rZ,c^^^ Please R handle this volume ^ with care. 5a The University of Coimeclicut ^S ^ Ubraries,Storrs BOOK 630. B66 c. 1 BOUSSINGAULT # RURAL ECONOMY IN ITS RELATIONS WITH CHEMISTRY PHYS 3 1153 0DDm3m 1 r\ RURAL ECOIOMY, IN ITS RELATIONS WJTH CHEMISTRY. PHYSICS, MI) METEOROLOGlf CHEMISTRY APPLIED TO AGRICULTURE. J. B. BOUSSINGAULT, MEMP'SR OF THE INSTITUTE OF FRANCS, ETC, ETC. TRANSJ.ATED, WITH AN INTRODUCTION &MD NOTES, BY GEORGE LAW, Agriculturist. NEW YORK: C. M. SAXTOX, BARKER & CO., 25 PARK ROW SAN FFvANCroCO: H. H. BANCKOFT & CO. 1860. i^w. THE AUTHOR'S PREFACE. In the work now published, I present the results of the inquiries in which I have been engaged for many years, and which were un- dertaken in the hope of throwing light upon various points of prac- tical agriculture. My first idea was, to cor fine myself to the mere re-impression of the several papers which I had communicated from time to time to different periodicals, v\uth the addition of a quantity of inedited matter which I had by me. But upon more mature con- sideration, I was led to believe that I should be doing a useful thing did I fill up the numerous gaps which must necessarily occur be- tween papers published isolatedly, at dates more or less remote from one another, and treating of the most dissimilar subjects. I have thus been led, in addition to my own observations, to give those of numerous writers on almost every branch of agricultural science, being only careful to confine myself in each instance to the most authentic practical conclusions ; for it is certain, that practical data have the most direct interest for rural economy, both in itself and in its bearings upon the general science of political economy. I have a further reason for the plan which I have adopted, which [ am the less disposed to pass by in silence, inasmuch as it may plead in excuse with those who might be c'isposed to criticize the tone, perhaps somewhat too didactic, of my work. I was invited, in conjunction with several o:,her professors attached to a great educational institution, to ^ve a course embracing my views upon the science of agriculture. I consented to this, and prepared my lectures ; but motives, to which I was entirely a stranger, having prevented the project from being carried out, 1 made up my mind to publish, not the lectures such as I should have iv author's; pref.ace. delivered them, but the documents which wculd have formed the basis of my teaching. The first part of this work treats in succession of the physical and chemical phenomena of vegetation ; of the composition of vege- tables and their immediate principles ; of fermentation ; and of soils. The second comprises a summary of all that has yet been done on the subject of manures, organic and mineral ; a discussion of the subject of rotations ; general views of the maintenance and economy of live-stock ; finally, some considerations on meteorology and cli- mate, and on the relations between organized beings and the atmo- sphere. I have endeavored, therefore, to give a summary view of all the questions of rural economy that admit of scientific treaiment. It may be found, perhaps, that the number of these questions is still ex- tremely small. Nevertheless, in regarding the multitude of inquiries that have been instituted within a very few years only, in viewing especially the ever-increasing interest attached to researches bear- ing upon practical agriculture, we are bound to anticipate progress, and to hope fur conclusions important as regards science, profitable to practice, and useful to humanity. EDITOR'S INTRODUCTION The following work is submitted to the agric ultural public in the fullest confidence that it stands in need of no recommendatory strictures on the part of those who have undertaken to present it in its present form to the English agriculturist. In the person of its distinguished author the man of science is happily associated with the practical farmer — the accomplished naturalist, the profound chemist and natural philosopher. The friend and fellow-laborer of Arago, Biot, Dumas, and all the leading minds of his age and coun- try— M. Boussingault's title to consideration is recognised wher- ever letters and civilization have extended their influence. Surely the collected and carefully recorded experience of such a man, experience by which the conclusions of the member of the In- stitute have been tested and weighed by the results of the farmer of Bechelbronn^ must have value in the estimation of every educated mind, and cannot fail to be especially welcome to that class of readers who are professionally engaged in the practical application of that noble science which his labors have contributed to illustrate and advance. When the following pages were confided to the editor, it was the impression both of the publisher and himself, that in the course of the work many points would necessarily arise demanding elucidation, others calculated to provoke controversy or challenge investigation, and others again which could be rendered available or instructive to the British agriculturist only by means of copious explanation, showing with what modification and under what circumstances the views advanced might be applicable to the art as exercised in the climate and soil of this country. But the minute and analytical perusal indispensable in the operation of investing the Author's thoughts and expressions with an English garb, has demonstrated the fallacy of this impression, and if possible has augmented the admiration of the untiring patience, the vast experience, and the as- tute, circumstantial, and elaborate accuracy of the accomplished Author, in whose researches the reader will find the profoundest sagacity, combined with a childlike simplicity which communicates to his work a charm n*ot necessarily inherent in the subject. This is not in*'-^nded to imply an unqualified approval of the illus- trious philosopher's manner of dealing with his own facts and obser 1 2 INTROUUCTION. vations ; still less of nis style of writing, which is often wanJering and diffuse, and which, in order to render it presentable to the Eng- lish reader, has required much compression and retrenchment. Still, however, instead of having, as was expected, to pause at each step of the Author's progress, and dissert upon his views upon this or that particular branch of his subject, the observations of the com- mentator must of necessity be restricted in a great degree to an in- dication of such parts of the work as in his judgment are the most valuable and instructive, together with such incidental objections as appear to be of sufficient importance to require stating at length. The chemical portion of the work is of inestimable value and con- ducted with consummate skill and knowledge ; and with a minute- ness and accuracy perfectly unexampled. At the same time the results of the writer's researches, as well as the means and process- es by which these results were obtained, are displayed with such absolute perspicuity as to be intelligible and instructive to every agricultural inquirer, however superficial his previous acquaintance may be with the details of chemical science. Nothing from the pen of the Editor could throw additional light upon the Author's brilliant and most interesting elucidation of vege- table physiology : his exposition is at once masterly and complete, and contains much that is both valuable and new. And even when the novelty of the facts which he adduces, or the originality of the inferences deduced and unfoldea may admit of question, they are fitill deserving of the most respectful attention from the new and striking lights in which he places them, and presents them to the agricultural reader, and the clear and convincing way in which he demonstrates their inter-dependency and their most intimate con- nection with many of the most important pecuniary and professional interests of the cultivator. Every intelligent farmer will find his account not merely in a repeated perusal of this portion of the work, but in regarding it as a text-book and manual to be kept by him for permanent reference and consultation. The arrangement of the subject, naturally and judiciously adopted by the writer, presents the consideration of soils as the first topic for the observations of the agricultural commentator ; but on this head the distinguished author is so thoroughly explanatory and judi- cious, that nothmg is left for the Editor but to approve, to acquiesce, and to recommend him with admiring confidence to the patient con- sideration and study of the intelligent inquii-er. At page 237 the subject of manures is taken up, and discussed with characteristic miimteness through many succeeding pages. It may perhaps be objected, that the various theories respet.*ting the origin, nature, efficacy, and relative nature of the different ma- nures in use, as well as the various modes of their production, con- coction, and application, which M. Boussingault has here collated and elucidated, contain nothing new ; that they have, in fict, under one form or other, been long familiar to practical men ; but without impugning the justness of this opinion, the Editor has long been convinced that the subject has received, generally, far less care and INTRODUCTION.. 3 attention than it so eminently deserves ; and, in short, tliat it ia much neglected by many who are accounted not merely intelligent, but scientific agriculturists ; and while admitting that much valuable information has been frequently given to the agricultural world by the repeated experiments of several enterprising individuals both in Scotland and England, he still most urgently recommends a careful study of this part of the work, which will probably lead the reader to the conclusion that the methods and practice recommended by the Author are, upon the whole, those best worthy of adoption. In page 260 will be found some very urgent warnings against what be (M. Boussingault) regards as the prevalent and pernicious 3us- tom of turning dunff-heaps " frequently." If, however, by the term *' frequently," a course not exceeding three complete turnings of the heap be comprehended, the Editor can by no means coincide with this opinion ; a long experience having convinced him that there are many circumstances under which the Author's recommendations would be found not merely over-cautious, but positively injurious. For drill crops, for instance, when it happens that the farm-dung is somewhat rough, which must generally be the case towards the close of every season, when the animal dejections are scanty and the great bulk of the already ripened manure has been carried out upon the land, and the fresh additions have not had the advantage of being compounded with matter already concocted, an extra turn- ing is very advantageous. Every farmer will, of course, turn his heap once, for the purpose of thoroughly mixing the various ingredients and different qualities of manure which it contains ; the extra turning, even admitting that it may to a certain extent promote the over-decomposition of the manure, and dissipate the ammoniacal principles which it is impor- tant to preserve, is not attended with so great a loss in this respect as that which is inevitable from keeping open the drill by the appli- cation of coarse dung, which cannot fail to be attended with a most serious loss of the more volatile principles, sometimes even laying the manure quite bare, and in the case of turnips, materially ob- structing the operation of sowing. Our Author brings forward the authority of several eminent inqui- rers in support of his own favorite view of the use of fresh or un- fermented manure ; but however plausible their theories may appear, and however just may be their views in the abstract, there are many intermitting circumstances connected with the general economy of a farm, which must govern and determine their adoption, and in which the practical cultivator must be guided by his own judgment alone. To the Author's 6th chapter the reader may be advantageously referred, as containing a very full and valuable description and dis- cussion, under the head of mineral manures, of the different varieties of the class usually denominated stimulants, and concluding with a brief but lucid and interesting account of Water, considered as an agent of vegetation, and of its importance for manuring purposes. The composition and preparation of liquid manures, as well as the 4 INTRODL'CTIO.N'. various means of procuring and preserving them, will be found t4) have engaged much of the Author's attention ; and he justly pointa to the rapidity of their ameliorating action as a peculiar excelli(nce, not otherwise attainable ; at tlie same time admitting tiiat in the great majority of cases, the great and unavoidable expense at- tending their application, however moderate may be the primo-coiit of the material, has always operated as an insuperable obstacle to their general adoption. In the justice of this vital objection, most practical agriculturists who have used them to any extent, will read- ily concur ; and it will not be uninteresting to the reader to learn that there is reason to believe that it will henceforth be effectually obviated by the use of a very simple and convenient apparatus, de- vised by Mr. JSmith of Deanston, a zealous and able friend of agri- culture, who at the Highland Society's meeting at Glasgow in autumn last, explained the details of his contrivance ; and the Edi- tor has reason to suppose that the particulars will be given in a report of the proceedings of the meeting, in the forthcoming January publi- cation of the Highland Society's Transactions. The Editor is anxious to direct especial attention to the Author's 7lh chapter, wherein he treats of the org.mic and inorganic manures, and of crops — of the elements of manures and of crops with their relations inter se. Sic. — a section of the work which presents, in synopsis, a more copious and complete body of new, interesting, and impoitant facts, of a nature more valuai)le to the practical farmer, than has ever been collected in any i)revious treatise on agricultural science. The great mass of this invalual)le information is condensed, as it were, for practical reference, and displayed in C(»pious and elaborate tabular data — a form which, though not attractive, has enabled the writer to comprise within succinct and managealile limits, a quantity of instruction which, in a more discursive shape, must have distended the work to double its actual size. The tables ad- verted to, present not meridy the results of multitarious experiments in illustration of the unportant subject of rotation-cropping, but also these results as especially alTecled by the aj>plication of the various manures to which the several experimenters had recourse. The rotations reported may appear strange and curious, and sometinies, perhaps, even amusing to the farmers of England and Scotland ; but not more so, in all probability, than those which are ♦'ollowed in many parts of our Island would appear to the cultivators of that part of Europe where our Author's agricultural spcculalions have been carried on, and where the bulk of his analyses have been ob- tained : indeed, locality and climate, and their inseparal)lc concomi- tants, will in every country be found to prescribe and contr<»I tht sorts of crops which may be rendered t!ie most subservient to the permanent advantage both pecuniary and economical of the hus- bandman. Thus, with regard to the Author's more diilactic obser- vations and positive directions on the subject of rotations, tbere is no reason to doubt that, in relatiim to the soil, climate, and geofrraphica! position of the east of France, where his experim.Mital course of rotations has been conducted, they arc highlv ludh-ious. and have INTRODUCTION. O not been prescribed and required without matuie consideration. Moi'eover, they are marked, like the deductions and inferences upon which they are founded, by his unusual acumen, patience, and saga- city ; but in their application to the more circumscribed range of culture to which the agriculturist is limited in the ruder and more fickle climates of north and of south Britain, the practice of the cul- tivator must be governed mainly by his own judgment and experi- ence in the circumstances by which he finds himself surrounded. The interesting and ample instruction conveyed in the observa- tions of this acute and profound observer upon the food and alimen- tary treatment of cattle of every species, accompanied as they are by minute details of the results obtained in the shape of organic and inorganic elements, cannot be too urgently recommended to the at- tentive consideration of every one interested in that important branch of rural economy to which they more particularly relate. The Author's strictures comprehend the economy of the domestic animals with the exception of sheep, a subject from which he pro- fessedly abstains, for the very sufficient reason, that in his opinion, his opportunities of obtaining accurate information thereupon have not been sufficiently ample to enable him to discuss it with confidence and advantage. His theory in favor of the superior fattening quali- ty of hay and the grasses in general above that which is found in tubers and roots, (though apparently supported by his usual convin- cing appeal to experiment,) will be received with considerable al- lowance by the practical farmer. We have many instances, in the present day, of theories ably, plausibly, nay even satisfactorily established, which are nevertheless met by opposite results in practice ; and the hesitation which the Editor ventures to intimate upon the particular point in question, will, he doubts not, be readily concurred in by many experienced feeders. It will be generally admitted that the boiled or steamed potato possesses a much higher nutritive value than belongs to it when in the raw state. In the former case, however, it requires to be mixed with some of the other roots which are not characterized by the same property, such as beet, turnips, &c. ; the Swede, (Ruta- baga,) or any of the harder sorts are best adapted for this purpose, and form a complete counteractive to the dangerous constipating tendency of the boiled potato when given alone. There are many different substitutes or equivalents in the shape of ma.shes, containing leguminous ingredients which are admitted to be fully as nutritious as the potato, still there are circumstances connected with market value which render it a most valuable re- source in farm alimentation. The popular notion that (when used 36 the feed of horses) the boiled or steamed potato is what is vul- garly called " soft meat," tending to unfit them for active work, is daily losing ground ; for not only is it rapidly getting into more gen- eral use among the farmers of England and Scotland, but even post- masters are adopting it for horses employed in road work. The meteorological section of the volume will be found no less instructive to the agriculturist than fascinating to the general reader; I* 6 INTRODUCTIO^r. no equally complete and extensive body of new and interesting fact? has ever before been presented in a collected form to the agricultural world. It will be observed that the capital, the all-important subject of Draining, as the great master-engine of agricultural improvement, is merely touched upon by our Author in a cursory way ; she ild this incite a feeling of disappointment, it must be borne in mind that he has accomplished all, and more than all, that he nroposed to him- self, which was not to write a complete work on practical tillage, but rather, as his title implies, on " Rural Economy," i. e., the eco- nomic production and application of the produce of the soil under the guidance of chemistry. Among the faults of execution for which the Translator ventures to solicit the agricultural reader's indulgence, is the occasional adop- tion of terms which are rather French than English. Many of these words are, in the original, not merely technical, but local and provincial, and are not inserted in any of the dictionaries. IMore- over, in the description of certain processes and operations, the Author has occasionally employed terms (ov which there is no Eng- lish equivalent ; and the Translator had frequently no other choice than that of either leaving the sense of the passage obscure and defective, or, on the other hand, of adopting the barbarisms in ques- tion, which not only deform the English of the construction, but cannot fail to be offensive to the taste and professional preposses- sions of the agricultural reader. With reference to the weights and measures made use of in the original, it majj^ be proper lo state, that (against strong temptation to let them stand as in the French, merely adding a table of eijuivii- lents) they have, at the instance of the Publisher, been reduced info their corresponding quantities in the English standard. Grammes, in the more delicate experiments, have been reduced into grains troy, assuming the gramme as equal to 15.138 grains; in less deli- cate experiments, grammes have been converted into pennyweights (dvvts.) and ounces troy. Kilogrammes are given in lbs. avoir- dupois ; and where the quantity was large, they are often brought into tons, cwts., qrs., &c., taking the French kilogramme at 2.2 lbs. avoirdupois. The Litre, or present French measure of liquids, has been reduced into pints, calculating the French measure at 1.76 pints English imperial measure. The Hectolitre employed in mea- suring grain, is rendered into bushels, estimating it at 22 gaUons English dry measure. The old French Quintal is also sometimes employed : this measure of weight has been either reduced to its proper corresponding quantity, 1 cwt. 3 qrs. '24 lbs. English, or where odd numbers migljt be disreuarded, it has been called 2 cwis. The Are, or French superficial measure of quantity, has been cal- culated throughout a» 120 square yards English : the Hectare at 2.4 acres English. The labor of reducing these measures into their English equiva- lents has been immense ; and errors, in spite of the best care which could be exerted, have doubtless in various instances crept into the INTRODlTCTiOX. 7 reductions. Slight discrepancies between ago^regate sums and their component quantities will aisit be apparent here an;l there, an inex- actness which arises from the number of decimal places not having always been carried out far enough. Our Author often quotes English agricultural writers, whose weights, &c., he has always been at the pains to reduce into their corresponding French equivalents. Not having at all times the works referred to at command, the Editor was compelled to bring back the French weight or measure into the corresponding English one by calculation. Thus from not knowing the precise equivalents adopted by M. Boussingault, some trivial discrepancy between the computed and ibe original weights, &c , may have resulted ; but as the quantities that have been treated in this way are especially im- portant as relative, scarcely ever as absolute quantities, the error where it occurs can be of no real consequence. Metres, centime- tres, and millimetres have been reduced into English feet and inches, assuming the metre as equal to 39.370 inches. Finally, and to conclude our list of reductions, (would that it had been shorter!) the degrees of the centigrade thermometer have been brought into degrees of the only scale in familiar use among us, viz. Fahren- heit's. In the translation the Editor has endeavored (not always with perfect success) to be as little technical as possible, with a view to the convenience of the general reader. In a very few places he has even ventured slightly to condense the style of the original in order to keep the volume within moderate dimensions, occasionally throwing the information contained in a table into the text or nar- rative ; and where the Author appeared to him to be forgetting the rural economist in the mere chemist, as where for example he de- scribes the special modes of preparing and purifying indigo, &c. he has made buld to retrench details, and give the results or conclusions only. All analyses bearing on the practical subject, whether it was the soil that produced, the crop that was grown, or the animal which fed on that crop, have been scrupulously retained. In conclusion, the reader is earnestly recommended to read an admirable little work, the joint production of Messrs. Dumas and Boussingault, en- titled in the original, " Essai de Statique Cbimique des Etres orga- nises," which has been presented in a clear English translation, under the title of, " An Essay on the Chemical and Physiological Balance of Organic Nature," and may be regarded as a most valuable intro- ductory aid to the perfect comprehension of Boussingault's Philoso- phy of Agriculture, and as a key to the more scientific and technical portions of the work now submitted to the publir. CONTENTS. CHAPTER I. "^ Phtsicat. phenomena of vegetation. — vegetable physiology $ II.— Chemical phenomena of vegetation 25 Germination 26 Germination of wheat 29 Continued germination of peas 30 Continued germination of wheat 31 § III. -Evolution and growth of plants 33 Experiment I. — Growth of Red Clover during three months 44 Experiment 11. — Growth of peas 45 Experiment III.— Growth of wheat 46 Experiment IV. — Growth of clover 47 Experiment V. — Vegetation of oats 48 $ IV. — Of the inorganic matters contained in plants — their origin — of the chemical nature of sap 52 Quantity of ashes contained in the diflerent parts of vegetables, according to M. de Saiissure 53 Composition of the substances found by M. de Saussure 55 Alkaline salts and insoluble substances contained in ashes 56 Alkaline salts and insoluble substances of ashes, according to M. Berthier. . 57 Composition of the ashes of several plants analyzed by M. Berthier 58 Sap of the Bambusa Guaduas 68 Sap of the banana plant (Musa Paradisica) 68 Milky saps 69 Sap of the papaw-tree {Carica Papaya) 69 Sap of the cow-tree 69 Milky sap of the Hura Crepitans (Ajuapar) 71 Milky sap of the poppy (Opium) 71 Milk of the Plumeria Jimericana 72 Sap of the caoutchouc-tree 72 Gummy and resinous saps 73 Saccharine saps -• 74 CHAPTER n. Of the chemical constitution of vegetable substances 75 $ I. — Quarternary azotized principles of vegetables 76 Composition of legumine obtained from difFer'»!:t seeds 78 $ II.— Proximate principles with a ternary composition : of starch 30 Inuline 87 Of woody matter and cellular tissue 87 Density of different kinds of wood, according to Brisson 90 Of sugar 114 Beet-root sugar 121 Palm sugar 126 Grape sugar 126 Saccharine principles not fermentai)le 128 Gum 129 Vegetable jelly : pectine and pectic acid 129 10 CONTENTS. Pan Of vegetable acids ' J^J Of the vegetable alkalies 1^1 Of fatty substances 134 Of essential oils }'*\ Of resin 142 Caoutchouc J^^ Vegetable wax {^■f Chlorophylle J^o Of coloring matters 1^^ III.— Composition of the different parts of plants |54 Roots and tubers 1?* B-'-ks :::: S Leaves • \^ Seeds |68 Fleshy or pulpy fruits i-^^ CHAPTER III. 193 Of the saccharine fruits, juices, and infusions used in the preparation OF fermented and spirituous liquors CHAPTER IV. Of SOILS ^ Classification of soils 223 CHAPTER V. Op manures 237 Excretions of the horse 267 Excretions of the cow 2f)8 Excretions of the pig 268 Animal excrements 285 Table of the comparative value of manures, deduced from analyses made by Messrs. Payen and Boussingault 297 CHAPTER VI. Of mineral manures or stimulants 303 Calcareous manures 'MKi Of alkaline salts 316 Growth of sainfoin upon soils gypsed and nnp^'p^^d in 1792, 1793, and 1794. 321 Compiirative growths of white clover, gypsed and ungjpsed, by .Mr. Smith. 322 Experiment with field-beet or mangel-wurzel, opening the rotation with manured soil, 1842 327 Mineral substances contained in the crop 32J Of ammoniacal salts 33^. Of water 336 CHAPTER VII. Op the rotation of crops 34 J ^ I. — Of the organic matter of mai.are and of crops :M1 Potatoes 348 Wheat 349 Wheat-straw 349 Red clover .'M9 Turnips 350 Oats 350 Oat-straw 351 Ficld-bccl or mangel-wurzel 351 Rye 351 Rye-straw 351 White pons 3S9 Pea-straw SSI CONTENTS. 11 Page Jerusalem potato or artichoke 352 Dried stems of Jerusalem artichokes 3o'i Table of the proportions of water contained in different substances 3.i:i 'Composition of the same sub^^tances dried in vacuo at 230" F 3.';3 Relation of manures to crops 3.51 Desiccation of half-made or half-decayed manure 3rj4 Experiment I 3j4 Experiment II 3.1.4 Exiieriment III. 3."j4 Analyses of half-made manures 354 Composition of the manures analyzed 355 Rotation course, No. 1 357 Rotation course, No. 2 357 Rotation course, No. 3 358 Rotation course, No. 4 358 Continuous Jerusalem potato crop. No. 5 358 Quatrennial rotation, adopted by M. Crud, No. 6 358 Summary 359 5 II -Of the residues of different crops 360 Potato tops or haum 3G1 Leaves of field-beet or mangel-wurzel 361 Composition of dry leaves 361 Wheat stubble 3C2 Clover roots 362 Composition of the roots 362 Oat stubble 302 Summary of the foregoing results 363 ^ III. — Of the inorganic substances of manures and crops 3.54 Composition of the ashes proceeding from the plants grown at Bechelbronn 366 Mineral substances taken up from the soil by the various crops grown at Bechelbronn upon one acre 366 Table of the mineral matters of the crops and manures in the course of a rotation 369 CHAPTER VIII. Of the feeding of the animals belonging to a farm ; and of the imme- diate PRINCIPLES OF ANIMAL ORIGIN 375 4 I. — Origin of animal principles 375 Of the Ibod of animals and feeding 386 Experiments on the maintenance of horses. ... 400 Experiment 1 400 Experiment II. — Introduction of Jerusalem potatoes into the ration 401 Experiment III.— Ristion of hay and potatoes 401 Experiment IV. — Substitution of oats and straw for a portion of the hay 402 Experiment V^. — Potatoes substituted for a portion of the hay 403 Experiment VI. — Jerusalem potato for a portion of the hay 403 Experiment VII. — Introduction of field-beet or mangel-wurzel into the ration 403 Experiment VIII.— Introduction of the Swedish turnip into the ration and replacing a portion of the hay 404 Experiment IX. — Introduction of carrots into the ration 405 Experiment X. — Boiled rye as a substitute for oats 405 Table of the nutritive equivalents of different kinds of forage 407 ^11. — Of the inorganic constituents of food 410 § III. — Of the fatty constituents of forage ; considerations on fattening 416 CHAPTER IX. Of the economy of the animals attached to a farm. — OF STOCK IN GENERAL, AND ITS RELATIONS WITH THE PRODUCTION OF MANURE 428 1 1 —Horned cattle 430 Table of milch-kine three years of age and upwards 440 12 CONTENTS. Pag« $n.--Milch-kine 444 Experunent I.— Two hundred days after calving ... 447 Experiment II.— Two hundred und seven days after calving 448 Experiment III.— Two hundred and fifteen days after calving 448 Experiment IV.— Two hundred and twenty-nine days after calving 448 Experiment V— Two hundred and forty days after calving 449 Experiment VI. Two hundred and seventy days after calving 449 Experiment VII.— Two hundred and ninety days after ciilving 449 Experiment VIII. 449 Experiment IX.— Thirty-five days after calving 450 Second Series. Experiment I.— Begun one hundred and seventy-six days after the calving. 450 Experiment II. — One hundred aid eighty-two days after the calving 450 Experiment III. — One hundred and ninety-three days alter the calving 450 Experiment IV. — Two hundred and four days after the calving. 451 5 III.— Fattening of cattle 452 § IV.— Of horses 460 $ v.— Of hogs ' 464 $ VI. — Of the production of manure 4T1 CHAPTER X. Meteorological considerations. 475 § I. — Temperature 475 § II.— Decrease of temperature In the superior strata of the atmosphere 478 ^ III. — Meteorological circumstances under which certain plants grow in dififerent climates 481 Cultivation of wheat, Alsace 482 Cultivation of wheat in America 4K! Intertropical region 4.~'3 Cultivation of bariey 483 Cultivatiitv- Fecundation accomplished, the office of the flower is at an end. It colIaj)ses, withers, and dies. But the impregnated ovary enlarges by degrees, until it has attained maturity, when it presents two dis- tinct parts, which by their union compose the fruit : these parts are the pericarp, and the seed — the husk or shell and the gram. The pericarp always surrounds the seed ; but it sometimes happens that It is so thin and delicate that it blends with the seed. The germination of seeds, the evolution of new plants, is only accomplished under certain physical conditions which demand our consideration. ROOTS, SAP. 23 We have already said incidentally, that in order that a «eed may germinate, it must be in contact with moisture, have communication with the air, and be under the influence of a certain temperature. The same conditions continue to be indispensable after the seed has sprung, and the plant has been organized ; and in addition the access of light is now imperative. Roots seek in the soil the moisture which is requisite to vivify the whole vegetable. These organs are terminated by hair-like fibres of extreme delicacy, and having sprngioles at their extremities : it is by these spongioles that absorption is effected. The following experiment is suliicient to prove that this is the case : let such a plant as a turnip be placed with the hair-like extremities of its root plunged in water, and the plant will continue to live, although almost the whole body of the root is in the air ; let things be now so ar- ranged that the hair-like filaments of the root are not in the water, but that the bulb or body of the plant is so : the leaves will soon droop and wither. The force which brings into play the suction power of the roots, resides in almost every part of the plant : thus a root deprived of its spongioles, a stem, a branch, and a leaf, exert this suction power when plunged in water. But the absorption effected in this way has a limit, and we soon discover the necessity of making fresh sections of the extremities, which have no power of renovation like the filaments furnished with spongioles, which terminate a root. We are still ignorant of the cause which produces the ascent of liquids in vegetables, and which carries them to the remotest leaves, in spite as it were of the laws of hydrostatics. We readily conceive how the spongioles of the roots, surrounded by earth abundantly charged with moisture, should imbibe by the simple effect of poro- sity. We can also understand how, after having been modified by the spongioles, the water and the principles contained in it should be transformed into sap ; but the porosity of the extremities of the roots, and the chemical modification effected by the spongioles upon the fluid imbibed, give no kind of explanation of the rapid ascent of the sap. The force which occasions this rise is very considerable, as was demonstrated by Dr. Stephen Hales in a series of ingenious experiments more than a century ago. Hales adapted a tube bent at a right angle and filled with water, to the extremity of the root of a pear-tree, the point of which had been cut off; the extremity of the tube opposite to that which was connected with the root dipped into a bath of mercury. In a few minutes a portion of the water contained in the tube was absorbed, and the mercury rose above the surface of the bath to the extent of eight inches. In the beginning of April, Hales cut off a vine stem at the distance of thirty -three inches from the ground. The stem had no lateral branches, and its cut surfiice, which was nearly cir- cular, had a diameter of ^ths of an inch. To this section, he adapt- ed a reversed syphon : and things being so disposed, he poured in a quantity of mercury, which after a time, and from the effect of the pressure exerted by the sap as it escaped, rose in one of the arma 24 VEGETABLE PHYSIOLOGY. of the syphon, and remained stationary at the height of thirty-eiglil inches above its original level. This coiumn of mercury, it is obvious, represents a pressure very much greater than that of our atmosphere. The ascent of the sap in trees takes place by the woody layers. It is easy to obtain conviction of this by making a plant absorb a watery solution of cochineal. By making sections in the stem at different heights, we can readily trace the colored liquid in its pro- gress; it is undoubtedly the course which the natural sap would have taken. We see no indication of the coloring matter in the pith nor in the bark, the woody tissue alone is colored, sometimes en- tirely, but more generally in its younger parts only. The dyeing which results from this injection of the wood is in lines, and parallel with the axis of the trunk, like the woody fibres themselves ; but in some cases the sap may deviate from the rectilinear course. Hales showed this by the following experiment : upon a tree he made four notches, one above the other ; each notch occupied one quarter of the trunk and reached to its centre. In this way the whole of the woody fibres were cut through at different heights, so that to continue its ascent the sap must necessarily experience a series of lateral deviation, which in fact took place. The ascending sap of vegetables, as it has hitherto been procured for examination, is an extremely watery fluid, holding in solution very small quantities of divers saline and organic substances. Having attained the leaves, the sap there undergoes modification, and becomes concentrated by losing water. It at the same time experiences, through the agency of the atmospheric air, under the influence of light, a great modification in its constitution. Thus elaborated, the sap takes a descending course ; following the libcr, it retrogrades towards the soil, and therefore performs a kind of cir- culation in its passage through the plant. The descending course of the sap is demonstrated by throwing a ligature round the trunk of a tree ; after a time there is formed, af)ove the part that is tied, an enlargement which is owing to the accumulation of the principles of the sap ; but below it the tree experiences no increase. 'I'he descending course of the elaborated sap is no elTect of simple gravi- ty ; because, if the ligature be thrown arounU>. tiuw ever, that tture was some slight (nsrns;aj:enK'nt of azote, as in the pnciding ixp«'r> ment. t Saussure. Rorh. Chimiquco, p. 2.1. X He t^.iu< ur»\ op. cit. p. 211. ^ Hanibnidt, Flora frihrrpt'nsis subterranen. p. l.Vi. EVOLUTION AND GROWTH. 33 In the botanical gardens of Berlin, Potsdam, and Vienna, this pro- perty of chlorine has been made available to excellent ends; by its means many old seeds, upon which a great variety of trials had already been made in vain to make them sprout, were brought to germinate. At Schoenbrunn, for instance, tliey had never succeeded in raising the clusea rosea from the seed ; but M. de Humboldt suc- ceeded at once, by forming a paste of peroxide of manganese, with water and hydrochloric acid, in which he set the seeds of the clusea, and then placed them in a temperature of from 62" to 75" cent. (143° to 167° Fahr.) It seems very likely that this discovery of M. de Humboldt may yet be taken advantage of in onr every-day hus- bandry. It is quite certain that the whole of the seed which we commit to the ground, does not spring up, especially when we are forced to have recourse to seed that is two or three years old ; the loss is then frequently very considerable. Bat a solution of chlo- rine, or a mixture which would evolve it, could not cost much, its use would add little or nothing to the very trifling expense which is generally incurred in pickling the wheat that is employed as seed. § III.— EVOLUTION AND GROWTH OF PLANTS. As germination advances, we see those organs acquiring shape and size which had appeared at first in the rudimentary state. The roots extend in length, and increase in number, and their extremities become covered with capillary fibres. The stem as it rises puts forth branches in all directions, which become covered with leaves. The cotyledons which had nourished the young plant during the .first days of its existence, witiier and fall. Under the influence of the solar light, the vegetation progresses amain, and the organic matter, which finally constitutes the plant when it has attained matu- rity, weighs vastly more than the same matter which existed pre- viously in the seed. To quote a single instance from the family of annual plants, a seed of field beet of the weight of .06175 of a jirain, may by the end of the autumn give birth to a root which with its leaves shall weigh 162099grs. or upwards of 281bs.* This immense and rapid assimilation can have no other source than the soil, the air, and water. Without, at this time, pausing to consider the useful influence which the soil, and the substances it contains, exert upon the entire development of vegetables, we shall here assume it as a general principle that water and the air of the atmosphere alone, are capable of furnishing them with all the ele- ments which enter into their composition, to wit — carbon, hydrogen, oxygen, and azote. In other words, a seed may germinate, vegetate, give birth to a plant which shall attain to complete maturity, by the * Actual weight of a beet-root grown at Berhelbronn in 1841 34 EVOLUTION AND GllOWTH. mere concurrence of water and the gases, or vapors which are d\t fused through the atmosphere. This fact is demonstrated by the following experiment : — In a sufficient quantity of properly moistened roughly pounded brick-dust, (which had been heated to redness in order to destroy every trace of organic matter,) a few peas were sown on the 9th of May, and the pot was transferred to a green-house in order to protect the plants from the dust and impurities which always fly about in the open air. On the 16th of July, the peas, which looked extren.elv well and healthy, were in flower. Each seed had sent forth one stem, and each stem, abundantly covered with leaves, bore a flower. On the 15th of August the pods were ripe; no more water was given, and by the end of the month the plants were dry. The length of the stalks varied from about three feet three inches to five feet ; but they were extremely slender, and the leaves not more than one third the ordinary size. The pods were 1.3 inch, by from 0.3 to 0.4 of an inch broad. They generally contained two peas each ; one contained a single pea only, but this was almost twice the size of any of the others. In the course of three months, therefore, these peas came to per- fect maturity — ripe seeds were gathered. The analysis of the crop which I shall give by and by, in connection with another qiiestior which we shall have to discuss, showed that the harvest obtained under the conditions indicated, contained a considerably larger pro- portion of each of the elements found than was originally contained in the seed from which it sprung. Carbon being the predominating principle in plants, it is our first duty to inquire into the origin of so mucli of this element as is as- similated in the course of vegetation. Carbon is met with in very small quantity in the atmosphere in the state of carbonic acid, and as this is one of the most soluble of the gases which enter into the constitution of the air, water always contains a considerable quantity of it in solution. Carbonic acid n)ay therefi)re be in relation with plants by the medium of the air amidst which they live, and of the watnr which is no less indispen- sable to their existence. We have now to ascertain in what way thii gas evolves and sets free its carbon in favor of living vegetables. Bonnet, having put some fresh leaves at the bottom of a jar con- taining spring water, observed that when exposed to the rays of the sun, they gave oil' bubbles of air. He sought to ascertain whether this disengagement of gas was due to the leaves, or to the liquid in which they were contained. For the spring water, he therefore substituted water deprived of its air by boilmg, and he found that the leaves exposed to the sun's light in this water, no longer gave otT any bubbles of air. Bonnet, therefore, concluded that the gas which he collected in his first experiment, proceeded from the water. In 1771, Priestley discovered, that by emitting oxygen, plants had the property of ameliorating atmospherical air, which had been ASSIMILATION OK CARBON. 35 vitiated by the respiration of animals or by combustion.* This un- expected discovery immediately arrested the attention of vegetable physiologists. Nevertheless, Priestley was not yet master, so to speak, of the capital experiment which he had announced to the world of science. He had not seized all the circumstances which assure its success. Occasionally the leaves which were the subjects of experiment did not cause the disengagement of any gas ; occa- sionally, too, the air disengaged, far from being oxygen — far from ameliorating the atmosphere, was found to be carbonic acid gas. It was Ingenhousz who made out the influence of the solar light upon the phe°nomenon in question. He proved, by a vast number of dis- tinct experiments, that leaves exhale oxygen when they are exposed to the light of the sun. He perceived, moreover, that in the dark they vitiate the air, rendering it improper for respiration and com- bustion.f But the origin of the oxygen disengaged from water by leaves exposed to the light of the sun still remained to be discovered. It was Sennebier who took this important step, by showing that it was to the carbonic acid generally contained in water that leaves ex- posed to the sun's light owed their faculty of evolving oxygen gas. With this interesting fact, it was easy to render an account of all the anomalies that had been successively announced : boiled water, as Bonnet had observed, could not afford any air, and spring water should usually give more than river water, as Ingenhousz had no- ticed, for the simple reason that boiled water neither contains carbonic acid gas nor any other kind of air ; and that well water generally contains a larger quantity of carbonic acid in solution than river water. In giving the grand features in the history of this brilliant discov- ery of the°eighleenth century, it may be said that Bonnet was the first who observed the phenomenon of the gaseous evolution effected by the leaves of vegetables ;t that Priestley announced that the gas disengaged was oxygen ; that Ingenhousz demonstrated the neces- sity of the solar light to the production of the phenomenon ; finally, that it was Sennebier, to whom was reserved the honor of showing that the oxygen gas obtained under these circumstances is the pro- duct of the decomposition of carbonic acid. It was, however, matter of supreme interest to study this decom- position of carbonic acid in its last details. It was imperative, for instance, to ascertain what relation existed between the volume of the oxygen disengaged and the volume of the carbonic acid decom- posed. This was admirably accomplished by M. Theodore de Saus- sure in a long series of remarkable experiments, of which I shall here endeavor briefly to state the main results. The conclusion which follows naturally from the discovery of Sennebier, was that carbonic acid exercised a favorable influence on vegetation by supplying plants with the carbon which enters into * Experiments and Observations, vol. ii. t Experiments on Vegetables. X Sur I'usage ries feuilles dan* /es planter, p. 31 86 EVOLUTIO:^ AND GROWTH. their constitution. Percival ascertained by direct experiment tht accuracy of this inference by placing plants in a current of atmo spheric air, mixed with a pretty large proportion of this gas. By means of a comparative experiment, he saw that a plant in such circumstances made much greater progress than one subjected to a current of ordinary air.* The researches of Saussure, in confirm- ing in all respects those of his predecessors, added this farther very important fact : that to act beneficially upon vegetables the carbonic acid must be mixed with oxygen. Under a bell glass of the capacity of 398 cubic inches, placed over mercury, with a delicate film of water swimming on its surface, he introduced three young peas, which displaced about y|y of the in- cluded air. The atmosphere was composed of common air and carbonic acid gas in different proportions. The experiments were conducted successively in the sunshine and in the shade. In the sun, the apparatus received daily the direct action of the light during five or six hours : when the light was loo vivid it was somewhat lessened by shading. In the sunlight the plants lived for several days in an atmosphere composed of equal parts of air and carbonic acid ; they then faded. But they died much more speedily in atmospheres which contained two-thirds, or three-fourths, or a fortiori which consisted entirely of carbonic acid. The young plants throve decidedly when the atmosphere contained about ^th of carbonic acid ; their growth was evidently more vigor- ous here than it was in simple air ; and at the conclusion of one ex- periment which extended over ten days, almost the whole of the carbonic acid was found replaced by, or clianged into oxygen : the peas had assimilated the carbon. The smallest quantity of carbonic acid added to the air, was found injurious to the plants when they were kept in the shade. Young peas lived only six days under sucii circumstances, when the atmosphere annind them consisted of a quarter of its volume of carbonic acid. They lived ten days when the proportion of this gas did not exceed a twelt'th ; but then they scarcely grew at all in the mixture ; they certainly n»adc much less progress than they would have done in common air. Saussure concluded, from these experiments, that cari)onic acid was useful to growing vegetables only when present along with oxygen, and that it ceases to be 60 wiien the atmosphere contains more than ,'.jth of its volume of the gas. To determine the proportion of oxygen set at liberty during the decomposition of carbonic acid by plants, Saussure composed an atmosphere of common air and carbonic acid, the latter in the pro- portion of 0.075 ; the mixture was confined under a bell-glass of the capacity of 5.7i6 litres or lO.lIC jiints, stantling over mercury as in tlie former experiments. Seven plants of the periwinkle were introduced into the apparatus, their roots dipping into 15 cub. centim. or 5.895 cub. in. of water — the water was limited as much as possible, ♦ MuncliONtor Mrmoirx, vol. li DECOMPOSITION OF CARBONIC ACID. 37 in order that the absorption of carbonic acid, which must, of course, take place, might be thrown out of the reckoning. The experiment was continued for six days, during which the plants received the direct rays of the sun from five to eleven o'clock in the morning. On the seventh day, the plants were withdrawn. They had pre- served their freshness. All the corrections made for temperature and pressure, the volume of the atmosphere in which they had lived was not found changed by more than about 20 cubic centimetres, 7.8 c. in., a quantity which is within the possible errors of compu- tation ; but the composition of the air had undergone very notable changes : the carbonic acid had disappeared, and the eudiometer proclaimed 0.24 of oxygen instead of the 0.21 which it contained originally.* RESULTS OF THE EXPERIMENTS. c. inches. Azote. Oxyg-en. Carb. acid. J?c/or« : Volume of atmosphere 2257 containing 1650 438.5 169.3 Jift^: " " 2257 " 1704 553 0__ 0 +54 +14.8 —169.3 The periwinkles, consequently, had caused 169.3 cubic inches of carbonic acid to disappear, and given off upwards of one hundred and fourteen cubic inches of oxygen. Had the whole oxygen of the carbonic acid been set at liberty, this volume would have been pre- cisely equal to that of the acid gas decomposed ; but as no more than one hundred and fourteen cubic inches of oxygen were obtained, it must be inferred that the periwinkles had fixed 54.6 cubic inches of this gas. This is the conclusion, indeed, to which M. de Saussure came, and subsequent experiments have confirmed its accuracy. The following table contains a summary of five experiments that were instituted : c. inches. c. inches. Exp. 1. Carbonic acid disappearing. ..169.3 Oxygen disengaged.. .114.7 Azote disengaged • 54.6 169.3 Exp. '2. " " " ...121.4 Oxygen disengaged... 88 Azote disengaged • • • 33 121 Exp. 3. " " " 58-5 Oxygen disengaged 47.5 Azote disengaged 8.2 55.7 Exp. A. " " " ...120.2 Oxygen disengaged 96.6 Azote disengaged . . ... 7*8 J04.4 Exp. 5. " " " 72.3 Oxygen disengaged 49.5 Azote disengaged 22. 4 71.9 There is one remark which it is impossible to avoid making in sur- Teyingthis table ; it is to the effect, that the azote disengaged rep- * Saussure, Rrcherches chimiqnes, p 40 4 38 EVOLUTION AND GROWTH. resents almost exactly the volume of oxygen which it would be necessary to add, in order that the oxygen collected should represent the whole of that which entered into the constitution of the carbonic acid decomposed. It is probable that the excess of azote which ap- peared in all these experiments was present in principal part in the air contained and condensed within the interstices of the plants, or held in solution in the water which bathed their roots. It would be difficult to assign it any other origin ; such, for instance, as that from changes in the azotized principles of the plants that were the subject of experiment. In his first experiment, in fact, iM. de iSaus- sure fixes the weight of the dry matter of the seven periwinkle plants at 41.6 grains. Now, from numerous determinations of azote which I have had occasion to make in regard to plants of very dif- ferent ages and species, I think I can say that these periwinkles, taken as dry, did not contain more than .385 of azote; this, in ref- erence to the weight assumed by M. de Saussure, would be 1.042 grs. or 20.8 cubic inches of azote ; and the volume of azote disen- gaged in this first experiment was 54.6 cubic inches. It is proj)er further to observe, that the state of health which the plants pre- sented on the conclusion of the experiment does not allow us to sup- pose a total decomposition of the azotized matters which entered into their constitution. These various considerations lead us to in- fer that the excess of azote collected must have been displaced by oxygen. We are, therefore, at liberty to presume, froni the experi- ments now referred to, that the volume of oxygen produced probably represents the volume of carbonic acid decomposed. The necessity of oxygen gas in the decompounding action which plants exposed to the light exert so energetically upon carbonic acid, loads us to study particularly tiie phenomena which oxygen exhibits in connection with growing plants. When a number of freshly gathered and healthy leaves are placed during the night iinder a bell- glass of atmospheric air, they condense a portion of the oxygen ; the volume of the air diminishes, and there is a quantity of free car- bonic acid formed, generally less than the volume of oxygen which Kis disappeared. If the leaves which have absorbed this oxygen during their stay in the dark, be now exposed to the sun's light, they restore it nearly in equal quantity, so that, all corrections made, the atmosphere of the bell-glass returns to its original composition and volume. Leaves in general have the same elTect when they are placed alter- nately in the dark and in the light; there is, however, a very obvious dilTerence in the intensity with which the phenomenon is produced, according to the nature of the leaves. The quantity of carbonic acid formed during the night is by so much the less, as the leavea are more fieshy, thicker, and therefore more watery. The green matter of lleshy leaved plants, of the cactus opunlia, to quote a par- ticular instance, does not j)roduce any sensible quantity of carbonic acid in the dark : but these leaves condense oxygen, and exhale il again like those which are less lleshy, when they are brought into he sun, after having been kept for st^nie time in the dark. DEC03IP0SITI0N OF CARBONIC ACID. 39 Saussure applied the names of inspiration and expiration of plants to these alternate effects, led by the analog^y — somewhat remote, it must be confessed — which the phenomenon presents with the respi- ration of animals. The inspiration of leaves has certain limits ; in prolonging their stay in the dark, the absorption becomes less and less : it ceases entirely when the leaves have condensed about their own volume of oxygen gas. And let it not be supposed that the nocturnal inspira- tion of leaves is the consequence of a merely mechanical action, comparable, for example, to that exerted by porous substances gen- erally upon gases. The proof that it is not so is supplied by the fact that the same effects do not follow when leaves are immersed in carbonic acid, hydrogen, or azote. In such circumstances there is no appreciable diminution of the atmosphere that surrounds* the plant. The primary cause of the inspiration of oxygen by the leaves of living plants is, therefore, obviously of a chemical nature. With the facts which have just been announced before us, it seems very probable that during the nocturnal inspiration, the carbonic acid which appears is formed at the cost of carbon contained in the leaves, and that this acid is retained either wholly or in part, in proportion as the parenchyma of the leaf is more or less plentifully provided with water. A plant that remains permanently in a dark place, exposed to the open air, loses carbon incessantly ; the oxygen of the atmosphere then exerts an action that only terminates with the life of the plant : a result which is apparently in opposition to what takes place in an atmosphere of limited extent. But it is so, because in the free air the green parts of vegetables can never become entirely saturated with carbonic acid, inasmuch as there is a ceaseless interchange going on between this gas, and the mass of the surround- ing atmosphere ; there is, then, incessant penetration of the gases, as it is called. There is a kind of slow combustion of the carbon of a plant which is abstracted from the reparative influence of the light. The oxygen of the air also acts, but much less energetically, upon the organs of plants that do not possess a green color. The roots buried in the ground are still subjected to the action of tiiis gas. It is indeed well known, that to do their office properly, the soil must be soft and permeable, whence the repeated hoeings and turnings of the soil, and the pains that are taken to give access to the air into the ground in so many of the operations of agricul- ture. The roots that penetrate to a great depth, such as those of many trees, are no less dependent on the same thing ; the moisture that reaches them from without brings them the oxygen in solution, which they require for their development. It is long since Dr. Stephen Hales showed that the interstices of vegetable earth still contained air mingled with a very considerable proportion of oxygen. The roots of vegetables, moreover, appear generally to be stronger and more numerous as they are nearer the surface. In tropical countries various plants have creeping roots which often acquire dimensions little short of those of the trunk they feed. 40 EVOLUTION AND GROWTH. If a root detaohed from the stem be introduced under a bell-glass full of oxygen gas, the volume of the gas diminishes, carbonic acid is formed, of which a portion only mingles with the gas of the receiver, a certain quantity being retained by the moisture of the root. The volume of the gas thus retained is always less than that of the root itself, however long the experiment may be continued. In these circumstances, whether in the shade oi the sun, roots act precisely as leaves do when kept in the dark. Roots still connected with their stems, give somewhat different results. When the experiment is made with the stem and the leaves in the free air, while the roots are in a limited atmosphere of oxygen, they then absorb several times their own volume of this gas. Tliis is be- cause the carbonic acid formed and absorbed is carried into the general system of the plant, where it is elaborated by the leaves, if exposed to the same light, or simply exhaled if the plant be kept in the dark. The presence of oxygen in the air which has access to the roots is not merely favorable ; it is absolutely indispensable to the exer- cise of their functions. A plant, the stem and leaves of which are in the air, soon dies if its roots are in contact with pure carbonic acid, with hydrogen gas, or azote. The use of oxygen in the growth of the subterraneous parts of plants, explains wherefore our annual plants, which have largely developed roots, require a friaWe and loose soil for their advantageous cultivation. This also enables us to understand wherefore trees die, when their roots are submerged in stagnant water, and wherefore the effect of submersion in general is less injurious when the water is running, such water always con- taining more air in solution than that which is stagnant. The woody parts, the fruit, and those organs of plants in general which have not a green color, stand in the same relations to oxygen as the roots : they merely change th-s gas into carbonic acid, which is then transported to the plant at large, to suffer decomposition by the green parts. In this action we observe a displacement, a kind of translation of the carbon of the lower to the upper parts of plants. The decomposition of carbonic acid by j)lants admitted, we have still to examine whether, in the phenomena of vegetation, the leaves decompose the carbonic acid of the atmosphere directly, or the acid gas, previously dissolved in the water, which m«)istens the ground, be conducted by the way of absorption into the tissues of vegetables, there to suffer decomp«)sition. The quantity of carbonic acid con- tained in the air is so small, and the growth of plants, on the con- trary, is often so rapid, that it might reasonably be suspected that the carbon which they require was introduced in great part by this way of absorption. In that series of beautiful experiments in which M. Saussure expuld therefore have weighed 1.072 gram., or 16.54 grs. troy. A-nalysis showed in the Peas sown. Peas collected. Straw and roots. Carbon 48.0 54.9 52.8 Hydrogen 6.4 6.8 6.2 Azote 4.3 3.6 1.6 Oxygen 41.3 34.7 39.4 100.0 100.0 100.0 RESULTS. Carbon. Hydrogen. Oxygfcn. Azole. Seeds 16.549, containing 7.950 1.065 6.523 0.710 Crop 68.560, " * 36.680 4.384 25.930 1.559 52.02 grs. by cultivation +28.73 +3.319 +19.11 +0.849 From this experiment it appears that 16.519 grs. of seed found in the air, and obtained from the water with which they had b»^en sup- plied during their growth, 52.02 grs of elementary matter in the course of ninety-nine days' growth, during the warmest months of the year; and that the quantity of azote originally contained in the seed was more than doubled in the produce arrived at maturity. * Teas 45.89 Straw and shells 22.66 Total weight of the crop 68.55 46 EVOLUTION AND GROWTH. THIRD EXPERIMENT. GROWTH OF WHEAT. Forty-six wheat corns were sown in burnt sand at the beginning of the month of August. At the end of September, the stalks were from fourteen to fifteen inches in height. The greater number of the lower leaves were yellow. The roots were of very considerable length, and formed a kind of mat, which made it difficult to wash and free them from sand. RESULTS OF THE ANALYSIS. Seeds. Crop. Carbon 46.6 48.2 Hydrogen 5.8 5.8 Azote 3.45 2.0 Oxygen 44.15 44.0 lUO.OO 100.0 RESULTS. Gru. Carbon. Hydrogen. Oxygtn. Azot* Theseed dried 2.5.38 containing 11.84 1.46 11.19 0.87 The seed dried 46.05 " 22.47 _2.67 a).57 0.92 Gain by culture 21^27 -flQ.C3 +1.21 +9.38 +0.05 In the course of three months' growth, therefore, the weight of the seed had, so to speak, doubled ; but the grain azote was scarcely appreciable. Nevertheless, this experiment upon the wheat had been conducted under precisely the same circumstances as thai made upon the clover. The two crops grew in the same apparatus ; they were watered with the same water, which they 'received very nearly in the same quantity ; the seed was even sown in vessels having exacilv the same extent of surface, in order that either crop iTiiglu be exposed to the same chances of error arising from the ac- cidental presence of dust in the atmosphere. The plants produced under the circumstances indicated vere far from presenting the vigor which they would have shown ban they been grown in the open ficM. After three months of growth, the clover was much less forward than some which had been sown, for comparison, in a manured and gypsumed soil at the same time. The whea< showed the same weakness; and after the second montli, I observed that each new leaf which was devehiped upward in the stem, caused one of those at the lower part to droop and grow yel- low. 'I'he peas, although they reached maturity, had much smaller leaves, and both fewer and smaller seeds than similar plants grown at large. It is well known that it is in great jiart due to the fertility of the soil in which seeds are grown that the health and vigor of young plants must be ascribed, A celebrated agriculturist. .Schwartz, as- certained, for examjjle, that young cobnvorts or cabbage plants ex- hausted in a remarkable manner the soU in which thry were raised for transplantation. The good efl'ects of the first nourishment ob- ASSIMILATION OF ELEMENTS. 47 tained in a well-manured soil must extend subsequently to every part of the vegetable ; and it is easily understood that a plant which has languished in its earliest periods of existence can never acquire a good constitution afterwards. It therefore became interesting to carry out experiments of the nature of those already related, in connection with plants vigorously organized, and which had been raised in the first instance in a fer- tile soil. FOURTH EXPERIMENT. GROWTH OF CLOVER. In a field of clover sown in the spring of the preceding year, several plants as like one another as possible were chosen. The earth adhering to the roots was removed by careful washing under a small stream of water ; the plants were then made dry between leaves of blotting paper, and exposed for a few hours in the air. Three of these plants preserved for analysis weighed when green 6.750 grammes, or 104.20 grs. troy. Three other plants, weighing 6.820 gram, or 105.28 grs. troy, were set in sand recently calcined and moistened with distilled water. The transplanting took place on the 28lh of May, and the plants were forthwith protected from dust. For some days they seemed to languish, but by and by they be- came remarkably vigorous. In a month the clover had grown to twice its original height, and the leaves were of the most beautiful green : the plants had in all respects as fine an appearance as the clover of the same age which had been left growing in the field. The flowers showed themselves upon the 8th of July, and by the 1 5th the flowering was complete : an end was put to the experiment on the 1st of August. RESULTS OF THE ANALYSIS. BEFOKE CULTURE. AFTER CULTUR«. Carbon 43.42 53.00 Hydrogen 5.40 6.51 Azote 3.75 2.45 Oxygen .47.43 38.14 100.00 100.00 RESULTS. Tlie trefoil transplanted, weighed when drj' and freed from ashes 13.64 After sixty-three days' culture on barren soil, it weighed 34.96 Gained during culture 21.32 Carbon. Hydrogen. Oxygen. Azote The plant contained : before culture 5.92 0.74 6.46 0.50 afterculture 18.52 2.23 13.32 0.864 Difference +12.60 +1.49 +6.8G +0.35 Thus in two months' growth at the cost of the air and water, the clover had, so to say, tripled its quantity of organic matter; and th« weight of azote contained in it was very nearly doubled. 49 EVOLUTION AND GROWTH. FIFTH EXPERIMENT. VEGETATION OF OATS. I always failed in my attenipts to transfer wheat plants from the ordinary soil in which the grain had been sown to barren sand ; they never survived the transplantation. It was not different with oat plants ; they also always died. It was at first supposed that the delicate radicles of these plants had been injured in the process of taking them up and freeing their roots from adhering vegetable soil ; but I soon saw that this could not have been the case, for the same plants, treated precisely in the same manner, took very promptly when transplanted to garden mould, and even when they were put with their roots in pure water. It was with water, therefore, that the following experiment was conducted. June 20th, several oat plants were taken up from a field, and their roots were washed and cleansed. Three plants preserved for analysis, weighed 159.011 grs. Four plants, the subjects of experiment, weighed '22 1. 844 grs. troy. They were protected from dust, their roots dipping into a vessel containmg distilled water, which was regularly kept up to the same level. By the middle of July the stalks of these plants had grown to twice their former length ; and at this time it would have been difficult to have distinguished them from those growing in the open field. By liie end of July the clusters had formed ; and on the lOlh of August the grain seemed ripe. It was, therefore, taken up and dried in the stove, and reduced to powder to complete the desiccation at 110" cent. (230" Fahr.) ANALVSIS OK THE CROP. Tran«plan(«d. Gathcnd from Om laid. Carbon 53.0 48.0 HydroRcn 6.8 6.3 Oxygen 36.4 44.0 Azote 3.8 1-7 100.0 100.0 SUMMARY. Carbon. Hyilroj^n. Oxygfn Atet*. The oats when transplanted conuiined 12.967 1.636 8.770 0.910 After 48 days of prowlh In dis- tilled water tliey confined -23.157 2-979 21180 0.818 + 10.190 +1.343 +12.410 -O.OW The analysis, therefore, indicates a trifling loss of azote. In recapitulating the conclusions obtained from these experiments, we find : First. That trefoil and peas grown in a soil absolutely without manure, acquired a very ajjprociable quantity of azote, in addition to a large quantity of carbon, hydrogen, and oxygen. ASSIMILATION OF ELEMENTS. 49 Second. That wheat and oats grown in the same circumstances, took carbon, hydrogen, and oxygen from the air and water around them ; but that analysis showed no increase of azote in these plants after their maturity. The mode of experimenting followed had it in view simply to determine the assimilation of azote by certain vegetables, without entering into the question of the means by which this was effected ; and, indeed, in reference to the point, I can only offer conjectures. Azote may enter the living frame of plants directly, or, as M. Piobert has maintained, in the state of solution in the water, always aerated, which is taken up by their roots.* The observations of vegetable physiologists are not generaly favorable to this view. It is farther possible that the element in question may be derived from ammoniacal vapors, which, according to some philosophers, exist in infinitely small proportion in our atmosphere. These vapors, dis- solved by rains and dews, would readily make their way into plants, and might there undergo elaboration. It is long since Saussure alluded to the probable influence of am- moniacal vapors upon vegetation. Prof. Liebig has more recently maintained the same opinion, and has taken particular pains to prove that rain-water always contains a very minute quantity of carbonate of ammonia. To this cause, which must have the effect of infusing an azotized principle into the tissues of plants, must be added another, which is perhaps not the least energetic. It is this, that under certain elec- trical influences, of which M. Becquerel has made a particular study, hydrogen in the nascent state, in contact with azote, may actually give rise to ammonia. By means of this view, it becomes easy to conceive how non-azotized organic substances, under the mere in- fluence of the putrid fermentation, might give origin to ammoniacal salts, which would then exercise a fertilizing action on the soil. During the growth of plants, a portion of the w^ater absorbed by the roots is evidently assimilated ; and this circumstance enables us to conceive the formation of many of the immediate principles of vegetables, the chemical composition of which is precisely repre- sented by carbon and the elements of water ; such as starch, sugar, etc. We can also understand the presence of those principles, which have further a certain proportion of oxygen in excess, inas- much as we have ascertained that during the decomposition of car- bonic acid by the green parts of vegetables, the whole of the oxygen is not eliminated. But there are substances elaborated by plants which, with reference to oxygen, contain a quantity of hydrogen much greater than is requisite to form water ; such are the resins and other carburets of hydrogen in the cone-bearing trees, and the fat oils in the oleaginous seeds. This excess of hydrogen led several physiologists to conclude that water was decomposed in the course of vegetation, — that there was fixation of its hydrogen and disen^ gagement of its oxygen gas. * Piobert, M6m. de I'Academie de Metz, 1837. 6 50 EVOLUTION AND GROWTH. Nevertheless, the presence of hydrogen in excess in certain im. mediate vegetable principles is no decisive proof of the disjunction of the elements of water ; and if no definitive conclusion has been come to on the point, up to the present moment, it is because these hydrogenized principles are produced in plants which live under the influence of certain organic substances that are met with in the soil, where they act as manures, their composition being always complex, and often highly hydrogenized. The experiments of M. de Saussure do not lead us to suspect the decomposition of water ; inasmuch as by keeping plants for a whole month, under receivers filled with atmospheric air freed from carbonic acifl, no apparent evohition of oxygen was observed. Operating in the same manner with air containing a certain propor- tion of carbonic acid, the quantity of oxygen disengaged was always less than that which entered into the constitution of the acid de- composed. This is the place to observe, and in connection with these very experiments of M. de Saussure, how little satisfactory this partial decomposition of carbonic acid, which corresponds to no definite proportion, appears. We already feel the difficulty of conceiving that this acid should be completely reduced by a living plant ; that is to say, that the whole of its carbon should become assimilated. The entire separation of a body so greedy of oxygen as carbon from its most highly oxygenated compound, must needs excite the greatest astonishment. The readiest conception suggested by the facts is this; that by the agency of the solar light, and under the influence of the green matter, carbonic acid is turned into carbonic oxide by losing a por- tion of its oxygen. This modification appears more in conformity with the ascertained principles of chemical and physiological science. Still it must be alhnved, that facts agree as little with this mode of viewing the question as with that which assumes the entire decomposition of the carbonic acid. On the lirst assumption, the proportion of oxygen set at liberty is too small ; in the second, it is too great. The negative results of M. de Saussure, in relation to the separa- tion of the elements of water durinsj vegetati<»n, were obtained in the absence of carbonic acid, whilst the experiments which estab- lished the decomposition of this latter body, were necessarily made under the influence of moisture. It is possible, therefore, that the water and the carbonic acid underwent sinuiltaneous decompcjsition ; and it becomes interesting, taking this view, to inquire whether the hypothesis according to which carbonic acid undergoes transforma- tion into carbonic oxide does not acquire a certain degree of proba- bility by callmg in the cflect of the decomposition of water in the phenomena observed. One volume of the gaseous oxide of carbon takes half a volume of oxygen gas to form one volume of carbonic acid. Reciprocally, one volume of carbonic acid gas, in undergoing transformation into ASSIMILATION OF ELEMENTS. 51 the oxide of carbon, will give one volume of the oxide, -f | a volume of oxygen gas. Thus, in the hypothesis which we now discuss, for each volume of carbonic acid that is modified by the vegetation, there will be half a volume of oxygen gas disengaged. Any oxygen more than this half volume which appears, must be regarded as proceeding from the decomposition of water, the hydrogen of which will have been assimilated by the plant at the same time as the carbonic oxide de- rived from the carbonic acid ; and this view would perhaps enable us to conceive how the volume of oxygen which is disengaged du- ring the process of vegetation, may exceed the volume which. ought to be produced, if the carbonic acid decomposed really passed into the state of carbonic oxide. We may perchance obtain a more convincing proof of the separa- tion of the elements of water, in analyzing plants grown in a soil absolutely without any organic matter capable of affording them hy- drogenous elements. In fact, if a plant, which is grown under such circumstances, con- tains hydrogen in any larger proportion than that which were neces- sary to transform its oxygen into water, we might conclude, with some certainty, that the elements of water had been separated ; the objection made on the score of the presence of manure would then be got rid of entirely. The analyses which have already been laid before the reader supply data for this investigation ; it has only to be ascertained whether, in the elements gained in the course of vegetation, the hydrogen is in excess with reference to the oxygen or not. The following table presents a summary view of our ex- periments : Oxysren Hydroj^en HyJroo^eii Hydrojren assimilated, assimilated, forming' water, in excess. Experiment 1. TrefoU 18.926 2.717 2.362 0.355 Experiment 2. Peas 19.096 3.319 2.392 0.926 Experiment 3. Wheat 9.386 1.204 1.173 0.030 Experiment 4. Transplanted Trefoil . • 6.854 1.495 0.849 0.646 Experiments. Oats 12.410 1.343 1.343 In the four first experiments, the hydrogen gained evidently ex- ceeds very sensibly the quantity required by the oxygen to form water. The experiment with the oats, indeed, presents an excep- tion ; but it must be remembered that here a loss of azote was ascer- tained. These analyses, therefore, appear to indicate an assimilation of hydrogen in the course of vegetation, in consequence of a decom- position of water analogous to that of carbonic acid, and very proba- bly effected by the same means. 52 INORGANIC CONSTITUENTS. § III.— OF THE INORGANIC MATTERS CONTAINED IN PLANTS— THEIR ORIGIN— OF THE CHEMICAL NATURE OF SAP. When a plant is burned, there always remains a residue, which is commonly designated as the ash. Every part of a plant gives a residue of the same essential kind ; but it varies in its quantity and somewhat also in its composition. Equal weights of dry herbaceous plants leave more ashes tlian woody plants.* In a tree, the trunk gives more ash than the branches, and these give less than the leaves. f The residue left by the combustion is com- monly composed of salts — alkaline chlorides, with bases of potash and soda, earthy and metallic phosphates, caustic or carbonated lime and magnesia, silica, and oxides of iron and of manganese. Seve- ral other substances are also met with there, but in quantities so small that they may be neglected. The principles irsually met with in the ashes of vegetables are always found in the soil whi(;h exercises the greatest influence upon the nature and quantity of the saline and earthy matters which re- main after the combustion of plants. Those which grow in a soil derived from silicious rocks, yield ashes that are richer in silica than those that are produced in a calcareous soil. But, according to M- de Saussure, the quality of the manure has a still more decided in- fluence on the nature of the ash than the geological constitution of the soil ; according to this observer, plants of the same species, which have grown upon a calcareous sand, and upon a granitic sand, contain the same kind of ashes, if they have been manured with the same dung ; and dilTerent species, although growing in the same earth, do not contain the salme and earthy constituents of thair ashes in the same proportions. | * Kirwnn, Memoirs of the Roynl Irish .\cademy, vol. ▼. t Pertuis, .\nnnles de Chimie, 1" s6rie, t. xix. X Saassure, Rechcrches chiiniques, p. 383. ASHES. 59 QUANTITY OF ASHES CONTAINED IN THE DIFFERENT PARTS OK VEGETABLES, ACCORDING TO M. DE SAUSSURE.* NAME OF THE PLANT. [Times when taken for analysis. Oak leaves Ditto do. . . . Oak branches barked Bark of these branches . Oak wood distinct from alburnum Alburnum from same wood Bark of same tree . Liber of the preceding bark Leaves of poplar Ditto ditto Trunk of ditto . Bark of trunk of ditto . Spanish mulberry-tree wood Alburnum of mulberry . Bark of ditto . Liber of ditto Chestnut-tree leaves Ditto ditto Flowers of chestnut-tree Ripe chestnuts Peas flowering Peas in pod . Beans in flower Ditto in pod . Bean straw Beans .... Jerusalem artichoke in flower Ditto in seed Wheat straw . Wheat . Bran Indian corn straw . Indian corn . Barley straw . Barley .... Oats .... Pine-tree leaves (Jura) . Ditto ditto (Brocken) Pine-tree branches without leavc~ ! 10 May 27 September 10 May May September 10 May 23 July 10 May 5 October 20 June 20 June 20 June Ashes. 0,053 0,055 0,004 0,060 0,002 0,004 O.OGO 0,073 0,066 0,093 0,008 0,072 0,007 0,013 0,089 0,088 0,072 0,084 0,071 0,034 0,095 0,081 0,122 0,066 0,115 0,033 0,137 0,093 0,043 0,013 0,052 0,084 0,010 0,042 0,018 0,031 0,029 0,029 0,015 All these estimates of ashes refer to plants dried during several weeks in a stove heated to 25° cent. (77° Fahr.) By such drying, however, vegetable substances are very far from losing the whole * Saussure, Recherches chimiques, p. 283. 5* 54 INORGANIC CONSTITUENTS. of the water which they contain. The quantities of ashes, there- fore, mentioned by M. de Saussure, if they be referred to vegetables absolutely dry, are somewhat too small. I present a few estimates of ashes from analyses which I have had occasion to make of some of those plants which are the usual sub- jects of cultivation with us. The drying here was always performed with care in an oil-bath heated to 110° cent. (230° Fahr.)* Substance dried at SSO" Fahr. Aihei. Subilance dried at 830" Fahr. Ashe*. Wheat Straw 0.070 Wheat 0.0-24 Rye straw 0,036 Rye 0.O23 Out straw 0.0.31 Oats 0.040 Potatoes 0.040 Beet-root 0,0G3 Turnip 0,076 Jerusalem artichoke 0,060 Stems of ditto 0.028 White i)eas 0.031 Pea straw 0,113 Clover hay 0,077 MeaiL.w hay 0.0(H) After gniss (meadow) 0,100 We owe to M. Berthierf the following results of the incineration of different kinds of wood burned in the state in which they are gen- erally used. Kind of wood. Ashes. Fir 0.0083 Birch 0.0100 False ebony O.Olii Hazel O.OI.I- White mullM-rry 0.0H50 S.iiiit Lucia wood 0,01 GO Elder O.OKVI Judea-tree 0,0170 Oak (branches) 0.(HM Oak bark O.lMiOO Lime-tree O.OoOO Kind of wood. Ashes. Poplar bark 0.0020 B.).\w»mm1 0.0036 Oik barked, ash. pine, birch, &c. 0,0040 Thorn O.OOiO Aspinlne 0,0060 Oak bark 0.0120 Black wiKMl 0.0149 Mahocany OOK-O Ebony O.(nr.0' Oak (fajjot) 0,0-220 Fearns 0,0430 We possess several analyses of ashes from diflTorent parts of the same plants in the researches of M.M. de Saussure and Berlhicr. As the knowledge of these saline substances may prove highly im- portant in our agricultural applications, and as it further completes, in some sort, the facts that l)car iip0 lO O O O O O O .-1 t-^ojc>jiOTrcriT}-ooo lo lo « (^^ ^ '1 --i "^ ^ ^^ ""i, o" o o" o" o o o o o o" o •T{SB}od JO apuomo o o o c: o c? ox i-o CO o CO CO (?}-^OC0OOC^OOO o" o''o'~o'~o'"o"o'^o'"o''o o" •qsBjod JO ajBqding > SI'S c S o^ o o^ « ■* "^i,^^^*^ ■&§ .cSo'oo i ©"o^o^o •qsBiodjo siBqdsonj O CSOOOt-iO c^ oo - ^ CO lO !!>? o C5 t- ^ en c^ - -'=tocoroo^-o o o" o" o" o" o" o" d" •sanqdsoqd Aqw^a O OOC5CJ>Oi0OOQ0»0 oj lo c£) lo io -^ ?i5 lo CO t^ cr? --H rH O (M O TT '■^ O O O CO o" o'"o"o''o"o"o'~o"o''o'"o" 1 11 II 11 1 Pi Chestnuts Meuyanthes trifoliata in flower (buckbean) The same cleared of seed Beans .... Wheat straw Selected wheat . Wheat bran Indian corn straw Indian corn Barley straw Barley in the husk , •STSitl'BU-B JO -Oil rH ci co^^^t^ooa^a^ 56 INORGANIC CONSTITUENTS. In his researches upon the same subject, M. Berthier determined the relation of the insoluble to the soluble matters in each species of ash examined ; and the two kinds of salts were then analyzed separately. oil. oil. M to 3 . 3 .0 r= .0 and ferruginous, laceous, calcare lat calcareous. argillaceous so pen field. part of a plank ong and calcare alcareous sand. ^; ^■% 1 is fsr ayey, sun ry dry, a ndy, som le same. tto. tto. tto. tto. Icarcous own in tl ndy clay. om Norw own in a icious an U> y.h aOOQ^JO '^ ^o}n a 1 -HOO(No^-:c;-o^oo'<#inooooQ0 o oocBt^QoootoooaDooaoi-ocnooto 10 oo oi ■3 0 1 c 0 0 0 0 0 0" 0" 0" 0" 0" d" 0" 0" o" 0 0' 0" 0" i 5 oiooaDOioo"^C50c;iOi.Toi-T = 0(ri QOOJ»ooto-[BO •3IBO •u.Baq ujojj O M C« O M I- C? O F-. CV — SOS t- o'cToo" o" © « ifl C) O irt o 'r 3; 1^ c* c^ c M M o o^ L-r c o o © o o' o c' o o" •* o « r; o o o'c © o'so r? 'o - ©© © o © JO C-. C © © o CO ?i©£^S S g ©'©©'o'o* ©' ©' © OO C; — O LT f^ C« — C-» vC 'J' O r-< , ■V_©©'»-0©© ' ©' ©' ©' ©' © o' ©" •- © r- t- oj « lo J^ r-. t~ ;C IC O © c(-^^©^©5o ©' ©' ©' ©' ©' ©' © 5<©o© r~ -^ i-< © C-l X jjj CC i?5 «"• ©' o" ©' ©' ©" '^^ -1 L-5 lo © lO © © «< © ©5 o oc -*> -r ■»!' o t- •<»■ Tj< o> -^ Tt< «© © TT ©o ©'©'©'©' ©'o" 1— L-! O 5;si© ©'©'©'©' © -^ -^ < ©©©© 5< Oi- © ©' ©' ©" ©" r:©©Tf-o©© ' © ©" ©'©"©'o"© © re X X © L'M ;^552^J58; ©'© © © ©'©'( . . © t- X ?;£§© © ©'©"© ce ©© m ©S© ©' ©' ©' ©' ©' o' ©" § ?? =5S8 ©'© ^^X X X © © © r: rr © , ce © © L': (5 - ©' ©' ©' ©' o" £• S © © X < © © © © o o © c; 32 s: K t, cc ^ •spunodiuoa aiqnios .III g -r • •' S ® c fl •£ o H c fctSS-S «^-C:r-~L5 X ^^ cs 'spunodiuo3 aiqniosuj 58 INORGANIC CONSTITUENTS. COMPOSITION OF THE ASHEi: OF SEVERAL PLANTS ANALYZED BY M. BERTHIER. Fern. Wheal straw. Horse-tail Heath. Tansy. grass. 0.120 0,050 0,033 0,114 0,012 0,090 .. 0,068 0,167 0.505 0.375 0,i'65 0,062 0,280 0.434 0.144 0,022 0.130 0.100 0,030 0,010 0.002 „ 0,014 0,007 „ o,o<;i 0,002 Observations. Sulphate of potash. • • Chloride of potassium Carbonate of potiish. • Silicate of potash . • • • Silica Carbonate of lime. • . . Sulphate of lime Phosphate of lime ... Macnesia Oxide of iron Oxide of manganese. • 0,007 0,730 0,248 0,010 0,005 0,004 0,032 0,130 0,715 0,096 0,023 The wheat itraw was IrDin » strong- calca- The wnjjr wm from « raiiily gu- ile n *uil. A remark made by Berthicr, and arisinj^ out of the preceding analyses, is the absence of ahimina in the constituent princi])b^s of the ashes examined. The results previously obtained bv M. de Saussure fully confirm this remark ; and if in some cases traces of alumina were detected, the circumstance was attributed to the clay which might accidentally have adhered to the plants. Accordinji: to M. Berthier the absence of alumina is probably owinfj lo its insolu- bility in water, and its weak affinity for the organic acids. The solu- ble salts of alumina with mineral acids are, it is well known, unfa- vorable to vegetation, and in an arable soil they could not exist along with calcareous or alkaline carbonates : they would be immediately decomposed. However, alumina appears actually to have been observed in the slate of salt in the juices of certain plants : hjcopodium cornplanatum, an infusion of which is employed as a mordant in dyeing, contains tartrate of alumina ;* the same salt has been detected in verjuice ; and as we shall see presently, ^'autjuelin found acetate of alumina in the sap of the birch-tree. 1 may add, that in a considerable numbi-r of analyses of ashes, produced from j)lants and seeds of my own grow- ing, I always obtained traces of alumina : but I would not venture to atfirm that the earth here was not accidental. Silica is met with in oidy very small quaniily in the ashes of wood. It is found, on the contrary, in con.siderable proportion in the ashes of several annual and biennial plants, anil more especially in those of the cereals. Sir Humphrey Davy found silica in the epidermis of the Indian rush. If we compare the ashes of the same species of wood grown in soils of diflerent kinds, we see, says M. Berthier, that tliey may dif- fer very perceptibly; which seems to establish the fact tliat the soil exercises a certain degree of inlluence on their constitution. Thus oak-wood from Hoque des Arcs, grown in a decidedly calcareous soil, yielded ashes almost entirely consisting of carbonate of lune, • Bcrzeliu^, Traits de ChintU. I. '. p. 130, Fr»nch trariilation. ABSORPTION OF SALTS. 59 while those left by an oak from the department of la Somme, contain- ed much magnesia and phosphate of lime.* The ashes from a white mulberry of Nemours contained more than 0,10 of phosphoric acid, while scarcely any traces of it were found in those of a similar mul- berry from the calcareous soil of Provence. The most remarkable inference deducible from the analyses of M. Berthier, is that which is connected with the composition of the ashes yielded by trees growing in the same soil. It is observed that, for analogous species, the ashes also bear the closest analogy ; and on the contrary, it is found that trees of very distinct genera yield ashes of quite a dif- ferent quality ; results which lead to this important conclusion, that plants possess the faculty of selecting in the soil the substances which are best suited to their special organizations. This is a point which we shall have an opportunity of discussing, when we come to treat of rotations of crops. The substances composing the ashes of vegetables, are not all in the state in which they existed in the vegetable tissue. In plants there constantly exist organic acids, which, in general, are combined with mineral bases. During the incineration of plants these organic acids are destroyed, and the result of their destruction is an alkaline carbonate, if the pre-existing acid was united with soda or potash ; a calcareous vegetable salt, again, yields carbonate of lime ; and a magnesian salt gives magnesia, from the well-known inability of this earth to retain carbonic acid at a high temperature. Thus, the greater part of the carbonates which enter into the composition of vegetable ashes, are formed by the mere fact of incineration. The salts which resist the action of a strong heat, as the phosphates, sul- phates, and chlorides, are the only ones which in the ashes retain the state in which they existed in the living plant. Water being the vehicle which must convey the mineral salts from the soil into the vegetable, we do not always perceive how they can penetrate. To explain the presence in plants of a salt so insoluble as the neutral phosphate of lime, M. de Saussure admits, from satis- factory experiments, that vegetable juices contain the double phos- phate of potash and lime, and of potash and magnesia, f Besides, several bodies considered in chemistry as insoluble, are not so abso- lutely. Silica seems to possess a certain degree of solubility, — at least, M. Payen has met with it in considerable quantity in the wa- ter of the Artesian well of Grenelle, and in the water of the Seine. We know% moreover, that several insoluble earthy salts are dissolv- ed in virtue of the carbonic acid always contained in the waters with which the soil is soaked. Lastly, it is not improbable that certain insoluble salts have their origin in the plant itself, engender- ed there by the successive arrival and reciprocal action of soluble salts. It now remains for us to examine by what means saline substances are introduced into the tissues of vegetables, and within what limits * These ashes were from the carbon of the oak ; the insoluble part gave 0.14 ol phosphate of lime, and 0.08 of magnesia. t Saussure, Recherches chimiques, &c. p, 321. 60 INORGANIC CONSTITUENTS. the water, which is essential to living plants, may be charged with them ; for it is within what may be called common experience, that saline solutions of certain degrees of concentration, oftentimes act injuriously on vegetation. The spongioles which terminate roots have too close a tissue to allow any thing but fluids to pass through them. All attempts to make them absorb solid bodies in a state of minute division, and held in suspension in water, have been ineffectual. In these attempts the spongioles have acted precisely like perfect filters, with which those that we employ in our laboratories cannot be compared. Further, the weakest solutions are not entirely absorbed by certain roots ; a kind of separation takes place ; a portion of the dissolved salt ap- pears to abandon the water at the moment of its penetrating the spongiole. This follows from the researches of ^I. de Saussure, instituted with a view to ascertain, 1st. If plants absorb substances dissolved in water in the same proportion as they absorb water ;* 2dly. If plants make a selection among different substances held in solution in the same liquid. f In solutions severally containing eight ten-thousandths (0.0008) of each of the following substances — chloride of potassium, chloride of sodium, nitrate of lime, sulphate of soda, hydrochlorate of ammo- nia, acetate of lime, sulphate of copper, sugar-candy, gum arabic, and extract of humus,| — several entire plants with their roots, of the polygonum persicario, (lakeweed »)r redshanks,) which had lived for some time in distilled water, until their roots had commenced growing, wore immersed. The plants lived in the shade during five weeks, throwing out r(»ots in one of the solutions mentioned. They languished, without show- ing any appearance of growth in the solution of hydrochlorate of ammonia, and could "only be kept alive in the sugared water, which soon became changed, by renewing it frequently. They died at the end of from eight to ten days, in gum wator, and in the solution of acetate of lime. They held out but for two or three days in the water which contained sulj)hate of ropper. Observations precisely similar made on the bidens cannabina pre- sented the same results, with the sole difference, thai this plant lived for much shorter times than the redshanks To estimate in what proportion the substances dissolved were ab- sorbed, relatively to the water, M. de Saussure made use of the solutions previously cnjployed ; but he brought the experiment to a close when the plants had taken up precisely half the liquid which was feeding them. Each solution kH\ a sufficient number of plants to allow of this condition being fulfilled in two days. Half of the liquid remaining after each experiment was analyzed, and the (juan- tity of salt fi)und therein, showed, by the difference between this and the quantity originally contained, the amount which had pene- trated ihr vegetable. Representing hy one hundred parts the whole • Siussurc. Rprhprches rhimiques, &.c. p. 247. t n»i0 Oxygen of the potash 0.411 lime 40.34 " lime 7.33V9.01ox. " magnesia 6.77 " magnesia 1.27) Carbonates ^7.56.71 The ashes of a pine from Mount La Salle yielded : Carbonate of pntasli 7.3t> Oxypen of the potash 0-85 J o q^ «- lime 51.f.y • lime S-lOp'^"- " magnesia 0.(M) M. Berthicr found in the ashes of a fir-tree from Allevard the following bases : Potash and Soda lfi.8 Oxygen 3.42) Mmc 2l>.5 " 8.20V12.82 Magnesia 3-2 " 120) 49.5 One part of the alkalies containintr l.*30 of oxygen was combined with mineral acids, forming sulphates, pliosphates, and a chloride The oxygen of the bases combined with the carbonic acid is conse- quently reduced to 11 6'2. The ashes of a Norway fir, according to the same analyst, con- taining : SAP. Potasb 14-10 Oxygen. Soda 20-70 " —^ «.io oi «-r,T„»„ Lime 12.30 « 3.4^ )► 12. 84 oxygen. Magnesia 14.35 " 51.45 In this ash the bases belonging to the inorganic salts contain 1.37 of oxygen. The oxygen of the bases of the carbonates, or in other words of the bases which formed organic salts in the tree, therefore, becomes 11.47. The numbers 9.01 and 8.95 on the one hand, and 11.62 and 11.47 on the other, which represent the quantity of oxy- gen of the whole of the bases in the ashes obtained from plants of the same species, differ so little, that they may be considered as identical. Accurate analyses of ashes of plants of the same species grown in soils of different kinds, will determine, says Prof. Liebig, whether the fact, deduced from the composition of the ashes of the pine and fir-tree, constitutes a definitive law.* Be this as it may, the utility of alkalies in vegetation cannot be a matter of doubt ; many usages in agriculture prove it in the clearest manner; and, according to M. Liebig, the fact of the forma- tion of the organic alkaloides in plants aflfords an additional proof of it. M. Liebig thinks that the organic alkalies have a particular tendency to form in the absence of mineral bases ; thus potatoes which germinate in cellars, under conditions where the soil cannot supply them with potash, soda, or lime, develop an organic alkali, solanine, which is not found in the tubers of this vegetable as usually cultivated. t In the cinchonas, quinine and cinchonine are combined with quinic acid ; but there is frequently found quinate of lime also. According to the same chemist, the latter base holds the place of a vegetable alkali in the organism ; the more prevalent it is in the soil, the less rich will the cinchona plant be in quinine and cinchonine.;^ These ingenious views certainly deserve the careful attention of physiologists ; they are calculated to add new interest to the study of the chemical constitution of the ashes of vegetables. The inorganic substances contained in vegetables evidently come from the soil. By growing seeds, as M. Lassaigne did, in flowers of sulphur, moistened with distilled water, the plant produced con- tained neither more nor less saline and earthy matter than was origi- nally present in the seed. The water absorbed by the roots, then, becomes charged during its stay in the ground with the various soluble substances which may be met with there, and which generally contribute to its fer- tility ; sucV. especially are the salts derived from decomposed organic substances. Water charged with small quantities of the soluble substances diffused through the soil, constitutes the ascending sap. When it has penetrated the plant, immediately after its passage by Ihe spongi.les of the roots, perhaps even while traversing these * Liebig, Chimie Organiqne, Introduction, p. cxi. t Liebig, idem. p. cxiv. i Liebig, idem. A* 60 TRANSITION OF INORGANIC INTO ORGANIC MATTER. parts, the organic matters dissolved in the fluid appear to undergo important nnodifications; for in the sap substances are detected which could not have existed in the water which moistened the soil. During its ascent the sap increases in density, as was ascertained by Mr. Knight, according to whom, the sap of an acer platanoides, taken at the level of the ground, has a density of 1.004 ; at 6.^ feet above it this density becomes 1.008, and at 13 feet, 1.012. From this Mr. Knight concluded that the sap took up nutritive matter deposited in the vegetable tissues which it traversed in its ascent.* We have already seen that the sap, at'ter being elaborated in the green parts of trees, takes a route the reverse of that which it fol- lowed at first, and we therefore spoke of this modified sap as the descending sap. It is very possible that in Knight's observations the liquid examined was a mixture of the two saps. We should not be over hasty in concluding that the action of the two species of sap was exerted separately in promoting the develop- ment of the plant ; it is very probable, as Dutrochet thinks, that the modified sap, by insinuating itself into the permeable tissue of the vegetable, is continually mixed with the ascending sap, in order to concur in promoting the growth of the buds.f The dilliculty of obtaining each particular sap separately, if such a separation is really possible, prevents the analytical conclusions we have from possess- ing all the accuracy that seems desirable. Vauquelin has studied the sap of the birch-tree, of the hornbeam, of the beech, of the chestnut, and of the elm. The sap of the hornbeam {Carpinus si/lcestris) was obtained in the months of April and May. At this period it is colorless and clear as water ; its taste is slightly saccharine ; its odor resembles that of whey ; it reddens turnsole paper. The sap of this tree contains water in very large quantity, sugar, extractive matter, J and free acetic acid, acetate of lime and acetate of potash, in very small quantity. This sap left to itself presents in succession all the phenomena ol the vinous and then of tlie acetous fermentation.'^ The sap of the Inrch-trcc reddens turnsole intensely ; it is color- less, and has a sweet taste. The water which forms the greater part of it, holds in solution sugar, extractive matter, acetate of lime, acetate of alumina, and acetate of potash. When properly concentrated by evaporation, it ferments on the addition of yeast, and then yields alcohol on distillation. The pre- sence of the acetate of alumina may appear extraordinary in this sap, for this reason, that alumina has not yet been discovered in the ashes of the birch-tree. Sap of the beech, {Fagus sj/lccslns.) The analysis was made in March and April. The color of the sap was a tawny red ; it had the taste of an infusion of tanner's bark ; it reddened turnsole slight- * Docandolle, riiysiulogie. t. I. p. 204. t Dutrochet, sur hi Structure, &.c. p. 36 i Probably nzoiizcd. ^ Vauquelin, Annates dc Chiinie, t. xxxl. p 20, lire i^ri*. SAP 67 \y. It contained, in very small quantity, acetate of lime, acetate of potash, acetate of alumina, extractive matter, tannin acetic acid, ind gallic acid. The sap of the chestnut-tree^ according to Vauquelin, who, foi want of a sufficient quantity of the fluid, was able to study it hut very superficially, contains mucilage, nitrate of potash, and the acetates of potash and lime. The sap of the elm was examined at three periods ; first, at the commencement of April, then some days after, and lastly, a month later. At the beginning of April its color was yellow, its taste sweet and mucilaginous ; it was scarcely acid. Analysis indicated : water 1027.90, acetate of potash 9.23, organic matter 1.06, carbo- nate of lime 0.80. At the second period it contained a little more extractive organic matter, and a little less carbonate of lime and acetate of potash. The last examination showed that these two salts had still further diminished in quantity. When exposed to the air, the sap of the elm undergoes decomposition, and becomes alkaline : the acetate of potash passes into the state of carbonate. M. Regimbeau found in the sap of the vine* bitartrate of potash, tartrate of lime, mucilage, and free carbonic acid. The sap of the maple-tree contains a very considerable quantity of sugar. In Canada, this sap, properly treated, yields sugar which is identical with that of the cane. The nature of the sap is subject to variations ; and Duhamel slates, that at a certain season it loses its saccharine taste, and acquires an herbaceous flavor. f Liebig and Will detected the presence of ammoniacal salts in the sap of the maple and birch-tree, and in the tears of the vine. M. Biot examined the sap of a considerable number of trees, and ascer- tained that the sugar in them often exists in two different states ; in that of cane-sugar, properly so called, and in that of grape-sugar, which, as chemists admit, diflTers from the former only in the pos- session of an additional equivalent of water. The saps which M. Biot examined, contained besides some animal matter {albumine) and a gummy matter ; he found no free carbonic acid. The object .whichlie had in view, namely, to study the changes which occur m the nature of sugar, did not lead M. Biot to notice the minute quan- tities of salts with organic acids which Vauquelin met with in saps. The trunk of a walnut-tree, tapped on the Uth of February, yielded a sap containing some cane-sugar. The saps of the syca- more, of the acer negundo, and of the lilac-tree, contained the same species of sugar ; but that of the birch-tree held in solution some grape-sugar. In the sycamore and birch-tree, M. Biot observed an extremely interesting fact. He ascertained, on felling these trees, that the greater portion of the descending sap was accumulated to- wards the middle of the trunk. That of the birch-tree was acid and saccharine ; the sap of that portion of the trunk which was * Journal de Pharmacie, t. xviii. p. 36. t Annales de TAgriculture, Franfaise, t. v. 26me s6rie, p. 339. fi8 TRANSITION OF INORGANIC INTO ORGANIC MATTER. buried in the ground, contained no sugar, but a substance possessing the principal characters of gum.* It was probably an effect of the season ; for Knight states, that he never could discover the least trace of saccharine matter during winter in the alburnum either of the stem or of the roots of the sycamore. f SAP OF THE BAMBUSA GUADUAS. The guaduas grows in the hot and marshy countries of the tropi- cal regions ; this grass frequently attains the enormous height of from 65 to 100 feet. Its stem, which is hollow, is divided through its entire length into joints spaced rather regularly at distances of from 11 to 12 inches. Each joint indicates the presence of a woody partition, which seems to divide the stem of the guaduas into so many super-imposed tubes. On perforating it immediately above a knot, a clear limpid fluid flows out, which cannot be distinguished from the purest water. This indeed is a store of water of which travellers have frequcMilly availed themselves. Tliis sap, as 1 have been assured by the iidiabitants of the countries where I observed the guaduas, never completely fdls the hollow space in<'luded be- tween two joints. Analysis satisfied me that the sap of the guaduas is almost pure water. Re-agents detected merely traces of sulphates and chlorides. On evai)oratin«T a considerable quantity of it, I wa« able to discover, independently of these traces of soluble salts, a very small proportion of organic matter and of silica ; the latter sub- stance is probably the element which predominates in the sap of the guaduas. SAP OF THE BANANA PLANT, (mLSA PARADISICA.) The sap of the banana possesses a well-marked astringent taste ; It reddens tincture of litmus. Immediately after psc:i{)ing from the plant, it is limpid and colorh^ss, like water ; nevertheless, it possesses the property of imparting a yellow color to stutTs immersed in it. Exposed to the air it becomes turbid, and throws down flocculi of a dirty rose color. It is to the action of oxyizen that this deposite is owing; for it takes place only in contact with the air. After the formation of this deposite, the sap no longer colors stulfs immersed in it. From a chemical examination which I instituted of the sap of the banana, during my sojourn on the banks of the Magdalena, I think I mav stale that it contains gallic acid, acetic acid, chloride of sodium, salts of lime and potash, and silica. The sap of vegetables, elaborated during its passage through the leaves, acquires adililional consistence. It generally c«intains pecu- liar principles, which are the result of this elaboration, and these now constitute the liquid which is usually designated by the name of the particular juice of the plant from which it is procured. This • Annfiles dii Miis^mn (t'Histoirc NaturcUo. t. ii. * Knight, quoted In Annates do TAKriculture Fran^aise, t. v. 2e siric, p. 3» SAP. 69 proper juice or sap is generally obtained by making an incision which penetrates a little below the bark. The characters and properties of the elaborated or descending sap^ are extremely various. It may, however, be divided into milky sap, saccharine sap, gummy sap, and resinous sap, according to the na- ture of the juices dissolved or suspended in the liquid. As several of the peculiar juices of vegetables contain principles employed in the arts or in medicine, they have been more carefully studied, and their history is more complete than that of the ascending saps. I do not propose to give a monograph gf these juices ; in this place I shall only mention those which have been examined with some care. MILKY SAPS. The milky saps, as their name indicates, have the appearance of milk ; they owe this milky appearance to globules of insoluble mat- ter, minutely divided, and suspended in a liquid. SAP OF THE PAPAW-TREE, (CARICA PAPAYA.) The carica papaya grows in tropical regions. The sap, which is extracted from the fruit by incision, is white, and excessively vis- cous. In a specimen of this sap, which came from the Isle of France, Vauquelin found water in large quantity, and also a matter having the chemical properties of animal albumen,* and lastly fatty matter. I took occasion to verify the correctness of the results obtained by Vauquelin, on the milk of the fruit of the carica papaya, during my sojourn at Caraccas, where I examined the sap which flowed from the trunk of the tree itself. This sap is less milky, and much more fluid than that which flows from the fruit ; it had the appearance of milk-and-water. Its odor is rather nauseating, even when coming from the plant ; its taste slightly sour. When exposed to the air it soon coagulates. It contains a considerable portion of matter, which may be compared to animal fibrine, and sugar, wax, and resin, in small quantities. Evaporated and burnt, it leaves a saline residue. This juice is employed by the inhabitants for medical purposes. SAP OF THE COW-TREE. Among the number of astonishing vegetable productions observed in the equinoctial regions, is a tree which yields a milky juice in abundance, similar in its properties to the milk of animals. At the time I left Europe, M. de Humboldt expressly recommended me to di- rect my attention to the milk of the cow-tree. A short time after my arrival in the Cordilleras, on the shore of Caraccas, M. Rivero and myself were able to comply with the wishes of the distinguished traveller.! The milk we examined came from the Palo de Lechc, the milk- tree, which is extremely common in the environs of Maracaibo. * Vauquelin, Annales de Chimie, t. xlix. p. 219, Ire s6rie. t Rivero and Boussingault, Annales de Chim. et de Phys. t. xxxiii. p. 229, 2e s6ne. 70 TRANSITION OF INORGANIC INTO ORGANIC MATTER. Vegetable milk possesses the same physical characters as that of the cow, with this sole difFerencfi, that it is, in a slicjht degree, vis- cous ; its flavor is agreeable, slightly balsamic. Wiih respect to chemical properties, these diflier perceptibly from those which are peculiar to animal milk. Acids do not curdle it ; alcohol scarcely coagulates it. Under the action of gentle heat, light pellicles are seen to form on the surface of vegetable milk. On evaporating it over a water bath, an extract is obtained resembling fritters ; and if the action of the fire be continued for a certain time, oily drops are observed, which increase in proportion as the water is dissipated, and ulti- mately form a liquid of an oily appearance, in which a fibrinous substance floats, w hich dries and becomes tough in proportion as the temperature increases. An odor is then difl^used, exactly like that of meat frying in fat. By the mere action of heat, then, the milk of the Palo de Leche is separated into two distinct portions : the one fusible, of a fatly nature, the other fibrinous, and presenting all the characters of ani- mal substances. If the evaporation of vegetable milk is not carried too far, wio fatty matter may be obtained unchanged ; it then possesses the fol- lowing properties ; — it is white, translucent, sufliciently solid to resist the impression of the finger; it fuses at 110' (Fahr. ;) boiling alcohol dissolves it coin|)letely ; it is eijually soluble in potash. The fibrinous matter presents all the characters of fibrine, obtained from the blood of animals ; for this reason we have called it fibrine. In fact, when put on a hot iron, it swells up, fuses, and becomes carbonized, exhaling the odor of grilled meal. Treated with weak nitric acid, it gives out nitrogen gas ; by distillation, it disengages ammoniacal vapors in abundance. The presence and nature of this animalized matter in the milk of the cow-tree, explains how this milk acquires the odor of old cheese on becoming changed. We considered the fatty mailer of the milk as analogous to beeswax ; I may even say that we made wax-candles of it. However, the property of being completely dis- solved in hot alcohol, combined with its ready solubility in potash, establish a well-marked difference between it and the wax of insects. This is a question which can only be completely cleared up by ele- mentary analysis, and we were altogether without the means of making any minute examination of the wax of vegetable milk. In the water which ludds the wax and animal matter in suspension, we met with some saline substances and a tree acid, the nature of which we were unable to determine. We did not succeed in delect- ing the presence of caoutchouc in vegetable milk. According to our researches this milk should contain : 1. A fatty substance similar to beeswax ; 2. An animal substance, similar to animal fibrine ; 3. Water, salts, a free acid, and a little sugar. SAP. 7. By incineration, we obtained ashes from the milk in which wer* found phosphate of lime, lime, magnesia, and silica. During their excursions in the Cordilleras, the inhabitants fre quently drink the milk of the cow-tree. M. de Rivero and mysell also used it during our sojourn at Maracaibo. The tree which produces the milk which we examined, is, accord ing to M, de Humboldt, the galactodendron dulce, of the family of the verticas, or fig-trees. But several trees are known in tht mountains along the coast, which yield a milky juice, and which are often confounded with that just described. For instance, in the environs of Maracaibo, according to M. Desvaux,* the clusia galac- todendron yields an abundance of very pleasant vegetable milk ; this milk, however, does not seem to contain much animalized matter ; at least it does not putrefy perceptibly, and instead of the waxy matter, a substance much less fusible and of a resinous character is procured from it. MILKY SAP OF THE HURA CREPITANS, (aJUAPAR.) The sap of the hura crepitans is dreaded, and not without good reason ; it is enough to be exposed to the emanations of this milky juice, when recently extracted, to be seriously affected by it. The use which is made of it, to poison the water of rivers, in order to obtain the fish, is a sufiicient indication of its pernicious qualities.! This vegetable sap would perfectly resemble that of the cow-tree, if it were not slightly yellowish. It has no smell ; its taste, which is very little marked at first, soon causes very violent irritation. It reddens the color of turmeric ; mineral acids produce in it a white and viscous curd ; the surrounding fluid is clear and of a yellow color. Left to itself, the milky sap of the hura crepitans yields all the products of the putrefaction of caseum. It contains : I. An azotized substance similar to gluten, or caseum. 2. A vesicating oil. 3. A crystallized substance, having an alkaline reaction. 4. Malate of potash, 5. Nitrate of potash. 6. A salt of lime, (the malate 1) 7. An odorous azotized principle. MILKY SAP or THE POPPY, (oPIUM.) The milky sap which, by concreting, furnishes the opium of com- merce, is obtained by making longitudinal incisions in the capsules of the poppy. The operation takes place before the fruit is ripe, and after the fall of the flower. * Renseignements coinniuniqu6s par M. Adolphe Brongniart. t Rivero et Boussingault, Annales de Chim. et de Phys. t, xviii. p. 430, 2e s6rie. What 1 shnll no.v state may give an idea of the energy- with which this milky juice acts on the animal economy : when M. Rivero and myself examined the milk of the hura crepitans, we became affected with erj'sipelas ; the affection continoed for sev- eral days. The milk had been sent to us in guaduas by Dr. Roulin ; the messengel who brought i-t was seriou-^ly affected by it ; and along the road the inhabitants of tht house's whipre he loko ; its young shoots serve as aliment ; from its fruit, while still green, a farinaceous food may be obtained ; and when perfectly ripe, it yields oil in abundance. Hammocks and various kinds of cloth are made of the fibrous portion of the bark of this tree ; the young leaves serve to make hats, mats, and sads for ships ; the tissue which surrounds the fruit furnishf-s the Indians wiih clothing ; the sap ferments and yields wine ; the trunk before fruc- tification contains an amylaceous marrow, of which bread is made , this marrow, on bec<»ming putrid, produces a vast multitude of l&rgs CHEMICAL CONSTITUTION OF VEGETABLES. 75 white worms which the Indians value as a most delicate dish ; finally, the woody part of the mauritia affords excellent timber for building. It is not necessary to enumerate farther the principles produced by vegetables ; we must now study them in reference to their ele- mentary composition. CHAPTER II. OF THE CHEMICAL CONSTITUTION OF VEGETABLE SUBSTANCES. From the very first period of vegetable life, during germination, the immediate principles which constitute the seed are destroyed or changed. The young plant, in developing its organs, creates new substances, which are added to the tissues already existing, so as to complete or extend them. In order to account for the productions or changes which take place in the organism of vegetables, it is ex- pedient first to study the intimate nature and general characters of the materials which compose them. Unfortunately, in the present state of science, this study is as yet but little advanced ; and, not- withstanding the efforts which chemical physiology has made in recent times, there still remain numerous and important questions to be solved. Carbon, hydrogen, oxygen, azote, combined in some cases with minute quantities of sulphur or phosphorus, are the only elements required by nature to give rise to that almost endless variety of vegetable substances, so different in their properties, as well as in their uses. In the food which sustains the life of animals, as in the virulent poison which destroys it, these same elementary bodies are always found combined in various and dissimilar proportions. The immediate principles of the vegetable kingdom may be divided into three groups, if we look to the number of the elements which constitute these principles as they exist in the several bodies : 1°. Quarternary^ containing carbon, hydrogen, oxygen, azote. 2°. Ternary, containing carbon, hydrogen, oxygen. 3°. Binary, containing carbon and hydrogen, or carbon and oxy- gen, or carbon and azote. It is by the examination of the immediate principles which ekist in the seed, that we should approach the study of the composition of vegetables ; and this the more, as we shall find these principles diffused throughout the organs of plants. Once we shall have fully considered their properties and their elementary composition, it will be sufficient merely to indicate where they are to )e met with in the organism. 76 CHEMICAL CONSTITUTION OF VEGETABLES. § 1. QUARTERNARY AZOTIZED PRINCIPLES OF VEGETABLES. It has now for some considerable time been ascertained thai several seeds contain azote, inasmuch as azotized matters, nearly similar to those obtained from the tissues of animals, can be extract- ed from them. M. Gay-Lussac expressed this fact in the most general manner, by laying it down as a law that every seed contains a principle abounding in azote.* Azotized animal matters, when heated in close vessels, yield an ammoniacal product ; and to satisfy ourselves of the generality of the law laid down by Gay-Lussac, all that is necessary is to subject any seed whatever to dry distillation. We do not always, indeed,, obtain an ammoniacal liquor immedi- ately in this way ; rice, for instance, when heated in a retort, yields a product having an acid reaction ; but it is easy to demonstrate in the acid liquor, the presence of ammonia by the addition of lime, which at once sets it free. Peas, kidney-beans, in a word all the legumens hitherto experimented on, yield a liquor directly, having a highly alkahne reaction. These ditterences, ni the products of the dry distillation of seeds, are explained in a very natural way. Throwing the husk out of the question, we may consider a seed as formed of two parts ; one, non-azotized, possessing a ternary com- position, and yielding by the action of heat a liquid with an acid re- action ; the other having a quarternary composition, consequently azotized, and yielding an ammoniacal liquor, so that the acid or alka- line reaction of the product, really depends on the predominance of one or other of these two distinct ingredients M. Gay-Lussac sui)jected every kind of seed he could procure to distillation, and all yielded ammonia either directly or indirectly. I shall add, that the numerous analyses which I have had occasion to make for several years back suj)port the generality of the principh^s laid down by the above celebrated chemist. >L Payen has come to the same conclusion, and has further shown that at the period of germination the azotized matter of seeds is determined towards the parts that are most recently organized. Thus the spongioles situ- ated at the extremities of the radicles constantly produce ammoniacal vapors during their destructive distillation by heat, even though pro- ceeding from seeds which, when distilled, yield an acid liquor where- in ammonia only becomes sensible on the addition of lime. f 4'he animalized or azotized substance is extracted readily enough from certain seeds, and has consequently been known to exist in them for a very long time. It is found in wheat, for example, in dif- ferent states, and is obtained with great case by simply kneading a mass of dough imder a small stream of water by which the starch is carried off, and by and by there remains in the hand a grayish highly * Gay-Lussac, Annates de Chiinie et de Physique, t. Itli. p. 110. So sAric. t Payen, M6moire sur la cninp«)«ition rhiniique de 82 CHEMICAL CONSTITUTION OF VEGETABLES. M. Payen, the change that takes place in the state of the fecula is owing to a swelling, a rupture, or disgregation of its granules. By heating a drachm cf starch, mixed with about a couple of ounces of ■water, to about 60° cent. (140" Fahr.) the microscope shows us that the smallest or youngest grains — those possessed of the least cohe- sion— have absorbed a considerable quantity of water, and that the expansion of the contents has caused a certain number of the glo- oules to burst ; at this temperature, however, some grains of fecula are observed, which do not appear to have yet attained their maxi- mum of enlargement, and whose contents consequently are not yet diffused through the liquid ; it is only between 72" and 100° cent. (161.6° and 21'2° Fahr.) that the maximum of expansion becomes general, and that the solution acquires its greatest consistency.* The remarkable property possessed by starch of making a gluti- nous solution or thick paste with water under the influence of heat, led M. Payen to conjecture that a contrary effect would be produced by lowering the temperature — that the starch might be recovered in its original state of distinct globules by suitable management ; and this he in fact accomplished by an ingenious procedure. Starch appears to suffer no actual change when diffused in water by exposure to a temperature of 212° Fahr. ; the granules have only swollen to about thirty times their original dimensions by the imbibition of a large quantity of water. We have already seen how starch may be extracted from wheat- en flour ; this method, however, is not the one that is usually followed to procure this useful substance, so large a quantity of which is consumed in the arts. Formerly, starch was universally obtained from grain, — wheat; at present the potato furnishes a still larger quantity than grain. In the equatorial regions of South America, starch is abundantly j)repared from the Yuca, {Jalropha manihot,) and from several species of palm. To obtain starch from wheat, the grain is either coarsely ground and mixed with water in large tubs ; or it is put to steep in sacks until it is so soft that a process of kneading suffices to set the starch at liberty. Starch from potatoes. The potatoes are grated after having been well washed, and the pulp being thrown on a sieve, the starch is carried off bv the water and deposited in suilal)le vessels. The washings in the manufacture of potato starch soon become putrid by reason of the azotized matter which they contain, and until lately occasioned much annoyance, until .M. Dailly conceived the happy /dea of turning them to account as liquid manure. Starch of the Yuca, or Jatropha inanihot. The manihot yields very large roots, rich in starch. These are taken up a little after the flowering, when the fecula is most abundant. To extract the starch, precisely the same process is employed as in the case of the potato. In South America the manioc is distinguished into yuru duke (mild) and yuca brava, (malignant ;) the latter epithet applying • Payen, M*»:oiro cit. p. 96. TERNARY PRINCIPLES STARCH. 88 lo the jatropha containing poisonous juice. The two yucas are, however, but one and the same species ; at least a skilful botanist, M. Goudot, who resided for several years in America, could not perceive any specific differences between them. The poisonous principle of the yuca brava must be very volatile, or readily destroy, ed by heat, for the root may be eaten with impunity after it has been roasted, while the animals who eat it in the raw state soon ex- perience the most distressing effects. The Indians seldom prepare starch from the jatropha ; but the root frequently constitutes the staple of their food. It is from the yuca brava that they obtain the cassava, which supplies the place of bread with them. Among the Indians in the country near the river Malta, one of the principal tributaries of the Oronoko, I have seen the cassava prepared in the following manner : the roots of the manioc were scraped on a sort of rasp formed of small fragments of flint stuck into a plank ; the pulp was then put to drain in a long strainer made of the entire bark of a species of fig ; the juice having drained away, water was added to finish the washing ; the liquid came out nearly clear and without bringing away any perceptible quantity of starch. To form the pulp into cakes of cassava, it was spread out on an earthen dish placed over the fire ; the process was complete when the cassava was dry, and slightly toasted on the out- side. Cassava bread is not very palatable, but it possesses the pro- perty of keeping for a long time in spite of heat and moisture, and is frequently an indispensable article of provision with the South Amer- ican traveller. The Indians say that they cannot obtain cassava from the yuca dulce. Starch from palms. In the Moluccas and Philippine Islands, and in the plains of Apure, there are certain palms which yield a species of fecula. This fecula is found in a soft substance, general- ly situated in the centre of these trees. The marrow of these palms is dried, and when sifted presents itself in the form of grains, which in commerce bear the name of sago. None of the amylaceous principles or feculas obtained by the processes which I have mentioned are absolutely pure ; even sup- posing all the soluble substances to have been removed by washing, they still retain fatty matters, azotized principles, and coloring substances. Starch is purified by following up the water washings by the action of alcohol, of acetic acid, and of ammonia. Starch in its state of greatest purity, and dried at 100" cent. (212° Fahr.) contains, according to the analysis of M. Jacquelain ; Carbon ... 44.9 Hydrogen 6.3 Oxygen 48.8 100.0* By slight roasting, amylaceous feculas undergo considerable changes ; they become soluble in water, and then present the pro- perties of gum.f Starch thus roasted, supplies the place of gum in • Jacquelain, Annales de Chimie et de Physique, t. Ixxiii. p. 181, 2e s6rie. t Vauquelin and Bouillon Lagrange, Bulletin de Pharnaacie, t. iii. p. 54. 84 CHEMICAL CONSTITUTION OF VEGETABLES. various manufacturing processes ; still it si.ould not be confeunded with gum in a chemical point of view. The acids act with more or less energy on starch, and give rise to different prod nets. Nitric acid, when it is dilated with water, merely dissolves fecula ; but at a certain degree of concentration it exerts a destructive action. Id this reaction several acids are formed, among others oxalic acid By employing very dilute sulphuric acid, Kirchhoff succeeded iL changing starch into a saccharine substance similar to the sugar of the grape. The operation may be performed in a leaden or silvei pan, or, what is preferable, especially when the process is carried on upon the great scale, in wooden vessels, in which the liquid mass is heated by steam. According to M. Couverchel, several organic acids are capable of changing fecula into sugar in a similar manner ; such are oxalic, tartaric, and malic acids. The artificial conversion of starch into grape-sugar has not yel been satisfactorily accounted for. The acid employed does not seero to undergo any change ; it is found in its original state and quantity after the operation. M. de Saussure thinks that the eflect of the reaction is the fixation of water ; thus 100 parts of fecula yielded him 110.40 parts of sugar.* M. Couverchel and M. Guerin, on the contrary, state that the quantity of sugar obtained was less than, that of the starch they employed. Gluten exerts a reaction on starch similar to that produced by acids ; Kirchhoff discovered, that under the influence of the azotized matters which are met with in flour, the fecula is converted into sugar. t Two parts of starch being mixed with four parts of cold water, on atlding twenty parts of boiling water, a thick paste is pro- duced ; if into this one part of dry powdered gluten be introduced, and the mixture be kept at the temperature of GO" cent. (140° Fahr.) the paste becomes more and more liquid, so that the mixture may be fdtered at the end of from six fo right hours. By concentration a sirup is obtained, in which small crystals of sugar are perceived. It is well known that during the act of germination, fermentable saccharine matter is produced. Kirchhoff concluded, from his ex- periments, that this production of sugar in genniiiation is attributa- ble to the reaction of the gluten on the starch. Germmating grain, barley-malt, for instance, reacts rapidlv^and powerfully on any fe- cula with which it is brought into contact ; a fact well known to, and constantly taken advantage of, by manutacturers of spirits from potatoes and raw grain, largo mashes of which arc rapidly converted into sweet fermentable iKjuids under the action of a little malt. These facts, it is evident, cannot be explained by Kirchhotrs ex- periment ; in the fermentation of the potato, the mass of fecula to be converted into sugar is too great com])are(l with the quantity of glu- ten which exists in the malted barley. Further, the gluten in grain which has not germinated, scarcely exerts any appreciable action. • 8au<«surr. Bihliothiijiic britanniciuc, t. Ivi. p. 333. t Kirchhoff, Journii! do Phanimcie, I. ii. p. iVk DIASTASE. 85 The principle which, in the preceding operations, cpnverts the starch into sugar, must therefore become developed during germination. This important point in the art of the distiller has been investigated ■with great ingenuity by M. Duhrunf;iut ;* and MM. Persoz and Payen succeeded in separating the peculiar matter in barley-malt which possesses the property of converting starch into sugar. This matter has been called diastase. Diastase exists in the seeds of all the cereals which have germi- nated ; it is met with more especially near the germs, it seems even that the radicles contain none of it. Nor is diastase observed in the shoots or roots of the potato ; it is to be met with only in the tubers, around the eyes or points where the young sprouts are developed, precisely as M, Payen has remarked, in the place where we should conceive its presence to be necessary for effecting the solution of the fecula. It is also found to exist in the bark and beneath the buds of trees, always in contact with starch. f Diastase is gene- rally obtained from malt, and when carefully prepared, its peculiar power is such, that one part by weight is sufficient completely to liquefy two thousand parts of starch. Diastase is solid, white, amor- phous, insoluble in pure alcohol, soluble in water and weak alcohol The solution very readily undergoes change ; it becomes acid, and then no longer exerts any action on fecula. When dried, it keeps much better ; still, at the end of two years, it seems to have lost its distinguishing properties. Diastase has no action on vegetable tinc- tures, on albumen, gluten, cane-sugar, gum-arabic, or the woody fibre. That which more especially characterizes it, is its powerful action on fecula ; it may be advantageously used to separate and purify the preceding substances, when they are mixed with starch. The presence of diastase in malt explains the phenomenon of the liquefaction of starch effected by the action of a small quantity of that substance. This solution is not effected by gluten, nor by hor- deine, as M. Dubrunfaut had imagined. By the action of diastase, or of malted barley, the starch on being liquefied is not entirely converted into sugar ; there are other dis- tinct products to be considered in this change. The sirup ob- tained by concentrating the liquefied starch, contains sugar capable of undergoing the vinous fermentation, and a gummy matter, dextrme. These two substances may be separated by means of dilute alcohol, which dissolves the sugar and leaves the gum untouched. The relative quantities of dextrine and sugar produced by the action ot diastase are variable, and depend both on the temperature at which the process is conducted, and on the continuance of the reaction. In the first period of the process, the dextrine predominates ; but it becomes less and less by degrees, and finally gives place to sugar. M. Guerin ascertained a curious fact, which show^s how the dias- tase developed in plants may act on their starch :^reaction takes place even at ordinary temperatures. In one of M. Guerin s experi- * Dubrunfaut. M6moires de la Soci6t6 Royale d'Agriculture, annee 1823, P- 146. t Payen and Persoz, Annales dc Chimie et de Pliysique, t. lin. p. 73 t. Ivi. p. 33< *5e stne. 8 R6 CHEMICAL CO>-STITUTION OF VEGETABLES. ments, at a temperature no higher than 20° cent. (68° Fahr.) a quan- tity of starch, at the end of twenty-four hours, was converted into sirup, which yielded 77 per cent, of saccharine matter.