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 S 585.T47 
 
 Science in farming. A text book on the pr 
 
 3 1924 000 911 820 
 
Cornell University 
 Library 
 
 The original of this book is in 
 the Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31 92400091 1 820 
 
SCIENCE IN FARMING. 
 
 A TEXT BOOK 
 
 principle^ of fericulture, 
 
 INCLUDING A TREATISE ON 
 
 AGRICULTURAL CHEMISTRY. 
 
 DESIGNED FOE USE IN 
 
 Schools, Granges, Farmers' Clubs, and by Farmers 
 and their Families. 
 
 By R. S. THOMPSON. 
 
 \ 
 Published by The Farmers' Advance, 
 SPRINGFIELD. OHIO. 
 1882. 
 
COPYRIGHT, 1882, BY R. S. THOMPSON. 
 
Success in Farming, 
 
 A Series Of Practical Talks with Farmers, 
 
 — BY — 
 
 WALDO F. BROWN, 
 
 One of the Most Popular Agricultural Writers in the United 
 States. 
 
 Handsomely Printed on Heavy Tinted 
 
 Paper and Elegantly Bound 
 
 in Cloth. 
 
 The Book is Well Arranged and Systematized, and Full 
 of Practical Common Sense. 
 
 PRICE, by Mail, Postpaid, .... ONE DOLLAR. 
 
 Published by " The Farmers' Advance," Springfield, 0. 
 
 Its twenty-one chapters consider : What constitutes success 
 in farming ? selection of farm, management, buildings, 
 fences, draining, fertilizing, hired help, implements, wheat, 
 corn, grasses, clover, potatos, rye, special crops, fruit, garden, 
 stock, poultry, timber, and country homes. 
 
 WHAT IS SAID OF SUCCESS IN FARMING. 
 
 Two Chapters Worth More than the Price of the Book. 
 
 I have received Success in Farming, and I have received 
 from two chapters — " Farm Building " and "Hired Help" — 
 benefit worth far more than the price of the book. 
 
 Frankfort, Ohio. A. B. Cline. 
 
 Every Farmer Ought to Have It. 
 
 I have read Success in Farming, and every farmer ought to 
 have it. It surpasses my most sanguine expectations. There 
 is no theory about it. It is all tacts. A child can under- 
 stand it. It only needs to be read to be appreciated. 
 
 Bacon P. 0., Ohio, Joseph Love. 
 
TO ALL WHO LABOR TO AD¥ANCE THE WELFARE, AND INCREASE 
 
 THE INTELLIGENCE AND HAPPINESS OF MANKIND. 
 
 THIS BOOK IS DEDICATED. 
 
INTRODUCTION. 
 
 The preparation of this book was suggested by the 
 number of inquiries I have received, both personally 
 and by letter, for a book treating on the elements of 
 agriculture. 
 
 Careful examination of all the books on the subject 
 I could find, satisfied me that although many of them 
 were excellent, none exactly met the needs of my 
 questioners. 
 
 Some of the books on the subject have been pub- 
 lished many years, and, as many of the most impor- 
 tant investigations in this direction have been made 
 in the past few years, these books are out of date. 
 
 Some books of this class were well adapted for the 
 student who was acquainted with the elements 
 of chemistry and physiology, but could not be under- 
 stood by those who had no knowledge of these sciences. 
 Other books were so large and expensive that they 
 exceeded the limits of the average farmer's time and 
 purse. 
 
 In others the attempt has been made to condense 
 the subject into such small space, that it had been 
 impossible to treat it in a clear or satisfactory manner. 
 
 The great difficulty in the production of such books 
 has been the fact that the men who have fitted them- 
 selves for their preparation, by lives spent in scientific 
 
Vi SCIENCE IN FARMING. 
 
 # 
 
 research, have, by the necessities of the case, been so 
 separated from the great body of the farmers of the 
 country, that it was impossible for them to understand 
 their needs. 
 
 The only special fitness that I claim for the prepa- 
 ration of a work of this character, is an intimate 
 acquaintance with the farmers of our country, a strong 
 attachment to the occupation of agriculture, and an 
 earnest desire to see it lifted to its proper place as one 
 of the most honorable, pleasant, and intellectual 
 occupations that can be followed by man. 
 
 It is not the design of this book to lay down rules 
 concerning the amount of manure to apply to an acre 
 — nor the exact depth to which grain should be planted, 
 nor the number of pounds of hay that should be fed to 
 a cow. These are things which constantly vary with 
 locality, season and circumstance, and which each 
 farmer must, to a certain extent, determine for him- 
 self. 
 
 This book teaches the laws and principles that 
 underly the practical work of the farm, a knowledge 
 of which will enable a farmer to intelligently construct 
 his own rules. 
 
 I have not attempted to write a book that can be 
 read merely for entertainment, without mental effort 
 — as a novel, or a fairy tale. It would not be possible 
 to write such a book and convey the information de- 
 sired. There is no "primrose path to learning." 
 
 The important scientific knowledge that is now 
 proving of such great value to the farmer was all ob- 
 tained by patient toil. They who would get the benefit 
 of this knowledge must be willing to give for its ac- 
 quirement at least a moderate amount of mental 
 labor. 
 
ESTKODtTCTION. VU 
 
 I have earnestly endeavored to make every portion 
 of the work so clear that it can be understood by any 
 who are willing to expend as great amount of mental 
 effort as is needed in the acquirements of other studies. 
 Greater simplicity than this can only be obtained by 
 the sacrifice of value. 
 
 Each chapter in this book prepares the way for that 
 which follows, and it would be as unwise to expect to 
 understand the latter chapters before mastering 
 those which precede it, — as it would be to expect a 
 schoolboy to work a sum by the rule of three, before 
 he understood the multiplication table. 
 
 I have not attempted to avoid the use of scientific 
 names and terms, my object has been to enable the 
 student to understand not only this book, but the 
 writings of others. I have therefore first explained the 
 meaning of scientific terms and then made use of 
 them. 
 
 The book is not one of mere theory. It gives the 
 results of long continued and careful experiments 
 made by the most competent men in the world. 
 
 No attempt has been made to explain the methods 
 by which the facts given have been ascertained, nor 
 space used in aruguments to prove that they are facts. 
 The aim has been to give the facts themselves, leav- 
 ing the explanation of the methods by which they 
 have been ascertained for books intended for scientific 
 men. 
 
 It may be that some readers who have had the ad- 
 vantages of a liberal education, may consider the book 
 too simple, and that too much pains have been taken 
 to explain that which can be understood without ex- 
 planation. 
 
 I would ask such to remember that this book is 
 
VU1 SCIENCE IN PABMING. 
 
 designed for men, many of whom have not had the 
 opportunities for the higher education that is given to 
 the young people of to-day. 
 
 It is a book intended to be studied — by the farmer 
 and his family around the fireside,-in the district school, 
 in the grange hall, and farmers' club. 
 
 If, by its study, some are enabled to see more of the 
 beauties, and understand more of the mysteries con- 
 nected with science in farming, and inspired to greater 
 zeal in their efforts to lift the occupation of agriculture 
 to the honored place which is of right its own, I shall 
 feel repaid for the days and nights of labor that have 
 been expended in its preparation. R. s. t. 
 
CONTENTS. 
 
 PAGE 
 
 CHAPTER I. 
 
 SCIENCE IN FARMING 13 
 
 CHAPTER II. 
 
 SCIENCE IN ITS ELEMENTS. 
 
 § 1. Terms Used 17 
 
 § 2. The Foundation of Science 19 
 
 § 3. Arithmetic 20 
 
 CHAPTER III. 
 
 SCIENCE IN HEAT AND ENERGY. 
 
 § 1. Their Nature 23 
 
 § 2. Transference of Heat 25 
 
 § 3. Practical Application 27 
 
 CHAPTER IV. 
 
 CHEMISTRY. 
 
 § 1. Its Nature and Language 30 
 
 § 2. Chemical Laws 33 
 
 § 3. Chemical Symbols and Formula . ... 36 
 
 $4. The Elements 37 
 
 § 5. The Compounds 41 
 
 § 6. Compounds of Acids and Bases .... 47 
 
 § 7. Organic Chemistry ....... 51 
 
 § 8. Combustion and Decay 58 
 
X SCIENCE IN FARMING. 
 
 PAGE. 
 CHAPTER V. 
 
 SCIENCE IN AIK. 
 
 $ 1. Its Composition and Characteristics .... 61 
 
 $ 2. Importance of Each Constituent .... 64 
 
 § 3. Summary 68 
 
 CHAPTER VI. 
 
 SCIENCE IN SOILS. 
 
 § 1 Origin of Soils 69 
 
 § 2. Composition and Classification of Soils ... 70 
 
 § 3. Properties of Soils 71 
 
 § 4. Chemical Characteristics of Soils .... 77 
 
 § 5. Mechanical Conditions of Soils .... 83 
 
 § 6. Value of Sand, Clay and Humus .... 86 
 
 § 7. Practical Application 88 
 
 CHAPTER VII. 
 
 SCIENCE IN PLANT GROWTH. 
 
 § 1. Composition of Plants 91 
 
 § 2. Germination 94 
 
 § 3. How the Plant Grows 95 
 
 § 4. Formation of Seed . 99 
 
 § 5. Summary and Practical Application . . . .101 
 
 CHAPER VIII. 
 
 SCIENCE IN ANIMAL LIFE. 
 
