prevailing erroneous views. Hence the " soapy 
 feel," and clayey constitution, and the crumbling in water, still 
 continued to be regarded by all as essential qualities and important 
 values of any manure operating as marl; and comparatively little 
 importance was attached to the calcareous ingredient — even when 
 that was not entirely disregarded or unknown. 
 
 Hence Bordley, an extensive reader of the best and newest 
 English agricultural boohs, himself an agricultural author, and 
 moreover a practical and wealthy farmer, on the "marl region" 
 (now so known) of Maryland, did not learn from his English 
 teachers and guides that marl was necessarily calcareous ; and never 
 suspected that the beds of fossil shells, so abundant in his own 
 neighbourhood (if not on his own farm), either were marl, or had 
 any value as manure. We may also infer that our great Virginian 
 agriculturist, John Taylor of Caroline, a much later writer than 
 Bordley, and also well acquainted with English agricultural authors, 
 had learned nothing more either of true marl, or of our beds of 
 fossil shells being (as indicated by the vulgar name), identical with 
 marl. Further : Philip Tabb, of Toddsbury, in Gloucester county, 
 was one of the earliest good firraers of Virginia, and deservedly 
 the most celebrated in his time for his judicious management, and 
 for his success in improving his farm and its productions. Yet 
 from all his lights, and doubtless his general knowledge of English 
 marling, he never suspected to be marl, and never thought of using 
 as such, or for manure, the bed of what is now called marl, which 
 underlies the whole farm, and is generally accessible within 4 or 5 
 feet of the surface. It has been only in latter days, that this most 
 abundant and easily accessible bed has been opened, and used 
 largely and advantageously as manure for this farm. 
 
 3. And further : No person, deriving his information solely from 
 the descriptions of marl by English waiters, and their remarks on 
 the subject, and searching for marl by aid of their directions, would 
 have supposed he had found the object of his search in the marine 
 fossil shell formation of this region — so entirely difiJerent as is this 
 from all the marls (true or false) described by those writers, in 
 outward appearance, texture, and other physical qualities always; 
 and in some cases there is no less diiference in the more important 
 chemical constitution, in regard to calcareous earth being an in- 
 gredient or not. 
 
MOST ANCIENT NOTICES OF MARL. 401 
 
 Marl and Marling of the Ancients. 
 
 I will add to these extracts, though merely as a matter of curi- 
 osity, the most ancient notices of marl extant, translated from the 
 •works of Varro and Pliny, respectively nearly 1900 and 1800 
 years old. Their great antiquity would alone serve to invest these 
 statements with much interest. And it is also interesting and 
 amusing to observe that nearly as much was known of the proper- 
 ties of marl by the then barbarous Britons, more than 1800 years 
 ago, as by their enlightened descendants 1700 years later. For if, 
 in the report by Pliny, the proper names were omitted, and the 
 piece appeared without date or authority, it might well be supposed 
 to be from some one of the English publications on marl which 
 appeared after the middle of the last century. Pliny, and the 
 Gaulish and British farmers from whom his statements were indirect- 
 ly derived, were as ignorant of the true character and action of marl, 
 as were the formers, and also most of the best agricultural writers, 
 as late as 1780 — but not more ignorant. Like these much later 
 writers, Pliny seems not to have known, or, if knowing, not to have 
 attached any importance to the calcareous quality of marl; nor 
 was he, more than they, at all precise in distinguishing between 
 marl and non-calcareous clay. Still it may be inferred, from the 
 context, and from indirect testimony rather than the direct state- 
 ments of the author, that either true marl or chalk was always re- 
 ferred to; and of course that it was truly calcareous manure of 
 which he spoke. The manure referred to as being used by the 
 Edui and Pictones, calx, is named with sufficient exactness; and 
 if not lime, as rendered in the translation, it must have been car- 
 bonate of lime in some form, as calx properly means. But by 
 using the word calx in this ease, and creta when chalk obviously 
 was meant, it seems likely that the former was designed for cal- 
 cined lime. 
 
 Translated from "Z>e Ee Rusiica.'" Var, Lib. I. Cap. 7. 
 
 " In Transalpine Gaul as far as the Rhine, when I commanded the army, 
 I went into some regions, where neither the vine, the olive, nor apples 
 grew, and where they manured their fields with a white chalk dug out of 
 ^ the earth [Candida fossicia creta]. 
 
 Translated from Plin. If at. Hist. Lib. XVII., Cap. 5, 6, 7, 8. 
 
 " To improve land (as some conceive) by the application of rich earth to 
 poor, or of porous and sandy to moist and very fertile, is the work of folly. 
 What can he hope who pursues such practice ? 
 
 " There is another method, which was discovered in Britain and Gaul, 
 of fertilizing land with a kind of earth which they call marl [^marga]. 
 Greater fertility is perceived. There is a peculiar fatness [at/fps] of this 
 earth which like the glandules in bodies serves as a nucleus for increased 
 fertility. 
 
 " The Greeks also have not neglected this plan ; for what have they failed 
 34* 
 
402 pliny's account op marl and marling. ■ 
 
 to try? A ■white clay \^candida argiUa'] 'whicli they use iu Mcgaris, but 
 only on moist and cold soils, they call Leucarjillon. 
 
 " It is proper to describe with care that used to enrich the soils of Gaul 
 and Britain. At first there were two kinds, but of late several others have 
 begun to be used as their information increased. There is the wliite, red, 
 dove-coloured, argillaceous, porous [^tophaceal, and sandy. Its character 
 is two-fold, rougli or unctuous [^agpera aut pinguis]. Specimens of both are 
 at hand. Its effect is likewise two-fold, either to bring grain alone, or also 
 to nourish grass. The white porous [topliacea alba] marl nourishes grain, 
 and if fountl among sjirings is immensely rich. It is rough to the touch, 
 and if applied in too large quantities it burns the land. The next is tlie red 
 marl, which they call cajjiumiarr/os, from the stone being intermixed with fine 
 sandy earth. The stone is crushed in the field itself, and for a few years 
 the stalks (of grain) are cut with difficulty on account of the pieces of stone. 
 Yet in consequence of its lightness it is applied at very little expense, less 
 than one-half the cost of the others. It is spread thin, and is thought to be 
 mixed with salt. Each kind once applied will last for fifty years, increasing 
 the product both of grain and grass. 
 
 " The white is the main variety of those which are known to be unctuous 
 l_pinffues'\. Of this there are several kinds. The most caustic [mordaccs- 
 simiini] is that of which we have spoken above. Another is a kind of white 
 chalk [alba cr-ela] used to scour silver. It is brought up out of the earth, 
 shafts being sunk often a hundred feet deep, narrow at the mouth, but en- 
 larging within as in mines. This kind is principally used in Britain, and 
 lasts eighty years. Nor is there an instance of any one who has twice 
 applied it to the same land during his life. A third kind of white they 
 call glischromaryon. It is a fuller's chalk [crcta fallonla) mixed with unc- 
 tuous [pingui] earth, better foJ'grass than grain, so that one crop being 
 taken off, befoi'e the next sowing, the richest grass can again be cut. 
 AVhen it is in grain, it brings no grass in addition. It lasts thirty years, 
 but when too thick it stifles the land like siguinum [old cement of terras, 
 gj^psum, &c.]. The dove-coloured the Gauls call by their name of Egleco- 
 pala. It is gotten out in clods like stones, biit by exposure to sun and frost 
 it separates into very thin laminoe. This is equally rich. The sandy is 
 used in default of otlier kinds ; in wet, oozy [ttUginosis] places, however, it 
 is used even when others can be had. The Ubii are the only people Ave 
 know, who when they cultivate very rich land, manure it by digging up the 
 earth more than three feet deep and spreading it on to a foot's thickness 
 [quacunque terra infra ires pedes effossa, et pedali crassiludine injecia Iceliji- 
 cetit]. But it does good for not more than ten years. 
 
 " The Edui and Pictoues* made their fields very rich with lime [cff/a-] 
 which likewise is found of the greatest benefit to both olives and vines. 
 All marl [?narga] must be put on ploughed land ; so that its fertilizing pro- 
 perties may be quickly absorbed ; and that which at first is too liarsh 
 l_aspera] and does not at once produce an abundance of herbage [qua in 
 hcrbas non effundilur], requires a small amount of dung, or else by its fresli- 
 ness [novitate] it injures the soil, and is not fertilizing till after the first 
 year. It is also important to note the kind of soil on which it is to be put 
 A dry marl, whether the chalk [ereta'] or the dove-coloured [columbina,'] is 
 best adapted to a moist soil, and an unctuous marl (pinguis) to an arid soil, 
 the one quality serving to temper the other." 
 
 ■" The Edui and Pictones were the ancient Gaulish inhabitants of the 
 modern Autoa and Poictiers, respectively, of Prance. — London Quarterly 
 Review. 
 
NOTE III. 
 
 THE EARLIEST KNOWN SUCCESSFUL APPLICATIONS OF FOSSIL 
 SHELLS AS MANURE. 
 
 The two old experiments described at pp. 114-15, though the only 
 applications of fossil shells known to me previous to the commence- 
 ment of my use of this manure, were not all that had been made, 
 and, whicli being deemed failures, had been abandoned and forgot- 
 ten. Another, within a few miles of my residence, was brought to 
 light and notice afterwards, by an old negro, who was perhaps tho 
 only person then living who had any knowledge of the facts. After 
 I had'^found enough success in using this manure to attract to it 
 some attention, Mr. Thomas Cocke of Aberdeen, was one of those 
 who began, but still with doubt and hesitation, to use marl to some 
 considerable extent. One of his early applications was to his gar- 
 den. The old gardener opposed this, and told his master that he 
 knew "the stuff was good for nothing, because, when he was a boy, 
 his old master (Mr. Cocke's father) had used some at Bonaccord, 
 and it had never done the least good." Being asked whether he 
 could show the spot where this trial had been made, he answered 
 that he could easily, as he drove the cart which carried out the 
 marl. The place was immediately sought. It was on the most 
 elevated part of a very poor field, which had been cleared and ex- 
 hausted fully a century before. The marled space (a sciuare of 
 about half an acre), though still poor, was at least twice as produc- 
 tive as the surrounding land, though a slight manuring from the 
 fai*m-yard had been applied a few years before to the surrounding 
 land, and omitted on this spot, which was supposed, from its 
 appearance, to have been the site of some former dwelling-house 
 and yard, of which every trace had disappeared except the perma- 
 nent improvement of the soil usual from that cause. A close 
 examination showed some fragments of the hardest shells remaining, 
 so as to prove that the old man had not mistaken the spot. This, 
 like other early applications, had been made on ground too poor for 
 the marl to show but very sliglit early efiect; and as only one kind 
 of operation of any manure was then thought of (that which dung 
 produces), it is not strange that both the master and servant should 
 have agreed in the opinion that the application was useless, and 
 that all persons who knew of the application remained under that 
 opinion until almost all remembrance of the experiment had been lost. 
 
 Since the printing of the previous pages in which references were 
 made to the earliest application of marl in Virginia, I have obtained 
 some further information thereupon, which, however imperfect, 
 may yet be interesting. In a recent conversation (1842) with 
 William Short, Esq., now of Philadelphia, the son of Major Wil- 
 liam Short who made the experiment, ho told me that he well re- 
 
 (403) 
 
404 EARLY TRIALS OF MARL. 
 
 collected when his father's first and accidental discovery of marl 
 •was made on the Spring Garden farm in Surry (in digging a ditch 
 across a wet swamp), and his sanguine and confident anticipations 
 of deriving from its use great improvement and profit. Mr. Short 
 further stated that he was then so young, and always so little 
 acquainted with agriculture, that he did not know what were the 
 precise focts in regard to the failure of his father's experiment and 
 hopes ; but he well remembers that the result was deemed an entire 
 failure, and that it caused total disappointment. 
 
 Such a conclusion I had supposed before being so informed. I 
 had also inferred, and no doubt correctly, that the supposed failure 
 and truly slight benefit, and the mistaken deductions from the 
 results, were such as have been stated. I have since written to 
 the present proprietor of the land, Francis Ruffin, Esq., to obtain 
 the latest information concerning the results of this application, 
 now some sixty-five years old ; and the most recent effects, as 
 learned from him, will be here stated in connexion with the earlier, 
 which will be repeated. 
 
 It was before said (page 114) that this old marling (of about 10 
 acres) was done on poor sandy land, kept (as was the then univer- 
 sal course of tillage) under exhausting culture and close grazing 
 for many years thereafter; that from 1812 the treatment had been 
 lenient; and that in 1819, the superiority of the marled part was 
 visible, and that part of the outline could be then distinctly traced. 
 In 1884, Mr. F. Rufl&n applied to this and some acres of adjoining 
 land, pine leaves at the rate of 75 one-horse cart-loads to the acre, 
 ^'he benefit from this vegetable cover was so much greater on the 
 marled part, that the superior growth of the next crop of corn and 
 of the succeeding crop of wheat, '' marked out the limits of the old 
 marling very conspicuously." The whole was sown in clover in 
 the spring while under wheat; that on the marled part lived and 
 stood pretty well, while nearly every plant of clover on the part 
 not marled died in the course of the year. In 1837, the whole 
 field was marled, without excepting the old marled part; and the 
 whole was again littered with pine leaves. The crops of corn and 
 wheat since have shown less improvement from these applications 
 on the piece thus re-marlcd, than on the adjoining land then marled 
 for the first time. Indeed, the recent and additional increase of 
 corn and wheat, since re-marling, has been very little. These re- 
 sults, early and late, are precisely such as might have been antici- 
 pated from the action of calcareous manures, and the condition of 
 this land and its management. 
 
 Another experiment of marling, made earlier than my first, by 
 ]\Ir. Richard Hill, in King William county, has been heard of 
 since the publication of the last edition, and of which the circum- 
 stances were given at length at pages 22 and 27 of vol. ix. Far- 
 
EARLY TRIALS OP MARL, 405 
 
 mers' Eegistcr, to whicli the reader is referred. It is enough here 
 to state, that the effects were beneficial at first; but so injurious 
 (because of the excessive quantity) on several succeeding crops, 
 that this trial also was deemed a failure, and the marling a source 
 of loss; and there was no repetition of marling in that neighbour- 
 hood until about 1820, when other and better views began there to 
 be first entertained. 
 
 There was also successful and continued use of this manure in 
 James City county, in Virginia, made earlier than mine ; and still 
 earlier by Mr. John Singleton, in Talbot county, Maryland. 
 It appears that the early (though chance-directed) combination of 
 putrescent manures with marl, in both these places, served to prove 
 the value of the latter, and perhaps to prevent it being there also 
 abandoned as worthless, as in the other cases. But though the 
 application was continued, and with great success and profit, the 
 knowledge of these facts and the example extended very slowly ; 
 and the then want of communication among farmers kept all igno- 
 rant of these practices for years, except in the immediate vicinity 
 of the commencement of each. I have since endeavoured to ascer- 
 tain the time of the first applications in James City, and have been 
 informed that it was in 1816. Mr. Singleton's, in Maryland, were 
 begun as early as 1805. His own account of his practice (which 
 will be annexed, as an interesting statement of the earliest profitable 
 use of this manure), was first published in 1818, in the 4th volume 
 of the Memoirs of the Philadelphia Agricultural Society (page 238). 
 The date of his letter is Dec. 31, 1817. My fii'st experiment was 
 made the following mouth (Jan. 1818), but more than a year before 
 I met with Mr. Singleton's publication, or had heard of any appli- 
 cation of fossil shells, except the two failures mentioned in page 115. 
 But, however beneficial may have been found the operation of marl 
 in Talbot and in James City, it is evident, from Mr. Singleton's 
 letter, and from all other sources of information, that the mode of 
 operation remained altogether unsuspected by those who used it; 
 and this was perhaps the principal cause why the practice was so 
 slow in spreading. It is now [1835] thirty years since the first 
 proofs were exhibited on the land of Mr. Singleton ; yet, according 
 to the report of the geological survey of the lower part of Maryland 
 (submitted to the legislature of Maryland at its recent session of 
 1834-5), it appears, though the value of marl is well understood, 
 and much use of it made in Talbot county, and part of Queen Ann's 
 county, yet that almost no use has been made of it on the other and 
 much more extensive parts of the Eastern Shore of Maryland — and 
 none whatever west of the Chesapeake in that state, where it is 
 found in abundance. Such at least are the inferences from Dr. 
 Ducatel's report, though in part drawn from indirect testimony, 
 more than direct and particular assertions. 
 
406 MR. singleton's marling. 
 
 The slight, and almost contemptuous manner, in which marl ig 
 mentioned by so well informed an agriculturist as Taylor, as late 
 as 1814, when his Arator was published (and which remained un- 
 altered in his 3d edition of 1817), proves that almost nothing was 
 then known of the value of this manure. All that seems to relate 
 to our abundant deposits of fossil shells, or to marl generally, ia 
 contained in the two following passages : — 
 
 " Without new accessions of vegetable matter, successive heavy dress- 
 ings with lime, gypsum, and even mai-1, have been frequently found to 
 terminate in impoverishment. Hence it is inferred, that minerals operate 
 as an excitement only to the manure furnished by the atmosphere. From 
 this fact results the impossibility of renovating an exhausted soil, by re- 
 sorting to fossils, which will expel the poor remnant of life ; and indeed 
 it is hardly probable that divine trisdom has lodged in the boiccls of the 
 earth the manure necessary for its surface." — Arator, p. 52, 2d edition, ]3alti- 
 more. 
 
 " Of lime and marl we have an abundance, but experience does not enti- 
 tle me to say anything of either." — Id. p. 80. 
 
 From John Singleton to the Hon. Wni. TUghman. 
 
 " Your fii-st question is, 'Avhether what I use be marl, or soil mixed with 
 shells ?' 
 
 "Whether it be marl or not, I will not pretend to determine, as I have 
 seen no description of marl that answers exactly to it ; but Mr. Tench 
 Tilghman informed me he had seen a description of marl used in Scotland, 
 exactly similar to what I use on the farm on which I reside, and which is 
 the improved land you mention. I have not seen the account myself. 
 However, this, and all mixtures of broken marine shells, of which there is 
 a great variety, are now denominated marl, here. What I consider the 
 best, and which I most use, is composed of small parts of marine shells, 
 chiefly scallop shell, about one-eighth of an inch square, or somewhat 
 longer or smaller, with scarce any sand or soil with it: some of it seems to 
 be petrified, and is dug up in lumps, like stone, from four or five, to forty 
 or fifty pounds in weight, hard to break even with the eye of an axe, and 
 will remain for years, tumbled about with the plough, before it is entirely 
 broken to pieces, and mixed with the soil ; indeed you may observe it in 
 some parts of the bank, where the soil has been washed from it, appearing 
 like rock stone ; but if broken and pulverized a little, it effervesces very 
 much with acids. * * * * * * 
 
 " I have applied it to all the soils on my farm, some of which is a cold 
 white clay, and wet ; others a light loam, and sandy. I find it useful to 
 each kind, and manure my land all over with it, without distinction, and to 
 advantage ; putting a smaller quantity upon the looser soils. I have applied 
 it as a top dressing on clover, and also where clover has not been sown, 
 with a view to improving the grass, and also to be satisfied whether it 
 would not be Ijest for the ground, to let it lie spread on the surface, for a 
 year before the ground was put into cultivation. But it has not answered 
 my expectation. I could not perceive any advantage from that mode of 
 application. I now constantly apply it to the ground cultivated in corn ; 
 carting it out in the winter and spring, and putting on from tAvcnty to forty 
 cart-loada per acre, according to the ground, and the 2:)revious quantity 
 
MR. singleton's MARLING. 407 
 
 that had been put on, in former cultivations, dividing each load into from 
 four to eight small heaps, for the greater ease in spreading, according to 
 the size of the load. Some is put on before, and some after the ground is 
 broken up, but it is all worked into the soil by the cultivation of the corn, 
 and it never fails of considerably improving the crop of corn, as also the 
 ground wherever the marl is, especially in largest quantity. There is a 
 small greeu moss, and black moist appearance, on the surface of the ground, 
 when not cultivated; as you perceive about old walls, and in strong ground. 
 Though the preceding is the commofl^mode in which I use the marl, I do 
 not think it the best ; I mix some in my farm-yard, with the farm-yard and 
 stable manure ; and would prefer mixing and applying all that I use thus 
 mixed, but for the labour of double cartage which I cannot as yet accom- 
 plish, manuring so largely as I do. I cultivate one hundred acres yearly, 
 and constantly manure the whole of what I cultivate ; employing only four 
 carts, and four hands with the carts, which do all the manuring and cart- 
 ing on the farm. 
 
 " Your next question is, ' what has been my rotation of crops, and mode 
 of cultivating, since I have used this manure ?' 
 
 " Since I began to use the marl, and bend my attention to improvement 
 by manure, I have cultivated only corn and wheat, sowing my ground in 
 clover, and using the plaster. Instead of cultivating all my ground in corn, 
 and sowing wheat on it as heretofore, I divided my cultivation into two 
 parts, of fifty acres each, putting one part into corn, which I was able to 
 accomplish manuring time enough for the corn, and making a fallow of the 
 other part, manuring as much of it as I could accomplish before the time 
 for sowing wheat; and disregarding, in a degree, all smaller crops, which 
 I could not attend to, as an object, without increasing my number of hands, 
 and interfei'ing with the main business. I went on in this manner, till I 
 found I could easily accomplish manuring one hundred acres and upwards, 
 per annum. Having got my ground to that state that I can risk making a 
 crop without manure, I am now about discarding fallow, being able to 
 manure my whole hundred acres time enough for cropping in the spring, 
 by beginning to manure for the next year as soon as the spring manuring 
 is finished. I shall in future have no wheat in fallow, but sow it after corn 
 and other crops, from which I am satisfied I can make more from my 
 ground than by naked fallow, which I always considered unprofitable, 
 though you made more wheat, except for the advantage of having more 
 time to manure. * * * * * 
 
 " In saving my com crop, I cut it up without pulling it from the stalk 
 as usual, and cart it in all together, then husk it out, leaving the husk to 
 the stalk : I lay these near my feeding yard, and throw them into it twice a 
 day : this gives us a large quantity of strong healthy food for the cattle, 
 which serves them all winter, and keeps them in good condition without 
 any other food ; makes a large quantity of excellent manure, and a fine dry 
 feeding yard. As opportunity can be found, we cart marl, fuller's earth, 
 clay, and any good soil that is convenient, into this yard, which being 
 mixed with the stalks, and straw, or anything else, penning the cattle on it 
 through the winter and summer, instead of penning on the field, in the 
 common way, we have a large quantity of manure to go out in the fall, and 
 next winter ; it is put into the field, in the intermediate rows, between the 
 rows of marl, as far as it will go, and they will get mixed in the cultiva- 
 tion. We also convert the scouring of our ditches, the head-lands of the 
 fields, and all waste-ground that we can, into manure, by carting litter, 
 from the woods, yard manure, or litter, &c., and mixing with them; so 
 that I can nearly, or quite, now, accomplish making farm-yard and this 
 
40S MR. singleton's marling. 
 
 kind of manure, Rufficient to go over my whole hundred acres annually. 
 For the hist two years, I have made more manure than I could accompliah 
 or effect carrying out, though I have manured from ten to twenty acres 
 more than my hundred, each year, with part marl and part farm-3'ard, but 
 not the whole with both, as I hope to be able to do in future; but it will 
 be necessary to increase my carting force to effect it, and I clearly sec I 
 can raise suQicient manure for the purjjose ; heretofore I have manured my 
 coi'n ground, fifty acres, with marl, and my fallow with part farm-yard 
 manure, and part marl, as mentioned before ; so that you will perceive the 
 improvement made on vay soil has not been effected by marl alone, but in 
 conjunction with farm-yard manure, clover, and plaster, and by making it a 
 point to manure with something all the ground I put into cultivation; so 
 that every time I cultivated a field, that field was imjirovcd, and not in any 
 degree impoverished by the cultivation. By this means, and the Divine as- 
 sistance, I have effected that improvement of my farm, which is so very 
 striking to the observation of every person acquainted with it. * * •>^ 
 "In August, 1805, in digging down a bank on the side of a cove, for the 
 purpose of making a causeway, I observed a shelly appearance, which it 
 struck me might improve clay soil ; 1 took some of it immediately to the 
 house, and putting it into a glass, with vinegar, found it effervesced very 
 much ; this determined me to try it as a manure ; accordingly, in Septem- 
 ber, I carted out about eighty cart-loads, and j)ut it on a piece of ground, 
 fallow, preparing for wheat, trying it in different proportions, at the rate 
 of from twenty-seven to about a hundred loads per acre, and the ground 
 was sown in wheat. I could not, myself, be satisfied that there was any 
 difference through the winter and spring, although General Lloyd, who 
 was viewing it with me in the spring, thought he could perceive some dif- 
 ference in favour of the marl ; but at harvest time, the wheat, tliough not 
 more luxuriant in growth, or better head, was considerably thicker on the 
 ground; and after the wheat was taken off, the ground where the mai-1 had 
 been put was set with white clover, no clover being on the ground on 
 either side of it. The nest year, 1806, I discovered it in the drain into 
 the head of the cove, which I immediately ditched, and from the ditch put 
 out seven hundred loads, on the fallow ground. The effect, as to the wheat 
 and clover, was the same (this was put, for experiment, at the rate of from 
 forty to a hundred and twenty cart-loads per acre), though the marl was 
 not of the same kind as the other, but more mixed with sand and surface 
 soil, being taken from the low ground, by ditching, and all mixed together. 
 I also tried it on corn ground, spread out as above mentioned, and found 
 the effect immediate, as to the corn; and in the same manner as above 
 described, as to the wheat sown on the corn ground. This induced me to 
 persevere in the use of it, which I have done ever since, adopting the mode 
 I mentioned before, and putting it at first from forty to seventy loads per 
 acre, till 1 have now come down as low as eighteen or twenty loads per acre, 
 going the third time over the ground yfith it." * * * * 
 
NOTE IV. 
 
 FIRST VIEWS WHICH LED TO MARLING IN PRINCE GEORGE COUNTY. 
 [From the Farmers' Register, Nov. 1839, with additions.) 
 
 Among the persons who have read with interest the " Essay on 
 Calcareous Manures," and have received as sound the novel theory 
 and doctrines there maintained, several have expressed their curi- 
 osity which had been excited to learn the earliest facts, or the train 
 of reasoning, which led to the suggestion of the causes of the de- 
 fect of naturally barren soils, and the remedy. Such inquiries 
 have been made of the writer by persons of investigating and well 
 informed minds, but of very different education and pui'suits; and 
 they were pleased to say, in regard to the concise verbal answers 
 made to their inquiries, that they deemed the details likely to be 
 interesting to many, and that if given to the public, they might 
 serve better to induce the consideration and enforcement of the 
 doctrines, than had been done by the mere arguments which had 
 been already published, convincing as they considered these argu- 
 ments to be. 
 
 Though, without these reasons and solicitations, the writer might 
 have still refrained from touching this subject, it was not that he 
 had not held the same opinion, and, except in his own case, would 
 have urged the same course. It- is certain, that the tracing of the 
 steps by which any new discovery or improvement has been reached, 
 must always be interesting in proportion to the admitted importance 
 of the results; and, indeed, such a statement seems almost pecessary 
 to induce the r^der to accompany the author from his first premises 
 to the remote conclusion, and which otherwise is only reached 
 through a devious and tedious passage, and by a course of reason- 
 ing which is wanting in interest, because the application and 
 tendency of the arguments and proofs are not seen when they are 
 first presented. The objection which restrained the writer from 
 before pursuing a course which he would have highly approved in 
 others, was, that such a narrative of opinions and facts would be 
 entirely a personal narrative, and therefore obnoxious to the charge 
 of egotism throughout. The statement of the reasoning which led 
 to the successful use of fossil shells on the poor lands of lower 
 Virginia, would be incomplete if not accompanied by a narrative 
 of early labours, and the early as well as latest results and effects. 
 lu the whole of this, there would be scarcely anything but state- 
 ments of what the writer thought, and reasoned, and performed. 
 But the subject must be so treated, or not at all; and having con- 
 sented to give the narrative, the writer will throw aside all scruples 
 and objections, and endeavour to enter as much into detail, as he, 
 if a reader of others' agricultural improvements and practical ope- 
 rations, would desire there to find. 
 
 35 ^ (409) 
 
410 THE AUTIIOU'a EARLY VIEWS . 
 
 With the begianing of the year 1813, when barely nineteen years 
 of age, the easy indulgence of my guardian gave to me the posses- 
 sion and direction of my property ; which consisted of the Coggins 
 Point farm, with the necessary and yet very insufficient stock of 
 every kind. It is scarcely necessary to add that, at my very early 
 commencement, I was totally ignorant of practical agiiculture ; 
 and such would have been the case, according to the then and now 
 usual want of training of farmers of Virginia, even if my farming 
 labours had been postponed to a mature age. But I had always 
 been fond of reading for amusement, and the few books on agri- 
 culture (then very scarce in this eountjy) which I had met with, 
 had been studied, merely for the pleasure they afforded, at a still 
 earlier time of my boyhood. The earliest known of these works 
 was an English book, in four volumes, the " Complete Body of 
 Husbandry," of which I have not seen the only known copy since 
 I was fifteen years old. This work was probably a mere compila- 
 tion, and of little value or authority ; but it gave me a fondness 
 for agricultural studies, and filled my head with notions which were, 
 even if proper in England, totally unsuitable to this country. 
 '' Bordley's Husbandry" next fell into my hands, and its contents 
 were as greedily devoured. This was indeed written in America, 
 and by an American cultivator; but as he drew almost all his 
 notions from English writers, his work is essentially also of foreign 
 materials. 
 
 Thus prepared, I commenced farming, ignorant indeed, but not 
 in my own conceit. The agriculture of my neighbourhood, like 
 all that I had ever witnessed, was wretched in execution, and as 
 erroneous -as well could be in system, whether subjected to the test 
 of sound doctrine, or the improper notions which I had formed from 
 English writers. I was right in condemning the general practice 
 of my neighbours; but decidedly mistaken in my self-satisfied 
 estimate of my own better information and plans. 
 ■ Just about the time that my business as a cultivator was com- 
 menced, Col. John Taylor's "Arator" was published; and never 
 has any book on agriculture been received with so much enthusiastic 
 applause, nor has any other had such wide-sjjread early effects in 
 affecting opinion, and stimulating to exertion and attempts for im- 
 provement. The ground had before no occupant, and therefore 
 this work had to contend with no rival. The larger land-owners, 
 of lower Virginia especially, had previously treated their own pro- 
 per employment, and their only source of income, with total 
 neglect; and very few country gentlemen took any personal and 
 regular direction of their farming operations. It was considered 
 enough for them to hire overseers (and that class then was greatly 
 inferior in grade and respectability to what it is now), and to leave 
 the daily superintendence to them entirely. The agricultural 
 
AND FARMING EBRORS. 411 
 
 practices, and also the products, were consequent!}^, and almost 
 . universally, at a very low ebb. The work of Taylor appeared 
 when these evils had become manifest; and it was received with a 
 welcome which in warmth was proportioned to the magnitude of 
 the evil, and to the exaggeration of the promises of speedy and 
 effectual remedy which the author made, with entire good faith no 
 doubt, but which were proved, by results, to be anything but cor- 
 rect to the great majority of his sanguine followers. 
 
 Of course, I was among the most enthusiastic admirers of " Ara- 
 tor,-" and not only received as sound and true every opinion and 
 precept, but even went beyond the author's intention (perhaps), 
 and applied his rules for tillage to lands of surface and soil alto- 
 gether different from the level and originally rich sandy soils of the 
 Rappahannock, where his labours and system had been so success- 
 ful. However, this error was by no means confined to ^myself ; 
 for his other disciples fully as much misunderstood the directions, 
 and misapplied the practices. 
 
 It was my main object to enrich my then very poor land; 
 and, for that, Taylor offered means that seemed to be sure and 
 speedy. According to his views, it was only necessary to protect 
 the arable land from all grazing, and thus let the vegetable cover 
 of the land, when resting, serve as manure — to plough deep, and 
 in ridges — to convert all the corn-stalks and other offal to manure, 
 and plough it under, unrotted, for the corn — to put the f;irm under 
 clover as fast as manured — and the desired result would be sure. 
 I hoped at first to be able to manure, say 10 or 12 acres a 'year very 
 heavily, with the barn-yard manure, and expected that such ma- 
 nuring would give a crop of 50 bushels of corn to the acre. The 
 space, so enriched, when in the succeeding crop of wheat, would 
 be put under clover — and its acquired productiveness be made 
 permanent, by the lenient rotation of two crops only taken from 
 the land in four years. But utter disappointment followed. The 
 manure was put on the poorest (and naturally poor) laud ; and it 
 produced very little of the expected effect in the first course of 
 crops, and was scarcely to be perceived on the second. Clover 
 could not be made to live on land of this kind ; and even on much 
 better, or where more enriched, it was a very precarious crop, and 
 which, where the growth was best, was certain to yield the entire 
 occupancy of the ground to natural weeds after one year. The 
 general non-grazing of the fields under grass, or rather under 
 weeds, produced no visible enriching efi"ect, and the ploughing of 
 billy land (as mine mostly was) into ridges, caused the most de- 
 structive washing away of the soil by heavy rains. These results 
 were not speedily made manifest; and before being convinced of 
 their certainty, I had labour-ed for four or five years in using these 
 means of supposed improvement of the soil, but all of which 
 
412 FORMER CONDITION OF LAND. 
 
 proYcd either profitless, entirely useless, or absolutely and in some 
 cases greatly injurious. And even after trying to avoid the fii'st . 
 known errors, and using all other supposed means for giving dura- 
 ble and increasing fertility to my worn and poor fields, at the end 
 of six years, instead of having already achieved great improve- 
 ment, I was compelled to confess that no part of my poor land was 
 more productive than when my labours commenced, and that on 
 much of it, a ten-fold increase had been made of the previously 
 large space of galled and gullied hill-sides and slopes. 
 