* Pure dextrine. M. Payen freed dextrine from the sugar which usually accompanies it by precipitating a sirup of fecula previously dissolved in dilute alcohol, by means of alcohol nearly free from wa- ter. Dextrine well dried, and reduced to powder, has a specific gravity of 1.51. The specific gravity of pure starch is 1.51, that ol the sugar of starch 1.61.t M. Payen found dextrine dried at a temperature of 212' Fahr. to consist of — Carbon 44.3 Hydrogen 6.0 Oxygen 49.7 100.0} a composition identical with that of starch. We have seen that water, acidulated with sulphuric acid, trans- forms starch into sugar ; and that in this respect, the acid acts pre- cisely in the same way as malted barley, like which, the acid first causes the fecula to pass into the state of dextrine : by checking the reaction at the proper moment, this substance may thus be obtained, as was shown by Messrs. Biot and Persozj^ When starch, for in- stance, is triturated with concentrated sulphuric acid, if the mixture be diluted with half its volume of water, and be left at rest for an hour, alcohol will throw down almost the whole of the starch employ- ed in the state of dextrine. M. Payen has remarked that starch is never met with in the vege- table tissues while in the rudimentary state ; the sponfjioles, the radi- cles, the foliaceous buds, the interior of the ovules, contain none of it. Nor is starch found in the epidermis, nor in the primary cells of the subjacent tissues. This proximate principle seems to be exclu- ded I'rom those parts of vegetables that are more directly exposed to atmospheric influences : it is only met at a certain depth ; and the globules which constitute starch increase in number and in size in the cells most remote from the surface. The subterraneous organs of plants, — certain bulbs, most tubers, abound in amylaceous matter. It migiit be maintaineil that light modified this substance, at the very moment that it was subjected to the vital influence, and that it was only preserved in the dark. On the globules of some species of fhow it distinct from true starch. In the first place, it is not colored by iodine ; and then acetic acid, w^hich is without action on starch, produces with inuline precisely the same effects as the sulphuric, phosphoric, and hydrochloric acids ; finally, diastase, whose reaction upon starch is so peculiar, so prompt, and so powerful, does not cause any change in inuline. It is therefore easy to separate these two substances when they are mingled, by treating the mixture either with acetic acid, which dissolves the inuline, or with diastase, which liquefies the starch. Inuline has been analyzed by M. Payen, after having been dried at 253° Fahr. and having been melted at 367° Fahr. In both cases it has the same composition. Carbon 46.6 Hydrogen 6.1 Oxygen 49.3 100.0 The composition here is obviously the same as that of starch and dextrine. OF WOODY MATTER AND CELLULAR TISSUE. The most solid part of plants, that w hich forms in some sort their skeleton, is the wood in trees, the woody fibre in herbaceous plants. Woody fibre, as it used to be prepared and considered, viz. by the reaction of certain agents which have the property of dissolving the gummy, resinous, and saline substances which are commonly asso- ciated with it, consists, in fact, of two substances, one the cellular substance, constituting the tissue of wood and of all the organs of * Payen, M6mnires cit6.s, p. 183. 88 CHEMICAL CONSTITUTION OF VEGETABLES. plants, the other the woody substance, properly so called, filling, and in some sort consolidating the cells. This distinction between these two elements of wood was first made by M. Mohl ; but M Payen was the first who fixed the opinion of chemists and of vege- table physiologists upon the true nature of these immediate princi- ples.* By treating the vegetable tissue in its nascent and still gelatinous state — the unimpregnated kernel of the almond, of the apricot tree, &c., the membranous matter of the cambium of the cucumber, the spongioles of radicles, leaves, wood, &c. — with differ- ent menstrua, M. Payen obtained the cellular tissue in the state of purity, and having an elementary composition almost identical, from whatever source derired ; a fact which may be seen from the fol- lowing table, which gives the composition of cellular tissue from different sources after having been dried at 352° Fahr. Carbon. Hyarogen. Oxygen. Ovules of the almond-tree . 43.6 6.1 50.3 " of the apple and pear 44.7 6.1 49.2 " of the helianthus annuus . 44.1 6.2 49.7 Pith of the elder 43.4 6.0 50.6 Cotton 44.4 6.1 49.5 Endive 43.4 6.1 50.5 Banana ...... 43.2 6.5 50.3 Leaves of the agave .... 44.7 6.4 48.9 Cotton of the Virginian poplar 44.1 6.5 49.4 Heart of oak 44.5 6.0 49.5 Pine-tree 44.4 7.0 48.6 Perispcrm of the phytelaphas 44.1 6.3 49.6 Musliroom 44.5 6.7 48.8 The primary tissue, consequently, which constitutes the skeleton of wood, is still isomeric or identical in elementary comjKisition with starch. With mineral acids the cellular tissue further undergoes changes which assimilate it with starch ; for on treating it with sul- phuric acid it is changed into dextrine and sugar. The composition of the cellular tissue differs considerably from that of the woody fibre as it has hitherto been obtained after the action of solvents, and been examined by preceding chemists. Pure wood or woody tissue consists of the following proportions of elements : Dumas, Conipfcs rcndus, vol. vlii. p. 53, WOOD. 89 1 1 V Authorities. Woody tissue of the oak of the beech 41.8 42.7 5.7 5.8 52.5 51.5 Gay-Lussac and Thdnard. of the box 44.4 5.6 50.0 Prout. of the wUlow 44.6 5.6 49.8 (( of the oak 49.7 6.0 44.3 <( of the beech 44.3 6.0 49.7 Payen. " of the aspen 44.5 6.1 49.4 (( Wood in the natural state : 45.6 6.4 48.0 (( " of the oak 39.4 6.2 54.4 (C « of the beech 39.3 6.3 54.4 i( " of the herminiera 46.9 5.3 47.2 « 1 From these analyses it appears that wood in the natural state contains more carbon than woody tissue obtained in the way of puri- fication, and that this latter substance is also richer in carbon than the cellular tissue which necessarily forms part of it. In the purified woody tissue, therefore, the cellular tissue is associated with the principle which fills its cells, or which incrusts it, and it is to this matter that M. Payen has applied the name of incrusting matter ; it is wood properly so called ; it is that which gives to wood its hardness, its tenacity ; it predominates in hard wood and in knots ; it corresponds with the duramen of physiologists ; it consti- tutes almost the whole of the hard particles which are met with in woody pears and in cork, and which are hard enough to blunt well- tempered steel instruments. As this incrusting matter is friable, in many instances it may be pulverized and separated from the tissue which surrounds it, this last tearing or yielding in shreds under the pestle. By means of the sieve the incrusting matter may in this simple way be obtained nearly in a state of purity. The analysis of M. Payen shows it to consist of : — Carbon 53-8 Hydrogen 6.0 Oxygen 40-2 100.0 Deducting resinous matters susceptible of solution in alcohol or ether, and of gummy and other substances which are soluble in water, the tissues of vegetables must consequently possess an elementary composition which varies between that of the cellular tissue and that of the incrusting matter ; these are the extreme terms, and the entire composition of the mixed tissues will be by so much the richer in carbon as they contain less cellular tissue. The incrusting mat- ter being soluble in alkaline leys, it was by treating wood with solu- tions of soda and potash that M. Payen succeeded in obtaining the cellular tissue, which is much less susceptible of the action of these 8* 90 CHEMICAL CONSTITUTION OF VEGETABLES. aorents. But treatment of different kinds, which it is not necessary to enter upon in this place, is required to procure the substance in a state of perfect purity.* The facts which liave just been exposed, in regard to the chemi- cal composition of wood, corroborate the observations of physiolo- gists. We now understand much better than we did formerly the changes which the cells of vegetables experience as they grow and become aged : it is by the appearance of the incrusting woody mat- ter that their walls, thin, transparent, and colorless at first, get thick, become opaque, and acquire consistence. By means of the dissec- tions effected by M. Payen with the aid of purely chemical means, we may obtain assurance that the tissues of all vegetables, whether phcenogamous or cryptogamous, may be reduced to a single substance, cellular tissue, having an invariable composition, and forming the vesicles or bladders of the cellular mass of plants. This matter exists nearly in an isolated state in the thick walls of the cells of the perisperms of various seeds, those of the date for example. From the microscopic researches of M. Payen and A. Brongniart, it appears that the matter which is added to the young cells is not deposited upon the inner surface of their walls, but that it penetrates and insinuates itself into their tissue. The relation of the cellular to the woody matter in the development of the walls of cells varies very much, some perisperms containing nothing but pure cellular tissue, while the stony concretions of the pear and of cork consist almost entirely of incrusting woody matter. Wood, in the general acceptation of the word, is the solid part of the trunk and branches ; the properties and aptitudes of the substance vary greatly, according to the plant which has produced it. Wood is of higher density than water, and if it tloats in this lluid it is only because of the air with which its pores are filled. .Saw-dust, chips, and larger pieces of wood sink when the air which they contain is expelled and replaced by water. Tl>e specific gravity of the white woods, such as tliose of the willow and pine, is about 1.46, that of the heaviest woods, such as those of the oak and the beech, 1.53. DENSITY OF DIFFKRKNT KINDS OF WOOD ACCORDINO TO BRISSON. Pomepranate 1-3.") Orange 0.70 Guaiac, Ebony l.Xl Uuince 0.70 Box 1.3^2 Elm. the trunk 0.67 Oak of CO years old, the heart. . . 1.17 Walnut 0-67 Medhir 0.«« IVar 0.66 Olive 0.i« Spanish Cypress 0.64 Spanish Mulberry 0.89 I^no 0.60 Beech 0.85 Hazol O.fiO Ash 0.84 Willow O-M Hornbeam 0.80 Thuya 0.56 Yew 0.80 Pine 0.55 Apple 0.71) Spanish white poplar 0.59 Plum 0.78 Pine 0.49 Maple 0.73 Poplar 0-38 Cherry 0.75 Cork 0.24 * For an account of these, see Payen in proceedings of the .\cademy of Science* rol. vll. p. 1053. WOOD. 91 It must not be forgotten, however, that age, climate, and soil ex- ert a marked influence upon the specific gravity of the same species of wood. Wood, according to the use for which it is intended, is distinguished into fiie-vvood, building timber, and dye-wood. When first cut down, all timber contains a considerable quantity of water ; 100 parts of walnut-tree dried at 212" Fahr. lost 37.5 parts by weight ; of white oak, 41 parts ; of maple, 48. On an average, the quantity of water contained in green wood may be estimated at about 40 per cent. ; and drying or seasoning for eight or ten months will not cause the loss of more than about 25 per cent of water. The wood which is used for burning almost always contains about a quarter of its weight of moisture, which not only does not assist in producing heat, but actually dissipates a great deal during its conversion into vapor. It is, therefore, highly advantageous in all operations where wood is the fuel, only to employ that which is thoroughly dry. So well is this fact ascertained, that in some manufictories the wood is previ- ously dried in stoves before being consumed in the furnace. The composition of woody matter may be represented by carbon and water : of carbon the mean may be stated at 52, of hydrogen and oxygen, in the proportions which form water, at 48. The defi- nitive products of its combustion ought consequently to be carbonic acid and water. The heat disengaged during this combustion, neces- sarily proceeds from the union of the combustible elements of the wood with the oxygen of the atmosphere. But in this particular case, the hydrogen being already present with the proportion of oxy- gen required for its combustion, it may be regarded as already burned, the state of condensation in which the oxygen exists being considered. The heat produced by the wood, therefore, depends solely on the quantity of carbon which it contains. Natural philosophers in France agree in designating as unity, in reference to caloric, the quantity of heat necessary to raise a kilo- gramme, or 2.2 lbs. avoirdupois of water, one degree of the centi- grade thermometer, (r.8 F.) The following table, by Rumford, is intended to show the different calorific or heating powers of dif- ferent kinds of wood, and its interpretation is this : since 1 kilo- gramme or 2.2 lbs. avoird. of lime-tree gave out 3460 units of heat, it follows that this quantity of the combustible would suffice to raise by 1 degree centigrade, (r.8F.,) for example, from 10° to ITcenl. 3460 kilogrammes, or 7612 lbs. avoirdupois of water. 92 CHEMICAL CONSTITUTION OF VEGETABLES. Kinds of wood. Units of heat evolved. Lime-tree, dry ..... 3460 The same, thoroughly stove dried 3960 Beech, dry, four years seasoned 3375 The same, well dried in a stove 3630 Elm, from four to five years seasoned 3037 Oak, fire-wood 3550 Ash, dry ...... 3075 Wild cherry . . ... 3375 Fir, dry . . . . . 3037 The same, well dried in a stove 3750 Poplar, seasoned ..... 3450 The same, well dried in a stove 3712 Hornbeam 3187 Oak, dry 3300 From the experiments of Clement, it appears that the heating power of charcoal is equal to 7050 units. Dry wood containing, aa we have seen, 5*2 per cent, of charcoal, its healing power has been deduced theoretically, as equal to 3066. Mr. Marcus Bull in Amer- ica, made a series of experiments to determine the relative quantities of heat given out by ditlerent kinds of wood, from which M. Peclel has been led to conclude that the same weight of dry wood of every kind has the same heating power, and that this for a kilogramme, or 2.2 lbs. avoird. of wood dried by artificial means, is equal to 3500 units, while the same quantity of the same wood having been cut and seasoned during from ten to twelve months, and containing froui 20 to 25 percent, of water, is no higher than about 260 units. By way of coniparison, 1 shall here add the healing power of the several combustibles in general use, in contrast wiih that of wood : 1 kilo^m. or 2.'2 lbs. avoird. of wood-chrircoal protlucps 7226 units of heat. colli r 26 to 100 47.r 39.3 Poplar 19 " 65 31.8 Pine 16 " 65 34.1 Plane • 36.1 Oak, Elm . 31.4 Birch 29.4 Beech > 16 " 48 28.2 Lime 25.9 Ash 23.5 Willow 11.7 Chestnut . ; 1 13 '* 48 36.1 Chestnut (anothe r variety) 28.2 Maple 10 " 48 28.2 Service 13 " 39 17.6 Acacia • 13 " 26 19.2 Hornbeam . ) 21.2 Mulberry . } 10 «' 23 16.5 Wild Pear . S 14.1 Crab 6 " 20 12.9 Walnut . 6 " 16 36.1 These may be taken as the measurement of trees at their full growth, and fit for felling. The soil being of the same quality, the dimensions of trees depend especially upon their age ; individual trees of the same species, however, occasionally acquire extraor- dinary dimensions. Every one must have noticed the rapidity with which young trees grow ; but is the growth the same for every period of the existence of trees, or do they attain a certain determinate size like animals, and then cease from further increase ? We have found that in those climates where vegetation is suspended for a portion of the year, the increase in the diameter of trees takes place periodically by the addition of a concentric layer of woody tissue ; so that it is possible to determine the age of a dicotyledonous tree by the number of its concentric rings, counted at the bottom of the trunk. With a view to ascertain the amount of increase in the woody layers at dif- ferent periods of vegetable life, De Candolle measured their thick- ness, and found that if the annual increase presented a certain re- gularity, it was still very far from being absolute even in the case of a single species. The oak especially offered strikinir anomalies ; thus a trunk which had grown slowly in diameter was found to have increased more rapidly as it got older. He found young trees of the same species, the growth of which, very slow at first, by and by became accelerated, and then fell off in a third period of their existence. From the whole of his observations, De Candolle con- 94 TREES — TIMBER. eludes that the growth of our common European trees havinor gone on with a certain rapidity to the age of from about fifty to seventy years, then became slower, but continued regular to extreme age. The inequalities of growth, con^ipicnous in the different thicknesses of different rings, he thinks are mainly due to the kind of soil which the mass of the roots encountered in their progress, or to the re- moval of other trees which grew in the \icinity. The diminished thickness of the rings, after trees have passed a certain age, he ascribes to the depth to which the roots have now penetrated, and their consequent remoteness from the air ; and further, to the resist- ance opposed to the expansion of the trunk by the bark, which has now become thick, hard, and unyielding. Mr. Knight found that old pear-trees, relieved of their outer bark, formed more wood in a couple of summers afterwards, than they had made in the twenty years that preceded the operation.* The forests of intertropical countries produce a vast number of gigantic trees, many of which might doubtless be turned to excellent use ; but the information we have on the trees of these latitudes is very imperfect. In New Granada, the wood which is known undei the name of wood of St. Martha, (aslroneum gravcolens ?) is fre quently employed for building purposes as well as for making furni- ture. It is very hard, and more beautiful than mahogany, its color being deeper. M. Goudot measured a tree of tliis kind, which was 1.6 metre or nearly 4\ feet in diameter, including the alburnum, and had 32 centimetres or upwards of 18 inches of heart-wood. Belfries having supports of this wood are met with, which have stood for more than a century exposed to all the inclemencies of tlie weather. This tree grows in the dry soils of the hottest regions of South America, and seldom at an elevation of more than aljout fifteen hun- dred feet above the level of the sea. Cedar {cedrcla odorata) is never attacked by insects, doubtless because of its aromatic odor ; this valuable property makes it in- valuable as building timber. The tree attains to large dimensions. M. Goudot measured one in the forest of Quindiu in South America, which was upwards of 150 feet in height by more than 6j feet in diameter. It grows freely throurrh a zone of considerable breadth, from a height of about 3280 to 65G0 feet above the level of the sea, a circumstance which, according to my own oi)servations, would in- dicate the extreme temperature of the district which it inhabits to be between 66" and 76" Fahr. There are several other beautiful and useful timber trees of the Cordilleras — the Nogal {juglans . . .1) which grows between C500 and 9800 leet above the sea line ; the escoho, {.Uepino {taxus montana Willd.) whose region lies between the 2.800 and 11.400 feet of ele- vation ; the arai/an and the guayacariy — all are serviceable in one direction or another. The caracoli {anacardium caracoli) and the fig (Igncrones) are trees which attain to extraordinary sizes, and afford light woods that prove uset'ul in rarious circumstances. Uc * De Candolle, Vegetable Physiology, p. 975. TREES TIMBER. 95 dcr the tropics, indeed, the trees generally exhibit a luxuriance of vegetation which strikes European travellers with amazement; M. Goudot, for example, measured a homhax {B. pentandrum) no more than sixty years old, the trunk of which was 8 metres or 26| feet in circumference, and whose boughs covered a circular area of 39 metres or 120 feet in diameter. There is a beautiful tree which grows in the valleys of Arragua in Venezuela, the Zamang, a species of mimosa, according to Hum- boldt, one of which, in particular, is greatly celebrated, and under the shade of which I rested on the 24th of January, 1823. This magnificent tree is to be distinguished at the distance of a league ; its branches form a hemispherical crown of 187 metres or 613 feet in circumference, extending like a vast umbrella, the points ap- proaching to within from 10 to 16 or 18 feet of the ground. The trunk of this extraordinary tree is nearly 65 feet in height and up- wards of 9} feet in diameter. This tree is an object of veneration with the Indians. It does not seem to have altered in its appear- ance since it was first particularly noticed ; the earliest conquerors of Venezuela seem to have met with it in the same state as it is at the present time. When Humboldt measured the Zamang de Tur- mero, its branches on one side were entirely stripped of their leaves. Twenty years afterwards I found it green in every part ; but the leaves and branches with the southern aspect were not so numerous nor so vigorous as the others. The dragon-tree of Orotava in the Island of Teneriffe is one of the oldest vegetable monuments of the present world. Humboldt gives it a diameter of 17 feet, and its height, as stated by M. Ledru, is upw-ards of 65 feet. When Teneriffe was discovered in 1402, this tree appears to have had the same dimensions which it presents at the present time. The mahogany {cedrela mahogani) is a very long-lived tree. In Jamaica it sometimes acquires a diameter of upwards of 6 feet, and Sir W. J. Hooker has calculated that two centuries at least are re- quired to supply timber of the large scantling which w^e constantly see in the yards of our timber merchants and cabinet-makers. The HymencEa courbaril, one of the largest trees of the Antilles, yields, like mahogany, a timber that is hard and in great request among cabinet-makers and inlayers. It sometimes grows to 19 feet in diameter. The Baobab (Adansonia digitaia) lives for centuries, and acquires extraordinary dimensions. Adanson saw one in the Cape de Verdes, in the trunk of which an inscription was found, which was covered by three hundred layers of wood ; it had been cut by two English travellers three centuries before. From positive observations col- lected by Adanson, a table has been constructed to show the pro- gress and probable age of the baobab : 96 SIZE AND LONGEVITY OF TREES. Age of the Baobab. Diameter of the Trunk. Height. 1 year, 0.10: feet 5.25 feet 20 1.04 16.40 30 2.41 23.30 100 9.84 30.84 1000 14.76 61.68 2400 19.03 68.24 5150 31.99 76.76 De Candolle has remarked that this longevity of the baobab is made the more surprising by the softness and liability of its wood to decay. But again, it must be considered that the great diameter of the trunk, in relation to the height, gives the tree a stability which is possessed by no other — by enabling it to resist violent gales of wind. It strikes me that there may very well be some mistake in Adan- son's estimates of the age of the baobab. When we see such irregu- larity in the growth of trees of the same species planted in the same soil, little reliance can be placed on any deductions drawn from the size of the trunk when the concentric rings cannot be counted. In proof of this I here give the measurements of two baobabs planted in 1821 in the Botanical Garden of French Guiana. In 1842 these trees were found : — fetu feel- No. 1. Length of .stem from pround Diainotcr of the base 5.41 to first branches 7.70 IV). at oripin of l)ranches 4.23 M„ o TV. air Dianirtcr of liaso 2A\3 "o-^- ^ ^•** Do. at origin of branches 1.48 In the tree No. 2 the branches were puny and nowise in relation with the size of the trunk. The bald cypress {taxodiwn disticfnim) is a tree that is very abundant in Mexico, and in the southern parts of the I'tiitcd States. At Chapultopec there is one of these trees called the cypress of Mon- tezuma, which tradition says flourished in the reign of that prince. In 1831 the tree was still vigorous, and its trunk was 41 feet in cir- cumference. There is another cypress near Oaxaca, under the shade of which Fernando C'ortez is still reported to have rested ; the trunk of this tree is upwards of 39 feet in circumference, and it is 105 feet in height. Alichaux measured several taxodiums in the Floridas which approached these two in their dimensions. We have only uncertain data in regard to the age which palms may attain to ; their sizes, however, are well known. In Fgypt, according to M. Delille, the date-trees are generally about 65 feel in height. In the Andes of Quindiu several ceroxylons were measured, the trunks of which were from 195 to 230 feet in height ! Martins assigns tho following as the j'Xtreme dimensions of the palms of the Brazils : from 75 to 127 or 128 feet in height, by a diameter of from 6 to about 12^ inches. •Aniong several palms {arica oleacera) planted in the Botanical (J:irdon of ('avenue in 1821, the tallest twenlv vears afterwards was SIZE AND LOxNfiEVITY OF TREES. 97 18 feet from the giound to the bottoiri of the crown, and 3 feet 6- inches in circiimfcicnce at the base ; at 0.\ feet from the surface of the ground the circumference was oidy XJ feet 1 inch, and a small fraction. As the palms and baobabs will be carclully protected in the Botanical Garden of Cayenne, an opportunity wil. jo afforded future observers of following these plants in their growth, with a perfect assurance of being correct as to their age. Particular trees of different kinds have occasionally acquired re- markable dimensions and lived to great ages in Europe. An elm is mentioned which grew on the promenade of Morges, the age of which, reckoned from the number of concentric layers, must have been three hundred and thirty-five years; its trunk was above 18 feet in diameter. The lime is another tree which in temperate countries sometimes grows to a great size. The one planted at Freiburg to commemorate the victory of Morat in 1176, in 1831 was 14.v feet in diameter. Near the same place there is another tree of the same kind which must be older than the last, inasmuch as it was already celebrated for its size a century ago ; in 1831 this tree was upwards of 30 feet in circumference, and about 72 feet in height. The lime-tree of Neustadt is scarcely less curious for its size and the immense spread of its branches than for the historical circumstances connected with it. Looking back to old documents, this tree must already have been of great size in 12'2y ; in a poem written in 1408 we are told that this tree was then supported by sixty-seven props; in 1654 it had eighty-two stone pillars to support its branches, and in 1831 the number had increased to one hundred and six. The cir- cumference of the trunk at 6j feet from the ground measured very nearly 39 feet. An old measurement made one hundred and fifty years before corresponds very nearly with this, a fact which shows that in the course of a century and a half the trunk of the lime-tree of Neustadt had not grown perceptibly. It is said to be from seven to eight hundred years old. The old lime-tree of Chaille in 1801 was upwards of 49 feet in circumference. The beech grows rapidly while young ; but in more advanced age with extreme slowness. In 1818 Deluc saw several beeches near Geneva, the trunk of which was from 14 to 16 feet in diameter. De Candolle measured a larch two hundred and fifty-five years old, the trunk of which was upwards of 5^ feet (5.84 ft.) in diame- ter ; and a larch of no more than fifty-four years growth has been measured which was more than 3^ feet in diameter. The celebrated chestnut-tree of Mount Etna has been stated to be upwards of 206,y feet in girth, (about 68 feet in diameter,) and must therefore be the largest tree described up to the present time ; but the tree has been supposed to be formed by several trunks springing from a common root which have grown together. Other remarka- ble chestnut-trees are mentioned. The plane is one of the largest growing trees of temperate coun- tries. A traveller, who visited the valley of Bujukdere, near Con- stantinople, met with a plane upwards of 95 feet in height, and the trunk of w^hich. hollow internallv down to the level of the ground, '9 98 SIZE AND LONGEVITY OF TREES. was more than 154 feet in circumference. A plane-tree, which grew in Norfolk, and was of the age of thirty-one years, was 7 J feet in circumference, according to Hunter. Cypress-trees often attain to a very great age. In the garden of the palace of Grenada there is one which has stood for more than three centuries. At La Somma, near Milan, a cypress is shown which in 1794 was 17 feet in circumference.* Tradition has it that an orange-tree of the convent of St. Sabina at Rome, was planted by St. Dominic in the year 1200 : this tree still exists. The orange-tree of Versailles, known under the name of the Francis /., is rather more than three hundred years old. In 1804, orange-trees were shown in the green-houses of Bonn three centu- ries old, and of which the trunks were more than 30 inches in cir- cumference.! In South America I had myself occasion to observe citron-trees of great age and of very considerable dimensions ; the trunks of several of these trees were nearly -27.' inches in diameter. A sycamore-tree of the village c^f Trons, in the Grisons, more than five hundred years old, is at this time between 8 and 9 feet in diameter. Many oaks have been described which had survived from eight hundred to one thousand years. Hunter saw one of these trees slill extremely vigorous which was 11' feet in diameter. Evelyn, wiio, in his delightful work entitled Sylva, has given a list of the largest oaks known in his day in England, speaks of one growing in Wel- beck Lane which must have been eight hundred and si.vty years old at least, and the diameter of whose trunk at the base was upwards of 12^ feet. The olive is one of the trees that reaches a great age ; Picconi describes one of about seven centuries, and a circumference of about 25 feet. The cedar of Lebanon grows vigorously and long, especially in soils that are sulficiently loose and permeable. According to M. Paul \'il)ray, of Sologne, the growth of this tree is more rapid than that of the coniferi in general. The cedars whiirb grew on Mount Lebanon, :md were measured by Xauwoltf in 1571, and again by Labillardiere in 1787, are generally allowed to be about the age of one thousand years. De Candolle, however, thinks that this age is exaggerated, and in contradiction with obj^ervalions made on trees, the age of which is positively known. I'he tollowing are a few of the measurements which have been reported by different observers : Aff. Ffcl circinifer. Ob»«nr»ri. Cf dar of Chelsen H3 1'2 oll'iiris 40 7 Thouin. of ditto W 9.4 Loiscleir. " Environs of London 200 16 Hunter '* Ditto 11.3 14 Dmo. " of .Mount Lebanon GOO 36.4 Muundrcl. " of Sologne 30 5 ofVilny The yew, as is well known, produces a very hard, close, and en- • De CandollB. Ph>»lolofle, p. 994. t ibid. p. WO. AGE FOR FELLING. Q9 during wood, qualities which contribute greatly to the longevity of trees. Some of the oldest trees known have been yews. Here are «, few that have been particularly described : Where thoy prow. Probable a^e. Circumferente. Observers. CountvofYork 1220 28.25 Pennant Ditto 1220 1.1.85 Ditto. County of Surrey 12S7 30.12 Evelyn. Fotheringal (Scotland) 2580 62-34 Pennant. County of Kent 2800 62.60 Evelyn. According to Duhamel it is extremely difficult to fix upon any age IS the best in a general way for felling trees, with a view to ob- taining the largest quantity of sound available timber. When tlie tree is too young, the timber has not all the excellence which it would have gained with greater age ; when too old, the pores are obstructed, and it has begun to decay in the parts of oldest forma- tion, so that it is not uncommon to find wood in the centre of the trunk which is lighter than that of the circumference. In trees which have already fallen into a certain state of decay, the worst timber in them is decidedly that which is taken from the centre at the base of the trunk ; and, indeed, the wood of the centre generallv is then of inferior quality to that of more recent formation. Very aged timber always perishes first in those parts which have formed the most internal layers of the tree. It is, therefore, an obvious and grave error to suffer any tree to stand that has given the slightest indications of decay, inasmuch as that which is ordinarily the most valuable timber is likely to be altogether lost Neither the age nor the dimensions are always the indications of the proper period for felling trees ; exposure, soil, situation, have immense influence upon their growth, vigor, and general qualities. Trees ought to be cut just when they are on the turn ; the proper moment is that which precedes immediately the alteration of the heart; and although the destructive effects of age are principally felt in the interior, this in- testine disorder is nevertheless proclaimed externally ; the whole tree suffers when it has taken place.* Duhamel has given the following characters, as indicating in- cipient decay, or decline of .vigor in trees :t 1. A tree, the top of which forms one uniform rounded mass, is not strong; a vigorous tree always throws out certain branches which surpass the others in luxuriance of growth. 2. When a tree comes into leaf prematurely in the spring, and particularly when the leaves turn, and fall prematurely in the autumn, it is a certain sign of weakness. 3. When several of the top or leading branches of a tree die, even at their mere extremities, the wood in the centre is beginning to undergo alteration. 4. Wlien the bark quits the trunk, or becomes cracked here and there, we may be satisfied that the tree is far gone internally. 5. Mosses, lichens, and funguses growing upon the bark, and red * Duhamel, Exploit des bois, t. i. p. 126. t Idem, t. i. p. 133. I 00 SEASON FOR FELLING. or black spots appearing upon it, always lead to a suspicion of change- in thf- wood. 6. When the sap is observed to flow from crevices in the bark, the death of the tree is at hand. In I'Vance, the cutting down of the smaller wood, such as is used for firing, takes place at from twenty to thirty years ; in the forests, the trees are commonly felled at from one hundred to one hundred and thirty years old, and a few trees are generally left as reserves, and for special purposes, till they have attained the age of from two hundred to two hundred and fifty years. The prevalent opinion among foresters, with regard to the proper season for felling, is, that it should be done when the sap is in the state of greatest repose, or when it is j)rcsent in least quantity in the trees. The season fixed by the old law of France (16(J9) was from October to March inclusive. But the experiments of Duhamel tend to show that this is not actually the season when trees contain the smallest proportion of sap, and that fellings made at other times of the year have had very satisfactory results. All things well weighed, says the illustrious cultivator, our only safe guide in sufh matters is observation ; and from numerous experiments he concluded that there was actually as much sap in trees in w inter as in summer, and that the spring and summer were the seasons most favorable for the speedy drying of the timber. Trees felled in summer were even found by Duhamel to yield timber which stood better and lasted longer than those that were cut down in winter; while he found the wood of etjual slreiifjth in cither case, lie concluded, therefore, that the season of the year at which timber was felled, had no in- fluence upon its qiiality or durability.* There is, in fact, no general rule observed in dilTerrnt countries as to the period at which timber is felled. The French still go on cutting from October to March ; the I'Jnglish fell in the winter. Convenience of dilTerent descriptions appears often to decide the question as to season. In order to procure bark for the tanneries, an act was passed by the Entzlish rarliament in 1003, prohibiting all felling of oak timber during the dead season, the penalty for in- fringement of the act being confiscation of the timber felled, or fine to the amount of twice its value. An exception, however, was still made in regard to limber destined for the public service in ship- building, &c. The price of bark afterwards rose to such a height, that it was Ibund most profitable to cut in the spring ; and the prac- tice then became so general, that it by and by became necessary to offer premiums to induce proprietors of oak forests to fell timber in the winter season, for the sake of the British navy. The inhabitants of the county of Statford appear at a somewhat early period to have sought to combine the advantages of the Ijark trade, with a fulfil- ment of the conditions that entitled them to the premium on winter- felled timber : they stripped the trees of their bark in the spring, and felled them the following winter. Ami Bulfon and Duhamel • Duhanifl, op. cit . t. i p. 400. INFLUExNCE OF SOIL ON TIMBER. 101 showed subsequently, that by barking trees two or even three years before cutting them down, the white external wood eoukl be render- ed nearly as hard and durable as the heart-wood of the tree. The recommendation of this procedure by these two distinguished men has not been followed in France ; bnt ever since 1770 the Dutch have adopted it, and it is now practised in many parts of England, particularly in the royal forests. It is quite certain fliat the nature of the soil exerts a considerable influence on the rapidity of growth and quality of the timber. The oak, the elm, &c., which have been grown in a damp soil, will not be so hard and compact as the same trees reared on a dry plot. Duhamel found, that although the trees which came in swampy bot- toms were verv sappy and wet, they were still lighter than others of the same kind which had grown on a dry bank. Their white wood is thick in comparison with their hard wood ; they are brittle, and do not readily take or keep the shapes into which they are bent for ship-building or for staves ; and then their pores l)eing large and open, and the whole wood being without that kind of varnish which impregnates good timber, they are readily permeable and unfit for the manufacture of vats, &c.— to say nothing of their being much more perishable. Such soft and porous timber is altogether im- proper for out-of-door constructions and for ship-building; but it answers extremely well for indoor and cabinet work ; for the latter it has even certain advantages, it is easily wrought ; and once fairly seasoned, it is neither so apt to warp nor to crack as harder wood. It was very probably to guard against any excess of sap in trees, so prejudicial in a general way to the timber they yield, that the Ro- mans, according to Vitruvius, surrounded those that were destined to be cut down with a trench six months beforehand.* Trees which have grown in a good soil sufficiently drained have a fine bark, and their white wood is moderate or small in quantity. Their woody layers, indeed, are apt to be thinner generally, than those of trees that have grown in a wet soil ; but they are much harder and tougher, their grain is more even and close, and their pores are filled with an incrusting matter. They are consequently very heavy, even when thoroughly dry, and with time and due seasoning they become extremely hard, and in the same degree acquire durability. Duhamel was "led by his experiments to conclude that the difference in point of density of timber grown in a marshy soil, and in one that was well drained and dry, was occasionally in the ratio of five to seven. The denser, dry-grown timber supports a relatively much greater weic^ht without breaking than the marsh-grown timber ; and when it does yield, it gives way by a large and splintering surfoce, while the softer, less dense M-ood snaps off short. In briet, there is no question as to which kind of timber is the most valuable ; and meas- ures oucrht to be taken by landed proprietors and timber-growers at all timel, not merely to grow trees, but to grow them under such cir- * Duhamel, Expl. des boi?. t. i. p. 46. 9* 102 SEASONING. cumstances as shall ensure their yielding good available timber when they have come to maturity. If wet soils then be unfavorable to the growth of timber of the highest value, in ship-building especially, what h;is b.een said mnst be taken as of application to those trees only which will grow in a great variety of soils. Damp and even marshy lands are well known to be favorable and even indispensable to certain trees, which, by their nature, delight in the neighborhood of water ; but these are generally kinds which are rather sought after for their height and lightness, than for their strength and durability.* Excessively dry soils, on the other hand, have also their disad- vantages for forest cultivation. In such ground, trees seldom ac- quire a sufficient growth to admit of their beini? applied to any im- portant purj)ose. It is certain, however, that absolute uniformity is never encountered in any piece of timber. The woody layers that have been formed in a wet or a dry year, in a warm or a cold year, feel and manifest the effects of the varying meteorological influences. They are of different thicknesses and densities, and, when carefully examined, are found to present the characters of the timber grown in soils of the most opposite description in point of wetness and dry- ness.f The treatment of trees after they are felled, the drying and sea- soning of the timber, are points of the highest importance. Standing trees contain a large (piantity of water in their composition. After being cut down the moisture is dissipated, rapidly at first, much more slowly afterwards. This drying process is, of course, favored or retarded by the varying stales of heat and moistness i)f the atmo- sphere. At length there comes a time when the wood no lonijer suffers any sensible change by longer exposure to the air; or if it does, the change is now on the one side, now on the other, and merely in harmony with the hygrometric stale of the atmo.sphere. Timber has then lost the whole of the moisture which it can gel rid of by this mode of drying; it is now fit for use; it is seasoned, to use the technical expression. Timber is sometimes seasoned by previous total immersion in water. It has been held that this process favored the ihorou^h dry- ing, by dissolving out certain deliquescent sails which are founil in the sap, and prevented after-shrinking. However this may be, il is quite certain that in warm countries especially, it is advantageous to sink fresh-cut limber in water, with a view to prevent it from split- ting, apparently in consequence (tf drying loo quickly. The old Venetians sank for a season in the sea, the oak limber which was destined for the construction of their galleys. Elm and beech, in particular, are said to improve greatly by the process of submersion in salt water, and to dry afterwards perfectly by simple exposure to the air | * We ImMicvp. however, that the live-oak. of which the American navy Is con striuted. and wliich supplies one of the most imperishable kinds of timber knowi^ grows exclusively in swamps. — Eso. Ed. t Dulianiel, t. i.. p. 57. t Knuwlos, Maritime and Colonial Annuls, 1835. DECAY. 103 Mr. John Knowles, who made a particular study of the means most generally employed in seasoninjT timber, has given an account of a series of experiments undertaken in the arsenals of Deptford and Woolwich, to determine the rate of drying and ultimate degree of dryness attained by timber variously treated — unprepared and prepared by previous submersion in water. The pieces of timber were placed vertically, now in the position they had occupied in growing, now in that opposed to this ; and it was found that, circum- stances the same, they dried more quickly in the former than n the latter. The general results of these experiments were as follows : 1st. That the pieces of timber were best seasoned by being kept about thirty months in the air, but in the shade and protected from wet. 2d. That they lost more of their original weight after six months' alternate immersions and dryings, than by being kept under water for six months and then dried. Ship-builders are generally agreed that it is not expedient to make use of timber until three years after it is cut.* Duhamel advises strongly, that in ship-building all timber from trees already on the decline should be rigorously rejected ; and this the rather, that the most careful examination often fails at first to perceive any alteration in the heart-wood of such trees, although it never fails to show itself by and by at a sufficient interval after the felling. This is undoubtedly a precept which it would be well to bear constantly in mind ; but timber does not always carry within itself the germs of its speedy decay ; and that which has been sea- soned with the most scrupulous care, and was originally of the best quality, does not escape the rot when it is placed under unfavorable circumstances, any more than that which was of inferior worth and less carefully treated. Wood appears to perish or decay through three principal a d ap- preciable causes, which all require similar conditions to con d into play, viz., stagnant air, sufficient warmth, and moisture. L;ke the generality of organic substances, wood, when moistened in contact with the oxygen of the air, and under the inlluence of a sufficiently high temperature, undergoes decomposition of a kind which has been compared to a slow combustion, upon which we shall find occasion to say more by and by. It is with a view to escape this kind of de- cay as much as possible that timber is never, or ought never, to be employed in the construction of ships and buildings until it has been thoroughly seasoned. Besides this first cause of decay, which may be prevented in a great measure by using certain precautions, wood has still two re- doubtable enemies, insects and certain plants of the family of the cryptogamiaj. In one case, the wood perishes because it is fed upon by certain animals which live and grow at its expense ; in the other it decays because it serves as the soil to one crop of fungus after another which luxuriate on its surface, while their roots penetrate deeply into its interior. There is nothing in either accident which * Dupln, Ann. de Cliimic, t. i\Ti. p. 277. 104 DRY-ROT. excites astonishment, now that we know the intimate constitution nf wood. We know, in fact, that among the number of soluble principles which impregnate the woody tissue, there is an azolized matter analogous in its composition to those that exist so abundantly in all the ordinary esculent vegetables. There is, therefore, in wood ample nourishment for the insects which we find living on it; and if I state now (reserving to myself the opportunity of demonstrating the fact) that all organic azotized matter becomes an active manure by decaying, we shall understand how it happens that plants, which have the power of living in dark, warm, and damp places, wax and multiply in the joistings of houses, and in the ribs and planks ol hips, causing a dry rot, which separates the integral layers of the wood, and reduces the strongest beams to dust. The rapidity with which wood is, in some circumstances, devour- ed by insects is almost incredible. Some years ago the thermites, or white ants, spread in such strength through the docks and ar- senals of Rochelle and Rofhefort, that in a very short space of time serious damage was done. A learned entomologist, M. Audouin, commissioned by the ministry to take information on the subject, reported that the ravages committed by these insects had been very considerable. But it is principally in warmer climates, where the tem- perature is steady throughout the year, and where there is no winter, that the thermites occasion the most alarming injury. At Popayaii, for example, it is difficult to meet in a building, even of recent con- struction, with a piece of wood which is not gnawed and ant-eaten. The hardest and most compact woods do not always resist the at- tacks of these insects, which, further, do not spare every kind of odo'ous wood, cedar for instance. In such countries it is altogether imp ssildc to preserve hooks and papers. I remember, in connec- tion vith this matter, that having received instructions to examine the archives of Anserma, one of the oldest towns in Popayan, in 1830, I found nothing but books illegible and in pieces; neverthe- less, the date of the documents, whith it was my business to conMilt, could not have been older than the year IfiOO. The dry rot, which results from the development and growth of cryptogimic plants upon wood, is the curse of navies. Mr. Knowles is of opinion that this disea.^e of timber has been known from ihe most remote antiquity ; he believes that he can even recognise dry- rot in the sore called house-leprosy, mentioned in the 14th chapter of Leviticus. A ship attacked by dry-rot, becomes in a very sliort space of time unfit for sea. The Foudroyant of 80 guns is often quoted as an instance of its destructive powers : launched in 17!)8, she had to be taken into dock and almost rebuilt so soon as IHO-J.* The fungi which induce dry-rot have been studied by Soweiby. Mr. Knowles signalizes two species in particular; one of whi«-h he describes under the name ni' Xt/Ioslromn gigantcu/n, the other U'idcr that of Boletus lacn/mans. The Xylostroma does n«)t extend beyond the part where it is developed ; but the Boletus, on the contrary, ii • rhipin. Ann. Hp rhiniie, f. Tvii. ]y '2'}!}. PRESERVATION OF TIMBER. 105 propagated with frightful rapidity, and disorganizes deeply and to a great distance around the texture uf the wood where it once appears These fungi are generally found on hoard ship, between the planking and the ribs, in damp situations, and where the air is scarcely, if ever, changed.* The temperature most favorable to the development of dry-rot has been found to lie between 7" and 32" cent, or 45" and 90" F. These are the extreme limits : below the minimum vegetation languishes ; above the maximum, the fungi droop. With tliis piece of informa- tion it was hoped that vessels might be freed from dry-rot by raising the temperature sufficiently. The trials were made in winter in the "Queen Charlotte," the air in the lower part of the ship being raised as high as 55" cent, or 130" F. But the general result did not an- swer expectations ; for although the fungi were destroyed in the low- er part of the vessel, it was found that their growth was rather fa- vored in places at a certain elevation above the kelson. The warm air, in fact, as it rose through the timbers became robbed in its course, and deposited the greater portion of the moisture wliich it had taken up at a lower level. Above the orlop deck, consequently, there was just about the temperature and the quantity of moisture most favora- ble to the development of the fungi. The evil was therefore ohly transplanted, not destroyed. It was now proposed to heat the "'tween decks" at the same time as the hold, making use of due ventilation ; but this method of p^-oceeding has not been put into prac- tice. The extreme slowness of the growth of trees stands in strong con- trast with the rapidity of their decay when they are reduced to the shape of timber and employed in constructions of almost every kind. In countries well advanced in civilization, every description of in- dustry tends to consume timber, at the same time that an increas- ing population is every day contracting the extent of forest land, and diminishing the number of trees grown. In some countries, in- deed, it is certain that the production of wood for all purposes, firing, &c., &c., is no longer in relation with its consumption. Tlie price of the article, necessarily high, is therefore tending continually to rise ; and it is not surprising that various measures have been sug- gested and essayed of giving this perishable material greater dura- bility. The well-known great durability of certain trees, the teak, ebony, lignum-vitae, &c , naturally led to the conclusion that the fatty or resinous matters which they contain have the property of preserving the W'Ood against the greater number of the ordinary causes of de- cay ; and unctuous and resinous matters appear in fact to have been the means most anciently employed to preserve wood from the air, from moisture, and from \he attacks of insects. But it is scarcely necessary, at the present time, to say that these varnishes only ac- complish the object proposed in their application in a very imperfect vi'ay ; paint and varnishes crack, rub, or scale off with the slightest • Dupin, Ann. de Chimie et de Physique, t. xvii. p. 291, 'ie s^rie. 106 PRESERVATION OF TIMBER. friction ; nor do they always remove the causes of internal decay on the contrary, by preventino: more complete dryness, they some- times even provoke or favor them, when applied to tender, that is, im|jerfecrly seasoned wood. Merely laid on the surface, indeed, it h-is always been seen that varpishes of any kind were but indifferent protectors ; that a really good preserver ought to penetrate the sub- stance of tic wood, and unite with ihe tissue itself. IJut herein lay the whole difficulty ; how was the needful penetration to be effected ? for the number of chemical substances, from which good effects might reasonably be anticipated, is pretty considerable, — unless in- deed we find ourselves prevented from using them by the considera- tion of the price; for it is imperative that any preservative proposed be extremely cheap. For a long time the only process for elTecting the penetration of timber by substances proposed tor its preservation was to mucerate them for a longer or shorter lime in a solution of the substance. But this means was found as tardy of accomplishment as it was or- dinarily imperfectly effected ; to have got to the heart of logs of large scantling, years would have been required. Any delay, how- ever, in such circumstances, is of itself a cause of enhanced price of the article. By and by a variety of processes, the elen\ent in one being pressure, in another exhaustion, were put in practice, and very satisfactory results obtaincil. M. Breant showed, that by mt-ans of strong pressure he could fill the largest loj^s from one end to the other with any unctuous or resinous substance propose.!, in the course of a few minutes. M. Moll, a learned German, proposed creosote introduced in the state of vapor by forcing, as an etfectual means of preserving timber, which it probably would be found ; but the high price of the antiseptic, were there nt) other objections, would neces- sarily be an obstacle to its general employment. TIjc same o!)jection applies to the bichloride of mercury, (Kyan's patent ;) and arsenic is inadvisable from its deleterious effects upon the animal economy. Some workmen are said to have lost their lives in conseipience of working timber which had l)een impregnated with a solution of while oxide of arsenic. It had been observed that vessels enjrageil in the lime-lrade lasted long; and then it was naturally lhouj,'hl that by impregnating the wood to he used for ship-buildinij with lime it would be rendered more durable. But the result did not answer expectation ; the tim- ber treated with lime did nt)t even seem to last the usual time.* ( Such was the state of the question when Dr. Bouiherie made a highly important communication to ihe Koyal Academy of Sciences on the preservation of tnnber.t Some estimate of its nature may be formed trouj the list of subjects discussed in this remarkable paper. 1. To protect timber against dry-rot and the ordinary wet-rot. 2. To increase its hardness and strength. 3. To preserve its flexibility and elasticity. • Dupin. Ann. de Chimio, t. xvil. p. 280 t l«lcni. t. Ixxiv. p. 113. PRESERVATION OF TIIMBER. 107 4. To counteract its alternate contraction and expansion in conse- quence of the varying state of moistness and temperature of the atmosphere. 5. To diminish its inflammability and combustibility. 6. To give it a variety of permanent colors and odors. In the whole of his experiments M. Boucherie set out from this proposition, the truth of which appears indisputable and to require no comment, viz : That all the changes which wood undergoes pro- ceed or depend upon the soluble matters which it contains. In confor- mity with this idea, the first step towards giving durability to timber was, either to render these matters insoluble and inert, or to remove them entirely. M. Boucherie, therefore, in his first trials sought to render the matters insoluble by charging the wood with a substance capable of combining chemically and forming a precipitate with the soluble matter left by the sap. To resolve this problem, M. Boucherie investigated the reactions between the soluble matter of wood, which it was his object to precipitate, and a variety of low-priced chemical agents. He found that the pyrolignite of iron combined the greatest number of desirable properties : it is very cheap, the oxide of iron forms stable compounds with the greatest number of the organic substances which are found in the sap of vegetables, and, to conclude, the crude pyrolignite contains a notable quantity of creosote. The facts upon which M. Boucherie relies as proving the preser- vative powers of the pyrolignite of iron flow from numerous experi- ments performed either on vegetable substances which in themselves readily and rapidly undergo changes ; or upon billets of wood of different kinds. A quantity of flour, the pulp of carrots, beet-roots, &c., impregnated with the pyrolignite resist decomposition in a very remarkable manner in contrast with the same substances when they have not been prepared in any way. The wood which was selected for trial, was generally of the most perishable kind. In December, 1838, several empty hogsheads and barrels made of the best timber unimpregnated and impregnated with the pyrolignite were placed together in the dampest parts of the great cellars of Bordeaux. In August, 1839, it was easy to see that the unimpregnated tubs were already deeply stricken, and after from two to tiiree years they fell to pieces with the slightest force ; the casks made of the prepared wood, however, were as sound as on the first day of the experiment.* M. Boucherie concluded from his experiments instituted with a view to the settlement of the question, that about ^^^th of the weight of the wood in its green state of the pyrolignite was adequate to precipitate and render insoluble all the principles obnoxious to change, which were contained in the woody tissue. M. Boucherie, while he regards the pyrolignite of iron as at once the most pow^erful, and one of the cheapest preservatives of timber, nevertheless indicates several soluble salts, which are readily avail- able in consequence of their low price, and also very effectual "when * Comptcs Rendiis, t. ii. p. 890. [08 PRESEIIVATION OF TI3IBE::. the wood, which they are to preserve, is not kept constantly wet. Solutions of common salt, of chloride of lime, the mother-water of salt-marshes, &c., were all tried and found useful : casks, the wood of which had been prepared with the chlorides, after having been long kept in very damp cellars, came out as fresh as those which had been impregnated with the pyrolignite of iron ; the flexibility of the wood preserved with these alkaline and earthy salts was further as great as at the beginning of the experiment. Having now come to a concUision in regard to the substances most effectual in preserving wood, the next business was to make them penetrate its tissue most intimately. Maceration, M. Bouche- rie soon found, like his predecessors in the same path, to be insuf- ficient, the substances in solution only penetrating a very little way. He then tried various processes of injection ; but all inferior to that imagined by M. Breant, and therefore less effectual. He then be- thought him of effecting the needful penetration of the wood in the green state, and before it had been sensibly altered by drying and seasoning: he askcl himself if the force which determines the ascent of the sap might not be taken advantage of after the tree was cut down, as a means of determining the entrance of a sohition of pyrolignite of iron ? And all his trials in this direction answered his expectations fully. M. Jioucherie had, in fact, discovered a means of securing the penetration of the minutest pores of the largest log by a substance capable of rcnderinij it incorruptible. No one before M. Boucherie thought of taking advantage ot an admitted physiolo- gical fact for such a purpose. He announces the principle upon which he proceeds in these terms: " If a tall tree be cut down at the proper season, and the bottom of the trunk be then immersed in a saline solution, weak or strong, the liquid is powerfully drawn up into the tree, penetrates its most intimate tissui^s, rises to its small- est branches, and even to its terminal leaves.''" In the month of September, a poplar, upwards of 90 feet high and nearly 10 inches in diameter, was cut, and the bottom of its bole plunged in a vessel containing a solution of pyrolignite of iron mark- ing 8" of the areometer of Beaume : in the course of six days it had absorbed upwards of 00 gallons of the fluid. In his flrst experiments, .M. Boucherie pn»curcd the nerdful absorption by placing the bottoms of his trees in vessels containing the solution ; but this mode of proceeding was obviously full of dif- ficulties and open to many objections : the weight of a green tree ot large size, with the whole of its top and branches, is often enormous, and to raise a mass of the kind once down again into the perpen- dicular was no easy task : it implied recurrence to certain mechani- cal means which are not always at hand, and necessarily expensive. M. Boucherie, therefore, tried other modes of making the trees absorb ; he adapted a sac of impermealile material to the bottom of tiie trunk laid on the ground, and irUo this sac he j^oured his solution, and this method answered very well, llr n«^xt took advantage of ' Ann. (If (hnnie, t. !\\i\. p. I.li. PRESERVATION OF TIMBER. 109 one or more of the roots to effect the imbibition. He next bored a hole into the bottom of the trunk, still erect ; and having brought the cavity thus made to communicate with a reservoir, he still suc- ceeded. This last plan was still further simplified in proceeding as follows : the trunk of the tree is pierced by an auger through nearly the whole diameter. Into the auger-hole thus made, a narrow saw- is passed, by working which on either side, the trunk is divided in- ternally to a very considerable extent, and the majority of its sap- vessels are thus cut across and made accessible. An impervious cloth is then tied round the trunk, below the opening, and this is made to communicate with the reservoir of liquid.* M Boucherie was almost necessarily led, in the course of his ex- periments, to inquire whether the absorbing power of trees differed at different seasons or not. He ascertained by trials made in the months of December and February, that though in the oak, the horn- beam, and the plane, the solution of pyrolignite of iron always rises several feet, and even several yards, yet that in the colder season of the year, it never rises so high as it does in summer, in spring, and especially in autumn, the season in which the power of ascent is most remarkable. This conclusion is obviously of interest pbysio- logically. It proves that if winter be a season of repose for the sap, it is not so absolutely. There is one remarkable exception to the general fact now announced, and this occurs among the resinous trees that keep their leaves till the spring. It has been ascertained, by direct experiment, that the ascent of tlie sap conliuues through the whole course of the winter in the cone-bearing trees, and this to such an extent, that it is always possible to impregnate every part of their trunk by the way of simple absorption at any period of the year. As M. Boucherie remarks, this fact might even have been foreseen from the fresh and green state of the leaves of these trees. It now became important, in connection with the practical appli- cation of M. Boucherie's view's, to ascertain whether or not the penetration was energetic in the ratio of the vigor of the tree itself, in proportion as it was more numerously provided with branches, more thickly covered with leaves. Experiment showed that the penetration still takes place after the removal of the greater number of branches, provided only the leading bough or terminal crown be left. A stem furnished with a number of leafy branches continues, as has been said, to imbibe, though separated from the roots ; but for how long a time will it continue to do sol This was a capital point to determine. At the end of September, the bottom of a pine- tree, about 14 inches in diameter, was first put into the solution 48 hours after it had been felled ; nevertheless the imbibition was com- plete. In June the same success attended the experiment made on a plane that had been cut for thirty-six hours. Still it is certain that the penetration takes place with so much the more energy as it is arranged close upon the time of the felling. The power by which it is determined declines rapidly after the first day is passed, and by * Boucherie, Ann. de Chimie, t. Ixxiv. p. 134. 2e s6rie 10 110 PKESERVATIO.X OF TDIBER. the tenth day it is almost entirely gone. In favorable circumstances these ten days suffice to effect the complete impregnation of the largest stem. In one of his experiments upon a poplar, I\I. Boucherie saw the absorbed liquid reach the height of about 95 feet in seven days. In the white woods it is found that there is an axis of variable diameter in different cases which escapes or rather which resists impregnation! In hard woods the parts which are not penetrated are the inner or undermost circles of the heart. INI. Boucherie, after having ascertained these facts, explains them thus : in the white woods, according to the testimony of the workmen, the centra! part which resists the penetration is at once the weakest and the most perishable portion of the log; there is no longer any circulation, any life there ; it is dead wood interred in the midst of the living woody layers. This absence of penetration of the woody tissue appears, on some occasions, elsewhere than in the centre of the trunk and branches; it presents itself under the most various forms and in different parts of the trunk : it appears to depend, as has been said, on the presence of wood abstracted from the influence of vital phe- nomena, and which, impenetrable itself, presents a barrier or ati ob- stacle to the passage of the solution to other parts; it is thus that a knot, or a piece of rotten wood, is generally found as the starting point of the zones that have escaped imbibition. As to the non- penetration of the most central parts of the heart of oak, elm, &c., M. Boucherie views it as affording umiuesiionable proof of the fact that there the living juices of the tree had long ceased to circulate. The distinction generally drawn l)etween the white or soft, and the perfect or hard wood, rests on the ditTorences of color presented by a transverse section of the trunk. In the oak, for example, the external and nearly white concentric layers are held as the stift and valueless portion of the big, and are commonly hewn away in squar- ing it ; the darker, more central portions constitute the heart-wood, the valuable timber. But, according to M. Boucherie, the distinc- tion is different when the fact of penetrability is taken as the guide, and all that portion of the trunk whic-h imbibes is con.sidered as alburnum, or soft wood, and all that does not imbibe is regarded as hard wood. The alburnum in this way is so much extended that it may be found constituting three-lourths of the whole mass of the trunk. Once introduced, the pyrolignite of iron, according to M. Boucherie, is not only useful in preserving the wood, it also in- creases the density of the timber. Impregnated with this salt of iron, wood becomes so hard as powerfully to resist the tools of the carpenter and joiner, who even complain of the increased difficulty vvitli which it is worked. Flexibility and elasticity in timber are qualities in request for cer- tain purposes, particularly for ship-building. The fir timber of the ncMth of 10uroj)e is much more prized than that of the south, espe- cially for masting, on account of its greater tlexibility and elaslicitv, qualities which appear to depend in a great measure on the quantity of mo'sture retained ; to increase these qualities M. Boucherie hat PRESERVATION OF TIMBER. Ill 9f\^ iiitKicmceci bv imbibition a deliquescent salt, such as the muri- ivi' )i li.Tiv.-, vvhicii retains moisture powerfully, as is well known, a;i i 35ems to have U\n=tLUction of costly furniture. The pyrolignite of iron alone gives an agreeable brown tint that harmonizes excellently with the natural color of the harder parts of so many trees which usually resist penetration. By following up the pyrolignite with an infusion of nutgalls or oak-bark, the mass of the wood is penetrated with ink, which presents a black, blue, or gray color, according to circumstances; a solution of another salt of iron succeeded by one of prussate of potash will cause a precipitate of prussian blue in the wood, &c. ; in short, by the numerous reactions of this kind with which chemistry is familiar, a great variety of colors may be ob- tained. Among the number of useful properties communicated to wood by impregnation with saline solutions, that of being rendered little apt for combustion ought not to be omitted. M. Gay-Lussac was the first who thought of rendering vegetable tissues incombustible by means of saline impregnations.* By incombustible, we are not to understand unalterable by a red heat; for every one must see that the protecting power of no salt can extend so far as this ; but tissues which take fire very readily, and burn with great rapidity, cease from giving any flame, and merely smoulder, after they have been impregnated with certain salts ; they take fire with difficulty, go out of themselves, become charred, and are incapable of propagating fire. And this is exactly what happens with wood which has been properly charged : it burns, and is reduced to ashes with e.xlreme slowness, so that two huts exactly alike, built one of charged wood, and the other of ordinary wood, having been set fire to at the same moment, the latter was already burned to the ground, when the in- terior of the former was scarcely charred. f The ingenious process of impregnating wood by the way of vital inspiration is not without certain objections. In the first place, it can only be performed at those periods of the year when the sap is in motion, and the trees are covered with their leaves. This tune, however, is limited to a few months of the year, and the usual prac- tice being to fell timber in the winter, wont and usage are opposed to cutting down trees in the spring and autumn. To meet these objections, iM. Boucherie engajjed in new experiments, which led him to a means of impregnating timber at all seasons, in w inter as well as spring and autumn, anil in a very short space of lime ; this second method is applicable to wood that has already been s<]uared as well as to the round trunk, provided it has been recently felled. To impregnate timber by this process, the logs are placed verti- cally, and the upper extrtmities are fitted with an impermeable sack for the reception of the saline solution destined to charge them : the fluid enters t'rom above, and almost at the same moment ilie sap is Been to begin running out below. There are some woods which • .\nn. de Chimie. t. xviii. p. 21), de sAria. ♦ Idem, t. Wtiv p. 1.V2. '2e %6r\e. PRESERVATION OF TIMBER. 113 include a large quantity of air in their tissues ; in this case the flow- does not go on until this air has heen expelled ; once begun, it goes on without interruption. The operation is terminated when the fluid, which drips from the lower part, is of the same nature as that which is entering above. In my opinion this method must he pre- ferable to that by aspiration. In the second mode of proceeding, in fact, we accomplish our object by a true displacement ; almost the whole of the sap is expelled, and the saline solution introduced has only to subdue or neutralize the very small quantity of soluble organic matter which may remain adhering to the woody tissue. By accomplishing such a displacement by means of simple water we should undoubtedly obtain results favorable to the preservation of timber, inasmuch as we should have freed it from almost the whole of those matters which are regarded as the most alterable them- selves, and the first cause of rotting in timber. The rapidity with which the fluid introduced is substituted for the sap which it dis- places, and the quantity of this expelled sap which may be readily collected, exceeds any thing that could have been imagined before making the experiment ; thus the trunk of a beech-tree about 52\ feet in length by 33^ inches in diameter, and consequently forming a cube of somewhat more than 29 feet and a half, gave in the course of twenty-five hours upwards of 330 gallons of sap, which were re- placed by about 350 gallons of pyroligneous acid. The liquid which penetrates in this way acts so effectually in displacing the sap, that M. Boucherie says we can readily procure or extract by its means the saccharine, mucilaginous, resinous, and colored juices contained in trees. It would, perhaps, be possible, and I beg to suggest this idea to colonial planters, to apply the method of displacement to the extraction of the coloring matters of dye-woods. The trade in dye- woods does not extend beyond localities favorably situated for ex- portation, so that at a certain distance from the shores of the ocean, or the banks of rivers, it is found absolutely impossible to carry on a trade, the material of which is so heavy and bulky as timber. The greater number of the coloring matters found in wood being soluble, it is possible to export them in the state of extract. Various attempts of this kind have already been made, and if they have not been successful, the obvious cause of tiiis lies in the method which has been followed, and which has hitherto consisted in treating the wood reduced to chips by means of boiling water, and then reducing the colored solution obtained ; but it is obvious that in the remote forests of America, or of Africa, where all mechanical means are wanting, nothing but failure could attend upon such a procedure By the method of M. Boucherie, the main difficulties appear to be got over : there is nothing more to be done, in fact, than to get the trees into the state of logs, and these are generally readily trans- portable, after which one or more evaporating pans seem all that are further necessary. Dye-iooods. — The greater number of these woods belong to the family of leguminosae ; the principal kinds met with in trade are : 1. Mahogany wood, {ha:matoxylon campechianum,') of a reddish 10* 114 SUGAR,' yellow, which hccomes brown with age ; this wood, besides a variety of alkaline and earthy salts, of volatile oil and unazotized matter, contains a particular coloring principle, called hematine, discovered by M. Chevreul* The mahogany grows in the hot intertropical regions of America ; Mexico and some of the West India islands export considerable quantities. Pernambuco or Brazil-wood is the name given in trade to the trunks of several trees of the genus Casalpinia. The Casalpinia crista of Jamaica, the C. sappan of Japan, the C echinata of Santa Martha, afford kinds that are very much prized. In point of chemi- cal composition Brazil-wood agrees with Campechv wood ; the col- oring matter which characterizes it lias been named Braziline by M. Chevreul ; it is obtained in small crystals of an orange color. This wood comes to Europe in fagots of about 39 inches in length. Red Saunders- wood is furnislied by the Plarocarpus san- talinus ; it contains a peculiar dye stuff, santaline, observed by M. Peltier.t To conclude, the yellow dye-woods of commerce are Y ustic, Rhus cotinus, of the family of turpentine trees, a native of the south of Europe, and the Cuba and Tampico woods, which are probably va- rieties of the Moras linctoria. OF SUGAR. Sugar is met with in almost every part of vegetables ; it has been found in flowers, in leaves, in stems, and in roots. It is less abun- dant in seeds ; and it may even be said that the quantitv of saccha- rine matter contaitjed in vegetables in general is invariably diminished at the period of ft»rmation of the seed. Sugar, consecjuenlly, as well as starch, appears to contribute to tlu) pr«»duction of the seed. The very characteristic taste <»f sugar generally suffices to pro- claim its presence ; nevertheless, it would be a great mistake did we rely upon this character alone for discovering the presence of sugar; several substances possess a very decided sweet taste, with- out being on that account sugar, in the sense which chemists attach ;,o the name. True sugars, according to chemiists, have one proj)eriy which distinguishes them from all substances with which they may have, in other respects, the greatest analogy ; this characteristic property is that of l)ecoming change. I, under the influence of water, a suitable temperature, and contact with yeast, into alcohol and car- bonic acid. It is certain, nevertheless, that certain bodies which do not belong to the chemical genus, sugar, may, under the influence of fermentation, yield alc(»hol. 1 have alieady quoted starch as coming under this head ; but it has been distinctly ascertained, as 1 have also said, that such substances, under the influence of the ferment itself, are first changed into sugar, which subsequently undergoes the vi- nous fermentation. ♦ Chimio nppliqute I'l la tciiuuro, '30e le^on. p. 88. t Chevreul, Clicinistry applied to dying, 30lh lecture, p. M. SUGAR. 115 It in admitted at tho p.esent time that fermentable sugars must be divided into two principal species, in harmony with characters which are most easily appreciated. One of these presents itself in the shape of hard, transparent crystals, and is met with in sufficient quantity to be profitably er.tracted from the juice of the cane and the beet, the sap of the maple and of certain palms ; the other is obtained with some difficulty in the solid state, being most frequently and readily procured in the iorm of sirup ; the taste of this is less sweet, less decided ; it exists in the grape and the greater number of fruits. The chemical characters of these two kinds of sugar, which are designated, cane-sugar and grape-sugar, are somewhat ditFerent ; and the elegant researches of M. Biot have shown, that from some of their physical properties, particularly the action of their solutions upon polarized light, they cannot be regarded as constituting one and the same species. In the vegetable kingdom, these two kinds of sugar are frequently met with mixed ; and there are certain chemi- cal means which enable us readily to transform cane-sugar into grape-sugar. The inverse transformation has not yet been accom- plished ; but there is nothing which leads us to conclude that it is impossible; and the time, perhaps, is not very remote when the sugar which is manufactured from potato-starch may be changed into crystallized sugar, similar to that which is obtained from the cane. Crystallized svgar. Cane-sugar is readily obtained in large transparent crystals, which are known under the name of sugar- candy. Sugar is fusible : under the action of a regulated tempera- ture, it acquires a dark-red color, and passes into the state of cara- mel; a higher temperature effects its decomposition. It is much less soluble in alcohol than in water ; highly concentrated alcohol, indeed, only dissolves an extremely small quantity of sugar. M. Peligot's analysis of cane-sugar shows it to be composed of — Carbon 42-1 Hydrogen 6.4 Oxygen 51.5 100.0* Such is the composition of sugar dried at the temperature of boil- ing water ; but the substance, like the majority of organic matters, still contains a certain proportion of constitutional water, which it abandons when it combines with certain bases. Thus sugar com- bines with oxide of lead, and forms a true saccharate, in which the sugar, deprived of its water of constitution, plays the part of an acid ; this combination, which presents itself to us under the form of white mammillated crystals, analyzed by M. Peligot, would indicate tho following as the composition of anhydrous sugar — Carbon 47. 1 Hydrogen 5.9 , Oxygen 47.0 100.0 • Annales de Chimie, vol. Ixviii. p. 134, 2e s6rle. 116 SUGAR. Ordinary sugar, deprived of its water of composition in &.ny other way, has the same elementary composition ; thus caramel obtained by heating sugar to 180" cent., (356' Fahr.,) until it no longer loses watery vapor, has, according to M. Pelicrot, the composition of an- hydrous sugar, such as it is found in combin;ition with oxide of lead. Setting aside all theoretical considerations, it is obvious that to have anhydrous sugar reconstituted ordinary hydrated sugar, it were necessary to add to 100 parts 11.76 of water, containing 1.3 hydro- gen and 10.46 oxygen ; the 111.76 parts then contain, in elements : Carbon 47.1 percent. 4-3.1 common susar Hydrogen 7.-2 '■ r>.4 Oxygen .">7.4t3 '• 51.5 Common sugar may therefore be viewed as composed of 100 anhy- drous sugar, and 11.8 water. The whole of the sugar which comes from South America and the West Indies, and a large proportion of that which comes from the East ludies, is extracted from tlie juice of the sugar-cane. In America three principal varieties of sug.ir-cane are cultivated, the Creole, the Butavian, and the Otaheitan. The Creole cane has the leaf of a deep green, the stem slender, the knots very ch>se to- gether. This species, a native of India, reached the new world after having passed through Sicily, the Canaries, and the West In- dia islands. The ISatavian cane is iiiding the rows the spaces may be about 18 inches. Where land is of no great value it is found more advantageous to give greater space, and so to favor the access of the air and the light. It is not uncommon to see plantations where the canes are spaced at distances of between 4 and 5 feet. The SUGAR-CANE. 117 time at which the setting of the slips takes place cannot be defini- tively indicated ; it depends entirely npon the epoch at which the periodical rains are anticipated. But in places where irrigation is possible, the setting goes on through all the months of the year. The holes for the reception of the slips are usually dug with a hoe, and a negro will make from sixty to eighty holes in the course of a day. When the ground has been previously ploughed, as it is in some of the West India islands, he will make twice as many. Loose rich soils, when they have a certain moisture, are the best adapted to the sugar-cane ; it does not thrive in an argillaceous soil, which drains with difficulty. In these moist soils the slips are not laid horizontally and covered, but with one end projecting a little way out of the ground. When the young shoots are covered with nar- row and opposed leaves, watering is particularly advantageous, and the plants are repeatedly hoed until they have acquired sufficient vigor to choke noxious weeds. About the 9tii month after the plan- tation of the slips, the shaft of the sugar-Ca"ie begins to lose its leaves, the most inferior falling first, the othcis in succession, so that when arrived at maturity, it only presents a tuft of terminal leaves. The flowering generally takes place with the conclusion of the year; and the cane is held sufficiently ripe in from two to three months after this epoch, when the stem has acquired a yellow or straw color. The planters, however, are by no means agreed as to the proper period of the sugar-cane harvest, — some even insist upon cutting before the flowering, believing that the quantity of su- gar diminishes on the appearance of the flower. It is unquestiona- ble, however, that the period that elapses between the planting and the harvest, must vary with the nature of the soil, and especially with that of the climate ; while in some places the cane may be cut when it is a year old, doubtless there are others where it requires to stand from fifteen to sixteen months. In A^enezuela, where the Ota- heite cane is grown at the level of the sea, and where the mean tem- perature of the year is between 81" and 82" Fahr., the cane ripens, according t^ I^olonel Codazzi, in eleven months. In districts at greater elevations under the same parallels of latitude, where the climate is of course not so hot, the cane requires a longer time to come to maturity ; where the mean temperature is about 7S" Fahr., twelve months are required ; where it is about 74" Fahr., fourteen months become necessary ; and where it is no more than about 67" Fahr., sixteen months are requisite.* The Otaheite cane grows to very difl?erent heights ; in very favorable circumstances it will reach a height of 16 feet and upwards, but its general height may be stated at from 9V to IO.7 feet. Great cane plantations are divided into squares of from 100 to 120 yards on the side, each of which coming to maturity in succession, the labor is easily performed, both in re- gard to field-work and the manufacture of the sugar. The cane is cut close to the root, and before being carried to the mill, the terminal tuft of leaves is struck oflf. These heads in the * Codazzi, Geography of Venezuela, p. 141. 118 SUGAR-CANE. green state afford excellent food for horses and cattle ; when dry they are used for thatching houses. After the first cutting, fresh sprouts arise, which require no other attention than hoeing. In good soils one planting -will yield five or six harvests by successive shoots ; but I have heard planters afiirm, that the produce in sugar diminishes from year to year. In A'enezuela, cane-pieces are re- planted every five or six years. The cane with its top struck off is carried to the mill, where the juice is expressed, and the stems, which are spoken of under the name of trash, are dried and used as fuel. The expressed juice contains crystallizable sugar, an nzotized substance analoijous to albumen, and some saline matters dissolved m a large quantity of water, which is dissipated by boiling, and the sugar finally won by crystallization. The manufacturing process is conducted with very different degrees of perfection in different places. In some the produce is obtained almost without admixture of molasses, in others the quantity of this article which drains away from the sugar is very large. It is now generally agreed that nio- lasses proceeds in great part from imperfections in the manutactnring processes employed, especially to changes which the sugar under- goes in the course of its concentration by boiling at a high tempera- ture. By the employment of what are called vacuum paux of vari- ous construction — pans from which the pressure of the atmos|)here is removed either by the air-pump, or the condensation of the vapor as fist as it is formed, rapid evaporation is elfectiMl at a temperature much below that of boiling water, by which it is found that the rela- tive quantity of sugar to that of molasses is greatly increased. It was long believed, indeed, and that on the authority of the first chemists, that there were two kinds of sugar contained in the sugar- cane, one crystallizable, the other uncrystallizable, and constituting the molasses or treacle. The researches of M. Peligoi* have shown (Icfiuitivelv that this conclusion is erroneous, that the cane con- tains no sugar that is not crystallizable. and that the ])rc-cxistenpe of uncrystallizable sugar or molasses is entirely chimerical. M. Plague iiad indeed come to the same conclusion some considerable time ago — as far back as 1820 ; but his labors were not made known bv publication till 1840. M. Casascca, professor of chemistry at Havana, has very lately confirmed these conclusions, so important for the sugar husbandry of the world. f The composition of the juice of the sugar-cane is therefore less complex than it was once believed to be ; making abstraction of very minute quantities of an albuminous azotized substance, of several salts and a little silica, substances which altogether do not amount to more than two or three hundredths, cane juice may be said to consist of water and of crystallizable sugar in the proportion of from 17 to 20 per cent | The Otaheile cane analyzed by M. Peligot actually yielded : ♦ Ann. Mnritimcs ct Coloniiilos, Aup. 1842. t Vido Coniples Rendus, 1844. X l'«3ligol. op. elk SUGAR-CANE. 119 Water 72.1 Woody matter 9.9 Soluble matter (sugar) 18.0 100.0 This conclusion was verified by M. Dupuy at Guadaloupe in 1841, who, operating on the spot, found the composition to be as follows : Water 72.0 Woody matter 9.8 Soluble matter (sugar) 17.8 Salts •• 0.4 100.0 The analyses of the Creole cane made by M. Casaseca at Havana appear to indicate a larger quantity of woody fibre : Water 65.9 Wood 16.14 Sugar 17.7 100.0 The quantity of sugar yielded by the cane, differs considerably. M. Codazzi assigns 6 and 15 per cent, as the extremes, and 7^ per cent, as the mean. M. Dupuy gives 7.1 per cent, as the average. The quantity is, of course, first and most intimately connected with the quantity of juice obtained. But the produce of juice is extremely variable. In Guadaloupe, the juice varies between 56 and 62 per cent, of the cane subjected to pressure. The generality of mills do not, in fact, enable us to obtain more than about 56 per cent. At New Orleans the usual quantity obtained is said to be 50, and in Cayenne only 36 per cent. At Havana, according to M. Casa- seca, the riband cane yields 45, the crystalline 35, and the Otaheitan 56 per cent, of juice. The Otaheite cane was examined by M. Peligot, under a variety of circumstances of age, growth, part of plant, &c. &c. The fol- lowing table contains the condensed results of his experiments : First shoots Second do. from original sprouts Third do. from second do. Fourth do. from third do. Inferior pjirt of c:\ne ]Middle part of do Superior part of do Knots Cane of eight months Cane of ten months Water. Soluble mut- ters (sujrar.) Woody fibre. 73.4 17.2 8.9 71.7 17.8 10.5 71.6 10.4 12-0 73.0 16.8 10-2 73.7 15. .5 10-8 72.6 16.5 10-9 72.8 15.5 11.7 ' 70.8 12.0 17.2 73.9 18.2 7.9 72.3 18.5 9.2 It would therefore appear, making exception always of the knots which occur in the course of a cane, that the composition of the plant in its various states and conditions, is almost identical. M. Peligot's important paper, while it informs us of the average com- position of the Otaheite cane, satisfies us that the gummy and mvv 120 SUGAR-CAMS. cilaginous substances and the uncrystallizable sugar, the existence of which was held as demonstrated, are, in fact, nowise constituents of the sugar-oane. Whence we may conclude, with M. Peligol, that every drop of molasses which drains from the sugar is the produce of the manufacture ; an opinion to which I assent the more readily from having myself seen oftener than once the juice of the cane yield nothing but crystallizable sugar These analyses further de- monstrate, more powerfully than could any discussion, the imperfec- tion of the processes usually followed in manufacturing sugar. They prove, in fact, that in the mill rather more t,han a third of the whole juice contained in the cane is left in the trash. This loss might be considerably diminished were more perfect pressure employed in extracting the juice. But it appears that the planters are indisposed to crush the trash too much, as by this it is rendered less fit for fuel, a considerable quantity of which, by the present mode of manufac- ture, is indispensable. M. Dupree, however, says that by insisting on obtaining from 65 to 66 per cent, of juice in all cases, the trash is still left with all its value as a combustible. The trash on coming from the mill appears quite dry. I have seen some which, after having been pressed twice consecutively, looked as if it were im- possible by any further amount of pressure to express more liquid. Nevertheless, it was enough to taste this pressed cane, to be satis- fied that it still contained a considerable quantity of sugar. To« procure this without usinjj more powerful machinery, M. Peligot proposed to steep the trash in water, and to press it a second lime. Hy this means a weak juice is obtained, which, addt^d to the first pressings, raises the produce of sugar from 7 to 10 per cent. uj)on the whole amount of cane employed. Hy following this process, suggested by theorv, upon the great scale, .M. I)u[)re«; has succeeded in obtaining 'ih more than the usual quantity of sugar without ma- king any change in his apparatus, and without findmg the trash loo much shaken to be burned under his coppers.* In some circum- stances the increase in the quantity of juice which this procedure implies, might be found an objection on account of the larger quan- tity of fuel re(iuired for its evaporation ; but wherever a supply of wood is to be had, M. Peligot's method ought undoubtedly to be ap- plied. The very dissimilar quantities of crystallizable sujrar obtained from canes, which as we have seen all contain very nearly the same quan- tity of this substance, prove that the processes of concentration and purifieation of the sap also c(»ntribute to the loss which has been in- dicated. M. Peligot has pointed out several causes which concur to deteriorate sufjar ; amoni: the numl)er : 1. A viscous fermentation which renders the sap thick anry age. In this premature or anticipated beet harvest, a less weight o( root is of course gathered than would hare been obtained at a later period ; but the nutritious powers of BEET AND BEET-SUGAR. 123 these beet roots are the same as they would ever have been. The grand questions to be determined were, whether the roots would keep or not, and whether the cattle would eat them from the pile as freely as from the field. All this was ascertained in the course of the winter : the beet kept perfectly, the cattle ate it as freely as ever. The procedure to be adopted therefore to secure a crop of beet of average weight, storing nevertheless some considerable time before the usual period, is simply to transplant somewhat more closely, and to put less space between the drills. If experience decides in favor of this method, the sole inconvenience which attends the cultivation of the beet in a freshly manured soil, and as the first crop in the rotation, that, namely, of causing a late and unfavorable seed-time for winter corn, will be completely got over. The beet which grows above the ground is best gathered with the hand ; kinds that grow under ground require to be loosened by run- ning a plough along the drill, &c. In Alsace it is the custom to take away the leaves, and to trim the roots upon the ground ; the refuse thus obtained constitutes a considerable mass of manure, which it is well to plough in immediately. To extract the sugar of the beet the plant is washed and rasped, and the pulp is then subjected to the action of a powerful press. Like the juice of the cane, the juice of the beet speedily undergoes a change ; it is therefore immediately heated to 70° cent, or ISSTahr., and a little lime is mixed with it to neutralize acid and favor the clarifi- cation, by combining with albumen. The liquor is skimmed, and in the course of an hour becomes quite limpid, and of a pale yellow color. The liquor is then run upon a filter containing animal charcoal, and from tliat is transferred to a boiler where it is properly reduced, the process being in all respects the same as in the manufacture of cane sugar. In France, the produce of each 110 lbs. weight of beet is estimated at 4.56, or somewhat more than 4^ lbs. of white sugar. The amount of loss in the manufacture may be conceived from the actual compo- sition of the beet, which, by the process followed by M. Peligot,* and which consists essentially in drying a certain weight of the root, cut into thin slices, and then exhausting the matter with boiling alcohol of moderate density, appears to contain from 4 or 5, up to 9, 10, 11, and even nearly 12 per cent, of sugar. This analysis of M. Peligot has been confirmed by the experiments of M. Braconnot,t who found the white beet of Silesia to have a very complex compo- sition, comprising as many as twenty-one different ingredients, among the number crystallizable sugar, albumen, woody matter, phos- phate of magnesia, phosphate of lime, oxalate of potash, and oxalate of lime, oxide of iron, an ammoniacal salt in small quantity, &c. On an average, the analysis of M. Peligot would lead us to conclude that the beet contained in one hundred parts — * Recherches sur I'analyse de la betterave a sucre. t Annales de Chimie, vol. Ixxii. p. 442, 2d. series. 124 BEET AND BEET-SUGAR. Water 87 Matter soluble in water (sugar) 8 Insoluble substances, (woody tissue) • 5 100 from which it appears that no more than about 5ths of the suga,! contained in the beet-root is extracted. As in crushing the cane, so in squeezing the rasped pulp of the beet, a part of the loss is owing to a certain quantity of sugar being left in the expressed pulp. In fact, with the presses generally in use, while from 60 to 70 per cent, of juice is obtained, the root actually contains 95 per cent. The loss here, however, is of less consequence than it is in the cane, the trash of which is used for fuel, while the pulp of the beet serves as food for cattle. The pulp, indeed, is A)und to possess very nearly the same amount of nutritive power as the root which produced it. One of the considerations which is perhaps of highest importance in cormection with the production of sugar from the beet, is iidierent in the difficulty of preserving the root after it is full grown. Gather- ed at the end of autumn the root suffers no less from severe fr(»st, than it does from mild open wenther : frost destroys its organiza- tion, and in miUl winters vejretatiou continues at the expense of the sugary princijjle, which had been formed during the growth. If the beet actually contains at every period of its existence the same quantity of sugar with reference to its weifrhl, there would probably be a great advantage in not waiting for the period of complete ma- turity^ by sowing .somewhat thicker than wont ; any ditlerence of weight would probably be made up, and then there would be no risk of loss from keeping. The quantity of beet gathered from a given extent of land neces- sarily varies with the soil, the pains bestowed upon the crop, and the quantity of manure that has been used ; the following are a few particulars from official documents : PRODrCE PKR ACRE. Ton. CwL Qr«. IJ>«. PasdcOilais 12 9 1 1» Dcpartiiicnt of tho North 12 10 2 25 l>ep:irtuipnt of Cher 15 1 39 but in Other departments the produce is considerably smaller, so that the average lor the whole country has been estimated at not more that 10 tons 9 cwt. 1 qr. 13 lbs. per acre; an averarje which ap- proaches very closely to that which I have obtained from my own I'arm at Bcchelbronn, calculated during a period of seven years. Assuming 4,",,ilis lbs. of sugar to be obtained from every 110 lbs. of beet, the produce in sugar from an English acre in the course of seven months will amount in the present stale of things to 9 cwt. 'J qrs. and 7 lbs. By way of comparison I shall here remind the reader that an English acre of land laid out in Olaheile sugar-cane yields in the course of about fourteen months, 15 cwt. 1 qr. 10 lbs. I find from my accounts for 1841, that to manage an English acre of land under beet-root in .Vlsace, 15.0 davs of a man, and li.l BEET AND BEET-SUGAR. 125 days of a horse was the amount of labor expended. In a document upon the sugar plantations of Guadaloupe whicli I have seen, it is stated that a domain of 150 hectares, or 370 acres, is worked by 150 negroes, which, reckoning the time that the crop is on the ground at fourteen months, would bring the number of days labor by a man, to 171.8 per English acre. Such an expenditure of labor must in the nature of things absorb the greater part of the profits ; and, indeed, in a commission of inquiry into the laws connected with the sugar trade, it was shown in reference to the plantation in ques- tion, that the cost of cultivation and manufacture was equal to the value of the produce. Still the cane presents one considerable advantage over the beet, that, namely, of furnishing the fuel necessary to the boiling, an advantage which will be better under- stood, when it is known that in the manufacture of every 110 lbs. weight of beet sugar, the consumption of coal amounts to 22 lbs. In countries where sugar is cheap, it becomes an ordinary article of diet; in the public market-places of the great towns of South America, one of the rations commonly exposed for sale consists of brown sugar and cheese. M. Codazzi estimates the quantity of sugar consumed by each inhabitant of Venezuela at 110 lbs. In England it amounts to about 22 lbs. ; in Ireland, to no more than 4 lbs. and joths ; in Holland it is 15j-^„ lbs. ; in France it is 8~- lbs. ; in Italy, 2f^ lbs. ; and in Russia, but lyV lb. per head. Maple sugar. {Acer saccharinum.) The maple is very common in the east of the United States of America. The tree is occa- sionally met with in clumps of several acres in extent, but it is more commonly found dispersed in the forest, growing among pines, poplars, ashes, &c. The tree grows particularly in rich soils, and attains the height of the oak; the trunk being often more than three feet in diameter. The maple becomes covered with flowers in the spring before the appearance of the leaves. It is supposed to be in its prime at the age of about twenty years. The sap of the maple is obtained by piercing the trunk to the depth of from six to ten inches. A piece of wood to serve as a gutter is placed in the hole, and the sap is received in a vessel placed underneath. It is usual to pierce the tree first on the side that is towards the south ; when the flow of sap begins to lessen, it is tapped upon the north side. The best season for making maple sugar is the beginning of spring, February, March, and April ; the sap continues to flow during five or six weeks. The quantity of sap obtained is found to be largest when the days are hot and the nights cold ; the quantity collected in the course of twenty-four hours will vary from about half a pint to thirty pints and more ; the temperature of the air has the most marked influence upon the flow of the sap ; it ceases completely, for instance, in those nights when it freezes after a very hot day. The maple does not appear to S'ffer from reiterated perforation ; trees are mentioned which were still flourishing after having yielded sugar for forty-tw^o consecutive years. In certain cases, which, however, must be held as exceptions to the rule, as many as 183 pints of sap have been tapped from a maple in the course of twenty- 11* 126 PALM-SUGAR. four hours, which j'ielded ij\ lbs. of crystallized sugrar. A maple of ordinary dimensions, in a good year, will yield, on an average, ahout 198 pints of sap, producing 5^ lbs. of sugar. The sap of the maple must therefore contain about 2.2 per cent, of its weight of marketable sugar. It has been found, that with care and attention the maple becomes more productive ; maples around which other forest trees have been felled, or which have been transplanted into gardens, yield a sap which is not only more abundant, but also richer in sugar, which, in fact, contains about three per cent, of sugar. The manufacture of maple sugar presents no peculiarity ; pre- cisely the same process is followed as in the case of the cane and beet. Unless very speedily boiled down, the sap ferments, and undergoes change ; in some parts of the United States, indeed, a vinous liquor is made of the sap, by allowing it to run into sponta- neous fermentation. PALM SUGAR. The palm which in the southern parts of India furnishes crystal- lized sugar in large quantity, is the cleophora of Gaertner, and reaches a height of about 100 feet. Its fruit hangs in clusters up- wards of a yard in length. The natives procure the sap by cutting short one of the shoots that is about to flower and carry fruit, and hanging under the cut part of a calabash or other vessel, into which the fluid 'distils ; in a large plantation such an apparatus is seen connected with each palm-tree ; the sap is removed every morning, and it is enough to reduce it by evaporation to obtain the sugar, which differs in no respect from the tinest sugar of the cane ; in the unrefined state it is known over the whole of the East under the name of jaggery,* and is then a kind of moist and sticky muscovado sugar. The sap of the palm-tree obtained in the way above indica- ted, is often turned into a vinous liquor, which is much prized in many places. The pith of the tree yields sago. The palm-trees cultivated in India consequently yield three most useful products — sugar, oil, and the farinaceous article of diet called sago. In rear- ing the cocoa-nut palm, those nuts are selected for seed which fall naturally, and they are dried in their husk. The ground which is to be sown is dug to a depth of eighteen or twenty inches, and it is left *o settle for three or tour days. Some portion of the surface is then taken away, and the fresh soil is covered, to the depth of ab«)ut six inches, with sand. The nuts are then placed upon the ground 80 prepared, and covered over with a little sand and a light stratum of vegetable mould ; they are then watered for three days consecu- tively. In the course of three nuuiths the young palms are fit to be transplanted, and they are set at the distance of about twenty feet every way from one another. For their reception in the permanent • This Is the poncric nnnw tor sucar. i»iul is obviously either the Lntin word wic- chnruiii, <)r from the smne r(K»t ns the Lilin word. The ciKo;i-nut tree lrci»te»l in the ■nine way ns tlie ileophori yields abundunce uf sugar, which is also known under ltt« name ol'jugKcry. — Eno. Ed. GRAPE-SUGAR, OR GLUCOSE. 127 plantation, holes are dug of about two feet in depth, in which a layer of sand, about six inches in depth, is put, upon which the young plants, still adhering to the fruit, are placed ; the hole is then filled with sand, and the surface is covered with a little earth. The young trees require watering every day during about three years. The palm begins to be productive at the age of seven or eight years, and it continues to yield fruit, or sap for the manufacture of sugar, during a very considerable period, without causing any further cost for cul- tivation.* The sap of the greater number of the palms appears to be rich in saccharine matter ; it is obvious, indeed, that every sap that is capable of supplying a vinous liquor by fermentation, may also furnish sugar; and if the palms have not generally been grown with a view to this product, it is because the fruit must then be given up, and, both in India and South America, the produce in the shape of oil from the nuts of the palm, is almost always more valu- able than that which can be had in the shape of sugar. f GRAPE SUGAR. We have already said that starch acted upon by acids, and by malted barley, is changed into a saccharine fermentable substance, which, both in regard to flavor and physical properties, differs in many respects from the sugar which we have hitherto been engaged in studying. As this substance exists naturally in the grape, it has been called grape sugar, a name for which the generic term glucose has been lately substituted in France, this term being used to include all the sugars that are analogous to grape sugar. Grape sugar oc- curs in the form of small white and very soft crystals, grouped in tubercular masses; it softens at 60^, (140° Fahr.,) and becomes quite sirupy at 90°, (194° Fahr.) Alcohol free from water dissolves none of it ; but diluted alcohol takes up a considerable quantity. In the grape this sugar is associated with cream of tartar, tartrate of lime, and several other saline matters. It is easily extracted from the fruit ; but the grape sugar of commerce is now universally prepared from starch ; large quantities, indeed, are manufactured on the continent for the preparation of spirit, and for the amelioration of wine, beer, cider, &c., in short, to supply sugar wherever it is defective in the natural or artificial musts that are subjected to fer- mentation. In England considerable quantities are also manufac- tured ; but here the law does not allow it to be used in the same ad- vantageous direction as in France and Germany ; all that is made is employed for mixing with adulterating cane sugar, which is an arti- cle of higher price. The sugar that is made from starch, and that is obtained from the grape are identical in composition, as is that also which is found in the urine of persons laboring under diabetes. * Buchannn. A Journey from Madras, &c., vol. i. p. 155. t In British India the cocoa-nut palm is beirinning to he extensively cultivated as a means of producing su^ar. A considerable portion of the East India sugar now brought to market, is manufactured from the palm-tree. It is not improbable, indeed, that the palm of one species or another will one day supersede the sugar-cane and the beetaa th8 source of all the sugar consumed in Europe.— Eng. Ed. 128 MA>i>A. Grape Sugar Sugar of Starch. Diabetic Sun* (Saussure.) (Guerin.) (PeligoiJ Carbon 36.7 36.1 36.4 Hydrogen 6.8 7.0 7.0 Oxygen .56.5 56.9 56.6 100.0 100.0 100.0 Like cane sugar, grape sugar in combining with certain bases ibandons a portion of its constitutional water. In the state in which it is combined with the oxide of lead it contains — Carbon 43.3 Hydrogen 6.3 Oxygen .50.4 100.0 From these analyses it appeals that crystallized grape sugar con- sists of — Anhydrous glucose 100 Water 19 On comparing the two kinds of sugar in the crystallized state, it becomes evident that glucose or grape sugar does not differ from cane sugar, except in containing a larger quantity of water. In fact the composition of grape sugar oiay be represented in this way : Carbon 42.2 1 Hydrogen 6.2 > 100 of cane sugar. Oxygen 51.6) w«.«1J:>J^^™;.-.::.-.;;::-.,J:5|^ 115.8 of grape sugar. The cane, the beet, the palm, the maple, the vine, and starch, turned into glucose, are the sources from whence all the sugar of commerce is obtained at the present day, although attempts more or less successful have also been made to extract sugar from the pine- apple, from tbe chestnut, from the sweet orange, and from the stem of the maize or Indian corn. It appears that before the conquest the .Mexicans prepared a sirup from the stem of the Indian corn, which was sold in the market-places. Pallas could not obtain more than about 3 per cent, of crystallized sugar from maize, but in -xn experiment which I made in South America along with M. Rou]..i, the quantity of raw sugar obtained from this plant was 6 per cent. SACCHARINE PRINCIPLES NOT FERMENTABLE. Manna ; manmte. This saccharine principle is met with in dif- ferent plants ; it has been found in the expressed juice of onions, and in that of asparagus, in the alburnum of several species of pine- trees, and in different mushrooms. Manna, which is an exudation from i\\e fraxinux ornus and larch, contains nearly 'ths of its weight of mannite, and it is therefore from this sub.stance that mannite is usually obtained, allhouorh it can also be had tVoni the juice of the beet and the onion ; hut then it is iiecess: ry to dpstroy t!ie cane or grape sugar which ihrv fonlain bv prf "joub vinous feuucutaliou. PECTINE. 129 and M. Pelouze has even maintained that themannite thus prepared is a product of fermentation.* Mai nite crystallizes in very white semi-transparent needles ; it has a slightly sweet taste, and is soluble in water. According to Liebig and Opperman it contains : Carbon 39.6 Hydrogen 7.7 Oxygen ■■•52.7 100.0 Liquorice. This substance, which is obtained from the root of the Glycirrhiza glabra., is too well known to require particular con- sideration ; it is soluble both in water and in alcohol. GUM. Gum is a substance very extensively diffused in the vegetable kingdom ; there is, perhaps, no plant which does not contain some. Gum is divided into two kinds ; gum, properly so called, the type of which we have in gum-arabic, and vegetable mucilage, such as we meet in gum-tragacanth. Gum in dissolving in water produces a thick and adhesive fluid. It is insoluble in alcohol. Some plants contain such a quantity that upon infusion they seem to give, as it were, nothing else : such are the althea, the jnalva officinalis, &c. Gum does not crystallize, it is met with in concrete masses which result from the solidification of the drops which flow spontaneously from the trees that yield it : by long boiling with dilute sulphuric acid it is changed into glucose. Nitric acid alters it, and several new products are the result, among the number of which is mucic acid. Gum-arabic, according to the analysis of M. Gay-Lussac and Thenard, consists of : Carbon 42.3 Hydrogen 6.9 Oxygen • 50.8 100.0 To obtain vegetable mucilage, a quantity of linseed is treated with water and expressed. It is also obtained by steeping gum traga- canth in about 1000 parts of water and pouring off the solution which covers the mucilaginous mass. The mucilage then forms a jelly more or less consistent, which diluted with a large quantity of water forms a ropy viscid fluid. Dried again, this mucilage becomes hard and translucid ; in water it regains its former state. f VEGETABLE JELLY — PECTINE AND PECTIC ACID. It is well known that the juice of all fruits contains a gelatinous substance to which many of them owe the property of forming jellies. * Annales de Chimie, voL xlvii. p. 419, 2d series.— The refuse wash of the distiller, appreciated by the taste, appears to contain a considerable quantity cf saccharine matter, which is probably mannite. — Eng. Ed. tBerzelins. Cheniistry, vol. v. 130 PECTINE, PEOTIC ACID. This matter may be obtained by means of alcohol. If into a quantity of currant juice lately expressed, a portion of alcohol be poured, a gelatinous precipitate is formed after a certain time ; this jelly, sub- jected to graduated pressure and washed with diluted alcohol, gives the gelatinous principle in a state of tolerable purity : this is pectine, discovered by M. Braconnot. Pectine dried is in membranous semi-transparent pieces resem- bling isinglass. Thrown into about one hundred times its weight of water it swells considerably and at length dissolves completely, giving rise to a stiff jelly. By increasing the quantity of water, a mucilaginous solution, having a slightly milky aspect, is obtained. Pure pectine is quite insipid ; it does not affect the color of litmus, the weaker acids have no effect upon it ; a slight excess of potash or of soda does not change it obviously, and nevertheless pectine is singularly modified under the influence of these alkalies, being chang- ed into a particular body, having acid reaction ; for on saturating the alkali employed, it immediately coagulates into a transparent gelatinous mass — pectic acid. As pectine acted upon by the fixed alkalies undergoes so remarkable a change, we may be aUowed to conclude, with M. Braconnot, that the peciic acid which is found ready formed in plants, has a similar origin ; a view moreover which tends to confirm that formerly announced by Vauquelin, when he ascribed the development of the acids of vegetables to the presence of alkalies.* Gelatinous pectic acid immediately becomes defluent upon the addition of a few drops of solution of ammonia. By evaporating this solution in a porcelain dish we obtain an acid pectate of am- monia, which swells in distilled water, dissolves in it, and thickens a large quantity of the fluid. As ammonia has no reaction upon pectine, M. Braconnot has taken advantage of this negative property to determine if pectic acid exists or not, ready formed, in certain plants. Thus in treating carrots with cold water, rendered slightly ammoniacal, a liquid is obtained, from which an acid immediately throws down a precipitate of pectic acid.f Pectine and pectic acid, therefore, may exist together in vegetables, and M. Jacquelain has proved that the acid there is often in a stale of combination as an alkaline or earthy pectate. It is to these pectates that M. Payen ascribes the origin of the carbonates of the same bases, which are met with in the ashes of plants, the organic acid having of course be«n destroyed by the combustion. | M. Braconnot has described an easy process for obtaining pectic acid in large quantity from carrots.^ M. Fremy has published analyses of pectine and pectic acid, which present this remarkable peculiarity, that the c ne has exactly the 6?vne elementary composition as the other. * Braconnot, Annnls of Chemistry, vol. xlvii. p. 274, £* lerics t Hnnonnot, op. cit. vol. .xxx. p. W. t Payen, Proceedings of the Aciuiemy of Sciences, vol. xv. p. OOT ( Op. cit. vol. xxx. p. 97. VEGETABLE ACIDS. 131 Peetinc. Pectie aeia. Carbon 42.9 42.8 Hydrogen 5.1 5.2 Oxygen • 52.0 52.0 100.0 100.0 I have thought it right to speak at some length of these two prin- ciples, as they appear to play an important part in the phenomena of vegetable life. A careful study of pectine and pectic acid will very probably aid in throwing light upon the metamorphoses which organic substances undergo in the act of vegetation, Pectic acid has been found in every plant in which it has been sought for ; M. Braconnot discovered it in the turnip, carrot, beet, peony, in all bulbs, in the stalks and leaves of herbaceous plants, in the wood and bark of all the trees examined, in all kinds of fruit, apples, pears, plums, cucumbers, &c. M. Braconnot is even very much inclined to think that pectic acid may constitute the essential principle in the cambium or organ-^ izable matter of Grew and Duhamel.* OF VEGETABLE ACIDS. In the series of bodies which we have now considered, one only, sugar, possesses the property of crystallizing. All the others are amorphous, and their globular disposition and gelatinous qualities have led to the presumption that they form in some sort the line of demarcation between things without and things endowed with life. It was also imagined that these amorphous matters, that these pro- ducts of the vegetable organization, almost organized themselves, would alone suffice for the nourishment of animals. This idea, however, is not well founded ; for if it be true that albumen, caseine, legumine, starch, and gum, are powerful elements of nutrition, it is equally so that sugar may perform an important part in this process, by acting in the same manner as starch, the oils, and other principles of ternary composition, in becoming like them a useful, often an in- dispensable auxiliary of azotized alimentary matters. This disposition to consider the amorphous state of the more im- portant immediate principles of vegetables as a special and distinctive character, cannot be maintained beside the recent observations of Mitscherlich. This illustrious chemist has found, that if the mineral precipitates which are deposited in liquids, are in many cases form- ed of crystals more or less regular, they are also sometimes compos- ed of small spheres or aggregated masses, the particles of which do not unite in a regular way as crystals, but remain separated by a thin layer of fluid. Examined under the microscope these masses present themselves under the form of flocks and of shreds, having a granular or gelatinous appearance, and which remain soft and flexi- ble like fresh vegetable or animal substances, so long as they are kept under water ; it is only in drying that they become pulverulent or acquire the vitreous aspect. f * Braconnot, op. cit. vol. xxviii. p. 171. 1 Berzelius, Ann. Report, 1841, p. 20. 132 VEGETABLE ACIDS. Th€ substances, the chemical constitution of which we have stDI to examine, may in general be obtained in the cry'stallized state ; their individuality seems more decided ; they are more stable, better characterized, and their specific properties often assimilate them to inorganic bodies. Such, for example, are the acids formed in the course of vegetable existence. Vegetable acids present all the general characters of mineral acids, while they participate in the properties inherent in organic substances. Thus they form salts by uniting with bases ; with potash, soda, ammonia, they form sahs soluble in water ; the other bases produce compounds that are soluble or insoluble, according to the nature of the acid. These acids, free or uncombined, are very frequently met with in fruit, sometimes in the leaves, more rarely in the seeds and roots ; but in combination with bases they are met with in almost all parts of plants. Already very numerous, they are increasing rapidly with the progress of discovery ; with the excep- tion of a very few employed in the arts, their study forms a subject of no great interest. I shall therefore confine myself to a few of thf. most extensively distributed of these acids. Oxalic acid. This acid exists free in the hairs of the cicer or chick-pea, and united with potash constituting an acid salt, the bin- oxolate of potash in the w ood sorrel and the common or garden sor- rel. It is from the former of these plants that the salt called salt of lemons, but which is, in fact, the binoxolate of potash, is still ex- tracted in some countries. The juice of the wood sorrel is expressed and yields about 0.003 of its weight of the salt, from which, by or- dinary chemical manipulation, the oxalic acid is readily obtained. At the present time this acid is prepared artificially by the action of nitric acid upon starch ; it is a powerful acid, and its atfinily for lime is such that it takes this base even from its union with sulphuric acid. Tartaric acid is met with above all in the grape in the state of bit;irtrate of potash, a salt which is deposited upon the sides of the casks ill which the wine is kept. After having been pn)perly puri- fied, it is known in commerce under the name of cream of tartar, from which the tartaric acid can readily be obtained. Another par- ticular acid, the raccmic acid, the composition of whicH is identical with that of the tartaric acid, has been discovered in the tartar of the wines grown on the Upper Rhine. Citric acid. This acid is found in the juice of many plants, and abundantly in the juice of lemons, oranges, currants, union ot ih'^ arid with the animal matter VEGETABLE ALKALIES. 133 18 immediately produced. By macerating a piece of raw hide in a solution of tannin, the same combination takes place even into the very interior of the tissue ; the whole of the tannin quits the solu- tion by degrees to combine with the gelatine of the skin. It is not in the bark only that tannin is encountered, it has been found in different organs of plants. Sir Humphrey Davy has stated these quantities of tannin as constituents of 100 parts of the follow- ing substances : Nutgalls ... . . 27.4 Oak bark 6.3 Chestnut bark .... 4.3 Elm bark 2.7 Willow bark 2.2 Inner white bark of an aged oak . 15.0 The same of young oaks , . 16.0 The same of the Indian chestnut . 15.2 The inner colored bark of the oak . 4.0 Sicilian sumac . . 16.2 Malaga sumac . . . 10.4 Souchong tea . . . 10.0 Green tea .... 8.5 Bombay catechu . . . . 54.3 Bengal catechu . . . .48.1 Gallic acid. This acid is found united with tannin in the greater number of barks, or along with the astringent principles of plants. Gallic acid appears to be the product of a kind of fermentation un- dergone by tannin, as the process by which it is prepared seems to indicate, and which consists essentially in exposing for about a month a quantity of nutgalls reduced to powder and kept constantly moistened. The solution of gallic acid does not precipitate gela- tine. I have added in a table the composition of the principal vegetable acids. I shall speak of the composition of fat acids when I come to treat of fatty substances. The different vegetable acids do not vary essentially in composi- tion, save in a single instance. With one exception they consist of definite proportions of carbon, hydrogen, and oxygen. The excep- tion alluded to is the hydrocyanic acid, which contains no oxygen, but a large quantity, nearly 52 per cent., of azote. OF THE VEGETABLE ALKALIES. The alkaline bases which are formed in the course of vegetation, always contain a certain proportion of azote. Their general prop- erties are those of alkalies ; their watery or alcoholic solutions re- store the blue color of the reddened tincture of turnsole, and they constitute salts by combining with acids. In their manner of be- having they bear a certain analogy to ammonia. Like ammonia, the organic alkalies combine with the hydrates of the oxacids, and when they are deprived of their water of crystallization, they fix the hydracids without losing weight. 12 134 FATTY SUBSTANCES. The discovery of the vegetable bases is due to Serluerner, who, in 1804, indicated the existence of morphine in opium. The ma- jority of the vegetable alkalies are insoluble, or little soluble in water ; all are soluble in alcohol ; some of them are sufficiently volatile to be susceptible of distillation. In elementary composition they are all very much alike, consist- ing of various, but, in each instance, definite proportions of carbon, hydrogen, oxygen, and azote, the carbon varying from about 50 to 75, the hydrogen from 6 to 12, the oxygen from 8 or 9 to 27 and even 37, and the azote from 1.6 to 12, 28, and even 35 per cent. OF FATTV SUBSTANXES. Under this title I comprise all the oily substances, liquid or solid, and those that are analogous to wax, which are found disseminated in different organs of plants. A character common to almost all fatty substances, is insolubility in water. They dissolve in sensible quantity in alcohol, and especially in ether. Fatly substances may be divided into two classes : one including those which are easily modified by the action of alkalies, and which form soaps ; the other not susceptible of this action, not susceptible of saponification, or, at all events, that are only attacked by alkalies in very particular cir- cumstances. When a mixture of fat oil and a solution of caustic alkali are heated, the oil is S(»on observed to incorporate with the alkaline liquid. After boiling for some time, if the alkali is in excess, clots or flocks appear, and in removing the excess of licpiid a white mass is obtained which is soluble in water — the oil is saponified ; and the product of the saponification is combined with a j)ortion of the alkali which has been emploved. If into a hot solution of this soap a quantity of hydrochloric acid he poured, the acid seizes ujion the pot- ash or the soda, setting at liberty the fatty body which had been combined with the alkali, and which collects on the licjuid. It is easy to discover that the fatty matter thus collected is no longer the same as that which had been originally cm{)l()yed ; for example, it is completely stduhle iu boiling alcohol, which, on cooling, dejiositea brilliant pearly crystals of a fatty substance pcjssessiug acid proper- ties. By evaporalirg the alcohol from which these crystals are formed, an additiona quantity is obtained, and, when the alcohol is entirely dissipated, another unctuous bovly is obtained, having also acid properties. Three acids having distinguishing characters are, in fact, obtained by the action of alkalies upon fatty substances : the stearic, margaric, and (deic acids. The alkalies consequently trans- form neutral oily bodies into acid substances, as first shown by the admirable researches of M. Ciievreul, before whose time it was al- ways assumed that soap was the result f f a direct union of fatty matters with alkalies. The fatly acids a^ not the only products of saponification, there are several others, particularly glycerine, which, however, need not occupy us particularly here. The experiments of M. fhovreul would lead us to view all fjitty FATTY SUBSTANCES. 135 matters as combinations of glycerine playinor the part of a uase with particular acids ; these combinations, analogous to salts if their con- stitution be merely considered, are generally mixed together u; oils and fats ; thus the union of stearic acid and glycerine forms stearine, which is fusible at the temperature of about 62" cent. (144° Fahr.) Stearic acid melts at 72° cent., (162" Fahr.,) oleine remains fluid at 4° cent., (24° Fahr.,) and oleic acid is liquid. An oil is, therefore, by so much the more consistent as a larger quantity of solid fatty acid enters into its composition, and it is, on the contrary, by so much the softer and more liquid as this acid is itself more fluid. The wax of the Myrica cerifera, for example, is sufficiently hard to be reduced to powder, and is almost entirely formed of stearine. In the fluid vegetable oils oleine always predominates. It is easy to separate these different fatty compounds from one another. Besides the solid and li(juid acids which are obtained from fatty substances, there are others known which are volatile. Fatty bodies absorb oxygen from the air. This absorption is at first extremely slow, scarcely appreciable ; but once begun, it goes on with great rapidity ; so rapidly, indeed, that if a large surface be exposed to the air, if, for example, a quantity of rags or tow be im- pregnated with oil, the mass may take fire. The consequence of this oxidation is always a thickening of oil, and there are some which become completely solid in its course ; these are designated by the title of drying oils, and are in particular request for the manufacture of varnishes. Nut oil which has remained long exposed to the air acquires the consistence of jelly, and its unctuous properties have so entirely disappeared that it no longer stains paper. The alteration which fatty substances undergo in contact with air and moisture is still more remarkable. The oils which are inodorous and without taste soon acquire under these circumstances a strong smell and a disagreeable flavor. Fleshy fruits which contain a large quantity of oil, such as the olive and the oleaginous seeds, when moistened suffer true fermentation, the result of which is the sepa- ration of the fatty acids from the glycerine. Oils subjected to the action of a high temperature are also greatly modified. The glycerine which they contain is decomposed, and gives rise to various pyrogenous products : stearic acid is changed into margaric acid, and oleic acid into sebacic acid, a crystallizable volatile acid which is soluble in hot water. The fatty substances of plants are principally accumulated in the fruit, and particularly in the seed. In the herbaceous parts they are less abundant, less perfectly elaborated. Oils appear to be included in the vegetable tissue under the form of globules, or minute drops. In such an oily seed as the common almond, when it is growing, we perceive that the cellular tissue is in the first instance full of a col- orless and transparent fluid ; but as the seed advances, each cell is seen to become filled with numbers of little oil globules which in- crease continually in size and number until the kernel is ripe ; there is at the same time a quantity of azotized matter deposited in the midst of the liquid, which disturbs its transparency ; it is this depos- 136 FATTY SUBSTANCES. ite which thickens the walls of the cells.