 § 1. Composition of the Animal 104 
 
 § 2. Animal Nutrition 105 
 
 $ 3. Uses of Food in the Body 107 
 
 § 4. Disposition Made of Food 108 
 
 § 5. Effect of Irisufficient Food ..... no 
 § 6. Effects of Exercise and Exposure to Cold . . .111 
 
INDEX. XI 
 
 PAGE. 
 CHAPTEE IX. 
 
 SCIENCE IN POODS. 
 
 $ 1. Food Constituents 113 
 
 $ 2. Composition of Foods 114 
 
 § 3. Digestibility of Foods 118 
 
 § 4. Valuation of Foods 121 
 
 § 5. Albuminoid Ratio 124 
 
 CHAPTER X. 
 
 SCIENCE IN FEEDING. 
 
 § 1. General Principles 129 
 
 § 2. Proper Food for Young Animals .... 133 
 § 3. Proper Food for Producing Milk . . . .135 
 
 § 4. The Fattening Animal 139 
 
 § 5- The Working Animal 144 
 
 § 6. Summary ... . 145 
 
 CHAPTER XI. 
 
 SCIENCE IN FERTILIZERS . 
 
 § 1. General Principles .... . 147 
 
 $ 2. Rendering Plant Food Available . 149 
 
 § 3. Manures ... . -152 
 
 § 4. Farm- Yard Manure . 154 
 
 § 5. Manure from Different Animals . 159 
 
 § 6. Relation of Food to Manure . 160 
 
 4 7. Valuation of Manure ' 166 
 
 § 8. Commercial Fertilizers . 173 
 
 $ 9. Adaptation of Manures to Crops . 176 
 $ 10. Summary . . . .178 
 
AUTHOR'S ACKNOWLEDGMENTS. 
 
 Had the writer paused at every step of his progress 
 to explain the sources whence his information had 
 been obtained, as much space would have been occu- 
 pied in acknowledgments as in statement of facts, 
 and the design of the work — as a condensed text-book 
 of information — would have been defeated. 
 
 In addition to the standard text-books of science, 
 special acknowledgments are due to those two valua- 
 ble works of Johnson's, How Crops Grow and How 
 Crops Feed ; also to Harris' Talks on Manures, arid 
 to "Warrington's Chemistry op the Farm — a book that 
 contains a great amount of valuable information in 
 small space. 
 
 Acknowledgments are also due to friends who have 
 kindly aided the work with good words and valuable 
 suggestions all the way, among whom should be 
 named W. I. Chamberlain, Secretary of the Ohio 
 State Board of Agriculture, Professor N. W. Lord, 
 analytical chemist of the Ohio State University, L. 
 N. Bonham, agricultural editor of the Cincinnati Com- 
 mercial, Waldo F. Brown, author of Success in Farm- 
 ing, J. W. Ogden, and others. 
 
CHAPTER I. 
 
 SCIENCE IN FARMIN.G. 
 
 1. Definition of Science. — Webster defines science 
 as " Truth ascertained" — " that which is known" — 
 " knowledge duly arranged." 
 
 According to this definition, facts ascertained and 
 duly arranged constitute science, and study of science 
 consists in studying established facts, their arrange- 
 ment and mutual relationship. A mere compilation 
 of facts, without arrangement and without regard to 
 the relations existing between those facts, is not 
 science. 
 
 2. Science and Practice. — A distinction is often 
 made between scientific and practical knowledge. 
 Strictly speaking, all scientific knowledge is practical 
 as it is a knowledge of facts, and practical knowledge • 
 becomes scientific when duly arranged. 
 
 3. Scientific knowledge is the result of careful ex- 
 periments conducted with an intelligent purpose. 
 
 4. In common language, practical knowledge is the 
 knowledge of a fact, and scientific knowledge the 
 knowledge of the principles and causes on which that 
 fact depends. 
 
 5. Illustration. — A. farmer learns by experience 
 that the manure produced by cattle fed on clover hay 
 
14 SCIENCE IN PABMING. 
 
 is more valuable than that produced by cattle fed on 
 straw. This is practical knowledge. Afterwards he 
 learns that this difference is due to the fact that clover 
 contains a larger amount of a substance called nitro- 
 gen, than straw, and that this nitrogen is valuable as 
 a manure. This is scientific knowledge, and this en- 
 ables him to know that manure produced by cattle 
 fed on any other substance containing much nitro- 
 gen will also be of special value, and he can consider 
 this fact in making his selection of foods. 
 
 6. The Farmer a Manufacturer. — The business of 
 the farmer is to produce certain articles such as 
 wool, cotton, beef, pork, butter, cheese, etc. These 
 can only be produced by bringing together other sub- 
 stances already in existence, and by combination and 
 re-arrangement changing them into the substances de- 
 sired. The farmer is therefore as truly a manufac- 
 turer as the man who makes plows or sewing ma- 
 chines. 
 
 7. The soil and air are the sources from which the 
 farmer draws his supplies of raw material, and the 
 plant and animal are the machines by which he works 
 up this raw material into useful manufactured pro- 
 ducts. 
 
 8. If the farmer would be successful, he must 
 therefore have a knowledge concerning the substances 
 from which his manufactured goods are to be pro- 
 duced, and of the sources from which he is to obtain 
 them. He also needs to be well acquainted with the 
 machinery he is using, and with the laws that govern 
 its working. This knowledge is the " science of farm- 
 ing." 
 
 9. In the earlier days, when the virgin soil was 
 ready to produce a crop if the opportunity were pro- 
 
SCIENCE IN FARMING. 15 
 
 vided — when the customs of life were simple, and the 
 farmer's needs were few, it was possible for men to 
 obtain a Living from the soil though they knew but 
 little of the " science of farming." But with the 
 change in the condition of our soil, the customs of so- 
 ciety, and in the manner of life upon the farm — it 
 has become necessary that a better knowledge of this 
 science should be diffused among the people, and the 
 day is rapidly drawing near when none can hope for 
 success in farming without a knowledge of science in 
 farming. ' 
 
 10. Chemistry. — An acquaintance with the ele- 
 ments of chemistry is the key which opens the door 
 to the mysteries of agriculture — for the growth of the 
 plant and the life of the animal are the result of op- 
 erations controlled by chemical laws. 
 
 As well might the child expect to read without 
 learning his letters, or the musician to understand 
 music without learning the notes, as the farmer 
 to~understand his occupation without having first 
 learned the elements of chemistry. Letters are not 
 reading ; notes are not music, and chemistry is not 
 farming; but as the child cannot read without a 
 knowledge of his letters, neither can the farmer un- 
 derstand the science of his occupation without a 
 knowledge of the elements of chemistry. 
 
 11. Agricultural Chemistry. — Strictly speaking, 
 there is no such science. Chemistry and its laws are 
 the same, whether applied to the arts, to manufac- 
 tures or the farm, and the thorough student must learn 
 these laws and principles without expecting to see an 
 immediate application. 
 
 12. But although a certain knowledge of the laws 
 and principles of chemistry is an essential preparation 
 
16 SCIENCE IN FABMING. 
 
 for the study of agriculture, there is much of the de- 
 tails of this science which may, without detriment, be 
 omitted. 
 
 In the treatise on chemistry contained in this work, 
 only that is given which is of importance to the 
 farmer. 
 
 All that is given should be studied and understood, 
 for it is the key, not to this book alone, but to the 
 books and writings of scientific men. 
 
 13. The complaint is often made that the writings 
 of scientific men are beyond the comprehension of 
 the people. The reason is that people have not stud- 
 ied the elementary principles of science. 
 
 14. Therefore these elements of science are of the 
 utmost importance. They are not only important in 
 themselves, and full of beauty and interest, but they 
 also prepare the way for wider, deeper, and more in- 
 teresting researches. 
 
CHAPTER II. 
 
 SCIENCE IN ITS ELEMENTS. 
 
 § 1. Terms Used. 
 
 In order to understand scientific facts we must first 
 know something of the terms used by scientific men. 
 
 15. Matter. — Everything that has weight or bulk. 
 Thus, iron is matter, and so is wood, or gold or air. 
 Different parts of matter are called bodies or sub- 
 stances. Matter can change its form — a solid may 
 become a liquid or a gas, and a gas may become a 
 liquid or a solid — or one substance may enter into 
 combination with another, and both lose their former 
 characteristics and gain new ones. But in all these 
 changes matter is neither created nor destroyed. A 
 house is built by bringing and fastening together 
 wood and iron and stone and brick and mortar, but 
 the house was built, not created — there was no more 
 stone and brick and wood and iron in existence after 
 the house was built than before. So when a plant or 
 animal grows, different substances are gathered to- 
 gether and combined to form the plant or animal ; but 
 nothing is created. There are no more of these sub- 
 stances in existence than before. Matter has only 
 changed its form. 
 
 16. If a house is torn down, and the material of 
 
 which it was built scattered, the bricks and wood 
 2 
 
18 SCIENCE IN FARMING. 
 
 and stone and iron are still in existence. So if, 
 after the plant is grown we put it on the fire and burn 
 it, the matter in the plant changes its form, but is 
 not destroyed. If we should carefully collect the 
 ashes and smoke and vapor and gas produced by 
 burning the plant, we would find they weighed the 
 same as the plant before it was burned. It is impos- 
 sible to create the smallest particle of matter, and 
 equally impossible to destroy it. 
 
