b'UNITED STATES OF AMERICA. \n\n\n\n\nc^^^ls^ \n\n\n\ni^-^ /\'U^^ \n\n\n\nCHEMISTRY FOR FAR3IERS. \n\n\n\nTHE \n\n\n\nELEMENTS of CHEMISTRY \n\n\n\nAS APPLIED \n\n\n\nTO AGRICULTURE. \n\n\n\n\nBy C. B. chapman, A. M., M. D., \n\nPROFESSOE OP CHEMISTRY. \n\n\n\nPUBLISHERS: \nCINCINNATI\xe2\x80\x94 WINTHROP B. SMITH & CO. \n\n\n\nEntered, according to Act of Congress, in the year Eigliteen Hundred and Sixty, \nby C. B. Chapman, in the Clerk\'s Office of the District Court of the United \nStates, for the Southern District of Ohio. \n\nSTEREOTYPED AT THE FRANKLIN TYPE FOUNDRY, CINCINNATI, 0. \n\n\n\nZ l>^ ?J \n\n\n\n1 \n\n\n\nfc-J\\h^,\\\'^lc> \n\n\n\n1^ \n\nPREFACE. \n\n\n\nThe importance of placing before the youth in our schools, as \nwell as in the hands of our farmers at their homes, the means \nof acquiring a knowledge of the elements of the science and art \nof agriculture, has long been acknowledged by teachers and \nothers. \n\nSuch means have already been available to those who had \nacquired a limited knowledge of chemistry ; but the most valuable \nworks, containing the facts most useful to the practical farmer, \nhave been too voluminous and expensive for his own use and \nmeans, or too technical for the use of his sons while in the common \nschools. \n\nThe material which is offered in this treatise, is the result of \nconsiderable practical observation, and has been used by the \nauthor, in his lectures to classes, during several years of pro- \nfessional labor. \n\nThe improvement which was apparent in these classes, has \nencouraged him to believe that the same materials might be used \nwith advantage and profit by teachers and pupils in public \nschools, especially in those districts where the people are gener- \nally engaged in agricultural pursuits. \n\nThe day has gone by when farmers were esteemed the most \nignorant among citizens, and it is now held absolutely necessary \nfor success, as well as indispensable to proper social standing, \nthat farmers should be educated thoroughly in their calling. \n\nIf the author shall have contributed anything to aid the farmer \nin his important work, or to furnish for young men who are look- \ning forward to this vocation, the means of more thorough prepa- \nration for their honorable and useful calling, his object in giving \nto the public this unpretending volume will be attained. \n\n(iii) \n\n\n\nCONTENTS \n\n\n\nPAGE \n\nIntroduction 7 \n\nCHAPTER I. \n\nTABLE AND SYNOPSIS OF ELEMENTS. \n\nTable of Elements 11 \n\nCHAPTER II. \n\nUNION OF ELEMENTS FORMING COMPOUNDS; NOMENCLATURE AND \nSYMBOLS. \n\nTable of Compounds of Nitrogen and Oxygen \xe2\x80\x94 Cohesion and \nAffinity Table, shoi;?ing Affinities 14 \n\nCHAPTER III. \n\nAGRICULTURE DEFINED. \n\nMechanical Agriculture \xe2\x80\x94 Scientific Agriculture 20 \n\nCHAPTER IV. \n\nMATERIALS OF WHICH SOILS ARE COMPOSED. \n\nOrganic Elements \xe2\x80\x94 Inorganic Elements \xe2\x80\x94 Inorganic Com- \npounds \xe2\x80\x94 Potash \xe2\x80\x94 Soda \xe2\x80\x94 Lime \xe2\x80\x94 Magnesia \xe2\x80\x94 Silex or Silica \n\xe2\x80\x94 Chlorine \xe2\x80\x94 Phosphoric Acid \xe2\x80\x94 Sulphuric Acid \xe2\x80\x94 Oxide of \nIron \xe2\x80\x94 Oxide of Manganese \xe2\x80\x94 Aluminum \xe2\x80\x94 Fluorine 22 \n\nCHAPTER V. \n\nORGANIC ELEMENTS. \n\nCarbon \xe2\x80\x94 Diamond \xe2\x80\x94 Charcoal \xe2\x80\x94 Anthracite Coal \xe2\x80\x94 Bituminous \nCoal \xe2\x80\x94 Graphite \xe2\x80\x94 Coke \xe2\x80\x94 Nitrogen \xe2\x80\x94 Oxygen \xe2\x80\x94 Hydrogen \xe2\x80\x94 \n\nPhilosopher\'s Lamp 32 \n\n(iy) \n\n\n\nCONTENTS. V \n\nPAGE \n\nCHAPTER VI. \n\nCOMPOUNDS PRODUCED BY DECOMPOSITION OP ORGANIC MATTER. \n\nWater \xe2\x80\x94 Carbonic Acid \xe2\x80\x94 Ammonia 42 \n\nCHAPTER VII. \n\nMATERIALS OF WHICH PLANTS ARE COMPOSED. \n\nCarbon \xe2\x80\x94 Nitrogen or Azote \xe2\x80\x94 Hydrogen and Oxygen 47 \n\nCHAPTER VIII. \n\nINORGANIC COMPOUNDS IN PLANTS. \n\nPotash \xe2\x80\x94 Soda \xe2\x80\x94 Lime \xe2\x80\x94 Magnesia \xe2\x80\x94 Phosphoric Acid \xe2\x80\x94 Sulphu- \nric Acid \xe2\x80\x94 Silica \xe2\x80\x94 Oxide of Iron \xe2\x80\x94 Oxide of Manganese 48 \n\nCHAPTER IX. \n\nORGANIC COMPOUNDS IN PLANTS. \n\nWoody Fiber\xe2\x80\x94 Starch\xe2\x80\x94 Gluten 50 \n\nCHAPTER X. \n\nSUBSTANCES FORMED MOSTLY OF CARBON. \n\nWoody Fiber \xe2\x80\x94 Starch \xe2\x80\x94 Gum \xe2\x80\x94 Sugar \xe2\x80\x94 Oil 62 \n\nCHAPTEPv XI. \n\nTHE ATMOSPHERE. \n\nAtmospheric Air \xe2\x80\x94 Uses of Nitrogen \xe2\x80\x94 Impurities \xe2\x80\x94 How sup- \nplied to the Atmosphere \xe2\x80\x94 Proportion of Carbonic Acid 63 \n\nCHAPTER XII. \n\nFORMS IN WHICH NUTRIMENT IS RECEIVED BY PLANTS. \n\nPower of receiving Inorganic Materials \xe2\x80\x94 Important Offices of \nLeaves 65 \n\nCHAPTER XIIL \n\nSOURCES OF NITROGEN. \n\nAmmonia \xe2\x80\x94 Carbonic Acid \xe2\x80\x94 Water 56 \n\n\n\ny[ CONTENTS. \n\nPAOE \n\nCHAPTER XIV. \n\nMATERIALS OF WHICH SOIL IS COMPOSED. \n\nInorganic Matter\' \xe2\x80\x94 Peaty Soils \xe2\x80\xa2. 58 \n\nCHAPTER XV. \n\nSOURCES OF THE INORGANIC PARTS OF SOIL. \n\nRocks which form Soils \xe2\x80\x94 Sandstone \xe2\x80\x94 Limestone \xe2\x80\x94 Marble \xe2\x80\x94 \nChalk\xe2\x80\x94 Slate CO \n\nCHAPTER XVI. \n\nCLASSIFICATION OF SOIL. \n\nSandy \xe2\x80\x94 Clayey \xe2\x80\x94 Calcareous \xe2\x80\x94 Loamy \xe2\x80\x94 Marly 63 \n\nCHAPTER XVII. \n\nMANURES. \n\nFarm-yard Manure \xe2\x80\x94 Animal and Vegetable Manures \xe2\x80\x94 Green \nGrass and Clover \xe2\x80\x94 Flesh of Animals \xe2\x80\x94 Dead Fish \xe2\x80\x94 Guano \xe2\x80\x94 \nNight Soil \xe2\x80\x94 Poudrette \xe2\x80\x94 Poultry-house Manure \xe2\x80\x94 Hay Ma- \nnure \xe2\x80\x94 Sheep Manure \xe2\x80\x94 Bones \xe2\x80\x94 Charcoal \xe2\x80\x94 Soot 65 \n\nCHAPTER XVIII. \n\nINORGANIC MANURES. \n\nGypsum \xe2\x80\x94 Quick-Lime \xe2\x80\x94 Salts \xe2\x80\x94 Action of Lime upon Organic \nSubstances \xe2\x80\x94 .Action of Lime upon Inorganic Compounds \xe2\x80\x94 \nChloride of Lime \xe2\x80\x94 Phosphate of Lime \xe2\x80\x94 Bone-black 75 \n\nCHAPTER XIX. \n\nDRAINAGE. \n\nSurplus Water\xe2\x80\x94 Shafts\xe2\x80\x94 Clay\xe2\x80\x94 Protoxide of Iron 88 \n\nAPPENDIX. \n\nDirections for using Apparatus - 95 \n\nDirections for Experiments 96 \n\nAnalysis of Manures and Crops 103 \n\nGlossary........ Ill \n\n\n\nINTRODUCTION \n\n\n\nIn order to understand the first principles of agricul- \nture, as a science, it is necessary that some of the simple \nlessons in chemistry should be learned ; and these are best \ntaught in the same manner as the elements of that science \nare presented in the common text-books. \n\nThere is no royal road to knowledge in any department \nof science, although the avenues to these acquirements may \nbe greatly improved by the adoption of a well-adapted ar- \nrangement of lessons ; and to make the best use of these \nlessons, it is necessary that a small amount of apparatus \nshould be used; but the arrangement of illustrations is \nsuch, that this is not indispensable to their profitable use \nin the school-room. \n\nTeachers may too often be deterred from -the attempt to \nuse apparatus, for illustrating their lessons, on account of \nnot having tested their ability to do so. Such may be \nassured, that, with proper care in observing the directions \ngiven, for the purpose of aiding teachers in their first \nattempts, they Vv^ill be surprised to discover the facility with \nwhich they will succeed. \n\nThere are some principles, or facts, in agriculture, which \napply peculiarly to each country or locality ; but these are \n\n(\') \n\n\n\n8 INTRODUCTION. \n\nfound iMCKstly to apply to tlae mechanical condition of soils ; \nand such as are remedied by drainage, pulverization, \nand MIXTURE with substances which will render the ar- \nrangement of its particles such as to subserve the uses of \nthe plant we propose to raise. \n\nThere are other principles which apply alike to all \ncountries and localities ; for each plant, as well as each \nanimal, requires certain elements as food, or material out \nof which their tissues are constructed. \n\nThe first scientific facts, or principles, in agriculture, are \nfew and extremely simple ; but it is no less important that \nthey should be thoroughly acquired, than that one who \nproposes to learn a language, should, first of all, become \nfamiliar with its alphabet. \n\nMany persons, already engaged in agricultural pursuits, \nhave, most likely, been deterred from the eff"ort to acquire \nthese first principles, by the belief that more time would \nbe required for its accomplishment, than would be compat- \nible with their other avocations. \n\nIt has been the aim of the author so to condense the \nstatement of the facts which are involved in the chemistry \nof this art, that the work might be adapted, not only for \nuse in the school-room, but for fireside perusal, and thus \nfurnish the means for rendering our young farmers as well \nversed in the science which belongs to their chosen pursuit, \nas those of any other country. \n\nThe farmer has too often been led to believe that his \nexperience is worth more to him than those aids which he \ncan derive from science ; but such persons should be aware, \nthat to become familiar with the principles of the science \nupon which his art is based, can most surely do him no \n\n\n\nINTEODUCTION. 9 \n\nbarm, and will, at least, enable him to judge more correctly, \nwith regard to the value of his experiences when thus \ncompared. \n\n^ The wealth of the merchant is increased, only by the \nwell-directed employment of his capital. On the same \nprinciple, the wealth of the farmer is mostly augmented \nby the best use of his grounds ; and this consists in adapt- \ning his crop to the present condition of his field, so that \nwhen defective, he supplies such manures as are best cal- \nculated to improve the crop he proposes to raise. ^ \n\' In some instances, instead of furnishing manure to his \nfield, he may introduce such crop as can be sustained by \nmaterials which the soil already contains. ^\' \nV Soil and manure, in a certain sense, are the farmer\'s \ncapital ; and while manures are cheap, and often furnished \nwithout the outlay of capital, especially when their nature \nis understood, the crops which they contribute to improve \nare sold for a considerable sum. That which was cheap, \nand in some instances worthless, is, by the processes of the \nfarmer, converted into that which is valuable. \n\nThis is the only rational basis on which the farmer is \nenabled to estimate the value of his capital, and his only \nsure guide in selecting the best methods for its employ- \nment. A superabundance of food is no more useful for a \nplant than for an animal; and consequently nothing is \ngained by adding a substance as a manure which already \nexists in sufficient proportion in a soil. / \n\nThere is no common material in soils, the use of which \nthe farmer is more interested in properly understanding, \nthan lime. This substance, when artificially used in its \n\n\n\n10 INTRODUCTION. \n\nvarious combinatious, may be employed to correct any \nexcess, eitber of alkalies, or of acids ; in accordance with \nthe nature of tbe elements which enter into the formation \nof the article employed. \n\nThe tests for determining the presence, and excess, of \neither alkalies or acids in soils, are so simple, and so easily \napplied, that they may be used by the farmer without seek- \ning an analysis by the practical chemist, although a care- \nful analysis, which will reveal the exact materials of which \nhis soil is composed, will often be a most useful invest- \nment for him, although attended with some expense. \n\nFor determining the presence of acids, or alkalies, he \nhas only to employ two common substances, which will be \nfound in the shops. These are an acid (sulphuric, or chlo- \nrohydric) for determining the presence of an alkali, or an \nalkali (ammonia), to test the presence of an acid. \n\nBy ascertaining whether a soil contains an acid or an \nalkali, in excess, the farmer may save the unnecessary \nexpenditure of much time and labor, as well, perhaps, as \nof a costly manure ; for it has too often been true, that as \nto their constituents, manures have been applied indis- \ncriminately, whenever a soil has been found unequal to \nthe production of a crop. This is but a simple example \nof the value of chemical knowledge to the farmer, and \nshows how easily and cheaply tests which may reveal fiicts \nof great practical utility, may be employed by every \nfarmer. \n\n\n\nAGRICULTURAL CHEMISTRY. \n\n\n\nCHAPTER I. \n\nTABLE AND SYNOPSIS OF ELEMENTS. \n\nThe language used in works on chemistry possesses \npeculiar advantages, in its brevity by the use of symbols, \nthus presenting to the eye, in a simple familiar operation \nand results, the description of which would otherwise con- \nfuse the mind by its length and complexity. \n\nThe whole number of elementary substances is but fifty- \nnine. \n\nAn elementary body is one which can not by any known \nprocess, be divided, and thus made to assume different \nforms. AVater, although it appears to us as a simple \nbody, may be analyzed by processes which are easily prac- \nticed by the chemist, and thus resolved into the two ele- \nments of which it is composed. \n\nThese elements are oxygen and hydrogen gases, neither \nof which can be again subdivided, but can be made to \nunite with still other elements, and thus produce other \n\n"What means are used to express the language of chemistry? \nWhat is the number of elementary substances ? \n\nWhat is an elementary body? Of how many elements is water \ncomposed? What are they ? Can either of these be again divided? \nWill they unite with other elements? \n\n(11) \n\n\n\n12 AGRICULTURAL CHEMLSTRY. \n\ncompounds, wliich will be found to possess none of the \nproperties of tlie original elements of which the body is \ncomposed. \n\nIt has been discovered, that when elements unite among \nthemselves, it is invariably in certain fixed proportions, or \nweights, or their multiples. \n\nWater is composed of oxygen and hydrogen, which are \nhere united in quite dijQferent degrees of weight and bulk, \nfor the weight is in the proportion of one of hydrogen to \neight of oxygen, while the hydrogen, when free, will occupy \ntwice the space of the oxygen ; or a given bulk of oxygen \nwill weigh sixteen times as much as the same bulk of \nhydrogen. \n\nAs hydrogen is found to unite with other bodies in a \nsmaller weight than any other known element, it has been \ncommonly adopted as the basis of unity of the scale of \nequivalent numbers. \n\nIn the following table, hydrogen is represented by the \nfigure one, and the combining or atomic weight of each of \nthe other elements, are rated in proportion from this \nnumber. \n\nThe symbols are expressed by the first, or the first and \none other letter of the name of the elements, and the \natomic weight is represented in the right hand column. \n\nWill compounds produced by such union possess any of the \nproperties of their original elements? In what way do elements \nunite ? \n\nIn what proportions, by weight, are the elements of water \nunited? In what proportions by bulk? \n\nWhat element is adopted as the basis of unity of the scale of \nequivalent numbers ? What figure represents hydrogen ? \n\nHow are symbols expressed? Where is the atomic weight \nrepresented ? \n\n\n\nTABLE AND SYNOPSIS. \n\n\n\n13 \n\n\n\n\\^TaJ)le of the whole number of Jcnoivn elements.\'] \n\n\n\nAluminum \n\nAntimony (stibium) \n\nArsenic \n\nBarium \n\nBismuth \n\nBoron \n\nBromine \n\nCadmium \n\nCalcium \n\nCarbon \n\nCerium \n\nChlorine \n\nChromium \n\nCobalt \n\nCopper (cuprum) \n\nDidymium \n\nFluorine \n\nGlucinum \n\nGold (aurum) \n\nHydrogen \n\nIodine \n\nIridium \n\nIron (ferrum) \n\nLanthanum \n\nLead (plumbum) \n\nLithium \n\nMagnesium \n\nManganese \n\nMercury (hydrargy- \nrum) \n\nMolybdenum . \n\n\n\nAl. \n\n\n13.69 j \n\n\nSb. \n\n\n129.03 \n\n\nAs. \n\n\nY5 \n\n\nBa. \n\n\n68.64 \n\n\nBi. \n\n\n70.95 \n\n\nB. \n\n\n10.90 \n\n\nBr. \n\n\n78.26 \n\n\nCd. \n\n\n55.74 \n\n\nCa. \n\n\n20 \n\n\nC. \n\n\n6 \n\n\nCe. \n\n\n46 \n\n\nCI. \n\n\n35.50 \n\n\nCr. \n\n\n28.15 \n\n\nCo. \n\n\n29.52 \n\n\nCu. \n\n\n31.66 \n\n\nD. \n\n\n49.6 \n\n\nF. \n\n\n18.70 \n\n\nGl. \n\n\n26.50 \n\n\nAu. \n\n\n98.33 \n\n\nH. \n\n\n1 \n\n\nT. \n\n\n126.36 \n\n\nIr. \n\n\n98.68 \n\n\nFe. \n\n\n28 \n\n\nLn. \n\n\n48 \n\n\nPb. \n\n\n103.56 \n\n\nLi. \n\n\n6.43 \n\n\nMg. \n\n\n12.67 \n\n\nMn. \n\n\n27.67 \n\n\nHg. \n\n\n100.07 \n\n\nMo. \n\n\n47.88 \n\n\n\nNickel \n\nNiobium \n\nNitrogen, or Azote.,. \n\nOsmium \n\nOxygen \n\nPalladium \n\nPelopium \n\nPhosphorus \n\nPlatinum \n\nPotassium (kalium). \n\nRhodium \n\nRuthenium \n\nSelenium \n\nSilicium \n\nSilver (argentum)... \nSodium (natronium) \n\nStrontium \n\nSulphur \n\nTentalium or Colum- \n\nbium \n\nTelurium \n\nThorium \n\nTin (stannum) \n\nTitanium \n\nTungsten (wolfram) \n\nUranium \n\nVanadium \n\nYttrium \n\nZinc \n\nZirconium \n\n\n\nNi. 29.57 \n\n\n\nTa. \nTe. \nTh. \n\nSn. \nTi. \n\nw. \n\nu. \n\nV. \nY. \nZn. \nZr. \n\n\n\niN.or \nAz. \n\n\n14 \n\n\nOs. \n\n\n99.56 \n\n\n0. \n\n\n8 \n\n\nPd. \n\n\n53.27 \n\n\nP.\'"\' \n\n\n*32.\'02 \n\n\nPt. \n\n\n98.68 \n\n\nK. \n\n\n89.00 \n\n\nR. \n\n\n52.11 \n\n\nRu. \n\n\n52.11 \n\n\nSe. \n\n\n89.57 \n\n\nSi. \n\n\n21.35 \n\n\nAg. \n\n\n108 \n\n\nJNa. \n\n\n22.97 \n\n\nSr. \n\n\n43.84 \n\n\ns. \n\n\n16 \n\n\n\n92.80 \n\n66.14 \n\n59.59 \n\n58.82 \n\n24.29 \n\n94.64 \n\n60 \n\n68.55 \n\n32.20 \n\n82.52 \n\n88.62 \n\n\n\nThree others* have been referred to in some works, but \nthese are of still less importance than any of those con- \ntained in the table. \n\nThese are Erbium, Norium, and Terbium. \n\nOnly fourteen elements are common, either in the com- \nposition of the EARTH, WATER, or ATMOSPHERE. Enumer- \nated with these are two others, bul they exist in very small \nquantities, as constituents of soils. \n\nHow many elements are common in the earth, water, and atmos- \nphere? What others exist in small quantity in soils ? \n\n* Graham\'s Elements of Chemistiy. \n\n\n\n14 AGRICULTURAL CHEMISTRY. \n\nWhen set free, and at common temperatures, mucli tlie \nlargest number of the elements are solids. Five are gases, \nnamely: Oxygen, Nitrogen, Hydrogen, Chlorine, and \nFluorine. Mercury and Bromine, only, are fluids. \n\nSome of the elementary bodies exist free in nature, and \nwere known long before the science of chemistry had im- \nparted a knowledge of their true character and relations. \nAmong these were several of the metals, as Iron, Copper, \nGold, Silver, Mercury, Lead, and Tin. \n\nOthers, as Potassium, Sodium, Calcium, Magnesium, \nas well as the largest number of common substances, are \nfound in nature only in combination with other elements, \nthe principal of which is oxygen. \n\n\n\nCHAPTER II, \n\n\n\nUNION OF elements FORMING COMPOUNDS; NOMENCLA- \nTURE AND SYMBOLS. \n\nThe union of two or more elements produces a com- \npound, and such compound commonly derives its name \nfrom the original substances of which it is composed. The \nmaterials which enter into the formation of a compound \n\nIn what condition are the largest number of elements found ? \nHow many are gases ? How many are fluids ? \n\nDo some exist free in nature ? Which have long been known ? \nCombined with what are the largest number found ? \n\nWhat does the union of two or more elements produce? Whence \ndoes such compound derive its name? \n\n\n\nNOMENCLATURE AND SYMBOLS. 