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TORO.NTO: HUGH SCOBIE, ADELAIDE BUILDINGS, KlJfO ST^ET. 1«50. AGI Matl T^^ TWO LECTURES ON AGRICULTURAL CHEMISTRY, BY HENRY YOULE HIND, Mathematical Master, and Lecturer in Chemistry and Natural Philosophy, at the Normal School for Upper Canada. TORONTO: HUGH SCOBIE, ADELAIDE BUILDINGS, KING STREET. 1850. The f( on Agric mer at Teacher Canada. object ( view. and fai Agricul possibli princip Tot' of prac illustra and gi The to the a hop judici< prisin PREFACE. The following pages contain the subslanoe of lectures on A'-riculmral Chemistry, delivered dnringthe past sum- ,„er at the preliminary meetings for the format.oa of Teachers' Institutes, in various County towns of Upper Canada. In preparing them for the press, the special object of general utility has been prominently kept m view. The lecturer has endeavoured to present m a br.ef and familiar manner, the chief points in a system of Agricultural Chemistry, confining himself as much as possible to the statement and elucidaUon of useful principles and facts. To the lectures there will be found appended, the mode of practising a few interesting and simple experiments, illustrative of the circumstances connected with the food and growth of vegetables. These lectures are now addressed in their present form to the Farmers and Schoolmasters of Upper Canada, with a hope that they may assist in calling forth a spirit of judicious enquiry, among the many intelligent and enter- pricing members of those numerous bodies. d 5 « O .- CONTENTS: Lecture I— Introduction-Object of Agricultural Chemistry- Conditions of Vegetable Life and Health-Air-Atmospheric Food of Vegetables-Carbonic Acid-Water— Ammonia- Proportion in which substances, originally obtained from the Atmospheie, exist in Vegetables— Solid Food, its entrance into Vegetables-The Soil-Mineral Ingredients necessary to Vegetable Life-Sulphur-Phosphorus-Potash-Soda-Mag iiesia-Lime-Flint- Iron -Chlorine -Iodine-Division of Vegetables into Potash, Flint, and Lime Plants-Analysis of a Soil from Chambly,L.C.-Ploughing-Draining-Fallowing- Rotation of Crops-Manures-Farm-yard Manure-Urine— Gypsum-Lime- Wood Ashes-Good Husbandry-Ratio of Gram Crops to Green Crops-View of this ratio in the County of York and Upper Canada Pages 5 to 44. Lecture IL— Compound Substances found in Vegetables- Woody Fibre-Starch-Sugar-Oils and Fats-Nitrogen Com- pounds-Comparative Table of Compound Substances found in Vegetables-Comparative value of different kinds of Manure Forage Rations-Milch Kine-Farm-yard Manure-The di- gestive and respiratory processes of Animals-Purposes served by Food-Diseases of Vegetables, produced by Fungals and Insects-Rust-Mildew-Smut-The Potato Disease-The Hessian Fly-The Wire-worm- Weeds of Agriculture- Chess-Canada Thistle-Other Weeds-Conclusion. Pages 45 to 77. Appendix.— Notes. LECTURES Chemistry— Umospheric Ammonia — ed from the its entrance lecessary to 5oda — Mag- -Division of LHilysis of a ''allowing; — e — Urine — 1^— Ratio of the County ?getables — rogen Com- nces found i of Manure B—The di- oses served ungals and lease — The riculture — )n. Pages • ON AGRICULTURAL CHEMISTRY. LECTURE I. iT^^^-o^ZVitS'^^^'^t'A''^' V.r. Id upper Canada. We rarely appreciate the value of any science in its state of infancy. It is generally impossible to foresee what useful results may flow from its practical application. When any new discovery is brought to bear with advan- taae upon industrial labour, it ^oon acquires a popular interest which ensures its rapid spread ; electricity itself had created no stir in the arena of practical life, until electro-plating and the telegraph gave it importance m the eyes of practical men; and now we know what i has done, our anticipations are almost boundless of what it may be made to do-many of us, looking with confidence to a day, not far distant, when some new discovery will convert it into a source of cheap and commodious motive power. .u i, i The science of chemistry has for ages been the hand- maid of the manufacturer in the preparation of raw materials for useful and refined purposes. It is only lately that her aid has been sought by the producer ; and B 6 LECTURES ON AGRICULTURAL CHEMISTRY. with sach successful results, that the light which the application of chemistry to agriculture has thrown upon his operations, enables him to convert au experimental art into an intellectual and noble science. A branch of knowledge, hardly a dozen years old in its practical application, can scarcely be supposed to have met with an extended appreciation among the farming communities of Canada, or even to have received the attention of those whose time and opportunities afford them facilities for improving their acquaintance with it. In its early stage of development the science of Agri- cultural Chemistry was necessarily very imperfect and often much misunderstood. A too sanguine expectation of the magnitude of its promised results, while still in this imperfect state, led to much disappointment, which had the effect of creating a violent prejudice in the minds of many practical men,-neither was it until materials drawn from experiments confirming, or modifying the prognostications of theory, were moulded into a rational system of Agriculture, that the visionary hopes of multi- tudes became sobered down into a proper view of the actual good to be obtained,-an event' which has taken place during the last 4 or 5 years. What Chemistry has already done for Agricuhure is immense : what she may yet do is incalculable. And now that a clear insight into the relationship is established, the difficulty of presenting a popular view of the subject has alnost vanished. Very strong prejudices exist among farmers against book farming, prejudices wLxch have arisen from disappointed hopes, and ruinous loss in following arbitrary rules. Agri- cultural science is no system of book-farming-it presents no prescribed rules to be implicitly obeyed. It portrays in simple language, devoid of technicalities, the reasons why farmers plough, drain, fallow and rotate their crops j it shows how repeated cropping without the application of manure must inevitably ruin for a time the most fertile soil i and It establishes such an intimate relationship 1 RY. ■ which the hrovvn upon xperiraental irs old in its jed to have he farming 3ceived the lities afford e with it. ce of Agri- 'erfect, and expectation lile still in , which had le minds of materials lifying the a rational 3 of multi- f the actual ikeu place I as already lay yet do it into the esenting a led. ainst book sappointed 3S. Agri- it presents )ortrays in asons why crops 5 it ication of ost fertile lationship LECTURES ON AGRICULTURAL CHEMISTRY. 7 between the soil and the \ind of vegetable growing upon it that every farmer may frame for himself a rational system of husbandry, as varied as the soil he rnay chance to cultivate. U has been occasionally urged by some, 1 who speak from experience acquired in a very contracted sphere that Canadian farmers in possession of a tertile soil, do not require the aid of a scientific system of agri- culture. Such an objection, rarely advanced, it is true, may be dismissed by a reference to the present deterior- ated condition of many fertile regions, and to that growing desire which every intelligent farmer exhibits to make himselt acquainted with the rationale of agricultural processes-as well as to the invariable success attending the acquirement of such information. Another objection to its >'» •"•- J — -> • ' • - tney grow. I2nd. Between vegetables and animals. I f LECTURES ON AGRICULTURAL CHEMISTRY. 9 THY, iform us that tn of farming a judicious Jring, to the -in a word to ill permit of ed that the is less than )arts of con- country will ifference in . There is which does ill-informed i treble the heir neigh- 3 successful ntal posses- ul industry nformation. ence alone, materially ich it was Js well by t when the idy nature. elementary system of 3ry variety 3 of being > trace the in vvhich Since there is not the slightest ground for the supposition that vegetables or animals create matter, every portion of their structure being derived from air and soil, it is mani- festly of great importance to know the nature of those sub- stanceo which serve the purposes of food. We can only obtain this information, by endeavouring to ascertain what simple substances* are common to air, soils, vege- tables and animals ^ and to trace, as far as the present state of the science enables us, in what way this mutual inter- change of substances takes place. It is almost needlessto remark, that we must not expect to find any simple sub- stance in a vegetable or in an animal which does not exist in air or in the soil. A very superficial examination of the circumstance under which vegetables grow, furnishes us with the condi- tions upon which their life and health are dependent. These are five in number. 1st. The presence of air. 2nd. The composition of the soil. 3rd. The moisture of the soil. 4th. The moisture of the atmosphere. 5th. The temperature of air and soil. Air —Pure country air is composed of two invisible gases,' in which a small amount of vapour of water is always dissolved, together with a minute quantity of a sour tasted gas, called carbonic acid or choke damp. In 100 gallons of air we find, 79 gallons of Nitrogen. 20 do. do. Oxygen. I pint of Carbonic Acid. 'i do. do. dissolved Water, on a cool summer's evening. These gases are intimately mixed together, and always in the same ; or very nearly the same proportions, and this is the case whether air is taken at the level of the sea or from the top of high mountains. [Nitrogen is a kind of simple air or gas, it is tasteless, invisi- ** _ . . . it upon the 'bJch, in its miles, and sight equal ace J it is, During air, causes • — a gas of and famil- 3rn. Rain Ilects from lependent, 's of three lication of embraced « 4.) LECTURES ON AGRICULTURAL CHEMISTRY. 11 IST NiNETKEN-TWENTIETHS BY WEIGHT, OF ALL VEGE- TABLES, ARE DERIVED ORIGINALLY FROM THE AIR WE BREATHE ; 2nd. The atmospheric food of plants exists in the FORMS of carbonic ACID, WATER AND AMMONIA. These important principles in agricultural chemistry may be made more evident, by the following illustration : Let us suppose we bum completely 1000 lbs. weight of hard wood in a stove or fire-place, and carefully weigh the ashes which remain behind. They will be found to con- stitute about one-twentieth of the whole mass of the wood, weighing not more than from 30 to 50 lbs., according to the kind of wood bmnt. The whole of that portion which goes off in the form of smoke, vapour of water and gases, existed at one period in the air we breathe, in the forms of carbonic acid, water and ammonia. The whole of the ashes were obtained from the soil in which the trees origi- nally grew. . , We may now proceed to consider the properties and sources of the atmospheric food of vegetables, and endea- vour to ascertain the manner in which it assists in building up their structure, also to what extent the formation of the different parts of vegetables is dependent upon a proper supply of each particular kind of food. Carbonic AciD.-*This important food of vegetables possesses many singular properties. It is poisonous to animals, and cannot support combustion. Water absorbs it with avidity, and thus acquires the power of dissolving chalk and limestone. It is also the most active agent in loosening and separating into their constituent parts, the surfaces of solid rocks, stones and soils. In 22 lbs. weight of carbonic acid, there are 6 lbs. of carbon or charcoal, and 16 lbs. of oxygen. The leaves of plants absorb it from the air by which they are surrounded, during the day time ' or take it up in water which enters at their roots, in both'cases light must fall upon the leaf to enable the plant . .1 1 r.^.«. ♦Vo /wvrron. ■wliio.h is returned to separate me cui uuu i tum a.- •-■-■^jj^—-, *(Note 6.; 12 LECTURES ON A0RICULT17RAL CHEMISTRV. to the air in its pure form of a simple gas. Durin. the side becomes archpd L} ««-^ib]e. The contracted earbonic acid t^binr^irth:" '^ '"""'''' '""" water, and forms woody "bT e arch '"'°*'"' """ "' oils. Carbon obtained fr„^T\ ' ^'"' ^"S" a^d to 50 lbs. in e °erv 100 n(Z ^ '"" "'"'' ^°"^ f™™ 45 ofo„ltiva.edXr"x;?ctXltfor''^ acid in the air we breathp i« ^. / f ®«6^ce of carbonic mals, ,he comZ^^TCnZ bo "''"r^™ "' ""'- vegetable matiPr i . ^ °'''*^' ^"'^ ""^ decay of limestone rXwhichCtir^'^r'-- '"« ««-^ve c™st. Pure limestoe 7,™ ^ , P""'"" "'^ *« ^^^h's one-hair carbor5:brrtrr„;^i:r oxygen ff tr'.i^T„a ti "'J: """""™ """ "■« •bsorbed by w.t' r and l^Tt """""' "'"'' ""'i'^'' » tables. It i ftomM^f v'" '"'° "" 'J"'*™ "f vege- ofc.rbonic'aXttryTvr.htr"'"''"''""^''' "Each new leaf U.^Z.^'^^T" »"' ""ny leaves. stomach." The Dowe7„f UT- """" f"""'"' '"°""' «"<< ine power of absorbing carbonic acid from th. ITRY. During the lined in the given off by separate the 3SS of night, possess the The motion Is upon the ed carbonic )03ed to the stiffens and Pi^ood, while 3 contracted e vegetable ?ht--a bril- 'ffect in the rated from nt parts of sugar and tis from 45 and seeds f carbonic on of ani- e decay of extensive he earth's iime and off in the he opera- rtile soils, with the which is 1 of vege- >ir supply ly leaves, outh and from the LECTURES ON AGRICULTURAL CHEMISTRY. 13 atmosphere is proportionate to the surface of the leaves. Straight and narrow leaved plants, those which are grown for their seed, as wheat, rye, oats, barley, depend more upon the soil, for their supply oi carbonic acid, than the Jerusalem aitichoke, the mangel wurtzel, or the beetroot which are grown for the sake of their roots. The great size of the roots, stalks and leaves of the root crops would lead us to suppose that they contained a much larger quan- tity of carbon than the grain growing crops-this is not strictly the ca«e-and the reason is found to he in the fact that, roots of turnips, mangel wurtzel, beets, potatoes con am from 700 to 900 parts of water in 1000 of the fresh roots- whereas, the quantity of water in grasses and gram, vanes from 120 to 150 pts. in the thousand. It is thus that grain crops exhaust the soil of vegetable matter, and consequently of fhe means for supplying carbonic acid to the young plpnts; they take more carbon from the soil, than they leave behind in the form of decaying roots and stubble. The roots of clover, the grasses, and the leaves of turnips, mangel wurtzel &c., which are usually left upon the land contain more carbon than the whole of the crop abstracted from the soil during its growth. A judicious rotation of crops leaves the land richer in vegetable matter than before the rotation began.] W -ITER.— This abundant and necessary fluid is known to the agriculturist in four states, the solid, (ice,) the fluid, (water,) the gaseous (vapour of water, steam,) and :a combination with certain bodies, (slacked lime.) Whea water freezes, that is, assumes the solid state, it expands with astonishing force, sufficient to break the strongest vessels. Many remarkable results are produced by the expansion of water when converted into ice, among which, the floating of ice is, perhaps, the most deserving of notice. If water, in becoming solid, followed the almost universal law of contraction, ice would sink, and yearly increasing in thickness at the bottom of deep seas, lakes and rivers, would produce such a change in climate as probably to convert the greater portion of the temperate zones into desolate and uninhabitable regions. We discover, how- ever, a still more beautiful provision for arresting the 14 LECTURES ON AGRICULTURAL CHEMISTRY. conversion of oceans and seas into solid masses of ice, in the singular property of water occupying the least space, and being consequently heaviest, at the temperature of 40 degrees-eight above the freezing point. The warmth of seas, at depths beyond the influence of the sun's heating rays, is thus perfectly uniform, effectually preventing the Arctic Oceans from becomingsolid and immoveable masses of ice. During the Summer and Autumnal months rain and dews penetrate the minute crevices and pores of solid ocks and clods of earth ; in the winter monfhs the water freezes and expanding, tears their particles asunder ; thus gradually reduces the hardest rocks into a soft and fdable SOI . To the alternate thawing and freezing of water in the ToitT^ f ""'^^ 'P""^ '"°"^^^' ^"^ ^'' consequent contraction and expansion, the ''throwing out" of young wheat p ants is to be attributed, a disaster which mly b! materially prevented by draining. When water is changed intosteamorgoesoffinto the form of insensible perspiration It absorbs a vast .quantity of heat.* This property should be we 1 remembered by farmers, since if evaporation takes P^ce to a great extent from the soil, its natural warmth is abstracted and the chill produced greatly checks and retards vegetation. Most solids and gases are soluble in water : the very existence of vegetables and animals is dependent upon this property. It is thus that river and well water contains small quantities of lime, potash, soda, magnesia, iron, besides air and carbonic acid. The refreshing and agreeable taste ofsprings is due to the presence of dissolved Zl^;"'-' '''-'''[ ''''^' -^- - -Pid and del'^tVanir?'^ 1 '"' ^''''^ ^"^^^^^ ^^^°^« ^a eou, t , ^//^°^^">^ ^ ^«ry ^ight and inflammable gaseous body. If we mix 8 pounds of hydrogen with 1 pound of oxygen, and pass an electric spark through the .m^a. Liiomists are acquainted with various *(Note 6.) J trNote?.) rRY. es of ice, in least space, nperature of The warmth un's heating iventing the lable masses months rain ores of solid IS the water Jnder; thus and friable iVater in the consequent " of young ich may be is changed erspiration, 3rty should alion takes warmth is and retards water; the dependent 'veil water magnesia, Jshing and fydissolved isipid and Hj before lammable en with 1 rough the pounds of 1 various LECTURES ON AGRlCULTtJRAL CHEMISTRY. 15 ways of converting water into its component gases. The perfectly clean surface of many metals, such as iron, zinc, copper, &c., will immediately take oxygen from water, and liberate a corresponding quantity of hydrogen, which at once assumes the. gaseous state. The oxygen separated by the metal forms with it a rust or oxide of the metal. Plants possess the power of decomposing water, and make use of its components to build up their structure. Ammonia.