 17. Solids, Liquids, Gases. — Matter exists in three 
 forms. A solid is a substance the particles of which 
 are firmly held together so that they will not move 
 upon each other. Iron is a solid. Liquids are sub- 
 stances in which the particles readily move upon each 
 other and which yet have some attraction for each 
 other. Water is a liquid. A gas is a substance in 
 which the particles seem to have no attraction for each 
 other. The air we breathe is a gas, or rather a mix- 
 ture of gases. 
 
 18. Atoms. — It is supposed that all substances are 
 composed of exceedingly small particles, so small 
 that no microscope has ever been able to reveal them 
 to the eye, and which are called atoms. Between 
 these atoms there exists a force that draws them to- 
 gether, and another that tends to separate them. 
 One is called the attractive, the other the repulsive 
 force. When the attractive force is the strongest, 
 matter exists in the form of a solid. When the two 
 are about equal, in the form of a liquid; and when the 
 repulsive force entirely overcomes the attractive, the 
 substance is called a gas. 
 
 19. Force is whatever acts on matter to change 
 it. Thus the force of heat can change a piece of ice 
 into water. Chemical force may cause two substances 
 
SCIENCE IN ITS ELEMENTS. 19 
 
 to combine, producing a different one. The force of 
 gravity will cause a substance when not supported to 
 fall to the ground. Like matter, force can neither be 
 created nor destroyed. This will be further explained 
 in the chapter on Heat and Energy. 
 
 20. Properties of Matter. — Those characteristics 
 which serve to distinguish one kind of matter from 
 another. Thus it is a property of flint to be hard, of 
 wax to be soft, of snow to be white, of charcoal to be 
 black. 
 
 21. Element. — In chemistry is a substance that 
 cannot be separated into other substances. Thus 
 gold is an element ; you may divide it into very min- 
 ute portions, but each piece, no matter how minute, 
 is still gold. Common table salt is not an element, 
 but can be separated into two very unlike substances 
 which are elements. There are only a little over sixty 
 elements known to chemists to-day. 
 
 The term element is often used to represent one of 
 the ingredients in a complex compound — as in the 
 expression, "The elements lacking in the fertilizer 
 were ammonia and potash" — though neither ammo- 
 nia nor potash is an element in the chemical sense of 
 the term. 
 
 § 2. The Foundation of Science. 
 
 22. All science is founded on the principle that 
 matter is subject to certain definite and unchangeable 
 laws, which may be ascertained, and when ascertained 
 will enable us to know positively the results of cer- 
 tain causes. Science may be said to rest on the prin- 
 ciple that every effect must have a cause, and that 
 the same cause, under the same circumstances, will 
 always produce the same effect. If it were not for 
 
20 SCIENCE IN FARMING. 
 
 this principle, scientific progress in any work would 
 be impossible. 
 
 23. If a substance is left unsupported, we know it 
 will fall directly toward the earth. No other action 
 is possible. The fact that wood will float in water, 
 and smoke ascend in the air, is not an exception, as 
 the wood is supported by the water, and the smoke 
 by the air. 
 
 24. If a farmer gets 30 bushels of wheat per acre on 
 one field, and only 10 bushels per acre on another, 
 the difference is not due to an accident, or a whim of 
 the crop ; but to a different condition of circumstances 
 in the two fields. If he can learn what was the cause 
 of the good crop in the one field, and secure that cause 
 in the other, he will be certain of as good a crop. Of 
 course, in practice it is not possible for the farmer to 
 control all the circumstances that affect a crop, but 
 just so far as he can control those causes he can con- 
 trol the result. 
 
 25. A knowledge of science is therefore a knowl- 
 edge of the properties of bodies, of the laws that gov- 
 ern their action upon each other, and the relations 
 that exist between cause and effect. 
 
 § 3. Arithmetic. 
 
 26. Science being exact, much of its results are to 
 be determined only by careful calculations, and it 
 will be difficult, if not impossible, for the student to 
 master any science without knowing something of the 
 rules of arithmetic. We shall assume, therefore, that 
 the readers of this book are at least moderately fa- 
 miliar with arithmetic, and call their attention to two 
 divisions of it only. 
 
 27. Per Cent. — By per cent is meant the number of 
 parts in a hundred. Thus, in 100 lbs. of good milk 
 
SCIENCE IN'lTS ELEMENTS. 21 
 
 there are about 87 lbs. of water ; so we say that milk is 
 87 per cent water. 
 
 28. The percentage composition of a substance is the 
 number of parts of each constituent in 100 parts of the 
 substance. A great many scientific tables are pre- 
 pared, giving the percentage composition of sub- 
 stances. 
 
 29. When we know the per cent of any constituent 
 and wish to learn the exact amount of that constit- 
 uent there would be in a given amount of the sub- 
 stance, we multiply the amount of the substance by 
 the per cent of the constituent, and divide by 100. 
 
 Thus we find that fat forms about 32 per cent of the 
 whole carcass of a fat ox. Now, if we wanted to 
 know how many pounds of fat there were in a fat ox 
 weighing 1,475 lbs., we would proceed thus : . ... 
 To divide by 100, we only need to strike off 32 
 
 the two last figures to the right, and call them 
 
 hundredths, and so we get the answer, that an 2 9 4 
 ox weighing 1,475 lbs., whose carcass was 32 442 5 
 per cent fat would contain 471^^ lbs. fat atTqo 
 
 30. Decimals. — It is found very convenient 
 
 in scientific calculations to use principally decimal 
 fractions — that is fractions represented in tenths, hun- 
 dredths, thousandths, and so on. Decimals are writ- 
 ten bv putting a period after the figures denoting the 
 whole numbers, and to the right of this the figures 
 representing the number of tenths, hundredths, thou- 
 sandths, as the case, may be. One figure to the right 
 of the period stands for tenths ; two figures for hun- 
 dredths, and three for thousandths. 
 
 Thus 1.9 would be read " one and nine-tenths;" 1.93 
 " one and ninety-three one-hundredths;" and 1.016, 
 " one and sixteen one-thousandths." A cipher an- 
 
255S SCIENCE IN FARMING. 
 
 nexed to the right of a "decimal does not change its 
 value ; thus, 1.90 would read " one and ninety one- 
 hundredths," which of course is the same as one and 
 nine-tenths. A cipher placed to the left of a decimal 
 reduces its value to one-tenth what it was in the for- 
 mer place ; thus, 1.09 would be read " one and nine 
 one-hundredths." 
 
 31. It frequently happens that a decimal is used 
 without a whole number ; thus, it is said that a good 
 soil contains .25 per cent of nitrogen, which means 
 that it contains twenty-five one-hundredths of one per 
 cent, or a quarter of a pound of nitrogen in a hundred 
 pounds of soil. 
 
CHAPTER III. 
 
 SCIENCE IN HEAT AND ENERGY.* 
 
 § 1. Their Nature. 
 
 32. The Same Principle.— Heat and energy are dif- 
 ferent manifestations of the same principle. Heat is 
 said to be a mode of motion. Heat can be changed 
 into energy, and energy may be changed into heat. 
 
 33. Illustrations. — Ifabarof iron is hammered on 
 an anvil, the energy that was used will be expended, 
 and the bar of iron will become hot, and the amount 
 of heat in the iron will be in exact proportion to the 
 amount of energy expended in the blows. If heat is 
 applied to a steam boiler, and the steam produced used 
 in running an engine, the heat of the fire will be ex- 
 pended, but instead we have the motion of the ma- 
 chinery. If a brake is applied to some part of the 
 machinery and the motion is stopped, the brake will 
 become hot, and the heat will be in exact proportion 
 to the amount of energy that had to be overcome. 
 
 If a pound of ice at 32 degrees is broken and mixed 
 with a pound of water at 174 degrees, the ice will be 
 entirely melted, and the temperature of the two 
 pounds of water will be but 32. One hundred and 
 forty-two degrees of heat will have been lost by the 1 
 
 *The word energy is here used to represent what might be 
 called active force, force producing work. 
 
24 SCIENCE IN FARMING. 
 
 pound of water, and the temperature of the pound of 
 water produced from the pound of ice will be no higher 
 than that of the ice. The heat had been changed into 
 the energy needed to overcome the attraction of the 
 particles of the solid ice and change it into a liquid. 
 
 34. If heat is applied to a quantity of water the 
 temperature of which is 32 degrees, it will gradually 
 grow hotter until it reaches 212 degrees ; then the 
 water will begintoboil or be changed into steam, but 
 the temperature of the steam will be no higher than 
 that of the water had been. If the heat is uniform, it 
 will take five and a half times as long to change the 
 water into steam as it did to raise the water from the 
 freezing to the boiling point. This heat has been 
 changed into the energy needed to overcome the attrac- 
 tion of the particles of water for each other and 
 change the liquid into a vapor. 
 
 35. When water is poured on quicklime, they 
 unite chemically, and the water becomes part of the 
 solid slaked lime. The energy that had before kept the 
 atoms of water separated is now changed into heat, 
 and the mixture is hot, though both the lime and the 
 water were cold before mixing. 
 
 36. Place a pan of hot water out of doors on a cold 
 winter day. The temperature of the water will fall 
 until it reaches the freezing point and the water be- 
 gins to freeze. Then it will remain unchanged until 
 all the water is frozen. The energy that has before 
 been keeping the atoms of water separated is con- 
 verted into heat, as the water becomes solid, and pre- 
 vents the further fall of temperature until all the 
 water is changed into a solid. 
 