15 \n\nmay be most easily expressed by a language of symbols. \nSuch would by no means be true, if the number of origi- \nnal elements were equal to that of the compounds which \nthey contribute to form. \n\nThe whole number of elements is but fifty-nine, and, \nconsequently, the symbols which are used to express these \nelements can only, correspond to that number. When \nmore than one atom of a given elemeiit enters into a \ncompound, such additional atoms are commonly expressed \nby a small figure at the right of the symbolic letter. \nThus, CO2. \n\nThe number of elements which will be described in \nthis work is but sixteen, and two of these need be but \nbriefly considered as elements connected with the organ- \nization of living beings. No more than sixteen symbols, \nthen, will be used in expressing these elements. \n\nExample. \xe2\x80\x94 Carbonic acid being composed of two ele- \nments, carbon and oxygen, and the proportion of these \nbeing one of carbon, and two of oxygen, this compound \ngas is thus expressed in symbols, CO2. \n\nAs the equivalent number for carbon is 6, and that for \noxygen is 8, it would be one of carbon, 6, and two of \noxygen, twice 8 \xe2\x80\x94 or the whole would be expressed in \nfigures, when added together, by 22, \n\nHow may such materials be most easily expressed? Would this \nbe true if the number of elements was equal to that of the com- \npounds which they form ? \n\nTo what does the number of symbols correspond ? When more \nthan one atom of an element, how expressed ? \n\nWhat number of elements are described in this work? Then, \nhow many symbols are used in it? \n\nOf what elements is carbonic acid composed? How many atoms \nof carbon? How many of oxygen? \n\nHow is carbonic acid expressed in symbols? \n\n\n\n16 AGEICULTURAL CHEMISTRY. \n\nNo figure is used when there is but one atom of an \nelement; for the symbolic letter is understood to stand, \nnot only for the element, but for one atom of the ele- \nment. \n\nElements unite with each other in fixed and invariable \nproportions, and the figure on the right of the symbol in \nthe table of elements, always represents these proportions. \n\nIf more than one equivalent of any given element unites \nwith another, it is never united in parts, but in another \nwhole equivalent proportion. \n\nExample. \xe2\x80\x94 Water is composed of one equivalent, or \natom, each, of oxygen and hydrogen, and is expressed in \nsymbols thus, H 0. \n\nNine pounds of water are composed of one pound of \nhydrogen and eight pounds of oxygen. \n\nBiNOXiDE OF HYDROGEN is formed of one equivalent \nof hydrogen, and two of oxygen, and is expressed in \nsymbols thus, H 2 . \n\nSeventeen pounds of binoxide of hydrogen are, conse- \nquently, found to be composed of one pound of hydrogen, \nand sixteen pounds of oxygen. \n\nA combination of two elements will produce a third \nsubstance, entirely unlike either of the original elements \nof which it is composed, and when the proportion of ele- \nments is different, the product will also vary, both in \nproperties and appearance. \n\nIs a figure used when there is but one atom of an element? \n\nDo elements unite with each other in invariable proportions? \nHow is water expressed in symbols? \n\nHow binoxide of hydrogen? Of how many pounds of each are \nseventeen pounds of binoxide of hydrogen composed ? \n\nDoes the union of two elements in different proportions always \nproduce a different substance? \n\n\n\nNOMENCLATURE AND SYMBOLS. 17 \n\nThe union of two elements in dilQferent proportions will \nproduce entirely dijffcrent substances. The uu^on of one \natom of oxygen and one of hydrogen, will produce water, \nand nothing else. The union of one equivalent of hydro- \ngen and two of oxygen, wdll form binoxide of hydrogen, \na substance which will not possess any of the properties \nof water. \n\nA good illustration of the change in the character of \nsubstances, as influenced by variation in the number of \nequivalents of elements which compose them, may be \nobvserved in those entirely different compounds which are \nformed of oxygen and nitrogen, the two elements which \ncompose the atmosphere. These two elements are not \nchemically combined in the formation of the atmosphere, \nbut their particles float in relation with each other by that \nmethod w^hich is properly called mixture. \n\nThe chemical combinations of these elements are five in \nnumber, and are expressed by the following symbols : \n\nProtoxide of Nitrogen, NO. \n\nDeutoxide of Nitrogen, N O2. \n\nHyponitrous Acid, N O3, \n\nNitrous Acid, N O4. \n\nNitric Acid, N O5. \n\nThe first two of these are properly called oxides, and \nexist in the form of gases. \n\nDoes the union of like atoms always produce a like substance? \nGive two examples. Of what two elements is the atmosphere \ncomposed? \n\nAre these chemically combined ? What is the number of chem- \nical combinations of nitrogen and oxygen? What are the two \nfirst called ? \n2 \n\n\n\n18 AtiPJCULTUIiAL CHEMISTRY. \n\nThe lirst (protoxide of nitrogen, NO) can be inhaled \nby the lungs, when it produces a peculiar exhilarating \neffect, which has given it the common name of laughing \ngas. \n\nThe second, (deutoxide of nitrogen NO 2,) although a \ngas, can not be received into the air passages ; for it excites \na violent spasm in the larynx, when an attempt is made \nto inhale it. \n\nThe last three are acids, and exist in the liquid form ; \nbut their properties, and the purposes which they serve, \nare quite different. \n\nHyponitrous acid, NO3, is a thin liquid. At common \ntemperatures its color is green; but, when cooled down to \nzero, it becomes quite colorless. \n\nNitrous acid, NO4, when at a low temperature, is a \ncolorless liquid; but it becomes yellow as the temperature \nrises. \n\nNitric acid, NO5, is the only one of these five com- \npounds which is of any special importance in the arts. \n\nThis powerful acid was first known some time in the \nninth century, and with its discovery may be regarded the \nbeginning of a knowledge of chemistry. It was long \nknown as aqua forth, which name it bore on account of \nthe great power which it possesses of acting upon, and \nuniting with, most of the hard metals. \n\nIts corrosive action upon all animal and vegetable \n(organic) substances, is immediate, and very powerful. \n\nWhat are the properties and effects of the first? What of the \nsecond? What are the last three properly called? \n\nWhat symbols express each of these? Which of these is of \nespecial importance in the arts? \n\nWhat was its early name? Why this name? \n\n\n\nnome:n-clature and symbols. 19 \n\nCOHESION AND AFFINITY. \n\nThe attraction of cohesion is understood to be that force \nwhich retains particles of a. like kind, "with various \ndegrees of tenacity," in relation with each other, as the \nparticles of a mass of metal, of which gold, silver, iron, \nand lead, may be taken as examples. \n\nThe attraction of affinity^ in chemistry, is that union of \nsubstances which takes place between two elements, or \nbodies, which are unlike in their properties, in order that \nthey may unite, and form a compound. \n\nThis change takes place between such substances only \nas are quite diverse in their character, as an acid and an \nalkali. \n\nWhen an acid unites with an alkali a union takes place \nbetween them, and a third substance is produced. Such \ncompound is entirely different from either of the original \nsubstances, both in appearance and in general properties. \nThe product of such union is called a salt. \n\nThe tendency to union between any given alkali, and \nthe different acids, is quite unlike. \n\nExample. \xe2\x80\x94 If the alkali selected be soda, the tendency \nto union, or to remain united, which indicates the strength \nof affinity, is indicated by the following table, soda being \nthe alkali used in the experiment : \n\nSoda, as the alkali, or base, \nSulphuric acid. \nNitric acid, \n\nWhat is the attraction of cohesion? What that of affinity? \n\nWhat does the union of an acid and an alkali produce? Is the \ntendency to union between any alkali and the different acids \nalike ? \n\n\n\n20 AGKICULTURAL CHEMISTRY. \n\nCliloroliydric acid, \nAcetic acid, \nCarbonic acid. \n\nThose which most strongly resist separation from the \nbase are found at the top of the table, and others are \nplaced in succession, in accordance with their strength of \naffinity for the alkali. Thus : sulphuric acid may be used \nto secure a resolution of the union which exists between \nthe soda, and any of the acids which are placed below \nthem in the table. \n\n\n\nCHAPTEE III. \n\nAGRICULTURE DEFINED. \n\n/ The oldest, the most universal, as well as the most \nindispensable of human employments, is agriculture. \n\nUpon the practice of this art not less than eight hun- \ndred millions of human beings depend for their daily \nsustenance, and about eight-tenths of the inhabitants of \nthe globe expend in it their daily labor. Something like \ntwo hundred millions of the inhabitants of the world sub- \nsist on such products of the earth as do not require the \nskill of husbandry. \n\nIn the earliest periods of the world\'s history the prac- \n\nNarae the order of affinity between soda and the five acids \nmentioned. \n\nWhere, in the table, is the acid which has the strongest affinity \nfor soda placed ? \n\nWhich is the oldest of employments? \n\n\n\nAGRICULTURE DEFINED, 21 \n\ntice of agriculture was confined to the raising of a few- \nkinds of grain, and the care of herds of cattle. \n\nTo the art of agriculture belongs a knowledge of the \nbest methods of putting the seed for the various crops \ninto the ground, of attending to them during the period \nof growth, of harvesting them at the proper time, and \nstoring them away for future use, or preparing them for \nmarket, and each of these with the smallest expenditure \nof time and labor. \n\nThe methods by which these operations are performed \nembrace what is called mechanical agriculture. \n\nAnother department, which must be understood in order \nto the most economical pursuit of agriculture, involves a \nknowledge of the elements of which the plant is com- \nposed, of the soil from which it grows, and of the various \nmanures which are used to enrich the soil, or to furnish \nfood for plants. \n\nThis is called scientific agriculture. \n\nAgriculture is pursued, then, both as a science and as \nan art. \n\nIn no country have mechanical devices which are in- \ntended to save the time and labor of the farmer, been \nmore extensively introduced than in the United States. \n\nThe applications of science to agriculture have, how- \never, been more carefully studied, and are understood by \na larger proportion of agriculturists in the countries of \nEurope, especially in Great Britain, France, Ger- \nmany and Belgium, than in the United States. \n\nWhat belongs to this art? In how many divisions is agriculture \nstudied? What ai\'e they? What is mechanical agriculture? \n\nWhere is mechanical agriculture best understood? Where \nscientific? \n\n\n\n22 AGRICULTURAL CHEMISTRY. \n\nThis knowledge is more necessary for tlie inhabitants \nof those countries, on account of the numerous popula- \ntion, for which a limited amount of land must furnish \nsubsistence. \n\nFor this reason, in China the skillful cultivation of the \nsoil is still more demanded than in any other country. \n\nAn acquaintance with both mechanical and scientific \nagriculture is necessary to enable the farmer to raise the \nlargest crop with the least possible injury to the soil, the \nsmallest expenditure of time and labor, and the most \neconomical investment of capital. \n\n\n\nCHAPTER lY. \n\nMATERIALS OF WHICH THE EARTH IS COMPOSED. \n\nAlthough the number of elements which compose the \nEARTH, AIR, and WATER, as well as the animals which \nexist on the globe, and the plants which grow from its \nsurface, are but fifty-nine : only sixteen of these are known \nto form any considerable portion of the whole mass of \nwhich they are severally composed. \n\nORGxVNIC ELEMENTS. \nFour of this number enter principally into the forma- \ntion of plants and animals, and are therefore distinguished \n\nWhy is this knowledge more necessary in European countries? \nWhere still more demanded? Why is a knowledge of both me- \nchanical and scientific agriculture required? \n\nHow many elements form any considerable portion of the crust \nof the earth \xe2\x80\x94 of air, water, and plants ? \n\n\n\nMATERIALS COMPOSING EARTHS. . 23 \n\nas ORGANIC ELEMENTS. Tliese are Carbon, Nitrogen, \nOxygen, and Hydrogen. \n\nThe other twelve exist in much smaller proportions in \norganized substances, but enter largely, though in very \ndifferent proportions, into the formation of the crust of \nthe earth. \n\nThese are Potassium, Sodium, Magnesium, Calcium, \nSulphur, Chlorine, Fluorine, Phosphorus, Silicium \nor Silicon, Aluminum, Manganese, and Iron. \n\nTen substances, which are mostly compounds with \noxygen, form the principal inorganic constituents of soils. \n\nThese are Potash, Soda, Lime, Magnesia, Silica, \nChlorine, Phosphoric acid. Sulphuric acid, Oxide \nop Iron, and Oxide of Manganese. \n\nThe first four of this group are called alkalies, and \nmay be distinguished by a peculiar taste, called alkaline^ \nas well as by their power to restore vegetable blues, when- \never they have been changed to red, by the action of an \nacid upon them. \n\nPOTASH \n\nIs the strongest of the alkaline substances. \n\nIt acts so powerfully upon the flesh of animals, and \nupon green vegetables, as to decompose them in a few \nliours. In the form in which it is commonly found in \n\nHow many organic elements proper? What are they? What \nare the other twelve? \n\nHow many substances form the principal inorganic constitu- \nents of soils? With what are they mostly compounds? \n\nWhat are they? How many and which are alkalies? What \ndistinguishes an alkali ? \n\nHow is potash distinguished? How does it affect animal and \nvegeta^ile matter.\' \n\n\n\n24 AGEICULTURAL CHEMISTRY. \n\nthe shops, it is a white substance; and, unlike others of \nthe same class, when exposed to the air, it absorbs much \nmoisture, by which it becomes soft, and finally nearly \nliquid. \n\nPotash is obtained by dissolving the soluble portion \nof wood ashes, and evaporating the solution by boiling, \nwhen it remains in the vessel as a hard mass. \n\nIn this form it is used in the manufacture of soap, \nwhich is formed by its combination with oil. It is also \nused in the manufacture of glass, in which process it \nmust be intensely heated with silex. \n\nPotash exists naturally in^ some soils, especially in \nthose latitudes where the successive growth and decom- \nposition of such plants as contain large quantities of it \nsucceed each other with great rapidity. \n\nWhen potash is exposed to an atmosphere which con- \ntains carbonic acid, it absorbs a portion of that gas, and \nis converted into carbonate of Potash^ or Pearl ash. This \nis expressed in symbols K 0, C O2. \n\nWhen another atom of carbonic acid is absorbed, it \nproduces a bicarbonate of Fotash, or saleratus ; which \nis expressed by K 0, 2CO2. \n\nPotash unites with silica, and forms silicate of pot- \nash. This compound is readily dissolved in water, by \nwhich it is enabled to circulate through the vessels of \n\nWhat is its appearance? How affected by moisture? How is \npotash obtained? \n\nFor what purpose used in the arts? What combined with to \nform soap? To form glass? \n\nWhere does potash exist naturally? What takes place when \npotash is exposed to an atmosphere which contains carbonic acid? \n\nWhat when another atom of carbonic acid is absorbed? What \ndoes potash and silica form ^ \n\n\n\nMATERIALS COMPOSING EARTHS. 25 \n\nplants. This is tlie principal source from which silex is \nfurnished to growing plants. \n\nSODA \nIs a white, crystalline substance, which, unlike potash, \nremains dry when exposed to the atmosphere. It was \nformerly manufactured from the ash of sea-weeds, or kdp^ \nbut is now mostly produced from sea water, where it \nexists in combination with chlorine, which union forms \nCHLORIDE OF SODIUM, or common culinary salt. \n\nThe principal difference in the soda produced from \nthese two sources, is, that iodine exists in the ash of \nplants which grow in sea water. \n\nSoda, like potash, is used in the manufacture of soap \nand GLASS. \n\nThe most common forms in which soda is found in the \nshops is a carbonate and bicarbonate. Another common \nform is the sulphate, which is commonly known as glau- \nber salts. \n\nLIME \nExists in nature in great abundance in combination \nwith carbonic acid, or as a CARBONATE. The forms of \ncarbonate of lime are three in number ; and, although \ncomposed of the same elements, their appearance is quite \ndifferent, and their uses are- equally diverse. \n\nThese forms are as LIME ROCK, marble, and chalk. \n\nFor what is this used by plants? Describe soda. From what \nwas it formerly manufactured? From what now manufactured? \nWhat is common salt? AVhat in addition does kelp contain? \n\nFor what is soda used in the manufactures and arts? In what \nform is it most commonly found in sliops? \n\nIn what form is lime mostly found? What are the forms of \ncarbonate of lime ? \n\n3 \n\n\n\n26 AGRICULTURAL CHEMISTRY. \n\nNine-twentietlis of tlie weiglit of lime rock is dimin- \nished by the aj^plication of heat, as in the common lime- \nkiln. \n\nBy this j^rocess the carbonic acid which it contains is \ndriven off into the atmosphere, where it constantly exists, \nin the proportion of four parts to ten thousand. The \nportion that remains in the kiln is quick-lime. \n\nWhen water is poured upon quick-lime, or when it is \nexposed to the atmosph-ere from which it absorbs water, \nheat is evolved; and this corresponds with the amount of \nwater which is absorbed in a given time. As soon as \nheat becomes apparent, the lime crumbles to a powder, \nincreases rapidly in weight, and assumes a form which is \ncalled the hydrate of lime. \n\nWhen further exposed to the atmosphere, carbonic acid \nis absorbed, and the mass gradually returns to the con- \ndition of a carbonate of lime. \n\nLime also exists in nature as a sulj^hate ; and in this \nform is commonly known as gypsum, or plaster. When \nthe -^ater which it contains has been expelled by heat, it \nforms a material which is used for stucco and plaster \nCASTS, and when thus prepared is known as Plaster of \nParis. \n\nThe fine, white, and variegated varieties, are called \nalabaster. \n\nHow much is lime rock diminished in weight, in the lime-kiln? \nWhat is driven off? What is left? \n\nWhat proportion of carbonic acid exists in the atmosphere? \nWhat takes place when water is poured upon lime? What effect \nupon its condition and weight ? What is it then called ? \n\nWhat takes place when further exposed to the atmosphere? \nIn what other form does lime exist in naiure? What are the \nhue, white, and variegated vHvieties called? \n\n\n\nMATERIALS COMPOSING EAETHS. 27 \n\nMAGNESIA \nIs abundant in nature in many rocks, in union with \nlime, where it takes the name of magnesian lime rock. \nMagnesia is found in the shops in three forms : in a \nvery light white powder, as a calcined magnesia; in \nirregular lumps, but also very light, as a carbonate; \nand in union with sulphuric acid, forming a salt, which \nis called a sulphate, or Epsom Salts. \n\nSILEX, \nOr Silica, is formed by the union of oxygen with \nSilicium or Silicon, and is commonly known as RocK \nCrystal, Quartz, Flint, Sand, and Sandstone. \n\nIt exists in the stems of some plants, to which it seems \nto furnish the principal support. \n\nIt is found most abundant in the straw of wheat, rye, \noats, and barley, and in the stalk of Indian corn. For \nthese purposes it is derived directly from the soil. \n\nIn the arts it is used in the manufacture of glass, por- \ncelain, and the various kinds of stone and earthen- \nwares. \n\nCHLORINE \nIs a heavy gas, of a greenish yellow color, and has a \nstrong, suftbcating odor. \n\nA taper will continue to burn freely in it, but with a \ndim, smoky flame. \n\nWhere does magnesia exist in nature? In what forms is it \nfound in shops? \n\nWhat is epsom salts? How is silex formed? By what differ- \nent names commonly known? \n\nIn what part of plants found? For what pm-pose used in man- \nufactures? Describe chlorine. What effect on a burning taper? \n\n\n\n28 \n\n\n\nAGRICULTURAL CHEMISTRY. \n\n\n\nIt is extremely irritating to tlie respiratory passages, \nwhen breathed even in the smallest quantities. It forms \na large proportion of common salt, (Chloride of Sodium,) \nand an equal proportion of sal ammoniac, (Chloride of \nAmmonia.) The proportion of chlorine in each of these \nsalts is sixty to every hundred pounds. \n\nChlorine gas is easily prepared by adding chlorohydric \nacid to the oxide of manganese in a retort, or gas bottle, \nand applying a gentle heat. \n\nIt may be collected \nin small quantities for \nimmediate use, in a tall \njar, by displacement; \nfor its specific gravity \nis nearly two and a \nhalf times greater than \nthat of the atmosphere. \nFig. 1. When gathered over \n\na pneumatic trough, like other gases, hot water, or a strong \nsolution of common salt must be used, else much of the \ngas will be absorbed. Pure cold water will retain twice \nits bulk of chlorine, and this is a convenient method for \nretaining the gas for some purposes. \n\nThis gas, as well as those compounds which produce it \nabundantly and economically, 4s used in the art of bleach- \n\n\n\n\nWhat eflPect on air passages? It forms a large propoi\'tion of \nwhat ? \n\nHow is chlorine prepared? In what, way is it collected? Why \ncan it be gathered by displacement? \n\nWhy necessary lo use warr \nia it. used ? \n\n\n\n\xe2\x80\xa2m water or brine? In what art \n\n\n\nMATERIALS COMPOSING EARTHS. \n\n\n\n29 \n\n\n\nPHOSPHORIC ACID \nIs a solid white substance, which, is seen, like white smoke, \nfloating in the atmosphere after the burning of a common \nfriction match. It is there formed by the oxygen of the \natmosphere uniting with the phosphorus, which is combined \nwith sulphur in the manufacture of matches. It exists in \nthe bones of animals in very large proportion, in combination \nwith lime, where it takes the name of phosphate of lime. \n\nPhosphoric acid is a very acid or sour substance, and, \nlike chlorine, is extremely irritating to the respiratory \npassages. It is very readily ab- \nsorbed by water, and this union \nis attended with so much heat \nas to produce a hissing sound. \n\nThis compound may be ex- \nhibited by burning a piece of \nl^hosphorus under a bell glass, ^^^. \nwhen the acid will fill the glass, ^ \nand descend as a fine light sub- ^^ \nstance, resembling snow. Fig. 2. \n\nSULPHURIC ACID, \nOr Oil of Vitriol, is an acid liquid of great specific gravity. \n\nIt appears like an oil when poured from a vessel, and this, \ntogether with its intense acid properties, gives it this name. \n\nWhen pure, it rapidly destroys animal and vegetable \nsubstances, and chars wood when in contact with it. \n\n\n\n\nDescribe Phosphoric acid. How is it formed ? Where does it \nnaturally exist? What are its properties? How may its forma- \ntion be exhibited ? \n\nWhat is sulphuric acid? What is its appearance? What its \neffect on organic matter? \n\n\n\n30 AGRICULTURAL CHEMISTRY. \n\nAltliougli naturally transparent, it is rarely seen in this \ncondition, as the least contact with an organic substance \nchanges it to a dark color. \n\nIt forms, when combined with various alkaline sub- \nstances, a class of compounds, which are called sulphates. \nThe principal of these are Sulphate of Soda, (Grlauber \nSalts,) Sulphate of Magnesia, (Epsom Salts,) Sulphate \nOF Alumina and Potassa, (Alum,) and Sulphate of \nLime, (G-ypsum.) These compounds are called salts. \n\nAlthough sulphuric acid is itself a very acrid substance, \nmost of those salts which it contributes to form possess \nno such properties. \n\nSulphuric acid is prepared by subjecting to a high tem- \nperature those substances with which it is found naturally \ncombined, when it distills over as an oily liquid. \n\nThe principal source of its preparation by this process \nis the sulphate of iron, commonly known as green vitriol. \n\nOXIDE OF IKON \nIs commonly known as iron rust. It is constantly form- \ning by the union of oxygen of the atmosphere with iron, \nwhich may be exposed to it in moist situations. \n\nThe surface of smooth or polished iron will thus be- \ncome rusted, and that rust is an oxide of this metal. \n\nWhen a thin strip of iron is ignited, and then plunged \ninto a jar which contains oxygen gas, the metal burns, \n\nWhy is it usually of a dark color? What does it form by union \nwith an alkali? What are the principal of these compounds? \n\nAs a class, what are these compounds called? Do these salts \npossess any of the original px\'operties of the acid ? \n\nHow is sulphuric acid prepared? What is its principal source? \nHow is oxide of iron constantly forming? How is it quickly \nformed? \n\n\n\nMATEEIALS COMPOSING EARTHS. 