* The capillary forca which retains fatty principles combined with the tissue of certain seeds must be very considerable, for having boiled some rape-seed, which contained 50 per cent, of oil, in water, there was not a trace of oily matter perceptible upon the surface of the liquid. Butter appears to be kept diffused in milk by something of a similar force, for milk when boiled yields but a very small quantity of this sub- stance M. Dumas and I maintain that the oil of seeds is intended for the production of heat by undergoing combustion at the period of germination ; a series of experiments performed in my laboratory by M. Letellier supports this opinion. Having ascertained by a preliminary trial the quantity of oily substance contained in a certain weight of seed, some of the same kind was put to germinate, and the quantity of oil which it contained was tested at two periods of the germination ; it was found that in the course of this. process a considerable proportion of the fatty sub- stance had disappeared ; one gramme or 15.438 grains of rape-seed before germination contained 0.50 of oil ; after the first period of germination, namely, when the cotyledons had begun to turn green, the quantity of oil was found reduced to 0.43, and at the end of the second period, when the cotyledons had become quite green and the radicles were from 3.9 to 4.6 inches long, the oil was reduced to 0.28. It would be extremely interesting to ascertain the extreme loss which the oily principles of seeds sustained in the course of the commencement of vegetation, and to follow the return of the same principles in proportion as the plant advanced towards maturity. M. Letellier is going on with these experiments. The numl)erless uses to which oil is put, make its manufacture an object of the highest importance. Vegetable oils are generally ob- tained from olives, from oleasiinous seeds, and from the nut of cer- tain palms. Oil is separated by pressure ; it may often be extracted from the seed in the natural state, in which case the produce is of fine quality, but seldom abundant. The castor-oil bean, for example, yields its oil under the simj)le action of the press. In .\merioa, however, to obtain this oil, the seeds are first roasted slightly, and being bruised they are then boiled in water ; the oil readily sepa- rates from the roasted seed. A similar process is sometimes follow- ed in procuring cacao butter. In the extraction of oil from the common oleaginous seeds, they .ire first groinid or bruised in a proper apparatus ; the paste or pow- der which they now form is generally heated, and being put into woollen sacks, and these enclosed in hair bags, they are subjected to the operation of the press; after one pressure, the magma whi.'h remains in the bags is crushed anew, heated, and pressed again. The oil obtained by the second i)ressing is never so pure as thai procured bv the first. The oil-cake is taken out of the bags, completely dry in appear- nce, but it still contains a large proportion of oil — from 8 to 15 per • Dumas. Chemistry, vol. v. OIL. 187 3ent. of its weight. It is used in fattening cattle and as manure Oil, when newly expressed, is always turbid and very mucilaginous ; it becomes clear by standing ; but it always retains certain sub- stances which lessen its quality, particularly when it is intended for burning in lamps. Greater obstacles are encountered in extracting the oil from some of the pulpy fruits than from seeds. In extracting olive-oil, the olives are crushed under millstones ; and the paste which results be- ing put into flat baskets of wicker-work, is subjected to the press. The first pressing yields virgin oil, which is used for the table. Having removed the baskets from the press, their contents are mix- ed with a little boiling water, replaced, and pressed again, by which a new quantity of oil is obtained. But the pulp is not yet exhausted ; by special treatment it still yields a quantity of oil of inferior quality, which is employed in the manufacture of soap. The fruit of the palm yields the oil which it contains with great readiness. I have extracted a butter of excellent quality and very agreeable taste by simply boiling the nuts or berries of the Palma real in water. The cocoa-nut yields two qualities of oil, according to the mode of extraction. To prepare the best kind, the flesby part of the fruit is grated, and the pulp being pressed, a milky fluid is obtained, which yields the oil by boiling. An inferior quality of oil is obtained by causing the cocoa-nuts to putrefy ; when the putre- faction has advanced to a certain stage, the oily pulp is thrown into copper vessels and exposed to the sun, and the oil which then rises to the surface is skimmed off. This oil is brown, and has a strong smell ; it contains fatty acids which have probably been set at lib- erty by the putrid fermentation. The value of the produce in oleaginous seeds of a given extent of land, and the quantity of oil which these seeds will yield, depend, as may readily he conceived, on a variety of causes which it is not al- ways easy to appreciate with precision ; such as climate, the nature of the soil, the system of husbandry followed, &c. The observations of M. Gaujac of Dagny on the various plants usually cultivated for the sake of their oleaginous seeds, will however suflice to give a notion of their comparative productiveness in oil and cake : Crop. WINTER CROPS. Colewort Rocket Rape Swedish turnip.. Curled colewort. . Turnip cabbage.. SPRING CROPS. Gold of Pleasure Sunflower Flax White poppy .... Hemp Summer rape Seed produced per acre in Cwts. qrs. lbs. Whole quantity Oil obtained per cent. of Oil olnained Cake per Acre m lbs. avoird. per cent. 875.4 40 54 320.8 18 73 641 .G 33 G2 595.8 33 62 G41.6 33 62 505.4 33 Gl 5A:^.S 27 72 275.0 15 80 385.0 22 69 5no.8 46 .52 220.0 25 70 412.5 30 65 • 13* 133 OIL. M. Matthew de Dombasle made some compar£:ive experiments at Roville on the cultivation of oleaginous plants. The results obtain- ed by this skilful agriculturist are much less favorable than those of M. Gaujac. Instead of 19 cwt. and 15 lbs. of colevvort seed yield- ing 875.4 lbs. of oil per acre, M. de Dombasle only obtained 11 cwt. 2 qrs. 21 lbs. yielding 392.3 lbs. of oil ; and the other kinds of seed in proportion. But as I have said already, the fertility of the soil, and the labor and pains bestowed upon it, may have contributed to the differences observed, because here the influence of climate may be overlooked. There is one circumstance, however, which may explain the great differences in the quantity of oil obtained, which is the perfection of the press employed to extract it. In a general way oil-presses are so imperfect that they all leave a quantity of oil more or less in the cake. Here are two examples : from 2765 lbs. avoird. of fine cole wort seed, gathered in 1842, and weighing 52 j lbs. per bushel, I obtained : Ibt. Of oil 1130.5 Of cake 1384.9 Loss • 249.6 27G5.0 In Other terms, per cent. : Oil 40.81 Cake 50.12 Loss 9.07 lUO.OO but by a careful analysis of the same seed in the laboratory, 50 per 3ent. of oil was obtained. 2d. In 1840 and 1841, I made some experiments on the cultiva- tion of the madia sativa, intermixed with carrots in a fertile soil, well manured with farm dung. The crop of the year 1840 was ex- cellent ; it required one hundred and twenty-seven days to come to maturity. llx. Seed, husks deducted 2424 Dried le.ives employed ns litter 7700 Carrots without their leaves 31966 The seed gave : Of oil 635.8 Of cake 17067.6 100 of seed gave : Oil 26.24 Cake 70.72 Loss .33.4 100.00 These results agree pretty nearly with those which have been published by other agriculturiis ; but the seed of this madia, whicli in the press gave 26.24 of oil per cent., actually yielded 41 per cent, by analysis in the laboratory ; this dilference between practical re- sults and those of the laboratory, shows us how large a quantity of oil is generally left in the cake. When the cake is used for feeding OIL. 139 cattle, the loss is perhaps less to be regretted, inasmuch as the oily matter evidently assists in the fattening ; but wben the cake is used as manure, the oil which it contains is almost entirely lost. It is often of importance to the agriculturist to ascertain precisely the quantity of fatty principles contained in oleaginous seeds. For this purpose, it is enough to bruise a given quantity of the seed and to digest it in successive portions of sulphuric ether. After a first digestion, the seed is bruised or pul-verized anew, and the bruising is now accomplished without difficulty. The process may be con- cluded by boiling with a mixture of equal parts of ether and alcohol. The ethereal solutions are decanted from the seed into a porcelain dish, the weight of which is known. The ether evaporates sponta- neously and the oil remains, the weight of which is then taken. The following sums may be taken as a pretty accurate estimate of the average quantity of oil yielded by the different oleaginous seeds : cole wort, winter rape, and other species of cruciferous plants, from 30 to 36 and 40 per cent. ; sunflower about 15 per cent. ; lin- seed from 11 to 22 ; poppy from 34 to 63; hempseed from 14 to 26 ; olives from 9 to 11 ; walnuts 40 to 70 ; brazil nuts 60 ; castor- oil beans 62 ; sweet almonds 40 to 54 ; bitter almonds 28 to 46 ; madia sativa 26 to 28 per cent. The quantity of oil yielded by any seed subjected to the press is always considerably less than that which it contains, and the oil re- tained in the cake appears to be in larger proportion as the starch, the woody tissue, and the albuminous matters are more abundant. Thus maize, or Indian corn, which contains from 8 to 10 per cent, of fluid oil, gives mere traces of its presence under the press. The oily and fleshy fruits, such as those of the olive and the palm, yield a considerable quantity of oil. In the southern countries of Europe, particularly those which are so well protected that their olive-trees escaped the severe winter of 1789, as many as about 816 J lbs. of oil per acre are obtained, with proper care. The trees which were killed during this memorable winter sprouted again from the roots, and at the present day yield from about one quarter to one half the above quantity, accocding to the spaces left between them, which vary considerably. Under similar circumstances in regard to climate, it will readily be understood, that the quantity of produce will be influenced by the quantity of manure put into the ground. In some countries the olive is never manured, save indi- rectly ; that is to say, the ground between the trees is only manured with a view to another crop, which is grown between them ; in other countries, again, in the neighborhood of Marseilles, for instance, it is the practice to manure the olive plantations, directly, every three or fonr years. The olive enjoys remarkable longevity ; I have mentioned one more than seven centuries old, and the term of the tree's existence appears only to be limited by the severe winters which cause it to die, from time to time. The produce must of course depend upon the age of the trees which compose a plantation. Up to eleven y^ars, M. Gasparin shows that an olive-tree still remains all but un- 140 OIL. productive ; and that the capital, and the interest upon the capital expended in this husbandry, must necessarily exceed the value of the produce up to the thirtieth year. Yet there are soils which are favorable to the olive, and which are useful for nothino: else ; a hole in a rock suffices it, if the climate be favorable and it receive a proper dose of manure. But the grand cause of the disadvantages attending the cultivation of the olive, in France, is connected with the periodical occurrence of severe winters, which kill it ; in an interval of one hundred and twelve years, from 1709 to 1821, the olive plantations have suffered three great mortalities, which give a mean duration of about forty years to each planting. The cocoa-nut-tree is one of those which yields the largest quan- tity of oil with the least lalmr. The tree grows vigorously in all hot countries, at no great distance t'rom the sea-shore ; wherever the tem- perature is from 78° to 82° Fahr., there the cocoa-nut thrives. It is also found ou the banks of great rivers ; and the common practice in planting the cocoa-nut is to put a little salt in the hole. When trans- planted far from the banks of rivers, it thrives best in the neighborhood of human habitations, which has led the Indians to say that the cocoa-nut-tree loves to hear men talking under its shade. It is a tree which requires a soil impregnated with saline substances, and these are never wanting near the habitations of man. Tiie tree bears its first flowers at the age of four years ; it produces fruit the following year, and continues to fructify until it is eighty years old. The spikes generally bear about twelve cocoa-nuts, and the number of nuts yielded by a tree in the course of a year may be taken at about fiCtv, which will yield about four litres, or rather more than seven pints of oil. Somewhere about ninety trees are generally found upon the acre of land, and these are capable of yielding about 825 lbs. of oil annually* The cocoa-iuit-trce must, therefore, be regarded as an)ong the most productive in oil, and also as the plant which requires the least outlay in its cultivation. Many hpccu-s of palm yield oils of a very agreeable flavor for the table, and the produce of all answers admira- bly for the manufacture of soap. In the same proportion as agri- cultural industry extends in the eijuatorial regions of the globe, will the production of palm-oils increase, and this must necessarily in- fluence the cultivation of the olive in a very serious way. The cul- tivation of th(; tree being already threatened in Europe by that of the mulberry, and the prodigious extensi»)n in the trade in palm-oil upon the coasts of Africa in the course of the last few years, justify this conclusion. In 1817, palm-oil was considered as among the list of mere medicinal substances. At this period a London perfumer thought of making it into a soap for the toilet-table. Friuii this time it became the sta()le of a bartering trade, which has been by s(» much the more profitable to the natituis engaged in it, as the purchase is always efl'ected by manutactured articles, such as cotton and wool len goods, hardware and crockery, arms, powder, &c. The falurb • ("oiiaz/.i. Rcnunon de liv Ccografiji de la Venezuela, p. 133. ESSENTIAL OILS. l41 extent of this traffic may be imagined when it is known that in 1817 the importation of pahn-oil into England did not much exceed 140,000 lbs., and that in 1836 it exceeded 70,000,000 lbs ! In tak- ing an acre of surface for unity, I find that on an average the Spring oleaginous plants yield 3201bs. ofoIL Winter oleaginous plants 534 " The olive (south of Europe) 534 " The Palm (Ainerica) 801 " OF ESSENTIAL OILS. Aromatic plants owe the odors which characterize them to certain volatile principles, which by reason of certain properties which they have in common with fat oils, such as insolubility in water, solubility in ether and alcohol, inflammability, &c., are gen- erally designated as essential oils. They are met with in all parts of plants ; but in one plant the oil is principally found in the flower, in another in the leaves, in another in the bark. Sic. It sometimes happens that different parts of the same plant contain oils of different kinds. From the orange-tree, for instance, three distinct oils are obtained, as the flower, the leaf, or the rind of the fruit is treated. In some cases the volatile principle is so thoroughly imprisoned in the vegetable cells, that drying does not dissipate it ; in others, as in the greater number of flowers, the oil is formed on the surface, and is volatilized immediately after its- formation. Essential oils are less volatile than water ; nevertheless they rise with the vapor of water, and it is by distillation that they are gen- erally extracted. The plant is put into a still or alembic containing w^ater, and heat is applied : the vapor formed is condensed in the receiver, and the es:^ence, by reason of its less density, is found swimming on the surface of the water which has been distilled. Some volatile oils are obtained by pressure, those of the citron and bergamotte, for example. • The volatile principles of plants present somewhat varied physical properties. They are generally limpid and lighter than water ; yet there are some which are more dense, and some, such as camphor, .which are solid. With reference to their composition, volatile oils may be divided into three classes ; 1st. Oils composed entirely of carbon and hydrogen. 2d. Oils composed of carbon, hydrogen and oxygen. 3d. Essential oils containing sulphur ; in addition to which, the essential oil of mustard seed contains azote. The essential oils undergo a change by long contact with the air : they absorb oxygen, ani many of them become acidified ; under the influence of this gas, the oil of bitter almonds is changed into ben- zoic acid, the oil of cinnamon into cinn-amic acid ; in a general way, acetic acid is produced. The volatile oil obtained from any plant almost always contains two distinct principles, which may be separated by careful distillation ; one of these principles is a car- buret of hydrogen, the other an oxygenated oil.. Camphor is com- bined with essential oils in many plants of the labiate family. It 142 RESINS. exudes from certain laurels ; it is from the Laurus camphora that all the camphor of commerce is extracted in the East, the extraction being eifected precisely by the same process as other essential oils. The chips of the Laurus camphora are put into iron stills, surmount- ed by earthenware capitals, in the inside of which a number of ropes made of rice-straw are stretched ; the camphor rises and is condensed on the surface of these cords in the state of a gray pow der ; it is refined by sublimation. According to M. Dumas, camphor contains : Carbon 79.2 Hydrogen 10.4 Oxygen 10-4 100.0 OF RESIN. Essential oils almost always hold certain substances in solution which make them viscid or sticky. The balsams which exude from the bark of certain trees are nothing more than sokitions of resin in essential oils. When the volatile oil has been dissipated by evapo- ration, the resin remains in the solid state. There is further a nat- ural relation in point of constitution between essential oils and resins. The greater number of essences absorb, as we have said, oxygen from the atmosphere, and by this absorption they become thick, and are changed into resins ; so that in one case the resin may be a product of the oxidation of an essential oil, in another it may merely be set at liberty by the dissipation of the essence which held it in solution. The resins constitute friable, or soft solids. They are fusible, extremely inflammable, and fixed. The resins are inodorous when pure : any odor which particular resins possess is generally attrib- uted to the essential oil which they still retain. The resins are in- soluble, or very sparingly soluble in water ; some of them dissolve readily in alcohol and in ether, and there are some also, su(!h as copal, which are only soluble in very small quantity. Some resins- show acid reaction ; they combine with bases, neutralizing thf.'m. The greater number of resinous matters obtained from plants are regarded by chemists as mixtures of several particular resins, the^ study of which is not ye* much advanced. Some resins are much* employed in the arts, such as colophony and copal, &c. Several balsams are also in familiar use, particularly as medicines, such as the balsam of tolu, balsam of copaiba, &c. Colophony, or rosin, is extracted from difl^erent kinds of the genus Pinus. In the Landes, or sandy plains of Bordeaux, it is the mari- time j)ine which yields it. When the tree is from thirty to forty years of age, incisions are made in the trunk, beginning at the lower part, two or three times a week, and these are continued to iho height of from 6 to 10 feet from the ground ; the last notch general- ly reaches this height about four years after the tree has been ntUch- ed for the first time. After this a new series of notches is brgun on the opposite side, setting out from the ground as before, and in VEGETABLE WAX. 143 this way the whole circumference of the tree finally presents a series of notches, so that a tree will continue to yield turpentine during a period of sixty years. The turpentine which exudes from the notches is collected in a hole dug in the ground. Crude turpentine always contains a quantity of intermixed foreign matters, earth, stones, leaves, &c. It is purified by being melted, and filtered hot through a bed of straw. By distillation it is separated into essential oil, which is condensed in the receiver, and colophony, or rosin, which remains in the still. From 250 lbs. of turpentine 30 lbs. of essence and 220 lbs. of rosin are generally obtained. Copal is the produce of a tree which is somewhat common in Madagascar, and which M. Perrotet has determined to be the //y- menaa verrucosa. The balsam or sap which exudes from the bark solidifies by contact with the air, and the resin is gathered in the state in which it is met with in commerce. CAOUTCHOUC. The caoutchouc which we have mentioned as forming a constituent in the sap of certain trees possesses some properties which assimi- late it with the resins. Thus pure ether, free from alcohol, dis- solves it. The greater number of the essential oils also dissolve it, particularly when hot. It is a solution of Indian rubber in rectified coal-tar oil or naphtha, which is now used so extensively for making stuffs water-proof. According to Faraday pure caoutchouc is composed of : Carbon 87.2 Hydrogen 12.8 ■ 100 VEGETABLE WAX. Some plants produce a considerable quantity of a substance which bears a great resemblance to beeswax, and which in some of its properties approaches fatty bodies. Proust discovered that vegeta- ble wax formed part of the green fecula of a great number of vege- tables. In the common cabbage it occurs in large quantity. It is often met with forming a varnish on the surface of leaves, fruit, and barks ; the substance, however, is far from being identical ; it al- most always results from the combination of several distinct princi- ples which have not yet been sufficiently studied, but among which there are obviously some true fatty substances, that is to say, bodies capable of saponification, and matters analogous to the resins. I shall here mention a few of the vegetable waxes which are best known. Wax of the palm. This is the product of the Ceroxylon andicola^ which is very abundant on the central Cordillera of New Grenada. I believe that I met with the Ijower limit of the ceroxylon upon the borders of the torrent of Tochecito, at the height of 7500 feet above the level of the sea, and I followed it to an absolute elevation of about 8500 feet. The extreme mean temperatures comprised be- 144 VEGETABLE WAX. tween these two limits may be valued at from IT to 18" cent. : 51.8° to 64.4° Fahr. Towards the superior limit, the ceroxylon is exposed to a cold durino^ the night, which approaches the freezing point of water ; it is therefore frequently met with in company with the great oak of x^merica, whose climate it stands very well. The Indians obtain the wax by scraping the bark of the palm : the scrapings are then boiled in water ; the wax swims — without, however, melting ; it is merely softened, and the impurities which it contains are deposited. The matter thus purified is formed into balls and set to dry in the sun. It is with this substance, to which, however, a small quantity of fat is often added to render it less brit- tle, that the loaves of wax and the candles of the country are form- ed. After it has been melted, the cera de palma is of a deep yellow color, slightly translucid, as brittle as resin, and presenting a waxy fracture well characterized. Its melting point is a little above that of boiling water. Boiling alcohol dissolves it readily ; in cooling, the solution sets into a gelatinous mass. Ether dissolves it, as do the alkalies also. The wax of the palm consists of two principles; one, fusible above the temperature of the boiling point of water, has all the physical properties of beeswax ; the other has the properties of resin. The composition of these substances upon analysis appears to be : Wax. Rftin. Carbon 81.6 83.7 HydroRcn 13.3 11.5 Oxygen 5.1 4.8 100 100 Wax of the Mi/rica cerifera. This wax is procured by boiling the fruit of several species of myrica in water. The tree is ex- tremely common in Louisiana and the temperate regions of the Andes. The fruit yields as much as 25 per cent, of wax, and a single shrub will yield from 24 to 30 lbs. of berries per animm. The crude wax is green, brittle, and, to be made into candles, requires the addition of a certain quantity of grease. According to M. Che- vrenl the wax of the myrica is saponifiaMe. Wax of the suirar-cauc. The sugar-cane, particularly the violet variety, is covered with a powder or bloom of a waxy nature, which melts at the temperature of 82° cent. (180' Fahr.) This wax is so hard that it can be pulverized ; it may be made into candles, which, for the brilliancy of their light, are not inferior to those of sperma- ceti. M. Avequin, who directed attention to this subject, found by his experiments that a hectare (nearly 2} acres English) of the violet cane would furnish nearly 200 lbs. of wax. This wax is entirely soluble in boiling alcohol ; ether does not dissolve it in the cold. It appears to constitute a perfectly defined inmiediate vege- table principle, the composition of which, according to M. Dumas, is the following : Ciirhon 81.4 Hydroffon 14.1 Oxygen 4.5 100 COLORING PRINCIPLES. 145 CHLOROPHYLLE. The green matter which colors the leaves of vegetables is so designated. The attempts which have been made to isolate this matter, render it probable that it is somewhat of the nature of the vegetable waxes. Pelletier and Caventou endeavored to procure it by treating with cold alcohol, the pulp remaining after expressing all the juices from the leaves of various herbaceous plants. By evaporation of the alcoholic liquor, a substance of a deep-green color was obtained, which is chlorophylle, a matter soluble in ether, in al- cohol, the oils, and the alkalies. Heated, it softens and is decom- posed before it melts. Acetic acid dissolves it in very appreciable quantities, so do the sulphuric and hydrochloric acids ; water precipi- tates it from these acid solutions. Berzelius says that chlorophylle exists only in very small quantity in plants, the leaves of a large tree will not perhaps contain more than about 100 grains. OF COLORING MATTERS. The matters which color the different parts of plants are extreme- ly numerous ; they present great varieties of shade, but are in gen- eral derived from red, yellow, and green. It is seldom that the col- oring matter of a plant exists isolatedly ; it is almost always allied with one or several immediate principles, which are themselves fre- quently colored. Thus red coloring matters are generally combined with yellow principles, which having nearly the same properties, one is with great difficulty separated from another. Coloring matters are solid, inodorous, and have little taste. Some are soluble in water, others only dissolve in alcohol or in ether. All combine with the alkalies, and several of them unite intimately with acids ; the greater number are powerfully affected, undergo a true destruction, on exposure to the sun's rays, especially when in contact with moist air. It is familiarly known that vegetable tissues of all kinds, beeswax, &c., are bleached by exposure to the sun and air ; a high temperature acts like light : some vegetable colors are altered, bleached, when they remain exposed for a time to a tem- perature of from 334° to 424° Fahr. The oxygen of the air, which so quickly destroys certain colors, develops others under particular circumstances. x\lkalies and acids, by uniting with vegetable colors, almost al- ways modify their tints and often change them entirely. Many blues, for instance, become reds, under the agency of acids, greens or yellows under that of alkalies. By neutralizing the acid or the al- kali, the color generally resumes its original tint. Several substances, which are colorless in the state in which they are formed in vegetables, become colored by the united action of oxygen and an alkali, such as orceine, which is oxidated and be- comes blue under the simultaneous contact of air and ammonia. The greater number of vegetable coloring matters are destroyed 13 146 INDIttO. and bleached by chlorine. Many of the same matters unite inti- mately with alumina and oxide of tin to form lakes, insoluble com- pounds in which the colors remain fixed ; thus a colored liquid often becomes colorless when it is shaken with a hydrate of alumina. Charcoal, in a state of extreme subdivision, acts like alumina, and is a powerful discharger of colors in every-day use in the arts. Coloring matters are generally ternary compounds, though some of them also contain azote ; and several of them exhibit the remarka- ble phenomenon, that in undergoing oxidation in contact with am- monia they assimilate the azote of this alkali. I shall now indicate the origin and the mode of preparing a few of the more important of these coloring matters. Indigo. This substance, so essential in the art of dyeing, has been one of the great staples of trade with Asia from the most remote times. For a long wliile indigo was regarded in Europe as a min- eral substance found in India ; it used to be designated Indian or In- dia stone, whence the name of indigo. It was not until after the dis- covery of America that the true nature of this dye-stuff was known, although before this period indigo had been made in Arabia, Egypt, and even in the Island of Malta. Indigo is volatile, so that to obtain it pure, it is enough to put a small quantity into a platinum capsule, to cover it with a lid and to expose it to heat. Indigo is volatilized in the state of violet-colored vapor, and collects in crystals upon the middle part of the sides of the capsule. Indigo gives nothing to water or to ether. Alcohol takes up a very small quantity of it ; concentrated sulphuric acid dissolves and modifies it. All bodies greedy of oxygen appear to reduce or deoxidize this coloring principle ; it changes to a yellow, and becomes soluble in water -in contact with alkalies ; by expi»sing the alkaline liquor charg- ed with the uncolored indigo to the air, it absorbs oxygen rapidly, and the indigo becomes insoluble and is precipitated with its original blue color. It is most easy, as said, to disoxidize indigo; it is suf- ficient t J bring it into contact with hydrogen gas in the nascent stale, a condition which is readily secured by throwing iron or zinc filings into water containing the coloring matter previously dissolved in sulphuric acid. The disengagement of the hyilrogen has scarcely commenced before the deep-blue color of the solution declines in intensity, anil by and by it.becomes of a very pale gray. When the discharge of color is completed, and no more hydrogen is disengaged, the colorless indigt) begins to react uj)on the air, it absorbs oxycen, becomes again oxidized, and by and by the liquid has resumed its deep blue. This property of indig«) of becoming soluble in alkaline solutions under the influence of disoxidizing bodies, is taken advan- tage of in our laboratories to obtain indigo in a state of purity, and in the arts to prepare a dyeing liquid. If a mixture be made of 15 parts of the indigo of commerce reduced to line powder, 10 [)arts ot the sulphate of the protoxide of iron, 15 parts of lime, and 00 parts of water, and it be left for several days in a closed vessel, a color- less liquid is obtained. The liquid decanted and exposed to the air INDIGO. 147 deposites the whole of its indigo after a time. It is with similar in- gredients that the dyer prepares his bath for blue colors. It is into the alkaline liquor so prepared that the stuff to be dyed is dipped ; it is then hung up in the air, where it soon becomes blue ; it is re- d'ipped and re-exposed again and again, until it has acquired the depth of tint required, after which it is washed. The indigo, re- generated bj the action of the air, remains fixed in the stuff, and proves, as all the world knows, one of the most solid of colors. Chemists are not agreed as to the true nature of colorless indigo which may be obtained in the solid state. Some regard it as indigo disoxidized, others as indigo hydrogenized. On the latter supposi- tion, the hydrogen fixed would be derived from the water decom- posed, the oxygen of which would be transferred to the bodies greedy of this element, which are brought into play. The latter of these views appears to have the ascendant at the present time. However this may be, the following is the composition of indigo in each of its states, as determined by M. Dumas : Blue Indigo. White Indigo. Carbon 73.1 73.0 Hydrogen 4.0 4.5 Azote 10.8 10.6 Oxygen 12.1 11.9 100.0 100.0 The plants which have hitherto been cultivated for the production of indigo with any profit are not numerous ; they belong to the genera Indigofera^ Isatis et Nerivrn; it is the genus Indigo/era which is most generally cultivated, and the species designated argentea is found to be the most profitable. M. Chevreul has ascertained that in the living plant the indigo is not colored, and that it is consequently during its extraction that it becomes blue. The experiments of M. Pelletier upon the Polygonum tinctorium have confirmed the old re- searches of M. Chevreul. After having dried a leaf, Pelletier di- gested it with ether in a closed flask. The whole of the chlorophylh was dissolved, and the leaf became completely blanched ; by expo sing it afterwards to the air, it turned blue if it contained indigo. In the republic of Venezuela, where I had an opportunity of study ing the cultivation of the indigo-bearing plants, I saw that those so'\\\* were preferred which were light and susceptible of irrigation, & condition indeed which seems to me all but indispensable to the pro- fitable exercise of agriculture within the tropics. Indigo requires a warm climate ; at an elevation of about 3250 feet English above the level of the sea, where the mean temperature is not more than from 72° to 75° Fahr., the indigo husbandry cannot be carried on w.th advantage. Nevertheless, the Indigofera sylvestris is met with at an elevation of about 4900 feet above the level of the sea; but the at- tempts that have been made to obtain coloring matter from the plant have proved fruitless. In the valley d'Aragua, where the best plan- tations are met with, the plant is sowed in lines, the holes destined to receive the seed being about If inch in depth, and somewhat more than 25 inches apart. A pinch of seed is dropped into each 148 INDIGO. hole, and is covered with a little earth. The sowing takes place in soils that are moist but well drained, or in situations generally which have no system of irrigation at the period of the first rains. The seeds shoot in the course of the first week ; hoeing is performed in the course of the month. The first cutting takes place when the plant is coming into flower ; from fifiy to sixty days generally inter- vene between the sowing and this cutting ; but the time necessary for the development of the leaves depends of course upon the cli- mate. In the neighborhood of Ma; acaibo, where the mean tempera- ture is about 78" Fahr., the gathering does not take place before the third month. The second cutting is performed from 45 to 50 days after the first ; and in this way several successive crops are obtained, until it is seen that the plant begins to degenerate In good soils the indigo will last for two years ; in soils of inferior quality the crop is generally annual. The indigo harvest is immediately transported to tanks or large rectangular reservoirs built of masonry, and disposed on different levels, the superior reservoir or steeping tank being much larger than the two others. In the valley d'Aragua, there are some which are upwards of 20 feet long by 15 feet wide, and 20 inches in depth. The second, or mashing tank, is narrower and deeper than the for- mer. The third reservoir, or depositing tank, receives the liquor from the mashing tank, and in it the indigo subsides. In some manu- factories the thini tank is not used, the deposition taking place in the mashing tank itself. The leaves, as the name implies, are thrown into the steeper, covered with water, and kept down by planks loaded with stones ; fermentation soon begins, and is allowed to continue during about eighteen hours; and in the management of this first operation lies much of the art of the indigo-maker. By continuing it too long some portion of the coloring matter is destroyed ; by stopping it prematurely, a quantity of indigo is left in the leaves. The fermen- tation judged to be sufiicicnlly advanced, the liquor is run otT into the battery, and vigorously stirred until the gram is deposited. The fluid is then either let into the subsider, or left in the battery, and the deposition is complete at the end of about twenty hours ; the supernatrnt lluid is drawn ofl", and the indigo paste is scooped out and placed upon cloths to drain When sulficiently firm, it is dividec^ into lumps, and these are set in the shade to dry. In the valley d'Aragiia it is estimated that with a good soil and careful manage- ment, each hectare of surface will yield 280 lbs. of marketable indi- (jo,* which is at the rate of about H2\lbs. per English acre. In Carolina the cultivation of indigo appears to be much less pro- ductive than in the equinoctial regions, atjtl the produce is of inferior quality. There they sow in drills in the comuirncement of the rainy season which follows the vernal equinox, and the first crop is gathered about the beginning of July ; the second is secured two months afierwanls, and when tiie autumn is mild, a third but insig- • Cudozzi, Rcsumin dc la Gfocriitia lU- V«MiozucI:t. p. 14-1. INDIGO. 149 nificant gathering takes place at the end of September. One negro is allowed to be able to work nearly two acres and a half of ground, from which about 160 lbs. of indigo are obtained. In the East Indies, upon the Coromandel coast, the growth of in- Jigo takes place upon sandy soils which are not irrigated, and in which vegetation is only possible during the rainy season. The loamy soils that admit of being irrigated are almost always reserved for the growth of rice. Immediately after the rains have set in, in December, the land receives two superficial ploughings ; the indigo is sown broad-cast, and the seed is harrowed in by dragging a fagot of bamboos over the surface, or by treading in by means of a flock of sheep. The first and principal gathering takes place in March ; any other crop that may be won is purely casual, and entirely de- pendent on the rain that falls. The crop rarely fails to feel the effects of the droughts which so frequently take place upon the Coromandel coast. It is never abundant, and the plants have little vigor. The harvest takes place after the flowering season. The crop is dried in the sun ; the plant is then beaten with switches, by which the leaves are detached from the stems, after which hey are exposed anew to the sun to secure their being perfectly dry. They are then reduced to coarse powder, and handed over to the' indigo- maker, for in India the planter is never himself the manufacturer of the dye-stuff. On the coast of Coromandel, indigo is always extracted from the dried leaves, which, bruised and broken, are infused in three or four times their bulk of cold water during two or three hours ; the infu- sion is then filtered through a loose stuff made of goat's hair ; the filtered liquor is beaten for two hours, and after this about five gal- lons of lime-water are added for every 100 lbs. of dried leaves ; the mixture is stirred, and then left to settle. When the deposite has formed, the supernatent liquor is drawn off, the sediment is washed with a little boiling water, and being thrown upon a cloth, the indigo is drained and dried. It is then pressed, and the paste is cut into cubical lumps which are thoroughly dried in the air, and of which each weighs nearly 3 ounces. In the Indian method of manufacturing indigo, all is accomplished, as appears, without fermentation. This indigo is little esteemed in commerce ; it is heavy, of a pale blue, without much of the coppery aspect, rough on the broken surface, and presents here and there white points and vegetable debris. An acre of land on the Coro- mandel coast will produce from 48 to 49 lbs. of indigo annually. In spite of the high price of indigo, so small a quantity would scarcely cover the cost of production, were not the wages of the Indian laborer exceedingly low. The whole expense of producing a kilogramme, or 2^^ lbs. avoird. of indigo, according to M. Plague, amounts to 3 francs, 20 cents, or about 2s. 8d. The cultivation of the indigo plant has been attempted several times in the south of Europe, particularl}'^ in Spain and Italy. There is no doubt but that indigo may be grown in Europe in those situations where for three or four months of the year the tempera- 13* 150 ORCHIL. ture is truly tropical ; but it seems probable that indigo can never be advantageously introduced into the agriculture of temperate coun- tries. Before indigo was so extensive an article of commerce as it is now, the south of France used to furnish almost all the markets of Europe with a blue dye, which was the best then known ; this was woad or pastel, the produce of the Isatis tincloria. The isatis is sufficiently hardy to stand the cold of winter. In the south it is sown in March, and the seed springs in from eight to ten days. When the plant has five or six leaves, it is hoed with care. The crop is gathered when the leaves have acquired their greatest size, when they even begin to fade a little. The prepara- tion of woad bears a certain resemblance to that of indigo, and need not detain us here. The Pohjgonum tinctorium has of late attracted the attention of European cultivators. The plant is a native of China, where it has been cultivateil from time inunemorial ; it was brouirht into France and propagated under the care of M. de Lille. In the course of three months the plant has thrown out all its leaves, and in the south of France it never fails to ripen its seeds. Fron) sl ii. \». 2^ SAFFRON. 153 Besides its roots, madder yields an abundance of leaves which are excellent forage. Reseda luleola, or dyers' weed, is a plant in common use, and owes its properties as a dye-stuff to the presence of a yellow crystalline principle, luteoline, discovered by M. Chevreul, This substance is soluble in ether, alcohol, and alkaline solutions. Dyers' weed is sown in autumn, stands throug-h the winter, and ripens in the month of August following. The plant is gathered when it begins to turn yellow, and it is in a marketable state after it is dried. An acre of land will produce about 1833 lbs. weight of marketable dye-weed. Saffron. This plant is cultivated in the south of France and in Austria, but appears to be a native of Asia. Saffron requires a light and yet fertile soil in order to produce abundantly, although it may also be cultivated in soils of middling quality. The ground, trenched one spit deep, is set out with bulbs from an old plantation. In the south the transplanting takes place in the month of June. The first flowers appear towards the middle of October; they are few during the first year. They are gathered, and the pistils removed ; the gathering continues for about a fortnight. In the course of the year which follows the planting, the ground receives a surface dress- ing ; it is freed from weeds, and the withered leaves are removed. The next gathering takes place at the same period as the former, but the flowers are now much more abundant, and the same process is continued until the roots are taken up, which they are in France at the end of the second year ; but in Austria the culture is contin- ued for a much longer period in the same piece of ground. The extraction of the pistils is an occupation in which the whole family of the saffron-grower take part, and employ their evenings ; in the course of an evening of five hours, eight persons will generally have drawn 250 grammes or about 8 ounces of saffron In some places the pistils are dried in the sun, in others by being exposed in a sieve over a fire of twigs ; the latter process appears to be the better one. M. de Gasparin estimates at about 110 lbs. the saffron which is gathered in the course of two years from about 2,Vths acres of land ; this would give a mean annual produce of about 43.7 lbs. per Eng- lish acre, and the price of saffron being from 27 to 28 shillings per pound, the value of the produce may easily be reckoned. In Aus- tria, where the crop is allowed to occupy the ground for three years, the produce has been estimated at about 19| lbs. per acre per annum. Roucou is a dye-stuff extracted from the fruit of the Bixa orel- lana, a tree which is extremely common in the hot regions of South- ern America. Chica. This and the former dye-stuff are in use among the na- tive Americans for staining the skin. It is obtained from the leaves of the Bignojua chica, which are of a beautiful green when fresh, but become red by drying. Chica has the color of cinnabar: it is without taste and without ftmell : a mass of this pigment may be compared to a mass of indigo 154 THE POTATO. It only differs from this substance in its color. Like indigo, it ac- quires the metallic polish when rubbed with a hard body. It dis- solves in alcohol, and in alkaline solutions ; it mixes readily with grease, and it is with such a mixture that the Indians paint their bodies, Chica has been employed in cotton-dyeing, and the color is found to stand the sun perfectly. § II.— COMPOSITION OF THE DIFFERENT PARTS OF PLANTS The immediate principles, the history of which has now been sketched, are met with in greater or lesser quantities in different parts of plants ; some of them are accumulated in the roots, others in the seeds, the barks, the leaves, &c. To complete the study of the chemical constitution of vegetables we have still to examine with reference to their composition certain parts or organs which present sutTicient interest either from their extensive employment or their importance in an agricultural point of view. ROOTS AND TUBERS. The Potato, {Solarium tuberosum.) This plant is a native of South America. Two English travellers, Messrs. Caldcleugh and Baldwin, were so fortunate as to meet with it lately m the vild slate in Chili, and not far from Monte Video, it is probable that the culti- vation of the potato spread from the mountains of Chili to the chain of the Andes, proceeding northward and obtaining a footing suc- cessively in Peru, at Quito, and upon the plateau of New Granada. This, as Humboldt observes, is precisely the course w hich the Incas took in their conquests. The potato does not appear to have been introduced into ^loxico until after the European invasion of that country ; and it is well ascertaineil that it was not known there un- der the reign of Montezuma, although there are not wanting some who maintain that the potato was found in ^'irginia by the first colo- nists sent thither by Sir Walter Raleigh. It is said that it was then brought into England by Drake ; but it seems well established that long before Drake's lime, namely, in 1515, a slave merchant, John Hawkins by name, had introduced tu!)ers of the potato from the coasts of New Granada into Ireland. From Ireland the new plant I)assed into Belgium in 1590. Its cultivation was at this time neg- lected in Great Britain, until it was introduced by Ruleigh at the beginning of the seventeenth century. \N'hen the j)()tato came from Virginia to Enghind for the second time it was already disseminated over Spain and Italy. It has been ascertained that the potato has been cultivated on the great scale in Lancashire since 1681 ; in Saxony since 1717 ; in Scotland since 1728 ; in Prussia since 1738.* ♦ Hunilinldt, Essai Poliliqno, t. ii. p -Jti' THE POTATO. 155 l\ flras about the year 1710 that the potato began to spread in Ger- many, and that it there became a plant in common use ; it had, in- deed, before this time been cultivated in gardens ; and had even made its appearance at the tables of the rich some time previously. Tlie severe dearth of the years 1771 and 1772* seemed necessary to lead the Germans to cuUivate this useful plant upon the great scale. From this time it was shown that it was a substitute for bread ; and once fairly introduced, men were not long of perceiving the many recommendations which it possesses as an article of food. In fact, of all the useful plants which the migrations of communi- ties and distant voyages have brought to light, says M. Humboldt, there is none since the discovery of the cereals, that is to say, from time immemorial, which has had so decided an influence upon the well-being of mankind. In less than two centuries it may be said literally to have overspread the earth, or to have been welcomed in every country suited to its cultivation, so that at the present day it is found growing from the Cape of Good Hope to Iceland and Lap- land. " It is an interesting spectacle," adds the illustrious traveller quoted, " to see a plant, a native of mountains situated under the equator, advance towards the pole, and growing even more hardily than the grasses which yield us grain, brave the inclemencies of the North."! The potato, like all other tubers, is a collection, an exu- berance which is evolved upon the subterraneous stems. Its varie- ties, which are very numerous, present rather remarkable differences in regard to size, form, color of the surface and of the interior, taste, and the time which they require to come to maturity. Next to water, fecula or starch is the principle which predominates in the potato, but it also contains a certain quantity of azotized mat- ter. Vauquelin has published a detailed account of the soluble mat- ters which are met with in the potato, and which, strange to say, have been neglected in the greater number of analyses of this useful vegetable which have been published. In 100 parts of potatoes he found : asparagine 0.1, albumen 0.7, azotized matter not defined 0.4, citrate of lime 1.2, and undetermined quantities of citrate of potash, free acetic acid, phosphate of potash, and phosphate of lime. In examining forty-eight varieties of potato he found that they contained in 100 parts : first, from 1 to 1| of pulp ; second, from 2 to 3 of soluble or extractive substances ; third, from 20 to 28 of starch ; fourth, from 67 to 78 of water. | In a variety grown in the neighborhood of Paris, Henry found the following ingredients, viz : pulp 6.8, starch 13.3, albumen 0.9, un- crystallizable sugar 3.3, acids and salts 1.4, fatty matter 0.1, and water 74.2=100.0. The proportion of starch varies considerably in the diflferent va- rieties ; M. Payen has ascertained the extent of this diversity in a certain number of varieties grown in the same soil and under the * Thaer, Principes raisonnes (rAgriculture t. iv. p lift. t Humboldt, op. cit. t. ii. p. 463. t Thdnard's Chemistry, vol. v. p. 82. 1.j6 THE POTATO. same circumstances. The results are contained in tlie following table : VarietfeB. One of seed potatoes JuceJ. j In 100 parts. i t Starch. Starch per Acre. i Produce per Acre. i Dry matter. Water. The Rohan The great yellow . The Scotch shaws The late Iceland . • The Segonzac The Siberian The Duvillers 58 37 32 56 32 40 40 tons. cwts. qrs. lbs. 14 14 2 16 24.8 9 8 0 27 31.3 8 3 2 2 30.2 14 6 1 23 20.6 8 3 2 2 28.8 10 4 2 12 22.2 10 4 2 12 21.7 75.2 68.7 69.8 79.4 71.2 77.8 78.3 ' tons. cwt. qrs. lbs. 16.6 2 9 0 12 23.3 12 3 3 4 22.0 1 16 0 1 12.3 1 15 1 2 20.5 1 14 0 5 14.0 i 1 8 2 16 13.6 1 1 8 0 12 In the particular circumstances under which this experiment was made, therefore, it is obvious that the Rohan variety contained the lartrest quantity of nutritive matter and starch. Potatoes which have been exposed to a temperature a few degrees bolow the freezing point of water, undergo so great a change in their texture, that it becomes dillicult afterwards to extract the starch which they contain. Tliey besides acquire so disagreeable a flavor, as all the world knows, that cattle sometimes refuse to eat them. After having ascertained that a potato has the same chemical com- position before and after congelation, M. Payen examined the starchy siibstance under the microscope, and found that the starch obtained from a frozen tuber presented itself in compound granular masses. four or five times the size of the largest natural grains of starch. 'rii(3 pulp which remained upon the sieve in the preparation of thi.s starch, was formed by a collection of cells, for the most part full of starch. It would therefore appear, that in consequence of iho changes of volume of the tluid successively congealed and liquefied y\\v. adhesion between the cells was destroyed : they become separa- l)lc with the slightest force, ant! merely part one from another by ilie action of the grater without being torn ; the larger number re- MKiin unbroken and still filled with starch. This fact enables us to understand how potatoes, which have been frozen, will yield nearly ihc whole of their starch if they be treated before they are thawed. The cells then sealed up by the congealed water resist suflicienlly to be broken by the teeth of the grater. Potatoes which have been iVozen, are generally less farinaceous, at the same time that they have a decidedly sweet taste, which, according to M. Payen, is owing to vegetation having already made some progress in the tubers before congelation ; and we know that durmg germination there is always a formation of sugar at the expense of the fecula. Frosted potatoes have always a disagreeable taste, and a most unpleasant smell, so that in many places they are thrown upon the dunghill. The elfecl of the frost, in fact, is to set the juices which are enclosed in the tissue of the potato at liberty, and the higher temperature which ac- companies Tiid tnllows a thaw, exposes those juices to he acted upon THE POTATO. 157 immediately by the air of the atmosphere, the consequence of which is. that they behave like all other veo^etable juices left to themselves, they become putrid. The putrid odor and the acrimony which are developed in the frosted potato, are by so much the more remarkable as a certain layer which exists immediately under the skin, and pre- sents various shades of color, tawny red or violet, is more highly developed. The tissue of this layer, examined under the micro- scope, was found by M. Payen to be totally without starch, but it contains the greater part of the (strong-smelling) coloring principles.* - These principles, which give such unpleasant qualities to frosted potatoes, appear to be soluble, or at least destructible by long expo- sure to the open air. Thus, if frosted potatoes be spread upon the groimd and exposed to the weather, they dry spontaneously, become hard, whitened, and they may then be preserved for a very long time. This method of making use of frosted potatoes has been several times employed in practice, and it might perhaps be recom- mended for general adoption, were it only ascertained that by such treatment the tubers did not lose a great proportion of their most nutritive principle, viz. albumen. However this may be, it is by a similar process that the natives of the Andes of Peru preserve and render more transportable the tubers which form a principal element in their food. In the steepest parts of the Peruvian Cordillera, nearly at the superior limit of vegetation, where a miserable field of barley and of Quinoa is only seen here and there, various tubers are collected in the hollows of the surface, such as the Mdca, the Oca, the Ulluco. To preserve these they are exposed for several days to the alternate action of the frost and of the sun. At these great elevations, which are upwards of 13,120 feet above the level of the sea, it always freezes in clear nights when the air is moderately calm. During the day the rays of the sun, which strike with great lorce, dry the tubers rapidly, the watery juices of which have been shed into the amylaceous tissue by the effect of the preceding night's frost. Thoroughly dry, they may be kept for more than a'yea" by being stored and protected from moisture. Various other modes of preparation are practised in regard to the other kinds of tubers which have been mentioned. By previously boiling the common potato, pealing it, and exposing it alternately to the'frost of the night and the heat of the sun, until it is completely dry, the Indians prepare one of their most agreeable and wholesome articles of subsistence. The potato thrives in soils of very various kinds, provided it be sufficiently fertile, and the climate is favorable. This crop, like the beet, is generally planted in freshly manured ground, and is suc- ceeded in the autumn by a winter crop of corn — wheat or rye. The potato is set when apprehensions of frost are no longer entertained ; in the east of France the setting is generally ended about the mid- dle of May. In Alsace the cuttings of the potato are dropped at the distance of about a foot from each other in furrows made by the plough, the furrows being from 18 inches to nearly 2 feet apart. * Payen, Journal of Practical Agrimlture, vol. i. p. 498. 14 158 THE POTATO. When the plants are from 10 to 12 inclies high, and the weather is dry, the furrows are lightly earthed up. In dry soils the earthing plough must not be carried very deeply ; and I may say that in the elevated table lands of America, where the natural drought of the climate is often to be apprehended, I have seen very fine crops of potatoes which had never been earthed up at all. The potato, like all plants that are hoed, requires considerable care ; but this care, as it is immediately profitable, is still more so remotely upon the white crops which are to follow. M. Crud reckons at 58.3 the number of days work that are required upon an acre of land which has received between 19 and 20 tons of manure. This is very nearly what we have found to be the truth at liechelbronn, where for the same extent of surface, manured in the same way, we reckon fifty days labor of a man, and rather better than eleven days of a horse. In Europe the potato harvest takes place at the end of autumn. In the intertropical Cordillera, where the cultivation depends prin- cipally upon the heat of a very steady climate, the potato remains in the ground from four to seven months, as it is cultivated at a greater or less height above the level of the sea ; it succeeds bp.»» where tfie mean temperature ranges between 13" and 18" centigrade. (56" and 65" Fahr.) In Venezuela, indeed, it is etill cuhivaied in places where the temperature is not far from 2i" centigrade, (76.5° Fahr.;) but I am doubtful that the culture is then advantageous. In warm and moist regions the potato yields a large (juantity of top, and few tul)ers. I have gathered some very bad ones at Riosucio de P]ngurama, a village situate at the distance of about 5900 feet above the level of the sea, where the mean and constant tempera- ture is about 22" centigrade, (72" Fahr.) The produce per acre, noted by ditl'erent observers, is as follows : Countries. Tons. Cwts. Qr^. lt)S. Prussia . 5 18 o 1 Palatinate, mean of ten years 5 7 1 14 Austria, mean of tbirtee It years 9 11 3 10 Brabant 11 17 0 2 West Flanders 9 13 0 17 Pays dc Waes 10 8 3 13 Pays de Tougres . G 14 0 25 England 10 o o 7 Lhigland 9 9 0 25 Ireland 9 9 3 14 Alsace 8 14 3 8 Alsace (Beclu'lbronn) 5 8 1 12 Neighborhood of Paris 11 2 2 13 Venezuela 9 IG 1 20« There is an obvii>us relation between the quantity of seed-potato planted and the amount of the crop. In Alsace from 25 to 30 bushels per acre are usually planted. In some places too much soed • This is ilio jiroduri* (»r two harv.-sts, whirti they gntlirr In t)ie snmo year. JERUSALEM ARTICHOKE. 159 IS used, in Others not enough. It were very desirable thai certain experiments were undertaken which should fix the proper quantity of seed-potato to be used for each variety of soil and situation. The Jerusalem Artichoke, {Helianthus luherosus.) Tliis plant is generally believed to be a native of South America, but M. de Hum- boldt never met with it there, and according to M. Correa, it does not exi.^.t in Brazil. The property which the tubers of this plant have of resisting the cold of our winters, and several botanico-geo- q^raphical considerations, lead M. A. Brongniart to presume that the plant belongs to the more northern parts of Mexico. The Jerusalem artichoke rises to a height of from 9 to 10 feet; tt flowers late, and I have not yet seen it ripen its seeds. It is pro- pagated by the tubers which it produces, and which are regarded, for good reason, as most excellent food for cattle ; in times when the potato was not very extensively known, it also entered pretty largely into the food of man ; when boiled, its taste brings to mind that of the artichoke, whence the name. The tuber of the Jerusalem artichoke, from an analysis of M. Braconnot, appears to contain in 100 parts : Uncrystallizable sugar 14.80 InuUne 3.00 Gum 1.22 Albumen 0.99 Fatty matter 0.09 Citrates of potash and lime 1.15 Phosphates of potash and lime . 0.20 Sulphate of potash . . . 0.12 Chloride of potassium ..... 0.08 Malates and tartrates of potash and lime . . 0.05 Woody fibre 1.22 SiUca 0.03 Water 77.05 100.00 M. Payen found a larger proportion of sugar in this tuber than that stated above, and he ascertained that the fatty matter consists chiefly of stearine and elaine. In the Jerusalem artichoke I myself found : Of dry maUer 20.8 Water 79.2 100.0 One trial for azote would lead me to conclude that M. Braconnot had estimated the albumen too low in his analysis, or, as is more probable, that several azotized principles had escaped him. The dried tuber gave me 0.16 of azote, a number which would indicate 1.0 as the proportion of vegetable albumen. There are few plants more hardy and so little nice about soil as the Jerusalem artichoke ; it succeeds everywhere, with the single condition that the ground be not wet. The tubers are planted exactly like those of the potato, and nearly at the same time ; but this is a process that is performed but rarely, inasmuch as the cultivation of the helianthus is incessant, 160 JERUSALEM ARTICHOKE. being carried on for nnany years in the same piece ; and after the harvest, in spite of every disposition to take up all the tubers, enough constantly escape detection to stock the land for the ft»llo\v- ing year, so that the surface appears literally covered with the young plants on the return of spring, and it is necessary to thin them b> hoeing. The impossibility of taking away the whole of the tubers, and their power of resisting the hardest frosts of winter, is an ob- stacle almost insurmountable to the introduction of this plant, as one element in a regular rotation. Experience more and more confirms the propriety of setting aside a patch of land for the growth of this productive and very valuable vegetable root. Of all the plants that engage the husbandman, the Jerusalem artichoke is that which produces the most at the least expense of manure and of manual labor. Kade states that a square patch of Jerusalem artichokes in a garden was still in full productive vigor at the end of thirty-three years, throwing out stems from 7 to 10 feet in length, although for a very long lime the plant had neither received any care nor any manure.* I could quote many examples of the great reproductive power of the helianthus ; I can affirm, nevertheless, that in order to obtain abundant crops, it is necessary to afford a little manure. I shall show in another chapter, however, that this is manure well bestowed. Like all vegetables having numerous and large leaves, the helian- thus requires air and light ; it ought, therefore, to be properly spaced The original planting of course takes place in lines, but in the suc- ceeding crops, and those which are derived from small tubers acci- dentally left in the ground, the order is of course lost ; it is only necessary to destroy a sutficirnt number of the young sprouts which show themselves in the spring, to leave those plants that are pre- served with a sufficient space between them. When the plants are somewhat advanced, the ground should receive one or two diggings with the spade, and a hoeing or two to destroy weeds. The leaves of the helianthus arc used in many places as forage, the stems being cut a few inches from the ground ; the gathering takes place at diflerent periods of the year, but probably to the detri ment of the tubers ; iv may be lucrative to destine the leaves for llv nutriment of cattle, but I believe we have to choose between th' green crop and the crop of tubers. It is unqiK'stionablc that tin premature removal of the green stems must prove injurious to tho roots; in my own farm the leaves are never removed, and my opir ion is, that it is vastly more advantaget)us to doj)iMid upon the crop of tubers alone. The tubers are gathered as they are wanted, f«>. , not dreading the frost, they remain in the ground the whole of the winter; they do not require, like the potato, to be collected and pit- ted at a certain period ; they require no particular situation, no pur ticular care for their preservation ; the «)iily disadvantage that ac companies their being left in the ground, is that iluring very hard frosts the labor required to get at them is very great. During win * Srhwrrix <^nltiirr of F riTnl*. THE CARROT. 161 ter the woody stems of ilie plant die and dry up, they are then use- ful as combustible matter , but a better use of them perhaps is to make them enter in certain proportions into the litter of the hog- stye ; the pith there absorbs a large quantity of the liquid manure. Schwertz estimates the mean quantity of dry leaves and stems at 3 tons, 1 cwt. 1 qr. and 15 lbs. per acre. The following quantities of tubers have actually been gathered in Alsace. Tons. Cwts. Qrs. lbs. Sandy soils 4 3 3 6 Soils of the best quality 10 8 3 13 At Bechelbronn (mean) 10 16 0 8 Bechelbronn crops of 1839-40 15 16 1 16 The Carrot, {Daucus carota.) This root is frequently cultivated, particularly by intercalation ; it is frequently grown along with the poppy, where the seed is raised for the sake of its oil, occasionally also being sown with white crops in the spring, it comes to maturity after them in the autumn ; it is a plant that is much liked by animals, but which by no means possesses the very high value as an article of food which is generally ascribed to it by husbandmen. The carrot requires a deep, somewhat loose and homogeneous soil, fresh manure, and much care in the cultivation. Schwertz, taking the mean of three years, estimates the produce per acre at 13 tons, 18 cwt. 1 qr. and 2 lbs. of roots, and about one-third the same quantity of green leaves, which are valuable as fodder and as elements of manure. In a field at Bechelbronn where this vegetable had been intercalated with the madia sativa, we obtained upwards of 5^- tons of roots in addition to our principal crop of oleaginous seed. The carrot contains a large quantity of water in its constitution — 87.6 per cent., according \o some of my experiments. The juice of the carrot contains sugar, albumen, a crystallizable coloring principle, called carrotine, a volatile oil, fatty matters, pectic acid, pectine, starch, malic acid and alkaline, and earthy phosphates. The parsnip, {Pastinaca sativa.) This plant is not very exten- sively cultivated, yet it has the advantage of standing the winter in the open field. It has been recommended as very useful in fattening cattle. In its composition it must assimilate with the carrot and beet. Drappier obtained as much as 12 per cent, of cane-sugar from the parsnip.* BARKS. Cinchona barks. The barks of cinchona, which are employed with so much success in medicine, are the produce of different species of a family of trees which grows in the mountains of South Ameri- ca; the active principle of all the varieties of bark resides in the vegetable alkalies, quinine, cinchonine, and cinchovatine. The medicinal properties of bark were made known to Europeans in 1638, on the occasion of an obstinate fever from which the Coun- tess of Chincon, vice-queen of Peru, suffered at Lima in that year. A corregidore of Loxa, who had been cured by the Indians while * Rerzclius, Chcmistn", vol. ii. d. 199. 162 CINCHONA BARKS. affected in the same way, recommended the bark. The medicine was completely successful ; and to show her gratitude, the vice- queen had large quantities brought down from the mountains for distribution among persons affected with fever. It was from this circumstance that the bark was at first known under the name of the Countess's powder. By and by, the members of the college of Jesuits having been charged with its distribution, it of course be- came the Jesuits' bark or powder. Lastly, the Cardinal de Lugo having brought it to Rome, the new medicine was known under tlie name of the cardinal's powder. The cinchonas are met with principally in forests at a considerable elevation above the level of the sea, in a temperate climate, and growing in a stony soil. The proper period for gathering is known by the circumstance of the inner surface of the bark, when detached from a branch, acquiring in a few minutes a red, yellow, or orange tint, according to the species. The trees are cut down one or two days before the process of barking begins, by which the operation is rendered more easy, and the cuticle is no longer liable to he rubbed off. The bark of the trunk and branches is removed by means of a large knife, in strips, or bands, which are kept as broad as possible. 'Ihe bark is placed upon cloths and put to dry in the sun, each piece being kept isolated, in order to facilitate the drying, and especially to favor the yi//// or rolling up ; when the bark is dried in a heap, and when the pieces touch, it often acquires a most disagreeal)le odor in consequence of incipient putrefaction, and the quilling does not take place.* The bark, when thoroughly dry, is packet! in bullocks' hides and sent to Europe. From my own observations, and those that have been supplied me by M. Goulot, the different species of bark appear to be distributed upon the mountains of New Granada in the following order : Ueijhu where mo»t abiiii>l«iiU Tern pern tur«. KifiO feci 42«»4 '• . 1%8 " 10° (rH-.i F.) 21° (70 F.) 24° (75i F.) 2.5° (77 F.) Cmy bnrk.C. lancitolm White bnrk.C. ovalilolia Red liark.C. (lUlonpilolia Yellow bark, C. cordifolia Pelletier and Caventou discovered in the gray bark, 1st, cincho- nme in combination with quinic acid ; 2d, a fatty substance ; 3d, red and yellow coloring matters; 4th, tannin; 5lh, quinate of lime : Gth, gum ; 7th, starch ; 8th, woody matter. In the yellow and rod bark these learned chemists found the same principles, and, moreover, quinate of quinine. Barks of the xcilloui and poplar. Decoctions of these barks are often employed with success in the treatment of intermittent fever. In searching after the active principle of these medicines, M. Uou.v discovered the particular substance, salieine, in the bark of the wil- low, (salix helix,) the medicinal effect of which is analogous with tliat of the febrifuge principles of the true barks. M. Braconnot haa • Ruiz, Quinologia. CORK. 165 further succeeded in obtaining another crystalline matter from the leaves of the aspen {popnlus trcwula) populjne. Cork. 'V\\Q oak which yieUis coik is known in Spain under the name of the alcor)ioqve It forms extensive forests upon the abrupt slopes of the Pyrenees, where it is oi'ten seen growing upon arid and stony soils, that seem doomed to eternal steiility. The cork-tree has flexible and strong roots, which creep over the naked surface of the granitic masses, turning round blocks, and searching everywhere for fissiues and collections of sand and alluvium, into which they penetrate deeply, in search of the nourishment necessary to the tree. At maturity, the alcornoque rises to a height of sixty-five feet, and its trunk may be three feet and a quarter in diameter. In the Spanish Pyrenees, the superior limit of the cork-tree region, is that of the vine, about 1640 feet above the level of the Mediter- ranean. In France this tree grows luxuriantly in the communes of Passa, Lauro, &c., the mean elevation of which is 1148 feet. In Spain, as in France, the soils on which the cork forests grow are of primitive origin ; and it is said, on good authority, that the cork- tree only grows on soils derived from granite, gneiss, mica-slate, or porphyry, and never on soils of calcareous origin. The cork-tree is reproduced spontaneously on these silicious soils, among cistuses and heaths ; but the reproduction in this way is so slow, that art often interferes advantageously to aid it. There are many varieties of cork oak; and as that which is covered with a smooth and grayish cuticle, yields the article which is most prized in commerce, the seeds of this variety ought to be selected for sow- ing. The acorns of the cork oak are tumid, of considerable size, and a sweet taste ; the acorns ripen from October to December, and are much employed as food for hogs. The Catalonians sow the acorns in a cuhivated soil at the same time that they plant the vine, and for twenty or twenty-five years the produce of the vine compen- sates the outlay upon the young cork-trees; but the produce of the vine diminishes as the cork-tree overshadows it, and finally there comes a time when the vines die out completely. The cork-tree is of slow growth, and at four years of age it may be from thirty-six to forty inches in height, and requires incessant care until the trunk is from seven to ten feet high, at which time it may be about twenty years of age ; and its total height, including its branches, may be about twenty-two feet. The barking of the cork-tree begins about the middle of July, and may be continued so long as the sap is in motion. When stripped off, good cork is formed of from ten to twelve layers, each of which indicates an annual deposition. The two outer layers constitute the cuticle ; the others adhere closely together, and although of vaiiable thickness they present a homogeneous mass. The time for remov- ing the cork is indicated by the interior acquirinsf a slightly rosy tint, which happens about the tenth year. The barking is performed by me^ns of an axe, with which a cut is made the whole length of the t» ink, care being taken not to wound the woody layers ; two otl*^'* ".TOSS cuts are then made at the top and bottom of the trunk. 104 TOBACCO. By mcmns of the handle of the axe, which is shaped like a wedge forced into the vertical cut, the cork is then loosened and stripped from the livinfjhark beneath it, the whole covering of the tree being often taken away in a single piece, although it is more commonly re- moved in two pieces. The process of barking is very easy when the sap is abundant. The cork-tree must be about forty years of age before its bark has any commercial value; that of a tree of twenty years is always treated as rubbish. An oak a century old may furnish 200 lbs. oi marketable cork ; as many as 480 lbs. however have been taken from a single tree ; the mean produce may be reckoned at about 106 lbs. per tree ; to fit it for the market, cork undergoes a variety of preparations which need not detain us here. LEAVES. The herbaceous parts of vegetables have all a very similar com- position, if they be regarded in the most general point of view. The leaves and green stems, along with the woody fil)re which ftirms in some sort their skeleton, always contain albumen or an analogous azotized principle, saccharine iind gummy substances, chlorophvlle, wax, fatty and resinous substances, free or combined acids, and fie- quently also essential oils. Such is the general constitution which chemists agree in assigning to clover, hay, leaves, in a word to green forage of all kinds ; nevertheless, to this constitution, which may be regarded as standard, we have frequently other particjilar matters added, some of which we have already studied, and which by their medicinal properties, or the economic uses they possess, render the plants that contain them of high importance in an afrricuUural point of view. I shall here otdy speak of two of these plants, tobacco and tea, the leaves of which, almost in universal use, are a source of great comniercial jtrosperity to the people who cultivate them. Tobacco, {Xicoliana tahacum,) a native of America. app<'ars to have been introduced into Spain and P«)rtnj:al about the middle of the sixteenth century Ijy Fernandez de Toledo. Its name is gen- erally believed to be derived from that of the Island of Tobatjo, one of the West India islands, at no very great di^tance from the coast of Venezuela, whence the first impoilations were made. Nicot, the French ambassador to i\)rtugal, lirst made its use known in France, whence the name nicotiaua. At the present time, the cultivation of tobacco appears to have spread almost over the whole surface »>f the globe. Tobacco requires a somewhat friable soil, rich in humus ; it con- Bequently succeeds in lands just broken in. In America the mode of cultivation and of preparation are almost everywhere the same. In Venezuela the seed is sown in a very rich loam, and after from forty to fifty days, the young plants are transplanted in rows, distant a little more than three feel from one another, the |)lants beinjr about two feel apart ; the transplanted plant is generally covt red w ilh a banana leaf ; but it is possible that tiie shades of color of the dilTerent kinds of tea depend solely upon the degree of roasting which they have undergone. GuiUemin has said nothing of the produce of the tea shrub in Brazil. In China, according to a man- uscript of M. Carpena, a shrub with care will produce annually during thirty or forty years from 2 lbs. to 2} lbs. of marketable tea. From the analysis of iM. Mulder, lea appears to contain : 1st. A volatile oil. 2d. Chlorophylle. 3d. Wax and resin. 4th. Gum. 5th. An extractive matter. 6th. A coloring matter. 7lh. Azo- tized substances analogous to albumen. 8th. Woody fibre and inor- ganic salts. 9th. A particular crystalline principle, — theine or cof- feine, which is ranked amofig the vegetable alkalies, and which is also met with, as implied by the name, in coHec : this new principle crystallizes in colorless needles of a silky aspect and bitter taste. It is little soluble in alcohol and in ether ; water dissolves about ^'jjth of its weight, and it sublimes without undergoing decoinp(»si- tion ; it is by sublimation, in fact, that Mr. Stenhouse proposes to obtain it from tea. This is und(»ubtedly the principle which communicates to tea its bitter taste, and several of its properties ; experiment has shown, that when administered even in considerable doses it produces no ill effect on the animal econumy ; different kinds of tea, as might have been presumed, contain it in different proportions. Mr. Stenhouse obtained from 100 parts of Hyson 100 ofCoffeine Congou 1.0"- A»s:un 1.37 Twnnkay, grrcn 0.98 SEEDS. Wheat. This valuable grain is the produce of several kinds of triticuin — winter wheat, and spring wheat, T. hi/bcrnum, and T astiru/n, speller, T. Spclla, and 7'. tyionoron. Wheat is sown either upon a falli»w or upon land that bus cariied WHEAT. 169 some forage crop, or such a crop as beans and peas. It requires a stiff rich soil, conjaining- a certain proportion of calcareous earth, and abounding in organic matter ; it does not thrive well in soils where the sandy element predominates over the clayey. For seed the best grain is selected ; but this and all other precautions do not ^uffice to preserve the plant from many diseases, such as smut, rust, mildew. Farmers are wont, before putting their seed wheat into the ground, to prepare it in various ways with a view to destroying the germs of certain parasites which are believed to adhere to it ex- ternally. The process is generally called pickling, or liming, be- cause milk of lime, in which the seeds are put to steep for twelve or fifteen hours, is often employed in its course. Means that are said to he more efficacious have also been recommended : some make use of alum, others of sulphate of iron, sulphate of zinc, sul- phate of copper, sulphate of soda, and even white oxide of arsenic. All these means appear to conduce to the same result. We employ sulphate of copper, which indeed is the custom in a considerable part of Alsace, and I can assure the reader that our fields of wheat are never infected. 100 grammes, or about 3| ounces troy, are allowed to a hectolitre or sack of neaily 3 bushels of wheat ; the salt is dis- solved in as much water as is held requisite for the submersion of the grain, which is steeped in the solution during about three quar- ters of an hour, after which it is thrown into baskets to drain, and being then spread out on the floor it is dried before being sown. The season at which wheat is sown in autumn ought to vary with the climate, and nothing can be more displaced than those precise dates which are set down by the majority of writers. The great point to be held in view is, that the young plant may have got a certain length before the frost sets in, that the roots may have pene- trated to a depth which shall protect them from the severe cold of the winter. In each district, experience has already proclaimed the proper time for sowing, and this can rarely or never be departed from without detriment. In the east of France, in Alsace, the sow- ing of winter wheat generally takes place in the first week in Octo- ber ; in the southern hemisphere, in certain parts of Chili, for ex- ample, the wheat is sown in April, and is expos&d to the cold weather of June, July, and August. The quantity of seed sown may vary from about 7 pecks to 18 pecks and more per acre. Farmers gen- erally agree, however, that we have seed enough when we employ about 2 bushels to the acre ; this is the quantity which is used at Bechelbronn ; but in the same district, and even on contiguous fields, :ve frequently see proportions of seed employed which vary in the •atio of from one half to twice the quantity specified, without, so far rs I know, any suflScient reason being given for this parsimony or prodigality. It is, however, a question of the very highest import- ince to ascertain the proper quantity of seed. The question may be considered in two ways : 1st, with reference to the produce of a tfiven extent of surface, and 2d. with reference to the produce from .;he grain sown. It is quite certain that in sowing thick, a larger produce per acre will be obtained than by sowing- very thin ; but on 15 ' 170 WHEAT. the other hand, thin sowing yields a larger ; ijmber of times the quantity of seed put into the ground. Tiie leasons which should guide us in determining the dose of seed are numerous and extreme- ly complex ; they must evidently be taken in connection with the value of the ground and of cultivation, the price of wheat and of straw, the cost of labor and of manure. Thus in countries where the rent of land is extremely low it may be a good practice to scat- ter but a moderate quantity of seed over a large extent of surface. I remember a field in the neigliborhood of Pampeluna, where the wheat was growing in isolated tufts, all extremely vigorous and very heavy in the ear : the ground had had but very little preparation ; nevertheless, they expected to gather from sixty to eighty limes the seed. This, without doubt, was a profitable crop ; nevertheless, I am satisfied that it could not have yielded more than from 6^ to 1\ bushels per acre. For the same reasons the first settlers of the United States must have followed a somewhat similar mode of cultivation. " An English farmer," says Washington, in a letter addressed to Arthur Young, "must have a very inditferent opinion of our soil when he hears that with us an acre produces no more than from 8 to 10 bushels of wheat ; but he must not forget that in all countries whtue land is cheap and labor IS dear, the people prefer cultivating much to cultivating well." In Alsace we do not reckon any crop profitable which yields less than from 19? to about 23 bushels per acre ; and in these circum- stances we do not receive back more than from 9 to 10 times the seed. Nevertheless, it must be allowed, even in these extreme cases in which the value of ground is so ditlerent, inasmuch as a may vary in the ratio of from 1 to 1000, that there are certain limits with ref- erence to the seed which must not be passed ; and there is without doubt an opportunity of making a scries of curious and useful exper- iments, with the view ol' ascertaining the true ratios which exist between the produce and the seed. I am well aware that the results of experiments of this kind have already been made public ; but I know also that these ilata have not been deduced from a sullicient number of facts perfectly comparable with one an«>l|icr, and noted under a variety of climatic intluences ; in a word, that they arc not such as they ought to be, to put an end to the uncertainly which still exists in the minds of the best-informed farmers and rural economists upon the subject. In Europe, the wheat that is sown in autumn generally stands upon the ground for from nine to ten months. The time, however, varies considerably with the climate ; in the Andes, it is in propor- tion to the proper temperature of each place. Wheat, which is now an important article of agricultural produce in America, was introduced from Eun)pe very shortlv afier the Con- quest The first particles of wheat sown in .NIexico l)efi)re 1530, are said to have been found by a negro belonging to Fernando Corlez among the rice destined for provision to the army.* Wheat • IIuinl>ol(lt'« Kr dextrine Water. Bran. 11.0 71..') 4.7 3.3 10.9 14.G r>(].5 8.5 4.0 12.0 2.3 12.0 (12.0 7.6 5.8 10.0 1.2 10.2 72.8 4.2 2.8 10.0 The method of analysis employed by Vauquelin, whose results 15* 174 WHEAT. are given above, by means of wasbing, is however far trom being very accurate ; it is impossible to prevent the loss of some gluten which passes with the starch, and the vegetable albumen is entirely lost by reason of its solubility in water : and then to dry gluten is a very long and de'icate process ; and if we would pretend to any de- gree of accuracy, we must ascertain the quantity of fatty matter contained in the samples. I therefore thought that with reference to the azotized principles particularly, the better way would be by proceeding to ascertain these by immediate ultimate analysis. The four azotized principles which we have already admitted have very nearly the same elementary composition ; the mean propor- tion of azote in each is 0.16. With this datum, it is evident that if a particular sample of flour is found to contain 0.04 of azote, it may be inferred that this azote represents 0.25 of gluten, albumen, fibrine, and caseine, dried at 140" C. (284" F.,) and as these are the most valuable elements in flour, I took the ])ains to ascertain their pro- portion in a considerable number of varieties of wheat, the whole of which were grown in the same year, in the same soil, which was well manured, and under climatic influences that were identical ; nor did I restrict myself to the azotized matters of these samples ; I also endeavored to ascertain the precise relative quantities of bran and of flour. The following table contains the results of my experi- ments. 175 he 2j ^ w »J 52 o 22 • o - o .;2 .•^ o iJ ^ o f^ o ^- b= ^= i b:§ P -I = -I :^ -I -I -"•! -= -^ o ° o o c; .ti -r c; c^ o CJ CIO t-- L.O CO Tf 'o -^ o r^ 'o ^ '^ Tt; cj »o cx) ci !>. 1-H o l^ l^ t- t- I- QC t^ 00 «^ l^ t-- 00 t^ t^ l^ CO QO l^ C^ 00 t^ C^ l^ 00 c S ^oo^oot^«ioir-'-o-j. t- t^ !LD 00 'O t^ 00 00 O) 00 l^ - - - - - 00 C^ CO GO !>• t^ 00 00 £^ l^ t^ 00 00 X t^ t^ C5 00 C5 O O? lO O O O O O >-0 O lO lO O lO L-^ ir; O O lO p to rH O CO 0( « 00 CO '^' Lf^ to O ^ -^ O GO C^ rH eO '^ Crj 00 C~ lO O 2^ en c3 . bjD — - ^1 3^ S S-a,^ 3 . ^ - O -- . i^ fcX' .^ ^ ^ O C *f g ^ rt ^ ^^ _^ 2 ^ = i § >^ ^ ^' ^ I •? ^ 5 ^ b. i; o C o ^ ^ E ^ O 4> OJ HasOScs^Qpi l moitiure. With human urine 35.1 39.3 25.6 " hullock's blood 34-2 41-3 25.5 " liumiin excri'tnenl 33.1 41.4 25.5 " sheep's dung 22. l» 42.8 .34.3 " coat's ditto 32.9 42.4 24.7 " horse ditto 13.7 (U.fi 24-7 " pigeon's ditto 12.2 63.2 24.6 " cow's ditto 12-0 623 2.1.7 Siiil not manured 9-2 66-7 24-1 It is apparent, therefore, that in general, for the exception on) refers to the pigeon's and the h(»rse dung, the wheal grown in groun manured with the most highly azotizcd matters yields the Target (pianiily of gluten. IJy way of addintj to and confirming these conclusions of Hermb stiidt, I shall give llie results of an experiment of my own, made i- 1830, in which the same variety of wheat was grown in the opci field, atid in garden ground very highlv manured. The grain wa. analyze*! after having been dried at 110" C, (iSO" F..) and gave : Fmm tlie np»n fir!il. From the jfkrJ 3.51 Ashes 2.41 2.31 100. (HI 100.00 In the produce of the garden there wore 21.91 — very nearly 22 per cent, of gluten and albumen ; in that of the open fieKl no more than 1-1.31 percent, of the same principles. Davy was of opinion that the wheal of warm climates was richer ■ in azotized principles than that of temperate lands. Southern coun- tries are known to produce harder, tourjiirr grain, the llonritf which RYE. 177 contains more g-luten than the soft and more friable wheat of the north ; and the inquiries of M. Payen appear to hear out the conchi- sion of the illustrious English chemist. M. Payen, in fact, foimd in the hard wheat of Africa 3.00 of azote, equivalent to 18.7 ; and in that of Venezuela 3.50 of azote, equivalent to 21.9 of gluten and alhumen. The experiments quoted above, however, prove that we may have w4ieat grown in Europe fully as rich in azotized elements as any that is grown between the tropics ; the influence of the soil in this direction is probably more than the influence of climate. In all the analyses of wheaten and other flour published up to the present time, we find no mention made of the fatty matters which they contain ; and late views in regard to the special part which these matters play in nutrition make it very necessary to supply the omission. A ong with MM. Dumas and Payen, I therefore deter- mined the qucntity of fatty matter contained in a considerable num- ber of the vegetables and vegetable substances used as food, from which it appears that grain of different kinds contains from 2 to 10 per cent, of oil. One hundred parts of winter wheat gathered at Bechelbronn lost 14.5 of water by drying at 110" C, (230" F.,) and therefore contained 85.5 of dry matter. 100 of this dry wheat gave 137 of bran and 86.3 of flour. Various analyses showed the composition of this wheat and its parts to be as follows : Dry matter. Gliileii aiiU Starch. Albumen. Bran 200 Flour 13.4 73.2 Wheat 14.3 63.2 Rye, {Secale cereale.) Rye is an important article or food, par- ticularly in the north of Europe, where the people live upon it almost entirely. It is a very hardy plant, and will thrive in soils which are altogether unfit to grow wheat. In the husbandry of the north this grain occupies the place of wheat in the south ; it requires much the same treatment, and stands upon tlie ground for nearly the same length of time. The bushel of rye weighs on an average about 60 lbs. avoird. The usual quantity of seed sown is from 10 to 11 pecks per acre, and the produce per acre, the seed being deducted, has been stated as follows : Bushels. Bral)ant 23.0 Flanders 32.4 Austria 20.6 England 220 France 19.0 The German agriculturists say, that the weight of the straw to the weight of the rye produced is in general as 100 is to 47 ; others say as 100 is to 50, and some have taken it even as high as 100 to 33. The relation seems to differ extremely in diflfeient years. At Bechelbronn, for example, in 1840-41 we had 63 of grain to 100 of straw; in 1841-42 we had but 25 of grain to 100 of straw. Rye yields flour that is not so white nor so fine as that of wheat, Glucose. (Su^ar.) Gum. Fattv matter. Woody 5.6 28.8 4.2 12.? 5.5 2.1 1.6 45.7 7.5 178 BARLEY OATS. which is in consequence of the woody covering of the graih getting ground, in great part, in the mill. If but from 50 to 65 parts per cent, of flour be taken from rye, it is white and looks well. The dough made with rye flour is not very adhesive ; it contains little vegetable fibrine, the azotized principle which gives gluten its elas- tic properties. It is this want of vegetable fibrine which renders it more difllcult to make good light bread of rye than of vvheaten flour, although experiment shows that rye flour of the first quality will form as large a proportion of bread as wheaten flour ; 100 of rye flour have given 145 of bread. Rye bread is more hygrometric than th.at of wheat, and conse- quently remains for a longer time soft and fresh. Rye generally contains 24 of bran to 76 of flour ; by drying at 230 F. it loses about 17 per cent, of water. Analyses of a dried sample grown at Bechel- bronn yielded : Gluten and albumen (azotized principles united) 10.5 St;.rch 64.0 Fiitty matters 3.5 Sugiir (glucose ?) 3.0 Gum 11.0 Woody matter and salts (phosphates) 6.0 Loss •■ 2.0 100.0 Barley, {Hordevni vulgore.) The usual produce of barley varies much from 15 or 20 to 50, 60, and even 70 bushels per acre ; the average for France is stated at about 43. t bushels ; and tbe weight of the bushel may be taken on an average at al)out 504 lbs. The ratio of the straw to the grain varies very mucii, but may be taken generally at that of 100 to 50. Barley contains : Of flour 68.6 Hriin 1P.4 Water 13.0 100.0 Dried, this grain gave 0.021 1 of azote, which represents 13.4 per cent, of gluten and other azotized [)rincij)les. Oats, {Ai'Otn saliva.) When oats yield 43 or 44 bushels per acre, the crop is a fair one. At Bechelbronn we have frequently had up- wards of 45 bushels per acre.* Schwerlz slates the relation between the straw and the grain as 100 is to 60. Some oats galhered in 1841-42 yielded 78 of meal and 22 of husk per cent. One hundred parts of tiiese oats lost l)y drying at 230° F., 20.8 of water ; thus dried, analysis showed that they contained : Of starch 46.1 " gluten, allmmen, &.c. 13.7 " fatty matter 6.7 " sugjir (glucose) 6.0 " gum 3.8 " wooUy matter, ashes, and loss 21.7 lOU.O * This would bo reckoned n poor crop in the North of England and Scotland, whcr* BO, 90, and even ICO Inishels oionts \xi \ctv are freiiurntly grown.— Exo. Ed MAIZE. 179 IMaize, {Zca mais.) This is the true wheat of the Americans, and it is now generally allowed that the plant is a native of the New World. It is also well known that maize was introduced into Spain long before potatoes. Oviedo states in his work, printed in 1525, that he had seen it growing in Andalusia and the neighbor- hood of Madrid. The cultivation of this useful plant was observed eveiywhere on the discovery of America by Europeans, from the most southern parts of Chili to Pennsylvania in the north ; and in the neighborhood of the equator, from the level of the sea to the high table-lands of the Andes. Garcilasso gives a particular de- scription of the procedure followed by the Incas in the cultivation (»f this plant, the kind of manure, &c. At Cusco the Indians ma- nured with human excrement dried and reduced to powder. On the coasts they employed in one place guano ; in others, as the dusty and sterile soils of Attica, Atiquiba, &c., they made use of the offal of fish. The uses of maize are very numerous. In America it is made into cakes, which are a substitute for bread ; by fermentation a vinous liquor is prepared from it called chicha. Before the conquest, the Mexicans manufactured a sirup from the expressed juice of the stems. In describing to Charles V. the various articles of provision that were met with in the march to Tlatclolclo, Cortez says, " They sold us the honey of bees, wax, and honey from the stems of the maize plant." Maize when ground and boiled makes a kind of pudding in universal use, and the ear, w^heii nearly ripe, whether boiled in water or roasted in the ashes, is held a luxury by all class- es. In the tropical Cordillera maize is advantageously cultivated from the level of the sea to the height of 9186 feet above it ; that is to say, it thrives in temperatures which vary between 14° and 27.5° C. (57.5° and 81.5° F. ;) this circumstance explains its very general introduction into Europe. Maize succeeds on all soils when they are properly manured ; I liave seen beautiful crops upon the most sandy soils and upon the stiffest clays ; it requires much the same management as our ordi- nary grain crops ; the climate alone should decide as to whether its introduction into a particular district is opportune or not ; a certain degree of heat is necessary to ripen it, and above all, the cold to which it is exJ)osed must not be too severe. It is for this reason, that in the east of Europe the maize is sown in spring, when there is HO longer any apprehension of frost ; there would be a real advan- tage in sowing late, were it not for fear of the frosts of autumn at the season of ripening. The susceptibility of maize to frost and climate generally, appears to me very analogous to that of the vine ; and I doubt whetiier it would be wise to attempt its cultivation on the great scale where the grape does not ripen in ordinary years. Maize is sown either with the dibble or with the hand, following a furrow opened by the plough ; I believe that it ought never to be sown broadcast, for it is a plant that requires room ; it is only in the hottest countries that the drill system is less necessary. In Alsace the drills are about 2h feet apart, and the seeds are sown at the distance of abou* a foot from each other. This very considerable space left be- 160 MAIZE. tween the maize plants appaars to authorize the general custom that prevails of interposing som3 other crop in the fields under Indian corn ; that which is most generally interposed is either the dwarf haricot or the potato. I observed the same custom in the more tem- perate valleys of the Andes, where it is almost as necessary as in Europe to leave free spaces between the plants to give them air and sun ; but the plant is cultivated alone in the hotter regions. Soon after maize has sprung it receives a first hoeing, and after it has got to a certain height, a second ; in Alsace, for instance, it is custom- ary to hoe towards the end of June ; but I never saw any operation of the kind performed between the tropics : the only care they seemed to take of their fields of Indian corn, was to pull up foul weeds In Europe it is usual to take away the sprouts which rise beside the principal stem : this precaution is also unnecessary in equatorial countries where the ground is fertile ; the more lateral stems thai rise, the better, as they all become richly laden with grain. I may also say as much for the system of topping which prevails among us, that system which consists in removing the extremity of the stem which bears the male flowers after the fecundation has been effected. The leaves and heads of stems which are obtained by this operation, compose a forage by no means to be despised. The time durmg which the crop of maize remains on the ground, is greatly influenced by the mean temperature of the climate ; in hot intertropical countries, the grain ripens in less than three months, and there are even farms upon which four considerable crops are gathered in the course of the year. On the temperate plateau or table-land of Bogota, the plant ripens in six months ; in Alsace about the same length of time is required, although at Hechelbronn, in 1836, the maize which was sown on the 1st of Juno was gathered ripe on the 1st of October. Mai/o is dried eitiier in exposing the spikes stripped of their covering upon the floor of a well-ventilated gra- nary, or by hanging them up in bunches or sheaves under sheds, or under the caves of the house. In warm countries the drying is accomplished by one or two days' exposure to the sun, after which the spikes are stored. The maize is freed from the stem with the hand in small farms, with the tlail in larger establishments. In America the operation is never done until the moment when the grain is want- ed, as it is said that the grain is less subject to be attacked by insects v/hen it is kept in the ear. When animals are t'o.d on maize, hey are accustomed to separate it for themselves. The produce in Indian corn varies greatly, as appears by the fol iowing table, in ilifferent countries : Counine*. Prcluce in buthtlt per acr*. Lnvnnth;il 81 Ciirinthia 55 Austria nnd Moravia W Hunpary and Troatia 49 Tusrany »6 France (rliniatc of Pi-\!«) 99 Alsacf 43 Venrr.tjoln 1^7 MAIZE. 181 By far the finest crops of Indian corn in America are obtained upon breaks of virgin soil. I do not hesitate to say that the husbandman gains from six hundred to seven hundred times his seed under such circumstances. The mode of proceeding upon these breaks, which I have frequently witnessed, deserves to fix attention for a moment. The planter chooses the end of the rainy season for cutting down the trees and the brushwood : every thing remains where it falls until it is sufficiently dry ; fire is then set to the heap, and the burn- ing extends and lasts even for weeks ; all the smaller branches are completely consumed, nothing but the charred trunks of the larger trees remain. As the rainy season is about to return, a man, with a pointed stick in his hand, goes over the burnt surface, making a hole of no great depth at intervals, into which he throws two oi three particles of Indian corn, over which he draws a little earth, or rather ashes, by a slight motion of his foot. This primitive mode of sowing terminated, the planter takes no further heed of the crop ; his habitation is often so remote, that he never visits it until harvest time : the rain and the climate do all the work. It is unnecessary to hoe, the burning having destroyed all the plants that were indi- genous to the soil ; nothing rises but the grain which has been sown. In such fields, stems of Indian corn are frequently seen of the height of from twelve to fourteen feet. It rarely happens that more than three consecutive crops are taken from the burnt soil ; and the last, though still very superior to any thing which we can obtain by our regular husbandry, is not to compare with the first. As there is no want of forest, it is held preferable to make a fresh break. Taking the seed as unity, it is found, from documents now pos- sessed, that 1 of seed will yield — in Mexico (an indifferent harvest) 150 ; in New California (beyond the tropics) 80 ; Alsace (the plants very far apart) 190 ; Venezuela (an ordinary crop) 238. Besides the grain and the straw, the husks and the cores of Indian corn are all extremely valuable upon the farm as forage, and as affording manure. Maize has been analyzed by M. Payen, and found to contain : starch 71.2 ; gluten, albumen, &c., 12.3 ; fat, oil, 9.0 ; dextrine and glucose 0.4 ; woody tissue 5.9 ; and salts 1.2 ; 100.0. I found 0.02 of azote in a sample of dry maize, which I analyzed, a quantity which indicates 12.5 of gluten and albumen, a result that coincides exactly with M. Payen's analysis. Rice, {Oriza saliva.) Rice is an aquatic plant which can only be grown in low moist lands that are easily inundated. The ground is ploughed or stirred superficially, and divided into squares of from twenty to thirty yards in the sides, separated from each other by dikes of earth, about two feet in height, and sufficiently broad for a man to walk upon. These dikes are for retaining the water when it is required, and to permit of its being drawn off when the inunda- tion is no longer necessary. The ground prepared, the water is let on, and kept at a certain height in the several compartments of the rice-field, and the seedsman goes to work. The rice that is to be used as seed must have been kept in the husk ; it is put into a sack. 16 182 COFFEE. which is immersed in water, until the grain swells and shows sign« of germination ; the seedsman walking through the inundated fvsld, scatters the seed with his hand as usual, the rice immediately sinks to the bottom, and may even pent.rate to a certain depth into the mud. In Piedmont, where the sowing takes place at the beginning of April, they generally use about fifty-five pounds of seed per acre. The rice begins to show itself above the surface of the water at the end of a fortnight ; as the plant grows, the depth of the water is in- creased, so that the stalks may not bend with their own weight. About the middle of June this disposition is no longer to be appre- hended ; the rice is no longer so flexible as it was, so that the water can be drawn ofl^for a few days to permit hoeing, after which the water is let on and maintained to the height of the plant ; in July it is usual to top the stalks, an operation which renders the flowering almost simultaneous. Rice generally flowers in the beginning of the month of August, and a fortnight later the grain begins to form. It is at this period especially that the stalks require to be supported, and this is eflectually done by keeping the water at about half their height. The rice-field is emptied when the straw turns yellow. The harvest generally takes place at the end of September. In the Isle of France, rice is cultivated in very damp soils, upon which a great deal of rain falls, but which are not flooded artificially. I have seen the same process followed in other tropical countries which I have visited, but I do not think that the produce is so great, or the crop so certain, as where inundation is empkiyed. In Pied- mont, the usual return from a rice-field is reckoned at about 50 for I of seed. At Muzo, in New Granada, the paddy fields, which are not inundated, under the influence of a mean temperature of 26° cent. (79° Fahr.) yield 100 for 1. Three kinds of rice yielded, on analvsis, the following quantities of— Caro'iia. Piedmont. Ricf. Starch 89..> 90.1 86.9 Gluten, albumen, &.C 3.H 3.0 7.5 Fatty miitters 0.-2 0.3 0.8 BtiEJir (glucose ?) 0.3 0.1) „- Gum 0.7 O.li "•* Woody tissue . .*. .')! 5.1 3.4 Phosphate of lime 0.4 0.4; q^ Chloride of jiotassium, phosphiito of ditto, &c. S luo.o TooTi 100.6 M. Payen's analysis indicates a propis any sugar ; it is starch that predominates. In this state, therefore, it is made a substitute for bread, for the potato, or Indian corn ; it may be considered a farinaceous vegetable. After having removed the rind, the banana is dressed by being roasted under the aiihes until the outer part is slightly brown ; it is then served up at table, and constitutes a kind of soft bread, very agreeable to the palat^^, and greatly preferable, in my opinion, to the produce so much vaunted of the bread-fruit tree. In the expeditions which are undertaken into the forest, and when the habitations of man are to be quitted for some considerable time, the green banana is always made a principal part of the provision ; but then it is pre- viously dried, first to lessen its weight, and then to destroy its vi- tality so far as to prevent its ripening. This drying is performed in a baker's oven, into which the green bananas, stripped of their husks, are introduced, and where they are kept for about eight hours. On being taken out, the bananas are hard, brittle, translucent, and pre- sent the appearance of horn ; 100 lbs. of the green fruit give but 40 of dry substance. The banana thus prepared is called /?/?, and will keep for a great length of time without change. To prepare it for food, it is put to steep in water, and then boiled ; by adding a little salted meat, a very substantial and nutritious meal is prepared. I once made a voyage on the Pacific, in a vessel which was princi- pally victualled with dried bananas, which were served out to the company like biscuit. When ripe, the banana is no longer farinaceous ; as it ripens, its starch is changed into gum and sugar, and an acid is developed. But between the farinaceous and the sugary or perfectly ripe state, there is one intermediate, in which it is generally eaten. Roasted in the ashes, the banana has then a taste which brings to mind that of •he chestnut ; it is also eaten as a vegetable, boiled in the usual way ,n water. Completely ripe, the fruit is eaten raw or dressed, it is then extremely sweet; a very common practice is to fry it, cut in slices, in grease. I have no data upon which to estimate the nutritive value of the bannna, still I have reasons for believing that it is more nutritious than the potato. I have seen men do a great deal of hard labor upon an allowance of about 6.'? pounds of half-ripe bananas, and two ounces uf salted meated per diem. 10.1 CHAPTER III. or THE SACCHARINE FRUITS, JUICES, AND INFUSIONS USED IN THE PREPARATION OF FERMENTED AND SPIRITUOUS LIQUORS. The juice ol* all the sweet fruits when expressed and left to itself under the influence of a suitable temperature, presents the re- markable phenomenon of fermentation, in the course of which the sugar disappears conipleiely, and is replaced by alcohol, the change from first to last being accompanied by the disengagement of car- bonic acid gas. Sugar alone does not suffice to cause the vegetable juices, which contain it, to ferment : for example, a solution of pure sugar in di.s- tilled water will remain for a very great length of time without suf- fering the least change ; exposed to the open air it would evaporate, and the saccharine matter would be found in the same' state as it was before solution If, however, a small quantity of that azotized principle which we have called albumen, gluten, &;c., be introduced into the solution, fermentation will speedily be set up, and will run through its usual course; it would, therefore, appear to be upon this principle that the commencement and continuance of fermentation depends. Fermentation is not set up immediately in the juice of fruits ; a certain time longer or shorter always elapses before it is manifested ; the reason of this is, that the albumen or gluten which always enters into the constitution of these juices, must itself have undergone a certain change in order to act as a ferment. The proof of this is comprised in the fact that all vinous liquors contain a very small but constant quantity of carbonate of ammonia, as was shown by M. Doebereiner. These azotized principles, which in the fresh state remain without action upon sweet juices, act immediately as powerful ferments when they are employed after having been ex- posed for some days to the contact of air and moisture ; after, in a word, they have themselves begun to suff'er change. The quantity of ferment used up or consumed in exciting and maintaining the fer- mentation of saccharine juices is so small, that we are led to believe that it really acts by its presence or contact alone. This view ap- pears the more likely, when we know that, after having added an azotized substance to induce fermentation rapidly in a liquid which, besidee sugar, contains albumen, we find from six to eight times the quantity of ferment after the phenomena have ceased, which had been added in the first instance ; that is to say, we find the whole, or almost the whole, of the original ferment, and, in addition, that which has been produced by the azotized principles pre-existing in the matter subjected to fermentation ; this fact is seen every day in the process of making beer. The ferment or yeast thus produced is but little soluble in water, and in composition bears a remarkable aftinitv to the azotized mat- 17 194 THE VINOUS FERMENTATION. ^ ters from whicl is derived ; M. Dumas has in fact found it to be composed of: Carbon 50.6 Hydrogen • 7.3 Azote 15.0 Oxypen ) Sulphur \ 27.1 Phosphorus ) 100.0 Under the influence of ferment, sugar becomes entirely changed into alcohol and carbonic acid. The composition of grape-sugar — which appears to be the only one that is susceptible of fermentation, for cane-sugar before undergoing this process passes into the state of grape-sugar, as was demonstrated by M. Henry Rose — the com- position of grape-sugar is as follows : Carbon 3R.4 Hydrogen 7.0 Oxygen -oG-S 100.0 and the constitution of the substances which are produced in the process of fermentation, viz. alcohol and carbonic acid, being as under : Anhydrom alcohol. Carbonic aciJ. Water. Carbon ^2.^0 27.27 Hydrogen 13.02 " 11.1 0.\ygen .34.70 72.7:< 88.9 100.0 100.0 100.0 It appears that the composition of 100 parts of grape-sugar may be expressed by : Carbon. Hrdroj^eii. Oxjgtn. Alcohol 46.16 containing 24.24 6.05 16.17 Carbonic ncid 44.45 " 11.12 " 32.33 Water '.9.09 " _" 1.01 8.08 lOO.OO 36.36 Toe 58.58 oy which it would appear that during the transformation of hydrated grape-sugar into alcohol and carbonic acid, the combined water is set at liberty. The first fermented vegetable juice of which 1 shall speak is cane-wine, ox guarapo of the South Americans, a drink which is in common use wherever the sugar-cane is cultivated. It is prepared from the juice of the sugar-cane sulTered to run into fermentation. The chiclia of South America is a fermented lii]uor prepared from Indian corn, and constitutes the wine of the Cordilleras. The grain is steeped for six or eight hours in water, bruised upon a stone and boiled ; the pulp which results is then diffused throutrh 4'- times its volume of water, and the temperature being from 00" to C5' F., a violent fermentation is soon set up in the Huid, which beoins to sub- side after a period of twenty-four hours, when the chirha is potable, and now constitutes a liquor of an agreeable and decidedly vinous flavor, in high repute with those who have ac(juired a taste tor it, although its muddy appearance and the sediment which it ahvavt CIDER AND PERRY WINEb. 195 nts fall in the vessel into which it is received, render it somewnat unpleasant at first to European eyes. The Indians, however, always drink it in the muddy state, and even shake the cask hefore turning the tap. The truth is, that chicha is at once a drink and a very nu- tritious food. Guarazo is another vinous liquor which the Indians prepare with rice much in the same manner as they proceed with Indian corn. Cider and Perry. In countries where the vine is not cultivated, a substitute for wine is found in the fermented juice of a variety of sweet pulpy fruits, more particularly of apples and pears. Of the numerous varieties of apples which are grown in cider countries, the preference is generally given to one w^hich has a rough and some- what bitter taste. The fruit is gathered by shaking or beating the trees, and the few that remain are taken off" by the hand ; the fruit is piled up in large backs placed in cellars. It is crushed about two months after it is gathered, and the pulp is left for ten or twelve hours to macerate in the juice, in order to give the rusty or yellow color which is esteemed in cider. The pulp is pressed and the juice is run intp large vat^ or tuns, in which it undergoes fermentation, which having gone on for about a month, the temperature being from 55" to 58" F., the liquor is racked off" into smaller vessels, in which the fermentation goes on slow^ly, and the cider is preserved. The fermentation of cider is, or always ought to be, slow ; still, with time, the whole of the sugar is transformed into alcohol, if the pro- cess be not interfered with. Wine. Grape-juice contains — 1st. grape-sugar ; 2d albumen and gluten : 3d. pectine ; 4th. a gummy matter; 5th. a coloring matter ; 6th. tannin ; 7th. bitartrate of potash ; 8th. a fragrant volatile oil, or cream of tartar ; 9th. water. It is obvious, therefore, that grape- juice contains within itself the elements necessary for the produc- tion of the vinous fermentation. The relative proportions of these diff"erent elements, however, are singularly modified according to the nature of the vine, the quality of the soil, and especially the heat of the climate. There are indeed few crops that are so much at the mercy of the atmosphere as that of the vine; even in the vine- yards that are most favorably situated, it is rare that wines of equal quality and flavor are produced in two consecutive years ; and in districts upon the verge of the productive limits of the vine, under what- may be called extreme climates, where the vine only exists in virtue of hot summers, its produce is still more variable, more in- constant. The limits to the culture of the vine in Europe are generally fixed where the mean temperature is from 10" to 11" C, (50" to 52" F. ;) under a colder climate no drinkable wine is pro- duced. To this meteorological datum must be added the further fact that the mean heat of the cycle of vegetation of the vine must be at least 15" C. (59" F.,) and that of the summer from 18" to 19° C, (from 65" to 67" F.) xiny country which has not these climatic conditions cannot have other than indiff"erent vineyards, even vvhen its mean annual temperature is above what I have indicated. It is impossible, for instance, to cultivate the vine upon the temperate 19(3 WINE. table-lands of South America, where they neverthelers enjoy a mean temperature of from 17° to 19^ C, (about 62.6° to 66.2° F.,) because that which characterizes the climate of these elevated equinoxial countries is the constancy of the temperature ; the vine grows, flourishes, but the grapes never become thoroughly ripe. In these equatorial countries good wine cannot be made where the con- stant temperature is not at least 20° C, (or 68° F.) In France the vine begins to sprout towards the end of March, and the vintage generally occurs in the course of October. As the quality of wine depends mainly on the ripeness of the grapes, of course the vintage does not take place until this is complete, or until there is no longer any prospect of improvement. The must of the grape is procured by treading and pressing the fruit ; the juice is run into vats, and the fermentation takes place in cellars ; different procedures, however, are followed in ditTerent places. The fermentation having subsided in the larger vessels, the wine is drawn off" into smaller casks, which are carefully filled up from time to time, and in which it is preserved. Wine may be defective, especially by wanting strength and being too acid. Sharp wine contains an excess of cream of tartar and free vegetable acids, and is always the proiluce of grapes which have not been completely ripe. The deficiency of strength is due to the same cause ;' for it is well known that as the grape ripens its acids disappear and are replaced by sugar. This deficiency of sac- charine matter in the must, is now habitually supplied by the addition of a quantity of artificial grape sugar, prepared from starch. In warm countries, where the grape always ripens, the quantity of tar- tar is small ; the sugar then predominates greatly, sometimes to such an extent that the azotized substance of the must is insufficient as a ferment, and it is then that we have wines of too sweet a flavor, such as those of Lunel and of Frontignac. When these musts, which are so rich in sugar, contain the proper quatUity of ferment they produce very strong wines, in which, of course, the sweet flavor no longer predominates ; such are the dry wines of southern vineyards, of wliich that of Madeira may be taken as the type. There are some wines which participate at once in the properties that distinguish the two varieties that I have mentioned, or that show- one of them in excess according to circumstances; such are the wines of Xeres, Alicant, Malaga. &c. Some of these wines are what are called boiled wines, that is to say, a portion of the must, as it flows from the press, is concentrated to a fourth or a fifth of its original bulk by boiling, and this being added to the rest, the strength of the resulting wine is increased. Sometimes the concentration of the juice is effected by drying the grapes partially. It is in ibis way that the celebrated Hungarian wine, called Tokay, is prepared ; the clusters are left upon the vines after they are rip< , an«i alternate- ly exposed to the cold of the night, which probably c ecomposes to a certain extent the texture of the grapes, and to the , eal of the sun. They shrivel and become partially dry. In this state the grapes are subjected to pressure, and a very sweet must, as may be conceived. WINE. 197 flows from hem. In less favorable climates, where the rains of au- tumn prevent the drying of the clusters upon the vine stocks, the same tiling is effected by laying the bunches upon straw in open or well-aired granaries or sheds. It is with the must procured from grapes so treated, that the sweet and often strong wines, which are called vins de paille, or straw wines, are obtained. Wines when stored in the cask always deposite with time a copious sediment, the lees. This sediment, in which tartar predominates, appears to be the consequence of an increase in the proportion of alcohol in the liquor. The alcohol may increase from two causes : first, by the fermentation which, though nearly insensible, goes on in most wines so long as there is any sugar left unchanged ; and next from mere keeping. It is well known, in fact, that wine j)ut into the best casks, and kept in a well-ventilated cellar, loses a very perceptible quantity by evaporation ; it is found necessary to fill up the casks from time to time : the loss has taken place through the -pores of the wood, in virtue of an attraction exerted between the substance of the wood and the included liquid ; and as this attraction is much greater between the organic matter and water, than between organic fibre and alcohol, it is easy to conceive how wine kept in wood should improve. The very same thing, in fact, appears to go on in regard to wine in corked bottles : the cork does not oppose all evaporation,, and it seems probable that it is not merely upon some new and little known change of a chemical nature in the constitu- tion of the wine that its improvement and mellowing in bottle de- pend, but also upon the loss of a certain quantity of its water through the pores of the cork. Throwing quality, flavor, &c., out of the question, it is well known that a vineyard, culivated in the same way, year after year, receiv- ing the same quantity of the same kind of manure, of which the vintage is managed in the same manner, the wine made by the same method, &c., yields a produce which differs greatly in regard to the quantity of alcohol it contains in different years. The vineyard of Schmalzberg, for example, near Lampertsloch, which has been under my management for several years, yields wines of the most dissimilar characters from one year to another. Some idea of this may be formed from the different quantities of alcohol which the wine of different years contains : Mean te mperature. Years. Of the whole term of Of the beginning of Wine Pure alco- cohol the growth of the Of the summer. vines. per cent. .... .e... de?. dng. Jeg. cleg. 1833 14.7C. 5ft.4F. i7.3(; 63.1F. 11. 4C. .51 .5F. 311 5.0 11.4 1834 17.3 G3.1 20.3 m.i 17.0 G3 314 11.2 40.3 183.5 15.8 G0.2 19.5 67 12.3 54 f21 8.1 50.0 1830 1.5.8 G0.2 21.5 71 12.2 54 .544 7.1 38.6 1837 15.2 59.5 18.7 G6 11.9 54 184 7.7 14.0 198 WINE. If we now inquire how the meteorological c rcumstances of each of these five years influenced the production of our wine, we see at once that the mean temperature of the days which make up the period of the cultivation of the wine has a perceptible influence. The temperature of the summer was 17.3" C. (63.1° Fahr.) of the year which yielded the strongest wine, and only 14.7° C. (58.4° Fahr.) in 1833, the wine of which was scarcely drinkable. A hot summer is naturally favorable to the vine : the mean heal of 18*33 did not exceed 17^° C. (63.^° Fahr. ;) with the exception o^ this year, which must be regarded as one of the very worst, th^ three favorable summers, 1834, 35, and 36, show a mean tempera- ture of about 20" C. (68° Fahr.) It is not, however, with the warm- est summer that we find the strongest wine to correspond. Besides the sustained heat, which is necessary during the whole year's growth of the vine, it would appear that a mild autumn was a con- dition necessary to the perfect ripening ot'the grapes : this is one of the essential conditions. We see, in fact, that in 1834, the months of September and October presented the extraordinary temperature of 17° C, (62.6° Fahr.,) while in 1833, the temperature of the same months did not rise higher than 11.4° C. (51.5° Fahr.) I shall here add, that the year 1811, so remarkable over Europe for the quantity and the excellence of its wines, was distinguished by the high temperature of the early part of its autumn ; we find, in fact, from the excellent series of observations with which M. Ilerren- schneider has presented Alsace, that in this year, af'ter a sunmier the mean temperature of which was 19.6" C. (67.8° Fahr.,) the heat of the months of September and October was maintained at 15° C. (59° Fahr.,) the usual temperature of the months of September and Octol)er not being higher tiian about 11.5° C. (5*2.7° Fahr.) If we deduct from these observations the years 1833 and 1837, which were decidedly bad, it seems that wo must conclude that me- teorological influences have a greater effect upon the quality of wines, than upon the whole quantity of alcohol formed ; thus, al- though the wine of 1836 was very inferior to that of 1834, it actual- ly yielded a larger proportion of alcobol from the acre. in Alsace, in order that a vear may be favoraltle to the vine, the lem|)erature of those months during which the i)lant is alive nuist be sensibly superior to the mean : a fact which appears from M. Herrensc'hneider's long series of observations. In a climate where the vine requires such a condition to succeed, it is oi>vious that its cultivation can never be advantageous ; and this, in fact, is the case • the cultivation of the wine would, inceed, be altogether ruinous, were it not for the circumstance that t -3 value of wine increased in a nuich greater ratio than its quality, so that one good year often in- demnifies the grower for many bad years. Another ciinsideration is this, that the vine, like the olive, grows and thrives in situations where it would be diflicult to put any thing else. The produce of a vineyard also (le[)en(ls upon its age ; and it would be curious to examine the progressive increase of the quanti- ty of wine yielded. This information I am able to give in connec- WINE. 199 tion with a vineyard established in Flanders ; I only regret that I have no means of presenting parallel observations from a country more favorable to the vine. The vineyard of kjchnia'zberg was planted in 1822, with new cuttings from France, and from the borders of the Rhine. The vines are trained as espaliers, and are now rather more than four feet in height. The vineyard began to yield wine in 1825, and the following table shows the results in the successive years up to 1837 : Years. 1825 1826 1827 1828 1829 1830 1831 Wine per Acre in Gallons. 68.75 192.0 0.0 115.0 55.9 0.0 153.0 l/fkOVO Wine per Acre in c ears. Gallons. 1832 209.9 1833 311.6 1834 413.4 1835 620.0 1836 544.5 1837 184.4 The mean quantity of wine furnished by this vineyard from the date of its plantation, is 224^ gallons per acre. M. Yilleneuve reckons the mean produce of many vineyards in the southwest of France at from about 146 to 192 gallons per acre, considerably less consequently than our vineyard at Schmalzberg ; and official docu- ments, while they give the mean produce of the vine for the whole of France as 170.9 gallons per acre, state the whole of the wine produced over the country at 970,906.414 gallons. From documents recently published, the whole produce of the vineyards of the German States brought to market appears to be 59,180,000 gallons. Pulque. This is a vinous liquor, indigenous to Mexico and some parts of Peru, and is prepared from the sap of the Agave Americana. When this plant is about to flower, a hole is made into the upper part of its stem< which i)y and by becomes filled with juice, and is removed two or three times in the course of the twenty-four hours; ihis sap is very sweet, runs quickly into fermentation, and yields the liquor called pulque. The flow of sap continues for two or three mon ;hs, and a single plant will yield from six to eight quarts per day. In the neighborhood of a large town, which ensures a ready sale for the produce, a plantation of Agave is one of the most pro- fitable possessions ; in the neighborhood of Cholula there are single plartations which are worth from je8,000 to JC 12,000. 