 37. Cannot be Destroyed. — Heat and energy can nei- 
 ther be destroyed nor created. In an elementary 
 
HEAT AND ENERGY. 25 
 
 work, such as this, it would be impossible to fully ex- 
 plain and illustrate this fact ; but it is an important 
 one. Heat and energy must always be derived from 
 some source where they have previously been stored. 
 The energy that moves our locomotives and keeps our 
 factories running, was received from the sun long ages 
 ago,, in the form of heat and light, stored up by grow- 
 ing plants, and is now changed into energy in the fur- 
 naces and fire-boxes. 
 
 38. The heat that keeps an animal alive, the force 
 which he expends in work and motion, are not created 
 by the animal, but are obtained from the food, and 
 were originally gathered from the sun. This last 
 fact will be more fully explained in the chapter on 
 Animal life. 
 
 39. Specific Heat. — If a pound of water and a 
 pound of mercury are both exposed to a uniform 
 source of heat, it will require thirty times as long to 
 raise the temperature of the pound of water a given 
 number of degrees as to raise the temperature of the 
 pound of mercury the same number of degrees. That 
 is, the water requires thirty times as much heat to 
 raise its temperature a given number of degrees as 
 would be required by an. equal weight of mercury. 
 Each substance requires a particular amount of heat, 
 peculiar to itself, and this amount is called the spe- 
 cific heat of the substance. 
 
 The reason for this cannot be explained in this 
 work. 
 
 § 2. Transference of Heat. 
 
 40. Heat moves, or is transferred from one place 
 to another by three methods, called conduction, con- 
 vection and radiation. 
 
26 SCIENCE IN FARMING. 
 
 41. Conduction. — If one end of a bar of iron is 
 placed in the fire, the heat will pass through the iron, 
 and the other end will become hot. This is called 
 conduction. 
 
 42. Difference in Conduction. — If two similar rods, 
 one of copper and one of iron, are heated at one end, 
 it will be found that the heat will pass through the 
 copper more rapidly than through the iron, and the 
 copper is said to be the better conductor. Substances 
 through which heat passes readily are called good 
 conductors ; those through which it passes slowly are 
 called bad conductors. All metals are good conduc- 
 tors. Liquids and gases are very poor conductors, 
 so poor that they are often called non-conductors. 
 Snow is a very poor conductor; hence when the 
 ground is covered with snow, the heat it contains does 
 not escape, and thus snow protects the crops. 
 
 43. Convection. — When heat is applied to the bot- 
 tom of a vessel containing water or some other liquid, 
 the particles in immediate contact with the vessel 
 become heated ; this causes them to expand and be- 
 come lighter, and they rise to the upper part of the 
 vessel while the colder portions sink, and in this man- 
 ner all the liquid in the vessel becomes heated. This 
 is called convection. Gases are heated in the same 
 manner. The portion in immediate contact with the 
 heated substance becomes warm and rises, and a cir- 
 culation is thus established. 
 
 44. Radiation. — If we stand near a stove or other 
 heated body, we feel the heat from it, though it is not 
 conveyed to us either by conduction or convection. 
 All bodies are constantly throwing off heat in straight 
 lines, like light. This is called radiation, and heat 
 thus transferred is called radiant heat. Radiant heat 
 
HEAT AND ENERGY. 27 
 
 passes through the air or any gas without imparting 
 warmth to it. 
 
 45. Radiation is influenced by the color and sur- 
 face of the body — a dark, rough surface radiates heat 
 more rapidly than a white or polished one. Hence a 
 brightly polished coffee-pot will keep coffee hot longer 
 than one that is dark and rough. 
 
 46. Absorption of Heat. — When radiant heat strikes 
 a body it is, to a greater or less degree, absorbed by 
 that body, and warms it. The same surfaces,that ra- 
 diate heat readily also absorb it readily. If a black 
 cloth and a white one are spread on the snow in the 
 sun, the black one will rapidly absorb the sun's heat 
 and melt the snow beneath it, while the white one 
 will not. So a black hat is warmer in the sun than a 
 white one, and a black soil gets warm more quickly 
 in the spring than one of a lighter color. 
 
 § 3. Practical Application. 
 
 47. If a jug of water in the harvest field is covered 
 with a thick cloth soaked with water, the heat of the 
 sun and air will be converted into energy to change the 
 water in the cloth into vapor, and the water in the 
 jug will remain cool until the water in the cloth has 
 been evaporated. 
 
 48. A wet cloth worn inside the hat protects from 
 the sun's heat. The British troops in India were ena- 
 bled to endure the heat only by constantly wearing 
 a wet cloth over the head. A shawl or woolen cloth 
 hung in the window of a room and kept wet, will 
 lower the temperature several degrees. Sprinkling 
 the walks, grass and trees around a house imparts a 
 delightful coolness to the air on a summer day. These 
 effects are caused by the conversion of heat into ener- 
 gy, required to change water into vapor. 
 
28 SCIENCE IN FARMING. 
 
 49. Perspiration protects from heat in the same 
 manner. If an animal in winter is caused to perspire 
 unduly by the use of food containing an excess of 
 water, heat is wasted. 
 
 50. "When the ground is filled with water, the heat 
 of the sun, instead of warming the soil, is converted 
 into the energy required to convert that water into va- 
 por, or in other words, the heat is used for pumping 
 instead of for warming. Hence advocates of drainage 
 tell us that it lengthens the season. 
 
 51. If a room is heated by an open fire, the radiant 
 heat from the fire does not warm the air of the room, 
 which can only be warmed by coming in contact with 
 the walls and furniture that have been heated by the 
 fire. Hence a grate or fire-place warms a room but 
 slowly, and the fire may feel uncomfortably hot while 
 the air of the room is yet cold. 
 
 A stove radiates heat less rapidly than an open 
 fire, but warms the air by convection. Hence an open 
 fire is better for warming the walls and furniture of a 
 room and so removing dampness ; but a stove warms 
 the room more uniformly. 
 
 52. The sun's rays pass through the air without 
 communicating any warmth to it. The air is warmed 
 only by contact with the soil. Hence the soil is often 
 several degrees warmer than the air. 
 
 53. Though gases allow radiant heat to pass 
 through them readily, yet the minute particles of water 
 suspended in the air will not. The partially con- 
 densed vapor always present in the air prevents the 
 heat that has been absorbed by the earth from being 
 radiated off into space. If it were not for this protec- 
 tion the earth would be uninhabitable. 
 
 54. In the same way, and to a greater extent, 
 
HEAT AND ENERGY. 29 
 
 clouds prevent the radiation of heat into space, and 
 so in a cloudy night in fall and spring there is little 
 risk of frost. Thus it is that the intensely cold nights 
 of winter are usually those when there are no clouds 
 and the air is very dry. 
 
 55. In fruit-growing districts crops are often saved 
 on nights when frost is threatened, by building fires 
 that will produce a heavy mass of vapor and smoke 
 that hangs like a cloud over orchards and vineyards. 
 In some places arrangements have been made by the 
 government weather stations by which warning of 
 approaching frosts is sent to the fruit-growers who 
 have their fires built ready to be lighted if needed. 
 
CHAPTEE IV 
 
 CHEMISTRY. 
 
 § 1. Its Nature and Language. 
 
 56. Chemistry treats of the composition of bodies, 
 the changes that are occasioned by their combination, 
 or the separation of those already combined, and the 
 laws that control those changes. 
 
 To understand chemistry, it is first necessary to 
 learn something of the language and terms used. 
 
 57. Chemical Combination. — The word combination 
 in chemistry means something more than it does as 
 usually employed. It indicates not only a bringing to- 
 gether of certain substances, but such a union of those 
 substances that their whole nature and character is 
 changed. 
 
 58. For example, quicklime is a white, caustic 
 solid ; oil of vitriol is an oily liquid, intensely sour, 
 and burns and corrodes whatever it touches. If 56 
 lbs. of quicklime, 98 lbs. oil of vitriol and 18 lbs. of 
 water are mixed, they will combine chemically and 
 we will have 172 lbs. of land plaster, which bears 
 scarcely any resemblance to the substances of which 
 it was made. In this combination 116 lbs. of liquids 
 were added to 56 lbs. of a solid and the result is a per- 
 fectly dry solid. This is the result of chemical com- 
 
CHEMISTRY. 31 
 
 bination, which is entirely different from a simple 
 mixture. 
 
 The air we breathe is a mixture of two gases, but 
 were those two gases to enter into chemical combina- 
 tion, all life would perish from the earth. 
 
 59. Chemie Force, — The power that causes sub- 
 stances when brought together to enter into chemical 
 combination is called chemism, or chemie force, or af- 
 finity. The last term is however less used now. 
 
 60. This force does not apply equally to all sub- 
 stances — there are some that cannot be compelled to 
 enter into chemical union at all, while others unite as 
 soon as brought together. 
 
 61. When two substances are united and a third 
 is added, it may displace one of the others. Thus, if 
 quicklime is exposed to the air, it will, in time, unite 
 with the carbonic acid contained in the air, forming 
 carbonate of lime. If to this vinegar is added, it will 
 combine with the lime and set the carbonic acid free. 
 
 62. Acids and Bases. — It would be impossible to ex- 
 plain the strict chemical definition of these terms to 
 the unscientific reader without devoting to it more 
 space than can be given in this work. The statement 
 that an acid is a compound of a non-metallic element 
 with hydrogen and oxygen, and that a base is a com- 
 pound of a metal with hydrogen and oxygen, is very 
 nearly the scientific definition. 
 