31 \n\nand in this process throws off many sparks, which are \nfound to be an oxide of iron. This does not differ from \nthat which is formed by the slow process of rusting. \n\nThe union of any metal with oxygen produces a sub- \nstance which is called an oxide, and the process by which \nthe change is effected is called oxidation. \n\nOXIDE OF MANGANESE \n\nIs a black mineral, and when finely pulverized, is not \nreadily distinguished, as commonly observed, from graphite. \n\nIt exists in considerable quantities in but few localities, \nbut is found in smaller quantities widely distributed. \n\nIt is found in considerable quantities in Bennington \nand Pittsford, Vermont; and in Kent, Connecticut. \n\nIt forms a small part of the ash of some plants, and is \nextensively distributed, but in very small quantities, in soil. \n\nAluminum and Fluorine should be described in con- \nnection with this group, although they are not known to \nconstitute any portion of organic substances. \n\nALUMINUM, \nWhen united with oxygen, produces alumina. It is \nnearly pure in the gems called ruby and sapphire. \n\nIn more impure conditions, or when combined with \nsilica, it yields the common clays. \n\nDoes oxide of iron prepared by burning iron in oxygen, differ \nfrom that formed by rusting in the atmosphere? \n\nWhat is the union of any metal with oxygen called ? What is \nthe process called? What is oxide of manganese? Where found? \n\nAre aluminum and fluorine known to form any portion of or- \nganic substances? \n\nWhat does aluminum form with oxygen ? What gems does it \nform? What does it form with silica? \n\n\n\n32 AGRICULTURAL CHEMISTRY. \n\nThe presence of alumina imparts to clays those prop- \nerties which fit them for the purposes of the potter, the \nbrickmaker, the manufacturer of PORCELAIN, and of the \nvarious kinds of earthenware. \n\nFLUOEINE \nIs found in combination with lime, as the fluoride \n\nOF CALCIUM, or FLOUR SPAR. \n\nIt also occurs in the Topaz, and in some other min- \nerals. It forms a small portion of the enamel of teeth, \nand of the hardest portion of the bones of animals. \n\nThe general properties of fluorine are not well under- \nstood, and it is known by its compounds only. \n\nFluorine combines with Hydrogen, forming hydro- \nfluoric ACID, and this compound is remarkable as pos- \nsessing the power of corroding glass. The process of \nETCHING upon glass was known, however, long before \nfluorine was suspected to exist. \n\n\n\nCHAPTER V. \n\nORGANIC ELEMENTS. \n\n\n\nThose substances or elements which enter into the for- \nmation of organic structures are few in number, but are \nfound in a great variety of forms and proportions. \n\nWhat properties does it impart to clay ? la what combina- \ntion is fluorine principally found? Where found in animal \nbodies? \n\nAre its properties well understood? What does it form with \nhydrogen? For what used in tlie arts? \n\n\n\nOKGANIC ELEMENTS. 33 \n\nThese are four, viz., Carbon, Nitrogen, Oxygen, and \nHydrogen. The last three of these are gases, while the \nfirst always exists in a solid form. \n\nCAKBON \n\nIs found in several forms and conditions, which are quite \ndiverse in character and appearance. These are the Dia- \nmond, Charcoal, Anthracite, and Bituminous Coal, \nGraphite, Coke, and Lamp-black. \n\nThe DIAMOND is the hardest known substance. It is \nnot acted upon by acids, or worn by friction, even when \nin contact with the hardest substances. It is, however, \nmore readily injured by heat than many substances which \nare less hard ; for when heated to the temperature required \nfor melting silver, it loses its value as a gem by becoming \npartially charred. \n\nThe diamond is the most costly of gems. The cele- \nbrated India diamond, the Koh-i-noor, now the prop- \nerty of the British crown, has been valued at ten millions \nof dollars. \n\nCharcoal is produced by the imperfect burning of \nwood, bones, and flesh. \n\nThat the burning may be rendered imperfect the ma- \nterial from which it is produced must be nearly covered \nwith earth, or some other substance, that will nearly ex- \nclude the oxygen of the atmosphere. Although it appears \n\nWhat are the organic elements? In what form do oxygen, \nhydrogen, and nitrogen exist? In what form carbon? \n\nWhat is the hardest known substance? Is it acted upon by \nacids or friction? What is the effect of heat upon it? \n\nHow is charcoal produced? How is the burning rendered im- \nperfect? What are its qualities? \n\n\n\n34 AGRICULTURAL CHEMISTRY. \n\nsoft, and may be easily broken, its fine particles are so \nbard as to scratch tbe hardest glass. \n\nAnthracite and Bituminous Coal are found imbedded \nin the earth, where they are often interposed among \nrocks. \n\nThe principal difference between them consists in the \nabsence of bitumen in the anthracite, which burns with a \npure flame, but is useless in the manufacture of coal gas. \n\nGrRAPHiTE, also Called Plumbago and Black-lead, is \nused in the manufacture of lead-pencils, and to prevent \nthe effects of friction in machinery. As it resists a high, \ndegree of heat, it is employed in the manufacture of cru- \ncibles. \n\nCoke is produced by subjecting bituminous coal to a \nhigh temperature, so as to expel its bitumen, as in the \nmanufacture of coal gas. \n\nLamp-black is produced by the imperfect burning of \nbituminous substances, as the oil of pine and resin, on \nwhich it rises in the form of a dense black smoke, and is \ndeposited in chambers prepared for its reception. \n\nKITEOGEN \nIs a gas which exists in the atmosphere, and in combi- \nnation with many substances which are used as food. \n\nThe other element of the atmosphere, which is oxygen, \nmay be separated from it by placing a piece of phosphorus \nin a tube with a bulb, or a bolt-head, over water. A por- \n\nWhere are anthracite and bituminous coal found? Uovr do \nthey differ? \n\nWhat is graphite? What are its uses? What is colie? How \nis lamp-black produced ? \n\nWhere does nitrogen exist? What other element in the atmos- \nphere? How are these elements separated? \n\n\n\nOEGANIC ELEMENTS. \n\n\n\n35 \n\n\n\n\nFia:. 3. \n\n\n\ntion of the phosphorus will be slowly con- \nsumed, for it unites with the oxygen of the \ncontained air. \n\nBoth the phosphorus and oxygen are engaged \nin the process of slow combustion, and the water \nwill rise and fill about one-fifth of the tube. \n\nThat portion of the atmosphere which remains \nin the tube will prove to be nitrogen gas. This \nexperiment proves that four-fifths of the atmos- \nphere is nitrogen, and the remaining fifth oxygen. \n\nIf it is desired to test the gas which remains \nin the tube, or bell-glass, it is necessary to \nplace the bolt-head and the vessel which contains the \nwater (see Fig. 3) in a water trough, in order to trans- \nfer the gas to another vessel, which must be at least one- \nfifth smaller in order to contain nothing but the nitrosren. \n\nNitrogen may also be pro- \nduced by burning phosphorus \nunder a bell-glass, over water \nor mercury ; when the oxygen \nof the contained atmosphere will \nbe burned out. or unite with the \nphosphorus, by which process \nphosphoric acid is formed. \n\nAfter the fumes have been \n\nabsorbed, if over water, or have Fig. 4. \n\nfallen down in white flakes upon the fluid metal, if over \nmercury, the contents of the bell-glass will be found to \nbe nitrogen gas. \n\nWhat change in the oxygen and phosphorus by this process? \nWhat effect on the water in the tube? \n\nWhat gas remains in the tube? How else may nitrogen be \nproduced ? \n\n\n\n\n\n36 AGKICULTURAL CHEMISTRY. \n\nWhen free from oxygen this gas will not sus- \ntain the life of animals, or support the flame \nof a candle. \n\nTo prove that it will not support flame, a \nlighted candle, or taper, may be lowered into \na jar filled with the gas, which has been pre- \npared by either process, when it will be extin- \nFig. 5. guished. \n\nOXYGEN. \n\nThe importance of OXYGEN will be inferred, when we \nlearn that it forms one-fifth of the atmosphere, one-ninth \nof water, and not less than one-third of the whole mass \nof the crust of the earth. \n\nOxygen, being the most extensively difi\'used element \nin nature, is found in combination with all the elements, \nexcept fluorine. \n\nIt is that portion of the atmosphere which is the chief \nagent in supporting animal life, and in the various pro- \ncesses of combustion. \n\nIts specific gravity is greater than that of the atmos- \nphere, the weight of which is intermediate between this \nsubstance and nitrogen. The particles of oxygen and \nnitrogen which compose the atmosphere are not chemi- \ncally combined so as to produce a third substance, as is \n\nWhat are the properties of nitrogen? How prove that it will \nnot support flame ? \n\nHow much each of atmosphere, water, and the earth, does \noxygen form ? \n\nWith what elements does it combine? With which does it not \ncombine? \n\nWhat is its principal use in the atmosphere? Is it chemically \ncombined with nitrogen ? \n\n\n\nOEGAXIC ELEMENTS. 37 \n\ntrue in the union of hydrogen and oxygen to form water \nbut float in rehxtion with each other, neither of them \nlosing their individual character. \n\n\n\n\nFig. 6. \n\nThis element may be produced from several substances \nwith which it has combined, and formed a solid. The \nseparation of oxygen may be effected by the application \nof heat, varying in intensity according to the substance \nemployed. The most convenient method for its prepara- \ntion is by mixing chlorate of potash with a small quan- \ntity of the oxide of manganese in a retort, and applying \nheat with a spirit-lamp. \n\nThe gas may be collected in a bell-glass over a pneu- \nmatic-trough. The lamp should be slowly removed from \nthe retort, in order to secure it against breaking. \n\nOxygen may also be produced in the same manner \nfrom the Peroxide of Mercury, (Red Precipitate,) but \nmore heat is required than when chlorate of potash and \' \nmanganese, or chlorate of potash alone is used. \n\nBy what means is oxygen prepared ? What are the most con- \nvenient substances used in its production? \n\nHow is this gas collected ? What other convenient method for \nits production? \n\n\n\n38 \n\n\n\nAGIIICULTUEAL CHEMISTKY. \n\n\n\nThis is one of the most interesting- experiments which \ncan be introduced, for both elements of which the sub- \nstance used is composed, may be collected and weighed; \nand the fact is thus demonstrated, that no part of the \nmaterials is lost, although their appearance and properties \nare entirely changed. \n\n\n\n\nFig. 7 \n\nBy this method the mercury, (quicksilver,) which is \nthe only metal that retains a fluid form at ordinary tem- \nperatures, may be collected in a globe, which takes the \nplace of Wolfs bottle. \n\nIf two hundred grains of peroxide of mercury are used, \none hundred and eighty-five grains of mercury will remain \nin the globe, and fifteen grains of oxygen will be gathered \nin the bell-glass over the pneumatic trough. The fifteen \ngrains of oxygen will be found to occupy forty-four cubic \ninches of space. \n\nWhy is its production by the use of oxide of mercury pecu- \nliarly interesting? \n\nIf two hundred grains of oxide of mercury are used, how many \ngrains of mercury are produced, and where found ? \n\nHow many grains of oxygen? How much space will the oxygen \noccupy ? \n\n\n\nOEGANIC ELEMENTS. \n\n\n\n39 \n\n\n\n\nFi2. \n\n\n\nThat oxygen, tliough not itself combustible, is one of \nthe supporters of combustion, may be proved by lower- \ning a taper, or bit of charcoal, with the smallest spark, \ninto a jar of the gas, when it will burn with a \nbrilliant flame, and be consumed with great \nrapidity; but whenever removed from the jar, \nthe combustion ceases ; but is renewed when \nthe charcoal is returned, provided it retains \nthe smallest ignited point. This may be \nrapidly repeated many times in the same jar \nof oxygen. (Fig. 8.) \n\nA w\\atch-spring, or fine wire, with a glowing \npoint, will kindle and burn very rapidly, \nthrowing off brilliant sparks, when plunged \ninto this gas. (Fig. 9.) \n\nHYDEOGEN. \n\nHydrogen forms the principal part of coal ^" \' "*\' \ngas, which contains, also, a minute quantity \'^\'^S- 9- \nof carbon, and other impurities. \n\nHydrogen gas is produced by pouring over some strips \nof zinc, or, what is better, some finely granulated zinc, \nor iron filings, some sulphuric acid, diluted with five parts \nof water. \n\nThe most convenient method for its prepa^-ation is, by \nthe use of a common gas bottle, with a wide mouth, fitted \nwith a cork, which is pierced by a tube, funnel-shaped at \nthe top, and leading to the bottom of the bottle, in order \n\n\n\n\nWhat are the properties of oxygen? What are its relations \nto combustion? \n\nWhat does hydrogen gas form the principal part of? How is \nit produced ? What apparatus is used ? \n\n\n\n40 \n\n\n\nAGRICULTURAL t\'HExMIBTRY. \n\n\n\nto facilitate the introduction of the liquid. Another tuhe, \nwhich must barely pierce the cork, should extend under \nthe bell glass, over the pneumatic trough. (Fig. 10.) \n\n\n\n\nFig. 10. \n\nNo heat is rec^uired in the preparation of this gas, but \nmuch will be evolved, if the acid is occasionally added \nto the mixture in the gas bottle. \n\nGreat care must be observed to avoid the mixture \nof atmosphere with this gas, as this combination, when \ninflamed, will produce a violent explosion. \n\nWhen pure, hydrogen will take fire on the application of \na lighted taper, and burn with a feeble flame and the most \nintense heat, especially when the jet is joined by one \nof oxygen. This union of the gases in the jet forms \nwhat is called the oxy-hydrogen blow-pipe. Hydrogen, \nthough combustible, is not a supporter of combustion. \n\nAny substance which is lighter than the atmosphere \nwill rapidly escape from a vessel, unless it is inverted. \n\n\n\nIs any heat required in its preparation ? Why should we avoid \na mixture of atmosphere with it when burned? \n\nWhat are its properties? What elfect if united with oxygen \nwhen burned ? \n\n\n\nOKGANIC ELEMENTS. 41 \n\nThose substances, only, wliich are heavier than the atmos- \nphere, are retained when the vessel stands upright. For \nthis reason oxygen will remain for a short time in an \nupright jar, while nitrogen and hydrogen will readily \nescape. \n\nHydrogen can be tested with regard to its property of \nnot supporting combustion, while it burns itself, only, when \nthe mouth of the vessel is turned downward. \n\nIf a burning taper is carried upward into a bell-glass \nfilled with hydrogen, it will be extinguished, after first \nsetting fire to the lower surface of the gas. The gas will, \nhowever, continue to burn, until, in a few seconds, all is \nconsumed. \n\nHydrogen may be prepared in a bottle with a pipe- \nstem or glass tube piercing the cork. \n\nThe gas will take fire by the application of flame, \nas it escapes from the orifice, and continue to burn \nwith a feeble flame. This has been called the \n" Philosopher\'s lamp." The cork should not be \nintroduced for a few moments after the mixture, in \norder that the air which the bottle contains may be \nexpelled, or an explosion may take place. (Fig. 11.) Fig. ll. \n\nThe most convenient plan for exhibiting the burning \nproperties of this gas is by placing the materials for gen- \nerating it in the bottom of a tall glass, and covering \nfor a few moments, in order that a small quantity may \naccumulate. \n\nDoes hydrogen support combustion? How proved that it does \nnot? \n\nDescribe the philosopher\'s lamp. What precautions are neces- \nsary in its use? \n\nWhat is the most convenient plan for exhibiting the burning \nproperties of hvdrogen ? \n4 \n\n\n\n42 \n\n\n\nAG-EICULTUEAL CHEMISTRY. \n\n\n\n\nFig. 12. \n\n\n\nOn removing tlie cover, and quickly \napplying a taper, a slight explosion will \ntake place. (Fig. 12.) \n\nHydrogen gas is the lightest of all \nknown substances, being fifteen times \nlighter than the atmosphere. This prop- \nerty renders it an appropriate material \nfor inflating balloons.* \n\n\n\nCHAPTER VI. \n\n\n\nCOMPOUNDS PRODUCED BY DECOMPOSITION OF ORGANIC \nMATTER. \n\nThe forms which organic substances assume when de- \ncomposed, are principally three. \n\nThese forms are water, carbonic acid, and ammo- \nnia; and they are compounds of the four organic ele- \nments, in various forms and proportions. \n\n\n\nHow much does 100 cubic inches of hydrogen weigh? Of ni- \ntrogen \xe2\x80\x94 atmosphere \xe2\x80\x94 oxygen \xe2\x80\x94 carbonic acid, and chlorine? What \nuse does its peculiar lightness fit it for? \n\nHow many forms do organic substances assume when decom- \nposed ? Of what elements are they composed ? \n\n*NoTB. \xe2\x80\x94 This table indicates the comparative weight of several com- \nmon substances. Fractions are omitted : \n\n100 cubic inches of hydrogen weigh 2 grains, \nnitrogen " 30 " \natmosphere " 31 " \noxygen " 34 " \n\ncarbonic acid " 47 " \nchlorine " 76 " \n\n\n\nOEGANIC COMPOUNDS. 43 \n\nWater is composed of oxygen and hydrogen, chem- \nically combined, in the proportion of eight parts of the \nformer to one of the latter. \n\nThis compound is one of the sources of the elements \nof which it is composed, as furnished to vegetable tissues. \nIts principal use is a physical one, for by its agency, the \nnutritive materials appropriated by plants and animals, are \nconveyed through their vessels. \n\nCarbonic acid is a gas, but it exists as a solid when \ncombined with the alkalies and ALKALmE earths. It \ncombines with lime, potash, soda, magnesia, and some \nother substances, and forms a class of compounds which \nare called carbonates. \n\nMany specimens of lime rock contain in each hundred \npounds, forty-four pounds of carbonic acid and fifty-six \npounds of lime. \n\nCarbonic acid gas is abundantly produced by the com- \nbustion of wood, and other substances which contain \ncarbon. \n\nIt is also furnished to the atmosphere, in very large \nquantities, by the breathing of animals, by the various \nprocesses of fermentation, and by the decay of animal and \nvegetable matter. \n\nConsiderable quantities may also be separated from \nmarble, chalk, and lime rock, by the application of heat, \nas in a lime-kiln. \n\nOf what is water composed? What are its uses? Where does \ncarbonic acid exist as a solid? \n\nWhat class of compounds does it form with alkalies ? How \nmuch carbonic acid in each 100 pounds of lime rock ? \n\nHow is it abundantly produced? How is carbonic acid natur- \nally furnished to the atmosphere? How separated from marble, \nchalk and lirae rock ? \n\n\n\n44 \n\n\n\nAGRICULTURAL CHEMISTRY. \n\n\n\nThis gas exists, free, in nature, in all well and spring \nwater, from which it is expelled by boiling. It is so \nabundant in many springs as to escape in bubbles from \nthe surface of the water, as those of Saratoga, in the State \nof New York, of Baden Baden and Carlsbad, in Germany, \nand of Pyrmont, in England. \n\nCarbonic acid is heavier than the atmosphere in the pro- \nportion of forty-seven of the former to thirty-one of the \nlatter, and, like chlorine, may be gathered by displacement \nof air from the vessel. \n\nIt sometimes accumulates in old wells, which are not \nused, and in deep caverns, where the air is seldom agitated, \nwhere it has long been known as Choke Damp, from its \nfatal effects when incautiously breathed. \n\n\n\n\nFiff. 