 When more correct opinions had been formed in after-time of the 
 actual condition and requirements of such poor soils, it seemed an 
 astonishing delusion, which would have been altogether ludicrous 
 but for its serious effects, that I should have counted so much on 
 improving such a soil, and by such means. With the exception 
 of a small part near the river banks (perhaps one-fifth of the then 
 cleared and cultivated land), which had been originally of very fine 
 quality, and, however abused and exhausted, was still good land, 
 the fiirm generally consisted of a soil of sandy loam, usually about 
 three inches deep, and through which a single-horse plough could 
 easily penetrate and turu up the barren and more sandy yellow 
 sub-soil. Grazing the fields, when not under tillage, had been the 
 regular practice ; and under it very little growth was to be seen 
 except the light and diminutive " hen's nest grass" (aristida gra- 
 cilis), which formed the almost universal cover of the poor fields 
 of lower Virginia, in the intervals between tillage. Add to these 
 circumstances of very poor and shallow soil, and barren and sandy 
 sub-soil, and almost no vegetable cover to turn under, that every 
 field was more or less hilly, and liable to be washed by heavy rains 
 — and the judicious reader will see nothing but false confidence 
 and ignorance displayed in my bold adoption of Taylor's system. 
 Nor was I convinced of my error until after nearly all the fields 
 bad been successively thrown into ridges by two-horse ploughs, and 
 all the hilly and more slightly inclined surface had been awfully 
 washed and gullied, by the exposure of the loose sub-soil to the 
 action of the streams of rain-water. 
 
 While these my supposed measures of improvement were in pro- 
 gress, I was in habits of frequent and familiar intercourse with my 
 oldest and best friend, and former guardian, Thomas Cocke, who 
 resided then on his Aberdeen farm, and since and now, on Tarbay, 
 adjoining my own land. My friend was a man for whose mind and 
 mental cultivation I could not but entertain a very high estimation. 
 But, though all his life a practical and assiduous cultivator, and 
 finding his greatest pleasure in his farming labours, he yet was a 
 careless, slovenly, and bad manager, and of course an unprofitable 
 farmer. Therefore, on this subject, I held in but light esteem the 
 opinions which he maintained, which were opposed to my own. 
 
Taylor's and davy's doctrines. 413 
 
 One of these (and which he had first gathered from some okl and 
 ignorant, but experienced practical cultivators of his neighbour- 
 hood), was the opinion that our land which was naturally poor 
 could not "hold manure," to any extent or profit, and therefore 
 could not be enriched. For years I heard this opinion frequently 
 expressed by him, and the evident inference therefrom, that the 
 far greater part of our lands, and of the whole country, was doomed 
 to hopeless sterility; and as often as heard, I rejected it as a 
 monstrous agricultural heresy — as treason, indeed, to the authority 
 of Taylor, and of every other author on agriculture whom I had 
 read or heard of. But at last I was compelled, most reluctantly, 
 to concur in this opinion. 
 
 What was then to be done ? I could not bear the idea of pur- 
 suing the general system of the country in continuing to lessen the 
 already small productiveness of my fields, by their course of culti- 
 vation. The whole income, and more, was requii-ed for the most 
 economical support of a then small but fast growing family ; and 
 for any increase of income or net profit, there was no hope, save 
 in the universal approved resort in all such cases, of emigrating 
 to the rich western wilderness. And accordingly such became my 
 intention, fully considered and decided upon, and which was only 
 prevented being carried into efi'ect by subsequent occurrences. 
 
 Just before this time Davy's "Agricultural Chemistry" had been 
 first published in this country ; and I read it with delight, notwith- 
 standing my then total ignorance of chemical science, and even of 
 chemical names, except as learned by that perusal. There was one 
 passage of this author which seemed to afford both light and hope 
 on the point in which disappointment had led me to despair. As 
 an illustration of defects in the chemical constitution of soils, and 
 of the remedies which proper investigation might point out, he 
 adduced the fact of a soil " of good apparent texture," which was 
 sterile, and seemed incapable of being enriched. The fact which 
 struck so forcibly on my mind was presented in the following con- 
 cise passage of Lect. iv. " If on washing [for analyzing] a sterile 
 soil, it is found to contain the salt of iron, or any acid matter, it 
 may be ameliorated by the application of quick-lime. A soil of 
 good apparent texture from Lincolnshire, was put into my hands 
 by Sir Joseph Banks as remarkable for sterility. On examining 
 it, I found that it contained sulphate of iron ; and I oftered the 
 obvious remedy of top-dressing with lime, which converts the sul- 
 phate into a manure." 
 
 Much the greater part of my land, and of all the land of lower 
 Virginia, seemed to me just such as Davy described in this single 
 and peculiar soil. It was certainly of " good apparent texture," 
 tliat is, it was neither much too clayey or too sandy, nor had it any 
 other apparent defect to forbid its being fertile ia a very high 
 35* 
 
414 SALTS OF IRON IN SOIL. 
 
 degree. Yet it was and always had been sterile, and, as my ex- 
 perience now concurred with that of my older friend in showings it 
 could not be either durably or profitably enriched by putrescent 
 manures. Could it be possible that the sulphate of iron (copperas) 
 which Davy found in this soil, and which he evidently spoke of as 
 a rare example of peculiar constitution, could exist in nineteen- 
 twentieths of all the lands of lower Virginia ? This could scarcely 
 be ; and yet, in despair of finding other causes, I set about search- 
 ing for this one. 
 
 It was not difficult, even for a reader so little instructed in 
 chemistry, to apply the test for copperas. It was only necessary 
 to let a specimen of the suspected soil remain soaking in pure 
 water, until any copperas, if present, would be dissolved ; then to 
 separate the fluid by pouring off and filtration, and then to add to 
 the fluid some of the infusion of nut-galls. If copperas had been 
 held in solution, the mixture would produce a true ink, of which 
 the smallest proportion would be made visible in the before per- 
 fectly transparent water. But all these first f^ttempts were fruit- 
 less, and I was obliged to conclude that the great defect, or impedi- 
 ment to improvement, in most of our soils, was not the presence 
 of the salts of iron. But though not a salt, of which one of the 
 component parts was an acid, might not the poisonous cjmdity be a 
 pure or uncomhined acid .^ This question was raised in my mind, 
 and the readiness produced to suppose the affirmative to be true, by 
 several circumstances. These were, 1st. That certain plants known 
 to contain acid, as sheep-sorrel and pine, preferred these soils, and 
 indeed were almost confiuod to them, and grew there with luxuri- 
 ance and vigour proportioned to the unfitness of the land for pro- 
 ducing cultivated crops. 2d. That of all the soils supposed to be 
 acid which I examined by chemical tests, not one contained any 
 calcareous earth.* 3d. That the small proportion of my land, and 
 of all within the range of my observation, which was slidlij, and of 
 course calcareous, was entirely free from pine and sorrel, and more- 
 over was as remarkable for great and lasting fertility, as the lauds 
 supposed to be acid for the reverse qualities. Shells, or lime, 
 would necessarily combine with, and destroy, all the previous pro- 
 perties of any acid placed in contact; and therefore, if acid were 
 present universally, and acting as a poison to cultivated plants, it 
 seemed plain enough why the shelly lands were free from this bad 
 
 * I was not then aware of the important and novel fact which I after- 
 wards ascertained and established, and Avhjch is now fully received (with 
 very slight acknowledgment of its source) by the geologists of this country, 
 ihaXalinost all the soils on the Atlantic slope of this country, and even including 
 nearly all limestone soils, are also entirely destitute of carbonate of lime, 
 tlioiigli that ingredient seems nearly if not quite universal in all the best 
 soils of England and the continent of Europe. 
 
SUPPOSITION OF ACID IN SOIL. 415 
 
 quality, and by its absence bad been permitted to grow ricb, and to 
 continue productive. Every new observation served to add strength 
 to this notion ; and in our tide-water region generally, and even in 
 my own neighbourhood, there were plenty of subjects for observa- 
 tion and comparison, both in small shelly and fertile spots, and a 
 vast extent of poor pine and sorrel-producing lands. Still, I could 
 obtain no direct evidence of the presence of acid, either free or 
 combined, by applying chemical tests to soils (as was tried in many 
 cases), nor was there any authority in my oracle, Davy's " Agri- 
 cultural Chemistry," nor in any other work which I had read, for 
 supposing vegetable acid to be present in any soil. Though Davy 
 adds to the supposition of the presence of the "salt of iron," "or 
 any acid matter," it is clear from the whole context that he had in 
 view the possible and extremely rare presence of a mineral acid (as 
 the sulphuric), and not vegetable acid, which my views required, 
 and my proofs were afterwards brought to maintain. Sulphuric 
 acid is sometimes found in certain clays, iind in combination with 
 iron is also in peat soils ; but these facts have no application to 
 ordinary soils of any country. Of course, this absence of authority 
 would, to most inquirers, 4iave seemed fatal to the position of an 
 acid principle being generalhj present in the soils of Virginia, and 
 in great quantity and power of injurious action. This was, indeed, a 
 great obstacle opposed to the establishment of my newly formed 
 opinion ; but it was not yielded to as insuperable. Diffident as I 
 then was of any such views of my own, and holding the dicta of 
 Davy as the highest authority, and even his omission of any posi- 
 tion as evidence that it was untrue, or unknown, still I was not 
 daunted, and supposed it possible that the soils of this country 
 might vary essentially in composition, in this respect, from those 
 of England; or hareJi/ possible that even the great chemical philo- 
 sopher might not have observed the presence of vegetable acid in 
 the comparatively few cases of its existence in English soils. The 
 later observations of subsequent years added much to my evidences 
 of the existence of acid in soils ; and still later and scientific inves- 
 tigations of chemists have served to establish that there is an acid 
 principle in most soils, in the Jiumic or geic acid. But these dis- 
 coveries of chemists had not been published in 1817 (if indeed 
 known to any), nor had my own observations reached to all the 
 proofs which I afterwards (in 1832) published in the first edition 
 (in book form) of the " Essay on Calcareous Manures," and which 
 were still in advance of the pu])lication of the now generally re- 
 ceived opinions of the geic or humic acid. It must therefore be 
 confessed, that if I reached a correct conclusion, it was not on suf- 
 ficiently established premises, and known chemical facts. However, 
 reached it was, whether by right or by wrong reasoning ; and how- 
 ever little supported by direct proof or authority, I was almost sure, 
 
41G FIRST EFFORT TO MARL. 
 
 in advance of any known experiment, first, that tlio cause of the 
 nnproductiveness and unfitness for being enriched of most of our 
 lands, was the presence of acid — and secondly, and consequently, 
 that the application of lime, or calcareous earth, would, by taking 
 up and destroying the poisonous principle, leave the soil free to re- 
 ceive and to profit by enriching manures. 
 
 But even if this theoretical position had been demonstrated, still 
 it might furnish no projitahU practical remedy. For, admitting 
 that the application of calcareous matters would relieve the soil of 
 its great evil, and make it capable of receiving subsequent improve- 
 ment, yet after being so relieved, the land, I supposed, would be 
 still as poor as before, and would require all the manure, labour, 
 and time, necessary to enrich any very poor soil; and these might 
 be so expensive, that the improvement of the land would cost more 
 than it would afterwards be worth. These considerations served 
 to lessen my estimation of the practical utility of the theoretical 
 truth, and to make my earliest applications of the theory to practice 
 hesitating, and very limited in extent. 
 
 Having settled that calcareous matter was the medicine to be 
 applied to the diseased or ill constituted soil, I was luckily at no 
 loss to find the materials. In some of the many ravines which 
 passed through my laud, and on sundry parts of the river bank, 
 were exposed some portions of the beds of fossil shells which un- 
 derlie nearly all tlie eastern parts of Virginia and several other 
 southern states ; the deposit which then had obtained in this region, 
 though improperly, and still retains the name of marl. I began 
 operations in February, 1818, at one of the spots most accessible 
 to a cart. The overlying earth was thrown off, and a few feet in 
 width of the marl exposed, in which a pit was sunk to the depth 
 of but three or four feet. When night stopped the very slow dig- 
 ging and throwing out of the marl, the slowly oozing water filled 
 the pit; and as no proper plan of draining had been adopted, the 
 first shallow pit was abandoned, and another opened. In this labo- 
 rious and wasteful manner there was as much marl obtained as I 
 was then willing to apply. It served to give a covering of 125 to 
 200 bushels per acre, to 2i acres of new ground. The wood on 
 the land'had been cut down three years before, and suffered to lie 
 and rot until cleared up for cultivation in 1818. Though poor 
 ridge land, and of what I deemed of the most acid class of soils, 
 still the previous treatment had given to it so much decomposed 
 vegetable matter, that its product would necessarily be made the 
 best which such a soil was capable of bringing. And because of 
 the superabundance of food for plants then ready to act, this was 
 not a good subject to show the earliest and greatest benefit of neu- 
 tralizing the acid. Howevei", notwithstanding this circumstance, 
 and the small amount and poverty of the marl (which contained 
 
FIRST RESULTS OP MARLING. 417 
 
 but one-tliird of calcareous matter), the improvement produced was 
 greater and more speedy in showing than I had dared to hope for. 
 "When the plants were but a few inches' high, and before I had ex- 
 pected to see the slightest improvement (indeed none had been 
 expected to show in the first year), the superiority of the marled 
 corn was manifest, and which continued to increase as the growth 
 advanced. My high gratification can only be appreciated by a 
 schemer and projector; but such a one can well imagine my feel- 
 ings and sympathize in my triumph. The increase of the first 
 crop, corn, I stated by guess, in reporting the experiment, to be 
 fully 40 per cent., and that of the wheat which succeeded was 
 much greater. Later measurements of other products of experi- 
 ments' have induced me to believe that I had underrated the 
 amount of increase in this first application. [This experiment is 
 the first stated, and at length, at page 117 of " Essay on Calcareous 
 Manures," 5th edition. Throughout this republished article, the 
 references to the pages of the " Essay on Calcareous Manures," 
 will be changed from the previous to the present edition.] 
 
 Great as had been the labour of this application, and small as 
 its increased product (comparing both with later operations), the 
 results served completely to sustain my theoretical views, and also 
 showed the remedy for the general evil to be far more quick, and 
 more profitable, than I had counted on. Another person would 
 probably have despised this small increase to the acre, if supposing 
 the elFect to be but temporary; and this all would have inferred, 
 whether judging by comparison with all other manures known in 
 practice, or even if by the authority of books. For the best in- 
 formed of the old writers (even Lord Kames, for example), while 
 claiming for the efi"ect3 of marl great durability, still consider that 
 at some period, say twenty or a hundred years, the effects are to 
 cease. But my views were not limited within any practical expe- 
 rience, or authority, but by my own theory of the action ; and 
 that theory taught me to infer that the benefit gained would never 
 I be lost, and that under proper cultivation, the increase of product 
 would still more increase, instead of being lessened in the course 
 I of time. In thus fully confiding in the permanency of the im- 
 I provement, I was at once convinced of the operation being both 
 I cheap and profitable. All doubt and hesitation were thrown aside, 
 j and I determined to increase my labours in marling to the utmost 
 extent of my views. Still the want of spare labour, and the esta- 
 ^ blished routine of farm operations which occupied all the force, 
 \ retarded my operations so much, that no more than twelve more 
 j acres (for the next year's crop) were marled in that year (1818). 
 j It forms an essential part of the character of an enthusiastic and 
 ') successful projector, and especially an agricultural projector, to be 
 j as anxious to inform others as to profit himself. Of coarse I tried 
 
418 EARLIEST OriNIONS OF SOILS. 
 
 to bestow upon and sliare my lights with all my neighbours and 
 other forjners whom my then humble position and secluded life 
 permitted me to meet. This disposition also caused my earliest 
 attempt at writiug for even so small a portion of the public as con- 
 stituted a little agricultural society of which I had induced the 
 establishment in my neighbourhood. To show my earliest opinions 
 and statements on this subject, I will here quote the material part 
 of a communication made to that society, and which'was written 
 in October of the year of my first experiment in 1818. I copy 
 the extract just as it then stood, and with all its defects of form 
 and of substance. I then shrunk in fear from the greater publicity 
 which the press would have afforded, and had not the remotest 
 anticipation that my first efi"ort, then made, would lead me ^o the 
 extended intercourse since established and maintained with the 
 public, both by writing and printing. 
 
 * * * * " We should be induced to infer from the remarks of 
 those writers who have treated on the improvement of land, that a 
 soil artificially enriched is equally valuable with one which would 
 produce the same amount of crop from its natural fertility ; and 
 that a soil originally good, but impoverished by injudicious cultiva- 
 tion, is no better than if it never had been rich. If this conclusion 
 be just (and the contrary has not been even hinted by them), it is 
 in direct contradiction to the opinion of many intelligent jiractical 
 farmers, with whom my own observations concur, in pronouncing 
 that soils naturally rich (although completely worn out), will sooner 
 recover by rest — can be enriched with less manure — and will longer 
 resist the eifects of the severest course of cropping, than soils of as 
 good apparent texture and constitution, and in similar situations, 
 but poor before they were brought into cultivation. Should the 
 latter opinion be correct, it is of the utmost importance that the 
 subject should be investigated ; as the only conclusion that can be 
 drawn from it is, that such land must have some secret defect in its 
 constitution, some principle adverse to' improvement; and until this 
 is discovered and corrected, it is an almost hopeless undertaking to 
 make a barren country permanently fertile, by means of animal and 
 vegetable manure. 
 
 '' That enclosing'^ has but little effect in improving land naturally 
 barren, is sufliciently proved by poor wood-land. This has had the 
 benefit of enclosing for perhaps thousands of years, and is yet 
 miserably poor. It may be said that leaves are not to be compared 
 in value to grass or weeds ; but surely leaves ought to improve as 
 much in a thousand years, as grass or weeds in twenty. Besides, 
 it is well known, that leaves taken from this very land, and applied 
 elsewhere, have produced much benefit; and the advocates of eu- 
 
 ■^" The iion-grazing system, or manuring land by its own growth. 
 
EARLIEST OPINIONS OF SOILS. 419 
 
 closing must agree witb me in ascribing to this cause tlic natural 
 fortuity of the most valuable [wood] land. 
 
 "As to manuring, there are but few farmers who have not, like 
 me, experienced complete disappointment in endeavouring to im- 
 prove land so little favoured by nature. In the usual method of 
 summer manuring, by movable cow-pens, the most negligent far- 
 mers give the heaviest covering, by suffering their pens to remain 
 stationary sometimes six or eight weeks. I have known the surfiiee 
 in this manner to be covered an inch thick with the richest of ma- 
 nures, and yet, after going through the same course of crops and 
 grazing with the adjoining unmauured land for six years, it could 
 not be distinguished. * ****** 
 
 *^f any one principle should be always found in one kind of 
 soil, and as invariably absent in the other, we might reasonably infer 
 that tliat was the cause of fertility or barrenness. Judging from 
 my very limited observations, it appears evident that calcareous 
 earth constitutes a part of every soil rich in its natural state, and 
 that whenever a soil is entirely or nearly deficient, it never can be- 
 come rich of itself, and if made so by heavy doses of dung, will 
 goon I'elapse into its former sterility. 
 
 " Let us observe how facts coincide with this opinion. The lower 
 part of Virginia is generally poor ; narrow stripes along the rivers 
 and smaller watercourses are nearly all the high lands that are 
 valuable, and in this class, exclusively, shells are seen so frequently, 
 and in such abundance, that it seems highly probable that they are 
 universally present, but so finely divided as not to be visible. 
 AVhen we know the change produced by calcareous earth in the 
 colour and texture of soil, and in a field of an hundred acres, all of 
 the same dark-coloured mellow soil, shells may be seen in only a 
 few detached spots, we cannot but attribute the same eiiects to 
 the same cause, and allow calcareous matter to be present in every 
 part. 
 
 " The durable fertility of land which contains shells in abundance 
 is so wonderful, that I should not dare to describe it, were not the 
 facts supported by the best authority. The calcareous matter for 
 ages has been collecting and fixing in the soil such an immense 
 supply of vegetable matter, that near two centuries of almost con- 
 tinual exhavistion have not materially injured its value. I have 
 seen fields on York, James, and Nansemond rivers, now extremely 
 productive, which are said to have been under cultivation for thirty 
 and forty years, without any aid worthy mentioning, from rest or 
 manure. 
 
 " The same cause operates on low lands, formed by alluvion, and 
 situated on streams accustomed to overflow. Such land is, with 
 very few exceptions, of the first quality; and it is made so by the 
 calcareous matter which the currents must necessarily convey from 
 
420 EARLIEST OPINIONS OF SOILS. 
 
 the strata of marl througli ■whicli they pass; and wliicli being in- 
 timately mised with sand, clay, and vegetable matter, is sufficient 
 to form the finest and deepest soil. All the rich low grounds 
 which I have had an opportunity of observing, have marl on some 
 of tho streams which fall into them, and I have not heard of any 
 on those few which are poor. Not a solitary instance of shells 
 being found in poor land of any description has come to my 
 knowledge. 
 
 " If these premises are correct, no other conclusion can be drawn 
 from them but that a proportion of calcareous earth gives to soil a 
 capacity for improvement which it has not without; and it also 
 follows, that by an application of shell marl, the worst land would 
 be enabled to digest and retain that food, which has hitherto l^en 
 of little or no advantage. * * * ^ * * * 
 
 " The property of fixing manures is not more important in marl, 
 than that of destroying acids. The unproductiveness of our lands 
 arises not so much from the absence of food as the presence of 
 poison. We are so much accustomed to see a luxuriant and rapid 
 growth of pines cover land on which no crop can thrive, that we 
 cannot readily see the impropriety of calling such a soil absolutely 
 barren. 
 
 "From the circumstance of this soil being so congenial to the 
 growth of pine and sorrel (both of which are acid' plants), it seems 
 probable that it abounds in acidity, or acid combinations, which 
 (although destructive to all valuable crops) are their food while 
 living, and product when dead. The most common forest trees are 
 furnishing the earth with poison as liberally as food, while it depends 
 entirely on the presence of the antidote, whether one or the other 
 takes effect. I have observed a very luxuriant growth of sorrel on 
 land too poor to support vegetables of any kind, from green pine 
 brush having been buried to stop gullies ; and it is well known how 
 much land on which pines have rotted is infested with this perni- 
 cious plant. Marl will immediately neutralize the acid, and this 
 noxious principle being removed, the land will then for the first 
 time yield according to its actual capacity. Sorrel will no longer 
 be troublesome; and, by a very heavy covering, I have known a 
 spot rendered incapable of producing it, although the adjoining 
 land was thickly set to the edge. Pines do not thrive on shelly 
 land, whether fertile or exhausted. To this cause I attribute the 
 great and immediate benefit I derived from marl on new ground. 
 The acid produced by the pine leaves is destroyed, and the soil is 
 capable of supporting much heavier crops, without being (as yet) 
 at all richer than it was.'' ******* 
 — Communication to Prince George Agricultural Societi/, 1818. 
 
 Before proceeding to state later experiments, and general prac- 
 
MISTAKEN IDEAS OP MARL. 421 
 
 ticc and results, it Avill be necessary to recur to some oilier con- 
 nected branches of the subject. The reader will pardon the apparent 
 digression. 
 
 80 well established and general has the opinion now become that 
 this marl is a manure, and a most valuable one, that it may seem 
 strange that I should have only arrived at such an opinion indirectly, 
 by the train of reasoning indicated above. There were hundreds of 
 persons who afterwards said, " Oh ! / never doubted that marl was 
 a good manure ;" but not one of whom had been induced before me 
 to try its operation. But passing by these postponing believers, 
 and all others who confessedly never attached any value to this 
 great deposit, it may require explanation why I had not learned its 
 value from English works which treat so extensively on marl, even 
 though I had then had access to but few of them. It was precisely 
 because I had read attentively some of the English accounts of 
 marl that I was deterred from using our marl, which agreed with 
 it (apparently) in nothing but name. Struck with the importance 
 attached to marl in England, I had earnestly desired to find it, and 
 had searched for it in vain, years before the early beginning of my 
 farming. The name induced a close examination of what was 
 called marl here; but the ''soapy feel," the absence of grit, the 
 crumbling and melting of lumps in water, &c., which were the most 
 distinguishing characteristics of the marl of the English writers, 
 were in vain looked for in our shell beds — of which the earth was 
 generally sandy, never " soapy," and of \^hich the lumps were often 
 of almost stony hardness, and if not, at least showed nothing of the 
 melting disposition of the English marls. I had before this found, 
 however, in the American edition of the " Edinburgh Encyclopae- 
 dia," more modern and correct views of marl, and had thereby 
 learned to prize calcareous matter in general as an ingredient of 
 soil, whether natural or artificial. But even admitting that the 
 shelly portion of our marl would slowly decompose, and gradually 
 furnish some manure to the soil, still it seemed that there was little 
 prospect of its operating as the English marl, of such very different 
 texture and qualities. I then supposed that the shells which had 
 resisted decomposition, even where exposed on the surface of the 
 beds, for centuries, would be as slow to dissolve, and to act as ma- 
 nure, if laid upon the fields. Still, notwithstanding these grounds 
 of objection, the general idea of the value of calcareous manures 
 would have induced me earlier to try fossil shells, but for being 
 deterred therefrom by the only actual facts then known of the use. 
 When speaking of my thought of trying marl to my friend Mr. 
 Thomas Cocke, he told me that it was not worth the trouble ; that 
 he (attracted merely by the name of "marl"), had made several 
 email applications, in 1803, on soils of diflerent kinds, and that he 
 had found almost no visible benefit ; and be had attached so little 
 36 
 
422 "euffin's folly." 
 
 importance to the trial, that be had never thought to mention it to 
 me, until induced bj my remark. This communication was enough 
 to check my then slight disposition to try marl. The old experi- 
 ments of Mr. Cocke, as well as some much older, heard of after- 
 wards, and, like his, considered worthless by the makers and almost 
 forgotten, are stated at page 115 of this edition of the "Essay on 
 Calcarc.ous Manures." 
 
 As soon as I was satisfied that I had found in marl a remedy for 
 the general and fixed disease of our poor lands, it became very 
 desirable to know the strength of difterent beds, and of the different 
 parts of the same bed. The rules of Davy for determining the pro- 
 portion of carbonate of lime were easy to apply ; and having pro- 
 vided myself with the necessary tests and other means, I was soon 
 enabled to analyze the specimens with ease and accuracy. This 
 was a delightful and profitable direction of my very small amount 
 of chemical acquirements, and served to stimulate to further study. 
 The amount of my knowledge was indeed very small — and is still 
 so, with all later acquirements added. But little as I had been 
 enabled to learn of chemistry, the possession led me to adopt my 
 views of ]^e constitution of soils, and enabled me to double the 
 product, and to much more than double the clear profit and pecu- 
 niary value of ray land, in the course of a few years thereafter. 
 
 Though my own doubts as to the propriety and profit of marling 
 had been removed by my first experiments, it was not so with my 
 neighbours. Induced by^iy example, small applications were in- 
 deed made by two of them only, in the next year after my first trial. 
 But either because the land had been kept too much exhausted of 
 its vegetable matter by grazing as well as by cropping, or because 
 the experimenters could not think of the operation of the manure 
 as different from that of dung, or stable manure, or for both these 
 reasons, it is certain that they were not encouraged by the results 
 to persevere. They stopped marling with their first trial, until 
 several years after, when both recommenced, then fully convinced 
 of the benefit by my results, and were afterwards among the largest 
 and most successful early marlers. One of these persons was the 
 late Edward Marks, of Old Town, and the other my old friend 
 Thomas Cocke — who, though he had led me to find out the disease, 
 could not himself be speedily convinced of its true nature, or of the 
 value of the remedy. As late indeed as 1822, when he walked 
 with me to an enormous excavation which I was then making in 
 uncovering aud carrying out marl, he said to me, " In future time, 
 if marling shall then have been abandoned as unprofitable, this 
 place will probably be known by the name of < Ruffin's Folly.'" 
 For some years, my marling was a subject for ridicule with some 
 of my neighbours; and this was renewed, when in after-time tho 
 
FIRST EFFECTS AS EXAMPLE. 423 
 
 great damage caused by improper applications began to be seen, and 
 which will be described in due order. 
 
 Having had in view from the beginning the true action of marl, 
 and fully believing that its good effects would be permanent, and 
 even increasing with time under a proper system of tillage, I was 
 no more discouraged by what some deemed small profits, than I 
 was annoyed by the incredulity and ridicule of other persons. Al- 
 most all the farms in the neighbourhood, except mine, were re- 
 gularly and closely grazed when not under a crop, and of course 
 they had not stored up in the soil much either of inert vegetable 
 matter, or its acid product. 3Iine had not been grazed since 1814, 
 and had been rested two years in every four ; and the poorest land 
 three years in four. And though, in truth, no increased production 
 had been obtained by this lenient treatment, inasmuch as the in- 
 crease of acid counterbalanced the increase of vegetable food, still, 
 when marl was applied, the acid was immediately destroyed, and 
 the food left free to act. The effect of marling was generally shown 
 most plainly on the first crop of corn, and the limits could be easily 
 traced by the deep green colour of the plants before they were five 
 inches high ; and the increased product of the first crop on acid 
 soils rarely fell under 50 per cent., was most generally 100, and 
 has been known to be 200 per cent. But even such increase was 
 not satisfiictory to many persons, until the action of marl came to 
 be better understood, and the permanency of the effects was credited. 
 In five or six years after my commencement, there were few if any 
 of those of my neighbours, who had marl visible on their lands, 
 who had not begun to apply it. And though it has been injudi- 
 ciously as well as insufnciently applied since, and not one-fourth 
 of the full benefit obtained, still the general improvement and in- 
 creased products of the marl farms of Prince George have been 
 very great. The existence of marl, too, which was known at first 
 but on a few farms in my own neighbourhood, has been since dis- 
 covered in many other and remote parts of the county ; and wher- 
 ever accessible it is valued and used. The like observations will now 
 apply to most of the other counties of lower Virginia. Wherever 
 the effects of marling could be seen for a few years, the early in- 
 credulity not only disappeared, but most persons were even too 
 read}' to believe in marl's possessing virtues to which it has no claim. 
 Thus, ignorant or careless of its true mode of operation, they crop 
 the marled lands more severely than before ; and if they arc not 
 thereby soon reduced as low as their former state of sterility, they 
 are made to approach it as nearly as possible, and at a sacrifice of 
 nine-tenths of the profit from marling which a more lenient and 
 judicious system of cultivation would have insured. 
 
 In 1819, the second year of my operations, my marling was in- 
 creased to 62 acreS; but most of it at much too thin a rate. In 
 
424 CONTINUED JMAIILING LAUOIjRS. 
 
 1820, only 25 acres were covered, thougli at GOO bushels or even more 
 to the acre. Up to this time I had done as most other persons have, 
 that is, attempted to marl "at leisure times," and without making 
 it a regular employment for a certain additional force, or reducing 
 the amount of cultivation, or of other operations on the farm. No 
 person will ever marl to much advantage who does not avoid this 
 error; and this year's labours showed the necessity of an alteration. 
 The nest year, two horses and carts, with the necessary drivers and 
 pit-men, were appropriated to marlhig at all times when weather 
 permitted, except during harvest, thrashing, and wheat-sowing 
 times. Viewing marling too as the most profitable operation, ex- 
 cept the saving of a crop already made, it was made a fixed rule of 
 the form that marling was to be interrupted for nothing else. My 
 corn shift for that year was reduced in size one-half — so that one- 
 half could be marled while the other was under cultivation. By 
 these means, I marled 80 acres this year, 1821 (and that much too 
 heavily), and had all the lessened corn-field on marled land. The 
 product of the half was equal to what the whole had brought before, 
 and I was enabled thereafter to have every field marled over in 
 advance of its next cultivation. In 1822, the land marled was 93 
 acres, 100 in 1823, and 80 in 1824, which served to cover nearly 
 all of the then cleared land requiring marling. The next three 
 years' marling amounted respectively to 50 acres, 24 acres, and 27 
 acres, being principally upon land subsequently cleared and brought 
 into cultivation. Since then, there has been no marling on the 
 farm, except on wood-land, not yet cleared, and on small spots for- 
 merly omitted, and of which no account was taken. With the 
 exception of such spots (and some such still remain, because of their 
 inconvenient position), all the land which was not naturally calca- 
 reous, or too wet, or too steep for carting on, had been marled by 
 1827 ; and none has required any additional dose, though some of 
 the thinnest covered places had been re-marled long before that time, 
 so as to bring them to a proper constitution. (1842.) 
 