200 SOIL. CHAPTER v. The solid mass of our earth does not everywhere present the same physical characters, or the same chemical composition. Tn traversing a mountainous country of any extent, we seldom fail to observe a notable difference in the nature and relative position of the rocks which compose it; the idea which forces itself upon the mind in such circumstances is, that these mineral masses have not had the same origin, that they have been formed and placed in their several situations at distinct and often distant epochs. In examining attentively the inequalities which mark the surface of the globe, we soon perceive that those rocks which generally form the most elevated points, the axis or skeleton of mountain chains, result from the agglomeration or intimate mixture of different mineral substances which may be isolated and separately studied. These crystalline masses are frequently covered to a certain depth, and even completely concealed by rocks of more recent for- mation, the fragmentary elements of which proclaim their origin from the attrition or breaking down of the strata wliich support them. The regular stratification of these superimposed rocks, the configuration of their minute particles, the remains of organized beings which are found in them, proclaim them to be deposites which have taken j)lace successively, and from the ocean. Ti»e formation of the crystalline rocks probably dates from the period at which the crust of the globe became solid. These elements, intimately mingled by fusion, combined as they cooled, according to the laws of allinity, to constitute the mineral species which we encounter; just as it hap- pens that mineral species, identical with those which we observe in nature, are j)ro(luced and crvstallize during the consolidation of cer- tain scoriae from our furnaces. The various circumstances which have accompanied the cooling o*" the crust of the globe, have doubtless occasioned the differences wnich we observe in the distribution of the minerals that enter into the composition of rocks. Thus granite and mica schist, which pre- sent so dissimilar a structure, are nevertheless, and very certamly, varieties of the same species, and contain quartz, felspar, and mica. In sienile,the mica is replaced by amphibolite, and in j/rotogenite by talc. In trachite, a volcanic rock, both of t)M«T and n)t»re recent date, quartz is almost entirely wanting ; the amjilnboliie is replaced by pyroxenite, and the felspar which is er)counlPii;d, is no longer identical in its chemical composition witli that wbirli enters into the constitution of granite. The liiucstttne rock, wbivh l.elonijs to the same Plutonic epoch, is granular or saccharoid ; occasionally ihe intervention of magnesia makes it pass into Jolornite. The sedimentarv strata do n«»i varv less ir ih^ir composition Tb« OIL. 201 causes which segregated the rocks of igneous origin, appear to have destroyed or removed one or several of their elements before their new consolidation ; one of the most common deposites, sandstone or grit, is almost wholly composed of grains of quartz, amidst which particles of mica are frequently encountered ; hut felspar is ex- tremely rare. In the oldest sedimentary strata of the series, as in the greywackes, the igneous elements are met with more complete, and less altered. The structure of the calcareous rocks of this epoch is often compact, clayey ; it becomes porous and friable in deposites of more recent date. The stratified rocks must have been deposited in parallel superim- posed layers, and these strata, horizontal in the beginning, have been forced into the inclined and perpendicular positions which they now occupy by the tumefaction or rising of the masses upon which they rest. The organic remains which they present, frequently in such quantity, proclaim that in the period when the revolutions of the globe took place that gave them birth, there were already animated beings and plants growing upon the surface of "the earth. The pro- duction of sedimentary strata, is an obvious proof that the igneous rocks of which they are the product, must have been segregated, so as to form beds of "gravel, and sand, and clay. The elements of all stratified rocks must necessarily have passed through these different states before the powerful causes which consolidated them, of the nature of which we cannot now form an estimate, came into play. The disintegration of the crystalline igneous rocks proceeds under onr eyes, as it were, from the combined actions of water and the at- mosphere. Water, by reason of its fluidity, penetrates the masses of rocks that are at all porous; it filters into their fissures. If the tempera- ture now fall, and the water comes to congeal, it separates by its dilatation the molecules of the mineral from one another, destroys their cohesion, and produces clefts which slowly reduce the hardest rocks to fragments, and then to powder. During the frozen state, the ice may serve as a cement, and connect the disintegrated parti- cles ; but with the thaw, the slightest force, currents of water, the mere effect of weight, suffices to carry the fragments to the bottom of the valley, and the rubbing and motion to which these fragments of rocks are exposed in torrents, tend to break them still smaller, and to reduce them to sand. The quantity of earthy matter brought down by streams and rivers. Is coifnderable : an idea may be formed of it from the thickness of the slnne or mud deposited by a river which has overflowed its banks. In many situations, the arable soil is either formed entirely, or is powerfully ameliorated by such alluvial deposites. The fertilizing powers of the mud of the JSile are well known ; according to Shaw, the waters of this river carry withthem aboutthe 132d part of their vol- ume ; those of I he Rhine, at the periods of its great increase, bring down more than the 100th part ; and Dr. Barrow, from observations made in China, estimates at the 200th part of the volume of the mass of fluid, the mud and slime which are carried towards the sea by the 202 SOIL. Yellow river. These fluviatile deposites accumulate tt ;he mouths of great rivers, and gradually encroach upon the ocean ; vhis is very conspicuous, for example, at the mouths of the Elbe, where, at the turn of the tide, when there is an interval of calm, the eartfiy n.at- ters which are held in suspension are precipitated, and a sediment results, which is thrown uj) by the next waves upon the beach. By these successive deposites, the beach rises gradually, and an extensive alluvium is formed which remains dry at neap and ordinary tides. These new lands, the fertility of which is truly surprising, constitute the polders of whicl ihe Dutch make so muith. Durinii spring tides, and storms from particular quarters, these polders would of course be all submerged, had not the active industry of the inhabit- ants raised dykes, which successfully oppose the waters of the ocean. Besides the mechanical causes of the destruction of rocks al- ready quoted, there is a chemical action depending upon meteoro- logical influences, which exerts a powerful influence u[)<)n the con- stituent elements of crystalline rocks. Felspar, amphibolite, mica, and the ])rotoxide of iron suflTer decomposition in certain circum- stances with surprising rapidity, without our being able to foresee, and still less to explain, this singular tendency to destruction. In granite, for example, the felspar and the mica h)se their vitreous and crystalline state, they become friable, earthy, and are trans- formed into an argillaceous substance, which is known in the arts under the name of kaoline, and which is extensively used in the manufacture of porcelain ; amphibolite, and pyroxenite, undergo an alteration of the same kind. In these minerajs the protoxide of iron passes to the state of the maximum of oxidation. The air and moisture appear to exert a great influence u[)on this alteration, which frequently extends to a great depth, as we see in the beds of porce- lain earth, which are worked in various granite districts, and as I have mvself ascertained, in a bed of deconiposeii syenilic porphyry where there are very extensive subterraneous works. In these works, which are carried on in auriferous strata, the alteration in the felspar and am{)hib()lite can be followed to a di'pth of nearly 330 feet. In the midst of the rocks so changed, we every here and there meet with masses which have resisted the decomposing action, and still possess all their original hardness and freshness. Historical monuments also show us unalterable granites ; such is that, for in- stance, which now forms the obelisk in the square of San (liovanni di Laterano at Rome, and which was cut at Siena, under the reign of a king of Thebes, t.irteen hundred years before the Christian era. Such is further the obelisk of the Place of St. Peter, which was consecrated to the sun by a son of Sesostris more than three thou- sand years ago. The schists, by reason of their structure, wear away with much greater facility. Calcareous rocks resist almt "pherical ajjencies somewhat better ; but their softness in general sulfers them to bo readily attacked by mechanical causes, and water even acts upon them as a solven'. through the medium of the carbonic acid whii^h SOIL. 203 it always contains. The resistance of the greywackes, and of the sandstones depends in a great measure on tiie nature and cohesion of the cement which unites their particles; their power of resisting, however, is generally inconsiderable, and these rocks fall down pretty rapidly into sandy soils. The modifications experienced hy the constituent minerals of rocky masses, do not happen solely from changes in the molecular state of their elements ; their chemical nature is further deeply changed, and some of their original principles disappear. The fel- spars, for example, into the constitution of which potash and soda enter, abandon almost the whole of these alkalies, in passing into the state of kaoline. This is made manifest by a comparison of ihe analyses of the mineral in its two states. Besides the alkali which is lost, we also perceive that in kaoline, the proportion of alumen relatively to that of silica, is much greater than in the undecomposed felspar, a fact which, according to M. Berthier, demonstrates that the alkali is removed in the state of silicate. The final result of the disintegration of rocks, and of the decom- position of the minerals which enter into their constitution, is the formation of those alluviums which occupy the slopes of mountains that are not too steep, the bottoms of valleys, and the most extensive plains. These deposites, however formed, whether of stones, peb- bles, gravel, sand, or clay, may become tlie basis of a vegetable soil, if they are only sufficiently loose and moist. Vegetation of any kind succeeds upon them at first with difficulty. Plants which by their nature live in a great measure at the expense of the atmosphere, and whick ask from the earth little or nothing more than a support, fix themselves there when the climate permits. Cactuses and fleshy plants take root in sands ; mimosas, the broom, the furze, &c., show themselves upon gravels. These plants grow, and after their death, either in part or wholly, leave a debris which becomes profitable to succeeding generations of vegetables. Organic matter accumulates in the course of ages, even in the most ungrateful soils in this way, and by these repeated additions they become less and less sterile. It is probable that the virgin forests of the new world have thus supplied the wonderful quantity of vegetable mould, in which the present generation of trees is rooted. At Lavega de Supia, in South America, the slipping of a porphyritic mountain covered completely with its debris, to the extent of nearly half a league, the rich plan- tations of sugar-cane which were there established. Ten years af- terwards I saw the blocks of porphyry shadowed by thick groves of mimosas ; and the time perchance is not very remote when this new forest will be cleared away, and the stony soil, enriched with its spoils, will be restored to the husbandman. The chemical composition of the earth, adapted for vegetation, must of course participate in the nature of the rocks and substrata from which it is derived ; and the elements which enter into the constitution of mineral species ought to be found in the soils, which, »y the elFect of time or human industry, may serve for the repro- duction of vegetables. It is on this account that it becomes inter- 204 SOIL. esting to know the composition of the minerals which are the most abundantly dispersed in the solid mass of the globe. The solid part of our planet, as is well known, occupies but one- third of its whole surface. The ocean occupies two-thirds, and the majority of the rocks of sedimentary formation must have been pri- marily deposited at the bottom of the sea. These rocks will there- fore be apt to contain the saline substances which are met with in sea-water, and it is a fact that many of the secondary sandstones show unequivocal traces of these substances. Deltas and low downs, left by the ocean, are constantly being brought under tillage, and the fierce winds of the sea frequently carry saline matters to vast dis- tances, even to the centre of great continents ; lastly, as we shall see by and by, the ocean supplies agriculture with powerful manures. Analysis shows that sea-water contains, besides chloride of sodium or common salt, hydrochlorate of magnesia, sulphate of soda, sul- phate of magnesia, sulphate of lime, carbonate of lime, carbonate of magnesia, and a quantity of carbonic acid, to which must be added the substances discovered in the mother waters of salt marshes, and which occur with reference to the others in quantities so small as to escape direct analyses of any moderate portions of sea-water : these substances are iodides, bromides, and certain ammoniacal salts. The minerals most generally found in rocks are quartz, felspar, mica, amphibolite, pyroxenite, talc, serpentine, and diallage. Quartz is frequently composed of silica nearly in a state of purity ; but I may save time by presenting in a single table the composition of the principal mineral s])ecies such as we find it indicated by th*» best chemical analysts : Miiirnl' COMPOSITION. I 1^ F»,'lspar of Lomnitz Ditto Doinito Ditto Albitcof Finlfind Ditto Albiteof Arendal Siberian Mica Mica from the U. States Amphibolite of Pargas . While Tyroxonite Green ditto Serpenliiu- Ditto, nnotiier kind ■•.. Spezian DiailH«c Talc from St. Bernard.. Ditto from St. Gothard. • 6<).8 Gl.O f)8.() f>H 42 U 48.;-) 4.=> .'■>4.f) .>4.lt 42.3 43.1 47.2 58.2 02.0 Ahi- uiina. 17..) l'J.2 iy.t> lft'.» 16.1 33.i) 12.2 0.2 0.3 3.7 traces Lime. Mag- 1.3 0.7 13.8 24.9 2.3.6 o..-> 13.1 I traces I 26.0 I 18.8 I 18.0 16..". I 44.2 ; 40.4 24.4 33.2 30.5 11.3 2.8 0.8 4.2 0.2 0.3 4.9 7.3 1.8 4.4 0.2 1.2 7.4 4.6 2.5 0.5 traces 1.3 0.2 2.0 0.4 2.0 3.0 13.3 12.5 3i2 3.5 0.5 If we now compare the analyses of the ashes of vegetables which we have already given with those just indicated, we see that the piineral substances which inoel us in plants alsc exist in the soil in Jependenlly of anv ;il Iitjop fiom inMnurc. "Wp nru- thi^rpfnrc lay ii SOIL. 205 down as a principle that the mineral substances encountered in vege- tables are obtained in the soil, and that the whole of these substances come from rocks which form the solid crust of our planet. I ought, however, to observe in this place that the phosphates, which are so constantly present in plants that it is to be presumed they are essen- tial to their or^^anization, do not figure among the elements of crys- talline rocks ; ive only meet with phosphoric acid in the strata of a more recent geological epoch, — strata the formation of which has in- deed followed the appearance of organized beings ; so that it would be quite fair to mamtam that this acid had been introduced into these new strata by the animated beings which are buried in them. Still the phosphates are by no means wanting in the rocks of igne- ous origin. In metalliferous strata, to quote those of more common occurrence only, we find phosphate of lead, of copper, of manganese, and of lime ; it is even difficult to discover a ferruginous mineral which does not contain a larger or smaller dose of phosphoric acid. And I must here add, that if phosphoric acid has been rarely indi- cated as a constituent of mineral substances, this is by no means from its uniform absence there, but because it escaped the researches of the analyst, in the same way as iodine and bromine for a long time escaped notice in all the analyses that were made of sea-water. Chemists, in fact, only discover those bodies readily which exist in some very appreciable quantity in the compounds they examine. The substances whose presence is not foreseen, those which only enter in extremely small quantity into a mineral, are apt to pass the eyes of even the most skilful and conscientious unperceived. The ashes of every vegetable examined up to the present time show us phosphates, and yet these salts have never been detected in any of the analyses of saps (not very numerous it is true) which we possess; it is, nevertheless, all but certain that the sap must contain phosphoric acid in some state of combination or another. Thaer compares the soil in husbandry to the raw material upon which the industry of the manufacturer is exercised ; the comparison would, perhaps, be more exact were the soil likened to the mechani- cal agents he uses ; and, in fact, even as the prosperity of manufac- tures and the perfection of their produce depend upon the perfection of the machinery employed, so are the quality and the quantity of crops connected in the most intimate manner with the quality of the soil. The highest skill of the husbandman, even under a favorable climate, and otherwise in the most advantageous circumstances, may all be made nugatory by the incessantly renewed difficulties which meet him in a barren soil. To be truly fit for agriculture the earth ought to present several essential qualities ; a soil, for instance, must be sufficiently open, sufficiently loose, to permit the roots of plants to penetrate it, and to prevent the water from stagnating upon it. The matter of which it is composed must, further, be of such a kind that the air may insinu- ate itself into it and be renew^ed, without, however, too rapid a des- iccation following. A great deal has been written since Bergman's time upon the 18 206 SOIL SAND AND CLAY. chemical composition of soils Chemists of great talent have made many complete analyses of soil j noted for their fertility ; still practical agriculture has hitherto derived very slender benefits from labors of this kind. The reason of this is very simple ; the qualities which we esteem in a workable soil depend almost exclusively upon the me- chanical mixture of its elements ; we are much less interested in its chemical composition than in this ; so that simple washing, which shows the relations between the sand and ihe clay, tells, of itself, much more that is important to us than an elaborate chemical analysis. The quality of an arable soil depends essentially on the association of these two matters. Sand, whether it be silicinus, calcareous, or felspathic, always renders a soil friable, permeable, loose ; it facili- tates the access of the air and the drainage of the water, and its in- fluence is more or less favorable as it exists in the state of minute subdivision, or in the state of coarse sand or of gravel. Clay possesses physical properties entirely opposed to those of sand ; united with water it forms an adhesive plastic paste, which, once moistened, becomes almost impermeable. With such charac- ters, it will easily be conceived how it is impossible to work to ad- vantage a soil that is entirely argillaceous. The proper character, or, if you will, the quality of a soil, depends, then, essentially on the element which predominates in the mixture of sand and clay thai composes it ; and between the two extremes, which are alike un- favorable to vegetation, viz., the completely sandy soil and the un- mixed clay, all the other varieties, all the intermediate shades can be placed. It is rare, indeed, that arable soils are formed solely of sand and clay : not to mention certain saline substances which are generally encountered, although in small quantity, we always find the remains of organic matters, remains which constitute that part of a soil which has been designated under the somewhat vague name of humus. Although a soil which is entirely without humus maybe cultivated by calling in the aid ofmatiure, and as humus, conseijucnt- ly, need not be regarded as indispensable, still this matter generally enters, in certain proportions, into the constitution of soils. The soils of forest lamls contain a large quantity of it, and some soils are mentioned which are very rich in this substance, and which yield abundant .-rops of grain for ages, and with very little attention. In examining a soil, attention ought to be directed, 1st, to the sand, 2d, to the clay, 3d, to the humus which it contains. It would, further, be useful to inquire particularly in regard to certain other principles which exert an unquestionable inllucnce upon vegetation, such as certain alkaline and earthy salts. Vegetable earth dried in the air until it becomes quite friable may, nevertheless, still retain a considerable quantity of water, and which can only be dissipated by the assistance of a somewhat high temperature. It is therefore proper, in the first instance, to bring all the soils which it is proposed to examine comparatively, to one constant degree of dryness. The best and quickest way (f drying such a substance as a portictn of soil, is to make use of the oil-bath ; a quantity of oil contained in a copper vessel is readily kept at ao SOIL ITS ANALYSIS. 207 almost uniform temperature by means of a lamp. A thermometer plunj^ed in the bath shows the degree to which it is heated ; the substance to be diind is put into a glass tube of no great depth, and sutiiciently wide ; or into a porcelain or silver capsule, if the quantity to be operated upon be somewhat considerable : these tubes, or ves- sels, are jilaced in the oil so as to be immersed in it to about two- thirds of their height. For the desiccation of soils, the temperature may be carried to 150" or. 160' C, (334^ or 352'' F.) The weight of the vessel is first accurately taken, and a given weight of the matter to be dried is then thrown into it.'after which it is exposed to the action of the bath. If we operate upon from 600 to 700 grains, the drying must be continued during two or three hours; the weight of tiie capsule with its contents, after having been wiped thoroughly clean, is then taken. It is placed anew in the bath, and its weight is taken a second time after an interval of fifteen or twenty minutes ; if the weight has not diminished, it is a proof that the drying was complete at the time of the first trial. In tlie contrary case, the operation must be continued, and no drying must be held terminated, until two consecutive weighings, made at an interval of from fifteen to twenty minutes, show any thing more than a very trifling dilTer- ence. Davy points out another and much more simple method, which, although far from accurate, may, nevertheless, suffice in many general trials. The soil to be dried is put into a porcelain capsule heated by a lamp, and a thermometer, with which the mass may be stirred, is placed in its middle, and shows the temperature at each moment. Lastly, in many circumstances the marine bath may sufiice. In drying, the main point is to do so at a known tem- perature, and one which may be reproduced; for the absolute desic- cation of a quantity of soil could not be accomplished except at a heat close upon redness, and this would, of course, alter or destroy the organic matters it contains. The organic matters contained in ordinary soi's consist, in part, of pieces of straw and of roots, which are usually separated by sifting the earth through a hair sieve ; the gravel and stones which the soil contains are separated in the same way. The earth sifted is now washed. To accomplish this, it is intro- duced into a matrass, with three or four times its bulk of hot distilled water, the whole is shaken well for a time, the matrass is left to stand for a moment, and then the liquid is decanted into a wide porcelain capsule. The washing is continued, fresh quantities of water being added each time, until the wliole of the clay has been re- moved, which is known by the fluid becoming clear very speedily ; the sand which remains, is then washed out into another capsule. The argillaceous particles, or the clay and all the matters held in suspension in the water, are thrown upon a filter and dried ; the desiccation is completed by the same process, and under the same circumstances as that of the soil had been. Tlie sand is, in like manner, dried with the same care. If we would ascertain the nature and quantity of the soluble salts. the whole of the water used in the washing must be put togcthe* 208 ' SOIL ITS ANALYSIS. and evaporated, which may be den . upon a sand-bath. The evapo- ration is pushed to dryness, and tL3 salts that remain, havings been previously weighed, are thrown into a small platinum capsule, in which they are heated to a dull red by means of a spirit-lamp, in order to burn out the organic salts, and thus distinguish, by means of a subsequent weighing, between them and the inorganic salts. The sand may be silicious or calcareous. The presence of car- bonate of lime is readily ascertained by treating it with an acid which will form a soluble salt with lime, such as hydrochloric, nitric, or acetic acid. Effervescence shows the presence of a carbonate ; the quantity of which may be estimated by weighing the sand dry before and after its treatment with the acid, particular care being of course taken to wash the remaining sand well before setting it to dry. This, however, is an operation of little use, the great object is to as- certain the quantity of sandy matter. Had we a particular interest in ascertaining the presence and estimating the quantity of the earthy carbonates contained in a sample of soil, it would be advisable to make a special inquiry, inasmuch as the finely divided calcareous earth being carried off along with the clay in the course of the wash- ing, the sand obtained never contains the whole of the carbonate of lime. The argillaceous matter procured by the washing is far from being pure clay ; it contains a quantity of extremely fine sand, particles of calcareous earth, and if the soil contain humus, the more delicate particles of this substance will also be included. To determine tiie quantity of humus, recourse is generally had to its destruction by heat. A known weight of dried earth is heated to redness in a capsule, and constantly stirred for a time, and when no more of those brilliant points or sparks, which arc indications of the combustion of carbon, are observed, it is set to cool and then weighed. This is the method which has been generally followed by Davy and others. It would l)c difficult to find a method more con- venient than this, but it is unfortunntely very inaccurate. Soils dried at a temperature at which organic matter, such as humus, &c., begins to change, still retain a considerable quantity of water in union with the clay. This water is disengaged at the red heat required for the combustion of the organic matters; and as their quantity is estimated by the loss of weiglit on the subse(]uent weighing, it is ob- vious that the loss from the dissipation of water is added to that which proceeds from the di^struclion of the humus. It is undouijted- ly to tliis cause of error that we must ascribe the large proportions of humus mentioned in the soils examined by Thaer and Einhoir; it is therefore better to restrict the examination to the determination of the presence or absence of humus than to attempt to ascertain its quantity by so imperfect a method. Priestley and Arthur Young were already aware that a more deli- cate operation was required to tletermiue the quantity of humus. They recommend calcination of the soil in a close vessel, and that the gaseous products should be collected. This mode of proceeding however, would have but sliofht advantages over that which I have SOIL ITS ANALYSIS. 209 just criticised, inasmuch as the volume of gas collected varies with every difference of heat employed. The only method in my opinion which we have of learning the quantity of humus, of organic debris, which is contained in a soil, is that of an elementary analysis. It is by burning a known quanti- ty of earth thoroughly dried by means of the oxide of copper, aided by a current of oxygen, that the carbon and hydrogen may be de- termined. But the most important point of all is to ascertain the amount of azote included in the organic remains of the soil ; and we have happily precise means in our elementary analysis of ascertain- ing the quantity of azote, from which the amount of azolized organic matter may be accurately inferred. It may be very useful to determine the presence or absence of carbonate of lime in a so I ; this knowledge would of course guide us in our applications of lime, marl, &c. Two modes may be em- ployed for this purpose ; 1st. the soil may be treated by nitric acid slightly diluted with water. Any effervescence will denote the presence, in all probability, of carbonate of lime. I say in all proba- bility, because the disengagement of carbonic acid gas under such circumstances generally indicates the presence of carbonate of lime ; it is not, however, a special character, because the disengagement may be due to the presence of any other carbonate. It is well to boil the acid solution upon the sample of soil that is analyzed ; the part which is not dissolved is thrown upon a filter and washed with distilled or rain-water boiling hot. Into the clear filtered liquor which results from all the portions of water used in the washing, a little ammonia is added ; if any precipitate falls, it is collected upon a filter and washed : to the new liquors obtained by this washing, a solution of oxalate of ammonia is added. If there be any lime pres- ent, it is thrown down in the state of oxalate, and the liquor, having been left at rest for five or six hours, becomes completely clear; the addition of a few drops of the solution of oxalate of ammonia to this clear fluid satisfies us whether the whole of the lime has been pre- cipitated or not. The oxalate of lime is received upon a filter, wash- ed, and dried ; it is then thrown into a platinum capsule along with the piece of filtering paper upon which it was collected, and is heat- ed to a dull red, until the paper of the filter is completely consumed and no further trace of carbon appears; the capsule is then taken from the fire or from over the spirit lamp, and cooled ; when cold, the matter which it contains is moistened with a concentrated solu- tion of carbonate of ammonia. The matter is then dried, great care being taken that nothing is lost by particles flying out, and the capsule is again heated to a dull red ; when cold, it is weighed accurately, and the quantity of matter contained then becomes known. This matter is carbonate of lime, 100 of which represent 56.3 of lime and 43.7 of carbonic acid. I have said that in arable soil other carbonates may be met with be- sides that of lime ; calcareous soils, for example, very commonly contain carbonate of magnesia. If we would ascertain the quantity of this earth, the mode of proceeding which I have just particularly 18* '5iO SOIL ITS ANALYSIS. indicated enables us to do so ; we have but to evaporate the liquid from which the oxalate of lime was deposited, and then to calcine the product of the evaporation in a platinum capsule. Any nitrate of maffnesia which may exist there will be decomposed at a dull red heat, as well as any oxalate of ammonia which may have resulted from ammonia added in excess. By treating the residue of the cal- cination with water we obtain the magnesia, which being washed. has only to be calcined and its weight ascertained by weighing. 2d. If we would be ;ontent with a simple approximation, we may judge of the quantity of calcareous carbonate contained in a vegeta- ble soil by measuring the quantity of carbonic acid which we obtain from it. We counterpoise upon the scale of a balance a phial con- taining some diluted nitric acid ; we weigh a certain quantity of the earth to be analyzed, and this is added by degrees to the acid. If the earth contains carbonates, effervescence ensues. The liquid is shaken with care, and having waited a few minutes in order to let the carbonic acid which is mixed with the air of the phial escape, the phial with its contents is again put into the balance. If there has been no disengagement of carbonic acid, it is clear that to restore the equilibrium it will be sufficient to add to the opposite scale the weight of the earth which was put into the phial ; whatever is want- ing of this weight represents precisely the weight of carbonic acid which has been disengaged. Presuming this acid to have been com- bined with lime, the weight of the calcareous carbonate can l)e cal- culated exactly. Sulpliate of lime is an occasional constituent of soils ; to ascertain its presence and quantity, the following is the method of procedure : The earth well pulverized is first roasted tor a considerable time in a crucible or platinum capsule, until all the organic matter is com- pletely destroyed ; it is advisable to operate an about 100 grammes, or about 3.2 ounces troy of soil. After this operation the matter is boiled in 4 or 5 times its weight of distilled water for some time ; water being added to replace that which is dissipated by evaporatiate. M. Schubler tried the retentive powers of the soil by tht following method. A metallic disc, fumished with a narrow rim. was suspended to the arm of a balance. Over this disc, the soil K * The abbreviate kil. in the alMivo tabic sicnifies killoprnriiino. n woipht rcjual to 2.S lbs. HVoir(lu|K)is. .\s the \viM!.'hts are princi|viliy interesting in their rel.ilinni to »n« uu)th«r, iC has not been thought necessary- to reduce them to English weighU. SHRINKING OF SOILS. 219 be tried and previously brought to the point of saturation with moist- ure, was spread as evenly as possible. The weight of the disc thus charged was noted, and it was weighed anew, after having been kept for four hourc in a temperature of 18.75" cent. (65.75° Fahr.) The weight of the water lost by evaporation was obtained by a second weighing; the complete desiccation of the soil was then completed in the stove. The following is the detail of one opera- tion : Weight of the moist earth 310 Weight after four hours' exposure to the air 260 Water evaporated 50 Weight of the moist earth 310 Weight after complete desiccation 200 Whole quantity of water contained in the soil tried ... 110 Thus 100 of water of imbibition lost 45.5 during exposure to the air for 4 hours at a temperature of about 66" Fahr. A more se- verely accurate method might readily be contrived, but that employ- ed by M. Schiibler appears sufficient for ordinary purposes. His results, in regard to the different kinds of soil he tried, are these : 100 parts of the water cont:»ii)ed in the soil lose Kinds of soil. in the course of 4 iioura at 66 (leg-. Fahr. Silicinus sand 88.4 Calcareous sand 75.9 Gypsum 71.7 Sandy clay 52.0 Stiffish clay 45.7 Stiff clay •. 34.9 "nrecUiy 31.9 Calcareous soil 28.0 Humus 20.5 Garden earth 24.3 Arable soil of Hoffwyll 32.0 Arable soil of the Jura 40.1 Of all the substances examined, sand and gypsum are obviously those which allow the water to pass off most rapidly by evaporation. The calcareous or chalky soil again has a high retentive power : but it varies much in different instances, apparently in consequence of different degrees of fineness ; it is however surpassed by humus, and the garden soil which was tried. Humus is therefore at the head of the list of substances in reference to retentive properties. All soils shrink more or less in drying, and form cracks, in the way already indicated ; the shrinking has been estimated by means of prisms of soils measured in the moist state, and after being dried in the shade : Kinds of soil. 100 parts cube shrink to. Carbonate of lime in fine powder 950 Sandy clay 940 Stiffishclay 911 Stiff clay 886 Pure clay 817 Humus 846 Garden earth 851 Arable soil of Hoffwyll 880 Arable soil of Jura 905 220 llYGr.03IETRIC POWER OF SOILS. Gypsiiin, silicious, and calcareous ?.-^:A do not appear in this table, because they do not shrink in drying The humus appears to have shrunk the most; and dry humus is liable to swell in the same pro- portion when it is moistened. This property explains the obvious elevation of certain turfy or mossy soils at the period of the rains. Hygromelnc property of soils. Agriculturists allow, that those soils which have the property of attracting moisture from the atmo- sphere are generally among the most fertile. This hygrometric property must not be confounded with that in virtue of which moist- ure is retained. It appears to depeid especially on the porousness of a soil, and, probably, also, in soi le degree, on the deliquescent salts which it contains, even in veiy small quantity. Davy was disposed to regard the hygrometric property of soils as a certain index of their good quality; and the experiments of M. JSchiibler upon the point, all tend to confirm the accuracy of this view. In M. Schiibler's experiments, the increase of weight of dry soils was ascertained by exposing them for a certain time m an atmosphere kept at tlie point of saturation with moisture, and at the same tem- perature, between 60° and 65° Fahr. Silicious sand Ciilc.ireous sand CyP'Um Licht ci:iy Stiffish clay Stroni; clay Pure cliy Chalky soil in fine powder FIniiiu-i Garden earth Arable soil of Ilorrwyll ... Arable soil of Jura 500 ceiiligTiimnnei, or 77.165 srains troy, of ooil, spread upon a burrace of 36,000 iinlliinnre^, or 141.43 square luches, absorbed m — 12 hours. Grains. 0 .154 0.077 I.e. 17 l.'.t'ii 2..310 •2.840 2.00-2 n.KW 2.(>9J I.2.T2 1.078 Grains. 0 .231 0.077 2.002 2.310 2.772 2.387 7.4()9 3.4f.5 1.771 1.403 0 .231 0.077 2.156 2.r,i8 3.080 3.096 2.r.i»5 8.470 3.a'>o 1.771 IWO Grains. 0 .231 0.077 2. 1 50 2.095 3.157 3.773 2.695 9.240 4.0OI 1.771 1.540 From the results comprised in the preceding table, we may con- clude, first, that the faculty of absorbing lessens as soils acquire moisture ; second, that iiumus is the most hygrometric of all the substances examined ; third, that the clays which absorb the largest quantity of moisture are those which contain the smallest proportion of .sand; and fourth, that silicious sand and gypsum do not absorb moisture in any appreciable quantity. Absorption of oxygen gas hy arable soils. Humboldt had already observed, before the year I7i)3, that argillaceous soils, the lydian stone, certain schists, and humus, deprived the air of its oxygen. He had also observed tluit the sides of the large cavities dug in the salt mines of Saltzl)urg, al)sorbed thi.s gas, and thus rendered the stagnant atmosphere of the workings irrespirable and incapable of supporting combustion. Finally, this illustrious observer had satis ABSORPTION OF OXYGEN BY SOILS. 221 factorily ascertained, at the same period, that earth taken from the galleries of these mines, only became fertile after having been ex- posed to the atmosphere for a considerable length of time. I have quoted these curious observations because they are, so far as I know, the first which established the necessity of the presence of oxj^gen in the interstices of the soil, or, as M. Humboldt then said, and, in- deed, as may still be maintained, the utility of a previous oxidation of the soil. All our agricultural facts, indeed, confirm this view of the necessity of air in the interstices of the soil that is destined for the growth of vegetables. When, by ploughing very deeply, for example, we bring up a portion of the subsoil into the arable layer, in order to in- crease its thickness, we always lessen the fertility of the ground for a time ; in spite of the action of manures, and of any treatment we may adopt, a certain time must elapse before the subsoil can pro- duce an advantageous effect; it is absolutely necessary that it have been exposed to the atmospheric mfluences, and it is then only that deep ploughing, which gives the arable layer a greater thickness, pays completely for the expense it has occasioned. I am disposed to ascribe the absorption of oxygen gas by clayey soils, to the oxide of iron, which they almost always contain, and which is in the minimum state of oxidation, when the clay lies at a certain depth. In the performance of some soundings in a tertiary soil of the department of the lower Rhine, which I performed in 1822, I had occasion to observe that the clays brought up white by the borer, very speedily became blue by exposure to the air ; and that in gaining color they condensed oxygen. I propose returning upon this fact to show the important part which this simple super- oxidation probably plays in the amelioration of soils.* M. Schiibler, again, has studied the action of oxygen gas upon the component parts of arable soils, and, according to him, the aljsorp- tion of this gas cannot be doubted ; it is very trifling in connection with sand and gypsum, very decided as regards clay, loam, and humus. As M. de Humboldt and M. de Saussure had already done, M. Schiibler observed humus to change a portion of the oxygen which it fixed, into carbonic acid ; but, in general, the other sub- stances, or soils, or elements of soils, upon which he experimented, appeared to absorb the oxygen by the intermedium of the protoxide of iron, from which they are never altogether free. Besides this .cause, due to the superoxidation of a metal, M. Schiibler thinks that a certain portion of the oxygen disappears by condensation within the pores of some soils ; and in support of his opinion he appeals to the admirable observations of M. de Saussure, on the condensation of the gases by porous bodies. Starting from the fact that the roots of plants require the presence of oxygen in order to thrive, he * Austin proved, that during the oxidation of mefdllic iron under water, there is a constant production of anunonia. Certain exi)erinients commenced souje time ago, and which I still continue, will establish in the mo:>t precise manner, as 1 hope, the fact that this formation of ammonia likewise lalies place during the passage of the protox- ide of iron to the state of hydrated peroxide. The theoretical conclusions deducible from th:s fact, and the economic applications which may flow from it, must be obvious. 19* 222 CAPACITY OF SOILS FOR HEAT. ascribes a greater power to the gases compressed or condensed within the interstices of the soil. But the action of the air upon the roots of vegetables is readily conceivable in soils of a loose nature, especially if they have been sufficiently worked, without the necessity of having recourse to such an explanation. Capacity of soils for heat. The quantity of heat which a soil will receive, retain, or throw off in a given time, depends upon the con- ducting power which it possesses. M. Schubler endeavored to measure this power comparatively by measuring the rates of cooling. In a vessel of the capacity of 595 cubic centimetres, or 234.2 cubic inches, filled with the substance to be tried, a thermometer was placed, with its bulb in the centre. The temperature having been brought up to 62.5° C, (144.5^ Fahr.,) the time was noted which each substance required to fall to 21.2° C, or about 70" Fahr., the temperature of the surrounding air being 16.2° C, or about 61° Fahr. Kind ofsoiL Power of retaining heat, that of calcareous saiiil beii.j 100. Time which S3.I.S cubic inches of ioil required 10 cool from IA\- to 70 = Fahr., the temperature of the surrouiidiii_^ air beiii^ about 61 = Fahr. Calcareous sand 100.0 95.6 732 76.9 71.1 68.4 66.7 61.8 49.0 648 70.1 743 h. m. 3.30 3.-27 2.34 2.41 2..30 2.24 2.19 2.10 1.43 2.16 2.27 oiiie ^rifTi^h /*l*t\r Stiffclay I1iiinu> Amble soil of Hoffwyll ... Amble soil of the Jiim-.. • The general observations which these experiments suggest, are that, for equal volumes, calcareous orsilicious sand possesses greater powers of retaining heat than any «»f the other substances tried. This fact explains the high temperature and the dryness which sandy soils maintain even during the iiij^jht in summer. Humus is obviously the substance which possesses the highest conducting powers. Degrees in ivhich soils become heated under exposure to the sun. There is no one who has not had occasion to observe tiie high tem- perature which bodies acquire when exposed to the rays of the bright sun. There are some, such as dry sand, slates, and certain colored rocks, which become burning hot. It is by the heal of the sun that the soil, before it is shaded by the leaves ami stems of plants, ri. 100.0 Several fertile soils of Senegal, examined by M. Laugier, con- ained : Rawei. Silicious sand and silica 87.0 Alumina 3.6 Oxide of iron 3.4 Carbonate of lime tnice Organic matter and water 4.4 Loss 1.6 100.0 100.0 lUO.O 100.0 100.0 M. Plagne, who has studied the agriculture of the Coromandel coast, divides the soils he met wiih there into argillaceous, or clayey, sandy, and mixed, and gives their several compositions as follows : Arj^i'iacroti*. Sanilx- Miud. Silica 22.0 8ia 64.0 Alumina .VJ.O 6.5 19.5 CarlM)nntc of lime 3.5 3.5 2.5 O.xidc of iron 2.5 4.0 4.0 rhn«i)h.itc of ninenesla "i an *»•<> Suiphntooflime^ " i ^'^ *""> A7.i>li7.cd organic mattrr 5.0 " 7.0 Water nn(llo>s '_ ^i! _^^^ _M "Too.o looTo loao The soils in which the tea-plant is grown in Assam and fhina, have been examined by Mr. Piddington;* they contain respectively: Chiiiric >oiI. A.«Mio toil. Silica and Mind 76.0 84.8 Aiuniina 9.0 4.5 Oxideofiron 9.9 7.0 Phosphate and sulphdte of lime 1.0 traces Organic matter 1.0 1.5 Water 2L0 SJ 99.9 100.1 Sir Iluniplirey Davy found the various soils most generally culti rited in Kiiglanil, to have the following composition ; • B«l»in-ui»son, Geognosy, vo' ii. p. 4G7. ARREST OF MOVING SANDS. 237 Downs do not bound the ocean like beaches. From the base of the first hillocks to the line which marks i he extreme height of spring tides, there is always a level over which the sand sweeps wiihoiU pausing. It was upon this level space that Bremontier sowed his first belt of pine and furze seeds, sheltering it by means of green branches, fixed by forked pegs to the ground, and in such a way that the wind should have least hold upon them, viz., by turning the lopped extremities towards the wind. Experience has shown^'that by proceeding thus, fir and furze seeds not only germinate, but that the young plants grow with such rapidity, that' by and by they form a thick belt, a yard and more in height. Success is now certain. The plantation so far advanced, arrests the sand as it comes from the bed of the sea, and forms an effectual barrier to the other belts that are made to succeed it towards the interior. When the trees are five or six years of age, a new plantation is made contiguous to the first and more inland, from 200 to 300 feet in breadth" and so the process is carried on until the summits of the hillocks are gradu- ally attained. It was by proceeding in this way that Bremontier succeeded in covering the barren sands of the Arrachon basin with useful trees. Begun in 1787, the plantations in 1809 covered a surface of between 9,000 and 10,000 square acres. The success of these plantations surpassed all expectation ; in sixteen years the pine trees were from thirty-five to forty feet in height. Nor was the growth of the furze, of the oak, of the cork, of the willow, less rapid. Bremontier show- ed for the first time in the annals of human industry, that moveable sands might not only be stayed in their desolating course, but actu- ally rendered productive. Like all other inventors, this benefactor of humanity was soon the object of jealousy among his contempora- ries. Doubts were of course entertained at fir.st of the possibility of consolidating the moving sands of downs ; and when this was de- monstrated, the honor of originality was denied him. The ingenious engineer defended himself with moderation, and demanded an in- quiry ; in the course of which it was satisfactorily proved that noth- ing of the same kind had been attempted by others previously to the year 1788. The labors of Bremontier must be regarded as another of those remarkable struggles which the industry of man has suc- cessfully waged with the elements. CHAPTER V. OF MANURES. vVhatever may be its constitution and physical properties, land yields lucrative crops only in proportion as it contains an adequate quantity of organic matter in a more or less advanced state of de- composition. There are favored soils in which this matter, desig 238 MANURES. nated by the name of humus, or mould,* exists by nature, while there are others, and they form the majority, which are either totally des- titute of it, or contain it but in insignificant proportion. To become productive, these soils require the intervention of manure ; for thi* there is no substitute, neither the labor which breaks them up, nor the climate which so powerfully promotes their fecundity, nor tho salts and alkalies which are such useful auxiliaries of vegetation. Not that land entirely destitute of organic remains is incapable of producing and developing a plant. We have already seen that the atmosphere, light, heat, and moisture, suffice for its existence ; but in such a condition, vegetation is slow and often imperfect ; nor could agricultural industry be advantageously applied to a soil which approached so near to absolute sterility. Plants, considered in their entire constitution, contain carbon, water, (completely formed, or in its elements,) azote, phosphorus, sulphur, metallic oxides united to the sulphuric and phos()horic acids, chloildes, and alkaline buses in combination with vegetable acids ; many of these elements form no part of the atmosphere, and are necessarily derived from the soil. Moreover, the manures most generally made use of are nothing but the detritus of plants, or the remains or excretions of animals, including by the very fact of their origin the whole of the elements which constitute organized beings; and although it is very probable that certain tribes of plants are more adapted than others to appropriate the azote or the ammoniacal va- pors of the atmos()here, experience proves that azotized organic re- mains contribute in the most efficacious manner to the fertility of the soil. Besides, we are far from being able to affirm that the carbon of plants is derived from the cari)onic acid of the atmosphere. Doubtless this acid is its principal source ; but it is possible that certain elements of carburetted dungs may be directly assimilated. The writers who have treated of manures, have generally formed them into two grand classes : 1st. Manures of organic origin, in which are again found all the elements of the living matter. 2(1. Mineral manures, saline or alkaline, wliich are particularly designated under the name of stimulants, thus ascribing to them the faculty, purely gratuitous, of facilitating the assimilation of the nu- triment which plants find in dung, and of stimulating and exciting their organs. 8uch a distinction has no real foundation, and nothing shows so much how scanty our knowled-ge upon this subject has hitherto been as this tendency in the ablest minds to connect vege- table nutrition with the feeding of animals. All the agents employed by the agriculturist to restore, preserve, and augment the fecuntlity of the soil, I shall term Manures. In my view gypsum, marl, and ashes are manures, as much as horse- dung, blood, or urine ; all contribute to the end proposed in employ- ing them, which is the increase of vegetable production. The best • .Mould, or vj'irctihlf ••;«rth, as the word !•* penrr.illy usrd. i< not exactly Animm^ ; liul as it il»>rivrs in prinoip:)! qualilics from tho pr»'s«'nrr of the hunius of (he cheiaiK 1 »hall (;(*nrrall>cni|il<>y the tcrin^ as synonyiiiou<.— Eno. Ed. , DECAY OF ORGANIC MATTERS. 239 manure, that which is in most general use, is precisely that which by its complex nature contains all the fertilizing principles required in ordinary tillage. Particular cultures may demand particular manures ; but the stand- ard manure, such as farm dung, for example, when it is derived from good feeding, supplied to animals with suitable and abundant litter, affords all the principles necessary to the development of plants ; such manure contains at once all the usual elements which enter into the organization of plants, and all the mineral substances which are distributed throughout their tissues ; in fact, carbon, azote, hy- drogen, and oxygen are found therein united with the phosphates, sulphates, chlorides, &c. In order to be directly efficacious, every manure must present this mixed composition. Ashes, gypsum, or lime spread upon bar- ren land, would not improve it in any sensible degree ; azotized or- ganic matter, absolutely void of saline or earthy substances, would probably produce no better effect ; it is the admixture of these two classes of principles, of which the first is derived definitively from the atmosphere, while the second belongs to the solid part of the globe, which constitutes the normal manure that is indispensable to the improvement of soils. Dead organic matter, subjected to the united influence of heat, of moisture, and of contact with the air, undergoes radical modifica- tions, and passes by a regular course of transformation into a con- dition more and more simple. The tissues, so long as they form a part of the animated being, are protected against the destructive ac- tion of the atmospheric agents ; in plants and animals this protec- tion is not extended beyond the period of their existence ; destruc- tion commences with death, if the accessory circumstances are suf- ficiently intense ; and then ensue all the phenomena of decomposi- tion, of that putrid fermentation which, at the expense of the primi- tive elements of the organized being, generates bodies more stable and less complicated in their constitution, and which present them- selves in the gaseous and crystalline conditions, forms which are affected by the inorganic bodies of nature in general. The mineral substances which had been taken up in the organiza- tion become freed, and are thus again restored to the earth. The organized substances which change the most rapidly, are precisely those into which azote enters as a constituent principle. Left to themselves, whether in solution or merely moistened, these sub- stances exhibit all the characteristic signs of putrefaction ; they ex- hale an insupportable odor ; and the result of their total and com- plete decomposition is finally the production of ammoniacal salts. The water wherein the phenomenon is accomplished facilitates it not only by weakening cohesion and enabling the molecules to move more freely, but it assists also by the very affinity which each of its own principles bears to the elements of the substance subjected to the putrescent fermentation. Proust observed that during the de- composition of gluten immersed in water, a mixture of carbonic acid and of pure hydrogen gas is disengaged, a phenomenon which 240 MANURES. he explains by the decomposition of the water ; at the same time are produced aminoniacal sahs, amonj which are acetates and lac- tates, whose acids are generated by the very act of fermentation. As a striking example of the agency of water in the transit of azote into the ammoniacal state in a quarternary compound, we may tak** the putrefaction of urea. Urea is found in the urine of man and of quadrupeds ; its compo sition, according to ]M. Dumas, is : Carbon 20.0 Hydrogen 6.6 Oxygen 26.7 Azote 46.7 lOU.O The animal substances dissolved in urine, as the mucus of the bladder, &c., undergo, on contact with the air, a modification which causes them to act upon urea like ferments. By their influence the elements of water react upon this substance, and transform it into carbonate of ammonia. Carbonate of ammonia is composed of: Carbonic acid 56.41, containing j OA>'p'e"n... .'.'.".."..'.. ....ll!^ Ammonia 43.59?containing . j ^l^^t\^^^!]\ W, [ W. [ W, [ "...^-^ But 100 of urea have been found to produce by fermentation 130 of carbonate of ammonia. Carbon. Hjrdroyen. Oxrjen. Atoit. Previom to fcrmentuion, lOOof urea ) oq qq 6 60 '2 67 46 7 contains .... J " After frrmcnt-ition, 130 of carbonate i 20 00 10 00 53.3 46 7 of ammonia contiins . . J ' ' Diirtrcncc Ol 3.4 26.6 0.0 So that during its transformation, the urea has gained 3.4 of hy drogen, and 26.6 of oxygen. In water the hydrogen is to the oxygen as 1 to 8. (: : 1 : 8.) Now it is precisely in tbis proportion that hydrogen and oxygen are found to l>e ac(}uired by the urea in passing into the state of ca' bonate of ammonia ; whence it follows that the elemcnt-s of wave are fixed in the process. Tbe putrefactuui of azotized substances is far from always pre- senting results equally precise ; most frequently in decomposmg they pass tbrough a series of changes, still very obscure, before they attain their ultimate limit, viz. tbe production of ammoniacal salts. Thus from putrefying caseum diffused in water, M. Hraconnoi obtained, among other products and ammoniacal salts, a very remark- able substance which he calls aposcpedine. Aposepeiline when purified is a white crystalline substance, soluble in water and in alcohol, capable of combination with the metallic oxides ; azote is one of its elements This substance, although engendered by the act of putrefaction, is nevertbeless itself capable of jjiitrefying and giving birth to the last products of the spontaneous decomjwsition of azotized matter. One of the most striking characteristics, at least that which i« DECAY OF ORGANIC MATTERS. 241 most readily remarked, is the fetid odor which animal substanceas exhale during putrefaction. It is not always the smell of ammonia which predominates ; that of sulphuretted hydrogen gas is often very strong ; yet that is not the emanation which is most repulsive : miasmata and nauseous principles are also developed which seem to be the changed matter itself carried away by the gases that are dis- engaged. Sulphur, like phosphorus, is almost always a constituent of or- ganic bodies ; its minute proportion, however, would be insufficient to give out the hepatic odor so intense as we often find it during putrefaction. The production of sulphuretted hydrogen is connect- ed w^ith the very curious fact, first appreciated by M. O. Henri, that sulphates dissolved in a medium impregnated with azotized matter in decomposition, do themselves undergo an actual reduction, pass into the state of sulphurets, and immediately give out sulphuret- ted hydrogen, either by the action of the carbonic acid of the at mosphere, or by that which is formed during the putrefaction of the organic matter. It is by a similar action exerted upon sulphate of lime that M. Henri explains the origin of the sulphureous waters of Enghien, near Paris ; and M. Fontan in his important work on min- eral waters has generalized this explanation. The causes of the destruction of sulphates under such circum- stances is easily understood. During the decomposition of organiz- ed substances, the carbon belonging to them forms carbonic acid gas ; by combining both with the oxygen of the substances themselves, and with the oxygen of the water, it is probable that the oxygen of ' the sulphuric acid contributes equally to this formation, and that the sulphur is liberated. The hydrogen of the decomposed water, as well as that of the solid matter, in contact with sulphur in the nascent state, combines with it to form sulphuretted hydrogen, which straightway reacts upon the base of the sulphate, producing from it, as we know, water and a metallic sulphuret. This sulphuret being unable to exist when exposed to the continued disengagement of carbonic acid gas which takes place in the centre of the mass in putrefaction, yields, as a definite result, a carbonate on the one part, and sulphuretted hydro- gen on the other. The faculty which azotized organic bodies possess of undergoing spontaneous decomposition in presence of water, and under the in- fluence of heat, seems to depend upon the tendency which azote has to unite with hydrogen in order to form ammonia. This tendency is perhaps the determining cause of the phenome- non of fermentation taken in the most general acceptation of the term. Organic bodies void of azote decompose less easily, and the kind of alteration which they undergo from the action of water and air, differs in many respects from the putrefaction of azotized mat- ter. Of this the difficulty experienced in effecting the fermentation of vegetable substances is a proof Nevertheless, the vegetable re- fuse which goes to the dunghill, all without exception, contains azo- tized elements, often, it is true, in extremely minute proportions; 21 242 MANURES. but we know that there is no example of a vegetable organic tissnc from which they are completely excluded. The refuse of plants, the most amply endowed with azote, such as cabbage, beet-root, beans, &c., are certainly those which are sus- ceptible of the most rapid and complete putrid fermentation ; straw, on the contrary, when alone, undergoes it slowly and imperfectly, the small quantity of the azotic principle which it contains is chang- ed, and reacts upon the ligneous particles which surround it ; but the effect is soon ariested, and even ceases entirely, unless substances richer in azote concur. The woody matter of the straw is exactly in the condition of sugar which has not had a dose of ferment suf- ficient for its total transformation into alcohol. Most organized substances, whether they belong to the animal or vegetable kingdom when placed in certain conditions, undergo the profoundest changes from the action of hydrogen ; these alterations ought to be studied with all the more care, because in practical agriculture we are interested successively in fostering or preventing the causes which produce them, according as our object is to accele- rate the decomposition of vegetable refuse for manure, or to adopt the precautions which experience suggests, in order to preserve the produce of our harvests unchanged. Organic substances moist- ened and exposed to the air under a temperature, the niinimum of which (I believe after several experimcntb;) may be fixed at 48° or 50' F., seize upon the oxygen and absorb it, in part, in order to form water with their hydrogen, and carbonic acid with their carbon. When these substances are accunnilatcd in a mass sufficiently great, the heat produced is not rapidly dissipated, the temperature rises, and promotes the reaction to such a degree as to produce active burning, a conflagration, in place of the slow coml)ustion manifested at first. It is not very unusual to see h:iy, which had been gathered in too damp a condition, tike fire in the stack ; and the high temperature acquired by wet rags placed in the fermenting: vats of paper mills, and the copious production of carbonic acid which results, show that we are right in assimilating this kind of action to the phenomenon of combustion. This sluggish combustion is not peculiar to azotized organic sui)stances : it takes place equally in those destitute of azote. The alteration of organic matters, the combustion which goes on at a low temperature by the action of the air, ditTcrs in its results from the decomposition which is etTected in the midst of a liquid mass. We have seen, fi»r example, that jjluten fermenting urjder water, disengages hydrogen gas. Now Berthollet has established, and Saussure has confirmed his observations, that an azotized body in putrefaction, the whole of whose parts are in contact with the air, never contributes either hydrogen gas or azote to the confined at- mosphere in which it is placed ; and on tbo other hand, Saussuni has shown, that organic substances which do not emit hydrogen gas during their spontaneous decompo.'^ition in a medium void of oxygen, do not alter the volume of an atmosphere of which this pas f«)rms a part; on tlie contrary, tiiese substances condense oxygen as soon aa DECAY OF ORGANIC MATTERS. 243 they attain that stage of their alteration in which they give out hy drogen. In pursuing with persevering sagacity the study of putrefaction, M. de Saussure discovered the cause of this condensation ; it con- sists in the fact, that an organic substance in course of spontaneous decomposition, acts in some respects like the platina sponge placed in a mixture of oxygen and hydrogen gas ; we know that platina recently heated and introduced into a mixture of these two gases, determines their union in the proportions required to constitute water. Now by substituting for the metal some moistened seeds, previously deprived of their germinating faculty, the same effect is produced : the two gases combine until one of the two entirely disappears. When this combustion of hydrogen, proceeding from the decomposi- tion of organic substances, takes place in the body of the atmosphere which contains azote, it is possible that a minute quantity of ammonia may be produced together with water ; nor is it going too far to suppose, that manures very slightly azotized, take up azote from the atmosphere during their fermentation ; that during the act of vegetation itself, the hydrogen proceeding from the decomposed water, or yet more, that which makes part of the essential oils form- ed by plants, may, in oxidating afresh, introduce atmospheric azote into their composition. Dead organized matter, such as wood, straw, or leaves, exposed to wet, and for a long time to the action of the air, ends by becom- ing transformed into a brown substance, which when damped is al- most black, which falls to powder when dry, and which is commonly known by the name of humus or mould. This is, so to speak, the last term of the decomposition of organic matter ; mould appears to belong already to the mineral kingdom ; and whatever may be the diversity of its origin, it presents a suf- ficient number of peculiar characteristics to be considered a distinct substance. In fact, the atmosphere continues to exert its action upon mould ; its inflammable elements are dissipated by a slow and imperceptible combustion, giving place to water and carbonic acid. But in this ulterior decomposition, those fetid products which char- acterize putrid fermentation are no longer observed. Wet saw-dust, placed for some weeks in an atmosphere of oxygen, forms a certain quantity (jf carbonic acid, and the volume of the gas does not perceptibly diminish. The wood at the surface acquires a deep-brown color. Several experiments made by Saussure, prove that dead wood does not absorb the oxygen gas of the atmosphere ; it transforms it into carbonic acid, and the action takes place as if the carbon of the organic matter alone experienced the effects of the oxygen ; for the gaseous volume remains the same. The loss, how- ever, undergone by the ligneous fibre, during its exposure to the air, is greater than it ought to be if carbon alone were eliminated : whence Saussure c(mcludes, that while the woody matter loses carbon, it also lets some of its constituent water escape. As a consequence of these observations, the relative proportion of carbon ought to augment in the humid wood changed by the ac 244 MA.NURES. tion of the atmosphere, since we have established that by this action the woody fibre suffers loss in the elements of water besides what it loses in carbon. This is confirmed by the following analyses. The first, made upon some oak wood, previously purified by washing in water and in alcohol, we owe to Messrs. Thenard and Gay-Lussac; the succeeding one to Messrs. Meyer and Will : Oak wood. Id. rotten. Id. rotten. Carbon 52-5 ."ia.G 5H.2 Hydrogen and oxygen, water -17.. 5 46-4 43-8 TOOTO 100.0 100.0 Wood decomposed under water, without being in direct contact with the air, undergoes a different modification ; it is blanched in- stead of blackened, and the carbon far from increasing is diminished. Saussure thinks that this kind of alteration depends mainly on the loss of the soluble and colorinir principles of the wood, principles containing more carbon than the ligneous matter itself: so that pure woody fibre exposed wet to the action of the air would yield pro- ducts analogous to those which result from its decomposition under water. The damp linen rags which are fermented in paper manufactories afford a j)roduct which is white, and but slightly coherent. The mass, which heats successively during the operation, loses about 20 per cent, of its original weight. This is exactly what takes place in wood decayed by the alternate action of water and air, namely, it becomes white and extremely friable. Some oak arrived at this stage of decomposition contained, ac- cording to Liebig : Carbon 47-6 Hydrogen 6-2 Oxygen 44.9 Ashes 1.3 100.0 Compared with the composition of oak wood when sound, these numbers show that during its modification the wood has lost carbon, and that ii has gained hydrogen. The elements of water must ne- cessarily have intervened, and become fixed during the reaction. Tjigneou.s fibre decayino under water is not thereby completely pro- tected from the atmosphere. Water always holds some air in solu- tion, and the oxygen of that air reacts exactly as if it were in the gaseous state. Upon all the phenomena of dei^omposition connected with fermen- fation, with j)Uirefaction, or with dilatory combustion, heat exerts an influence which has certainly not been sufficiently appreciated. Organic bodies sunk in a large mass of water are not exposed to changes of temperature so various and abrupt as when they are placed in the atmosphere; their decomposition is more gradual, more uniform, and the s(»luble materials which they contain, or which are the result of the alteration they are undergoing, are in a great measure dissolved. Temperature may al.so produce great differencet DECAY OF ORGANIC MATTERS. 245 m the final result of the decomposition. Peat, which is derived, as we know, from the slow decomposition of submerged plants, does not appear to be formed in the swamps of warm cHmates ; it has, per- haps, never been encountered in the stagnant waters of liie equinoc- tial regions ; there the woody fibre appears to be totally dissipated in carbonic acid gas, and in marsh gas, the probable source of the insalubrity of those countries. Lakes with peat bottoms are not found except on the very high table-lands of the Andes, in localities where the mean temperature does not exceed 49" or 50" V. The alkalies are powerful agents in the decomposition of certain organic substances, whether in determining or in accelerating it. There are some, indeed, which experience no change without their intervention, whatever may be the other conditions favorable to de- composition. Thus, according to M. Chevreul, many coloring sub- stances may be preserved in solution almost indefinitely, without change, in contact with gallic acid ; but the presence ot a very small quannty of free alkali suffices for their immediately acquiring the power of absorbing oxygen, and at the same time of acquiring a brown tint, M. Chevreul observed that 3.087 grs. of hematine dissolved in potash will absorb 3.857 grs. of oxygen in forming 0.925 of car- bonic acid. The oxygen which enters into the carbonic acid, there- fore, represents nothing like the quantity which was fixed by the solution, and it is almost certain that this gas likewise reacted upon the hydrogen of the coloring matter. The use of the alkalies for accelerating the destruction of organized matter has been long known to agriculturists. Straw, fern, and the ligneous parts of plants are sometimes strat- ified with quick-lime, in order to facilitate their disintegration, and consequently their decomposition. The utility of this old practice cannot be disputed while confined whhin certain limits ; but it is often abused ; for it is beyond doubt that alkalies mingled indiscrim- inately with manure become in reality more injurious than advan- tageous for the end proposed in their introduction. The appearance of a certain brown substance, little soluble in water, but easily dissolving in alkalies, is a characteristic proper to all vegetable mailer under decomposition ; a characteristic which becomes more marked as the decomposition advances towards its last stage, namely, the production of humus. This substance is ulmine, which, on account of some acid properties which it pos- sesses, is also named ulmic acid. It forms a part of mould, and M. P. BouUay constantly found it in the water of dunghills. In 1797, Vauquelin discovered ulmine united with potash in the matter of the exudation from the ulcer of an elm-tree. In 1804, Klaprolh confirmed this observation. M. Braconnot succeeded in obtaining ulmine artificially by subjecting woody fibre to the action of alkalies. This substance is easily procured by carefully heating in a silver capsule, and continually stirring a mix- ture of equal parts of potash and of saw-dust slightly damped. At a certain time the woody matter softens and suddenly dissolves ; the mass then begins to swell up, and the fire is slaked. The product 21* 246 HUMUS. obtained dissolves almost totally in water. The solution is of a very deep brown color, and contains as principal ingredient ulmine com- bined with potash ; the ulmine is precipitated by the addition of a sufficient quantity of weak sulphuric acid. After having been washed and dried, ulmine is black and brittle, and resembles jet ; while still wet, it reddens turnsole paper, and its solution in potash forms with several salts, and by the way of double decomposition, insoluble ulmates. M. Peligot assigns to ulmine the following composition : Carbon 72-3 Hydrogen G.2 Oxypen 21.5 100.0 Dunghills, rotten wood, and mould, always contain a brown sub- stance, which possesses properties very similar to those which char- acterize ulmine obtained by the action of alkalies upon ligneous fibre. Mould which contains this ulmine in abundance, and in the con- dition most favorable to vegetation, ought on that account to be examined with attention. Its history has, indeed, been so ably traced by M. de Saussure, that science at the j)resent day can add but little to the important deductions of the celebrated author of the Re- cherches Chimu/ues. M. de Saussure defines vegetable mould (humus) to be the black substance which covers dead vegetables after they have been long exposed to the combined action of water and oxygen, llis experi- ments refer to mould nearly pure ; that is, separated by a fine sieve from the vegetable remains which are always nnxed with it ; to mould which had been gathered on high rocks, or from the trunks of trees, where it could not have been exposed to admixture or to any influence, other than that of the spontaneous decomposition by which it had been produced. All the varieties of mould collected in this way appeared terlile, especially when they were previously mixed with gravel, which supplies support to the roots of plants, and permits the access of the air. That variety, however, must be ex- cepted which was obtained from the interior of trees, and had been formed in such a situation tint the rain-w.iter which entered found no free outlet ; the humus then contained extractive i)rinciples, de- rived in part from the living {)lant, and which seemed to <»bstrucl the pores of the vegetable io which it was applied as manure. In making comparative calcinations in close vessels of different varieties of humus, and of plants similar to those from which they had proceeded, and collecting the charcoal on one hand, and the volatile and gaseous matters on the other, M. de Saussure di^covcr- ed that they conlamed, for the same weight, a larger quantity of carbon and of azote than the vegetables whence they proceeded. The larger proj)orti(m of azote in the humus seeins to imply that during tlieir dccom|)osition, vegetables do not throw otf this element ; but to this cause must be added that w liich might be connected with the spoils of insects which live in humus. HUMUS. 247 Weak acids have no other effect upon humus than to dissolve out the metallic, earthy, and alkaline elements which it contains. The more powerful acids, such as the sulphuric acid, frequently cause a diseno-a^rement of acetic acid. Alcohol scarcely acts upon humus, merely dissolving out of it a few hundredth parts of resinous matter, which probahly pre-existed in the vegetable. Potash and soda dis- solve humus almost completely, causing an evolution of ammonia. From this solution, acids throw down a brown, inflammable powder, possessincr the characters which we have recognised in ulinine. ihe ulmine which is separated in this way, is tar from corresponding with the weight of the matter treated with the alkalies, which is evidently due to the humus containing principles which are not pre- cipitated from the alkaline solution. A quantity of humus which yielded no more than one tenth ot ashes by incineration, onlv lost one eleventh of its weight under re- peated treatments with boiling water. The humus thus exhausted, was exposed in a moist state to the action of the air for three months, and crave a new quantity of soluble matter under renewed w;ashing wiih^water; and the same effect is constantly reproduced. By^ex- posino- moist insoluble humus to the air, therefore, a quantity of so- luble extractive matter is formed. This matter, obtained by evapo- ratincT the water which is charged with it, is not deliquescent ; it yieldl ammonia on distillation. The watery solution, brought to the consistence of sirup, is neutral to re-agents, and its taste is sensibly It is familiarly known that the alkaline salts, which enter into the constitution of vegetable juices, but rarely exhibit the reactions that are proper to them ; the plant or the sap must be dried and inciner- ated before their presence can be ascertained. It is the same with recrard to the salts contained in humus. Humus, as I have already observed, is the last term in the putre- faction of vegetable organic matter ; its elements have acquired a stability which enables them to resist all fermentation. M. de Saus- sure preserved humus for a whole year in vessels filled with distilled water, and plunged in mercury, without remarking any emission ot gas. Still it is unquestionable that the organic portion of humus is completely destructible when exposed moist to the action of tlie air ; in the course of time it is dissipated, and by and by there remains nothincrmore than the fixed saline and earthy matters which it con- tained." This fact M. B. de Saussure had already perceived from his observations upon the vegetable soil that occurs in the country between San Germano and Turin. This destructibihty of vegetable earth, says M. de Saussure, sen., is a fact without exception ; and as often as aoriculturists have proposed to supply the place of ma- nure by repeated ploughings, they have had sad experience of its truth : the soil is gradually impoverished, and fertile fields ultimate- ly become barren. 1 may add, that the nature of tlie climate has a vast influence upon the dissipation of the fertilizing principles ot the soil and that Europeans are certainly in error when they object to the superficial ploughings or hoeings which the land so commonly £48 - >>ITRIF1CATI0N. receives in tropical countries. It is there well known that toojnuch stirring of the soil is i 'ten prejudicial even in irrigated lands, where consequently the bad «.ffects cannot be attributed to too great a de- gree of dryness. The information which has lately reached the Academy of Sciences upon the agriculture of the French posses- sions in Africa, tend to make us perceive that the same cause pro- duces the same effects in Algeria, and that it is not without reason that the Arabs only work their lands that are preparing for grain crops, very superficially. Humus is, in fact, dissipated by a process of slow combustion in the air : in contact with oxygen, it produces carbonic acid, as is proved by the experiments of M. de Saussure. Pure humus, moist- ened with distilled water, confined in bell-glasses placed over mci. cury, formed carbonic acid, causing the disappearance of the oxygen of the air. The. volume of the acid gas formed, corresponded i volume with that of the oxygen wliieh had disappeared. Humus, therefore, in contact with air, gives off carbonic acid, and the phe- nomenon here still takes place as if carbon were not alone consumed. The loss experienced is greater than that which ought to occur from the quantity of carbon which unites with the oxygen ; and Saussure concluded that there is, at the same lime, a lo^js of the elements of water. The capital fact which results from these experiments of Saussure, the deduction directly applicable to the theory of manures is this : that humus is dissipated when it is exposed to the air, and that during the slow combustion v.hich it undergoes, it is a constant source of carbonic acid gas. To complete the views that may throw ligiit on the part played by Hianures, I have still tp speak of an imj)orlant phenomenon which occasionally takes place under the same ct>nditions as tliose that ac- • company the decomposition, the putrefaction of animal matters: I mean the sj)ontaneous formation of nitric acid — the occurrence of nitrification as it is called. Nitric acid results iVom the union of azote with oxygen. Such at lea.st is the constitution of this acid when it is combined in s,ilts ; but in its isolated state, it is always united with a certain ijuantity of water. It has not yet been obtain- ed, and it appears indeed not to exist, in the perfectly dry or anhy- drous state. The azote, therefore, does not couibine directly with the oxygen ; tl\ere must be, at all events, the intervention of water, and to effect the union of tlie two gases by means of the electric spark, the mixture, according to Cavendish, nnist be moist. Never- theless, the combination of azote with oxygen appears to be singular- ly favored by the presence of earthy or alkaline bases, seeing thai in nature the nitrates are met with in a certain abundance ; but the circumstances which (Ictermine their tormation are still invi)lvetl ii? deep obscurity. Three distinct origins may be assigned to the natnial nitrates: 1st. certain soils, still imliffcrently studied, show an etUorescence of nitrate of potash on their surface, or by lixiviation yield large quan- tities of this salt. Such is the source of the saltpetre which is iiu- ported from India. PRODUCTION OF NITRE AND NITRATES. 249 Accordinof to M. Proust, the soil of cnrtain localities in the neigh- borhood of Saragossa is an inexhaustible mine of saltpetre. I have myself seen, near Latacunga, a short way from Quito, upon a soil formed of trachytic dehris, a similar production of nitre taking place as it were under my eyes. 2d. On the coast of Peru, in the desert of Tarapaca, at a short distance from the port of Iquique, and in an argillaceous soil of ex- tremely recent formation, there are numerous stratified deposites of nitrate of soda, analogous to, and perhaps contemporaneous with, the deposites of common salt which are worked upon the same coast, in the desert of Sechura, near the equator. This is, so far as I know, the only instance of a nitrate being dug out of the bowels of the earth as a mineral mass. The nitrate of soda of Tarapaca, reaci.es Europe at the present time in large quantities, and supplies the place of nitrate of potash in many chemical processes. Various ex- periments have also been made upon the value of the salt as a ma- nure ; but at present these experiments have been very contradic- tory, and further experience seems necessary before any definitive judgment can be come to on the matter. 3d. The greater number of the soils that are exposed to animal emanations — heaps of rubbish proceeding from buildings that have been long inhabited, the soil of stables, cow-houses, cellars, &c., almost always contain a quantity of nitrates. In countries where rain seldom falls, and where consequently these salts, which are ex- tremely soluble, can accumulate in the soil, in Egypt, for example, the ruins of ancient cities are at the present time true nitre-beds. It is with the formation from nitre in such circumstances that we feel particularly interested. The presence of the salt is frequently proclaimed in our agricultural operations ; it is formed during the preparation of our dunghills, in the midst of our cultivated fields, and we discover it in the plants which we gather. We are by so much the more interested in discovering its existence, and in ascer- taining its mode of action, as in the actual state of our knowledge we are still unable to say wlieiher or no nitre is an auxiliary in the phenomena of vegetation, and contributes to the production of the azotized principles which enter into the organization of plants. To have nitrates formed, the presence of azotized organic matter is not sufficient ; it is further necessary that this matter during its decomposition be in contact with alkaline, calcareous, or magnesian carbonates. It has been observed that rocks of a crystalline struc- ture do not nitrify so readily when they are without the substances which have just been named. The calcareous and magnesian rocks ivhich are most favorable to nitrification, under the influence of ani- mal emanations and of vegetables in a state of decomposition, are those which are the least coherent, or which are most porous, such as chalk, tufa, &c. In those countries where the soil does not un- dergo spontaneous nitrification, certain arrangements of circum- stances, known to favor the production of saltpetre, are made : arti- ficial nitre-beds are prepared. In the north of Europe where the rocks are granitic, in a hut or shed built of wood, a mixture is made 250 THEORY OF THE FORMATION OF NITRIC ACID. of common earth, of calcareous sand or marl, and of wood-ashes. This heap is watered with the urine of herbivorous animals, and the mixture is stirred or shifted from time to time to favor the access of the air ; and with the same view, the Avorkmen are very careful never to beat or press the heap, which is o^enerally from two to two and a half feet in thickness, and usually of the whole length of the hut or shed. Experience has shown that the process of nitrification goes on best in the shade. In Prussia, the practice is to wet with the water of a dunghill a mixture composed of five parts of vegeta- ble earth, and one part of wood-ashes and straw. With this kind of mortar, solid walls or masses from twenty to four and twenty feet in length, by about six feet and a half in thickness, are built, rods of wood being introduced during the construction in considera- &le numbers, and in such a way that they can be pulled out when Ihe mass has acquired sufficient solidity ; by this means it is obvious that a very free access of air is secured to the interior of these aitre walls, which are always built in damj) places, and thatched over with straw to preserve them both from the sun and the rain. The aiass is watered from time to time, and after the lapse of a year, •he materials are held sufficiently impregnated with saltpetre to be worth lixiviating. In these artificial nitre-beds we perceive the object to be, to com- )ine the circumstances under which the nitrates are formed in the oil of stables, and in the cellars of human habitations. Organic jatters, rich in azote, are, in fact, brought into contact with earthy . kaline carbonates. The necessity that is fell in the arrangement c ' nitre-beds for the introduction of substances of animal origin, L \ds us to presume that the greater part of the nitric acid which is j.iDduced, is derived from the azote of these substances. But whether lliis azote combines with the oxygen of the air, or with the oxygen of the organic principles, we do not know — we are still ig- norant of the way in which the acidification is eflected. Professor Liebig, setting out from the lact that azoti/ed ortjanic substances always produce ainnn)nia during their putrefaction, ant! next perceiving that (hiring the combustion of ammoniacal gas, mixed with a large excess of hydrogen, llu-re is always oxidation of the azote, concludes that nitrification is the result of the slow com- bustion of the ammonia which is the pr«)duct of the azotized matters in })foreveiil the appear- ance of nitrous acid ; and on the contrary, l)y taking measures to favor lh.> production of this acid, for example, by passing a current of ammoniacal gas over peroxide of iron or manganese in a red hot tube, abundance of nitrate of ammonia is obtained. The same re- sult follows exposure of a mixture of oxyijon and ammoniacal gas to the action of incandescent spongy platinum. The determining cause of the acidification of the azote, which lorms an element of the ammonia, is probably due to this, thit during the combustion two DETECTION OF NITRATES IN THE SOIL. 251 bodies are formed which are capable of combiniiiL; immediately : nitric acid, on one hand, and on the other water, without which this acid could not exist. Tlie phenomenon, however, only takes place m this, instance at a considerably elevated temperature. At ordi- nary temperatures, combustion of the elements of ammonia has not, as far as 1 know, yet been observed ; and in a series of experiments ■which I undertook, proceeding all the while upon ideas completely in conformity with those advanced by Liebig, I did not succeed in ibrming any nitrates by enclosing mixtures of chalk, potash, &c., in an atmosphere composed of oxygen and ammoniacal vapor. In a communication made to the Academy of Sciences, M. Kuhl- man announces that he had ascertained the presence of nitrate of ammonia in the products of the putrefaction of animal matter. If this announcement be confirmed, if nitric acid be in reality one of l[ie numerous products of the putrid fermentation, the nitrification of soils in contact with organic matters would be readily explicable. f must sav, however, that I have sought in vain for nitrate of ammo- nia in the product of the putrid fermentation of caseum. And after all, we should still be at a loss to account for the formation of nitre in many places, where it appears to be produced in the absence of organic matter, as in the saltpetre soils of India, South America, and Spain. Dr. John Davy, who visited the nitre districts of Cey- lon, and Proust, who long inhabited the Peninsula, have given it as their opinion that the nitre appears in soils which contain no vestiges of organic matter. The assertion of Proust, however, is open to suspicion, inasmuch as in his memoir he affirms that the lands close to those that produce the nitre are extremely fertile, so that they yield abundant crops without ever receiving manure. But at the ipresent day, it is a law that every fertile soil must contain or receive dead organic matter. In Ceylon, according to Davy, the caverns, the walls of which become covered with an efflorescence of salt- petre with such rapidity, have a fertile and thickly wooded soil lying over them, the percolations from which may readily penetrate their interior. The observations which I had an opportr lity of making upon the nitre soils near Latacunga, were not perhaps of sufficient precision ; but I think I can affirm that the soil was not without hu- mus : patches were perceived here and there that were covered with turf. It must still be admitted, however, that in the localities which have been particularly indicated there must exist some peculiar and permanent cause of nitrification ; inasmuch as in other and fertile soils, saltpetre only appears as it were accidentally, and never in extraordinary quantity. Whatever the value of the ingenious but still very imperfect theo- ries of nitrification, it is still of importance to ascertain the exist- ence or absence of nitrates in the soil. Wollaston recommended a process which enables us to do this very readily. It is founded on the property possessed by the aqua regia — a mixture of the nitric and hydrochloric acids — to dissolve pure gold, which, as is familiarly knuwn, resists the action of either of these acids applied separately. The soil in which the presence of a nitrate is suspected is treated 252 FAR3I-YAKD DUXG. with boiling distilled water, and thrown upon a filter. The filtered fluid is reduced by evaporation to a very small quantity, which is then poured into a test tube, and a little pure hydrochloric acid is added ; some particles of leaf gold are then introduced, apd the fluid is stirred with a glass rod. If any nitrates have been present, the particles of gold are speedily dissolved. Having now described the circumstances which determine, and the phenomena which accompany the decomposition of dead or- ganic matter, I have next to treat of manures in particular, of their preparation, of their application, and of their relative values. Speaking generally, the manure which is derived from the dejec- tions of animals, supplied in a farm-yard with abundance of food and of litter, used with the double object of cleanliness and health, is the best of all. The principal substances which contribute day by day to increase the mass of our dunghills are straw, and the ex- cretions and urine of horned cattle, horses, hogs, &c. These va- rious substances, besides the organic elements which enter into their composition, further contain the various mineral substances which are indispensable to the development of vegetables. Animal excre- ments of every kind, in fact, when they are burned, leave quantities of ashes which are frequently very considerable, and in which are encountered the same saline and earthy ingredients that pre-existed in the forage with which the animals were su])plied. Excrements, therefore, jiecessarily vary in their composition according to the kind of food that is consumed, and the nature and the state of health of the animal which produced them. Those of the hcrbivora have never been suflicitnlly examined. Thaer and Kinhof have merely ascertained that cow-dung contains an extractive principle, partly coagulable by heat, and that remains of the food may be separated from it. All excrcmentitious matters, in fact, contain a certain quantity of the alimentary matter which has escape*! digestion, especially when animals are abundantly supplied with food. Some albuminous matter is also found ihert; ; but the substance after vege- table remains that appears to predominate is bilious.* \Vc know that after mastication, the food, miti«,Med with saliva and the secretions of the mucous glands, passes into the gullet, and from thence into the stomach. There it imbibes gastric juice, turns sour, becomes modified, and is finally converted into a kind of pulp which is called chyme. Once formed, chyme passes into the small intes- tines, where it encounters the bile and pacreatic juice, which modify it, and cause it to separate into chyle, which is absorbed by the ves- sels of the bowels, and excreincntitious residue, which descends into the large intestines, where it bceomcs a fetid mass that is expelled from time to lime by the animal. * Tlic l;»tost Inquiries of the physiologiril chtinir-ts would le.id ua to !«a«|KTt thii this was not the case. Bile ought only to be an occasional, and even an unnutiiril constituent of animal excrement, if these views be well founded. It >eems that the elements of bile added to the element-* of starch supply the pn-cise eh-menU of lat ; a substance so abundantly formed in the process of digestion. The bile that is poured Into the upiter part of the alimeiitarv canal is prol>,-»H'v nil U'od up in fonning fnU — Kiio. En. MANURES — urinp:. 253 The bile which accompanied the fecal matter is secreted by the Jiver, and is familiarly known as a viscid, bitter fluid of a yellowish green color and a peculiarly nauseous odor. According to M The- nard, the bile of the ox contains : — Water 700 Picroniel* 69 Fatty matter 15 Soda, phosphate of soda, chlorides of potassium and ) ,„ sodium, sulphate of soda \^^ Phosphate of lime, oxide of iron 1 795 Urine is a liquid secreted by the kidneys from arterial blood ; it passes into the bladder by the ureters. Its composition varies ac- cording to the animals which produce it. Urea is its most charac- teristic principle ; and in the water which it always contains in large proportion, various saline substances and animal matter, which is re- garded as mucus of the bladder, are encountered. The urine of the horse, according to M, Chevreul, contains carbonate of soda, of lime, and of magnesia, sulphate of soda, chloride of sodium, hippurate of soda, urea, and a red-colored oil. The urine of horned cattle has a similar compositon, with this dif- feience, that it is much more watery. In the urine of our cow- houses which had undergone change, I have ascertained the presence of the alkaline carbonates, of common salt, and of the reddish oil mentioned above. Having at various times had occasion to evapor- ate considerable quantities of the urine of the horse, I always ob- served that on coming to the boiling point, a quantity of azotized matter which resembled albumen was coagulated. I also perceived in the urine of herbivorous animals a volatile acid, to which its odor is probably owing. In the urine of the camel, M. Chevreul found the carbonates of lime and magnesia, silica, sulphate of lime, and oxide of iron, in very small quantities ; chloride of potassium, carbonate of potash, sulphate of soda, in small quantities ; sulphate of potash, in large quantity ; urea ; an alkaline hippurate ; and a reddish oil. The urine of the rabbit, according to Vauquelin, contains carbon- ate of lime, of magnesia, and of potash, chloride of potassium, sul- phate of potash, sulphur, urea, and mucus. The urine of birds is distinguished by the large proportion of uric acid it contains. Food, however, has a great influence upon this proportion ; highly azotized aliments increasing it considerably, Wollaston observed that the excrements of a fowl which was fed * Picromel, discovered ia the bile of the ox hy M. Thenartl. is colorless, and of the consistence of sirup. It produces upon the ton<:ue an acrid and bitter sensation, which rapidly changes to a flavor slightly sugary. The recent researches of Messrs. Tiede- mann and Gmelin have discovered in ox bile substances which had escaped the first in- vestigations. These chemists fcund : 1st. a subst:ince having the smell of musk, and which is probably one of the c;;uses of the odcr peculiar to the excrement of kine ; 2d. ftitty substances ; 3d. biliary resin : 4lh. a cry^stallized substance called taurine ; 5th. biliary sugar, of which p.zote forms one of the elements. According to Messrs. Tiede- mann and Gmelin, the picromel of Tvl. Thenard re? ults from the union of sugar and biliary resin. 22 st loss and destrur-tion of manure over a great ])art of these countries. The dunghill is often arranged as if it were a matter of moment that it should bo exposed to the water collected from every roof in the vicinity, as if the business were to take ad- vantage of every shower of rain to wash and cleanse it from all it contains that is really valuable. The main secret of the admirable and successful husbandry of French Flanders may perhaps lie in the extreme care that is taken in that country to collect everything that can contribute to the fertility of the soil. Our agricultural so- cieties, which are now so universally established, would confer one of the greatest services on the community if they would encourage l)y every means at their command economy of manure ; premiums awarded to those farmers who should preserve their dunghills In the most rational and advantageous manner, woulil prove of more real service than [)remiums in many other and more popular direc- tions. The place where the dung of a farm is laid ought to be rather npar to the stables and cow-houses. The arrangen»enls may be * Rorliorrhrs Chirniqiio-. p. '207. MANURES THE DUNG-HEAP. 257 yaried to infinity, but they oiip^ht all to combine the following condi- tions : 1st. That the drippings from the heap should not run away^ but should be collected in a tank or cistern under ground ; 2d. That no water, except the rain which falls on the dung-heap, or any wa- ter that may be thrown upon it on purpose, should be allowed to drain into this reservoir ; 3d. That the place for the dunghill be of size enough to avoid the necessity of heaping the manure to too great a height. The ground upon which the dung is piled ought to slope gently one way or another — from each side towards the centre is best — so that the dri))pings may be collected in the tank or cis- tern. It is also desirable that the soil underneath should be clayey and impermeable ; where it is not so, it becomes necessary to pud- dle, to cement, or to pave the bottom of the dunghill stance as well as the bottom and sides of the tank or cistern. The water which runs from the heap should be thrown back upon it occasionally, by means of a pump and hose, so as to preserve it in a state of constant moistness. The opening into the tank, which is best placed imme- diately under the centre of the dung-heap, is closed by means of a strong grating in wood or iron, the bars being sufficiently close to prevent the solid matters from passing through. One very impor- tant arrangement, one which, in fact, must on no account be over- looked, is that the drains from the stables and cow-houses be so contrived, that they all run to the dunghill. The litter, however abundant, never absorbs the whole of the urine, especially at the time when the cattle are upon green food ; and it would be quite unpardonable in the husbandman did he not take measures to se- cure this, the most valuable portion of the manure at his disposal. The litter mixed with the droppings of the animals, and soaked with their urine, ought to be carried from the stables to the dunghill upon a light barrow. The practice of dragging out the manure with dung-hooks, which is often permitted when the field upon which it is to be spread is at no great distance, ought on no account to be al- lowed; the loss from the practice is always considerable. Materials ought not to be thrown on the dunghill at random or hap-hazard ; they should be evenly spread and divided ; an uneven heap gives rise to vacancies, which by and by become mouldy, to the great detriment of the manure. It is of much importance that the heap be pretty solid, in order to prevent too great a rise of tem- perature, and too rapid a fermentation, which are always injurious. Particular care must also be taken that the heap preserves a sufTi- cient degree of moistness, not only of its surface but of its entire mass, which is effected by watering it frequently. At Bechelbronn, our dung-heap is so firmly trodden down, in the course of its accu- mulation, by the feet of the workmen, that a loaded wagon drawn by four horses can be taken across it without very great difficulty. The thickness of the heap is not a matter of indifference : besides the convenience of loading, which must not be forgotten, any great thickness may become injurious by causing the temperature to rise too high ; circumstances occurring which should compel us to keep a mass in this state for any length of time, the decomposition would 22* 253 PREPARATION OF MANURE. make such pr();Tress as to occasion very great loss. Experience has shown that the thickness of a dung--heap ought not to exceed from about four feet and a half to six feet and a half; it ought certainly never to exceed the latter amount. With a view to prevent the drying of the dung-heap and its con- sequences, too great a rise in temperature and destruction of manure, it is the practice in some places to arrange the dung-heap on the north side of a building, which is undoubtedly advantageous, but not always to be realized, especially in connection with a farm of some magnitude, where the immediate vicinity of a large mass of matter in a state of putrid fermentation is not only unpleasant, but may he unwholesome. In the north of France, the dung-heap is somelimes shaded from the sun by means of a row of elms, and the shelter thus secured is vastly preferable to that which it has been proposed to obtain by means of a roof or shed, which, besides other inconveni- ences, would be found costly at first, liable to speedy decay, &c. If circumstances, su(;h as the smallness of the farm, the permeable nature of the soil, d:c., prevent the construction of a reservoir, there is risk of the dung-water being quite lost ; but such waste may be prevented by covering the bottom of the pit or stance for the dung- heap with a bed of sand, peat marl, or any other dry and porous sub- stance capable of absorbing liquids. This practice is often followed by the farmers of>Alsacc. In some farms, the ditfcrcnt kinds of dung are piled apart from one another in particular heaps; that of the stable being put by it- self, as well as that of the cow-house, that of the hog-stye, and that of the sheep-pen. In great establishments, such a separation is often one of necessity ; but the advantages which are ascribed to it are questionable at least, and the remarks that have been made upon it by writers do not appear founded on any accurate observation. Without denying that certain crops answer better when special ina- lures are employed, it still seems to me more advantageous to pile ^very kind of manure together, when the difficulties of the situation are not such as to make this cither particularly inconvenient or ex- pensive. In this way, indeed, a dung-heaj) of medium constitution is obtained, which is regarded with reason ;is that, the application of which to the soil is attended with the greatest advantages in the majority of instances. The distinction which some have sought to make between the relative qualities of manures of ditferent ori^^ins is fir too abstdute ; and this is the reason, without doubt, wliich renders it so diflicult to bring the observations of dilFerent agricultu- rists to agree. Thus, according to Sinclair, the dung of the hog- stye is the most active of all, the richest in fertilizing principles ; according to Schwertz, ou the contrary, it is the most indifferent manure of the farm-yard. The fact is, that manures, which are the produce of the same animals, often present greater differences in regard to quality, tjjan manures which proceed from dif'^rent sources I shall show by and by that the value of manure il<,»cnds especially upon the feeding, the age, and the condition in which the animal is placed that pro- PREPARATION OF MANURE. 250 duces it. It is well known that the dunnf of cattle, fed during winter upon straw, is greatly inferior to that which they yield wtien con- suming food of a more nutritious quality. When the litter mixed with animal excrements is accumulated in sufficient quantity in the pit or on the dung stance, fermentation speedily sets in, and abundance of vapor is disengaged. As car- bonate of ammonia is among the volatile products of this decomposi- tion, it is of importance to hold it under control ; this is done by keeping the heap in a state of proper moistness, and in excluding as much as possible the access of air. The daily addition of fresh quantities of litter from the stables and stalls, contributes powerfully to impede the dispersion of the volatile elements, which it is so im- portant to preserve in manure ; duly spread upon the heap, each ad- dition bbcomes, in fact, a fresh obstacle to evaporation ; it forms a covering which plays the part of a condenser, at the same time that it protects the inferior layers from the direct contact of the air. So long as the dung-heap is kept up and attended to in this way, the fermentation is limited to the inferior layers of the mass. Thaer even satisfied himself that air collected from the surface of a dung- heap, undergoing moderate fermentation, does not contain much more carbonic acid than that which is taken from the mass of the atmosphere. Neither does a vessel containing nitric acid, when placed upon the fermenting mass, produce those dense white vapors which are a certain indication of the presence of ammonia. The slow decomposition which it is of so much importance to effect, is not readily secured save in messes sufficiently trodden down, and in which the litter of different kinds has been spread as evenly as pos- sible. It is an important point that the manure should be carried out to the field before the upper portions recently added begin to undergo change, otherwise the whole mass enters into full fermentation, and the volatile elements, being no longer arrested by the upper layer, escape and are lost. One means of preventing this loss in any case (which however can but rarely occur) in which there was a neces- sity for suffering the mass to become made through its whole thick- ness, would be to cover it with a layer of vegetable mould, in which the volatile principles would be condensed ; the layer of earth would in fact thus be converted into a most powerful manure. The loss of carbonate of ammonia, during the fermentation of farm-dung, is further prevented by the use of certain salts which have the power of changing the volatile carbonate into a fixed salt. It was with a view of bringing a re-action of this kind into play, tlisrt M. Schattenmann, the able director of the manufactories of Bauchsweiler, proposed to add to dung-heaps, in the course of their accumulation and preparation, a certain quantity of sulphate of iron or of sulphate of lime, either of which is decomposed by the carbo- nate of ammonia evolved, and a fixed ammoniacal salt (the sulphate) is produced.* The loss of ammonia from dung-heaps in the course * Annales de Chimie, 3e s6rie, t. iv. p. 116. 260 PREPARATION OF MANURE. of regulated fermentation, must not however be estimated too hignly ; when the decomposition is carefully conducted, the mass having been well trodden and properly damped, the loss is really very small. The gentle fermentation, secured by these means, has characters which differ essentially from those that accompany the rapid putre- faction which never fails to take place when matters are not well managed. As an example of the rapid and injurious fermentation of which I speak, I may cite that which frequently takes place in piles of horse-dung : everyone must have seen such dung-hills loosely thrown together, left to themselves, without any addition of water, acquiring a very intense heat in the course of a few days, and have even heard of their taking fire. I have seen piles of this kind reduced to their merely earthy constituents! Such are never the results of the moderate and gradual decomposition which farm- dung ought never to exceed. ^Vhen the pit or stance is emptied, in which a slow and etjual fermentaii(m has taken place, the superior layer is seen to be very nearly in the same st:iie in which it was when it was piled ; the layer immediately beneath this one is chang- ed in a greater degree, and sometimes exhales a slight ammoniacal odor. In the lower strata, the modification is yet greater in dciiree : the straw has lost its consistency, it is fibrous and breaks into pieces with the greatest ease ; the mass is also progressively darker in color as we go deeper, and on the grt>und it is completely black : the smell which this j)art of the heap exhales, is that of sulphuretted hydrogen, and when it is tested, sulphate of iron is discovered ; no doubt these sul[)hurous products are all the consequence of the de- composition, under the influence of the organic mailer, of the sul pbales which were contained in the manure. This is the sign by which I know that firm-dunii is duly prepared ; the presence of sulphurets and of the hydrosulphate of ammonia will have no ill etfect upon vegetation ; for scarcely is the manure si»read upon the ground, than these products are changed into sid[)hates, and then the manure emits that musky smell which is })eculiar to it. Fur- ther, there is no doubt but that the slate in which a carefully tended dung-heap is found in the end, is due to the circumsiances in which it has been placed and ki'pt during the whole time »)f its preparation ; its constituent elements would hive jroiie through a t»»l.illy ditferenl course in the progress of their moilificaiitm had ihey been left ex- posed to the opduced immediately into the ground, there und(^rg()es precisely the same changes, and gives rise to the same products as it does when subjected to preparation in a dung-heap in the manner already described ; there is only this difference, that being scattered and mixed with a large quantity of inert matter, the decomposition takes place much more slowly than it does in the heap. The (piestion which has been so actively dis- cussed, therefore, reduces iisoU' to ibis : is it advantageotis to have the manure fermented in the soil it is intended to fertilize ? We may be allowed to express surprise that such a question should have been raised in the present day, and still more that the allirmalive answer should have been disputed by agriculturists of distinguished merit. Some have even gone so far as to maintain thai fresh ex- crements were injurious to vegetation Proofs to the contrary are readily obtained ; it is enougli to recollecr that in the grazing and folding of sheep and kine, the dung and urine pass directly into tho ground of our {)astures and fields, and who shall say that the land is not benefited by wliat it thus receives ? I'nquestionably fresh manure in excess proves injurious to vegetables, but as much may be said in regard to the best-fermented dungs. M. (lazzeri, an Italiin chemist, has devoted himself with the most laudable perseverance to inquiries haviug for their object to show that the general custom of leaving manures to become da- VALUE OF FRESH AND MADE MANURES. 263 composed before leading them out to the field is attended with a considerable loss of fertilizing principles, and that it is therefore advantageous to use them in the state in which they come from the stable. To remove all doubts which might yet be entertained upon the effects of unfermented manures, M. Gazzeri showed that wheat could be successfully grown in land which had received an extraor- dinary dose of pigeon's dung, which is regarded as one of the most active of all manures ; and horse droppings, taken at the moment they were passed, mixed with earth, in the proportion of one-fourth of the whole bulk, had no injurious effect on the growth of the cereals. To ascertain the amount of loss which fresh manures suf- fered from fermentation, M. Gazzeri placed certain quantities, as- certained by weight, to putrefy under flivorable circumstances ; and the decomposition completed, be weighed them again. In this way, he ascertained that horse-dung, in the course of four n.onths, lost more than the half of the dry matter which it contained before its putrefaction. Davy, indeed, had already shown that there is a loss of volatile principles, during the decomposition of fresh manures, that must be useful to vegetation. Davy's experiment consisted in introducing manure into a retort, the extremity of which communi- cated with the soil under turf, and he found that in the course of a few days the grass which was thus exposed to the emanations from the retort, grew with particular luxuriance. Although it appears certain, then, that in conducting the preparation of manure in the heap with prudence, the volatile and ammoniacal principles which appear in the course of the putrefaction may be retained, it is never- theless unquestionable that the employment of manure directly and without previous fermentation, would most effectually prevent the loss of matters that must be valuable. Thaer, Schwertz, Mr. Coke, and others, have consequently admitted the advantages of the latter procedure. In agreeing with them completely, which I do, it still remains certain that on the greater number of farms, dung-heaps must be formed as matter of necessity. Manure is only available at certain determinate seasons of the year ; it cannot be carried out and spread as it is produced. In Alsace it is carried out to the fields on which it is to be spread whenever circumstances will permit, and without regard to its more or less advanced state of decomposition. The circumstances which lead to its being kept in the pit for two or three months, also lead to the manure being half or more than half matured before it is led out ; and this, after all, is perhaps the best state in which it can be put into the ground. It is then easily incor- porated with the soil, and its fertilizing principles are already in that condition which enables them to act, within a limited time, with greater energy than they would do were the manure employed quite fresh. This is the condition in which our manures almost always are at Bechelbroim wlien we carry them out : it rarely happens that they have been three months on the stance before their removal. Speediness of action is a point which is not without importance. Fresh dung will always act more slowly than that which has reach- ed a (pertain point of decomposition, and the advantage which mostl}/ 264 VALUE OF FRESH AND MADE MANURES. accrues to the farmer in forcin per cent, of 18;k"*-'.» -i-J.-i ( dry matter. Pripjired in summer of 1839 19.6 Medium 20.7 Water 79.3 Analysis yielded the following results: Tiroei of preparation. Carbon. Hydrogen. Oxygen. Axota Atht*. Winter of 1837-8 32.4 3.8 25.8 1.7 ."W.S 32.5 4.1 26.0 1.7 35.7 38.7 4.5 28.7 1.7 26.4 Spring of 1838 • 36.4 4.0 19.1 2.4 38,1 1839 40.0 4.3 27.6 2.4 25.7 " " 34.5 4.3 276 2.0 31J COMPOSITION OF FARM-YARD DUNG. 267 On the average, farm-dung dried at 238' contains ; Carbon 35.8 Hydrogen 4.2 Oxygen 25.8 , Azote 2.0 Suits and earths 32.2 100.0 When moist, its composition is represented by — Carbon 7.41 Hydrogen 0.87 Oxygen 5.34 Azote 0.41 Salts and earths 6.67 Water.... 79.30 100.0 The constitution of dung-heaps must of necessity vary ; those; however, which have a common origin do not seem to present very great differences in the proportion of their elements. Thus, horse- dung, in the south of France, yielded, on analysis, in the dry state, 2.4 per cent, of azote. This manure contained only 61 per cent, of moisture. Did we but know the composition and the quantity of the excre- tions passed, in the course of the twenty-four hours, by the various animals which contribute to the production of manure, we should be able to determine approximatively what the elements are which have been eliminated in the course of the fermentation. It would be suf- ficient to compare the elementary matter in the litter, or fresh dung, as it comes from the stable, with that which exists in the fermented or prepared manure. I have data which I think sufficient to enable me to institute this comparison. It must always be borne in mind, however, that the analyses which I shall now detail, were made upon the excrements of a single individual of each kind. It would certainly have been preferable to have had average analyses of average qualities ; but the object I had in view, when I undertook these experiments, was quite different from that which I have nov; before me. EXCRETIONS OF THE HORSE The horse was fed upon hay and oats. The urine and the excre- ments together contained 76.2 per cent, of moisture. In twenty-foui hours the excretions weighed — moist, 34.2 lbs. ; dry, 8.1 lbs. Their composition was found to be — In the dry state. Moist ditto. Carbon 38.6 9.19 Hydrogen .5.0 1.20 Oxygen 36.4 8.66 Azote 2.7 4.13 Salts and earth 17.3 4.13 Water " 76.17 11X).0 100.0 • The size of the horse was rather below the average usual size of farm horses. 26r COMPOSITION OF FARM-YARD DUNG. EXCRETIONS OF THE COW. The COW was fed upon hay and raw potatoes. The urine and the excrements together contained 86.4 of moisture. The weight of the excretions, in twenty-four hours, was — moist, 80.5 lbs. ; dry, 10.9 lbs. Their composition by analysis was : Dry. Wet. Carbon 39-8 5-39 Hydrogen 4-7 0.64 Oxygen 35-5 4.81 Azote 2.6 0.36 Salts and earth 17-4 2.36 Water " 86-44 100.0 UK). 00 EXCRETIONS OF THE PIG. The pigs, upon which the observations were made, were from six to eight months old. They were fed upon steamed potatoes. The urine and the excrements lost by drying 82 per cent, of moisture. The average of the excretions yielded by one pig in twenty-four hours was : moist, 9.1 lbs. ; dry, 1.6 lb. Composition : Dry. Moitt. Carbon 38.7 6-97 Hydrogen 4-8 0-86 Oxypen 325 5.85 Aztite 3.4 061 Salu and earth 20-6 87-1 Water " 82-00 100.0 100.00 The litter that is generally employed is wheat-straw. This straw, in the condition in which it is used, contains 26 per cent, of moist- ure. Its composition is : Dritd. Undnea. Carbon 48.4 35-8 Hydrogen 5-3 3-9 Oxygen 38-9 28-8 Azote 0-4 00-3 Salts and earth 7-0 5-2 Water -• " 26-0 lUO-0 100-0 At Bechelbronn each horse receives daily as litter 4. 1 lbs. ; each cow 6.6 lbs- ; each pig 4.1 lbs. of straw- To the stables and the cow-houses together are given every twenty-four hours 132.0 lbs. of straw for thirty horses ; 198.0 lbs. for thirty horned cattle ; 06. 0 lbs. for sixteen pigs; making 396.0 lbs. of straw, estimated when dry at 292.6 lbs. The composition of the materials which constitute the dung pro- duced in one day are set forth in the following table : COMPOSITION OF FARM-YARD DUNG. 269 Excretions yielded in 24 hours by Weight when dry. Weight in the wet state. Elements of the dry matte.-. Carb. Hydrog- Oxygen Azi%t. Salts &' ting (he earths, i^^' matter Thirty horses Thirty horned cattle Sixteen pigs Straw used in litter Ihs. 245.08 326. 3G 26.40 292.60 lbs. 1028.28 2416.48 146.74 3%. 00 lbs. lbs. 94.00 12.32 130.24 1-J.40 10.12, 1.32 41.68 15.62 lbs. lbs. 89.10 6.oO 116.16 8.. 58 8.58 0.88 113.74 1.10 I lbs. 42.46 783.20 56.98 2089.12 5.50 120.34 20.46 103.40 The average or mean composition of this mixt-ire may be taken as follows : In the dry state. In the wet state. Carbon. Hydrog. Oxygen. Azote. Salts. Carbon. Hydrog. Oxygen. Azote. Salt. Water. 42.3 5.0 1 36.7 1.9 14.1 9.4 1.2 8.2 0.4 3.2 77.6 That of the resulting Dung : 1 1 1 1 35.8 4.2 25.8 2.0 32.2 7.4 0.9 5.3 0.4 6.7 79.3 On comparing the composition of the dung-heap with that of the different kinds of litter collected in a day, little difference is ob- served ; the larger quantity of saline and earthy matters discovered in the fermented manure is readily explained from the additions of ashes incorporated with it, and also by the accidental admixture of earthy matters proceeding from the sweepings of the court, the earth adhering to the roots consumed as food, &c. — refuse of every kind, the residue after cleansing the various kinds of fodder for the stable and stall, &c., all goes to the dung-heap. Lastly, and with reference to the elements that are liable to be dissipated in the state of gas, or which may be changed into water, the azote is percepti- bly in larger quantity in the prepared manure than in the unfer- mented litter and excretions. This is at once seen on comparing the composition of these two products after the saline and earthy- matters have been deducted. Carbon. The composition of fresh litter, is 49.3 That of dung 52.8 Dung is, therefore, somewhat richer in carbon than litter, and it contains less oxygen. It is the property of lignine undergoing de- composition, that it yields a product which relatively abounds more in carbon than the original matter, in spite of the carbonic acid which is formed and thrown off during the alterations undergone ; this is owing to the elements of water being thrown off in relatively still larger quantity at the same time. Fermented dung contains less oxygen than that which comes from the stable ; it ought also to contain less hydrogen : but this analysis does not proclaim. It must be observed, however, that the 23* Hydrogen. Oxygen. Azote 5.8 42.7 2 6.1 33.1 3.0 270 DURABILITY OF MANURES. quantity of oxygen (4.6,) the loss of which appears would require no more than 0.57 of hydrogen to constitute water ; and this is a quantity which jt is impossible to answer for in experiments made upon such substances without excessive delicacy of manipulation. This much may be certainly concluded, viz., that manure wfiich has undergone preparation contains a larger relative proportion of azote than the substances which have concurred in its production ; and for this reason, it is very probable that upon the whole a very trifling loss of this element is experienced if the fermentation has been carefully managed, and the manure has been carried out and dis- tributed upon the land before its decomposition is too far advanced. This conclusion, which I am particularly anxious to establish, is partly explained by the interesting researches of Mr. Hermann, which go to prove that woody fibre in rotting attracts and fixes a quantity of the atmospheric air. Azote is in fact the element which it is of highest importance to augment and to preserve in dung. The organic sul)stances which are the most advantageous in producing manures are precisely those whicli give origin by their decomposition to the largest proportion of azotized matters soluble or volatile. I say by their decomposi- tion, because the mere presence of azote in matters of organic ori- gin does not suffice to constitute thetu manure. Coal, for example, contains azote in very apprecial)le quantity ; and \*et its ameliorating influence upon the soil is absolutely null ; this happens from coal resisting the action of those atmospheric agencies wliich determine that putrid fermentation, the ultimate result of which is always the production of ammoniacal salts, or other azotized compounds favor- able to the growth of vegetables. While wc admit tlit* high impor- tance, indeed the absolute necessity of azotic principles in manures, then, we must not tliorefore conclude that these principles are the only ones which contribute to fertilize the earth. It is uiKiuestionable that the alk;iline and earthy salts are further indispensable to the accomplishment of the phenomena of vegeta- tion ; and it is far from being suflicieutly shown that the organic principles void of azote j)l;iy a mert^y passive part when added to the soil. But with few exceptions, tlie hxed salts, water or its ele- ments, and carbon supcriibound in manure. The element which exists there in smallest proportion is azote, which is the one also that is most apt to be dissipaletl during the alteration of the bodies that contain it. For these reasons azote is really the element whose presence it is of highest moment to ascertain ; its proportion is that in fact which fixes the comparative value of dilTerent iiiiinures. 8ince it is by undergoing modification in the course of their de- composition by putref;iction that those azotized substances which are favorable to vegetation are developed in quaternary compounds, it will be readily understood that all tilings else being equal, a manure which is completely (lecompoundal)le into soluble or gaseous produces in the course of a single season, will exert in virtue of this alone the whole of its useful influence upon the first crop. It is entirely diflferent if the manure decomposes more slowly ; its action upon tlia STRAW, STEMS, ETC. 271 first crop will be less obvious, but its influence will continue longer. There are manures which act, it may be said, at the moment they are put into the ground ; there are others, the action of which con- tinues duvincT several years. Nevertheless two manures, although actincT within periods so different in point of extent, will produce the same final result if they severally contain the same dose ot azotic elements, if they are of the same intrinsic value. The durability of manures, the length :f time during which they will continue to" exert thJr influence, is a matter of great impor- tance. It often depends on their state of cohesion, or on their in- solubility, though climate and the nature of the soil have also a marked influence on their decomposition and consequent effects. It ■is not easy in the present state of knowledge to predict with cer- tainty how long the beneficial effects of a given manure will con- tinue to be felt ; but we know well enough what will hasten the decomposition of manure, and what will retard this final result, and so apportion as it were the fertilizing principles among the different crops in the rotation. Aware of the importance of azote in manures, M. Payen and I undertook an extensive series of analyses, with a view to ascertain the proportion of this principle in the various mat- ters and mixtures made use of in the improvement of the soil. This labor enabled us to class manures ; and assuming farm-dung as the standard, to refer each to its place in a comparative scale, I shall give the conclusions to which we came in the tabular form ; but be- fore doing this, I think it necessary to premise a few observations . upon the°several manures, or substances usually employed in prepar- ing manures. j rru e Straw, looody stems, haum, leaves, and zveeds. I he straw ot corn, the haum and stalks of various plants of farm growth, weeds of all kinds, and leaves collected in the woods, all contribute to in- crease the supply of manure. • , 1 Straw is the article that is generally employed for litter ; its hol- low tubular structure, which makes it apt to imbibe urine, renders it peculiarly valuable for this purpose ; and it at the same time sup- plies a soft and warm bed for the cattle. The weight of the straw used as litter may be doubled by the absorption of urine and admix- ture with excrements ; but it is by its very nature and of itself a manure which is not to be slighted, since it contains from 2 to 6 thousandths of azote. The stems of leguminous plants— bean and pea straw— are much more highly azotized than the straw of corn ; it is certainly best to consume this article as forage when it is not too woody and hard. As litter it is often unfit to form a good bed for cattle, and should therefore not be so employed alone ; but it presents the twofold ad- vantage of adding to the manure a large proportion of azotized prin- ciples'^ and at the same time of effecting a saving of straw. At Bechelbronn we have found it very advantageous to mix a certain quantity of the dried stems of the Madia saliva (gold of pleasure) "with both our cowhouse and stable litter. In forest districts, the leaves of trees are frequently used as lit- ill'2 LEAVES BEAN-STRAW. ter ; they perhaps absorb urine in smaller quantities than straw does, but as they are much more highly azotized, they greatly improve the quality of the dung. It is desirable that the materials used for litter should be capable of imbibing a large quantity of liquid ; and these same materials are by so much the more advantageous as the pro- portion of azote which enters into their composition is high. The leaves of trees combine both of these conditions, and are therefore an immense resource in districts where they can be procured in abundance. Where the woods are strictly preserved, the removal of the leaves is generally prohibited ; and it is doubtless injurious to deprive the soil of them in young plantations ; but where the tim- ber is further advanced, the objections to their remuval are infinitely less, and it is therefore generally permitted to carry them away within certain limits. And when it is seen that from natural causes a great part of the leaves is actually lost to the soil of the forest, the wind sweeping them into the ravines, whence they are carried away by the rains, it is evidently far better to aMow the poorer cul- tivators to profit by them. The benefit obtained appears the greater, as the time and labor bestowed in collecting the leaves is not taken into the reckoning. Bean straw, and other stalks of a very hard and thready nature, make but indilTerent litter, they are often s«) hard that they hurt cat- tle ; and then their cuticle being impermeable, they absorb little or no urine. It has been proposed to crush them in the mill or to cut them in pieces, but cither of these processes is attended with expense. The best thing to do would sometimes be to place them where ihey would get crushed under the wheels of the farm carts. The use of woody stems of every description would bo attended with unques- tionable saving in the useful article of straw, and it must never be forgotten that to economize straw as litter, is to increase the quan- tity of available forage. If, for example, it were possible to reduce to the state of litter the wooiiy stems of the Jerusalem artichoke in places where this vegetable is grown to any extent, the advantages would be very decided ; the (juantity of these stalks collected from an acre may amount to from four to five tons ; the pith of wiiich they are almost entirely composed is of a very spongy nature and well fitted to absorb tluids. These stalks arc light, and properly bruised, would probably replace an oinal weight of straw, first ^ litter and then as an element of the dunghill, instead of being burn- ed as at present to heat the oven or to boil the copper, >vhich seems of all methods the worst to derive any adv:uitage from the woody haum, whether of the Jeru.saleiu artichoke, the potato, rape, &c. These substances contain about 4 per 1000 of az(»ie, and are most prolital)ly tr:insformed mto manure. We have found th.il by placing them at the hotlom of the dung-heaps, they end by undergoing de- composition ; even the most vvtiody stems of vegetables, indeed, de- compose pretty rapidlv when ihey are impregnated with urine and mixed with the dropi)ings of animals. Mere moisture without «»llier addition does not sullice, they then rot with extren\e slowness. The green parts of vegetables bnrieil in the ground with the wji- GREEN MANURES. 273 let they contain, undergo decomposition rapidly ; the best plan of using them as manure would therefore hs to plough them in at once, were there not certain objections to this. In the first place it cannot always be done, on account of the season and the crops upon the ground ; and then it might be imprudent to return to the earth the noxious weeds which had just been pulled up, frequently full o. seeds, which would not fail to make their existence known before long. It is besides often impossible to bring loads of weeds to the farmstead ; the best thing that can then be done is to change them rapidly into manure in a corner of one of the fields which has pro- duced them. This is readily accomplished by means of lime ; a bed is first made of the weeds about 14 inches thick, this is then covered with a thin layer of quick-lime, from half an inch to an inch in thickness ; another layer of weeds is laid on, and then another layer of quick-lime, and so on in succession. After a few hours the action between the dry lime and the moist herbage begins, and it may be so intense as even to go the length of burning, to prevent which the pile must be covered with earth or with turf, and every means used to prevent the access of air. The process is generally complete within twenty-four hours, and the heap may then be spread as manure. Before proceeding to such an operation, however, it would be highly proper to calculate its cost. All depends on the price of the lime and the labor ; and all things considered, I myself much doubt whether the plan could be followed with advantage. Green manures. Under this title I include the green pa°rts of vegetables which form part of our crops, such as the haum of po- tatoes, the outer leaves of carrots, cabbages, beet, turnips, &c. These articles are at once forage and manure, and it is for the hus- bandman to decide in conformity with his position and particular resources whether he ought to bury them at once, or to use them first as food for cattle. From my own experience I should say that the leaves of beet and of turnips, and potato haum were articles which ought only to be given to cattle in cases of necessity. It is generally much better to bury them in the ground immediately after the crop is gathered ; if they be very indifferent food, they are on the contrary excellent manure, superior in quality even to the best farm dung. From the experiments I have made on this subject, I find that the potato tops from an acre of ground may be equal to 6 or 7 hundred weight of that manure presumed to be dry ; and the leaves of the beet, from the same extent of surface, are equal to more than 21 hundred weight of the same manure, also in a state of dryness. It is among green manures that we are to class the sea-weed or marine plants, which in many places are employed for improving the soil. These cryptogamic plants, which abound in azote, have a fertilizing power superior to that of common dung, a fact which explains the great store which is set in Brittany by the sea-weed that is collected on its coasts. Sea-weed is employed either fresh and as it comes from the sea, or half dried or macerated, or roasted, and even partially bijmed. It appears to act at once in virtue of the azotized or- £74 GREEN MANURES SEA-WEED. ganic matters which it contains, of the hygrometric properties which it possesses, and of the saline substances which enter into its com position. The agriculturists of Brittany have employed sea-weed as manure from time immemorial ; and so have the people ot Scotland and Ireland. In Brittany, the sea-weed is gathered at periods fixed by law. The first gathering, as well as that which has been cast up by the waves, is given up to the poor. The gath- erings then take place at regular intervals by means of a kind of cutting rake. The sea-weed cut from the rocks is piled upon rafts or thrown into barges, and carried to the shore ; and there is a tiade carried on in the article all along the shores of the channel between Genest and Cape La Hogue, from the Chansey Isles, and from the coast of Calrados. When sea-weed is employed in the fresh state, it is ploughed in as speedily as possible. For those kinds of citips which require made manures, the sea-weed is stratified with dung and so left to ferment. In some places the sea-weed is roasted or imperfectly burned, by which, while a large proportion of the vegetable tissue is destroyed, an azotized product is still left behind. Before burning the sea- weed, it is exposed for a time to the air and the rain, and it is then dried, being frequently turned. In this state, it is even used as fuel in places where wood is scarce. One great advantage in sea-weed which has been particularly indicated, is its total freedom from the seeds of noxious weeds. Aquatic plants which grow in fresh water may also be employeil as manure ; the common reed cut and buried green, decomposes rapidly. And here I may mention that to destroy reeds which are often a cause of great annoyance in ponds, Schwertz reconmiends lowering the water about 16 inches, cutting the plant, and then rais- ing the water to its old level ; the water enters the interior of the items and they all die in a very short space of time. Crops which are buried green, for the improvement of the soil, are also to be ranked in the list of the manures which now engage us. The plan of burying green crops dates from the most remote an- tiquity ; it was greatly recommended by the Honums, and is followeil in Italy at the present day. TUe plants usually grown for the pur- pose of being burned green are colza or colewort, rape, buckwheat, tares, trefoil, &c. The preference, however, is given to one or other of the leguminous plants, such as tares. lupins, &c., plants which appear to have the hijihest power of extracting azotized prin- ciples from the atmosphere ; and indeed the value ot" the whole pra cess is founded upon this fact, for otherwise it would be impossible to give any reason for this long accredited mode of improving the soil. This, too, is one of the ways in which fallowing becomes use- ful ; it is not merely the rest which the land thus obtains, it is also benefited by the vegetables which grow upon it spontaneously, which come to maturity and die, leaving in this way in the ground all they had attracted from the atmosphere, or fixed 'rom the water with which they had been supplied. Seeds, Oil-cakc. It is in the seed that by fs; the largest proper OIL-CAKE MANURE. 