13. \n\n\n\nThis gas may be conveniently prepared by pouring some \ndiluted CHLOROHYDRic ACID upon CHALK, or any of the \ncarbonates, by which process the carbonic acid is sep- \narated. \n\n\n\nWhere does carbonic field exist free in nature ? \nIn what proportion is it heavier than the atmosphere? Where \ndoes it sometimes accumulate? How can it be prepared? \n\n\n\nORGANIC COMPOUNDS. \n\n\n\n45 \n\n\n\n\nFit?. ]-i. \n\n\n\nThis gas does not support animal life or \ncombustion. That it does not support com- \nbustion may be demonstrated by lowering a taper \ninto a jar filled with the gas, when it will be \nextinguished. \n\nThat it is heavier than the atmosphere may be \nproved by pouring it from a jar, into one which \nhas a burning taper, (figs. 14 and 15,) at the \nbottom, when the light is soon extinguished. \n\nCarbonic acid is the princi- \npal source of food for plants, as \nmost of the carbon which enters \ninto their formation is derived \nfrom it. \n\nAmmonia is a gaseous com- \npound, and is naturally pro- \nduced by the decomposition of \nsuch animal and vegetable sub- , \nstances as contain nitrogen. It \nis composed of hydrogen and \nnitrogen, and its composition is \nexpressed in symbols, thus : Hg N \n\nIt is a volatile alkali, \nthose which are fixed or solid. \n\nIt may be produced by heating in a flask equal quan- \ntities of slaked lime and sal ammoniac. \n\nAs it is lighter than the atmosphere, it may be col- \n\n\n\n\nFig. 15. \n\n\n\nwhich term distinguishes it from \n\n\n\nWhat are its pi-operties? How proved that it is heavier than \nthe atmosphere? \n\nWhat does it contribute to growth of plants? What is am- \nmonia? How naturally produced? Of what elements composed? \n\nWhat kind of an alkali is it? How may it be artificially pro- \nduced? \n\n\n\n46 \n\n\n\nAGRICULTURAL CHEMISTRY. \n\n\n\n\nlected, by the method of displacement of air, the \nvessel in which it is received being inverted over \nthe tube from which the gas escapes. (Fig. 16.) \n\nAmmonia is remarkable for its strong affinity \nfor water, and is consequently readily absorbed \nby it. This solution is called aqua ammonia, \nand is the form in which it is most commonly \nsold and used. \n\nBy union with acids, like other alkalies, it forms \nsalts, and thus loses the pungent odor peculiar to \nFig. 16. this gas. \n\nWhen ammonia is combined with aromatics, it forms \nthe smelling salts of the shops. \n\nAmmonia is one of the most active elements of farm- \nyard manure ; but, without great care, large quantities of \nthis valuable fertilizer are lost from the farm-yard, and \ncarried off in the atmosphere. \n\nThat ammonia has a strong affinity for acids \nmay be shown by bringing a glass rod, which \nhas been dipped in chlorohydric acid, over a \nvessel containing ammonia, when a dense white \ncloud is seen to rise, which is chloride of am- \nmonium. (See Fig. 17.) \n\n\n\n\nFig. 1^ \n\n\n\nIs it heavier or lighter than the atmosphere? How proved? \n\nFor what is ammonia remarkable? In what form is it most \ncommonly used ? \n\nDoes it form salts with acids? Does it thus lose its pungent \nodor? \n\nIs it an active element of manure? Why is it readily lost from \nmanure ? How proved that it has a strong affinity for acids ? \n\n\n\nMATERIALS COMPOSING PLANTS. 47 \n\n\n\nCHAPTER VII. \n\nMATERIALS OF WHICH PLANTS ARE COMPOSED. \n\nAll plants, among wliich are numbered the wliole \nrange of vegetables, trees, and grains, are composed \nof two kinds of materials, or parts, which are distin- \nguished by the terms ORGANIC and INORGANIC. \n\nThe ORGANIC portion is readily burned away in the \nfire; and this quality distinguishes it from the inorganic \nportion. \n\nThe INORGANIC part is not consumed by the action of \nfire, but remains after the organic part is burned away, \nand is known as their ashes. \n\nThe organic portion of all plants is much greater than \nthe inorganic part, but the proportion varies very greatly \nin the dilEFerent kinds of plants, or woods. This portion \nvaries from ninety to ninety-nine parts in a hundred, in \nthe diiferent grains and woods. \n\nThe elements which compose the organic part are very \nfew in number, but they exist in a considerable variety \nof forms. These elements, being four in number, are \nCarbon, Nitrogen, or Azote, Hydrogen, and Oxygen, \n(See Organic Elements.) \n\nOf what two classes of materials are plants composed ? How \nis the organic portion separated? Which part is the greatest? \n\nHow great is the organic portion ? What elements compose the \norganic part of plants? \n\n\n\n48 AGRICULTURAL CHEMISTRY. \n\n\n\nCHAPTER VIII. \n\nTHE INORGANIC COMPOUNDS IN PLANTS. \n\nThose inorganic substances which exist in the largest \nquantity in plants are as follows, and are placed in the \norder in which they exist in most plants in the largest \nproportion. They are Potash, Soda, Lime, Magnesia, \nPhosphoric acid, Sulphuric acid, and Silica, Oxide \nop Iron and Oxide of Manganese exist in plants, but \nin much smaller proportion. \n\nThe four first elements, or the combinations which they \nform, being driven off, or consumed by heat, the inor- \nganic portion remains, but may afterward, mostly, be dis- \nsolved in water, and then gathered in troughs, while in \nsolution. \n\n/ The most common and abundant of these substances is \nPotash, which is procured by the process of leaching of \ncommon wood ashes, and then evaporating the solution \nby boiling. Large quantities of this substance are pro- \nduced in those localities which abound in forests, and \nsold for the purpose of manufacture into soap and glass. \nThis article has been the source of considerable revenue \nfrom foreign countries. \n\nSoda is much more abundant in the ashes of marine \n\nWhat are the principal inoi\'ganic substances? In what con- \ndition may the inorganic substances be gathered? \n\nOf these which is the most abundant? How is it procured? \nWhat localities produce most potash? For what purpose used in \nthe manufactures? \n\n\n\nmORGANIC COMPOUNDS IN PLANTS. 49 \n\nplants, (kelp,) but exists, tliougli in much smaller pro- \nportion, in the ashes of common plants and woods. \n\nLime forms but a small portion of the structure of \nplants. It constitutes a larger portion of the ashes of oats \nthan of any other common grain. In some instances the \nproportion is as much as ten per cent. \n\nMagnesia exists in much larger proportion in the ashes \nof wheat than in lime, for the proportion is nearly ten per \ncent, in wheat, while that of lime is less than two per cent. \n\nPhosphoric acid is found in very large proportion in \nthe ashes of some grains. In wheat, oats, barley, and rye, \nit forms between forty and fifty per cent. It exists mostly \nin conjunction with lime, forming the phosphate of that \nsubstance. \n\nSulphuric acid constitutes but a small proportion of \nthe inorganic part of common plants ; for it forms less \nthan one per cent, in most of them. \n\nSilica, although it exists in vast quantities as a con- \nstituent of the earth, forms from less than one to more \nthan twenty per cent, of the ashes of common grains. It \nis found in the largest proportion in that of barley. \n\nOxide of Iron exists in the largest proportion in oats, \n\nIn what plants is soda most abundant? In what proportion \ndoes it exist in common plants? In what plant is lime most \nabundant? \n\nIn what plant is magnesia most abundant? In what plants \nis phosphoric acid most abundant? In which does it form more \nthan 40 per cent, of the ash? \n\nWith what is it mostly in conjunction ? Does sulphuric acid \nconstitute much of the inorganic part of plants ? \n\nWhat is the range of the proportion of silica in the ashes of \nthe common grains? In the ashes of what grain is it most \nabundant? \n5 \n\n\n\n50 AGRICULTUEAL CJIEMISTRV. \n\nin which grain it forms about five per cent, of the ashes. \nIt forms a little more than one per cent, of the ashes of \ncommon grains. \n\nOxide of Manganese may be discovered in the ashes \nof grains, but in most of them it forms but a very small \npart, often much less than one per cent. \n\nIt has already been ascertained that the ashes of all \nplants, of whatever kind, are composed of but nine com- \npound substances, although minute traces of a small ad- \nditional nu7nber may sometimes be discovered in them, \nonly by the most delicate tests. \n\nThese substances are destined to perform a variety of \noffices in the economy of common vegetables. They fur- \nnish a means of support to the stem of some, while in \nothers they exist mostly in the fruit or berry. \n\n\n\nCHAPTER IX. \n\nORGANIC C03IP0UNDS IN PLANTS. \n\nThe common organic forms which exist in i^lants are \nchiefly Woody Fiber, Starch, and Gluten. Sugar, \nOil, and Gum, exist as a constituent peculiar to some \nplants, and are much like starch in their characteristic \nchemical elements. \n\nIn the ashes of what grain is the oxide of iron most abundant? \nHow much in the ashes of common grains? \n\nDoes the oxide of manganese constitute much of the ashes of com- \nmon grain? \n\nWhat number of compound substances in the ashes of all plants? \nWhat are the oflfices of these substances in plants? What are the \ncommon organic forms in plants ? \n\n\n\nORGANIC COMPOlfNDS IN PLANTS. 51 \n\nAVooDY FIBER is that material which forms the largest \nportion of all kinds of wood, of the stems of common \nplants, as hay, grains, and grasses, of chaff, and husks, \nof the shells of nuts, the fiber of cotton, flax, and hemp. \n\nStarch exists in great abundance in the roots of some \nplants. It forms nearly the entire substance of some \nbulbous roots, as the potato and arrow-root, and exists \nin large proportion in wheat and rye flour, in oat and \ncorn-meal, and in the flour of all grains which are culti- \nvated as food. It is also found in the stems of some \nplants or trees, and there is called pith. \n\nGluten exists along witlv starch in the flour of mo\'St \nkinds of grains. \n\nIt may be separated from starch in flour with which it \nis associated, by first wetting the flour, and making it into \ndough, and afterward washing with water, which should \nbe done over a sieve or thin cloth. This will allow the \nstarch to pass through, aud the gluten will be left as a \nsoft mass, for it is not dissolved by water. \n\nThe starch is not dissolved by this process, but its par- \nticles (granules) are so small, and so readily separated \nby water, as to pass through the small openings in the \ncloth. \n\nOf these substances, woody fiber is most abundant in \nthe stems of plants, while starch and gluten are mostly \nfound in their seeds. \n\nWhat is woody fiber ? Where is starch found ? With what is \ngluten associated ? How may starch and gluten be separated ? \n\nHow is the starch disposed of? Where is woody fiber abund- \nant? Where is starch and gluten found? \n\n\n\n52 AGKICULTUEAL CHEMISTliY. \n\n\n\nCHAPTEE X. \n\nSUBSTANCES FORMED MOSTLY OF CARBON. \n\nFive common substances which are produced by plants, \nconsist principally of carbon. These, as before mentioned, \nare woody fiber, starch, gum, sugar, and oil. \n\nThe last four serve as food for men and animals, while \nthe first is mostly useful as fuel, and as material for ma- \nchinery, architecture, and the manufacture of cloth. \n\nCarbon is the princij^al element in these five substances, \nand exists here in combination with other elements, \nbut in quite dilferent proportions. These other elements \nare oxygen and hydrogen, which are here combined in \nthe form of water. \n\nEvery nine pounds of water are composed of eight pounds \nof oxygen, and one pound of hydrogen. \n\nEvery thirty-six pounds of woody fiber are composed of \neighteen pounds of carbon, and eighteen pounds of water. \n\nEvery forty and a half pounds of starch or- gum are \ncomposed of twenty-two and a half pounds of water, and \neighteen pounds of carbon. \n\nEighty-five and a half pounds of loaf-sugar are com- \n\nWhat five common substances consist principally of carbon ? \nWhat purposes do the last four serve? What the first? \n\nWith what element is carbon here associated? In what form \nhere do the other two elements exist? \n\nWhat are the proportion of these elements in water? In thirty- \nsix pounds of woody fiber? In forty and a half of starch or \ngum? \n\n\n\nTHE ATMOSPHERE. 53 \n\nposed of forty-nine and a half pounds of water, and thirty- \nsix pounds of carbon. \n\nStarch, then, is composed of the same three elements \nwhich form charcoal and water. Woody fiber and gum are \ncomposed of the same elements, but in different propor- \ntions, although their appearance and uses are so unlike. \n\nMuch of the material out of which these substances \nare formed, is derived from the atmosphere in the form \nof carbonic acid, this compound being always present in \nthe form of a gas. \n\n\n\nCHAPTER XI. \n\nTHE ATMOSPHERE. \n\n\n\nAtmospheric air is composed of oxygen and nitrogen \ngases, in the proportion of about one part of oxygen to \nfour of nitrogen. \n\nAlthough oxygen forms but one-fifth of the atmos- \nphere, it is the active agent in the combustion of wood \nand coal, and in the decomposition of plants and animals. \n\nExperiments prove that if the atmosphere was com- \nposed of pure oxygen, every organic substance would \nspeedily be burned up, and all metals would be rapidly \nchanged by the process of oxidation. \n\n\n\nIn eighty-five and a half of loaf-sugar? What other substances \nare composed of the same elements as starch? \n\nWhat is the source of much of the material out of which these \nare built up? In what form? \n\nOf what is the atmosphere composed? Which is the active \nagent in combustion and decomposition? W^hat if the atmosphere \nwas composed of pure oxygen ? \n\n\n\n54 AGRICULTURAL CHEMISTRY. \n\nNitrogen seems to be siijDplied to the atmospliere in \norder to dilute its oxygen, and thus reduce the intensity \nof its effects. \n\nThe atmosphere contains other substances, but in small \nquantities. These are commonly called impurities, but \nthey are such only with regard to animals, for they are \nfound to promote the growth, and contribute to the health \nof vegetables. \n\nSuch substances, in addition to carbonic acid, are water \nand ammonia, (see p. 57,) and are mostly furnished to the \natmosphere by the decay of vegetables and animals. \nHowever, some are furnished from other sources. \n\nThe proportion of carbonic acid in the atmosphere is \nabout one j^art in twenty-five hundred, and although a \nlarge portion (at least one-half) of all vegetable substances \nis derived from this source, its proportion in the atmos- \nphere is always nearly the same. \n\nWe thus learn that carbonic acid is constantly produced, \nand in large quantities, and is as constantly used by plants \nin the building up of their structure. \n\nCarbonic acid being formed of carbon and oxygen, is \ncomposed for every twenty-two pounds of the compound, \nof sixteen pounds of oxygen and six pounds of carbon. \nIts source, in addition to the breathing of animals, and \nthe decay of animal and vegetable substances, is by the \nvarious processes of fermentation, as of beer, wine, and \n\nCIDER. \n\n\n\nWhat seems to be the use of nitrogen ? What other substances \ncalled impurities in the atmosphere ? How are these principally \nfurnished ? \n\nWhat is the proportion of carbonic acid in the atmosphere ? \nWhy does the quantity not accumulate in the atmosphere? What \nadditional sources of carbonic acid ? \n\n\n\nFORMS OF FOOD FOR FLANTS. 55 \n\n\n\nCHAPTER XII. \n\nFORMS IN WHICH NUTRIMENT IS RECEIVED BY PLANTS. \n\nThe materials out of wliicli plants are constructed \nare received by tliem, in tlie form, either of liquids or \ngases ; but every plant possesses within itself the power \nto change these substances, and to fit them for future \nuse. \n\nPlants possess the power of receiving certain inor- \nganic materials from the earth, and so changing their \nproperties as to fit them for contributing to the support \nof other plants, and of animals. \n\nThey receive carbonic acid gas from the atmosphere, \nthrough the agency of their leaves, for these are the respi- \nratory organs of plants. \n\nIt has been estimated that more than a hundred and \nseventy thousand small openings (stomata) exist upon the \nsurface of a leaf of some plants, while others are supplied \nwith a much smaller number. These openings are mostly \nfound upon the under surface of the leaf. \n\nLeaves, then, perform important offices in the growth \nof plants, for they assist in the preparation of the sap, ;^n \n\n\n\nIn what, forms are materials of which plants are constructed \nreceived by them? What an agency in the change of gases in \nplants? \n\nWhat changes do plants themselves effect in the materials \nwhich are destined for their support? \n\nThrough what organs do they receive carbonic acid? What \nother office do leaves perform \':\' \n\n\n\n56 AGRICULTUKAL CHEMISTRY. \n\nthe evaporation of water, and in the separation of \noxygen from the carbonic acid, which is returned \nagain to the atmosphere. The carbon remains in \norder to contribute to the formation of the woody \nfiber, fruit, etc., and this is principally effected \nFig. 18. under the influence of light. (Fig. 18.) \n\n\n\n\nCHAPTER XIII. \n\nSOURCES OF NITROGEN. \n\n\n\nNitrogen is mostly furnished to plants by means of \nammonia, and this element is fixed from ammonia by pro- \ncesses which to some extent correspond to the retention \nof carbon from carbonic acid. \n\nAmmonia is composed of hydrogen and nitrogen. (See \n\np. 1.) \n\nSeventeen pounds of ammonia are composed of three \npounds of hydrogen and fourteen pounds of nitrogen, and \nis written in symbols thus, N H3. \n\nThe muscles of animals, and that portion of plants \nwhich is called gluten, as well as vegetable albumen, con- \nsists mostly of nitrogen, but in combination with other \nelements. \n\nWhat becomes of the carbon of the carbonic acid ? What of the \noxygen ? \n\nBy what means are plants furnished with nitrogen? Of what \nis ammonia composed? \n\nWhat number of atoms in each element in seventeen pounds \nof ammonia? \n\nWhat parts of animals and plants are composed mostly of \nnitrogen ? \n\n\n\nSOURCES OF NITR0GEJ7. 