 In 1824, I first observed (and had never before suspected such 
 effect), the injury caused by having marled acid soil too heavily. 
 To show my first impressions, I will copy the words of my farm 
 journal, written on the very day on which the discovery was fully 
 made. 
 
 " June 13th, 1824. Observed a new and alarming disease in a 
 large proportion of my corn ; and, what makes the matter much 
 worse, the evil is certainly caused by marling. The disease seems 
 to have commenced when the corn was from G to 10 inches high, 
 and to have stopped its growth. Its general colour is a pale sickly 
 green, and the leaves appear so thin as to be almost transparent : 
 next, they become streaked with rusty red, and then begin to die at 
 the upper ends. Several pulled up, showed no defect, or injury 
 
DAMAGE TO CROPS BY MARLINO. 425 
 
 from insects, among the roots. All the land marled from pits Nos. 
 7 and 9 (both yellow) from 1820 to 1822, is so much diseased as 
 to promise not more than half a crop. The corn is twice as large 
 as on the spaces left for experiment without marl, yet looks much 
 ■worse ; though three weeks ago its superiority in colour and vigour 
 ■was even more than in size. With but few exceptions, the land 
 newly marled from the same pits, and the old marling from Nos. 1 
 and 8 (both blue), as well as that not marled, are free from this 
 disease. The parts most affected are those which were driest and 
 poorest, and of course were least covered with vegetable matter. 
 Yet though the corn on this old marling is generally so bad, it is^ 
 yet evident that the land is more benefited by the manure than at 
 first. Flourishing stalks of corn, 18 to 24 inches high, are seen fre- 
 quently within a few feet of those most hurt by this disease." 
 
 Subsequently, when the whole extent of injury could be seen, 
 the following remarks were written in the journal, at the date 
 below. 
 
 " October 15th. The damage caused by marl to this crop I sup- 
 pose to be about one-third of what the land would otherwise have 
 made, judging from the present and former measurements of the 
 same land, where experiments were made. 
 
 " Nearly all the heavy marling in Fiunies (at 800 bushels), about 
 20 acres,* suffered by it; the poorest and lightest most injured, 
 here and in Court-House field. The few rich spots escaped, as did 
 most of the piece plastered (on the heavy marling) in 1820. The 
 marks of this expei-iment were destroyed, and the superiority was 
 not so regular as to enable me to trace the outlines of the gypseous 
 earth — but an acre of corn might be taken which certainly was 
 plastered, better than any other acre in the old land. This at least 
 proves that <jyp&um contained [if any] in the marl has not caused 
 the disease. The poor land, lightly marled in 1819, showed but 
 little of the disease, and none was found in the piece not marled, 
 nor in any marled since the last crop [or now first cultivated since 
 being marled.] 
 
 "In Court-House field the injury was confined to 19 acres, the 
 poorest part of the field, which was in corn in 1821, "j' marled and 
 fallowed 1822, and in wheat 1823, corn 1824. The remainder of 
 the old land, which had not been cropped so severely, and was 
 covered as heavily with hlue marl, brought a fine crop, quite free 
 from the disease. The new ground was mostly marled very heavy 
 (800 bushels of 45 per cent.),| and this and all my former clear- 
 ings (some marled equally heavy) were also quite free. These 
 
 * See Exp. 10, p. 132, Essay on Cal. Man. 
 
 t Exp. 11, p. 135. 
 
 X Exp. 1 to 4, pp. 117 to 121. 
 
 3G* 
 
426 DAMAGE TO CROPS BY MARLING. 
 
 facts satisfy me tliat it was not the quality, but the over quantity 
 of marl which has caused the evil; and that the land which has 
 escaped, owes its safety to its containing more vegetable matter. 
 I forgot to state that on some of the lightest spots of South field the 
 wheat was much injured, though blue marl was used there. 
 
 '' If I had followed my own advice to others, ' to put no more 
 marl at first than would but little more than neutralize the soil, and 
 repeat the dressing afterwards,' this evil would not have fallen on 
 me. The present loss is not much ; but it makes me expect the 
 same on all similar land, marled as heavily. I shall endeavour to 
 avoid it, by giving vegetable matter to the soil; either by manur- 
 ing, or by allowing one or two more years of grass in the first term 
 of the rotation. Why the quantity of marl applied should do harm 
 ia any case, is more than I can tell ; but I draw this consolation 
 from the discovery — if a certain quantity (say 500 bushels per 
 acre) is too much for present use of the soil, it proves that it will 
 combine with more vegetable matter,»and fix more fertility in the 
 soil, than I had supposed. That the second crop should be injured, 
 and not the first, is owing to the unbroken state of the shells at 
 first, and, by their being reduced, twice as much calcareous matter 
 is in action after a few years." 
 
 Thus it will be seen, from these entries made at the time, that I 
 took a correct view of this great and unlooked-for evil, and was by 
 no means discouraged, or induced to lessen my efibrts in marling. 
 But in all later operations on poor land, the quantity was lessened 
 from 500 and 600 bushels (and even more of the poorest marl), to 
 about 300 bushels. With this alteration, the operation was con- 
 tinued with as much zeal as before ; and also at a later time on an- 
 other farm (Shellbanks) purchased afterwards, and where I marled 
 upwards of 400 acres. 
 
 Wlien this injury was first discovered, about 250 acres of very 
 similar land had been marled so heavily that the like mischief was 
 to be looked for in the next crop, and thenceforward, if not guarded 
 against. For a more full account of this disease, and my opinions 
 thereon, I must refer to what has been before published.* It is 
 sufficient here to say that by pursuing the means there advised — in 
 allowing more rest from grain crops, furnishing vegetable matter 
 to the land, in its natural cover of weeds, in clover, and in farm-_yard 
 manure so far as the limited supply sufliced — that no very great 
 loss was subsequently sulfered, except in the field where the disease 
 was first discovered, and which was marled in 1819. This field 
 was too remote and inconveniently situated, to be manured from 
 the barn-yard; and from that and other causes (including the 
 failure of the first seeding of clover), that field only still shows in- 
 
 * Esisay on Calcareous Manures, ante, 155. 
 
REPORT TO BOARD OF AGRICULTURE. 427 
 
 jury from marling in the present crop (1839); so much diminished, 
 however, that its general average product this year [1842] is 
 fully twice as much as the land could have brought before being 
 marled. 
 
 NOTE V. 
 
 DESCRIPTION AND ACCOUNT OP THE DIFFERENT KINDS OP MARL 
 AND OP THE GYPSEOUS EARTH, OP THE TIDE- WATER REGION OP 
 VIRGINIA. 
 
 Report to the State Board of Agriculture, hy Edmund Ruffm, 
 
 Member and Corresponding Secretary of the Board, made in 
 
 1842, and note corrected, altered, and enlarged. 
 
 Within the last twenty-five years there have been produced from 
 the application of calcareous manures more improvement and bene- 
 fit, both agricultural and general, in lower Virginia, than from 
 all other means and sources, numerous and valuable as have been 
 the agricultural improvements made. And for the latter half of 
 that time, no one agricultural subject has been treated of more at 
 length in the publications of this state. Still, there is much re- 
 quired to be known ; and it has very often, and not less so recently 
 than formerly, been required of the writer, who has furnished to 
 the press the larger part of all that has thence i^roceedcd on this 
 subject, to give answers to inquiries, which, however variously 
 worded, amounted in substance to the question, "What is marl ?" 
 — or " Is my marl (or whatever earth was so termed) good marl, 
 and likely to be profitable as manure ?" It has therefore appeared 
 to the writer that it would be useful to prepare sometliing like a 
 natural history, or general and full description of the marls of low- 
 er Virginia ; and also of the kindred and yet very diff'ercnt mineral* 
 manure, the gypseous earth, or " green-sand" earth, concerning 
 which latter so much error and delusion have been spread and long 
 maintained, and so little of truth or useful information derived from 
 the scientific sources generally respected as the highest authority. 
 
 The main difficulty in the treating of this subject is presented in 
 the outset in the very term " marl,'' which is altogether misapplied 
 now in this country, though not so much as it has been, and per- 
 haps still is in England. Since this general course of misapplica- 
 tion was set forth by the writer at length in the " Essay on Calca- 
 reous Manures," there have become general in this country still 
 other misapplications of this always misapplied term. For the 
 " green-sand" earth of New Jersey, which before had been called 
 
428 CHARACTER OP TRUE MARL. 
 
 ''marl" by illiterate farmers only, has been since received under 
 that name by chemists and the scientific reporters of geological sur- 
 veys ; and thus confusion has become still " worse confounded/' 
 In the following pages, I shall be compelled, as heretofore, to yield 
 in part to such misapplication of the term ; but at the expense of 
 some otherwise useless repetition, and frequent explanation, shall 
 hope to avoid misleading readers as to each of the particular earths 
 under consideration. And I shall in no case fipply the term marl 
 to any but a calcareous earth, or mixture of earths, and of which the 
 calcareous ingredient or proportion of cai'bonate of lime is deemed 
 sufficient to constitute the most important, if not indeed forming the 
 only important or appreciable agent of fertilization ; and therefore 
 I shall not so designate either the fine clays (not calcareous, or very 
 slightly so), and formerly, if not now, called marl, in England, or 
 the green-sand earths of New Jersey, Delaware or Virginia, when 
 containing very little or no carbonate of lime. 
 
 True marl, as correctly understood by mineralogists, is a fine 
 calcareous clay, containing very little silicious sand, and none coarse 
 or separate ; of firm texture — not plastic, or very adhesive ; does 
 not bend under pressure, but breaks easily, and after being dried, 
 the lumps speedily crumble when immersed in water. . It is man- 
 ifest, from its laminated appearance and fracture, that this true marl 
 had been originally suspended in rapidly flowing waters, and de- 
 posited at the bottom by subsidence, when the waters became com- 
 paratively still ; as when a rapid river, turbid with calcareous clay, 
 reached a lake. Thus, from its manner of formation, such marl, 
 however argillaceous, was of a texture very difierent from the almost 
 pure or the most tenacious clays. The carbonate of lime also tends 
 to preserve an open and mellow texture in true marls, disposing the 
 lumps readily to yield and crumble, or fall to powder or to thin 
 flakes, under atmospherical influences, which would only afi"ect clay 
 by making it an intractable sticky mortar when wet, or lumps of 
 almost stony hardness when dry. IMoreover, there seems good 
 reason to believe that in true marl there is a chemical covibination 
 (and not merely a mixture) of the argillaceous and calcareous in- 
 gredients, induced by their suspension in water, when the particles 
 of both were in the finest possible state of division, and most inti- 
 mate intermixture, while so suspended. Besides the crumbling 
 quality just stated, so different from clay, there is a still stronger 
 reason for believing that the calcareous and the silicious parts of 
 true marl are chemically combined, which is, as I have found, that 
 they cannot be separated by mechanical means, such as agitation 
 and subsidence in water.* For the suggestion that the dift'ercnt 
 
 *The silex and alumina which compose the purest clay, are chemically 
 combined in the proportions of nearly 05 parts of silex to 35 of alumina; 
 
MARL AND SHELLS OF FRANCE. 429 
 
 earthy parts of true marl are in a state of chemical comhinatiou 
 with each other, I am indebted to the '^ Ussaisur la Marne," of M. 
 Puvis, wliich work, in-, an abridged form, I translated and published 
 in the third volume of the Farmers' llegister. The author there 
 also states that the marls of France are principally, if not always, 
 of fresh-water formation, as is shown by the shells they contain be- 
 ing cither such as belong to rivers and lakes, or to the land. This 
 is different from anything known in lower Virginia; all our known 
 marls, whether properly or improperly so termed, being deposits 
 made in a former sea, and the shells being those of sea-animals.* 
 But though it is proper to describe that which only is traly 
 " marl," before speaking of what is improperly so called, it is also 
 true that there is nothing to tell of the use of any true marl in 
 Virginia, and scarcely of its existence in the tide-water region. — • 
 I have as yet seen it in but few places, and there in thin layers 
 only, and then overlying ordinary beds of fossil shells, and inter- 
 mixed therewith. 
 
 and with this, to constitute true marl, carbonate of lime is also combined, 
 forming a triple earthy compound, or perhaps a quadruple compound, if 
 including the small proportion of oxide of iron, which is a general or uni- 
 versal constituent part of all clays. 
 
 * " It may be of some interest to scientific investigators to know more 
 particularly the shells of these marls of France. In a catalogue annexed 
 to the original ' Ussai sur la Marne,' the author names the following shells : 
 
 In a marl sent from St. Trivier — yellowish, compact, of homogeneous ap- 
 pearance, and coming to pieces finely and easily in water — 
 Land shell — Turbo elegans. 
 River shells — Helix fascicularis, Helix vivipara, -j-Helix tcutacula, f Mya Pic- 
 
 torura. 
 
 In a marl from Cuiseaux, Saone et Loire — 
 River shell — IMelanopside (of Lamarck.) 
 
 In a marl from Leugny, in Yonne — 
 Land shell — fChassilie ridee (of Lamarck, and Draparnaud, f Helix lubrica. 
 
 In a marl from St. Priest in Dauphiny — earthy, yellowish, very easy to 
 crumble in Avater — 
 Land shell— ]■ AnihvQii^ alongee, of Lamarck and Draparnaud, f Helix hispida. 
 
 In an analogous formation of marl, in the basin of the Rhone, between 
 Meximieux and Montluel, the Helix striee, a land species, is found in great 
 abundance." 
 
 M. Puvis states that among these, and among all the species of shells 
 found in the marls of the basin of the three great rivers, Saone, Rhone, 
 and Yonne, there are no remains of sea shells. All seem to have been 
 formed under fresh water. " But (he continues) as these marls contain 
 land shells, often in great abundance, we must conclude, that the revolution 
 wliich heaped up the marls, has been preceded by a time in which the land 
 was not covered by water, in which the earth producing vegetables, per- 
 mitted the multiplication of the species of land shells which were found in 
 these marls." — Essai sur la Marne, p. 8 to p. 24, and translation in Farmers' 
 Register, iii., note to p. C92. 
 
 •j-Living species are still found in the same region similar to those marked 
 thus. 
 
430 FORMATION OP TRUE MARL< 
 
 This marl was thus found in two of my diggings, one on Cogging 
 Point farm, and the other at Shcllbanks, in Prince George county. 
 In both cases, though perfectly characterized, the quantity of true 
 marl was too small to be used separately from the more calcareous 
 and much thicker stratum of shell marl below. This true marl was 
 in many horizontal layers, few of which were severally more than an 
 inch in thickness, separated by other layers, sometimes very thin, 
 of almost pure shells, broken very small, with some only of the 
 very smallest entire. The pure argillaceous marh is blue (though 
 sometimes of buff colour), firm and compact, breaks easily, but does 
 not bend however moist, and is cut smooth by a knife, leaving a 
 surface like that of hard soap. This marl contained, in the argilla- 
 ceous part, free fi-om the shelly parts, only 10 per cent, of calca- 
 reous matter. Several other specimens, from other localities in the 
 same region, were about the same strength. Therefore, even if 
 more plenty, there would seem to be no inducement to use our true 
 marl where the beds of fossil shells, called marl, and usually so 
 much richer in calcareous matter, can be drawn from. But in Eu- 
 rope, clay marl is reported as rich as 40 to 60 per cent, of calca- 
 reous matter, and indeed richer, gradually running into lime-stone 
 or impure chalk.* 
 
 But though it is proper to know, o,nd to bear in mind, what is 
 understood by the term marl, by mineralogists, and by the best in- 
 formed English and French agricultural writers, in regard to the 
 extensive marlings in those countries, yet it is necessary in Virgi- 
 nia to conform generally to the usage which gives the name of marl 
 to all earths largely mixed with fossil shells, or their fragments ; 
 and as the term is so far improperly extended, I would carry it still 
 farther, and make it embrace all natural calcareous earths not of 
 stony hardness. This arrangement then would indeed include true 
 marl, but merely as one class, and that one the least noticeable for 
 abundance or value of all in this country. The following scheme 
 of classification will conform to this view, and serve to make more 
 clear the descriptions that will follow : — 
 
 *Such Gases as are named above can scarcely be deemed exceptions to 
 the entire non-existence of true marl in this region. These limited de- 
 posits were doubtless formed by the abrading, stirring up, and suspension 
 of the upper part of the beds of shelly earth, by some strong current or 
 agitation of the sea, and the subsequent deposition of the finest parts in 
 tranquil water. The small shells and shelly powder sometimes seen be- 
 tween these layers of clay marl, were brought and deposited during other 
 intervals of more agitated water. I have often seen such deposits of per- 
 fect true marl, artificially produced, in the small open drains of mai'l-pits 
 (of our fossil shells), by the gradual settling of the suspended fine earthy 
 matters from the turbid water. 
 
Classification of marls. 
 
 431 
 
 «j I 
 
 I 1. Lime-stone proper. 
 
 textuie"^ 1 -• Marl-stone. 
 
 3. Recent oyster or other hard shells. 
 
 rs; to 
 
 «^o 
 
 
 fl. Chalk. 
 
 2. Impure chalk. 
 
 3. Travertin or calcareous tufa. 
 
 4. Argillo-calcareous marl, or true 
 
 marl (of mineralogists). 
 
 II. Earthy 
 
 texture, 
 
 or marl in 
 
 general ■< 
 
 and in 
 
 most ex 
 
 tended 
 
 5. Shelly sea-sand. 
 
 G. Shell-marl. 
 
 A. Fossil 
 
 fresh-water 
 
 shells. 
 
 B. Tertiary 
 fossil sea- 
 shells. 
 
 ' a. Sandy mi- 
 occne marl. 
 
 W i 
 
 ( b. Claj'ey mr- 
 1_ ocene marl. 
 
 f c. Calcareous 
 eocene marl, 
 with very lit- 
 tle if any 
 green-sand. 
 
 d. Calcareous 
 matter and 
 green-sand, 
 both consi- 
 derable. 
 
 m 
 
 l« 
 
 e. Gypseous 
 or green- 
 sand earth, 
 with little if 
 any calca- 
 [reous matter. 
 
432 CHALK AND "ROTTEN LIME-STONE." 
 
 This plan of classification has reference to the agricultural or 
 manuring characters only of the substances named. Those wliich 
 do not come under the head of marl, in the extended sense adopted 
 above, and which are not important in Virginia, will be dismissed 
 with but slight notice. 
 
 The general and very comprehensive term calx is here used to 
 include every natural (or indeed artificial) formation of earth, stone, 
 or shells, separate or in mixture, in which carbonate of lime is a 
 considerable and the most important part. All such substances be- 
 long to one or the (rther of the two great divisions — I., of stony hard- 
 ness, and II., of softer or earthy texture. 
 
 I. The stony bodies requii'c to be burnt to quick-lime, to be 
 used profitably as manure. Such are, 1, compact or ordinary lime- 
 stones ; 2, marl-stone, or the hardest and largest stony nodules or 
 continuoiis layers in softer marl ; and 3, oyster or other recent and 
 hard shells. 
 
 II. The calcareous substances of earthy texture, soft enough to 
 be used as manures, Avithout being reduced by calcination, all come 
 under the general and extended term marl, as here used. The 
 most important substances to be included under this head, are the 
 following : — 
 
 1. Chalk proper (nearly pure carbonate of lime), such as is 
 abundant in parts of England and France, is said by geologists not 
 to exist in North America. But there is what may be deemed, in 
 agricultural sense, an impure chalk, (2,) which spreads over or un- 
 der an immense extent of this continent. This is in Alabama and 
 Mississippi called " rotten limestone." It underlies, in beds of se- 
 veral hundred feet of thickness, large portions of these states, and of 
 Florida and Arkansas ; much of Texas, and, as I believe, most of 
 the vast prairie region between the Mississippi river and the Rocky 
 Mountains. This earth, so far as known to me by specimens only, 
 is composed of carbonate of lime principally, but with some 20 to 
 35 per cent, of clay. It is of a dingy whitish colour when dry ; ha^ 
 about the degree of hardness of chalk, to which this earth approaches 
 more nearly in composition, texture, and colour, than to either lime- 
 stone or to true marl. It may be inferred from the words of de- 
 scription in Fremont's Report, that this is the earth which forms 
 the great region through which part of the river Platte passes, and 
 which is found from the lowest visible depths to the summits of the 
 crumbling cliffs, some of which are many hundreds of feet high, so 
 remarkable along the banks of that river. I further infer that it is 
 this chalky and highly calcareous character of the surface-soil and 
 sub-soil which renders this region generally so barren, and usually 
 so destitute of water ; while the continual crumbling of the banks of 
 the same liarren earth into the river, and the earth being carried 
 down l>y the floods, intermixed with other suspended earths, and 
 
TRAVERTIN AND ARGILLO-CALCAREOUS MARL. 433 
 
 finally deposited upon the lands flooded by the Mississippi, serve to 
 constitute the wonderfully fertile borders of that river. 
 
 3. Travertin, or calcareous tufa, is another subject of the many 
 provincial and improper applications of the term marl. It is the 
 deposit made by the precipitation of carbonate of lime from its 
 previous solution in lime-stone water. The rain-water, in falling 
 through the atmosphere, absorbs carbonic acid ; which impregnation 
 enables water to dissolve and hold in solution carbonate of lime, 
 with which the water meets in abundance in lime-stone regions. 
 Thus the springs and streams of lime-stone water are produced. 
 But the carbonic acid absorbed by the water is retained with but 
 little force, and parted with to the atmosphere very easily. This 
 occurs wherever the water, so charged, is in contact with the at- 
 mosphere ; and consequently the more in proportion to the exposure 
 of its surface by the agitation of the water. Hence, at rapids and 
 cascades of lime-stone streams, this precipitation is always found 
 most abundant; and sometimes in immense quantity. It is prin- 
 cipally of carbonate of lime (about 70 or 75 per cent, in the trials 
 I have made), of cellular and open, though hard consistence, when 
 of newest formation, and not difficult to reduce; and much more 
 loose and soft in other cases. This deposit will be found the cheapest, 
 and also a very rich calcareous manure (though never yet used, to 
 my knowledge), for the neighbouring lands. It is the product only 
 of lime-stone streams, either ancient or existing. 
 
 4. Argillo-calcareous marl, or true marl, has already been de- 
 scribed, as to its texture and constitution. This marl is not pro- 
 perly shelly, though shells may be accidentally intermixed during 
 the deposition. Nor can any coarse or separate sand belong to it, 
 nor any other coarse and heavy matters, which would not remain sus- 
 pended in water flowing with but a moderate current. 
 
 This true marl is formed by the washing away and suspension 
 of calcareous and other earth in the waters of transient land 
 floods of rain-waters, or of rapid rivers and smaller streams. The 
 finer parts only of the difi'erent earths can remain long suspended 
 in the flowing waters, after the current ceases to be violent. These 
 finest parts of all, aluminous and silicious as well as calcareous, are 
 most intimately mixed, and chemically combined, while suspended ; 
 and finally are deposited in the form and quality of marl, when 
 reaching a lake, or other comparatively still part of the water. Of 
 course no such marl could have been formed unless the source of 
 original supply of materials existed, and also the manner of abra- 
 sion, transportation, and subsidence ; and no such soui'ce of calca- 
 reous earth could be presented except in higher chalk or chalky 
 beds, or otherwise highly calcareous soils and sub-soils. Compact 
 lime-stone alone, no matter how abundant, because of its hardness, 
 could scarcely serve as a source of supply. It follows, that such 
 37 
 
434 SHELL SAND — FRESH-TV ATER SHELL JLA.RL. 
 
 luarl may be presumed to bave been found and to exist in the 
 places of ancient lakes, or otber still waterS; in all cbalk regions — 
 in the vast " i-otten lirae-stoue" and prairie region of the southern 
 and western (or interior) parts of North America — rarely, if ever, 
 in our mountain lime-stone region, and certainly never in our tide- 
 water region. The calcareous beds of the tide-water region have 
 entirely a different origin, having been originally deposited or 
 formed and grown on the bottom of the ancient ocean, and since 
 upheaved to their present higher elevation. And it would be as 
 useless to search for the latter formation in the higher country. 
 Hence, the geological character of any region will indicat-e very 
 accurately whether either one, and which of these kinds of marl;, 
 or neither of them, can be found. 
 
 5. Sea-sand is used to great advantage as manure in some parts 
 of France, and Britain and Ireland. A large, and sometimes the 
 larger part of this sand consists of finely reduced shells, rubbed to 
 gi'anular state by the power of the waves ; and this calcareous in- 
 gredient is the all-important fertilizing part of this manure, though 
 its operation and even its presence may be sometimes unknown to 
 the ignorant users.* 
 
 6. Shell marl may be divided into (A) fossil fresh-water shell 
 marl, and (B) fossil sea-shell marl. 
 
 A. The first of these kinds is what is usually, if not always, 
 understood by the name " shell marl" by Euglish writers. It is 
 formed by the gradual accumulation of the shells of small fresh- 
 water shell-fish, of existing species, on the bottoms of the shallow 
 lakes and ponds where the animals had lived and died. When the 
 bottom had been raised by this long-continued accumulation, and 
 perhaps increased by like deposits washed from higher sources, 
 nearly to the level of the surface of the water, then water-plants 
 began to grow and to form a new accumulation of vegetable matter, 
 intermixed with the continuing deposits of earthy matter from 
 occasional turbid floods. Finally, by these means, the lake was 
 changed to a peat-bog, wet and miry, though usually free from 
 standing water. It is usually under peat, and sometimes at con- 
 siderable depths, that this peculiar and very rich calcareous manure 
 is found. It is almost pure carbonate of lime. It has been sold 
 in Scotland by the bushel, at a high price, and in great quantity, 
 for manure. f 
 
 * A notice of tlie Englisli sand, showing old opinions of its value and 
 operation, was quoted at page 381 of this Essay. 
 
 fin the Edinburgh Farmers' Magazine, vol. iv. p. 153, there is an inte- 
 lesting article (most of which was republished in the Farmers' Register, 
 vol. i. p. 90), describing a large body of this kind of shell marl, under 
 liesteneth peat-moss, ForfaT, Scotland. Most of the shells are of the wa- 
 
TERTIARY SHELL MARL. 435 
 
 This formation has been found in Vermont, in western Nevt 
 York, and probably exists in many parts of all the other northern 
 states. I have never heard of its existence in Virginia, but infer 
 that it is to be found in the western and mountainous region. It 
 may be sought for with the greatest probability of success, in 
 regions where ancient lakes or pools had been filled by gradual de- 
 positions — and especially if such waters had been impregnated by 
 carbonate of lime, affording abundant supply of material for the 
 shells of the animals. A cool and moist mountain region also 
 favours the formation of peat. The presence of this substance is 
 connected with that of such shelly deposits below only so far as 
 this : that the collections of waters which would produce and 
 finally be filled up by the gradual deposition of shells, in such a 
 climate, would be most apt to invite the formation of peat subse- 
 quently. Therefore, under peat, if in hollows, the deposits of such 
 shell marl are most likely to be found. 
 
 B. Tertiary fossil sea-shell Mart. 
 
 The second division of shell marl is the great and almost only 
 marl of the tide-water region of Virginia — and also of Maryland, 
 the Carolinas, and Georgia. It was produced by the gradual depo- 
 sition and accumulation of the shells left by the animals, mostly of 
 species now extinct, which had lived and died in them, on the bot- 
 tom of the ancient ocean. This former bottom of the ocean was 
 subsequently elevated, by some great convulsion of the earth, much 
 above the original level, and generally much higher than the sur- 
 face of the ocean waters. Thus, these wide-spread beds of shells, 
 with the various admixtures of sand, clay, or pulverized shells, 
 brought by currents, or the force of the waves, became high land; 
 and the different conditions and qualities are such as might be in- 
 ferred from the different operations of the original producing 
 causes, with the additional aid of a subsequent state of i-est for 
 countless ages. After the production and accumulation of these 
 beds of shells, to depths varying with circumstances, a mighty 
 flood, proceeding from the direction of the present higher lands, 
 swept over this great region, washing off and carrying away much 
 of the higher parts of these shelly beds, and then covering the re- 
 mainder with the drift of various earths brought and deposited by 
 this great land flood. Thus the beds of fossil sea-shells are gene- 
 rally thin in lower Virginia, and entirely wanting in many and 
 wide intervals ; and are mostly covered by a far greater thickness 
 
 ter snail (helix putris, Linnaeus), others are bivalves (generally tellina, ani- 
 mal tcthys, Lin.) From this deposit, the proprietor had sold as much for 
 manure as brought him £12,000 sterling, in tlae twelve years after its use 
 had been begun. 
 
430 SHELL MARL OF VIRGINIA. 
 
 of layers of drifted and barren sands or clays, or both, with a sur- 
 face-soil usually poor and thin. Farther south, the denuding and 
 destructive power of this flood was so much less, that the shell 
 bed is left several hundred feet in thickness. In Virginia, the re- 
 mainins: bed is in most cases less than fifteen feet in thickness, 
 and rarely much more. 
 
 As there is good reason for believing that all the present great 
 tide-water region of the countries last named was formerly the 
 bottom of the ocean, for an immense length of time, we may in- 
 fer that the whole was originally covered, to greater or less depth, 
 with a continuous bed of shells. Wherever this formation is now 
 wanting, it must have been removed by the subsequent washing 
 flood, previous to its later action of depositing the enormous bed 
 of drifted earth, which overlies the shells, or their former place. 
 
 The fossil shell beds of Virginia, which will be the main subject 
 to be treated of here, may be again conveniently divided, for de- 
 scription and observation, into two kinds, of (B 1) Miocene, and 
 (B 2) Eocene. These terms (with others) were introduced by 
 Professor Lyell, and designate the formations of different geologi- 
 cal eras. As they are now of general acceptation by geologists, 
 and also are generally understood by agricultural readers, these 
 terms will be convenient, and will be here used to designate the 
 different marls to which they belong. If the difference between 
 these two kinds were merely geological, or in regard to comparative 
 ages of formation, or to the respective fossils of each, it would be 
 useless to preserve it in writing on agriculture, however marked the 
 difference, and however interesting to the geologist. But there is 
 also a difference of agricultural character and value in these two 
 kinds of marl. In relation merely to each other, the terms eocene 
 and mioccne may be sufficiently understood as the older and newer 
 formations. But it will not do as well to substitute the latter 
 terms, because, though correct as to each other, they are not so 
 generally, or in relation to other marls and geological formations. 
 For there are some (of secondary formation) much older than the 
 eocene, and others (older and newer pliocenes and post-pliocene) 
 much more recently formed than the mioccne. With neither of 
 these is it necessary to encumber this report, by other than slight 
 notice, as neither are known in Virginia; nor elsewhere do they 
 present important differences of agricultural character and qualities. 
 
 The different periods of time of these two different deposits of 
 shells were very remote from each other, and the latest of them 
 was also very remote from the present time. In the miocene marl 
 of Virginia, or later of the two, of the numerous species of shells 
 found, there are but few kinds belonging to races of animals known 
 or believed to be yet existing; and in the eocene marl of Virginia 
 there are almost none that now exist, and very few that belong 
 
MIOCENE MARL. 437 
 
 also to the miocene marls. According to the highest geological 
 authority, most of the races of animals whose remains formed the 
 latest as well as the earliest of these deposits, were extinct before 
 the creation of man. 
 
 Although it might be more conformable to regular or scientific 
 arrangement to commence a general description with the older and 
 lower deposit, the eocene marls, yet it will better suit the purpose 
 of agricultural instruction to reverse the order, by describing first 
 the miocene marls, as the highest in the series and the first reached, 
 and by very far the most abundant and extensively accessible ; and 
 which, therefore, though usually less powerful for fertilization, are 
 much the most important to agriculture in Virginia in general. I 
 shall therefore proceed first to treat of the miocene marls, which 
 arc the only kinds known to me in Virginia, with the exceptions 
 of the two comparatively small districts of eocene marl, which will 
 be hereafter treated of in their order. 
 
 Miocene Marls. 
 
 When my investigations and practical labours on this subject 
 were commenced, more than twenty-four years ago (in 1818), the 
 existence of marl of any kind, or rather its shells, obvious to the 
 sight, had been noticed in lower Virginia at but a few places, where 
 naturally exposed along steep river banks, and where cut through 
 by deep ravines, and thus rendered conspicuous ; and the deposit 
 was supposed to be very limited, by the few persons who had ever 
 cast a thought upon the subject. But the attention and observa- 
 tion subsequently directed to the search, soon showed that the 
 quautit}' M'as very far more extensive ; and now, though not gene- 
 rally near the surface of the earth, nor everywhere accessible, it 
 seems pi-obable that beds of fossil shells underlie much the greater 
 part of all the region between the falls of the rivers and the sea- 
 shore. Except at or near the places where exposed on the surface, 
 as above mentioned, the overlying (drift) earth is generally 20 or 
 30 and sometimes even 50 feet thick. All the marl-beds appear to 
 be nearly horizontal, and of course are the most deeply covered 
 under the highest lands, and are most easily accessible in low de- 
 pressions. The deposit dips gently towards the east, so that it lies 
 too deep to be visible near the sea-coast. At Norfolk, the marl 
 has been recently reached, in boring deep for water, at 40 feet be- 
 low that low surface, and, of course, much below the sea. 
 