— Ammonia, in popular language. Spirit of Hartshorn, is formed in the air by the action of lightning. It is composed of hydrogen and nitrogen. Three pounds of the former combining with fourteen pounds of the latter to form seventeen pounds of ammonia. This body possesses a singularly powerful odour, and an equally remarkable attraction for water, which dissolves 780 times its volume at the temperature of melting ice. Ammonia is emitted from decaying vegetables and animal matter ; it is also found in the perspiration of animals and given off from the leaves of many plants, as well as from the flowers of a still greater number. Rain water always contains am- monia, washed from the air through which it passes. The characteristic smell of close stables is due to ammonia proceeding from the decomposing urine. Many solid bodies exhibit the power of absorbing large quantities of ammonia— such as partially burnt clay, rust of iron, gypsum, and especially powdered charcoal aud decayed wood : these substances relinquish much of what they have condensed within their pores, to the water with which they may be saturated. Ammonia is a very impor- tant portion of the food of vegetables. It has been remarked that the three bodies Carbonic Acid Water, and Ammonia, constitute nine-tenths of the food of vegetables, and are composed of four simple or elementary bodies, thus. Carbonic Acid, from Carbon and Oxygen ; aier, iruiu vAygcii aiiu nj^i-^^^n. , Ammonia, from Hydrogen and Nitrogen. The ratios in which these simple substances enter into 16 LECTURES ON AGRICULTURAL CHEMISTRY. the composition of vegetables is nearly the same for all species. If the wood of the oak, the beech, the elm, the maple, or the straw and seeds of wheat, barley, oats, &c., be dried in an oven, so as to drive away all moisture, and' the remaining portion subjected to analysis, it will be found that these, and indeed all vegetables contain in every hundred pounds weight. From 40 to 50 lbs. of Carbon, 35 to 45 - - - Oxygen, 5 to 7 - - - Hydrogen, 1 to 3 - - - Nitrogen, 2 to 10 . - - Ash. A more exact composition of some important vegetables is given in the following table :— - « Wheat, Oats Wheat Straw,. . . Oat Straw, Clover Hay, (red). Carbou.lHy'eeu. lbs. lbs. 4«.l 50.7 48.4 50.1 47.4 5.8 6.4 5.3 5.4 5.0 Oxygen. Iba. 43.4 36.7 38.9 39.0 37.8 Ni'gen. lbs. Ash. lbs. 2.3 .2 .4 .4 2.1 2.4 4.0 7.9 5.1 7.7 100. 100. 100. 100- 100. In illustration of the above tables-let us take as an example-Red Clover Hay. We find that 100 lbs. when well dried, is composed of 47yV lbs. of carbon, 5 lbs. of hydrogen, 37-pV lbs. of oxygen, 2^ lbs. of nitrogen, and Ty^ of ash. Or, in other words, 92^ lbs. out of 100 obtained from the three substances Carbonic Acid Water and Ammonia, and only 1-^^ lbs. out of 100 lbs. derived from the solid substances of the earth. When vegetables decay, many and very complex changes take place, but all these finally result in those which restore to the air we breathe, and the soil we tread upon, the sub- stances from which the plant was constructed. " All the innumerable procucts of vitality resume, after death, the orj^nalform from which they sprung. Thus, the destruction of an existing generation ber.omRs the, rr,oo.,c ^^- *>, j,. _ tionof a new one, and death becomes the source of life."— (Liebig.) FRY. same for all the elm, the jy, oats, &c., loisture, and I, it will be I contain in ;en, n. t vegetables LECTUABC ON AfiRKULTUIUL CHfiMUTRF* 17 h. i. 4 9 1 7 = 100. = 100. = 100. = 100- = 100. take as an ) lbs. when 1, 5 lbs. of trogen, and lut of 100, cid, Water )s. derived ix changes lich restore 1, the sub- " All the death, the lestruction 16 produc- aflife."— The extremitiea of the roots of vegelablda are fiimilarin their conutruotion to a sponge. They consist of a member of exceedingly sm^U. openings or moutlw, through which water, containing solids in solution, is *lone capable of entering. It is t^us that water forms the peans of intro- ducing into vegetables various mineral substances, which are absolutely necessary to their growth, as essential indeed, to the perfection of their different organs, as the air and its admixtures. During the winter months impor- tant additions are furnished to the ends of the roots, in tl^e form of new spongy extremities, which enable them io commence early and active absorbing operations in the first warm days of spring. We now arrive at another principle in Agricultural Chemistry, briefly enunciated as follows :— Before any solid can enter into the composition of VEGETABLES, IT MUST BE IN A STATE OF SOLUTION IN WATER. The general structure of a vegetable is admirably adapt- ed to the conditions under which it exists. ^ Its leaves are continually bathed in an atmosphere containing the main source of its food, while its roots repose in a soil where abundance of moistm-e is ready to convey into its interioi those mineral ingredients which assist the plant in digest- ing and assimilating its atmospheric nutriment. The leaves are employed during the day time in incessantly searching from the moving air which agitates them, the carbonic acid which supplies, them with carbon: the roots are engaged in drinking from the earth a copious supply of water containing ammonia and solid substances in solution. These, the vital energies of the plant, fabricates together, and forms from their crude elements its varied and beautiful tissues. The quantity of water transmitted through. the, system of plants is immense. From the leaves* of a well wooded acre of land, not less than three-hundred thousand gallons pass off in the form of invisible vapour during the four months intervening May a tid October. ' *(Noie 8.) I IS LBCTVREi ON AQRICULTVBAL CHCMItntT. We may imagine how easily disease in Tegelables ifl engendered, when eraporation from their leaves is sup- pressed by any external causes. (The potatoe disease, rust on wheat, mildew, &c.) The SoiL.—The uniform constitution of the atmosphere differs widely from the heterogeneous mixture we meet with in soils, which are as variously compounded as the roc'is upon which they repose. The elements forming common air are few in number, and simple in character. The substances we find in soils are frequently numerous, and often complex in their constitution. All soils spring originally from the disintegration and decomposition of solid rocks ; the agents most active in effecting these changes are water, temperature, air, and vegetables them- selves. Various bodies are found in soils, which do not enter into the composition of vegetables. In an elemen- tary view of Agricultural Chemistry, we do not require to consider their properties, without their presence effects such a change in the relations of the soil to temperature and moisture as seriously to affect the growth of vegeta- bles. It is sufficient for our present purpose if we consider the relation to vegetable life, of certain ingredients which necessarily enter into their composition, and invariably form part of fertile soils. The transmission of water through the roots and stems of vegetables, and its final escape at the leaf, furnish us with the remarkable mode in which dissolved solids are conveyed into their interior, and made to assist in the formation of their diff-erent organs. These solids are nine or ten in number, and are named respectively, 1. Sulphur; 2. Phosphorus; 3. Potash; 4. Soda. 5. Lime; 6. Magnesia ; 7. Iron ; 8. Flint; 9. Chlorine; 10. Iodine. Water possesses the property of dissolving small quantities of these bodies, either directly or indirectly ; all,^with the exception of Iodine are required by land plants, and they IT. igetablea 10 ves is 8up- lisease, rust itmosphere we meet lied as the its forming character, numerous^ oils spring position of ing these ^les them- ich do not 1 elemen- require to BO effects mperature jf vegela- e consider nts which nvariably nd stems urnish us solids are St in the } are nine L Soda • J HL0RIN£ ; llmntitioa with the md they I.ICTUli:8 ON AGRICULTURAL CHIMISTRY. 19 constitute what is termed the < Ash', when vegetable sub- stances are burned in the open air. The quantity of ash found in cultivated vegetables varies remarkably with the nature of the soil, and the species under examination. It is evident that every fer- tile soil contains the constituents of ash in abundance, also in Buch a state, that enough for the wants of the growing crop, are soluble in water, in order that they may be conveyed into the interior of the vegetable. The waters of rivers, springs and wells always contain a small quantity of various solids in a state of solution. By washing a soil repeatedly with pure rain water, we find that each time of washing the quantity of some of the substances dissolved is diminished, until, at length, no portion is tak Ml up. It is evident that a large supply of soluble subst; ices, can not exist in ordinary soils, exposed to rains, snow, and dews. Every little stream is bearmg its load of dissolved materials, to that great storehouse and depository, the Sea. The continual action of rains washing out the soluble portions, and either conveying them altogether away, or transporting them into the subsoil below, coupled with repeated croping without the return of one particle in the form of manure, must, in the long run of years, render the most fertile soil destitute of solu- ble mineral substances, and consequently unfruitful. The quantity yearly abstracted by these means may be per- fectly insignificant compared with the abundant store remaining behind-that small quantity, nevertheless, is of vital importance,-for, although there may be thousands of tons of sulphur, potash, soda &c., present in the soil, yet IF NO portion is soluble IN WATER, the soil, with reference to immediate agricultural purposes, is absolutely barren The fertility of such a soil can be restored by the hand of time ; and its restoration can be axscelerated by those means which science suggests, and experience approves, for I giving solubility to as much as will satisfy the imperaiive demands of growing cropp. 20 I,lCTUIUa.ON AOBICULTUilAL CHKBflSTRV. The analysis of a good crop of wheat will exhibit the quantity of solid ingredients abefraotetl from the soil dar- ing Its growth, and conveyed away in the straw and grain. A crop of t wenty-fiye bustiels to the acre, contains about 200 lbs. of solid mineral ingredients : an average crop of clover from 250 to 300 Ibg. of solid miaeral ingredients. . These quantities appear to be small, but when we consider that .n many parts of this Province, little return is made in the .orm of manure, that crop after crop of the same kind of vegetable is oftea grown for years together, and that rams are continually washing out, and streams and rivers bearmg to the sea, the soluble ingredients of the soil-- when we assocL J these considerations with the circura. stance, that it requires many months and even years for temperature, moisture, and air, to render soluble in water a sufficient quantity ol each particular kind of ingredient required by growing crops, we can not be surprised that complaints are made of diminishing scales of produce. SuLPHUR.-Certain organs or parts of plants r6(^ttife' for their formation a small amount of sulphur. It is of no importance to know, at present, the name and disposition of those organs ; the bare fact that the presence of sulphur IS absolutely necessary will deteimine the agriculturist in investigating the subject. In 10,000 lbs. of the ash of wheat there were found 12 lbs. sulphur. do, straw, oat grain, do. straw. Vetch, •» 170 « (c Peas, « 171 (( u These numbers vary slightly with the nature of the soil • they serve, however, to show the hind of plants which require much sulphur, to which may be added hops, aspar- agus, sugar cane, grape, black and white mustard, tnrnin, toDacco, &c Wheat, barley, rye and Indian corn; require comparatively imle sulphur. The most common and widely do. do. do. do.. do. do. it, a t( ({ iC K tt 40 » 40 «« 90 « 151 « 170 « 171 « « tt tt A exhibit the he soil dur- w apd grain. mtains about rage crop of ^redients. 1 we consider n is made in e same kind ar^ and that s and rivers f the soil— the circura-* ill years for >le in water ' ingredient '•prised that reduce. require'foir It is of no disposition of sulphur culturist in lbs, sulphur. « te ■■( . a..« »-", ^_*.3i.««-- iron, &c. &c.] c2 23 LECTURES ON AGHICULTUBAL CHEMISTRY Phosphoric Acid is always found in very minute quan- tities m pnmuive rocks, when sought for. Its detection is frequently a matter of some difficulty : u exists in all soils, olten, however, in a state very insoluble in water, and it IS one of those bodies, which like sulphur, do not, under ordinary circumstances iind their way to the manure heap, ^nosp. us 13 found in many parts of the animal frame especially m the bones. England imports annually very hirge quantities of bones for the purposes of manure. The bones are either crushed or dissolved in sulphuric acid, and applied to the soil, in order to restore a small portion of the phosphorus which, during centuries of cultivation has been washed away by rains, or abstracted by crops' ^0 far back as 1827, England imported 40,000 tons of Denes, having a value of 600,000 dollars. Since that period a great increase has taken place in elTnt'\ " """'^ ''' '^'' "^"">' ^^^«^ ^'''^^^ ^re now emp oyed in conveying from South and North America, ^ • ilir, JTn ^T '^ ^"^°P^' '^' b""^« °f ^"i"^^'l« to J; ^^^ff J^°^ ^nS-land. No grain crops can suc- ceed m a sod destitute of a supply of soluble phosphates j and one pound of bones contains as much phosphorus as ;s required by one hundred pounds of wheat. At the ^^o..e.s calculation enough phosphorus was exported from Canada in the year 1847-8 to build up the bony framework or skeleton, of sixty-thousand full-grown men. Every good cow in one year abstracts from the soil, as much phosphorus as is contained in 80-100 lbs. of bones, much ot which enters into the composition of milk, and the remainder IS lost in the urine, (see urine.) Pure phosphate of hme (the substance which gives strength to the bones) s found in many parts of Canada, in certain rocks. The ime may not be far distant when it will be profitable to coi.ect and grind it for agricultural purposes. Potash, Soda and Magnesia. These substances exist in variable quantities in all cul- ...ops. Vej^utables appear to possess a limited power of making indiscriminate use of them, especially of I ITKY LECTURES ON AGRICULTURAL CHEMISTRY. 23 minute quan- ts detection is sts in all soils, water, and it do not, under manure heap, nimal frame, .nnually very lanure. The Iphuric acid, small portion f cultivation, 'ed by crops. ),000 tons of ten place in i3ls are now th America, f animals to ps can suc- phosphates ; losphoius as at. At the ported from framework n. Every 1, as much Hies, much ik, and the 3 phosphate the bones) >cks. The rofi table to in all cul- a limited pecially of potash and soda. This is not the case with sulphur and phosphorus; no seed nornwfri/ious juice, can be formed without definite quantities of each. A few examples will serve to illustrate the very variable quantities in which potash, soda and magnesia are introduced into wheat. In six analyses of wheat made by celebrated chemists, there were found in 100 lbs. of the ash, in No. 1. 26 lbs. Potash, No. 2. 6 lbs. 6 do. Magnesia, 13 do. do. Soda. 28 do. lbs. Potash, No. 4. 30 lbs. 131 do. Magnesia, 16^ do. do. Soda. do. Potash, No. 6. 21% lbs. Magnesia, 1 3 No. 3. 24 m No. 5. 33| lbs. 13^ do. do. Potash, Magnesia, Soda. Potash, Magnesia, Soda. Potash Soda. 9^ 15| do. do. Magnesia, Soda. Red Clover, Potatoes, and especially Potato tops, Beet- roots, Mangel Wurtzel and Peas, in a word most green crops require much potash, soda and magnesia. A com- paratively small quantity of these substances will satisfy grain-growing crops. An acre of Clover abstracts from - - 90—100 lbs. do. of Beetroot or Mangel Wurtzel, 80—100 do. do. of Potato tops, 130—150 do. do. of grain and straw of Wheat, - 30— 50 do. The large quantity of Potash and Soda in Potato tops, contradicts the impression frequently found to prevail, that ihey are of little use as manure. Lime.— A very important constituent of all vegetables cultivated for the food and use of man— and if possible an equally important agent in the hands of the agriculturist for ameliorating the condition of many kinds of soil. Its effects as a manure will be considered under that head ; it is suffi- cient for our present, purpose to become acquainted with those kinds of vegetables which particularly require lime for the due formation of their various organs. 24 LECTURIS ON AGRICULTURAL CHEMISTRY. An Acre of Clover abstracts from 70—90 lbs. of Lime, do. Hay, do. do. 30—60 do. do. do. Wheat Straw, do. 15—20 do. do. do. Oat Straw, do. do. 10—18 do. do. Various vegetables possess the power of assimilating more than an average quantity of lime, if presented to them in a proper form. Its effects upon the straw of grain-growing crops is very remarkable. Farmers are acquainted with lime in three different states,— 1st. in the form of common limestone, which consists of lime and carbonic acidj 44 lbs. of carbonic acid and 56 lbs. of pure lime, forming 100 lbs. of common limestone, which, when burned in a kiln parts with the carbonic acid and then constitutes ; 2nd. quick or caustic lime ; 3rd, in the form of slacked lime! When 9 lbs. of water are thrown upon 28 lbs. of caustic lime, the lime swells, evolves great heat, and entering into combination with the water produces 37 lbs. of slacked lime. Lime is found in the soil in the state of carbonate of linriejits presence is indicated by effervescence when an acid is poured over it. In the caustic state it possesses very powerful properties, causing the rapid decomposition of vegetable and animal substances. Flint.