57 \n\nWhen these substances are decomposed, they unite with \nhydrogen, and thus form ammonia, and the ammonia thus \nformed in turn is furnished as food for phmts. \n\nCarbonic acid, being hirgely formed by the decompo- \nsition of vegetables, ammonia, in like manner, is largely \nproduced by the decomposition of animals ; but a certain \nportion of each is formed by the decomposition of both \nplants and animals. \n\nAmmonia, like carbonic acid, pervades the atmos- \nphere, but is imbibed by plants, mostly, if not entirely, by \na different set of organs. It enters into the circulation, or \nsap of plants, through the fine spongy extremities of \ntheir roots, (spongioles,) and consequently must first be \ndissolved. \n\nWater has the power to absorb many times its bulk \nof ammonia, and ammonia, in turn, has a strong ten- \ndency to approach water, and to be absorbed by it. It is \nby this means that rain water, snow, and dew, are always \ncharged with a certain quantity of this compound, which \nthey impart to plants, to promote their growth. \n\nWater from wells, springs, and streams, does not con- \ntribute to the growth of plants to the same extent, unless \nit has previously been charged with ammonia. \n\nWhen decomposed, with what does it unite? "What does it thus \nform ? \n\nWhat compound is mostly formed by the decomposition of vege- \ntables? What of the decomposition of animals? \n\nBy what organs is ammonia absorbed by plants? In -what con- \ndition? \n\nBy what substance is much ammonia absorbed? What com- \nmon substances contain ammonia? \n\nWhy does not well and spring water contribute as much as \nthese to the growth of plants? \n\n\n\n58 AGEICULTURAL CHEMISTRY. \n\nThe body of an animal, by its decomposition, produces \nboth carbonic acid and ammonia, in addition to water. \nCarbonic acid is furnished by the decomposition of the \nfatty portion, and ammonia by the muscles of animals. \n\nA small quantity of ammonia, only, is furnished by the \ndecomposition of vegetables, for but a limited portion of \nsubstances which contain nitrogen enter into their com- \nposition. One of these substances (carbon) is mostly \nreceived through the leaves of plants, while the other \n(nitrogen) is imbibed by their roots. \n\nThe substance which is derived from the atmosphere is \nreceived through the leaves of plants in the form of a \ngas, and the other, dissolved in water, is imbibed through \ntheir roots. \n\nAlthough the atmosphere is composed of nitrogen and \noxygen, (see p. 53,) we have no evidence that either of these \nelements furnish any material which contributes to the \nstructure of plants. \n\n\n\nCHAPTER Xiy. \n\nMATERIALS OF WHICH SOIL IS COMPOSED. \n\nSoils from which plant* ^row, like plants themselves, \nare composed of organic and inorganic materials. \n\n\n\nWhat substances are formed by the decomposition of animals? \nFrom what is carbonic acid furnished ? \n\nFrom what part is ammonia furnished? Why is so little am- \nmonia furnished by the decomposition of vegetables? \n\nDoes nitrogen of the atmosphere furnish material for the struc- \nture of plants? -Of what materials are soils composed? \n\n\n\nMATERIALS FORMING SOILS. 59 \n\nThis fact is proved by the same method, or that of \nburning. \n\nMineral, or inorganic matter, is not aifected by \nburning in such way as to diminish its weight or bulk, \nbeyond what is lost by driving off the water which it may \ncontain, when it escapes in the form of vapor. \n\nIf a given quantity of soil is exposed to fire, or the \naction of heat, a portion is consumed, or driven off, in \nthe same manner as the organic part of wood. The ashes \nwhich remains will be the exact proportion of the inor- \nganic part of the soil. \n\nThe organic portion of soil is derived from the roots, \nstems, and leaves of plants, from the excrement and \nremains of the various animals and insects. \n\nThe organic part of the most fertile soil composes from \none-tenth to one-twentieth of its weight. \n\nIn PEATY SOILS, the organic portion is sometimes equal \nto three-fourths of its whole weight, but such soils are \npoorly adapted to the growth and support of common \nvegetables. \n\nPeaty soils are unproductive and they are so on account \nof their resistance to decomposition, for this is necessary \nin order that any soil may become food for plants. \n\nThe proportion of organic matter in soils will be dimin- \nished by the crops which are raised from them. Some \n\n\n\nHow is this proved? How is the proportion of inorganic \nmatter in soils determined? \n\nFrom whence is the organic portion of soils derived? What is \nthe proportion of organic material in fertile soils? \n\nWhat is the proportion of oi\'ganic materials in peaty soils? Are \nsuch adapted to the support of common vegetables? \n\nWhy are peaty soils unproductive? How is the oi"ganic matter \niu soils diminished? \n\n\n\n60 AGEICFLTUEAL CHEMISTRY. \n\nmaterials may be removed while others remain, and this \nwill correspond in degree, with the nature of the crops which \nare raised. \n\nWe learn with regard to the adaptation of a soil, for \nthe raising of any given kind of grain, by first ascertaining \nwhat the materials are of which the grain is composed, \nand then the substances which exist in the soil. \n\nA soil may be quite well adapted to the raising of one \nkind of grain, and at the same time poorly adapted to \nproduce another, while the proportion of organic elements \nmay remain about the same, but may differ in kind. \n\nThe farmer will learn with regard to the most profitable \ncrop which he can raise from a given field by first ascer- \ntaining the particular organic materials which exist in that \nfield. \n\n\n\nCHAPTER XV. \n\nSOURCES OF THE INORGANIC PORTION OF SOIL, \n\nThe inorganic portion of soil is derived from the \ncrumbling down of the various kinds of solid rocks. \n\nThis fact may be verified by observing the character \nof the earth which is found by the side of any given ledge \nof rocks. Such earth will be mostly composed, in its in- \norganic constituents, of the same materials as the rocky \nmass by the side of which it is found. \n\nDoes each crop remove all materials alike? May a soil be \nwell adapted to the raising of one grain and poorly adapted to \nanother? \n\nHow does the farmer learn to adapt his crop to a given field? \n\nFrom whence is the inorganic portion of soil derived? How \nmay this be verified? \n\n\n\nI \n\n\n\nSOURCES OF INORGANIC MATERIALS. (Jl \n\nThese changes in the condition of materials of which \nrocks are formed, are produced by a variety of agencies. \nThe most common, and constantly acting agency in secur- \ning such change, is the union of the original material of \nwhich the rock is formed with the oxygen of the atmos- \nphere. \n\nThose latitudes where the change of temperature in the \ndifferent seasons is greatest, are best adapted to j)roduce \nthese changes, even in the most solid rocks. \n\nThe crumbling down of rocks is sometimes effected on \nan immense scale by the action of frost upon such masses \nas contain considerable water, for large fragments are often \nseparated by the expansive force of water while freezing. \n\nRocks are not only broken down by these means, but \nsmaller fragments, and particles even, are thus separated, \nand crumble down to fine dust. These processes furnish \na soil which is composed of matter similar in its chemical \nconstituents to the rock itself. \n\nEOCKS WHICH FOKM SOILS. \n\nThose rocks which contribute mostly to the formation \nof soils are Sandstone, Limestone, and Slate. \n\nSandstone, which is composed mostly of silica, is of \ndifferent colors, and this variation in color is principally \nproduced by the presence of a very small quantity of some \none of the different forms of iron. The largest number \n\nBy what agencies are changes eflFected in the matei\'ials of which \nsolid rocks are composed? What latitudes are best adapted to \neffect these changes? \n\nHow does water contribute to eiFect these changes? What kind \nof soil do these processes furnish? \n\nWhat rocks contribute mostly to the formation of soils? Of what \nis sandstone composed? Of what colors is it found? \n\n\n\n02 AGRICULTURAL CHEMISTRY-. \n\nof sandstones are red, or white, but they are found of a \ngreat variety of hues, some of which are black, gray, and \ngreen. \n\nLimestone is found in great abundance and in many \nlocalities. The most common form is the gray lime-rock; \nbut it is often combined with magnesia, when it takes the- \nname of magnesian lime-rock. \n\nThe next most abundant form of carbonate of lime is \nCHALK, which exists in large masses on the coast of Eng- \nland, especially along the British Channel. \n\nMarble is the least abundant form of this kind of \nrock, but it exists in such masses, in a few localities, as to \ncontribute to give character to soil. \n\nMarble is found of a great variety of cojors and tex- \nture, from the pure white materials used for statuary, to \nthose which are variegated, and of various hues, some of \nwhich are used for building purposes. \n\nSlate or Shale, is a source of clay soils. It is found \nin masses, arranged in thin layers, as those from which \nslates for the school-room, and slate roofing are made. \n\nSlate is not found in as great abundance as the quantity \nof clay found in soils would naturally lead us to expect. \n\nWhat is the most common form of limestone ? What is the next \nmost abundant form of carbonate of lime? \n\nDoes marble contribute to give character to soils ? What is the \nsource of clay soils? \n\nIn what form is slate found? Is it abundant? \n\n\n\nCLASSIFICATION OF SOIL. \n\n\n\n63 \n\n\n\nCHAPTER XVI. \n\nCLASSIFICATION OF SOIL. \n\nSoils are named from the amount, or proportions, of \nthe various substances which enter into their formation. \nIf a soil consists principally of sand, it is called a sandy \n\nSOIL. \n\nIf the largest portion is clay, it is called a clayey soil. \nWhen lime predominates, it is called a calcareous \n\nSOIL. \n\nThose substances may exist together, but in different \nproportions, in the same soil, in which case it usually \nreceives a distinct name. \n\nA mixture of sand and clay, with a small portion of \nlime, is called a loaji. \n\nIf it contain much lime, it is called a calcareous \n\nLOAM. \n\nIf it is composed of clay, with much lime, it is called \n\na CALCAREOUS CLAY. \n\nA certain proportion of these substances has given \nspecific names to soils. \n\nPure clay, which is commonly called pipe clay, is com- \nposed of about sixty parts of silica, and forty parts of \n\nFrom what are soils named? What is a sandy soil\xe2\x80\x94 a clay \nsoil \xe2\x80\x94 a calcareous soil? \n\nWhat constitutes calcareous clay? What gives specific names \nto soils? \n\nWhat is pure clay commonly called? Of what is it com- \nposed ? \n\n\n\n64 AGRICULTUBAL CHEMISTRY. \n\nalumina, witli a small quantity of oxide of iron. This kind \nof clay contains no silicious sand whicli can be separated \nby washing with water. It forms but a small quantity of \nsoil, and is found in comparatively few localities. \n\nTile clay forms the strongest clay soils. It consists \nof pure clay, mixed with from five to fifteen per cent, of \nsilicious sand, which can be separated from it by boiling, \nor washing. \n\nClay loam contains from fifteen to thirty per cent, of \nfine sand, which can be separated by boiling. The differ- \nent parts of this soil may be very easily separated, and is \nconsequently more easily worked. Such soil is very prop- \nerly sought for in the selection of a farm. \n\nA LOAMY SOIL contains from thirty to sixty per cent, \nof sand, which is retained so loosely that it can be readily \nseparated from it by washing. \n\nA SANDY LOAM leavcs from sixty to ninety per cent, of \nsand. \n\nA SANDY SOIL consists mostly of sand, and contains no \nmore than ten per cent, of clay. \n\nIn a MARLY SOIL the proportion of lime must be more \nthan five per cent., but less than twenty per cent. \n\nMarls are called sandy, loamy, and clayey, in accord- \nance with the proportions they may contain of these sub- \nstances, provided they be free from lime, or do not contain \nmore than five per cent, of this material. \n\n\n\nDoes this contribute to form much soil? Of what does tile clay \nconsist? What does clay loam contain? \n\nIs clay loam a valuable soil? What does a loamy soil con- \ntain? A sandy loam? Sandy soil? A marly soil? \n\nWhat different names are given to marly soils? What is the \nsource of these names? \n\n\n\nI \n\n\n\nMANURES. 65 \n\nSoils are denominated calcareous when the proportion \nof lime exceeds twenty per cent., and thus by its quantity \nbecomes an important constituent. \n\nThere are also calcareous clays, calcareous loams, \nand calcareous sands, which take their names from the \nproportion of clay and sand which they may contain. \n\nVegetable mold is sometimes a prominent charac \nteristic of a soil. \n\nIn peaty soils, its proportion may be equal to sixty \nand sometimes as much as seventy-five per cent. \n\nGarden mold contains no more than five per cent, \nof organic matter. \n\n\n\nCHAPTER XVII. \n\nmanures. \n\nManures may be regarded as the food of plants, and \nthis must be composed of the same elements as the plant \nitself, although they may exist in quite different forms \nand proportions. \n\nThe adaptation of manures to the raising of a given \ncrop can only be learned by first acquiring a knowledge \nof the constituents of the crop itself. \n\nA field, as before mentioned, may be fertile in regard \nto one crop, and barren in regard to another. \n\nWhat soils are denominafed calcareous? What gives names to \ncalcareous clays, loams, and sands ? \n\nDoes vegetable mold sometimes give character to soils? How \nmuch organic matter in garden mold? \n\nWhat are manures ? Of what must food of plants be composed ? \nHow do we learn to adapt manures? \n6 \n\n\n\n66 AGRICULTURAL CHEMISTRY. \n\nThe defect in a soil which renders it poorly adaj^ted \nto produce a given grain, may often be readily supplied \nby a small exj^euditure of money, provided the particular \ndefect is well understood by the farmer. \n\nManures, as well as the plants which they are destined \nto feed, are composed of both inorganic and organic \nmaterials. \n\nThe inorganic materials are mostly found in the earth \nfrom which plants grow, but whenever defective, they may \nbe supplied by art. \n\nOrganic food for plants is furnished by the decay of \nother plants, which have preceded them in the same soil, \nor it may be furnished in the form of farm -yard manures. \n\nFarm-yard manure is usually composed of hay, straw, \nand excrement of animals, mixed in some instances with a \nsmall quantity of earth. \n\nManures are sometimes distinguished as animal, vege- \ntable, and MINERAL. \n\nAnimal and vegetable manures are used by plants only \nwhen they are decomposed into the form of carbonic acid \ngas, when it escapes into the atmosphere, from which it \nis imbibed mostly through the agency of the leaves of the \nplant; or, when those parts which are composed of nitro- \ngen are decomposed into ammonia, and afterward dissolved \n\nHow to supply defects? Of what are manures, as well as \nplants, composed? Is inorganic food often needed to be supplied \nby art? \n\nHow is their organic food furnished? Of what is farm-yard \nmanure mostly composed? \n\nBy what names are manures distinguished ? How are animal \nand vegetable manures changed before being used by plants? \n\nWhat does their decomposition produce? By what organs la \ntheir carbonic acid taken up? By what their ammonia? \n\n\n\nMANURES. 67 \n\nin water, in wliicli it is mostly absorbed through their \nroots. \n\nVegetable manures are furnished by such plants, as, by \ntheir decomposition, may furnish appropriate food for a \nsucceeding plant, which may grow from the same soil. \nWhen plants decay in the soil from which they grow, \nduring their period of decomposition, they contribute to \nform vegetable mold, or mold. \n\nTo this class of manures belong hay, straw, weeds, \n\nPOTATO-TOPS, GRASS, BUCKWHEAT, RYE, and CLOVER. \n\nGreen gRx\\ss and clover are sometimes plowed in \nwhile growing vigorously. By this means the whole crop \nis added to the soil as manure, but the value of such plan \nwill depend upon the depth at which they are buried, and \nthe kind of soil in which they are placed. \n\nIn Great Britain, where artificial manures are most \nneeded, the quantity of potato-tops, as manures, is much \nincreased by breaking off the blossoms. \n\nHaving learned the constituents of plants, and of the \nvarious soils from which they grow, we may be supposed \nin a measure prepared to decide correctly with regard to \nthe supply of such defects in soils as render them unequal \nto supply that which is demanded for the perfect growth \nof a given crop. \n\nThese defects in soils are accurately learned, only by \nthe use of those tests, which chemistry teaches us to \napply, except so far as one may be furnished with evi- \n\n\n\nHow are vegetable manures furnished? During the period of \ndecomposition of vegetable substances in soils, what do they \nproduce? \n\nWhat belong to this class? How is green grass and clover \nsometimes treated? How is the value of potato-tops increased? \n\n\n\n68 AGRICULTURAL CHEMISTRY. \n\ndence by observing the cliaraeter of the vegetable and \nanimal matter which is allowed to decay in it. \n\nFlesh of animals, by its decomposition, produces am- \nmonia, and this substance serves to furnish materials for \nthe formation of the nitrogenous portion of plants. \n\nThe fat of animals and the largest portion of vegetables, \nby their decomposition, produce carbonic acid. This con- \ntributes to build up those portions composed of carbon, \nwhether it be for the woody fiber of the stem, or the \nstarch, which is the principal material found in the \nvarious grains of pith, or in the roots, or gum, which is \ndissolved in the sap, and sometimes exudes from the bark, \nor cuticle ; or sugar, which is also dissolved in the sap of \nmany trees, or plants, from which it is procured by the \nprocess of evaporation by boiling ; or oil, which is abund- \nant in the seeds, and fruit, of a large number of common \ntrees and vegetables. \n\nThe decomposition of any one of those substances which \nare built up of carbon, which has been derived from car- \nbonic acid, inasmuch as they furnish this material, con- \nstitute the proper food for plants when thus disposed of. \n\nWhen a soil, then, is defective in carbon, or nitro- \ngen food, the proper remedy will be readily under- \nstood. \n\nThe refuse portions of almost any animal, or vegetable, \nmay be employed as manure, but if we are not careful to \n\nHow learn to supply defects of soils ? What does the flesh of \nanimals by its decomposition produce? What does this furnish \nto plants? \n\nWhat does the fat of animals and the largest portion of vege- \ntables furnish? What does this contribute to build up? What \nelse used as manure? \n\n\n\nMANURES. 69 \n\nascertain the chemical properties of such substances, as \nwell as of the plant we propose to raise, injury, instead \nof benefit, is done to the crop. \n\nDead Fish, which have been cast upon the shore of \nseas, or lakes and rivers, are sometimes used with profit \nin enrichino- soils. These can not be used with advant- \nage, without first being mixed with earth, or marl, so as \nto form a compost, and this should be turned over sev- \neral times before it is prepared for use as a fertilizer. \n\n2^itrogen, or ammonia, must be furnished to most plants \nin order to their perfect growth, but quite different pro- \nportions are demanded by different plants. \n\nThis element is most commonly furnished by the liquid \nportion of fcirm-yard manure, and by the decay of animal \nsubstances. \n\nIt is of little consequence from whence these substan- \nces are derived, provided they are not furnished in such \nconcentrated form as to injure the plant by their caustic \nproperties. \n\nAYhen farm-yard manure, and the other common sources \nof these substances, do not furnish the necessary supply \nof nitrogen food, recourse may be had to guano. \n\nGuano, a bird manure, is imported from islands near \nthe coast of Peru. Birds which frequent these islands \nsubsist almost entirely upon fish. Their excrement is \n\nWhat cai-e must be observed when dead fish are used? Do all \nplants require like proportions of ammonia? \n\nAVhat is its most common source? In what condition is it used \nby plants ? \n\n"What precaution in its use? What can we have recourse to \nwhen common sources fail ? \n\nWhat is guano? On what do birds subsist, which produce \nguano? \n\n\n\n70 AGRICULTURAL CHEMISTRY. \n\ndropped in a climate where rain is almost unknown, and \nwhere the atmosphere is so dry that but little loss of \nits soluble portions is sustained. This valuable fer- \ntilizer is brought from these islands by whole ship- \nloads. \n\nAfter being applied to land, if exposed to much rain, \nor even a moist atmosphere, much of the ammonia which \nit contains is lost by evaporation, unless care is taken to \nretain it in the soil. \n\nThis is best accomplished by plowing it in to consider- \nable depth, when but small quantities will be brought into \nrelation with the plant, or the atmosphere during the first \nseason, otherwise the crop may be injured by its strength. \nor the caustic properties of its ammonia. \n\nGuano has become widel}- known, and much used as a \nmanure on account of the fertility which it has been \nfound to impart to such soils as had been regarded as \nworn out, and rejected as unfit for cultivation. \n\nThe fact should not be lost sight of, however, that \n\nPOULTRY DUNG, STABLE MANURE, and NIGHT-SOIL, may \n\nmostly be used for the same purpose, and that the one \nadds to the wealth of the farmer by its importation, ^hile \nthe other adds to the wealth of the country as well as of \nthe farmer, by saving the amount paid to the country \nwhere it is naturally produced. \n\nNight-soil is among the most valuable of manures, \nprovided the methods for its preparation, and use are well \nunderstood by the farmer. Night-soil has long been used \n\n\n\nWliy naturally preserved? What precautions when applied to \nland ? What does it impart to soils? \n\nWhat are home substitutes for guano? Why should these be \nsought in preference to guano? \n\n\n\nMANURES. 