275 lion of the azotized matter assimilated by vegetables during their growth is finally concentrated at the period of their maturity. Seeds are consequently very powerful manures, and great advantage is taken of them. In Tuscany, lupin seed is sold as manure ; it con- tains 3i- per cent, of azote. It is employed after its germinating power has been destroyed by boiling or roasting. The cultivation of the lupin is carried on in districts, the situation of which is such that difficulty would be experienced in exporting more bulky crops. Grains from the brewery would also make excellent manure were it not generally found more advantageous to use them as food for cat- tle. °In some places, however, where there is no adequate demand for them in this direction, they are dried upon a kiln, and are then equal to twice and a half their weight of farm dung ; in some places they are actually sold at a proportionate price. The state if divis- ion of grains admits of their being regularly spread. In some parts of England, grains are used in the proportion of from 40 to 50 bushels per acre for wheat or barley.* The refuse of the grape in wine countries contains a large quantity of azotized matter. The decomposition of the grape stones being slow, this refuse answers admirably as a manure for vines. Oleaginous seeds after the extraction of the oil leave a residue which is an article of commerce, and is familiarly known under the name of cake. Oil contains no appreciable quantity of azote ; this principle is contained entirely in the cake, which becomes through this alone most excellent manure. The proportion of azote which cake contains, varies from ^ to 9 per cent. Oil-cake, from its mode of preparation, contains but very little moisture, and consequently of- fers great facilities in the way of carriage ; it may be taken without difficulty to situations whither a load of dung could scarcely be carried. Cake is applied in two modes : 1st. In powder, and by sowing upon the field, sometimes mixed with the seed. 2d. Mixed in vi^ater or in the drainings of the dung-hill, in which case the liquid contain- ing the products of the decomposition of the cake is distributed over the land. By putrefaction under water, cake yields a matter of ex- treme fetor, comparable both in point of smell and of effects on vege- tation to human excrement obtained from privies. Although cake, from the large proportion of albumen and legumen which it contains, be an excellent food for cattle, it is still found more advantageous in many districts to use it as manure than for feeding. England imports oil-cake from all parts of the continent. France alone, from 1836 to 1840, exported more than 117,860 tons of the article. Oil-cake has been particularly recommended as manure for light sandy soils. When the soil is clayey and cold, Schwertz recommends a mixture of one part of lime and 6 parts of powdered cake. To me, however, the addition of lime has always appeared a questionable auxiliary in such manures as give rise readily to ammoniacal products, as is the case with oil-cake. For clayey lands, it would perhaps be advisable to employ oil-cake in a state of ♦ Sinclair, Agriculture, vol. i. B76 REFUSE OF BEET AS MANURE. decomposition and diffused in water ; its effects, I imagine, would not be doubtful. Oil-cake, as a manure, is employed at very different seasons, ac- cording to the nature of the husbandry. It is always well to employ it in rainy weather. Its effect is always certain, if it comes on to rain two. or three weeks after it has been put into the ground. Drought suspends its action ; it frequently happens, indeed, that the first crop shows none of its good effects ; but these never fail to ap- pear in subsequent crops. Schwertz remarks very properly, that this circumstance has led many farmers to overlook the real advan- tages that belong to this manure. Cake, in fact, according to the dryness or moistness of the season, may act as a manure either of difficult or of easy decomposition, and so produce more immediate or more remote effects. In England about 800 weight of oil-cake per acre are commonly applied. Mr. Coke, of Holkham, ploughed in the powdered cake about six weeks before sowing turnips, but it is held more economical and more advantageous to strew it in fine powder along the furrow with the seed. The latter view, however, must not be too confidently acted on by farmers ; the general recommendation to sow the fields with powdered cake, either some weeks before or some weeks after putting it in the seed, and when the plants have already sprung, appears to be the right one. We have various ob- servations made by one of our most experienced practical farmers which prove that oil-cake used dry anrin, in Mid'^on Riis:;iimp vol. i. p. '204. REFUSE OF THE SUGAR-HOUSE, ETC. 277 of similar value. The animal charcoal of the sugar refinery, after it has served its office there, is an admirable manure. It is, in fact. bone or ivory-black, mixed with the coagulated blood which has been employed to clarify the sirup by entangling impurities, and a very small quantity of sugar. This mixture, so rich in azotized princi- ples, used actually to be turned into the sewers until the year 1824, when M. Payen showed its value as manure, since which time near- ly 10,000 tons have been annually employed in ameliorating the soil, to the great advantage of practical agriculture. The importance of the trade in this residue of the sugar-house, and complaints of the occasional indifferent quality of the article, attracted the attention of the department of the Inferior-Loire in 1838, and led to the appoint- ment of an inspector of the manure shipped from the port of Nantz. I may here observe, that in testing a manure it is by no means enough to limit attention to the quantity of organic matter which it contains. The only sure means is to determine the amount of azote ; it is not organic matter, but the amount of azotized organic matter upon which almost alone depends the value of the manure. The residue of the sugar refinery is another of those articles which presents an occasional anomaly in its application, and which must not be left unnoticed. Its effect upon the ground has not only been extremely variable, but it has sometimes happened that this manure, laid on very soon after coming from the manufactory, has been found decidedly injurious to vegetation. Kept for some time, for a month or two, in a heap before being applied, its effect has not only been found more certain, but also uniformly favorable. It is not difficult to explain these divers and opposite influences : the sugar contained in the refuse undergoing fermentation yields first alcohol, and than acetic and lactic acids. Employed in this state, the substance must necessarily prove injurious to vegetation. It is only after it has lain for a sufficient length of time exposed to the air, to have had the animal matter it contains changed into am- monia, and the organic acids engendered saturated with this base, that it becomes truly useful to vegetation. The heap indeed then shows alkaline, not acid re-action.* The residue of the starch manufacturer, the fetid water which is obtained in such quantity in the process of making starch from grain, is a powerful manure, and ought not to be suffered to run to waste. The pulp or residue of the potato which is now produced in con- siderable quantity in the potato starch manufactories, is known to be an excellent article of food for hogs and cattle. Towur^is the end of the season, however, it is apt to be of very indifferent quality, and green food having by this time come in abundantlv, it often goes to the dung-hill. In the dry state, it is worth its; own weight of farm dung; wet, 100 of the pulp may be equal to about 131 of farm-yard dung. The water which has served for washing out the starch from the pulp, as in the case of wheat and other grain, con- tains an organic substance which when dried constitutes pulverulent * Payen and Boussingault, Ann. de Cliiniie, v. iii. p. 05, 3c serie 24 276 ANIMAL REMAINS. manure that is equal to about- half its weight cf .he dry manure pre. pared from night soil, which the French call pcidrette. M. Daill} made a comparative trial of these two kinds cf manure, and from actual experiment foimd that 200 parts of the deposite from tb« starch manufactory might be used for 100 of poudretle. Even the water that is used in the manufacture, and from which the substance m question is deposited, is an excellent manure when thrown upon the ground, a circumstance which is by so much the more fortunate that this water by standing putrefies and throws otf most offensive ex- halations. By using the liquor to his fields, at once, M. Dailly pre vents every kind of annoyance to himself and his neighbors, and moreover from his great starch manufactory he realizes in this way an additional profit which he estimates at upwards of £Q0 per an- num. Analysis has shown that 100 of this water from the potato starch manufactory represents 17 of moist farm-yard dung. In cider countries, the pulp of the apples that have been pressed is always thrown upon land as manure. At Bechelbronn we reserve it for our Jerusalem artichokes ; in Normandy it is thought excel- lent for meadows and young orchards. Analysis of the pulp of ap- ples grown in Alsace shows that when dry it contains a quantity of azote, which places it on the same footmg as farm-yard dung. .Smclair informs us that in Herefordshire the pulp of the cider press is made into good manure by being mixed with quick-lime and turned two or three times in the course of the following summer. Doubtless the addition of lime will hasten the decomposition of the woody matter of the pulp ; but it strikes me that this will take place rapidly enough of itself in the ground without contriving any means of accelerating tlie process. Animal remains. Tlie remains of dead annuals and the animal matters obtained from the slaughter house are powerful manures, which are nmch sought after in places where their value is properly appreciated. iScraps and the refuse of skin, liair, horn, tendons, bones, feathers, &c., all form invaluable manure. The llesh of ani- mals which die, and so much of that of horses that are slaughtered which cannot be used as food ft)r animals, may be dried after having been previously boiled, and then reduced to powder and applied as nianure. The blood of slaughtered animals is less proper as food for hogs, although it is often used in this way, than muscular tlesh ; it even occasionally gives rise to serious diseases among these ani- mals. It is most easily j)repared as manure, however, for which it answers admirably : it is enough to coagulate it by exposure to heat, and then having broken it down, to dry it in the air or in the stove. Liquid blood has been employed as manure, but decompo^iti^)n then takes place so rapidly, that the produc s are exhaled without pro- ducing much elTect. This objection may be remedied by two means, either by diluting the blood in a large quantity o( water, with which the land is then irrigated, or by mixing it with a considerable mass of vegetable earth, which is then applied like ordinary manure. There is even a pulverulent manure of which blood forms the basis, prepared in special establishments in the vicinity of various larpe BONES. 279 iowns. The large quantity of azote contained in these manures sliows how their value may be such as to permit of their being advantageously exported to great distances beyond seas. Bones are employed in agriculture after having had the fat which they contained extracted from them by boiling. They are crushed by being passed between the teeth or grooves of a couple of cast- iron rollers. They must be regarded as a manure, the action of which is of long duration, because the animal matter contained in them decomposes slowly, protected as it is by the earthy casing which surrounds it. In England from 50 to 60 bushels of bruised bones per acre are usually put upon land prepared for turnips. The employment of bones as manure has given rise to the most various and contradictory observations. In certain circumstances their effect upon vegetation has been almost null ; in others their action has been decisive and most favorable. M. Payen has given a solution of these anomalies which is perfectly satisfactory. Ac- cording to my learned colleague, bones in their interstices, contain a quantity of fat of various consistency, which may be removed by long boiling in water ; the average quantity of grease obtained from fresh bones is about 10 per cent. It has been observed that this fat- ty matter diminishes gradually in bones that dry by long exposure ; it even disappears almost entirely when they are dried at a high temperature. This happens from the water which is disengaged from the bony tissue by the effect of evaporation, being replaced by fat melted by the heat. The consequence of this is, that the organic tissue of bone, which was already sufficiently rebellious to decom- position, becomes still less alterable when it is impregnated with grease. The grease, in fact, by reacting upon the carbonate of lime of the bone, has formed an earthy soap which long resists at- mospherical influences and change under ground. It will readily be understood that bones in this condition can have little or no action upon vegetation, unless indeed they be reduced to very fine powder. This alone will explain how it may happen that somg bones, after having remained four years in the ground, have been found to have lost no more than 8 per cent, of their Vi^eight, while those, the grease of which has been removed by boiling water, have lost in the same space of time from 25 to 30 per cent, of their weight.* These observations of M. Payen show how completely Schwertz was mistaken when he ascribed the indifferent quality of the ma- nure prepared from old bones, or from bones that had been boiled, to the absence of fat, which he regards, I know not on what authority, as a substance extremely favorable to vegetation. It is not very obvious how fatty substances should act as manures. I myself ascertained, from experiments made some years ago with a view to test the conclusions of an agriculturist who ascribed the good effects of cake to the fatty matters which it containen, that rape-oil had no kind of favorable influence upon the growth * Paj-en, Maison Pusfique, v. i. p. 194. ^80 GRAVES WOOLLEN RAGS, ETC. of wheat. I have said nothing here upon the importance of tn€ earthy matter of bones, particularly of the calcareous phosphate which they contain, but which is nevertheless acknowledged to be of great importance. The refuse from the glue-mafier's, washed and pressed, contains all the animal matters which have resisted the action of boiling water, such as portions of tendinous and skinny substance, hair, pieces of bone, of horn, and of flesh, a calcareous soap, and earthy matters. This mixture putrefies rapidly ; but dried, it may be pre- served for a great length of time. Analyzed dry, it yields about 4 per cent, of azote. From 4 to 5 cwt. per acre are employed, but it is necessary to manure every year. The refuse (f the talloir-melter, graves, as it is called, a residue c(^nsisting in great part of the membranes which have enveloped the fat of our domestic animals, mixed with a little blood, some flesh, and bony matter, and grease, has hitherto been emj. fayed almost exclusively as food for dogs. Of late, however, graves have been used as manure, and analysis shows that this substance must be estimated as equal to about 3.;, farm-dung being fixed at 1. Used in this proportion, graves produce a marked effect. The action of graves, which may be thrown on in fragments and dry, or after having been steeped in hot water, and reduced to the state of a pulp, will continue for three or four years. Shreds of ivoollen rags form a good manure for vines and olive- trees especially, though they are also available in husbandry of every description. The large proportion of azote, and the small quantity of water contained in woollen rags, constitute them not only one of the richest manures, but also one of those that is most easily transported ; 25 cwts. per acre of woollen rags, the cost of which, in France, may be about jC3, have been found sufficient as manure for three years. The slowness with which wool decomposes, indeed, causes its action to be continued during six or eight years. Twenty- rive cwt. of woollen rags m;iy be held e(}uivalent to upwards of 40 Ions of farm-dung, which, at the price of 3s lOd. per ton, would irost jC1'2 16.S-. At the end olthree years, M. Delonchamps, an excellent prai^tical farmer, gives his land a dressing of farm-dung for three years more, when he returns to the wool. Bet'ore spreading rags they must be cut into pieces, which is effected either by a machine, or by a piece of scythe-blade fixed in a block of wood. In England, the quantity of woollen rags allowed to the acre is generally about 13 cwt. Sinclair says that they are best suited for dry and sandy or chalky soils, and this because they attract moisture. I have not found the fact to be so. In the very dry soil of a vineyard manured with this article, I have found the pieces to decompose witli extreme slowness, and, up to this time, the effect upon the vines has been scarcely perceptible. The raspings and shavings of horn form a manure of great power, that seems api)licable to ^very variety of soil. In England, aboul 40 bushels per acre are usually allowed. Tendons, trimmings of hides, hair, feathers, cjr., are manures very SHELLS MUD. 281 analogous to the last, and of which the value may be estimated from the quantity of azote which they severally contain. This value once determined, every farmer knows the quantity which he must lay upon his land ; and he thus proceeds upon a much more rational foundation than when he takes for his guide one or other of those vague and arbitrary indications that have been given. Sinclair, for example, would have us lay on nine bushels of feather rubbish to the' acre, and Schwertz recommends from four to five times as much more. Nothing, in fact, is more arbitrary and uncertain than to estimate such materials by the bulk ; it must be obvious that the weight of a bushel of hide-trimmings, of horn-shavings, and of feather-rubbish, must differ very widely, not only with reference to one another, but also according to the state of division in which each is measured. As a general rule, it is by weight, and weight alone, that the quantity of manure must be estimated. Shells and mud from the sea-shore and the bottoms of rivers, are matters that are not often very highly azotized ; nevertheless they may contain an equivalent of the all-important element, azote, which may bring them near to wet farm-yard dung in point of value. The abundance of such matters in certain situations makes them ex- tremely useful. The alkaline and earthy salts, which they generally contain in considerable quantity, also add to their fertilizing proper- ties. The sea-sand which is employed in Brittany under the name of marl, (merl,) consists, in great part, of the remains of corallines, madrepores, and shells, mixed with a few hundredths of highly azotized organic manner. This marine marl is found in great abundance at the mouths of the river of Morlaix, where there is a considerable traffic carried on in the article. It is said to be repro- duced, new banks of it being met with from time to time. It is obtained by dredging from barges, and the process is only allowed to go on from the 15th of May to the 15th of October, when the quays of the town of Morlaix are seen covered with the produce. It is carted to a distance of five leagues inland. A barge-load weighing seven tons, sells at from 6^. 6d. to 8.?. This same species ef marl is now obtained upon the coast of Plancourtrez and in the roads of Brest. It has also been discovered near the mouth of the river Quimpert. It appears, finally, that the shell sand so much employed by the farmers of Devonshire and Cornwall is of the same essential nature. In the neighborhood of Morlaix, from five to six tons per acre of this calcareous sand are employed upon light dry soils ; from eleven to twelve tons are given to clayey lands. This quantity would probably be too great for porous and damp soils, inasmuch as sea- marl belongs to the class of warm manures ; that is to say, it under goes speedy decomposition. There can be no doubt that sea-marl acts further, in virtue of the calcareous matter which it contains, and also of its merely mechanical properties upon the strong argilla- ceous lands of Brittany, for which sand alone is an excellent im- prover. It is also to the carbonate of lime which it contains, that *ts good effects upon lands that show an inflorescence of iron pyrites 24* SS2 SHELL MARL. must he ascribed. It is well to lay this shell-marl upon the land shortly after it is taken from the sea ; by long exposure to the air, it suffers disaggregation and loses a portion of its good qualities. There is another kind of sea-sand called trez, which forms banks in the neighborhood of Morlaix, and which is known under the name of tanque on the northern shores of France, which is favorable to vegetation, particularly after it has been washed and freed from the greater part of tbe salt which it contains. It is thrown upon the land in larger quantity than the marl. The small quantity of animal mat- ter which It contains putrefies and is lost when it remains exposed to the air for any lengtli of time, so that a distinction has been made between fresh or live trez^ and old or dead Irez, the one being the article as it comes from the sea, the other after it has been exposed some time on the shore ; the article which has been exposed un- doubtedly contains a smaller quantity of organic matter than that which is quite fresh. This variety of sea-sand is particularly avail- able upon close and clayey lands, which sometimes receive as many as sixteen tons per acre with advantage ; lighter lands, of course, require much less. Shells, sand, slime, and sea-weed, are not the only useful mate- rials supplied to agriculture by the sea ; Jish, or their ojf'al, is fre- quently employed as manure. The practice of manuring with fish is very old, and is universal wherever it can be had recourse to. I have already had occasion to say, that at the period of the con- quest of America, the Spaniards found it established among the Indians, on the shores of the Pacific ocean. The lands are oc- casionally manured with fish along the sea-board of Great Britain and Ireland, and the low lands of Lincohishire, Cambridgeshire, and Norfolk, also receive occasional supplies of the same power- ful manure. The offil of the herring fisliery, of cod, of skate, and of the pilchard, in Cornwall, the dog-fish entire, and other kinds, that are either less esteemed, or that are caught in quantities greater than can be consumed as food, are all admirable manures. We have been recommended to mix the fish or fish-offal with quick-lime ; but, unless in certain circumstances, the practice is very questionable ; the addition is probably only j)roper where the materials are ex- ceedingly oily, as is the case with pilchards, herrings, g« Peroxide of iron J 100.0 The vitriolic ashes of Forges-les-Eaux are more highly azotized than those of Picardy ; they contain 'J.7*J per cent, of azote. The effect of the imperfect combustion of these pyritic turfs, the product which results from it, explains to a certain extent the bene- ficial effects of the practice o( paring and burnim^, an important and widely spread practice, the utility of which it would be ditlicult to understand, were it not connected in some way with the production of ammoniacal ashes. The useful effects of paring and burning, are, in all probability, connected with the destruction of organic matter, very poor in azo- tized principles ; in the transforn)ation of the surface of the soil into 1 porous, carbonaceous earth, made apt to condense and retain the ammoniacal vapors disengaged during the combustion ; lastly, by the production of alkaline and earthy salts, which are familiarly known to exert a most beneficial intluence uj)on vegetation. These MANURES. 285 conditions seem so entirely those, the object of which it is to realize by paring and burning, that in order to make the operation favorable to the soil which undergoes it, the vegetable matter which it has produced, must of necessity be transformed into black ashes ; when it goes beyond this, as Mr. Hoblyn has well observed, when the in- cineration is complete, and the residue presents itself as a red ash, the soil may be struck with perfect barrenness for the future. The burning, therefore, that was not properly managed, that led to the complete incineration of all the organic matter, would, for the same reason, have a very bad effect in the preparation of the Picardy ash- es ; which might indeed act in the same way as turf ashes from the hearth and oven, but which, deprived of all azotized principles, would not ameliorate the ground in the manner of organic manures. I have frequently seen the process of burning pertormed in the steppes of southern America. Fire is set to the pastures after the grass which covers them has become dry and woody ; the flame spreads with inconceivable rapidity, and to immense distances. The earth becomes charred and black ; the combustion of those parts that are nearest to the surface, however, is never complete ; and a few days after the passage of the flame, a fresh and vigorous vege- tation is seen sprouting through the blackened soil, so that in a few weeks the scene of the desolation by fire, becomes changed into a rich and verdant meadow. ANIMAL EXCREMENTS. Horse-dung. The composition of horse-dung would lead us to infer that its action must be more energetic than that of cow-dung. Nevertheless, agriculturists frequently consider it as of inferior qual- ity. This opinion is, even to a certain extent, well founded. Thus although it be acknowledged that horse-dung covered in before it has fermented, yields a very powerful manure, it is known that in general the same substance, after its decomposition, affords a manure that is really less useful than that of the cow-house. This comes entirely from the fact that the droppings of the stable, by reason of the small quantity of moisture they contain, present greater difficulties in the way of proper treatment than those from the cow-house. Mixed with litter and thrown loosely upon the dung-hill, horse-dung heats rapidly, dries, and perishes : unless the mass be supplied with a suf- ficient quantity of water to keep down the fermentation, and the access of the air be prevented by proper treading, there is always, without the least doubt, a considerable loss of principles, w-hich it is of the highest importance to preserve. I can give a striking instance of this fact in the changes that happen in the conversion of horse- dung into manure in the last stage of decomposition : fresh horse- dung in the dry state contains 2.7 per cent, of azote. The same dung laid in a thick stratum and left to undergo entire decomposition, gave a humus or mould, from which, reduced to dryness, no more than one per cent, of azote was obtained. I add, that by this fermen- tation or decomposition, the dung had lost nine tenths of its weigLt 286 HORSE-DTTMG. From these numbers every one may judge how great had been the loss of azotized principles. In practice, however, little care is be- stowed on the preparation of horse-dung ; the fermentation is rarely, if ever, pushed to this extreme point indeed : but it is not the less true that it is constantly approached in a greater or less degree ; and that the consequences, although not altogether so unfavorable as those which I have particularly signalized, are neve/theless extremely destructive. All enlightened agriculturists have, therefore, long been aware of the attention necessary to the management of horse- dung, which requires a degree of care, that may be perfectly well dispensed with when the business is to convert the dejections of horn- ed cattle into manure. To obtain the best results in the management of horse-dung, it appears to be absolutely necessary to give it a much larger quantity of moisture than it can ever receive from the urine of the animal ; if it be not watered it necessarily heals, dries, and loses both in weight and quality ; while, by being kept properly moist, it produces a manure, which half rotted, is of quality superior, or at all events equal, to the same weijiht of cow-dung. M. Schattenmann, who has the produce of stables containing two hundred horses to manajie, follows a process of the most commend- able description in the preparation of his manure, and which is attended with the very best results. His dunghill stance, of no great depth, is about 440 yards square in superficies, and divided into two equal portions. The bottom of this stance is so arranged as to pre- sent two inclined planes, which bring all the liquids that drain from it to the middle, where thf re is an ample tank for their reception, furnished with a pump for their redistribution to the dunghill. There is also another spring-water pump destined to supply the water that is necessary to preserve the dunir-heap in an adequate stale of moist- ness. The latter auxiliary is (juite indispensable ; the quantity of water necessary is so considerable when masses of such magnitude are to be treated, that we cannot trust to any casual sojircc of supply. The two portions of the area are alternately pile«l with the dung as it comes from the stables : it is heaped to ihe height of 10, 12, or 14 feet ; it is trodden down carefully, as it is evenly spread, and plentifully watered from the sprinsj-waier pump. Due consolidation, and a state of constant humidity, are the two conditions that are ihe most indispensable to the successful preparation of hor.se-dung. M. Schattenmann is in the habit of adding to the liquid, saturated with the soluble matters of the dunj^hill, a (juanlity of sulphate of iron in solution, or of sulphate of lime (<:ypsum) in j)0wder ; he also throws the same salts upon the surface of his heap : the object of this is evidently to transform into sulphate, the volatile carbonate of ammo- nia formed in the course of the decomposition, and so to prevent its escape and loss. IJy these means a pasty manure, as rich as thai which is yielded by horned cattle, and of a quality, the excellence of which is proclaimed by the remarkable crops that cover the lands which receive it, is produced in the course of two or three months.* • Bchattcniiiann. Annates (If Chiinio, 3c sdrio, vol. iv. p. 117 HORSE-DUNG. 287 It is almost useless to add, that great care must be taken not to in- troduce too large a quantity of sulphate of iron, which might have a prejudicial influence upon vegetation, into the dunghill or the drainings from it. In making use of sulphate of lime there is noth- ing to fear on this score ; this salt in excess would be rather favor- able than hurtful ; in general, gypsum is certainly the preferable substance, both on account of its never doing mischief, and of its greatly inferior price.* Farmers generally advise horse-dung to be reserved for argilla- ceous, deep, and moist soils ; this recommendation is given in con- nection with the manure that is obtained by the usual imperfect pro- cess of preparation. With regard to the horse-dung, prepared in the manner which I have just described, and as practised by M. Schat- tenmann, it is adapted to soils of all kinds ; and if it differs from the dung of the cow-house, it is only by its superior quality. This last fact is at once explained by the elementary analysis of the ex- crements of a horse fed upon hay and oats. 100 parts of the urine of the animal so fed, yielded 12.4 of dry extract, the composition of which was as follows : ■^ In the state of extract. In the liquid state. Carbon 36.0 4.46 Hydrogen 3.8 0.47 Oxygen 11.3 1.40 Azote 12.5 1.55 Salts 36.4 4.51 Water • " 87.61 100.0 100.00 The droppings of the same horse after drying, gave 24.7 of fixed matter, the analysis of which indicated : Dry excrement. Moist excrement. Carbon 38.7 9..56 riydrogen 5.1 1.26 Oxygen 37.7 9.31 Azote 2.2 0.54 Salts 16.3 4.02 Water •... " 75.31 100.0 100.00 The dung of horned cattle is often extremely watery ; it is espe- cially so when furnished by animals kept upon gieen food ; this ex- treme humidity renders its preparation easy. Its equivalent number is higher than that of horse-dung ; it is, in fact, less highly azotized, and consequently less active. If the food have a great effect upon the quality of the manure, it is quite certain that the circumstances or slates of the cattle have an effect which is scarcely less remark- able. Milch cows and cows in calf always furnish a manure that is less highly azotized than stall-fed and laboring oxen ; and this is readily understood : the azotized principles of the food are diverted to secretions, which concur in the development of a new being in the one case, in the production of milk in the other ; for the same * Every farmer who shonld have something like a cart or wagon-load of gypsum brought to the farm every year would find his profit from the practice.— Eifo. E». 288 hog's dung — pigeon's dung. reason the dejections of young animals, all things else being equal furnish a manure of less power and vaUie than those of adult ani- mals. I shall have occasion to recur to this important subject, which has never yet been sufficiently studied. The urine and excrements of a milch cow, which is giving about 12 pints of milk per diem, have shown upon analysis, the following quantities of elements : 100 of the urine contained 11.7 of dry ex- tract, and had this composition : Urine dry. Urine liquid. Carbon 27.2 3.18 Hydrogen 2.6 0.30 Oxygen 2«.4 3.09 Azote 3.8 0.44 Salts 40.0 4.68 Water • 0.0 88.31 100.0 100.00 100 of fresh excrement left on drying 9.4 of dry substance, and in each state contained : Excrement dry. Excrement moist. Carbon 42.8 4.02 Hydrogen .'j.2 0.49 O-xygen 37.7 3.54 Azote 2.3 0.22 Salts 12.0 1.13 Water 0.0 90.60 100.0 100.00 Hog'^s dung. From all I have seen, I conclude that hogs well kept and put up to fatten, yield dejections which are highly azotized, and wliich must consequently furnish a manure of excellent quality. Schwertz has, indeed, ascertained that this manure acts more pow- erfully than cow-dung. Sheep-dung is one of the most active of manures, a fact which is confirmed by analysis ; for it is by no means watery, and in the usual state contains upwards of one per cent, of azote. The mode of managing sheep generally implies that they manure the ground immediately. Schwertz calcuhitos that in the course of a night, a sheep will manure something more than a square yard of surface ; at Bec'hrlhronii we have found the (pianlity manured to be about 4 square feet, 'i'hc following are the details of one experiment : Two hundred sheep were folded fur a fortniijht upon a rye-stubble, of an extent which gave as nearly as possible four square feet of surface per sheep. The manuring thus effected was found to pro- duce a maximum effect upon the crop of turnips which followed the rye. Pigeon\s dung is known as a hot manure, and of such activity that it must be used with discretion. Pigeon's dung is available for crops of every description ; Schwertz has made use of it for a long time, and always with the greatest success, mixed with coal ashes, upon clovers. The Flemish farmers procure pigeon's dung from the (h'partnient of the Pas de Calai:*, where there are a great num- ber of dove-cotes, one of which, containing from six hundred to six hundred and fifty pigeons, will let for the sum of about £4 per annu n. GTJANO. 289 mere y for the sake of the dung; the quantity yielded in this tinne may be about a wagon-load. In the neighborhood of Lisle, this manure is applied particularly in the cultivation of flax and tobacco. According to M. Cordier, the dung of between seven hundred and eight hundred pigeons is sufficient to manure nearly 2- acres of ground. The dung of three hundred and twelve pigeons, therefore, would sufl^ice for an acre. The value of pigeon's dung may be es- timated from the large proportion of azote which it contains ; that which I analyzed from }3echelbronn gave S] per cent, of this prin- ciple, a result which ought not to excite surprise when it is known that the white matter that appears in the excrements of birds, con- sists of nearly pure uric acid. 'I'he manure of the hen-house is nearly or quite as good as pigeon's dung. Guano is a manure of the same nature as pigeon's dung, and the use of which, long familiar on the coasts of Peru, has lately extend- ed to these countries, the article being now imported in large quan- tities, both from the South American and African coasts. Guano appears to be the result of the accumulation for ages of the excre- ments of the sea-fowl, which live and nestle in the islets, in the neighborhood of the great southern continents of the new and old world. The mass in many places forms beds of between 60 and 70 feet in thickness. The principal places whence guano is obtained, are the Chinche islands near Pisco ; but other deposites of the sub- stance are known to exist more to the south, — in the islets of Iza and Ilo, at Arica, and in the neighborhood of Payta, as 1 had an op- portunity of ascertaining during my stay in that port. The inhab- itants of Chinche are the principal traders in guano ; and a class of small vessels, called Guaneros, are constantly engaged in carrying the manure.* Fourcroy and Vauquelin were the first who fixed attention on the nature of guano. The specimen which they examined was brought to Europe by M. de Humboldt, and contained : Uric acid (0.25,) ox- alate of ammonia, chlorhydrate of ammonia, oxalate of potash, phosphates of potash and of lime, chloride of potassium, fatty matter, and sand. Since this time Dr. Fownes has again analyzed guano. The sample upon which he operated was of a light brown color and ex- tremely offensive smell ; it yielded : Oxalate of ammonia i Uric acid \ 66.2 Traces of carbonate of ammonia and organic matter j Phosphates of lime and of magnesia 29.2 Phosphates and alkaline chlorides, and traces of sulphates 4.6 100.0 Another sample, deeper in color and without smell, contained : Pure oxalate of ammonia, 44.6; earthy phosphates, 41.2 ; alkaline Dhosphates, sulphates, and chlorides, 14.2=100. The composition of guano would confirm, were there any occasion * Humboldt, Annales de Chimie, vol. Ivi. p. 258. 35 290 NIGIIT-SOIL. for confirmation, the opinion that has beer, formed as to its origin. The islets which supply it are still tenanted, especially during the night, by a multitude of sea-fowl. Nevertheless, from the calcula- tions of M. de Humboldt, the excrements of these birds in the course of three centuries, would not form a layer of guano of more than one third of an inch in thickness ; — imagination stops short, startled, in presence of the vast lapse of time which must have been neces- sary to accumulate such beds of the substance as now exist, or rather, as lately existed in many places ; for it is rapidly disappear- ing since it has become a subject of the commercial enterprise of mankind.* The average composition of guano must by no means be inferred from the preceding analyses of picked samples: earthy matters are usually present in much larger proportion than they are here stated. The guano generally imported into England and France yields a proportion of azote very far short of that which the '2o per cent, of uric acid which has sometimes been stated to exist in this substance would yield. In three trials the azote found was 0.14, 0.05, and 0.05 ; the mean would therefore be 0.08, which represents the quan- tity of azote in pigeon's dung. The litter and excrement of the silkworm is used as manure in the south. Analysis indicates 3 per cent, of azote in its constitution. Human excrements are regarded as one of the most active ma- nures that can be employed. In countries where agriculture has made real progress, this article is highly prized, and no pains are spared to obtain so powerful a manure. In Fiattders, feculent inat- ters form the staj)le of an active traflic ; and in the neighborhood of large towns, they form an invaluable material for the amelioration of the soil. The Chinese collect human e.\cren)ents with the great- est solicitude, vessels being placed for the purpose at regular dis- tances along the most frei[uented ways. Old men, women and chil- dren, are engaged in mixing them with water, which is applied in the neighborhood of the plants in cultivation. f Tiie fresh excrement is occasionally worked up with clay, and A>rmed into bricks, which are pidverized when dry, and the jiowder is applied as a top-dress- ing. One of the advantages resulting from the almost exclusive use of this manure in China is this, that the fields seem to grow nothing but the plant which is the object of solicitude with the farmer; it is there extremely difficult to meet with a weed. The quality of feculent matter as a manure depends much on the nature and abundance of the food consumed by those who furnish it. M. d'Arcet relates a curious anecdote in connection with this fact : a farmer had purchased the produce of the cabinet of one of the most * Dr. John Drwy, all whose scientific rcoarchr^ rquil in nccurncy the briihnnt in vc<'tis::itioiis of lu< iilustri«)Us l»n>thcr, litis latfly turnrtl his attrr.tio'n to tliis ^uhjcft: he timl'* that we hiivo collections of pinno in Crcat Britiin thit sire reilly not to bo (iespi-iotl in some cases. The Mirface of the ground under old-e^lililishcd rookeries is n true cuano bed; and removed and u>ed as manure in the open field, priHluc<»s most excellent ollecu. Seo Dr. Davy's paper in Ed. Lond. and Dub. PhMos, M>ig. OcL 1, 1844.— Eno. Ed. t Julien, Annates d«; Chimie, vol. iii. p. Co, 3d »eries NIGHT-SOIL. 291 celebrated restaurateurs or taverns of the Palais Royal ; encouraged by the success he obtained in ennploying this manure, and desirous of obtaining a larger supply of the article, he routed the produce of several of the barracks of Paris. The manure which he now obtain- ed, however, he found to {)roduce an effect greatly less than he had anticipated, so that he lost money by his bargain. Berzelius found the following substances in human excrements : Remains of food 7.0 Bile 0.9 Albumen 0.9 A peculiar extractive matter 2.7 Indeterminate animal matter, viscous matter, resin, and an insoluble residuum 14.0 Salts 1.2 Water 73.3 100.0 The salts had the composition following : Carbonate of soda 29.4 Chloride of sodium 23.5 Sulphate of soda 11.8 Ammoniaco-magnesian phosphate 11.8 Phosphate of lime 23.5 100.0 Human wine is one of the most powerful of all manures. Left to itself it speedily undergoes pufiefaction, and devolves an abun- dance of ammoniacal salts, as all the world knows. Its composition, according to Berzelius, is the following : Urea 3.01 Uric acid 0.10 Indeterminate animal matter ) ^ -, Lictic acid, and lactate of ammonia ) Mucus of the bladder 0.03 Sulphate of potash 0.37 Sulphate of soda 0.32 Phosphate of soda 0.29 Chloride of sodium 0.45 Phosphate of ammonia 0.17 Chlorhydrate of ammonia 0.15 Phosphate of lime and of magnesia 0. 10 Silica traces Water 93.30 100.00 The phosphates of lime and magnesia which it contains are ex- tremely insoluble salts, and have been supposed to be held in solution by phosphoric acid, lactic acid, and very recently by Professor Liebig, by hippuric acid, which he now states to be a regular con- stituent of healthy human urine. From the interesting inquiries upon urine made by M. Lecanu, it appears that a man passes nearly half an ounce of azote with his urine in the course of twenty-four hours. A. quantity of urine taken from a public urine pail of Paris, yielded 7 per 1000 of azote. The dry extract of the same urine yielded nearly 17 per cent. Human soil as commonly obtained consists of a mixture of fecu- lent matters and urine. It may be applied immediately to the ground 292 FLEMISH MANURE. as U :,omes from the privy. In some parts of Tuscany it is mixed with three times its bulk of water, and so applied to the surface. I liave myself seen night-soil as it was obtained, and without prepara- tion, spread upon a field of wheat without any ill effect : so that the Tuscan preparation may be regarded as a simple means of spread- ing a limited quantity of manure over a given extent of ground. It is in French Flanders, however, that human soil is collected with especial care ; it ought to be so collected everywhere. The reservoir for its preservation ought to be one of the essential articles in every farming establishment, as it is in Flanders, where there is always a cistern or cess-pool in masonry, with an arch turned over it for the purpose of collecting this invaluable manure. The bottom ib cemented and paved. Two openings are left : one in the middle of the turned arch for the introduction of the material ; the other, smaller and made on the north side, is for the admission of the air, which is requisite for the fermentation. The Flemish reservoir may be of the dimensions of about 35 cubical yards. Whenever the necessary operations of the farm will permit, the carts are sent off to the neighboring town to purchase night-soil, which is then discharged into the reservoir, where it usual- ly remains for several months before being carried out upon the land. This favorite Flemish manure is apj)lied in the liquid state (mixed in water) before or after the seed is in the ground, or to transplanted crops after they have been dibbled in. Its action is prompt and energetic. The sowing completed, and the land dressed up with all the pains \-hich the Flemish farmer appears to take a pleasure in bestowing uj)on it, a charge of the manure is carried out at night in tubs or barrels. At the side or corner of the field there is a vat that will hold from 50 to 60 gallons, into which the load is discharged, and from which a workman, armed with a scoop at the end of a handle a dozen fert in length or more, proceeds to lade it out all around him. The vat emptied in one place is removed further on, and the same process is repeated until the whole field is watered.* The purchase, the carriage, and the application of this Flemish manure cannot be otherwise than costly ; we therefore see it given particularly to crops which, when luxuriant and successful, are of the highest market value — such as llax, rape, and tobacco. This manure, the sample of it, at least, which M. Payen and I examined, is of a yellowish green color, and with reference to smell cannot be compared to any thing belter than a weak solution of hydrosulphate of ammonia. This salt is undoubtedly present ; but exposure to the air converts it rapidly into the sulphate of the same base. According to M. Kuhlmann, the quality of the liquid Flemish manure is to be judged of by its smell, its viscidity, and its saline and jharp taste. By the fermentation which takes place in the cess- pools, which are never emptied completely, the feculent matter, kept for some time there, does in fact acquire a slight viscidity. Wheo ■olid excremenlitious matter predominates in the fermented mass • Cordier, Apriculturc of French Flanders, p. 140. FLEMISH MANURE. 293 its effect upon \egetation is of longer continuance ; but when it is derived entirely from urine, it acts almost immediately after its application. In either case, the effect of Flemish manure does not extend beyond the season ; like all the other organic substances which have undergone complete putrid fermentation, it is a true annual manure. Occasionally, a quantity of powdered oil-cake is thrown into the reservoir. This is either when the manure is supposed to be too dilute, or when there is little night-soil at command. The following, according to Professor Kuhlmann, is an example of the employment of the Flemish manure in a rotation which is common in the neigh- borhood of Lisle, and in the course of which the crops are colza or colewort, wheat and oats. First year. In October or November, the land is manured with farm-dung, which is ploughed in, in the usual way. At this time a dose of the liquid manure, amounting to about 5000 gallons per acre, is applied : a second ploughing is given, and the colewort is planted. Second year. The colza is gathered, the ground is ploughed foi autumn sowing; from 1000 to 1300 gallons or so of liquid manure are distributed, and the wheat is sown. Third year. The wheat stubble is ploughed down at the end of the autumn, and about 1000 or 1100 gallons of the liquid manure per acre are distributed ; the oats are sown in the spring. If cir- cumstances should prevent the application of the liquid manure in autumn, it is laid on in March, and then it has been found that one-fifth \ess will suffice ; but its application at this season is avoided as much as possible on account of the havoc that is made by the passage of horses, carts, and men over the surface of the soft ploughed land. It is with a view to avoid this disturbance of the surface that in many places oil-cake in powder is applied to the fields under colza when the manuring has to be performed after the crop is in the ground. For beet, the dose of Flemish manure is carried the length of from 1300 to 1400 gallons per acre ; but when the root is intended for the manufacture of su^^ar, liquid manure is sedulously avoided, experience havmg shown that it has the very worst effect upon the production of sugar, a circumstance which is very easily explained upon ground? that have already been given. The price of Flemish manure at Lisle is 2\d. for a measure con- taining 22 gallons. In Flanders, it is held that this quantity, which will weigh hard upon 2 cwt., is equal to about 5 cwt. of farm-yard dung. The liquid manure which I analyzed yielded 2 per 1000 of azote. Farm-yard dung, in its usual state, contains as much as 4 per 1000 ; it follows, therefore, that the real equivalent number of Flemish manure is 182, that of farm dung being 100 ; in other words, it would require 182 of Flemish manure to replace 100 of farm-yard manure ; a conclusion that differs widely from that which is usually acted upon. But it must be observed that from its nature, the Flem- ish manure produces its maximum influence in the couise of the "5* 294 POUDRETTE. season in which it is applied. It seems to have no effect on the crop of the succeeding year. Farm-yard dung, on the contrary, only exerts a portion of the whole amount of its beneficial indiience in the course of the year in which it is laid on ; it has still something, often much, in reserve for succeeding years. To compare liquid manure with farm-yard dung, with reference to an annual crop, is to compare this manure to the unknown fraction of the fiirm-yard dung which comes into play in the course of the first year, and from such a contrast no possible inference can be drawn in regard to the rela- tive value of the two kinds of dung. I have insisted upon this cir- cumstance, because it is often involved in the estimates that are made of the relative values of the difl^erent species of manure ; and because, from losing sight of it, unfavorable conclusions are frequently come to in regard to manures that undergo decomposition very slow- ly ; these manures, nevertheless, acting for a great leniith of time, produce both a greater amount and a more durable kind of ameliora- tion of the soil. Rapidity of action, in a manure, is undoubtedly a quality that is highly valuable in many cases ; and Flemish manure possesses this quality in the highest degree. Nevertheless, it is also an advantage to possess a manure which elaborates gradually, and according to the exigencies of vegetables, those principles that contribute to their growth, and which suspend in a great measure this elaboration in the course of the winter — which remain during the cold and rainy season in an almost inert condition, when any fecundating matter produced would merely be washed away and lost. These advantages, to winch must be added that of breaking up and lightening the soil, are all possessed by good firm-yard manure. They are such, in fact, that this manure, even in Flanders, is still indispensal)le ; the li(iuid manures of that country are nothing more than annual auxiliaries. The iTiethod followed in Flanders of using night-soil is certainly highly rational ; it is the same as that which is adopted in Alsace, in the neighborhood of towns, with this dilference, that our farmers collect no store of the material ; they go inquest of it at the moment it is wanted. It is applied as in Flanders, or it is incorporated with absorbent substances, such as straw, or uith other more coQsistent manures. The night-soil of Paris, which in the course of a year amounts to an immense quantity, is treated in a totally ditTerent manner, which appears to be in opposition to the simplest notions of science, of economy, and of all that is conducive to health. I allude to the mode of preparing /?o//(//-c// Dried in the air. Fucus saccharinus . 40.0 2.29 1.38 117 345 85 29 Idem 75.5 0.54 135 74 Fresh. Burnt sea-weed . . 3.8 6.40 0.38 26 95 488 105 Oyster shells . . . 17.9 0.40 0.32 20 80 488 125 Sea shells .... 0.05 0.05 3 13 3750 769 Dried sea shells of 1 Dunkirk. Mud of the Morlai.x 1 river 3.7 0.42 0.40 ' 21 100 464 100 1 Sea sand. Trez of Roscoff roads 0.5 0.14 0.13 1 7 32.5 1393 308 Sea-side marl . . . 1.0 0..52 0.51 26.5 128 377 78 Salt cod- (ish . . 38.0 10.86 6.70 1 557 1675 18 6 Cod-tish washed and pressed .... 10.0 Wji 16.86 961 4215 10 2i Dried in the air. Fir saw-dust . . . 24.0 0.22 0.16 11 40 886 2.30 Idem 24.0 0.31 0.28 15 57.5 174 > Dried in the air. O.ik saw-dust . . . 26.0 0.72 0.54 36 135 2j6 74 i White lupine seed . 10 5 4.35 3.49 223 872.5 45 llli Tuscan, boiled & dried Malt grains .... 6.0 4.90 4.51 2.51 1127.5 40 0? (iriipe husks . . . 48.2 3.31 1.71 169 1 427.5 57 Oil. cake of linseed . 13.4 6.00 5.20 307 'l;-<00 33 Q Ditto of cole wort . . 10.5 5.50 '-.92 282 12.30 35 g Ditto of Arachis . . G.G ! 8.89 8.33 655 2082.5 21 4^ Ditto of inudia . . 11.1 : 5.70 5.06 292 1265 34 8 Ditto of sesame . . 6.5 5.93 5.52 304 1378 33 7* Oil-cake of hempseed 5.0 4.78 4.21 245 1052 41 n vr Ditto of poppy . . 6.0 : 5.70 5.:36 292 1340 34 Ditto of beech mast . 6.2 3.53 3.31 181 1 828 55 Ditto of walnut) . . 6.0 5.59 5.24 287 1310 ! 35 .s* Ditto of cotton seed . 1 11.0 ; 4 52 4.02 231 , 1000 , 32 ^8 MAISURES. g Quality ac- Equivalent "^ i 100 ol matter. cording to state. according to stale. Kind of Dung. '..emarkt. Dry. Wet. Div. Wet. •"'■ Wet. Ditto from refiners . 10.0 3.92 3.*i 201 883 60 lU !Ke ent fat by means' ot poplar sawdust. ' Ditto ditto .... 7.7 0.58 0.54 30 135 a32 75 Fish oil by ditto ditto. Cider-apple refuse . 6.4 0.63 0..J9 32 147 309 68 Dried in the air. Refuse of hojjs . . Beet-root refuse . . 73.0 2.23 0.56 114 140 88 67 9.3 1.26 1.14 t>l 28.3 155 3o Dried in the air. Ide.ii 70.0 . . 0.38 64 85 .. m Fresh froni the press. Squeezed beet-root . 94.5 1.76 0.01 90 2 Ill 4137 Process of Dombasle. Jfotato refuse . . . 73.0 1.95 0.53 100 131.5 100 76 I'ot.ito juice . . . 95.4 8.2S 0.38 425 94 23 106 Settled and decanted. Water 1 92 3&1.5 24 i Dried in the uir. rinlid cow-dung . . &5.9 2.30 0.32 117 80 &i 123 Urine of cows . . . 88.3 3.S0 0.44 194 110 51 91 .Vlixid cow-dung . . &1.3 2.59 0.41 132 102.5 75 98 Solid hor»e-dung . . Hor.."s-t"d 73.5 17.00 4.51 871 1128 111 9, Just out of the press. Dried in manufactonr. Ins..|iiblfdru-d blo'Nl 12.5 17.00 14.88 871 3719 2} Dress from Prussian blue manufactory . 53.4 3.80 1.31 144 hTS 7 m 1 .Animnlir-ed with bloodj Melter's bones . . . 7.5 7.58 7.oa 388 17.34 96 6^ Drietl III the air. 1 Fresh bones .... 30.0 , . 5.31 1336 n .\» sold by the meltera. I'lit (tones, not jieatel A Including 0.10 of fat. Dress of bone glue . ( line dres' .... 42.0 33.6 0.91 5.63 0.53 :<.73 47 2S^.4 133 9:«.5 2*14 35 76 As sold hy the m»ker». liravcs 8.2 12.93 11.88 663 3'6yi53 15 3i 1 .\iiimal black of the 47.7 2.01 1.06 104 263 96 38 \% sent out. Sugar reliner's black 27.7 19.01 13.75 974 ^7 103 8B From Paris. Scum from the sugar From the sugar bakery refinery .... Rnglish black . . . 67.0 1.58 0.54 81 L-M 127 75 of Vijrneiix. BiootJ. Tune, scot. 13.5 8.02 6.JV) 411.4 173S 21 6 Featl.ors 12.9 17.61 1.5.M 903 :^i> 11 H Cow-hair flock . . 8.9 15.12 13.78 ;i443 W. 3 Woollen rags . . . 11.3 90.2J 17.98 It'ttt 44;i3 ,n ai Horn shavings . . . no 15.78 14.*; 1 Mf.t ■3.i*) J Coal soot .... 15.6 1.59 1.3. 81 2r.3 122 30 Wood soot .... 6.6 1.31 1.15! 67 287.5 149 33 Picardy ashes . . . 9.3 0.71 0.65 36 162-5 375 ts ; Voget. mould from hu- mu«dung(terreau) •• 1.03- 53 liJ 33 Drien m the slove. MANURES. 299 It is almost unnecessary to give any explanation of the uses that may he made of the preceding table : I shall, however, give a few il- lustrations from instances which have actually occurred in my ex» perience. Oil-cake is cheap at this time, (1842 ;) and the question is, whether it couki be advantageously employed in connection with the culti- vation of wheat. The presumption is, that wheat obtains the whole of its azote in the soil, that it acquires none from the atmosphere ; and again, I assume that the whole of the azote put into the ground w^ould be used up by the crop. Under the mo^t favorable circum- stances of heat and moisture, this would probably be the case ; were it not so to the letter, the active matter which remained in the ground would operate advantageously in succeeding years. The following, then, are the elements of the question : 1st. In the wheat grown at Bechelbronn there is on an average 0.025 of azote. 2d. In the straw of 1841, I have just found 0.003 of azote. 3d. The oil-cake which I propose to employ coi.lains 0.055 of azote, and its actual price, crushing included, is 3^. 4d. per cvvt. 4th. The relation in point of weight of the grain to the straw is as 47 : 100. A sheaf or bundle of wheat, 220 lbs. in weight, consists of: Wheat 70.4 lbs., containine 1.760 of azote, and is worth 4s. 8d. Straw 149.6 lbs. " '^ 0.415 " •' Is. 8d. Total of azote 2.175 Total value 6s. 4d. Diiference of value 5s. 4d. To grow which, 39 lbs. of oil-cake would be required, of the value of Is. 2d. So that 39 lbs. of oil-cake, converted into a sheaf of wheat, would be increased in intrinsic value to the extent of 5.?. 2d. Supposing that but one-half or one-third of this amount, as indicated by theory, is realized in practice, it is obvious that the addition of the oil-cake might be made with advantage ; and that no means should be neglected to ensure the success of its application as a manure.* The production of oil-cake in France, the Netherlands, and other countries of Europe, is very considerable ; in round numbers, 100 of oleaginous seeds yield 60 of cake ; but it has been calculated, with rare ability, and from authentic documents, by M. Leroy de Bethune, that not only is the whole of the oil-cake, which is the produce of the soil of France, exported, but that likewise of the oleaginous seeds which she imports from other countries. This M. de Bethune looks upon as a very lamentable agricultural fact. I have shown, indeed, from the example which I have quoted, that every pound of cake represents a primary material, which, properly treated, may be transformed into nearly 6 pounds vi^eight of wheat- grain and straw, having a value infinitely greater than that of the oil-cake originally employed. * Our author hns of course left many other elements very necesstiry to be included out of his calculation here, such as labor, seed, rent charge, interest on capital, k* Eva. Ed. SOO EXPORTATION' ; F MANURES. While I agree with M. de Bethu: e, that it is generally wibC to encourage exportation, I also admit with him that there are sub- stances in reference to which it woi Id be prudent to discourage ex- portation ; oil-cake, this powerful rjeans of giving fertility to the soil, might be placed in the foremost rank of such substances. I am far from adopting all the principles if economists, which appear to me to be frequently far too absolute. In my opinion, any exportation, the consequence of which is the impoverishment of the soil, ought to be prohibited. I should, for instance, oppose the exportation of arable soil ; and in the same way, to allow an active manure to pass into the hands of strangers, is, in my eyes, tantamount to exporting the vegetable soil of our fields, to lessening their productiveness, to raising the price of the food of the poor ; for as much labor is re- quired, as much care and capital must be expended upon an ungrate- ful soil to obtain a little, as upon a fertile soil to procure an ample return. To permit tbe exportation of oil-cake is to hinder the hus- bandman from taking advantage of all the circumstances with which nature presents him ; it is as if a chill were to be brought over the genial climate of France.* I have shown the advantages of the application of oil-cake in the growth of wheat. I shall now inquire whether or not it is equally useful in connection with hay and potato crops; the price of the article being presumed to be the same as before. Upland meadows, when they have not been soiled, yield miserable returns, and their situation renders them difficult of access to carts : oil-cake in such circumstances comes powerfully to our aid. Taking the price of hay at os. per 22i) lbs., which is about its present price in France, and taking into account the composition of the after-math, we may reckon the azote contained in the hay of natural meadows at 0.015. 220 lbs. of hiiy, ronUininp 'A Ihs. of a7.«)tr, will be worlh 5*. Od. To produce which ."»f) lbs. ofaike (azoto 3.3 lbs.) worth 1*. Sd. would \>c n-qnirnl. Difference in value bolwoen the cost and the crop 3*. 4d. Upon this showing, nil-cake may be advantagponsly employed in the amelioration of upland meadows. IJcsides the cost of the ma- nure, however, there are the very necessary additions to be made of the price of labor and rent. From the observations wiiich I made at Bechelbronn in 1839, I * I own I ani surprised at this pa.«i.s.Tpr in my rstornnd .-•uthor. There is nothlne parallel in the inst.inces lie quotes. Did not the French liu>ti:in(lnien and oil -presser* profit by the exportation of oil-cake they wonid ke«'p it at home; and the profit of the farnier and inanufacinrer is the profit oi" the whole commnnity. To ex(M>rt the soi; wouUI indeed be madness: it would obviou-;|y l)e killinu tin- p«Kxo F.n. USE OF THE PRECEDING TABLE. 301 find that the relation between the weight of potatoes as they come from the ground, and that of the tops or haum, supposed to be dry, is as 100 is to 6.4. The tubers contain : Azote 0.0036 per 10000 parts ; and 220 lbs. contain 0.729 of a lb. of azote, and are worth Is. 8d. The tops or haum, dry, contain : Azote 0.0230 per 10000 parts ; and 14 lbs. contain 0.330 of a pound of azote. Total of azote 1.122. Now 20.4 lbs. of cake which would be required to produce 220 lbs. of potatoes, contain 1.1 lb. of azote, and are worth Os. l^d. Difference 1*. O^d. The oil-cake at the price of 3.?. 2d. per cwt. may therefore be ad- vantageously used for the production of potatoes : rent, labor, se^'d, &c., considered as before. At the price of 75. 6d. or 8^. 6d. per cwt., however, to which oil-cake occasionally rises, it would not be possible to employ it profitably in this way. The cost of the manure would then amount to nearly as much as the value of the crop. The equivalent numbers in the table express the relative values of different manures ; they proclaim the proportions in which one substance must be substituted for another, and when purchases are to be made, they will show at a glance which is the article that is really, and in fact, the cheapest. The equivalent number of one variety of oil-cake, for instance, is 7.25; that of farm-yard dung is 100 ; which is as much as to say that in reference to mere fertilizing elements, 100 parts — lbs. cwts. or tons, of farm-yard dung may be replaced by 7| parts — lbs. cwts or tons of oil-cake ; — 2 cwt. of farm-dung, for instance, by 14^ lbs. of cake. The 2 cwt. of farm- dung is valued in the table at ^d., or about 5s. per ton ; the 14^ lbs. of cake would cost 5^d. It is obvious, therefore, that even at the above low price of oil-cake, there would be no real advantage in substituting it generally for farm-yard dung ; in situations, however, remote from large towns, where it is almost impossible to procure dung, or where the carriage of large masses of dung would be both difficult and expensive, there would then be advantage in the sub- stitution. Woollen rags at the price of about 2^. 10c?. per cwt. are more pro- fitable than farm-yard dung at 3d. per cwt. The equivalent of the rags is 2.22, and this quantity (2.22 lbs. avoird.) of rags is worth about ^d. ; by the substitution of the rags for farm-yard manure, therefore, a saving is effected of about 2ld. on every cwt. of the latter that must have been employed. In good farming, however, it is less with reference to the money advantage of substituting one manure for another, that calculations are made, than with reference to the possibility of procuring either one manure or another at a moderate price. The estimated value of the dung in one of the columns of the table gives us at once the price that may be paid for it ; for this purpose it is enough to know the value of standard dung : let this be as it usually is, 3d. per cwt. ; if we would now know what may be paid for a hundred weight of bones simply Hried in the 26 802 VALUE OF DIFFERENT 3IA-N"RE:5. air, the number designatinfr thesebeing 1554, we have only to make a simple equation in the following terms : — 100 : 3d. : : 1554 : i,to have the solution : =35. 10k/. The most careful consideration of the relative value of different manures under th,. guidance of the analytical elements which I have indicated, justifies the preference which is given in practice to one kind over another, which on simple examination appears to offer greater advantages. Thus, by diffusing oil-cake through water, and leaving the mixture to ferment, a manure is obtained which presents all the characters, which possesses all the properties of human soil that has undergone fermentation in privies or cess pools. And it is to this mixture of putrid oil-cake that the husbandmen of French Flanders have recourse, as we have seen, when their supply of night-soil runs short. When oil-cake is low in price, say about ^s. 3d. or 3.?. id. per cwt., it might seem advantageous to manufacture Flemish manure with it ; expensive carriage and time would be saved ; for night-soil has generally to be fetched from a distance, and containing but 0.002 (y ffi^ths) of azote, it is bulky, and its equiv- alent is in the same proportion high. (Jameline oil-cake contains 0.055 (y,^^- ths) of azote ; to make Flemish manure that should con- tain 0.00-2 of azote, it wouhi be requisite to add to every 100 parts of cake 2,650 parts of water ; the cwt. of this manure would then come to 1:7^., while Flemish manure prepared with night-soil, would cost the farmer but l\d. I have here taken the cake at a low price; were it 7*. 6d. per cwt. instead of 3.?. dd., which is perhaps much nearer its usual average cost, it is obvi(»us that the cwt. of manure prepared from it, would cost twice as much more. The proportion of azote, the value, and the equivalents of the several manures are given in the table, lK)lh for the substances ab- solutely dry, and for the condition in which they arc commonly em- ployed. This distinction is one of gn-at importance. The water, the quantity of which is indicated in the first column, is a most variable constituent ; its presence, of course, depreciates the ma- nure in the precise ratio in which it occurs. The reference of ail the elements of each particular manure to that manure in a stale of absolute dryness, is a very important feature in the table. In pur- chasing manuri 8, the precaution of drying them chemically must never be neglected, more especially in connection with articles, which by their nature are capable of absorbing water in considcr- l.ble, and often in very different, quantities. LIMING. 303 CHAPTER VI. OF MINERAL MANURES OR STIMULANTS. At.i the organic manures, when burned, leave ashes composed of earthy and sahne substances. The action of these substances upon vegetation is quite unquestionable, and it is certain that an organic manure, were it ever so rich in azotized principles, and ever so as- similable, would still be imperfect did it not further contain the truly- mineral matters which plants require to meet with in the soil, in order to complete their growth and bring their seeds to maturity. The most active organic manures are always abundantly provided with inorganic principles. Farm dung (dry) contains about one- fourth of its weight of such substances, and the water which is used for irrigation invariably holds saline matter in solution. Nevertheless, repeated cropping will often end by depriving the soil of the mineral substances which plants require ; the salts con- tained in the manure supplied are sometimes inadequate to meet the demands of successive crops, and then the return falls off. It IS consequently necessary in certain cases to furnish the soil anew with saline matters, in order to supply the continued drain that is made upon it, or to meet the exigencies of particular crops which are known to require an unusually large quantity of salts for their successful cultivation. It is in this way that clover, lucern, and sainfoin require plaster, (gypsum ;) the cereals, silica, and certain calcareous salts ; the vine, potash, &c. Practice got the start of science in tlie application of mineral ma- nures or stimulants. If their useful influence cannot be denied, as it cannot, if the circumstances in which it is advantageous to admin- ister them, if the conditions and the doses in which they ought to be given to the ground have been the subject of long and careful obser- vation with farmers, it must still be admitted that we are far from understanding exactly in what way they act ; this is another motive for continuing to study them with perseverance. CALCAREOUS MANURES. • In certain soils we have said that the calcareous element is either wanting, or present in very small and inadequate quantity ; other soils, again, abound in calcareous matter, and observation appears to prove that the presence of carbonate of lime in a soil adds unequivo- cally to its fertility. The majority of the good wheat lands hitherto examined have been found to contain a notable quantity of this earth or earthy salt. It is usual to put lime into the ground in the state of caustic or quick-lime ; this is liming, properly so called. But it is also ap- plied in the state of carbonate, as when we make use of chalk or marl, or shell-sand from the sea-shore. 304 LIMING. The limestone that is used for burning is seldom pure; it fre- quently contains clay, quartzy sand, metallic oxides, and occasionally carbonaceous matter ; frequently too it is so largely mixed with magnesia that it acquires peculiar characters ; this is the magnesian limestone or dolomite. The purest carbonate of lime, by exposure for some time to a white heat, loses 43.7 of carbonic acid, and con- sequently contains 56.3 of caustic lime. Limestone is one of the most common of«rocks ; in the crystalline and saccharoid state, or of closer and finer grain, it often constitutes mountain masses, and is met with in every part of the geological series ; it meet* us as chalk in beds of enormous thickness, filling up extensive basins in the tertiary series ; such are the chalk beds of the south and west coasts of England, extending through the counties of Kent and Sussex, &c. The only mineral substance with which chalk, limestone, or car- bonate of lime is likely to be confounded, is gypsum or sulphate of lime. But it is easy to distinguish either of these salts from the other: carbonate of lime dissolves with effervescence in dilute hydrochloric acid ; sulphate of lime is insoluble in this liquid. Carbonate of lime is quite insoluble in water ; sulphate of lime is very sensibly soluble, and a copious precipitate falls on the addition of a solution of oxalic acid or of oxalate of ammonia. Gypsum is always so soft that it can be scratched with the nail ; limestone, save in the state of chalk, is generally so hard that it resists the nail. The burning of lime for agricultural uses is carried on m the same way as for building and other economical purposes. Burnt or quick- lime is a very ditTcrcnt artiile from chalk or limestone ; it is power- fully caustic or destructive of the oroanic tissue, and instead of being altogether in.soluble, it is now soluble in about 030 parts of cold water. All the world knows how Inne from the kiln, when watered, rises in tcmi)erature, breaks first into larger and then into smaller pieces, and finally falls down into fine powder ; but every one is not aware that there is a true cheniical union of water with the earth, and that the resulting powd»*r is in chemical language a hydrate of lime, a substance which is much less caustic than pure lime, but still distinctly alkaline in its reaction. It is generally admitted that the soil which is without a certain, and that a considerable proportion of the calcareous element, never possesses a high degree of ft'itdily. This in particular is the opin- ion of English agriculturists, who apply lime with a kind of profu- sion ; and the great improvement it frequently produces on the crops of grain, leaves no doubt as to the advanta<;cs of the procedure. Still it is now generally recognized that liming ceases to be useful upon binds that are already sulficienlly calcareous, or ihit rest on a sub-soil of chalk. It is, therefore, by .supj)lving the calcareous ele- ment which land requires to constitute it a soil adapted to the growth of corn, that the application of line becomes useful ; liming, in fact, enables us to make this neces&iry addition at least cost. Like other mineral manures, lime of itself produces little or no effect ; LIMING. 305 it is in concurrence with organic manures that it becomes truly use- ful ; it is nowise, and never can become, a substitute for these. The geological constitution of a country is perhaps the best guide 10 the necessity or advantages of liming. Soils that are derived from pluionic or igneous rocks, in which felspar, mica, or quartz predominate, are on the face of things likely to be improved by the introduction of lime. Direct analysis would of course give more decisive information on the fact. In any case, the measure recom- mended by prudence is to make a few preliminary trials upon the small scale ; the experimental method is the only safe one in agri- culture, when the question is in regard to the adoption of new plans. In England it is customary in liming clayey lands to allow from 230 to 300 or 310 bushels of stimulant per acre ; on lighter soils the dose may vary from about 150 to 200 bushels, according to their character. In France the quantity usually employed is greatly less, from about 60 to 70 bushels being all that is generally thought ad- visable, and this at intervals of seven or eight years. In the neigh- borhood of Lisle little use is made of lime, although there the land is generally any thing but calcareous ; perhaps the want of lime is not felt in consequence of the universal practice of employing the Flemish manure, which, as we have seen, contains ammoniacal salts, (and both human urine and excrement contain a large quantity of phosphate of lime and phosphate of magnesia in addition, the very salts that the generality of vegetables crave.) In the vicinity of Dunkirk, however, lime is frequently applied in the dose of be- tween 40 and 50 bushels per acre, and with effects that are said to continue for ten or twelve years. The dose of lime introduced into the soil in different countries, is moreover in a certain relation with the time during which the action of the earth is believed to continue ; as the quantity administered at once is small, the dose must be repeated more frequently. Near Dunkirk they use from 40 to 50 bushels per acre every 10 or 12 years ; in the department of La Sarthe, according to M. Puvis, they scatter on some 9 or 10 bushels only ; but they do so every three years. This would lead us to conclude that soils which really wanted lime should receive a dose in the proportion of about 3| bushels per acre annually. But the crops gathered from the ground every year, certainly do not abstract any thing like this quantity of calcareous matter ; which would induce us to infer, that after a cer- tain time the land will contain such a quantity of lime as to make any further addition of it unnecessary, or at all events, unnecessary save at rare and distant intervals. One of the great advantages which lime has over all the other forms or kinds of calcareous stimulants employed, is unquestionably the state of extreme subdivision which it acquires in the quenching. In the course of falling down into this extremely fine powder, lime, as has been said, combines with a large quantity of water. But the change experienced does not stop short here ; the air always contains some lOjOOOths of carbonic acid gas, for which the hydrate of lime has a powerful affinity, so that it absorbs this gas greedily, aban- 26* son LIMING. doning, at the same time, its constitutional water, by which, in due season, the hydrate of lime becomes changed into the anliydrous carbonate of iime. This process is always slow; more rapid at first, when the interchange l)etween the carbonic acid and water lakes place freelv ; it becomes gradually slower and slower as there is less and less water left in the particles : the afiinity of the lime for the water seems to increase continually in the ratio of the smail- ness of the quantity which it still contains. It must, therefore, con stantly happen tl)at in incorporating lime, in powder and partially carbonated with the soil, we also intrtiduce lime that has preserved its causticity in some measure ; it must be observed, however, that, once intimately mixed with the soil, this lime must speedily pass into the state of carl^onate, because the soil and the water with which it is moistened always contain a considerable quantity of carbonic acid. Though we commence operations with quick-lime, conse- quently, it is carbonate of lime that is deilnitively introduced into the ground. 1 have thought this a point of sufiicient importance to en- gage o«ir attention for a short time, inasmuch as it simplifies the view of the end that is to be sought in applying lime; this, as M. Puvis has most satisfactorily established, is neither more nor less than the intr(»duction into the ground of that pr(»portlon of the calca- reous element which it either wanted originally, or which it has lost in the course of repeated cropping, in order to enable it to produce abundantly. Quick-lime incorporated with the soil must pass, as I have shown, very rapidly into the state of carbonate ; but, before attaining to this state, it may, unquestionably, react upon the organic substances it encounters, disorganize them, favor their decomposi- tion, in a word, l»ehave as it does when used in composts. On the other hand, in causing the destruction of organic particles already in a state of decomposition, it must produce an unfavorable inllu- ence. Lime, previously quenched and cold, is generally spread by being raked out from the cart upon the field, in little heaps, from five to six or seven yards apart, each containing fr«»m half to two-thirds of a bushel. It is or ought then to be spread immediately as evenly a.s possible over the surface. There is only the disadvantage attending this mode of proceeding, that slaked lime is twice the bulk of lime in the shell or lump, and that, by slaking, it lakes up at least one- fifth of its oriiiinal weight of water. There is saving of labor, therefore, in di.stributing ilip lime unslaked, in heaps, and waiting the slow process of extinction and pulverization by the moisture of the atmosphere. The lime is often laid in a corner of the field, anne sample of marl which we analyzed, gave 0.00'J of azote ; another, from the Lower Rhine, gave rather more than O.OOI of the same element. It were, there- fore, very proper, in analyzing marls, chalks, *.Vc , to have an eye tc iheir organic or azotic, as well as to their mineral constituents ; there can be very little question of the azotized elements being at the bot lom of the really wonderful fertilizing influences of the maris of certain districts. Marl ought, like lime, to be spread very evenly over the land ; i: is generally laid on in the same way as lime — in little heaps at re gulai distances, and then scattereil abroad. It appears to be a verj general opinion that it is not advisable to cover it iiiMnedialely, or verj MAUL. 909 Bhortly after it is dug from the bed that supplies it ; the practice where its employment is most general, and proliably best understood, is to let it lie exposed through the summer or winter, or even the whole year before laying it on the land. It is also held not to be proper to cover it in marl deeply. Marl is advantageously laid out in heaps upon stubbles in the autumn ; and in the early spring when it has been pulverized by the frost, it is spread with the shovel. When it is to be used with winter wheat or rye, it is laid on in the sunmier, and spread at the time of ploughing; the latter plan of proceeding, however, as Schwertz observes, can only be followed with marl that pulverizes readily. In England it is also laid down as a kind of principle that marl ought to be exposed for as long a time as possible to the influences of the atmosphere ; that it ought to have a sunmier's heat and a winter's cold before it is applied. And that, in fact, which is at all consistent, and has not been expos- ed to the frost, scarcely pulverizes sufficiently to be readily miscible with the soil even under the influence of repeated ploughings ; more- over, it produces very little obvious effect upon the crop with which it is first used. After spreading, a rough harrow is passed over the surface of the ground, which is then ploughed superficially two or three times, the harrow being again had recourse to repeatedly to break lumps, and so bring out the effect of the marl. The quantity of marl that may be advantageously given varies according to the circumstances of the district. Marl, it may fairly be said, is frequently abused. In an excellent paper on the subject, M. Puvis lays it down as a principle that the first element in the calculation of the proper dose of marl, is the quantity of calcareous matter that is wanting in the soil. He says that every soil which contains more than 9 or 10 per cent, of carbonate of lime can dis- pense with marl ; and that soils in which the lime falls short of this quantity, may advantageously receive a dose or successive doses of the substance that will bring them up to the point. The proper dose, consequently, depends first on the proportion of carbonate of lime contained in the soil, and then on that which the marl itself includes. Considered from the rational point of view which M. Puvis has taken, marling is no longer an arbitrary process, but one that may be conducted on determinate principles. The extravagant quanti- ties that are often laid on without other assignable reason than blind custom, are shown to be, if not injurious, yet useless : the quantity of marl to be incorporated is determined by the quality of the sub- stance which is at our disposal, and by the depth of the layer of vegetable ea-th taken in connection with its chemical constitution. To facilitate the calculation of the proper dose, M. Puvis has drawn up a table, which, as it may be found useful in practice, I append. It shows at a glance the quantity of marl in cubic feet that ought to be put upon an acre of ground, the depth of the arable soil being considered in connection wath the composition of the marl at com- mand : — SIO MARL. Table of the Number of Cubic Feet of Marl applicable upon an When 100 Acre of Land ploughed to the depth ot : parts of marl contain of carbonate of 1 ' . 1 . 3tV 4r'.r 5,^0 6,-^^ I 7,-\ 8r1r lime inches. inches. inches. inches, i inches. inches. 333 444 554 666 776 888 10 166V 222 277 333 388 444 20 111' 146 I84fj 222 258^?^ 296 30 83 ,V ill 138^T 166 r. 194 222 40 66,^ 88 A llOf'o 133 rV 155A 177/, 50 55, -\ 74 9^r> 111 129rlr 148 60 47A 63^ 79 rV 95rV iioA 126A 70 41.'^ 55,-\ 69,1, 83rlr 97 111 80 37 49,3, 6li 74 86 i% 98^ 90 33.^0 44,V 55A 66r'ff 77A 88rV 100 M. Puvis does not by any means give the doses in this table aa those that should be invariably employed ; the table is one of aver- ages, deduced trom practical results, and tested by experience as most truly useful. But special cases may occur that would make departure from these conclusions not only advisable, but advantage- ous.* The use of marl produces an unqnrstionable effect on the pro- ductive properties of the soil. According to M. Puvis, the applica- tion of the proper dose of a sandy marl, c«>ntainiiig from 30 to GO per cent, of carbouate of lime, doubled the produce of a piece of parched land in the doparlment of the Isere. Before the applicali(ui of the marl nothing but dwarfish crops of rye were gathered, yielding at most three for one of the seed ; at present, eight for one of seed, and that wheat, are obtained ; and the good elFects are found to contmue for ten and even twelve years The action of marl is not unlimited any more than that of lime, as th6 last sentence will give the reader reason to conclude. With every harvest, a certain proportion of it is carried otT, and the land is finally left with an inadequate quantity of the calcareous element, which thou requires to be rest*>re(l. Tlie nature of the crop, how- ever, has the most miMked influence on the quantity of lime that is taken up and carriei'k away from the soil ; alhiwiug the broadest margin, and judging from the coiu[)ositi()n of the ashes of the planta that form the subjects of our ordinary crops, we can see that the quantity of 3', bushels of marl of the usual composition per acre, which is assumed as the average quantity to be laid on, is vastly more than can be absol.itely necessary. Wood ashes contribute to improve the soil. They contain, besides silica, both phosphate and carbonate of lime and alkaline sulphates, phosphates, and carbonates. In a general way, everything derived ♦ Puvi«i in .\nnaU of French .Agriculture. v.»l. nvlil. p. 208, 2iJ serie«. PEAT ASHES. 311 frciin plants that have lived must be useful to plants that are about to live, or that are actually living. Although the utility of wood ashes, then, is generally admitted, the numerous purposes to which they are applied in the arts, and their high price, which is the con- sequence of this, enable the husbandman to employ them but rarely on his land ; they are almost always lixiviated in order to procure the carbonate of potash they contain. In countries which are thick- ly wooded, indeed, the trees are actually cut down and burned for the sake of their ashes, just as oxen are run down and slaughtered in the vast plains of South America for the sake of their hides. The good effect of wood ashes upon vegetation is known to com- munities the least advanced in civilization. The Indians of South America burn the stems and leaves of the maize in order to improve the soil. The same practice occurs among the natives of Africa : on the banks of the river Zaire, according to Tuckey, the ground is prepared by having little piles of dried herbs placed on it, to which hre is set ; and upon tha spots where the ashes are collected, they sow peas and Indian corn ; these ashes are in fact the only manure that is employed. In England, wood ashes are esteemed as parti- cularly useful upon gravelly soils ; about 40 bushels per acre are applied in the spring, where the article can be obtained. The lye-ashes from the soap-boiler contain a small quantity of soluble saline matter which has escaped the lixiviation, mixed with a large proportion of lime, partly in the state of carbonate, the lime having been added to bring the carbonate of potash employed in the manufacture of soap into the caustic state. This ash or refuse is much sought after, and is administered in quantities that vary from 45 to 70 bushels per acre, a dose in which its action is felt for ten years or more. In wooded districts, where there is a good deal of potash prepared, ash of this kind is obtained in large quantity ; it is there employed alternately with organic manures, wishes are ap- plied in the same way as lime, with this difference, that it is held better not to plough them in until they have received a little rain. There are places where the ashes that remain in the lixiviating tub are thrown on in the dose of 170 bushels per acre. Turf 07' peat ashes. Peat is the result of a peculiar spontaneous change that takes place in vegetables. It is produced in bogs or swamps, and in connection with stagnant waters ; turfy deposites are also encountered on the banks of rivers, in valleys, at the bottoms of former lakes, and at the mouths of rivers. Peat is met with from the level of the sea to the elevated platforms of the A^osges and Alps ; it lies in horizontal beds, frequently divided by strata of grave!, sand, or clay. It is always a product of comparatively re- cent formation, a fact which is attested by the thin layers of vege- table soil that lie over it in many places, and the animal remains and products of human industry that are frequently encountered in it. The state of decomposition of the vegetables that form turf or peat is seldom so far advanced as to make the remains of the plants which compose it doubtful. It is of different kinds : hard or woody, 312 PEAT ASHES. »nd sof/ o' h^fba^eois peat. Some of it is cxtremrly compact, Mack, and like veo^etfjble mould in appeanuice ; generally speaking it is light, sponger, ind of a lighter or deeper shade of browa. When quite dry, it is often extremely light ; a *^ub c metre, which is about one-eleventh more ihan ac^ibif. yard, wil weigh from 5 to 6 cwt. The circumstances in which turf has been found lead us to infer that it must contain the elementary insoluble elements of the plants that produced it. It appears, however, to contain a somewhat lar- ger proportion of azote than the average quantity met with in her- baceous vegetables, supposed dry ; but we have seen that in the slow alteration of lignine, azote becomes concentrated, as it were, in the residue ; and that, in fine, mould contains a larger quantity of azote than the wood from which it proceeds. It appears further from some experiments very lately performed by Mr. Hermann, that during the putrefaction of the woody prmciple, azote is actually ta- ken from the air to concur in the formation of certain products that are perfectly definite. Mr. Hermann quotes the following experi- ment : Twenty-eight parts of wood taken from a log already attacked with rot, and in which, indeed, there were several points already decayed, were moistened and enclosed in a jar containing atmo- spherical air over mercury. The bulk of the atmosphere contained in the bell-glass was 262 volumes. The wood was kept there for ten days at a temperature of 75.2° Fahr. The apparent volume of the air continued unaltered to the end of the experiment ; but a large quantity of carbonic acid had been formed : RESULTS ON THE I.NCLUDED AIR. Before. After. The air contained : Azote 207 vols. 194 vols. Carbonic acid 40 " Oxygen •••• 5.5 28 " ai2 282 The moist wood in its decomposition during ten days had conse- quently caused thirteen volumes of azote and twenty-seven volumes of oxygen to disappear. And Mr. Hermann found that it now con- tained principles analogous to those of humus, one of which, nitro- lin, is highly azotized, and by the ulterior action of air and moisture, gives rise to ulmate of ammonia. These experiments of Mr. Her- mann are new, and the conclusions to which they lead are both inter- esting and important * Turf or peat is virtually the woody principle in the last stage of modification by atmospherical influences ; but it appears still to con- tain, although modified, the usual principles which enter into the constitution of herbaceous vegetables also. M. Payen detected a quantity of fatty matter in it, analogous to that which exists in leaves, and M. Reinsch found it to contain tannin. One sample o( * Vide his \M]M'T in Journ. fur prakt. Chernie, b. xxiii. %. 379. PEAT ASHES. 31% turf (from the neighborhood of Moscow, by the way) examined by Mr. Hermann, yielded of carbonaceous matter, nitrolin and vegeta- ble remains 77.5 ; of ulmic acid 17.0 ; extract of humus 4.0 ; am- monia 0.25 ; and ash 1 25=100.0 The elementary composition of these varieties of tutf, analyzed oy M. Regnault, gave from 57 to 58 of carbon ; 5.1 to 5.G hydrogen ; 30.8 to 31.8 oxygen and azote ; and 4.6 to 5.6 ashes. Turf or peat has consequently a certain resemblance to mould or humus ; it differs, however, in the absence of substances soluble in water ; and it is easy to imagine that, produced as it is in connection with water, continually soaked in moisture, soluble matters ought not to be expected in it in appreciable quantity. Peat might, in fact, be likened to the insoluble part of humus left after lixiviation. A.nd there is this further resemblance, that peat, like the humus tvhich has been thoroughly lixiviated, if exposed to the air, by and ■)y acquires a quantity of soluble material, the evolution of which is also hastened by the contact of the alkalies. The employment of nirf as manure, in some countries, confirms the propriety of this mode of viewing its nature and constitution ; and then it is well known that bogs consisting of pure turf, when drained and limed, become tolerably fertile lands, yielding magnificent crops of oats and turnips especially. The ashes of turf we might expect to contain the mineral sub- stances usually found in the ashes of plants, and further a certain (quantity of additional earthy matter. But this is not the case : sev- eral alkaline salts, indeed, have been discovered in very small pro- portion ; but no chemist, to my knowledge, has ever even suspected the presence of any of the phosphates ; a special search which was made for them in my laboratory failed to discover them. This is a fact which, I own, amazed me ; some coal ash, and another ash produced from lignite, gave a result equally negative. We might imagine the disappearance of the soluble salts ; but how the eartjiy phosphates should disappear ; how the ashes of coal should come to be without a trace of phosphoric acid, when we see that the iron ore, in connection with the coal fields, is always more or less phos- phorigerous,* is surprising. Turf or peat ashes are valuable improvers of the soil, and are in ^reat request among intelligent farmers. Analysis, in fact, indicates several substances in their composition as calculated to assist vege- tation ; carbonate of lime, in a state of extreme subdivision ; occa- sionally sulphate of lime, (gypsum ;) calcined clay, whose action upon strong and retentive lands is always beneficial ; silica in a fa- vorable state for assimilation ; finally, alkaline salts, chlorides, sul- phates, carbonates, and, perhaps, in spite of the negative given by chemical analysis, traces of the phosphates. The peat of the bogs of Sceaux, near Ch^teau-Landon, leaves 19 per cent of ashes, composed, according to M. Berthier, of: — * Our author might have added the fact, that llie common hog iron ore of this coun try is a phosphate of iron. — Enq. Ed. 27 S14 PEAT ASHES. Caustic and carbonated lime 63.C Clay 7.5 Gelatinous silica 13-0 Alumina 7.0 Oxide of Iron 0.0 Carl-<- late of potash 0.5 100.0 The peat of VoksLmra, dug upon the frontiers of Bavaria and Bohemia, contains the remains of trees ; it leaves 1.7 per cent, of ashes, composed, according to M. Fikenscher, of: Silica 36.5 Alumina 17.3 Oxide of iron 33.0 Lime 2.0 Magnesia 3.5 Sulphate of lime 4.5 Chloride of calcium 0.5 Carbonaceous matter not incinerated 2.7 100.0 The brown herbaceous peat of the neighborhood of Troyes, leave* 11 per cent, of residue ; it contains : Carbonic acid and sulphur 23.0 Lime 'i3.0 Macnesia 14.0 Alumina and oxide of iron 14.0 Clay and silica 2ti 0 100.0 rhe peat of Vassy is compact, and of a brown color ; it is mixed with fragments of chalk. On incineration, it leaves 7.2 of residue per cent., containing : Clay 11.0 Carbonate of lime 51.4 Sulphate of lime 20.0 Oxide of iron 1 1.5 100.0 The peat of Champ-du-Fcu, near Framont, (Vosges,) leaves 3 per cent, of ashes, which consist of: Silica 40.0 Alumina and oxide of iron 30.0 Lime 30.0 100.0 The peat of the environs of Haguenau (Lower Rhine) produces 12.5 per cent, of ashes, which, according to the analysis made in my laboratory, contain : Silica and sand 65.5 Alumina 16.2 Lime 6.0 M:ipncsia 0.6 Oxide of iron 3.7 Potash and soda 2.3 Sulphuric acid 54 Chlorine 0 3 100.0 Supposing the whole of the sul^thuric acid found to hare been la COAL-ASHES. 315 combination with lime, this peat could only ha\e contained 4.1 per cent, of gypsum. These analyses will show that the composition of peat, or turf, is very various. The varying and dissimilar effects produced by turf- ishes, may probably be owing to this variety of composition. Turf- ashes, in a general" way, may be used as a substitute for gyp»sum ; but this is upon the presumption that tbey contain lime, either in the state of carbonate or of sulphate. The Vassy turf-ashes, for ex- ample, may be employed for gypsing meadows, inasmuch as they contain a quarter of their weight of sulphate of lime. The ashes from pyritic turf ought not to be used without great circumspec4,ion ; they usually contain a quantity of iron pyrites which has not been destroyed in the burning, and which, exposed to the action of the air, gives rise to the formation of green vitriol, or sulphate of iron, which may prove prejudicial to vegetation. These ashes are generally of a red color, and very heavy, in con- sequence of containing a quantity of the oxide of iron. Good turf- ashes ought to be white and light ; the sack ought to weigh some- thing less than a hundred-weight. Sciiwertz recommends us to keep theni from the wet; but at Bechelbronn, where we use large quanti- ties of peat-ashes, we find no ill effects from leaving them exposed to the rain ; frequently, indeed, we moisten them with water from the dunghill, in order to add to their properties as a mineral manure, those that belong to organic manures. On the whole, however, it is cer- tainly better, for many reasons, to keep them dry ; they are more easily carried, and they are more easily spread. Turf-ashes of a good quality, that is to say, which include in theii composition a large proportion of calcareous and alkaline salts, are adapted to crops of every description ; but it is upon clover especially that their influence is truly surprising. This fact is well established in Flanders ; but one must have employed them one's self to have any adequate idea of the improvement they produce. There is no risk of giving too large a quantity. In winter, when we have peat-ashes at our disposal, we give as many as 60 bushels per acre to our clo- vers ; we scatter them even upon the surface of the snow, and dis- tribute them by means of the rake in the spring. The Dutch use these ashes in still larger quantity, applying, at two different times, from 100 to 160 bushels per acre to their clover fields. Accord- ing to Sinclair, the Dutch also make use of an ash procured from a turf which during winter is in contact with brackish water, a cir- cumstance which renders this ash particularly rich in alkaline salts. It is sowed by hand, in the spring, upon clover, and the following year an abundant crop of wheat is obtained. The same material is also used in the cultivation of the hop ; and it is said that, administer- ed in small quantity to the roots of the vine, they preserve the plant from the attacks of destructive insects. Coal-ashes. Coal, like the two last combustible materials, is the product of vegetables, which, however, have undergone such a change as to have lost almost every trace of organization. Coal of diifcrent kinds contains from 1.4 to about 2.3 per cent, of ashes, and 316 ALKALINE SALTS. about 2 per cent, of azote. The ash of a variety of coal of vet7 excellent quality gave of — Argillaceous matter (silica"?) not soltble in acids 02 Alumina 5 Lime « Magnesia 8 Oxide of manganese 3 Oxide and sulphuret of iron 16 100 Coal ash also contains very minute quantities of alkaline salts, which usually escape analysis when they are not especially inquired after. One specimen analyzed in my laboratory, gave nearly 00.1 of alkali. Coal-ash is particularly useful on clayey soils ; it acts by lessening the tenacity of the soil; and further, doubtless, by the in- troduction of certain useful principles, such as lime and alkaline salts. OF ALKALINE SALTS. It is impossible to doubt that salts having potash and soda for their base are useful in agriculture. The influence of wood-ashes, and of paring and burning is unquestionable ; and they are so, in some con- siderable degree at least, in consequence of the salts of these bases which they supply, and which always enter into the constitution of vegetables. Theie are even certain crops which, in order to thrive, require a particular alkali ; the vine, for example, the fruit of which contains bitartrate of potash, and sorrel, whicl\ contains the binoxa- late of the same base, must needs have supplies of potash. The plants which are grown for the production of soda, the salsola, dfc^ from which barilla is made, must come in a soil that naturally con- tains a salt of soda, such as tliat of the sea-shore. It would appear, however, that the salts of soila or potash, must not exceed a very small proportion in the soil. All the experiments that have yet been undertaken with a view to ascertain the action of different saline substances on growing vegetables, have led to no very certain conclusion but this, that they must be used very sparing- ly. M. Lecoq has published an account of some experiments, made apparently with great care, which go to prove that common salt, in the dose of from 1| to2',cwts. per acre, favored the growth of barley, wheat, lucern, and flax. Chloride of calcium and sulphate of soda, he also found ti» have the same good effects. M. de Dombasle, how- ever, came to conclusions totally opposed to them, with reference especially to conmion salt, which, applied in the doses advised by M. Lecoq, was not found to produce any sensible elTcci. M. Puvis also obtained results that were equally negative. It would perhaps have been well had M. Lecoq begun by determining the proportion of alkaline salts wiiich existed previously in the soil on which he conducted his experiments. If he operated on a soil that was either destitute of these salts, or that contained them oidy in minimum proportion, very probably he did good by adding ihem. Nitrate of potash has been repeatedly recommended sr an agcm; useful in agriculture. The conclusions that have been come to, however, from its use, arc far from accordant. In the processta NITRATE OF SODA. 31 or modes of using nitre to the soil, it is not uncommon to find it associated with soot, or with vefjotable mould, substances which require no assistan^^e of any kinl to coiisritute them powerful maniires, and the addition of whicli is therefore calculated to raise strong doubts of the advantageous qualities ascribed to nilre alone. Were the advantages of nitrate of potash much less questioned than they are, however, the high price of tlie salt would probably always oppose insuperable obstacles to its employment. This is the reason, in all likeliiiood that has turned the attention of Eng- lish agriculturists, for several years past, to nitrate of soda, a salt that is imported in quantity from Peru, and of which the price per cwt. may be about forty shillings ; a price which, were it found really useful, would permit of its being used. Admitting the ac- curacy of the experiments that have been made, indeed, we can- not doubt the efficacy of nitrate of soda on soil already furnished with organic manure. The quantity that has been recommended is about one cwt per acre. Mr. Barclay made a ff'w experiments after having heard much of the nitrate of soda from his neighbors, of the results of which the following examples will suffice to give a comparative estimate : Withoui nitrate. Witk nitrate. Difference in favor of the nitrates. Wheat 31 bush. 2 r.ecks. 35 bush. 3 pecks. 5 bush. 3 pecks. Straw 21 cwt. 0 qrs. 19 lbs. 23 cwt. 2 qrs. 26 lbs. 3 cwt. 2 qrs. 7 lbs. The produce of the land treated with nitrate, however, did not fetch so high a price at market as that grown without it ; and every item of expense taken into the reckoning, the use of the nitrate was attended with no commercial benefit. Still this does not militate against the fact, that the production of vegetable matter was in- creased upon land treated with the nitrate of soda. And indeed much of the information which M. de Gourcy collected in England, is of a kind that tends to confirm the favorable influence of this salt on vegetation. Wheat, clover, and Swedish turnips are particular- ly specified as benefiting from its use. These facts admitted, we may ask : how does the nitrate of soda act ? The chemical consti- tution of the nitrates is such, that we might conceive their acting at once a.' mineral and as organic manures. The important point for solution was to ascertain whether the azote of the nitrate contribu- ted in any way to the formation of the azotized principles of plants. Davy, in taking with much distrust the report of Sir Kenelm Digby's experiments on the influence of nitre in the cultivation of barley, shows no disinclination to believe that the azote of the salt may concur in the production of albumen and gluten.* This, however, is a point in {physiology which may be put to the proof by experi- ment, and seems peculiarly worthy of being tested in this way. I have admitted it as extremely probable, that the azote of the azoti- zed principles of plants has its source either in the ammonia, which is the special iltimate product of the organic manure we employ, or Agricultural Chemistry. 27* 318 MANURE b : .^SUM. in the azote of the atmosphere, or in both simultaneously; bit the opinion which should maintain that the ammonia derived from the organic constituents of the soil, passes into the state of nitric acid before penetrating the tissues of plants, would find support nearly in the same facts which I have quoted as favoring the former view. We have seen, moreover, in our general considerations on nitrifica- tion, with what facility the azote of ammonia undergoes acidification in certain circumstances, a fact from which an argument of much potency for the nitric acid theory naturally flows. I shall here add an observation to which I have, up to this time perhaps, attached too little importance. When M. Rivero and I examined the hig' ly irritating and poisonous milky sap of the hura crepitans, we had oc casion to leave a considerable quantity of the water derived from the sap, after separating the caseum, to itself; by the spontaneous evaporation of this water, we collected really a considerable quanti- ty of nitrate of potash. Since this time I have had occasion to note the same salt in the sap of several trees of the tropics. In the leaves and fruit, however, I have nevei* foutid more than very minute qu''.. cities. Gypsum, sulphate of lime, or plaster of Pans, is a comp<-jnd of 41.5 lime with 58.5 .«ii.lptmric acid ; gypsum generally contains a quantity of constitutional water, in which case it consists of 79.2 s>ilphate of lime, and 20.8 water == 100. This hydrate of sulphate of lime is one of the abundant minerals on the surface of the earth ; it is met with in the crystalline state, and in granular and fibrous masses in the strata of most recent formation. It has no sensible taste, but is slightly soluble in water, this fluid dissolving xsn of its weight of the salt. Exposed for some time to a white heat, it loses its water of constitution, and passes into the state in wliich when ground it is known under the name of plaster of Paris. Gypsum is one of the most commonly employed of the mineral manures. Its virtues appear not to have been unknown to the an- cients : but until lately its employment was limited to a few circum- scribed districts. It was onlv about the middle of the eighteenth century that the prolestant pastor, .M.iver, took up the study of gyp- sum in the principality of }IohenK>he, proceeding upon certain in- formation which he hud obtained from llehlen of Hanover, in the neighborhood of which, it was employed as an improver. By extending a knowledge of the virtues of gypsum, both by his example and his writings, Mayer did great service to agriculture. Experimenis were soon instituted in all quarters. Tschiirdi in Switzerland, Schubart in Germany, and Franklin in America, wrote on its effects, or practically demonstrvted them to the satisfaction of all. But it appears to be the fate c " all u.scful discoveries, oi all happy applications of principles, to be opposed at first, and oidy lo bo admitted alter having been vainly disj»uted. The use of gypsum soon arouseil formidable opposition ; and there is a curious episod* in the history of the paper war that was long carried on upon In subject, which I think worth noting. Amcuig the most strenuous enemies of the use of gypsum, were the proprietors of the salt-pans. GYPSUM. 319 They declared that gypsnm was not only incompetent to replace schlot or the refuse of their pans, as had been proposed, but that it was injurious ; schlot was the only veal improver, the stimulant of stimulants, for which there was no substitute. But it turned out by and by, that the schlot of the salt-pan was found to be neither more nor less than sulphate of lime, than gypsum — the article that was not only inefficient, but injurious. These gentlemen were afraid that the use of gypsum extending, they would want a market for their refuse. The use of gypsum once introduced, extended rapidly in P^rance, particularly around Paris, whence it crossed the Atlantic, and the fiehls of North America were actually manured with the produce of the quarries of Montmartre. The lately cleared lands of America abound in humus, and the plants indigenous there were most bene- ficially acted on by gypsum, which really produced remarkable effects ; in both the new and the old world, its power, as one of the most useful auxiliaries of vegetation, soon appeared to be estab- lished. We must not blind ourselves to the fact, however, that the parti- sans of gypsum were guilty of exaggeration. They spoke of the substance as a universal manure, capable of supplying the place of every other, as advantageous for every description of crop, as appli cable to every variety of soil. Experience soon set bounds to sue! indiscriminate laudation ; it was found that gypsum alone was inad- equate to produce fertility, that it always required the concurrence of organic manures, if the soil did not contain them of itself; that it only acted beneficially on a certain, and that a very small number of plants ; lastly, that it was upon artificial meadows, constituted by clover, lucern, and sainfoin, that it produced its best effects ; its action, on the contrary, being scarcely perceptible upon natural mead- ows, doubtful in connection with hoed crops, and null with the cereals. These negative results cannot be called in question ; they were come to by parties who were every way interested in having the decision otherwise. The best season for spreading gypsum is the spring, and when the clover, sainfoin, or lucern, has already made a certain degree of progress ; calm and moist weather is the best for laying it on. Opinion wa* long divided as to whether it should be applied in its natural state, and simply ground, or first burned and then ground. But it is now generally admitted that burning adds nothing to the qualities of gypsum. Although the usual practice is to sow or pow- der the meadows with the ground gypsum, it is still acknowledged that good elfects are obtained from incorporating the substance witii the soil. The advantage of the practice of scattering it on in pow- der, so as to adhere to the wet leaves of the growing plants, I find explained in the equality of distribution which is by this means effected. In some places, the number and extent of which are by no means inconsiderable, no good effect whatever has attended the application of gypsum, although it has been administered in favorable conditions, 3*20 GYPSUM. and in connection with crops that elsewhere derive the highest amount of advantage from its use. This anomaly has been explained by assuming, without proving experimentally, however, that the fact is so, that the soil in these districts naturally contains a sufficient dose of gypsum. It has also been said that gypsum produces no eifect on low-lying and damp soils. The quantity of gypsum employed in different places, varies great- ly : from H to 16 cwts. per acre have been recommended. The quality of the article employed has a great influence on this question, to say nothing of the price, which in many places is high. The opinions of practical men, with regard to the advantages and propriety of applying gypsum, although they agreed in certain de- terminate circumstances, were still far from being unanimous upon every point. A particular inquiry into the subject was therefore held worthy of its attention by the French government, and a com- prehensive report on all the information collected, was made by M. Bosc to the Royal Central Agricultural Society of France. This report shows in a striking manner the advantage that may be deriv- ed from the lights of practical men ; in a single line or sentence we frequently find a summary of twenty or thirty years of experience. It is, however, indispensable to go to these gentlemen for their in- formation ; the agriculturists who devote themselves to cultivation, it is notorious, write very little, and those who spend very little lime in this way, on the contrary, write a great deal. It may be that the reason for the silence of the one, is that also tor the elo- quence of the other. The following series of questions and answers I believe to em- brace most of the points connected with the employment of gypsum, that are of interest. 1st. Does plaster act favorably on artificial meadows] Of 43 opinions given, 10 are in the affirmative ; 3 in the negative. 2d. Does it act favorably on artificial meadows, the soil of which is very damp ! Unanimously, no. Ten opinions given. 3d ^Vill it snp[)ly the place ol organic manure, or of vegetable mould ? /. c. will a barren soil be converted into a fertile one by tiie use of plaster ? No, unanimously. Seven opinions given. 4lh. Does gypsing sensibly increase the crops of the cereals? Of 32 opinions, 30 negative, 2 affirmative. The information thus obtained, valuable as it is, cannot yet be held to embrace every thing that seems desirable. Happily, all that was wanting has hern supplied by the individual inquiries of Mr. Smith in Binglatid, and ot'M. de A'lllcle in France. The soil upon which Mr. Smith made his experiment:* was light, with a substrate i»f chalk ; the vegetable earth w:is a yard in de|>lh at the top of the field, and lessened gradually, in such a way that at bottom it was but three inches thick. FiVery |)recaution was tak«Mi that the respective breadths contrasted should be as nearly as possi- ble in the same circumstances. The following table shows Uie results : RYPSUM. 321 GROWTH OF SAINFOIN UPON SOILS GYPSED AND UNGYPSED IN 1792, 1793, AND 1794. n 1 2 1 3 4 ! 1 Remarks. Dry- herb par acre. Seed per acre. VVeipht of total crop. Proportion of stalk to seed. Crop on the deeper ungypsed soil Crop upon the contiguous breadth, which had received about 15 bushels of gypsum in April, 1794 Difference in favor of the gypsed breadth . . . . Crop upon the same soil, of less depth, and not gypsed . Crop on contiguous soil, dressed with about 15 bushels of gyp- sum in April, 1792 . Difference in favor of the gypsed breadth Crop on the same soil, 3 inches deep, and not gypsed Crop on contiguous soil, dressed with about 15 bushels of gyp- sum, 17th May, 1794 . Difference in favor of the gyp- sed piece .... Crop on the contiguous soil of experiment. No. 3, gypsed with the same dose in May, 1792 . . . . . Difference in favor of the crop gypsed twice, at an interval of two years .... lbs. 3357 5462 lbs. 419 582 lbs. 3776 6044 100:12.5 100:10.7 100:8.9 100 : 8.7 100 : 3.2 100 : 4.3 100 : 4.8 2105 2766 4381 163 245 379 2268 3011 4760 1615 2068 4879 134 66 211 1749 2134 5090 2811 4310 145 205 2956 4515 2242 139 2381 *22 GTPStJM. These results show to what extent gypsum is favorable tO' thfi production of sainfoin. The cro . from the unplastered breadth be- ing taken as 100, that upon the plastered breadth is 231 ; it is more than doubled. The influence of gypsum was also found by Smitl^ to extend to grain ; assuming the grain crops on the ungypsed land at 100, those on the g\psed soil were 192 : they were nearly doubled. On comparing the weight of the herbaceous portion of the sain foin to that of the seed produced, widely ditFerent relations are ap- parent. These Mr. Smith attributed to the different depths of the vegetable soil in different parts of the field. In the first experiment, where the relative proportion of seed is highest, the arable soil was three feet in thickness ; the other crops were taken from parts where the depth of vegetable mould was considerably less. Thus the gypsed soil produced at the rate per acre : cwts. fjrs. lbs. In the first experiment of 5 0 In the second experiment of 3 1 In the third e.xperiment of 1 3 With this interesting fact before him, Mr. Smith imagined that soils of little depth wanted some principle essential to fructification, which gypsum, in spile of the unquestionable assistance it gives, is yet incompetent to supply. This principle is in all probability or- ganic matter, which is naturally moie abundant in the layer of true vegetable mould which is deepest. Mr. Smith's observations on white clover were quite as decisive in favor of gypsum as those on sainfoin, and are Cdufirmatory of the conclusions of the generality of farmers on the subject. The gyp- sum in connection with this crop was applied in the dose of 6 bush- els per acre, on the 22d of May, a date at which the clover looked pale, and seemed to want sap. A fortnight afterwards, the effects of the gypsum were obvious; although no rain had fallen in the in terval, the clover'had become vigorous, and soon t'ormed a covering thick enough to protect the ground iVoin the scorching rays of the sun, which burned up all the parts whicii had not been gypsed. 22 the depth of ^oil being 3 feet. 15 '• " 18 iiiches. 15 " " 3 inches. COMPARATIVE GROWTHS OF WHITE CLOVER, GVPSED AND UNGVPSED, BV MR. SMITH. 1 EXPERIMENTS. Herb or g^ . Total weight of the crop. Proportion | of hi-rl) to sei-d. A. Gypsed . . A. Not gypsed . . Difference . . B. Gypsed . . . B. Not gypscr . . . Difference . . . \U<. Ib^. 2226 316 839 ! 56 \h<. 2542 895 100: 14.3 100: 6.7 WO : 7 6 100 : 7.0 1387 2270 500 260 174 61 1647 244-: 561 1770 113 1883 GYPSUM. 323 The mean o' these two experiments shows that the crop of white clover on the ungypsed land being 100, that on the gypsed is 225 — twice and a quarter more. The experiments of M. de Villele may be viewed as supplemen lary oi complementary to those of Mr. Smith. They were per- formed in the south of France, in accordance with the routine that IS generally followed, viz : clover-hay, or sainfoin, previous to grain, upon soils of considerably different nature, and with doses of gyp- sum that varied from 8 to 3 on the same extent of surface. His conclusions or crops are stated in the following table : 1 ■-S2 Excess of T-3 Iji \^ \ 1 2 = Gyp Dry crop Dry crop the crop gypsed over the ^ S ^ - i)-: E ^ .; KIND OF 1 SOIL. 1 -ll Crop. sum per on tlie gyp.-ed on mea- dow not E-2 1 = Q. acre. ijrouiid gypped. crop not lo^ Saa.^o ^t per acre. per acre. gypsed. =1 ^u> 0 0 1 s. d. >. d. (is «. d. 1 Light, dry, ex-'i posed to the 1 south, 6 to It ) iiiclies deep, | cwt.qr. cwt.qr.lbs. cwt.qr.lbs. cwt.qr.lbs. 1 'Sainfoin 6 3 28 2 6 IH 0 1 10 2 15 17 7 6 9 A9 ^S 2 Sainfoin 2 2 3-2 2 27 1(> 1 13 16 1 13 ,27 1 ^1 V 25 0 3 Sainfom 4 4 27 0 1 17 0 21 19 3 8 |16 3 5 1 li 2 aad ouchiilk.J i 1 i Stony clayey, i niuist, about i 1 ! Clover 1 4 0 40 3 19 20 1 23 20 1 23 '33 10 3 2 2 3 16 inch, deep | 2 Clover 5 3 32 2 27 19 2 16 13 0 11 ,21 8 12 5 14 2 on a stiff clay. > 1 1 1 1 The unquestionable fact of a mineral salt stimulating the growth af certain plants in so remarkable a manner as to double and even U) triple the usual quantities grown per acre, naturally aroused the curiosity of mankind to inquire into and endeavor to discover the cause Explanations in abundance have been proposed ; but so lit- tle satisfactory in general, that I do not think myself bound to men- tion them all. I shall limit myself, indeed, to two ; one proposed I V Davy some time ago, and one advocated by Liebig very lately. Davy assumes that the plants of artificial meadows simply absorb sulphate of lime. He assures us that he had found a large propor- tion of this salt in the ashes of vegetables grown in soil which had been treated with turf ashes abounding in the substance. He be- lieved that the gypsum entered particularly into the constitution of the woody fiibre. And it is not uninteresting to observe, that the ulants which gypsum certainly favors in the highest degree, are of very rapid growth ; and that in all probability they would find it difficult to obtain the whole of the sulphate of lime they require from ordinary or ungypsed soils within the period of their growth. Let it not be forgotten, however, that if it be true that saline substances are indispensable to the organization of plants, it is also true that these substances can only be absorbed within certain limits ; a salt the best calculated by its nature to aid vegetation, would become in- jurious by its excessive proportion, did the water which moistened the general soil contain too large a proportion of it in solution : if a plant languishes when it has sot enough of one or other of its natu- ral saline constituents, it also dies when furnished with the «aniSf iubstance in excv,ss. 124 GYPSUM. Let us now remember that salts can only act on vegCvables in the state of solution, and we shall understand how those only which are but sparingly soluble, can ever be advantageously employed in agri- culture. Water, in fact, having the power to dissolve only a verv limited quantity of the mineral manure, will present it to the grow- ing plant nearly in a constant quantity, so long as the soil contains any fair proportion of the substance. It is in this way precisely that gypsum appears to gain its superiority over the generality of mineral or saline manures ; water does not take up more than j^^th part of its weight before it becomes saturated ; a certain proportion of the moisture of the earth being dissipated by evaporation, there is forthwith a precipitation of sulphate of lime ; but the moisture that remains is nevertheless charged as before, neither more nor less, and in the fittest state, as it seems, to administer to the wants of the growing plant. If instead of sulphate of lime we suppose some salt that is much more soluble, sulphate of soda for example, we have nothing of the same state of equilibrium between the quantity of moisture and its charge of saline ingredients maintained. Suppos- ing the moisture of the ground to hold ^g-j^th of sulphate of soda in solution, and this quantity calculated to produce good effects upon growing vegetables : suppose now that a drought sets in, which by dissipalmg one-half of the moisture, increases the charge of saline matter to yjjoth of its bulk, it may very well happen that this pro- portion, instead of proving beneficial, will be felt as injurious to vege- tation. The hypothesis of Davy, supported by these ingenious views of INI. Chaptal, would therefore lead us to regard gypsum as behaving to plants in the same general way as the insoluble salts which usual- ly form an element of the soil or of manures, the phosphate and car- bonate of lime, in particular, salta which are made a})t to enter the tissues of plants by the carbonic acid which is found in all the water that falls from the clouds and that moistens the soil, nnd which has the property of dis.solving small quantities of them. But while the str.ngth of these solutions, weak at all limes, is liable through at mospherical vicissitudes to vary, when the mere traces of salina matter which at best they offer at any lime are inadequate to meet the demands of a crop disposed to grow rapidly and lu.vurianlly, such us clover, sainfoin, and lucern, the solution of sulphate of lime, of the same strength at all linjcs and under all circumstances, is ready to supply the plants with ihe mineral substance they require, however rapid and vigorous their growth. The theory of the action of gypsum proposed by Professor Liehig is extremely ingtuiious. Ho admits, with M. de Saussure, the pre- sence of carbonate of ammonia in the atmosphere, and consequently iu rain-water. This fact establistuul, and it appears undeniable, the iulluence of gypsum would consist in its ficulty of fixing the infinite- ly small quantil y of carbonate of' ammonia which is brought down by the rain and the dew, and so preventing its dissipation on the return of drought and sunshine. Carb(male of annnonia, in fact, as vp hivp al I nndv srni, wlirn speaking of manures, in contact wilb GYPSUM. 325 the sulphate of lime decomposes this salt, carbonate of lime and sulphate of ammonia being formed. I shall by and by inquire whether the reaction that takes place is of the precise nature of that here stated ; but admitting; for tiie present, that it is, it would still be comprtent for us to ask if the quantity of ammonia condensed in this way was likely to suffice for the production of such decided ef- fects as we frequently witness in connection with the crops that are assisted by gypsum. Professor Liebig observes that a pound of sulphate of lime once converted into sulphate of ammonia, would introduce into the soil a quantity of ammonia equivalent to that which would be afforded it by 6.250 lbs. of horse's urine ; a showing upon which it would be easy to demonstrate, taking the composition of sainfoin to be as I have sho vn it, that a pound of plaster fertilizing the ground to this extent, would be adequate to increase one hundred-fold the quantity of dry fodder produced. According to my manner of viewing this question, it must be ex- amined on a totally different basis. It is certain, for instance, that gypsum has no effect upon natural meadows ; positive experience has satisfied me of the absolute inutility of the substance here ; so that upon my natural meadows at Bechelbronn, I now never employ a particle of it. But let us review Professor Liebig's theory in con- nection with the production of sainfoin and clover, which in a gene- ral way derive an advantage from gypsum, which no one disputes. Our harvest of clover, taken as dry, amounts on an average from strongly gypsed land, to 2 tons 1 cwt. very nearly per acre ; and this quantity agrees pretty well with that which appears common in Germany. It is generally allowed that by gypsing we double the produce. It would follow from this, that an acre which had not been gypsed, would yield no more than 20j cwts. of dry clover ; in my opinion the reduction would be still greater. Dry clover hay, made from the plant cut when in flower, contains about 2 per cent, of azote. The 20| cwts. of forage gained by the intervention of the gypsum would consequently contain 110 lbs. of ammonia, equivalent to 134.2 lbs. carbonate of ammonia. This consequently is the quan- tity of carbonate of ammonia which the gypsum ought to have been the means of procuring from the rain which falls upon an acre of land during the time that clover is upon the ground, in order to fur- nish the azote contained in the increased quantity of the crop. Now in Alsace, from the time of gypsing in April, to the time of mowing in July, there falls on an average 3.92, nearly 4 inches of rain, which would amount in round numbers to 982 tons per acre. Were the azote of what may be spoken of as the surplus produce, derived from the rain in fact, all the water that falls ought to contain TTm of its weight of carbonate of ammonia. It is very question- able, however, whether any such proportion of ammoniacal salts exist in rain-water ; yet the proportion ought to be very much great- er, inasmuch as we have supposed the whole of the rain that fell to penetrate the ground, none cf it to run off; but the truth is, that a very considerable proportion of the rain that falls never sinks iato 28 -j6 gypsu:.i. the soil ; once the surface is thoroughly ioaked, much that falls drains off, passes away by the ditches, and is lost with all it may contain that would prove beneficial to vegetation. It is in fact alto- gether impossible to make any approximation, even of the roughest kind, in regard to the quantity of rain-water that soaks into and that runs off the ground ; and thus no kind of estimate can be formed of the relation between the moisture absorbed by plants, and that which escapes direct by the evaporation, without passing through them at all. But even in admitting that it was really the ammonia contained in the rain-water, to which the very considerable increase of the crop of clover, lucern, and sainfoin was owing, it would still be left for us to explain wherefore, meteorological and other circumstances remaining the .same, the same relative effects were not produced upon natural meadows covered with grasses, upon hoed crops, such as beet and turnips, and upon wheat ; finally, the most serious ob- jection that can be urged against this theory is founded upon the fact, that gypsum has no truly beneficial effect upon artificial mea- dows, save and except when the soil to which it is applied contains an adequate proportion of azotized organic manure. In a moderate- ly manured soil, gypsum, as all the world knows, produces no sen- sible improvement ; and as M. Crud, one of those men whom long experience has placed at the head of practical farming, said : It is to throw away both money and trouble to put gypsum upon an un- kindly and impoverished bottom. It would seem, however, that if gypsum really fixes ammonia in the soil, in consequence of its action upon the rain-water tbat falls, converting its carbonate into sulphate of ammonia, the ammoniacal salt once introduced into the soil, ought to act independently and witliout the concurrence of another manure. That it really does act isolatedly, and of its own proper force when it exists, has been proved by the experiments of M. Schattenmann, who demonstrated on the large scale the beneficial effects of the sulphate of ammonia directly applied to natural meadows. It is obvious, that if tlie tbeory which I discuss be true, the greater num- ber of practical observations which I have quoted must necessarily he false ; or, on the contrary, these observations being accurate, the theory nuist be erroneous. I have given reasons for maintaining tho accuracy of the practical results ; nevertheless, the better to establish this conviction, I have thought it advisable to aild a few ficls to the many that are already extant. I was, therefore, induced to undertake a series of experi- ments with a view to study, indepeiulently of all hypothetical idea, tlie action of gypsum upon certain hoed crops and cereals. These experiments were made upon patches of land of 140 square yards each. Every precaution was taken to render the experiments strictly comparable one Tith another. Thus tlie ground appropri- ated to each particular crop was divided into three e(iual contiguous zones. The first zone. A, always received gypsum in the ratio of 4| bushels per acre. The second zone, B, and the third zone, C, were not gypsed. Each zone was sowed with the same quantity of ieed, or planted with nn equal number of beet plants or potatora MANURE- -GYPSUM. 