— Called by chemists Silica, composes a large proportion of the ash in all grain growing-plants ; its office in vegetables is to give strength to those parts which seem particularly to require additional aids. The wheat plant affords an admirable illustration of elegance in form united with wonderful strength. A column 576 feet high and 3 feet in diameter, bearing a weight upon its summit equal to that of the column itself, represents a multiple of a wheat plant four feet high and one-fourth of an inch in diameter. No selection of materials, or contri- vance in binding them together, would enable an artificial structure of these proportions, to resist the force exerted by a gentle breeze. A good crop of Wheat, from one acre, abstracts in the straw alone from 120 to 150 lbs. of Flint ; of Oats, seed and TRY. of Lime, do. do. do. lilating more to them in a :ain -growing lainted with I of common acidj 44 lbs. ling 100 Iba. i in a kiln, itutes; 2nd. acked lime. I. of caustic nd entering I. of slacked f carbonate sence when it possesses composition 3es a large -plants; its hose parts aids. The if elegance olumn 576 eight upon spresents a le-fourth of , or contri- m artificial exerted by cts in the I, seed and LKCTX7RBS ON AGRICULTUIUL CHflMIBTRlTi. S9 straw, from 40 to 60 lbs. ; Mangel WurtzeLwid L^ets, from 12 to 18 lbs. of Flint. Iron. — Iron is present in all fertile soils, and is also an invariable constituent of vegetables. It greatly increases the tenacity of clays when found in the soil in the state of black 0Xid6 or rust of iron, — it may be converted irtto the red oxide or rust by exposui-e to air. The black oxide is soluble in water and prejudicial to vegetables : the red oxide is sparingly solublie, and a harmless or rather useful product. Iron is found in all the clay soils of Canada, in the form of the black magnetic oxide of iron : on the shores of lakes Ontario, Simcoe, Huron, St. Clair, &c., it oocurs in very large quantities mixed with white and red sand — it may be separated by means of a magnet. Chlorine. — This substance does not exist in a simple or pure state ; it is always found in combination with other bodies: common salt is the great storehouse of chlorine. Salt is composed of a metal sodium in union with chlorine. When used as a manure salt yields soda and chlorine to vegetables. Iodine is only found in sea plants, or those growing in the immediate neighbourhood of salt water. It will be observed that different kinds of cultivated vegetables, require for their due formation, different quanti- ties of flint, lime, potash and soda. A variety of convenient ^nd useful arrangements of vegetables, can be framed on the basis of their respective requirements. Thus we have as a very general and necessarily imperfect method of airangemcQt, the following, ilint, potash and lime plants — Flint Plants. Potash and Soda Plants. Lime Plants. Wheat, Turnips, Peas, Oats, Beet-root, Beans, Kye, .' Mangel Wurtzel, Clover, Potatoes. Hay partaking of the character of the three classeaCLiebig.) 26 LKCTURfiS ON AGRICULTURAL CHEMISTRY, Bf. Other, and more exact modes of arrangement of differ- ent kinds of vegetables with reference to each other, naturally suggest themselves, when the number under consideration is diminished ; these will be introduced here- after, under < Rotation of Crops.' The recent analysis of a soil-from the Seignory of Charably, in Lower Canada, by T. S. Hunt, Esq., Chem- ist and Mineralogist to the Provincial Geological Survey - ' exhausted by having yielded crops of wheat for many successive years without receiving any manure," gave the loJJowing results : In 100,000 lbs. of the soil there were found of Lime 374 lbs.. Sulphuric Acid 31 lbs., Magnesia 888 lbs., Phosphoric Acid 126 lbs.. Potash and Soda 580 lbs., Soluble Flint, 80 lbs., We here discover an abundance of all the necessary substances which plants require. The plea of deficiency theretore cannot obtain, in this instance. The present barrenness of the sod is unquestionably due to the state in which some of those bodies exist at present. This view is confirrned by the remark of Mr. Hunt, that it supported nothing but *' a scanty growth of a short wiry grass, which IS regarded as indicative of an impoverished soil, and known as lierbe d. cheval." The same soil when subjected to the action of water, gave only minute traces of sulphates of lime, magnesia po ash and soda; there being proportionately two pounds of sulphur in one miU.on pounds of the water with which the soil was treated, while analysis showed that there was upwards of three thousand one hundred pound, of sulphur m one million pounds of the soil, in an insoluble state. No mention is made of phosphates soluble in water, therefore we may conclude Uiat the quantity was too insignificant to be detected by ordinary means of analysis. We have had nnHop nnnniA^^^r. _-m i . i. ^ penod wa, eminenlly fertile- having yielded succossive erops of wheat for 30 ye«r.,-at present, however, barren, LKCTVRCS ON AGRICULTURAL CHCMISTRY. 27 ment of differ- each other, number under iroduced here- 3 Seignory of , Esq., Chem- ical Survey, — leat for many re," gave the und, of 31 lbs., 126 lbs., ' lbs., he necessary of deficiency The present o the state in This view it supported grass, which ed soil, and on of water, « magnesia, vo pounds of h which the t there was ^ of sulphur e state. No 3r, therefore Ignificant to itch at one successive ver, barren, and yet possessing in abundance, a supply of all needful substances for thousands of crops of wheat, ot an3'' ctlier vegetable which at the pleasure of the cultivator could be grown u^oon it. The present example affords a good illus- tration of the condition of other soils which have been subjected to an injudicious course of cropping. It becomes then, a question of much interest and moment to practical farmers, to ascertain the nature of those artifices they must employ in order to restore and render permanent the fer- tility of such depreciated soils. The chief agent in effecting the solubility of the neces- sary quantity of mineral substances is Air. All the operations of the farmer aie in the main directed to the intro- duction of air into the soil, and affording time for its influence to be exerted. He ploughs for the purpose of exposing fresh surfaces to air ; he drains to admit air into its pores and crevices ; he fallows to give time for air to exert its powerful influence ; he employs a rotation of crops for precisely the same object. Ploughing. — It has been remarked that the beneficial effects produced by ploughing, are mainly due to the free admission that operation gives to the uir, whereby the de- composition of the mineral portion of the soil is greatly faci- litated, as well as the conversion of decaying vegetable matter into caibonic acid, ammonia and water. Air is necessary to the germination of seeds, hence the reason why so many different kinds of weeds spring up when the soil is first stirred to the depth of six cr eight inches, the dc.mant vitality of the seeds being revived under its pow- erful influence. Ploughing also cleanses the soil from weeds, and rendering it more porous, it permits the young and tender roots of plants to penetrate in search of food — it also facilitates the absorbtion of rain water. Many clays contain a quantity of iron in the form of the black rust of iron, a subslaiice noxious to vegetables ; in the presence of air it is converted into the red rust of iron, a harmless compound. The change in the character of S8 UBCTUlUBa ON AURlOCLTtfJlAL CBBMISTWffc w. the iron rust d«8troys the stiffness and tenacity of the ^Jays, and converts ihein into ciomparatively loose and Ifiable soils* Farmers frequently skim the surface etf their fields with the plou^. It is evident from th* rationale of/ the operation that the deeper the plough penetrates^ the greater benefit is likely to result. ; nhuui. .u.iA I The subsoil plough is much Used in Great' Britain,— it serves to break up and loosen the earth 10 or 12 inches below the limit to which the cortiinon plough penetrated. Subsoil ploughing is of litMe avail On soils possessing a' retentive bottom, without tihojough draining. ' Draining.— The ext'shsive introduction of a proper sys- tem of draining, constitutes, unquestionably, the great modern improvement in the Art of 'Agriculture. Its effects are due, 1st. To the greatly increased porosity of drained soil^ . allowing, the circulation of air among their particles with every change of temperature. 2nd. To the rapid removal of superflupus and stagnant water, which on undrained soils fiils the pores or small spaces between their solid particles and opposes the intro- duction of air into its place. 3rd. To the alteration which takes place intLe mechan- ical composition of the soil, whereby it is rendered loose, friable, more easily worked, and at an earlier period of the year than when undrained. 4lh. To the great change it produces in the temperature of the soil. Recent experiments have satisfactorily established that the evaporation of one pound of superfluous or drainage water, that is, of one pound of water, over and above the quantity which a soil is capable of retaining by its power of attraction or absorbtion, lowers the temperature of the SSnil ton Aanfaaa Tf .U— In. . — ..... .....g.^^.^. ii iHc uiju pouuu 01 water pass off by the drains, and not by evaporation, no reduction in temper- ature tak-ss place.! STRYi LECTURES ON AGRICULTURAL CHEMISTRY. 29 y of the ^Jays, B aod Iftable of their fields tuDnale of « the iSi the greater It* Britain, —it or 12 inches ^h penetrated, possessing A- I proper sys- ly, the great Irained soil^,. (articles with and stagnant res or small es the intry- tLe mechan- dered loose, ?r period of temperattire blished that or drainage id above the )y its power ature of the pass oft by in teraper- The mean highest temperature of the air in March, (the earliest agricultural month in Canada,) is 54 degrees. The warm sun melts the snow and frozen surface of the soil. If thoroughly drained, the water will slowly filter to the drains during some hours of the day-time, and air at the temperature of from 50 to 54 degrees will Jollow the water, — thawing, before it is cooled much, frozen soil. In April the mean highest temperature is 71 degrees, the mean temperature 42 degrees ; during many hours of the day, warm air, on drained soils, will follow the water, and rapidly impart much of its warmth around and below the young roots of plants, thus inducing an early and rapid growth in that very important part of the plant. Experi- ments have been made in England on the temperature of undrained soils ; they exhibhed the singular and very important fact, that the temperature of a wet soil never rose during many months above 47 degrees — seven inches below the surface. The same soil when drained indicated a temperature, after a thunder storm, of 66 degrees at 7 inches below the surface, and at a depth of two feet seven inches, a temperature of 48 degrees. What woutd be the effect in this country where the temperature of air and rain is so much greater than in England ? [A very large number of scJid bodies exhibit an attraction for water, as wood, glass, iron, &c. All fatty bodies and oils, show a decided repulsion for the particles of water ; they cannot be wetted by it. Water will remain attached to the surface of a clean piece of glass, even when turned upside down ; common quicksilver would roll off from glass, but not from a clean piece of zinc. Zinc can be wetted by quicksilver when the surface is free from rust. Let as suppose that a thin and very narrow piece of glass be bent round, so as to form a long and exceedingly narrow tube; if the end of the tube be placed in water, the fluid will be seen to rise rapidly, until the attraction of the glass for water is exactly counterbalanced by the weight drawn up. Such a tube is called a capillary tube, und the force exerted by the glass, or any other body having the form of a fine tube» capillary attracticr.. The roots of plants consist of an 30 LECTURES ON AGRICULTUR/ L CHEMISTRY. assemblage of exceedingly fine tubes,— all porous bodies, in fact, may be considered as bundles of small tubes, their length and direction not affecting their attractive power for water. It is thus that soils which are very porous, absorb and retain water— the fluid absorbed is called their water of attraction. If a lump of clay be completely dried in an oven, afterwards suspended by a string and water poured slowly upon it, a large quantity will be absorbed. Thus from 106 lbs. of dry soil, water will begin to drop, if it be a quartz sand, when it has absorbed 25 lbs. Calcareous sand (lime sand) 29 do. Loamy Soil 40 do. Chalk 45 do. Clay Loam 50 do. Pure Clay 70 do. (Johnston) When water of attraction slowly disappears during the process of evaporation, the soil contracts and occasions fiseures, this effect is particularly observable on clay soils. It is worthy of remark, that soils absorb much moisture from the atmosphere. « Different soils possess this property in unequal degrees. During a night of 12 hours, and when the air is moist, according to Schubler, 1000 of a perfectly dry^Quartzy Sand will gain lbs. of water. Calcareous Sand 2 do. LoamySoil 21 do. ClayLoam 25 do. Pure Agricultural Clay 27 do. And peaty soils, or such as are rich in vegetable matter, a still larger quantity." We discover in this property the reason why potato plants always appear refreshed in dry weather, after the earth has been stirred by the hoe round about their roots. The soil is made more porous, in effect a much larger surface is exposed to the air and the moisture it may contain— the moisture is absorbed, and ministers to the growth of the drooping plants.] It is occasionally urged by practical farmers, that tiiorougii ^raining will not succeed in the hot and dry sumroer season of Canada. This is a mistake, the roots of vegetables shun stagnant water, they turn aside when their "* [STAY. porous bodiei, all tubes, their :tive power for porous, absorb id their water ely dried in an water poured »rbed. 1 1 bs, do. do. do. do. do. (JohnstoD) irs during the and occasions on clay soils, nuch moisture is this property urs, and when of a perfefitly I lbs. of water. do. do. do. do. able matter, a i property the reshed in dry the hoe round )us, in effect a the moisture d ministers to irmers, that tiot and dry i, the roots of e when their LECTURES ON AGRICULTURAL CHEMISTRY. 31 descent would bring them in contact with it. They will penetrate many feet into the soil if it be well drained. But what is the case with our Canadian fields ? When the roots of wheat or other vegetables begii;i to grow in the spring months, they discover at the depth of six or seven inches, asupply of stagnant water, which can find no escape but by cold-producing evaporation. The roots are not only chilled, but absolutely prevented from penetrating deeper in search of nutriment, they can not thrive when surrounded by drainage water, their growth is retarded, and their range limited ; on a drained soil they strike directly downwards to the level of the drains, and in those depths, they discover a supply of moisture in seasons of drought, springing up from below by the power of capillary attraction, besides that which every soil possesses the power of absorbing. It has been ascertained by vegetable physiologists, that roots cease to grow, as soon as the plant begins to form the seed. Its energies are then exclusively devoted to that object. The formation of the seed, in many kinds of cul- tivated grain growing crops, begins in June or early in July. A dry summer parches the soil to the depth of five or six inches. The limited depth to which the roots have pene- trated, prevents *,iem from obtaining a sufficiency of moisture, the crop consequently suffers from drought, a disaster which has taken place to a very large extent this year, with respect to clover and hay, and if the dry weather had continued a fortnight longer, the labors and hopes of the farmer, in many parts of the province, weuld have been altogether defeated. Comparatively little dam- age would have been done on drained soils, for the roots of vegetables, following their own natural tendencies, would have been able to penetrate during the early spring months, deep into the soil, and there find a supply of moisture, removed from the rapidly evaporating influence of a hot sun and a dry atmosphere. [The great obstacle to thorough draining in Canada, is the cxpfi7ise— coupled with the low price of farming produce. Within a convenient distance from large towns, where a I 32 LECTURES ON AGRICULTURAL CHEMISTRY. market for wheat, oats, hay, peas, tnrnips, mangel wurtzel, is generally to be obtained, this objection can scarcely hold good. The great incre.:'8e in the average produce, the supe- riority of the sample, the early maturity of the crops, their comparative safety from the f fTects of drought and the fly : all support the presumption of a rapid and profitable return for an outlay of capital. In districts remote from markets^ the expense of thorough draining constitutes an insuperable objection to its introduction. Much good can, however, be accomplished by clean open furrows 10 or 12 inches deep — and so cut that they may admit of a continuous fall of water through their whole length, so that no portion may remain in any part of the furrow. An inclination of one foot in three hundred will be quite sufficient to cause an unbroken cur- rent, if the fall be quite uniform. Where the land lies low, the most beneficial results will be produced by a drain, dug to the depth of two leet, with here and there a hole to the depth of three and a-half or four ieet — the holes and drain being filled up to within one foot from the suiface, with stones from two to six inches in diameter, then covered with a sod. trampled down, and filled up with earth. It may here be remarked, that open drains with an occasional under-ground drain, require more care in construction than is usually devoted to them. Thorough draining is an art in itself, and implies an acquaintance with the characteristics of springs, soils and climate, besides a practical knowledge of levelling. A recent writer on draining, possessed of thirty six years experience, closes his remarks with the following caution. " Our parting words shall assure our readers, that every reputed case of failure in draining, which we have investigated, has resolved itself into ignorance, blundering, bad materials, and bad execution." The same writer recommends the use of pipes, having an inch or inch and half bore, with collars to lay over the joinings, and pre- vent dis-arrangement. Collars are short pipes which slip over the joinings of two contiguous drain pipes, and effect- ually prevent the uniformity of the juncture from being disturbed by 'faults' in the floor of the drain, or by an upheaval,] Fallowing. — A Fallow implies the repose of the soil, or in other words time, to permit air, water, and temper- LECTURES ON AORICULTURAL CHEMISTRY. 