71 \n\nby the Chinese as a fertilizer, and this may account for the \nhirge popuhition which is sustained in that country. \n\nWhen properly used, it has been found to increase the \ncrop upon a given field, at least three-fold. If a field had \nproduced but eight bushels of grain, the yield would at \nonce be increased to twenty-four bushels. \n\nIn addition to this increase of the produce of a district, \nby proper care of night-soil, the health of its inhabitants \nmay be promoted by this disposition of it. \n\nIf such substances are allowed to decompose and escape \ninto the atmosphere, a noxious gas is furnished, which is \ninjurious to the health of the inhabitants of the neighbor- \nhood. \n\nThe same means that are available for retaining such \nexhalations, are also efi"ectual for preserving them, and \nstoring them up, so that they may be used as manures, \nat such times as may be desired. This is most easily \naccomplished by mixing with them a small quantity of \ncharcoal, prepared muck, or some other good absorbent. \n\nThe product of this mixture is called Poudrette. \n\nIn order to render this method most efi\'ectual, a small \nquantity of the substance used as an absorbent, must be \nadded every few days. \n\nWhen this method is practiced, no odors will be found \nto rise from the vault, as all gases are taken up by the \nabsorbent, as soon as they escape. \n\nIll what country has night-soil been long used ? How much \ndoes it increase tiie produce of a field? \n\nWhat other purposes served by its retention by absorption? \nHow is this elfecfed? \n\nWhat is the product of this mixture called? What care in \nusing the proper absorbent? Why does this method prevent odors \nirom vaults ? \n\n\n\n72 AGRICULTURAL CHEMISTRY. \n\nPouDRETTE, like guano, must be used only after being \nmixed with some absorbent, else the crop will be injured \nby the strength of the ammonia. The absorbent may as \nwell be a portion of the soil in which it is to be placed. \n\nPoultry-house manure is much like guano in its \nproperties as manure, and may be used in the same way. \nIts value is greatly increased by constant care, in adding \nan absorbent at very short intervals to the floor of the \npoultry-house. \n\nMuch of its value is soon lost, in a moist atmosphere, \nby evaporation and leaching. \n\nHog manure, on account of the rich quality of the \nfood of swine, is of a superior quality, when properly pre- \npared. \n\nIts value is greatly increased by furnishing vegetable \nmold, muck, or charcoal, to the sty ; for swine will work \nthis over, and by mixing it thoroughly, save much labor \nto the farmer. \n\nThe manure of swine at slaughter-houses is peculiarly \nrich, as they are often fed upon blood, and other animal \nfood, which render it very rich in nitrogen and the phos- \nphates. Its ammonia is retained by mixture with absorb- \nents, and this also protects the plant from injury. \n\nSheep manure is less valuable, on account of the large \nproportion of nitrogen and mineral constituents which are \nappropriated in the formation of wool. \n\nWhat, care must be observed in using poudrette ? What may \nthe absorbent be ? \n\nWhat is poultry-house manure like? How may its value be \nincreased? How naturally soon lost? \n\nWhy is this manure of superior quality? What is the manure \nof swine at slaughter-houses rich in ? What of sheep manure ? \nWhy less valuable ? \n\n\n\nMANURES. 73 \n\nBones contnin gelatin, and this being a nitrogenous \nsubstance, ammonia is produced by its decomposition. \n(See page 45.) \n\nThey also contain lime and phosphoric acid, both of which \nbelong to the class of inorganic manures. (Pages 25 and 29.) \n\nIn those countries where land is highly cultivated, on \naccount of a necessity for its supporting a large population, \nmany substances which have been unknown to us for such \npurposes, are used as manures. Among these are saw- \ndust, spent tan-bark, woolen rags ; waste of woolen fticto- \nries, paper mills, and binderies, hair, and soot. \n\nCharcoal has been long used by farmers in place of \nmanure, but with too little knowledge, (in some instances,) \nwith regard to the manner in which it acts. \n\nCharcoal is composed of nearly pure carbon, but does \nnot contribute, like manures proper, to the growth of \nplants, by its own decomposition. \n\nThe value of charcoal resides in its remarkable power \nto absorb from the atmosphere, and to condense within its \npores, those gases from the atmosphere and elsewhere, \nwhich serve as food for plants. \n\nIt has been computed that charcoal will absorb and \ncondense ninety times its bulk of ammonia, thirty-five \ntimes its bulk of carbonic acid, but only nine times its \nbulk of oxygen, and seven times its bulk of nitrogen. \n\n\n\nWhat do bones contain? What does gelatin by its decomposi- \ntion produce? What else do they contain? \n\nAVhat substances used in countries where land is highly culti- \nvated ? Has charcoal been used in place of a manure ? \n\nDoes charcoal itself contribute to the growth of plants ? In \nwhat does its value reside ? \n\nHow much ammonia will charcoal absorb? How much carbonic \nacid \xe2\x80\x94 oxygen \xe2\x80\x94 nitrogen ? \n\n7 \n\n\n\n74 AGRICULTURAL CHEMISTRY. \n\nIt also absorbs from tlie atmosphere large quantities of \nwatery vapor, whicli it retains in soils, and by this means \ncontributes to retain a certain quantity of moisture during \ndry seasons. \n\nThese properties are possessed in a higher degree by \nthose specimens which are finest, and consequently con- \ntain most pores, and in a lower degree by the more loose \nand spongy. \n\nIt has been estimated that a cubic inch of charcoal must \nhave at least an absorbing surface of one hundred square \nfeet. It is upon the interior surface of the pores that \ngases are condensed, -and the quantity absorbed is in pro- \nportion to the extent of this surface. \n\nThe value of charcoal in preserving meats, and in re- \nstoring those which are tainted, depends upon its power \nto immediately remove the results of their decomposition. \n\nSoot contains much carbon, and may be used in some \ninstances in place of coal. It also contains some sulphur, \nand this serves as food for plants. \n\nThe ammonia which it contains is mostly in the form \nof a sulphate, which is not volatile, and consequently does \nnot evaporate when applied as a top-dressing. The odor \nof its sulphur, when thus used, serves as .a good protection \nagainst some kinds of insects. This is the source of its value \nwhen thrown upon young cabbage plants, and melon vines. \n\nWhat else does it absorb? To what does this contribute? What \nspecimens of charcoal are most valuable? Why? \n\nWhat is the absorbing surface of a cubic inch of charcoal ? On \nwhat does the value of charcoal in preserving meats depend? \n\nWhat does soot contain? What may it sometimes be used in \nplace of? \n\nIn what form is the ammonia which it contains? W^hat pur- \npose does the odor of sulphur serve? \n\n\n\nINOKGANIC MANUEES. 75 \n\n\n\nCHAPTER XVIII. \n\nINORGANIC MANURES. \n\nThe inorganic or mineral manures exist naturally in \nsufficient quantity in many soils. In some, however, they \nare so defective as to require their artificial supply. \n\nThese manures act in a variety of ways, in addition to \ntheir use as furnishing food for the inorganic part of \nplants. \n\nSome of these perform an office in changing both the \norganic and inorganic manures which exist in the soil, and \nthus fit them for absorption by the roots and leaves, in \norder that they may be assimilated by the plant. \n\nOthers seem only, or mostly, to change the mechanical \ncondition of soils, and still others are useful as absorbers \nof carbonic acid and ammonia. \n\nSome of the inorganic manures are furnished to the soil \nby the decay of organic manures, or the decay of certain \ntrees and plants. The ashes of such substances are left \nafter their decomposition, in the same manner as when \ntheir organic portion has been burned away in the fire. \n\nIf the crop which is grown from any given piece of \nland be at once returned to it as manure, such field will \nconstantly increase in fertility. \n\nIs inorganic food sufficient in most soils? In what ways do \ntbey act ? \n\nHow are some inorganic manures furnished to soils? What \nif a crop be at onct\' returned to a field? \n\n\n\n7($ AGRICULTURAL CHEMISTRY. \n\nThe cliief object in cultivating land, however, is not \nrealized to the farmer by this process, for; like the miser, \nmuch is accumulated by the land, which is not made \nuseful for any purpose whatever. \n\nWhen we have learned the constituents of any plant, \nwe are prepared to adapt it as a fertilizer in the most \neconomical way. \n\nExample. \xe2\x80\x94 The ashes of the potato contain more pot- \nash than any other inorganic substance, while the ashes \nof clover contain lime as a principal ingredient. \n\nIt is apparent, then, that each of the green crops, when \nused as manure, has a definite value with regard to the \ncrop we propose to raise. As the ashes of wheat and rye \ncontain a large proportion of potash and soda, and that \nof oats a larger proportion of lime than either of these, \nwe are enabled to apply these substances in a way that \nwill contribute to the production of these grains. \n\nPotash and soda have been found in all clays, when \nthey have been sought for, but their proportion is quite \ndifferent in different localities. \n\nLiTME, in some of its forms, is the most constant and \nimportant of the inorganic constituents of soils. The most \ncommon form is that of a carbonate, as lime-rock, chalk, \nand marble. (See p. 62.) \n\nThe next form is as gypsum, or sulphate of lime. \n\n\n\nIs the chief object in cultivating land realized by this process? \nWhat teaches how to adapt a fertilizer most economically ? Give \nan example. \n\nHas each green crop a definite value as a fertilizer? Mention \nthe special value of some, and why. Where is potash and soda \nalways found? \n\nWhich is the most constant and important of the inorganic con- \nstituents of soils? Which is the next most important? \n\n\n\nINORGANIC MANURES. 77 \n\nQuiCK-LTME, an oxide, Is produced by heating either of \nthe carbonates, by which their carbonic acid is expelled. \n(See p. 26.) \n\nLime is a principal inorganic ingredient of several \ngrains and grasses, as oats and red-clover, while it exists \nin still larger proportion in lucerne. \n\nIt exists in very large proportion in the bones of ani- \nmals, and in the shell, or outer covering of mollusks, as the \noyster and clam, and of the Crustacea, as lobsters and crabs, \nand mostly in the form of a phosphate and a carbonate. \n\nThere is no substance used in agriculture that serves \nsuch variety of purposes, as lime. \n\nIn addition to furnishino; materials for animal and veue- \ntable structure, it is used : \n\n1. To hasten the decomposition of other substances in \nsoils. \n\n2. To remove excess of acids. \n\n3. To cause the mineral matter in soils to crumble. \nLime being itself an alkali, which, when in excess, is \n\ninjurious to soils, unites with acids, which are also inju- \nrious, and thus forms another substance which is called \n\na SALT. \n\nSalts are the principal forms in which inorganic mate- \nrials serve for the support of plants, either by contribut- \ning to their structure, or by changing the mechanical \ncondition of soils. ^ \n\nLime being an active decomposing agent, serves to \n\nHow is quick-lime produced? In what grains is lime most \nabundant? \n\nWhere in animals does lime exist? What different purposes \ndoes it serve in agriculture ? \n\nHow useful in soil which contains acids? In what principal \nform is inorganic material used by plants ? \n\n\n\n78 AGEICULTURAL CHEMISTRY. \n\nhasten the decomposition of organic matters, and to sep- \narate them from the inorganic materials with which they \nare associated, when they escape in the form of gases, and \nare then in a condition to be absorbed by the roots and \nleaves of plants. \n\nThe action of lime upon organic substances secures \ntheir decomposition into the same elements as those of \nwhich they were originally constructed. The lime does not \nunite with animal and vegetable matter, and thus produce a \nthird substance, as when it acts upon inorganic matter, or \nunites with acids. \n\nWhen it acts upon the fat of animals, or upon the \nsubstances formed of carbon which exists in plants, the \nsubstance produced is carbonic acid. \n\nBy its action upon the flesh of animals, or any other \norganic substance which contains nitrogen, the product of \nsuch decomposition is ammonia. \n\nWhen the substance subjected to its action is formed of \nboth carbon and nitrogen, the result will be both carbonic \nacid and ammonia, and, at the same time, wafer. \n\nThe decomposition, then, of all organic substances, of \nwhatever kind, will produce at least one, and, sometimes, all \nof these three substances, viz. : water, composed of oxygen \nand hydrogen; CARBONIC ACID, of carbon and oxygen; \nand AMMONIA, of hydrogen and nitrogen. \n\n\n\n\\ \n\n\n\nWhat is the effect of lime on organic matter? What substan- \nces does this decomposition produce? \n\nDoes lime ever unite with animal and vegetable matter? Does \nit unite with inorganic matter? \n\nWhat is produced when it acts upon the fat of animals ? What \nwhen it acts upon their flesh? \n\nWhat will the decomposition of all organized substances pro- \nduce? \n\n\n\nINOEGANIC MANURES. 79 \n\nAs lime forms no part of these compounds, it is appar- \nent that it acts only as an agent in securing these changes, \nand thus fitting them for the support of plants. \n\nSuch soils as contain an injurious quantity of acids, \nwhich render them fitted for the support of inferior \nplants only, as sorrels and other weeds which are them- \nselves injurious to useful plants, will be rendered fertile \nwith regard to most grains, by the addition of a small \nquantity of lime. Such lime must b^ in a form that does \nnot already contain an acid. The form used for this pur- \npose is quick-lime. \n\nIxNORGANic COMPOUNDS are so acted upon by lime as to \ncrumble down into fine particles. By its union with some \ncompounds of this class, both are rendered soluble. \n\nBy its union with Silica, it forms a silicate of lime. \nThe silica in this instance seems to take the place of an \nacid. \n\nThe MECHANICAL changes which are produced in soily \nby the agency of lime, are also calculated to facilitafe cer- \ntain CHEMICAL changes, for the finer particles being thus \nexposed more fully to the influence of the atmosphere, \nwill more readily undergo that chemical change which is \ncalled oxidation. It is also thus better prepared to absorb \nnutritive material for plants, from the atmosphere. \n\nThe addition of a small quantity of lime to a compact \n\nWhat the use of lime, then, when thus used ? What its use in \nimproving lands which contain acids? \n\nWhat, must such lime not contain? What form should be used? \nWhat is the action of lime on inorganic compounds? \n\nWhat substance is thus rendered soluble? What does silica \nseem to take the place of? What purposes do the mechanical \nchanges which it effects, serve? \n\nWhat is its effect upon compact clay ? \n\n\n\n80 AGRICULTURAL CHEMISTRY, \n\nclay, or aluminous soil, will render it loose, and thus fitted \nfor easy cultivation. \n\nThe quantity -of lime which is proper to use, should be \ncarefully regarded in each particular case. \n\nA proper quantity will greatly facilitate the decompo- \nsition of organic substances, while a larger quantity may \nproduce too rapid decomposition of the same substances, \nand thus induce a useless waste of the best materials for \nthe support and growth of the plant. \n\nAn excess of lime will have the effect to exhaust a soil, \nfor that which is not readily used by the plant, escapes as \ngas into the atmosphere, and is lost to the field which it \nis designed to improve. \n\nThese gases may be stored up and used at a future time, \nprovided some absorbent is furnished, or exists naturally \nin the soil. \n\nThe best artificial absorbent which can readily be pro- \nvided for this purpose, is charcoal. \n\nThe most common natural absorbents are clay and alu- \nmina, especially during a long dry season, during which \nmuch ammonia is stored up for future use in the pores of \nthese substances. \n\nLime should be used with much care, especially when \nassociated with animal manures, as an excess will cause a \nrapid and wasteful discharge of ammonia. \n\nCare should be observed to procure lime which is \n\nShould its quantity here be carefully regarded? Why careful \nabout quantity when added to organic substances ? \n\nHow may gases which escape be stored up ? What is the best \nartificial absorbent? \n\nWhat are the most common natural absorbents? Why should \nlime be used with care when it is associated with animal manures? \n\nWhat care is necessary in selecting lime? \n\n\n\nINORGANIC MANURES. 81 \n\nfree from impurities, the most common of wliicli is mag- \nnesia. \n\nThe best lime for enriching soils is produced by the \nburning of shells, for such is free from the noxious agen- \ncies which are elsewhere found. \n\nSulphate of lime, or gypsum, is also called Piaster \nof Paris, because it exists in abundance in the rocks which \nunderlie the city of Paris. \n\nGypsum is made to serve two important purposes as \na fertilizer, for the sulphur which it contains, supplies that \nelement to plants. \n\nUnlike the oxide, or quick-lime, it acts as an absorbent \nof ammonia. \n\nThis quality indicates the utility of sprinkling it about \nstables, privies, and poultry-houses, where it absorbs nox- \nious gases, and by this means renders such places more \nhealthful, and better fitted for the abode of animals. \n\nWhen gypsum is used to excess, it promotes the growth \nof sorrel ; for the land is rendered sour, by the separation \nof lime for the use of the plant, while the acid is left free \nin the soil. This condition is readily corrected by the \naddition of quick-lime. \n\nChloride of lime may be easily produced by the mix- \nture of lime and salt, or by slacking quick-lime by the \nuse of sea-water. \n\nIt may be used to absorb ammonia and other gases, and, \n\nWhat is the most common impurity? From what is the best \nlime produced ? What purposes does gypsum serve ? How unlike \nquick- lime? \n\nWhy should it he sprinkled about stables? What is its effect \nwhen used to excess ? How is this condition corrected ? \n\nHow is chloride of lime produced? For what purpose is it \nused ? \n\n\n\nk \n\n\n\nS\'^ AGKICU LTUHAL UHEM ISTK V. \n\nlike quick-lime, for the decomposition of animal and yege- \ntable substances. \n\nPhosphate of lime, or bone earth, wliicli is formed \nof phosphoric acid and lime, is one of the most common \nconstituents of animal and vegetable substances. \n\nIt is called bone earth, because it is the form of lime \nwhich exists most largely as an earthy constituent in the \nbones of animals. \n\nPhosphoric acid exists in large proportion in the ashes \nof various grains. It forms about one-half of the ashes \nof wheat, buckwheat, rye, corn, and oats ; but in slightly \nless proportion in barley, peas, and beans. It also exists \nas an important substance in potatoes and turnips. About \none-fourth of the ashes of milk is composed of phosphoric \nacid. \n\nThe various methods by which phosphoric acid is \nremoved from soils, and the limited number of natural \nmethods for its return, render the study of the relations \nof this substance to soils and plants, as well as animals, \namong the most important in agriculture. \n\nEvery bushel of wheat removed from a farm, takes away \na little more than half a pound of phosphoric acid ; or \neach hundred bushels of wheat removes nearly sixty \npounds of this acid. \n\nIt has been estimated that each cow which feeds in a \npasture during a whole summer, will remove not less than \n\nOf what is phosphate of lime formed? Where abundant in \nanimals ? Where does it exist in grains? \n\n1 In what grain does it form much of the ashes? In what others \nis it an important substance? \n\nWhat is its proportion in the ashes of milk ? Why should the \nrelations of phosphoric acid be carefully studied? \n\nHow much does every bushel of wheat remove? How much \n\n\n\nUllGAXlC MAN UliEB. 