327 A. and C were the surfaces which I proposed to myself to contrast ; the intermediate zone, B, was a kind of neutral ground employed merely to prevent the immediate contact of the g-ypsed with the un- g^ypsed zone. I may here remark, that it would be well always to take such a precaution in making experiments on the effects of dif- ferent manures. In 1842 I tried the effect of gypsum upon w heat coming after three different crops. 1st. After clover ploughed in. 2d. After beet- root. 3d. At'ter potatoes. The gypsum was applied the 19th of May, at which time the wheat looked extremely well. The crop was cut between the 21st and 26th of July, and the following are the results obtained : P Weig-ht o^' grain, corn, and straw. P A. piece gypseil. B. not g-ypseJ. C not gypsed. Wheat after clover 319 lbs. 323 lbs. 327 lbs. Wheat after mangel-wurzel 195 " 17G " 158 " Wheat after potatoes 235 " 158 " 2C4 " Average of the three experiments 250 '* 248 " 250 " The year 1842 having been unfavorable to wheat in consequence of the long drought, the experiment required to be repeated. This was done in 1843 ; and it must be allowed, that an experiment could scarcely be conducted under circumstances of weather more favora- ble to the cultivation of grain ; the results here are given for equal spaces of three French acres, equal to 385 square yards. The gyp- sed zones had been treated with 70 lbs. of silphate of lime each : Year 1843. Sheaves. Grain. Straw, chaff, anil waste. lbs. lbs. lbs. Rye with eypsum 516 137 379 Rye without 472 127 345 Wheat with gypsum 462 147 315 Wheat without 510 156 254 Wheat without 453 143 310 Oats with g^-psum 329 112 217 Oats without 368 113 255 From these numbers it is obvious that gyp&um produces no appreci- able effect upon wheat, oats, and rye, conclusions that agree with those come to in the previous year. EXPERIMENT WITH FIELD-BEET OR MANGEL-WURZEL, OPENING THE ROTATION WITH MANURED SOiL, 1842. The plants were transplanted and waterel, and the gypsum was applied at the time of earthing up ; a good deal of rain fell, and Bhortly after having been laid on, he^ gypsum had become incorpo- rated with the ground. The crop vas gathered on the 8th of Octo- oer, three months after the gypsing, and from two equal surfaces, each of 242 square yards in extent, weighed as follows : From the gypsed ground ^3 cwt. 2 qrs. 6 lbs. From the ungypsed i 2 " 2 " 3 " The gypsum would therefore appear to have had no beneficial effect ; for the difference in favor of the gypsed piece is so trifling S26J GYPSUM. that it cannot be reasonably ascribed to the mineral manure : in fact, the quantity obtained from the gypsed surface does not exceed that which we constantly take from fields in the ordinary course of cul- tivation, and which have received no gypsum. The action of gypsum, limited as it is to certain crops, will not allow us to admit that it produces its effect by fixing in the ground the carbonate of ammonia contained in rain-water ; were it connect- ed with any fixation of ammonia, it would be manifested generally, and not in particular instances only. Davy's theory therefore ap- pears the more plausible, and requires discussion Did the ashes of the clover grown in gypsed soils actually contain a large proportion of sulphate of lime, as affirmed by the illustrious English chemist, the action of gypsum would be readily understood. The whole question, therefore, seems to turn upon the composition of the ashes. I have analyzed the ashes of clover grown at Bechelbronn, with- out and with the concurrence of gypsum. I shall here give the conclusions come to in 1841, a year remarkable for the heavy crops of clover, and those also for the year 1842, when the clover crop was but indifferent. The first table contains the results in the order in which they were registered ; the second contains those obtained after the deduction of the carbonic acid and carbon which had re- mained in the ashes examined : Carbon and Carbonic acid included. Exlraonlinary Crop of 1841. Aihes of Clover. Ung'ypsed. Carbonic acid Chlorine Phosphoric acid Sulphuric acid Liuie Magnesia Oxide of iron, manganese ; alumina Potash Soda Silica Loss and charcoal 14.2 3.4 8.0 3.2 23.7 6.3 1.0 iy.6 1.0 Ifi.H 2.8 100.0 Gypgfd. Unfavorable Crop of IMS. Aithet of Clover. Ungypsed 22 1 *2'.9 6.9 2.6 22.4 *5.1 0.6 27.8 0.7 7.H 1.0 21.5 2.5 5.4 2.4 25.4 5.6 0.5 22.5 2.2 io!o 2.0 lOC.O 100.0 Gyp««d. 2.2 5.8 23 26.7 7.4 traces. 25.3 0.2 2.7 0.6 100.0 Carbonic acid and Lou de Jucted : Chlorine Phosphoric acid Sulphuric acid Lime Magnesia 0,xide of iron, manganese ; alumina Potash Soda Silica 4.1 9.7 3.9 28.5 7.6 1.2 23.6 1.2 20.2 100.0 3.8 9.0 3.4 2«».4 0.7 1.0 3.-..4 J). 9 10.1 100.0 3.3 7.1 3.1 33.2 73 06 2'.t.4 29 13.1 100.0 3.0 8.2 3.2 36.7 10.2 traces. 34 7 03 3.7 lOOX GYPSUM. 329 The analyses here do not, indicate the modes in which the various substances found were combined >" the ashes ; but supposing that the whole of the sulphuric acid existed in combination with lime, which it most probably did, the preceding results would meet us in the following shape : the ashes of the clover grown upon soil with- out gypsum contain 6.0 per cent, of sulphate of lime ; those of clover grown upon a soil with gypsum, 5.7 per cent. As it is impossible to answer for so small a difference as Sj^^-^ parts in researches of this kind, we must presume that the two ashes contained the same proportions of sulphate of lime. Here, however, as in all other agricultural questions, isolated analyses throw but little light on the subject of inquiry. In order that they may enable us to arrive at any definite conclusion, two new elements must be taken into the discussion : 1st. The propor- tion of ash furnished by a given weight of the forage gathered ; 2d. The quantity of forage yielded by a given surface before and after the use of gypsum. I have taken from my own observations the quantity of dry forage yielded by the two cuttings of 2d year's clover after gypsum, as amounting to 41 cwt. per acre. The same surface in the 1st year, and before the use of gypsum, would have produced but 9 cwt. 100 of dry clover gave : Year. Ashes. Clover ungypsed 1841 12.0 Idem 1842 11.2 Clover gypsed 1841 7.0 Idem 1842 7.7 Ashes freed from carbonic acid per ceut. 10.3 8.8 5.4 3.6 Per acre. 103 lbs. 89 " 248 " 257 " MINERAL SUBSTANCES IN THE CROP FROM 2A ACRES. i ■g 12 1 02 s 3 .2 c il si |3 Year 1841. Fallow ung^'psed .... lbs. 10.1 6.6 18.4 lbs. 24.2 53.2 15.4 50.3 lbs. 9.6 20.2 6.6 19.8 lbs. 70.8 174.6 70.8 22G.1 lbs. 18.9 39.8 15.6 62.7 lbs. 3.0 5.9 1.3 lbs. 58.7 210.3 62.9 213.8 lbs. 3.0 5.2 6.1 1.7 lbs. 48.9 61.8 27.9 22.8 lbs. 248 594 234 616 Year 1&12. Fallow ung>-psed .... Fallow gypsed It is therefore obvious, that in the course of the three months which followed the application of the gypsum, the soil must have supplied the plant with very considerable quantities of mineral sub- stance ; the crops taken from the gvpsed soils contained in fact two 28* 830 GYPSUM. or even three times the quantity of these substances which those grown previously to the gypsing contained. Representing, for ex- ample, by unity the quantity of the several bases and acids of the crop grown without gypsum, we should have the quantities of the same principles contained in the crops produced upon the gypsed soils represented by the following numbers : Phosphoric Sulphuric Mag-nesia and Potash and Chlorine. aciJ. aoid. Lime. metallic oxide. ioda. Silica. 1841 2.2 2.2 2.1 2.5 2-1 3.5 1.0 1842 2.8 3-3 3-1 3-1 3.7 3.2 1.0 Silica appears to form the onl}' exception here, which would lead us to conclude that this earth was only absorbed by clover in the first period of its growth. Potash and lime are the bases which enter in largest proportion into the mineral constitution of clover ; and there is another fact made evident which deserves particularly to fix at- tention : it is that the lime assimilated subsequently to the gypsing, bears no kind of relation to the quantity of sulphuric acid fixed dur- ing the same space of time. The excess of acid and of lime obtain- ed from the ash of the gypsed clover over that of the ungypsed, is for: 1841, Sulphuric acid 4-8 Lime 47.2 1842, " 6.0 '• 70.6 Supposing further, that the sulphuric acid assimilated subsequently to the gypsing was taken up in the state of sulphate of lime, we find that : In 1841 the ^psed crop absorbed 18 lbs. of this salt. In 1842 " 22 lbs. These quantities are so small as to lead us to suppose that the utility of gypsing consists in furnishing the plant with the large pro- portion of lime which it seems to require. Gypsing would then be equivalent to the application of lime ; and in fact, according to Schwertz, Paris plaster is replaced in Flanders by slaked lime, by the lye-washed ashes of wood, and by peat-ash, witii decided advan- tage.* Some peat-ash contains sulpliate of lime, others none at all. What is employed successfully, most likely presents sulphuric acid in the state of an alkaline sulphate. Wood-ash, which is certainly the best manure for artificial mead- ows, may contain upon an average one per cent, of sulphuric acid, and when lye-washed, the proportion ought to be much less; if per- fectly washed, it ought to be null ; at all events, there is no sulphate of lime present to fix the ammonia of the rain-water. Independently of earthy phosphates, so useful to all plants, lye-washed ashes fre- quently yield more than 80 per cent, of chalk. We thus perceive, in a general way, that the manures which stimulate the vegetation of clover are always calcareous, the lime being either in the slate of sulphate or carbonate, which exists abundantly in the crops, com- bined with organic acids, and tVeed consequently of nearly the whole of the inorganic acid with which it was originally associated. As- suiwig that gypsum acts like chalk, it may be conceived that when * Schwertz, Culture dcs Plantes fourrageres, p 7? GvrsuM. 331 the former is incorporated with the indispensable manure, it is de- composed, and carbonate of lime, ■« a state of minute division, and for that reason easily absorbed, is ^he result. It is only upon tl)is supposition that I can understand the elimination of the sulphuric acid of the gypsum ; for if the lime really entered the vegetable in the state of sulphate, the ashes ought to be much richer in that acid than analysis shows. This same difficulty occurs in the hypothesis of Liebig. If the 56 lbs. of ammonia derived from the atmosphere penetrated the plant in the form of sulphate, there must enter at the same time 130 lbs. of sulphuric acid, and which ought to be recover- ed in the ashes of the crop from one acre. Now, the ashes of 41 cwts. of gypsed clover, abstracting the carbonic acid, weigh 2 cwts. 8 lbs., containing in the 100, 3^ of sulphuric acid. But the amount of ash, were the acid of the ammoniacal sulphate fixed in the crop, would rise to 3 cwt. 1 qr. 20 lbs., and the ash would then contain 70 per cent, of sulphuric acid. Before promulgating this last objection against received theories, I thought it right to ascertain whether the ashes contain, in the state of sulphate, the whole of the sulphur pre-existing in the incinerated plant. For it w^as not impossible that at the high temperature em- ployed, the silica might react upon the sulphates so as to expel a portion of the sulphuric acid. However improbable this expulsion, owing to the great excess of potash always present in clover ash, it seemed expedient to determine the fact. After having made out as exactly as possible the quantity of ash left by the hay, and also the sulphuric acid, I took a certain weight of the same hay, burned it in a platina crucible along with a mixture of chlorate and carbonate of potash, and then sought for the sulphu- ric acid in the product of the ignition. 1000 parts of the plant furnished directly 3 of sulphuric acid, and by analysis of the ash, 2.8. Thus, the alkaline ashes retain all the sulphur pre-existing in the plant which produced them. I have laid stress upon the small proportion of sulphuric acid in a crop of clover, because there yet remains for consideration a third theory of gypsing, which I have helped to propagate, although doubtful concerning the author. This is founded upon the assumption that the proportion of sulphur is much greater in the leguminous than in the cereal tribe. Now, as gypsum is generally adapted to the manurement of leguminous plants, the origin of the sulphur has been ascribed to sulphate of lime incorporated with the soil. This view appeared the more plausible to M. Dumas and myself, inas- much as in accordance with it plants operat^-d as reducing agents. It is, besides, very probable that sulphur, as an immediate constituen principle of vegetables, is derived from sulphates ; but do leguminous plants really contain more than the cereals ? This seems doubtful since careful investigation of the azotized principles of plants has shown gluten, caseine, and legumine to be nearly identical in com- position. I moreover find upon analysis of the ashes, that clover haricots, and beans do not sensibly contain naore sulphur than rye, 682 AMMONIAC A L SALTS. wheat, oats, and potatoes. There appears to be no doubt, therefore that the sulphur required by plants is supplied abundantly by the soil enriched with ordinary manure, as happens in the culture of the cereals, roots, and tubers. In a word, it may be presumed that Paris plaster acts usefully on artificial meadows by introducinjr lime into the soil. This is con- sistent both with the analysis of the ashes of the crops produced and of the soil ; for according to the researches of M, Rigaud de Flsle, gypsum operates only upon soils which do not contain a sufficient dose of lime in the state of carbonate.* OF AMMONIACAL SALTS. The last products of the putrefaction of azotized matters bei.ig ammoniacal combinations, it necessarily follows that salts having ammonia for their base, must act usefully in vegetation. This is confirmed by the employment of guano, and by experiments in which ammoniacal compounds have been directly applied as manure. I have already pointed attention to the observations of Davy relative to the favorable effect of carbonate of ammonia upon the develop- ment of plants, and shall now detail some recent trials made by M. Schattenmann with the sulphate and muriate of the same base. These salts were introduced into the soil as a solution marking one degree of Beaume's areometer, and in the dose of 10*2 bushels per acre. In 1843, the effects produced upon wheat by muriate and sulphate of ammonia were most distinct ; as was also the case with natural meadows, which yielded under the influence of this liquid manure 8-2 cwts. of hay per acre, precisely double the crop afforded by the same meadow land without the salts of ammonia ; but another important fact, and which M. Schattenmann announces with confidence as having been proved by repeated trials, is this ; that solution of sulphate of ammonia employed in the same dose, and at the same degree of concentration, causes no appreciable meliora- tion upon trefoil and lucerne. The result of a solution of sal-am- moniac was equally negative. These observations agree in certain points with those formerly made by Rigaud de Tlsle, and more lately by M. Lecoq. IJut they are in direct opposition with the experiments of several phvsiologists who have studied the action of ammoniacal salts presente(i separate- ly to vegetables, a circumstance very dilferent from that wherein annnoniacal solutions are incorporated with arable hind. Thus, M. Bouchardatf has stated that y«>ung plants of mcnt/ia aquatica and syh'estns, and of jnimosa pudica die very soon, when made to ve- getate with the roots plunged in very weak solutions of muiiate, nitrate, and sulphate of annnonia. In offerinji, some years back, divers consideraiions upon guano, I promulfiatet^-ip^ oo*«.boioc50to^ccv>inw Carlsonate of lime. • • H- O O • • • k) ii. ■^ • tooo b is if^ Carbonate of magnesia. • • o o o •• 0.5 0.6 2.0 1.9 • • traces idem idem Silica. lo C*5 • Ci W JO Vi 00 • In io C5 io ^ to to n H- tO O ^ ^ OS in 1- to C J^ in i-- W oos^^^coJ-Itowcb w.-cs Sulphate of lime. ' • to CO ^ • 0.6 1.2 7.0 traces 0.7 Siilph.ite of magnesia. Sulphate of Soda. 16.8 5.1 10.2 J7 Po r • rpr «**?»►-• • t Chloride of calcium. ^ c o ►- 0.8 1.7 4.0 traces idem Chloride of magnesium. 12.6 traces 2.5 gVotocotoco- • ^g' • riiloride of sodium (marine salt.) OS traces traces of lime Nitrates. tracco idem idem idem traces idem idem idem strong traces 0.6 0.3 0.4 1 Organic matter. ro OS rf"' JO p^ p i». bo w be to 00 t— ^tOtO*-titOWtn rfi. — H- ODOcscsosp — ►-*^7J;-JOcao **>. OS OS ■*. ^ be lo bo In "-J be c to Total weight of matter. Ditto • Tingry Ditto Ditto Guindant Ditto Bouchardat Ditto Ditto Ditto Cohn Ditto Ditto Ditto Ditto Bo»,usingault Dupasquier Boussingault Dupasquier 3. ROTATION. 341 The water of the Artesian well at Grenelle, near Paris, according to the analysis of M. Payen, contains, in 100,000 parts : Carbonate of lime 6.80 Carbonate of niiignesia 1.42 Bicarbonate of potash 2.96 Sirtphate of potash 1.20 Chloride of poUissium 1.09 Silica 0.57 Yellow matter, not defined 0.02 Organic azotized matter 0.24 14.30 CHAPTER VII. OF THE ROTATION OF CROPS; § 1. OF THE ORGANIC MATTER Oii' MANURE AND OF CROPS. It is known that the atmosphere and the organic matters diffused through the earth concur simultaneously to maintain the life of plants ; but how far each contributes is undetermined. We shall now study the theory of the exhaustion of the soil by culture, and the rotation of crops. When a succession of crops is grown upon fertile land without renewal of manure, the produce gradually diminishes ; and after a certain period, if it be grain, the quantity which at the outset was eight or nine times the amount of the seed, will be reduced to three times or even to twice the seed. Thus crops impair the fertility of the soil, and eventually exhaust it. It has been long admitted that different species of plants manifest great diversity in their powers of exhaustion. Certain kinds, indeed, as trefoil and lucerne, far from exhausting it, communicate new vigor. As a general rule, however, every plant may be said to impoverish the soil in which it grows. This impoverishment is al- ways manifest when the plant after maturity is completely removed, but is less sensible when much rubbish is left. Thus, for example, clover, after yielding two crops, which are generally cut as fodder, might still yield a third ; this last, however, is generally ploughed into the ground as manure, being buried along with a considerable quantity of roots. This plan of meliorating the soil by the cultiva- tion of trefoil is what is called manuring by smothering ; a method practised from a remote period in the south of Europe, and which offers decided advantages in those districts where there is abun- dance of pasture land. Hence, in smothering trefoil, the soil is amended at the expense of the nutritive matter it contains. Thaer, who endeavored to make theory and practice mutually agree, laid it down as a rule, that the exhaustion occasioned b^ 29* S42 ROTATION. cropping is proportioned to the amonnt of nutriment in the crops estimating the nutritive value according to Einhof 's determination But the above deduction is founded upon error. In fact, to adopt the above principle is tacitly admitting that the whole organic matter of plants originally comes from the soil. This, no doubt, contributes in a certain proportion to the developinent of plants, but so also do air and water. On the other hand, physiolo- gists, in opposition to the ideas of the school of Thaer, have perhaps exaggerated the material withdrawn from the air. Thus, M. de Saussure reckons that a sun-flower derives from the ground during its growth not more than 2^*0 th of its weight, supposing the plant dry. The reasoning upon which he formed his conclusion is based, on the one hand, upon a knowledge of the extractive matter of garden- mould ; on the other, upon the quantity of water a plant like sun- flower may absorb in a given time, to return it again to the air by transpiration.* Little objection could be urged against the above conclusion, did not the experiments of M. Gazzeri tend to prove that roots virtually exercise, by their contact with solid organic matter, an incontesta- ble absorbent action in imparting solubility f I migbt refer to an observation of M. de Saussure, in which he states that plants grown in garden-mould deprived of its soluble components by repeated washing, reached, nevertheless, perfect maturity, although the pro- duce in seed was less abundant than it might have been.| It is most probable that both parties have promulgated extreme opinions. Plants possibly draw from the atmosphere more than agriculturists commonly suppose, and the soil furnishes, independently of saline and earthy substances, a proportion of organic matter larger than certain physiologists admit. There is every reason to believe, from what I could learn respecting guano during my sojourn on the coast of Peru, that the greater part of the azotized principles of plants originates in the ammoniacal salts which exist or are formed in ma- nure.^ In discussing the advantage of one course of crops over another, the question always hinges upon that of exhaustion. Wherever an unlimited supply of dung and of handiwork can be procured, there is no absolute necessity for following any regular system of rotation. Under such favorable circumstances, it is expedient to ascertain what kind of cultivation is, commercially speaking, best suited to the climate and the soil. There is little to fear that by a continued succession of similar crops, the fields will got infested with noxious weeds, because this inconvenience may be obviated by labor. Nor is impoverishment of the soil to be dreaded, since that can be re- medied by the purchase of manure. The whole craft of agricult"ire is reducible to comparison of the probable value of the crop with the cost of manure, labor, &c. Farming of this sort excludes the * Saussure, Rocherches Chiniiqucs sur la V6g6tation, p. 268L t Anniiles «lc rA^Ticulturr IVancaisc, No. iii. p. 57 X Saussure, Recherches Chimiqu'es, p. 171. ^ Annales de Chimie, t. Ixv. ann^e lti37. ROTATION. 343 keep and propagation of cattle, and may be strictly regarded morft as gardening than as agriculture. But where manure cannot be had from without, things must be reduced to a system ; and the amount of produce which it is possi- ble to export each year is fixed within bounds, which cannot be ex- ceeded with impunity. When by judicious cultivation land is rendered fertile, it is ne- cessary, towards securing its fertility, to supply after every succession of crops equal quantities of manure. In considering this in a purely chemical point of view, it may be said that the produce which can be taken away without damaging the fertility of the land, is the or- ganic matter contained in the crops, abstraction made of that present in the manure. Indeed, this latter substance must in some form or other return to the soil to fecundate it anew. It is capital placed in the ground, the interest of which is represented by the commercial value of the produce of all the other agricultural operations. Where lands are extensive, population scattered, and means of communication difficult, there is less necessity for being tied down to systematic cultivation. There is always enough for a scanty popu- lation. A field yields grain, and after the harvest is converted for a series of years into meadow-land ; such is the pastoral system in all its simplicity. To this primitive state of husbandry may be referred those plantations on cleared land in countries covered with forests. When the trees are felled and burned upon the spot, the soil yields for long and without manure, crops of maize and of wheat of sur- prising quality, at the cost of the fecundity acquired during ages of repose. But when from increased population the land becomes more valu- able, a larger amount of produce is demanded. Imperfect culture would prove inadequate. Accordingly a triennial rotation of crops was very anciently adopted in the north of Europe, consisting as is well known of fallow land frequently ploughed during summer, fol- lowed by two years of grain. The fallow land received a certain quantity of manure to repair the exhaustion occasioned by the two crops of grain ; hence when this mode of rotation is adopted there should be always sufficient meadou-latid to supply manure. Leaving waste one third of the surface has always been held a grave objection against triennial rotation. Hence various attempts have been made to get rid of the summer fallow. Some encourage- ment was given to these attempts from what occurs in horticulture, where the ground is rendered continually productive.* In certain countries, moreover, tillage is only interrupted by severe weather. On the other hand, it has been long remarked that it is not always beneficial to grow grain during several consecutive years in the same ground, even when it is fertile and ni'inure is abundant, owing to the almost insurmountable difficulty of destroying weeds. The fallow was justly considered the most efficient and economic means of getting rid of these. For this ]^uvpose fallow -crops, as they were * Thaer, Agriculture raisonn^e. 344 ROTATION. called, were introduced. Peas, beans, vetches w. re at first thi only plants used as fallow-crops. However, it was soon perceived that the fallc .v-crops occasioned a very sensible diminution in the produce of corn ; to counteract this inconvenience recourse was had to a surcharge of manure ; but as this cannot. always be obtained, it was necessary either to reduce the cultivated surface or to appropriate a certain amount of meadow. Still the fallow-crops had this advantage, that they enabled the farm- er to derive from land a greater amount of produce in a given time without prejudice to the raising of corn. Hence the plan of turn ing the fallow to account was soon generally adopted. The introduction of clover so modified the system of fallow-crops as at one time to induce the belief that the point of perfection had been attained in agriculture.* This was when it was ascertained that trefoil, which had hitherto been only cultivated in small enclo- sures, might be sown in spring upon corn land, and occupy next year the place of the fallow in the triennial rotation Trefoil, so far from exhausting the soil, was found to give it new fertility, and the succeeding corn crop yielded a plentiful harvest. It may he easily conceived what advantages were expected in substituting for the unproductive fallow the cultivation of a plant which did not impoverish the land, and furnished a quantity of ex- cellent fodder that served as food for an additional number of cattle. It was even alleged that this plant cleared the fields of weeds. A few years' experience sutHeetl to show that trefoil did not pos- sess all the advantages attributed to it. On renew ing the clover every third vear on the same piece t)f ground it sometimes failed. Scluibarth, the most zealous and enlightened advocate tor its use, limited the renewal of the artificial meadow at first to the sixth, and eventually to the ninth year ; and finding that it did not completely destroy the weeds in ct)rn, h(^ had recourse to hoed-crops for that purpose. The introduction i)f trofiwl has gradually led to the system of al- ternate rotation of crops generally adopted at present; and more- over, contrary to the anticipations of Schubarth, it may be renewed every four or five years on the same parcel of land. The impossibility of substituting trefoil for the fallow of the trien- nial rotation was oiVered as a fresh proof of the principle maintained from time immemorial by agriculturists, namely, that different species of plants should be cultivated in succession on the same land, and that the sanu* species should not recur except at considerable in- tervals ; the earth yielding much finer crops when the same species do not fi)lIow in immediate se udiUd. according to the rer^it roscarclu-s of M. Braconnol, the bay-rose with douhle flowers, and Papdvcr somnifirum. That liistingtii-ihed chemist teriiiiiiates his ineinoir a.s follows : " My exiH>riinents are unfa von hie. as may l)e perceived, to the theory of rotation of c-ops hiised on the excretions of the roots. These e.\cretions if really occurring in the lormal sLite are so obscure and little known as to lead to the inference that the general system of rotations must be referred t« some other source." (Rccherches sur rinfluence dos plantes sur le sol, .\nnales d4 Chimie t Ijtxii. p. 27.) ROTATION. 347 in theory that should agree with practice is this, that in no case is it possible to export more organic matter, and particularly more azo- tized organic matter, than the excess of the same matter contained in the manure which is consumed in the course of the rotation. By acting upon another presumption the productiveness of the soil woulc/ he infallibly lessened. This irrefragable condition as to the term of exportation from a farm suggests some critical remarks upon sundry notions lately pro- mulgated. The manufacture of beet-root sugar is an instance. European agriculture may probably derive certain advantages from this modern branch of industry, altliough these have been mu'^h overrated by certain speculators, who contend that sugar may thus be obtained through rotation of crops without lessening the other produce of the domain ; so that the sugar constitutes an additional source of income. This seems to me erroneous If an estate yields annually 100 tons of beet-root for the support of cattle, their number must be diminished if the root is to be used for making sugar. The organic matter of the sugar extracted there- from, is just so much nourishment withheld from the cattle. To assert the contrary would be equivalent to saying that potatoes grown upon a couple of acres of land, and submitted to the process of dis- tillation before being employed as fodder, would feed as many animals as if eaten directly : assuredly, the organic principles of the potato converted into alcohol are lost as regards nutrition. This does not imply that the manufacture of indigenous sugar, and of potato spirit, is less productive than breeding and fattening cattle. My sole object is to show that only a limited quantity of organic matter can be advantageously exported from an agricultural establishment. It must depend upon local and commercial circum- stances whether this is to be exported in the form of sugar, corn, spirit, or butcher-meat. The above statement is in apparent contradiction with generally received notions. Many persons believe that the manufacture of sugar, instead of injuring, is favorable to the breeding of cattle. It appears, from a Parliamentary return on this subject, in 1836, that in certain estates where sugar was made, the number of animals was increased ; the numerical results are no doubt exact, but this augmentation in cattle is rather to be ascribed to an improved mode of farming than to the manufacture of sugar. In establishments where the triennial rotation with fallow was pursued, a rotation of four or five years with clover and weed-destroying plants has been introduced ; so that it is by no means to be wondered at, that inde- pendently of beet-root, there should have been a considerable increase in other things. The introduction of this root, where it was not formerly grown, is of itself an important melioration. But in highly cultivated countries, where the most productive rotations have been long followed, the extraction of sugar would not effect such advan- tageous changes as those announced in the above return. If at Bechelbronn a time should ever come, and at present it seems far distant, when it would be deemed expedient to make sugar from the 348 ELEMENTS OF CROPS. beet there grown it would certainly be requisite to diminish the number of cattle, or else to annex more meadow land. It is only indirectly, therefo: e, that the manufacture of home-sugar can pro- mote the breeding of cattle, and so prove serviceable to agriculture. From the definition given by me of the mosi advantageous course of crops, theoretically considered, it may be inferred how closely the study of rotations is connected with that of the exhaustion of the soil. Hence, to discuss the value of divers rotations, we must, in consonance with theory, compare the quantity of organic matter in a sequence of crops, with that in the manure expended upon them. From a well-managed farm, where for a series of years an invari- able system of culture has been steadily pursued, we must look for data. This I have done, as regards Bechelbronn, determining by analysis the composition of the manures and crops, and also of the more ordinary kinds of fodder or food. For a long time, a five years' rotation has been there adopted in tbe following order : 1st year. — Potatoes or beetroot mnnured. 2d year.— Wheat sown the autumn of the first year ; clover interposed in the spring. 3d year. — Trefoil (clover) two crops ; the third crop ploughed in or smothered. 4th year. — Wheat on the clover-break, turnips after the \\ heat. 5th year. — Oats. The crop of oats which ends the rotation is generally scanty. The soil is then brought back to the point of fertility which it had before being dunged ; and it is known by e.xperience that it will not now yield a crop of any value. I now proceed to detail the analyses of the different substances which enter into the rotation, indicating at the same time the average produce per acre. POTATOES. In the rather strong soil of Bechelbronn one acre prod 1.8 of azote. This notable ditTerence, perhaps, depends on the analysis not having been made immc erated, left 0.0758 of ash : I. II. Carbon 42. HO 49.93 Hydrogen 5.54 5-61 Oxygen 42-40 42.20 Azote l.(W 1.68 Ash 7.58 7.58 100.00 100.00 OATS. As this grain closes the rotation, the produce is not great. The average crop is 37 bushels per acre, at the weight of 331 lbs. per bushel ;* one of oats con pletely dried weighs 0.792 ; one of dried j>ats leaves 0.0398 of ash . I. II. Carbon 30:i2 51.09 Hydrogen ... 6.32 6.44 Oxygen 37.1-J 36.25 Azote 2.24 2.24 Ash 3. ganic matter necessarily enters into the constitution of the plants which spring up during the rotation ; no doubt a considerable por- tion of the manure is lost through spontaneous decomposition, or is carried away by the rain ; and another portion may remain a long time dormant in the soil, to act as a fertilizer at a more or less dis- tant period ; just as in the present rotation the manure formerly in- troduced co-operates with that recently added. One thing is certain, viz., that the proportion of manure indicated is essential for a>erage crops ; by diminishing it the produce is necessarily lessened. Last- ly, it is proved that after the rotation the crops have- consumed the manure, and the earth will not yield its increase unless a fresh quan- tity be added. I now proceed to consider the relation subsisting between the quantity of organic matter buried in the soil as manure, and what is recovered in the crops. In this way the respective proportions of elementary matter which various crops derived from the air and the soil, may be determined approximately, and a knowledge obtained of those rotations which least exhaust the land, or in other words, which obtain from the atmosphere the largest amount of organic matter. The rotations set down in Tables I. and II. are those definitively adopted at Bechelbronn, and throughout the greater part of Alsace. These two rotations, which dilTer only in the hoed crop introduced, potatoes in one, beet-root in the oilier, are almost identical; nearly the same quantity of dry matter being produced per acre, and nearly the same quantity of organic material withdrawn from the atmo- sphere. The rotation No. 3 was introduced by Schwertz at Hohenlieim ; theoretically, it is one of the most advantageous ; it was tried at Bechelbronn but abandoned, because, from meteorological causes, peas and vetches fail frequently. Table No. 1, shows the triennial rotation with manured fallow ; this is disadvantageous in point of theory. The organic ct)nsii- tuents of the crop exceed but little those of the manure. Suppos- ing that even the whole of the straw were converted into manure, the farmer would still be compelled to procure manure from abroad, in compensation for the out-going of wheat. It is thus ol)vious why triennial rotation always requires a great deal of meadow land. In table No. 5, the result of the continuous cultivation of Jerusa- lem artichokes is given. At Bechelbronn these are dressed every two years with about ten loads of dung per acre. Upon an average 20 tons of tubers and about 2 tons of woody stems are gathered in the course of two years. It will be perceived from perusal of this table, that the culture of Jerusalem artichokes presents, theoretical- ly, considerable advantages. The organic matter of the crop greatly exceeds that of the manure. Moreover, in .\lsace, where it is very common, it is held to be most productive. Still, the organic matter of the stems must be taken into account, which, practically speak- ing, are nearly worthless. IN CROPS AND MANURE. 357 Table No. 6 comprises the data relative to a quadrennial rotation, adopted by M. Crud, and in which are grown successively : 1st. Potatoes or beet-root. 2d. Wheat. 3d. Red clover. 4th. Wheat. The first sowing is dressed with about 18 tons of half- wasted farm- yard dung. The gain in organic matter obtained by this rotation surpasses that of the preceding ; but as the clover crops are not very sure when repeated every four years, M. Crud, for reasons which may be called in question, follows this rotation with one of lucern, which gets a fresh supply of manure. It cannot be denied that lu- cern furnishes a great mass of fodder, and in this respect the fertili- ty of the land ought to be vastly enhanced, were this consumed on the spot ; but I can discover no objection to the renewal of clover, if the lucern succeeds so well as M. Crud says it does. From too frequent repetition, farmers have gone into the opposite extreme of cultivating clover only every five or six years. This subject offers an important field for research. It is not impossible that the ill- success depends often on premature mowing of the clover during the first year, and before its roots have acquired sufficient vigor. This practice has been abandoned with us for some years, and there is now every thing to assure us that the second year's crop is there- by secured. ROTATION COURSE No. 1. Years. Substances. Crops per acre. Crops dry. Carbon. Hydro. gen. Oxygen. Azote. Salts and earths. • 1st 2d 3d 4th 5th Potatoes . . . Wheat , . . Wheat-straw . Clover-hay . . Wheat . . . Wheat-straw . Turnips C2d crop) Oats .... lbs. 11733 1231 2798 4675 1521 i!^ 1232 1650 lbs. 2828 1052 2070 3693 1300 2557 656 975 1176 lbs. 1244 1002 1750 2832 61 110 185 75 'i 62 63 lbs. 1264 564 995 278 358 458 lbs. 42 24 ,1 30 10 11 21 5 lbs. 113 .1 11 179 50 39 60 Oat-straw . . Total .... Manure employed ^S 16307 9314 10236 3426 m 6575 229 185 926 2999 Difference . . 6993 6810 500 4172 « 2073 ROTATION COURSE No. 2. 1 ! Years. Substances. Crops per acre. Crops dry. Carbon. Hydro- gen. Oxygen. 1 Salts Azote. 1 and 1 earths. 1st 2d 3d 4th 5tb Mangel wurzel . Wheat .... Wheat-straw . . ^iS'^'^f : : : Wheat-straw . . Turnips .... Oats Oat-straw . . . Total Manure employed Difference . . . 1086 2468 11675 1520 1 2907 3693 1300 2557 65.5 975 1176 lbs. 1244 428 .1 599 495 589 % 53 98 185 75 135 63 lbs. 1262 403 710 1396 ^1 i? 458 I 10 J! 5 lbs. 182 1 i 60 ^^ 1G018 9314 III 11 6423 2403 231 185 975 ; 2999 ] 6704 4079 1 473 4020 46 1 2024 1 359 RELATIONS OF ELEMENTS. ROTATION COJRSE No. 3. Years. Substances. Crops per acre. Crops dry. Carbon. Hyd ). gen. O-xygen. Azote. Salts and earths. lbs. lbs. lbs. lbs. lbs. lbs. lbs. 1st Potatoes .... 11733 2828 1244 164 1264 42 113 2d Wheat .... 1231 ia54 485 61 457 24 25 Wheat-straw , . 2798 2070 1002 110 805 145 3d Clover-hay . . , 4675 3693 1750 185 1396 78 284 4th Wheat .... 1515 1300 599 75 30 31 Wheat-straw . . 3456 2558 1238 135 qOA 10 179 Turnips .... 87M 656 282 36 278 11 50 5th Peas (dunged) . . 1001 915 425 56 366 38 28 Pea-straw . . . 2558 112 803 52 255 fith Rye 1.539 1278 590 71 565 22 30 Rye-straw . . , Total 3420 2^80 1387 155 1129 8 100 148280 21388 10035 1160 8622 323 1240 Manure employed Diflerence . . . 148285 11176 4000 470 2883 223 3599 10212 6035 690 5739 100 2359 ROTATION COURSE No. 4. Years. Substances. Crops per acre. Crops dry. Carbon. Hydro- gen. Oxygen. Azote. SalU and earths. 1st 2d&3d Dunged fallow . . Wheat .... Straw Total Manure employed Difference . . . lbs. 3041 6875 lbs. 2600 5080 lbs. 96i 2462 lbs. loO 270 lbs. 1128 19,9 lbs. "eo 20 lbs. *62 356 9916 18330 7680 3795 3413 1358 g 3107 979 80 76 1^ 8414 3885 2055 261 2128 4 801 No. 5, CONTINUOUS POTATO CROPS- Yean. [ Substances. Crops per acre. Crops dry. Carbon. "^'^^ Oxygen. Azote. SalU and earths. 1st & 2d Potntoes .... Stalks .... Ibv 4S173 25850 lbs. 10083 2M97 Ibv , lbs. 4366 bSo 10289 1215 lbs. 4S66 I02te lln. 161 90 Il». 605 630 Total Manure em ployed . Difference . . . 74323 41663 32.-«) I4t;o 3087 1800 362 14tii5 2225 2.-.1 172 1235 2777 1643 1 23956 11568 I 1438 12430 79 No. 6, QUATRENNIAL ROTATION, ADOPTED BY .M. CRUD. Years. Crops grown. Crops per acre. ELEMENTARY INGREDIENTS Of THE CROP. Crops ' dry. Carbon. 1 Hydro- gen. Oxygen. ) SulU Azote. and 1 earths. 1st 2d&4th 3d Hiilf nrre of ^ta toes Ditto ..fbeel-roota . Wheat, 153 bushels . Wheat-straw . . . Clove' lhre« cuttings Total Manure consumed . DifTerence .... lbs. , lbs. lbs. 3331 i 2847 1312 7333 1 5243 2537 7333 i 5793 2746 lbs. 128 130 16.5 278 290 ll>s. 987 970 1215 2(M0 2190 "% ! "Si III i^ '^ ^ 991 330 7422 2154 13; 5JJ§ 9960 I 5535 641 5268 111 1 1578 IN CEOPS AND MANURE. 359 SUMMARY. 1 Dry manure Dry produce Gain in org^an- expended upon Azote con- obtained in Azote con- ic mailer in Gain in azote 1 one acre in tained in the one year upon tained in the one year upon in one year one year. manure. one acre. produce. one acre. upon one acre. lbs. lbs. lbs. lbs. lbs. lbs. No. 1 1862 37 3261 46 1996 9 No. 2 1862 37 3204 46 1746 9 No. 3 1862 37 3564 54 2513 17 No. 4 1247 23 2567 26 1565 3 No. 5 3710 86 16299 125 12758 39 No. 6 2087 42 4582 70 2889 ■^ f From all that precedes, it is obvious that rotations which include trefoils, red clover, lucern, and sainfoin, are those that afford con- siderably the largest proportion of organic matter ; a fact, indeed, which if not legitimately established, has still been long acted on in that system of cropping which embraces forage plants as an ele- ment. Lucerns, too, when they have taken kindly, yield an extra- ordinary quantity of forage, as every one may see by turning to the produce of the piece under that crop which in the system of M.Crud succeeds the quatrennial rotation. At the end of his rotation, M.Crud always lays on manure in the ratio of 18 tons per acre, which lasts for six years, and may be said to suffice for the succession of crops in the appended table : Crops. Lucern dry, Wheat, Straw .. Produce per acre. 1st year 3080 lbs. 2d year 9240 3d year 114.58 4th year 9240 5th year 7333 6th year 1448 3645 Dung employed 40233 Contents in azote. 72 lbs. 215 269 213 172 H 980 205 Total gain in azote 775 Gain in azote per annum and per acre 130 In glancing at these tables, it is obvious that the azote of the crop always exceeds the azote of the manure. Generally speaking, I admit that this excess of azote is derived from the atmosphere : but I do not pretend to say in what precise manner the assimilation takes place. I shall only quote the conclusion of a paper which I published on the subject in the year 1837.* Azote may enter immediately into the constitution of vegetables, provided their green parts have the power of fixing it ; azote may also enter vegetables dissolved in the water which bathes their roots, and which always contains it in a certain proportion. Lastly, it is possible that the air may contain an ii\finitely minute quantity of arnmoniacal vapor, as some natural * Annales de Chimie, t. Ixix. p. 3Cb. 360 RELATIONS OF ELEMENTS philosophers* have maintained, and that this assimilated, decom- posed, and recomposed anew by the plant, is the source of its azotized constituents. ^ 2. OF THE RESIDUES OF DIFFERENT CROPS. The vegetable matter which is produced in the course of a season is never found entirely in the crop. A certain quantity of it, for instance, always remains in the ground. It is, therefore, a point of interest to ascertain what quantity of elementary matter is left in the soil after each kind of crop in the rotation ; precise knowledge of this description may even be important in calculating rotations, for it is obvious that the remains of the crop now on the ground must influence that which is to follow, and in the course of a rotation the sum of the residuary matters must be regarded as a supplement oi addition to the manure put into the ground at its commencement. In the systems of rotation very generally followed at the present time, the intiaenoe of these residuary matters is manifest, and it is partly by their means that we can explain how a quantity of manure, frequently very moderate, should suffice for tlie whole of the crops in a productive rotation. The remarkable effect of clover has not failed to arrest attention even from the most unobserving. The wheat crop which comes after our drill crop in Alsace, beet or potatoes, averages from 18 to 20 bushels per acre ; but the wheat crop that succeeds our clover averages from 23 to 24 bushels per acre. The improvement of the soil, so obvious in connection with clover, in all probability also occurs in connection with the residues of other crops ; but as in most instances the residue merely compensates the loss, or lessens its extent, the effect produced is less remarkable, and is less, indeed, in amount. All the world acknowledge, then, that the residues of the crops that enter into a rotation compensate in greater or less degree for what is carried away in the shape of harvest, and that in some cases they even add to the fertility of the soil ; for in growing crops that leave a large quantity of residue, it is precisely as if a smaller quantity were taken from a given extent of surface. But what is the amount of residue or refuse which is returned to the soil by such and such a crop ! What, in a word, is the value of this residuary matter considered as manure ! This is a point upon which only the most vague and mdefinite ideas are generally entertained ; and it was with the purpose of substituting positive facts for mere guesses, that I determined on weighing and analyzing the vegetable residue of the several crops that enter as elements into our more usual rotations. My experiments were made upon breadths of land which varied from 120 to 500 square yards in extent. The clover roots and stubble were taken up with the spade, and before being dried, were freed from adhering earth by washing. The beet-leaves and pota- to-tops were dried at once in the oven ; and it was from each of the • Saussurc Recherches Chimiques, and Liebig. Agricultura] CheiuUtry. IN CROPS AND MANURE. 36 general masses reduced to powder (hat samples were taken for ulti- mate analysis, before proceeding to which, the)^ were carefully dried in vacuo at 230° F. It is not likely that any accurate mean result should have been come to from an examination of the produce of a single season. I should even say that the year in which these inquiries were under- taken was little favorable to them, inasmuch as the crops were gen- erally bad ; but it is obvious that they form a nucleus, around or by the side of which the results of other seasons may be arranged, and an average from larger premises come to. POTATO TOPS OR HAUM. A piece of land measuring 120 square yards, marked off from a spot that had suffered from drought, yielded 47.0 lbs. of green tops, which were reduced by drying to 18.4 lbs. A similar extent of surface, selected from a part of the field that looked well, gave green tops 79 lbs., which dried in the air Vv'ere reduced to 16 lbs. We should thus have 23| cwts. of green, and Q\ cwts. of dry tops per acre. The crop of potatoes in 1839 yielded at the rate of 101^ cwts. per acre. One hundred grammes, or 3 oz. 4 dwts. 8 grs. troy, of the top dried in the air, lost 12 grammes, or 7 dwts. 17 grs. by thorough drying at 230° F, The weight of the tops yielded per acre, taken as dry, consequently amounts to 5 cwts. 2 qrs. 14 lbs., and by elementary analysis they were found to have the following composition : Carbon 44-8 Hydrogen 5.1 Oxygen 30-5 Azote 2. .3 Salts and earths 17.8 100.0 LEAVES OF FIELD-BEET, OR MANGEL-WURZEL. Upon a surface of 500 square yards, 976 lbs. of leaves were gath- ered, the weight being taken two days after the roots were pulled up. 55 lbs. of leaves reducible to powder by drying in an oven, were hrought to 6.6 lbs. 3 oz. 4 dwts. of leaves dried and pulverized, lost by desiccation at 230" F. 3| dwts. of moisture. The 6.6 lbs. brought to that state of dryness would have weighed 6. 1 lbs. With these data it is found that the 976 lbs. of green leaves gathered upon 500 square yards would have weighed when dry 108.9 lbs. ; and that the acre produced 85| cwts. of green and 9j cwts. of dry leaves. The crop of roots which answers to that quantity of leaves, was in 1839 but 6 tons, 2 cwts., that is to say, little more than half a crop ; for our average is about 10^ tons. GOMPPSITION OF DRY LEAVES. Carbon 38.1 Hydrogen 5-1 Oxygen 30.8 Azote 4.5 Salts and earths 21.5 100.0 31 362 ORGANIC ELEMENTS 1 MANl RES AND CROPS. WHEAT STUBBLE. From 120 square yards of ground we have obtained 13 lbs. of Btubble dried in the air. The same surface in another field produced 171 lbs. Thus we have 5| cwts. of stubble per acre ; but as wheat recurs twice in the rotation, the residues must be doubled ; say, IH cwts. Stubble loses 0,26 of moisture when dried completely at 230°. In 1839, the wheat after the drilled crop, or after clover, was only 17 bushels per acre. I have assigned to stubble the same composition as that of straw. CLOVER ROOTS. A surface of 120 square yards gave 44 lbs. of roots, weighed after being thoroughly dried in the sun ; when pulverized after drying in the stove the weight was reduced to 37 lbs. 3 oz. 4 dwts. of powdered roots lost by drying, at a temperature of 230° F., 5 dwts. of moisture. Thus the U lbs. of roots dried in the sun would have weighed 34 lbs., and one acre would have furnished 12^ cwts. of residue perfectly dry. In 1839, the clover crop when reduced to hay was far below the average. COMPOSITION OF THE ROOTS. Carbon 434 Hydrogen 5.3 Oxygen t 36.9 Azote 1-8 Salts and earth -.-Ig.ti 100.0 OAT STUBBLE. The residue of the oat crop, whichconcludes the rotation course, does not act upon the present, but on the next rotation ; in the same way as the organic remains left in the ground by the oats which ter- minatfd the antecedent course, e.xerted their influence upon the present one. In 1839, the oat crop was above the average ; it wa« as high as 16 cwts. 2 qrs. 18 lbs. per acre. One French are of the land, equal to 120 square yards English, yielded 20 lbs. of stubble dried in the air, or at the rate in round numbers of 8 cwts. per acre. In the following table 1 have given a s- mmary of the results above stated, combining therewith the quantity ind the composition of the manure expended in the rotation. ORGANIC ELEMENTS OF MA^^XES AND CROPS. 363 SUMMARY OF THE FOREGOING RESULTS. Nature of the crop. k II Nature of the residues buried in llie soil. = Q.£i Elementary matter of the residues. Residues taiiied u one uc Residues at 110 d 6 ii S i < 111 Potatoes . 1 Beetroots . 1 Wheat . . Clover-liay Oats. . . . Total . . . lbs. 113b7 i3(i;8 2150 2292 18t)2 lbs. 2739 16b'8 1837 1810 1474 Potatoetops . Beetroot leaves Stubbie. . . . Roots dried in the sun . . . Stubble .... lbs. 1283 lbs. 630 1070 950 1418 596 lbs. 282 410 460 615 299 lbs. 32 55 50 75 32 lbs. 189 330 369 .523 232 lbs. 14 48 4 26 2 lbs. 67 178 30 16182 i 4664 2066 244 1643 1 94 617 ! Manure 1 employed 44995 9314 3335 391 2403 186 2995 It therefore appears that the refuse or residue of the several crops of a rotation represent, both in quantity and nature, somewhat less than one half of the manure originally put into the ground; I say somewhat less, because it must be remembered that in the sum of these residuary matters, the beetroot leaves and potato tops must not be allowed to stand together, the one crop naturally excluding the other, or at all events the two hoed or drilled crops not entering in this proportion into the same rotation. The large quantity of organic matter restored to the soil by several of the crops in the series, consequently explains how the rotation may be closed without its being found indispensable to supply any additional manure in its course. It seems indubitable that without this addition of elementary matter, the fertility of the soil would decline much more rapidly than it does ; the residue of each crop is nothing more than a portion of the crop itself restored to the ground ; it is as if we only carried off one portion, the larger portion of the crop, and buried another portion green. In the five years' rotation, it may be observed that there are two crops, the hoed crop and the forage crop, w^hich yield substances to the ground that are both abundant in quantity and rich in azotized matter, and it is unquestionable that these crops act favorably on the cereals which succeed them. But data are wanting for the appre- ciation of their specific utility in the general rotation. We see, for instance, that despite the large proportion of residuary matter left by the beet or mangel-wurzel, this plant lessens considerably the pro- duce of the wheat crop that comes after it. The potato, though it leaves much less refuse than the beet, seems nevertheless to act less unfavorably than this vegetable. Clover leaves more residue than the potato, and on this ground, alone, ought to favor the cereal that follows it ; but it has a favorable influence out of all proportion with its quantity, contrasting this with the residue of either of the hoed crops ; a fact from which we learn that the visible appreciable influ- ence of the residuary matters of preceding crops, upon the luxuriance of succeeding crops, does not result solely from their mass, even supposing ear'- to be possessed of equal qualities ; this other, this 364 inohctAxic elements of manures and crops. additional effect, depends especially on an influence exerted on the 5uil by the crops which leave them. Had these crops been power- fully exhausting, we should expect that their refuse or residue, how- ever considerable in quantity, could do no more than lessen the amount of exhaustion produced ; in which case, its useful influence, however real, would pass unnoticed, were it estimated by the produce of the succeeding crop. If, on the contrary, a crop has been but slightly scourging, whether in consequence of the smallness of its quantity, or because it may have derived from the air the major part of its constituent elements, the useful influence of the residue will not fail to be conspicuous. When the relative value of different sys- tems of rotation is discussed in the way we have done, we in fact estimate the value of the elementary matter derived from the atmo sphere by an aggregate of crops; but the procedure generally fol- lowed is silent when the question is to assign to each crop in particular the special share which it has had in the total profit. To reply to this question, of which a knowledge of the various residues is one of tiie elements, we must first ascertain the quantity of ele- mentary matter supplied by the soil and the atmosphere, with refer ence to each of the crops which enter into the rotation ; in other words, the same investigations must be undertaken in reference to each plant considered by itself, that have been made in reference to the series collectively. There is untpiestionable room, in this direc- tion, for an important scries of experiments. ^ 3. OK THE INORGANIC SUBSTANCES OF MANURES AND CROPS. We have but just considered the organic matter developed in a series of successive harvests. To complete the study of rotations, to the extent at least that this can be done in the present state of science, we have still to examine the relations that may exist between the mineral substances which enter into the constitution of the pro- duce, and those that make part of the manure given. We have already shown in a general way that certain mineral salts, certain saline matters or salifiable base?, are essential to the constitution of vegetables. To the best of my knowledge, no seed has yet been met with that is without a phosphate ; and it is now known that the alkaline salts powerfully promote vegetation. Such is their ascertained mfluence, indeed, that tobacco, barley, and buckwheat sown in soils absolutely without organic matter, but containing saline substances, and only moistened with distilled water, produced perfect plants, which flowered and fruited, and yielded ripe seeds.* Whence it follows, that the presence of saline matter fa- vors remarkably the assimilation of the azote of the atmosphere during the act of vegetation. The importance of considering rotations in connection with the inorganic substances that arc assimilated by plants was perfectly well known to Davy. " The ex[ rtalion of grain from a country which rec«nves nothing in exchange that can be turned into manure, must exhaust the soil m the long run," says the illustrious chemist j * Liebig, in Jnurn. dc Phnriniirio, vol. Iv., M ^vnct, p. 94. INORGANIC ELEMENTS OF MANURES AND CROPS. 365 who ascribed to this cause the present sterility of various parts of Northern Africa and of Asia Minor, as well as of Sicily, which for a long succession of years was the granary of Italy. Rome un- questionably contains in its catacombs quantities of phosphorus from all the countries of the earth. Professor Liebig, in insisting with the greatest propriety on the useful part played by alkaline bases and saline matters in vegetation, has shown the necessity of taking inorganic substances into serious consideration in discussing rotations. It is long since I came to the same conclusion myself; but it strikes me, that to be truly profitable, such a discussion must necessarily rest on analyses of the ashes of plants which have grown in the same soil, and been manured with the same dung, the contents of which in mineral elements were al- ready known. There is in fact a kind of account current to be es- tablished between the inorganic matter of the crop and that of the manure. Although I give every credit to the fidelity of the analyses of vegetable ashes that have been published up to the present time, I have not felt myself at liberty to make use of any of them in the direction which I now indicate. • I have not thought that it would be fair or reasonable to contrast such heterogeneous compounds, as the ashes of plants grown at Geneva and Paris, under such dissimilar circumstances, with those of vegetables produced on a farm of Al- sace, where the point to be explained, through the results of this contrast, had reference to a particular series of agricultural phenom- ena. And then my business was not merely with the scientific ques- tion ; the manufacturing or commercial element in the consideration also touched me. I had to ascertain how I was likely to stand at some future time, did I presume to act upon the conclusions to which I came. There was nothing for me therefore but to analyze the ashes of the several vegetables which entered as elements into the rotation followed at Bechelbronn, but confining my inquiries to that portion of the vegetable which is looked upon particularly as the crop, so much of the plant as remains on the ground and is turned in again, of course taking nothing from it.* The ashes examined were almost all from the crops of 1841, two analyses having generally been made of each substance : and here I ought to say, that in this long and tedious labor, in which I spent nearly a whole year, I was most ably seconded by Mr. Letellier. By way of preface, I should say that in these analyses, losses will fre- quently be apparent, which for the most part exceed the limits that in the present day are tolerated in the more careful operations of the laboratory. These deficiencies, which puzzled me a good deal at first, I by and by discovered to proceed from the difficulty of incin- erating certain vegetable substances completely. When they abound in alkaline salts, they leave ashes that melt so readily, that it becomes difficult to prevent their agglutination, and the charcoal that is not consumed is then effectually protected against any further action of the fire. There is nothing for it in such cases but to incinerate at the lowest temperature possible, and then a little moisture is apt to be left ; the charcoal, however, is the substance that occasions the 31* 306 INORGANIC ELEMENTS OF MANURES . ND CROPS. main difficulty, and the more important loss. To quote one of the instances, that of wheat, where the loss or deficiency is as high as 2 4 per cent. I may say that a direct inquiry after charcoal brouglK it out equal to 2, by which the actual deficiency is reduced to 0.4. I have not, however, introduced any correction for carbon, but pre- sent the reader with the results as they actually presented them- selves to me. Among the number of the products of the analyses, alumina figures beside the oxide of iron. Alumina is an earth which I have always met with in minimum quantity in the ashes of plants, and is perhaps accidental ; it may proceed from the earth which ad- heres to all herbaceous plants, and from which it is so difficult to free them completely. COMPOSITION OF THE ASHES PROCEEDING FROM THE PLANTS GROWN AT BECHELBRONN. Acids. c%: •c U i i^^ -==> Substances which II F V ' « .5 "= 2 r.^i yielded the ashes. ^1 6 •- !lli 1 i jZ |1 n Pntdtoes .... 13.4 71 11.3 2.7 1.8 5.4 51.5 traces .5.6 0.5 0.7 Mnngel-wurzel IH.l 1« 6.1 5.2 7.0 4.4 39.0 6.0 8.0 8 5 4.2 Turnips . . 14.0 H)9 6.0 2.9 10.9 4.3 3:1.7 4.1 6.4 1 2 5.5 Piitato tops . Il.O 2.2 10.8 1.6 2.3 1.8 44.5 traces 13.0 5.2 7.6 Wheat. . . 0.0 1 0 4/.0 traces 2..9 15.9 2!t.5 traces 1.3 0.0 2.4 Wheat-straw 0.0 1 0 3.1 0,6 8 5 5.0 9^^ 0,3 67.6 10 3.7 (MU . . . 1.7 10 14.9 0.5 3.7 7.7 12.9 0.0 5:^.3 13 3.0 0;it.straw ■A.2 41 3.0 4.7 8.3 2.8 24.5 4.4 40.0 2.1 2.9 f'lover . . 2.1.0 2. ,5 b.3 2.6 24.6 6.3 26.6 0.5 5.3 0.3 0.0 2.3 1.1 I'CJIS . . . 0.,T 4.7 3,).l 1.1 10.1 11.9 33.3 2.5 1.5 traces French beans ■.u 1.3 26.8 0.1 5.8 11.5 49.1 0.0 1.0 • rures Horse beans . 1.0 u 'H.2 0.7 5.1 8.6 45.2 0.0 0.5 Inices 3.1 1 1 If these analytical results be now applied to the produce of an acre of ground, we should have the precise quantities of minera. substances abstracted from the soil by each of the several crops tha enter into the rotation. Here they are in a table : MINERAL SUBSTANCES TAKEN UP FRO.M THE SOIL BY THE VARIOUS CROPS GROWN AT BECHELBRONN UPON ONE ACRE. Acids. !i . ^ t i .£ i . .- * Crop. 1 1 il 1 5 1 ^ 4 1 Silica Oxide of ulumn &.C. Ihs. \i» Iba. lbs. lbs. ll-s lbs. Ihs Ih* lb*. ibc NitaUies 2828 4.0 113 ♦ 13 8 3 8 6 58 6 17, 3eet-roots .... 29UH 6.3 183 11 3 9 13 8 83 15 4) Jalfcrop of turnips, ) consumed otT the} (Jjti 7.6 50 3 5 U 5 2 19 3 0.7 ground. S Potato U>ps .... 5042 1 6.0 303 33 7 4 • 6 133 39 16 Wheat . . , 10.2 I 2.4 £ 12 03 8 7 0.4 ... 1 Wheat-straw 2»8 i 7.0 179 5 1.5 1 1 9 17 131 1* Oats . , . 975 ; 4.0 39 6 0.4 0.2 lb 3 5 21 0.6 Oat.straw . 1176 l5.1 60 U 2 5 3 5 !>» 17 M 1 Clover . . 3693 j7.7 284 18 7 7 70 15 0.9 Mannrt-d \teni 915 3.1 28 1.3 0.3 3 3 10 0.5' truces. French beans 1448 3.5 51 13 0,7 0.1 3 g a-. 0.6 traces. Ilurse beans 1944 3.0 58 20 0.75 0.5 3 ^ 26 0.3 trucet. 1 INORGANIC ELEMENTS OF MANURES AND CROPS. 367 On looking at this table we perceive that a medium crop of wheat takes from one acre of ground about 12 lbs., and a crop of beans about 20 lbs. of phosphoric acid ; a crop of beet lakes 11 lbs. of the same acid, and further, a very large quantity of potash and soda. It is obvious that such a process tends continually to exhaust arable land of the mineral substances useful to vegetation which it con- tains , and that a term must come when, without supplies of such mineral matters, the land would become unproductive from their ab straction. In bottoms of great fertility, such as those that are brought under tillage amidst the virgin forests of the New World at the pres- ent day, it may be imagined that any exhaustion of saline matters will remain unperceived for a long succession of years ; for a suc- cession of ages almost. And in South America, where the usual preliminary to cultivation is to burn the forest that stands on the ground, by which the saline and earthy constituents of millions of cubic feet of timber are added to the quantities that were already contained in the soil, I have already had occasion to speak of the ample returns which the husbandman receives for very small pains.* Under circumstances, in the neighborhood of large and populous towns, for instance, where the interest of the farmer and market- gardener is to send the largest possible quantity of produce to mar- ket, consuming the least possible quantity on the spot, the want of saline principles in the soil would very soon be felt, were it not that for every wagon-load of greens and carrots, fruit and potatoes, corn and straw, that finds its way into the city, a wagon-load of dung, containing each and every one of the principles locked up in the several crops, is returned to the land, and proves enough, and often more than enough, to replace all that has been carried away from it. The same principle holds good in regard to inorganic matters, which we have already established with reference to organic substances. The most interesting case for consideration is that of an isolated farming establishment — a rural domain, so situated that it can obtain nothing from without, but exporting a certain proportion of its pro- duce every year, has still to depend on itself for all it requires in the shape of manure. I have already shown, with sufficient clearness, I apprehend, how it is that lands in cultivation derive from the at- mosphere the azotized principles necessary to replace the azotized products ff the farm, Avhich are continually carried away in the shape of grain, cattle, &c. I have now to show how the various saline substances, the alkalies, the phosphates, &c., which are also exported incessantly, are replaced. I believe that I shall be able, with the assistance of chemical analysis, to throw light on one of the most interesting points in the nature and history of cropping, and succeed in practically illustrating the theory of rotations. In what is to follow immediately, I shall always reason on the practical data collected at Bechelbronn, and which have already served for the * The first breaks of the early English settlers in North America are now either very indifferent soils, or they have only been restored to some portion of their original fer- tility by manuring ; so that the supply of fertilizing elements is not ineirfiaustible — Eno Ed 368 INORGANIC ELEMENTS OF MANURES AND CROPS. illustration of other particulars. My farm, I may say, by way of preliminary, is an ordinary establishment ; the lands which have been brought by a system of rational treatment to a very satisfactory state of fertility, are not rich at bottom and originally, and they fall off rapidly if they have not the dose of manure at regular intervals, which is requisite to maintain them in their state of productiveness. My first business was to determine the nature and the quantity of the mineral substances contained in my manure ; and with a view to arrive at this information, I burned considerable quantities of dung at different periods of the year, mixed the ashes of the several in cinerations, and from the mixture took a sample for ultimate analysis The mean results are represented by : (Carbonic 2.0 Acids -^ Phosphoric 3.0 (Sulphuric 1.9 Chlorine 0.6 Silica, sand 6G.4 Lime 8.6 Magnesia 3.6 Oxide of iron, alumina 6.1 Potash and soda 7.8 100.0 But our farm-yard dung is not the only article we are in the habit of giving to our land ; it further receives a good dose of peat-ashes and gypsum. I here recall to the reader's mind that the mean com- position of prat-ashes is this : Silica 65.5 .Alumina 16.2 Lime 6.0 Magnesia 0.6 Oxide of iron 3.7 Potash and soda 2.3 Sulphuric acid. 5.4 tnilorine 03 100.0 In the system lul lowed at Bcchclbronn, the farm-yard dung laid upon an acre contains '2(\ cwts 3 qrs. of ashes. On our clover leas we spread the fir.sl year 7 cubic feet of turf-ashes ; and in the begin- ning of spring of the second year, we lay on as much more, say 14 cubic feet, in nil weighing about 2 tons. I do not take the 8 cwts. of gypsum wliicli, in conformity with usage, the second year's clover generally receives, because 1 believe this addition to be perfectly useless after the very sufficient dose of peat-ash which we employ. The whole of the mineral substances given to the land in the course of five years per acre is as follows, viz. : Ashes contained in the manure and in the peal-ashes, 7()'3 1 lbs.; consisting of phos- phoric acid DO Ih.s., 8iil|iluiric acid 'M)l \hs , cldoiine 4.5 lbs., limt* 532.5 lbs., magnesia 135. (j lbs., potash and siula 339 lbs., silica aii'l sand 4030 lbs., oxide of iron, &c., 353 lbs. It is therefore easy to perceive, from the preceding data, tliat what with the manure ami the ashes it receives, the land is more than suj)plied with all \ho minenil sub.slances re<|iiire«l bv the sev- eral crops it produces in the course of ifie rotatmn. Lti us cast '^ I^tORGANIC ELEMENTS O. MANURES AND CROPS. 309 glance over these with reference to their mineral or inorganic con- stituents, as we have already clone in so tar as the organic matters are concerned ; let us compare, in a word, the quantity and the na- ture of the mineral substances removed m tiie course of five succes- sive years, in contrast .with the quantity and the nature of the same substances supplied at the commencement of the series, and we shall find that the sums of the phosphoric acid, sulphuric acid, and chlo- rine, and of the alkaline and earthy bases of the crops, are always smaller than the quantities of the same substances which exist in and are supplied to the arable soil. I shall institute the comparison with the rotation No. 1, which begins with potatoes; and further, with a continuous crop which, as the one that is most common and convenient, shall be Jerusalem artichokes. I have not thought it advisable to discuss the rotation No. 2, in which beet replaces the potato, because the ashes of these two crops are so much alike, that it may be assumed to be matter of indifference which of the two enters as the drill-crop element into the series. With reference to the Jerusalem artichoke, I shall only remind the reader that the piece of land where it grows receives a dose of manure every two years, in the proportion of 41245 lbs. per acre, which manure contains 27TG lbs. of mineral constituent. Fur- ther, in the course of each winter peat-ashes, in the ratio of 2700 lbs. per acre, are laid on the land ; and that the stems are generally in- cinerated on the spot, and the ashes they contain returned directly to the soil. TABLE OF THE MINERAL MATTERS OF THE CROPS AND MANURES IN THE COURSE OF A ROTATION. Average crop per acre. S^ . L=| = g'phos- 1 Sul- phoricjPhuric ROTATION NO. I. Potatoes 2(1 and 4th years : wheat . Ditto ■ wheat-siraw • •• 3d year: clover 5th year : oats Ditto ■ oat-straw 2d crop turnips ; half crop. Sum of mineral substances Mineral substances of the manure Excess over the mineral matters of the crops INCESSANT PRODUCTION OF THE JE RUSALEM POTATO. Jst and 2d years : mineral matters cf the tubers Mineral matters of dung Ditto of turf ashes Whole mineral matters of manures Difference in favor of the manures lbs. 113 .50 358 284 39 927 7582 2777 4583 lbs. 13 24 11 18 6 IS 3 76S 90 83 lbs. lbs. 3 27 304 13 53 248 301 31 15 287 120.5 lbs. lbs. 2 6 1 8 30 18 70 18 1 3 5 1^ 5 2 14 500 117 yi Ibs.j lbs. 58 6 15 I 31 I 242 77 j 15 5 20 17 24 19 3 310 339 5049 114 |473G 79 1843 3002 4845 47671 370 INORGANIC ELEMENTS OF MANURES AND CROPS. It was at one time asserted, that in order to ensure to a crop of wheat the necessary quantity of phosphates, its cultivation was pre- ceded by one of roots or tubers, or leguminous plants, which were supposed to contain a much less proportion of these salts. By ref- erence, however, to the table of mineral substances, removed from the soil by different crops, the absurdity of such reasoning becomes evident. For example, beans and haricots take 20 and 13.7 lbs. of phosphoric acid from every acre of land ; potatoes and beet-root from the same surface take but 11 and 12.8 lbs. of that acid, exactly what is found in a crop of wheat. Trefoil is equally rich in phos- phates with the sheaves of corn which have gone before it, and this large dose of phosphoric acid whhdrawn from the soil, will nowise diminish the amount which will enter into the wheat that will by and by succeed the artificial meadow. It may be readily under- stood, that if the ground contains more than the quantity of mineral substances necessary for the total series of crops in a rotation, it is a matter of indifference whether the crops draw upon the soil in any particular order, and these succeed according to rules generally adopted for quite different reasons. It suUs well, for instance, to begin a rotation with a drill crop sown in spring, and which, conse- quently, follows in our system the oats which closed the preceding rotation ; it is a great advantage to be able to collect and cart out the manure during winter. Besides, the order is quite at the farm- er's discretion, and there are places where, from particular reasons, quite another course is pursued. One part of the produce returns, as has been shown, to manure, after having served as fodder for the animals belonging to tiie farm. The inorganic matters are restored to the eartii from which they came, deducting the fraction assimi- lated in the bodies of the cattle. Lastly, the whole of the wheat, and a certain amount of flesh will be exported, and with these a no- table quantity of inorganic matter. Thus, in the above described rotation of live years, the minimum exportation of saline substances which must be removed from every acre of land, may be represent- ed by 27\ lbs. of phosphoric acid, and from 30 to 45 lbs. of alkali ; this is just so much lo.st for the manure, and as there is definitively found at the end of tlie rotation a quantity of manure equal and nearly similar to that disposed of at the commencement, it is essen- tial that the loss of mineral substance be made up from without, unless it be naturally contained in tiie soil. In my first researches on the rotation of crops,* I stated that wherever there are exportable products, it becomes indispensable to keep a large proportion of meadow land, quoting, as an extreme case, the triennial rotation with manured sununer-fallow. It is, in fact, the meadow which restores to the arable land the principles which have been carried off. This point, advanced upon analogy, is amply confirmed by the results of analysis. 1 have examined, in reference to this question, the ashes of the hay of our meadows of Durrcnbach, irrigaleil by tiie Saner. The • Memoir couiniuiiicatrd to the Acaiii-iiilc des .^rience.", in 183d INORGANIC ELEMENTS OF MANURES AND CROPS. 371 analyse were made with ashes furnished by the crops of 1841 and 1842. I. II. III. Average (Carbonic 9.0 5.5 " 73 Acids < Phosphoric 5.3 5.3 5.5 5.4 (Sulphuric 2.4 2.9 " 2.7 Chlorine 2.3 2.8 " 2.6 Lime 20.4 15.4 " 17.9 Magnesia 6.0 8.3 " 7.2 Potash I6.I 27.3 " 21.7 Soda 1.2 2.3 " 1.8 Silica 33.7 29.2 " 31.5 Oxide of iron, &c. 1.5 0.6 0.5 0.9 Loss-. 2.1 0.4 " 1.0 100.0 100.0 100.0 No. 1 yielded 6.0 per cent, of ash. No. 2 " 6.2 idem. In admitting as the average yearly return of our irrigated mead- ows, 3666 lbs. of hay and after-grass for the acre, it appears thai we obtain, from a corresponding surface of land, 223.6 lbs. of ash, containing : C Carbonic 16.3 Acids < Phosphoric 12.1 (Sulphuric 6.0 Chlorine 5.7 Lime 39.1 Magnesia 16.1 Potash and soda 52.0 Silica 70.4 Oxide of iron, and loss 4.2 221.9* In reckoning, as I have done, the lowest annual exportation of mineral substance from one acre of arable land at 5.5 lbs. of phos- phoric acid and 8.2 lbs. of alkali, (potash and soda,) there must, in order to make up for loss, arrive each year at the farm a quantity of hay corresponding to about 1800 lbs. for every acre of ploughed land, which would establish between the arable and meadow land, a relation somewhat less than 1 to |. In practice, the relation in question is sensibly less than that de- duced from analysis ; in some farms the meadow-land only occupies a fourth or fifth of the w^hole surface. When rye replaces wheat, the extent in meadow-land may be still more limited. It deserves notice, that I have supposed the arable land as destitute of proper inorganic matter, and that all came from the manure ashes and lime laid on, which is not rigorously true. There are soils containing traces of phosphates, and it is difficult to find clay or marl exempt from potash. Nevertheless, many clear-headed practical men begin to suspect that meadow has been too much sacrificed to arable land. In localities placed in similar conditions to those in which we are, removed from every source of organic manures, which, as I have shown in concert with M. Payen, are always furnished with saline * The sum is only too small here from the number of places of decimals not having "been carried out far enough. — Eno. Ed. 372 INORGANIC ELEMENTS OF MANURES AND CROPS. principles, an attempt has been made to imitate what is done in more favored districts, where it is possible, for example, to add animal remains to the manure. The corn crops felt this new procedure ; nor could it be otherwise. But now there is a reaction in the op- posite sense, and I could name most thriving establishments, where one-half of the farm is in meadow. The ever-increasing demand for butcher-meat will further this movement to the great advantage of the soil. In consequence of our peculiar position at Bechelbronn^ nearly halt jur land is meadow, which allows of a large exportation of the prodjce of the arable land. In applying the results of the preceding analyses, I find that each year, provided there is no los? the hay ought to bring at least : 1254 lbs. of phosphoric acid, 627 ' ' sulphuric acid, 602 ^ ' chlorine, 4155 * ' lime, 1672 ' ' magnesia. 5456 ' ' potash and s>oda. 7312 ' ' silica. This large amount of mineral substances is supplied by the mead ows, which have no other manure tiian the water and mud thereby deposited, after flowing over the A'osges* freestone ; they receive no manure from the farm, but are merely earthed with the sludge and mire i)orne down by tlie stream ; these are real sources of saline impregnation. Meadows without running water ougiit not to be ranged in the same category, they only give the principles naturally contained in them ; hence, they must be always manured every three or four years, and indeed, if not situate upon a naturally rich soil, are, according to my experience, very far from profitable. The excess of mineral matters introduced into the ground over those that issue with the crops, an excess that ought always to be secured by judicious management, enriches the soil in saline and alkaline principles, whii-h accumulate in the lapse of years, just as vegetable remains and azotized organic principles accijnuilate un- der a good system (»f rotation. By tliis, even in localities the most disadvautageously situate for the })urrhasc of manure, temporary recurrence may be had to the introduction of such crops as liax, rape, <^'c., which being almost wholly exported, leave little organic residuum in the earth, and at the same time carry off a considerable quantity of mineral substance ; circumstances which determine, as may be easily conceived, the maximum of exhaustion, and for that reason i?nd to reduce a soil becoming over- rich to what may be called tbe standard fertility. In reviewing tbe chief points examined it will be seen, that as far as regards organic matter, the systems of culture which in borrow- ing most froui tbe atmosphere, leave the most abundant residues in the land, are tho.'^e that constitute the most productive rotations. In respect to inorganic matter, the rotation, to be advantageous, to have an enduring success, oupbt to be so manajjed tha{ the crops ex- INORGANIC ELEMENTS OF MANURES AND CROPS. 373 ported should not leave the dung-hill with less than that constant quantity of mineral substance which it ought to contain. A crop whicli abstracts from the ground a notable proportion of one of its mineral elements, should not be repeatedly introduced in the course of a rotation, which depends on a given dose of manure, unless by the effect of time mineral element has been accumulated in the land. A clover crop takes up, for example, 77 lbs. of alkali per acre. It the fodder is consumed on the spot, the greater portion of the potash and soda will return to the manure after passing through the cattle, and the land eventually recover nearly the whole of the alkali. It will be quite otherwise if the fodder is taken to market ; and it is to these repeated exportations of the produce of artificial meadows that the failure of trefoil, now observed in soils which have long yielded abundantly* is undoubtedly due. Accordingly, a means has been proposed of restoring to these lands their reproductive power, by applying alkaline manure.* If under such circumstances carbo- nate of soda would act as favorably as carbonate of potash or wood- ashes, the soda salt, in spite of its commercial value, might prove serviceable, and deserves a trial. The lime manures naturally promote the growth of plants of which calcareous salts form a constituent ; but here a capital distinc- tion must be made. A soil may contain from 15 to 20 in the 100 of lime, and still be unable to dispense with calcareous manure ; be- cause the lime is in some other state than as it exists in chalk, as in the rubbish of pyroxene, mica, serpentine, and the like. A soil of this kind, although replete with lime, might still require gypsum for artificial meadow, and chalk for wheat and oats. It is from the carbonate that plants of rapid growth derive the lime essential to them, as was established by the researches of Rigaud de Lille, re- searches which have been censured by agricultural writers to whom they were unintelligible. I advocate the opinion of Rigaud, be- cause in the Andes of Riobamba I have seen lucern growing in au- gitic rubbish, very rich in calcareous matter, and yet greatly bene- fited by liming. The operation of gypsum is to introduce calcareous matter into plants. This I have endeavored to demonstrate from the analysis of the ash on the one hand, and on the other, from the consideration that finely divided carbonate of lime, as it exists in wood-ashes, acts with equal efficacy upon artificial meadows. By what means gyp- sum, if it does not enter the vegetable as a sulphate, parts with its sulphuric acid, is at present conjectural. It appears highly proba- ble that calcareous matter is chiefly beneficial from the particular action it exercises on the fixed ammoniacal salts of the manure, transforming these successively, slowly, and as they may be wanted, into carbonate of ammonia. In the most favorable condition, the earth is only moist, not soaked with water, but permeable to the air. New researches will perhaps illustrate the utility of ammoniacal va- pors thus developed in a confined atmosphere, where the roots are * Information communicated by M. Schattenmann. 32 374 INORGANIC ELEMENTS OF MANURES AND CROPS, in operation. At least, it would be difficult to assign any other office to chalk in the marling or liming of land intended for corn, when we know how little lime corn absorbs. If, indeed, gypsum promotes the vegetation of trefoil, lucerne, sainfoin, &c., by furnishing the needful calcareous element, it could not fail to exercise an equally favorable agency upon wheat and oats, did they require it. The ex- periments adduced prove it not to be so, and their results are in some measure corroborated by analysis. Thus, if we compare the different quantities of lime withdrawn from the soil by trefoil arul corn, we find them as follows : The clover crop takes from 1 acre of ground nearly 70 lbs. of lime. Wheat " " " 16 Oat " " '• 6.4 With this comparison before us, it seems evident that if the marl- ing and liming of corn lands had no other object than the introduc- tion of the minute portion of lime which is encountered in the crops, it would be difficult to justify the enormous expenditure of calcare- ous carbonate which is proved by daily experience to be advan- tageous. It may be inferred from the foregoing, that in the most frequent case, namely, that of arable lands not sufficiently rich to do without manure, there can be no continuous cultivation without annexation of meadow ; in a word, one part of the farm must yield crops with- out consuming manure, so as to replace the alkaline and earthy salts that are constantly withdrawn by successive harvests from another part. Lands enriched by rivers alone permit of a total and contin- ued export of their produce without exhaustion. Such are the fields fertilized by the inundations of the Nile ; and it is difficult to form an idea of the prodigious quantities of phosphoric acid, magnesia, and potash, which in a succession of ages have passed out of Egypt with her incessant exports of corn Irrigation is, without doubt, the most economical and efficient means of increasing the fertility of the soil, out of the abundant for- age which it produces, and the resulting manure. Plants take up and concentrate in their organs the mineral and organic elements contained in the water, sometimes in projiortions so minute as to es- cape analysis ; just as they absorb and coiuletise, in modified forms, the aeriform principles which constitute but some 10,000th parts in the composition of the atmosphere. It is thus that vegetables col- lect and organize the elements which are dissolved in water, and disseminated through the earth and the air, as a preparative to their being assimilated by animals. ORIGIN OF ANIMAL PRINCIPLES. 375 CHAPTER VIII. OF THE FEEDING OF THE ANIMALS BELONGING TO A FARM ; AND OF THE IMMEDIATE PRINCIPLES OF ANIMAL ORIGIN. ^ 1. ORIGIN OF ANIMAL PRINCIPLES. It is now generally admitted that the food of animals must ne- cessarily contain azote ; and this circumstance has led to the infer- ence, that the herbivorous tribes obtain from their food the azote which enters into the constitution of their bodies. In a general way, the individual consuming a certain portion of food every day, nevertheless does not increase in his average weight. This is what occurs with animals upon the quantity of food which is known to be sufficient for their keep ; and it has been found that the human subject, living very regularly, returns at a cer- tain hour, or at certain hours of the day, to a certain mean weight. Grooms, farm servants, &c.. are perfectly well aware of the fact, that with a certain allowance of hay and corn, a horse will be kept in the condition necessary to do the work required of him without either gaining or losing in flesh. Under such circumstances, the whole of the elementary matter contained in the food consumed, ought to be found in the dejections, the excretions, and the products of the act of respiration. And as- suming that this is so, it might then be maintained that none of the elements is assimilated, assimilation being taken in the sense of an addition of principles introduced with the food to the principles al- ready present in the body. Yet is there unquesti(jnably assimila- tion, in the sense that the alimentary matters of the food become fixed in the system, having there undergone modification or change ; and that they replace, or come instead of other elements of the same kind, which are daily thrown off by tiie vital acts of the economy. During the nutrition of a young animal, and also in the process of fattening an adult, things go on differently ; here there is unques- tionably definitive fixation of a portion of the matter contained in the food : there is no longer balance between the waste and the supply ; an animal then increases in weight notably and rapidly. Looking at the question of feeding in the most general way, then, I admit that an adult animal, upon the daily allowance, voids a quantity of matter in its various excretions precisely equal to the quantity which it receives in its food :* all the elements, the same in nature and in quantity, which are contained in the food, are also contained in the excrements, vapors, and gases, which pass off from the living body ; carbon and azote, hydrogen and oxygen, phospho. * Boussingault, Annates do Chiniie, 2e s^rie, t. Ixxxi, j). 113» 376 ORIGIN OF ArvI3IAL PRINCIPLES. rus, sulphur, and chlorine, calcium, magnesium, srdium, potassium and iron, as they are all encountered in the food ■ j are they all en countered in the body, and also in the excretions cfan animal ; ano it seems certain, that no one of these primary or simple substance* can be wanting in the nutriment without the body very speedih feeling the ill effects of its absence. Iron, for example, is a con stant principle in the coloring matter of the blood ; it also exists ii large quantity in the hair ; and he who should live on food that con tained no trace of it would certainly, and before long, become disor dered in his health. In what has just been said, I take it for granted that animals dc not absorb or assimilate any of the azote which forms so large a constituent in the air they breathe ; and I am warranted in this by the researches of every physiologist of any name or distinction. Not only do animals obtain no azote from the atmosphere, but they actu ally exhale it incessantly, as was proved by M. Despretz in the course of his numerous experiments, and as I myself also demon- strated in the inquiries I undertook to ascertain whether herbivorous animals obtained azote from the air or not. The azote exhaled, il was discovered, proceeded entirely from the food consumed by the animal ; a fact which, already of great importance in a physiologi- cal point of view and in reference to general physics, bears at the same time so immediately upon one of the most important questions of agriculture, that I think it well to give the particulars of one of the procedures by which it has been established. The experiments in this case were performed on a milch-cow and a full-grown horse, which were placed in stalls so contrived that the droppings and the urine could be collected without loss. Before being made the subjects of experiment, the animals were bal- lasted or fed for a month with the same ration that was furnished to them during the three days and three nights which they passed in the experimental stalls. During the month, the weight of the ani- mals did not vary sensibly, a circumstance wiiich happily enables us to assume that neither did the weight vary during the seventy-two hours when they were under especial observation. The cow was foddered with after-math hay and potatoes ; the horse with the same hay and oats. The cjuantities of tbrage were accurately weighed, and their precise degree of moistness and their composition were determined from average samples. The water drunk was measured, its saline and earthy constituents having been previously ascertained. The excrcmentitious matters passed were of course collected with the greatest care ; the excrements, the urine, and the milk were weighed, and the constituti(ui i)f the whole estimated from elementary analyses of average specimens of each The results of the two experini' its are given in this tublc : ELEMENTS OF FOOD AND OF EXCRETIONS. 377 FOOD CONSUMED BY THE HORSE IN 24 HOURS. | Weight in llie wet stale. Weight in Hie dry slate. Elem.nlary niatler in the food. ] Forage- Carbon. 'Hydrogen. Oxygen. Azote. Sails and earlhs. Hny, . - - Oiits, Water, - . Total, . . Ills. 20 lbs. or. 17 4 5 2 lbs. oi. 7 11 2 7 lb. oz.dwi. 0 10 7 0 3 18 lb. oz.dwi. lb. ox. dwt. 6 8 8 0 3 2 1 10 14 1 0 1 7 1 . . Ii. oz.dwi. 1 6 14 0 2 10 0 0 8 69 22 6 10 6ll2 5l87 2|04 9| 1 9 12 PRODUCTS VOIDED BY THE HORSE IN 24 HOURS. Products. Wei-ht in the wet state. Weight in tlie dry stale. Elementary matter in the products. Carbon. Hydrogen. Oxygen. 1 earths. Urine, - - Excrements, - Total. - . Total matter of } the food, - 5 Difference, Ih. oz. dwt. J 1 '1 lb. oz. dwt. 0 9 14 9 5 6 lb oz.dwi. 0 3 10 3 7 17 lb. oz.dwt. 0 0 7 0 5 15 lb. oz.dwt. 0 1 2 3 6 14 Ib.oz. dwt.lb.oz. dwt. 0 1 4 1 0 3 10 0 2 10 1 1 6 10 41 8 17 69 0 0 10 3 0 22 6 0 3 11 7 10 6 0 0 6 2 1 2 5 3 7 16 8 7 2 0 3 14 0 4 9 1 10 0 1 9 12 27 3 3 12 3 0 6 6 13 0 8 3 4 11 6 0 0 15 1 0 0 8 WATER CONSUMED BY THE HORSE IN 24 HOURS. WATER VOIDED BY THE HORSE IN 24 HOURS. W^ith the hay, .... With the oats, . . - . Taken as drink, .... Total consumed. lbs. oz. 2 3 0 14 35 3 With the urine, .... With the excrements. Total voided, Water consumed. lbs. oz. 2 6 23 8 38 4 25 14 38 4 Water exhaled by pulmonary and cutaneous transpiration, 12 6 FOOD CONSUMED BY THE COAV IN 24 HOURS. Fodder. Weight in the wet stale. Weight in the dry state. Elementary matter of the food. Carbon. 1 Hydrogen. Oxygen. | Azote. 1 Salts and earths. Potatoes, - Atler.raath hay. Water. - . Total. . - lb. oz. dwt. 40 2 5 20 1 2 lt» 0 0 lb. oz. dwt. 11 2 1 16 11 S lb. oz. dwt. 4 11 2 7 11 11 lb. oz. dwt. 0 7 15 Oil 7 lb. oz.dwt. lb. oz. dwt. 4 10 17 1 0 1 12 5 10 17 0 4 17 b. oz.dwt. 0 6 13 1 8 6 0 1 12 220 3 7 28 1 1 12 10 13 1 7 2 10 9 14 1 0 6 9 2 4 11 PRODUCTS VOIDED BY THE COW IN 24 HOURS. Product*. Weight in the wet state. Weight in the dry state. Elementary matter in the products. Carbon. [Hydrogen. Oxygen. Azote. Salts and earths. Excrements, . Si!- .--• "^matter of food. Difference, lb. oz. dwt. 76 1 9 21 11 12 22 10 10 lb. oz.dwi. 10 8 12 2 6 17 3 1 0 lb. oz.dwi. 4 7 0 0 8 7 1 8 3 lb. oz. dwt. 0 6 13 0 0 16 0 3 3 lb. oz.dwi. 4 0 9 0 8 3 0 10 G lb. oz. dwt. 0 2 19 0 1 3 0 1 9 b. oz.dwt. 1 3 8 1 0 6 0 1 16 120 11 11 220 3 7 16 4. 9 28 1 1 6 11 10 12 10 13 0 10 12 1 7 2 5 6 18 10 9 14 0 5 11 0 6 9 2 5 10 2 4 11 99 3 16 111 8 12 ' 5 11 3 0 8 10 5 2 16 0 0 18 0 0 19 WATER CONSUMED BY THE COW IN 24 HOURS. WATER VOIDED BY THE COW IN 24 HOURS. With the potatoes. With the hay, .... Taken as drink. . . . - T# *.al consumed. lbs. oz. 23 12 132 b With the potatoes. With the urine, .... With the milk. Total voided Water consume'^, .... lbs. oz. 53 10 15 14 16 3 158 5 85 11 158 5 Water passed off \ )y pulmon iry and cu taneou stra nspiration . - . 72 10 373 COMBUSTION OF CARBON. From these sums it appears that the azote of the excrements is less by from 339.6 to 455.0 grains than that of the forage consumed. It appears also that the whole q. antity of elementary matter con- tained in the excrements is less than that which had been taken as food ; the difference is of course due to the quantities which were lost by respiration and the cutaneous exhalation. The oxygen and hydrogen that are- not accounted for in the sum of the products have not disappeared in the precise, proportions re- quisite to form water ; the excess of hydrogen amounts to as many as from 13 to 15 dwts. It is probable that this hydrogen of the food became changed into water by combining during respiration with the oxygen of the air. The loss of carbon, which is very considerable, seeing that in the two experiments it asiounts to nearly 12^ lbs., must have gone to form the carbonic acid, which is known to be so large and import- ant a constituent in the expired air, and which is also exhaled iVorn the general surface of the body. Neglecting the latter, it appears that each of the animals produced in the course of twenty-four hours upwards of 13 cubic feet of carbonic acid gas, the thermome- ter supposed at 32*^ F., the barometer at 30 inches.* During respiration, then, or as a consequence of respiration, the carbon and hydrogen of the food have disappeared and given rise, by the concurrence of the oxygen of the air, to carbonic acid and water, precisely as if they had been burned. And an animal may, in fact, be regarded as an apparatus or system, in wliich a slow com- bustion is incessantly going on ; there is perpetual disengagement of carbonic acid gas and of the vapor of water, just as there is from a stove in which any organic substance, wood, for example, is burn- ing. In either case there is evolution of heat ; all animals have a temperature above that of the medium which surrounds them, and the excess of the elevation is in some sort relative to the activity of the respiratory process, or, in other words, to the intensity of the combustion. Under the influence of the oxygen that is taken into the body, the soluble principles of the blood pass through a series of modifications, the last of which is carbonic acid, which is exhaled and dissipated in the air ; and it is in this way that a portion of the carbon of the food is returned to the atmosphere, after having accomplished the important function of supplying the animal with the heal that is ne- cessary to its existence. Far from deriving any thing from the air, consequently, animals, on the contrary, are continually pouring car- bon into it. The tbod is, therefore, the only source whence animals derive the matter that enters into their constitution ; and, as the primary food of animals is obtained from vegetables, herbivorous creatures must necessarily find in the plants they consume all the • The large qimntity of carbonic acid shows the necessity for laree and well-venti- lated stable-* iiiul cow-houses. A cow, i' appears, will vitiate 66 cubic feet of air In a day. It will b ' observed in the tJible tliat the saline and earthy nmttcrs of thd ejecta exceed those of the ingesta in both instances. This is from error in observa tion, and is owing to the difficulty of dUermining exactly the quantities of these sub stances. I'he error is less in the case f the horse than .n that of the cow. IDENTITY OF ANIMAL AND VEGETABLE PRINCIPLES. 37.0 elements they assimilate. It might be expected from this, that the material constitution of animals should approach, and sometimes ever. be identical vvitii that of vegetables ; and it is found, in fact, that a considerable number of ternary or quarternary organic compounds, of either kingdom, present the greatest analogy to one another ; their identity, iti some cases, is even complete. Some fatty substances of animal origin do not differ in any way from vegetable fats ; the margaric acid which is obtained from hog's lard has the precise characters of the mavgaric acid which is furnished by olive oil, and the same identity is preserved through the entire series of quarter- nary azotized principles, as a glance at the following^ table, which contains the results of the analyses performed by Messrs Dumas and Cahours, will show. FIBRINE. ALBUMKN. CASEINE. AniraaL Vegetable. Animal. Vegetable. Animal Vegetable. 52.8 7.0 23.7 16.5 53.2 7.0 23.4 16.4 53.5 7.1 23.6 15.8 , 53.7 7.1 23.5 15.7 53.5 7.0 23.7 15.8 53.5 7.1 23.4 16.0 Hydrogen Azote 100.0 100.0 100.0 100.0 100.0 100.0 These principles, to which must be added gelatine, the fats and several earthy and alkaline salts, constitute the frame-work of the animal tissues, or the fluids which penetrate them ; it is therefore necessary for us to examine each of them shortly. Gelatine is met with in almost all the solid parts, in the bones, tendons, cartilages, skin, cellular tissue, muscular flesh — all contain it. It is readily soluble in boiling water ; cold water only takes up a small quantity of it. Two or three parts of gelatine dissolved in 100 parts of hot water, suffice to turn the fluid into a tremulous jelly when it has become cold. Tannin, or infusion of gall-nuts, precipi- tates gelatine completely from its solution, the precipitate being v^ry bulky and perfectly insoluble in water ; and it is this chemical com- bina ''on or principle which lies at the bottom of the art of tanning. Gelatine is extensively used in the arts, under the familiar name of glue. Isinglass consists of gelatine nearly pure, and, according to Mulder, contains : Carbon. 50.8 Hydrogen. 6.6 Azote 18.3 Oxygen 24.3 100.0 Fihrine occurs in a state of solution in the blood, and forms the principal ingredient in muscular flesh. It is readily obtained by whipping a quantity of blood just taken from the veins of a living animal ; the white stringy masses that adhere to the rod are fibrine, which, by gentle kneading under water, become colorless. Fibrine, 380 ALBUMEN, CASEUM. when moist, is a highly elastic and flexible substance ; dried, it loses about 30 per cent, of water, and becomes brittle, horny, semi-trans- parent. Thrown into water, it gradually imbibes all it had lost by drying, and regains its former properties. Burned and incinerated, fibrine leaves a quantity of ash, which consists, for the major part, of phosphate of lime, with which is mixed a small quantity of phos- phate of magnesia and of oxide of iron. Albumen exists in large quantity dissolved in the water or serum of the blood, and in the white of tbe egg ; it is also found in almost all the animal fluids that are not excretions, or destined to be thrown off as useless to the system. Albumen, as familiarly known, has the remarkable property of coagulating or setting into a soft fluid, at a certain temperature — 158° Y. Caseum, or caseine, is the distinguishing principle of milk. By combining with acids it forms an insoluble compound ; and it under- goes a remarkable coagulation, as all the world knows, in contact with a piece of the inner membrane of the stomach of a young ani- mal : from a fluid it sets into a soft solid, which by degrees separates into two portions — whey and curd. The curd, or caseum, always contains fat, and, when burned, leaves a considerable quantity of ash. Physiologists distinguisl> three principal tissues in the bodies of animals ; the muscular, the nervous, and the cellular. The muscular tissue consists of an assemblage of contractile fibres, here disseminated through the masses of organs, there colh.'cted into bundles and constituting the tlesh. This is the instrument by which animals perform all tlicir voluntary motions, and it is that also by "which all the active but involuntary movements of the body are ex- cited. Muscular flesh is always a compound substance, however ; it consists of fibrine, the contractile or proper elenjent, albuujen, fat, gelatine, an odorous extractive matter, lactic acid, dilTercnt salts and the coloring principle of the blood. Put into cold water, so h)ng as the temperature is below from 130° to 110" F., little etfect is produced beyond the solution of the soluble salts which it may contain, and of a }>ortion of its extractive matter and albumen. At from 175" to 195", the albumen which had been dissolved, coagulates and rises to the top as scum, and the fat melts and floats on the surface. The fil)rinous element of the meat, how- ever, preserves its characters even after the action of boiling water continued for some time. The nervous tissue constitutes the brain, spinal marrow, and nerves, distributed to all parts of the body. Brain in its composition contains a large quantity of water, — 80 percent. — certain fatly mat- ters, albumen, osmazono, phosphorus in combination with fat, sul- phur, and phosphates of potash, lime, and iiKii^nesia. The c»)mposition of the brain of animals, the dog, the sheep, the ox, appears to be very analogous to that of the human subject. Cellular tissue is the general connecting medium throughout the animal body, and is not only met with, it may be said, everywhere, but forms a main element in many of the textures of the body, such BONES, 2L00D. 381 as the serous and mucoi s membranes, the cartilages, the bones themselves, which are in fact only cellular tissue impregnated with calcareous salts. Tendons may be viewed as condensed ropes of cellular tissue ; by long boiling in water they melt entirely into gela- tine. Bones consist of cellular tissue, as stated, resolvable into gelatine, and of a large proportion of saline earthy matter, consisting princi- pally of pliosphate of lime. The {)resence of this phosphate is not extraordinary, inasmuch as wc have found that it forms an element in all the vegetables upon which animals are supported. By boiling bones even reduced to powder under the usual pressure of the atmo- sphere, but a small quantity of their gelatine is obtained ; but by put- ting them into a Papiu's digester, and subjecting them to a consider- ably higher temperature than that of boilmg water, we can dissolve the whole, or nearly the whole of the animal matter, and leave the earthy parts unchanged ; or by proceeding in another way, by soaking bones for a time in dilute muriatic acid, we can dissolve out the earthy matter, and leave the bone, having its original form indeed, but as an elastic, pliant gristle. The relations between the earthy and organic matter of bone, vary with the species, but especially with the age of the animal. In early life the cellular element predominates ; in adult age the salts predominate. We have three analyses of bone, which I shall here present : Man. Ox. Ox. Cartilage susceptible of change into gelatine 33.3 33.3 50.0 Sub-phosphate of lime 53.0 57.4 37.0 Carbonate of lime 11.8 3.9 10.0 Phosphate of magnesia 1.2 2.0 1.2 Soda, and a trace of common salt 1.2 3.4 " 100.0 100.0 98.3 Hair has a very complex composition, no fewer than nine different principles or substances having been detected in its constitution ; among the number, mucus, various oily matters, sulphur, and iron ; wool, fur, and horn, are all similar in their composition to hair. Blood, in all the higher animals, is a sluggish fluid, of a deep red color ; in many of the inferior tribes, however, such as insects, crus- taceans, and shell-fish, it is limpid, a?nd generally colorless. Under the microscope, red blood is seen to consist of two distinct portions, a serum or whey, in which float a multitude of minute, solid, opaque corpuscles — the globules of the blood of physiologists, particles which have different characters in different classes of animals. Blood is a very heterogeneous compound. Left to itself, after being drawn from a vein, it sets or coagulates into a soft gelatinous solid, which by and by begins to separate into two portions, one watery, of a yellowish color, and opalescent, the water, whey, or serum ; another solid, of a deep red or reddish brown color, the clot or coagulum. The watery portion contains a large quantity of albu- men in solution. M. Lecanu, in his analysis of the blood, speaks of as many as twenty-five different substances as entering into its com- position : 882 BLOOD, NILX. Water. 7904 Oxygen, azote, free carbonic acid Iron Hydrochlorates of soda, potash, aramonis Sulphates of potash and of poda Subcarbonate of lime and magnesia Phosphates ot^ soda, lime, and magnesia l 11 0 Lactate of soda A soap, having soda and fixed fat acids fcr its elements An odorous, volatile salt, a fat acid A fatty substance, containing phosphorus Cholesterine Seroline Albumen dissolved in the water 67.8 Globules and fibrine 130.8 1000.C The blood globules consist principally of albumen combined with a little fibrine and red coloring matter. Any difference observed between one sample of blood and another, is connected especially, almost exclusively, with the relative proportions of the liquid part or serum, and the solid part or clot. The solids are in larger propor- tion in males than females, in grown-up persons than in aged indi- viduals and children, in subjects well and abundantly fed than in those indifferently supplied with food. No analysis that has yet been made has thrown any true light on the cause of the difference of color perceived between arterial and venous blood ; nevertheless, it is positively known that it is by the-concurrence of the oxygen of the atmosphere that the arterial blood in the living body acquires the characters which distinguish it, and that carbonic acid gas is evolved or thrown off in the course of the action that takes place. Ox blood, thoroughly dried, has been found to consist of: Carbon 52.0 Hydrogen 75 Azote 15.1 Oxygen 21.3 Ash 4.4 100.0 Milk. This well-known fluid may be said to combine in itself all the organic principles and mineral substances which enter into the constitution of organized beings. Caseum. identical with fibrine and albumen, fatty matters, sugar of milk, and different salts, among the number of which the phosphates staid distinguished. The ciseum, the sugar, and a port on of the salts, are in solution ; the fatty matters are held in susper sion in the milk in the form of globules. The following table will b^ found useful, as giving a com- prehensi e survey of the compositioi of different kinds of milk. MILK. 383 ^1 ^ ^ i2 c . Milk. 1 1 1 1 i 1 Remarks. Authors of the analyses Of the cow. . 3.6 4.0 5.0 87.4 12.6 Average of 12 Le Bel and Bous- analyses at Be- singaalt. chelbronn. Of the cow. . 3.8 3.5 6.1 86.6 13.4 Average of 6 an- Qnevenne, alyses in the en-j virons of Paris. | Of the cow. . 4.5 3.1 5.4 87.0 13.0 Idem. Henri and Chev- alier. Of the cow. . 5.6 3.6 4.0 86.8 13.2 Idem. Lecanu. Of the cow. . 5.1 3.0 4.6 87.3 12.7 An analysis, Giessen. Haidlen. Of the ass... 1.7 1.4 6.4 90.5 9.5 Average of 5 an- Ptligot. alyses. j Of woman... 3.1 3.4 4.3 89.2 10.8 Of good qnality. Haidlen. Of woman... 2.7 1.3 3.2 92.8 7.2 Of middling qnal-Haidlen. ity. 1 Cow's milk always shows slight alkaline reaction ; its density is about 1.03. According to M. Haidlen, it contains no salt formed by an organic acid, no lactates, and the alkali is in combination with caseum, the solution of which it assists. It may contain about a half per cent, of ash, the several constituents of which appear to be very stable, though their proportions vary greatly. In 100 parts of milk, taken from two different cows, Haidlen found the following salts : Phosphate of lime 0.231 -0.344 Phosphate of magnesia 0.042 0.064 Phosphate of iron 0.007 0.007 Chloride of potassium 0-144 0.183 Chloride of sodium 0.024 0.034 Soda 0.042 0.045 0.490 0.677 As cow's milk is that which is by far the most directly interesting to agriculture, I shall enter somewhat particularly into its history ; having, however, already spoken of caseum, its distinguishing con- stituent, and albumen, I shall here confine myself to the subject of the sugar and the oil or butter. Sugar of milk is prepared for commercial purposes, in countries or districts vv'here cheese-making is carried on to a great extent, and the quantity of whey at command is very large. In some Can- tons of Switzerland, sugar of milk is obtained by simply evaporating whey properly clarified, to the consistence of sirup, which deposites the sugar in the crystalline form as it cools. This first produce is brown, and contaminated with various impurities, from w^hich it is freed by repeated solutions and crystallizations. It then becomes colorless, transparent, and nearly tasteless, feeling gritty betw^een the teeth, and having only an obscure sweet taste. It requires from 8 to 9 parts of cold water to dissolve it ; in hot water it is more soluble. According to Proust, it consists of: S84 MILK. Carbon 40.0 Hydrogen 6.7 Oxygen • • ..53.3 100.0 Butter. To understand the preparation of batter thoroughly, it is absolutely necessary to know the physical constitution of the milk from which it is obtained. Now the microscope shows us that milk holds in suspension an infinity of globules of different dimen- sions, which, by reason of their less specific gravity, tend to rise to the surface of the liquid in which they float, where they collect, and by and by form a film or layer of a different character from the fluid beneath ; the superficial layer is the cream, and this removed, the subjacent liquid constitutes the skim-milk. This separation ap- pears to take place most completely in a cool temperature from 54' to 60" F. Allowed to stand for a time, which varies with the temperature, milk becomes sour, and by and by separates into three strata or parts : cream, whey, and curd, or coagulated caseum. By suffering the milk to become acid before removing the cream, it has been thought that a larger quantity of this, the most valuable constituent of the milk, was obtained ; and the fact is probably so ; but in dis- tricts where the subject of the dairy has been most carefully stud- ied, it has been found that it is better to cream before the appearance of any signs of acidity have appeared. When a knife can be push- ed through the cream, and withdrawn without any milk appearing, the cream ought to be removed.* Butter is obtained from cream by churning, as all the world knows ; by the agitation, the fatty particles cohere and separate from the watery portion, at first in smaUor and then in larger masses. The remaining fluid is buttermilk, a fluid sHghtly acid, and of a very agreeable flavor, containing the larger portion of the caseous element of the cream coagulated, and also a certain portion of the fatty principle which has not been separated. The globules of milk appear, from the latest microscopical ob- servations,! to be formed essentially of fatty matter, surrounded with a delicate, elastic, transparent pellicle. In the course of the agita- tion or trituration of churning, these delicate pellicles give way, and then the globules of oil or fatty matter are left free to cohere, which they were prevented from doing previously, by the interposition of the delicate film or covering of the several globules. Were thr butter simply .suspended in the state of emulsion in the milk, we should certainly expect that it would separate on the application of heat ; but this it does not : cream or milk may be brought to the boiling point, and even boiled for some time, without a particle of oil appearing. Could jM. Homanct show any of these pellicles, apart from the oil-globules they enclose, it would be very satisfacto- ry, and would certainly enable us to explain the effect of churning Churning is a longer or shorter process, according to a variety of * Thaer, Principes, tc, t. iv. p. 341. t M. Romam;t, MSS. MILK. 385 circumstances ; it succeeds best between 55 and 60" F. So that, in summer, a cool place, and in winter a warm place, is chosen for the operation. There is no absorption of oxygen during the process of churning, as was once supposed ; the operation succeeds perform- ed in vacuo, and with the churn filled with carbonic acid or hydro- gen gas. On being taken out of the churn, the butter is kneaded and press- ed, and even washed under fair water, to free it as much as possible from the buttermilk and curd which it always contains, and to the presence of which must be ascribed the speedy alteration which butter undergoes in warm weather. To preserve fresh butter it is absolutely necessary to melt it, in order to get rid of all moisture, and at the same time to separate the caseous portion. This is the process employed to keep fresh butter in all the warmer countries of the world. In some districts of the continent, it is also had re- course to with the same view. The butter is thrown into a clean cast-iron pot, and fire is applied. By and by the melted mass enters into violent ebullition, w'hich is owing to the disengagement of wa- tery vapor ; it is stiried continually to favor the escape of the steam, and the fire is moderated. When all ebullition has ceased, the fire is withdrawn, and the melted butter is run upon a strainer, by which all the curd is retained. M. Clouet has proposed to clarify butter by melting it at a temperature between 120° and 140^ F., and keep- ing it so long melted as to dissipate the water and secure the depo- sition of the cheesy matter, after which the clear melted butter would be decanted. I doubt whether by this means the water could be sufficiently got rid of, a very important condition in connection with the keeping of butter, though certainly all the caseum would be deposited. The moisture and curd contained in fresh butter may amount to- gether to about 18 per cent. ; at least we find that we lose about 18 lbs. upon every 100 lbs. weight of butter which we melt at Bechel- bronn. The information which we have on the produce in butter and cheese, from different samples of milk, is very discordant, so that I prefer giving the results of a single experiment made under my own eyes. From 100 lbs. weight of milk, we obtained : Cream 15.60 lbs. White curd cheese 8.93 " Whey 75.47 " 100.00 The 15.60 lbs. of cream yielded by churning: 3.3 lbs. butter, or 21.2 per cent., and 12.27 " buttermilk. The reckoning with reference to 100 lbs. of milk consequently stands thus : Cheese 8.93 Butter 3.33 Buttermilk 12.27 Whey 75.47 100.0 33 386 FOOD AND FEEDING. Taking the whole of the milk cotained and treated at different seasons of the year, I find that 36,000 lbs. of milK yielded 1080 lbs. of fresh butter, which is at the rate of 3 per cent. From the state- ment of M. Baude, it appears that near Geneva a proportion of butter so high as 3 per cent, is never obtained, probably because there a larger proportion of fatty matter is left in the cheese. In the dairy of Cartigny, 2200 gallons of milk gave : Butter 363 lbs. or about 1.6 percent Gruyere cheese 1515 " 6.9 " Clot from the whey, obtained by boilinji 1140 " 5.2 In the same neighborhood, another dairy, that of Lullin, gave from the same quantity of milk : Butter 418 lbs. or 1.9 per cent. Cheese 1485 67.5 Clot from whey 908 4.4 " * OF THE FOOD OF ANIMALS AND FEEDING. The identity, in point of composition and properties, which ap- pears to obtain between certain substances derived from either king- dom of nature, naturally led to the conclusion that animals do not form or originate the substances which enter into their organization, but that they find these ready formed in their food, and merely ap- propriate them ; whence we must conclude, that herbivorous animals assimilate several of the pro.viinate j)rinciples of plants immediately, causing them to undergo but slight modifications, and that the ele- ments of the animal tissues and fluids pre-exist in vegetables, which further contain the earthy phosphate that forms the distinguishing characteristic in bone.t The food of herbivorous animals must, therefore, always contain, and in fact always contains, four essential principles, which, by their combination or reunion, constitute nutritious matter, properly so called : — 1st. An azotized matter, such as albumen, caseine, gluten, substances which are prol)al)ly the original of flesh. 2d. An oily or fatty matter, which approaches more or less closely to fatly bodies in general. 3d. A substance having a ternary composition, sugar, gum, fecula. 4th. Certain salts, particularly phosphates of lime, magnesia, and iron. This mixed constitution, which a forage plant must needs ofl^er, justifies the general ideas propounded by Dr. Prout on nutrition. This al)le chemist has said that milk was to be viewed as the standard food, and that all alimentary matters must resemble it in composition, in greater or less degree : that is to say, besides phosphates, food must contain an azotized principle, a non-azoiized principle, and a fatty body, to stand in lieu of caseum, sugar, and butler. The fundamental principle that animals find the several substances which make up their bodies, ready formed in the substances ihey * In all the (lalr>' counties of England, the nulk is never required, like the ground, to give a doul)le crop ; it yields either Imller or cheese, not both. Hence the greater rich- ness of English rheese in general. — Eno. Ed. t Dumas and Boussingault. The Chemical and Physiological Balance of OrninU Nature, post 8vo. London. Bailliere, 1843. (.\ vor)- useful little work.— Emq. Eo.J FOOD AND FEEDING. 387 consume, seems very well calculated to assist the practical farmer in managing the food of the animals upon his land ; for if flesh, fat, and bone exist all but ready formed in the food, it is obvious that the best kind will be that precisely which, under the same weight, contains the largest quantity of the various matters of the organi- zation. It is by no means easy to ascertain precisely the amount of the azotized constituents, gluten, and albumen, contained in plants ; to do so requires both time and pains. But let it be once admitted that the nutritive properties of forage increase in the precise ratio of these matters, this is clearly as much as to say that the value is in proportion to the quantity of azote contained in the food, and that it becomes a matter of the highest moment to have at hand a ready mode of determining the point. I believe it infinitely better to get at the quantity of azote immediately, which is easily done, than by any roundabout and laborious process to ascertain the amount of albumen and gluten : the quantity of azote ascertained, it is most easy to deduce the quantity of albumen and gluten — in other words, ofjiesh — contained in each particular species of food examined ; for, as a general rule, vegetable food does not contain any other azotized principle. It is true, indeed, that all the azotized principles of vege- table origin cannot be considered as nutritious; some of them, on the contrary, are virulent poisons or active medicines, according to the dose in which they are administered. But these poisonous sub- stances are not met with in appreciable quantity in the plants which are commonly grown for the food either of man or beast. Still, all the truly nutritious articles of food contain an azotized principle. The experiments of M. Magendie have shown, that substances which contain no azote, such as sugar, starch, oil, will not support life ; and, on the other hand, it is ascertained that the quality of alimentary matter, flour for example, increases with the amount of gluten which it contains. It is because the seeds of the leguminous vegetables are richer in azotized principles — that is, in Jlesh — that they are also more highly nutritious than the seeds of the cereals. These several considerations, therefore, induce me to conclude; that the 7iiitritious principles of plants and their products reside in their azotized principles^ and consequently that their nutritious pow- ers are in proportion to the quantity of azote they contain. From what precedes, however, it is obvious that I am far from regarding azotized principles alone as sufficient for the nutrition of animals ; but it is a fact, that every highly azotized vegetable nutritive sub- stance is generally accompanied by the other organic and inorganic substances which concur in nutrition. In seeking to learn the precise quantity of azote contained in a great number of articles used as food for cattle, I have had it in view particularly to find a standard or fixed point for estimating their comparative nutritive properties. It is long since more than one of the most distinguished farmers, both of England and Germany, essayed to resolve this important problem in rural economy. Thus Thaer and many others have given tables of the quantities by weight 38S FOOD AND FEEDING. in which one article of alimentation might be substituted for another These tables are in act tables of equivalents with reference to food. But it is unfortunate that there should be considerable diversity of statement among th nr authors. Yet, even up to the present time, it could not well have been otherwise, and these discrepancies will only surprise those who are unacquainted with the difficulties of the subject. One grand cause of difference probably exists in the de- gree of dryness of the article subjected to experiment. The nature of the soil, a very dry or very rainy season, the climate, &c., must all be regarded as so many causes influencing the quantity of water contained in plants, and in consequence their actual nutritive quali- ties. The only sure mode of proceeding, in short, appears .o be, to reduce the several articles to a state of complete dryness, and to make their quantity in this condition the first element in the reckoning. I may state, that the theoretical data obtained by proceeding in this way have already been approved by practical applications. Hay may be assumed as the most common or universally used of all kinds of fodder : it is in some sort the staple food of the animals that are particularly attached to an agricultural concern, and may therefore be appro{)riately made the standard of comparison tor all other kinds of food or forage. Hay itself, however, varies greatly in point of quality : in assuming it as the standard, I have therefore to state, that meadow hay of good quality is to be understood. The analyses which I have made of this article at different times, satisfy me that in the state in which it is cominonly used, it contains from 1.0 to 1.5 of azote per cent. In choosing a specimen lor analysis, it is, of course, highly necessary that it be an average specimen ; that it consist of equal or rather relative proportions of the several elements which enter into its constitution, such as stalks, leaves, flowers, and seeds. Taking a sample of hay, for instance, weighmg exactly 5 lbs. avoird., I found that it was made up of — Hani woody steins 2.393 IIm. Bottniiis of leaves and verj- fine stems 0.847 Flo\ver.s, leaves, and i\ few seeds 1 .760 5.000 The ultimate analysis of which gave : Of azote jxT cent. 1.19 Military contract hay of 1840 gave of azote per cent 1.21 Hay made in .Alsace in 1F:15 " " 1.04 Hay made in Alsace in 1837 " " 1.15 Average of azote per 100 1.15 Hay, as it is generally used, contains from 11 to 12 per cent, of water, which is got rid of by thorough drying. And as albumen, caseum, and vegetable gluten contain 16 per cent, of azote, we perceive that the azotized matter which is the representative of flesh, in hay may be represented by the number 7.2 per cent. Hay does not, itideed, always contain so much azote ; that which is won from marshy lands o)iitains much less : and again there are samples that contain more. After-math, or second-crop hav, is certainly more nutritious thar first-crop hay, a fact which we have ascertainec FOOD AND FEEDING. 389 repeatedly at Bechelbronn ; but this hay is nevertheless held less suitable for horses, probably because, being made late in the season, it is commonly stacked more or less damp, and suffers change in consequence : After-math hay gave 2.0 per cent, of azote A choice sample 'f the best hay 1.29 " The flower or eai, containing Uttle woody stem 2.1 " These examples suffice to show, that when an animal is to be put upon another kind of food than hay, it is very necessary to take the quality of the latter article, which has been employed, into the ac- count. In the table which I shall immediately present, I have as- sumed good meadow-hay, containing 1.15 of azote and 11 of water per cent, for my standard. The importance of a table of equivalents for forage has long been felt by farmers ; and they who have given their attention to the accumulation of data for its construction, de- serve our best thanks. The use of a table of equivalents is extreme- ly simple : the numbers placed underneath the value of hay in- dicate the weights of the several kinds of forage named in the first column, which may respectively be substituted for 100 parts of hay by weight. Thus, according to Block, 366 lbs. of carrots may be substituted for 100 lbs. of meadow-hay. Pahst holds 60 lbs. of oats to be equivalent to 100 lbs. of hay. If the question be to replace 7.26 or 7| lbs. of oats in the ration of a horse by Jerusalem arti- chokes, we find in the table that 60 of oats are equivalent to 274 Jerusalem potatoes, and we therefore infer that 35.2, say 35| lbs. is the weight of the root to be substituted for that of the oats. Certain information on the nutritive value of the various .articles consumed by cattle as food, is really of high importance in rural economy ; it is obviously the only guide for the feeder in the use or purchase of forage. Let us suppose, for example, that a measure of potatoes (22 gallons) weighing 165 lbs. is worth 10^/. at market, and that hay is worth 25. 6d. the cwt. ; 2 cwts. or rather 220 lbs. would cost 5s. Let us now admit, on theoretical grounds, that this quantity of hay is equivalent to 693 lbs. of potatoes; it plainly ap- pears, on looking at the cost of these equivalents, that there would be a positive advantage in using potatoes, inasmuch as they are worth no more than 3s. 6kd. There would indeed be money to be made by selling hay, and purchasing its equivalent in potatoes. The equivalents which I have deduced from my elementary ana- lyses, agree on many occasions with the conclusions of practical men ; in others, they differ notably from them ; at the same time it must be observed, that the practical equivalents differ from one another in at least an equal degree. We see, for instance, that Schnee and Thaer think 220 lbs. of hay will be replaced by 1465 lbs. of wheat straw, while Flottow gives 429 lbs. as the equivalent number. According to Mayer, 630 lbs. of turnip are equivalent to 220 lbs. of hay, while Middleton gives 1760 as the equivalent num- ber of turnips, a number which coincides remarkably w^th that infer- red from theory. Block assigns 66 as the equivalent number of peas. Thaer makes it more than twice as high, viz. 145. Mangel 33* 390 FOOD AND FEEDING. wurzel, according to Thaer, is represented by 1012; while Mayei and Pabst call it but 550, .ud M. de Donibasle states it a little high- er, viz. 574. However highly we estimate the difficulties of com- ing to accurate conclusions on the subject of alimentation or feeding, it is not easy to account for such discrepancies among practical men ; and then, as to the astonishing similarity which their conclu- sions bear to one another upon many heads, it is impossible to over- look the fact, that the resemblance is far more in appearance than in fact ; for it is notorious, that the generality of those who have committed themselves to writing have generally copied each other. Indeed, it is not always very obvious whether the equivalent number which we find assumed, has been determined by the farmer from his own observation or experience, or has been adopted from some other observer. No one who is not a total stranger to the art of making experiments will ever be brought to believe that eleven experiment- ers, operating separately, could have fallen plump upon the number 90 as the equivalent for lucern, or even that any five of them could have lighted upon 600, neither more nor less, as the equivalent num- ber for cabbage ! The method which I have myself pursued, that namely of infer- ring the nutritious quality from the contents in azote, is far from being free from objection ; on the whole, it may be said to place the equivalents somewhat too low, inasmuch as by the process of ele- mentary analysis, the quantity of azote is apt to come out a little too high, some portion of it being derived from the nitrates present in vegetables, which are certainly of no avail in nutrition. This is the source to which I ascribe the anomaly presented by the leaves of mangel-wurzel. And, then, it is not to be forgotten that in dosing the azote we have regard but to the Jlcsh contained in the article of food, which althougli unquestionably the principle that is of highest value, and the one which is apt to be most deficient, is still not all. The neutral non-azotized subbtances, starch, sugar, gum, oil, are in- disj)ensable as auxiliaries in the alimentation of cattle ; the three first undergo changes in the course of the digestive process which fit them to be absorbed immediately, and the oil is brought to the state of an emulsion, and so is taken u() and adds to the fat. The woody fibre alone of vegetables appears to have no direct share in the nutrition of animals ; it is discovered almost or altogether un- changed in the dejections. It is therefore every thing but matter of indifierence whether a par- ticular article of forage contains a larger or a smaller proportion of starch, sugar, &c., associated with a given quantity of azolizcd or truly aniinalized matter. The potato and meadow-hay brought to the same state of dryness, contain as nearly as possible the same proportions of azote — from 1.3 to 15 per cent.; in other words, about 8.7 per cent, of albumen anil gluten, i. c, of flesh. Hut in the pota- to, alnmst the whole of the 1)1', per cent, of the remainder consists of starch ; while in hay it is woody fii)re, inert matter as we must presume it, that is present in by far the largest proportion. And this explains the higher value of the same weight of dry potato a« FOOD AND FEEDING. 