 The marl is formed by the deposit and gradual accumulation of 
 sea-shells, mostly left where the animals died ; and the vacancies 
 between the shells were filled by the sand or clay, or mixtures of 
 both, with fragments of older shells, brought by tide and currents, 
 and deposited in what was then the bottom of the sea. The re- 
 markably perfect state of preservation of many very thin and 
 37* 
 
438 MIOCENE MARL. 
 
 alwaj^s fragile shells, and still more the many pairs of bivalve shells 
 that yet arc found connected or in contact, jDrove that such sheila 
 could not have been transported, or even much agitated, by the 
 force of the water. But other beds of marl, and also frequently 
 the upper layers of such as have been just referred to, show as 
 clearly the action of currents, or of water in violent and long-con- 
 tinued motion, which served to grind down the shells to small 
 fragments, and which also left, in shaping the surface of the marl, 
 the marks of whirlpools or other violent disturbance. From such 
 supposed causes might be expected such effects as many of the 
 various marl-beds actually exhibit. In different places, and some- 
 times in the same place, the shells and their fragments are found 
 of all sizes, and of all conditions of preservation ; and intermixed, 
 in various proportions, with such clay, or fine sand, as might be 
 suspended in or borne by currents, or waves of the sea ; so as to 
 form beds of every degree of texture and shade of colour. The 
 shells, and their fragments, or the carbonate of lime, are in 
 various proportions of quantity, from 10 per cent, (or even less in 
 rare cases) to 90 per cent, or more, of the mixture, or whole mass. 
 In different beds, and sometimes in contiguous layers of the same 
 bed, the shells are in every state of preservation or of decay ; from 
 that of being firm, and often entire in their calcareous structure, 
 and the most delicate parts of their beautiful forms preserved, to 
 that of being mostly broken down, and almost reduced to a coarse 
 powder, and sometimes even forming a homogeneous mass of still 
 finer particles, in which the forms of but few if any shells are dis- 
 tinguishable. The original bright and various colours of the shells 
 are lust, and they are nearly all white — a few of the hardest kinds 
 only being brown or gray. The texture of the mass also varies, 
 from a loose sand to a firm body of almost stony hardness. The 
 earth intermixed with the shells is generally much more sandy 
 than clayey, and more especially in the poorer marls. Even when 
 the admixture of earth is clay, it rarely makes the m'arl appear the 
 least clayey in texture, or plastic or adhesive, because the clay is 
 usually but in small proportion to the shelly matter. Even when 
 the proportion of clay is great, the carbonate of lime, according to 
 its quantity and degree of reduction, counteracts the tendency of 
 the clay, and prevents the mass being tough, adhesive, or obdurate. 
 The colour of the miocene marls is also various — generally either 
 pale yellow or dingy white, or blue, sometimes bright, but more 
 often a dull blue, or ash colour. The richest marls, of homogene- 
 ous texture, are nearly white when dry, and approach in ajipear- 
 ance to a coarse or impure chalk. 
 
 The shell marls of Virginia are confined almost entirely to the 
 tide-water region, or the space eastward of the granite which forms 
 the falls of all our eastern rivers. But near Petersburg (on the 
 
MIOCENE MARL, 439 
 
 farm of Dr. William I. Dupuy, and other adjoining lands) there 
 is an exception to this general rule, the marl being found about a 
 mile farther west, overlapping the eastern and lowest part of the 
 granite, and passing under a small stream which empties into the 
 Appomattox, a mile above the lowest falls. 
 
 The only important fertilizing ingredient of the miocene marls is 
 the carbonate of lime, or shelly matter. There may be, and proba- 
 bly is, some slight additional benefit sometimes, from accidental or 
 peculiar admixtures of other substances ; as, of animal matter still 
 remaining, or, in limited spaces, the phosphate of lime supplied by 
 bones of large fish or sea reptiles ; or of vegetable extract in blive 
 marls, of the oxide of iron, of a very small proportion of green- 
 sand generally; and even of the clay or the sand, respectively for 
 soils deficient in either. But either and all of these additional mat- 
 ters, though giving some value as manure, are of but little im- 
 portance in miocene marls, in comparison to the main and great 
 agent of fertilization, the shelly or calcareous matter. According 
 then to the greater or less proportion of this main ingredient, and 
 to its state of division or readiness to be reduced to a state of mi- 
 nute division in the soil, may be rated the comparative values of 
 marls for manure. In regard to the much larger proportions of 
 green-sand in miocene marls, as asserted by other authority, and de- 
 nied by m"e, some additional remarks will be hereafter submitted, in 
 the proper order for consideration. 
 
 As might be inferred from the obvious manner of the deposition 
 of the marl, as before stated, by waters of the sea in violent and 
 yet varying degrees of motion, the diff"erent horizontal layers of 
 marl, successively deposited in the same bed, and even within a few 
 inches of perpendicular distance of each other, sometimes exhibit 
 remarkable differences of appearance, composition, and of value ; 
 while there is also generally as remarkable a uniformity of charac- 
 ter of each particular layer (though differing much in thickness at 
 different places) throughout not only the different diggings of the 
 same place, but sometimes for miles in extent. I have seen often, 
 in diggings on diflerent farms, atid several miles apart, layers of 
 marl so precisely alike, and so marked in peculiar character, that 
 there could be no doubt of their being parts of the same particular 
 deposit, made at the same time, and by the same operating natural 
 causes. Under such circumstances, a practised eye can by com- 
 parison fix very nearly the chemical composition of similar varie- 
 ties, and even more correctly, for general averages of value, than 
 would be usually obtained from the accurate chemical analysis of 
 one or two specimens only. For the usual danger of error is, not 
 in the chemical analysis (which is easily enough made, and the 
 mode sufiicicntly correct), but in the selection of equal and fair 
 specimens of marl to exhibit the average strength of the whole body 
 
440 MIOCENE MARL. 
 
 excavated ; wliicli requires mucli more experience and accuracy than 
 are usually exercised by most operators, and still more in regard to 
 proprietors who send specimens of their marls to be analyzed by 
 other persons. It is highly important to the farmer to know the 
 strength of the marl he is using. And to this end, it is necessary 
 that every layer should be carefully analyzed, or, what is better, a 
 .specimen from an equal and continuous shaving of the whole ver- 
 tical section of a digging, so as to furnish a fair average of the whole 
 body. But after this trouble is once taken, the general result will 
 serve for all the future diggings at the same place, and also for 
 similar bodies more or less remote. 
 
 The layers of marls formed by shells left "in place," or where 
 the animals died, are in general the poorest ; and for this obvious 
 reason, that all the hollows of and interstices between the shells are 
 filled by what is mostly earth (but mixed with more or less of shelly 
 fragments), and that earth is principally silicious sand. Marl so 
 formed, will not have more than 35 to at most 40 per cent, of cal- 
 careous matter, and more often only from 25 to 35. The sand or 
 earth that would be required to fill all the hollows and chinks of a 
 body of entire shells, of ordinary form, though touching each other 
 at their edges and points, would necessarily be as much as 65 to 75 
 per cent, of the whole mass. And therefore, it is only because of, 
 and in proportion to, the quantity of shelly particles mixed and 
 borne along with the earth brought by currents and deposited among 
 the whole shells, that such marl is sometimes richer than 25 to 35 
 per cent, in calcareous matter. The degree of admixture of shelly 
 fragments in this filling earth, may be easily judged of by an expe- 
 rienced eye, and the proportion of shells and large fragments will 
 depend much on the forms of the prevailing kinds of shells. It is 
 easy to know the marls formed by shells left in their original place, 
 by the state of the shells. Either the shells being whole, and es- 
 pecially the more fragile varieties, or the two sides of bivalve shells 
 being found in close contact, as when the animal was living, will 
 show clearly that the dead shells had not been much agitated, or 
 borne along by currents. The beds or layers formed by removal, 
 are as easily known by the broken and finely reduced state of the 
 shells. These marls are usually much the richest in calcareous 
 matter; for, by the grinding operation of the currents, and the 
 diiference of specific gravity in the particles carried along, the cal- 
 careous powder and clay are deposited together, with but little sili- 
 cious sand. Among the richest marls are some having whole shells 
 in their original places, but of which the interstices are filled by 
 such fine calcareous and clayey earth as could have been deposited 
 only in waters nearly still. Such are the rich marls in and about 
 Williamsburg, and in Surry, and that belt of country generally, con- 
 taining 70 to 80 per cent, of carbonate of lime. 
 
VARIETIES OF MIOCENE MAUL. 441 
 
 The different varieties of miocene marls, whicli will now be more 
 particularly described, are not always separated in different beds, 
 but sometimes form some of the different and even adjoining layers 
 of the same bed or digging. The differences of colour, &c., caused 
 by the greater or less quantity of various accidental ingredients, 
 however striking to the eye, are not often of much importance to 
 the value of the marl ; but only (or principally) such differences as 
 are caused by the greater or less proportion of shelly matter, and 
 its state of disintegration and division. 
 
 Broivnish yclloxo marl. — This kind, wherever found, always 
 forms the highest layers of the particular body. That is, if there 
 be layers both of yellow and blue marl in the same body, the yel- 
 low is always above and the blue below, and never in the reverse po- 
 sition. But sometimes the yellow continues to the bottom, and 
 sometimes the blue forms the top as well as the bottom. 
 
 Yellow marl is usually found dry ; that is, having no springs or 
 oozing waters, which are generally reached on digging lower in the 
 body. But the lower part, where wet, is sometimes, though rarely, 
 of the same yellowish or dingy white tint, so as to make it manifest 
 that the colour is not dependent on the degree of moisture or dry- 
 ness. The yellowish tint is owing to the presence of oxide of iron, 
 and is pale or deep, approaching sometimes to reddish brown, ac- 
 cording to the quantity of that colouring matter. 
 
 Yellow sandy marl is the kind most abundant in Prince George 
 county on and at some miles distance from the banks of James river, 
 and from which some farms entirely, and others principally, in that 
 neighbourhood, have been marled. It is of shells left in their original 
 place, the filling earth being mostly of coarse sand, and the whole 
 body poor in calcareous matter, varying in its proportion usually 
 from 20 to 30 per cent, and rarely richer than 35 per cent. But it 
 is of such open and loose texture (and the more so as the sand is the 
 more abundant), that this marl is easily and cheaply worked, and 
 the labour so applied is therefore often better compensated than in 
 diggings of much richer marl. In this variety of marl, the shells 
 are usually entire, or in large fragments, but are not firm or well 
 preserved. In some beds, or thick layers, they are so finely reduced 
 that the mass seems to the eye to be wholly, as it is indeed prin- 
 cipally, a body of silicious sand. From one bed of this kind, which 
 its proprietor supposed from its appearance to be merely silicious, 
 the earth was used as sand to mix in lime-mortar for masonry, and 
 it was found to serve well for that purpose. Subsequently this 
 bed of sand was found to be enough calcareous to be used as manure ; 
 and was so used, and to such good profit, that the proprietor sup- 
 posed it to be rich marl. In that opinion, however, he was mis- 
 taken, at least as to the proportion of calcareous contents. 
 
 Yellow day marl. — But most of the richest as w^ell as of the 
 
412 TAKIETiES. 
 
 poorest mioeeno marls, are yellowish. "Wlien rich, say containing 
 proportions of carbonate of lime from 45 to 80 per cent., the marl 
 is usually formed of shells broken down, when under the sea, to 
 small fragments or to powder, by the grinding action of the water 
 in violent motion, and left afterwards to settle in stiller water, ac- 
 cording to the specific gravity. Or it is the same kind of rich and 
 finely divided water-borne matter deposited on and filling the hol- 
 lows in and between whole shells remaining in their original 
 place. In either case, the small quantity of earth first suspended 
 in the current, and then deposited with the finely reduced shelly 
 matter, is mostly if not entirely clay ; as silicious sand, having more 
 specific weight, could not be suspended by the current so long, or 
 carried so far, before being deposited. The few rich clay marls of 
 Prince George are of the first-named variety, or composed entirely 
 of fine fragments of shells intermixed with clay. The much richer 
 marls in and about AVilliamsburg are of the other kind, there being 
 also numerous whole shells in place, as well as the interstices being 
 filled almost entirely by water-borne fragments, and fine powder of 
 other shells. The other contents, making from 15 to 25 per cent, 
 of the body, are principally of a very fine clay of pale yellow, and 
 much less of silicious or white quartz sand, oxide of iron, and a 
 little green-sand. Much of the same kind of rich marl is also in 
 other parts of James City and York, in the lower part of Surry, 
 and in Isle of Wight, New Kent, and King William counties, which 
 I have seen — and probably throughout the middle belt of the marl 
 region of Virginia. There has been little or none of this rich clay 
 marl seen by me in the upper range of marl counties (those next 
 the falls of the rivers), and not much more near to the eastern 
 limits, or next to where the marl dips so deeply, as to disappear 
 from the surface, and is accessible only by deep digging. Perhaps 
 observations more extended than mine have been, might present 
 diflfercnt conclusions. 
 
 The rich marls just described, when separated mechanically (by 
 the sieve, and by carefully washing in water), seem to consist, for 
 the much greater part, of pure shelly matter, mostly in large or 
 small fragments, slightly coloured brown by oxide of iron, and the 
 remainder of a very fine and apparently pure pale yellow clay. But 
 this clay is also composed in part of finely divided carbonate of 
 lime; and the fine shelly matter is intermixed with some silicious 
 sand and a little green-sand. The bed of marl near Surry Court 
 House (which is similar to the marl at most other places thereabout) 
 is of this kind and general character ; and from it, a large body of 
 land has been manured with great benefit. This body of marl was 
 reputed, upon the authority of the State Geological Surveyor, to be 
 among the richest in green-sand. From a much larger sample of 
 the marl of this bed, carefully selected by the proprietor, at my re- 
 
RICHEST MIOCENE MARLS. 443 
 
 quest, and for my examination, an average portion taken was com- 
 posed as follows : — 
 
 1780 gi-ains, separated mechanically, by the sieve and by washing 
 and subsidence in water, consisted of 
 
 Carbonate Fine argillaceous Siliciovis Qrecn-sand. 
 of lime. •3arth. sand. 
 
 1036 grains of shells and coarse 
 fragments, nearly pure, and 
 so coanted, - - 1036 
 
 483 grains of fine shelly frag- 
 ments, &c., which consisted 
 
 of - - - - 268 - - - 120 45 
 
 277 grains fine yellow clay, &c., 
 
 which consisted of - 65 - 212 
 
 34 loss in the process. 
 
 1780 1369 212 120 45 
 
 Which may be stated of parts to the hundred, thus : 
 
 100 grains of marl contained of carbonate of lime, - 77 grains. 
 Silicious or quartz sand, very pure and white, - - 6| " 
 
 Green-sand, __.-.___ 2^" 
 
 Fine yellow clay or argillaceous earth (and the loss in 
 
 the latter process), __..._ 13| '« 
 
 100 " 
 
 The richest bodies of these marls show very few shells, or even 
 fragments, and have a homogeneous texture and appearance to the 
 eye, like a very impure chalk or sandy clay. Such marls are 
 found in James City, New Kent, King William, and Middlesex 
 counties. The following are some of them of which I have analyzed 
 specimens : — 
 
 FROM 
 
 King William, (Lipscomb's land) — 82 pr. ct. of carbonate of lime. 
 
 «< (Slaughter's land)— 88 " " " 
 
 New Kent, (Mount Prospect)— 88 '< " " 
 
 Middlesex, (Oaks' land)— 83 " " " 
 
 Most of these marls are soft enough to be used for manure as 
 dug from the pits ; but the hardest lumps may need burning to 
 lime. Any marl hard enough to need burning, and as rich 
 as 85 per cent., will make good lime for cement, as well as for 
 manure. 
 
 Under a peculiar combination of circumstances, the great rich- 
 ness of some marls operates to lessen the value of the body as ma- 
 nure. Rain-water, when just fallen, always contains come carbonic 
 acid, which admixture causes it to be a solvent of carbonate of lime. 
 When rain-water then can descend by percolation into rich dry 
 jnarl, in its passage it dissolves some of the calcareous matter, 
 
444 CRYSTALLIZATION OP MARL. 
 
 ■which is again left solid, and in crystals, by the slow evaporation 
 of the fluid. These crystals of carbonate of lime arc slowly added 
 to by every recurrence of the like causes, until the cavities of large 
 shells, and other openings into which the water had settled, are 
 comj^letely filled with crystallization. If layers of marl, less per- 
 vious to water than in general, oppose the descent of the water, the 
 crystallization forms in connected horizontal layers, separated by 
 the thicker layers of softer marl. Such crystallized layers are 
 found abundantly in the very rich marl in the cliffs at Yorktown, 
 serving by their stony hardness to impair the otherwise great value 
 of the manure. At Belfield, Col. Robert McCandlish's farm, a few 
 miles higher on York river, the hollows of large shells have been 
 filled with beautiful and brilliant crystals thus formed. In Surry 
 also, on the land of the late William Jones, such crystallization is 
 abundant. For such eflect to be produced, there are several con- 
 ditions necessary. The superincumbent earth must be of open 
 texture, and not very thick — or rain-water could not pass through. 
 It must not be a hill-side — as the water would flow off the surface 
 and not penetrate to the marl. And the marl must be dry — or 
 evaporation could not take place, and, of course, crystallization 
 could not. 
 
 Gloucester, though one of the outside marl counties to the east, 
 is most abundantly supplied with marl, accessible on almost every 
 farm, whether of high or of low grounds. It is generally of the 
 poorer yellow kind. But three marked exceptions were seen, 
 which as such deserve to be named. One is the rich clay marl 
 forming the north bank of Ware river on the fiirm Df JMr. Alexan- 
 der Taliaferro. Another is the general sub-soil (as it may be con- 
 sidered from its position) of the lowest land of the farm of Mr. 
 Jefferson Sinclair, near the mouth of Severn river. This is an al- 
 most pure body of coarse shelly powder, or fragments, seldom found 
 larger than two or three grains in weight, and a very few shells, of 
 as minute size, entire enough to be distinguished, This mass of 
 shelly matter is as loose and incohesive as coarse sand, yet is tinged 
 slightly with green by the admixture of greenish clay. A speci- 
 men analyzed contained 72 per cent, of carbonate of lime. (See 
 more full account at page 181, vol. vi. Farmers' Register). The 
 third is the marl used by Capt. P. E. Tabb, and dug from beneath 
 the low grounds on North river. It is a mass of pulverized shells, 
 coloured by red or brown oxide of iron.* 
 
 Blue marl. — This is the most common kind in the upper range, 
 or near the western limits of the great marl deposit. Thereabout, 
 
 * This is the marl so abundant, and of easy access, on Toddsbury, the 
 property and residence of the deceased Philip Tabb ; and of which marl the 
 value as manure had not been tried, or suspected, by that experienced and 
 deservedly distinguished farmei*, diu"ing his long life on that farm. 
 
BLUE MAUL. 445 
 
 blue marl usually forms the whole thickness of the bed. More 
 eastward, and lower down the country, it sometimes forms the 
 whole of low-lying beds, but more usual!}' only the lower layers of a 
 bed, of which the upper part is yellow. 
 
 Blue marl is generally such as remains " in place/' or where the 
 shells were left by the death of the enclosed animals, and the inter- 
 mixed earth is mostly silicious sand ; and therefore (and not because 
 of its colour), this marl is rarely found as rich as 45 per cent., and 
 is still more rarely equal to the yellow clay marls, though generally 
 richer than the yellow sandy marls. 
 
 Blue marl in the bed is always wet, being made so by water 
 slowly oozing from every part, though seldom fast anywhere," or 
 showing springs or veins of running water. The blue colour is not 
 caused by moisture (for some yellow marls are also permanently 
 wet), but by vegetable extract or other dark-coloured organic mat- 
 ter, brought in the percolating water. This inference I have drawn 
 from extensive observation of the natural beds, and also from seve- 
 ral accurate though accidental experiments, of which the first that 
 was observed will be here stated. A small stable yard was covered 
 6 to 10 inches thick with a rich dry yellow mai'l, for the purjDOse 
 of retaining by chemical combination the juices of the putrescent 
 manure which was to be thrown there from the stable. After re- 
 maining for this use a year or more, this flooring of marl was dug 
 up and carried out for manure ; when it was found to be changed 
 in colour to a deep and vivid blue, and precisely like the natural 
 colour and appearance of the under-stratum of the same body of 
 marl, which being an open and almost pure mass of pulverized (and 
 water-borne) fragments of shells, was readily penetrated by and 
 always full of water. A general fact confirming this view is that 
 all marls found lying immediately under swampy soils, full of 
 vegetable matter, are blue. And this colouring vegetable matter 
 in marl is not merely intermixed with, but must be held in chemi- 
 cal combination by the calcareous matter; and serves, according to 
 its quantity, in blue marls, as an addition to the fertilizing power 
 of the calcareous matter alone. The particular body of marl above 
 referred to, the under-stratum of which is the most marked or vivid 
 blue ever seen in marl, is at Shellbanks farm. Prince G-eorge, and 
 from which I dug and applied a large quantity. The greater part, 
 and all the richest layers, seemed to be of shells broken down to a 
 coarse powder, or of sizes less than fine gravel, through which clear 
 water rose and passed, so freely as to forbid digging to the bottom. 
 The small quantity of clay or other earth intermixed with the cal- 
 careous earth of this marl is altogether insufficient to hold so much 
 colouring matter; and moreover, if the colouring matter were not 
 chemical/?/ combined with the calcareous, the continued free pas- 
 sage of water must have dissolved and washed off any uncombiued 
 38 
 
53 
 
 per 
 
 cent. 
 
 25 
 
 
 it 
 
 64 
 
 
 a 
 
 69 
 
 
 (( 
 
 9 
 
 
 (I 
 
 446 BLUE M^UIL. 
 
 vegetable extract. This wliole body of marl, both the dry and yel- 
 low lying at top, as well as the blue and wet below, was all brought 
 and deposited by currents, as is manifest by the different layers of 
 different specifie gravity, and still more by the many intervening 
 layers of a fine calcareous clay (before mentioned), which may bo 
 considered as the true marl of mineralogy, though in very small 
 quantity. Analyses were carefully made of every different quality, 
 and the results may be interesting as showing how much one layer 
 may vary from the one next adjoining; and different specimens not 
 more than a few inches of perpendicular distance apart. 
 
 Upper dry part, •yellow, and loose as sand, varying 
 (by unevenness of surface) from 3 to 7 feet, con- 
 tained of carbonate of lime .... 
 
 Next layer below, brownish yellow, through which 
 water passes, ...... 
 
 About 12 inches lower, in the blue, 
 
 " " " " " " another specimen 
 
 •below ........ 
 
 Layers of clay marl, interspersed through the above 
 
 And in a subsequent digging, the strength of four specimens of 
 the blue part of the marl was as follows : — 
 
 In the first foot depth of blue under-stratum . 32 per cent. 
 
 In the second foot ..... 33 " 
 
 At 3i feet 76 " 
 
 At 4 feet, and lowest digging then effected . 70 " 
 
 It may readily be inferred, from these various results, that if 
 one or two specimens only had been analyzed, and these taken with 
 no more care than is commonly used, that a very deceptious report 
 would have been furnished from making even the most accurate 
 analyses. 
 
 Conchologists and geologists, who have treated so much of marls, 
 but merely in reference to the shells they furnish, or to their 
 geological character, speak of the blue marl as formed by shells 
 being imbedded in a blue day. But the earth is not generally a 
 clay, nor anything even approaching to a clay, but is mostly of 
 silicious sand. The ordinary blue marl contains usually from three 
 to four times as much pure and separable silicious sand as of clay. 
 From various specimens of two diggings in such marl, from which 
 more than 300 acres' were marled of the Coggins Point farm, the 
 following results were found by analysis : — 
 
 Yellow marl (wet) thin layer at top, contained of car- 
 bonate of lime ..,,.. 24 graioa. 
 
BLUE MAKL. 447 
 
 Within 24 inches of top, shelly matter finely divided, and the 
 mass uniform dull blue colour, 100 grains contained : 
 Carbonate of lime, ...... 34 grains. 
 
 White silicious sand, . . . . . " 47 " 
 
 Clay, black when moist, and dark gray when dried, 19 " 
 
 100 
 Of similar blue marl from another pit in the same body, 100 
 grains contained : 
 Carbonate of lime, ...... 34 grains. 
 
 Silicious sand, ...... 62 " 
 
 Clay, 14 " 
 
 100 
 Of another specimen from the same, and of similar 
 
 marl, 100 grains contained of carbonate of lime, 29 " 
 
 At 6 feet deep (the shell not much reduced), carbo- 
 nate of lime ....... 44 '' 
 
 At 13 feet deep, and one foot from bottom, . . 33 " 
 
 Some few hard lumps of conglomerated shells and 
 
 earth scattered through the general mass, . 73 " 
 
 From a digging at three-fourths of a mile distant, of marl of the 
 same appearance and believed to be the same body as the preceding, 
 the general average of strength, as obtained from several trials at 
 different depths, was in 100 grains of marl, 35 of carbonate of lime. 
 The thickness of this body, where penetrated, varied from 11 to 14 
 feet ; where tiiere was a marked lessening, though not entire ab- 
 sence of shelly matter, and increase of silicious sand of the same 
 blue tint. The deeper removal was stopped because of the obvious 
 poverty, and no further examination of more than a foot or two in 
 depth was made in this poor substratum. In but few of all the 
 various diggings made by myself, or of others heard of, has the bot- 
 tom of the marl been reached — though in many, and most generally 
 when penetrated deeply enough, it becomes so poor as to be not 
 worth the labour of removing. In most of the few known cases, 
 when digging the marl for manure, that the bottom of the miocene 
 was reached, the stratum below was of eocene green-sand earth, or 
 eocene marl. In digging a well, at Shellbanks, my then residence, 
 after passing through a bed of firm blue marl, of broken (or water- 
 worn) shells, obviously the same kind dug at another place for ma- 
 Dure, and described at page 445, a soft brown sand was reached, 
 apparently destitute of calcareous matter, and from which rose an 
 abundant supply of pure and soft water to the height of 13 feet, 
 which stood altogether in this blue marl, without its purity being 
 affected either by the calcareous matter of the marl, or its colour- 
 
448 LOSS OF CALCAREOUS) MATTER. 
 
 ing matter. The continued purity of this water is an additional 
 proof that the blue colouring matter is chemically combined with 
 the carbonate of lime — and the combination is a visible illustra- 
 tion of the manner in which marl holds to and fixes putrescent 
 manures. _ 
 
 Mr. William Carmichael, of Queen Ann's county, Maryland, an 
 intelligent agriculturist, and an experienced and observant marler, 
 is of opinion that there is a perceptible superiority of effect of blue 
 marls over others of equal (and even greater) strength in calcareous 
 matter. (Farmers' Register, vol. vii. p. 106.) This superiority 
 of elFect probably is caused by the vegetable or other putrescent and 
 alimentary matter being combined with the calcareous, and by its 
 presence giving colour to the blue marl. And that the blue colour 
 is thus produced is fully proved by the facts stated at page 445, 
 and by my more general observation. 
 
 Excepting then the additional value in the vegetable extract 
 which gives the colour, there is no difierence between the blue and 
 the yellow marls, other than the difference, as of any marls of simi- 
 lar colour, in their respective amounts of calcareous matter. And 
 the same may be said of wet and dry marls, which are generally, 
 but not always, distinguished by the above colours ; and also of any 
 other miocene marls, excepting for such small proportion of " green- 
 sand" as is sometimes present. But there is reason to believe that 
 wet marls, in many cases, have lost some of their ancient strength, 
 by the continued though very slow percolation and subsequent dis- 
 charge of water through the mass. If recent rain-water penetrates 
 wet marl, it dissolves some carbonate of lime (by means of the car- 
 bonic acid in the rain-water) ; and, as the water slowly flows off, or 
 oozes out, instead of being evaporated, the dissolved lime is washed 
 into the nearest stream, and is lost, instead of being left, crystal- 
 lized or otherwise, as in dry marl. Again — if water flows over 
 having sulphate of iron (copperas) in solution, (which is not a very 
 rare case,) that dissolved salt acts with the carbonate of lime to 
 produce the decomposition of both the sulphate of iron and the 
 carbonate of lime, and from two of their component parts to form 
 sulphate of lime. And as this is slightly soluble in water, it must 
 be carried off by the slowly oozing water, as long as any of these 
 new salts remain. In this case, the carbonic acid is evolved, and 
 the iron is precipitated — and often fills, or coats the interior of the 
 spaces before filled by the shells which this chemical process had 
 decomposed and removed. This eftect, when produced, is seen at 
 the up2)er part of the marl, where the copperas water first touches 
 the shelly matter. In Henrico, near the western limit of the marl, 
 and in Hanover, more eastward, there is generally over the pre- 
 sent highest shells a body of earth of colour and general appear- 
 ance very similar to the marl below, and full of hollow impressions 
 
COMPARATIVE VALUES OF MIOCENE MARLS. 449 
 
 of shells, though no shelly nor even any calcareous matter now 
 remains. In other marls, there is often seen an upper layer 
 coloured brown by this deposit of iron. Both these are different 
 modes of the same operation ; the waters charged with sulphate of 
 iron having in the latter case decomposed and removed but part, 
 and in the former all the calcareous matter, to some depth below 
 the former top of the stratum of marl. The marl, in the upper 
 part of which the shells have been thus dissolved and removed, 
 has a decided sulphureous odour, which is left very perceptible ou 
 the hands, after handling the marl as dug; and this odour is still 
 more manifest in the marl when it has been dug and thrown out, 
 and exposed some days to the weather. Such marl is within a few 
 miles of Richmond, at Dr. Chamberlayne's and Col. C. W. Gooch's 
 farms. It is poor in calcareous matter. 
 
 The comparative values of marls are fixed by the comparative 
 proportions of carbonate of lime contained, other circumstances 
 being alike ; yet if these other circumstances are very different, 
 they may make a marl containing but 25 per cent, worth more 
 than another of 50 per cent. The more finely reduced, or the more 
 soft the shells, the quicker the action will be, and the more profita- 
 ble the marling. But all the white shells, however hard and 
 entire when applied, are dissolved in a few years, if the soil really 
 needs so much lime — that is (according to my views), if there be 
 acid of soil enough to combine with the lime. But the gray or 
 slate-coloured shells seem to be insoluble and almost indestructible, 
 and do very little good as manure. These shells are the several 
 species of scallop (^pccteii) and of fossil oyster (ostred), and some 
 few others, all fortunately being but in small proportion compared 
 to the numerous white and softer shells. Some beds of marl, 
 however, or layers, have mostly these hard shells, and therefore 
 are worth very little compared to what their chemical analysis 
 would indicate. 
 
 It is not necessary to speak otherwise than very concisely as to 
 the practical applications and effects of miocene shell marl ; for 
 this is the kind in general use throughout lower Virginia and Mary- 
 land, and to such small extent as has been used in North Carolina, 
 and therefore the operation is well known. All the usual and 
 general and highly beneficial effects of marl known, with but few 
 exceptions in the limited districts of eocene marl (hereafter to be 
 described), are due to the miocene marls. And of such effects 
 there have been numerous statements, general and particular. The 
 operation of the eocene marls, and especially those largely mixed 
 with " green-sand," is different, and superior ; but their use has 
 been so limited, and so few statements of effects pviblished, that 
 nearly all the particular results and general statements of effects 
 38* 
 
450 EOCENE MARL. 
 
 yet laid before the public, in tbe "Essay on Calcareous Manures" 
 or elsewhere, have been in relation to the mioceue marls. 
 
 My personal examinations of marl, in place, have not been ex- 
 tended to the Rappahannock. From such information as has 
 reached me, I infer that the marls of that basin are generally much 
 poorer in calcareous matter than those of the basins of James 
 river, York, Mobjack bay, and Piankatuck river. 
 
 Eocene Marl. 
 
 (c) Calcareous marl, coyitaining hut little green-sand. — The ex- 
 istence in Virginia of the marl now known as eocene, was first dis- 
 covered in 1819 by myself, in the south bank of James river, un- 
 derlying the promontory of Coggins Point j and in the same year 
 it was tried as manure. The texture and general appearance of 
 this marl were obviously peculiar ; and its efifccts as manure were 
 .soon also observed to be in some measure different from and supe- 
 rior to those of the other marls, which I had then used, and which 
 were all of the kind now distinguished as miocene. At that time 
 these terms had not been introduced, and for perhaps fifteen years 
 afterwards, I did not so much as hear of the terms "eocene" and 
 '' miocene j" but the difference of age, appearance, and agricultural 
 character of the two kinds were not therefore the less evident and 
 obvious to my uninstructed observation. The manifest difference 
 of effect, as manure, was then ascribed by me to the general if not 
 universal presence of a small proportion of sulphate of lime, or 
 gypsum, in the eocene marl. The belief in the general presence 
 of gypsum was very early induced by my seeing in a few places 
 small crystals overlying and in contact with the surface of the bed 
 of marl ; and also by tbe apparent results of such poor attempts 
 as I subsequently made to ascertain the pi'esence of this substance, 
 by means of chemical tests. Upon such imperfect trials, and the 
 still more imperfect knowledge and skill which I could apply to the 
 investigation, very little reliance ought to have been placed. Never- 
 theless, I thence inferred that there was universally present and 
 diffused through the body of this marl a small proportion of sul- 
 phate of lime, and subsequent agricultur?.l pi-actice has supplied 
 tbe confirmation, which has not yet been sought for by the supe- 
 rior chemical knowledge and skill of any other and later investi- 
 gator. In the earliest publication of my views on calcareous ma- 
 nures in 1821, the gi/pseuus character of this particular body of 
 marl was affirmed, and the peculiar character of the results of the 
 first experiments with it stated.* And in the edition of 18B2 of 
 the "Essay on Calcareous Manures," the general and full descrip- 
 
 * American Farmer, vol. iii., p. .317, and also the same experiments num- 
 bered 18, 19, 20, of tlie present edition of "Essay on Calcareous Manures." 
 