 In popular language the term acid is applied to 
 any substance that has a sour taste, and that readily 
 enters into combination with the oxides of the metals, 
 and a base is a metallic oxide. Both acids and bases 
 in their ordinary condition contain the elements of 
 water. 
 
 63. Acids and alkalies are distinguished by the 
 
32 SCIENCE IN FARMING. 
 
 fact that acids turn blue litmus paper red, and alka- 
 lies restore the blue color. Litmus paper is made by 
 soaking "blotting paper in a solution of litmus and 
 drying it. Litmus is a blue substance obtained from 
 a lichen. Litmus paper is the common test to deter- 
 mine whether a substance is acid or alkaline. 
 
 64. Exceptions. — Ammonia, which is not the oxide 
 of a metal, possesses so distinctly all the character- 
 istics of an alkali that it is universally recognized as 
 such, and hydric chloride, though containing no oxy- 
 gen, has all the properties of an acid, and is commonly 
 known as muriatic acid. 
 
 65. Salts. — Compounds produced by the union of 
 an acid and a base. According to chemical lan- 
 guage common table salt is not a salt. 
 
 66. Solution. — When sugar is placed in water it 
 gradually disappears, and we say it is dissolved. 
 When finely powdered chalk is stirred up with water 
 it remains for a time mixed with, or suspended in the 
 water ; but if the mixture is allowed to remain undis- 
 turbed, the chalk will finally settle to the bottom. 
 The first case is an instance of solution ; the second, 
 of mixture or suspension. Rivers often carry, sus- 
 pended in their waters, large quantities of mud and 
 sand, and also, in solution, salts that have been ob- 
 tained from the soil. 
 
 67. , A substance that will dissolve in water, such 
 as salt or sugar, is called soluble. One that will not 
 dissolve in water, such as sand or chalk, is called insol- 
 uble. Many substances that are commonly called insol- 
 uble, are really soluble, though only to a slight extent. 
 
 68. Some substances will dissolve in one liquid 
 but not in another. Common resin will not dissolve 
 in water, but readily dissolves in alcohol. 
 
CHEMISTRY. 33 
 
 69. Water containing other substances in solu- 
 tion will sometimes dissolve substances that are 
 ordinarily insoluble. Thus water containing carbonic 
 aoid and certain organic acids will dissolve many sub- 
 stances that are usually quite insoluble, and thus pre- 
 sent them as food for plants. This is commonly the 
 result of chemical action. Thus chalk will not dis- 
 solve in pure water, but if vinegar is added, the 
 chalk is dissolved. In this case the vinegar combines 
 with the lime in the chalk, forming a soluble com- 
 pound. 
 
 70. Substances when not combined are called 
 " free." Thus we speak of the free nitrogen of the 
 air, and the combined nitrogen in albumin. 
 
 71. Organic Substances. — Compounds that are pro- 
 duced under the influence of animal or vegetable life, 
 are called organic compounds. Thus sugar, starch 
 and gum are organic substances. So also are albu- 
 min, fat, etc. In general, the term organic is applied 
 to all animal and vegetable substances. 
 
 § 2. Chemical Laws. 
 
 72. Combining Proportions. — Substances may be 
 mixed together in all proportions, but chemical com- 
 bination always takes place in fixed and definite pro- 
 portions. This may be illustrated in three of the 
 most common elements — carbon, oxygen and hydro- 
 gen. Hydrogen and oxygen will combine by weight 
 in the proportions : 
 
 Oxygen. 16 parts. 
 
 Hydrogen 2 parts. 
 
 Or, 
 
 Oxygen 32 parts. 
 
 Hydrogen 2 parts. 
 
 If 16 lbs. of oxygen were mixed with 3 lbs. of hy- 
 3 
 
6' 
 
 34 SCIENCE IN FAKMINGt. 
 
 drogen and the mixture caused to unite chemically, 
 the oxygen would combine with 2 lbs. of the hydro- 
 gen, forming 18 lbs. of water, and the 1 lb. of hydro- 
 gen would be left uncombined. 
 
 73. Carbon and oxygen will unite in the propor- 
 tions : 
 
 Carbon 12 parts, Oxygen 16 parts. 
 
 Carbon 12 parts. Oxygen .... 32 parts. 
 
 74. Carbon and hydrogen combine in numerous 
 
 proportions, but they are all such as : 
 
 Carbon 12 parts. Hydrogen 4 parts. 
 
 Carbon 24 parts. Hydrogen 4 parts. 
 
 Carbon 24 parts. Hydrogen 2 parts. 
 
 It will be seen that in all these cases carbon enters 
 into combination in the proportion of 12, 24, and so 
 on ; hydrogen, 1, 2, 3, and so on, and oxygen, 16, 32, 
 48, and so on. Every element has some definite pro- 
 portion in which it always enters into combination. 
 
 75. Atomic Theory. — This property of matter is ex- 
 plained by what is called the atomic theory. It is 
 supposed that the atoms of which each element is 
 composed (18) are always of exactly the same weight, 
 but that the atoms of different elements have different 
 weights. When elements unite chemically, it is due 
 to a union of the atoms. One atom of an element 
 may combine with one, two, or more atoms of another 
 element ; but as an atom is something that cannot be 
 divided, it is impossible for atoms to combine with 
 fractions of atoms. 
 
 76. If an atom of carbon weighed 12 ounces, and 
 an atom of oxygen 16 ounces, and'an atom of hydro- 
 gen 1 ounce, it follows that a combination of oxygen 
 and carbon must be in the proportion of 12 to 16, or 
 12 to 32 ;• that a combination of hydrogen and oxygen 
 must be in the proportion of 1, or 2, or 3, or 4 of hy- 
 
CHEMISTRY. 35 
 
 drogen to 16 or 32 of oxygen, and this is the case. 
 We cannot know what is the actual weight of an 
 atom, but the relative weights of the atoms of all the 
 elements have been ascertained, and as the atom of 
 hydrogen is the lightest of all, it is taken as the stan- 
 dard, and the weight of the atom of an element, as 
 compared with the weight of an atom of hydrogen, is 
 called the atomic weight of that substance. And thus 
 we say that the atomic weight of hydrogen is 1, of 
 carbon 12 and of oxygen 16. 
 
 77. Molecular Weight. — When the atoms of two or 
 more elements combine, they form a compound atom 
 called a molecule.* Of course the weight of this mol- 
 ecule will be that of the combined weight of all the 
 atoms of which it is composed. Thus carbon dioxide 
 is composed of: 
 
 1 atom carbon weighing 12 
 
 2 atoms oxygen weighing 16 each 32 
 
 Making 1 molecule carbonic dioxide weighing 44 
 
 This is called the " molecular weight " of the com- 
 pound. When compound bodies enter into combina- 
 tion, they always do so in the proportion of their mol- 
 ecular weight. Thus, the molecular weight of car- 
 bonic dioxide, is as we have seen 44 ; that of calcic 
 oxide (quicklime) 56, and when these two combine it 
 will be in the proportion of 44 parts, by weight, car- 
 bonic dioxide, and 56 parts, by weight, calcic oxide, 
 forming 100 parts of calcic carbonate — or carbonate of 
 lime. 
 
 78. Equivalents. — In the older chemistries, the word 
 equivalent was used to represent the same idea that 
 is now represented by the words atom and molecule. 
 
 *The word is derived from a Latin word meaning a little 
 mass. 
 
36 SCIENCE IN FARMING. 
 
 Thus, carbonic dioxide was said to be composed of one 
 equivalent of carbon and two equivalents of oxygen, 
 instead of one atom of carbon and two atoms of oxy- 
 gen ; and calcic carbonate was said to be composed of 
 one equivalent of carbonic dioxide and one equivalent 
 of lime instead of one molecule of carbonic diox- 
 ide and one molecule of lime. The word equiva- 
 lent was also used to represent atomic and mol- 
 ecular weight. Thus it was said that the equiv- 
 alent of carbon was 12, of carbonic dioxide 44, 
 and so on. The term is about discarded, but is still 
 occasionallyseen. 
 
 79. Application. — A knowledge of the atomic and 
 molecular weight of bodies enables us to know the 
 proportions in which these substances are contained 
 in their compounds. Thus we learn that tricalcic 
 phosphate (commonly called bone phosphate) is com- 
 posed of three molecules of lime, and one molecule of 
 phosphoric acid. The molecular weight of lime is 
 56, of phosphoric acid 142 (when in combination) so 
 Ave know the composition of tricalcic phosphate to be : 
 
 3 molecules lime weighing 56 each 168 
 
 1 molecule phosphoric acid 142 
 
 Making 1 molecule tricalcic phosphate 310 
 
 And we know that the phosphate contains £f fths of 
 its weight of phosphoric acid. 
 
 A knowledge of these facts also enables us to know 
 in what proportion chemicals should be used to secure 
 certain results. 
 
 § 3. Chemical Symbols and Formula. 
 
 80. Symbols. — For convenience in representing the 
 composition of bodies, chemists have adopted certain 
 signs, each of which represents an element, and is 
 
V 
 CHEMISTRY. 37 
 
 calle.d its symbol. Usually the first letter of the name 
 is used — thus stands for carbon, for oxygen, H for 
 hydrogen. When the names of two elements begin with 
 the same letter, the two first letters of one are used— 
 as Ca for calcium. Sometimes the first letter of the 
 Latin name of the element is used, as K for potas- 
 sium, the Latin name of which is kalium. 
 