391 an aiticle of sustenance. To give our theoretical equivalents all the precision that is really desirable, it would be necessary to as- certain the quantity of organic matter which escaped digestion with reference to each particular species of food. This is an inquiry which it is my purpose to enter upon by and by. The labor com- pleted, we should then be in possession of tables in regard to the proportion of the non-azotized as well as the azotized principles ; and further, to the quantity of inert matter which it would be proper to deduct from the weight of the ration allowed in each case. To have determined the azote in an article of food, then, is not to have done all that is strictly necessary : still azote is the scarce element in all kinds of vegetable food ; starch, gum, sugar, pectine, oil, are universally present, and generally in adequate quantity. As articles, as unlike one another as possible, I have mentioned' pota- toes and meadow hay. Now the theory indicates 300 of the root for 100 of the dried grass ; and I can state positively, from long and re- peated observation, that it is not advisable in practice to substitute less than 280 of potatoes for 100 of meadow-hay. The state of dryness of certain kinds of forage may have a mark- ed influence on their nutritious qualities. They may even decline in nutritive value by the process of drying, so that analysis of itself may lead us into error in regard to the nutritive value of dry articles of food. Breeders have in fact long suspected that green fodder is more nutritious than dry fodder; that grass, clover, &c., lose nutri- tious matter by being made into hay. That the thing is so in fact, appears to have been demonstrated by a skilful agriculturist, well acquainted with the art of experimenting,* who found that 9 lbs. of green lucern were quite equal in foddering sheep to S,-^,, lbs of the same forage made into hay, while he at the same time ascertained that, 9 lbs. of green lucern would not on an average yield more than 2.02 lbs. of hay. In allowing each sheep Sp^ lbs. of lucern hay as its ration, consequently, it was as if the animal had had 14.34 or more than 14| lbs. of the green vegetable for its allowance. These practical facts are obviously of great importance ; they prove beyond a shadow of doubt that the belief of agriculturists in general as to the immense advantages of consuming clover and lu- cern as green meat is well founded. Nor is this all ; it is not mere- ly the absolutely greater feeding value of the crop green than of the crop dried and made into hay ; there is further, the saving of ex- pense in making the hay, and still further, the escape of all risk from loss through bad weather during the process, by which that which was valuable fodder but a few days before, may become fit only for the dung-hill. Still, because 100 of green clover or lucern repre- sent 23 of the same articles dried, it does not follow that the feeding properties of the fodder in each of the two states can be truly re- presented by the ratios of these numbers to one another. Messrs. Perrault find from their experiments that the true relation is 8 to 3. By assuming 71.5 lbs. as the quantity of dry forage obtained from * M. Perrault de Jotemps, in Journ. d'Ajjricult. v. iii. p. 97. 392 FOOD AND FEEDING. 220 lbs. of greoi clover or lucern, the quantity which is actually obtained on an average, the ratio comes out 8 to 2.G, a number which falls somewhat short of that which is assumed, but not much. With regard to the difference in the feeding or nutritive value of green and dried fodder, the loss may in a general way be ascribed to loss of the more substantial parts of the plants especially experienced in the process of drying. This is the conclusion, at all events, to which M. Crud came ; I have myself, however, found that clover-hay, made in the field and ricked in the usual way, had not the same nutritive value as a quantity of the same crop carefully dried Jn the laboratory. By way of pendant to the conclusions of Messrs. Perrault, from their valuable observations, I shall here add the average of some experiments that were made at Bechelbronn, in 18-41, on the con- version of clover into clover-hay. The clover crops of this season were magnificent ; the plant in its second year growing to more than a yard in height. Green clover on the average may be considered as consisting of: Clover-hay 29.85 Water 70.15 100.00 As extremes in our experiments of 1841, we add : Clover-hay 35.7 25.0 Water 64.3 76.0 100.0 100.0 Analvsis gave the number 75 as the nutritive equivalent number of clover-hay. Assuming 76 to represent the moisture lost during the drying, the equivalent becomes 311 for the same fodder in the green state, meadow-hay, the standard, being 100. But practice is not here in harmony witii theory ; the value of clover-hay, in point of nutritive power, is found not to differ essen- tially from that of meadow-hay ; and the equivalent of green clover is generally placed between 125 and 500. And I may say, that daily experience in the stable tends to show that the theoretical equivalent of clover-hay is too high, that its nutritious properties are not so great as they are inferred to be. From a mean of four weighings, I find that four cows upon green clover consume 2499 lbs., or 624 1 lbs. each per diem. The usual allowance to one of our cows, however, is 33 lbs. of hay of good quality ; from which it would 'oUow, that the equivalent of (rroen clover would be 445. But the animals on the green fodder fitiencd apace, and every thing showed that they were very ditferently nourished than they would have been with llicir 33 lbs. of meadow-hay. According to theo- retical data, each cow in its 624 j lbs. of green food per day received an equivalent of 47.3 lbs. of hay ; and if it be considered, that during the season of green forage they have it alnu>st at will, it must he conceded that during this period the quantity «»f fool c«MJSuincd ii actuallv jireater than wh^^n it is reuujiirlv dolcil out. \ llnional ex- FOOD AND FEEDING. 1393 periments are therefore necessary to decide t!ie question as to whether forage eaten green is really more nutritious than the same forage consumed when converted into hay. For my own part, I should not be surprised, from what I have seen, were it found that dry fodder, previously moistened and carefully portioned out, was actually more nourishing than the same food would have been had it been eaten green. Green forage, of a very soft or watery nature, is notoriously possessed of purgative properties, which must, lessen its value as food ; but my observation leads me to say, on he other hand, that animals kept upon dry fodder require more care with re- gard to watering than is generally bestowed upon them. The abso- lute necessity of a sufficient degree of moistness in the food, in order to secure its due and easy digestion, greatly countenances the prac- tice which is beginning to be introduced in some places of steeping hay for some time in water before giving it to cattle. This neces- sity further explains the gieat advantages in associating with dried fodder other very watery articles, such as roots and tubers, turnips and field-beet, potatoes and Jerusalem artichokes. The oleaginous seeds contain a considerable proportion of animal- ized matter, similar in composition and qualities to the caseum of milk ; and the cake which comes from the oil-mill retains almost the whole of this substance. The proportion of from 0.05 to O.Ofi of azote, indicates nearly 42 per cent, of the representative of flesh in oil-cake. Theory, in fact, rates the nutritious power of this sub- stance so high, that 100 of hay may be replaced by from 22 to 27 of cake. The almost universal use of oil-cake in the feeding and fattening of cattle, is of itself sufficient evidence of its highly nutritive quali- ties. It has even been found possible to keep sheep and oxen upon this food almost exclusively. M. Bouscaren finding considerable difficulty in getting rid of his oil-cake, thought of associating with his oil-mill an establishment for feeding cattle ; and he found that oxen put up to fatten throve perfectly upon a mixture of the refuse of the wine-press and oil-cake. Cows, upon a diet of this kind, give on an average I23- pints of milk per diem. The allowance per head is about 15 lbs. of oil-cake in three meals, given each time imme- diately after the animals have been watered, and in the interval, each is allowed about 12 lbs. of straw or chaff. The cake broken in pieces is steeped in water, and worked up into a paste of the consistency of dough. If the animals show any disinclination to this food at first, they are brought to like it by having a ball of it, the size of the fist, administered to them two or three times. Supposing that the cows fed in this way would be adequately maintained upon 33 lbs. of hay, and that 13 lbs., of straw are equiv- alent to 3 lbs. of hay, it appears that in the allowance given, 15 lbs. of oil-cake will supply the place of 30 lbs. of hay; the equivalent of the cake, therefore, is 51.5, a number very different from the 22 deduced from analysis. The equivalents of those who have sought to appreciate the alimentary value of oil-cake are, however, suffi- ciently at variance with one another. It will be seen in the table, 394 FOOD AND FEEDING. that the numbers assigned by different authorities are 42, 57, and 108 ; and M. Perrault, "rom direct experiment, found the equivalent number of colza-cake U be 36, analysis giving 23 as the theoretical Qumber. On the whole it may be said, that in practice, the results, although sufficiently different, still agree in ascribing to oil-cake a nutritive value inferior to that indicated by theory. I have thought it important to insist upon the discrepancy which is here so conspicuous between the inferences from chemical analy- sis and those arrived at by experience, because it appears to me to depend upon a particular circumstance which frequently intervenes in the feeding of cattle, and which it is very important to be aware of: I allude to the influence of the bul/c of the allowance of food. Vegetable food of every description has nearly the same specific gravity ; it is but little above that of water ; the bulk of the allow- ance therefore depends upon its weight. Every one will conceive that a ration of highly nutritious food, which for this reason would occupy but little space, would be open to many objections. A cart- horse, of the ordinary size, from what I have myself repeatedly observed, requires from 26 to 33 lbs. of solid food, and about the same quantity of water in the twenty-four hours. The bulk of this allowance, when masticated and brought to the state in which it is swallowed, will be upwards of 9j cubic feet. Now, if for the ordi- nary forage, one that is five times more nutritious were substituted, oil-cake, for example, the dry ration, according to the rule of equiv- alents, would be reduced to 6.6, or a little more than l\ lbs., and its hulk would not surpass 5| cubic feel. The animal would not feel satisfied with this allowance, it would still feel hungry, or the food given in such a concentrated shape would disagree with it. If, on the contrary, a forage that is very little initrilious were substituted, such as wheat-straw, the equivalent of which is 500, the ration would then become too bulky to be eaten in the course of a day, it would amount to as many as 165 lbs. It is therefore absolutely ne- cessary to take into consideration the bulk of the food allowed : the belly must of necessity be filled ; whatever the nutritive value of any article, it miist be given in a certain quantity ; and in the case of such a substance as oil-cake, the consumption to fill the stomach would cease to be in any kind of proportion to the nutritive equiv- alent. It is extremely difficult t(» appreciate the precise limits beyond which an article of forage or a given ration ceases to be nutritious. When a?iy addition is made to an allowance known and admitted to be sufficient, the effect of the extra quantity is scarcely perceptible; so that, in practice, we are apt to fall into the err«>r of estimating at too low a rate the nutritious powers of food given in too large quan- tities. I have had proof of this in a series of experiments on tlio maintenance of a number of milcli-kine. To a cow which was receiving the e(iuivalent of 33 lbs. of meadow-hay in dry fodder and Jerusalem potatoes, an aiidilion was made of 6} lbs. of oil-cake, by ivhich the allowance of nourishment was doubled theoretically ; the animal only ate the half of the cake, however : still, the quality of FOOD AND FEEDINrr. 395 the milk was not improved. Experience here would compel us to set down the 3} lbs. of cake consumed as nil ; yet it is positively ascertained that the article is one of the most substantial known. The hard and husky grain which is given to cattle frequently escapes digestion, because it has escaped the teeth — a circumstance which leads to the formation of an estimate of its nutritious quali- ties inferior to those it actually possesses. To prevent this loss, oats are now often bruised, as are beans and peas also ; or they are mi.xed with chopped hay or straw, which the animals are compelled to chew thoroughly before they can swallow it ; or the corn is steamed or steeped in boiling water before it is put into the manger. Some experiments that were instituted by order of the French vete- rinary commission, however, seemed to show, that the loss of corn from passing through the stomach and bowels unchanged was really xo trifling, that it might be safely left out of the account. Tubers and roots are invaluable fodder for horned cattle, and in the course of the winter, come instead of hay to a considerable extent. Our experience at Bechelbronn also enables us to say, that horses are readily brought to a regimen of the same description, which, judiciously instituted, becomes the means of great economy in the maintenance of these animals. Roots, turnips, and mangel-wurzel, are frequently thrown down whole before the animals. It is vastly better ; nay, it is so much better that it ought to be made an invariable rule never to give them save cut into slices and mixed with cut straw or chaff. There is always a great advantage in combining any very soft and watery article of food with one that is dry and hard, to say nothing of the chaff absorbing and rendering useful the juices that would escape and be lost. Mangel-wurzel, turnips, carrots, and Jerusalem potatoes, are always given raw. The potato is frequently steamed or boiled first ; yet 1 can say positively that horned cattle do extremely well upon raw potatoes ; and at Bechelbronn, our cows never have them other- wise than raw : they are never boiled, save for horses and hogs. The best mode of dealing with them is to steam them ; they need never be thoroughly boiled as when they are to serve for the food of man. The steamed or boiled potatoes are crushed between two rollers, or simply broken with a wooden spade or dolly, and mixed with cut hay or straw or chaff before being served out. It may not he unnecessary to observe, that by steaming, potatoes lose no weight ; whence we conclude that the nutritive equivalent for the boiled is the same as that for the raw tuber. Nevertheless, it is possible that the amylaceous principle is rendered more readily assimilable by boiling, and that by this means the tubers actually become more nutritious. Some have proposed to roast potatoes in the oven ; and there can be little question but that, treated in this way, they answer admirably for fastening hogs or even oxen. Done in the oven, pota- toes may be brought into a state in which they may perfectly supply the place of corn in the foddering of horses and other cattle. There is but the expense of the firing to be taken into the account. 396 FOOD AND FEEDING. The only mode of ascertaining the favorable or unfavorable influ- ence of any particular system of diet or regimen upon animals, is by weighing them. In ref^.rd to- full-grown animals performing regular work, such as cart a:,d plough horses, and to milch-kine, the allowance ought to be such as will maintain them at the same or nearly the same weight. Any thing like stinting is immediately followed by loss of flesh and of weight, of strength and spirit, in the animal. The allowance being continued the same, similar effects will follow any increase of work, any exaction of unusual effort on the part of the animal. An essential condition, therefore, in all experiments on the due dieting or feeding of animals, is, that they be performed under precisely similar conditions of labor. Young ani- mals receiving a sufficiency of wholesome food, increase from day to day by a quantity which we shall have occasion immev-iately to mention ; and all changes of regimen are followed at once by notable variations in the ratio of the growth ; if the new regimen be less nutritious than that which went before it, the balance immediately proclaims the fact. Cattle put up to fatten are always supplied with a superfluity of fodder ; the excess may be regarded as an addition to the quantity requisite to maintain them in health and strength. The increase in the weight of an animal is often so great within a given time, as to be very appreciable by weighings made even at very close intervals ; the balance also shows us that the rate of increase varies at different periods of the interval during which the fattening is ?oing on. An animal put up to fatttMj for the butcher, is not the best subject for coming to conclusions upon in regard to the nutritive value of dif- ferent articles of sustenance ; still it is useful, in a practical point of view, to determine the influence of this and of that course of regimen on the production of fat. Any mi^^application of nutritive equivalents is speedily proclaimed by the animal's losing weight, instead of maintaining or gaining upon the amount to which it had attained. When the quantity of fodder has been ascertained which an ani- mal ought to have in the twenty-four hours to maintain it in full health and vigor, or that may be necessary to enable it to lay on additional flesh and fat, it is to be weighed, and the article or mix- ture of articles which it is the business of the experimenter to try, is to be given in part or in whole. After the lapse of a certain time the animal is weighed again, and the weight upon this occasion euables us to say whether the new or amendrd ration is superior, equal, or inferior, to that which had preceded it. Such is the pro- cedure generally followed : but in putting it in practice myself, I saw that it was liable to lead to rather serious mistakes, which I then used every effort to diminish or to nullify in the experiments which I tmdertook on the keep of horses — exporimt'iits which I Miink interesting enough to deserve being particularlv related. In a considerable number of observations with which 1 had be- »me familiar, I saw that the course had not alway.s been continued >r a sufTu-if-r I^n-'ih of \'vr\f : so tin' rhnn<7P- u^irh were the FOOD AND FEEDING. 397 effect of mere accident must frequently have boen ascribed to the effects of regimen. In a general way, it is acknowledged that an adult animal, upon the ration that is known to be adequate for its maintenance, returns at the same hour every day to the yesterday's weight : this, however, is only strictly true in reference to a series of weighings continued through a number of days, to make any irregularity between one weighing and another disappear. With a view to discovering the amount of variation which an animal experiences in point of weight when it is fed in the same uniform manner, is foddered precisely at the same hours, &c., I weighed a horse and a mare, which were leading the most regular and unvaried life possible, for they were both employed in working an exhausting machine for several days in succession, the weighings being performed at noon each day before they were watered, and from four to five hours after their breakfast. Here are the results in a tabular form : Date of the weighings. Weight of the horse. Weight of the 16 December, 1841 17 18 19 20 21 22 23 24 25 27 28 29 30 31 Mean weights Maxima Minima Greatest difference above the mean Greatest difference below the mean Difference between the extreme weights- kii. 453.0 4.55.0 456.0 454.0 449.0 449.5 449.0 454.0 454.0 459.5 448.0 452.0 454.0 448.0 452.5 lbs. avoird. 996.6 998.8 1010.9 985.6 994.4 kil. 494.0 497.0 497.0 497.5 487.0 487.5 492.0 496.5 484.5 452.0 994.4 459.5 1010.9 448.0 985.6 491.8 497.5 484.0 16.5 8.8 7.7 1086.8 1092.7 1065.S 490.5 496.0 491.0 484.0 1064.6 491.0 1081.9 1092.7 1064.8 10.8 17.1 6.3 Another horse (Old Fox) 12 years old, taken fasting, at four o'clock in the morning of the 28th of April, 1842, weighed 1051 lbs. ; at the same hour of the 29th, he weighed 1060 lbs. ; ditto on the 29lh, 1038 lbs. It is obvious, therefore, that a horse foddered most regularly and weighed at the same hour, nevertheless presents differences in his weight that may amount to nearly 30 lbs. ; and which, without as- surance of this fact, we should be disposed to ascribe to the effect of our regimen. This is enough to satisfy us that in all experi- ments upon feeding, it is absolutely necessary to carry them on for some considerable time, in order to escape, or at all events to lessen the errors that would be introduced into the conclusions by these ac- cidental differences of weight. They may vary with reference to 34 398 MAINTENANCE OF ANIMALS. different animals ; they are necessarily smaller in amount among those that are young and small, such as calves and sheep, than in adult oxen and horses ; bi ; they do not occur the less on that ac- count, and must, therefore, occasion errors of the same description. What, then, shall we say ot' those small variations in the weig^ht in a ewe or a ram, amounting perhaps to H or 2 lbs., ascertained in the course of an experiment carried over two or three days, though . conducted with the most scrupulous attention to accuracy in the world 1 That they may very possibly have been purely accidental. The first in every series of experiments on the maintenance of animals, ought in fact to have it in view to ascertain the amount of accidental variation in the weight of the creatures which are their subjects ; as this variation is now on this side now Ou that, there is an obvious advantage in having a certain number upon trial at a time ; any error that occurs will thus be more apt to be corrected ; afid the results may be held more worthy of confidence in propor- tion as the numbers have been large from which they have been de- duced Another cause of error, which I had occasion to discover in the course of my experiments, appears to be connected with the weight of the allowance. Equal in nutritious value, different allow- ances may still have very different weights ; it is obvious, that a ra- tion of hay and corn will weigh much less than its equivalent in roots, tubers, or green meat. Animals that have been kept tor some lime upon a dry diet, if put on one that is very bulky and watery, will inmiediately increase very considerably in weight ; and their increase is both so sudden and so great, that it is impossible to as- cribe it to augmented nutrition, to tlesh and fat laid on. The ani- mals are simply distended, their paunch and bowels are filled with a larger quantity of food than they were before ; and the state of dis- tension continues, though it suffers accidental variations, so long as the new course of feeding is persisted in. In opposite circum- stances, as when animals that have been long upon soft and watery food, are suddenly put upon hard diet, they always drop very con- siderably in weii^ht. These sudden changes throw disorder and contradiction into the conclusions, and puz/lcd me greatly until I discovered their cause. It is obvious that no kind of reliance can be placed upon the conclusions which have been come to from single weighings made at the end of each partii-ular course of alimentation, 'i'o get at results which shall be worthy of any credit, the animals that are to be made the subjects of experiment nmst be tVd for sev- eral days upon the particular ration that is to be approved, in order to be brought to the state of body which may be said to belong in particular to each system of dieting, before being weighed ; it is only when this is attained, indeed, that the experiment can be held to be properly begun ; and then it is to be continued for a sufhcient length of time to lessen the influence of those accidental variations of weight, of which I have spoken so particularly. It is perhaps needless to observe, that any increase in weight and the maintenance of that increase, are not always of themselves sufficient signs for afhrming that tnc course then followed is superior or equal to the MAINTENANCE OF ANIMALS. 399 one which preceded it. Various other circumstances of divers char- acter must be taken into the reckoning-, and in particular the state of the animals. It is very necessary to have an eye to the state of the coat, to the spirit or liveliness of the animal, to the nature of the dejections, the size of the belly, the disposition of draught animals for their work, the quantity of milk given by milch-kine, &c. Nev- ertheless, and as a general proposition, it may be said that a station- ary condition, or a slight increase of weight, is almost always in favor of the course along with which it is gained or maintained, while any loss is almost always an indication of an inadequate al- lowance or of deficient nutritive qualities in the ration, taken in con- nection with the work required or the milk obtained. The experiments which I am about to detail were undertaken to determine the nutritive value of a variety of forages associated with the ordinary articles in keeping the horse. The great dearth of for- age that was felt in Alsace, in consequence of the extraordinary droughts of 1840, led us to feel the full importance of researches in this direction ; for then we were compelled 'o replace by potatoes a very large proportion of the hay usually consumed in the stable. And, indeed, by assuming the theoretical equivalent as the basis of this substitution, I found that I saved money by the course, at the same time that the health and strength of my draught cattle were maintained unimpaired. Still, as every quesiion that bears upon the keep of the animals attached to a farm is too important to be left to the decision of theory alone, I thought it imperative on me to con- trol the inferences of chemical analysis by the results of experience. The best food for horses has long been admitted to be hay and oats in combination ; neither article alone would have the same happy effect that the two together produce. A ration of hay alone would be too bulky ; one of oats alone would not be bulky enough. But the horse is not particular in his food. Barley in southern countries replaces oats, and answers equally well. I have my- self kept horses and mules for long periods of time on maize and the tops of suffar canes exclusively ; and on the elevated table- lands of the Andes, and in the steppes of South America, the horses, though they do much hard work, are kept wholly on green meat. Much of course depends on the way in which the animal has been brought up. In the circumstances in which we are generally placed in this country, I do not imagine that there would be any actual advantage in replacing the ordinary food of our horses by roots and tubers ; I doubt even whether the substitution would have good effects. I know, indeed, that horses have been kept through the winter upon potatoes and mangel-wurzel ; but it is a different matter to feed an animal and keep him standing quiet in the stable without work, and to feed him at the same time that a certain quantity of labor is re- quired of him every day. A horse in full work would scarcely get through the bulky ration, which should consist of beet-root alone ; his meal-times are restricted ; if he has certain hours for his work. 60 has he certain hours for his breakfast, dinnM. ;ni.i supper also. 400 MAINTENANCE OF ANIMALS. This is one reason why carriers' horses and pi 5t-horses, horses, in a word, which have lung and severe work to perform, receive the larger portion of their allowance in corn. Tlie inconveniences of bulky rations are much less felt in the cow-house than in the stable ; not to speak of their particular organization, which actually enables them to take in a much larger quantity of food than the horse, the steer and the cow have always a longer time allowed them for their meals than are regularly given to the horse. The experience of nearly a whole year having satisfied me that a cart-horse may have half his ration in roots or tubers, I set out from this fact in the experiments which I instituted. EXPERIMENTS ON THE MAINTENANCE OF HORSES WITH MIXED FOOD. The usual allowance to a horse at Bechelbronn for the twei.ty- four hours consists of : Hay . . 22 lbs. Straw ... 5i Oats . . . . 7i With this ration the teams are kept in excellent condition. Two teams were selected as subjects of experiment, each consisting of four horses ; these I shall distinguish by the titles. Team No. 1 and Team No. 2. Each remained under the care of the same ser- vant throughout. Team No. 1 was composed of: Braun, a mare, 7 years old. Schinimel, a horse, 7 " Hans, do., 16 " Gaty, do., 8 " Team No. 2 was composed of : Old Fox, a mare, 16 years old, Braun, do., 5 " Nickel, do., 14 Hengst, a horse, 5 " EXPERIMENT I. One half the allowance of hay was replaced by potatoes lightly steamed ; 280 of the tubers being assumed, according to theory, as equivalent to 100 of hay. The ration, therefore, consisted of: Hay . . .11 lbs. Straw . . 5i Oats . . . . li Potatoes ... 30 8-10 The potatoes were broken down and mixed with chopped straw, and never put into the mangers until cold. From accidental circumstances, particularly bad weather during the course of the autunmal labors, the teams were exposed to very hard work, an event which of course throws uncertainty over the results of this trial. After having been upon the course of food in- MAINrENAxNCE OF ANIMALS. 401 dicated for a few days, the teams were weighed once, and again after an interval of twenty-four hours : Team No. 1. No. 2. Both teams. Mean per horse. First weighing 4617.8 4461 9079.4 1134.9 Second weighing 4554.0 4334 8888.0 1111.0 In 24 hours loss 63.8 127 191.4 23.9 The loss experienced here authorized me to conclude, that the al- lowance under the circumstances was not sufficient. The 30.8 lbs. of steamed potatoes could not have adequately replaced the 11 lbs. of hay ; it would have been highly interesting to have ascertained how horses kept on the standard and usual allowance would have stood the same amount of fatigue. Unfortunately this comparison could not be made, all the horses in the stable having been put on the potato regimen at the same time. There is this much to be said for the particular course tried, however, that the animals did their work with great spirit, and continued in excellent health. EXPERIMENT II. INTRODUCTION OF JERUSALEM POTATOES INTO THE RATION. Jerusalem potatoes are held excellent food for the horse ; they are eaten greedily, and he thrives on them. In this second experiment, SOjoths lbs. of Jerusalems cut into slices were substituted for 11 lbs. of hay, the same theoretical equivalents being assumed for them as for the common potato. The ration now consisted of: Hay . . . .11 lbs. Straw ... 5^ Oats . . . . tJ Jerusalem potatoes . 30.8 Having been accustomed to this regimen for some days, the teams were weighed, and having gone on for eleven days they were weighed again : Team No. 1. No. 2. Both teams. Means per horse. First weighing 4556 3245 8901 1112.7 Second weighing 4611 3412 8923 1113.6 In 11 days gain 55 loss 33 gain 22 gain 0.9 A result which leads to the conclusion, that the equivalent as- sumed for the Jerusalem potato was correct ; the animals had done their work, and gained, one with another, j^ths of a pound in weight. EXPERIMENT III. RATION OF HAY AND POTATOES. Eleven pounds of hay, in the usual allowance, were replaced by 30.8 lbs. of potatoes ; the whole of the oats and straw, by 15.4 lbs. of hay. These substitutions were made upon the supposition, that 100 of hay was equivalent to 280 of potatoes, to 50 of oats, and to 620 of straw. The ration, then, was composed as follows : Hay 26.6 lbs. Potatoes 30.8 " 34* 402 MAINTENANCE OF ANIMALS. This was a ration which it was the more interesting to try, from the circumstance of Professor Liebig* having come to the conclu- sion, from certain theoretical views, that it must be impossible to keep horses in health and strength upon hay and potatoes exclusively. The experiment was continued for a fortnight : Team of No. 1. No. 8. Both teams. Mean n-eijht per horse. First weighing 4020 4312 8932 1116.5 Second weighing 4675 4697 9372 1171.5 In 14 days. gain 55 385 440 55.0 In one fortnight, consequently, the weight of eight horses had in- creased by an aggregate sum of 440 lbs., or 55 lbs. per head — an increase at the rate of, as nearly as possible, 3.9, say 4 lbs. per diem ; and allowing the greatest latitude for error, it seems that we caimot estimate the increase per head at less than 1.76, say 1^ lbs. per diem. The condition of the horses was most satisfactory ; the de- jections were healthy in appearance ; the only inconvenience ob- served was, the considerable bulk of the allowance, and the addi- tional time which had to be given the teams to their meals. This inconvenience was particularly obvious in the case of the older horses. Besides the two experimental lots, other twelve horses were put upon the same regimen, and with the .same good effects. The equivalents adopted in the composition of the ration, in this third experiment, may therefore be regarded with perfect confidence as suitable. Experience, indeed, would rather lead us to conclude, that the nutritive power of the potato had been estimated at some- what too low a rate. KXPEULMENT IV. SUBSTITUTION OF OATS AND STRAW FOR A PORTION OF THE HAY. The ration here consisted of : Hay 11 lbs. Straw 11 Oats 12.1 " The horses, having been two days on this diet, were weighed. The experiment was continued for eleven days : Team No. I. No. f. Both trim*. Artrtgt per hon«. First weighing 4.j64.8 4348.3 8il33.1 1116.7 Second weigJiing 4593.6 4352.7 8946.3 1118.2 Inlldays giiin 8.8 4.4 13.2 1.5 Under this regimen, consequently, the weight of the teams re- mained very nearly the same as it was before beginning the experi- ment; still there was something gained. In conducting this experiment, wc had an opportunity of observing how imp being substituted for 11 lbs. of hay. The team No. 2 was alone subjected to this experi- ment, being kept on it for 16 days, and firs^ weighed after having had it for some time : First weighing No. 2. 4395 lbs. Average weight per horse 1098.9 Second weighing.. " 4396.7 " " " 1099.1 In 16 days gain 1.7 0.2 This result confirms that which was elicited by the second ex- periment. EXPERIMENT VII. INTRODUCTION OF FIELD-BEET, OR MANGEL-WURZEL, INTO THE RATION. Horses readily get accustomed to field-bett. The root is sliced, and mixed with chaff, (cut straw.) For 11 lbs. of hay, which I re- trenched, I allowed 44 lbs. of beet; i. e. I took 400 as the equiva- lent number of the root. The ration consisted as under: 404 MAINTSNANCE OF ANIMALS. Hay 11 lb;. Straw 5.5 " Oats 7.2 " Beet. 44.0 " A horse, after having been kept on this diet for some time, \^a^ weighed ; and the regimen having been continued for a fortnight, he was weighed again : First weighing 1014.0 lbs. Second weighing 1023.0 " In a fortnight. gain 9.4 This horse was all the while doing rather hard but very regular work ; for eight hours every day he was in the shafts of a grinding mill. He did not alter in condition ; the dejections were healthy. During the winter of 1841-2, our cows ate a considerable propor- tion of our beet ; and, as a substitute for the 33 lbs. of meadow-hay, which is their usual allowance, we gave 72^ lbs. of beet. The ration then stood thus : H:iy 22 lbs. Bett 72.G " Slniw 4.4 " Upon this regimen, the weight of the inmates of one of our stables was : On the 29th J;inuniy 24015 lbs. On the 21st April 26488 Increase due to births and to growth 1837 It thus appears that, in foddering kine, the quantity of beet allow- ed with advantage may be large ; but it is also obvious, that the nutritive value of the root is not great. At Bechelbronn, at all events, we found it requisite to replace 9 or 10 of hay by 40 of root. Our beet, it is true, contains but 12 per cent, of dry matter ; in other places, where the proportion of dry substance to the water is larger, it is possible that a smaller proportion would be found to answer the end. EXPERIMENT VJIl. INTRODUCTION OF THE SWEDISH TURNIP INTO THE RATION AND REPLACING A PORTIO.N OK THE HAV. Swedish turnip, combined with some dry forage, answers excel- lently with the horse. Analysis, indicating 280 as the equivalent of this article, two horses were put upon the fallowing ration, in which 11 lbs. of the usual allowance of hay were replaced by Swe- dish turnip : Hay 11 lbs. Stniw 5.3 O.its 7.2 Swedes 30.8 It was obvious before the lapse of but a few days, that the horses were falling oft* upon this regimen, that they were not fed ; and ou weighing them, this plainly appeared : First wcighinft 2J83.6 .\vcr. of each horse 1141.8 Second weighing, 9 diys afterwards 2178.0 " lOey.O Lossin9days 105.6 SOJB MAINTENANCE OF ANIMALS. 405 The equivalent for the Swedish turnip adopted, had therefore been too high ; the allowance was not sufficient. This led me to analyze the article again ; and I discovered that the true equivalent of the sample with which I was operating, was at least 676, and not 280 as I had presumed before. Indeed, in another experiment with the same pair of horses where the equivalent of Swedish turnip was as- sumed at 400, I found that though the animals kept up their weight at the point to which it had fallen, they gained nothing ; whence it may be safely inferred that the No. 400 was still too low, and that the new equivalent 676 is nearer the truth. EXPERIMENT IX. INTRODUCTION OF CARROTS INTO THE RATION. Horses are extremely fond of carrots*; and there is no root per- haps, the nutritious qualities of which have been more vaunted or exaggerated. Yet, analysis appears to indicate that 350 of carrot are required to replace 100 of good meadow-hay. On one occasion, in the stable at Bechelbronn, when the potato in one of our rations was replaced by an equal weight of carrots, the effect was highly disadvantageous ; and even in following the theoretical equivalent of the carrot (350) we had still no reason to be perfectly satisfied. I now believe, in fact, that as many as 400 of carrots may be found requisite to replace 100 of good meadow-hay. The carrot crop of 1841 having been a failure, I had to limit my- self to observations made on a single horse, which was put upon a ration in which 11 lbs. of hay were replaced by 38.5 lbs. of carrots. The horse, habituated to this diet. Weighed 1025.2 lbs. A fortnight after 1014.2 Loss in a fortnight 11.0 Nevertheless he remained in good condition, so that the equivalent 350 is probably not far from the truth. I ought to say, however, that the men think this number too low ; an opinion in which they would be borne out, could we but be certain that the loss of weight of the horse just indicated was not accidental. EXPERIMENT X. . BOILED RYE AS A SUBSTITUTE FOR OATS. It has been stated, that rye boiled till the grain bursts may be used as a substitute for an equal bulk of oats in the keep of a horse. The experiment which I made on the point is very far from bearing out any thing of the kind. By preliminary trials I had ascertained that rye of good quality swells to twice its former bulk by boiling. The two horses that were made the subjects of experiment now, had been kept for some time on a ration formed of : Hay 2.2 lbs. Oats 5..5 =3.8 pints. For the oats, the same quantity by measure, 8.8 pints of boiled rye were substituted, containing 4.4 pints of raw grain, weighing 4.15 lbs. On the 11th day it was deemed prudent to interrupt the experiment, of which the following are the results : 406 MAINTENANCE OF ANIMALS. First weighing : Both horses 2010 lbs. Average of each : 004-5 Second " " 1927 " 963.0 Loss in 11 days 83 41.5 In fact, with such a ration as this, in which water was made to replace solid corn, no other result could reasonably be expected. In continuing it, the health of the horses would very certainly have soon been seriously compromised. There is no objection to rye in Itself as an element in tbe food of a horse ; but then it must be sub- st.mted in the quantity indicated by the table of equivalents, by adopting which, Mr. Dailly found that he could keep the post-horses of Paris in good heart, at a time when the difference between the price of oats and rye made it advantageous to substitute the latter for the for.iier. The experiments of Mr. Dailly on the subject were so decisive and so ably conducted, that I telt myself relieved from the necessity of inquiring further into it myself. From these experiments, the particulars of which have now been given, it may be concluded that the nutritive equivalents of the po- tato, beet, Jerusalem potato, and carrot, as they come out upon ana- lysis, or as they are inferred from the amount of azote they contain, may be adopted without detriment to the health of horses. If ihey err at all, it is that they assign equivalents somewhat loo high, which is the same as saying that their actual nutritive power is rather less than these numbers give it ; so that a portion of the hay of tiie standard ration being substituted for its equivalent of tuber or root, the diet will be improved. Thus, 100 of good meadow-hay may be taken, as ascertained by experiment, to be equivalent to : a^(l |)otatoe-<— by analysis, equal to 315 280 Jerusalems 311 400 beet 548 400 Swede (t(M) little) CTfi 400 carrot 382 In the following table of nutritive equivalents, to the numbers as- signed by the theory, I have added those of llje whole which I find in the entire series of observations that have come to my knowledge. I have also given the standard quantity of water, and the quantity of azote, contained in each species of food. When the theoretical equivalents do not differ too widely from those supplied by direct observation, I believe that they ought to be preferred. The details of my experiments, and the precautions needful in entering on and carrying them through, must have satisfied every «ine of the difficul- ties attending their conduct ; yet all allow how little these have been attentively contemplated, and what slender measures of precaution against error have been taken. Our equivalent for field-beet is 400, a number come to by introducing 14 lbs. of the root into the ration, in lieu of 11 lbs. of hay ; had we introduced 56 lbs., the equivalent number would have come out 500; and it is que.stionable whether the final result would have been affected by this substitution. In my opinion, direct observation or experini'^nt is indispensable, but mainly, solely as a means of checking within ratlier wide linnits the results of chemical analysis. • MAINTENANCE OF ANIMALS. 407 C^C"^ ?-a s o o . 2. r 'if 0-2 s^" £-=!■' p ?i i, n 3- § « ^ 2 =- ' -crj' r. ^^ g P 3 ^ "■ ■ Pi?' '^S 3 . 2. . . o. CC30 2 5 ~-3 3 c 5 0< JO _•- 1 o > _--J tC i= t>s CO _--a ti o 1 S; p So 05 — cji to ov oi 00 o I o CO ot *• b • o lu io Id o o to 32 o en o o ex CO -- CC 00 »- »- to 00 CO Cn 00 c? oi S 5i IE po IS ^ '" ~ '" ' *" '" ~ ' ' cotnbo'H-cr.obobo Standard water per cent. tOH-tO — H-J-'i-'COJ-tO ^ i lu. *. ^1 ^ bo "-.1 bi " to ooc>cooocooo;ai;£i pp op ooooooo ..tC— '1--OOI— *0000 — OOO ^-i^-tObO"— '*-* i-'ppppj-'>-'pp>-'pppp>— p pop I— _i— to to l-i — it^cooociyt.— o*;siri!to'g;.iito'colututoa-. b>'co'--ocok-i ui--jo>oc;'*>."-ooQocoot-coH-co^it.*.5coooai Azote per cent, Azdteper cent. in the nrlicle not dried. ■ ootocooogo-.H-ootj^ w- mm 8' ■ S- ■ ^■l gggi g ill'' |i I : Theory. Block. Petri. Meyer. sKSS gSS' iiss Thaer. 5i?SS >criwi Oi Pabst. Flottow. |II Pohl. Rieder. §g?S Gemerhausen. Crnd. ?g^i : I Weber. 81 life- to gr. ss Dombasle. Krantz. :?: Schnee. Midleton. Wurre. Andre. Boussingault. 408 MAINTENANCE OF ANIMALS. kmmm 1 ill 1 iliii?ii.iiii-.rii m -r. H S ? € ke . to , 0 St ditto ) ditto s the wine ' i'l ^ r. . -:. . i|i|ll press, air ;;;;;;;;;;;;;; 11= ill k £. 1^- «.• • 3 ■ • ' 6.5.9 79.4 76.8 6.4 70.0 14.6 7.9 8.6 6.0 9.0 18.0 12.5 13.2 13.0 13.0 20.8 12.4 14.0 11.5 11.5 10.5 14.5 16.6 12.1 37.1 13.8 7.6 13.4 8.0 11.2 13.4 10.5 6.5 5.0 6.8 6.0 6.2 6.6 48*2 Standard water per cent. CO 00C0Cn«>*-«iU'<3-.0'*'^ObStCbS0SI>Bt0tC — N-MtctCtStCbHlS*.ifc.*.CI'Oi O— "-«- h- JSgiJgSaSSSo'S5g233cS5S^S3SSlgt*S*=*kS^SSg8SS- S55SS Azote per cent. N-OQ0C0 5n«>*.0'*.0'tPC0 — etc — tCtCtibabO — — N- — ^60 — IOH-*.*.C«30^*»OCOCO Azote per cent, in th« article nut dried. ffiSs8?KS253SSSSS2£2SgS2Ri:S-Sg:Sr^86gS2:2:gT8;SgE?S5JSsl^^=S Theory. : ; : *. : : : : : 1^: : : § • 8- = • a • is* : : : jc: : : : gg^: : |; s Block. @: : : : : : : : 8: : : : : : : : : s : &•: s: : £S:S: skes: : :i Petri. • • • • g-. : : = 8 Meyer. .... .... «s • CJJ. • • • S ftS : : : : '•'•' •■ S: : 3: a* • s* •■ * • ffisa' • :g Thaer. «• ' •g PaUt. g- • • * •«• 8- • s & '%' :g Flottow. s" • • ■i Pohl. • • • s •»• s ft Rieder. • . 1 . .jg. S- 'B . . . • • , , , , Gemerhausen. Crud. • . . . • • ' • • , , , , ,,,,,,,,, •5 ! ; . .3 : ; : ::;::::::• Weber. : . . . . •::*;;:;; •5 , Dombasle. , • ' ' ■' • t '8' ! . 1 1 1 ! I 1 t ! ••S 1 Krantz. :!!::; ! '. ! ! : '. ! : I '. ; : •■s Schwertx. ig'. : : '. : ; ; ; ; : Schnee. : .' : 1 ; : : : ; ; ; Midleton. :::::::;: Murre. ft :.::;:: : : ; Andr*. s : : : ; e : : : :S Bounincault. MAIN TELA NCE OF ANIMALS. 409 To complete the preceding ample table, I shall still add the equiv- alents of a few articles of forage that have not yet been examined chemically. 100 of meadow-hay bjre replaced by : From 85 to 90 of sainfoin hay, according \o Petri and Meyer. By 90 of spurry hay " Petri. 325 to 500 of green i^purry " Pabst and Fiottow 42 to 50 of cliestnuts *' Blocli and Petri. By 50 of Indian chestnuts " Petri. C2 of turnsole seeds " Petri. 109 of rye-bran " Block. In the list of substances there are so.ne which are used almost exclusively for the food of man, and 1 have thought it not uninter- esting to contrast these different articles wiih reference particularly to the quantity of azote they contain. I have composed the follow- ing table or list of equivalents on this basis ; ha\ ing assumed wheat- en flour as the standard and called it 100. 'Vs all herbs, roots, leaves, &c., may be pulverized after drying, I ha re spoken of these articles dry under the name of meal. Wheat flour (good quality) ... 100 White-heart ( abl age 810 Wheat 107 Cabbage meal 83 Barley-meal 119 Potatoes 613 Barley 130 Potato meal 126 Rye Ill Carrots 757 Buckwheat 108 Carrot meal 95 Maize 138 Turnips 1335 Yellow peas 67 Mealy bananas (Fi^us Indica) 700 Horse-beans 44 Manihot (casava plant) 700 White French beans 56 Name "? (discorea saliva) 300 Rice 171 Apio? (arracacha) 1050 Lentils 57 Judging from the equivalents, leguminous vegetables must be pos- sessed of a much higher nutritive value than wheat ; and it is known, indeed, that haricots, peas, and beans, form in some sort substitutes for animal food. The difference indicated is so great, however, that it may surprise those who have never thought of the subject that engages us. In a general way we are all perhaps disposed to re- gard the articles that enter habitually into our food as highly nutri- tious. The fact, however, is, that tubers, roots, and even the seeds of the cereal grasses are but very moderately nutritious. If we see herbivorous animals getting fat upon such things, it is only because their organization enables them to consume them in large quantities. 1 doubt very much whether a man doing hard work could support himself on bread exclusively. I am aware that countries are quoted where the potato and where rice form the sole articles of food of the inhabitants ; but I believe also that these instances are incom- plete. In Alsace, for example, the peasantry always associate their potato diet with a large quantity of sour or curdled milk ; in Ireland with buttermilk. The Indians of the Upper Andes do not by any means live on potatoes alone, as some travellers have said they do ; at Quito, the daily food of the inhabitants is lorco, a compound of potatoes, and a large quantity of cheese. Rice is often cited as one of the most nourishing articles of diet; I am satisfied, however, af- ter having lived long in countries where rice is largely consumed, 35 ilO INORGANIC ELEMENTS OF FOOD. that it is any thing but a substantial, or, for its bulk, nutritious arti- cle of sustenance. This is an important question, inasmuch as in some departments of the public service rice is sometimes served out as a substitute for other articles of diet. In the French navy, for example, 60 grammes, or about 20 dwts. of rice may be substi- tuted for 60 dwts. of split peas or haricots ; but I cannot hold such a substitution to be either fair or reasonable. At a period when ] had myself the charge of the rations for a detachment of men, I found that the experience of the country where I was, assigned 3 lbs. of rice as the equivalent of 1 lb. of haricot beans; and analysis confirms this practical conclusion. Haricots, in fact, contain about 0.046 of azote ; rice no more than 0.014. And if the nutritious pr«)perties be really in proportion to the amount of azote, it is obvious that 3j of rice will be required in lieu of 1 of the leguminous seed. We hear it constantly repeated that rice is the sole nutriment of the nations of the whole of India. But the fact would appear not to be precisely so ; and I may here quote M. Lequerri, who, during a long residence in India, paid particular attention to the manners and customs of the inhabitants of Pondicherri. " The food,'' says M. L., " is almost entirely vegetable, and rice is the staple ; the infe- rior castes only ever eat meat. But all eat kari, an article prepared with meat, fish, or vegetables, which is mixed with the rice boiled in very little water. It is requisite to have seen the Indians at their meals to have any idea of the enormous quantity of rice they will put into their stomachs. No European could cram so much at a time ; and they very commonly allow that rice alone will not nour- ish them. They very generally still eat a quantity of bread."* f} II. OF THE INORGANIC CONSTITUENTS OF FOOD. We discover in the bodies of animals the several mineral sub- stances, the existence of which we have ascertained in vegetables. The bones, as we have seen, contain a large quantity of phosphate of lime ; it is requisite therefore that the elements of this salt, phos- phoric acid and lime, should form part of the ration or diet-roll ; this is a point upon which all physiologists arc agreed ; but the point upon which there is nothing like uniformity yet attained has refer- ence to the precise (piantitv of mineral matter which must enter into the constitution of the food. The analyses of ash* s which 1 have given show that if vegetable aliments all contain nearly the same inorganic principles, they still contain them in very dillerent proportions : thus potatoes, wheat, oats, and beans, contain much less lime than clover, straw, and peas. The phosphoric and sulphuric acids and the alka- lies do not vary less ; so that we are led to ask whether a ration c^ompounded of such and such an article, or of such and such arti- cles, will furnish the animals to which it is supplied with the neces- ♦ The Irish iHvisnntry, who live so much on pontoe^. hnvo buttrrniilk wlUi them at lc;ist. often salt herring; and a luboring man, it is said, will consume 13 or 14 lbs per diem I— Eno. Ed INORGANIC ELEMENTS OF FOOD. 411 sary dose of inorganic principles, which must he assimilated daily, and which is quite indispensable to maintain them in health and vigor. It is easy to arrive at a knowledge of the mineral principles which are necessary as elements of the diet, by ascertaining their quantity in the ration, which long experience has shown to be sufficient. Yet as there is reason to believe that in many cases mineral substances are present in excess, I have thought that it might be useful to de- termine by means of analysis the nature and the proportion of the inorganic elements which are actually assimilated by an individual, in order to have a minimum which might serve as a basis for any reasonings or inferences on the subject. My experiments were per- formed in two opposite circumstances in which I regard assimilation as most rapid and most complete : videlicit, a calf in full growth, and a milch-cow in calf. The calf was six months old, and weighed 369 lbs. Some days before being made the subject of experiment it was fed with hay. During the two days when it had this fodder ad libitum, it ate 19 lbs. In the course of the 1st day the calf passed 21.49 ibs. of excrements. 2d day " 20.39 41.88 Which, dried, was reduced to 7.41 lbs. In the course of the two days 5.584 lbs. of urine were collected, which, evaporated, yielded 2933.2 grains of extract, the animal hav- ing in the same interval drunk 45.7 pints of water. Analysis discovered in 100 : Of the hay Azote 1.6 Ashes 7.6 Of the dry excrements " 2.1 " 12.7 Of the urinous extract "4.0 " 40.0 Now if we inquire from these data in regard to the quantity©^ azote and of mineral matters which were assumed with the food in the course of two days, we have : half-Jrachms. lialf-ilrachms. In the food, discarding fractions, Azote 69 Mineral substances 328 In the excrements " " 50.5 " 214 In the urine " "3.8 " 38 Together 54-3 252 Therefore, azote fixed or exhaled in 2 days 14-7 half-drachms. Mineral substances fixed in 2 days 76 " The composition of the ashes obtained from the hay and from the excrements, shows us approximatively both the quantity and the nature of the several inorganic substances which had been assimi- lated. The composition of these ashes is as follows : Oftliehay. Of the excrements. Of the urine. (Carbonic 9.0 2.0 17.3 Acids < Phosphoric 5.3 5.1 0.2 < Sulphuric 2.4 2.3 7.0 Chlorine 2.3 1.9 9.9 Lime 20.4 16.0 0.9 Magnesia 6.0 6.5 6.0 Potash and soda 17.3 12.5 57.3 Oxide of iron, alumina 1.5 1.0 " Silesia 33.7 51.0 1.2 Lobs 2.1 1.7 100.0 100.0 lOOO 412 INORGANIC ELEMENTS OF FOOD. if the hay consumed contained 3-28 half-drachms of ash or mineral matter, the excrements and urine 252 half-drachms of the same matters ; the difference between the two sums, 76 half-drachms,* is the quantity of mineral matter fixed in the course of two days, of which 200.6 grains were phosphoric acid, and 494.0 grains were lime. This quantity of lime, however, is more than four times as much as is necessary to constitute a subphosphate of lime such as exists in the bones. It is true, indeed, that there is always a quan- tity of carbonate of lime associated with the subphosphate in bones; 10 of carbonate for 38 of phosphate, according to Fourcroy and Vauquelin, in those of the ox. JStill the quantity of lime assimilated was vastly more than it ought to have been, had it only gone to assist in the formation of bone. If there was no error in the observations, it is probable that the base in question enters into the constitution of the salts with organic acids which are encountered in all parts of the animal body. By a series of weifjhings, I ascertained that my calf, fed simj)ly upon hay, increased every day by a (juaniity equal to 9725.9 grains troy, in which were included 858.35 grains of mineral substances, the calcareous phosphate and carbonate of the bones in this quan- tity being represented by 262 4 grains, or nearly 3 per cent, of the entire weight acquired in the course of twenty-four hours. In the experiment with the milch-cow in calf, I limited my inqui- ries to the phosphoric acid and the lime taken in and given out. The animal, four years old, was 2',- months gone with calf, anO weighed 1452.6 lbs. JSbe had the same allowance during the expe riment as she had had. for several days before, and which for twenty four hours consisted of — Hay Ifi.a lbs. Cut wheat-straw — 9.9 Beet 59.4 The experiment was continued for four days, during which iho excrements, the urine, and the milk, Avere carefully collected and weighed, and the ashes, both of the food consumed and of the pro- ducts rendered, were determined by chemical analysis Suffice it to say, that, representing the quantity of mineral matters assumed into the body in the course of the experiment by 849.9 half-drachms, the quantity voided amounted to no more than 556 half-ilrachms. In ihr quantity assumed, there were 100.2 half-drachms of phosphoric acif course introduce a much larger proportion ; some waters in the quantities above speci- fied will contain from 138 to upwards of 400 grains of saline matter, one half of which may be carbonate of lime. And I am here speak- ing of clear or filtered water ; that whicli is muddy or turbid con- tains a still larger quantity of eartliy matter in suspension than in stilulion. In an experiment made fi)r the purp«»se of getting at the amount of earthy matter taken by a milcli-cow from the watcring- * .\n nsh of in-\izo. annlyzed in my 1 \ln>rTitt>ry h\ M. lA!tcHicr, contained but IJ pel •eiit. of lime to 50.1 of phosplioric iiciil ami 17.0 ul in :tpnt">l:i. t I seviTil times saw childrea chaiili;u:U m Indian villages who bad t>ccn caugk •atiiig earth. INORGANIC ELEMENTS OF FOOD. 415 trough in the course of the day, I found that it amounted to about 770 grains troy. Notwithstanding these facts, it is still doubtful whether the lime contained in ordinary well-water would prove sufficient to supply a growing animal with the material requisite to the formation of its bones ; in adults, indeed, changes in the elements of the bones ap- pear to proceed so slowly that a very small quantity of calcareous matter probably suffices to repair losses ; but it is otherwise with young and growing animals. I have shown that a calf six months old receives with its forage a quantity of phosphoric acid which cor- responds to 555.7 grains of phosphate of lime. A calf a few week.s old, when it has 17 or 18 pints of milk per diem, receives 802.7 grains of mineral substances, into which subphosphate of lime or bone earth enters in the proportion ot 370.5 grains. It would be in- teresting to ascertain what quantities of these substances were as- similated by so young an animal, and at a period when the growth is so rapid that the increase from day to day sometimes exceeds 2 pounds. The importance of the inorganic principles of the food once re- cognised, it concerns us to take note of their nature and quantity in the ratio we allow to our domestic animals. It is in fact this con- sideration which has led me to determine the quantities of phospho- ric acid and lime contained in the various articles of food the ashes of which have been analyzed. With these data the proportion of bone earth contained in a given ration is forthwith perceived. One thousand parts of the forage gathered at Bechelbronn in its ordinary state contained : Hay Potatoes Beet Turnip Jerusalem Potato Wheat Maize Oats Wheat-straw — Oat-straw Ciover-hay Peas Haricots Beans Mineral Substances. Azote. Phospho- ric acid. Lime. Bone earth. 62.33 11.50 3.37 10.04 GDO 9.64 3.70 109 0.17 0.33 7.70 2.10 0.4G 0.54 0.95 5.70 1.30 035 0.62 0.72 12.47 3.75 1.35 0 29 0.56 20.51 20.50 9.64 0.60 1.16 11.00 16.40 5.51 0.14 0.27 31.74 17.87 4.73 1.17 2.27 51.00 3.00 1.61 441 3.32 35.70 3 00 1.07 2.97 221 73.50 21.00 4.63 18.08 9.85 30.00 38.40 9.03 3.03 5.83 35.00 45.80 9.38 2.03 5.114 30.00 51.10 10.26 1..53 9.27 We seem here to observe a certain relation between the proportion of azote ard that of the phosphoric acid contained in the food ; the most highly azotized are also those that generally contain the largest quantity of the acid, a circumstance which seems to indicate that in the vegetable kingdom the phosphates are connected more especially with the azotized principles, and that they accompany them in pass- ing into the textures of animals. With the assistance of the above table it is easy to ascertain the quantity of phosphate of lime which 416 FATTY ELEMENTS OF FOOD, AND ON FA'iTENING. enters into a given ration. Let us take that given to the horses in experiment 3d, in which the half of the hay was replaced by pon- toes, one of the articles that contains the smallest proportion of Vm^f, and we find in the 26.6 lbs. of hay C32.9 grs. phosphoric acid and 1867.9 grs. of liire. 30.8 lbs. potatoes 387.7 " 37.0 10-20.6 1904.9 numbers which correspond with 1798.5 grains of bone earth, X' 978.7 grains of uncombined lime. In his usual allowance a work-horse at Bechelbronn receives : Hay 22 lbs. containing 524.8 grs. phosphoric acid, and 1543.8 grs. of lime. Straw 5.5 " 60.7 Oats 7.2 " 230.2 81.57 In other word.s, 1735 grains of bone earth, and 864 grains of frei lime. I have foimd that very young foals, growing rapidly, and weigh ing about 374 lbs., consume per diem : "-'-^ Hay J9.8 lbs. containins of phosphoric acid 463 qrs. : lime 1389 grs. Oits ... 7.2 '• •' 231 " 58.6 which represent 95 of bone earth or subphosphate of lime. As a consequence of the relation which appears to exist between the azote and phosphorir acid of an article of sustenance, it comes to pass that like nutritive equivalents also indicate like proportions of phosphoric acid ; so that by introducing a suitable quantity of hay or clover, articles that al)ound in lime, into the ration, we are always certain of having food favorable to the development of the osseous system, whatever the nature and quality of the t)lher articles that enter into the constitution of the allowance. The relation of the phosphoric acid to the azote approaches the ratio of 3 to 10. in the more ordinary articles of forage ; but the same relation hs no longer apparent in the cereals and leguminous vegetables ; in grain and in peas, beans, Sec, the phosphoric acid amounts to about a fourth of the azote contained. Thus we have : Thporrii.-nl Ph.»phor.r. ThtoiTiical Phoaphoric einnvnltiil. .C..1 ■.,.).« eqiilTalent. »q ii»al*ul. ■ciJ in Ui* equimleiu. Hay .. . inn 0.W 0.35 0.28 Ont-straw ■ .380 r>8 0.40 0.T2 Beet ....'V48 Mn\7jo 70 0.38 Turnip . . . W.-J 0.31 Wheat.... 43 0.41 Jerusalenis • Dry clover •• Wheat-straw ...273 ... 75 0.37 n..H4 Peas 25 0 23 Haricots •.. 27 0.25 ...235 0.37 Beans 23 0.24 ^ III. OK THK. FATTY CONSTITUE.NTS OF FOR.VGE : CONSIDERATIONS ON FATTENING. When fat was observed af cumulating in the tissues of the animal body, and it was unknown that the presence of fatty matters in plants is wliat may be termed a general fact, men naturally con- ceived tl at the fat was produced from the food in the a.-t of dii,^* FATTY ELEMENTS OF FOOD, AND ON FATTENING. 417 tion, that it was composed in ihe animal body much in the same way as it is formed in the seed and leaf of the living;- vegetable. The inquiries which I am about to present, however, all tend to make us conclude that fatty substances are only produced in vege- tables, and that they pass ready formed into the bodies of animals, where they may either undergo combustion immediately, so as to evolve the heat which the animal requires, or be stored up in the tissues in order to serve as a magazine of combustible matter. This latter view appears the most simple ; but before discussing the experiments which bear it out, it seems necessary to pass in brief review the notions that have been entertained at different times on the formation of fat. When the great burying-place of the In- nocents was emptied, for example, it was commonly imagined that one of the effects of the putrefactive process was to convert the flesh, the brain, the viscera, &c., into fat — adipocire, as it was called ; it was not, indeed, till after the researches of M. Chevreul had been undertaken, and that it was discovered adipocire contained the same acids as human fat, which had, in fact, only been partially saponified by ammonia, — until the inquiries of M. Gay-Lussac were made public — that it was acknowledged that muscular flesh or fibrine subjected to putrefaction leaves no larger a quantity of fat than can be obtained from it by proper solvents before it has undergone any change : the effect of putrefaction is to destroy the fibrine, and so to expose the fatty substance which it contained. It may therefore be said, that all these fortuitous opinions upon the supposed formation of fat by chemical processes, have vanished as they have been successively subjected to careful examination. Let us now turn to the inferences come to by physiology. The Dodies of carnivorous animals are often loaded with fat ; and none can be detected in any of their excretions. It is therefore in these animals that it must be most easy to ascertain the source or origin, and mode of disappearance of fatty matter. When the progress of digestion is watched in a dog, it is soon disc*overed that the chyle is far from being a fluid having uniformly the same characters and qualities. That which is produced under the influence of a vegetable diet, abounding in the starchy principle and in sugar, or after a meal of perfectly lean meat, is always and alike poor in molecules or globules. The chyle is then nearly trans- parent, extremely serous, and yields very little fat when w^ashed with ether. But if the animal have a meal of fat food, the chyle that re- sults from it is opaque like cream, very rich in particles, and, digest- ed with ether, yields a large quantity of fatty or oily matter to that solvent. These facts, observed by M. Magendie, and confirmed with more ample details by Messrs. Sandras and Bouchardat, show that the fatty principles of our food minutely subdivided or made into an emulsion by the act of digestion, pass without undergoing any es- sential change into the chyle, and from that into the blood, whither they can in fact be followed, and in which they can be shown tc remain for a longer or a shorter time unaltered, at the disposal of 418 FATTY ELEMENTS OF FOOD, AND ON FATTENING. the economy, as it were. Such observations have naturally Jed physiologists to conclude that the fatty principles of the food were the principal, if not the only sources whence animals derive the fat which is met with stored up in their tissues, or which appears in the butter of their milk. And this view, so long as the carnivorous tribes alone are considered, has not a single feature which makes it objectionable. But when we would extend it to the herbivorous tribes, two difficulties meet us on the threshold of the inquiry. 1st. Do vegetables actually contain such a quantity of fatty matter in their structure as will explain the fattening of cattle and thn for- mation of milk ? 2d. Is it not more simple to suppose fat and butter the product of certain transformations undergone by starch and sugar in the animal economy ] It appears at first sight most opposite to nature to suppose that th« feeding ox finds the whole of the fat he lays on ready formed in the food he eats ; it is only, in fact, after having made repeated analyses of plants, and discovered fatty matters almost everywhere, and in quantities generally superior to any that had been suspected in tho composition of plants, that the idea begins to acquire likelihood ; finally, the chemist becomes convinced that it is so when he finds a regular association of neutral azotized substances and fatty principles in all the articles usually employed as food for cattle, — in the grass- es and cereals, in the leaves and stems and seeds of plants. Fatty substances appear to be principally formed in the leaves, where they frequently show themselves under the form and with the properties of wax. Taken into the bodies of animals, mingled with the blood, and exposed to the infiuence of the oxygen of the inspired air, they vvill undergo an incipient oxidation, whence will result the stearic or oleic acid that is lound as a constituent of suet. By uiiderg()ing a second elaboration in the bodies of the carnivora, the same fattv substances, oxidated anew, would produce the mar- garic acid which characterizes their fat. These divers principles, by a still further degree of oxidation, would give rise to the fat vX)\a.- tile acids which make their appearance in the blood and in the per- spiration. Finally, did they sutfer complete oxidation, i. e. combus- tion, they would be changed into carbonic acid and water, and be in this shape eliminated from the economy. Among the various properties possessed by tatty substances, there is one which may play an important part in the phenomena of fatten- ing ; this is the solvent power which they severally possess in re- gard to oiie another ; the property of mixing in all imaginable pro- portions, still preserving the general features which severally dis- tinguish them. In the stomach, in the intestines, in the chyle, and in the blood, fatty substances of various kinds may I'orm luunoge- neous matters by their intimate admixture, and become divided into globuh's of complex composition, but everywhere the same. Another propcrtv of fatty matters of every kind, which deserves particular attention, is that of insolubility in water. We find, in fact, that when an animal eats a soluble substance, that in general il FATTY ELEMENTS OF FOOD, AND ON FATTENING. 419 is consumed by a true process of combustion, which converts its carbon into carbonic acid, and its hydrog^en into water ; or otherwise, it is simply eliminated without change in the urine. Fatty matters may, indeed, disappear under the first form ; but so long as they escape remarkable modification, it is certain that they do not pass off by the urine, and that the quantity eliminated by the perspiration is insignificant. Their insolubility, therefore, retains tbem in the economy once they have entered the blood or the tissues ; and it is in virtue of this quality that they constitute a kind of magazine of combustible matter in the animal body. This is the principal reason wherefore individuals supplied with food in excess get fat, and that those insufficiently fed fall lean ; the fatty matter being deposited in the interstices of the tissues in the former case, being taken up from them and burned in the second. This explanation is attractively simple ; but in our attachment to it we must not forget that other explanations have also been given ; and in particular it must be contrasted with a view which has been formed upon certain inquiries undertaken by M. Dumas. It is known, for instance, that sugar may be regarded as a compound of carbonic acid, water, and defiant gas. Now there is nothing to pre- vent olefiant gas becoming detached and taking different states of condensation, to give rise to bodies which by undergoing oxidation would produce fat acids and consequently fats. Since it has been known that the oil of potato spirit is also met with in the spirit obtain- ed from the refuse of the grape, and in the spirit procured from malt, and from the molasses of beet-root sugar, the assurance that the oil is a product of the fermentation of sugar appears to be com- plete. We ought even to be prepared to admit a phenomenon of the same kind as taking place in plants, when we see the sugar of their stems disappearing in the same ratio as their seeds or fruits become charg- ed with oleaginous njatter : all the palms elaborate sugar before producing oil. It is upon chemical views of this kind that the second opinion as to the source of fat in animals has been formed, and which may be said to stand in direct contrast with that which assumes this sub- stance as pre-existing in the food, which regards it as produced in the blood itself, under the influences of the most intimate forces of animal life. For my own part, I adopt the view which supposes dn animal to be supplied with fat already formed, mainly because it presents itself to me as more in harmony with the facts which T observe in our stables. Still I do not deny that it may be possible for a certain quantity of fat to be elaborated in the bodies of herbi- vorous animals, under the influence of a special fermentation of the sugar which forms an element in their food ; although I feel satisfied, from practical facts, that sugar plays no essential part in the fatten- ing of cattle. The formation theory, nevertheless, is not without data of a very curious and important kind, which require notice. Huber had found that bees fed upon honey, and even upon sugar, did not lose the 420 FATTY ELEMENTS OF FOOD, .'.JVD ON FATTENING. power of producing wax for a long period. And Messrs. Milne Edwards and Dumas have lately confirmed the occasional accuracy at least of this conclusion. Their first experiments were unfavora ble to the conclusions of the celebrated bee-master of Geneva. A swarm fed with lump-sugar yielded very insignificant quantities of wax ; three other swarms, placed in glazed hives, and fed on honey and water, failed to produce any wax ; but a fourth swarm gave a totally diflferent result. The procedure by analysis was now instituted. The absolute quantity of wax contained in the body of a bee, or in the bodies of a certain number of bees, was first ascertained ; second, the quantity of wax in the combs constructed by the laborers was determined ; third, the quantity of wax contained in the honey consumed was dis- covered. The final result of the inquiry was, that a swarm of 2005 laborers, after having in the course of a month consumed 12889.43 grs. of honey, had produced 2407 grs. of wax.* Granting the accuracy of this conclusion, admitting that the bee fed upon honey has the power of producing wax, I might still ask whether it was therefore legitimate to conclude tjiat the ox was endowed with any faculty of the same kind ? J>till,tothe interesting physiological fact above quoted, may be associated the remarkable fact of llie conversion of sugar into butyric acid, observed by Messrs. Pelouze and Gclis, a conversion offected by mixing a small quantity ofeaseum with a solution of sugar, and adding a sufficiency of chalk to neutralize acid as it was formed. This mixture, placed in a tem- perature of from 77" to 86° F., by and by passes through a series of changes, the last term of" which is the butyric fermentulion. Tiiis butyric acid is a volatile, colorless, and very limpid fluid, having an odor that brings to mind at once that of vinegar and rancid butter. Although it has a resemblance to the acids which prevail in different kinds of fat, it nevertheless, by uniting with glycerine, constitutes a fatty body, butyrine, which forms about one-hundredth part in the constitution of butler, and must therefore be received as one of the elements of the fats; and the observations of Arthur Young would even incline us to presume that butyric acid exerts a favorable influence in the fattening of animals. ( 'omparative experi- ments satisfied Young that hogs fattened more quickly on food that had become sour, than on tlie same food before it had turned. Now it is very probable that there was production of butyric acid in the course of the fermentation. The question in reference to the formation of fat is of much morn limited interest to the farmer than to the physiologist. The agricul- turist, in fact, cares little whether a couple of pounds of honey con- sumed by a hive of bees will give origin to some 10 dwts. or so of wax ; the matter that concerns him is, as to the degree in which the roots or tubers that he grows are fattening ; and whether or not he can advantageously substitute a cheaper for a njore costly article in his piggery or stalls ' And her , as in so many otlier places * Vidr CoMijile.* rpndtis dr I'.Acad^niip dcs ?cl«^nrr« t. xv\\. p. 131. FATTY ELEMENTS OF FOOD, AND ON FATTENING. 421 pra(!tice got the start of theory ; and I own, with perfect humility, that I think its conchisioiis are in general greatly to be preferred ; ihe universal custom of giving oil-cake and oleaginous seeds to our mileh-kine and fatting oxen and sheep, appears to me to supply an argument of much greater force than any that can be obtained from ciiemical researches pursued in the laboratory. Such articles as the potato and the banana, which answer admi- rably for the keep of hogs after they are weaned, are not adequate to fatten them for the butcher ; they contain but very small quantities of fatty matter, and tho\]gh the animals will grow rapidly upon them, and even attain to and maintain a certain condition, all that is re- quired can only be secured by adding some other article to the ration that is richer in oleaginous or fatty prmciples. At Bechelbronn, whatever others have said on the subject, we find that our hogs will not fatten on potatoes alone ; so that I agree with Schwertz when he says, that while hogs will get into good flesh upon potatoes, and even seem to fatten for a time, they soon cease from improving, and only begin to advance again when they receive in addition an allow- ance of barley or of split peas or beans. A young pig will consume about 13 lbs. of potatoes ])er diem, into which, as analysis of the ashes informs us, there enters but about 17.2 grs. of lime. But this quantity is probably too small to meet the demand for bone earth in a young animal in full growth, and hence the great advantage of the whey or small quantity of skim milk which is so commonly added to the potato ration. It ought to be laid down as a general rule, that young creatures as well as adults ought to have a ration which contains the earthy elements of the bony system, the azotized elements of the flesh, and the fatty matter of the fat. From a series of experiments which I undertook, in concert with Messrs. Dumas and Payen, it appears that all the arti- cles acknowledged the most pow^erful as fatteners, are those also that contain the largest proportions of fatty principles. The follow- ing substances contain the numerical quantities of matter soluble in ether in 100 parts : Common maize 8.8 Dr^'lucern 3.5 Beaked Lombardy maize 7.8 Mead«\vhay 3.8 Large white Parisian maize 8.1 African wheat straw 3.2 Rice 0.8 Ditto Alsace 2.2 Oats 5.5 Ditto near Paris 2.4 Ditto 3.3 Oat straw 5.1 Rye 1.8 Beanmeal 2.1 Rye flour 3.5 Beans 2.0 Hard Venezuela wheat 2.6 Haricots 3.0 Hard African wheat 2.1 Peas 2.0 Wheat flour 2.J Lentils 2.5 Ditto 1.4 Potatoes 0.08 Fine bran 4.8 Mangel-wurzel 0.1 Coarsebran 5.2 Carrots 0.17 Dry clover- 4.0 Oil-cake 9-0 M. Payen found that the oil was everywhere present in the seeds of gramineous plants. The embryo contains much, the husk less, the farinaceous portion still less. But maize and oil-cake contain ■about 9 per cent., whence the universally admitted superior fattening power of these two articles. 36 422 FATTY ELEMENTS OF FOOD, AND 3N FATTENING. If we now discuss particularly one or more of the rations or allowances to oxen put up to fatten, or to milch-cows, we shall find that they uniformly contain a larger quantity of fatty matters than the secretions, excretions, and fat which have been produced under their influence. Thus a cow, in good condition, that produces 72 pints of milk, containing 3.3 lbs. of butter, while she eats 220 lbs. of meadow-hay, will have consumed more than 6.6 lbs. of matter soluble in ether — fatty substances. The quantity of fat contained in the food, over and above that which is discovered in the milk, has passed with the excrements, which are never entirely free from sub- stances analogous to fatty matters. With a view to comparing as accurately as is possible in inquiries of this kind, the quantity of fatty matter contained in the forage consumed by a cow, with that found in the milk and in the excre- ments, the following experiment was made. A cow, Esmeralda, No. 6 in the stable at Bechelbronn, calved on the 2Gth of September, and she was put to the bull again on the 4tli of November. Up to the 22d of January (inclusive) Esmeralda received the usual allow ance, viz : After-math hay 11 lbs. Oil-ciike 22 " Turnips 66 " Wheat chaff 22 " and the milk she gave in the course of the month of January, amounted on the — Pinm. PinU. Istlo 12.9 12th 12.3 2d 12.3 1.3th 11.4 3d 12.3 nth 11.4 4th 11.4 15th 12.3 5th 10.5 16th 10.5 6th 12.3 17th 11.4 7th 12.3 IHth 10.5 8th 12.9 19th 11.4 9th 12.3 20ih 11.4 10th 10.5 2Ist 11.4 11th 11.4 22*1 11.4 The average quantity of milk, therefore, per day, in the course of the week that preceded the experiment, was 10.287 pints. From the 23il of January, when the ration was altered to — Hay 16.5lbs. (' 111 )p|H'il wheat straw 9.9 " Ueet-riM)t..... 59.4 " the quantity of milk yielded was : Jnniiiirv. Piiit». Jniuinrv. Pinti. 2,3(1.'. 11.4 27th'. 11.6 24th 10.5 . 2.>'ih 11.4 2.->th 10.5 Litth 11.4 aoth 10.5 30th 11.4 on an average 1 1 8 pints per diem ; a little more than with the form- er allowance. The excrement passed by this cow was analyzed during four days, from the 2 Ith to the 27ih of January ; the whole quantity being weighed moist every day, and well mixed, a mean sample of about 6 oz. in weight was taken for analysis. This bemg stove-dried, th« FATTY ELEMENTS OF FOOD, AND ON FATTENING. 423 entire quantity of dry matter contained in the moist excrement was readily ascertained : Dates. Moist excvement. Dry excrement. Milk in pints. Milk in lbs. Jan. 24 40.7 lbs. 6.8 lbs. 10.5 13.5 25 41.8 7.3 10.5 13.5 26 62.1 0.0 10.5 13.5 27 43.4 7.1 10.5 13.5 188.0 30.2 42.0 54.0 To ascertain the quantity of fatty or waxy substances contained in the food, the several samples were first treated with hot water, then with ether, and finally with a mixture of ether and alcohol boil- ing. The fatty element of the butter was determined by Peligot's method. Fatty Matters in the Food per cent. < 1st E.xperiment 3.6 ^ 2d ditto. 3.9 \ 1st E.xperiment 2.4 < 2d ditto 2.0 Hay... Straw Fatty Matter in the Excrements and Milk per cent. Excrements (dry, j J' •^Xr'"';:;; .::; ^.I:? Milk 3.7 Let us say, that the proportion of fatty substance contained per cent, in the several articles consumed as food', was as follows — Hay 3.7 Straw 2.2 Beet 0.1 Dry excrements. 3.6 Milk 3.7 and we shall have the results of the experiment in this shape : FOOD CONSUMED IN FOUR DAYS. EXCREMENTS AND MILK IN FOUR DAYS. Fattv matter. * Fatty matter. Beet 237.6 lbs. 1667.3 grs. Excrements 30.4 lbs. 7688.1 grs. Hay 66.0 1776.1 Milk 54.3 14125.7 Straw 39.6 6113.4 Fatty matter in excrements Fatty matter in food.. 24956.8 and milk 21813.8 I'he excretions 21813.8 Fatty matter fi.xed or burned 3143.0 The natural conclusion from this experiment appears to be this : that the cow extracts from her food almost the whole of the fatty matter it contains, and that she converts this matter into butter. It would perhaps be possible to make the proportion of butter contained in the milk to vary within certain limits. It is well known that the butter of cows in the same district varies notably according to the nature and abundance of the forage ; the butter of the same country-side, for example, has been ascertained to contain 66 of margarine to 100 of oleine in summer, and 186 of margarine to 100 of oleine in winter. In the first case, the cows are grazing on the mountains, (the Vosges ;) in the second they are eating dry fodder in the stall. I have besides had an opportunity to make a direct experiment upon this subject, which appears to me quite conclusive^ Having substituted for one half the allowance of hay an equivalen 424 FATTY ELEMENTS OF FOOD, AND ON FATTENING. quantity of rape-cake, still very rich in oil, the cows were kept in excellent condition ; but the butter was extremely soft, and had the taste of rape-seed oil to a degree that was perfectly intolerable. I do not know a single instance in any of the systems followed at Bechelbronn, in which a milch-cow does not receive in her ration a quantity of matter analogous to fat, superior to that which is con- tained in the milk she yieTds. Having upon a certain occasion put a cow exclusively upon beet, I anticipated an unfavorable effect on her milk ; and in fact a very sensible diminution in all its valuable ele- ments occurred, and the animal began to sutfer. By simply adding a few pounds of straw which had been taken away, the milk resumed its standard quality. Tlie two rations thus composed may be con- trasted under the two points of view of contents in fat and contents in organic matter. In the ration of beet and straw (beet 119 lbs., straw 7.t lbs) there were 140 dwls. 20 grs. of fatty matter ; in that composed exclusively of beet (132 lbs.) there were but 38d\vts. 14 grs. of fat. The ill eftects of the beet-root ration could not be ascribed ti» deficiency of inorganic elements, for the phosphate of lime it contained amounted to 37 dwts. 7 grs — amply sufficient for all the purposes <»f the economy. The information we have from M Damoiseau, one of the most careful of the observers who have investigated the subject of the production of milk, confirms us in our views of the necessity of fatty matters in the daily ration of the milch-cow. The following are the elements of three of the rations for a cow in .M. Damoiseau's establishment. No. I. Nn. ». N'o. I. Beet, or ninnpnl-wurzel.. 88 lbs. CarroU 74 lbs. PolAtoos 35 lbs. Bmn. 6.6 " 6.6 " 6.6 Pollard. 5.5 " 5.5 " 5.5 Luccrn 6.6 " 6.6 " 6.6 Oiit-slriiw 13.-2 " 13 2 " 13.2 Siilt 0.11 " 0.11 •' 0.11 121.0 107.0 88.0 Maximum. MeJitim. Miiiiinum. Quantity of milk yiihled . . From 25 to 26 pt-*. 16 t«i 18 pw. 12i pts. Let US now calculate the actual nutritive value of the different items in the above rations ; or, selecting one, let us lake ifiat with the beet for particular consideration, as among the most usual. 6.0 lbs. of bmn and 5.5 lbs. of iMill.ird at 5 |)cr cont.=0.fiO of fatty matter 6.6 lbs. liicorn 3 " =.{).X\ 13.2 lbs. cKit-straw 5 " =().tiO 1.53 Whence it follows, that a cow here received upwards of 1} lbs. of matter of a fatty nature with her food — a quantity more than suf- ficient to produce not only 16 or 18, bu. the maximum ipiantity of 25 or 26 pints of milk, very rich in cream. Did the cow receive an additional 40 lbs. of beet-root, slie would find somethinu like 12 II)S. more of solid matter in this article composed especially «»f sugar, wiiich sne would burn to keep up her temperature, and nearly 25 ^wts. of oily matter, which she would transfer to her milk, — to say FATTY ELEMENTS OF FOOD, AND ON FATTENING. 425 nothing of new azotized principles which would be converted into caseine. If we now, by an easy transition, pass to the phenomena of fatten- ing, we still find that the principles which have been laid down can be most satisfactorily applied. Setting out from the numbers ob- tained from the experiments of Mr. Riedesel, which, in many points, agree with all I have seen myself, we arrive at the following con- clusions. An ox weighing 1320 lbs. avoird. will keep up his weight upon about 22 lbs. of good hay per diem. Put up to fatten, the same ani- mal would require about twice this quantity, say 44 lbs., upon which he would gain at the rate of about 2 lbs. per day. Now, if we even take Mr. Riedesel's conclusions as a little too fa- vorable, as giving at least the maximum nutritive value to the hay and its equivalents, we may still admit, with him, that 22 lbs. of hay will produce about 17 pints of milk, or about 2 lbs. avoird. of flesh, con- taining 0.55 lbs., or rather more than ^ lb. of fat. Now, 22 lbs. of hay contain nearly 12 oz. 12 dwts. of principles soluble m ether, i. e. of fatty or waxy matter. The fatting ox, consequently, fixes a certain proportion of these principles in the same way as the cow. There is only this differ- ence, that the cow returns with the milk she yields a considerable quantity of the fat she finds in her food. There consequently exists an obvious relation between the formation of milk and fattening — a position which would gain support, did it require any, from a note which I owe to the politeness of M. Yvart, who, in summing up a long array of facts, concludes with these words : " The secretion of milk appears to alternate with that of fat. When a milch-cow fat- tens, she loses her milk ;" and the converse of the proposition is no less true ; when we would fatten a cow, we must let her go dry. The breeds of kine admitted to be the best milkers remain long lean after the calving. In some of the short-horned English breeds, the quantity of milk is often very considerable shortly after the calving; but the animals are much disposed to get fat, and getting fat, the secretion of milk neither continues so long, nor is it so plen- tiful, as in some of the other less improved kinds. English hogs, which become much fatter than French hogs, appear not to be such good nurses. Now, if we admit that there is this intimate relation between the formation of milk and that of fat, we are obviously very near the admission, that articles of food containing fatty substances indispensable to the production of milk, are also indispensable to the production of animal fat. And, then, has it ever yet happened that animals have been fattened with food devoid of grease"? I have not, for my own part, met with a single fact which countenances such a proposition. I have referred to the distinguished agriculturist, who attempted to fatten pigs upon potatoes, but who only succeeded by adding a certain quantity of graves to the food — an article which, as every one knows, contains a considerable proportion of fat in its com- position. M. Payen has, in fine, made some experiments which appear alto 36* 426 FATTY ELEMENTS CP FOOD, AND ON FATTENING. gether conclusive, and from which it follows, that two Hampshire liogs which, having consumed 66 lbs. of gluten, and upwards of 30j lbs. of starch, had only gained 17^ lbs. ; while other two animals of the same breed, having been fed with 99 lbs. of the flesh of sheeps' heads, containing from 12 to 15 per cent, of fat, had gained 35 lbs. Yet, judging from elementary analysis, these two rations were almost identical ; they contained the same quantity of dry nutritious matter. The first ration contained 26.4 lbs. of dry gluten, and 30.4 lbs. of starch ; the second contained 20.9 lbs. of dry flesh, and 15.4 lbs. of fat. The quantities of carbon and azote were, therefore, a little higher in the vegetable than in the animal ration ; but they differed notably in this, that the latter contained an equivalent of fat for the equivalent of starch contained in the former. In a second experiment, four hogs, ted upon boiled potatoes, car- rots, and a little rye, gained 117.7 lbs. ; while other four animals, of the same age, and in the same conditions, but fed upon sheeps' heads, gained as many as 226.6 lbs. In the course of these experiments, M, Payen was struck with this circumstance, that the increase in weight of an animal that is fat- tening being represented by 50 per cent, of water, 33.3 of fat, and 16.6 of azotized matter, the conviction is forced ujjou us that he ac- tually fixes the greater proportion of the tat of his food in the cellu- lar tissue of his body. The first hogs, tor example, had eaten 14.74 lbs. of fat, and had gained 11.44 lbs. in weight; the four last re- ferred to had had 18.48 of grease, and had increased 14.74 lbs. in weight. It has now been the practice for several years, in various places, to maintain hogs in considerable numbers upon muscular flesh, horse- flesh; and it has been ascertained that the article, if extremely lean, though it keeps the animals in good heart and condition, though they grow and thrive on it, yet they will not tatten. When they are to be got ready for the butcher, they must, in addition, be put upon a course that is known to be proper to fatten them. The scientific question of fattening having, of late years, attracted very general attention, the o|)inions which have now been announced have l)een very actively contested. Among other arguments, the general freedom from fat of the l>odies of carnivorous animals, and the usual fat state of those of the herbivorous races, has been cited. Whales have even mistakeidy l)ecn incliidcd m the list of lal vege- table feeders; but it is known to all naiuraUsis, that the great ma- jority of the whale tribes, the wlude of those that inhabit the northern seas, are carnivorous. And, indeed, the mention of this tact leads me to revert to one of the most curious problems in the physics of the globe — that, to wit, presented by the vast amount of animal life amidst the waters of the ocean, and its support by a quantity of vegetables which to us appecr alloixether inadetjuate to such an end. '^I'he beautiful researches of M. Morrcn, however, seem calculated to throw some light on this interestir)g subject, — that inquirer having shown that certain animalcules possess the t'acully of decomposing carbonic acid in the same way as vegetables ; and it is probably ia FATTY ELEMENTS OF FOOD, AND ON. FATTENING. 427 virtue of this power that the enigma is to be explained, of the source whence the myriads that people the deep derive their food. But is it absolutely true that herbivorous animals only abound in fat? Who has not seen fat dogs and cats; and in the Cordilleras, where palm-trees abound, there is a particular species of bear, which lives in a great measure on the oily palm-nuts and young shoots of the palm-tree, which becomes remarkably fat, and proves a great attraction to the tigers of the country.* Before coming to a close with this discussion, I think it right to refer to the experiments of M. Magendie, who has so well establish- ed the fact, that the chyle of animals fed on fat food contains a large quantity of fat ; and that animals kept long on such food frequently become affected with what is called the fatty liver. f To sum up, then, experiment 'demonstrates that hay contains a larger quantity of fatty matter than the milk and excretions which it forms ; and that it is the same with all the other mixtures and varie- ties of food that are usually given to animals. That oil-cake increases the production of butter, and that, like maize, it owes the fattening properties it possesses to the large quantity of oil it contains. That there is the most perfect analogy between the production of milk and the fattening of animals ; that potatoes, beet, carrot, and turnip, only fatten when they are conjoined with substances that contain fatty matters, such as straw, corn, bran, and oil-cake of various kinds. That in equal weights, gluten mixed with starch, and flesh meat abounding in fat, have a fattening influence on the hog, which differs in the relation of 1 to 2. Lastly, that fat food — food which will afford fat in the digestive canal — appears to be the indispensable condition of fattening. If it be necessary that the respiration be diminished or lessened in extent, this is only that the fatty substances taken into the stomach, and which have made their way into the blood, may not be oxidated, may not be burned ; not that their formation may be favored. All these facts are in such perfect harmony with the simple view of assumption and assimilation of fatty matters, that it is difficult to conceive on what foundation the opinion can repose which would have them composed out of their elements in the animal body. Nevertheless, 1 am myself the first to admit, that more extensive experience may l^ad to the modification or even entire change of the opinion which I advocate. The facts on which that opinion is based, despite their number, are not probably yet sufficient to }on- stitute a perfectly satisfactory or conclusive theory. New researches * These bears, evidently, cease to be cnrnivorous while they live on pilm-nuts and leaves. For niv own part, I do not think the point seUled yet. The fatty inntter of the j^jenerality of vegetables is wax rather than grease. And then some of the herbiv- orous tribes seem never to get fat. — Eng. Ed. t I may here state the contrary- fact, as announced to me by a physiological friend, In whose report I place great reliance, that the chyle of animals fed with substances that give mere traces of waxy matter, contains fat or oil that can be collected in larg* drtpi — Ewa Ed. 428 ECONOMY : f farm animals. are, therefore, indispensable : it would be requisite to show, that a cow kept on a reg-irnen abundant in point of quantity, but as poor as possible in matters analogous to fat, will continue to maintain her condition and yet yield milk abounding in cream ; and that it is really possible, as some persons affirm, to fatten animals rapidly on roots and tubers alone.* CHAPTER IX. OF THE ECONOMY OF THE ANIMALS ATTACHED TO A FARM OF STOCK IN GENERAL, AND ITS RELATIONS WITH THE PRODUCTION OF MANURE. Agricultural industry generally extends to the breeding and fat- tening of cattle ; the breeding, or at all events the maintenance, of horses ; the breeding and feeding of sheep and swine. The cir cumstances, indeed, in which the tiller of the ground sees himself spared the necessity of attending to these matters, are rare excep- tions to the general rule, and in fact only occur where it is easy lo obtain abundant supplies of manure from without, or in those few favored spots where the fertility of the soil is such that it continues to yield its increase without addition in the shape of manure. In the vicinity of great centres of population, where dung can be bought cheap, or of guano islands, wiiere a cargo costs a trifle, and in some tropical countries, large farming establishments may be found to- tally without stock in the shape of sheep and horned cattle. IJut in a general way the agriculturist is obliged to give himself up to the care of flocks and herds of one (lescrij)tion or another; and, in fact, we now know that there is a certain and very indispensable relation to be maintained between the extent of surface under crop and the number of cattle to be provided for, variable as regards farms dif- ferently situated and circumstanced ; but invariable when circum- stances are the same, and the system of managenient pursued is similar in its principal features. The question as lo whether the cultivation of grain or other use- ful j)lants, or the rearing of cattle, is more profitable, which is often agitated, must receive a ditferent solution in regard lo each diflerent locality. In one place it may be more advantageous to breed cattle or horses ; in anotlier to rear or tatten them : here, the production of milk, butter, and cheese, may be the best husbandry ; there, the growth of hay, (as for miles round London on the north and west ;) and again, wheat and the other cereal grasses may be tlie staples ot ♦ Whoever would try cx|>erimtMit-« in this (lirrclion, wxK l>ocnrrfnl to luii his food; one article alone nevi-r aprees. 'J'he ,\mt ricans Hay, a pig will die ii|M)n |iunipkinK and upon apples alone- but he will live and latten on n mi.xtiire (if the two. I hive my- self seen scores of oxen fattened U|H)n urnip-t. with a nuxlemte allowance of ^trtw or bog-Jiay ; and have seen pigs get into udiniruble cunditiun fur the butcher un little mor« than potatoes.— £Na. Eo. ECONOMY OF FARM ANIMALS. 429 prod action. Even supposing that the growth of grain is that which is most advantageous on the whole, it by no means follows that the farmer shall give himself up to this exclusively; it is seldom that he can do so, indeed ; he must have manure, and this entails the necessity of keeping cattle. If the latter, liowever, be the least profitable item in the economy of a particular domain, it will of course be kept within as narrow limits as possible. In many places where the land is well adapted to the plough, and where the production of grain is unquestionably profitable, stock ap- pears to olfer few advantages ; it sometimes happens, indeed, that the balance as regards the stall and cow-house is on the wrong side for the farmer, when the actual value of the forage that has been con- sumed is taken into the account. The loss is only made up for by the manure, which is in fact the return. This is the view that M. Crud obviously takes when he speaks of the stock upon a farm as a neces- sary evil."^ I am far from participating in his opinion ; the cattle upon a farm are no evil, though they may be very necessary. To be satisfied of this, it is enough, in fact, to recollect the principle which has been established in treating of rotation courses, viz : That in no case is it possible to export a larger quantity of organic matter, and particularly of organic azotized matter, from a farm, than is represented by the excess of the same description of matter contained in the manure consuined in the course of the rotation. By acting otherwise, the standard fertility of the soil would ijievi tably be diminished. This principle recognised, and I believe that it cannot be disputed, it is obvious that a portion of the produce of the fields must be re- turned to them to fecundate them anew, and it is precisely this por- tion of the forage crops destined to furnish manure that must be consumed in the stable and cow-house. Reasoning abstractly, the forage plants which it is not intended should quit the farm, might be buried directly as manure, without being made to pass through the bodies of animals ; their fertilizing influence on the soil would come out sensibly the same ; and this is what is done, in fact, so often as we manure by smothering. But we have scarcely made the first step in the rudiments of agriculture before we discover the immense advantages of following the usual custom, which first employs as forage for cattle the crops that are grown w^ith a view to the pro- duction of manure. And we shall by and by find, in fact, that by adding to that portion of these crops a supplement of forage plat ts which it would be legitimate to export, without trenching upon tne fundamental principle above laid down, we obtain the same quantity of njanure, and turn the whole of this supplement into useful forces, or into animal products which possess a market value greatly supe- rior to that of the forage before its assimilation. It is only the price of this portion of the forage, fixed or modified by the cattle on the farm, which can fairly be set down to the debit account of wool grown, of power created, and of flesh and dairy articles producecL • Theoret. and Pract. Economy of Agricul. vol. ii. p. 235, (in French.) 430 HORNED CATTLE. As to the forage plants which are immediately turned into manuie, it seems to me impossible to regard them as possessed of the proper market value ; the farmer could not have sold them at this. In my mode of looking at the thing, the cost of producing the forage crop, and the value that it actually has, constitute a circulating capital, the annual interest of which, estimated at a certain rate, expresses the true cost-price or value of the manure employed in the 3ourse of a rotation. In a word, in my eyes, the value of the manure which gives fertility to the soil is represented by the price of the labor, the rent charge, &c. — by the general outlay entailed by the growth of the forage from which it is obtained. [ shall endeavor, by and by, to illustrate this topic by examples ; but in order thoroughly to understand this mode of estimating the price of manure, there are several elements wanting, which I pro- pose to assemble in this chapter. With this view, I shall first pre- sent the facts which I have been able to collect, or which I have myself had an opportunity of observing in reference to the economy of the domestic animals attached to a farm ; and I shall then make an attempt to deduce the relation that exists between the consump- tion of forage and litter, animal reproduction and increase, and the formation of manure. ^ HORNED CATTLE. It were foreign to the purpose of this work, did I enter into the natural history of the animals that are usually attached to farming establishments : neither will I pretend to discuss the relative merits of the dilTerent breeds of sheep and oxen, nor speak of the best methods of improving them. I confine myself to the varieties which I have on my own farm, or which I see on the farms of my neigh bors, and upon which 1 have opportunity of making daily observa- tions. It will be enough if I give a brief summary, in this place, of the general principles admitted by practical men of the highest name and authority upon these j)oints.* Between the external forms of animals and the internal organs essential to life, there is the most obvious and intimate connection. A broad and deep chest is the sure indication of ample lungs and a good general constitution. The pclns, or bony cim-ture formed by the rump and haunches, ougiit to be spacious in the f(»males. A small head is generally the indication of a good kind. Horns in our domestic animals must be regarded as objectionable rather than use- ful ; and by adopting measures which tend to repress their growth, we undoubtedly favor both the production of fiesh and wool. The strength of animals depends far more on the degree in which their muscular system is developed than on the mass of their bones ; it is, besides, llesh, not bone, that has value in the butcher's eyes ; so that the farmer's business is by all means to strive after a delicate but well-covered skeleton. Animals which have been indifferently • Cllnc. in GcnomI Report of Scotland ; Communication to the Bo4»rd of Aprirni turc ; SixnctT on llie choice of male animals for breeding from ; Cully's Introduction, ttc, on live stock, Slc. BREEDING. 431 fed while young, have often the bony system very disproportionately developed. Two modes are generally followed with a view to improving the external shape of domestic animals. One of these consists in only breeding from animals of the most faultless forms of the same race, and generally of close degrees of kindred ; anoti.er in crossing females with the males of a neighboring race, each possessing in the greatest degree the qualities which it is held desirable to trans- mit to the future race. The former of these plans is spoken of as the method of breeding in and in ; the second as the method by crossing. Certain disadvantages have been stated as belonging to the sys- tem of breeding in, by the side of several unquestionable and more immediate advantages. While the race acquires small bones and shows a decided disposition to take on fat readily, it is said after several generations to lose in constitution, to become more subject to disease ; the cows to give less milk, and the males, in losing their characteristic masculine forms, to show themselves less fit for pro- pagation. The English breeders who take this view of the subject, are, therefore, in the habit of having recourse to males of the same race, but bred at a distance from themselves. I must for my own part say, that I have seen no reason to admit any ill eifects from propagation continued in the same direct line. Our live-stock at Bechelbronn has not been otherwise renewed for a very long time, and without the race appearing to suffer in any way ; our bulls, on the contrary, have very much improved. Mr. Cline insists greatly on the selection of females not only of good shape, but so much above the mean height as to approach the standard of the males. When the bull is very much larger than the cow, ihe progeny is apt to fall off instead of improving ; the reason for which Mr. Cline finds in the large size of the fcetus, the issue of a large male, which a small female can neither accommodate properly in her womb, send easily into the world, nor suckle duly when it is born. Whatever we think of this explanation, tbere can be no doubt of the propriety of giving the principle pointed at the most careful consideration in practice. Mr. Cline refers to the great improvement that has been effected in the breed of English horses mainly through crosses with small barbs and Arabian stallions ; the introduction of Flemish mares would upon the same principle have been another means of still further improving the race. The neg- lect of tbis principle, Mr Cline is of opinion, lies at the bottom of the numerous failures and disappointments that have been encoun- tered in attempts to improve the breed of horses. A striking illus- tration of it occurred some years back, when bay horses of great height were in particular request ; the Yorkshire breeders had their mares covered by the tallest stallions that could be found ; but they immediately found that the progeny was merely long-legged, that it was narrow-chested, and without either weight or bottom. Spencer acknowledges with breeders in general that the bodily »nd constitutional qualities are almost always those that preponder- 432 MANAGEMENT OF CATTLE. ated in ancestors, and that the qualities of the father predominate in the posterity, particularly as regards oxen and sheep. This point settled, the choice of a good male is evidently the first point of con- sequence in attempting to improve a hreed. As it is not possible, however, to find either a bull, or a tup, or a stallion, quite perfect, the one must be chosen that is most free from defect, particularly the defect or defects which we have it in view to correct in our breeding animals, our cows, ewes, and mares. Certainly no reason- able breeder would bring together animals that presented similar de- ficiencies ; on the contrary, he will strive to have his female served by the male which shows all the qualities in the very highest degree that are most wanting in her. On the whole, the association of animals of the same race appears to me the best mode of continuing desirable qualities, especially when this is conjoined with ample sup- plies of good food to the young. The influence of feeding is im- mense ; in my own neighborhood I see that the progeny of the Bechelbronn bulls are often inferior both in stature and shape to those that are brought up in our own stables. Great size, however, is not always to be regarded as an improve- ment ; height is by no means a constant indication of vigor of con- stitution. Improvement in those particulars of form and stature which are ascertained to be best suited to the circumstances of the locality, the climate, the pasture, &c., are the points to be especially attended to. It is above all indispensable to breed animals of vigor- ous constitution : over-refinement of original races has often led to indifferent conformation of body, and to undoubted delicacy of con- stitution, which has rendered the herd or the flock much more ob- no.xious to attacks of epizootic diseases. The degree of refinement of an original stock is evidently con- nected with the quantity and quality of the forage of the district. In cold and mountainous districts, where the herbage is scanty, it is necessary to restrain the ambition of having highly-improved stock within considerably narrow limits ; in such circumstances, the grand affair is to have a hardy race, not over nice in its food, w hich, through a considerable portion of the year, consists of but coarse grass. The ox {bos tnurus) has been reduced to domesticity from tiie remotest ages, and nothing but conjecture can be oflered with regard to its original race. The animal accommodates himself with won- derful facility to the most opposite climatic circumstances ; he mul- tiplies with astonishing rapidity in the hottest regions of the tropics; unknown at the period of the conquest, he has now overrun the steppes of the vast basins of the Oronoco and the Amazons ; and is met with in vast herds on the highest and coldest table-lands of the Andes, even up to the line of perpetual snow ; wherever there is food, he appears to thrive ; the extremes of temperature seem to have little or no influence upon him. The buffalo (the bos bubuhis of naturalists) is the only other mem- ber of this family that has been domesticated. He is fond of warmth, and is supposed to have been introduced into Italy towards the sixth century, from Eastern Asia. The buffalo is also found in Hungary MA.N'AGKMENT OF CATTLE. 433 and Greece ; and wherever he is met with, he is made serviceable as a beast of draught and burden, and as food. In breeding oxen, the great consideration is the bull. According to Tliaer, the bull ought to have a short thick neck, the head short and small, the forehead broad and curled, the eyes black and spark- ling, the ears long and well placed, the chest broad and deep, the body long, the legs short and columnar in shape.^ A well-made bulf would serve "seventy or eighty cows were the season spread equally over the whole year ; but as it is not so, Thaer thinks that twenty is as many as can properly be given to the same animal ; and this, ill fact, is the number whi(?h we adopt at Bechelbronn. The cow gives more milk than any animal known. A great va- riety of external signs of a good milker have been particularized ; but it may be said that there is none infallible. In a general way, I think that race has much to do with the point ; the cow that is the offspring of a mother of a good kind, and a free milker, will herself be a good milker also. I wall only add. that among the milch-kine which I have had an opportunity of observing, those that showed little tendency to take on fat, while they kept their appetite, have ap- peared to me to yield milk in largest quantity, and for the longest time. The age at which it is advisable to put heifers to the bull, depends a good deal on the way in which they have been kept and brought up, and also on their growth. Young animals of a good kind, that have been well fed from the birth, and received all the care which contributes so powerfully to their development, will be ready to re- ceive the bull when they are between a year and a half and two years old. At Bechelbronn, we bull the greater number of our heifers at the age of about eighteen months. Whenever they enter into heat with any thing like force, whatever their age, they ought to be put to the bull, or there is risk of the disposition to receive him dying away, ancl never returning ; the heifer then begins to lay on fat, and ever after refuses the male. The rule, however, is not to allow the young female to be leaped until she is nearly at her full growth ; this, in fact, is the season when the desire for the male usually first shows itself. If there be no new indication of heat, in the course of three or four weeks after the male has been admitted, there is reason to be- lieve that the animal is pregnant. The cow goes wdth calf about forty weeks ; the delivery generally takes place between the 2'77th and the 299th day after the access of the bull ; but periods so short as 240 days, and others so long as 321 days have been observed.f The calf that is brought up with proper care is generally allowed to suck for five or six weeks ; but it sometimes happens that even at three weeks old the quanity of milk supplied by the mother is insufficient : an additional quantity of food is therefore requisite. One of the best drinks for calves is made by mixing a proper quantity of oil cake with tepid water ; the large proportion of vegetable ca- seum,of oily matter, and of phosphates which the substance contains, * Principles of Agriculture, vol. iv. p. 296. t Teissier in Annals of French Agriculture, vol. ix. 2(1 series. 434 REARING CALVES. makes it peculiarly appropriate food for calves ; diffiised in water, it ill fact bears a close resemblance to milk in point of chemical com- position. It is now, too, that the calf begins to play with a little hay, so that it is always advisable to place some within his reach, the finest and softest portions being picked out. But it is by no means necessary that the calf should ever be allow- ed to suck ; it drinks without difficulty, or can be made to drink, as every dairy man and woman knows, by putting a finger or two into the animal's mouth under the surface of 'the drink. A little warm water is added to the milk during the first few days, in order to give it due warmth. Some begin from the very first to measure the milk ; but those who are best informed upon the subject of breeding and rearing do nothing of the kind. Crud allows his calves to drink as much milk as they will take for the first week After this time they have an allowance of about seven pints of new milk mixed with the same quantity of fresh whey. They are weaned at seven weeks. From the age of between nine and ten weeks to a year, a calf will consume about a fourth of the ration of a grown cow, say 6h lbs. of hay per diem. During the second year, the allowance of hay may be estimated at about 13 lbs., or a little more ; and in the third year it will amount to between 19 and 20 lbs. This is to be understood of cattle brought up carefully but frugally. In some of the best dairies of Switzerland, the procedure is differeui. During the first six weeks the calves are allowed to drink as much milk as they will take without a surfeit. At a month old, they are served with chopped hay and roots, or better still, if the season ad- mits of it, with green clover or luccrn, which they have at discretion till they are seventy days old. Treated in this way, a calf is nearly twice as large and twice as heavy as one that has been brought up economically. During the remaining 295 days that make up the first year, the animal is allowed from 8 to 9 lbs. of hay ; and this quantity is doubled during the second year. By proceeding in this way, a heifer at two years old may herself be a mother and contri- buting to the produce of the dairy. Our procedure at Bechelbronn is calculated on the Swiss plan. The calves suck till they are six or seven weeks old, being put to the cows night 'and morning. Any thing tiicy leave is milked off. After numerous trials by gauging and weighing. I find that our calves take each during the forty-two days they arc allowed to suck, from 028 to GOO pints of milk ; in other words, from 14.] to ISA pints per diem. The quantity of milk which a calf takes immediately after its birth, does not indeed amount to any thing like even the smaller of these quantities ; still it is considerable. A calf which weighed at its birth on the ISth of >ray 108.9 lbs., after having sucked, weighed 112.4 lbs. ; so that it had taken 3.0 lbs. of milk to its meal ; and as it had two of thes«.' in the day, 7.0 lbs. in all. The same calf, thirteen days afterwards, weighed 130.9 lbs ; and after having sucked, 139.0 lbs. ; it had therefore taken 8.1 lbs. to its meal, or 1G.2 lbs. per day. About the third week after birth, our calves have hay of the best REARING CALVES. 435 quality set before them ; they take very little at first, but they soon get accustomed to it, and at weaning time it commonly suffices for their support. It may happen, however, that at this period they fall off a little, but they soon recover again ; still, if any of them appear delicate, it will be prudent to allow about a couple of quarts of milk a day mixed with water, for some little time, which is gradually withdrawn as the animal becomes accustomed to its new food. Calves grow with great rapidity during the suckling time. The only experimental data with which I am acquainted in regard to the increase of weight of calves during the first period of their lives, are those of M. Perrault de Jotemps. These observations I shall asso- ciate w^ith those which I have myself made at Bechelbronn, where, by a happy coincidence, we have the same Swiss race of cattle as Messrs. Perrault at Feuillasse. The weight of three calves at birth was found by JNI. Perrault to be : No. 1 70.4 lbs, No. 2 83.8 No. 3 80.8 Average 78.0 At Bechelbronn the weight of six calves at birth was : No. 1, born in May 108.9 lbs February 88.0 Ditto 90.2 April 100.1 June 88.8 May 101.2 Average 96.2 M. Ernest Perrault found that a calf. No. 1, during the first eighteen days of its life increased on an average 2.8 lbs. per diem ; No. 2 increased at the rate of 1.8 lbs. per day ; and No. 3 at the rate of 2.7 lbs. per day ; average increase 2.4 lbs. per day. An- other calf, born at Feuillasse, which weighed 101.2 lbs., when nine- teen days old weighed 151.2 lbs. ; so that it had gained 50 lbs., or at the rate of 2.6 lbs. per diem ; a rate which corresponded precisely with what was observed in the case of nine other calves fed for the butcher, the average increase of which per diem was 2.7 lbs., during which each has had about 19.3 pints of milk daily. The conclusions come to at Bechelbronn bear a close resemblance to those of Feuillasse : A calf wbich at birth weighed 108.9 lbs. Weighed 13 days afterwards 139.0 Increase in 12 days 30.1 Increase per day, 2.5 lbs. A calf born 12th of Feb. weiehed. . 88.0 lbs On the 30th of March it weighed. .171.6 Increase in 46 days 83.6 Increase per day, l.S The same calf, weaned the 21st of April, weighed 198.6 lbs. Increase in 21 days 22.0 Increase per day, 1.08. It is obvious, therefore, that from the time of weaning, the growth ceases to be so rapid ; the transition from the milk diet to one of 436 REARING CALVES. hard dry food, is often critical for young animals ; and I have al- ready said that it is one at which they frequently lose weight. If we reckon the daily increase from birth, that is to say, for 69 days of mixed alimentation, we have 1.5 lb. for the quantity. Crescent, born the 27th of June, Tveighed. .. S8.S lbs. Eleven davs later 112.1 Increase 28.3 per dav, 2.1 lbs. At the age of 37 days he weighed ISS.l Increase in 26 days 27.1 per day, 2.5 Six days afterwards he weighed 202.4 Increase in 6 days 14.8 per day, 2.3 Another calf at "birth weighed 101.2 At weaning, aged 41 days 189.2 Increase 83.0 per day, 2.1 These various observations give about 2.2 lbs. for the average daily increase of a calf in weight during the period it is sucking. Tlie'data of M. Perrault make a little higher, 2.T lbs. So that it may be assumed that a calf which is receiving from 15 to 19 pints of milk in the day, will be gaining 2.48, or very nearly 2^ lbs. in weight per diem. It will readily be understood that in places where milk is of con- siderable value, as in the neidiborhood of cities, the farmer may find his profit in selling that article directly rather than in turning it into veal or beef, more especially if the usage of the district be to give the calves milk till they are three or even four months old. Noth- ing, in my eyes, can justify such a needless expenditure of milk ; especially since I have had an opportunity of witnessing what I may call the '/ifi/u?Y7/ course of rearing cattle in the steppes of South America. There the young animals only receive milk in any thing like quantity for two or three wwks ; they soon get accustomed to live on gra^s. In the warmer countries of the earth, too, cows give much less milk then they do in tem])erate latitudes, and the secre- tion also dries up much sooner. The value of the milk, and the high price of butter and cheese, arc unquestionably at the bottom of the immen.se slaughter that takes place in France among the calves even at a very early age, when they are fat, but do not weigh more than from lU) to 112 lbs. This 'circumstance undoubtedly stands in the way of the production of meat in that country, and causes the notorious scarcity of meat of the best cjuality. Of the two millions of calves which it is calculated are slaughtered in Franc>?, ,"oths arc killed before they are a month old, and when they do not weigh, one with another, more than from 90 to 110 lbs. But wc have seen that at two months old the weight will have increased to from 15-4 to 170 lbs., more than half as much again ; so that, by merely keeping the animals fur «ine month more, the quantity of butcher-meat brought to market would be increased by about 120,000,000 lbs.* It does not by any means follow, however, as the excellent au. thority 1 have (pioted seems to think, that this increase of butcher, meat would add to the actual amount of food protlucetl by the agrL • Perrault de .Totonips, in Jonrnal d'Asfrlcnlturo, 1. r. REARING CALVES. 437 cultural industry of the country. To produce 2 lbs. of veal, in fact, I have sliown that something like 22 lbs. of milk must be consumed ; but it is evident that 1,200,000,000 of pounds of milk represent an amount of nutri; ive matter superior in value to 120,000,000 of pounds of veal. Could llie production of the addi'ional quantity of meat in the course of the second month be eflected by means of any other food less costly than milk, which is itself a fluid of great value as food, with ordinary forage, for example, or linseed tea, or oil-cake, &c., the state of the question would be changed, and there would then be no doubt of the advantage to the community of the addi- tional supply of butcher-meat. This indeed is so well understood, that all the efforts which have been made to improve upon the ordi- nary and simply natural mode of rearing young cattle have been directed with a view to economizing milk. The interesting work of M. Ernest Perrault, from which I am about to make several ex- tracts, was not written with any other purpose. M. Perrault set out Avith the view of ascertaining experimentally, 1st, whether the large quantity of milk generally allowed to sucking calves is really indispensable, and whether it is possible to diminish it without detriment to the animals ; 2d, whether a portion of the milk can be replaced by hay-tea, an article prepared by pouring 14 or 15 pints of boiling water upon a pound of fine meadow-hay, and infusing for a few hours. The observations were made upon three calves taken after wean- ing. A was kept for 94 days on the usual allowance to calves at Feuillasse ; B had a smaller quantity of milk, and from 42d day after birth had an increasing allowance of solid food ; C in the course of the comparative experiment had 476 pints of hay-tea, and as it is impossible to regard the infusion as of higher nutritive value than the article from which it is prepared, I shall set down this drink as equal to 28J lbs of hay. The allowance of milk was stopped 48 davs after the weaning. A, B, and C' were "kept on their respective rations for 95 days. The three were kept for the first 18 days on milk entirely, during which it was calculated that each had had from the mother 337 pints H3re are the rations in a tabular and comparative manner. A. On the usual allowance. B. On a reduced allowance of milk. c. On hay-tea. Milk in pints. Hay or an equivalent. •s, a S si 11 '5. a 11 i i lbs. Food, 94 days.. .;14G0i 374 j Suckling, 13 days; 34S| . . 1 Days 112 ... jlSOS' 374 Food. 95 days. . . Suckling, 18 days Days 113 .... !ibs.l 1216 396 Food, 95 days... 232 34S, . . j Suckling, 18 days 348 1564 396 Days 113 i 5S0 lbs. 591 _59i 438 REARING CALVES. It would have been desirable to have had these three calves weighed immediately after the termination of the experiment ; as this was not done, the results have not the whole of the precision that seems desirable. Nevertheless, M. Perrault from his observa- tions concludes ; 1st. That A, kept on milk alone, weighed at birth ... 88 lbs. At the age of 452 days 771.0 Total increase 683.0 Increase per day 1.5 2d. That B, on the reduced allowance of milk weighed at birth 83.6 lbs. At the age of 224 days 404.2 Total increase 820-6 Increase per day 1.4 3d. That C, on hav-tca, weighed at birth 111.2 lbs. . At the age of 101 days •.....••• 270.6 Total increase 150.4 Increase per day 1.67 M. Perrault's general inference is, that the calf which had the hay- tea ration grew more rapidly than either of the other two brought up either on pure or on dilute milk. The differences, however, are within the limits of the variations noted in animals that are reared on the same ration. If we reduce the various articles consumed in these experiments to food of the same nutritive value — to hay, for example — we find, that— A consumed in 112 days, 1857 lbs of hay* B " 113 " 1137 " C " 113 " 906 " The mininum ration for the maintenance of calves, to which M. rerrault comes from his experiments, diifoi-s little from that which we think amijly sufficient at Bechelbronn ; and our animals certainly are not inferior to tho.'^e of Feuilla.'ise. This fact may be judged of by the following particulars, which I have selected as affording the elements of contrast with M. l*erraults B and C : Sophy weighed at birth 100.1 lbs. At the age of 102 days 279.4 Total increase 179.3 Incroa.0.0 Apl.21 678.4 July 9 S84.4 Aug. 3 950.4 Esmtralda 8 Orphan 2 Galatea 6 Gitana 6 Ihmnchen 7 Pavsanno ... — . . 7 R:iffa!ea 8 I'riina Donna 8 Formosa 9 EcUc ct Bonne 11 G.iin between one Time Increase weigliiiiK ct another, elaiised. ln24houi8. Rem.irks. lbs. Days. 42 s ., ,f. Fed with hay and ^•^" roots. 19.8 14 1.41 85.2 41 0.85 40.4 25 1.21 80.6 62 1.32 128.4 82 1.50 Was fed on green 206.0 79 2.48 clover at discretion 66.0 25 2.64 INE THREE YEARS OF AGE ANT) UPWARDS. l8t 2d Inte.ral botwcen DilTrV^S o. welKliln/. wciKlilnp. Difference, the welRhlngs. J'crdaj. lbs. avoir. lbs. dvolr. Day-. IbH. 1 1445 1555 110 82 + 1.8 2 1315 1434 119 " + 1.5 IMO 1394 . 146 -17 1820 1886 66 + 0.8 1100 1236 186 + 0.2 1449 1640 91 + 1.1 1672 1727 66 + 0.6 n.-U 16M 130 -1.6 1.^.78 ICOl 28 + 0.4 8 1.^6 12S7 69 -0.6 Taking the procc lin.;- number.;; as tlie authority, and until we liavc a larger number of weighing,'^. I think we may conchido that the living weight of cattle of thv Swiss breed increa.'^es by the follow- ing (juan-ities per diem : Durln? the porlod of suckling at the rate of 2.4 lbs. Under three yc.irs 1.6 Above three years 0.2 Tlie increase of weight of growing animals depends much on the kind of food they have ; and it i.s mat'cr of grea' moment lo know the precise amount of fodder which neat cattle require in order lo thrive. 'J'hoise who have treaied of ir, specially, are as far from being agreed as to the proper ration : ami then many who have ppecifiod the kind nnd qunntiiy of the food, hawMvgNvcd the ;\^-3 ALLOWAXCK TO CATTLE. 4 1 I the absolute weights, the amouiit of labor required, and the inilk ob- tained from the animals. It is subject of simple observation, that an animal of great size, all things else being equal, will require a larger quantity of forage than another of less bulk. Once the allowance of food is well established, it is greatly to be desired that it be continued with the greatest regularity. Nothing is more injurious to cattle than stinting. Still there is a term in every year when the live stock, or some portion of them, at least, are almost necessarily stinted in their food ; in the depth of winter the animals that are not put up to fatten, consume little or nothing but straw\ At this season, consequently, the stock fall off consider- ably in flesh, in strength, and in the milk they give ; and when the loss has been very great, the animals are sometimes too far gone to recover when the spring has come round. This state of things is greately to be deplored, and, indeed, ought to be viewed as most pre- judicial ; it will be altogether impossible to advance the economy of neat cattle to the point of perfection which it is fitted to attain, until means are taken to secure every portion of the stock, at every period of the year, a sufficiency of properly nutritious food. Happily, with the progress of agriculture, this condition is becoming every year more and more easy ; the introduction of roots, (turnips and mangel- wurzel.) and of tubers, (potato,) into the routine of every farm that is respectably managed, supplies a fodder, through the whole of the wnnter, that is equivalent to the grass and other green meats of spring and summer. Thaer fixes at 13 lbs. the quantity of hay per diem which a cow requires for her maintenance in perfect condition ; and if the animal be in milk, he allows as many as from 22 to 33 lbs. But the ration must vary, as I have said, with the weight of the animal. M. Per- rault states 27 lbs. as the allowance for a milch-cow weighing about 880 lbs. ; he having, in his experience, found that an animal in milk required about 6i lbs. of hay for every 220 lbs. of living weight. Pabst, who paid great attention to the feeding of cattle, admits, that for the ordinary allowance of an ox doing nothing, or of a cow which is dry, 3.85, or upwards of 3| lbs. of hay, are required for each 220 lbs. of carcass weight ; 4.4, or about ih lbs., if the animal be a draught-ox ; and 6.6, or upwards of Ga lbs., if it be a milch-cow. The inquiries which I have made into this subject have led me to conclusions somewhat different ; from which I infer, that the rela- tion between the weight of the living animal and the necessary fod- der is not an invariable quantity. A very large ox or cow, relatively to its weight, requires less food than an animal of smaller dimensions. And this circumstance is a grand argument with those breeders who are in favor of very large cattle ; they saw that if a large ox con- sumes more food than a small one, still the increase of consumption is by no means in the ratio of the increase of weight. The milch-cows at Bechelbronn have no more than 33 lbs. of hay per head per diem, or the equivalent of this quantity of forage. But the smallest creature on the farm, at the time my experiments were made did not weigh less than 1110 lbs. '79 stone, 4 lbs.) ; the rela- i42 ■ALLOVTANCE. tion of the living weight to the food being, therefore, as 100 is to 2 73, say 2f . The largest cow, again, weighed 1784 lbs., (127 stone 4 lbs.,) so that the relation is here as 100 is to 1.85, or 1 ioths. The average relation, taking the whole of the cows in the stable, came out as 100 is to 2.25 ; in other words, for every 100 lbs. of carcass weight, 24 lbs. of meadow-hay per day had to be allowed. It thus appears, from these inquiries, that growing animals require moi'e food relatively to their weight than when they are adult. The young animals, upon which I made my observations, were from 5 to 20 months old ; and for this age I found that for every 100 of living weight 3.08, or upwards of 3^ lbs., of hay were required. The fol- lowmg table will give my conclusions at a glance : 0 •o -C — v^ ■o« 1 1 c is i-ss So 0 Average age of the several ^2 111 EEMAEKS. a < i to animals. IS' lbs. lbs. months, days. lbs. lbs. lbs. No. 1 2 107 119 [418 14.3 3 26 209 7.15 3.43 In February 3 4 12G 130 m 14.7 4 6 242 7.85 8.06 ditto. 