EOCENE MAEL OP OOGQINS POINT. 451 
 
 tlon of this marl was given precisely as it now stands in pages 144, 
 145, of the latest edition. My still earlier discovery of and ob- 
 servations upon the peculiar character of the underlying bed of 
 gypseous or ^^ green-sand" earth (which will be treated of subse- 
 quently), led me to observe the peculiarities of the eocene marl, 
 which being less distinctly marked, might otherwise have escaped 
 my notice. 
 
 As stated above, it was not from any knowledge of geological 
 theories of successive formations, and different ages and periods, 
 of all which I was profoundly ignorant, that my opinion of the 
 peculiar character of this marl was influenced. But judging 
 solely from the more rotten and disintegrated state of the shells,, 
 and their entire disappearance generally, even though their calca- 
 reous material remains — and from the total difference of kind of 
 the few shells remaining whole, or of which the shape is distinctly 
 marked, from any others of the many shells then known to me in 
 any other marls, I very early formed the opinion that this bed was 
 one of the remains or ruins of a condition of the earth much more 
 ancient than that in which the ordinary mai-ls had been formed. 
 I remember having stated this opinion to one of the earliest of the 
 several geologists who at different times visited my dwelling-place 
 and my marl excavations. This was the since notorious Feather- 
 stonhaugh, to whom I pointed out this curious and to me highly 
 interesting deposit, and directed his attention to the more modern 
 and very different (miocene) marl lying immediately upon and in 
 close contact with the much more ancient formation below. This 
 remarkable feature I also showed at a later time to Professor AVil- 
 liam B. Rogers, who was much struck with the fact, and attached 
 so much importance to it, that he has referred to it in several of 
 bis subsequent publications. 
 
 The most ready and certain mode of distinguishing eoc«ne marl, 
 is by reference to some of the shells belonging to this kind, and 
 which are never found in miocene marls. There are many such ; 
 but the most common and well marked are the tvfo following : 1st. 
 The cardita ]}lanicosta, a bivalve white shell, having numerous re- 
 gularly formed flat ridges running from the point at the hinge of 
 the valves to the circumference of the outer or opening parts, and 
 widening as the ridges extend — both valves alike, and having out- 
 lines approaching to circular — sometimes seen four inches across, 
 and the connected valves two inches through ; but generally of 
 much smaller and various sizes. 2d. The ostrea seIla:'/ormis, or sad- 
 dle oyster, a curiously and variously contorted gray and very hard 
 bivalve shell, the larger valve of which approaches the shape and 
 reversed curves of a saddle. This shell is sometimes found more 
 than five inches in length. Both of these shells are abundant, 
 especially the cardita ]pla.nicosiaf in this particular bed of eocene 
 
452 EOCENE MARL. 
 
 marl, and also in the upper part of all the other eocene marls since 
 known elsewhere in Virginia. Without reference to these, or to 
 some other characteristic shells, the eocene marl might not always 
 be distinguishable by its texture or general appearance from the 
 miocene. And even these two shells, the most abundant and 
 characteristic of the eocene formation generally, are neither to be 
 found in the lower layers of any bed that I have been enabled to 
 examine. 
 
 For some years after the first discovery and application of this 
 calcareous eocene marl on Coggins Point farm, it was not known 
 to exist elsewhere. For even where then visible, and at later times 
 used, its different character was neither known nor suspected by 
 its proprietors. As chance furnished to me opportunities of seeing 
 the beds, or as small _ specimens of the marl were sent to me for 
 examination, I gradually came to know the greater extent of this 
 bed. It is now known at various points in an area of about twelve 
 miles in length, from east to west, and eight or ten miles wide, 
 which area takes in parts of the counties of Prince George (which 
 has much the larger knou-n portion), Charles City, and the lower 
 point of Chesterfield. And in this area also is the broad bed of 
 James river, and the lower parts of its tributaries, Appomattox 
 river, and Bailey's, Powell's, and Herring creeks. The marl is 
 exposed to view on the southern side of James river, at the fol- 
 lowing several points : Coggins Point, Maycox (a mile below, and 
 the most eastern exposure as yet known), Tarbay, Wm. H. Harri- 
 son's farm, and Beaver Castle, all above on the river — Eelbank 
 and Hawksnest (the most southern exposure), on Powell's creek — • 
 the Old Court House tract and Spring Garden farm, both on Bai- 
 ley's creek, and the latter from one to two miles above the head 
 of its tide, and three miles south of the Appomattox where oppo- 
 site. Tlte last is the most western exposure. On the northern 
 side of the Appomattox, it is seen in the river bank at Bermuda 
 Hundred, and north of James river, and of Herring creek, at 
 Neston and Evelynton. 
 
 Through nearly all this large area, this bed of marl preserves 
 remarkable uniformity of appearance, texture, chemical character 
 and composition, and even of the thickness of the stratum, and 
 of the succession and variations of character of the several smaller 
 layers of the general body. The bed lies nearly horizontal, but 
 dips slightly and irregularly eastward and northward. At Coggins 
 Point, its lower part is 10 to 12 feet above high tide, while at 
 Maycox, a mile to the east, and at Evelynton, three miles north, it 
 is lower than high tide mark. Yet not so much diflerence of ele- 
 vation as this is seen in all the greater extension westward to 
 Bermuda Hundred. The stratum varies from 4 to 10 feet thick, 
 being thinnest at its south-western exposure, Spring Garden, 
 
EOCENE MARL. 453 
 
 and thickest at the Borth-eastern, Neston and Evelynton. At 
 Coggins Point, -where traced along the face of the river cliff con- 
 tinuously for more than half a mile, it is usually 6 feet thick, 
 never more than 8, and never less than 4 feet, except where 
 terminating. The general and almost uniform colour is a j^ale 
 dingy yellow. The few shells remaining are not perceptible with- 
 out careful ohscrvation, and the whole mass, when dug down for 
 use, is scarcely distinguishable from many common and barren 
 sub-soils, or clay river cliffs, of like colour. Two thin but con- 
 tinuous and separate layers of almost stony hardness extend 
 through the whole bed. These contain from 85 to 90 per cent, 
 of carbonate of lime, and may be burnt to excellent quick-lime 
 for cement. The marl intervening with these hard layers is simi- 
 lar to them in colour and general appearance; but is quite soft and 
 mellow in handling, and in that respect differs from all other known 
 marls. The very uniform calcareous proportion of this part is 
 about 53 per cent. ; and taking an equal section of the whole 
 thickness of the bed, and with the greatest care to obtain a fair 
 average sample, the strength in carbonate of lime was found to be 
 62 per cent. This is far less of calcareous matter than is con- 
 tained by many miocene marls which show less effect than this as 
 manure. But besides its calcareous matter, this eocene marl has 
 some little gypsum, some kind of saline matter which cattle are 
 fond of licking (believed to be sulphate of alumina) and some 
 amount of the granules of "green-sand" — and more of this than 
 most of the miocene marls. The other earth of this marl is mostly 
 of yellowish clay, and composed more of argillaceous than sili- 
 cious matter. I confess that all these additional ingredients, toge- 
 gether, do not seem to me sufficient to account for the superiority 
 which this marl exhibits as manure. 
 
 Though this peculiar kind of marl was so early known, and its 
 value appreciated, and, though it underlies the whole of Coggins 
 Point, yet it is covered there so deeply by the overlying earth, and 
 is therefore so difficult to work extensively, and, moreover, is so 
 distant from the main body of the farm, that this has not been 
 applied to more tlian 65 acres, out of some 700 marled on that 
 farm. Other proprietors have elsewhere made much more extensive 
 applications of this marl. The peculiar effects of this kind of marl 
 were tested with the most accuracy by Messrs. Collier H. Minge, 
 then of Walnut Hill, and Hill Carter, of Shirley ; both of whom 
 used this marl from Coggins Point, water-borne to distances of 
 twelve and fifteen miles. Though the marl was given to them (in 
 the bed), it was yet very costly in the labour of digging and trans- 
 portation ; and therefore they used it with strict economy, and 
 carefully estimated the results. But highly as they both thought 
 
454 EOCENE MARL, 
 
 of, and have rcportod the effects,* in comparison with either lime 
 or aiioceue marls, the expense and trouble were so great, that it is 
 now considered by some of the most judicious farmers on the tide- 
 water rivers, that they can better afford to buy stone-lime, at its 
 present low price (8 to 10 cents the bushel), than to transport 
 marl of any kind by water. This, however, is an erroneous esti- 
 mate. A bushel of such marl is worth more as manure, than a 
 bushel of slaked lime (though slower in operation), and can be 
 transported twenty to forty miles by water, and delivered for 4 
 cents the bushel. 
 
 Since the foregoing pages were written, I have learned of two 
 farther exposures of this body of eocene marl. One is four miles 
 north of Evelynton (in Charles City county), where the marl was 
 reached and penetrated by the digging of a well in 1814. At 
 about thirty feet deep, after passing through the marl, and a layer 
 of rock, water was reached, which rose to the top of the well, and 
 continues to flow over, forming the only Artesian well known in 
 this region. The other locality is in Henrico county, on Turkey 
 Island creek, its eastern boundary, and about eight miles north of 
 City Point. This marl I recognised to be the same, by a s^^ecimen 
 recently brought me for examination. It is below the surface of 
 swampy ground, and is coloured dark gray. It is much fuller of 
 green-sand, and indeed in that respect makes some approach to the 
 green-sand marls of the Pamunkey, of which the nearest exposure 
 is only sixteen miles from this place. It is probable that the marl 
 extends continuously from the one place to the other, and may be 
 found throughout the interval by deep digging."}" 
 
 (fi) The Gypseous Earth or Green Earth of James River. 
 
 Before proceeding to consider the next and only remaining 
 known variety of our marls, the eocene green-sand marl, it is ne- 
 
 * See Farmers' Register, vol. v., pp. 189, 247, 511. 
 
 f After the publication of this report, I first learned, from the examina- 
 tion of hand specimens, that eocene marl -was exposed on the new railway 
 route between Fredericksburg and the Potomac river. The specimens ex- 
 hibited to me were very hard, and seemed (to the eye) to be also poor. 
 
 The most extensive, rich, and valuable body of marl, of the Atlantic 
 States, is eocene, and which I first knew, and then examined extensively, 
 during my Agricultural Survey of South Carolina, in 1843. This im- 
 mense body extends across lower South Carolina, and also the connected 
 parts of both North Carolina and Georgia. The bed is full 300 feet thick 
 under Charleston, and of unknown depth elsewhere. It contains usually 
 from 65 to 90 per cent, of carbonate of lime — has but few whole or distin- 
 guishable fragments of shells remaining — and is of more homogeneous 
 appearance and firm or stony texture than any other beds of marl. 
 
GYPSEOUS EARTH OF JAMES RIVER, 455 
 
 ccssary to treat in advance and separately of the peculiar earthy 
 compound, called "green-sand" by geological writers, of which the 
 large admixture, and sometimes even larger proportion, or other- 
 wise some other ingredient usually accompanying the green-sand, 
 gives additional value and peculiar character and action to the greater 
 number and quantity of the eocene marls yet known in Virginia. 
 But important and valuable as may be the green-sand in itself, and 
 necessary to be considered in connexion with the subject of eocene 
 marl, with which it is so inseparably connected, I wish especially to 
 avoid confounding the two earths under one name or one character ; 
 and to be understood as protesting against the prevalent error, in 
 giving currency to which scientific writers have concurred with the 
 unlearned cultivators, of applying to the non-calcareous green-sand 
 eai"th the name of "marl," and thus adding another, and the most 
 important, to the many previous misapplications of this wonderfully 
 misused and misunderstood term. This misapplication is universal 
 in New Jersey, where the green-sand earth is most abundant, and 
 is generally very rich in its distinguishing ingredient (usually con- 
 taining 75 to 90 per cent, of pure green-sand), and where this earth 
 has been long and is now extensively used as a manure, and has 
 been found to be of great value as a fertilizer. I shall hereafter 
 refer to both the points of resemblance and of difference (both of 
 which are important and interesting,) between this green earth of 
 New Jersey and that of James river; but, for the present, my re- 
 marks will be confined to the latter, and its use as manure, as 
 known principally, and indeed almost entirely, from my own ob- 
 servations and practical experience, there having as yet been but 
 few trials of it made by other persons. 
 
 It was mentioned in the foregoing section, that the first notice or 
 observation of the eocene marl, on James river, was induced by the 
 previous discovery and examination of the green or gypseous earth 
 — the latter being the universal underlying bed of the former, and 
 connected with it in more respects than merely its subjacent posi- 
 tion. It was my chance, or the result of habits of observation of 
 marls and other earths, and not of any scientific knowledge or pi'e- 
 vious preparation for such investigations, which led me, in 1817, to 
 be the first to observe this bed of green earth in the river banks of 
 Evergreen and Coggins Point, and to trace it where visible along 
 the intermediate ground, a distance of about eight miles. Since 
 then, it is known to be much more extended ; for it not only under- 
 lies all the eocene marl of the same neighbourhood, wherever that is 
 found, and part of the yellow sandy miocene, but also extends be- 
 yond, and is found at various places where no eocene or even mio- 
 cene marl is present. The most western limit, seen after a long in- 
 terval, or concealed existence of this formation, is at Petersburg, 
 where it shows in the ravines south of Poplar Lawn. 
 
450 GYPSEOUS EARTH OF JAMES RIVER. 
 
 "What first directed my attention to this earth was the existence 
 in the river bank at Evergreen (tlie place of my birth, and of resi- 
 dence in early life,) of curiously shaped and beautiful crystals, 
 which subsequently I learned were selenite or gypsum. The like 
 crystals (though much smaller in size) I soon after found in differ- 
 ent places at Coggins Point, my own farm and then residence. And, 
 in making examinations for this purpose, I observed that wherever 
 any gypsum could be found, it was always in a peculiar kind of 
 earth, which, though varying much in appearance in different places, 
 and at different elevations at the same place, yet possessed charac- 
 teristic marks by which it could be easily distinguished from all 
 others. This was the earth in question. For want of any known 
 or more appropriate name, I at first applied the term '' gypseous 
 earth" to this deposit; and though I subsequently abandoned this 
 name in (undeserved) deference to scientific authority, and have 
 used instead, in my later publications, the name '''gree2.-sand earth," 
 I now believe that my original term (in reference to the more gene- 
 ral and universal manuring qualities) was the better of the two, for 
 reasons which will appear in the course of these remarks. And 
 besides that " greeu-sand earth" is inconvenient for its length, it is 
 not truly descriptive ; for the entire granules from which the pe- 
 culiar character of the earth is derived, are not green, but black 
 superficially, or so appear; and are not what is usually understood 
 as sand, but in texture ai-e like fine and unctuous clay. Still worse 
 is it to term the whole mass " green-sand," as is usually done when 
 the pure "green-sand," even if that were properly named, may not 
 form one-fourth or even one-tenth of the whole mass of earth. I 
 therefore would prefer for the deposit, and shall use indifferently, 
 either my first designation of gypseous earth, or the name of green 
 earth, which latter is convenient, is sufficiently descriptive, and, 
 moreover, affirms nothing except as to the colour, which is generally 
 manifest in the whole mass, and, if not, is certainly so in the sepa- 
 rated and mashed granules, which distinguish the earth. 
 
 As the lower part of the river bank is mostly exposed and kept 
 bare by the frequent washing by the waves driven by strong winds 
 and high tides, the bed of gypseous earth can be easily traced 
 through nearly its whole course along the river side. As thus ex- 
 posed to view, it has generally a green colour, most frequently in- 
 termixed and mottled with smaller streaks and spots of bi-ight yel- 
 low. The earth, as seen firm in the bank, and with a smooth wasL- 
 ed surface, might be supposed to be somewhat of a clay; but, on 
 handling it, and breaking down a lump, its texture is more like 
 sand ; as indeed the larger proportion of the mass is silicious sand. 
 A very general distinguishing mark of this earth is its containing 
 numerous hollow impressions of eocene shells, of which the forms 
 
GYPSEOUS EAUTH. 457 
 
 remain perfect, though neither the shells themselves nor any portion 
 of their calcareous substance remain, as the earth in this part, and 
 where most generally seen, contains not a particle of carbonate of 
 lime. Among the yellow spots there are also other small spots and 
 streaks of reddish brown-coloured clay, very pure, soft and unctuous 
 to the touch. The bright yellow clay is doubtless largely impreg- 
 nated with iron, or is a true ochre. Though soft within the bed, 
 this yellow ochre hardens when exposed to the air on the outside, 
 and even when uuder water. Many of the yellow spots made by 
 this ochre, as seen on the surface of a smooth section of the bed, 
 have a faint resemblance to the shape of sections of bivalve shells ; 
 and these contrasted with the general green ground, and with the 
 exception of the colours being different, give to such a section of 
 the bank somewhat the appearance of the beautiful black marble 
 used sometimes for mantel-pieces, in which the white traces of what 
 were formerly shells show throughout. In some places near to and 
 below the beach, the earth is seen much darker coloured, indeed is 
 almost black when moist in the bank, though more of dark and 
 dull green when dry. This deeper colour is owing to the green 
 granules being present in larger quantity ; and generally, if not 
 always, the lower part of the bed of earth is richer in that ingre- 
 dient than the upper. The empty impressions which were former- 
 ly filled by shells are still found in penetrating below ; but as the 
 depth increases, first are seen some fragments, and then whole shells, 
 though greatly decaj^ed, and the parts having scarcely any coherence. 
 Still, generally, even below, where these shells are most abundant, 
 their quantity would not furnish as much as two per cent., and gene- 
 rally not one per cent., to the whole thickness of the bed; and, 
 therefore, the carbonate of lime, though of course useful in pro- 
 portion to its quantity, can give no appreciable addition of value 
 to the mass as manure. 
 
 Here and there, but rarely, in the upper and dry part of this bed, 
 crystals of gypsum are found, generally so small as to be barely 
 distinguishable by the eye. In the lower and wet part, gypsum is 
 never visible ; but it is nevertheless believed to be always present 
 in some proportion. 
 
 But the important and most characteristic mark of the green 
 earth is present in the black granules called " green-sand," which 
 give colour to the mass. To ascertain the presence of these gra- 
 nules, let a small sample of the earth or marl supposed to contain 
 them be dried, and then crumbled between the fingers, or, if too 
 hard for that, by being rubbed in a mortar, not too finely and closely. 
 Then take a pinch of the powder between the thumb and finger, and 
 sprinkle it very thinly over a piece of white paper. If any of the 
 separated grains appear black (or green), mash one of them with 
 39 
 
458 GREEN-SAND. 
 
 tlie moistened point of a pen-knife; and if it be "green-sand," the 
 granule will mash like fine soapy clay, and make a vivid green 
 smear. 
 
 For greater accuracy, let the earth (or marl) be well washed by 
 agitation in water, and pour off the pure clay and other lighter mat- 
 ters which will remain longer suspended in the fluid. The grains 
 of green-sand will then be left with nothing else but the quartz or 
 silicious sand, and moreover the former will be made more percepti- 
 ble, in consequence of being cleared by the washing of any previous 
 covering of fine clay. 
 
 My first published account of this earth was made in or about 
 the year 1828, in the old series of the " American Farmer." A 
 much more extended article "On the Grypseous Earth of James 
 River," I afterwards published, July, 1833, in the first volume of 
 the Farmers' Register, beginning at page 207. Though up to that 
 time I had never so much as heard of the term "green-sand," and 
 though I adopted and used the new and unauthorized designation 
 of "gypseous earth," the earth in question was described so minutely 
 and accurately that it was impossible for any intelligent and atten- 
 tive reader of the article, and subsequent observer of the kind of 
 earth in question, to mistake the subject of description. In this 
 piece I also asserted the identity of this gypseous earth with the 
 " green marl" of New Jersey. I trust that I may be pardoned for 
 thus specifying my claim to the first discovery of this earth in Vir- 
 ginia, inasmuch as that merit (if it be one) would be ascribed by 
 every otherwise uninformed reader of the first report of the geolo- 
 gical survey of Virginia, and some other of the publications from 
 the same source, to the author of these pieces.* Upon this occasion, 
 it would be improper to say more on this question than thus con- 
 cisely and explicitly to assert my just rights. 
 
 Before proceeding to offer the more precise and more valuable 
 information concerning this earth obtained by very recent investi- 
 gations, it will be proper to state something of the progress and 
 changes of opinion on this subject, which operated at different 
 times either to encourage or to obstruct the use of this earth as 
 manure. 
 
 From 1818 to 1835 inclusive, I made numerous trials, and in 
 some cases extensive applications of the Coggins Point gypseous 
 earth as manure. The results of my general j^ractice, and also of 
 many particular experiments, noted at the times when made, were 
 reported in a communication to the Farmers' Register, commencing 
 at page 118, vol. is. The effects stated were very different and 
 apparently contradictory — sometimes beneficial and profitable in a 
 remarkable degree, but more generally of little value, or of no 
 
 * Trofcssor W. B, Rogers, formerly Geological Surveyor of Virgiuia. 
 
GYPSEOUS EARTH. 459 
 
 benefit wliatever. The inferences -which I drew from all my expe- 
 rience (and there existed scarcely any other known facts or experi- 
 ments), were that this earth as manure acted in the same manner 
 as gypsum, though more powerfully — and in no other manner than 
 as gypsum would under like circumstances ; that like gypsum, on 
 my land certainly, and as I inferred in our tide-water region gene- 
 rally, this earth had no eifect whatever on any acid soils — and rarely 
 on any other crop than clover (and other leguminous plants), even 
 when properly applied on neutral or calcareous soils ; and that when 
 naturally acid soils were made calcareous by being marled, this 
 green earth then became generally operative thereon as a manure 
 for clover (and for other plants of the clover or pea tribe), in the 
 game manner as is usual in regard to gypsum.* And though the 
 effects, when any were produced, were greater than those of any 
 usual or known dressings of gypsuna, and sometimes in a very re- 
 markable degree, still the failures and disappointments were so many 
 that I did not deem the practice worth being continued. In 1841, 
 my son, the present occupant of the Coggins Point farm, at my 
 request, recommenced the applications of gypseous earth, for ex- 
 periment; and on the clover of this year, 1842, he has extended 
 the dressings over more than 60 acres. f The results were, as in 
 former years, very unequal, and for the greater space of ground 
 covered, unprofitable, and barely if at all perceptible. But on 25' 
 to 30 acres the benefit was remarkably great, and in some cases (of 
 summer dressings) improvement was obvious within ten days after 
 the application. But what was most interesting in the results was, 
 that a clue seemed to be thereby furnished to explain the frequent 
 previous failures of this manure, even when applied to clover grow- 
 ing on neutral or calcareous soil, which are the only circumstances 
 in which it has ever been found profitable in practice. My former 
 applications had been generally made from the upper and greener 
 stratum of the gypseous earth (designated in a succeeding page as 
 C), or if from the lower and blacker part (^D), the digging did not 
 penetrate more than a foot, or, at most and rarely, two feet below 
 the before exposed outer surface. But in the recent larger opera- 
 tion, the digging (made on the river beach) was so much more ex- 
 tensive, as to furnish earth from depths of three or four feet, as well 
 as of portions nearer to and at the surface. I ascribed the remarka- 
 ble differences of effect to the kind and place of the earth; inferring 
 that the exposed parts, and all perhaps near the surface, had, by 
 exposure to air or water, lost a large proportion of the soluble or 
 
 * See these views more fully set forth in the article above referred to, 
 nnd also in another on the green-sand marls of Pamunkey, at pp. 679 and 
 CyO, vol. viii. Farmers' Register. 
 
 f See the facts and results stated in two communications to Farmers' 
 Register, pp. 86, lOo and 252, vol. x. 
 
460 GYPSEOUS EARTH. 
 
 decomposaLlo fertilizing ingredients. As tlie applications had not 
 been made with any view to this question, the experiments are not 
 to be deemed as conclusive, and the correctness of this inference is 
 yet to be fairly tested by future experiments.* But the benefits 
 from some of the dressings, and all of those supposed to be from 
 the deeper digging, were so great, and so speedily produced, that 
 renewed aud strong interest was excited in regard to this manure. 
 The quantity applied was generally 40 bushels of the earth to the 
 acre. And this quantity seemed (from an accurate comparative 
 experiment) to produce as much benefit as 200 bushels. The 
 growth of clover was increased in degrees varying from 100 to 300 
 per cent. And where the application was most successful, the in- 
 crease and profit were sufficient to compensate the expense, even 
 though no further benefit shall be found than in this one crop-^or • 
 that a new application shall be required, and be made, for every 
 succeeding crop of clover, or once in each round of the rotation of 
 crops. 
 
 An observation made by accident last spring led to further i 
 chemical as well as other examinations of this earth, and to im- 
 portant results. Upon heating a lump of it to red heat, I found i 
 that strong fumes wei'e thereby extricated, which were almost suf- , 
 focating if inhaled incautiously. The odour was manifestly sul- 1 
 phureous in part, and principally ; but it seemed not altogether so, i 
 but to be mixed with some other, much like that of muriatic acid 
 gas. Similar trials were made on many specimens, and all the i 
 darker and (as supposed) richer layers of the green earth at Cog- 
 gins Point showed the like result. From specimens of the upper ' 
 and lighter green stratum (C) when heated red, there was nothing ^ 
 of this suffocating odour produced. And it may be useful to state 
 here, in anticipation of subjects to be hereafter more fully consi- | 
 dered, that I subsequently found that the New Jersey green-sand [ 
 earths yielded not a particle of this gaseous product. 
 
 This odour, so far as it was sulphureous, was obviously the pro- j 
 duct of the decomposition (by red heat) of sulphuret [or bi-sulphu- j 
 ret] of iron — which was thus proved to be universally diffused, j 
 though invisible, through all the darker and better kinds of this 1 
 earth. Sulphur would have shown like results, with a much less \ 
 degree of heat ; but it could not be that, because the heat sufficient j 
 to decompose sulphur (and to evolve its fumes) had no such effect | 
 on the earth. I also observed that lumps of the earth, after having ■ 
 been applied as naanure, and exposed on the surface of the ground 
 for some months, often had a smell of sulphur; and, in some cases, j 
 
 * Subsequent experiments have not sustained the above idea. But the j 
 results, though not uniform, have been so generally beneficial on clover, i. 
 that this earth is ai^plied to from 00 to 80 acres every year. 
 
GYPSEOUS EARTH. 461 
 
 the same effect was exhibited in specimens taken from the diggings, 
 and kept dry. The siilphuret of iron, if universally present, would, 
 by its decomposition in contact with carbonate of lime (as when on 
 calcareous land), form sulphate of lime (gypsum). This showed a 
 source for the universal supply of that manure to some extent. 
 Further, my friend Mr. M. Tuomey,* had found sulphate of lime 
 ready formed in specimens of loct earth, which I supposed the least 
 likely to retain that ingredient — and thus was indicated another and 
 more general supply of gypsum already formed. 
 
 The increased interest excited by these new observations, and 
 also the new views as to the cause of the failures of most of the 
 former applications of this manure, induced the sinking of a pit in 
 the gypseous earth, on the river beach at Coggins Point, to the 
 depth of 18 feet below ordinary high tide. This digging for the 
 lower 13 feet was in a very compact and fine clay (^), or clay marl, 
 as it would have been designated in England, from its texture and 
 sensible qualities, but which contained no visible or apparent fer- 
 tilizing ingredient, except a very small sprinkling of shells, and 
 elsewhere some little sulphuret of iron in small lumps and in minute 
 crystals, visible in a few detached spots only. The appearances 
 promised so little of value or remuneration (and less so as the dig- 
 ging was sunk lower), that the work was suspended. But the 
 blacker earth above (Z)) and also the clay (^E) were carried out for 
 experiment on clover (May 26th), of which the first crop had just 
 been grazed off" closely, and the cattle removed. As the season was 
 so far advanced, and benefit so little counted on, the covering was 
 made heavier than in the winter and early spring before (and of 
 which the full benefit had been already seen on the first or spring 
 crop of clover) ; 100 bushels of the upper and better earth, or 1.50 
 of the clay, being applied to the acre. A good rain fell the next 
 night; and in less than ten days there were visible and manifest 
 beneficial effects from both kinds of earth, but better from the upper 
 — which effects increased to fully the doubling of the growth by the 
 1st of August. The hard lumps of the compact clay soon split 
 and crumbled when exposed to the air, and even without rain. The 
 remarkable benefits of these applications induced the resuming of 
 the digging, and another and much deeper pit was dug as early as 
 the other labours of the farm permitted, and a statement will pre- 
 sently be made of the section thereby exposed. But previous to 
 this, it is proper to describe another like operation, and its results, 
 at a more interesting locality. 
 
 The same general appearance of the gypseous earth, and mostly 
 of the poorer kind of greenish colour, mottled with pale yellow clay, 
 
 * Now Professor of Geology and Agricultural Chemistry in tlie Univer- 
 sity of Alabama. 
 
 39* 
 
462 GYPSEOUS ExVRTII AT EVERGREEN. 
 
 is exhibited all along the I'iver bank of Coggins Point and the lands 
 above, to the Evergreen farm — interrupted only by the parts of 
 marshy or more ancient alluvial lands ; or where the stratum has 
 been broken and concealed by the ancient land-slips which have 
 greatly altered the original levels and form of the surface of that 
 whole stretchy of land bordering on the river and overlying the 
 gypseous earth formation. This operation by the land slipping and 
 sinking continues, and some new effects are seen every year. At 
 many places along this stretch, gypsum is perceptible in the green 
 earth, either in crystals or in powder, and sometimes, and rarely, in 
 considerable proportion, say from 5 to 15 per cent, of the whole 
 mass for xevj limited spaces. At the upper part of the river line 
 of the Evergreen farm (at the mouth of Bayley's creek, and two 
 miles below City Point), the river bank has peculiar and remarkable 
 features, which deserve particular notice. It was here, in 1817, that 
 I first discovered this green earth formation, and thence traced it to 
 my own farm and then residence, Coggins Point, and elsewhere iu 
 that neighbourhood. 
 
 The lower visible part of the body of gypseous earth at Ever- 
 green is laid bare by the wasting encroachment of the river (by 
 which it is rapidly washing away), for 200 yards in length. The 
 southern or upper extremity, for some 20 yards, approaches nearly 
 in appearance to the general character of the upper stratum before 
 described. But all the remainder is different, and much richer in 
 the dark or green granules than generally elsewhere. 
 
 Since this article was commenced, Capt. H. H. Cocke, the pre- 
 sent proprietor of Evergreen, at my suggestion and request, had a 
 shaft dug for examination, which, with an extension of my own after 
 he had ceased his operations, added to the natural and higher ex- 
 posure of the section, 27 feet below the beach, and 25 below com- 
 mon high tide. The several strata of the whole section, and their 
 variations, will be described in their descending order. 
 
 At top — 
 1st. Surface soil (sloping back irregularly to the table land, which 
 is much higher), on (2d) gravelly and sandy sub-soil, pervious to 
 water, of various depths — lying on strata nearly all horizontal. 
 Next, 
 10 feet of yellow sandy miocene marl. 
 8 feet of yellowish clay (supposed eocene), intermixed throughout 
 with very small crystals and powder of sulphate of lime — the clay 
 not compact or solid, but open and loose throughout. (Query : la 
 not this the equivalent of the eocene marl at Coggins Point, 
 with its former shells and carbonate of lime completely changed 
 to sulphate of lime, and the greatest proportion dissolved and 
 lost ?) 
 5 feet of gypseous earth — the general colour, green mottled and 
 
THE DIFFERENT LAYERS. 4G3 
 
 streaked with yellow oclire, and full throughout of very minute 
 crystals of sulphate of lime, supposed by the eye to be about 10 
 to 15 per cent, of the whole mass. No shells or casts seen in 
 the part exposed by digging for examination. 
 
 7 feet of brownish mottled clay, feeling smooth and soapy, con- 
 taining numerous small crystals of sulphate of lime. 
 