33 ATURE, to convert a certain amount of insoluble ingredienlfl in the soil, into soluble and available food for plants. A naked fallow is deprecated by many practical agriculturists and agricultural writers— they consider it as so much land thrown away for a time, and propose in its stead a judicious rotation of crops. It is very questionable, however, whether a naked tallow is not occasionally absolutely necessary in ihis country, where the growth of weeds is extremely rapid, and where the high price of labour is always an obstacle to many uands being employed upon a farm. A naked summer fallow seems to offer to the Canadian farmer the most available and cheapest method of cleaning his fields, especially where numerous patchf;8 of uncultivated land, every road side, and every neglected farm is a nursery for Canada thistles, wild mustard, wild chamomile, chess, muUen, foxtail, burrs, and other noxious weeds. Green Fallow, is a term used with reference to the cultivation of wheat, rye, barley, and oats. The principles it involves will be introduced under the head of. Rotation of Crops. —The origin and constitution of some favoured soils, is such as to require the active operation of air for a very limited period, to enable them to offer an abundant supply of soluble solid food for the purposes of vegetables, without any extended rotation of crops. Wheal, a flint plant, and tcbaccco a lime p^ant, have been grown alternately on large tracts of land in Hungary, within the memory of man. without any application of manure. In many parts of Upper and Lower Canada, in the valley of the Thames and the Richelieu, wheat has been taken from the soil for 40 and even 50 successive years, the soil even- tually becoming incapable of returning a profitable crop. The repose of a fallow for a few years, restores its fertility. During the period of fallow, air, water, and lemperatuKB, exert their decomposing influence, upon the soil, and con- vert an abundance of insoluble mineral ingred^ents^mto soluble food for veg^ables. The alternate growth of wheat and tobacco, upon the fertile soil of Hungary, presents us with an easy and familiar illustration of the benefits spring- d2 84 LECTURES ON AGRICULTURAL CHEMISTRY. ing from a rotation of crops. Wheat requires a large amount of flint ; iobacco, an equal quantity of lime. While the wheat is growing, the lime in a soluble state, is accu- mulating in the soil, and the growth of the tobacco, acts as a fallow for the preparation of the soil for wheat^ because tobacco does not require those particular ingre- dients, which are essential to the growth of wheat. It will be seen that the principle of a rotation of crops depends upon the cultivation of a Flint plant one year, a Potash plant the next, and a Lime plant the third, and so on. The character of the soil determines whether one, two, three or four years should intervene the introduction of dif- ferent kinds of vegetables. The following table given by Liebeg, may afford an apt illustration of this important principle. In lOOlbs of the ash of the following vegetables, the proportion of Potash and Soda, Lime and Magnesia, and Flint, are given under their respective heads. Pot. and Ljme and Soda. Mag. (Oats, straw and seed, 34Ibs. Wheat straw, 22 '* Barley straw and seed 19 « Kye stiaw, is « Tobacco, 24 *« Pea straw 28 ** Potato Stalks, 4 nsequently ind decays, (For the e roots, see getables, is )-Wood), to et much of r the upper rimed lately From the irough the descent; i! of the old ^m Manures. — Whatever is added to the soil for the purpose of increasing its fertility, is termed a manure. The object of the farmer, in the use of manures, is either to place within the reach of vegetables, the substances they require to build up their structure, or to change the nature of the soil, that its fertility for oultivated plants maybe increased. The most convenient mode of exhibiting the action of different manures, is to describe each separately, and state the effects they are capable of producing. Farm-Yard Manure is unquestionably the best kind for general purposes : it is easily accessible, and contains all the substances required by cultivated vegetables. The excrements of animals consist of a solid and fluid portion : the fluid portion is immeasurably richer in saline and mine- ral ingredients, and in ammonia, than the solid portion. In 100 lbs. of the solid excrements of the horse, there is generally to be found about 19 lbs. of vegetable matter, 3 do. saline and mineral ingredients, 78 do. water. 100 do. The vegetable matter is slowly decomposed in the pre- sence of air, and becomes converted inio carbonic acid, water and ammonia — the atmospheric food of plants. In a ton of fresh horse manure we find about 40 lbs. of Flint, 7 do. " Potash, l^do. " Soda, I do. '' Iron, 3 do. '* Lime, 2 do. " Magnesia, 4 do. " Phosphorus. I do. ** Sulphur. iiC uiuci iiiaiiUitr lOj mv iv -i- t vf^-.ft --f- -- — -- tains, owing to its decomposition, and consequent escape, in the form of carbonic acid, water and ammonia ; at the 38 LECTURES ON AGRICULTURAL CHEMISTRY. .^1 same lime, the mineral ingredients will remain undi- minished in quantity. It is evident, that a ton of old manure contains far more mineral substances than an equal weight of fresh manure ; hence the reason why farmers prefer old manure for soils rich in vegetable matter. Urine. — The fame of guano as a fertilizer is spread throughout the world. Many farmers would consider the possession of a few tons, as a surety for the success of future harvests. What is guano f The excrements of birds, composed of various saline and mineral ingredients, together with acids in combination with ammonia, of which latter substance guano contains from 7-17 per cent. Its beneficial effects are due to the presence of ammonia and phosphcus in a soluble slate. Canadian farmers would not think of purchasing guano, even if a supply were at hand. The price of 40 to 60 dollars a ton, presents an insuperable objection to its use as a manure for agricul- tural purposes, especially when a substitute of almost equal value is to be found in the urine of the stables. The urine of a full grcnvn cow, or horse, contains a quantity of soluble saline and mineral ingredients, e.iactly equal to the quantity of the same substances contained in the food consumed. In the solid excrements are found those ingre- dients which, as they passed through the body of the animal, resisted the action of the fluids with which they came in contact. This somewhat singular statement will appear perfectly credible, when we consider that a full grown horse, or cow, consumes food for years together without increasing in weight ; that is to say, the mean or average weight of a milch cow, a working horse or ox, is the same throughout a period of many years. Certain constituents of the food assume the form of muscle, bone, fat and blood, supplying the place of an equal amount of worn out and useless materials which are discharged from T„ innn \u~ — :^Ui. ill iv/w lua. wtHi'Lii ui IIIC uiiiiu ul the horse, there are found about 45 lbs. of soluble saline and mineral ingredients, and 31 lbs. of a substance called LECTURES ON AGRICULTURAL CHEMISTRY. 39 I mean or :; uuiiu ui urea, which, upon decomposition, resolves itself altogether, into carbonic acid and ammonia. In 1000 lbs. of the urine of a cow, there are found about 43 lbs. of saline and mineral ingredients, besides 18 lbs. of urea. A horse voids, on an average, 3 lbs. of urine in a day. From November to March he will void about 450 lbs., containing 14 lbs. of urea and 20 lbs. of soluble solids, as much as is contained in 200 lbs. of guano. A cow voids from 20 to 40 lbs. of urine in a day, accord- i ng as she gives milk or not. If we take the lesser number, her urine will afford, during five months, 64 lbs. of urea, and 130 lbs. of soluble solids, as much as is contained in 600 lbs. of guano. (The urine of a cow is valued, in Flanders, at 10 dollars a-year It contains 900 lbs. of solid matter, and this, estimated at the price of guano, is worth £A sterling.— Johnston.) A drain from the stable, or cow-house, to a barrel sunk in the earth, afibrds a convenient mode of collecting the urine, from which it may be carted, either in the liquid form to serve as a top-dressing, or thrown upon the dung- heap. Ammonia is a very volatile substance ; that is, it rapidly separates itself from the urine, and becomes dif- fused throughout the atmosphere. Gypsum, charcoal, or partially burned clay, thrown into the barrel or upon the floor of the stable, will collect and fix this very volatile and useful body. A layev of clay, occasionally strewn over the dung-heap, is very effectual, not only in retarding decomposition, bul also in fixing its gaseous products. if a dung-heap be exposed to the weather, too great care cannot be tak n in collecting and preserving the drainage water, and applying it as far as possible to young growing crops: h contains a very large quantity of dissolved solids and gases, every particle of which, is capable of being taken into the structure of vegetables, increasing their growth,and facilitating their absorbtion and digestion of other CaSAnilR nnr) Rnlirl fnnrl Aot-\vror\ fmm t\\a a'lfanA *\\a 0ir\'tl Gypsum. — Gypsum (Plaster) is a very necessary article in the hands of the farmer : he may use it as a top-dressing, ! 1 40 LECTURES ON AGRICULTURAL CHEMISTRY. or strew it over the floor of the stable, or sprinkle it upon his dung-heap, or sow it with the seed. In all casej it serves two purposes : — 1st, to fix ammonia ; 2nd, to give sulphur and lime to his crops. Gypsum is especially useful on most soils, as a top-dresbing for clover and grasses. The mode in which it exercises its beneficial influence, pro- bably differs according as it is used for a top-dressing, or distributed with the seed. Its effects depend very much upon the time it is sown, when used as a top-dressing ; and on the season, when planted with the seed— as with Indian corn or potatoes. It is most advantageously sown upon grasses and clover when the leaves are well developed, and before a shower of rain. It cannot be expected to pro- duce much effect upon Indian corn or potatoes in a dry season, because of its great insolubility in water. Lime.— Lime has been the successful agent in accele- rating the restoration to fertility of numberless worn-out farms in Europe and America. It quickens the decompo- sition of clay, and forms with the potash, soda and flint of the clay — new compounds soluble in water. It opens and increases the porosity of stifl" soils, depriving them of that tenacity and adhesiveness which is frequently an obstacle to working them, and a still more serious impediment to the expansion of the roots of young plants. Lime hastens and increases the effects of manures, and improves the sample of all kinds of cultivated crops, especially those grov^n for the sake of their seed. Many pernicious weeds are destroyed, and nutritious grasses improved, by the action of lime. It exerts a decided influence upon the duration of their growth, occasionally hastening their maturity by several days. Its effect upon soils containing a large quantity of vegetable matter is remarkable. Many acids are formed in the soil, during the decomposition of roots, manures, &c. These are often highly injurious to cultivated crops. Linfie- however^ neutralizes them, and occasionally forms nutritious compounds out of the un- wholesome or poisonous ingredients. The quantity of lime to 7, LECTURES ON AGRICULTURAL CHEMISTRY. 41 ]e it upon 11 casej it id, to give ally useful isses. The ence, pro- fessing, or v^ery much ;sing ; and nth Indian «own upon developed, :ted to pro- 5 in a dry in accele- 3 worn-out decompo- nd flint of opens and jm of that m obstacle 3diraent to ne hastens proves the ially those ious weeds jd, by the upon the ning their containing le. Many position of njurious to them, and af the un- y of lime to be applied to the acre is dependent upon the nature of the soil ; from twenty to forty bushels are frequently required by retentive clay soils. The effect upon the amount of pro- duce is often astonishing : numberless instances are re- corded of a single application having raised the averagie from eighteen to twenty-eight bushels of wheat per acre. Virginia owes the restoration of her worn-out soil to a judicious application of burned lime. The effect of a ^ood dose of lime is distinguishable for many years. Leached Wood Ashes. — When wood is burned, many of its mineral and saline ingredients become insoluble in in water. This is especially the case with the lime, and compounds containing sulphur and phosphorus. The solu- ble portion of ashes consists almost altogether of potash and soda, which are dissolved out when water is filtered through them, in the process of making black salts or ley for the soap-boiler. In treating 100 lbs. of good ashes with water, from 20 to 40 lbs of soluble ingredients are conveyed away by the water, the remaining portion weighing from 60 to 80 lbs., fcrms an excellent manure, which may be used as a top-dressing, or mixed with the dung-heap. Good husbandry implies the elevation of the standard o^ fertility and production, to the highest remunerative point, and its continuation there. A due attention to all the minutisD of farming labour is far from being sufficient : con- tinued success can never attend the most industrious farmer, if he neglect tbose precautions which experience and the science of agriculture suggest. It is a fact, which rests upon the most abundant and conclusive evidence, that no ordinary farm can continue for a succession of years to yield a fair return, if attention be not paid to rotation of crops, the application of manures, and at least surface draining. A very fair view of the condition of husbandry, on a farm, or in township, county or province, can be acquired by an inspection of the number of acres under diffefont kinds of cultivated crops, exhibiting the ratio which grain crops bear to green crops, and these again 4o pastiwe and fallow. »i:| Ill 4a LECTURES ON AGRICULTURAL CHEMISTRY. I! No FARM CAN CONTINUE TO PRODUCE GRAIN-GROWINCJ CROPS ON A GREATER SURFACE THAN ONE-THIRD OF ITS CULTIVATED EXTENT, FOR MANY SUCCESSIVE YEARS, WITH- OUT DIMINISHING SCALES OF PRODUCE : that is to Say, a farm of fifty acres in the clear, and under cuUivation, cannot sustain a larger amount of grain-grovjring crops than seven- teen acres ; or a farm of one hundred acres in the clear, and under cultivation, not more than thirty-four acres, pro- ducing at the same time high averages, and preserving their fertility undiminished. The very indifferent and careless manner in which sta- tistical returns of crops and produce are rendered by farmers, materially diminishes the value of what would be otherwise highly instructive and important information. We can deduce an approximate view only, of the condition of husbandry in the Province of Upper Canada, by exa- mining the returns of 1848. Our comprehension of its most important features, will be greatly facilitated by instituting a comparison between the agricultural statistics of the whole province and some one county, say the County of York. County of York. 1847. .15f bush, per acre, do. Wheat Barley Rye . Oats . Peas 20 Indian Corn.27 Potatoes . . .82 .19§ .16| .31§ Upper Canada. 1849. 1847. 19^ bush... 12j-\bush. do. do. do. do. do. 18f 15 241 16 37 124 18 12 25 21 22 83 The crops appear to have been distributed in the fol' lowing ratio : — COUNTY OF YORK. UPPER CANADA* Gram-growing Grop8(Flint Plants)168,414 ac. .999,039 ac. Green crops (Potash-Lime Plants) 79,1 15 do. . . 165.965 do. ^^^'^"'■e 94,168 do. . . 766,768 do. Fallow (suppose) io,000 do. . . 100,000 do. LECTURES ON AGRICULTURAL CHEMISTRY. 43 Let us imagine two farms, of 100 acres each, to be divided in the same ratio with respect to crops, and we obtain the following results : County or York, 1849. Upper Canada, 1847. 48 acres Flint Plants 47 acres Flint Plants. 22 do. Potash-Lime Plants 121 do. Pot.limedo. 27 do. Pasture 36 do. Pasture. _l do. Fallow 4^do, Fallow. 100 ^ England, in 1835. 21 acres Flint Plants. 12 do. Potash-Lime Plants. 58 do. Meadow and Pasture. 9 do. Fallow. 100 The ratio which the grain-growing or flint crops bear to the whole hundred acres, are in. County of York. . 48 to 100 equal to one-half nearly. Upper Canada . . 