 81. A compound is represented by writing together 
 the symbols of all the elements it contains. Thus CO 
 would represent a compound of carbon and oxy- 
 gen. HSO a compound of hydrogen, sulphur and 
 oxygen. 
 
 82. The symbol not only represents the element, 
 but exactly one atom of that element. Thus CO- 
 would represent a compound composed in the propor- 
 tion of one atom of carbon and one atom of oxygen. 
 When it is desired to represent more than one atom 
 of an element, it is done by placing a small figure 
 after the symbol and a little below it. Thus C0 2 rep- 
 resents a compound of one atom of carbon and two 
 atoms of oxygen. The symbols representing the com- 
 position of a substance are called its formula. Thus 
 CO 2 is the formula of carbonic dioxide. In this way 
 the chemical composition of a substance can be stated 
 with an accuracy, clearness and brevity not otherwise 
 possible. When more than one molecule is to be rep- 
 resented, it is done by placing a large figure before 
 the formula of that molecule, thus CaS0 4 2(H 2 0) 
 represents a compound containing one molecule of 
 calcic sulphate, and two molecules of water. 
 
 § 4. The Elements. 
 
 83. Of the sixty- three elements known to chemists 
 agriculture deals with only fifteen. We give the list 
 of these with their symbols and atomic weights ; 
 
38 SCIENCE IN FARMING. 
 
 Name. Symbol. Atomic Weight. 
 
 'Oxygen .- 16 
 
 Hydrogen H 1 
 
 Nitrogen N 14 
 
 -Chlorine CI 35.5 
 
 , Carbon C 12 
 
 -Phosphorus P 31 
 
 ■Sulphur S 32 
 
 -"Silicon Si 28 
 
 -Potassium K* 39.1 
 
 -Sodium Nat 23 
 
 •Calcium Ca 40 
 
 -Magnesium Mg 24 
 
 \ Aluminum Al 27.5 
 
 -iron Fe{ 56 
 
 >'\ Manganese Mn 55 
 
 The first four are gases, the next four non-metallic 
 solids, and the last seven metals. This being a work 
 on agriculture, and only treating on chemistry so far 
 as necessary to a comprehension of the science of 
 farming, we devote no space to the other elements, 
 and consider the fifteen named specially in view of 
 their importance to the farmer. 
 
 84. Oxygen. — A gas that forms about one-fifth of 
 the atmosphere. It very readily unites with a great 
 number of other substances. It was formerly called 
 " vital air," as without it animals could not live and 
 fires could not burn. _ Any substance that will burn 
 in the air will burn more readily in this gas, and even 
 substances that will not usually burn at all, such as a 
 piece of iron wire, or a steel watch spring, will burn 
 brilliantly in a jar of this gas. An animal when 
 drowned dies from lack of oxygen, and fires are 
 checked by excluding oxygen. An animal confined 
 in the pure gas becomes excited and feverish, and 
 soon dies from over excitement. Oxygen causes the 
 decay of animal and vegetable substances, and with- 
 
 *From Kalium. tFrom Natrium. JFrom Ferrum. 
 
CHEMISTRY. 39 
 
 out it fermentation and decay cannot take place. Fruit 
 keeps in air-tight cans and ensilage in silos because 
 the oxygen of the air is excluded. Though the pro- 
 moter of fermentation and decay, it is also the great 
 purifier, for where oxygen is supplied in abundance 
 decay is rapidly carried so far that the material is re- 
 duced to harmless forms. Oxygen is necessary not 
 only for animal but also for vegetable life. It is one 
 of the most abundant of all elements, forming one- 
 fifth of the atmosphere, eight-ninths of the water, and 
 a large proportion of all rocks. 
 
 85. Hydrogen. — The lightest known substance. A 
 cubic foot of it weighs only one-sixteenth as much as 
 a cubic foot of oxygen. It can be breathed without 
 injury, but an animal confined in the pure gas would 
 die from lack of oxygen. It burns with a blue flame, 
 and with air or oxygen gas forms a very explosive 
 mixture. It is never found in nature except in com- 
 bination. 
 
 86. Nitrogen. — This gas forms about four-fifths of 
 the air. It will not burn, and though not poisonous 
 an animal confined in the pure gas will die from lack 
 of oxygen. It does not readily enter into combination 
 with other elements, and except in the air is not 
 abundant. It is an essential element however, in 
 many organic substances. 
 
 87. Chlorine. — A greenish yellow, heavy, poisonous 
 gas, never found in a free state in nature. One of the 
 elements of table salt. Used for bleaching and as a 
 disinfectant. 
 
 88. Carbon. — Well-known in three forms : charcoal, 
 black lead and diamond. The first two are nearly 
 pure, the last perfectly pure carbon. Contained in 
 nearly[ali;organic^ matter. It forms more compounds 
 
 » 
 
40 SCIENCE IN FARMING. 
 
 than any other element. At ordinary temperatures 
 it will not enter into combination with any other ele- 
 ment, and is completely insoluble: When uncom- 
 bined it is therefore without value as food for either 
 plant or animal. When heated in the air it takes fire 
 and burns, combining with the oxygen of the air to 
 form carbonic dioxide — which readily enters into fur- 
 ther combination and is the source from which the 
 carbon in all its compounds is obtained. 
 
 89. Phosphorus. — A waxy yellow substance that 
 burns so readily it is usually kept under water. Used 
 in commerce in the manufacture of friction matches. 
 Combined with oxygen and hydrogen it forms phos- 
 phoric acid, a substance of great agricultural impor- 
 tance. 
 
 90. Sulphur. — Well known as "brimstone," or 
 " flowers of sulphur." It is contained in some organic 
 substances. With oxygen and hydrogen it forms sul- 
 phuric acid. 
 
 91. Silicon. — A brown solid, known only in combi- 
 nation. 
 
 92. Potassium, Sodium, Calcium and Magnesium — 
 Metals known only in their compounds, which will 
 be described in the next section. 
 
 93. Aluminum. — A hard white metal of considera- 
 ble value in the arts. In combination with silicon 
 and oxygen it forms common clay. 
 
 94. Iron.— In some form iron is necessary to the 
 life of plants and animals. It forms two compounds 
 with oxygen — one called the black oxide, the other 
 the red oxide. kSubstances containing the first oxide 
 are injurious to vegetation, and soils containing it are 
 therefore unproductive. By exposure to the air the 
 
CHEMISTRY. 41 
 
 black oxide is converted into the red oxide, which is 
 of much value. 
 
 85. Manganese. — A metal resembling iron, but of 
 muqh less importance. Its compounds cannot take 
 the place of those of iron in the soil. 
 § 5. The Compounds. 
 
 96. In describing compounds we shall use the 
 
 chemical symbols and formula, for the double reason 
 
 that they can be more clearly and briefly represented 
 
 in that way than in any other, and that it will be 
 
 good practice for the student. It will be well for the 
 
 student to refer to the table of atomic weights, and 
 
 calculate for himself the proportion of each element 
 
 contained in a compound. Thus we shall give the 
 
 composition of sulphuric acid as H 2 S0 4 . A molecule 
 
 of it is therefore composed of 
 
 2 atoms of hydrogen, weighing 1 each 2 
 
 1 atom of sulphur, weighing 32 
 
 4 atoms of oxygen, weighing 16 each 64 
 
 Making one molecule of sulphuric acid, weighing 98 
 
 Sulphuric acid is therefore composed, by weight, of 
 ^ths hydrogen, ffths sulphur, and ffths oxygen. 
 
 The formula of starch will be given as C 6 H 10 O 5 . 
 From this we learn a molecule of it contains 
 
 6 atoms carbon, weighing 12 each 72 
 
 10 atoms hydrogenrweighing 1 each 10 
 
 5 atoms oxygen, weighing 16 each 80 
 
 Making one molecule of starch, weighing 162 
 
 Which shows the proportion of each element con- 
 tained in starch. 
 
 Suppose, for example, the reader wishes to know 
 how many pounds of nitrogen are contained in a ton 
 of sodic nitrate, commonly called nitrate of soda — a 
 
42 SCIENCE IN FARMING:. 
 
 popular fertilizer. Its formula is given as NaN0 3 . 
 It is therefore composed of 
 
 _-:» 
 
 1 atom sodium, weighing 
 
 1 atom nitrogen, weighing 14 
 
 3 atoms oxygen, weighing 16 each * 48 
 
 Making one molecule sodic nitrate, weighing 85 
 
 A ton of it therefore contains ifths of a ton of nitro- 
 gen, and the number of pounds of nitrogen in a ton 
 would be determined by multiplying 2000 (the num- 
 ber of pounds in a ton) by the numerator of the frac- 
 tion, and dividing by the denominator. Thus : 
 A ton of pure nitrate of soda therefore 
 contains 329f£ lbs. of nitrogen. 14 
 
 97. Water.— H 2 0. Mol. Wt. 18.* Wa- 2000 
 
 ter is the great natural solvent by «5)28000C329 
 which plants and animals obtain their 255 
 
 food. Its elements are also contained 
 
 in a large number of organic and inor- 250 
 
 ganic substances. It is commonly re- ' 
 
 ferred to in four forms : water of combi- §qq 
 
 nation — as it exists in land plaster, 765 
 
 which contains a little over one-fifth of 
 
 its weight of water in combination; " hy- 35 
 
 drostatic water," which means water ■ 
 that will flow out of the substance containing it, if 
 opportunity is afforded ; capillary water, that which 
 is retained within the pores of a substance and will 
 not flow out, but is still perceptible to the senses; and 
 hygroscopic water, that which is not perceptible to 
 the senses, but can be driven out by heat. Nearly all 
 substances that have been dried in the air contain 
 hygroscopic water. 
 