 9 feet very pure white clay or fuller's-earth, in horizontal layers, 
 separated by veins of the yellow clay (or iron ochre) before- 
 mentioned, other veins of the same sometimes also inclined and 
 crossing the horizontal veins — the outsides of the lumps of clay 
 coloured by oxide of iron. The clay all broken into irregular 
 lumps, as if the fissures had been formed by the contraction in 
 drying of clay soft and distended with wetness. No shells, nor 
 appearance of them, but many pure and transparent and beauti- 
 ful crystals of sulphate of lime here and there, some weighing 
 several ounces. This stratum changing gradually into the next of 
 
 4 feet of dark bluish clay, the colouring matter being green-sand, 
 mottled with irregular streaks of bright yellow, becoming brown 
 below where oozing water begins to show and is reddish with 
 sulphate of iron, or other ferrugitfous matter in solution. This 
 stratum full of large and solid crystals of sulphate of lime, 
 amounting apparently to from 20 to 25 per cent, of the whole 
 mass — the crystals coloured dark gray, because of some impu- 
 rities in small grains (green-sand ?) being enclosed, and diffused 
 through them. No shells. This changing into the next, of 
 
 11 feet of same dark or nearly black clay, nearly uniform colour, 
 and still compact texture, and feeling smooth and soapy — with 
 very few crystals, and much less sulphate of lime than the pre- 
 ceding, but many small and scattered eocene white shells, quite 
 rotten, and being moist, as soft as dough. The shells, mostly 
 several kinds of very large turritellae. Fewer shells as descend- 
 ing. At top of the stratum some large and very perfect speci- 
 mens of the ostrea compressirosti-a(f) To level of the river at 
 common high tide. 
 Below high tide. 
 
 14 feet very similar to the last, the shells very few for the greater 
 part, but increasing near the next. No crystals or other sulphate 
 of lime visible. The green-sand granules coarser — sometimes 
 in small lumps quite pure, or unmixed with anything else. 
 These granules breaking easily, though as if hard or brittle, and 
 not like a soft soapy clay as usual — though as green as before. 
 Many small cylindrical tubes seen (made by the burrowing of 
 pholades, or other shell-fish of the like habits), which seem to 
 be formed on, or coated with pure greeu-sand in mass, and green 
 in colour, and the hollows filled with looser black granules. 
 
 11 feet of shells lying generally close together, and serving to 
 
464 GYPSEOUS EARTH AT EVERGREEN. 
 
 make the wliole stratum a calcareous marl, of perhaps 30 per 
 cent, or more of carbonate of lime — the earth filling the shells 
 and between them being the same black earth, as rich as before 
 in green-sand. At top, some very large and perfect shells of 
 ostrea comjircssirostra, and another much thicker ostrea, not 
 known.* The shells mostly very large turritcllcB of different 
 species — near bottom fewer of these, and mostly crassatellce. 
 The shells nearly as numerous as before, at this depth, at which 
 the digging was abandoned, at 25 feet below tide. 
 
 The whole section, from the top of the highest undoubted 
 eocene stratum to where the digging ceased (without any indica- 
 tion of being near the end), is 61 feet — and if the clay and gyp- 
 sum stratum below the miocene be added, which, though not cer- 
 tain, I believe to be eocene, there would be 69 feet. And if this 
 and the two other Lower clay strata be deducted, there will still re- 
 main 45 feet of strata exposed, all rich in green-sand, and of it 9 
 feet very rich also in sulphate of lime or gypsum, and 11 feet mode- 
 rately rich in carbonate of lime. Such a deposit is well worth the 
 examination of geologists and chemists, and the trial of farmers. f 
 
 It was remarkable that at this place only of all the usual strata 
 of all the then known deposits of green-sand or eocene marl in 
 Virginia, were found exposed, the shells of the ostrea comjyressi- 
 Tostra — and below tide the other before unknown and very thick 
 and heavy ostrea ;| and that at this place there has not been found 
 a single shell of either the ostrea selhrformis or cardita plaiii- 
 costa, the latter of which is so abundant through all other known 
 eocene deposits, and the former in the calcareous eocene else- 
 where. These facts seemed to indicate (as well as the general 
 dip to the eastward) that the strata at Evergreen are much more 
 elevated than the same at Coggins Point — and that by digging 
 deeper, the lower and all the strata of the former might be found 
 
 * One of these last (both valves) -weighed 5 lbs. Mr. M. Tuomey, to 
 ■whose much better information on this subject I ought to defer, supposes 
 this very large and heavy shell to be an 0. compressirostra of unusual age 
 and growth.- If so, however, it is certainly vei-y different in appearance 
 from that shell, as usually seen higher up in this bed, even ivhen wider 
 than this very thick and heavy ostrea. 
 
 [f The lowest known layer of this rich deposit has since been traced 
 three miles westward to City Point ; and from the latter place the marl has 
 been used extensively, and to much benefit. 1851.] 
 
 % This last shell I have since learned (by specimen) is also found in 
 the green-sand marl at North Wales, near the upper termination of the 
 Pamunkey bed — and near the bottom of the marl. And later personal in- 
 spection has shown clearly the identity of the deposits and the fossils at 
 these two points ; one being the bottom of the Pamunkey bed, and tlio 
 other nearly (as is presumed) to the bottom of the James river bed of 
 grccn-sand marl. 
 
GYPSEOUS EARTH AT COGGINS POINT. 4G5 
 
 at otlier parts of the known area (before described) of the eocene 
 formation. 
 
 This inference added to other considerations caused to be sunk 
 the second shaft above-mentioned in the beach of Coggins' Point, 
 130 yards distant from the first one, which by this time had been 
 filled completely by the sand driven by storms and high tides. The 
 digging was made at a low part of the bank, and which therefore 
 did not show either the eocene marl or the miocene, the former of 
 which is seen in the higher bank at a short distance, and both 
 together at the distance of a mile. The different strata of the 
 actual section at the new digging, taken descending from the top 
 of the bank, were as follows : — 
 
 1 foot, surface soil — gray loam. 
 
 7 feet of (drift) pale yellow clay, containing much coarse silicious 
 
 sand. 
 4 feet (drift) rounded or water-worn pebbles, of all sizes, from 4 
 
 inches through to coarse gravel, held together by enough clay 
 
 and ferruginous earth to fill the interstices between the pebbles. 
 
 None of the pebbles calcareous. 
 
 2 feet of (drift) very thin layers of hard and gritty gray clay, 
 alternating with others of coarse ferruginous sand. 
 
 2 feet of poor greenish earth, more than half the surface of the 
 section brown in spots, and indurated with oxide of iron. 
 (Here should be, as elsewhere in the neighbourhood, though 
 
 absent at this particular locality, either one or both, the miocene 
 
 marl (J.), and nest below the eocene calcareous marl (i?) described 
 
 in the preceding pages). 
 
 (C) 9 feet of the ordinary upper layer of gypseous earth — green 
 colour, mottled with spots of bright yellow clay (or ochre), and 
 some other spots of unctuous reddish browa clay. Very slight 
 eflflorescence of gypsum on the surface. 
 
 (JP) 3 feet of darker and nearly uniform colour, almost black, from 
 the greateT proportion of green-sand. This and the preceding, 
 containing many impressions of shells, but no shells or frag- 
 ments, and no carbonate of lime. JMore efflorescence of gypsum, 
 and also on next — 
 
 (Z>) 3 feet of same, except that some shells are seen — and inci^ase 
 in the next to level of river at common high tide. 
 
 (D) 6 feet of same (next below tide) — the shells mostly cardita 
 planicosta — fewer of cytherea and corhula. No ostrea or turri- 
 tella. Small and slender shark's teeth (so called) in perfect 
 preservation, the points and edges being as sharp as in teeth of 
 the living animal. 
 
 (i?) 15 feet bluish gray or lead-coloured clay (from G to 22 feet 
 below tide), having nearly the texture of clay marl. Very com- 
 pact and firm in texture — unctuous to the touch, but not adhe- 
 
46G DIFFERENT LAYERS OF THE BED. 
 
 sive or toiigla — does not bend to pressure, but breaks — cuts 
 smooth, except when the edge of the knife meets parts of shells, 
 or-grains of silicious sand, which, as well as granules of green- 
 sand, are irregularly intermixed throughout. The shells very 
 rotten, and flattened by pressure. Sometimes in masses, or thin 
 bauds or regular layers, becoming less and less in quantity aa 
 descending, and but few seen at and below 10 feet of this stra- 
 tum. Numerous particles of mica throughout. Changing gra- 
 dually to next. At 12 to 13 feet of its depth, many hard lumps 
 of sulphuret of iron. The upper three or four feet of this 
 penetrated by numerous hollow cylinders, of an inch or more in 
 diameter, and in every direction — obviously having been bored 
 by shell-fish. These hollows are filled by the green earth of the 
 stratum above, which thus makes nearly half the mass. (This 
 clay and the layer above (D) were the kinds used for manure 
 from the first opened pit.) 
 
 3 feet (22 to 25 below tide) of brownish and more friable clay, in- 
 termixing at first with the above. G-reen-sand much more 
 abundant than in the preceding, and partly in very large granules. 
 
 3 1 feet (25 to 28 below tide) of very smooth and firm clay, of 
 delicate lilac colour at first, but becoming paler as descending, 
 until nearly white. Splits easily into flakes like thick slate ; and 
 still thinner laminae show that the earth was a deposit in tranquil 
 waters. Thin flakes (not thicker than writing paper), and some- 
 times a mere powder of pure sulphuret of iron visible between 
 many of the layers of clay, and causing them to separate easily. 
 The upper foot of this penetrated everywhere by small hollow 
 tubes (from an eighth to the third of an inch in diameter), which 
 are filled by the brown and green variegated earth of the stratum 
 above — causing a lump when cut smooth to appear like a con- 
 glomerate of difi"erently coloured marbles. Except in these bor- 
 ings, no green-sand deposit, and no shelly matter. The sulphuret 
 of iron, which is through this stratum visible in powder, or thin 
 layers, and above in small masses or lumps, is difi"used through 
 all the strata containing green-sand, except the highest (('). 
 Through this and the upper gray clay (^E) some small black 
 pebbles seen, which appear as if formed by melting. The same 
 found in the eocene marl. A sudden change to the next — 
 
 2 J feet (282- to 31 below high tide) of remarkably smooth and 
 unctuous, but firm clay of reddish brown colour (or dull brick 
 red), and homogeneous texture as well as colour. Cuts as smooth 
 as the best hard soap. Deposited in thin lamina?, and breaks or 
 splits easily in straight lines both in the direction of the laminae 
 and lengthwise at right-angles to their direction — the grain and 
 fracture appearing like that of rotten wood. Across these two 
 directions; the fracture very uneven. Near the bottom of the 
 
THE DIFFERENT LAYERS. 407 
 
 richest green stratum (i)) there is a barely perceptible oozing 
 of water. All below dry, and the two last strata remarkably 
 dry. They could not be more so if within three feet of the 
 surface of a high knoll, and in summer. 
 1 foot (31 to 32 below tide) of same as the last in texture, but of 
 
 pale blue colour. 
 1 foot (32 to 33 below tide) mixture of the last, in small lumps 
 imbedded in the next, as if broken up by a violent current, and 
 deposited in rapid water. 
 17 feet (33 to 49 below tide, the lowest digging) black earth — 
 richest in green-sand (supposed to be 40 per cent.) mixed with a 
 few fragments (less than 2 per cent, on an average) of shells, 
 mostly small, and all very rotten. Kinds, mostly of turritella 
 (some of which are large), myfylus, corhula, and crassatcUa . 
 Many small and a few large shells of ostrea comjiressirostra near 
 the top of this stratum and again near the lowest part, where 
 the work was stopped by the water rising from below. 
 The whole, so far as dug, added to the before exposed bank, 
 amounted to 66 feet of the eocene deposit, of which 49 feet was 
 below the level of high tide. The last stratum, which was pene- 
 trated for 17 feet before the rise of spring water compelled the work 
 to be discontinued, was manifestly the same with that at Evergreen 
 which was even with high tide (and extending above and below), 
 and which was there 25 feet thick. It was a subject of much re- 
 gret, after so much labour, that the still lower stratum, full of shells, 
 could not be reached, and which probably might have been done in 
 8 feet more of digging. However, enough was done to show that 
 the quantity is inexhaustible of the layers richest in green-sand 
 (whatever may be that degree of richness), independent of the 
 other layers. 
 
 Besides the main object of this laborious examination by digging 
 as low as possible, to learn more of the quality and quantity of the 
 earth for manure, and as a matter of curiosity, there was another 
 inducement. The whole bottom of the river across to Berkley 
 (below the thin covering of loose and soft mud), according to its 
 variation of depth, must be formed of one or another of the same 
 layers shown in this digging of 49 feet below the water level ; and, 
 of course, Harrison's Bar, which lies between the Coggins and 
 Berkley shores, must be so formed. No earth more strongly re- 
 sists the washing action of water than the gypseous earth, even 
 when the least mixed with clay. This peculiar quality must be 
 the cause of the existence of this bar, which presents so serious an 
 obstacle to the navigation of the river ; and it may be thence in- 
 ferred what would be the degree of difficulty of its removal, and 
 also that the removal, if effected, would be permanent. 
 Various and contradictory as had been many of the results of 
 
468 GREEN-SAND OF NEW JERSEY. 
 
 my experiments of the green earth as manure, there had been per- 
 fect agreement in some respects. Thus, as before stated generally, 
 the earth has never been beneficial as manure on acid soil — but 
 rarely on corn, and never (directly) on wheat ; and (on proper soils) 
 generally and greatly beneficial on clover, and perhaps all plants 
 of the clover and pea tribe — and the efi'ccts, Trlien produced, have 
 never been permanent, nor even very durable. And the efi"ects 
 shown in these points of agreement were nearly all the reverse of 
 those ascribed to the New Jersey green-sand. In regard to these 
 effects, in the absence of all certain and particular information to 
 be obtained otherwise, I found it necessary to seek information in 
 person. The results of my inquiries and personal examinations, in 
 general, showed that the green-sand (called marl) of New Jersey, 
 though agreeing in some respects with ours in action as manure, is 
 operative generally on the greater number of soils and on most 
 crops, and is also very durable in effect. On the other hand, much 
 larger quantities are applied there (usually 200 bushels, and some- 
 times 400, or more, to the acre) than I have done with ours ; and 
 something of the more general benefit and longer duration may 
 perhaps be owing to that circumstance.* Whether the green-sand 
 is indeed the principal, or a very important manuring agent, of the 
 James river earth, or whether the other ingredients may not be 
 still more active than its green-sand, is yet undecided. f 
 
 It is indeed strange that such doubts should exist at this late 
 day as to the manuring action and effect of this earth — and still 
 more so that the chemical composition and ingredients of the 
 earth should not have been long ago ascertained. Yet previous to 
 the recent imperfect application of tests above referred to, there 
 had been no known full or correct chemical analysis made of the 
 earth in question ; nor even any partial examination for and report 
 of the ingredients, that was entitled to any respect for accuracy 
 and fidelity. For these reasons I engaged the services of Professor 
 C. U. Shepard, for the analyses of specimens which I selected from 
 the different strata of the earth, at Coggins Point, exposed in re- 
 cent diggings, including several which had been tried as manure, 
 and had operated with remarkable power and benefit. His report 
 of the partial analyses, which has been received since the preceding 
 and subsequent portions of this article were written, will now be 
 
 * See report at length on the New Jersey green-sand, and its operation, 
 at page 418, vol. x., Farmers' Register. This deposit is of secondary for- 
 mation, -while that of Virginia is of the tertiary. This difference of age and 
 probably of the materials of the formation would seem to indicate a differ- 
 ence of chemical constitution — as there certainly is of manuring operation. 
 
 f [I have lately heard that phosphate of lime had been discovered as an 
 ordinary accompaniment of the green-sand of New Jersey, in the clay 
 which is a regularly existing ingredient. I do not know what reliance may 
 be jilaced on this report. — 1851.] 
 
GREEN-SAND. 4G9 
 
 presented. It enables me to furnish more of -what is valuable, be- 
 cause more certain than everything else I could offer, or than has 
 before been offered to the public on this subject — prominent as it 
 has been made in the reports of the geological survey of Virginia. 
 
 " iSfew Haven, October 20, 1842. 
 
 "Dear Sir — The specimens of green-sand and accompanying eartlis have, 
 agreeably to your request, received my particular attention ; and I now 
 proceed to apprise you of the results at which I have arrived. 
 
 " Commencing with the mechanical analysis of the green-sand, I was not 
 a little suuprised to find that the green particles, when cleared by washing 
 of a slight investment of clay, assumed the aspect of chlorite and green 
 earth, and more rarely of grains of serpentine and fine scales of mica. The 
 other ingredients of the earth were chiefly grains of quartz (some of which 
 were penetrated by chlorite), and more rarely specks of garnet, iron pyrites, 
 and what appeared to be yellow phosphate of lime. Fragments of shells, 
 in a very decayed state, occur disseminated through the earth ; and I de- 
 tected also small teeth and bones of fishes. The proportions of the leading 
 ingredients are very difficult to establish with precision ; and after all my 
 examinations I can only give them approximatively, and within wide limits. 
 Thus, the quartz grains may be said to constitute from GO to 80 per cent., 
 the chloritic and micaceous grains from 10 to 15 percent., and the fine clay 
 from 3 to 5 per cent. 
 
 " Nothing is plainer than that the green particles possess the character 
 here attributed to them ; since they jjut on all the properties so common to 
 chlorite, being sometimes in regular hexagonal plates, though usually in 
 little granules made up of impalpable grains, which under the pestle easily 
 separate, with an oily feel, into bright green specks. Subjected to acids 
 and heat, it agrees with true chlorite. 
 
 " The existence of such a mineral in the present formation oifers nothing 
 remarkable in a geological point of view, since it may have originated in 
 the decomposition of chlorite slate rocks, or of veins in primitive rocks (in 
 which chlorite often abounds), and in both cases iron pyrites is its common 
 attendant. Besides, it may have been derived from the metaraorphosis of 
 pyroxene, or from amygdaloidal traps, a source of green earth very often 
 recognised in Europe and America. Indeed, chlorite (which is but another 
 name for green talc) is often interchanged for mica, as an ingredient of 
 primitive rocks, and is everywhere little prone to decomposition, being, on 
 the whole, one of the most persistent of the simple minerals. 
 
 "Neither can it be objected that its chemical constitution is incompatible 
 with the results obtained for green earth ; for here we must bear in mind, 
 also, that it is impossible acciu'ately to separate the green particles from 
 the mica, serpentine, and other ingredients with which they are associated. 
 
 " M. Berthier found the following composition in the green grains from 
 the green-sand of Havre (France) — 
 
 Silica 50.00 
 
 Protoxide of iron 21.00 
 
 Alumina . • 7.00 
 
 Potassa 10.00 
 
 Alumina 11.00 
 
 99.00* 
 
 " Mr. Seybert found in that of New Jersey — 
 
 * Geological Manual, by H. T. de la Beche, Phila., 1832, p. 255. 
 40 
 
470 ANALYSIS OF GREEN-SAND. 
 
 Silica 49.83 
 
 Alumina 6.00 
 
 Magnesia 1.83 
 
 Potassa 10.12 
 
 Water 9.80 
 
 Protoxide of iron / 21.53 
 
 Loss 89 
 
 100.00* 
 
 "Prof. Wm. B. Rogers found in the green-sand of Virginia — 
 
 Silica 51.70 
 
 Protoxide of ii'on 25.20 
 
 Potassa 10.33 
 
 Water 10. 
 
 Magnesia, a trace 
 
 97.2.31 
 
 " The foregoing may be taken as a fair exhibition of the composition of 
 the green particles in green-sand ; and the following analyses may serve to 
 show the constitution of such chlorites and mica as may be presumed to be 
 most analogous to the green substances in the earth under consideration. 
 M. Vauquelin found in the green-earth of Verona — 
 
 Silica 52.00 
 
 Magnesia 6.00 
 
 Alumina 7.00 
 
 Protoxide of ii-on 2.S.00 
 
 Potassa 7.50 
 
 Water . . . . • 4.00 
 
 99.50+ 
 "Dr. Thomson found in the chlorite-earth, from the highlands of Scot- 
 land — 
 
 Silica 48.166 
 
 Magnesia 2.916 
 
 Alumina 16.851 
 
 Oxide of iron 19.000 
 
 Potassa 6.558 
 
 Lime 2.675 
 
 Water 2.350 
 
 98.718?, 
 "The composition of the most common silvery mica fromZinwald (Bohe- 
 mia) was ascertained by M. Klaproth to be the following — 
 
 Silica 47.00 
 
 Alumina 20.00 
 
 Potassa 14.50 
 
 Ox. iron 15.50 
 
 Ox. manganese 1.75 
 
 98.75|| 
 ' Having described the grounds on which I arrive at the conclusion that 
 
 * American Journal of Science, vol. xvii., p. 277. 
 f Farmers' Register, vol. ii., p. 131. 
 j Shepards' Mineralogy, vol. ii., p. 225. 
 
 I Idem, ii., p. 225. 
 
 II Idem, ii., p. 41. 
 
MODE OF ANALYSIS. 471 
 
 the gi'cen grains of this cartli are chlorite, or chlorite blended Tvith mica, 
 and rarely specks of serpentine, I cannot but express the opinion, that as a 
 mineral manure the efficacy of the green particles has been greatly over- 
 rated. As these particles are vei-y little liable to decomposition, their ac- 
 tion, whatever it may be, must be slow, and, I should infer, nearly imper- 
 ceptible. Indeed, I am rather disposed to regard its favourable operation, 
 if indeed it has any, as flowing from a mechanical agency, after the man- 
 ner of a clay, than as arising from the liberation of its potassa through 
 chemical decomposition. Not that I would call in question the usefulness 
 of the earth taken as a whole, for happily this is too well established. But 
 when I find a decided content of sulphate of lime, with carbonate and phos- 
 phate of lime in addition thereto, together with distinct traces of organic 
 matter, it appears to me unnecessary to look any farther in order to account 
 for the phenomena in the case. 
 
 " I now proceed to state my method of examination, together with the re- 
 sults obtained. 
 
 " The specimens were kept in a dry room, exposed to air in shallow dishes, 
 for several weeks ; after which, portions free from crystals of sulphate of 
 lime visible by the naked eye, and large fragments of shells, were heated 
 in a platina capsule to 300°, Fah., in order to expel hygrometric moisture, 
 and subsequently to low redness, to decompose organic matter.* The or- 
 ganic matter is very inconsiderable, and was in no instances rigidly de- 
 termined. 
 
 " Having ascertained by experiment that the iron-pyi'ites was not decom- 
 posable by tepid dilute hydrochloric acid, the following method was resorted 
 to for the determination of the phosphate of lime. Two hundred grains - 
 of the triturated earth were suffered to stand (with occasional agitation) in 
 contact with a dilute hydrochloric acid for three hours. The whole was 
 then transferred to a filter, and the earth well washed thereon, with abund- 
 ance of tepid water. The clear fluid and washings thus obtained were 
 super-saturated with ammonia, and the precipitate subsequently digested 
 in a warm potassic solution for the removal of the silica and the alumina. 
 The per-oxide of iron and phosphate of lime now remaining, after being 
 well washed, were treated with a cold, dilute acetic acid, whereby the 
 phosphate alone was taken into solution. It was then precipitated by 
 ammonia, dried, ignited, and weighed. Having found reason to believe 
 that the proportion of finely divided phosphate of lime was pretty uniform 
 in the different specimens of the green-sand, I was only at the pains to 
 determine its exact proportion in specimen No. l.f Having ascertained 
 how much per-oxide of iron each sample contained, this amount was de- 
 ducted from that yielded by the treatment of the same specimen with nitro- 
 hydrochloric acid (aided by gentle heat), whereby the sulphuret of iron 
 was decomposed. Thus the exact quantity of iron which was engaged by 
 the sulphur (and consequently the amount of bi-sulphuret of iron) was 
 ascertained. 
 
 " The carbonate of lime was determined in the usual way, viz., by treating 
 the first obtained solution in hydrochloric acid with ammonia, whereby the 
 
 *This last step was always attended with the extrication of a little sul- 
 phur. 
 
 ■f I will here observe that, by the process now described, it was ascer- 
 tained that had the whole of the precipitate by ammonia from the hydro- 
 chloric acid solution been taken for phosphate of'lime, it would have in- 
 volved the error of an over-estimate of the phosphate by nearly 800 per 
 cent. 
 
472 ^ ANALYSES OP Gll'SEULfS EARTH. 
 
 silica, alumina, per-oxide of iron, and phosphate of lime were thrown down, 
 leaving the lime and magnesia alone in a state of suspension. The former 
 ■was precipitated by oxalate of ammonia, and subsequently the latter by 
 phosphoric acid. 
 
 "The sulphate of lime was ascertained by boiling a determinate quantity 
 of the green-sand in water until the whole of this salt present was taken 
 into solution. The clear solution was treated with chloride of barium, and 
 the sulphate of baryta ignited and weighed. The sulphuric acid present in 
 the earth was thus arrived at, an..'^, by subsequent calculation, the sulphate 
 of lime oi'iginally present was ascertained. 
 
 " Sulphate of alumina (but no sulphate of iron) was found to exist, in 
 traces, by the precipitation of alumina, occasioned on the treatment of 
 the water boiled on the earth with ammonia. But in each case it was too 
 inconsiderable for the determination of its proportion. Chloride of calcium 
 (muriate of lime) was ascertained by treating the same fluid with nitrate 
 of silver. Its proportion did not exceed that in which it exists also in 
 common soils. 
 
 " Results obtained on sjiecvmens of green-sand earth froyn Coggins Point, James 
 
 river. 
 
 *"No. 1. From 8 inches within the exposed side of a ravine, where a 
 stream flowed by, and 15 feet from the top of the green earth.'* [Mid- 
 dle part of stratum D, see page 465.] 
 
 Hygrometric moisture (lost at 300°) . . . 5.50 
 By heating to low redness, it lost in addition 2.03 
 
 Phosphate of lime 0.25 
 
 Carbonate of magnesia, in decided traces. 
 Sulphate of alumina, in traces. 
 " 'No. 3. Same as number 1, except from a deeper excavation.' 
 Hygrometric moisture (lost at 300°) . . . 4. GOO 
 By heating to low redness, it lost in addition 2.200 
 
 Carbonate of lime 1.550 
 
 Bi-sulphuret of iron 3.0G6 
 
 Carbonate of magnesia and sulphate of alumina in traces. 
 Phosphate of lime, about as in number 1. 
 
 Sulphate of lime 0.813 
 
 " 'No. 6. Three feet below the river beach [from pit, lower part of D, 
 half a mile distant from preceding.'] 
 
 Hygrometric moisture 5.400 
 
 By heating to low redness, it lost in addition 2.060 
 
 Carbonate of lime 0.535 
 
 Bi-sulphuret of iron 2.060 
 
 Sulphate of lime 0.661 
 
 Carbonate of magnesia and sulphate of alumina in traces. 
 Phosphate of lime as in number 1. 
 " 'No. 9. See foregoing, page 465. This alone having sulphuret of iron 
 visible in powder, or minute crystals ;' [taken from 14 feet below the 
 beach, in E.~\ 
 
 * This specimen was not thoroughly analyzed, and therefore the contents 
 are reported but in part. The next (No. 3) was deemed the most important, 
 and a more correct specimen of this layer (D), and therefore to it the 
 examination of Prof. Shepard was especially requested, and was so directed. 
 It is therefore that the contents of bi-sulphuret of iron, carbonate of lime, 
 and sulphate of lime are not stated of No. 1, as in No. 3. E. 11. 
 
ANALYSES OP GYPSEOUS EARTH. 473 
 
 Carbonate of lime 2.350 
 
 Ei-sulpliuret of iron 5.821 
 
 Sulphate of lime 2.309 
 
 (Carbonate of magnesia not found.) 
 " 'No. 10. Several thin layers of compressed shells, 1 to 3 inches thick" 
 Lcontained in stratum U."] 
 
 Carbonate of lime 56.00 
 
 Phosphate of lime 0.84 
 
 "No. 2. [Z>] from 4 feet lower than number 1, vras examined with results 
 similar to 1 and 3. 
 
 "No. 4. [Z>] from 4 feet below beach, and half a mile from number 1, was 
 found to be rich in sulphate of lime and to contain bi-sulphuret of iron. 
 
 "No. 5. [Z>] 'From another spot, and has since been exposed to the 
 weather from last winter to June on the field where applied as manure.' 
 Is richer than No. 2 or 4 in sulphate of lime, but inferior to cither in bi- 
 sulphuret of iron. It likewise affords more sulphate of alumina than any 
 sample examined. 
 
 " 'No. 11. The clay at 16 to 18 feet deep ;' [supposed when selected to 
 be the poorest part of stratum U.] 
 
 Carbonate of lime 1.45 
 
 "It is rich in sulphate of lime, and has traces of sulphate of alumina, 
 and bi-sulphuret of iron. 
 
 " It is to be kept in mind that in these analyses no account is taken of 
 such sized crystals of sulphate of lime as readily meet the eye, or of large 
 fragments of shells, the occasional presence of both which must often 
 essentially enhance the gypseous and calcareous contents of these samples. 
 The proportions in which they may occur at different depths and localities 
 can readily be determined, however, by the practical agriculturist. The 
 same may be said of the jDhosphatic ingredient so far as the teeth and 
 bones of fishes are concerned. 
 
 If we assume the average proportion of bi-sulphuret of iron in these 
 earths to be 2 per cent., and suppose the wliole of the sulphate to become 
 oxydized, it would give rise to 2.722 per cent, of sulphuric acid ; to saturate 
 which would require 1.905 of lime, and thereby i^roduce 4.G27 per cent, 
 of (anhydrous) sulphate of lime. Eut 2.722 of lime would demand 3.383 
 per cent, of carbonate of lime in the soil. Now in the three analyses (Nos. 
 3, 6, and 9), made, the bi-sulpihuret of iron, by average, equals 3.649 per 
 cent., and the carbonate of lime in the same equals but 1.478 per cent. — 
 a quantity too small for the saturation of the acid, even after a liberal 
 allowance is made for the increase of calcareous matter from the occasional 
 presence of large fragments of shells. 
 
 "It would therefore appear to be an obvious deductron from these inqui- 
 ries, that dressings of lime, and especially of calcareous bands, like No. 
 10, should be employed in conjunction with the green-sand soil. 
 
 " Having now replied in the best way I am able to your various inquiries, 
 I leave it for you to make such other practical inferences from the inform- 
 ation afibrded as in your more experienced judgment it may seem to 
 authorize — and remain, very respectfully, your obedient servant, 
 
 CUAELES UpUAM SuEPARD." 
 
 "Edmund Ruffin, Esq." 
 
 The specimens numbered above 1, 2, 3, were from one locality, 
 
 and of earth which was used as manure for clover of this year, 
 
 on marled land, with effect as great as any ever known ; and with 
 
 no certain benefit on an adjoining space (also in clover), of the 
 
 40* 
 
474 GYPSUM THE OPERATIVE INGREDIENT. 
 
 same soil naturally, but not marled. Numbers 4, 5, and 6, were 
 from the pit dug iu the beach, half a mile distant, apparently 
 similar to each other, and to the preceding specimens. All these 
 are of the dark stratum (Z>) richest -in green-sand (except the 
 lowest, E), and all before rated by me as containing 50 per cent, 
 of the pure granules. Professor Rogers stated the same to contain 
 GO to 70 per cent. (See F. Register, vol. ii., p. 750.) Even if leaving 
 the green-sand out of consideration, and out of the estimate of 
 value, there would still remain enough of active manuring princi- 
 ples to produce a large share (at least) of the beneficial effects which 
 I have found from the use of this earth ; and I have heard of but 
 few other applications in Virginia, other than those made on Coggins 
 Point form, and of none with different or better certain efi'ects. 
 With the help of surplus carbonate of lime in the soil (furnished 
 by nature or by previous marling or liming), 100 bushels of this 
 earth, averaging in strength the ingredients of these specimens 
 analyzed by Professor Shepard, would furnish nearly 5 bushels of 
 pure sul2)hate of lime (gypsum) ; and 40 bushels to the acre would 
 furnish 2 bushels of sulphate of lime. Not one of these specimens 
 contained any gypsum visible to the eye ; and but one specimen 
 (number 9) contained any visible sulphuret of iron; and therefore 
 these ingredients may be fairly supposed to be at least as abundant 
 in the earth dug in any considerable operation. What the green- 
 sand or any other ingredients may do in addition, I pretend not to 
 estimate. But so far as I have learned from my own experience 
 and all known experience of other persons, the whole operation of 
 this earth, when used alone, is precisely of such kind as I would 
 anticipate from gypsum, though yielding more of benefit in mea- 
 sure and value. Nor should I therefore be understood as placing 
 a low estimate on the value of the effects produced. Since seeing 
 the effects this year, and especially since having formed the opinion 
 that the upper and exposed parts (most generally used formerly) 
 are comparatively worthless and should be avoided, I count on 
 much benefit being derived from this manure, and am desirous that 
 it shall be largely used; as my son and partner, and the sole 
 director of our farming, proposes to do for the next year's growth 
 of clover. Still, I am now as far as ever from believing in or ex- 
 pecting such great and regular benefit as would be inferred to be 
 certain from views and statements which rest upon the authority 
 of the former geological surveyor of Virginia.* 
 
 * Professor Shepard, in the above letter, asserts the identity of the gra- 
 nules of "green-sand," with chlorite, or green talc. The proportions of 
 the constituents of chlorite are far from being uniform ; though the same 
 kinds are usually found, iu various proportions. Of these, magnesia seems 
 to be always present. If so, may not this be an important manuring ele- 
 
EOCENE GREEN-SAND MARL. 
 