47 to 100 equal to one-half nearly. ^-r^g^^nd 21 to 100 equal to one-fifth nearly. The high average of 19^ bushels of wheat to the acre, in the County of York, for the year 1849, affords proof of 'the existence of much good land, and some good farming : the ratio which the grain-growing crops bear to the soil under cultivation, is equally indicative of a very large extent of bad farming. The produce of the pastu/es in the same county is repre- sented by the wool of 102,986 sheep, amounting to 321,441 lbs. The weight of the average fleece is a trifle over 3 lbs. ; that of the whole province being 2| lbs. Of cheese and butter, we find for the home markets or ex- portation 504,957 lbs. ; containing, with the wool, many thousand pounds of phosphorus, lime, magnesia and soda, which never find their way back to the soil again. In the long-run, the exports of a country greatly afl'ectthe character pf that system of husbandry which is productive of 44 LECTITRES ON AGRICULTURAL GHEMISTRV. the greatest advantage. This is particularly the case in Canada, where the severity of the climate compels the farmer to house his cattle during rr. ny months of the win- der season. The solid and fluid excrements are accumu- lated in one spot, and require care for their preservation and after disposition ; a precaution with refereru?e to the fertility of pasture lands, which is not needed where cattle can remain in the fields night and day for eleven months in the year, as in Holland, Belgium, and some parts of England and Ireland. Under ordinary circumstances, the farmer takes soluble saline and mineral ingredients from his farm in the form of grain, hay, wool, butter, cheese, beef and pork, faster than atmospheric influences can create a fresh supply by the decomposition of the soil ; and if he do not return a part so abstracted, in the form of manure, and give time, by a rotation of crops, for the solubility of the remaining part required, the fertility of his soil will decrease, and dimish- in^ scales of produce will not fail to point out his error. iftf IV. he case ia ompels the of the win- e accumu- Tvation and the fertility- cattle can mths in the jf England kes soluble the form of faster than 3ply by the turn a part TIME, by a aining part nd dimish- s error. LECTURE II. Compound substances found in Vegetables— Woody Fibre— Starch— Sugar- Oils and FaiB— Nitrogen Compounds— Comparative table of compound substances found in Vegetables-Comparative value of different kinds of Manure— The digestive and respiratory processes of Animals- Purposes served by Food— Diseases of Vegetables produced bv Fungals and Insects-Rust-Mildew-Smut-Tlie Potato Disease-Trie Hessian Fly-Tlie Wheat Fly-The Turnip Fly-The Wire- worm-Weeds of Agriculture— Chess— Canada Thistle— Other Weeds— Conclusion. The results of modern investigations into the chemistry of vegetables and animals, furnish us with most striking and comprehensive views of the relationship existing between them. The products of vegetable life are capa- ble of being converted by the wonderful process of digestion, into bone, sinew, flesh, and blood. In other words, the gases of the air and the mineral ingredierts of the soil, assume the form and substance of sentient and moving beings, through the instrumentality of vegetables, and those 'ital energies with which animals are endued by the Creator. The purposes served in the animal economy, by the compound bodies, such as starch, oil &c., which are found to exist in vegetables, constitute a subject of deeply interesting enquiry: and in no other field of scientific research, have the labours of chemists been rewarded with such beautiful and surprising results. Among the innumerable products of vegetable organiza- tion, not more than nine or ten are of direct interest to the farmer, with respect to the feeding and improvement of stock. These are susceptible of division into two classes, according to the elementary substances of which they are composed. Thus, we have FIRST CLASS. Woody Fibre, ) Starch* Gum, Sugar, Oils. £2 Composed of Oxygen, Hydrogen, and Carbon. rj 46 LECTURES OS AGRICULTURAL CHEMISTRV. SECOND CLASS. Compounds containing Nitrogen. [The presence of Nitrogen constitutes the great difference between the two classes of vegetable substances. It will be found to exercise the naost astonishing influence upon the purposes served by ihem in the animal economy, when used as food, it will be seen that the nutritious parts of vegetables — those which go to form bone and muscla, are distinguished by the presence of Nitrogen. Particular atten- tion is due to this substance in treating of the feeding of animals.] The most remarkable circumstance connected with some of these bodies, is their perfect identity in composition. Thus we have the bodies, starch, gum and sugar, which differ so widely in external characters, in their appearance, their taste, their odour, composed of precisely the same materials, united together in the same proportions. [In 162 lbs. of sugar, starch or gum, there are exactly 72 lbs. of carbon, 80 lbs. of oxygen, and 10 lbs. of hydrogen. Jn 34 lbs. of oil of turpentine, or oil of citron, — two liquids differing widely in their properties, there are contained 30 lbs. of carbon and 4 lbs. of hydrogen. The difference in properties is due to the arrangement of the particles of which they are composed. We may suppose the mode in which this arrangement differs to be as follows : — In one body, say starch, one unit of hydr(^en may be associated with 6 of carbon and 8 of oxygen, to form one unit of starch. In sugar, we may imagine 2 units of hydrogen, to be combined with 12 units of carbon and 16 of oxygen, to form one unit ol sugar.] The various properties of these bodies, being dependent upon the mode in which their particles are arranged together, afford us an excellent illustration of the beautiful simplicity and admirable contrivance exhibited in all of Nature's works. Woody Fibre. — Woody Fibre forms nearly the whole mas.s of forest trees : and about one-half of the stalk of grasses and straw of grain-growing crops. Its quantity in succulent roots, such as the turnip, beet, carrot, potato &c.. LECTURES ON AGRICULTURAL CHEMISTRY. 47 difference . It will i upon the ny, when i parts of uscia, are ilar atten- feeding of nih. some iposition. .r, which jearance, the same tly 72 lbs. ogen. In vo liquids ntained 30 Perence in 3 of which in which body, say with 6 of tarch. In combined m one unit ependent arranged beautiful ia all of he whole 3 stalk of uantity in lotato &c., is very small, being rarely more than from two to four per cent. Woody Fibre is formed of carbon and the elements of water, it decomposes (decays) slowly, when exposed to moisture or air ; it is then converted into two compounds, carbonic acid and vegetable mould ; when the last named substance is exposed in a moi.st state to air, it absorbs oxygen with rapidity, and gives ofT an equal quantity of carbonic acid. It is thus that the decay of vegetable mould, affords an abundant supply of food to young plants. When woody fibre is in contact with potash, soda or mag- nesia, its decay is much accelerated ; when surrounded or impregnated with an acid substance, as strong vinegar, or weak spirit of salt, decomposition is very much retarded. The decay of woody fibre is a question of some interest to farmers aiid builders; great expense is occasionally incurred in renewing sleepers, sills, gate posts, fences, &c., which have decayed immediately above the soil, where they come into contact with moisture, the potash, soda, and lime of the soil, and the oxygen of the air. If charred by burn- ing, or coated with pitch, coal tar, &c., the decomposition of the wood will be greatly retarded. An excellent mode of preserving wood is extensively used at present in Eng- land : it consists in placing the wood to be cuied in a com- mon boiler, which is then nearly filled with tar oil, and the air pumped out by means of exhausting air pumps : a fresh supply of oil is then forced into the boiler, by hydraulic pressure, and the whole allowed to remain for some hours. The effect produced is such as to render any kind of wood perfectly insensible to exposure, and free from the attacks of insects; iron boUs will not rust when driven into it. The expense of preparing the wood in England, is from 13 to.18 shillings per load. Pure woody fibre is found in the forms of the fibres of cotton, hemp, flax, and thus constitutes a most important material for the manufacture of textile fabrics. Bleaching consists in the GestructiOu of oils, resins and other matters whjcl< are associated with the woody fibre and discolour it. Woudy fibre may be converted into gum, sugar or starch, all of If': k 48 LECTURES ON AGRICULTURAL CHEMISTRIT. which bodies are identical in coraposilion, and may be said to consist of carbon and water. By a process requir- ing a little nicety in manipulation, it is changed intoa very explosive compound, known as gun cotton. Starch — This very important vegetable substance, is found in the seed and roots of all cultivated plants. Wheat Flour contains from 50 to 75 per cent. Barley Flour 65 to 70 do. li'ce 80 to 85 do. Indian Corn 75 to 80 do. l^otatoes 13 to 15 do. It is found also in the bark of many trees, especially in that of the willow and pine ; by a simple process it can be obtain- ed from shorts in large quantities : the shorts must be mixed with water, and allowed to remain in the vessel until the whole mass ferments and becomes sour, for the purpose of removing the gluten, which would otherwise retard the separation of the slarch. One of the first results of the germination of seeds is the conversion of their starch into sugar : which, being composed of carbon, oxygen, and hydrogen, serves as the food of the young plant for the formation of its first roots and leavec. The process of ger- mination is imitated in malting. The starch of the grain is converted into sugar, which, in the manufacture of beer breaks up into two new substances, carbonic acid, risino- in bubbles (froth) and alcohol. [Starch is completely insoluble in pure cold water; the roots of the maple, beech, &c., contain a substance (disastase) which possesses the property of rendering starch soluble in water. Buring the autumnal months, slarch is deposited in the wood through which the sap ascends. When spring commences, water is forced up through the roots and dissol- ves a portion of ihe substance (disastase) just alluded to, this again dissolves the starch the water meets with in its course, and converts it into sugar. The process is similar to that which takes place during the malting of barley.] Sugar.— Sugar is found in the juices of many vegetables, TRY. and may be ocess requir- anged in toa >n. substance, is Eints. er cent, do. do. do. do. ^iallyinthat in be obtain - ist be mixed sel until the 3 purpose of ) retard the suits of the r starch into xygen, and ilant for the cess of ger- )f the grain ture of beer acidj rising it', the roots e (disastase) :h soluble in deposited in Vhen spring s and dissol- t alluded to, i with in its is similar to arley.] v^egetables, LECTURES ON AGRICULTURAL CHEMISTRY. 49 particularly the sugar cane, beet roots, carroty birch, maple, &c. [Upwards of Ave hundred millions of pounds of cane su^ar were imported into the United Kingdom during the year 1838- /n the same period, France and Belgium manufac- tured from the beet toot not less than one hundred and forty- five millions of pounds. From the maple, in the year 1848, Canada obtained four millions of pounds. The quantity brought into the markets of the world— of sugar obtained from different vegetables, amounted twelve years ago, to the enormous number of If "3 millions of pounds.] In the manufacture of leet root sugar, the first operation consists in washing the roots, which is usually done by a rotatory movement upon a grating, in a shallow trough containing water ; they are next submitted to the grinding process of a rasp, consisting of a number of small saws, attached to adrum, having a rapid and uniform movement j when thus reduced to pulp, the semi-liquid mass is col- lected in bags and submitted to pressure ; the juice is then conveyed to the boiler ; before boiling it should be mixed with common slacked lime, in the ratio of 1 lb. of lime to 88 gallons of juice ; after boiling for a short time it should be again filtered through blanket stuff, and then concen- trated by boiling, in the usual manner of making maple sugar ; if a fine quaHty is required, after the second boiling has been carried on for some,— until the juice attains the consistency of thin syrup,— it is to be filtered through a layer of bone black or finely powdered charcoal, and then, concentraied by boiling until crystalization takes place. Oils and Fats.— More or less of these substances ar» found in all vegetables ; they consist of a solid and fluid portion, which can be separated, by first subjecting the oils or fats to cold, for the purpose of hardening them, and afterwards submitting them to pressure between folds of linen. The oil is absorbed by the linen, and may be obtained pure, by immersion in hot water. The solid por- tions of many oils and fats are identical iu composition, thus,, 50 LECTURES ON AGRICULTURAL CHEMISTRY. Ihe solid ingredient of olive oil, butter, the goose, and of man are alike. There are contained in 100 lbs. of White Mustard Seed 36 lbs. of Oil. Black Mustard Seed 15 lbs. do. Sunflower 15 lbs. do. Beech Nut 15-17 lbs. do. Nitrogen Compounds.— A large number of compounds containing nitrogen are found in vegetables. Many of these are identical in composition vf'iXh. the various parts of the animal frame . It is a remarkable fact that a substance, exactly like perfectly clean muscle, is found in the juices and seeds of vegetables, together with two other ingre- dients ; one similar to the white of an egg, the other to the curd of milk. They all contain sulphur, in the proportion of one part of sulphur for every twenty-five parts of nitro- gen. It is thus that the muscular matter of animals, and the chief portion of their blood (dissolved muscular matter) is furni ad by vegetables. A vegetable which does NOT CONTAIN ANY NITROGEN iNGREDIENTS, L.'NNOT ASSIST IN ADDING ONE PARTICLE OF MUSCLE TO THE ANIMAL FEEDING UPON IT. It will be hereafter shown that a daily waste takes place in the animal body, that worn-out and dead particles of flesh are removed in the urine. The places of these useless and rejected particles,can only be supplied by the nitrogen compounds contained in their food ; it therefore follows, that diet which does not contain nitrogen compounds can not serve as nutriment. An animal feeding on such diet would soon become wasted, feeble, and diseased. "A horse may be kept alive by feeding it with Potatoes, a food containing a very small quantity of nitrogen; but life thus supported is a gradual starvation : the animal increases neither in size nor strength, and sinks under every exer- tion." — Liebig. Subjoined is a table prepared by Professor Johnston, to illustrate the average composition and production of nutri- LJiCTURfiS ON AGRICULTURAL CHEMISTRY. 51 e, and of il. 0. 0. io. )mpounds Many of IS parts of ;ubstance, the juices ler ingre- her to the proportion J of nitro- mals, and ar matter) riCH DOES ASSIST IN L FEEDING ikes place les of flesh se useless le nitrogen re follows, ounds can 1 such diet ised. " A oes, a food Lit life thus increases very exer- ahHston, to n of nutri- tious matter per acre, for each of the usually cultivated crops. This table will be of interest to farmers, for the purpose of exhibiting the relative value of their crops, with reference to the feeding of cattle. Wheat .... Oats Barley .... Indian Corn Peas Potatoes. . . Turnips. . . Carrots. . . . Mead. Hay . Clover Hay. Drumhead ) Cabbage ) i Bush. 25 40 35 30 25 6 tons. 20 " 25 " ' li" i 2 " .20 •' lbs. 1,500 1,700 1,800 1,800 1,000 13,500 45,000 56,000 3,400 4,500 45,000 Woody Fibre. lbs. 225 240 270 270 130 675 1,350 1,6-0 1,0-iO 1,120 Sugar Starch. lbs. 825 850 1,030 900 800 1,620 4,50(k 5,600 1,360 1,800 Nitrog. \ Oils or Conip. Fats. lbs. 1 lbs. 150to220 30 to 60 230 1 95 21(5 45 216 90 to 170 380 45 300 45 540 130 840 200 aio 70 to 170 420 135to225 1,500 • • Saline [ngred. lbs. :«) 00 36 27 45 120 400 5«0 220 4()0 It has been shown by the most exact experiments, that such substances as starch, gum, sugar and oil, which do not contain nitrogen, cannot support animal life for any length of time. All substanc in cultivated crops containing nitrogen, are capable of assuming the form of animal flesh and blood, when used as food. The nutritious powers of vegetables are therefore dependent upon the amount of nitrogen they contain. It is to be observed, that the term ** nutritious powers " refers to the capability of the vege- table to supply the materials of flesh, blood, and bone, for young animals, or for the daily waste which takes place in adults, and has no allusion whatever to fat, which is either provided by the oil or fat of the food, or obtained from the decomposition of starch, sugar and woody fibre. In the above table we find, that 1,500 lbs. (25 bushels) of wheat contain from 150 to 220 lbs. of nitrogen compounds. If we take the lower calculation, we find that 100 lbs. contain 10 lbs. of nitrogen compounds. It appears also that 45,000 lbs. (20 tons) of turnips will contain 540 lbs. Oi tile same imporisni. suDsiancss. lUv lus. oi lurnips wiii contain therefore 1} lbs. of nutrUive matter. 100 lbs. of wheat are consequently more than eight times as valuable, for 62 LECTURES ON AGRICULTURAL CHEMISTRY. ! i the purpose of giving bone, muscle and blood to aniraals) as 100 lbs. of turnips. [In the juices of vegetables, nutritious substances, tegether with saline matter, are found in a dissolved state; when, by the slow process of evaporation, the water is expelled, these dissolved substances assuoie the solid form, they are then less easily acted upon by the organs of digestion. It is thus found in practice, that green fodder is more nutritious than in the dry state— in the green state than when made into hay. A French chemist found that 9 lbs. of green lucern were quite equal in foddering sheep to 3^^ of the same forage made into hay ; while he at the same time ascer* tained, that 9 lbs of green lucern would not on an average yield more than 23Llbs. of hay. These facts must therefore be borne in mind, in considering the following table by Bouissangault.] Comparative Table of the Value of different kinds of Food for €attle, Meadow Hay being taken as a standard. Name of Vegetable. Water in 1,000 lbs. Nitrogen in 100 lbs. of the Article, not dried. Ordinary Meadow Hay - ■ Ditto, fine quality - - - ■ Red Clover Hay, 2d year's gr. Red Clover, cut in flower, do. Wheat Straw - - - - - Gat Straw ------ Pea Straw ------ Vetches cut in flower, and cried into Hay - - - Drum Cabbage - - - - Field Beet or Mangel Wurtzel Carrots ------- Jerusalem Artichokes - - Potatoes ------- Whhe Peas (dry) - - - - Oats Field Beans . - - - - 110 140 101 750 200 210 85 110 923 878 876 792 659 86 208 79 Tiieoretlcal Value. lbs. 11 13 15 6 3 3 17 11 3 2 3 3i 3| 38 17 51 1000 980 750 3110 4000 3800 640 1010 4110 5480 3820 3482 3190 270 680 230 E.Yample. — In 1000 lbs. of meadow hay, there are con- tained 11 lbs. of nitrogen, and 110 lbs. of water. Its nutri- ¥. to animals;^ ;es, tegether e; when, by pelled, these ley are then 1. It is thus tritious than n made into green lucern of the same time ascer" n an average ust therefore ing table by '^ of Food for dard. in )f Theoretical le, Value. i. 1000 980 750 3110 4000 3800 640 1010 4110 5480 3820 3482 3190 270 680 230 lere are con- r. Its nutri- LECTURES ON AGRICULTURAL CHEMISTRY. 