83 \n\nfifty pounds of bone earth. As one thousand pounds is \nthus removed by each twenty cows, it becomes apparent \nthat the exhaustion of pasture lands is very rapid, so that \nin a few years a fertile pasture may be reduced to a bar- \nren waste, and this may be true, while it contains all the \nother materials which are demanded in order to constitute \na fertile field. \n\nIt has also been estimated that the removal of bone \nearth from the farms of some of the older states, has \ncaused more emigration than all other causes combined; \nand this, when a limited knowledge of the constituents of \nsoils, and of the methods for ascertaining and remedying \ndefects, would have rendered the restoration of such fields \nboth certain and economical. \n\nThe principal source from which phosphoric acid may \nbe furnished to exhausted fields, is by the use of bones \nof animals, for these contain a large proportion of phos- \nphate of lime. \n\nBones seem to be the receptacles in which large quan- \ntities of phosphoric acid are stored up, from whence it may \nbe used by plants at such times as it may be required. \n\nBones, when dried, consist of about two parts of inor- \nganic" material, most of which is phosphate of lime, and \none part of organic matter. \n\nThe organic portion is mostly composed of gelatin, a \n\ndoes each cow remove? Each twenty cows? What is the effect of \nthis removal on fields? What is the source of most emigration ? \n\nHow could this have been remedied ? How may phosphoric acid \nbe returned to exhausted fields? \n\nWhere is phosphoric acid stored up in animals? What do dried \nbones consist of? What is the organic portion mostly composed \nOf? \n\n\n\nQ4 AGiUCULTUKAL CHEMISTKY. \n\ncompound which consists principally of nitrogen, and \nwhich, by its decomposition, like other compounds which \ncontain nitrogen, produces ammonia. \n\nBones are sometimes crushed in mills, and then sepa- \nrated into heaps, and such heaps are composed of frag- \nments of similar size. These are distinguished by dealers \nas inch, and half-inch bones, and bone-dust. \n\nSpecimens of crushed bones are selected as fertilizers, \nin accordance with the rapidity of the action which is \ndesired. Bone dust will act the most rapidly, but its \naction will accordingly be soonest exhausted. \n\nWhole bones are sometimes used for enriching soil, but \nthis is the least desirable method, for their decomposition \nis too slow to produce the best results. \n\nIt has been estimated that one bushel of bones, properly \nprepared, will produce more results as a fertilizer in five \nyears, than ten bushels used whole, or but slightly broken. \n\nBone black is produced by burning bones in a retort, \nor in such way as to protect them from the atmosphere \nduring the process. By this means all the organic portion, \nexcept carbon, will be expelled. The product of this pro- \ncess is called bone black, or ivory black, and consists of \ninorganic matter, and carbon of the bones. \n\nThe nitrogen having been disposed of, no ammonia can \nbe formed by its decomposition. This is compensated for \n\nWhat does this produce by its decomposition ? How are bones \nprepared for market? How distinguished by dealers? \n\nWhat condition preferred as fertilizers? Why are not whole \nbones more used? \n\nWhat is the comparative value of whole bones and bone dust? \nHow is bone black produced? \n\nBy this process what is expelled? What does the product con- \nsist of? \n\n\n\nINORGANIC MANURES. 85 \n\nby tlie carbon, which is retained in a form which renders \nit a good absorbent in the soil. The whole may be reduced \nto fine particles much more easily than before it was charred. \n\nThe decomposition of bones may be secured by com- \nposting them with ashes. The strongest unleached ashes \nshould be used for this purpose. The bones should be \nplaced in some water-tight vessel, in layers of a few inches \nin thickness, alternating with layers of ashes. These \nshould be kej)t constantly wet. \n\nIf they become dry, or approach that condition, they \nwill send off an offensive odor; and this is accompanied \nby loss of ammonia, and consequently loss of value. \n\nThe reduction of bones by this method will usually \nrequire a year. At the end of that time they may be \neasily washed away, when they will be readily appropri- \nated by soils and plants, while the ashes will be of nearly \nequal value as a fertilizer. \n\nMagnesia exists in small quantity in the ashes of vege- \ntables ; but its presence is so constant in soils as rarely to \nrequire its application to fields, to fit them for better sus- \ntaining a crop. \n\nWherever required, it may be applied in the form of \nmagnesian lime, but this combination of magnesia already \nexists in many soils, in such proportion as to be injurious \nto its fertility. \n\nHow is the loss of nitrogen compensated for? In what other \nway may the decomposition of bones be secured ? Describe the \nmethod. \n\nWhat if allowed to become nearly dry? How much time will \nthis reduction of bones require ? What their condition at the end \nof a 3\'ear? \n\nDoes magnesia exist in the ashes of vegetables? Is its artificial \napplication often required? How is it, applied when required? \n\n\n\n86 AGRICULTURAL CHEMISTRY. \n\nSulphuric acid is a very important constituent of some \nvegetables, especially of oats and the root crops. \n\nFor this reason it is sometimes defective in soils which \nhave been long used for potatoes, and other root crops. \n\nIn such instances, the most convenient and economical \nmethod for supplying the defect, is by the use of plaster \nof Paris, from which the sulphuric acid is abstracted, and \nthe lime is left free, in which condi-tion it may serve for \nthe mechanical reduction of soils. \n\nIt is sometimes desirable to add the sulphuric acid \nalone, esiDCcially wdien the use of lime would be injurious, \nbut in such instances it must be largely diluted with \nwater. \n\nSulphuric acid is sometimes added to compost heaps, \nin order to secure the change of ammonia, which is vola- \ntile, and escapes easily into a sulphate, which is not vola- \ntile, but is readily dissolved in water, and thus absorbed \nby plants. \n\nThose w4io are employed in manufacturing fertilizers \nhave sometimes paid five and even seven cents a pound \nfor sulphate of ammonia, in order to add it to their prod- \nucts ; while the farmer who is not informed with regard \nto the value of this compound, and the cheap and easy \nmethod of producing it, will throw away vast quantities \nof the riches of his soil. \n\nSilica, or sand, nearly always exists in soils in sufficient \n\n\n\nIn what crops is sulphuric acid an important constituent? How \nis it most econoiiiically supplied when required? \n\nWhat takes place when gypsum is used? When may it be \nnecessary to add sulphuric acid alone? \n\nWhat caution is necessary when it is used? For what purpose \nis sulphuric acid added to compost heaps ? Describe the utility \nand economy of this plan. \n\n\n\nINORGANIC MANURES. 87 \n\nquantity, but not in a proper condition for the support \nof plants. When the weakness of the straw of grains in- \ndicates a demand for silica, the rule is not to add silica \nto the soil, but such alkalies as, by combining with it, \n;\\vill produce silicates ; for these are soluble, and readily \njtaken up by the roots of plants. \n\nSand is also useful as a mechanical manure, for when \nmixed with stiif clay, it loosens \xe2\x96\xa0 such soil, and renders \nit better fitted for cultivation. \n\nChlorine is a necessary constituent of plants, and when \nnot present in soils in suJB&cient quantity, it may be sup- \nplied in the form of CHLORIDE op sodium, (common salt,) \n\nor CHLORIDE OF LIME. \n\nChlorine is naturally supplied in abundance to such \nplants as grow near the sea-shore. \n\nOxide of Iron is one of the most commonly present \nsubstances in soils, and is seldom, if ever, required as a \nmanure. \n\nThere are two common oxides of iron \xe2\x80\x94 the protoxide \nand the peroxide. \n\nThe protoxide exists most largely in common deep \nsoils, and is always injurious to vegetation. \n\nThe peroxide is not only inoffensive, but actually \nnecessary to a fertile soil. \n\nThe protoxide of iron may be readily changed to the \n\nIs snnd often required to be applied artificially? When straw \nof oirain is weak, why not add silica? What is the proper course? \n\nWhat is the utility of sand with stiff clay? How may chlorine \nbe supplied to plants? \n\nWhere is it naturally supplied? Is oxide of iron common in \nsoils? In what two forms? \n\nWhich is injurious to vegetation? Where does protoxide of iron \nexist ? \n\n\n\nSB AGRICULTURAL CHEMISTRY. \n\nperoxide, by turning up the soil which contains it quite \noften, so as to expose it freely to the oxygen of the at- \nmosphere, from which it imbibes an additional atom of \nthis element. \n\nOxide of Manganese is not recognized as an essen- \ntial constituent of plants or soils, and is not commonly \ntaken into the account in manuring land. \n\n\n\nCHAPTER XIX. \n\nDRAINAGE. \n\nDrains, or under drains, serve a variety of purposes, \nand are constructed in different ways. They are mostly \nused for the purpose of removing surplus water, in order \nthat land may be cultivated. While this is being accom- \nplished, other purposes are very often unconsciously real- \nized by the f\\irnier. \n\nA necessity for the removal of surplus water arises from \na variety of sources, the principal of which are the pres- \nence of springs, or a subsoil which prevents the trans- \nmission of water, either upward or downward, with the \nfacility demanded, in order to render the surface soil pro- \nductive. \n\nA soil composed mostly of clay may itself be sufficiently \ncompact to demand the use of this means for the removal \nof water. \n\nHow may protoxide be changed to the peroxide? Is oxide of \nmanganese an essential constituent of soils? \n\nWhat purposes do drains serve? What soils require tliem \nmost? \n\n\n\nDRAINAGE 89 \n\nClay is sometimes associated with small quantities of \noxide of iron. Such stratum is often so compact as to \nprevent the transmission of water, nearly as efiectually as \nthe most solid rocks. \n\nGreat advantage may be conferred in such cases by sink- \ning shafts, or wells, to such depth as to reach a layer of \ngravel, into which water may be received, and thus con- \nveyed away, or absorbed. \n\nDrains are commonly placed at a depth of two and a \nhalf to five feet; and the purposes they serve, at these \ndiiferent depths, vary mostly in their degree of action ; and \ntheir depth will also suggest the distance from each other \nat which they should be placed, for the influence of a \ndrain will extend in accordance with its depth. \n\nSuch drains as may be useful for a considerable number \nof years, may be cheaply arranged by placing stones of \nfour to six inches in diameter, along the sides of a trench, \nand laying slabs, or other cheap boards over them, leaving \na space between the rows of stones, through which the \nwater can flow. \n\nAn early method of constructing drains, was by placing \nbranches of trees in the bottom of the trench, filling it to \nconsiderable depth, and covering the earth immediately \nupon them. Others placed small stones in the bottom of \nthe trench, and covered them in the same manner. \n\nThis plan served the purpose of a stratum of gravel, \n\nthough in a less degree. If these had been covered with \n\nflat stones, or plank, in order to prevent the packing of \n\nearth into the interstices, their utility would have been \n\ngreatly prolonged. \n\nWhen are shafts or wells required? At what depth are drains \ncommonly placed? How far apart? How may they be cheaply \narra nged ? \n\n\n\n90 AGRICULTURAL OHEMLSTRY. \n\nA more recent method is by the use of earth baked \nlike earthenware, which may be made of any form and \ndiameter, and in sections of any length desired. \n\nDrainage is mostly practiced for two purposes : \n\n1. For the removal of surplus water from a locality, or \nfrom a soil ; and, \n\n2. For the purpose of bringing the materials of which \na soil is composed into such relation with the atmosphere \nthat its elements may contribute to the production of cer- \ntain changes in the soil, and thus render it better fitted \nfor the suj:)port of plants. \n\nThose soils which demand this method for their im- \nprovement are mostly formed of clay, or contain a very \nlarge proportion of this material. \n\nClay may be an essential ingredient of the surface soil, \nor, it may contribute to form a compact layer beneath the \nsurfiice, and thus constitute a subsoil, which, from its com- \npactness, may prevent ihe natural development of the plant \nby impeding the proper descent of their roots. \n\nSuch materials can not long remain as a hard layer, \nafter the water which it contains has been drained off, so \nas to admit of the descent of the atmosphere ; for this \nelement is known to pervade, not only water in streams \nand lakes, whenever their surface is exposed, \'but also \nthe earth to a considerable depth, when it is not satu- \nrated with water, and when not consolidated into a hard \nlayer. \n\nThe PROTOXIDE OF IRON, which is often an ingredient \nof such hard stratum, is not only injurious, when in union \n\nWhat our present method for their construction ? For what \npurposes are drains introduced? \nWhat foils require drains? \n\n\n\nDEAINAGE. \n\n\n\n91 \n\n\n\nwith clay, by rendering it more compact, but is always \ninjurious to plants in any situation. \n\nWhen such mixture is brought to the surface by the \nuse of the plow, or when exposed to the atmosphere \nthrough the agency of so far removing water from the \nsoil as to admit the access of air, the protoxide of iron, \nwhich is injurious to plants, by receiving an additional \natom of oxygen from the atmosphere, is converted into a \nPEROXIDE, which is a necessary material for their support \nand growth. \n\nChemical changes in soils which contain either protoxide \nof iron, or lime, are greatly retarded by the presence of \nsurplus water. Such changes may be either proinotcd^ or \nretarded^ by the presence of water, and this will be in \naccordance with its amount, and the nature of the soil, \nfor some soils are much more injuriously affected by drouth \nthan others, and those lands which are most improved by \nfrequent variation in the amount of water they contain, \nare those which are composed of lime, with clay, and a \nsmall quantity of iron. \n\nAlthough the necessary action of oxygen upon a soil \nis prevented by excess of water, some moisture is abso- \nlutely demanded for this purpose. \n\nWhen a soil is too dry, its materials can not be brought \nsufficiently under the influence of chemical agencies to \nadmit the necessary changes, although the amount of \nwatery vapor in the atmosphere even, is often sufficient \nfor this purpose. \n\n\n\nWhat does removal of water admit to soils? What change in \niron does this secure? \n\nWhat lands are most improved by frequent variation of amount \nof water they contain ? \n\nWhen a soil is too dry. th^ influence of what ao-encies are cut off \n\n\n\n92 AGRICULTURAL CHEMISTRY. \n\nWhen a soil is rendered loose, by draining away the \nsurplus water which it contains, the atmosphere will gain \naccess to its particles, to considerable depth, and thus \nbecome an agency in effecting certain mechanical changes \nin its condition. \n\nSuch mechanical changes in a soil will admit of those \nnecessary chemical changes which are secured only through \nthe agency of the atmosphere. This process also admits the \nabsorption, by the soil, of carbonic acid and ammonia, which \nare here stored up, in order to become food for plants. \n\nDrainage not only induces changes in the inorganic \nmaterials in soils, but promotes the decomposition of or- \nganic matter ; for too much water prevents these changes, \nand renders this kind of food for plants quite useless, as \nmeans for promoting their growth. \n\nWater may serve as a necessary solvent of the various \nmaterials which are naturally destined as food for plants, \nor it may act injuriously, by washing them away, so as to \nplace them beyond the reach of the plant. \n\nDrainage does not deprive a soil of the necessary \namount of moisture, for it increases the facilities for its \ncirculation, and thus renders it the bearer of those sub- \nstances which are required by plants, as well as fits them \nfor their support. \n\nThe roots of most plants extend to a considerable dis- \ntance through the soil, those of some extend along near \nthe surface, and others penetrate downward several feet, \nmany of them not less than two or three. \n\nA plant may grow luxuriantly through the early part \n\nWhat other than chemical changes are secured by drainage? \nWhat double purpose does water serve? \n\nDoes drainage deprive a soil of necessary moisture? Why not? \n\n\n\nDRAINAGE. 93 \n\nof a season, and then droop, and ftiil to mature, and this \nbecause its roots have penetrated through a superficial soil, \nwhich has thus far furnit^hed it with the necessary nutri- \nment, but later in the season have penetrated to a layer of \nhard pan, or to some noxious ingredient, which, by its \npoisonous qualities has arrested its devekipment. \n\nThis often takes place when the remedy would be easy \nand effectual by the introduction of proper drains, so as to \nadmit of the necessary chemical changes. \n\nA dry season is not without its utility, both to the soil \nand to the plant, for the observing farmer has long been \nacquainted with the fact, that a good crop is likely to \nsucceed to a dry season. \n\nThe principal source of this utility is in the condensa- \ntion of ammonia and of carbonic acid in the pores of such \nsoils as are not already occupied by water; for although \nwater is a good absorbent of ammonia, its office for this \npurpose is much better accomplished when in an attenu- \nated condition, as in the form of vapor, or of snow-flakes. \n\nThe circulation of water through a soil is indispensable \nto render it available as a means of conveying nutriment \nto giants, and this, (like the circulation of the blood in \nanihials,) does not so much depend upon its quantity, as \nupon the means which are provided for its transmission. \n\nThe genial shower is of little, or of no use, to a soil, \nwhen it is already occupied by water which it can not dis- \nplace ; and those valuable constituents which are brought \ndown from the atmosphere, are thus carried away by the \nsurface flow of water. \n\nWhat may cause plants to fail to mature ? What is the remedy ? \nWhat are the utilities of a dry season? How may the natural \nbenefits of a shower be prevented? \n\n\n\nAPPENDIX \n\n\n\nDIRECTIONS FOR USING APPARATUS. \n\nMore complete directions for the use of apparatus, \nthan are contained in this treatise, or in most of the text- \nbooks, as well as special directions for conducting each \nexperiment, have been deemed proper. \n\nIt is hoped that by this plan, some who may have \nomitted the introduction of experiments in the class-room, \nwill no longer hesitate in the use of the-se invaluable aids. \n\nThose who may introduce experiments for the first time, \nwill seldom fail, provided they are vigilant in observing \nall the directions which are found, both in their proper \nplace in the text, and in these special directions. \n\nTKANSFERRING GASES. \n\nBefore the effort is made to transfer gases from one \nvessel to another, it will be well for those who are entirely \nunaccustomed to this manipulation, to imitate the process \nby the use of atmospheric air, over a water-trough. \nThis may be done in the following manner: \nPlace a glass^ (inverted) on a shelf in the trough, in \nwhich the water rises a little above the shelf. This will \n\n-^ Straight glasses, of uniform diameter, are introduced in this work, in \nplace of the bell glass, (whenever admissible.) as they are more economical, \nless easily broken, and can be turned up without transfer of gases. \n\n(95) \n\n\n\n96 AGRICULTURAL CHEMISTRY. \n\nleave the glass full of air, wliicli is there confined by the \nwater, beneath the surface of which the edge of the glass \nrests. \n\nAnother glass, which has been inverted while beneath \nthe surface of the water, is raised till its edge is near \nits surface. The edge of the glass filled with air is then \ncarried under the one filled with water. The top of the \none containing air is now slowly inclined to one side, when \nbubbles of air will rise through the water, the same as \nwhen gases are transferred. \n\nThe only object in repeating these manipulations before \nengaging in actual experiments, is to enable the operator \nto become familiar with the uses of the most simple appa- \nratus, in order to avoid waste of gases. \n\n\n\nDIRECTIONS FOR THE SEVERAL EXPERIMENTS. \n\n\n\nEXPERIMENT I. \nPREPARATION OF CHLORINE. \n\nPut one part of oxide of manganese, and three to seven \nparts of chlorohydric acid, in a retort or flask. (See p. 28.) \n\nThat the precise quantity of acid is unimportant, may \nbe inferred from the diversity of proportion directed by \ndifferent authors. \n\nWhen a gentle heat is applied, the chlorine will be seen \nto rise in the retort, being of a greenish 3^ellow color. \nIt may be gathered by displacement of dry air, and its \nability to support combustion tested. Or, it may be re- \n\n\n\nAPPENDIX. 