 475 
 
 It may not be useless to note another point of recent resemblance 
 between these two manures, both of which seem so capricious and 
 uncertain in operation in general. This year (1842), the applica- 
 tions of the green earth on the Coggins Point farm, whether made 
 in the beginning of the winter preceding, in March, or in the be- 
 ginning of summer, have acted more quickly and powerfully than 
 any known before. This I had ascribed to the earth being mostly 
 obtained from deeper excavations. But I have lately heard, from 
 Messrs. Hill Carter and John A. Selden, both extensive and ex- 
 perienced and successful users of gypsum, that they have never 
 before known the good effects of that manure to be so remarkable 
 as in all their applications of this year. 
 
 (c7.) Eocene green-sand marl. 
 
 Except in the lower stratum exposed in the pit recently dug at 
 Evergreen, this peculiar and valuable kind of marl has not yet been 
 known to me in Virginia elsewhere than on and near the borders 
 of the Pamuukey river; though there can be but little doubt that 
 this or other eocene deposits are to be found elsewhere than within 
 the limits here stated of the now known localities. It is more than 
 probable that other rivers cut through and expose some of the eocene 
 as well as miocene deposits; and that deep diggings would reach 
 them also in the intervening high lands. The Pamunkey eocene 
 formation is seen first, or exposed most south-eastward, at North- 
 bury in New Kent county ; and it is found (either as marl or gyp- 
 seofts earth) on nearly every farm above, to South Wales, in Hano- 
 ver, the farm of Mr. William F. Wickham, just below the junction 
 of the North Anna and South Anna rivers, and on North Wales, 
 the farm of Mr. Williams Carter, across the Pamunkey, in Caroline 
 county. This distance in a straight line is about 22 miles ; and 
 
 ment of our green-sand earth, as well as that of New Jersey ? Cleaveland 
 gives the followiug contents of three difi'erent kinds of chlorite, ascertained 
 by different chemists: 
 
 Chlorite — analyzed by 
 
 Vauqueliij. 
 
 Klaproth. 
 
 Iloepfner. 
 
 100 parts consisted of 
 
 
 
 
 Silex 
 
 2G. 
 
 53. 
 
 41.15 
 
 Alumina 
 
 18.5 
 
 12. 
 
 6.13 
 
 Magnesia .... 
 
 8. 
 
 3.5 
 
 89.47 
 
 Lime 
 
 0. 
 
 2.5 
 
 1.5 
 
 Oxide of iron .• . . . 
 
 43. 
 
 17. 
 
 10.15 
 
 Muriate of soda and potash 
 
 2. 
 
 0. 
 
 0. 
 
 Water 
 
 o 
 
 11. 
 
 99. 
 
 1.5 
 
 9y.50 
 
 99.90 
 
 Vauquelin found a specimen of common talc to contain 27 per cent, of 
 magnesia. — Cleaveland. 
 
476 GREEN-SAND OR GYPSEOUS MARL. 
 
 the very -winding course of the Pamunkey serves to make the ex- 
 posure of the bed of marl show an average width of three or more 
 miles. Throughout this area, it is found in great abundance at 
 numerous points — though of great variety of appearance and of 
 value at different elevations, and in very different degrees of access, 
 or "ease of working. 
 
 This marl everywhere has its calcareous portion (which is usually 
 small in comparison to good miocene marls) intermixed with a 
 large proportion of green-sand. The calcareous earth varies from 
 10 to 40 per cent, at different diggings, or different layers at the 
 sarne locality; and the green-sand perhaps from 10 to 30 per cent, 
 as estimated by the eye. In some places, the one ingredient pre- 
 dominates in quantity, and elsewhere the other. No one specimen 
 has been found rich in both of these ingredients. 
 
 There are various and very different kinds of earth, if considered 
 in reference to their chemical constitution and qualities, and values 
 as manure, which together make up this extensive area and great 
 depth of the eocene formation; and all of which varieties, however 
 different, have in common been deemed and termed marl by the 
 people of the neighbourhood. That all these various earths belong 
 to the same eocene formation is evident from the fossil remains, or 
 from other as certain proofs where there are no such remains visi- 
 ble. The principal and most notable of these different earths will 
 be here described. 
 
 The most extensive exposure of calcareous marl, which I will 
 designate as L, (and embraces beds 4 and 5 in the profile view, 
 which will be hereafter given), is along the river for five or six miles 
 in a straight course, above and below Newcastle ferry ; and a very 
 much longer course, if following the crooked course of the Pamun- 
 key. This marl is more than 24 feet thick at Clifton, the farm of 
 Mr. J. W. Tomlin, next below Newcastle ferry. From that locality, 
 it becomes thinner in the extensions both up and down the river. 
 At two miles above the thickest part, it gradually thins out to 
 nothing, in Marlbourne farm (my own property) ; and before reach- 
 ing the nearest outline of Marlbourne, this marl (L) is barely 2 feet 
 thick, and not worth for use the cost of removing the overlying 
 drift or other earth. This marl and all the other accompanying 
 beds, are inclined; the dip being towards the east or south-east. 
 The ancient flood proceeding from the north-west had washed away 
 the highest raised western parts of all these beds, and reduced them 
 to their now nearly horizontal surface; and this ancient "denu- 
 ding" action is the cause of this marl, and the other beds, succes- 
 sively thinning out at the surface as proceeding up the river. 
 
 This most extensively exposed body of marl is of four principal 
 kinds, without noticing some less important differences. The lower 
 6 or 7 feet of its thickness (x) and which includes all of 4 in the 
 
GREEX-SAND OR GTrSEOUS MARL. 477 
 
 figure, except tlie black line at bottom), is the richest in calcareous 
 matter, and much the best as manure. This is mostly of compact 
 and uniform earthy texture and appearance — of dark gray colour, 
 with a greenish tint in some cases. The shelly matter, for the 
 greater part, is finely reduced, the fragments being generally so 
 small as not to be obvious to the sight. But few shells, mostly of 
 the harder gray kinds, remain entire ; and of these, the saddle oyster 
 furnishes nearly all of the perfect and still very hard specimens. 
 Near to the bottom of this layer the marl is somewhat softer and 
 poorer, and yet the entire though very soft shells are there nu- 
 merous. This marl (a;) contains from 35 to more than 40 per cent. 
 of carbonate of lime, on an average. 
 
 Above this richer part (./;), the marl (marked 5 in the figure) is 
 softer, and in some degree admits the slow penetration of water, to 
 which the other marl (x) is a perfect barrier. In other respects 
 this (y) appears to the eye very similar, and not less rich in calca- 
 reous matter than that below. But in fact it does not contain more 
 than proportions varying from .30 to as little as 11 per cent., and 
 usually becoming poorer as nearer to the top of this layer. This 
 marl (_y), more generally than the richer below, I have found to 
 contain finely divided sulphuret (or bi-sulphuret) of iron, as does 
 the gypseous earth of James river, and also the gypseous earth of 
 Pamunkey. This combination of sulphur and iron, when exposed 
 to air, changes gradually to sulphate of iron (copperas) ; and this 
 last, and the carbonate of lime of the marl, decompose each other, 
 and one of the new products is sulphate of lime (gypsum), in place 
 of proportional quantities of the decomposed copperas and shelly 
 matter. This process has doubtless been proceeding for ages in the 
 bed, though very slowly for want of air ; and has served to remove 
 much of the formerly existing shelly matter — which was fii'st thus 
 changed to sulphate of lime, and this soluble substance was then 
 mostly carried off by the slowly percolating water. This decom- 
 position and subsequent removal of the lime also served to make 
 pervious the before compact and impervious marl, and thus per- 
 mitted more easily the progress of further decomposition and re- 
 moval of the former calcareous portion. However much of the 
 produced gypsum has been thus slowly dissolved and removed, there 
 is still a considerable proportion remaining. Thus, this part (_y), 
 especiall}^, not only contains a notable proportion of gypsum before 
 formed by this process, and not yet removed in solution by the 
 slowly percolating water — but there is also generally present (in y 
 especially), more of material, in the as yet undecomposed sulphuret, 
 to form more gypsum hereafter. I infer that this mode of conver- 
 sion of part of the carbonate to sulphate of lime has served to more 
 or less diminish, and in some layers to remove entirely, the consi- 
 derable amount of carbonate of lime formerly contained. More 
 
478 GREEN-SAND OR GYPSEOUS MARL. 
 
 carbonate must be so changed to sulphate of lime, after any marl 
 which still contains sulphuret of iron, is applied as manure. The 
 exposure to air (and attraction of oxygen) will soon convert the 
 yet remaining sulphuret to sulphate of iron ; and this will imme- 
 diately act on the carbonate of lime, in contact, and so form sul- 
 phate of lime. This proportion of gypsum, either ready formed, or 
 soon to be formed, making altogether from 2 to 6 per cent, of the 
 marl, is one of the main sources of the early (but, as I anticipate, 
 transient) fertilizing effects of this and other varieties, which are 
 poor in calcareous matter. The long continued action of the sul- 
 phuret of iron (which seems to be still generally present, and may 
 be inferred to have been universal at first in all the beds) is suffi- 
 cient to account for the partial or total disappearance of shells, and 
 of carbonate of lime, in nearly all these layers of the one great 
 eocene bed of marl and gypseous earth, both of Pamunkey and 
 James river. 
 
 A third variety (u) exists but in few places, and on the northern 
 Bide of the river. It is the highest of this whole calcareous bed — 
 is dry and yellowish (being nearly or quite destitute of green-sand 
 and organic colouring matter), and though as rich in carbonate of 
 lime as the average of the whole stratum (and richer than all i/), it 
 is much inferior in fertilizing effects, at least for some years, and as 
 long as they have been separately observed. It may be inferred 
 that this light-coloured marl is not only without the potash (which 
 green-sand contains in small proportion), but also without gypsum ; 
 and, like nearly all miocene marls, acts only by its carbonate of 
 lime. 
 
 A fourth variety (2;) is the universal thin bottom layer of this 
 calcareous stratum (and below x — represented by the broad black 
 line in the figure), which forms a continuous layer of separate 
 stony lumps, like a pavement, and varying from 6 to 15 inches 
 thick. These stony masses contain 60 per cent, or more of car- 
 bonate of lime. Being difficult to dig, and to raise, this layer is 
 usually left by most marlers. On account of its greater richness, I 
 deem it the most valuable for its quantity. In a few years after 
 being ploughed under the soil, most of these lumps are softened 
 enough to crumble. 
 
 These several layers of this one general calcareous stratum con- 
 stitute the marl mostly used in latter years, by the marling farmers 
 of this neighbourhood. My own use has embraced all these varie- 
 ties, but was mostly of the more compact earthy marl (x), as that 
 was in greatest quantity. 
 
 Another bed of rich calcareous marl (M,) is exposed for the few 
 miles of the most western extremity of the general eocene forma- 
 tion, iu the farms of South Wales in Hanover, and North Wales 
 in Caroline county, and extending nearly to the lowest part of the 
 
OLIVE EARTH. 479 
 
 granite range, which makes the foils of this and other rivers. Thig 
 marl is darker coloured (nearly black in the bed), and apparently 
 richer in green-sand than the former kinds, and also nearly as rich 
 as the best (x) in carbonate of lime. I found of this bed, in dif- 
 ferent specimens selected by myself from the pits of Messrs. Wm. 
 F. Wickham and "Williams Cai'ter, proportions varying from 32.50 
 to 44 per cent. This kind also contains some finely divided and 
 diffused sulphuret of iron; and consequently, gypsum, if not al- 
 ready present (as I infer is always the case), must be formed from 
 the changes of the sulphuret after the application of the marl. 
 
 This bed, though lying the highest, where exposed, in its pre- 
 sent level and elevation, is the lowest in order of all the different 
 beds of this great eocene formation. Below it is a bed of gravelly 
 sand and rounded pebbles, without any appearance of fossil remains; 
 or manne deposition. 
 
 For some 12 miles (if in a straight line, but following the much 
 longer course of the river), and stretching from the final thinning 
 out of the marl (a;, or 4), in Marlbourne farm to the first appear- 
 ance (of M, or 1) in South Wales, the whole interval is filled by 
 difiercnt layers and kinds of green or gypseous earth. The general 
 appearance is much like that of Coggins Point, before described, 
 but generally containing some little admixture of shells. For a 
 considerable part of this exposure, this gypseous earth is as desti- 
 tute of shelly matter, and as deficient in other fertilizing matters, 
 as I have found, or supposed, to be the upper or exposed parts of 
 the James river gypseous earth. In some layers there is enough 
 of shelly matter to make from 2 to 5 per cent, of the mass. Also 
 there are some bands of a few inches thick only, quite rich in shells. 
 In other places, there is no carbonate of lime ; and although some 
 gypsum and less potash must be present (as in general of all these 
 eocene beds), this poorer earth (miscalled ''marl") has been found, 
 when used as manure, of little effect, and less profit. 
 
 Overlying all the exposed upper marl and green earth of this 
 whole eocene formation (and also extending south-eastward over 
 the nearest miocene) is an unconformable layer of variable but 
 always small thickness of what is here known as " olive earth," 
 from its greenish brown colour. (It is designated by the broad 
 irregular baud o, o, in the figure.) It varies from a few inches to 
 4 feet of thickness — is not uniform in texture — but usually very 
 adhesive (as found wet in the bed), and difficult to remove. My 
 observations have satisfied me that this earth was formerly marl, 
 or rather a mixture of all the different layers of marl and green 
 earth now below, which after being washed up by the violent cur- 
 rent of the ancient denuding flood, was, during a cessation of the 
 greatest violence of the current, deposited over the Avhole before 
 denudal and then bare surface. Subsequently, the violence of the 
 
480 OLIVE EARTH. 
 
 current vras renewed, and witli it were brouglit and deposited tlie 
 layers of drifted pebbles, sandy gravel first, and nest sand, -whicli 
 now overlie all the olive earth and eocene formation. This lower 
 sandy gravel is ferruginous, and everywhere supplies ferruginous 
 spring-water, and probably the impregnation being partly in the 
 form of sulphate of iron. Both the sulphates of iron and of 
 alumina are sometimes perceptible to the sight and taste, in these 
 strata. The slowly oozing spring-water thus bringing either of 
 these salts of sulphuric acid, must gradually decompose any carbo- 
 nate of lime in contact. And hence, the higher deposit of what is 
 now olive earth, being permeable by water, has had all its former 
 carbonate of lime changed to gypsum, and this, in solution, mostly 
 removed by the water passing oif. If these suppositions are correct, 
 the olive earth ought still to contain all that it did formerly, when 
 it was marl, except the carbonate of lime; and with some increase 
 of sulphate of lime. Hence, this earth ought to have more or less 
 of fertilizing value — and enough to be worth using, especially as 
 its very laborious excavation and removal have always to be 
 effected, for the purpose of reaching the marl below. But it was 
 universally believed that the olive earth was useless j and it was 
 put to no use, not only by those farmers who had good marl below, 
 but by others who encountered all the labour of uncovering, and 
 removing this sticky and troublesome layer, to reach merely the 
 gypseous earth below, probably worth no more than the olive earth, 
 except for its very small proportion of carbonate of lime. While 
 I drew marl from other land to my present farm, the distance was 
 too great for me to try this olive earth as manure. But since I 
 have (very lately) discovered good marl, of workable thickness, on 
 Marlbourne farm, I have carried out all the overlying olive earth, 
 though it is more sandy here than is usually found. I had begun 
 this course before having heard of any useful effect of such appli- 
 cation. But since (in the summer of 1852), I have learned very 
 remarkable effects of other (and probably much richer) olive earth, 
 as tried by two neighbouring farmers, Messrs. Henry Jones and 
 John Beale. The most accurate and conclusive of these trials 
 (though all were very beneficial) was an application of this earth 
 alone, 400 bushels to the acre, on stiff and poor (long exhausted) 
 land. The application was made for the corn crop of 1850, and 
 produced not much, if any, perceptible effect. The benefit was 
 much greater, though still small, on the succeeding crop of wheat. 
 But of the next following clover, which I saw in May and June, 
 1852, the growth was more luxuriant than any on the richest other 
 land; and the effect of the olive earth alone, was greater on the 
 clover (as compared with adjacent ground without this or other 
 dressing) than from marl, with its unquestionable accompaniment 
 of gypsum, or other manure elsewhere on similar lands of this 
 
GYPSEOUS EARTH OF PAMUNKEY. 481 
 
 nciglibourhood. Still, I believe that gypsum is the principal ma- 
 nuring principle — and that these wonderful effects will therefore 
 be confined mostly to clover (or other leguminous plants), during 
 its temporary action. The remains of bones and teeth also are 
 more numerous in this olive earth (immediately above the marl) 
 than anywhere lower ; and hence this layer, apparently, is better 
 supplied with phosphate of lime — a manure of very great and 
 peculiar value for other crops, and especially for wheat. 
 
 All these different beds, or thinner layers and varieties, of this 
 great eocene formation, except the high yellowish layer («), con- 
 tain either a considerable or a large proportion of green-sand — 
 and of course some little potash — which, as chemists inform us, is 
 a universal though small proportion of green-sand. Also, from 
 the very general indications either of white and tasteless efflores- 
 cence, or of manifest sulphuret of iron, or both, I infer that gypsum 
 also is a very general, if not a universal ingredient, to some amount. 
 
 Until within the few latter years, all the various layers and 
 qualities of the whole eocene formation, were confounded in com- 
 mon understanding and parlance, through this neighbourhood, under 
 the one name of ''marl." The green or gypseous earth was used 
 indiscriminately with the calcareous marl, by those proprietors who 
 had both exposed by the same excavations, without their looking 
 for or observing any difference of operation. The existence of this 
 strange error, and its general continuance (in this neighbourhood) 
 for eight or ten years, can only be accounted for by the following 
 circumstances : The two different layers were generally obtained in 
 the same excavations, and were more or less mixed in use — and 
 never kept entirely separate for experiment : The soils (of Pamun- 
 key low-ground) being mostly or nearly neutral, did not exhibit 
 much effect from marl on the earlier grain crops, (as acid and much 
 worse soils would have done — ) and when clover followed, the great 
 benefit which that crop always received from the large quantity of 
 gypsum in the green earth, even if with very little admixture of 
 calcareous matter, would make nearly as much show on that crop 
 as the marl alone. And before these early and transient benefits 
 of gypsum would be ended, perhaps another slight dressing of 
 marl would be applied, or some other treatment which would help 
 to conceal the respective opei*ations of these different manuring 
 earths. 
 
 But more lately, no farmer of this neighbourhood has deemed 
 the green earth worth applying as manure, if he could obtain 
 marl. Still, some who have easy access to the former only, have 
 begun its use within the last few years, and so far, they report 
 encouraging results — which the gypsum, with very little shelly 
 matter, can furnish for a few years. And so inveterate is esta- 
 blished error, that some other farmers, even to this day, would 
 41 
 
482 INUTILITY OF GREEN-SAND AS MANURE. 
 
 prefer a green-sand marl, however poor in carbonate of lime, to 
 any miocene (or other) marl thrice as rich in the latter and all-im- 
 portant ingredient, but destitute of the misunderstood and there- 
 fore highly prized green-sand. This erroneous view is the result 
 (and the only abiding result to agriculture known to me) of the 
 statements and instructions of the late geological surveyor, and his 
 exaggerated and unmodified panegyrics on the asserted value of 
 green-sand as manure — the " discovery" of which in Virginia was 
 claimed as his own, and cried up as the greatest possible benefit to 
 agricultural improvement. Yet still (and long before that gentle- 
 man had either written about green-sand, or seen so much as a hand- 
 specimen), my own use of this earth alone, far exceeded in quan- 
 tity all other applications in Virginia, and has only since been ex- 
 ceeded in amount by the later applications of my son and successor 
 on Coggins Point farm ; and no user of it has yet been rewarded 
 for his labour, from any possible efi"ects of the green-sand alone. 
 All the aj)preciahle and known benefits have been produced by the 
 gypsum, or the carbonate of lime, or both, used generally in con- 
 junction. Where neither of these aids was present, either in 
 the manure or the soil, I have never yet heard of a profitable use, 
 in Virginia, of the earth having no manuring ingredient save the 
 green-sand. Still, I do not deny that it may be valuable — and 
 should be much gratified and greatly profited as a farmer, to be 
 assured that such value and profit as have been claimed for this 
 earth are indeed available. In my own extensive trials of the 
 green earth of James river, and the still more extended and more 
 beneficial recent applications on my former property, by the present 
 proprietor, there has been no eifect found that could be ascribed to 
 green-sand, or to its potash — or to anything but the gypsum, and 
 that only on either marled or naturally calcareous or neutral soil. 
 And in the much more extended practice of my neighbours on the 
 Pamunkey, who have largely used this earth as marl, but almost 
 always more or less intermixed with some carbonate of lime, there 
 is nothing in the known efi'ects which would go to contradict the 
 opinions on this subject which I have here concisely, and formerly 
 at greater length, expressed. It is important to know all the value 
 of this earth as manure, and to avail ourselves of it fully; but to 
 do that, it is essential that the true source of the beneficial opera- 
 tion should be known, and that the delusion produced by the 
 influence of scientific but undeserved authority, should end, as it 
 surely will, soon or late. 
 
 The occurrence of the very different appearances and qualities 
 of this formation, as found by digging, or in the natural exposures 
 on the river banks, has been generally deemed altogether irregular 
 and subject to no rule of position. Hence it was supposed that the 
 
ORDER OF THE PAMUNKEY BEDS. 483 
 
 finding of marl, by boring in places where the existence was not 
 before known, and the variety or quality of whatever could be 
 so reached, were matters of chance. Of course all searches for 
 marl, by boring, were directed by no rule except that of selecting 
 surfaces of low level. And this one object was mistaken, and would 
 often cause the concealed marl bed to be missed by borings made in 
 its close neighbourhood. For if in land of alluvial formation, the 
 ancient flood most generally had swept off all the previously exist- 
 ing marl, and the vacancy so made was afterwards filled by either 
 the succeeding drifted earth, in part, or entirely by still later allu- 
 vial deposits. 
 
 But if proper attention is given to the general dip of the whole 
 formation, and the succession of the different layers, as exposed 
 naturally, and nearer the surface, or to some extent in perpen- 
 dicular cuts and excavations, there may be found reliable indica- 
 tions of the position of each layer in other places. With the aid 
 of this guide it might be generally known, in advance of all search- 
 ing, and for miles of surface upon which the seeker for marl had 
 never trod, whether and where marl would probably be found, and 
 of what quality, and where there would be none worth working. 
 
 This very thick formation, or bed of many layers of different 
 qualities, as has been stated, has a general dip to the south-east, or 
 down the general course of the river. In the opposite direction, 
 up the river, or as proceeding north-westward, all the layers, (unless 
 running out earlier,) in succession, rise above the level of the river; 
 and concequently, each of these layers, in succession, becomes the 
 upper one at some locality, and is there the first and perhaps the 
 only one to be reached by digging. And as the ancient flood had, 
 by its denuding action, washed away all these raised edges of layers, 
 and so made a new surface approaching to horizontal, it follows 
 that each layer, after ajipearing as the highest and most accessible 
 at some place, thence thins out as proceeding westward, until that 
 layer disappears, and the next one in order, below, becomes there 
 the highest and most accessible layer. The figure of the following- 
 section, though for much the greater part conjectural, will serve for 
 better explanation, and may serve to indicate, either as to this or 
 other beds and localities, how to direct searches for concealed marl, 
 with the best prospect of success, and to avoid the loss of useless 
 examinations. The supposed surface line is designed for the south- 
 ern side of the Pamunkey, and the eocene beds (and overlying 
 miocene also, in part) where exposed nearest to the river. The in- 
 clination of the dip, and also the perpendicular distances, are both 
 greatly magnified in proportion to the horizontal distance, for the 
 purpose of making the successive layers more distinct, and of 
 bringing the whole extent of surface within convenient size. 
 
Wf.ST, 
 
 South Wales. 
 Broadneck. 
 
 Stevenson's. 
 
 Gold Hill. 
 
 Summer Hill. 
 Dabney's Ferry. 
 
 Spring Garden. 
 Marlbourne. 
 
 Newcastle. 
 Ferry. 
 
 Clifton. 
 
 Farmingtan. 
 Springfield. 
 
 Ketreat. 
 Nortlibury. 
 
 Hampstead. 
 
 High lands. 
 J ] East. 
 
OllBER OF THE TAMUNKEi' BEi>S. 485 
 
 Explanations of profile, or perpendicular section 
 
 a, a, Level, or surface of Pamuiikey river — air-line between extremes of 
 
 section, 26 miles. 
 
 b, b, Surface of land, " second lovr ground" nearest to river. 
 
 1, 1, The lowest, and 8, 8, the highest bed of the whole eocene formation, 
 of marl and gypseous earth of various kinds. 
 
 0, 0, Layer of olive earth laying on the raised and denuded ends of lower 
 
 beds, forming the present upper surface of the eocene formation. 
 e, e, Sandy gravel and rounded pebbles, lying beneath the lowest eocene 
 bed. 
 
 1, 1, Lowest bed — rich marl, rising above river and exposed at South 
 
 AVales. 
 
 2, 2, Green or gypseous earth, without calcareous matter. 
 
 3, 3, 3, 3, Green or gypseous earth beds, with very small and variable 
 
 amounts of shells, cither in thin bands, or very slight general admix- 
 ture. All poor as manure, and mostly not worth using. More shelly, 
 and richer otherwise, where highest and next to 
 
 4, Lower and richer part of the upper calcareous beds of the eocene, 
 
 (designated as L and x and y), in foregoing general description, 
 stony layer (z) at bottom. 
 
 5, Upper and softer part of the good eocene marl — poorer jn calcareous 
 
 matter, and containing bi-sulphui-et of iron, generally. 
 
 6, Green or gypseous earth, with some calcareous matter — or poor marl. 
 
 7, Green earth, destitute of calcareous matter, and worthless as manure. 
 
 8, Green earth, with some calcareous matter, or poor marl. 
 
 9, Miocene marl of Hampstead, lying immediately on the eocene bed. 
 
 10, Ordinary miocene marl, lying higher than the Hampstead bed. 
 
 The various beds of this formation, in regard to estent, succes- 
 sion, and particular qualities (as before intimated), are represented 
 mostly upon conjecture. Even of the actual exposures above the 
 •water-line (a, a), I have seen but a small extent ; and, of course, 
 as to what is below the depth of actual excavations and the river, 
 all rests on conjecture, or reasoning from analogy. Neither is it 
 designed to be conveyed that the different strata or layers preserve 
 the regular proportions of thickness, as represented in the figure. 
 On the contrary, it is more usual for each different layer to vary 
 much in thickness, in a long stretch of distance, and in some cases 
 to " run out," and come to an end. Still, after making due allow- 
 ance for all such sources of uncertainty and error, this figure, and 
 the judicious deductions which every reader may make for the fea- 
 tures of his own locality, may be of great use in searching for the 
 richest layers of marl, and still more in avoiding such labour when 
 certain to be disappointed. According to this conjectural section, 
 if it were possible and useful to sink a shaft, or boring, deep enough 
 on the most eastern point exhibited, every separate layer or bed 
 would be reached in regular succession. It might be as low as 300 
 feet or more — but at some depth it is probable that the rich marl 
 (M.) now only known (and accessible) at the north-western extreme, 
 could be reached under the south-eastern, or more than twenty miles 
 41* 
 
486 bULPIlURET OF lllON IN GYPSEOUS EARTH. 
 
 distant. But omitting such merely speculative matters, there are 
 practicable and profitable operations to be based on the knowledge 
 of the succession and dip of the strata. Thus, when the existence 
 of rich marl is known in any point, and its depth, it is almost cer- 
 tain that it will thin out towards the north-west, and cither thicken, 
 or maintain its then thickness, as proceeding south-eastward. Oa 
 land north-westward of the disappearance (at top) of a rich bed, 
 (as 4), and however near, it would be in vain to search for the like. 
 The boring for any practicable depth on most of the river land of 
 Marlbourne (for example) could reach only the poor beds exposed 
 at the surface for some ten miles, including the beds marked 3 and 
 2, perhaps, also. But on land south-eastward, and near to the 
 surface exposure of any rich marl, it might be expected to reach 
 the like at some greater depth. The lowest eocene marl which I 
 reached by sinking the pit for examination 25 feet below tide on 
 Evergreen (described p. 462), and which must have been near to 
 the bottom of the lowest bed, exhibited the same peculiar appear- 
 ance, and some of the peculiar fossils, which are also to be seen in 
 (M) the lowest of the Panmnkey layers, and at an exposure thirty 
 miles distant. In no other localities had I seen cither the same 
 appearance of marl, or the same rare shells, as some of both common 
 to these places only. In the much deeper pit sunk for examina- 
 tion on Coggins Point (p. 405), though the rising of water at 49 
 feet prevented deeper digging, the fossils then reached indicated 
 the near approach to the same lowest marl found at less depth at 
 Evergreen, and exposed much above the river at North and South 
 AVales. Hence, it may be inferred that this lowest and very pe- 
 culiar bed of this great formation, as well as the formation generally, 
 is continuous under all this broad surface of territory. 
 
 Many specimens of the marl and gypseous earth of the Pamun- 
 key beds, were made partially red hot, for the purpose of showing 
 whether sulphureous fumes were so disengaged, as was stated on a 
 foregoing page (460) to be the case with most specimens tried of 
 the James river gypseous earth. This result was obtained in all 
 of sundry trials of the gypseous earth (3) below the marl (4) — in 
 the marl at South Wales (M), and in some cases, but not generally, 
 of the richer marl 4. In the still higher and poorer marl (5), 
 which I lately have excavated extensively in the Clifton bank, the 
 sulphureous fumes were obtained in every trial. A specimen of 
 marl from Pipingtree, and many specimens of the gypseous earth 
 (upper part of 3) from Newcastle ferry, Newcastle farm, and from 
 Marlbourne, all gave out these fumes. Sundry other specimens of 
 calcareous green-sand marl which were thus treated, yielded no 
 fumes. The latter results were found in specimens from the several 
 diggings at Newcastle (both sides of the river), and at Mr. G-. AV. 
 Bassctt's bank, Parmingtou. It may not be useless to repeat hero, 
 
GREEN-SAND SUPPOSED IN MIOCENE MARLS. 487 
 
 and thus to place in connexion with these results, that all the dark 
 green or blackish earth (Z>) of Coggins Point gave out these suf- 
 focating fumes, and also the gray clay (^E) below, and most power- 
 fully — and that no such product was found from any of the very 
 shelly bands. Thus it would seem that most generally the non- 
 calcareous earths (or nearly non-calcareous) gave out fumes, and 
 the calcareous not. But exceptions were found to both. And of 
 the New Jersey green-sands, containing no carbonate of lime, six 
 specimens were tried at red heat, of the beds most esteemed for 
 manure, and not the slightest disengagement of such fumes was 
 produced.* 
 
 This extrication of sulphureous fumes by the first beginning of red 
 heat, is a sure indication of the presence of sulphuret (or bi-sul- 
 phuret) of iron. And wherever this exists in contact with marl, and 
 with the access of air and water, first the sulphate of iron will be 
 formed, and next this salt will decompose as much carbonate of lime 
 as its quantity will act upon, and so form gypsum. Therefore, 
 wherever the sulphuret of iron is present in marl, or is put in con- 
 tact with it, in soil, it is certain that, in the same proportion, carbo- 
 nate of lime will be decomposed, and sulphate of lime formed. Of 
 course no addition of other gypsum is needed, or could act if 
 Applied, on land recently supplied, in marl, with enough sulphuret 
 of iron, even if the parti9,l previous decomposition of the latter 
 had not already formed gypsum in the bed of marl, as is usually 
 the case. 
 
 Of Green-sand as an ingredient of Miocene Marls. 
 
 In a previous page (439), the presence of green-sand in miocene 
 marls, as an important and general ingredient, was denied ; and the 
 subject then passed by, with the promise of its being subsequently 
 resumed. Having treated of the gypseous earth and of eocene 
 green-sand marls, of both of which green-sand forms large and im- 
 portant proportions, it is now most appropriate to inquire into the 
 alleged extent and operation of this substance in miocene marls. 
 
 In 1834, Professor William B. Rogers (then and long before a 
 resident of lower Virginia) announced that he had discovered green- 
 sand to be a considerable ingredient of nearly all the many ordinary 
 miocene marls which he had examined either in place or by speci- 
 mens ; and from which observations he inferred the same admix- 
 
 * The New Jersey "marls" thus tried were selected by the writer from 
 the pits of Josiah Heritage and Thomas Bee of Gloucester, and Henry 
 Allen, Allen Wallace, J. Riley, and J. Cauley, Salem county. The same 
 results were found as to the poorer (or less valued) overlying strata of 
 Heritage, R. Dickenson, J. Cauley, and also of the barren green clay or sub- 
 soil. See all described in my report on the New Jersey green-sand earths, 
 Farmera' Register, vol. x. p. 429, 
 
488 rROFESsuii roukks' discuv±;iu'. 
 
 turo to bo general as to other miocene mai-ls ; and that the propor- 
 tions of green-sand so contained were large enough to form useful 
 additions to, and in some cases the most valuable portion of the 
 manuring ingredients of such marls (Farmers' Register, vol. ii., p. 
 129). At a later time, he added to like general opinions and state- 
 ments the following : " In some of these deposits [marl beds in the 
 vicinity of Williamsburg], so large a proportion as 80 and in 
 some specimens 40 per cent, [of pure green-sand] has been found; 
 and in cases like this, if we are to trust to the experience of New 
 Jersey, a very marked addition to the fertilizing power of marl 
 must be ascribed to the presence of this ingredient." (Farmers' 
 Register, vol. ii., p. 747.) In a subsequent communication to the 
 Philosophical Society of Philadelphia in 1835, and again in the first 
 report of the geological survey of Virginia, the material parts of the 
 above statements are re-asserted, in substance, and nearly in the 
 same words. These statements and opinions were received, when 
 announced, as undoubted, and they have not since been questioned 
 in any publication ; nor have they since been either confirmed by 
 any additional proof or testimony, nor have they, in direct terms, 
 been modified or retracted by their author. Yet the correctness or 
 incorrectness of the assertion of such abundance and general diffu- 
 sion of green-sand in the miocene marls of Virginia is a matter of 
 great interest ; and, in its bearing on the application of marl and 
 the rationale of its operation, of great importance to agricultural 
 improvement. It is certain that to this day [1842], many proprie- 
 tors consider that their marls are peculiarly valuable because of the 
 supposed large proportions of green-sand therein ; such opinions 
 being founded either on the publications, or, with still more confi- 
 dence, upon the personal examinations and verbally expressed 
 opinions of the former state geologist. 
 