53 tious value as food is considered equal to 1000, which is taken as the standard of measurement. Red clover Iiay, second years' growth, contains in 1000 lbs. 15 lbs. of nitro- gen and 101 lbs. of water. It3 value as food is represented by 750 ; that is to say, 750 lbs. of red clover hay, second years' growth, afford as much nourishment as 1000 of mea- dov^ hay. Again :— 3190 lbs. of potatoes, containing 659 lbs. of water and 3'| of nitrogen, in 1000 lbs. of the root, ar& as nutritious as 1000 lbs. of meadow hay. Or if we feed an animal with 270 lbs. of peas, it will obtain as much nourishment from them, as from 3820 lbs. of carrots, or from 680 lbs. of oats, as from 3800 lbs. of oat straw, or from 1000 lbs. of meadow hay, as from 5480 lbs, of turnips. Let us suppose, for the sake of illustration, that the stock of hay runs short, and that instead of giving 20 lbs. to his horses per diem, the farmer can only afford 10. The prob- lem he has to solve is this: — What quantity of turnips, carrots, potatoes, mangel wurtzel, oats, or oat-straw, will afflird a substitute for 10 lbs. of hay, and keep the teams in good working condition. The table informs us that 10 lbs. of good hay, are as nutritious as 67 lbs. of turnips, 38 lbs. of carrots, 31 lbs. of potatoes, 54 lbs. of field beet, 6 lbs. of oats, or 38 lbs. of oat-straw. Now, there are many circumstances which interfere with the practical value of this table in its present condition. It contains within itself, however, the elements of much useful information. A working hoise requires more food than one which is idle ; a cow giving milk, more than one that is dry. Nutritious diet, packed in a comparatively small space, is essential to a working horse — otherwise he would not have time to consume his food. But a kind of diet, occupying a very small space, would not fill the stomach of the animal ; he would consequently feel hungry, although enough had been eaten to supply all the purposes of nutrition. Boussingault says, that a horse of the ordinary size, requires from 26 to 33 ibs. of ealid food, and the same quantity of water, in the twenty-four hours. If fed with oil-sed to the iet of straw ter. Their s, they are Htion, that hey regain Lttening an cleanliness, succulent 8, and good sr. the horse [ food they Ds. of hay, 1 be about ater which timate the le quantity Dns of hay, the winter, the food is aten by a (s than 120 ist suppose me 70 tons ng he will age age of er to be 6 decompose and gases, 20 tons of sight before of manure will serve which afe LECTURES ON AGRICULTURAL CHEMISTRY. 59 easily accessible. Good farm yard manure is taken as the standard of comparison, and its value represented by 100:— ^ Farm-yard manure , . , iqq jbg. Solid cow dung j25 Solid horse dung 73 Cow urine • 92 Horse urine 15 Sheep dung 3g Pigeon dung 5 Fresh bones • ■ri [Bousingault. From the above fable, we learn that 100 lbs. of good farm-yard manure may be expected to produce as much effect as 125 ibs. of cow dung, 73 lbs. of horse dung, 91 lbs. of cow urine, 16 lbs. of horse urine, &c. The purposes served by the constituents of food in the animal economy, constitute a subject of very interesting inquiry, and of some practical value to farmers in the management of stock. A brief view of the digestive and respiratory processes will enable us to trace the changes which take place in articles of food, before they minister to the well-being of animals. The digestive organs of the horse and the ox differ in many respects— the succes- sive steps, and the final result obtained, are the same in both instances. The food is introduced into the mouth, and having been well masticated, is conveyed into the stomach, where it is subjected to the dissolving influence of the gastric juice. It passes from the stomach into a large intestine. Into this intestine two liquids, called bile and pancreatic juice, are being continually poured from the liver, and pancreas or sweetbread. The food is now resolved into two portions, one of which is absorbed by a number of small vessels, which terminate in the inner coating of the intestines, the other is transmitted on- ward, and as residual matter, is carried on through the intestine, and finally given off as excrements; the fluid absorbed by the small vessels, is collected 60 LKCTUABS ON AGRICULTURAL CHEMISTRy ii ill a receptacle, situated behind the stomach, and near the back bone in man- From this receptacle, a tube or duct, conveys the prepared food to a vein, situated at the back of the neck. It here mixes with the blood and is taken directly to the heart, in the impure form of venous blood ; from the heart it is forced through a system of veins to the lungs, where it comes in contact with the oxygen of the air drawn into the lungs during the process of respira- tion. A considerable portion is now given off in the form of carbonic acid ^nd vapour of water through the mouth ; and what remains, constituting purified or arterial blood, goes back to the heart to be propelled to every portion of ihe body, supplying nutriment where it is required. In rumi- nating animals, we find four stomachs, all connected con- tinuously with the gullet or meat pipe. It is in the last of these stomachs that the process of digestion is carried on. The first is called the paunch, and prepares the food for rumination, by softening it. The food then passes into the second stomach, where it is rolled into pellets for the purpose of being returned to the mouth for remastication, (the cud). From the mouth it is conveyed directly into the third stomach, where it suffers a second softening process, after which it is propelled into the fourth stomach, where diges- tion is completed, as before described. The time which elapses before food is returned to suffer ramastication, is about 16 hours : very hard aad coarse diet, requires a much longer period for preparation in the paunch and second stomach. In breathing, the air is taken through the wind-pipe into the lungs, which are somewhat similar in structure to a very fine sponge, enclosed in a bag. The sides of vast numbers of the small cells of which the lungs are composed, consist chiefly of blood vessels, so that when impure or venous blood is forced from the heart to the lungs, it is diffused by means of the small blood vessels over a very large surface, and at the same time exposed to the air which is contained in the lungs, the sides of the blood vessels being so thin and porous, that although they are capable of retaining liquid ■ ich, and ptacle, a , situated ^lood and 3f venous I of veins )xygen of f respi ra- the form } mouth ; lal blood, tionofihe In rumi- cted con- le last of irried on. food for 3 into the i purpose the cud), the third ess, after sre diges- ne which cation, is 3S a much id second ough the it similar 1 a bag. of which i vessels, led from is of the !, and at led in the thin and ng liquid LECTURES ON AGRICULTURAL CHEMISTRY. 61 blood, they cannot oppose the passage of oxygen and carbonic acid. When an inspiration takes place the lungs are filled with air, a portion of its oxygen passes through the sides of the minute blood vessels surrounding the air cells, and part unites with the carbon and hydrogen of the venous or impure blood, which is given off again in the form of carbonic acid and water, the other portion is absorbed by the blood, and conveyed to every part of the system. We here observe a great distinction between the respiration of plants and animals. Vegetables absorb CARBONIC acid, AND DECOMPOSE IT IN THEIR LUNGS— THE LEAVES ; ASSIMILATING THE CARBON AND EMITTING THE OXY- GEN J Animals absorb oxygen, and compose carbonic and WATER IN THEIR LUNGS, GIVING THEM OFF WITH EACH EXPI- RATION. The wisdom and beauty of this arrangement will be appreciated, upon an examination of the effects which would be produced upon air, were the results of animal respiration to remain unchanged. One cubic foot of car- bonic acid in ten cubic feet of air, renders it unfit for the sup- port of animal life, a far less quantity is highly prejudicial and oppressive. The quantity of Carbon consumed daily by the inhabitants of Canada (780,000)amount8 at the lowest average to 200,0001bs., producing 700,000 lbs. of carbonic acid ; other breathing animals, stock, &c., consume about five times as much. In one year by respiration alone, the enormous quantity of 438,000,000 lbs. of solid carbon is con- verted mto carbonic acid and given off into the air. This supply of carbon is obtained from the food consumed, and serves to support animal heat. The annual production of carbonic acid by the inhabitants of the world is estimated at 156,000 tons, formed from 42,000,000 tons of carbon. If to this we add that which is produced by other breath- ing animals, by the decay of vegetable matter, and by burning bodies, we arrive at numbers absolutely over- whelming. Vegetables feed upon this result of animal respifuiiori ; they purify the air of a noxious gas, which 18 to them, as necessary for their growth, as the oxygen, which they return in equal volume to the carbonic acid «t 'I' a 63 LECTURES ON AGRICULTURAL CHEMISTRY. i'i ' nn absorbed, is essential to the preservation and well- being of animals. When oxygen combines with carbon, or with hydrogen, heat is liberated, it is thus, that the union which takes place in the lungs, gives rise to animal heat, preserving a uniform temperature of the blood under all circumstances of health. A horse consumes daily about four pounds of carbon, that is to say, about four pounds of carbon are daily obtained from the food and dis- solved in the blood, these, combining with oxygen during respiration, go off in the form of carbonic acid. About ten ounces are consumed in the lungs of a man daily, the carbon must necssarily be supplied from the food ; the starch, gum, woody fibre, sugar and oil, or fat, furnish this carbon to herbivorous animals, the fat and flesh of their food, to carnivorous animals, and their own fat and flesh, to starving animals. We are now enabled to trace with greater accuracy, the purposes served by food in animals. An ox, we will suppose, consumes a quantity of food, equal in nutritious qualities to 401bs. of hay ; 401bs of hay are composed of— Water • • • • . . . • » 4 lbs. Woody Fibre 12 '« Sugar and Starch 15| *^ Nitrogen Compounds •••••••• 4 ** Oilorfat U " Saline Ingredients 2J " 40 lbs. The water and undissolved substances are ejected in the excrements ; the dissolved sugar, starch and woody fibre serve to support respiration, they are given off in the form of carbonic acid and vapour of water, by the mouth and skin, (perspiration). In a state of repose, a portion of the starch or sugar is converted into fat. The nitrogen com- pounds are employed to form additional muscle or flesh. The worn-out particles of flesh are given off from the body in the urine. The oils and fat of the food serve two pur- LECTURES ON AGRICULTURAL CHEMISTRY. $9 poses,— Ist. That of supporting respiration and the tem- perature of the blood-2nd. That of assuming the form of animal fat. The saline ingredients replace the daily Joss which takes place in the bones and juices of the flesh. The rejected substances being found in the urine. [The production and maintenance of animal heat, involves many interesting considerations with reference to food The temperature of the blood in man is very uniform. In a slate of health and repose, it is the same, whether tested in the cold of an Arctic winter, or in the sultry climate of the torrid zone. Two processes combine to produce this result -respiration and perspiration. The temperature of the blood in birds, IS from 104 to 107 degrees; of serpents, from 50 to 60 degrees j of fishes, from 2 to 4 degrees above that of the tned.um in which they live. In all cases the production of heat IS connected with the absorbtion of oxygen, and its union with carbon and hydrogen. Heat exists in two states-free or sensible, and hidden or latent. Sensible heat 18 that amount of temperature which can be measured by a thermometer; latent heat is that which is intimately asso- ciated or combined with the particles of bodies in which it resides. A change in form frequently causes bodies to give out latent heat, or to absorb it from surrounding bodies. When air is compressed into a small space, it gives out a large quantity of heat. When cannon are bored, the boring instrument frequently loses its temper by the great heat evolved. A blacksmith hammering cold iron for a few suc- cessive mmutes can make it red-hot. All these facts furnish us with Illustrations of the conversion of latent heat into sensible heat. If equal quantities of cold water and sul- phuric acid be mixed together, the temperature rises sud- denly above that of boiling water. When salt and snow are mixed together, the temperature of the mixture falls thirty degrees below the freezing point. In the former case, heat IS evolved; in the latter, it is absorbed. The former illus- trates the mode in which heat is liberated, when during the process of respiration, the oxygen of air combines with the carbon and hydrogen of the food dissolved in the hlood. The latter exhibits the manner in which heat is absorbed from the body, when its moisture goes off in the form of insensible perspiration. When an animal is suffering from fever, the 64 LECTURES ON AGRICULTURAL CHEMISTRY. temperature of the blood rises, because the superabundant heat evolved is not absorbed in the change of water into the vapour of water. It has been remarked, that fat, starch, gum, sugar and woody fibre, supply the carbon and hydrogen for the purposes of respiration. It is evident that a large supply of carbon and hydrogen is required by the inhabitants of a frigid climate, where the quantity of oxygen taken into the lungs and absorbed by the blood during each respiration, is probably greater than in the temperate or loirid zones. We discover a beautiful connection between the quantity of oxygen absorbed and the nature of the food consumed. The Esquimanxdevour large quantities of blubber and oil, sub- stances consisting almost altogelh(;r of carbon and hydrogen. The natural heat of the body is sustained by such diet. The lumber-men on the Ottawa complain of the leanness of the pork raised on the banks of the river. The fat pork of Ohio finds a profitable market for the winter consumption of men, exposed to all the severities of a climate where the thermometer falls twenty degrees below zero. According to Thomson, the blood in an adult weighs about 26 lbs. avoir- dupois; it circulates through the body in 3^3_ minutes. During each inspiration, 16 cubic inches of air enter the lungs, and |^, or nearly one-half of a pound of blood is ex- posed to its' action. During every inspiration, i^, or rather more than one-half of a cubic inch of oxygen is absorbed by the blood ; and 4| cubic inches of oxygen, combining with carbon or hydrogen in the animal system, evolve one degree of heat; during every inspiration, therefore, the oxygen ab- sorbed, evolves about one-sixth of a degree of heat, so that one degree of heat is evolved in six inspirations. Hence, in a day of twenty-four hours, the heat evolved by the union of the oxygen of air with the carbon and hydrogen of the food, ■would heat a middle-sited man thirty-three degrees. Hy- bernating animals breathe very slowly, the heat of the body is sustained by the union of the oxygen of the atmosphere with the carbon and hydrogen of their fat.] Diseases of Vegetables (Fungals, Insects.)— Culti- vated crops in Canada are liable lonnany diseases produced by microscopic vegetables and the depredations of insects. Among the former, the most prevalent and destructive, are lY. perabundant 'ater into the t fat, starch, ind hydrogen that a large le inhabitants en taken into h respiration, loirid zones, le quantity of isumed. The and oil,sub- ind hydrogen, ch diet. The 'aiiness of the i fat pork of [jtisumptionof lie where the According to 26 lbs. avoir- 3 3 minutes, air enter the ■ blood is ex- 13, or rather s absorbed by mbining with Ive one degree je oxygen ab- f heat, so that ions. Hence, i by the union ;en of the food, iegrees. Hy- ;at of the body he atmosphere 3TS.) — Culti- ises produced ms of insects, jstruclive, are LECTURES ON AGRICULTURAL CHEMISTRY. 65 Rust, Mildew, and Smut. Among the latter, the Hessian- fly, the Wheat-fly, the Turnip-fly, and the Wire-worm. Rust is a fungus (a minute vegetable) of exceedingly rapid growth, and fruitful character. It is not confined to cultivated grain-growing crops. No vegetable, indeed, is free from lia- bility to its attacks. The general appearance of Rust on wheat is entirely dependent on the state of the atmosphere. During the spring, summer, autumnal, and even winter months, the air contains multitudes of the germs or seeds of small mic- roscopic plants, which a carried about by winds, and be' ■ 1 to grow whenever they alight upon a suitable soil. T; • .escent of rain or mist brings down myriads of these seeds, invisible to the naked eye, which fall upon the leaves and stai^vS, or pass into the system of plants with the water which enters at the roots. If the plants are in a state of perfect health, the vitality (life) of the sap prevents their germination and growth ; if the motion of the sap is retarded for any length of time, the pores on the leaves and stem become filled with stagnated and consequently life- less sap. When the rust seeds reach these pores, they germinate, throwing out a number of stalks ; at the end of each is a ball, which rapidly ripens, and bursting, scat- ters around a dust composed of particlec so extremely minute, that they can only be seen by p. powerful micro- scope, when a number are aggregated together. Each little particle is capable, under proper circumstances, of producing a new plant. There are many species of Rust plants ; the most common and destructive are the orange and the red. When found to a large extent on grain-grow- ing crops, they absorb the nourishment of the plants, and frequently destroy the most promising crops. it has been already remarked that the continuous jiow of the sap in vegetables is mainly due to the pressure of the atmosphere, caused by the evaporation of the water of the sap from the surfaces of the leaves and stalks. If evaporation is suppressed, by any external causes, the sap ceases to flow ; it accumulates by capillary attraction in the vessels of the plant, and stagnates at the surfaces of the G 66 LECTURES CN AGRICULTURAL CHEMISTRY, u- ^• stalk and leaves, affording a suitable soil for the growth of raicrosoopic fungi. [The small mouths or pores through which evaporation of moisture takes place, are found in all parts of healthy plants except the roots. When seen through a microscope, they preseat the appearance of small slits, communicating with the vessels of the bark or rind. Their number on some species of vegetables is very great. On I square inch of the leaf of the common clove pink, there are no less than 38,500 on the upper and under surfaces} on the upper surface of the vine leaf, I3,60t), and on the under side of the common lilac, there are 160,000 to the square inch. In a very moist state of the atmosphere, the minute vessels connected with these pores become filled with sap, the opening or pore is distended, but evaporation does not take place, because the moist air can receive no more vapour of water. It is easy to understand how these minute vessels, with distended mouths, filled with motionless sap, form a secure and favour- able resting place for the seeds of microscopic fungi.] Now, the evaporation from the surfaces of vegetables ceases when the air is loaded with moisture, as after rain, in fogs, and in damp weather generally. Air, it will be remembered, can only contain a certain quantity of mois- ture, dependent upon its temperature. When there is but little difference between the warmth of the air in the day and night times, as in damp sultry weather in June, July, and August, the quantity of moisture suspended in air, is nearly uniform, and evaporation ceases as long as that uni- formity continues. Rust is most frequent upon rank and luxuriant crops, as might be expected from Iheir great evaporating surface. Since the prevalence of rust is entirely dependent upon the condition of the atmosphere, and the more or less lux- uriant growth of the vegetable, the attention of the farmer must be directed to two circumstances, in order to lessen the effects liable to be produced by these destructive fungi. Ist* To the ^^sriod of the season in which the occurrence of damp and sultry weather is to be looked for. 2nd. To the habit of the plant. If Rust strike the plant before the seed LECTURES ON AGRICULTURAL CHEMISTRY. 