97 \n\nceived into a jar of cold water, for this will absorb twice \nits bulk of the gas. \n\nThis is the most convenient method for testing the bleach- \ning properties of chlorine; and this effect may be observed \nby placing in the solution some strips of colored cloth, \nfor it is found to remove such colors as have been pro- \nduced, either by vegetable or animal substances. \n\nEXPERIMENT II. \nPEEPARATION OF PHOSPHORIC ACID. \n\nIgnite a few grains of phosphorus, in a capsule or \nwatch-glass floating upon water, and cover immediately \nwith a glass. While the oxygen of the contained atmos- \nphere is being rapidly consumed, or unites with the phos- \nphorus, the water rises rapidly in the glass. (See p. 29.) \n\nIf prepared over water, the product, (phosphoric acid,) \nwill be greedily absorbed, and may, like other acids, be \ntested by litmus. , \n\nWhen prepared over mercury, instead of water, the \nphosphoric acid will descend in flakes upon the surface \nof the fluid metal. \n\nA common glasB jar of the shops may as well be used, \nfor the intense heat which attends the combustion of \nphosphorus, is quite likely to break the vessel used in \nthis experiment. \n\nEXPERIMENT III. \nNITROGEN WITHOUT OPEN COMBUSTION. \n\nA piece of phosphorus upon the end of a glass rod, \nmay be carried up into the bulk, and the open end placed \nin water. (See p. 35.) \n\nIf the tube is not unnecessarily large, while the bulk is \n9 \n\n\n\n98 AGEICULTURAL CHEMISTRY. \n\nof considerable size, so mucli of the oxygen of tlie con- \ntained air will be consumed in the time commonly occu- \npied by a recitation, as to enable tlie class to observe that \nthe water has risen in the tube, and occupied the place of \nthe consumed oxygen. (See fig. 3.) \n\nSeveral hours (at least twenty-four) will be required to \ncomplete this process. The exact quantity of phosphorus \nused is unimportant, as all action will cease when the \noxygen is consumed. \n\nGreat care should be observed in handling phosphorus, \nas it takes fire by slight friction, or elevation of temper- \nature, when exposed to the atmosphere. It should always \nbe cut while under water, from which it should not be \nunnecessarily removed. \n\nEXPERIMENT IV. \n\nNITKOGEN BY OPEN COMBUSTION. \n\nThis experiment is conducted the same as that for the \npreparation of phosphoric acid, and the same apparatus \nmay be used. \n\nThe two experiments may be conducted as one, provided \nthe teacher prefers to do so, for the only difference con- \nsists in the observation of results. \n\nThe plan for testing the gas is the same, and the results \nthe same, when prepared by either method. \n\nEXPERIMENT V. \n\nTEST OE NITliOGEN GAS. \n\nThe gas may be transferred to a gas bottle, (see fig. 5,) \nand then tested by lowering a taper into it, when it will \nreadily be extinguished. \n\nA small animal, as a mouse, will soon die when con- \nfined in this gas. \n\n\n\nAPPENDIX. 99 \n\nEXPERIMENT VI. \nOXYGEN WITH CHLORATE OF POTASH AND MANGANESE. \n\nMix one liundred grains of chlorate of potash with thirty \ngrains of manganese. The manganese should jfirst be heat- \ned, in order to expel what moisture it may contain, which \nmay be done on a strip of sheet iron, over a spirit-lamp. \n\nA retort, or Florence flask may be employed, but the \nflask requires more care, as an additional tube must be \nused, which must be connected by a cork. \n\nWhen the gas begins to come ofi", the heat should be \nmaintained nearly uniform as long as the gas escapes. \nThe lamp should be slowly removed, which, if neglected, \nthe retort will be liable to be broken from cooling too \nrapidly. \n\nThe stopper should be removed, or the end of the tube \nraised above the water, in order to prevent its entrance \ninto the retort, for, as it cools, a vacuum will be formed, \nwhich will be occupied by the water. \n\nOne hundred grains of chlorate of potash will produce \nforty grains of oxygen, which will measure one hundred \nand eighteen cubic inches. \n\nEXPERIMENT VII. \nOXYGEN WITH OXIDE OF MERCURY. \n\nThis experiment is conducted like the last, except that \na bulb, or globe, is interposed between the reto^-^ \nglass, into which the mercury is conu. -.\xe2\x80\x9e, ..^xxc; the \noxygen passes forward to the glass over the trough. \n\nMore heat is required than in the former experiment, \nand the retort will consequently be more likely to be \nbroken, a result which is not uncommon in either case, \n\n\n\n100 AGEIC.ULTURAL CHEMISTRY. \n\nfor these experiments are liable to be undertaken at tlie \nexpense of a retort. \n\nThe last miiy sometimes be omitted, but its results \nshould be carefully studied, as it is one of the most inter- \nesting experiments in chemistry. \n\nEXPERIMENT VIII. \nTEST OF OXYGEN. \n\nWhen a straight jar is used for collecting oxygen, it \nmay be turned up without transferring the gas. \n\nA piece of charcoal, with an ignited point, held in a \nspoon or wire-forceps, may be lowered into the gas bottle, \n(see fig. 8,) when its combustion will become very rapid. \n\nThis may be removed from the bottle, and several times \nreturned, in order to prove that oxygen, like hydrogen, \nwill not remain ignited, when the burning body is removed. \n\nEXPERIMENT IX. \n\nOXYGEN BURNS METALS. \n\nA watch-spring, or small wire, should perforate a cork \nwhich fits the mouth of a gas bottle ; and when ignited, \nit should be pushed down as rapidly as it burns away. \n\nEXPERIMENT X. \nPREPARATION OF HYDROGEN. \n\nThe granulated zinc, or iron filings, are placed in the \nbottle ; (see fig. 10 ;) some diluted sulphuric acid is poured \non, and the gas allowed to generate for a short time, in \norder to expel the atmosphere from the flask, otherwise \nan explosion may take place. \n\nThe funnel tube should be carried down to the bottom \n\n\n\nAPPENDIX. 101 \n\nof the jar, or into the liquid, in order to prevent tlie \nescape of gas. \n\nThe dikited acid may be added through the funnel tube, \nas required, which will be indicated by the diminution of \neffervescence. \n\nThe decomposition of one ounce of zinc, will produce \nsix hundred and fifteen cubic inches of hydrogen gas. \n\nA glass filled with the gas, may be removed from the \ntrough, with the mouth still downward, and a lighted taper \ncarried quickly under it, when a slight explosion will be \nobserved. The flame will pass up in the jar, and in a few \nseconds all the gas will be consumed. \n\nCarry the lighted taper, quickly, above the burning sur- \nface, in order to prove that hydrogen does not support \ncombustion; for it will be extinguished as soon as it \npasses above the flame, and be rekindled, as often as it is \nbrought down to the burning surface. \n\nA light balloon may be filled with the gas, when it will \nascend to the ceiling. \n\nEXPERIMENT XI. \nPHILOSOPHICAL CANDLE. \n\nAny common bottle may be used for this experiment. \nPut some zinc into the bottle, and pour on diluted sul- \nphuric acid. The gas should be allowed to escape for a \nfew moments before the cork is introduced, in order to \navoid an explosion. \n\nEXPERIMENT XII. \nHYDROGEN BY CONVENIENT METHOD. \n\nPut some zinc and diluted sulphuric acid (as in other\' \nexpei\'iir.cnts) in a tall glass, and cover. When it has \n\n\n\n102 AGRICULTURAL CHEMISTRY. \n\naccumnlated for a short time, on removing the cover and \nquickly applying a taper, a slight explosion will result. \n\nThis may be several times repeated while the gas is gen- \nerating from the same material. \n\nThis experiment is one of the most convenient and sim- \nple, and the means for its introduction are nearly always \nat hand. It is quite sufl&cient to illustrate the burning \nproperties of hydrogen. \n\nEXrERIMENT XIII. \nPREPARATION OF CARBONIC ACID. \n\nUse the same apparatus as for generating hydrogen. \n(See fig. 10.) \n\nPut some one of the carbonates (chalk is the most con- \nvenient) into the flask, and add diluted chlorohydric acid, \nor any of the common acids. \n\nThe gas is rapidly generated, and may be gathered in \na glass over water, although a small quantity will be ab- \nsorbed by the water. \n\nCarbonic acid may also be gathered in a tall glass by \ndisplacement of air, the same as chlorine in the first ex- \nperiment. \n\nEXPERIMENT XIV. \n\nTEST OF CARBONIC ACID. \n\nCarbonic acid is tested in the same way as nitrogen, \n(see fig. 5,) and its effect upon combustion and animal life, \nwill be found to be the same. \n\nEXPERIMENT XV. \n\nPOURING CARBONIC ACID. \n\nTo prove that carbonic acid may be poured from one \nvessel to another, and that it will not support flame, \n\n\n\nAPPENDIX. 103 \n\nplace a lighted candle in the bottom of a glass, and pour \nin the gas from another when the light will be extin- \nguished. \n\nEXPERIMENT XVI. \nPREPARATION OF AMMONIA. \n\nThe muriate of ammonia and quicklime may be placed \nin a flask, and heat applied. \n\nThat ammonia is an alkali, may be proved by placing \nin the gas a litmus paper, which has been slightly red- \ndened by an acid, when its blue color will be restored. \nThe litmus may as well be reddened by carbonic acid gas. \n\nEXPERIMENT XVII. \n\nCHLORIDE OF AMMONIUM. \n\nPour some aqua ammonia into a wine-glass. Dip a \nglass rod in chlorohydric acid, and carry near the ammo- \nnia, when white fumes, (chloride of ammonium,) will be \nseen to form over the o-lass. \n\n\n\nANALYSIS OF MANURES AND CROPS. \n\n\n\nA knowledge of the results of analysis of common ma- \nnures and crops may be of much advantage to the practical \nfarmer, for he will thus be enabled to see at a glance what \nare the constituents of the crop he may propose to raise \nfrom a given field, and thus be prepared to select such \nmanures as contain the proper constituents. \n\n\n\n104 AGRICULTURAL CHEMISTRY. \n\nPlants in different localities, and of different varieties, \nare sometimes found to contain a variable quantity of their \ncommon materials. \n\nThe first point to be ascertained in the analysis of soils, \nmanures, or plants, is, with regard to the proportion of \nwater, of organic and of inorganic matters which enter \ninto their composition. \n\nFor soils, this is best accomplished by selecting a given \nquantity, which is neither more dry, nor more wet, than \nthe average in the field from which it is taken. This \nshould first be carefully weighed. \n\nThe proportion of water may be determined by the appli- \ncation of such grade of heat as will slowly expel its mois- \nture, but will not char its organic ingredients. \n\nWhen this is completed, the mass may be again weighed, \nwhen the difference in weight will exhibit the quantity of \nwater it contained, and what remains will be the propor- \ntion of inorganic, and of organic matter. \n\nThe mass should now be subjected to the process of \nburning, but in such way that the ashes which result, may \nnot be mixed with those produced by the fuel. \n\nAfter the burning has been completed, but a small part \nof the original mass will be left, but what remains will be \nthe exact proportion of inorganic matter, while the differ- \nence between the former and the present weight will indi- \ncate the proportion of organic material. \n\nThis process simply reveals the proportions of these \nthree constituents, without indicating with regard to the \nchemical materials which composed them. To determine \nthe chemical constituents of the organic, as well as of the \ninorganic matters, requires a separate analysis. \n\n\n\nAPPENDIX. 105 \n\n\n\nANALYSIS OF WHEAT* \n\nThe average composition of wheat, including the grain \nand straw is to each 1000 : \n\nGrain. Straw. \n\nOrganic matter 866 835 \n\nInorganic matter 17 45 \n\nWater 117 120 \n\n1000 1000 \n\nThe proportion of bran and flour contained in wheat \nof diiferent kinds varies considerably. The fine flour, \nwhich is composed of starch and gluten, with a very small \nquantity of vegetable albumen, will commonly constitute \nfrom 70 to 80 per cent., the middlings from 11 to 17 per \ncent., and the bran from 6 to 8 per cent. \n\nResults of analysis by Vauquelin of two specimens of \nwheat, one grown in France, the other near Odessa: \n\nWheat. French Wheat. Odessa Wheat. \nStarch 710 578 \n\n\n\nGluten -| \n\nAlbumen / \n\n\n\n110 145 \n\n\n\nSugar 47 85 \n\nGum 33 49 \n\nFixed Oil \xe2\x80\x94 \xe2\x80\x94 \n\nSoluble Phosphates \xe2\x80\x94 \xe2\x80\x94 \n\nBran \xe2\x80\x94 23 \n\nWater 100 120 \n\n1000 1000 \n\nThe inorganic substances contained in wheat are also \n\n* Access has been had to the works of Liebig. Solly, and Johnston, in \nthe arrani\'ement of these tables. \n\n\n\n106 AGEICULTURAL CHEMISTRY. \n\nfound to vary considerably in specimens from different \nfields, even when of the same variety. Different varieties, \nwhen grown from like fields, are also found to vary in \ntheir inorganic, as well as in their organic constituents. \n\nTwo specimens of wheat, according to an analysis by \nWay, gave the following results : \n\n10,000 parts of ashes respectively were found to con- \nsist of: \n\nWHITE WHEAT. HOPETON WHEAT. \n\nGrain. Straw. Grain. Straw. \n\nSilica 263 7050 329 6710 \n\nPhosphoric Acid 4744 577 4444 705 \n\nSulphuric Acid \xe2\x80\x94 331 trace 559 \n\nLime 339 353 821 444 \n\nMagnesia 1405 329 967 327 \n\nPeroxide of Iron 67 14 8 154 \n\nPotash 2991 1276 3214 1003 \n\nSoda 187 68 214 85 \n\nIt is apparent that data of this kind will indicate the \nquantity of each substance taken off from a field by each \ncrop which is raised from it. \n\nANALYSIS OF BAELEY. \n\nThe kinds of materials of which barley is composed are \nabout as follows : \nOf the grain : \n\nOrganic matter 825 \n\nInorganic matter 25 \n\nWater 150 \n\n1000 \n\nThe proportion of each substance, when produced with \nand without manure is as follows : \n\n\n\nAPPENDIX. 107 \n\nBarley. No Manure. Manure. \n\nStarch 625 596 \n\nGluten 29 59 \n\nAlbumen 1 6 \n\nSugar 50 44 \n\nGum 47 44 \n\nFixed Oil 1 4 \n\nSoluble Phosphates 1 7 \n\nHusk 136 136 \n\nWater 110 105 \n\nFrom two analyses of the grain by Way 10,000 parts \nof its inorganic portion, or ashes, consist of: \n\nI. II. \n\nSilica 3273 2360 \n\nPhosphoric Acid 3169 2601 \n\nSulphuric Acid 79 272 \n\nLime 148 279 \n\nMagnesia 745 867 \n\nPeroxide of Iron 51 9 \n\nPotash 2077 2743 \n\nSoda 456 5 \n\nChloride of Sodium \xe2\x80\x94 860- \n\nANALYSIS OF OATS. \n\nOrganic matter 872 \n\nInorganic matter 28 \n\nWater 100 \n\n1000 \nThe proportion of proximate elements with and without \nmanure are : \n\nNo Manure. Manure. \n\nStarch 600 531 \n\nGluten 19 44 \n\nAlbumen 2 5 \n\nSugar 64 50 \n\nGum 70 67 \n\n\n\n108 AGRICULTURAL CHEMISTRY. \n\nNo Mauure. Manure. \n\nFixed Oil 3 4 \n\nSoluble Phosphates 1 6 \n\nHusk 120 170 \n\nWater , 108 130 \n\nComposition of inorganic matter, or aslies in 10,000 \xe2\x80\x94 two \nkinds used in analysis : \n\nI. II. \n\nSilica 3848 5003 \n\nPhosphoric Acid 2646 1887 \n\nSulphuric Acid 110 10 \n\nLime 354 131 \n\nMagnesia 733 825 \n\nPeroxide of Iron 49 27 \n\nPotash 1780 1970 \n\nSoda 384 135 \n\nChloride of Sodium 92 7 \n\nANALYSIS OF POTATOES. \n\nThe analysis of potatoes exhibit greater variety of pro- \nportions of starch, and of the azotized substances, than \nmost of the materials used as foods. \n\nThe ultimate composition of dry potato is : \n\nCarbon 440 \n\nOxygen 447 \n\nHydrogen 58 \n\nNitrogen 15 \n\nInorganic matter 40 \n\n1000 \nThe proportion of different compounds ; two kinds being \nsubjected to experiments, were found to be as follows : \n\n\n\nAPPENDIX. 109 \n\nKed Potato. Sweet Potato \n\nStarch 155 151 \n\nAlbumen 14 8 \n\nGum 41 16 \n\nStarchy Fiber 40 82 \n\nWater 750 743 \n\n1000 1000 \n\nGrood potatoes are composed of 10 to 25 per cent, of \n\nstarcli, 3 to 8 of fiber, -2 to 4 of gum, and but 1 to 2 of \n\nazotized matter, which is albumen, and 70 to 80 of water. \n\nThe proportion of inorganic matter in 100,000 parts of \n\ndry potato tuber has been found to be as follows : \n\nPotash 1291 \n\nSoda 748 \n\nLime 106 \n\nMagnesia 104 \n\nAlumina .., 16 \n\nOxide of Iron 9 \n\nOxide of Manganese trace \n\nSilica 27 \n\nSulphuric Acid 174 \n\nPhosphoric Acid 128 \n\nChlorine 50 \n\nIt will be observed that the proportion of potash in the \nashes of the potato is quite remarkable. \n\nANALYSIS OF INDIAN COPvN OE MAIZE. \n\nOrganic matter 857 \n\nInorganic, matter 13 \n\nWater 130 \n\n1000 \nDry maize contains : \nStarch 712 \n\n^^"^^^ \\ 123 \n\nAlbumen j \n\nFixed Oil 90 \n\n\n\n110 AGRICULTUEAL CHEMISTEY. \n\nGum 4 \n\nWoody matter 59 \n\nInorganic matter 12 \n\nTn 100,000 parts of the grain, 1312 parts of inorganic \nmatter have been found. In the straw the proportion was \n3985. These were : \n\nGrain. Straw. \n\nPotash 200 189 \n\nSoda 250 4 \n\nLime 35 652 \n\nMagnesia 128 236 \n\nAlumina 16 6 \n\nOxide of Iron trace 4 \n\nOxide of Manganese \'... \xe2\x80\x94 20 \n\nSilica 434 2708 \n\nSulphuric Acid 17 106 \n\nPhosphoric Acid 224 54 \n\nChlorine 8 6 \n\n1312 3985 \n\n\n\nNOTE. \n\nComplete sets of apparatus, together with chemicals, \nrequired for repeating the experiments described in this \nwork, have been arranged by the author, in order to \nfacilitate their introduction into district schools. \n\nThe set contains a trough, retort stand, and spirit-lamp, \ntogether with more than thirty additional pieces. \n\nThe whole, including chemicals, are put up in a case, \nwith lock and key, in order that they may be protected \nin the school -room. This apparatus will also be found \nsufficient for illustrating most of the lessons contained in \nthe common text-books on chemistry. \n\nThe above are hept for sale ly Henry Ware, No. 7 \nWest Fourth street, Cincinnati. Price $20. \n\n\n\nGLOSSARY \n\n\n\nAcid\xe2\x80\x94 A compound, capable of iiniting witt bases, and \n\nthereby forming salts\xe2\x80\x94 turns litmus red. \nAlkali\xe2\x80\x94 A salifiable base, having the power of changing \n\nblue vegetable colors to a green. _ \n\nAlkiline Earth\xe2\x80\x94 a term applied to magnesia lime, \netc., on account of their earthy character, and alka- \nline qualities. \'T .. \n\nAmmonia\xe2\x80\x94 An alkali which is gaseous, or aeriform, m its \nuncombined state. \n\nAromatic\xe2\x80\x94 Odoriferous, or fragrant. \n\nAssimilation\xe2\x80\x94 The process by which bodies convert other \nbodies into their own nature, or substance. \n\nAzotized\xe2\x80\x94 Nitrogenous \xe2\x80\x94 containing azote or nitrogen. \n\nB^SE_An alkali\xe2\x80\x94 a substance which, by union with an \nacid, forms a salt. . \n\nCarbonate\xe2\x80\x94 A salt formed by the union of carbonic acid \nwith a base. \n\nChlorohydric Acid\xe2\x80\x94 Muriatic acid. ^ \n\nCombustion\xe2\x80\x94 The union of an inflammable substance with \noxygen, or any supporter of combustion. \n\nCompost\xe2\x80\x94 A mixture of various manuring substances for \nfertilizing land. \n\nCompound\xe2\x80\x94 Composed of two or more elements. \n\nCrystalline\xe2\x80\x94 Consisting of crystals. \n\nDecomposition\xe2\x80\x94 Separation of a compound substance into \nits original elements. \n\nDemonstrate\xe2\x80\x94 To exhibit a process\xe2\x80\x94 to prove to be cer- \ntain. \n\nDilute\xe2\x80\x94 To weaken\xe2\x80\x94 as an acid, or alcohol, by admixture \nof water. \n\nDisplacement \xe2\x80\x94 To remove, and introduce a substitute. \n\n\n\n112 AGRICULTUEAL CHEMISTRY. \n\nElement \xe2\x80\x94 A body which can not be divided by chemical \nanalysis. \n\nEvaporation \xe2\x80\x94 The conversion of a fluid into vapor, which \nis specifically lighter than the atmosphere. \n\nEvolve \xe2\x80\x94 To throw out \xe2\x80\x94 to emit. \n\nExhale \xe2\x80\x94 To send forth, as fluid in the form of steam, \nor vapor. \n\nFermentation \xe2\x80\x94 A chemical change in animal and vege- \ntable substances, accompanied by heat and efierves- \ncence. \n\nFertilizer \xe2\x80\x94 Enricher of soil \xe2\x80\x94 a manure. \n\nGtRAPHITE \xe2\x80\x94 Carburet of iron \xe2\x80\x94 used for lead pencils ; also \ncalled black lead and plumbago. \n\nIllustrate \xe2\x80\x94 To explain \xe2\x80\x94 to make clear. \n\nInorganic \xe2\x80\x94 Devoid of organs. \n\nNitrogenous \xe2\x80\x94 Pertaining to nitrogen. \n\nOrganic \xe2\x80\x94 Consisting of organs \xe2\x80\x94 incident to life. \n\nPeroxide \xe2\x80\x94 The highest degree of oxidation of which a \nsubstance is capable of undergoing. \n\nPhysical \xe2\x80\x94 Action of material objects distinct from chem- \nical. \n\nPith \xe2\x80\x94 The soft spongy substance in the center of the \nstems of plants and trees. \n\nPneumatic Trough \xe2\x80\x94 A water trough used in experiments \nwith air and gases. \n\nPorcelain \xe2\x80\x94 A fine earthenware \xe2\x80\x94 chinaware. \n\nRespiratory \xe2\x80\x94 Serving for respiration. \n\nSalt \xe2\x80\x94 A body composed of an acid and a base. \n\nSiLEX \xe2\x80\x94 The name of an earth of which flint is composed. \n\nSpecific Gravity \xe2\x80\x94 Specific weight, as compared to air or \nwater. \n\nSymbol \xe2\x80\x94 An emblem \xe2\x80\x94 a representation of something else. \n\nTissue \xe2\x80\x94 A web-like structure \xe2\x80\x94 the elementary structure \nof plants and animals. \n\nVolatile \xe2\x80\x94 Easily evaporated. \n\n\n\nUBRARY \n\n\n\nCONGRESS \n\n\n\n\n'