 My own personal examinations of marls in place, and analyses of 
 specimens of other beds, have been very extensive; and my atten- 
 tion has been given especially in regard to this point to sundry 
 specimens, including several of the particular bodies of marl which 
 it is understood that Professor Rogers had pronounced to be very 
 rich in green-sand — containing, say, 20 to 30 per cent, of the black 
 granules so called. I have found some gi-een-sand (but generally 
 in very small proportion) in nearly all the specimens examined 
 particularly for this substance ; and believe that Professor Rogers 
 was correct so far as inferring that it is a very frequent ingredient. 
 And for the first observation of this curious and interesting fact ho 
 is justly entitled to the entire credit. To such extent as green-sand 
 is present, and according to the manner of the operation of that 
 earth (whatever that may be), the green-sand in the miocene marls 
 must be effective and useful. But whether such cflTect be of any 
 distinguishable and appreciable value, or not, depends on the quan- 
 
EXAMINATION OF ITS WORTH. 489 
 
 tity and proportiou of green-sand in the marl ; and, so far as all my 
 experience and observation enable me to judge, I cannot but believe 
 that the above stated estimates of quantities and proportions of 
 green-sand are greatly exaggerated, and extremely incorrect and 
 delusive. I do not mean to assert, and cannot be expected to prove, 
 the negative of the assertion of such abundance of green-sand. But, 
 from all my means for arriving at conclusions, it is my confident 
 belief that but few of the bodies of miocene marls in Virginia con- 
 tain as much as 2 per cent, of green-sand — if even as much as 1 per 
 cent. ; and that an average proportion, throughout any considerable 
 digging for manure, of as much as 5 per cent, of green-sand is 
 extremely rare. With but a single peculiar exception, which 
 will be described presently, the largest proportion (estimated by the 
 eye) that I ever found was supposed to be 5 per cent. ; and that 
 was in a very peculiar marl, found at Coggins Point farm and else- 
 where in that neighbourhood, or rather a loose calcareous sand, 
 which forms the overlying layer of a compact blue marl. This sand 
 contains only about 20 per cent, of finely divided shelly matter, and 
 the whole mass would appear, to slight observation, similar to, and 
 as poor and as loose, as the deep sands of the roads through a sandy 
 country. But few persons would have used this sand for manure, 
 or would have dignified it by the name of marl. Howevei", the 
 case with which it could be worked, and the necessity for removing 
 it to uncover the better marl below, induced me to carry out and 
 apply it as a second dressing to an adjacent part of a field which 
 had been just before marled from the richer blue layer. The eftects 
 were so marked, and so superior to the single marling, that I was 
 ready to believe that the green-sand caused the difference. The 
 loose calcareous sand mentioned at page 443, which one of my 
 neighbours supposed (from its good effects) to be rich in calcareous 
 earth, is precisely like mine in general appearance, and in position 
 in the bed ; and appears to have a like unusually large proportion 
 of green-sand, which no doubt served to produce some small part 
 of the benefit which was ascribed wholly to the carbonate of lime. 
 This peculiar deposit furnishes the only cases known to me of any 
 ordinary miocene marl (if this loose sand can be so termed) being 
 rich enough in green-sand for the benefit from the latter to be 
 known. And even this benefit would not have been distinguished 
 or suspected, but that the poverty of the earth in calcareous matter 
 required it to be applied very heavily. The much thicker body of 
 compact marl, lying under this poor calcareous sand, contains (by 
 supposition) not so much as 2 per cent, of green-sand. 
 
 But it is true, that when attention was not particularly directed 
 to green-sand, proportions not exceeding 5 or G per cent, might 
 have escaped the notice of one who had handled and examined 
 the specimens of marl, or who even analyzed them, merely with a 
 
4r,0 TESTIMONY IN OPPOSITION. 
 
 view to their proportions of calcareous matter. But proportiong 
 so large as 40, 30, or even 20 per cent, of green-sand could not 
 thus escape even careless and superficial observation ; for even the 
 smallest of these proportions would give a very manifest greenish 
 or gray tint to any otherwise light-coloured marl. Knowing the 
 great uncertainty of the gucssings at proportions of green-sand 
 naturally intermixed with marl or other earth, I did not rely on 
 them except as to the absence of any very large proportion. For 
 more accurate testing, the clayey parts were washed off in water ; 
 in others the calcareous parts were also removed by weak acid. 
 And for still better means of judging by comparison, I mixed toge- 
 ther, in different and known proportions, measured quantities of 
 light-coloured marl (such as are all those about Williamsburg), and 
 pure green-sand prepared by washing some obtained from the 
 richest beds in New Jersey. And of such artificial compounds, 
 examined by the eye both when dry and in powder, and wet, and also 
 after being again dried in mass, the admixture of green-sand, even 
 when as small as 10 per cent., was obviously more abundant than 
 in the miocene marls reputed to be among the richest in green-sand. 
 Under these circumstances, without denying the possible existence 
 of such cases, it is proper to wait for and to require further proofs 
 of assertions of such large proportions as 20 to 40 per cent. 
 
 But there is much better support for my position, of the general 
 scarcity of green-sand in miocene marls, than any proofs, positive 
 or negative, that I can adduce, presented by Prof, llogers himself, 
 in his " Report of the Progress of the Geological Survey" for 1837. 
 He therein gives a tabular statement of 148 specimens selected by 
 his assistants, and their analyses made under his own direction. It 
 is to be presumed that so many specimens, and thus obtained, must 
 present a fair and correct average of general quality of the marls 
 of the region in which they were found ; or at least that their con- 
 tents would not be too little favourable to the geologist's preconceiv- 
 ed opinions, or assertions. The specimens were from eighteen coun- 
 ties, viz. : Lancaster, Westmoreland, Richmond, Northumberland, 
 King George, Mathews, Middlesex, Gloucester, King and Queen, 
 King William, Essex, Isle of Wight, Nansemond, Elizabeth City, 
 Surry, Prince George, James City, and Warwick. Of these 148 
 specimens, of one only (S. Downiug's, Lancaster) is the quantity 
 or proportion of green-sand stated with any approach to precision. 
 This is said (no doubt by guess) to contain '" 10 or 12 per cent, of 
 green-sand," and only 17 per cent, of carbonate of lime. Of five 
 others, the green-sand would seem to be in notable quantities, but 
 as no numbers or proportions are named, it may be inferred that 
 the proportions were deemed less than the one just stated. These 
 five are described as follows, in regard to this ingredient : Calla- 
 han's, Lancaster, " large grains of green-sand in considerable quau- 
 
TESTIMONY IN OPrOSITION. 491 
 
 tity;" Gloucester Town, " richly specked with green-sand;" Saun- 
 ders', Isle of Wight (one only of three strata), " considerable 
 green-sand." Stith's, Surry, "quite richly specked with green- 
 sand." A. C. Jones's, Surry, and at Kingsmill, James City, " in- 
 termixed with green-sand." Now what proportions these descrip- 
 tions designate, it is not for me to determine; but 3 or 4 percent., 
 at most, would abundantly serve to meet all their requisitions. 
 There are also 7 other of the specimens named marked in less de- 
 grees by the presence of this ingredient, and which are described in 
 this respect in such phrases as these : containing " a little green- 
 sand" — "specked with green-sand" — "quite perceptibly specked 
 with green-sand" — " tinged with green-sand" — and " slightly inter- 
 mixed with green-sand." There remain of the list 135 other speci- 
 mens, of which 48 are stated to contain of "green-sand a trace" 
 (by which term chemists understand a proportion so small that its 
 presence is barely certain), and of the other 87 specimens no green- 
 sand is mentioned, and therefore it may be inferred that not even 
 " a trace" could be found. 
 
 If this list of marls and statements of their fertilizing contents 
 had been presented by the author distinctly as a designed refutation 
 of his previously and repeatedly published assertions of the frequent 
 abundance and general presence in useful quantity of green-sand in 
 miocene marls, nothing could have been more to the purpose, or 
 more conclusive. 
 
 Nevertheless, few and rare as may be the cases in which the value 
 and beneficial eflfects of miocene marls are increased in any consi- 
 derable degree by the presence of green-sand, or of any other in- 
 gredient than carbonate of lime, it is important that such auxiliary 
 fertilizing matter^ should be searched for, and their absence or pre- 
 sence known. The great value and uniform fertilizing effects of 
 carbonate of lime will be the most highly appreciated by those 
 farmers who undei'stand and estimate them separately and alone; 
 without confounding the operation of that manuring earth with 
 those of any other intermixed and unknown substances, no matter 
 what increase of benefit such intermixture may produce in particu- 
 lar cases. 
 
 Some years after the publication of the first edition of this Re- 
 port (as originally made to the State Board o^ Agriculture of Vir- 
 ginia, and published, with other reports, by order of the legisla- 
 ture), I learned that a particular bed of marl, worked at Hampstead 
 in New Kent, and more lately found and now worked both at Oak 
 Spring and Liberty Hall, in King William county, furnished an 
 exception to the general rule above asserted, of the absence of any 
 large proportion of green-sand in miocene marl. This particular 
 
402 PECULIAR iAIIOCENE MARL. 
 
 bed has been found (by boring) on both sides of the Pamunkoy 
 river, near to and in the same general range with the eocene bed, 
 and within a mile of two different excavations of eocene marl, or 
 gypseous earth, in different directions. Further, this Hampstead 
 marl contains apparently as much green-sand as the neighbouring 
 eocene bed ; and there is no obvious difference in the texture, co- 
 lour, or general appearance of the two kinds. When I first visited 
 this locality (May, 1842), the digging had been suspended, and the 
 pits were full of water; so that no marl or shells could be seen in 
 the bed. BIy examinations therefore were limited to heaps of the 
 marl which remained unspread upon the field. I was surprised to 
 find all of the few shells which met my eye in this imperfect view, 
 of species such as were unknown to me, and which I had not seen 
 in any other marl. But this did not induce me to suspect that 
 the formation was not eocene, as I was not then acquainted with 
 many eocene shells. Subsequently, however, by more full exami- 
 nation, and aided by the scientific knowledge of my friend M. 
 Tuomey, Esq., whom I induced to visit with me this singular de- 
 posit, I learned that the shells, so far as recognised, were miocene ; 
 though mostly not known in any other of the miocene beds in Vir- 
 ginia — of which, sundry exposures, with numerous different shells, 
 are within a few miles of the Hampstead bed. There are three 
 shells only, of some 22 species, which I found here, known to me 
 also in the other miocene marls of Virginia.* 
 
 This bed is underlaid by the ordinary eocene of the neighbour- 
 hood. Suspecting this to be the fact in advance of any proof, I 
 procured an excavation to be sunk much lower than any had been 
 done before ; and, without any obvious change of general appearance 
 and texture, the eocene marl was reached — as was made evident 
 by the finding of perfect shells of the ostrea sellceformis. 
 
 From all the circumstances it would seem that the earthy mate- 
 rials of this miocene formation had been mainly derived from the 
 earlier formed and close adjacent eocene bed below, and which 
 spreads out to the westward; and that while some flood had torn 
 up, swept along, and suspended for a time, and then deposited, this 
 fine green earth for the matrix, that the peculiar conditions permit- 
 ted the existence, with a few exceptions only, of shell-fish not belong- 
 ing to the ordinary miocene. The supposed position of this peculiar 
 miocene is represented (at 9) in the annexed profile of all the 
 strata. 
 
 This peculiar deposit, and this alone so far as known to me, would 
 accord with the cases asserted by Professor Rogers, of the frequent 
 and general occurrence of green-sand in large proportions, in ordi- 
 nary miocene marls. But even this case afforded no support to his 
 
 * There three are cardita gramilata, an astartc, and one other. 
 
HAMPSTEAD BEDS. 493 
 
 assertion, when it was published. This bed is of peculiar character, 
 in this respect. No other similar marl is yet known. It was every- 
 where concealed by its depth, and was found only by boring. The 
 discovery of the marl itself did not occur until long after Professor 
 Rogers had published these assertions ; and it was much later still, 
 before it was even suspected that it belonged to the miocenc forma- 
 tion. Therefore, however conveniently the peculiar character of 
 this marl might have been used, if known earlier, as at least one 
 evidence for Professor Rogers's assertions — as the facts are, it affords 
 to them, as made, not the slightest support. 
 
 THE END. 
 
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 Sermons by Rev. J. D. Blair, 8vo., sheep. 
 
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 Jefferson's Memoir and Correspondence, 4 vols, 8vo., half calf. 
 
 Edgar's Sportsman's Herald and Stud Book, 8vo., sheep. 
 
 Winckler's Hints to Piano Forte Players, 12mo., boards. 
 
 Southern and South-western Sketches ; Fun, Sentiment and 
 Adventures, 12mo., paper. 
 
 Justices' Record Book of Judgments, cap, half bound. 
 
 Martin and Brockenbrough's History of Virginia, 8vo., sheep. 
 
 Campbell's History of Virginia, 8vo., muslin. 
 
 Howe's History of Virginia, 8vo., sheep. 
 
 Cottom's edition of Richardson's Virginia, North Carolina, 
 Maryland and District of Columbia Almanac, 
 
 Randolph's Pocket Diary and Almanac. 
 
 Lee's Strictures on the Writings of Jefferson, 8vo., muslin. 
 
 Plantation and Farm Instruction, Regulation, Record, Inven- 
 tory and Account Book ; by a Southern Planter, 4to, half morocco. 
 
 BOOKS IN PRESS :— Jefferson's Notes on Virginia, a new 
 edition, with Mr. Jefferson's last corrections and additions, 8vo., 
 with plates. 
 
 Uncle Robin in his Cabin in Virginia, and Tom without one 
 in Boston ; by a gentleman of Virginia, 12mo. 
 
 Bm^ke's Virginia Springs, new edition, 12mo. 
 
 BOOKS IN PREPARATION :—Hening and Munford's 
 Virginia Reports, 4 vols., new edition, with notes. 
 
 Digest of the Laws of Virginia adapted to new Code. 
 
 Practice adapted to new Code. 
 
 Barradall's Virginia Reports, 8vo. 
 
 Randolph's Gardening, 12mo. 
 
 Book of Forms, adapted to the Code of Virginia, 8vo. 
 
121 Main Street, Eichmond, Va. 
 
 J. W. RANDOLPH has I'ust published SOUTHERN and 
 SOUTHWESTERN SKETCHES; FUN, SENTIMENT 
 and ADVENTURE. Edited by a gentleman of Richmond. 
 Price 37 cents. 
 
 It is believed that the present volume CDntains as great a variety 
 of mirth-moving and interesting matter as any like work which has 
 ever been published. The peculiar humor of the South, and its 
 characteristic qualities of reckless daring and profuse generosity arc 
 happily illustrated in many of these Sketches. Those who love that 
 innocent mirth which leaves no pain, and relish the honey of wit, with- 
 out the poison which it sometimes leaves, will find in these pages 
 ample sources of entertainment. 
 
 " The Book is a collection of Tales, which had their origin chiefly 
 in the South and Southwest. We most heartily commend it to the 
 attention of the public. The selections are very judicious, and as it is 
 Southern in character, and in every respect home made, it is particular- 
 ly deserving public encouragement. We trust it will meet with a wide 
 sale. There are many stories in it that arc alone worth the price of 
 the Book." — Dispatch. 
 
 PLANTATION BOOK. 
 
 J. W. RANDOLPH, Richmond, Va., has just published the 
 PLANTATION and FARM INSTRUCTION, REGULA- 
 TION, RECORD INVENTORY and ACCOUNT BOOK, 
 
 for the use of managers of estates, and for the better order- 
 ing and management of plantation and farm business in every 
 particular, by a Southern planter. 
 
 " Order is Heaven's first law." — Pope. 
 
 A larger edition is also published - for the use of Cotton 
 Plantations. 
 
 This Book is by one of the best and most systematic far- 
 mers in Virginia, and experienced farmers have expressed the 
 opinion that those who use it, will save hundreds of dollars. 
 
 This work is designed to aid the manager of a plantation, or 
 other large estate, by the useful and valuable suggestions which it 
 eontaies ; by the method and system which it will enable him to es- 
 
J. W. Randolph, Bookseller, 
 
 tablish ; and by the order in ■which all ac30unts may he kept in its 
 pagea. In such cases it must prove an invaluable work. 
 
 \_New York Booh Trade. 
 
 Every farmer who will get one of these Books, and regulate all his 
 movements by its suggestions, cannot fail to realize great benefits from 
 it. We cannot too highly commend it to the consideration of agri- 
 culturists. — Richmond Whig. 
 
 It will prove a most valuable assistant to the planter, manager or 
 overseer, and a work that will facilitate them greatly in the trans- 
 action of business. — Richmond Dispatch. 
 
 The Book we should suppose to be indispensable to any one 
 having the management of a large estate. — Richmond Republican. 
 
 We hope many farmers will buy the work, and make an effort to 
 keep things straight. — Southern Planter. 
 
 It is full of useful information, and is well calculated to induce a 
 methodical system, industry and energy, especially vital to a success- 
 ful and profitable cultivation of mother earth. — Richmond Enquirer. 
 
 We have received a copy of this work, which is designed as a 
 record of the daily services performed on the plantation or farm, with 
 every item of expense for labor, cattle, tools, purchasing of clothes, 
 provisions, &c., &c., and of all sales, with annual and quarterly inven- 
 tories. The form is concise and methodical, while it embraces every 
 thing appropriate to such records. It is well executed, on good pa- 
 per, and must prove very serviceable to those for whom it is intended. 
 
 [^Plongh, Loom and Anvil. 
 
 We should think that this Book would be a valuable acquisition 
 to farmers, for the orderly management of every department of agri- 
 cultural business. It is the result of mature experience and observa- 
 tion. — Mcthodiat Quarterly/ Review. 
 
 A friend, in whose judgment we have great confidence, and who is 
 one of the best farmers in Virginia, assures us that this publication is 
 one of real value to Southern agriculturists ; as there is a wide field 
 before it, the publisher ought therefore to expect for it a large circula- 
 tion. To such of our readers as may not have an opportunity of ex- 
 amining the Book, we may say that it contains formulas for a daily 
 record of plantation work ; for an inventory of negroes, with the 
 quantity of clothing, tools and medicines given them, and a register 
 of their births, deaths and marriages; for a list of stock; for a state- 
 ment of produce made by the proprietor, &c.j &c. : to all of which are 
 
121 Main Street, Richmond, Va. 
 
 prefixed some useful hints to overseers as to plantation management. 
 The Book is well gotten up, and is offered at a very moderate price. 
 
 \_SoiUhern Lkerari/ Messenger. 
 
 A Southern planter has reduced to a complete system tlie entire 
 business of a plantation, and publishes it as a guide to others. The 
 minuteness with which the detail of all the operations on a plantation 
 is treated, is a model for farmers. — The Cultivator. 
 
 J. W. RANDOLPH, of Richmond, Virginia, has published a 
 most admirable work, one which every planter and farmer should 
 not only possess, but carry out its objects and aims, both in the 
 letter and in the spirit, for they all tend to the introduction of 
 system in the management of landed estates. The Book purports 
 to have been gotten up as a guide to overseers and managers ; 
 but is so filled, so arranged, that the proprietors of such estates Would 
 themselves be equally benefited by personally carrying out its nume- 
 rous plans, bints and suggestions ; for after carefully looking through 
 and studying its details, we most conscientiously say, that they are 
 founded in wisdom, and, if practised upon, would be promotive alike 
 of economy and humanity — economy in the management of the farm 
 or plantation — and humanity in providing for the comfort and health 
 of the slaves, as well as stock. 
 
 It contains a chapter explanatory of the manager's duty — shows 
 how his journal or daily record should be kept. Upon this head, as 
 well as upon the employment and treatment of the negroes and ma- 
 nagement of the plantation, the remarks are alike copious and judi- 
 cious; so also are those upon the manner in which the stock of all 
 kinds are to be cared for. Its observations upon the saving and ap- 
 plication of manure, the cultivation of the plantation or farm, as well 
 as upon the proper rotation of crops, are sensible, and show an ac- 
 quaintance with the several subjects on the part of the author. The 
 tables, illustrative of the three, four and five field systems of rotation, 
 are full of instruction, and may be studied with decided advantage. 
 
 It contains a useful " table, showing the number of spaces con- 
 tained in an acre of land at various given distances, which will be 
 found useful in fixing the proper distances to place marl, lime or other 
 manures, so as to give any desired quantity to the acre'^ — a rule for 
 measuring the contents of a corn crib — two rules for ploughmen — a 
 table showing the actual number of pounds in a bushel of different 
 kinds of grain, potatoes, bran, clover seed, timothy and Kentucky 
 blue grass seed, flax seed, hemp seed, castor beans, dried peaches and 
 apples, onions and salt — a table of planting distances — a table show- 
 ing how the contents of any bulk of grain may be ascertained — one 
 showing the weight of various materials — -an instructive chapter upon 
 
/. W. Randolph, BooksGller, 
 
 meclianical power — tables of weights and measures — of the United 
 States currency — English currency — rule for reducing sterling money 
 into United States currency — data in mechanics and rural economy. 
 Besides which, there are ruled blanks for recording all the details of 
 farm and plantation duties, from the beginning to the end of the year, 
 so arranged as to make the labor so plain and easy, that if anything 
 can induce farmers and planters to record the operations of their 
 estates, this work will lure them to it. That it may find a ready sale 
 we most fervently wish, as it is pregnant with much good. 
 
 \_American Farmer. 
 
 WYTHE S REPORTS 
 
 J. W. RANDOLPH has just published in one 8vo. volume. 
 Price $4 in sheep, and $4 50 in calf binding. 
 
 Decisions of cases in Virginia, by the High Court of Chancery, 
 with remarks upon decrees by the Court of Appeals, reversing some 
 of thoso decisions, by George Wythe, Chancellor of said court; se- 
 cond and only complete edition, with a memoir of the author, analy- 
 sis of the cases, and an Index, by B. B. Minor, L. B., of the Rich- 
 mond Bar, and with an Appendix, containing references to cases in 
 Pari Materia, and an essay on lapse, joint tenants, and tenants in 
 common, &c., by William Green, Esq. 
 
 In Orr^s heirs v. Iricin's heirs and devisees, 2 Carolina Law Re- 
 pository 465, Taylor, C. J., delivering the opinion of the court, 
 says : " To these [^English'] cases may be added a decision made by 
 the late Chancellor Wythe, in Virginia, which may be cited as equal 
 in point of authority, if not superior, to any of the British decisions, 
 from the luminous and conclusive reasoning on which that upright and 
 truly estimable Judge founds it — clarum et venerahile nomcn." He 
 then makes an extract of several pages consecutively, from the report 
 of Farlei/ v. Skipper, in Wythe, (1st edition,) 135, (2d edition,) 254 ; 
 and concludes his opinion in these words : " AVe have transcribed thus 
 largely from the work of the Chancellor, because it is not in every 
 library, and the discussion of the question, which is new in this court, 
 being the most able and copious we have anywhere met with, cannot 
 fail to be instructive to the student, and acceptable to the practitioner, 
 who will both be disposed to allow that the excellence of the matter 
 atones for the length of the extract." — La%is laudari a laudato viro. 
 
121 Main Street, Richmond, Va. 
 
 All of the old editions of this work are imperfect, and yet copies 
 have been sold at auction as high as $10, such has been the demand for it. 
 
 For sale by J. W. RANDOLPH, Richmond, CAMPBELL'S 
 HISTORY OF THE COLONY and ANCIENT DOMI- 
 NION OF VIRGINIA. Price $1 50. 
 
 CHARLES CAMPBELL, Esq., of Petersburg, a gentleman bet- 
 ter informed upon the History of Eastern Virginia than any one we 
 have met in the course of our investigation, and to whom we are in- 
 debted for much valuable information." — Henry Hoioe, Editor of His- 
 torical Collections of Virginia. 
 
 We do not doubt that this is the most authentic History of Vir- 
 ginia, as a Colony, which has yet appeared. — Petersburg Intelligencer. 
 
 "We take great pleasure in giving our cordial recommendation to the 
 work. — ^\'atclima7i and Observer. 
 
 No work in Virginia, we will venture to say, has appeared for many 
 years, which has been enriched and illustrated with so many original 
 facts and explanations. — Literary World. 
 
 We are of those who love a straight forward and unvarnished chroni- 
 cle ; we, therefore, like Mr. Campbell's Book. — Princeton Review. 
 
 No one can even glance at the work without imbibing the convic- 
 tion, that its author has been a long and loving student of Virginia 
 History, and has his mind embodied with the result of his extensive 
 experience and ripe discrimination, in a style at once terse, vigorous 
 and pleasing. — Literary World. 
 
 You have presented the outline of early Virginia History in an 
 unusually attractive form, and one well fitted to lead the reader to 
 pursue more fully its minuter details. 
 
 \_Profcssor Gammell, of Brown University. 
 
 The Book will be a very useful compend for the inhabitants of 
 Virginia, as well as for general readers in other parts of the country. 
 
 [.lared Sparks. 
 
 Mr. Campbell's History op Virginia is presented to the public 
 in a very unpretending form, and is written in a clear, agreeable and 
 manly style, without affectation, with new and elaborate conceits of ex- 
 
J. W. Randolph, Bookseller, 
 
 pression, and defaced by no ambitious and deliberate flights of rheto- 
 ric. The subject is a good one, and it is treated as if the author felt 
 assured of its intrinsic attractions. He has evidently scrutinized the 
 appropriate evidences in their sources, and the reader may repose with 
 confidence in his statements. — North American Review. 
 
 An Essay on Sla'very^ by Thomas R. Dew, late President of 
 William and Mary College, Williamsburg, Va. Second edition, 
 Richmond, Va. J. W. Randolph, 121 Main Street. 
 
 This Essay has peculiar claims to the attention of the Virginian, 
 and is not wanting in interest to the statesman everywhere. We do 
 not think we err in saying, that it is the clearest and ablest defence of 
 the institution to be found in the English language. The writer 
 views that institution in its historical and its scriptural aspects, and 
 discusses at large the plans for the abolition of negro slavery. While . 
 we cannot accord with all the views he has expressed in regard to the 
 colonization movement, we yet think the facts he arrays, and the prin- 
 ciples he urges, are entitled to the gravest consideration, as the re- 
 sults of unwearied labor, and of a mind well balanced and well train- 
 ed. We believe that all parties are agreed as to the evil of emancipa- 
 tion, without removal. The painting of the scenes, which would en- 
 sure such an event, is drawn with a master hand. — Repuhllcan. 
 
 A Cfuide to Commissioners in Chancery, with practical forms 
 for the discharge of their duties ; adapted to the new Code of Vir- 
 ginia, by James M. Matthews, Attorney at Law, Richmond. J. 
 W. Randolph, 121 Main Street. 
 
 Mr. Matthews has in this publication furnished a valuable addition 
 to the small stock of Virginia Law Books. The Work is not only of 
 essential service to the Commissioner; it is also a valuable vade mccum 
 to the Chancery Lawyer. The following opinion is expressed of it by 
 a legal friend : 
 
 " I have had occasion to use Mr. IMatthews' Guide to Commission- 
 ers as a book of reference in the course of my practice at the Bar. I 
 have uniformly found it to be correct, and it materially aided me 
 while attending the settlement of accounts before the Commissioner." 
 
 The following table of contents may be acceptable to our legal read- 
 ers in the country : 
 
 Chapter I. Of the origin of Commissioners in Chancery, their ap- 
 
121 Main /Street, Richmond, Va. 
 
 pointmcnt, the reference of accounts to them, and the proceedings 
 thereupon. — Chap. II. Of fiduciaries generally, and the settlement of 
 their accounts by Commissioners in Chancery. — Chap. III. Of Guar- 
 dians and Wards. — Chap. IV. Proceedings under decrees and orders in 
 the Commissioner's Office, and herein : — Of References and Reports ; 
 The examination of parties upon interrogatories ; Admissions of par- 
 ties; Of the onus prohandi ; The examination of witnesses upon in- 
 terrogatories; Enquiries as to heirs at law, next of kin, &c. ; Pro- 
 duction of documents ; Of scandal and impertinence ; Of the princi- 
 ples on which accounts of executor or administrator should be stated; 
 When interest not to be involved in administration account; When 
 account of executor or administrator should be closed ; What pay- 
 ments not to enter into the general account ; When annual rests are 
 to be made ; Formula in stating account of executor or administrator; 
 Principles on which Guardians' account should be stated ; How to 
 state the account of one who is in name an execiitor, but is in fact a 
 guardian or trustee ; How to ascertain value of life estate or annuity ; 
 Table of longevity ; Adjournment by Commissioner ; Report and Ex- 
 ceptions; Review of Report. — Chap. V. Of surcharge and falsifica- 
 tion.— Chap. VI. of Notices.— Chap. VII. Of Evidence.— Chap. VIII. 
 Of means for compelling debtor to discover and surrender his estate. 
 Chap. IX. Of fees of Commissioner in Chancery. — Chap. X. Of de- 
 scents and distributions. — Chap. XI. Of the payment of debts accord- 
 ingtotheir priority. — Chap. XIT. For preventing commission of crimes. 
 By the Code of Virginia, Chapter 201, Section 1, Commissioners 
 in Chancery are constituted conservators of the peace, and the last 
 chapter is a summary of the proceedings on peace warrant, &c. Every 
 Commissioner should have a copy of this Work. — RepnUican. 
 
 VIRGINIA REPORT on the Resolutions of '98-'99, concern- 
 ing the ALIEN and SEDITION LAWS. 
 
 We have received from our friend, J. W. RANDOLPH, a neat 
 and well printed copy of the "Virginia Report on the Resolutions of 
 '98-99, concerning the Alien and Sedition laws." We were struck 
 with the truth of the remark of the editor of the first mentioned vo- 
 lume, that this " report had been more praised than read." Every 
 statesman should be familiar with its contents. It is certainly a va- 
 luable commentary on the Federal Constitution, and both parties may 
 find here some of the strongest arguments in support of their several 
 theories. Wc shall notice this AVORK more at large hereafter. 
 
 [Kichmond Republican. 
 
10 J. W. Rmidoli^li, Bookseller. 
 
 A comprehensive DESCRIPTION OF VIRGINIA and the 
 DISTRICT OF COLUMBIA, containing a copious collection of 
 geographical, statistical, political, commercial, religious, moral and 
 miscellaneous information, chiefly from original sources, by Joseph 
 Martin ; to which is added A HISTORY OF VIRGINIA, from its 
 first settlement to the year 1754, with an abstract of the principal 
 events from that period to the INDEPENDENCE OF VIRGINIA, 
 by W. H. Brockenbrough, formerly Librarian at the University of 
 Virginia, and afterwards Judge of the United States Court in Florida. 
 
 The above Book contains G36 printed pages, 8vo., bound in strong 
 sheep. Price $2. 
 
 J. W. RANDOLPH, 121 Main Street, Richmond, Virginia, hav- 
 ing bought the remainder of the edition, will supply the work in any 
 quantity. Copies sent by mail postpaid to all who remit the price in 
 money or stamps, 
 
 J, W, RANDOLPH has published a Catalogue of his stock of 
 Books, (amounting to 120,000,) with size, binding, and price of each, 
 which may be had gratis at 121 Main Street, Richmond, Va. 
 
 Books sent by mail postpaid to all who remit the price in money or 
 stamps. 
 
 Gentlemen or societies forming or adding to" their libraries will save 
 money by sending their orders to J. W. RANDOLPH. 
 
 Rare old works bought and sold. 
 
 HANDSOME BINDING.— In J. W. RANDOLPH'S window, 
 at No. 121 Main Street, may be seen a BIBLE, bound in his estab- 
 lishment by one of his workmen, which in point of neatness of finish, 
 beauty of style and durability, cannot be excelled. Our citizens 
 would do well to bear these facts in mind, and have their Books bound 
 at home, instead of sending them to the Northern abolitionists. 
 
 [^Reptiblican. 
 
 COUNTRY MERCHANTS, Teachers and others, can buy on the 
 best terms Standard, School and Miscellaneous Books, Stationery, &.c. 
 
 BLANK BOOKS made to order, and BINDING done in any 
 quantity and style. 
 
 rz-h