67 growth of (Oration of Ithy plants icope, they ating witli ir on some inch of the han 38,500 surface of le common very moist lected with or pore is jecause the It is easy 1 distended and favour- ing'-] vegetables after rain, it will be ^ of mois- lere is but in the day une, July, 1 in air, is s that uni- 1 rank and Iheir great ident upon ir less lux- the farmer X to lessen stive fungi. ?urr6nce of nd. To the re the seed begins to form, the most disastrous effects may be pro- . duced : if after the seed has been formed, yet before it is ripe, little apprehension need be entertained for the safety of the crop. Now, experience shows, that in the climate of Canada the condition of the atmosphere is very seldom such as to favour the germination of the seed of Rust, before the last week in June ; if, therefore, at that period, the wheal plant is so far advanced as to be beyond the influ- ence of Rust, as regards the formation of the grain, the danger is provided for. [Wheat was gristed at Merrickville, on the Rideau Canal on the 19lh of July, in 1849.] * The precautions to be taken against Rust, happily con- stitute a necessary step in good husbandry— they are drain- ing and liming; both operations accelerate the growth and ripening of wheat, and the strength of the straw. There is no question that by a judicious introduction of these artifices, the destructive effects of Rust on wheat, would be very much diminished, if not in many seasons entirely prevented. MiLDffiw is occasioned by microscopic fungi, which attacks all kinds of vegetables, under circumstances fa- vourable for their production. The stalk of wheat seems to be particularly liable to their depredations. Numerous species are known to infest the grain-growing crops. Their growth is dependent upon the moist state of the atmosphere, and like the germs of Rust, their seeds are constantly floating about the atmosphere, and driven to and fro by winds. The stalks and leaves of healthy plants are pro- vided with a coating of vegetable wax, which prevents the rain from wetting their surfaces. We discover this wax (bloom) on peaches, grapes, plums, the stalks of wheat, oats, rye, on the leaves of the nasturtium, &c. As long as the wax remains, there is little danger of Mildew, or Rust, but in moist weather, with a loaded atmosphere, or under other circumstances unfavourable to the production of a healthy plant, wax is not formed. The remedy against 68 LECTURES ON AGRICULTUEAL CHEMISTRY. :> ■'^' ''■\i the attacks of these fungi ia the production of a healthy plant — the remedy for Rust, liming and draining — offers the only available means to the Canadian far-^ er. [It will be observed that in healthy plants, the dew is ibund in the morning in pearly drops, either upon the surface of the leaf or round about its edges. But dew falls equally upon every portion of the upper surface of a leaf, on cloudless nights j it can not wet the leaves of healthy plants on account of the delicate covering of vegetable wax. Th« small particles of moisture attract each other, and form a drop. When the leaf or stalk is wetted all over, the forma- tion of wax has not recently taken place, and the plant is liable to be struck with Mildew, whose minute seeds find on the wetted surface of the stalk, a soil favourable for their growth. If dry weather succeeds, no disastrous result* need be apprehended : in a continuance of moist and heavy weather, much harm may be done.] Smut. — Smut presents us with another form in which minute parasitical plants prey upon vegetables of larger growth. It is usually found to affect grains of wh.eat. There are two varieties of this noxious fungus. One not discoverable until the husk is opened, when it appears in the form of a black powder, having a very vlisagreeable and characteristic smell. The other variety shows itself on the outside of the grain. Farmers possess a remedy for both, which consists in steeping the seed in some liquid which will destroy the vegetative powers of the fungal seeds. These seeds are so minute, that a grain of smutty wheat will infect the contents of a bushel ; and wheat placed in bags which have at one time held smuUy wheat, will cer- tainly be infected. The best sample for seed should always be steeped before sowing. Various liquids are selected for that purpose — stale urine, brine, and blue vitriol dissolved in water. The last is perhaps the best. Five pounds of blue vitriol (sulphate of copper) are dis- solved in ten gallons of boiling water. When the solution cools, three bushels of wheat may soak in it for six hours, the light floating grains being skimmed off. The wheat shou dried tion c whea smut. Po-] malac in pro cherai prima atmos the pn knowi: terapoi water i moistu As i] plant { thrown soil for water e the root have fr( with n accelert vegetab All re potato, J is of rec( as the p( founded surface i success. plant has repeating ripen. The } Hessian f healthy ffers the is ibund urface of equally leaf, on ly plants X. The a form a e forma- ! plant is ?eds find for their j results id heavy I which f larger wh.eat. One not pears in ireeable W6 itself remedy le liquid al seeds, y wheat aced in ,vill cer- , should jids are nd blue ;he best, are dis- solution X hours, le wheat LECTURES ON AGRICULTURAL CHEMISTRV. 69 Should then be drained through baskets or sieves, and t1 of hi ^"^ ' , '^\" ^^P^""^ '' ^^"^^- The same solu. ^on of blue vuriol will serve to steep twenty bushels of wheal, and effectually provide against the appearance of Potato DisEASE.-^The universal prevalence of this malady seems to ,mply the existence of a universal aln ^he'^sts^^:' "• J'' '''^'' ''''^ investigations olr; primary cause, which is to be found in the state of the temTo ' P°^^^^^'«^^«« wears to be occasioned by a ternporary incapacity of the atmosphere to receive [he wat. of evaporation from the leave's, when loadTd .v^h As in the case of rust on wheat, the vessels of the potato plant are then filled with stagnant sap, which is rapidt hrown into a state of decomposttion, andV s ^ su f b e 01 for the growth of fungi taken into its system Cthe water entering at the roots. Diseased potaLs, although the root may appear to be perfectly sound on the out "de have frequently, when cut open, exhibited a cavitTfilled wi h m.,ute vegetable forms. The disease is Lady ace erated by small insects, which habitually feed upon veg tables, such as the far-famed Aphis VastaL, &c. ' pott and'tWe'" "'^'"^ ^' ^'^ ^^'"^ ^^^^ - ^^e potato, and there is no reason to suppose that the maladv as the potato has been used as an article of food. A cure u cess I con T'^ ^' '"" '^^P^^' ^" ""^'^'^y -i^^ success. It consists m mowing off the top leaves when the repeating the operation every five weeks, until the tubers g2 70' LECTURES ON AGRICULTURAL CHJEMISTRY. was supposed to have been introduced into this Continent. Popular opinion ascribed its introduction to the straw brought over by the Hessian troops, in the year 1776. The fly appears in the fall ; the female then lays her eggs, from one to eight in number, between the leaf and stalk of the wheat plant, immediately above the first joint. The worms eat into the stem, and frequently cause it to break. They winter in the torpid state, and subsist during the spring months upon the sap of the plant. They then pass into the chrysalis state, and in autumn assume the form of the fly. It seems to be well established that a strong wheat plant will support without material injury to itself, the growth of two or three worms,while a weak and sickly plant would fail under the increased tax upon its energies. It is the frequent custom, where the Hessian fly prevails, to grow wheat after wheat. In ploughing the stubble into the ground, and then by a second ploughing preparing it for the seed, the chrysalis is first buried, and afterwards turned up to the sur- face, or sufficiently near the surface, to permit the chrysalis to assume the fly state during the growth of the next crop of fall wheat. The females deposit their eggs upon the leaves of the young plants, which growing upon a soil ex- hausted by many succeeding crops, can not sustain the assaults of the newly-hatched worm. If a proper system of rotation of crops were introduced upon a farm where the Hessian fly prevails, the act of ploughing very early in the autumn, and allowing the land to remain in the rough state until the spring operations for green crops commenced, would bury the chrysalis for a length of time, and effectually destroy it. Burning the stubble is also found advantageous in checking the ravages of this insect : the crysalis being lodged immediately above the first joint, is consumed by the tire passing over the field. The Hossian fly is very local in its habits : very wet weather after harvest destroys multitudes of these insects in their cbry -'^is state. !]Jontinent. the straw ear 1776. her eggs, id stalk of •int. The : to break, uring the then pass le form of ng wheat itself, the ckly plant ;ies. It is lis, to grow he ground, e seed, the to the sur- 3 chrysalis ext crop of upon the a soil ex- ustain the )er system where the arly in the rough state mmenced, effectually ^antageous ialis being sumed by very wet 3se insects L£CTUR£S ON AGRICULTURAL CHEMISTRY. 71 The Wheat FLY.-(Cecidomyia Tritici.)--A small orange-coloured fly which lays its eggs in the ear of wheat dunng the ^ast week of June or the first week of July, The eggs are hatched in six or seven days : the insect exi. .in cue worm slate for about three weeks, feeding upon the substance of the grain ; it then assumes the forrn ol^a mmute chrysalis, after which it passes into that of the The great object of the farmer in providing against the depredations of the wheat-fly, is to have his^heat so far advanced, that when the fly appears, and lays its eggs, the newy^hatched worms may not be able to penetr'ate' the tiuslc. The means which suggest themselves for eff-ectinjr so desa-able a result are to favour the early maturity of tht plant by limmg, draining, and a careful selection of seed WiRE-WoRM.-(Elater Striatus.)-The grub of a beetle, which may be seen in localities where the wire-worm abounds, on the leaves of wheat, &c. The beetle folds Its legs on the approach of an enemy, and falls to the ground. The wire-worm feeds on the under-ground stems or young plants, and frequently destroys them. Buckwheat is highly recommended as destructive to the wire-worm. A clean summer fallow is also instrumental m starymg them out. It is very probable that the ammo- niacal hquor of the gas works would be found a very useful agent in destroying these pests. TuRNrp-FLY.-(Haltica Nemorum.)-Thisinsect (beetle) IS one of the most formidable enemies to the turnip crop It appears and continues during the whole of spring and summer. Danger is only to be apprehended in the early stages of the turnip's growth, before the third and fourth leaves have been developed. Every endeavour shou-ld be made to force on the young plants, by means of manure, itie liquid portion of stable manure is most favourable to their rapid growth. To drive away the fly, many farm- ens sprinkle their young turnip crops with soot ; urine and the ammoniacal liquor of the gas works would be TO LECTURES ON AGRICULTURAL CHEMISTRy] » I tef found equally efficient in preserving the plant from its depredations. The turnip-fly is seldom seen during the day time ; it then occupies the under surface of the leaf. When the sun has set, the fly may be found in abundance on the upper surface. The sense of smell of this beetle is remarkably acute ; it can discern the odour of the turnip — its favourite food — at great distances. Hence the reason why the odour of ammonia — the characteristic odour of soot, urine, and the ammoniacal liquor of the gas works, is so repugnant to the delicate sense of smell possessed by this minute and destructive beetle. Weeds of Agriculture.— Chess (Bromus Secalinus). — The appearance of this common and troublesome weed is the source of more dispute than any subject which comes within the province of the agriculturist to investigate. Tlie most erroneous impressions respecting its origin, prevail among farmers throughout the whole of Canada and the neighbouring. States. Popular opinion ascribes to what is termed diseased wheat, or winter-killed wheat, the pro- perty of transmutation into chess ; and this opinion is pro- mulgated and sustained in the most positive manner, upon the deceptive and erring evidence of individual observa- tion, without the slightest reference to the botanical dis- tinctions which ra. rk wheat and chess. Chess is a very hardy and fruitful kind of grass, called in Britain the soft brome grass. Its seeds possess the power of lying dormant in the soil for many years, without losing their vitality. There are many modes of account- ing for the presence of this weed among wheat and other crops. It is sown with the wheat, or its seeds, lying dor- mant in the soil, have their vitality called into action when the soil is ploughed up and exposed to light, air, and warmth, or it is conveyed by floods, or carried by winds, or carted on to the soil with manure. The reason why chess surplanis wheat, and grows with luxuriance. n n nn_ drained -^oils, and especially on those parts where water is m LECTURES ON AORICULTUItAL CHEMISTRy. 73 permitted to lodge, the wheat plant is winter-killed or thrown out ; ehess, being a more hardy vegetable than wheat, survives the winter, and produces a most abundant crop of seed. Good surface draining, the use of clean seed, and a rota- tion of crops, will soon extirpate chess, and effectually remove the impression of an imaginary transmutation. We might, with as much reason suppose that the oak was capable of changing into the pine, the pine into the birch, the beech and maple into the poplar, the grass of the prai- ries into white clover. All these apparent transmutations do take place, but the reason is to be found in the death of one kind of vegetable preparing the soil for, or permit- ting the growth of, those vegetables whose seeds are lying dormant in the soil. Canada Thistlj:— (Cnicus Arvensis.)— Throughout the length and breadth of Canada this weed may be met with in the greatest abundance. During the present year cer- tainly not less than one-eighth of the wheat crop of the country has been '« thrust out of life" by the Canada thistle. No one travelling in the months of July and August on the shores of lake Ontario, from Cojborne to Pickering, could have failed to observe here and there a field of wheat almost free from the presence of this noxious weed, and yet surrounded by wheat fields on neigbouring farms, purple with their blossoms, presenting a forcible illustra- tion of the good effect of careful farming. The only sure " cure" for Canada thistle is a rotation of crops in which clover forms a prominent element : two years of a good clover lay will destroy the Canada thistle root and branch. Many other weeds call for the care and perseverance of the farmer in their destruction,— none, however, appear to prevail so generally as chess and the Canada thistle : careful cuhivation, with draining, an occasional summer fallow, and a judicious rotation of crops, will check tha production of these enemies to successful agriculture. 74 LFXTUR£S OK AGRICULTURAL CHEM); TRY. From the foregoing brief exposition of the principles of AgricuhurEi Science, it will appear, that husbandry in all its branches affords a wide and interesting field for intel- ligent observation. The most insignificant operation of practical agriculture presents material for refiectior. and minute enquiry. The farmer may engage in a routine of manual labour, established by experience, and requiring the mere exertion of muscle, with results satisfactory to himself; he may also associate with bodily exertion the higher exercise of his mental gifts, promising greater remuneration and better acknowledgement of his privileges as an intelligent member of society. Let us, in concluding, take a cursory view of the several conditions of vegetable life and health, which unite with the operations of husbandry in establishing the results of which the agriculturist is in quest. He can exercise no control whatever over the air plants and animals breathe ; and yet many of the most terrible visitations he fears are dependent upon the condition of air. Upon its state, rests the appearance of Eust, Mildew and many parasitical insects, all of which lead most effectually to destroy the anticipated results of his industry. The condition of per- fect humidity in a warm atmosphere, at certain seasons of the year, will suffice to cause his crops to be clothed with the most destructive of microscopic plants. This humid state may occur in March, April, September, &c., without being the cause of prejudicial results, if it happen in May or June great danger is to be apprehended. From obser- vation, we learn, that coarse luxuriant wheat grown on rich moist soils is very liable to be struck with Rust or Mildew. This is often the case on fertile river bottoms— on the rich bottoms of the Thames &c. It is also remarked that in late seasons Rust is most destructive ; that the time when it strikes the plant is generally in the month of June — if late in that month, the straw only suffers, if early, straw and grain are both lost. Now, as the humidity of the atmosphere is beyond the control of man, he must adapt his labours to the circumstances of the climate. He bh ,y. rinciples of ndry in all d for intel- peration of ectior and a routine of 1 requiring isfaclory to xertion the ng greater 5 privileges the several unite with e results of 3xercise no Is breathe ; e fears are state, rests parasitical destroy the tion of per- 1 seasons of lothed with rhis humid tc, without )en in May i^roni obser- t grown on ^ith Rust or r bottoms— remarked lat the time nth of June •s, if early, lumidity of 1, he must imate. He f.ECTURES ON AGRICULTURAL CHEMISTRY. 