5 6 7 205 170 IT)-? -1267 86.0 5 9 811.8 18.0 2.89 July. 8 115 9 16-J 11.0 5 10 297.0 6.5 8.70 February 12 g 206 323 290 9.8 6 23 861.4 465 2.68 Septem. 3 4 289 2479 66.0 9 5 495.8 83.0 2.66 Julv. 1 252 • 10 239 9 341 8 303 } 303 2fi5 2586 62.7 9 13 607.8 81.85 2.47 ditto. 10 ''52 11 304 22.0 10 627.0 11.0 8.50 February ] 12 13 14 371 19.1 13 5 B50.0 9.55 8.48 ditto. ! 743 483 2063 62.7 20 5 1027.0 81.35 8.05 ditto. A.verag e per c ent of li vlng weight. . 8.08 1 In the course of the experiments, the calves were kept on good meadow-hay. allowed thom at will, accordinir to our usual custom. tJK^ hay that was put into the crib once a day was woighi^l. and an account was kept and deducted of any that had been loft of the pre- vious day's allowance. The length of time during which each .sev- eral e.xperiuR'iit was continued, varied from 2 to 13 days; and I have thought it right to indicate the season of the year, lest that .should have any influence. To sum up. then, it may be said, tliat for every 100 of living weight neat cattle require : FRKDIXG SALT. 443 For simple sustenance (Pabst) 0.75 or J lbs. meadow-hay. AVhen laboring (Pabst) 2.0 When in milk, (Pabst) 3.0 " (Perrault) 3.12 " " " (Boussingault, large cows). 8.73 ■ " Growing rapidly [Boussingault] 3.0S " The forage ought to be given to cattle witli great regularity, and care should be taken that thej' do not eat too hastily. Generally speaking, thoy have their allowance three times a day, constituting so many meals, which, however, are well divided, the whole quan- tity for each meal not being placed before the animal at once. This precaution is particularly necessary when the allowance consists of green fodder. The watering should take place in the intervals be- tween meals, the animals being driven to the trough night and morning ; though, when the heat is excessive, it is better to water them three times a day. The water ought to be of good quality, though, if it have no deleterious substance dissolved in it, cattle seem to make no objection to that which is turbid, and which can- not, we should think, be very palatable. Our cattle are watered, during a part of the year, with water from a shaft pierced through a highly argillaceous soil. Cattle seem to dislike excessively cold water ; they then drink as little as possible. The cattle in the great South American plains, drink water at a temperature of from 85° to 97- F. In Europe, the best water in point of temperature in winter is that of a deep well. Every one is familiar with the taste which herbivorous animals show for salt, and this is one of the articles which is advantageously made to enter into the ration when its price is not too high. In France, it is absolutely necessary to use the article with extreme pirsimoay — a circumstance which I much regret, and which I can- not but view as prejudical to rural economy : — [in England, where the odious salt-tax has been got rid of, salt, of the most beautiful quality, is one of the cheapest of all manufactured substances.] I know that many feeders do not think salt indispensable; but their authority is opposed by that of some of the highest names in Ger- many and England, and my own mind has long been made in regard to the value, to the excellent effects of this substance. I ascertain- ed, for instance, that milch-kine, though they would not do upon potatoes alone, throve very well when they had from two or two and a quarter ounces of common salt added to the ration. A celebrated English breeder, Mr. Curwen, recommends about 3.] ounces of salt to be given daily to cows and heifers in calf, and to draught-oxen, and something less to fatting oxen, to young animals, and to calves.* The high price of salt in France does not allow us to be so liberal at Becheibronn ; yet we make a distribution of the article three times a week, and in quantities which bring the allowance to some- thing more than about an ounce and a half per day. By way of eking out the allowance of saline matter, we further supply, from time to time, a quantity of Glauber salt, which comes in all to rather * Sinclair, Agriciilture. 444 MILCH-KINE. more than half an ounce per head per diem. The nse of this salt, sulphate of soda, has long been common in Alsace, and also on the other side of the Rhine ; and its effect on the health of horses and of sheep, as well as of horned cattle, has been reconized as highly advantageous. In Wurtemberg, the horses have, very commonly, 725 grains, neat cattle 463 grains, sheep 305 grains, and swine 250 grains of Glauber salt twice a week."^ Salt appeal's to be more especially useful in hot weather and in warm climates. In the steppes of South America, it is held by the llama keepei*s as an axiom that cattle cannot live without salt. AVherever a flock thrives particularly well, it may be averred a priori, that there is a salado there, a salt lick of the North Ameri- cans, or place where there is a salt-spring. In the savannas that are without saline springs, the herdsmen make a distribution of salt every day. On the plateau, or table-land, of Nueva Granada, com- mon salt is replaced with Glauber salt, as in Alsace and Wurtem- burg, and I may say, that it was matter of much interest to me to find the same custom prevailing on the table-lands of the Andes as upon the banks of the Rhine. ^ II. MILCII-KINE. I have already had occasion to say, that the signs by which the qualities of kine as milkers wore sought to be appreciated, are some- what deceitful. Still, I am far from denying that practice and ex- perience do not enable many persons to pronounce with some cer-. tainty upon this jiarticular. The ])Owcr of doing so, however, is in some sort tlie peculiar privik^ge of him who possesses it ; at least, I have seen all the general rules that have been laid down on the sub- ject fail ; I have situ cows of the most opposite conformations equally productive. I have also said, that race or descent hud nuich to do with this (juality ; the heifer that comes of a mother, a good milker, will be very likely to turn out a good milker also. Tlie legitimate way, therefore, of obtaining a good race of milch-kiiie, is to breed them from a stock that is already noted in tliis respect. At the time of my penning these lines, there are two animals on the farm that are remarkable as milcli-kine : one is a tall, unseemly animal, the bones projecting, and altogether thin and miserable ; the other is a small cow, with rounded outlines everywhere, the bony frame but little cons[)icuous ; her skin soft, her hair sleek and fine. Xevertheless, these two animals have one character in coinmou — the udder is of extraordinary size. We ought not to be hasty in judging of the value of a milch-cow after the first calf; age has great influence on the secretion of milk. It is generally allowed that a cow does not attain to her maximum capacity of yielding milk until she has passed l-cr sixth year. With rega'rd to the means we have of judging of the age of a cow, they arc princi[)ally derived from the horns. The teetli do not af- ford us any i(idic;itioii, as in the horse and sheep. In the ox, about * r.tnimnnirnted hv M. Pohattcnm.anit MTLCII-KINE. 445 the fifth year, there is a ring formed about the root of each horn ; in the cow,' this ring- makes its appearance after the first calving, and from this epoch there is a new ring formed each year, which pushes on the former one. In aged animals these rings have become faint, and can scarcely be counted. It is also evident that the horns which, in early life, were thicker at the base, and tapered gradually toAvards the tips, about the ninth or tenth year of the animal's life present an opposite conformation ; they exhibit a kind of constriction at the roots. The depression above the eye increases with age, and the iiilse hooves become long and often bent. Thaer reckons that, one with another, in well-regulated establish- m .^nts, cows will continue in milk for about 280 days, and yield in all about 22G5 pints, or 283 gallons. But it is certain, that the yield- ing of a cow varies greatly with circumstances, race, age, climate, and individual. The cows that graze at liberty in South America, do not give more than about three pints of milk per diem ; which, as it is almost wholly used in bringing up the calf, the dairy is there of very little importance. In established farms, a cow is reckoned to yield about 40 lbs. of cheese per annum. Mr. Curwen estimates the quantity of milk at 6580 pints, or 822 gallons, per cow ; M. Per- rault states it at but 2992 pints, or 374 gallons ; and Mr. Low gives the quantity at 5994 pints, or 7491 gallons. The differences between these several quantities are obviously enormous, and can scarcely be reconciled with any conceivable diversity of circumstances. They are probably connected with the method taken to ascertain the quantities. The following table comprises the whole of the statements with which I am acquainted. Authorities. France : La Feuillasse [Ain] Louiprics [Ain I . . . . Roville [Mearthe] Lyonnais [montagnes] Bachelbronn [Bas-Rhin] England Do. Belgium : Antwerp Do Holland : Low countries — Do Canipine .. Saxony : Meissen ... Altenburg Austria: Carinthia Prussia : Moeglin Neighborhood of Berlin Switzerland — Hofifwyll - . . P. de Jotemps. D'Angeville. Do Doinbasle. Grognior. Eel & Boussinf Low jCurwen iScbwertz. Schwartz. Schwertz. 'Alton. Schwertz. Schweitzer. Schmalz. Burger. Thaer. Thaer. D'Angeville. D'Angeviile. 'lt.l j lbs. lbs. pts. 88o! 27.5 2992 605 14.31610 22.02492 " |1284 33.0| " Observations. pts. Cows 8.2 In the house 28.6 6580' 27.2 4495 27.2 3967. " ,3400! " 7066' » 9318 18.6 26S7| ' j 30.8 3412: 5| " 2752; 122.0 2648, 1 "j 27.5 30041 11036 " 2992; !l320' 33.5 4685 16.2 17.8 12.3 Do Do, Ill-fed in winter Do. Do. Do. [house. 10.9 At grass & in the 9.2iln liouse, winter 19.4 26.51 17.3,Kept in house. 9.2| 7.5 Well fed. 7-2 Kept in house. 8.2 8.2| Do. 12.8. Well fed. At Bechelbronn we have seven cows whose allowance per head is 33 lbs. of hay per diem. The milk is measured night and morn- 38 446 MILCn-KINE. ing, and the quantity given by each cow is particularly noted. The herd consisted of Raflfalea, 8 years old, whose milk failed the 21st of April, and reappeared the 18th of June without her having calved ; — La Paysanne, 7 years old, whose milk ceased the 21st of February, and she calved the 29th of April ; — Prima Donna, 8 years old : milk stopped February 19th, calved December 5th; — Formosa, 9 years old : ceased milking 1st April, calved 2d June ; — La Gitana, 6 years old: ceased milking 30th September, calved 9th November ; — Gala- tea, 6 years old : ceased milking 9th July, calved 2d October : — Belle et Bonne, 114 years old : ceased milking the 15th February, calved 3d April. These seven cows gave in the course of the year, neg- lecting fractions, 30576 pints, or 3822 gallons of milk. In the month of January, in round numbers, 1870 pints; in February, 1260 pints; A[arch, 1260 pints ; April, 1657 pints; May, 2527 pints; June, 3726 pints ; July, 4180 pints, August, 3661 pints ; September, 2913 pints ; October, 2622 pints : November, 2540 pints ; December, 2360 pints ; having, one with another, given 546 gallons of milk, and milked on an average 302.\ days each ; the entire herd having milked during 2118 days, and the average c{uantity yielded by each cow having been 14.6 say 14.^ pints for every day she was in milk ; the quantity for each day of tlie year amounts to 11.9, say ]0 pints. June, July, and August arc obviously the months most productive of milk, during which the cows had scarcely any other food than clover. The average quantity for these months was undoubtedly raised from three of the cows having calved in March, April, and May, so that these were severally giving their largest measures dur- ing the three summer months. It may be enough to state, that the largest quantity of milk is ob- tained in the course of the three first months after calving ; the pro- duce then will amount to 18, 20, and even 24 pints per day, while the mean quantity during the whole time of milking will very little exceed 12 pints. The observations for the year 1842, which I referred to some short way back, showed a mean of 14.6. say 14A pints of milk for each cow. But in the mode of reckoning pursued, there were sources of error, which have been avoided in the estimates just given. The only mode of securing accurancy of result is to take the quantity of milk yielded by each cow between the period of calving one year to the same event the following year. This mode of reck- oning gives the quantity 13 jiinls per day for each cow, which I am disposed to adopt as the standard for the Swiss breed, fed with 33 lbs. of good meadow-hay, or an e(|uivalent of wholesome roots, &c. I am also disposed to look upon 310 as the mean number of days during which a cow will give milk after calving. We sometimes see quantities of milk mentioned as given by par- ticular cows that are truly surprising, and that seem even calculated to excite suspicion of the veracity of the reporters. Some have spoken of cows that gave 44 and 52.^ pints of milk a day for several months. M. Crud says that cows of great size indeed have even given as many as 70.4 pints in twenty-four hours ; and Thaer goes MTi.rii-inxE. 447 Btill further when he states that persons worthy of every credit say they have seen cows in first-rate pastures, which, at the height of tlioir milking time, produced as many as from 74 to 82.} pints of milk in the twenty-four hours. Such a fkix of milk can only be very tem- porary, and indeed must occur but very rarely. The herdsmen at Bochelbronn have often diverted me with tales of such marvels ; but since I have accurately guagcd the dairy produce of the farm, 1 have met with nothing whicli would lead me to credit their reality. We have had cows indeed which have given 26i, and even 31^ pints a day for several weeks ; but these are still very far from the quantities which have been mentioned to me. Good feeding is undoubtedly required in order that cows may pro- duce milk abundantly ; but I believe that the influence of particular kinds of forage on the production of milk is often greatly exaggera- ted. Each breeder or feeder seems to have his own favorite article, however, so that there is nothing like uniformity among them ; with one it is the carrot that is in the ascendant ; with another it is the beet that is supreme ; there is no root, in fact, which has not alter- nately had its apologists and detractors. The truth lies between the extremes here as it does in so many other instances ; and I am sat- isfied that each and all the roots and other articles of forage that are generally introduced into the rations of milch-kine, are calculated to produce" abundance of good milk ; it is only necessary that the sub- stances be alloAved in ample quantity, that no mistake be committed in regard to the nutritive equivalents of the several articles. I do not hesitate to add, that the opinions of the generality of farmers and dairymen on the subject are based on observations which are always more or less imperfect. It is but a few years ago that a series of experiments were under- taken at Bechelbronn, with a view to ascertain whether the particu- lar nature of each of the several articles consumed by milch kine influenced the quantity or chemical constitution of the milk in any appreciable manner. * The purpose of ihese inquiries being purely practical, having been undertaken with as pecial eye to the dairy and its produced the inquiry was confined to the articles that are usually given to cows with us. These necessarily vary with the season, but I have already said that the dole to each head is equiva- lent to .33 lbs. of meadow-hay, which, indeed, always enters in con- siderable quantity into the ration, whatever else be given, unless, indeed, the animals are exclusively upon green meat, Avhen, of course, the use of every thing else is suspended. In winter the hay is mixed with beet, potatoes, turnips, or Jerusalems. In spring the hay is gradually replaced by green fodder, which in the first instance is rye cut green, and by and "by clover. The experiments which I shall now detail were made upon a cow which had calved two hundred days, and was again pregnant. 1st EXPERIMENT. 200 DAYS AFTER CALVING. The cow fed on hay alone gave 65.42 pints of milk in the course of seven days, or 9.34 pints per day. This milk consisted of: MS MILCH-KIN E. Caseum 3.0 Butter "^-^ y Solids 12 4 Sugar of milk 4.7 ^ ^^olids 1^.4 Ash of caseum 1.0 , Water 87.7 100.0 2d EXPERIMENT. 207 DAYS AFTER CALVIXG. 'Fed with turnips and cut straw, (the ration consisting of turnips eq lal to 29.7 lbs., and straw equal to 3.3 lbs. of hay,) the same cow gave in the course of eight days 84.4 pints of milk, or 10.5 pints per day. The composition of this milk was : Caseum 3.0 ) Butter *-2 l Qnlids 12 4 Sugar of milk. 5.0 f ^^'""^ ^^-^ Ash of caseum 0.2 ) Water 87.6 100.0 The animal discussed her provender with good appetite, but the ration was too large ; about 11 lbs. of the turnips being left each day unconsumed. 3d EXPERIMENT. 215 DAYS AFTER CALVING. Tlie ration here consisted of : Field-beet, an equivalent for 29.7 lbs. of hay. Chopped straw " 8.6 " In the course of fourteen days the quantity of milk obtained amounted to 137.G pints, or 9.8 pints per diem, and was composed as below : Caseum 3.4 Mifklugar •::::::;:::::;;.;;;:: 6:° >soiid« 12.9 Ash of caseum 0.! Water 87.1 3.4) 4.0 f 8.3 ( 0.2) 100.0 4th EXPERIMENT. 229 DAYS AFTER CALVING. Tlie ration consisted of: Tlnvr potatoes equivalent to 29.7 lbs of hay. Choi)ped straw " 3.6 " In the com-.^e of eleven days the cow gave 9G.1 pints of milk, or at the rate of 8.7 pints per day, the fluid consisting of: Caseum 8.4 ) ?n,V^,,.ar::; ::::::::;::■:.•;■ J:§ so"-"' "■= -\sli of caseum 0.2 J Water 86..-) 100.0 The cow did not do well upon this regimen : she became heated, and refused oue-liaif the straw. In a general way we do not uivc tubers to a greater extent than is equivalent to one-half of the allow- ance of hay. in which proportion cows do very well upon ra\y potatoes. MILCH-KINE. 449 5th EXPERIMENT. 240 DAYS AFTER CALVING. The forage here consisted of the full allowance of hay, or 33 lbs. In the preceding experiment the milk, which had hitherto kept up to from about 9^ to 10.^ pints a day, fell suddenly to little more than 8.] pints. To ascertain whether the fall was owing to the potato regimen or not, the cow was returned to the ration of hay, under which in the 1st experiment the daily average of milk was 9.3 pints. In the course of thirty days 188 pints of milk were collected, at the rate of 6.2 pints per day. The declension in the quantity secreted consequently cannot be ascribed to the potatoes which were given in the fourth experiment. 6th EXPERIMENT. 270 DAYS AFTER CALVING. The ration here was raw potatoes, with salt and straw — the ration of the fourth experiment, with the addition of about 2^ oz. of salt. The animal ate this salted ration with appetite ; she also made away with the whole of the chopped straw, and it agreed well with her ; nevertheless, the milk continued to decrease in quantity ; it had failed off to 5.9, say 6 pints a day. 7th EXPERIMENT. 290 DAYS AFTER CALVING. In this trial the ration consisted of Jerusalem potatoes equivalent to 33 lbs. of hay, under which the milk may be said to have remain- ed stationary, though it was above rather than under the 6 pints per diem as in the 6th experiment. In composition it was as follows : Caseum 3.3 ^ ?SVm,iv;;/.v;.;.:v.-..:::: I5 h°M^i2-5 Ash of Caseum 0.2 } Water 87.5 100.0 The quantity of the milk had obviously decreased from the first down to the two last experiments ; but its chemical constitution does not appear to have varied during the entire course of the trials ; the varied regimen has had no influence on the proportions in which its several ingredients are encountered. But there was still one point to be ascertained, viz. : whether the milk secreted very shortly after the delivery differed from that which was formed at a period remote from that epoch. 8th EXPERIMENT. A cow which had calved twenty-four days before, and, upon a mixed regimen of hay and green clover, was giving at the rate of 18.6 pints of milk a day, was brought under observation. Analysis showed this milk to consist of : Caseum 3.0 ) S'ofm,it.::;;;;:.;:.;;;::; ti soM'"-^ Asli of caseum 0.2 j Water 8S.8 100.0 PR* 450 MILCH-KINE. 9th EXPERIMENT. 35 DAYS AFTER CALVING. The same cow, upoa green clover, was now producmg 21.2 pints of milk a-duy, and of the following composition : Caseum 3.1 ^ IS^'of-miik;:;;;;;:;:;;::::::42[soiidsi3.2 Ash of caseum 0..3 ) Water 86.8 100.0 This milk evidently presents a larger quantity of butter than ap- pears in any of the preceding analyses. But no hasty conclusion must be drawn from th's : for the succeeding experiments will ex- hibit a change equally sudden in the proportion of the fatty element, but in a difterent way. In a second series of experiments I set myself the task of ascer- taining whether green fodder had any such remarkable influence on the production of milk, and especially of its fatty element, or butter. 1st EXPERIMENT. BEGUN 17G DAYS AFTER THE CALVING. The ration here consisted of winter fodder : Potatoes equivalent to 16.5 lbs. of hay. Ilay " 1G.5 " Upon which the cow had long been kept though the milk was only measured during the last six days. The quantity was 16.3 pints a day, and consisted of : Caseum 3.3 Butter 4.8 1 q-uj. i., r Sugar of milk 5 ^ l^ Solids 13.o Ash of caseum 0.3 Water 86.5 100.0 2d EXPERIMENT. 182 DAYS AFTER THE CALVING. Mixed regimen: Green clover equivalent to 16.5 lbs. of hav. Hay " 16.5 " Upon which the quantity of milk was at the rate of IT pints a day, 3d EXPERIMENT. 193 DAYS AFTER THE CALVING. Green meat : Clover equivalent to 33 lbs. of hay. Quantity of milk, 17.2 pints a day, composed of. CaJioum 4.0 f;'r;.fn,uw:;.v:;.v.;:;; ">soM>n.i Ash of caseum Water S9.7 4.0) 2.2 ( 4.7 f 0.3 j 10O.O MILCH-KINE. 451 The small quantity of butter here induced me to repeat the analy- sis, but the result came out very nearly the same, the quantity being still but 2.35 per 100. 4th EXPERIMENT. 204 DAYS AFTER THE CALVING. Green fodder : same quantity as before. Milk per day 13.7 pints, composed of : Caseum 3.7 ^ l'„°Jar«fn,iii-.:::;::::;:;:;:::?;2[so.wsi2.6 Ash of caseum 0.2 j Water 87.4 100.0 It would therefore appear that fresh-cut clover has no such virtue as that of increasing the quantity of milk given by cows. Under the winter fare, in fact, the milk produced in the course of the twenty-four hours amounted to 16. f pints ; under green clover it was but 14.9 pints. It would be a great mistake, however, as I conceive, to ascribe the diminution here to the use of the green forage ; it is due, I apprehend, exclusively to the greater length of time that has elapsed since the period of calving. The chemical composition of the milk varied little, as I have already incidentally remarked, in the course of these experiments. The differences in respect of the caseum, by which let me say I understand the whole of the azotized constituents, the whole Jlesh of the milk, rarely exceed one hundredth part. The proportion of the fatty element varies suddenly, and, as it seems, independently of the various circumstances in which the cows are placed. The general inference from these experiments, then, is that the nature of the food does not exert any marked influence on the quan- tity and chemical constitution of the milk (I do not now speak of the quality of the fluid) if the cows but receive the proper nutritive equivalents of the several sorts of provender. It is of great impor- tance to insist on this point ; fur it is quite certain, that if the weight of the several rations be not calculated according to that of ■ the equivalents, variations in the secretion of milk would be forth- with conspicuous ; but then these variations would have the increase or diminution of the provender allowed as their cause. "When cows are kept through the winter upon straw alone, they cease to give milk ; but on the return of green forage, in the spring, the secretion is restored. The re-appearance of the milk in this case, however, is not connected with the coming in of the fresh provender, but with the return of plenty ; the animals are not only fed, from having been starved, but they are more than fed ; they have something to spare, which their economy turns partly into milk. In well-managed estaldishments, where a good system of hus- bandry secures an abundant supply of good nutritive provender to the cattle during winter, the produce of the dairy during this season differs much less from that of the summer than is generally supposed. I am besides persuaded that we estimate the nutritive powers of 452 FATTENING. green forage at too low a rate, and that v^•^,on cattle arc upon wet clover or lucern, they are in fact mnoli n; re effectually nourished than under ordinary circumstances. If it be true, as it evidently is, that the quantity of milk produced depends especially upon the absolute Cjuanlity of nutritive food con- sumed, it is not so with the quality of the tiuid. It is undeniable, that the milk of spring and summer, formed upon green and succu- lent food, is much more palatable than that of the winter season; the butter is also much finer and better flavored. The green herbs of our pastures undoubtedly contain volatile principles which are dissipated and lost in the processes of drying and fermentation which they undergo in their conversion into hay. If chemistry be powerless in seizing such principles, it still informs us of the possi- bility of introducing a variety of articles into the food of cows which have the property of communicating those qualitie.«! which we prize in milk. In all grazing countries certain vegetables are pointed out as giving, in the vulgar opinion, a particular aroma to the flavor of milk. ^ III. FATTEXIXC. OF CATTLE. Under a parity of circumstances, feeding cattle for the butcher may occasionally be found more advantageous than the dairy to the farmer. In feeding for the market there is, in the lirst place, a quicker return for the outlay than in keeping milch-kine through the whole of the year. In the first oj)eration. the capital is realized at the end of lour or five months ; that which is cmjiloyed in produ- cing milk, and butter, and cheese, is always lying out like a sum at interest. The quantity of food requisite to bring cattle intended for the butcher into condition, does not vary less than that which is recjuired to secure a ))kntiful production of milk. Thus the stature, the age, the race of the individual, and the relative proportions of tiesli and fat which we would have laid on, all imply varied doles of various kinds of forage. The age in esjiecial lias to l)e considered ; for in putting uj) a young animal to fatten, we have both flesh and fat to form. This is what always occurs in the fattening of oxen of two years old, and of jngs of ten or eleven niontlis. The increase in living weight experienced at various ages, is not equally owing to accumulation of fat ; this indeed may be so in the ca>e of beasts, the muscular system of which liaa already attained complete devel- opment, but it is otherwise with young lyul still growing animals. Practice does much in enabling us to select the animals that will fatten readily. In a general way it is well to choose young animals that have a large chest, the body bulky and rounded, tlie ribs fnicly arched, the bones snuill, the limbs short, the neck thick for its length, the skin soft, pliant, velvety to the touch, and moveable ovit the body, particularly over the ribs, the tail should be seanty, tho buttocks not deeply cleft, but fleshy — well breeched, as the phrase runs in some diatricts. The look of the animal should be sluirp FATTENING. 453 and bold ; the liorus slender, whitish, and rather transparent. Tho animal must have been cut while he was stiU at the teat. The celebrated Kn,5lish breeder, Robert Bakewell, succeeded, after a long- and troublesome course of experiments, in creating a race of neat-cattle and of sheep which show themselves particularly disposed to take on fat. The iundamental principles established by Bakewell, after all his experience, are these : that smallness of bone, fineness of skin, and cylindrical shape of body, are the surest indications in cattle of the disposition to lay on fat readily, and upon the smallest quantity of provender. The most striking features in the breed obtained by Bakewell, commonly known as the Dishley breed, may be summed up in the following terms : 1st. The animal low on his legs. 2d. The back-bone straight. 3d. The carcass rounded and almost cylindrical. 4th. The chest deep and large. An ox is held to have grown rapidly and well, when at the age of three years he weighs from 1016 to 1051 lbs. avoirdupois, from 72 to 75 stone. The disposition to fatten young is also a precious quality in the beast which it is intended to bring for the butcher ; the feeder comes the sooner at his return, Sinclair thinks, that in- dependently of good constitution, which is indispensable, this quality is derived especially from meekness of disposition, from good tem- per ; and as docility is generally the result of good treatment in early life, young animals ought always to be treated with great gentleness and made perfectly familiar. The different races do rjot all. yield meat of the same quality, and this quite independently of age. The best meat has a very decided and characteristic flavor after it is dressed, which indifferent meat wants, or which is replaced by a savor that is disgusting rather than agreeable. The fat in the best meat, as well as being laid on superficially, is distributed through the substance of the muscles, so as to give the flesh a marbled aj-jpearance. In fattening cattle it is perhaps of more importance than in gene- ral feeding, that the provender should be distributed regularly ; plenty of soft litter, and the greatest attention to cleanliness, aid materially in fattening. The cow-house ought to be dark and quiet ; in a word, all the conditions ought to be combined which conduce to sleep, and secure freedom from disturbance of every description. The age at which cattle fatten most readily is that from 7 to 8 years.* Animals under this age, which have not yet come to their full growth, will nevertheless get into excellent condition ; but they require both longer time and more food, for the reason, apparently, that they are still forming both flesh and fat. In fattening during winter, which is done almost exclusively with hay in some countries, an ox weighing 748 lbs., upon 40 lbs. of hay per diem, will increase by about 2 lbs. daily. According to Mr. * This is as in the original, and may be true, but in England and Scotland we havo seldom an opportunity of pro-\ ing it so. — Eng. Ed. 451 THE OX. — FATTEXING. Low, an ox weighing 770 lbs., and consuming about 2223 lbs. of tur- nips per week, if he thrive, will gain in the same space of time nearly a stone in weight. Admitting that the equivalent number for turnips is 676, 1 find that the ration of hay for this allowance comes out 47.8 lbs., having produced exactly 2 lbs. of increase. In the information obtained in the Rhenish provinces by M. Moll, in regard to the fattening of cattle under the influence of a regimen which would give 11 lbs. of hay to every 100 lbs. of dead weight, the animal will increase one third in weight in the course of three or four months. To these general results I add a few particular facts, which are, indeed, the only data in rural economy that can ever be received as having much value. In a series of experiments which he undertook, Mr. Robert Stephenson proposed to compare the progress of the increase in weight of oxen upon different alimentary regimens. Starting with the principle which we have already established, that animals con- sume a quantity of food in proportion to their weight or size, when they are under the same conditions, he had of course to divide his stock into several lots, each made up of animals of as nearly as pos- sible the same weight. Oxen of two years old, brought up on the same farm, and kept in the same manner, were the subjects of exper- iment. I shall select one experiment, in which the observations were made upon three lots of six beasts each. The weight of each lot was ascertained before and after the experiment, which was car- ried oil for 119 days. The first lot was put upon white turnips, linseed oil-cake, beans, and oats ; and for the last 24 days each beast had 20 lbs. of pota- toes every day in addition. Tlie second lot was f.'d like the first, with the diflference that it had no cake, and that during the last 24 days the quantity of pota- toes allowed was but 10 lbs. per diem. The third lot had no other provender than turnips. Here are the weights and the nature of the provender consumed by the animals during th3 119 days, with a column added contain- ing the equivalent in hay corresponding with each of the articles consumed : LOT I. LOT II. LOT IIL Equ Talent F/)uiTi|«nt &iaiT«l?nt Kqalvalrnt ProT-nJi-T. W.ifht in hay Wrijht in hay W«.ght In hiy a,»unn4. Whlto turnips.! 1513 171.6 ifi93 m.3 1122 '"l27' 835 Swedes 13:336 197.5.4 133S1.3 19S0 12012 1777.8 676 Beans 853 1559.S 8.->S 1559 " " 23 Oil-cake 8S9 17t>S " » " « 22 Oats 178 279 173 279 " •' 62 Potatoes 479 151 289.8 77 " " 315 Ration expressed in hay 6904 8971 1905 It tlierofore plainly appears that the lot which had the largest THE OX. FATTENING. 455 allowance of provender, the food which contained the greatest quan- tity of azotized principles — oi flesh, m fact — produced the largest amount of dead weight in a given time, and that the lot which had the shortest allowance increased in the smallest measure both in flcsli and fat — results which might have been readily foreseen. It is also apparent, from the table, that in proportion to the nutritive value of the article consumed by each lot, the increase in carcass weight was greatest in that Avhich received its allowance in the least bulk. Thus reducing the different rations to a standard forage, we find that in the first lot, which was most plentifully supplied, 100 of hay gave 4.2 of increased weight ; while the same allowance of hay produced 6 in the third lot which was fed parsimoniously. This fact is most readily explained : over a certain limit, the more food an animal receives, the smaller is the fraction which is assimilated and turned to use in the body. Breeders have consequently discov- ered, that it is by no means generally advantageous to push animals beyond a certain point of fatness. The excess of weight which is obtained with the assistance of quantities of food, exaggerated as it were, no longer compensates for the additional expense incurred. This is a circumstance which Mr. Stephenson's experiments also illustrate, and indeed they led him to the conclusion which has just been stated. Judging by the market price of the several articles of provender employed by this distinguished breeder the first lot appears to be that the fattening of which turaed out the least advantageously: while each pound weight of flesh produced here cost about 5(i., the price of production in the second lot did not much exceed M. (43 th ;) in the third it was a little more, (4|ths.) With these observations of Mr. Stephenson, we find the following numbers to express the daily increase in weight of the cattle during the period of fattening : Hay consumed per day Inorea»« per he«d Increase per day and and per h"ad. In lIBdayy. par h<)ad. lb«. lbs. lb*. 49.7 247.5 2. 34.3 231.6 1. 9 16. 112.6 0.9 The weight of the several animals must also be taken into account' in seeking to estimate the increase realized upon every 100 lbs. of live weight during the fattening. In the 1st lot— 100 of live -weight In 119 days gained, 22.2 2d » " 22.8 3d " " 14.2 It is seldom that cattle are fattened in the house upon clover or lucern in the green state ; nevertheless, animals will fatten upon this forage with great rapidity. An ox will eat as much as 1 cwt. of clover cut in flower in the course of the day. In case the green food should relax the bowels too much, a fraction of the allowance may be given dried, and towards the end of the fattening a little cake may be given. But these additions do not appear to me indispensa- ble ; they are always attended with additional cost : and I have A T -rage weight of the oxen before fallenh;g. lbs. 1st lot. 2d " . 3d " . ...1115 . . . 1016 ... 794 456 THE ox. FATTEXIXG. frequently seen cows, upon green clover at discretion, acquire a remarkable degree of fatness, although they had not ceased to be regularly milked. In those countries, the nature of whose climate is favorable to pasturage, the rearing of cattle presents immense advantages ; but the animals can only be fattened in those that are the most fertile. The meadow that suffices for the growth and keep of a bullock will not always bring the animal into condition for the butcher. Those countries where the climate is moist, but long droughts rarely felt, where neither the summer heats nor the winter colds are excessive — the conditions, in fact, which are met with in the beautiful pasture lands of England, in special — are those that prove most favorable to the rearing and feeding of cattle. The pasture lands of Nor- mandy and Brittany in France, of Switzerland and Holland, several of the provinces watered by the Rhine, &c., are also remarkable for their luxuriant herbage. In such situations and with such advatages, the grand object with the farmer is the production and fattening of cattle. Whenever it has been possililc to lay down extensive and productive meadows, it is now beginning to be clearly understood that the introduction of even the best system of rotation were to make a false application of agricultural science. In my opinion, there is no system of rotation, however well conceived and carried out, which will stand comparison in point of product ivene.-?s with a natu- ral meadow, favorably situated and pro])er]y attended to. The rea- son of this is obvious, ans. of his absolute weight : Of m.irkctaMe iripnt M.5 lbs. An ox somewhat fatter will yield. .. S5 " And one completely fat as niany as. . .62.2 " Mr. Layton Coke's estimate is : For a lean ox f>») per cent, of marketable meat For an ox in middling condition. . . 65 And for a fat ox 73 '• These estimates appear to me exaggerated, and I much doubt from the sales of cattle which we make ourselves, whether they would readily be admitted by the buyers ; they are in fact too high as re- gards the available meat. From a great numbor of actual trials made with animals of about two years old, and which were all as nearly as possble in the same THE OX. FATTENING. 459 condition, Mr. Stephenson was enabled to determine with great ac- curacy the actual weight of the butcher's meat in contrast with the entire weight of the animal. Mr. Stephenson comes to the follow- ing conclusions : Butcher's meat per cent 57.7 Tallow 8.0 The hide 6.5 The entrails and oflfal. 28.8 100.0 The precise quantities of marketable meat and of ofFal have also been determined by Mr. Mallo in an ox of the Durham breed which was slauiihtcred in his presence. The weight of the animal on its feet was 1490 lbs. Per fenlage of ».«. l;ve weight. The two fore quarters weighed 405.9 | ^^ . The two hind " 423.5 f ^'^ The skin 62.7 4.2 The tallow 112,0 7.5 The blood 110.0 7.4 The head, fat, and entrails 381.7 25.5 1496.0 100.0 These relations as to meat, tallow, and skin agree in a very con- siderable measure with the estimates of Mr. Stephenson. Sir John Sinclair gives the following numbers as the results ob- tained in connection with an ox of the Devonshire breed, slaughtered at the age of 3 years and 10 months. "Weight of the living animal, 1549.6 lbs. Per rentage of lbs. the live weight. Butcher's meat, the four quarters 1083.5 70.0 Theskin 84.9 5.5 Tallow 143.2 9.2 Entrails and blood 163.6 10.5 Head and tongue 86.7 2.4 Feet 17.1 1.4 Heart, liver and lungs 20.4 1.3 1549.4 100.0 The animal here was not in prime condition. On the whole, the relations as stated by Mr. Stephenson may be taken as those that will be found nearest the average truth, and as his numbers are de- duced from numerous actual experiments, I feel disposed to adopt them. ]\I. Dubois has found that an ox which will weigh 473 lbs., sinking the ofi'a!, will be brought by fattening to the w^eight of 763 lbs. We have, therefore, for the w^eight of an animal as it stands : Before fattening 828 lbs. After fattening 1386 Gain in weight 508 The fatteninsr having been effected in eight months, the absolute increase in weight per diem will amount to 2 lbs,; the increase per cent, upon the weight is 61.4. We have seen that during the fattening, the mean consumption, reckoning the provender in hay, amounts to 6600 lbs,: the increase obtained being 508 lbs. gives 16,9 lbs. of living solid for every 220 ^^'0 THE H0R35. lbs. of Iifiy '^onsTimcd. Lastly, the mean ratioL beln,? settled by M. Dubois at 2G.4 lbs. of hay per head and per diem, and the ■sveig'ht of th ; animal on being taken into the meadow being 828.3 lbs., this ra- tion corresponds to 7.1 lbs. of hay for PA'erj 220 lbs. weight of th(» living animal. To sum up from the facts just stated on the subject of fattening, it appears that the increase per day is : According to Thayer 0.98 per cent, on the hay consumed. « Low 0.91 " Stephenson, 1st lot 0.94 " " " 2d 20.99 " 8d 0.45 Dubois 0.95 § IV. OF HORSES. In -what follows I shall limit myself to the consideration of the horse in his relation to agricultural industry, and shall give the re- sult of certain experiments which I have made upon his growth with a view of solving the question, much disputed in various places at the present time, whether or not the general farmer can breed horses ■with advantage to himself. The horse employed in farm labor ought to be spirited and strong : attention to external form is only to be given in so far as it is an indication of the qualities that are required. He ought thv^refore to be broad in the chest and in the haunches, and his muscular system must in general be decidedly developed. A horse of considerable size, if he be otherwise exempt from defects, is generally preferable to a small animal ; he is stronger, taki-s longer steps, and does more for his keep than the other. We are not to require in the draugiit- horse the vivacity and amount of spirit which we look for in the saddle horse, yet he ought to have that liveliness which is almost always a sign of health in animals. Thaer does not approve of the practice commonly followed at this time of mixing with good draught horses the blood of stallions of elegant shape, but little adapteil to stand hard work. Although this remark, is not without truth, it is still impossible to deny that in m;iny cases the employnv.'nt of stallions of some breeding has much im- proved the race of draught-horses in various districts. It is not besides unworthy of attention, that it is really important for the farmer to have a breed which he can readily dispose of to advantage, particularly in those countries where horses for cavalry and artillery service are in request. My own observation would lead me to say, that the breeds in France are frequently improved by crossing with stallions of the royal studs. The effect from this proceilure has not perl laps been s.> great as might reasonably have been expected, still evident progress has been made. The mare will take tho stallion at about the age of three years ; but it is seldom that the animal is eovered at so early an aire : on the farm she will be at least live or six years of are before t'.iis is allow- ed, especially if the animal is to be worketl during the time she is with foal : and the sam ' c mh! 1 Tatian la In n> t•^ s;u-. that a mare THE HORSE. 401 oupfht not to be covered oftener than once in two years, although it is very possil^Ie to have a foal from lier every year, for she ficfiuent- ly comes into season towards the 11th day after foah'no:, i^"d she goes with young for a term which varies between 333 and 346 days. A brood mare may be employed in ordinary work during tlic first period of her pregnancy ; but when the time is further advanced, when she is in the tenth month, for example, every possible precau- tion must be taken against accident. This is the period at which we withdraw our brood mares from the common stable, and put them into separate boxes. After she has foaled, the mare receives in small quantities and frequently repeated, warm drinks and bran mashes. While she is giving suck, her food ought to be of a more substantial or better kind than that which is generally allowed. The mare may be put to light work twenty days after she has foaled ; but it is requisite not to demand anything like exertion from her within eight or ten weeks after this event ; she then goes out accompanied by her foal which is generally suckled for aljout one hundred days. Foals are frequently brought up in the stable or in the loose box ; this is our practice in Alsace ; but it is well, with a view to the growth and health of the young animal, that it be taken out every day. On quitting the teat, foals are fed upon choice hay ; ill the course of the second year a portion of the hay should be re- placed by an allowance of oats, and in the season the use of green clover cannot be too highly recommended. According to Thaer, the daily allowance to a horse of middling heiglit, and doing ordinary work, may be regarded as good when it consists of: Hay 8.2 lbs. = Hay 8.2 lbs. Oats 9.2 =Ditto 14.2 Allowance reckoned in bay 22.4 In England the following allowance has been particularly men- tiond as that of certain well conducted stables. Cut Hay 11.0 lbs. = Hay 11.0 lbs. Cut straw. 2.2 =- Ditto 0.55 Oats 11.0 = Ditto 16.9 Beans 1.1 —Ditto 4.7 Allowance reckoned in hay. 88.2 According to M. Tassey, veterinary surgeon in the Municipal Guard of Paris, the provender of the horses in this corps in 1840 consisted of : Hay 11 lbs. =-Hay 11 lbs. Oats. 8 —Ditto , ..., 12 Straw for litter 11 — Ditto 2J Total allowance 25^^ The same authority reckons that horses employed in severe draught receive or require : Hay 16',lbs.-na7 16^ lbs. Oats 17' —Ditto 26 Total allnwar.-*^ 42i 39* 462 THE HORSE. Until very lately (previously to 1840) the allowance of troop horses in the French army consisted for the reserve cavalry of : Hay nibs. =■ Hay 11 lbs. Oats 8 —Ditto 12 Straw 11 =Ditto 2^ Total allowance 25^ For the cavalry of the line : Hay 8.8 1bs.= Hay 8.8 lbs. Oats.. 7.5 =Ditto 11.5 Straw 11 =Ditto 2.7 Total allowance 23.0 For the light cavalry : Hay 8.81bs.= nay 8.8 lbs. Oats fi.6 = Ditto 10.1 Straw 11 =Ditto 2.T Total allowance 21'6 Influenced by the consideration of the frequent indifferent quality of hay, and its*^ injurious effect upon the health of the horse, it was decided in 1841 to replace a portion of the hay ration by a lar-xer quantity of oats, an article much less liable to be adulterated, or to be indifferent in quality. The allowance now consisted for the re- serve cavalry of: lbs. lbs. Hay 1.8-Hay 8.9 Oats. 9.2-Dltto 14.2 Straw 11 —Ditto 2.7 Total allowance 25.7 For the cavalry of the line : lbs. lbs. Hay 6.6 — Hay 6.6 Oats 8.8 — Ditto 18.5 Straw 11 —Ditto 2.7 Total allowance 22.3 For the light cavalrv : lbs. lbs. Hay 6.6-Hay 6.6 O.Hts 8.3 — Ditto 12.8 Straw 11 —Ditto 2.7 Total allowance 22.1 From what precodos, it ajipoars that the substitution of oats for hay was made upon a calculation which squares well with the theo- retical inferences in regard to the relative nutritive powers of these two articles. The allowance to the horse ought to be distributed into three por- tions, constituting as many meals, and put before him in the morning before going to work, in the middle of th.e day, and in the evening ; he is generally watered at meal times. It is also highly advantage- ous to the health of tlie horse that he be made to work with a cer- tain regularity. Our horses at Bechelbronn, upon an allowance equivalent to iili lbs. of hay, work from 8 to 10 hours a day, having an hour's rest at midday. THE HORSE, 463 There is, of course, a certain relation between the height or, if you will, the weight of the horse, and the quantity of provender he requires. Some attention, as we have seen, has been given to this point, in connection with horned cattle ; but with reference to the horse I know of no data but such as I myself possess. Seventeen horses and mares, aged from 5 to 12 years, and having each proven- der equivalent to 33 lbs. of meadow hay, weighed together 18,190 lbs. The mean weight of each horse being represented by the num- ber 1070 lbs., we perceive that for every ioO lbs. of live weight 0.7 Ihs. of meadow-hay are required for the daily ration, the horses working from 8 to *^10 hours a day. This relation differs very little from that which we have obtained in reference to caltle. I was anxious to ascertain the rate of growth of the horse ; and in connection with our breed, which have a mean weight of about 1100 lbs., I found that the foals weighed as follows : ^ ^ ^ 2 a eight ;kl"ing. eight •- .o .£P « ^3 • ^9. "5 ■S ps o ® 43 o 1 fo 4= 3 S =" Increasi daring t Increase pel lbs. Ihs. days. lbs. lbs. Filly of Chevreuil 25 May, 1S42 110 20 Aug. 1S42 294.8 87 184.8 2.1 Filly of Heehler 12-June,lS42 IIB 7 Sept. 1S42 2S6. 87 172. 1.9 Filly of Brunette. 12June,lS42 113 7 Sept. 1S42 354. 87 241. 2.7 The moan increas3 por day daring the period of suckling in the three cases quoted above, therefore, appears to have been rather more than 2 and ^-^ths lbs. avoirdupois. Immediately after weaning, j-oung horses appear to experience an arrest of their growth for some sliort time, an event which indeed happens to animals generall3\ I found, for example that Chevreuil's filly, which on the day of weaning weighed 294 llis., nine days after- wards weighed but 288 lbs., and Lad consequently lost 6 Ibs.*^ I shall add a few weighings of horses further advanced in age, although still young : Alexander, a colt, weighed at birth 110 lbs. : at the age of 128 days, 337 lbs. ; increase 227 lbs., or about 1.8 per dtem : 51 days afterwards, 490 lbs. ; increase 105 lbs., or per day 1.4 lb. Finette, a filly, weighed, when weaned at the age of 86 days, 295 lbs. ; 83 days afterwards, 396 lbs. : increase 101 lbs. ; per day, 1.1 lb. ^ ^ Heehler 's filly weighed when weaned at the age of 87 days, 286 lbs. ; 65 days afterwards, 358 lbs. ; increase 72 lbs. or per day 1.1 lb. From what precedes we may conclude : ^38 4G4 TnE HOG. 1st. That foals, the issue of mares weighing from 960 to 1100 lbs., weigh at birth about 112 lbs. 2d. That during suckling for three months, the -weight increases in the relation of 278 to 100, and that the increase corresponds very nearly to 2 and y^^ lbs. avoirdupois for each individual per diem. 3d. That the increase of weight per diem of foals from the end of the first to the end of the second year, is about 1^^ lbs. avoirdu- pois ; and that towards the third year, the increase per day falls something under 1 lb. avoirdupois. After three years complete, the period at which the horse has very nearly attained his growth and development, any increase becomes less and less perceptible. These conclusions in regard to the horse, differ very little from those which I have had occasion to draw in connection with horned cattle. I have also made a few experiments with reference to the quantity of provender consumed by foals in full growth, and have found that Alexander, Finette, and * Hcchler's filly, weighing together HOG lbs., consume per dav : Hay *■ 19.8-Hay 19.8 Oats 7 —Ditto 11 Total allowance 80.8 Per head 10.22 The mean weight of these foals was ?,C)^.G lbs., so that the hay consumed for every hundred poiuids of live weight was 2.85 lbs., with which allowance the daily increase amounted to about 1.2 lb. ('onsccjuently. a mixed provender, equivalent to 100 lbs. of hay, had produced 12' lbs. of live weight. I must confess that this result appears to be somewhat too favorable, but I can only set down the immbers as they presented themselves to me. The flesh of the horse is not generally used, or at least openly u.vd. as food for man, though there are countries in which it is ex- posed for sale and counnonly eaten. At Paris, indeed, in times of srarcily, horse-flesh has been consumed in (juantity. During the IJevolulion, a knacker exposed publicly for sale, in the Place de Grc've, joints from the horse.<< which he had killed, and the sale con- tinned for three years without any ill effect ; in 1811, a scarcity obliged the Parisians to have recourse to the same kind of food, and it is said, indeed, that the trnflic in horse-flesh as an article of human sustenance is still continued to a very considerable extent in the I'Vench metropolis : at the )irc.=;cnt moment, a distinguished writer on Medical Police, M. Parent-Duchatclet, has even proposed to legalize the sale of horse-flesh as food for man. ^ v. OF nofjs. There is ])erhaps no farming establishment which does not keep a certain number of hogs, a measure by which offal of all kinds that would go directly to the dunghill, is turned to the very best account. The dairy, the kitchen-crarden. and th(> kitchen, all yield their con- tingent of food to the pig-stye, which is moreover an excellent means of using up certain portions of the harvest, lint the rearing THE HOG. 4[;5 and fatteninj^ of hogs, altliougli frequently looked upon as mat*rra of course, and requiring very little care, do in fact demand consider- able attention and certain conveniences in situation. The rearino- of hogs, in a general way, may be said to suit the small farmer better than the great agriculturist. Our common domestic hog appears to derive his origin from the common wild hog of PJurope. The breeds are extremely numerous. The blacJv hog. covered with rather fine hair, and commonly found in Spain, is a native of Africa. This is the race which has been carried to South America, where it has multiplied in a truly surpris- ing manner. It grows rapidly ; and if it has little to recommend it with reference to fattening, it is nowise nice in the matter of food and general entertainment ; the flesh is excellent when the animal has been kept upon the banana, and fattened off upon Indian corn. The hogs of the east of Europe are remarkable for their size ; they are of a deep gray color, and have very long ears ; they are not very prolific, the brood swine having rarely more than four or five at a birth. The Westplialian breed, on the contrary, though they resemble the last, are highly prolific, the litter generally con- sisting of from ten to twelve. In Bavaria the hogs are remarkable for the smallness of their bones, and the readiness with which they take on fat. Lastly, the Chinese race, which is common in England, and begins to extend on the continent, differs from those hitherto known, in having the back straight or even hollow, and the belly large. This breed is also remarkable for its quietness ; the pork ■which it yields is of the very best quality. One of the great advantages connected with the hog being its extreme fecundity, it is important to have a breed which is distin- guished in this respect. There are some brood swine which have regularly borne ten or fifteen, and even eighteen pigs at a Utter ; a more general number is eight or nine. According to Thaer, the hog that is disposed to take on fat is ' distinguished by length of body, long ears and a pendulous belly. The hog attains his growth, at the end of about a year, until which time the female ought not to be put to the boar. One boar generally suffices for about ten females. The hog, as all the world knows, is an animal the least dainty in his food ; he is omnivorous, nothing comes amiss to him ; but his food is by no means matter of indifference when the quality of the flesh comes to be considered. Thaer seems to think that maize is of all articles that which is the best for feeding swine ; and I have had occasion to verify the accuracy of his conclusion in South America, where I may add it is found that the oily fruit of the palm- tree contributes powerfully to the fattening. Husbandry, in regard to the hog, comprises two distinct periods : the growth of the animal, and his fattening. It is generally admit- ted that it is most advantageous not to fatten swine for the butcher until they have completed or nearly completed their growth. A hog which has been well kept from the period of its birth, may be ]>nt up to fatten at the ace of about a vear. The female shows signs 466 THE HOG. of heat at the age of about five or six months, and goes with young on an average 115 days, and will produce regularly two litters per annum ; when particularly well kept, she may have three littere in the courss of from thirteen to fourteen mouths. The hogs which are destined to be fattened for the knife are ge- nerally cut at the age of six weeks, particularly if they are to be put up to fatten at the age of nine or ten mouths, as is often done. Almost all the varieties of roots and grain produced upon the farm are suitable for the maintenance of the hog ; but in Alsace, and I believe generally, the staple is the steamed potato, with which are associated various articles in smaller quantity, such as peas, and barley aod rye meal, &c. The farrow sow ought to have food by so much the more abun- dant and nutritious as she is required to suckle a larger number of pigs. Our allowance at Bechelbronn to the hog with five youug ones during the six weeks of suckling is as follows : lbs. lbs. steamed potatoes 24.75= bay 7.8 Ryeraeal 2.45=- " 4.0 Skimmilk 18.2=- " 6.2 Total allowance 18.0 After the fifth week, when the animal is no longer giving suck, the ration consists of : lbs. lbs. Steamed potatoes 12.1 -= hay 7'8 Eye meal 1.0-= " 1.6 Skim milk [sour] 6.5— " 8^ Total allowance 12.2 This allowance is gradually reduced to the end of the second month after the farrowing, when the animal is upon the maintenance ration of tl'.c farm, consisting of : lbs. lbs. Steamed potatoes. 16.5— hay 6.2 The potatoes are nii.xed with dish washings, which certainly con- tribute to improve theii; nutritive jiower, although I am altogether at a loss to estimate the value of the article. The young jjigs begin to taste the food given to the mother at the age of about a fortnight, but they never take to this kind of food fracly until they are four or five weeks old and arc weaned ; up to this time they have an allowance of skim milk and whey. To five pigs at the time of weaning we allowed per day : lbs. Steamed potatoes 22.0 — hay 7.8 per head 1^4 Ryrmeai. 1.0 '^ " 1.6 " 0.88 Skimmilk 6.0- " 2.9 " 0.67 29.6 11.7 This allowance was modified by der^rees ; the quantities of milk and rye meal were gradually abridged, and the proportion of ])ota- toes increased, so that about the third month the allowance per head was from 11 to l.T lbs. of potatoo^s mixed with greasy water. This 1 THE HOG. 407 is the rc'ximen, equivalent to about 5 lbs. of hay, upon which our store })igs are maintained until they are put up to fatten. During tlie three montlis which follow the weaning, therefore, we may reckon that each animal has consumed 3.8 lbs." of meadow-hay per day, and that from the third month the consumption may be repre- sented by 5.2 lbs. of the same article. We have attempted in vain to replace the potato by rape or madia oil-cake ; the pigs refused it obstinately ; but they showed no objec- tioii to poppy seed, walnut and linseed cake ; during the season they will also eat clover, and are partly maintained upon this plant. In summer they are put entirely upon green meat, animals from five to six months old consuming about 19 lbs. of clover a day, a quantity vrliich represents very nearly 5 lbs. of clover hay. 'J'he hog may be fattened at any age ; but as we have already said, it is not generally advisable to fatten before he is ten months or a year, some say fifteen months or a year and a half old, at which ])'?riod the animal is undoubtedly in flesh and at its full growth. The other extreme limit appears to be about five years ; but it is only a brood sow that is ever kept to five years of age. It is generally allowed that twelve weeks are required to bring a hog into prime con- dition, when he ought to have a layer of fat under the skin upwards of an inch in thickness. Sixteen weeks may be required to obtain an animal really fat ; and twenty weeks to have him at the highest point that is attainable. The hog requires to be fed regularly. After weaning, pigs should have five or six meals in the course of the day ; the number of meals is diminished gradually, and towards the end of two months they amount to but three in all. I was curious to ascertain the weight of the pigs at the moment of their birth, so as to determine their rate of increase during the period of suckling. On the 5th of September a sow farrowed a litter of five. lbs No. 1 weighed .... 2.205 No. 2 " ....3.025 No. 3 ....2.476 No. 4 » ....2.750 No. 5 " ....3.300 Weight of the litter 13.756 Average weight per head 2.751 On the 11th of October the weight of the litter was 86.6 lbs., or 17.3 lbs. per head ; increase in thirty-six days, 73.2 lbs. ; per head, 14.6 lbs. : per day, 0.409 lbs. On the 15th of November the weight was 177 lbs. : increase in thirty-five days, 90.2 lbs.: per head, 18 lbs. ; per day, 0.506. During the thirty-six days of suckling, con- sequently, 100 of live weight at birth had become 632. In another instance, I found that eight pigs which at the time of weaning weighed 114 lbs. or 14.3 lbs. per head, at a year old weighed 1320 lbs., or 165 lbs. per head : increase in eleven months 1206 lbs., or 150 lbs. per head. The increase per diera since the weaning had been 0.4. — not quite 4 08 THE HOG. half a pound ; and as the food consumed may be represented by 5.2 lbs. of hay per day and per head, it will follow that 100 of forage had produced 8.58 of live weight. This ratio is too high, however : for these pigs besides the regular allowance had whey and various scraps of which no account was kept ; and we know that whey alone contains a considerable quantity of the representatives both of flesh and fat. Baxter came to some interesting conclusions on the growth and fattening of young hogs. Four animals each of the age of nine months weighed at the beginning of the experiment 458.2 lbs. ; twenty-one days afterwards, 620.8 lbs. : increase of weight 162.6 lbs., to obtain which there were consumed : lbs. ibe. Barley 151 equivalent to hay, 250 Beans 140.8 " 611 Malt grains 440 " 257 1229 So that a quantity of nutritive matter represented by 100 lbs. of hay produced 13.21 lbs. of live weight. Assuming the weight of each pig of nine months old before her fatting to have been 29 lbs., the increase per head was 40.6 lbs. in the course of twenty-one days, or at the rate of 1.9 lbs. each. Bax- ter.reckoned the carcass weight, sinking oflfal, at 7.4 per cent. One of the pigs between nine and ten months old weighing 159.5 lbs., at the end of twenty days weighed 198.8 lbs. : increase in twenty days, 39.3 lbs. ; increase })er day. 1.9 lbs. During these twenty days, the animal had consumed 188 lbs. of barley, equivalent to 314 lbs. of hay. The increase would consequently give for every 100 lbs. of hay consumed an increase of live weight of 12.52, say 12.i lbs. Arthur Young, by keeping pigs of a year old on peas-meal, obtain- ed the following results. No. 1 weighed 99.0; 85 days afterwards 157.5; gain 58.5; per day 1.678 No. 2 " 91.7; 42 " 145.4; 6.3.7; " 1.876 No. 8 " 86.6; ft? " 189.4; 62.8; " 0.836 I shall hero give two sctIcs of f)bservations made at Bechelbronn on the fattening of hogs. September 6th, 1841, seven hogs, aged fifteen months each, already in good condition, were put up to fatten. They had hitherto had the usual hog's food — sour milk and boiled potatoes after weaning , l>y and by from 11 to 15 lbs. of potatoes, *whey, and dish washings. The seven porkers weighed 1691.8 lbs. ; or 241.67 lbs. each. The increase had been at the rate of 0.528, rather better than half a pound per day and per head, supposing them to have weighed 13.7 lbs. each, at the time of weaning. After fattcnln:r. 2iith December, the 7 swine weighed 2101. ft Before *• 6th September " 169.8 Increase in 104 day?, 4' 9.2 lbs. ; or per ho.vl 58.9 Incr.^R«p pi»f d^v and p«r hcnd ft..*.7*2 THE HOG. 469 .772 .1042.! 9504 equivalent to hay 1144 ^ » 4171 8296 In the course of the 104 days, there were consumed : lbs. lbs. Barley — Peas.. Potatoes Greasy water and whey— quantity not detcnnincd • • 8388.6 So t!uit with th3 provender equivalent to 100 lbs. of hay, 4.91 lbs. of live woi:rht had been produced. These' seven porkers, slaughtered, yielded : 1 Weight of 1 Hogs. Weight Weight after Weight of the blood. the porkers without Weigbt of heads and heads or feet. Offal. lbs lbs. lbs. lbs. lbs. 32^.0 312 11 26S.0 44-0 2 259 0 248 11 208.4 39 6 3 283 0 272 11 208.2 63-S 316.0 305 11 263.2 41-8 5 264 257.4 6.6 220.0 37.4 6 259.6 250.8 8.8 213.4 37.4 7 393.8 876.2 17.6 321.2 55.0 2098.6 " " 1702.6 1 It must be admitted that these animals had increased both in flesh and in fat ; but in spite of this, the experiment appears to be un- favorable to the opinion that fat in animals is the effect of dn-ect as- similation of the substance. The whole increase in weight of the seven porkers had been 409.2 lbs.; supposing 27 per cent, of fat in this increase, its amount must have been 110.4 lbs. in all ; but the food consumed did not contain more than 57.4 lbs. It would there- fore be necessary to admit that the food which had not been taken into the account had contained as many as 53.0 lbs. of fatty matter, which I own does not appear to me probable. But no definitive conclusion can be drawn from the circumstance, owing to the actual state of fatness of the animals, when they were specially put up to fatten, not having been ascertained ; perhaps the absolute quantity of fat already accumulated is greater at this time than is generally supposed. /. -, ^ ^ iu 1 -11 J 4- I find, for instance, that a young porker of 196.9 lbs., killed at the time when he might have been put up to fatten specially, yielded as many as 26.3 per cent, of fat. ^ ^ ,, x- The following are the data afibrded by the fattening of the farm porkers for 1842 : ,,-,-, i j • Nine porkers, from thirteen to fifteen months old, and already in good condition, were put upon the full fatting allowance on the 1st of October, on which day they weighed : ibt 1940 November 23th, after having been bled, they weighed. . -2307.8 Increase in 68 days per head and per day 88.2 ■10 470 THE HOG. In the course of fifty-eight days the hogs had consumed : lbs. lbs. Rye 770 equivalent to hay 1141.8 Peas 1302 " 5209 Potatoes 4796 " 1861 Greasy water and whey undetermined 8221. S The nine animals gave 1746.8 lbs. of meat, fat and lean, or 75.7 per cent, of their weight as they stood alive ; besides which, 141.9, say 142 lbs. of lard were obtained from the internal parts. Now supposing that in the increase of weight obtained in tne course of fifty-eight days, the fat w^re to be represented l^y 29 per cent., the fat fixed would amount to 100.1 lbs. ; while the whole of the fatty substances contained in the food consumed would not amount to more than 59.6 lbs. It would therefore be imperative to us, did we main- tain that all the fat was obtained ready formed from without, to sup- pose that the whey and dish washings administered in indeterminate quantity, had introduced 40.5 lbs. of fat into the bodies of the animals. Some experiments which are going on at Bechelbronn at this mo- ment will, I trust, settle the question definitively as to whether during the fatting of hogs and other animals there is any formation of fat at the cost of the starch and sugar of the food. The observations which I have made on the fattening of hogs may be summed up in these terms : ^ •o § &• 1 5S t-: -30 s-^ -S^-S ■ gcg IJ Is ncrease pt ire weight om every of proven Duration of the experi- ment Ph a- <^ lbs. lbs. lbs. Months. Months. Days. 5.1 0.440 8.53 1 11 13.5 O.S.<^6 13.21 • 9 21 15.7 1.95>{ 12.52 n " 20 " 1.254 " 12 »* 11.6 0.572 4.91 15 " 104 15.4 0.660 4.21 14 " 58 The allowance to the hogs in the preceding observations was al- ways abundant. To determine the quantity of potatoes con.sumed each day by a hog in full growth, and whose weight wa.*; known. I had him weighed at intervals, as well as the potato ration, placed before him at will, which he ate daily, and found that when he wei«'-lied : ^h». Iba. Iha. l.»r w'iirhi 1 138 ho ate 11 equivalent in hav to .3.4 H5 " 13.2 " 4.2 160.5 " l.\4 '• 4.8 1S4.8 " 17.6 " 5.5 2.52 2.89 80.1 8.02 THE HOG. 411 To these observations on the keep and fatting of horned cattle, horses, and hogs, I would gladly have added remarks of like extent on the growth and fattening of sheep ; unfortunately, I have only been able to obtain very imperfect information on this branch of rural economy. I have, however, sought to ascertain approximately the relations which exist between the weight of a young animal, the food consumed, and the increase in live weight, by means of the fol- lowing experiment : Two sheep six months old weighed together 184.2 lbs. Sixteen days afterwards they weighed. 151.8 Total increase 17.6 Increase per day, per head 0.55 In the sixteen days the two sheep ate : Hay 22.0 = TIay 22.0 Potatoes 53.3 = Hay 16.9 38.9 Or per head in hay 19.45 Or per head per day . — 1.21 This would give us about 2.9 of hay provender per cent, of the live weight, so that a ration which should be represented by 100 of hay would be followed by an increase on the weight of a sheep of six' months old of 27.7 per cent. ^ VI. OF THE PRODUCTION OF MANURE. The forage consumed on the farm being the source of the manure produced there, it would seem that it must be easy to calculate the value of all that comes from the stables and cow-houses day after day. I do not mean the mass or weight of the dejections here, for it is certain that the more or less w^atery nature of the food mate- rially influences the weight of the dung produced; and if a common iiiode of calculating the quantity of dung by merely multiplying the weight of food consumed by three be correct in some cases, it is very far from the truth in others. 1 he dung produced on the farm must be calculated on different grounds from this ; and without pre- tending to any degree of accuracy which is really unattainable, it is still very possible to get at the quantity of azote which is contained in the litter and in the dejections, so as to be able to refer to a stand- ard the quantity of manure made. Were not the azotized principles of the food partly exhaled by animals, the whole quantity not appearing in the excretions, it is ob- vious that it would suffice to have ascertained the quantity of azote contained in the food, to be in a condition to decide on that con- tained in the dung adde-d to the litter. But this cannot be done ; to be convinced of the fact, it is enough to take the least complex case, that of a full-grown liorse, receiving as his allowance per day : Hay 22 lbs. containing 1775.3 grains of azote. . Oats ...•;. 11 " 13S9.4 Straw 11 " 308.7 Litter 8.8 " IDS.O Azote 85S1.4 472 THE nor.. Now assuniinc^ 2 por cent, as the contents in azote of dry farm- yard diini^:, we see that the food consumed by the horse, speaking- theoretically, mij^ht or should form 'if). 5 lbs. of dry manure. r>ut we have seen that ahorse or cow will exhale from ^{55.0 to ir;.8 «^rs. of azote, which is all derived from the lbt»d, and is consetjU ully lost to the tlunij^-heap. Now 385. 9 c^rs. of azote represent 2.7;') ll)s. of dry manun^ ; so that the dry dunuf produced by the horse kept in the stable, will be reduced from 2C^S) lbs. to 23.1 lbs. In the course of a year, upon this calculation, the azote exhaled will diminish tlii weii^'-ht of dry dung produced by one horse by a quantity equal to KM;") lbs. The azote of the food of a cow is still more considerable in quan- tity, and tiie loss to tlu; dunirhill proportionally larger ; inasmuch as to the amount she exhales, must be added all that goes to constitute the milk she gives. I'ractical men, without pretending to get at the cause of the thing, have long been aware of the fact, that a cow ])roduccs less dung than a lu)rse ; and the truth of this is readily demonstrated on scientific grounds, v^uppose a cow, consuming the ecpiivalent of ',VA lbs. of hay. and giving ab(mt 17 pint^ of inilk p( r day : 44 " straw for litter contain. Azoto 2798 — 19.8 lbs. of dim j; supposoit to bo dry. But in the 24 hours, there have bciMi of Azote exhaled 895.9 (fralns, and of Azoto In 17 pints, or '22.7 lbs of milk carried off, 802.7 grains. 11SS.6 — S.8 of dry dun^. The X\ lbs. of hay digested by the cow, con.sctiuently, the litter added, have only product'd 8.H of dry »lung. The iizote of the food, of which we find no account in the dejections, amounts per aimum to nearly 'M) cwls., {'A'M){) lbs..) the deficiency in the case of the horse amounting to no niore tiiau 10 If) lbs.. (I) cwts. 1 qr. 9 lbs.) The estimation of the dung j)roduced by growing animals, pre- sents several special dilViculties. inasmuch as, besides the azote exhaled from the lungs, there is the quantity that is fixed in the liv- ing body. In one of the experiments which I have related, it appears that a calf six months old, consuming : Hiiy 9.6 Ib.s. containing 1069.S aiot*. Dlschftri;o<.8 " Azote fixed r"" oxhaled In 24 hours ... 281.5 " The azote lost to tlie manure by tlie fixing of azote is therefore very considtTalile. in t!»e ca.se of young animals as well as of milch- kine. We find, for example, that for every 100 lbs. weight of hay consumed : A horse ."supplies the equivalent of 51 lbs. of dry standard dung. A nillch-cow ... 82 " ' " A calf of six months 4"> THE noo, 473 To estimate with any rijj^or tho quantity of azotized manure which ou[. Arago has found that a thermometer, buried at 20] feet under the surface, d')es not reman absolutely stationary. In climates of greater constancy, as may be conceived, tlie layer of invariable temperature will be found much nearer the surface ; were the temperature of the air in- variable, the layer of invariable temperature would ncccs.«arily be- found at the surface of the ground. In countries under and clo.sc to the equator, this, in fact, is found to be the case. From a series of observations which 'I mal.; in So ith AniM-ica, b;^tweeii the 21 paral- lel of southern and the 11th of northern latitude, I found that, near the line, the layer of invariable temperature is found nearly at the surface ; the thermometv^r, ])Iaced in a hole al>out one foot deep, under the shade of an Indian cabin, or a shol, does not vary by more than from one tenth to two tenths (»f a degree Cent. It was probably under the influence of the internal or proper heat of the globe, according to ^[. do Humboldt, that the same species of animals which are now confmed to the torrid zone, inhabited, in former and remote ages, the northern hemisphere, covered as it then was by arborescent ferns and stately palms. It is easy to imagine how, as the surface of the earth cookvl, the distribution of climatt'S became almost exclusively dependent on the action of the .«;olar rays, and how also those tribes of plants and of animals, the organization of which required a higher temperature and more cciuable climate gradually died out and clisappoared.* ♦ IIumboldt'9 Central Asia, v. til., p. 98. METEOROLOGY.— TEMPERATURE. 477 In the State of stability to which the surface of the globe appears actually to have attained, the sun must be considered as the agent wS most directly i.!li>..-s the temperature ot our atmosphere. T^en^tl ot 1 e ky, tl:e na.nber of hours during which the sun is above tii^io coupled with the height to -^ich he asee^^^^^^ such is the cause with which the temperature of each particular lati- tude s pi'imarily connected ; and, in looking at the subject practi- cahy it found to be so precisely ; not only is the mean tempera- tuiif the year dependent L the length of thedays, af «- --^;- altitude of the sun, but the mean temperature ot eadi month in the year is essentially connected with the same eircumstances L the iorthern hemisphere, the temperature rises from j^bout the middle of January, slowly at first, more rapidly in April and May, to reach Us maximum point hi July and August, when it begins to fall agam until mid-January, when it is at its minimum. , i :,. The hi-lest iBcan annual temperature is, of course, observed m the ii^^Borhood of theequator /between Qo and 10° or 120o lati- tude on either side, at the level of the sea, where besides the equa - ty orday and night, the sun, always elevated, passes the zemt^i twice a vear. The observations that have been made up to this time lead us to conclude that this temperature oscillates between oao nnd '20O cent : 78.8^' and 84.2° Fahr. "\t! eaHh present unvarying uniformity of -face no^^-^^ with reference to elevation but to constitution, so that th^ ^wer «f absorbin- and of radiating heat should be everywhere alike, the cli- mate o a place would depend almost entirely on its geographiced Bositioi the points of equal temperature would be found on the r.me pL^lle^^ latitude, or, to employ the happy expression mtro- dS W M de Humboldt, the Mermal lines would all be parallel wlhthJequator. But the surface of our planet is covered w^^^^^^^^^ dulations and asperities, which cause i. «. ^^^^^^^^^ ^ J^selt of slnd and then the soil is dry, or swampy ; it is ^,^^3f,^''!^,\tll th^ or covered with umbrageous and ^^V^'^'^^j'J^^^^^^^ causes corresponding varieties in climate, foi J^^ ^/^^^^'^.fcond?- heatedin diffluent degrees as it is m one or « ^^J^ .^^ ^^\^^^^^^^^^ tions. Another very important consideration is hat the surface ^s a continent, or an island in the ocean : the cl mate of ^ ^o^^^^^' ^^ a district, is vastly influenced by Its FO'™^>t^ "[^.^^^ mass S thp ^-1 The difficulty, the slowness, with which such a mass ui "uiras th'^ccanboL^es either heated or cooW,.*e cause f the temperate character both o'l t'>^f ™"='? ^"^""il's^^lifc shores it bathes, and the islands of moderate ^ favorable 66.0 65 8 Frankfort, A M. Paris .... 66.2 64.4 Wine scarcely drinkable. 64 1 Vine not cultivated. Cherbourg . . C3.2 In high latitudes the disappearance of vigorous vegetation in plant* may depend quite as much on intensity of winter colds as on insuf- ficiency of summer heat. The equable climate of the equatorial re- gions is therefore much better adapted than that of Europe to de- termine the extreme limits of temperature between which vegetable species of different kinds will attain to maturity. Thus it has been found that the vine between the tropics is productive in temperatures that vary from 09" F. to 79" or 80". I shall terminate with a list of the temperatures favorable to the particular vegetables in the success of which man is more especially interested. The cocoa, or chocolate bean 82° F. Banana " Indigo " Sugar-cane " Cocoa-nut " PilllU " Tobacco " Manihot " Cotton-tree " Maize " Haricots " Orchil " Rice " Calabash " Carica papaya " M.iximiim. Minimum. 73° F. 64 71 71 78 78 65 72 67 Maximum. Minimum. Pine-apple .Melon Vanilla .. (.UKiiias.. The vine . .Anise II Wheat 74 Barley •••• 74 Potatoes .75 Arachaca 75 Flax Apple Oak . . ^ IV. COOLING THROUGH THE NIGHT; DEW, RAIN. When the sky is clear and calm during tlie night, vegetables cool down and very soon show a temperature inferior to that of the air which surrounds them. This pri»pf rty of cooling in such circum- stances beh)ngs to all bodies : but all do not possess it to the same degree. Organic substances, for instance, such as wool or cotton, feathers, &c., radiate powerfully and sink low ; polished metals, on the contrary, have a very weak enjissive or radiating power ; and air and the gases in general radiate still more feebly. Inasmuch as a body is continually emitting heat, its temperature can only remain stationary so long as it receives from surrounding objects at every instant a quantity of caloric precisely equal in quan- tity to that which it loses from its surface. From the moment that these incessant exchanges cease to be i. a state of perfect ecpiality, the temperature of a body varies ; it ma) even experience a considerable degrte ol" cooling if it is exposed during a clear night in an open sp»>t. In such circumstances, a body g»ves off towards all the visible j)arts of the heavens more heal than ^ receives ; for the higher regions of liie atmosphere are excessive* METEOROLOGY. NIGHT COOLING. 487 ly cold, a fact which is proved by the rapid diminution \)f tempera- ture experienced on ascending mountains, or by rising into the air in balloons. The internal temperature of the globe, the tendency of which would be to compensate the loss experienced by the body which radiates, has scarcely any efTect in lessening the cooling, be- cause it is propagated with extreme sU)wness, in consequence of the indifferent conducting powers of the earthy substances of which its crust is composed. The air, lastly, which surrounds the radiating body, does not warm it save in the most minute, inappreciable degree, and rather by its contact than by transmitting to it rays of heat, tor the gases have only very limited emissive powers. It is even in consequence of the small amount of this power that the stratum of air in contact with the surface of the ground, does not by any means sink in tlie same proportion as the surface upon which it lies. Thus, in the circumstances which I have indicated, a thermometer laid upon the ground always indicates a temperature lower than that which is proclaimed by one suspended in the air ; and the difference is by so much the greater as the radiating power of the bodies ex- posed is more decided, or as it may take place into a greater extent of the heavens. Every cause which agitates the air, which disturbs its transparency, which contracts the extent of the visible sphere, interferes with nocturnal radiation, and therefore with cooling. A cloud, like a screen, compensates either in whole or in part accord- ing to its proper temperature, for the loss of heat which a body upon the surface of the earth experiences in radiating into space. Wind, by continually renewing the air which is in contact with the surface of bodies tending to cool by radiation, always diminishes its effect to a certain extent. It is for this reason that a cloudless sky and a calm atmosphere, when nocturnal radiation attains its maximum, are most dangerous or injurious to our harvests. In a night which combines all the conditions favorable to radiation, a thermometer of small size laid upon the grass will be found to mark from 10° to 14" or 15" Fahr. below the temperature of the sur- rounding atmosphere. Thus in the temperate zone in Europe, as Mr, Daniell has observed, the temperature of meadows and heaths is liable to fall during ten months of the year by the mere effect of nocturnal radiation to a temperature below the freezing point of water; this is particularly apt to happen both in spring and autumn, when the destructive effects of radiation are most to be apprehend- ed, the nocturnal radiations of those seasons frequently lowering the temperature several degrees below the freezing point. A few observations which I made upon nocturnal radiation at dif- ferent heights in the Cordilleras, seem to indicate that its effects there are less decided than in Europe, in consequence perhaps of the greater quantity of heat acquired by the ground in the course of the day. It appears that in this mountain range it rarely freezes at a height less than 6560 feet above the level of the sea ; although there are certain circumstances there which favor nocturnal radia- tion sc much, that it is really impossible to indicate any very precise limits. In a general way it may be said that the crops of those 489 meteorol:gy. — night cooling. plains which are sufficiently elevated to have a mean temperature of from 50" to 58° Fahr. are exposed to suffer from frost ; it fre- auently happens that a crop of wheat, barley, maize, or potatoes, of the richest appearance, is destroyed in a single night by the effect of radiation. In Europe during the fine nights of April and May, when the air is calm and the sky clear, buds, leaves, and young shoots are frequently cut off, are frozen ; in a word, although a ther- mometer in the air indicates several degrees above the point of con- gelation. Market gardeners and others who are much exposed to loss from this cause, ascribe the effect to the light of the mc jn of the months of April and May ; and they ground their opinion upon the fact that when the sky is clouded, the destructive effects of frost are not apparent, although the same temperature of the atmosphere be indicated by the thermometer. In the lower ranges of the Cordilleras, farmers also ascribe the same injurious consequences to the light of the moon, with this dif- ference, that according to them the destructive influence continues throughout the year ; and it is not unworthy of remark that, in the neighborhoods of Paris and of London, the mean temperature of the months of April and May (from 50" to 57°, or 58" F.) represents ex- actly the invariable climate of those places among the Andes, where the effects of frost upon vegetation are particularly to be apprehend- ed. M. Arago has shown, that the cold ascribed to the light of the moon is nothing but a consequence of the nocturnal radiation, at a season when the thermometer in the air is frequently at f>om 40" to 43" F. and the sky is clear and calm. At this temperature a plant, radiating into space, readily falls below the point of congelation, and then the hopes of the gardener and farmer are destroyed. The phenomenon takes place particularly in a bright night : and if the moon happen to be up when it occurs, the itiHuence is ascribed by the vulgar to her light. Were the sky cl»)U(ied, the principal con- dition to radiation would be wanting ; the temperature of objects on the surface of the ground would not fall below that of the surround- ing medium, and plants would not freeze unless the air itself fell to 3-2" F. The observation of gardeners, therefore, as M. Arago remarks, was not in itself false, it was only incomplete. If the freezing of the soft and delicate })arls of vegetables in circumstances when \he air is several degrees above the freezing point, be really due to the escape of caloric into planetary space, it nuist hapj)en lliat a screen placed above a radiating body, so as to mask a portion of the heav- ens, will either prevent or at least diminish the umoiml of the cooling. And that this lakes place in fact, apj)ears from the beautiful experi- ments of Dr. Wells. A thermometer, placed uinm a plank of a certain thickness, and raised about a yard abuvu the groiind, oc- casionally indicates in clear and calm weather from fi to 7' or ^'■ F. less than a second thermometer attached to the lt>\\er surface of- tiie plank. It is in this way that we explain thi* use of mats, of layers of straw, in a word, of all those slight ciiv«'rings which gar- deners are so carefifl t(» supply during the night lu delicate [laula al METEOROLOGY. NIGHT FROSTS. 489 certain seasons of the year. Before men were aware thai bodies on the surface of the ground became colder than the air which sur- rounds them during a clear night, the rationale of this practice was not apparent ; for it was altogether impossible to conceive that coverings so slight could protect vegetables from a low temperature of the air. The means indicated, as simple as they are elTeciual in protecting plants in the garden, are rarely applicable in farniing, where the surface to be preserved is always very extensive. Nevertheless, in severe winters, the frost by penetrating the ground would frequently destroy the fields sown in autumn, were it not that in high latitudes the snow which covers the surface becomes a powerful obstacle to excessive cooling, by acting at one and the same time as a covering, and as a screen preventing radiation. As a covering, because snow is one of the worst of conductors, one of those substances which lor a given thickness opposes the passage of heat most effectually ; it is, therefore, an obstacle almost insurmountable to the earth beneath it getting into equilibrium in point of temperature with the atmosphere. As a screen, because in shelteririg the ground it prevents it from undergoing the cooling which it would not fail to experience in clear nights by radiation into the open firmament. It is familiarly known in many parts of Europe, that the accidental want of the usual cov- ering of snow will cause the loss of the autumn-sown crops of grain It is on the surface of the snow that the great depression of temper- ature takes place ; and the substance being a very bad conductor, the earth cools in a much less degree. In the month of February, 1841, I made some experiments, which show that the snow which covers the ground acts in the manner of a screen. I had first a thermometer upc^n the snow, the bulb of the instrument being cover- ed by from 0.078 to 0.1 17 of an inch of snow in powder ; second, a thermometer, the bulb of which was situated completely under the layer of snow in contact with the ground ; third, a thermometer in the open air, at about 37 or 38 feet above the surface, on the north of a building. The layer of snow was about four inches in thickness, and had covered a field sown with wheat for a month. The sun shone brightly upon the field on those days when my experiments were made. Feb. 11. Five o'clock in the evening; the sun has been hidden by the mountains for half an hour ; the sky is unclouded, the air very calm : thermometer under the snow, 32"' F. ; thermometer upon tha snow, 29° F. ; thermometer in the air, 36.3' F. Feb. 12. The night very fine, no clouds, the air calm. At seve.i o'clock in the morning, the sun is not yet upon the field : thermom eter under the snow, 26.2' F. ; thermometer upon the snow, 10" F. , thermometer in the air, 26.3" F. At half-past five in the evening, the sun behind the mountains : thermometer under the snow, 32° F, ; thermometer upon the snow, 29" F, ; thermometer in the air, 37.5° F. Feb. 13. At seven in the morning ; the sky gray, the air slightly in motion : thermometer under the snow, 28° F. ; thermometei upon the snow, 17° F. ; thermometer in the air, 25° F. 490 METEOROLOGY. DEW. At half-past five in the evening ; the air calm, the sky cloudless, the sun already concealed for some time : thermometer under the snow, 32° F. ; thermometer upon the snow, 30° F. ; thermometer in the air, 40" F. Feb. 14. Seven in the mornino^, wind W., a fine rain falling: thermometer under the snow, 32" F. ; thermometer upon the snow. 32" F. ; thermometer in the air, 35.7° F. When we reflect upon the losses occasioned to formers and mar- ket gardeners by frosts that are entirely due to nocturnal radiation ft seasons of the year when vegetation has already made considera- ble progress, we ask eagerly if there be no possible means of guard- ing against them. I shall here make known a metiiod imagined and successfully followed by South American agriculturists with this view. The natives of the upper country in Peru who inhabit the elevated plains of Cusco are perhaps more than any other people accustomed to see their harvest destroyed by the effects of nocturnal radiation. The Incas appear to have ascertained the conditions under which frost during the night was most to be apprehended. They had observed that it only froze when the night was clear and the air calm : knowing consequently that the presence of clouds prevented frost, they contrived to make as it were artificial clouds to preserve their fields against the cold. When the evening led them to apprehend a frost — that is to say, when the stars shone with brilliancy, and the air was still — the Indians set fire to a heap of wet straw or dung, and by this means raised a cloud of smoke, and so destroyed the transparency of the atmosphere from which they had so much to apprehend. It is easy in fact to conceive that the transparency of the air can readily be dvstroyed by raising a smoke in calm weather ; it would be otherwise were there any wind stir- ring; but then the precaution itself becomes unnecessary, for with air in motion, with a breeze blowing, there is no reason to apprehend frost from nocturnal radiation. The practice t'ollowed by the Indians just described is mentioned by the Inca (iarcillaso de la A cga in his Royal Commentaries of Peru. Garcillaso in the imperial city of Cusca, and in his youth, had fiequi ntly seen the Indians raise a smoke to preserve the fields of maize from the frost.* The cooling of bodies occasioned by nocturnal radiation is always accomi)anicd by a dcposile of moisture ujion their surface under the form of minute globules : this is dew. The ingenious experiments ot' Wells having demonstrated that the appearance of dew always follows, never j)recedes the fall in temperature of the bodies on ^vhich it is deposited, the phenomenon cannot b«i attributetl to any thing more than a simple condensation of the watery vapor con- tained in the air, comparable in all respects to that which takes place upon the surface of a vessel containing a fluid that is colder than the air.f The quantity of moisture dissolved in the atmosphere * The piod efFfcts of smoke in proventinp nortiiriial congelation are nlso signaliied by Pliny tlic naturalist. t Arn.no, .Annuaire des Longitudes, .\\jn*o 1837, p. 160. METEOROLOGY. DEW. 491 is bv SO much the greater as the temperature is higher. In very warm climates the^dew is so copious as to assist vegetation essen- ^allv supplvino- the place of rain during a great part of the >ear Accordn^ to soml meteorologists dew is most copious near the «pn hmrd of -i country ; very little flills in the interior of great con- iTel'and iKle dt'said oiJiy to be apparent in the vicinity ot lakes and HveTS.* I cannot agree in any statement of this kind made so absolutely I have ne^er had occasion to see more copious dexs than those which occasionally fall in the steppes of ban Martin to the e\rof tl^e eastern Co'rdilleras, and at a very great dis ance from tht sea -the dew was so copious that for several nights I found [[TrnpossS'to employ an artificial horizon of black g ass in order to t^ke the meridian altitude of the stars ; the moment the apparatus was exioseT there was such a quantity of water deposited on the rurfaceE t soon gathered into drops and trickled oif. I found it neceiary to have recourse to mercury to reflect the star under ob- "ervitToif During the clear cahn nights the turf of these immense ph ns ?ecei^^s a considerable quantity of moisture in tlie form ot Sew whlh materially assists vegetation, and by its evaporation fem^ers the excessive heat of the ensuing day. In tropical coun- tries the forests contribute to keep down the temperature. In very hot countries it is rare to be out in a cleared spot, when the mght s favorable to radiation, without hearing drops ot water, produced by theTop ousness of the dew, falling continually from the surrourid- inVtiees so that forests contribute further to produce and to main- am spri^as by acting as condensers of the watery vapor dissolved n the air^ I midit cite a number of observations upon this point m the air. i mi a bivouac between the St] 5™ oVjU 18 7 tte mgh'vas .magnificent ; nevertheless, fn the fo.^stvvhich began at the distance o( a few yards from our encampmenjt™i«./afr«-/«"''y.- by the l.ght of the unclouded mooTw" could see the water running from the branches. Tt is DOSsMe that the transpiration from the green parts of the trees mlh have been added to the dew condensed, and ^o 'ncreased » Kaemtz, Meteorology, translates! Uy W. Walker. London, 1844. 492 METEOROLOGY. KAIN. cooled during- brig-ht nights, and to judge from the influence which forests exert in lowering the temperature of a country, it is enough to recollect with M. de Hu aboldt that by reason of the vast multi- plicity of leaves, a tree, the crown of which does not present a hori- zontal section of more than about 120 or 130 square feet, actually influences the cooling of the atmosphere by an extent of surface several thousand times more extensive than this section. The proportion of watery vapor which a gas will retain in solu- tion is by so much the greater as the temperature of the air is higher. All the causes which cool air saturated with watery vapor occasion, as we have already seen, the precipitation of a certain quantity of moisture. When this condensation takes j)lace in the midst of a gaseous mass, the precipitated water collects into small floating vesicles, which trouble the transparency of the medium that momentarily holds them in suspension. Mists, fogs, and clouds are collections of these vesicles ; a fog, as a celebrated naturalist said, is a cloud in which one is, and a cloud is a fog in which one is not. The vesicles of clouds tend towards the earth, like all heavy bo- dies, but by reason of their specific lightness the resistance of the air which they displace lessens the rapidity of their descent. When they are of larger size they coalesce and form drops of water which fall with greater celerity. When these drops pass tiirough strata of very dry air they undergo partial evaporation, and this is the reason wherefore there is sometimes less rain upon plains than upon mountains. In opposite circumstances it is tiie inverse phenomenon that is observed ; the drops increase in size in passing through the inferior strata of an atniosphore saturated with moisture, condensing vapor in their course. This is what happens most generally. In taking a survey of a large anunint of observations, meteorolo- gists have inferred that the aimual quantity <>f rain varies with the latitude ; that, greatest at the eipiator, it gradually lessens as higher northern and soutiiern latitudes are attained ; this is as much as saying that the quantity of rain is greater as the temperature of tlie climate is higher. But to this rule there are numerous exceptions ; for instance, under the line at Payta on the sea-coast it only rains very rarely ; a shower of rain is an event, and when I visited the country eighteen years had elapsed since they had had any thing of a fall of rain. Local causes have the greatest influence upon the flill of rain, so that countries on the same parallel of latitude aro far from being cquallv disting\iished i)y dryness or humidity. It is believed that in Europe it rains more heavily and more fre- quently in the day than in the night. In the eipiinoctial regitJtis, at least in those jiarts that I have visited, it would seem that the op- posite rule held good. Every one in South America allows that it rains principally during the night, and the observations which I made in the neighborhood of Marniato enable me to state that of V.871 inches of r;iin which fell in the ujonth of October, 1.336 inches fell in the day, 5.(538 inches in the night ; of 8.881 inches which <^ll in the ir.ontli of Xovember, 0.707 inchrs came down in the day, METEOROLOGY. RAIN. 493 8.174 inches in the night : of 5.934 inches which fell in December, 0.786 inches fell in the day, 5.148 inches in the night. Two series of observations taken in the same country al two sta- tions not far from one another, but situated at very different eleva- tions, seem to confirm, in reference to the equatorial regions, the conclusions of European meteorologists as to the fact that the an- nual quantity of rain which falls diminishes as the height above the level of the sea increases. They also show that in latitudes which do not differ materially, more rain falls where the mean temperature is 68° F. than where it is 58° F. Marmato lies in N. lat. 5° 27", and 75" 11" (?) W. long., at a height of 4676 feet above the level of the sea ; Santa Fe in N. lat. 4° 36'', W. long. 75° 6", at a height of 8692 feet above the level of the sea. And while the quantity of rain at the former place amount- ed, according to my own observations for 1833, to 60 inches, ac- cording to Caldas, in 1807, at the latter there fell but 39.4 inches. In temperate climates the quantity of rain that falls varies with the seasons. Near the equator, where the temperature remains constant throughout the year, the rainy season conmiences precisely at the period when the sun approaches the zenith ; and whenever the latitude of a place in the torrid zone where it rains is of the same denomination and equal to the declination of the sun, storms occur. In such circumstances the sky in the morning is of remarkable pu- rity, the air is calm, the heat of the sun insupportable. Towards noon clouds begin to show themselves upon the horizon, the hygrom- eter does not advance towards dryness as it usually does, it remains stationary, or even falls towards extreme humidity. It is always after the sun has passed the meridian that the thunder is heard, which being preceded by a light wind is soon followed by a deluge of rain. In my opinion the permanence or incessant renovation of storms in the bosom of the atmospliere is a capital fact, and is con- nected with one of the most important questions in the physics of our globe, that of the fixation of the azote of the air by organized beings. The most recent inquiries show dry atmospherical air to consist in volume of: Oxygen 20.8 Azote 79.2 The air contains in addition from 2 to 5 10,000ths of carbonic acid gas, and quantities perhaps still smaller of carbureted combustible gas. The experiments of M. Theodore de Saussure, as well as those of Professor Liebig, have further demonstrated in it traces of ammoniacal vapor. I have already shown that animals do not directly assimilate the azote of the atmosphere. Azote is nevertheless an element essen- tial to the constitution of every living being, and is met with indif- ferently in either kingdom of nature. If we inquire into the source of this principle in connection with the herbivorous tribes of animals, we find it as an element in the food which sustains them. If we next inquire into the immediate origin of the azote which enters 43 494 METEOROLOGY. RAIN. into the constitutu/n of vegetables, it is discovered in the manure which proceeds more >jpecially from animal remains ; for vegeta- bles, to thrive, must receive azotized aliment b}- their roots. We thus come to apprehend that plants supply animals with their azote, and that these restore it to plants when the term of their existence is accomplished ; we are led to discover, in a word, that living or- ganic matter derives its azote from dead organic matter. This view leads us to conclude that the amount of living matter on the surface of the globe is restricted ; that its limits are in some sort determined by the quantity of azote in circulation among organ- ized beings ; but the question must be viewed from a loftier emi- nence, and we must ask what is the origin of the azote which enters into the constitution of organic matter considered as a whole ? If we no"' turn to the possible sources or magazines of azote, ^e shall find, setung aside organized beings and their remains, tnat there is in truth l)ut one, tlie atmosphere. It is therefore extremely probable that all living beings have previously obtained their azote from the atmospliere, just as it seems very certain that they have thence derived their carbon.* The most reasonable supposition in the actual stale of science, is to consider the ammoniacal vapors diffused through the atmosphere as the prime source of the azotized principles of vegetables, and then through them of animals; a consequence of which hypothesis would be to assume with Liebig, that carbonate of ammonia existed in the atmosphere before the appearance of living things upon the face of the earth. The phenomena and efiects of thunder-storms appear to me cal- culated to support this opinion. It is known, in fact, that so often as a succession of electrical sparks passes through moist air, there is formation and combination of nitric acid and ammonia. Now ni- trate of ammonia is one of the constant ingredients in the rain of thunder-storms. But nitrate of ammonia, being a fixed salt, cannot exist in the atmosphere in the state of gas or vapor; and then it is not the nitrate, but the carbonate of ammonia that has been signal- ized in the air. In bringing to mind the series of n-aclions of which I have spoken, it is not didicult to perceive how the nitrate of am- monia, precipitated in thunder-showers, and thus brought into contact with calcareous rocks, should suffer decomposition, pass into the state of carbonate on the return of fair weather, and become fitted to undergo dilfiision in the state of vapor throuirh the atmosphere. We should in this way be led to rcoarcl the electrical agency, the flash of liiihtning, as the means by which the azote of the atmosphere is made fit for assimilation by organized beings. In Europe, where thunder-storms are rare, an office of so much importance will per- haps be ac{;orded reluctantly to the electricity rth siile of the valley, liad become so narrow tiiat ti/t slightest rise in the water of the lake covered it completely; a * Ilunilwldt, vol. V. p. 173. INFLUENCE OF AGRICULTURE ON CLIMATE. 499 continu.niG N.E. wind was sumcient to flood the road winch led from iManioaiho to New Valencia ; in short, the fears which the in- habitants of the lake had entertained for so long a period had entirely changed their nature ; they were now no longer afraid ot the lake dry- incT up ; they saw with dismay that if the water continued to nse as it had done lately, it would in no long space of time have drowned some of the mosi valuable estates, &c. Those who had explained the diminution of the lake by supposing subterraneous canals novN hastened to close them up in order to find a cause for the rise in the level of the water. . ^,.iiiinul In the course of the last twenty-two years important political events had transpired. Venezuela no longer belonged t« ^P^^^- \';'^ peaceful valley d'Aragua had been the theatre o many a bloody c^, .- u'st ; war to the knife had desolated this beauti ul cotintry and deci- mated its inhabitants. On the first cry ot independence raised, a great numbe.- of slaves found freedom by enlisting under the banners o 'he new republic; agricultural operations ot any extent were abandoned, and the forest, whic. makes such rapid pvog-ss in the tropics, had soon regained possession ot the surtace which man had V on from it by sont^thmg like a century of sustained and painful tod With the increasing prosperity of the valley many ot the prin- cipal tributaries to the lake had been turned aside to serve as means otM rigation, so that the beds of some of the rivers were abscd.itely drv fo^more than six months in the year At the penod uhich now refer to, the water was no longer used in this way, and the beds of he ivers were full. Thus with the growth ot agricultural mdus- t V n the Valley d'Aragua, when the extent ot cleared surtace was cm. inually on the increase, and when great tarming establishments Zre multiplied, the level of the water sunk; but by and by, during : period of'disa^ters, happily passing in their -^'^^^^^J^^^, clearincr is arrested, the lands formerly won from the forest aie m paTt iestored to it, and then the waters first cease to fall m their le- vel and bv and by show an unequivocal disposition to rise. I shall now, without, however, quitting America, -r^-y my read- ers into a district where the climate is analogous to that o burcpe wheie the surface is occupied by immense fields, covered with the oereals as with us. I spelk of the table-lands of New Granada ot u'sevaley raised from 10,000 to 13,000 and 14,000 feet above te Teve oTthe sea, m which the mean temperature throughou l e vear rancres from 58" to about 62° Fahr. Lakes are frequent in the Cordut^sVand it would be easy for me to describe a great num- ber Is! 'ai, however, confine myself to those which became subjects ^'it^t^^e :\ 'vZl T::. sUuated m the neighborhood of two lakes Some seventy years ago these two 1^^- tormed n. oii^, the oil itdiabitants saw the water shrinking and new fields pie s nt ng Ihemselves year after year. At this P---^^^^^^ ^^tm- vvheat of extraordinary luxuriance occupy levels that were com pletelv inundated 30 years ago. • 1 1 . u^^^ nf Tlhate ^ It IS enough indeed to perambulate the neighborhood of Ubate, 500 METEOROLOG-i: . to consult the old sportsmen of the country, and to refer to the annals of the various parishes, to be satisfied that extensive forests have been cut down in the whole of the surroundingf country : the clearing, in fact, still continues ; and it is certain that the recession of the waters, although much slower than il was in former times, has not yet entirely ceased. A lake, situated in the same valley, to the east of Ubate, deserves our particular attention. By means of baromt trie measurements, made with extreme care, I found that this lake had precisely the same level as that of Ubate. Nearly two centuries ago, it was vis- ited by Piedrahita, Bishop of Panama, an author of great accuracy, to whom we owe the history of the conquest of New Granada. He states this lake to be ten leagues in length, by three leagues in breadth ; but Dr. Roulin having had occasion, a few years ago, to make a plan of the lake, he found it a league and a half in length, by one league in breadth ; my own impression is, that at the time Piedrahita wrote, there was but a single lake, extending all the way from Ubate to Zimijaca, not two lakes as at present, a supposition which would take away every thing like exaggeration from tiie state- ment of Piedrahita. But the fact of the retreat of the waters of these lakes is unquestioned ; the inhabitants of Zimijaca all know that the village was founded close to the lake, whereas, at the pres- ent time, it is nearly a league from its banks. Formerlv, there was no difficulty in obtaining all the building timber that was wanted ; the njountains w^hich rose from the valley on either hand were cov- ered up to a certain height with the trees proper to these cold re gions ; the oak of the Andes abounded; numerous myreias were also in existence, from which abundance of wax was obtained : ^d^ the present time these mountains are almost stripped of their trees, an event mainly brought about by the eagerness to procure fuel in manufacturing salt from the springs of Taosa and Knemocon. To these authentic facts, which I could multiply and su{>j)ort by many others of a similar kind, it may be replied, that the diminution of the water, incontestable as it is, might perhaps have taken j)lace without the clearing away of the ft>rests. It may indeed be main- tained, that the dr* ing up of the waters is owing to a totally ditfcr- ent cause, altogether unknown to us ; that it must be ranked among the numerous phenomena, the reality of which we perceive, but without being able to render any account of their cause. I cannot, in the instance last quoted, as in that of the lake of Va- lencia, refer to any increase of the lake connected with the suspen- sion of agricidture, or the reappearance t>f the forest. I might, however, adduce in favor of the oi)inion which 1 defend, the slow- ness with which the decrease in the lakes of the valley of Ubat has hitely gone on, and since the felling of trees in the neighborhood has almost entirely ceased. Extensive plots of fertile ground are now no longer left dry and available to the husbandman by the re- reat of the lake ; he already begins to think of means tor obtaining by artifice that which nature, assisted by the clearing of the country presented him with in former times. In the year 1826 there was 9 METEOROLOGY. 501 speculation on foot for draining the valley completely by cutting a canal and letting off the water. Further proof of the fact which 1 am urging is obtained in another way. It is not difficult to show, that lakes in the immediate vicinity of those that have shrunk most remarkably, but around which no destruction of the forest has taken place, have undergone no change in their level. The lake of Tota, situated at no great distance from the valley of U^ate, at an eleva- tion that must approach 13,000 feet above the level of the sea, in a region where vegetation has almost entirely disappeared, has pre- served its pristine level unaltered. The lake is nearly circular ; and Piedrahita, in 154-2, gives it two leagues in breadth. It is sub- ject to violent storms, which render its navigation dangerous ; and even travelling along its banks, from the particular circumstances in which the road is situated, with the lake on one hand and a perpen- dicular cliti' upon the other, is not without risk. In 1652, the road passed as it does at present, the water laving the foot of the same rocks, and its level having suffered no change, any more than the sterile country which surrounds it. I shali conclude what I have to say on the lakes of South America by speaking of that of Quilatoa, because it has been made the subject of accurate observations sufficiently remote from one another — 1740 and 1831. Living at Latacunga, a town situated at no great distance from Cotopaxi, the traveller is sure to hear of the wonders of the Laguna da Quilatoa. From time to time this lake, it is said, casts forth flames which set fire to the shrubs and withered grass that grow upon its banks, and frequent detonations are heard, the sound of which extends to a great distance. M. de la Condamine, in 1738, visited this lake, which he found of a circular form, and about 1278 feet in diameter ; on the 28ih November, 1831,1 also visited the Lake of Quilatoa. It cannot be better compared to any thing tliau to the crater of a volcano filled with water ; I found it nearly 13,000 feet above the level of the sea, in the cold region, therefore ; and indeed it is surrounded with immense pastures ; but the information which I obtained from the shepherds in the neighborhood of the Lake of Quilatoa, dissipated all that was marvellous in its history ; they had never seen any flames issue from its bosom, they had never heard any detonations ; in short, I found the lake as M. de la Con- damine appears to have found it, every thing having remained for nearly a century without change. ^The study of the lakes which are so common in Asia, would probably supply conclusions similar to those deduced from observa- tions made in South America, viz., that the waters which irrigate a country diminish as the forests are cleared away, and as agriculture extends. The recent labors of M. de Humboldt, which have thrown so much new light upon this quarter of the world, appear to leave no doubt upon the subject. After having shown that the system of the Altai is about to lose itself by a succtssion of slopes in the steppes of Kirgiz, and that consequently the Ural chain is not con- nected with that of the Altai, as was generally believed, this celebrated .^02 METEOROLOGY. geographer shows, that precisely in the situation where the Alghinic mountains are usually set down, a remarkable region of lakes com- mences, which extend into the plains that are traversed by the Ichim, the Omsk, and the Obi.* It would appear that these numerous lakes are reniainders as it were of an immense sheet of water, which formerly covered tlie whole of the country, and which had become divided into so many particular lakes by the configuration of the surface. In crossing the steppe of Baraba, in his way from Tobolsk to Baraoul, M. de Humboldt perceived everywhere that the drying up of waters increases rapidly under the influence of tne cultivation of the soil. Europe also possesses its lakes ; and we have still to examine them from the particular point of view which engages us. M. de Saussure, in his first inquiries in regard to the temperature of the lakes of Switzerland, examined those which are situated at the toot of the first line of the Jura. The Lake of Neufchatel is eight leagues in length, and its greatest breadth does not exceed two leagues. On visiting it, Saussure was struck with the extent which this lake must formerly iiave possessed ; for, as he says, the ex- tensive level and marshy meadows which terminate it on tlie south- west, had unquestionably been covered with water at a former period. The Lake of Bienne is three leagues long and one broad ; it is separated from the Lake of Neufchatel by a succession of plains that were probably inundated. Lake Morat is also separated from the Lake of Neufchatel by low and level marshes, which beyond all question were formerly sub- merged. Unijuestionably, adds Saussure, the three great lakes of Neufchatel, Bienne, and Morat, were formerly connected, and formed one great sheet of water. f In Switzerland, as in America and Asia, the old lakes, those that may be spoken of umler the title of the primitive lakes, and which occupied the bottoms of the valleys when the country was unculti- vated and wild, have become divided, and now form a variable num- ber of smaller atui independent lakes. I shall wind up the present subject by referring to the observations of Saussure upon the Lake of Geneva, which may be looked upon as the starting point of the admirable works of this distinguished philosopher. Saussure admits, that at an e])och long anterior to the times of history, the mountains which surround this lake were themselves submerged ; a great catastrophe let olf this inmicnse collection of water, and by and by the current possessed no more than the bottom of the valley ; the Lake of Ciencva was lormed. In merely considering the monuments left by man, it is impossible to doubt that within 1'200 or J 300 years the waters of the Lake of Geneva have gradually fallen in their level. It is evidently upon the levels which have thus been left that the quarter de Kive, and Ihe lower streets of the city of (ieneva have been built. This de * HumlM>lcit, Fr:ifjmcn3 .A.^ljitiquo. U 1. p. 40-30. t iSuuKNure, Voyage duns lu.s Alpes, t. ii. chap. 6. METEOROLOGY. 503 pression of the surface, continues Saussure, is not merely the effect of any deepening of the bed of the Rhone, by which the lake is dis- charged ; it has also been produced by a diminution in the quantity of water which flows into it. The conclusions which it seems legitimate to draw from the ob- servations of Saussure are, that in the course of from 1200 to 1300 years the quantity of running water has sensibly diminished in the districts around the Lake of Geneva, No one will, I apprehend, deny that in this long period there have not been extensive clear- ings of forest lands in Switzerland, and a continual increase in the extent of cultivated land in this beautiful country. Here, conse- quently, as elsewhere, an attentive examination of the levels of the lakes leads us to conclude, that where extensive clearings from for- est have been effected, where agriculture has extended, that there has in all probability been diminution of the running waters which irrigate the surface ; while in those districts where no change has been effected, the amount of running stream does not appear to have undergone any variation. The effect of forests considered in this pomt of view would there- fore be to keep up the amount of the waters which are destined for mills and canals ; and next to prevent the rain-water from collecting and flowing away with too great rapidity. That a soil covered with trees is further less favorable to evaporation than ground that has been cleared, is a truth that all will probably admit without discus- sion. To be aware that it is so, it is enough to have travelled, a short time after the rainy season, upon a road which traverses in succession a country that is free from forests, and one that is thickly wooded. Those parts of the road that pass through the unencum- bered country are found hard and dry, while those that traverse the wooded districts are wet, muddy, and often scarcely passable. In South America, more perhaps than anywhere else, does the obsta- cle to evaporation from a soil thickly shaded with forests, strike the traveller. In the forests the humidity is constant, it exists long after the rainy season has passed ; and the roads that are opened through them remain through the whole year deeply covered with mire : the only means known of keeping forest ways dry, is to give them a width of from 260 to 330 feet, that is to say, to clear the country m their course. • • v j If once the fact is admitted that running streams are dimnushed in size by the effect of felling the forests and the extension of agri- culture, it imports us to examine whether this diminution proceeds from a less quantity of rain, or from a greater amount of evapora- tion, or whether perchance it may be owingto the practice of irrigation. I set out with the principle that it must be next to impossible to specify the precise share which each of these different causes has in the general result; I shall, nevertheless, endeavor to appreciate them in a summary way. The discussion will have gained some- thing if it be proved that there may be diminution of running streams in consequence of clearing off the forests alone, without the whole of the causes being presumed to act simultaneously. 504 METEOROLOGY. With regard to irrigation, it is necessary to distinguish bct\^een that case in which an extensive farm has been substituted for an im- penetrable forest, and that in which an arid soil, which never sup- ported wood, has been rendered productive by the industry of man. In the first case it is very probable that irrigation will have contri- buted but little to the diminution in the mass of running water ; it may readily be imagined that the quantity of water used up by a dense forest will equal, at all events, if not exceed, that which will be required by any of the vegetables which human industry substi- tutes for it. In the second case, that is to say, where a great extent of waste country has been brought under cultivation, there will evi- dently be consumption of water by the vegetation which has been fostered upon the surface ; agricultural industry will thus tend to diminish the quantity of water which irrigates a country. It is ex- tremely probable that it is to a circumstance of this kind that we must ascribe the diminution of the lakes which receive so large a proportion of the running streams of the north of Asia. It is al- most unnecessary to add, that in circumstances of this kind the effect which is due to the simple evaporation of rain-water is not increased ; the loss by this means must be rather less, because from a surface covered with plants evaporation takes place more slowly than from one that is devoid of vegetation. In the considerations which I have presented upon the lakes of Venezuela, of New Granada, and of Switzerland, the diminution may be directly ascribed to a less mean annual quantity of rain ; but it may with equal reason be maintained to be a simple consequence of more rapid evaporation. There arc, in fiict, a variety of circumstances under the influence of which the diminution of running streams can be shown to be con- nected with more active evaporation. 1 shall confine myself to the mention of two particular instances, one noticed by M. Desbassyns de Richemond, in the Island of Ascension ; the other is from obser- vations by myself, and is among the number of facts which I regis- tered during my residence for several years at the mines of ISIar- mato. In the Island of Ascension there was an excellent spring situated at the foot of a mountain originally covered with wood ; this spring became scanty and dried up after the trees which covered the moun- tain had been felled. The lot^s of the spring was rightly ascribed to the cutting down of the timber. The mountain was therefore plant- ed anew, and a few years afterwards the spring reappeared by de- grees, and by and by flt)wed with its former al)undance. The metalliferous mountain of Marmato is situated in the provmco of Popayan, in the midst of immense forests. The stream along which the mining works are established is formed by the junction of several small rivulets which take their rise in the taljlc-land of !San Jorge. The country whicii overlooks the establishment is thickly wooded. In 1826, when I visited the mines for the first time, Marmato con- sisted of a few miserable cabins, inhabited by nefjro slaves. In METFOROLOnr. 505 1830, when I quitted the country, Marmato had the most flourishing appearance ; it was covered with workshops, it had a foundry of gokl, machinery for grinding and amalg-amating the ores, &c., and a free population of nearly three thousand inhabitants. It may be readily imagined, that in the course of these four years an immense quantity of timber had been cut down, not only for the construction of machinery and of houses, but as fuel, and for the manufacture of charcoal. For facility of transport, the felling had principally gone on upon the table-land of San Jorge. But the clearing had scarcely been effected two years before it was perceived that the quantity of water for the supply of the machinery had notably diminished. The volume of water had been measured by the work done by the ma- chinery, and actual gauging at different times showed the progressive diminution of the water. The question assumed a serious aspect, because at Marmato any dimimition in the quantity of the water, which is the moving power, would be of course attended with a pro- portional diminution in the quantity of gold produced. Now, in the Island of Ascension, and at Marmato, it is highly improbable that any merely local and limited clearing away of the forest should have had such an influence upon the constitution of the atmosphere as to cause a variation in the mean annual quantity of rain which falls in the country. More than this, as soon as the diminution of the stream at Marmato was ascertained, a pluviometer, or rain-gauge, was set up, and in the course of the second year of observation a larger quantity of rain was gauged than in the first year, although the clearing had been continued ; still there was no appreciable in- crease in the size of the running stream. A couple of years of observation are unquestionably insufficient to show any definitive variation in the annual quantity of rain that falls. But the observations made at Marmato still establish the fact that Jhe mass of running water had diminished in spite of the larger quanti- 7 of rain which fell. It is therefore probable that local clearings ol Torest land, even of very moderate extent, cause springs and rivu- lets to shrink, and even to disa])pear, without the effect being ascri- bable to any diminution in the amount of rain that falls. We have still to inquire, whether extensive clearings of the forest — clearings which embrace a whole country — cause any dimi- nution in the quantity of rain that falls. Unfortunately, the observa- lions which we have upon the quantity of rain which falls in par- (icular districts, are only of sufficient antiquity and accuracy in Europe to be worthy of any confidence, and there the soil was cleared before observation, in the generality of instances, began. The United States of America, where the forests are disappearing with such rapidity, will probably one day afford elements for the complete and satisfactory solution of the question, whether or not the cutting down of forests causes any diminution in the quantity of rain which falls in the course of the year. In studying the phenomena accompanying the tall of rain in the tropics, I have come to a ('(mclusion which I have already made known to manv observers. Mv own ojiinioii is, that the felling of -13 506 METEOROLOGY. forests over a large extent of country has always the effect of less- ening the mean annual quantity of rain. It has long hoen said, that in equinoctial countries the rainy sea- son returns each year with astonishing regularity. There can be no doubt of the general accuracy of this observation, but the mete- orological fact must not be announced as universal and admitting of no exception ; the regular alternation of the dry and rainy season is as perfect as possible in countries which present an extreme variety of territory. Thus, in a country whose surface is covered with forests and rivers and lakes, with mountains and plains, and table-lands, the periodical seasons are quite distinct. But it is by no means so where the surface is more uniform in its character. The return of the rainy season will be much less regular if the soil be in general drv and naked ; or if extensive agricultural operations take the place of the primeval forest ; if rivers are less common, and lakes less fre- quent. The rains will then be less abundant ; and such countries will be exposed, from time to time, to droughts of long continuance. If, on the contrary, thick forests cover almost the whole of the terri- tory, if its rivulets and rivers be numerous, and agriculture be limited in extent, irregularity in the seasons will then take place, but in a diflerent way ; the rains will prevail, and in some seasons they will become as it were incessant. The continent of America presents us, on the largest scale, with two regions placed in the same conditions as to temperature, but in which we successively encounter the circumstances which are most favorable to the formation and fall of rain in one case, and to its absence in the other. ^Setting out from Panama, and proceeding towards the south, we encounter the Bay of Cupica, the ])rovinces of San Bonaventura, Choco, and Esmeraldas ; in this country, covered with thick forests and intersected with a multitude of streams, the rains are almost incessant ; in tlie interior of Choco, scarcely a day passes without ram. Beyot)d Tinnbez, towards Payta, an order of things entirely difrereni commences : the forests have entirely disappeared, the soil is sandy, agriculture scarcely exists, and here rain is almost un- known. When 1 was at Payta, the inhabitants informed me that it had not raineii for seventeen years ! The same want of rain is common in the whole of the country which surrounds the desert of Sechura, and extends to Lima ; in these countries rain is as rare as trees are. In Choco, where the soil is thickly covered with trees, it rains almost continually ; and on the coasts of Peru, where the soil is sandy, without trees, and devoid ol" verdure, it never rains; and this, as I have said, under a climate which enjoys the same tempera- ture, and whose general features and distance from the mountains are nearly the same. Piura is not more remote from the Andes of Assuay than are the moist plains of (Jhoco from the Western Cor- dillera. The facts which have now been laid before the reader seem to luthorize me to infer — METEOROLOGY. 507 1st. That extensive destruction of forests lessens the quantity of running water in a country, 2d. That it is impossihle to say precisely whether this diminution is due to a less mean annual quantity of rain, or to more active evaporation, or to these two eflects combined. 3d. That the quantity of running water does not appear to have suffered any diminution or change in countries which have known nothing of agricultural improvement. 4th. That independently of preserving running streams, by oppo- sing an obstacle to evaporation, forests economize and regulate their flow. 5th. That anfriculture established in a dry country, not covered with forests, dissipates an additional portion of its running water, 6th. That clearings of forest land of limited extent may cause the disappearance of particular springs, without our being therefore authorized to conclude that the mean annual quantity of rain has been diminished. 7th, and lastly. That in assuming the meteorological data collect- ed in intertropical countries, it may be presumed that clearing off the forests does actually diminish the mean annual quantity of rain which falls.* * These meteorological observations are hijihiy interesting, and worthy of every consideration. That unforesting a country maiies it absolutely drier, seems unques- tionable ; but whetlier that be in consequence of less rain falling, or of that which falls going further, making more show, cannot be easily determined. It does not seem very legitimate to decide, that becaiise a country is covered with wood, therefore it is wet: tlie converse of that proposition appears much more probable — viz., that because H country is wet, therefore it is covered with trees. There is one part of the ocean which is called by mariners "The Rains ;" because it rains there almost ceaselessly, as it does in the province of Choco : but " The Rains" has no forests to account for its dripping sky. Did that region consist of dry land instead of salt-water, then doubt- less its surface would be covered, as that of Choco is, with an impenetrable forest The subject is adverted to here, however, not to discuss the general question, but to throw out the suggestion that under the hand of man, the soil and even the climate of our immense Australian possessions might possibly be improved. Drought is the grand enemy of Australian settlers ; and the country is generally barren of wood. Governors, district governments, and farmers, and all who are interested in the pros- perity of the colony, surely ought to encourage, by every possible means, the growth of the UiWer trees and shrubs that are indigenous to the country. Expeditions might be made once or twice a year, at the proper season, for scattering or planting the seeds of these trees or shrubs. Could every knoll witjiin a hundred miles of Sidney be seen crowned with a thick screen of leafy trees, there can be little doubt but that the rain which falls would be economized ; and that the beds of the livers, instead of being dry for eight or nine months, would be occupied all the yeal round by at least a moderate stream of water. — Eva. Ed. TBI BUD. y^. mm K ■