 *Henceforth we shall use the abreviation At. Wt. for atomic 
 weight, and Mol. Wt. for molecular weight. 
 
CHEMISTRY. 43 
 
 98. Ammonia. — NH S . Mol. Wt.17. A colorless gas, 
 with a peculiar, pungent odor, often perceived about 
 stables and manure heaps. It is very valuable as a fer- 
 tilizer, afid will be further considered in succeeding 
 chapters. Being a gas, it readily escapes into the air 
 and is lost. Water absorbs it readily, arid a strong 
 solution of it forms the " aqua ammonia," " spirits 
 ammonia" of the drug stores. In this form it is val- 
 uable in the household. It is useful in place of soap, 
 in cleaning paint, removing grease, etc. A little 
 added to the water for the bath has a very refreshing 
 effect. A few drops, given in water, makes an excel- 
 lent stimulant in cases of fainting, poisoning, etc. A 
 tea-spoonful added to a quart of water, is an excellent 
 fertilizer for pot plants, but caution should be exer- 
 cised not to use too much. It is often retailed at 5 or 
 10 cents an ounce, but can be bought at wholesale at 
 from 4 to 6 cents a pound. 
 
 99. Carbonic Dioxide. — C0 2 . Mol.Wt.44. Commonly 
 called carbonic acid. A gas with a sour taste. About 
 one-half heavier than the air, which contains about 
 x^nrth of its weight of this gas. When breathed in quan- 
 tity it is highly poisonous, but the small amount 
 present in the air is not injurious to animals, and is 
 essential to vegetable life. It is given off in the 
 breath of all animals, and by the fermentation or de- 
 cay of organic matter. When wood or coal is burned, 
 the carbon it contains unites with the oxygen of the 
 air, producing this gas. Hence, if the smoke and gas 
 from a fire are allowed to escape into a room, the air 
 becomes poisonous. Lamps burning in a poorly ven- 
 tilated room soon produce an injurious amount of this 
 gas. It is the amount of this gas given off in the breath 
 that makes the air grow foul in crowded rooms unless 
 
44 SCIENCE IN FABRMING. 
 
 abundant ventilation is provided. Water absorbs 
 this gas freely, and though poisonous when breathed, 
 its solution in water is both palatable and wholesome. 
 Spring water owes its sparkling to the presence of this 
 gas. The water in the soil always contains this gas 
 in solution. Water containing this gas will dissolve 
 many substances not otherwise soluble, and thus pre- 
 pare them for the food of plants. Hard water usually 
 owes its hardness to limestone, which will dissolve in 
 water containing cabonic acid, but not in pure water. 
 As boiling the water drives off' the gas, kettles in such 
 regions of country soon become crusted with a coating 
 of lime. Carbonic dioxide forms many compounds 
 with bases, which are called carbonates. 
 
 100. Phosphoric Acid.— H 3 P0 4 . Mol. Wt. 98. This 
 is really a compound of phosphoric pentoxide (P 2 5 ) 
 with three molecules of water, and is sometimes writ- 
 ten thus: P 2 5 3(H 2 0) Mol. Wt. 196. In its combi- 
 nation with bases, one, two, or three molecules of 
 water are replaced by one, two or three molecules of 
 a base, and the compound is called a phosphate. 
 Phosphates containing one molecule of base and two 
 of water are distinguished by the prefix mono ; those 
 containing two molecules of a base and one of water, 
 by the prefix bi ; and those containing three molecules 
 of base by the prefix tri. This will be more fully ex- 
 plained later in this chapter. In analyses of foods 
 and fertilizers, the term " Phosphoric acid " is used to 
 represent P 2 6 , called by chemists phosphoric pent- 
 oxide. ' 
 
 101. Nitric Acid.— HNO g , Mol. Wt. 63. Known in 
 the drug stores as " aqua fortis." It is formed to a 
 small extent in the atmosphere by the direct combi- 
 nation of its elements under the influence of electric 
 
CHEMISTRY. 45 
 
 ity, and combines with the ammonia in the air, and is 
 washed out by the rains. It is also formed to a consid- 
 erable extent in the soil under certain circumstances 
 by the oxidation of ammonia and organic substances 
 containing nitrogen. Its compounds with bases are 
 called nitrates. 
 
 102. Sulphuric Acid.— H 2 S0 4 . Mol. Wt. 98. A 
 heavy, oily liquid, commonly known as oil of vitriol. 
 A pint weighs a little over If ft>. It is very corrosive, 
 burning and destroying most forms of organic matter. 
 It should always be handled with great care. When 
 mixed with water great heat is produced, and it is a 
 dangerous experiment when incautiously done. In 
 making the mixture, the acid should always be poured 
 into the water, and never the water into the acid. It 
 is usually sold in large glass vessels called carboys, 
 and costs from 1-J to 3 cents a pound. Its compounds 
 with bases are called sulphates. 
 
 103. Silicic Dioxide.— Si0 2 . Mol. Wt. 60. Com- 
 monly called silica and sometimes silicic acid. It is 
 commonly known as quartz, flint, etc. Nearly all 
 rocks contain it. Water containing certain organic 
 substances dissolves it to a small extent, and it is thus 
 taken up by the plant with its food. Its compounds 
 with bases are called silicates. 
 
 104. Potassic Hydrate.— KHO. Mol. Wt. 56.1. An 
 exceedingly caustic substance sold in the drug stores 
 as caustic potash. It is always present in good soils, 
 and is essential to vegetable life. It is a large constit- 
 uent in ashes, and gives them their value as a manure. 
 It is contained in many rocks, which, by their decay, 
 supply it to the soil. A mineral called kainit con- 
 tains it in large quantities and is now extensively 
 used as a fertilizer. The term " potash," as used in 
 
46 science nsr faeming. 
 
 giving the analysis of foods and manures, means K 2 0, 
 called by chemists potassic monoxide, a substance 
 usually known only in combination. 
 
 105. Sodic Hydrate.— NaHO. Mol. Wt. 40. Caustic 
 soda. It is used by plants to but a small extent, and 
 cannot take the place of potash in the soil. 
 
 106. Sodic Chloride.— NaOl. Mol. Wt. 58.5. Com- 
 mon table salt. 
 
 107. Calcic Oxide.— CaO. Mol. Wt. 56. Quicklime. 
 Obtained by burning chalk or limestone, (calcic car- 
 bonate.) This is a compound of lime and carbonic 
 dioxide, and when exposed to heat the latter is driven 
 off and the lime remains. Quicklime readily unites 
 with water, forming slacked lime, with the formula 
 H 2 Ca0 2 . When quicklime is exposed to the air, it 
 gradually absorbs water and falls into a white powder 
 — slacked lime. It also gradually absorbs carbonic 
 dioxide and returns to its original condition of calcic 
 carbonate. Hence, when lime is kept, it is necessary to 
 exclude the air as much as possible. When applied 
 to the soil it is very rapidly converted into carbonate 
 of lime, but in a much finer powder than it could pos- 
 sibly be reduced to by any other means. Lime is of 
 value as food for plants, and it also has other proper- 
 ties which will be more fully considered in the chap- 
 ter on fertilizers. It has a strong " aflinity" for all 
 acids, and when mixed with - a salt, will frequently 
 combine with the acid it contains and set free the 
 base with which it had been previously combined. 
 Thus, if sulphate of ammonia and quicklime are 
 mixed, the result will be sulphate of lime and free 
 ammonia, which, being a gas, will escape. Hence, 
 lime should not usually be mixed with the manure 
 heap. 
 
CHEMISTRY. 47 
 
 § 6. Compounds of Acids and Bases. 
 
 108. Nitrates. — Nearly all the compounds of nitric 
 acid are soluble. The only ones of importance to the 
 farmer are potassic nitrate, (KN0 8 , Mol. Wt. 101.1) 
 commonly known as nitrate of potash, or saltpeter, 
 and sodic nitrate, (NaN0 3 , Mol. Wt. 85,) commonly 
 called nitrate of soda, or Chili saltpeter. 
 
 Nitrate of potash occurs in abundance in the soils 
 of some tropical countries, and is also produced arti- 
 ficially in what are called " saltpeter plantations." 
 Heaps of soil and organic matter containing nitrogen, 
 are made, with lime or potash in some form, and left 
 for many months to decompose — being kept con- 
 stantly moist. The nitrogen in the organic matter 
 combines with oxygen from the air, forming nitric 
 acid, which combines with the potash or lime in the 
 soil, forming nitrate of potash or lime. This is after- 
 wards dissolved out by water, and when purified be- 
 comes the saltpeter of commerce. It is too expensive 
 for use as a fertilizer, but its formation naturally in 
 the soil is a matter of great importance. 
 
 Chili saltpeter derives its name from the fact that 
 it is imported in large quantities from South America. 
 It is largely used as a fertilizer to supply nitrogen to 
 the soil. It contains about fifteen per cent of nitrogen. 
 