75 must endeavour to have an early crop-with a thin, strong, flinty stem. It has been before remarked, that the means for ensuring the ripening of wheat, from two to three weeks earher than the average period, are to be found in draining and limmg,both operations, besides ensuring early maturity improve the sample and strengthen the straw. ' The agriculturist is dependent upon other meteorological phenomena, with the due occurrence of which, the health of his crops is most intimately associated ; upon rain and ternperature. He has occasionally to deplore the occurrence oi dry weather in the spring, and of wet weather in the- harvest time. The seasons of the present year were par- ticularly distinguished by these drawbacks. Those arti- fices which are commended by experience and suggested by the science of agriculture, present him with the only means capable of lessening the amount of evil ilowincr from such casualties. On drained soils, the roots of cult tivated crops descend deep, and find in dry weather a supply of moisture. Their early maturity saves them from that destruction which is always more or less to be la- mented in wet harvests. In backward and wet seasons the grain crops lose many days of warm spring weather on undramed soils, before they commence growing. The heat of the sun must first drive oflf the superfluous water which is lodged in every hollow and depression, although It may not be visible at a superficial view. Cold raina mvariabiy check the growth of vegetables, and a cold watery bottom (pan) to the soil in which the roofs repose, can never be expected to favour the growth of a healthy plant. The appearance of yellow leaves upon wheat in the spring, is the result of disease, and may be produced by excess of moisture or by excess of drought. It has been already shown, underthe head of draining, that that opera- tion greatly increases the temperature of the soil, by allowing warm air to circulate through its pores. Vegeta- "" •-• .".ttnj liiiivxs v.iicii iiic sunace or me soil is exposed to a great increase of temperature; it is when heat descends to the roots that they feel its invigorating m i 41 ¥1 it 76 LECTURES ON AGRICULTURAL CHEMISTRY. inflaence. The warm sun of April and May cannot pro- duce the same effects in vegetable growth, on a heavy clay soil, or even on a vegetable mould, aa upon one of a light, sandy, porous character. We have seen that uncultivated vegetables derive a very larce portion of their substance from the admixtures of air, carbonic acid and ammonia. Cultivated crops obtam these elements of food, not only from air and decaying vegetable mat.er, but also from manures. That department of hus- bandry which involves the production, preservation and applicalion of manure, necessarily calls for the careful attention of the agriculturist. Chemistry and experience both set their mark upon farm-yard manure, as constituting the most useful means of improving the fertility of the soil ; and of farm-yard manure, the liquid portion, the urine ot animals, is unquestionably the most valuable. The solu- tion of mineral ingredients in water, previously to their entrance into the roots and system of vegetables, directs particular observation to the composition -of soils, and the properties possessed by their component parts. It appears that the same kind of vegetable growing for a succession of years upon the same soil, abstracts certain soluble mineral ingredients, faster than the great agerrts, heat, air and moisture, can create a supply from the vast store which exists in an insoluble state in the soil. Hence the vegeta- ble cultivated under such circumstances, becomes deterio- rated in quality, and approaches nearer and nearer to that primitive, wild state, in which its kind existed before cui- tivation produced the wmidrous development of its organs which fit it for the food of m«n. (Witness the wild potato, the apple, the plum, wild f ice, wild wheat, wild oats, &c.> To avoid this deterioration, experience and agricultural! chemistry point to rotation of crops, fallowing under certam circumstances, farm-yard manure, mineral manures, as lime, wood-ashes, gypsum, &c. The growth of weeds among cultivated crops, la an increasing and serious evil. Nourishment which, in th^ir absence, would fi'od its way into farming pcoxiuce, feeds LECTURES ON AOHICULTURAL CHEMISTRY. 77 not pro- ivy clay a light, e a very 38 of air, lin these egetable t of hus- Ltion and 3 careful perience nstituting ■ the soil ; I urine of rhe solu- f to their 38, directs I, and the It appears icession of le mineral t, air and Lore which he vegeta- es deterio- rer to that Defore cul- its organs vild potato, 1 oats, &c.> igricultural ider certair* lanures,. 'a& thenn into a luxuriant and fruitful habit, which at once sup- presses the growth, diminishes the yield, and impairs the saiv pie of those vegetables for whose benefit all the artifices ■ ^ husbandry are expressly practiced. The use of clean eed, the practice of clean cultivation, of draining, and of tation of crops, can alone eradicate those hurtful vegeta- bles, which, from past neglect, seem now to be successfully ytruggling to gain exclusive possession of many fertile tracts of country. The cold of winter is sometimes so severe, that the wheat plant loses its vitality, even on drained soils. This happens when there is a deficiency of snow. A covering of snow prevents radiation of heat from the earth into the clear expanse above. The temperature of two plants, one exposed to air on a fine clear cold night, the other covered with a very loose coating of straw, differs by many degrees. A few loads of long dung or litter, strewed over the wheat in the month of December, will retard radiation, and pre- vent the temperature of wheat plants from sinking so low during severe winter nights, as to endanger their vitality. Lastly, the economy of a farm cannot in general be pre- served without a due proportion of stock for the production of manure, and the preservation of a judicious rotation of crops. rops, ifl an ch, ill their iace^ feeds '%,) . I •'I!'! i 'J APPENDIX. Note 1.— A simple substance is one from which nothing else but itself can be obtained— as lead, iro.i, gold, oxygen, carbon* &c. Sugar, water, milk, are compound bodies : they consist of two or more simple substances combined together. Whenever a compound body is broken up into other bodies, or into the simple substances of which it is formed, it is said to be decom- posed. Thus when water is decomposed, it is converted into oxygen and hydrogen gases. When wood is burnt, it is almost entirely converted into carbonic acid, water, and ammonia. Note 2.— Nitrogen. Place a short candle in a basin, pour some lime water (see note 6) round about the candle, until it rises within an inch of the wick. Take an empty bottle, with a wide mouth, light the candle, and carefully put the inverted bottle over it, until it dips half an inch below the surface of the water. In a few seconds the candle will go out, having con- sumed all the oxygen. The water will rise in the bottle when it cools. Cork under water, and shake the bottle. The carbonic acid produced by the burning candle, will combine with dis- solved lime, and render the water milk-white. Nitrogen, nearly pure, remains in the form of an invisible gas. Note 3.— Oxygen.— Fill a glass with water : invert it, and let it rest upon a saucer filled with the same fluid. (This may be effected in a common bucket, by putting both glass and saucer under water ; having filled the glass, let it rest on the saucer, and lift both out.) Place some green leaves under the glass and expose them to the direct light of the sun ; bubbles of gas will soon be seen to form upon the surfaces of the leaves. The gas is pure oxygen. It is obtained from the decomposition of car- bonic acid by the (eaves, under the influence of the sun's rays. The bubbles will cease to be formed when all the carbonic acid contained in the leaves and water is decomposed. Put some bits of chalk or limestone and a few drops of vinegar into the water; the operation will be renewed; carbonic acid being liberated from the chalk. 1.1 80 LECTURES ON AGRICULTURAL CHEMISTRY. 1 m Note 4.— ^/nmo/ua.— Put a small quantity of spirit of liarts- horn (ammonia) into a spoon, and hold it over the candle ; at the same time, heal some spirit of salt (muriatic acid) in another spoon. and blow the fames of ammonia in the direction of the spoon containing spirit of salt. A dense white cloud will be formed immediately. Muriatic acid gas combines with ammonia, and forms the solid sal-ammoniac. Pour some spirit of salt into a spoon, warm it over the candlti or fire, and take it into a close stable : white fumes of sal-am- moniac will be formed. The ammonia in the stable proceeds from decomposing urine. Note b.— Carbonic Acid.— Vonr strong vinegar upon some pieces of chalk or limestone. Violent effervescence will be observed, caused by the liberation of carbonic acid from its union with the lime of the chalk cr limestone. If the chalk is at the bottom of a deep glass vessel, heavy carbonic acid will displace the air, and a lighted piece of paper being introduced, will be immediately extinguished. Note 6.— Lime Water.— Vmr rain water on newfy-burned lime, decant the clear liquid, and breathe into it through a straw or tobacco pipe. The water contains dissolved lime, the car- bonic acid of the breath combines with the lime, and forms cba Ik, (carbonate of lime, pure limestone) which renders the water milk-white. Continue breathing ; after a lime it will become clear again The water absoibs carbonic acid as the air from the lungs passes through it, but water absorbing carbonic acid acquires the power of dissolving chalk, or pure limestone, hence the clearness of the liquid. The presence of lime at the ' ttom of many kitchen utensils, arises from the heat to which .ney are exposed driving oflf the carbonic acid from the water, which is thus rendered incapable of retaining lime in solution. Note 7.— If a pint of water be converted into steam by heat, and the steam thus formed passed through live pints of water, it will raise the whole to the boiling point. From which it is in- ferred that the steam coiitains five times as much heat as the boiling water from which it was formed. When water evcpo- rates slowly, it absoibs heat from surrounding bodies— hence evaporation always produces cold. Note 8.— /iVrogen.— Introduce some iron turnings or bits of ,• -. : -4- _ _.„„ii v.nffiQ Maifp n Vinlp fhrnii»rh the cork and 2inC into a aiTlan DOIUS. i->"?%f- - •— -- = -- - LECTURES ON AGRTCULTgRAL CHEMISTRY. 81 " liarts- ; at the another :tion of e cloud nes with e caiidit! sal-am- proceeds on some will be its union IS at the displace , will be y-bupned h a straw , the car- ins chalk, the water 1 beconne s the air ; carbonic imestone, ne at the : to which the water, olution. n by heat, ' water, it :h it is in- at as th" ,ter evC; • - iea— hence 5 or bits of cork and insert the stem of a tobacco pipe, so that it fits accurately. Mix some oil of vitriol (sulphuric acid) and water ; about one part of the Cotvner to four of the latter. Pour the mixture on the metal, cork the bottle tight with the prepared cork, and after the lapse of a minute apply a light to the extremity of the pipe. The gas issuing from it will take fire. It is hydrogen, and is obtained by the decompcation of the water. Take a small 'ry phial and collect some of the gas by holding it over the pipe; bring it immediately to the flame of a candle-an explosion will take place and water be formed, the phial becoming dim with waieu Note 9.— Descent of the sap in Vegetables.— U two fluids of different densities be separated by an animal membrane, after a short time, portions of either fluid will pass through the mem- brane, and mix with the other fluid ; this operation will go on until their densities are uniform. If, therefore, we take a long glass tube, either straight or bent, tie round one extremity a por- tion of the intestine of an ox, sheep, or pig, and puur a quantity ofbrme into the open end of the tube; then plunge the whole . into a short tube or glass, containing a small quantity of pure water, we shall observe the fluid in the long tube rise many inches above its former height ; the water in the glass vessel will diminish, but taste strongly of salt. The operation will go on until the fluid in both vessels attains the same density. Here we have an example of what takes place in the vegetable fabric. The porous substance of the leaves and bark, represents the porous animal membrane,-the glass of water, the sap in the newer wood and the water in the soil,-the long tube in which the fluid rises, the stalks, branches, and bark of trees, coumenc- mg in the roots, going on through the newer wood, the leaves and the inner bark, to the roots again. The brine repr. .nts the dense sap produced by the evaporation from the leaves p-d bark. It IS evident that the operation of diffusion is cor-'/.-niiy gow^r ou after the water has entered at the roots; i' ^g^^ on more rapidly as the sap ascends; its rapidity Is greatly Tncreased after the sap has been thickened by the great evaporation from the surfaces of the leaves. The pr-?ure o( »he ata .>sphei-e, owing to this evaporation, together with capillary attraction, keeps up a constant supply of pure water, derived Irom the •oil. Note lO.-Water from, leaves of Ve^etahies.-Encloae a lesif, while still attached to the tree, in a iify botlie ; cio^^ the muuia -41 82 LECTURES ON AGRICULTURAL CHEMISTRY. With wax and cover the wax with paper, to prevent the .un ll :" in"; it. After a few hou. the ^-1^^^^^^^^^^ w.th moisture. After a few day. it will be half full of water. Note ll.-Porosifi,o/£oiies-Condmsafiono/airi.«Amt dissolved ter, it con- e of iiine or gypsum. When ammonia is introduced and causes a reddish- brown precipitate, the water contains iron. When oxalate of ammonia is mixed with the water, and produces a cloudy ap- pearance, it contains lime, which after a while will fall to the bottom, in the form of oxalate of lime. — (Oxalic acid is the cause of the agreeable acidity in rhubarb.) If effervescence takes place upon the addition of a little vinegar or oil of vitrio', the water contains carbonic acid. If a bulky precipitate appears when ammonia is poured into ihe water, a quantity of spirit of salt must be added, until the precipitate vanishes, and ammonia again introduced ; if no precipitate appears, the last observed con- sisted of magnesia, coloured probably by iron. If the precipitate does appear in the same quantity as before, the water contains alumina — (the body which gives rise to the tenacity of clay, but which is not always found to enter irto the composition of vege- tables or animals) — if less in quantity, that which has vanished contains magnesia, and what remains consists chiefly of alumina. These experiments will serve to indicate the presence of the substances mentioned, in a soluble state in the soil, or in water of wells, springs, rivers, &c. They do not in themselves pos- sess any other value. The correct analysis of a soil is a very tedious and difficult operation. None but a practiced chemist should attempt it, in the hope of obtaining reliable, and conse- quently useful, results. The nature of the necessary processes may be seen in the appendix to Johnston's large work on Agri- cultural Chemistry. British Military Ration in Canada. OFFICEr^S* HORSES, DRAUGHT HORSES, AND OXTN. pounds of Oats, Barley, Indian Corn, or 14 pounds Bran. 16 ditto of Hay. 6 ditto of Straw. When Oats or Bran cannot be had> 32 pounds of Hay. 6 ditto of Straw. CAVALRY AND ARTILLERY. 10 pounds of Oats. 12 ditto of Hay. 6 ditio of S'UttW* 84 LECTURES ON AGRICULTURAL CHEMISTRY. (j^The writer of these pages has received numeroas applications from school-teachers and farmers, for a list of the apparatus and materials which are required in illus- trating a brief course of lectures on Agricultural Chemistry, or individual study of the science. It has been, at the same time, urged, that considerable difficulty occurs in parts of the country, remote from large towns, in obtaining the necessary materials. An arrangement has, therefore, been entered into with Mr, F. Richardson, Practical Chemist, King Street, Toronto, for furnishing boxes of apparatus and materials. Each box will be provided with a short description of the mode in which a large number of experiments can be made, not only illustrative of the sci- ^ ence of Agricultural Chemistry, but also of some of the ' most important phenomena of Heat. A Box of Apparatus can be obtained upon application to Mr. F. Richardson, after the 1st of January, 1851. The price will probably not exceed six dollars. Page 14, C( Page 17, Page 29, Page 35, Page 35, Page 52. rlA Page 53 Page 61 umeroas ir a list of in illus- hemistry, n, at the occurs in obtaining therefore, Practical ; boxes of ^ jrided with ? number of '' of the sci- I )me of the plication to .851. The j ERRATA. Page 14, last line— for Note 6, read Note 7. « <« for Note 7, read Note 8. Page 17, last line— for Note 8, read Note 10. Page 29, line 7--for " before it is cooled much, frozen soil," read '^ before it is cooled to 30°, much frozen soil." Page 35, line 8— for "Flint Potash Plant," read Flint- Potash Plant." Pacre 35, line 15-for " Lime Potash Plant," read " Lime- " Potash Plant." « « —for Flint Polush Plant," read " Flint- Potash Plant." Pacre 52, line 36— after «' Field Beans," &c., read « Swedish Turnips, 91-1t\-6700. Page 53, line 13-for « turnips," read " field beet." Page 61, line 31-for « 156,000 tons," read « 156,000,000." "mm