 109. Sulphates. — Calcic sulphate dihydrate, CaS0 4 
 2(H 2 0), is commonly known as gypsum, or land 
 plaster. It is used as a manure, and furnishes both 
 sulphuric acid and lime to the plant. The method of 
 its action as a fertilizer is not well understood. When 
 added to matter containing carbonate of ammonia, an 
 exchange takes place — resulting in sulphate of ammo- 
 nia and carbonate of lime. This makes it valuable 
 for use in the manure heap and about stables to pre- 
 
48 SCIENCE IN FARMING. 
 
 vent waste of ammonia. "When gypsum is heated it 
 parts with the two molecules of water, and is converted 
 into calcic sulphate (0aSO 4 ) or plaster of Paris. 
 
 Amnionic Sulphate, 2(NH 4 )S0 4 , Mol. Wt. 132 — 
 Sulphate of ammonia. Largely used as a fertilizer 
 on account of the large proportion of nitrogen it con- 
 tains, amounting to about 21.2 per cent. 
 
 Ferrous sulphate, commonly known as sulphate of 
 iron, copperas, green vitriol. Valuable as a disin- 
 fectant. When it is present in the soil in considera- 
 ble quantity, it is poisonous to vegetation. The addi- 
 tion of lime results in the formation of carbonate of 
 iron and sulphate of lime. 
 
 110. Phosphates. — The important compounds of 
 phosphoric acid are those it forms with lime. 
 
 Tricalcic phosphate, Oa 3 P 2 8 , Mol. Wt. 310. Bone 
 phosphate. Forms about 55 per cent of all bones. Is 
 also found in minerals called coprolite, apatite and 
 phosphorite, of which there are large natural deposits 
 in South Carolina, Canada, England, Spain, and some 
 other countries. It is insoluble, and only available 
 as plant food as it undergoes decomposition in the 
 soil. 
 
 Bicalcic phosphate, Ca 2 H 2 P 2 O g . Mol. Wt. 272. 
 Obtained from the tricalcic phosphate by a process 
 that will presently be described. Is slowly soluble, 
 and can be used as food by plants. 
 
 Monocalcic phosphate, CaH 4 P 2 O s . Mol. Wt. 234. 
 Is readily soluble, and immediately available as plant 
 food. 
 
 111. Preparation of Phosphates. — To understand the 
 preparation of the bicalcic and monocalcic phosphates, 
 it may be well to represent their composition- in this 
 way — keeping in mind that phosphoric acid (using 
 
CHEMISTRY. 49 
 
 that term to represent P 2 s , called by chemists phos- 
 phoric pentoxide when not in combination) is usually 
 in combination with 3 molecules of water, or some 
 base. 
 Tricalcic phosphate, 0a 3 P 2 O 8 , is equal to 
 CaO) 
 
 CaOV P 2 O s 
 CaO^ 
 or three molecules of lime and one of phosphoric acid. 
 Bicalcic phosphate may be represented 
 CaO) 
 
 CaO \ P 2 5 
 H 2 0) 
 or two molecules of lime, one of water, and one of 
 phosphoric acid. 
 Monocalcic phosphate may be represented 
 CaO ) 
 
 H 2 0[ P 2 5 
 H 2 0i 
 or one molecule of lime, two of water, and one of 
 phosphoric acid. 
 Sulphuric acid, H 2 S0 4 , may be represented 
 
 H 2 SO s . 
 If we put together one molecule tricalcic phosphate 
 one of sulphuric acid and two of water, they may 
 be represented thus : 
 
 1 Molecule 1 Molecule 2 Molecules 
 
 Tricalcic Phosphate Sulphuric Acid Water. 
 
 Sol p 2 o 6 |°5 g»g 
 
 CaO) a ' u 2 
 
 By re-arranging these we can get 
 
 caoUo 5 o-oso.{g;g 
 
 H 2 0) 
 
 4 
 
50 SCIENCE IN FARMING. 
 
 By adding the elements under the first bracket, it 
 will be found they constitute bicalcic phosphate, and 
 by adding those under the second bracket, it will be 
 found they constitute calcic sulphate dihydrate, and 
 thus by mixing bone phosphate, sulphuric acid and 
 water, we get, as the result of the chemical action, 
 bicalcic phosphate and gypsum. 
 
 If we add to the tricalcic phosphate double the pro- 
 portion of sulphuric acid and water, the result will be 
 one molecule of monocalcic phosphate and two mol- 
 ecules of calcic sulphate dihydrate. The process of 
 manufacture of the bicalcic and monocalcic phos- 
 phate differs only in the amount of sulphuric acid 
 and water used. The principle is the same in both 
 cases. To aid the student in comprehending the prin- 
 ciple, we will represent the process of making the 
 monocalcic phosphate by words, instead of by symbols. 
 
 One Molecule Two Molecules Four Mol- 
 
 Tricalcic Phosphate. Sulphuric Acid. ecules Water. 
 
 , — * > , " -s , ' , 
 
 Phosphoric acid Sulphuric acid* Water 
 
 Lime Sulphuric acid Water 
 
 Lime Water Water 
 
 Lime Water Water 
 
 This gives us one molecule phosphoric acid, three of 
 
 lime, two of sulphuric acid* and six of water. They 
 
 can be re-arranged thus: 
 
 One Molecule One Molecule One Molecule 
 
 Monocalcic Phosphate Gypsum Gypsum 
 
 Phosphoric acid Lime Lime 
 
 Lime Sulphuric acid* Sulphuric acid* 
 
 Water Water Water 
 
 Water Water Water 
 
 This subject is of importance because it explains the 
 
 *Properly speaking, sulphuric oxide, S0 3 , sulphuric acid 
 being composed of one molecule sulphuric oxide combined with 
 the elements of one molecule of water. 
 
CHEMISTBY. 51 
 
 conversion of bones and rock phosphate into super- 
 phosphate. The practical application, proportions 
 needed, etc., will be given in the chapter on Fertilizers. 
 
 112. Carbonates. — Carbonic dioxide is readily dis- 
 placed from its compounds by other acids ; and car- 
 bonates can usually be recognized by the fact that 
 they boil up or effervesce when an acid is poured' 
 on them, the effervescence being caused by the escape 
 of the carbonic dioxide in the form of gas. 
 
 The carbonates that interest the farmer are calcic 
 carbonate (carbonate of lime), and ammonic carbon- 
 ate (carbonate of ammonia). Calcic carbonate is 
 well known as chalk and limestone ; it is of some 
 value in the soil. Soils that contain it in consider- 
 able quantity are called calcareous, and may be rec- 
 ognized by effervescing when vinegar or some other 
 acid is poured on them. 
 
 Ammonic carbonate is a white solid produced by 
 the combination of ammonia and carbonic dioxide. 
 It very readily passes into the form of vapor. It has 
 the pungent odor of ammonia. As manure in decom- 
 posing gives off carbonic dioxide as well as ammonia, 
 the ammonia in manure usually exists in the form of 
 carbonate unless some stronger acid is present to com- 
 bine with the ammonia. 
 
 113. Ammonic Chloride.— NH 4 CI. Mol. Wt. 53.5. 
 Commonly called sal ammoniac. It is used as a fer- 
 tilizer to supply nitrogen of which it contains rather 
 more than ammonic sulphate. 
 
 § 7. Organic Chemistry. 
 
 114. Organic chemistry treats of those substances 
 that are produced under the influence of animal or 
 vegetable life. As these compounds all contain 
 
52 SCIENCE IN FARMING. 
 
 carbon, this division of chemistry is frequently called 
 the Chemistry of the Carbon Compounds. 
 
 115. All organic substances are composed from the 
 elements named on page 38 with the exception of sil- 
 icon and aluminum. Silicon is not found in animal 
 substances, and seems to be present in vegetable mat- 
 ter rather as an accident than as an essential element ; 
 and aluminum is not found in any form of organic 
 matter. Besides these thirteen elements, very minute 
 portions of a few others are sometimes found. 
 
 116. Isomerism. — A large number of organic sub- 
 stances are found to be composed of the same ele- 
 ments, combined in the same proportion. Thus starch 
 and cellulose, though quite unlike, are composed of 
 the same elements combined in the same proportions. 
 Such substances are said to be isomeric, and this par- 
 ticular property can only be accounted for on the 
 supposition of a different arrangement of atoms. 
 
 117. Organic substances are divided into nitrogen- 
 ous and non-nitrogenous. The non-nitrogenous com- 
 prise the 
 
 Carbohydrates, or amyloids ; 
 
 The pectose group ; 
 
 Fats; 
 
 Vegetable acids. 
 
 The nitrogenous comprise the 
 
 Albuminoids ; 
 
 Amides ; 
 
 Alkaloids. 
 
 118. Carbohydrates are so called because they all 
 contain hydrogen and oxygen in the proportion to 
 form water. Many of them are isomeric. Most of 
 them can be changed from one form to another, either 
 — when isomeric, by a re-arrangement of their atoms, 
 
CHEMISTRY. 53 
 
 or when not isomeric, by the addition or subtraction 
 of the elements of water. 
 
 119. Cellulose. C 12 H 20 O 10 , forms the solid sub- 
 stance of most plants. » It is not soluble in water but 
 dissolves in weak acids. As the plant becomes older, 
 another substance is deposited with the cellulose, 
 called lignose, the exact chemical composition of 
 which has not been ascertained, but which probably 
 contains a larger proportion of carbon than cellulose. 
 It is harder and less readily dissolved. 
 
 120. Starch. O 6 H 10 O 5 .* This is contained in 
 nearly all plants. It is insoluble in water, but read- 
 ily changed into soluble substances, and hence is 
 easily digested. Inulin is a modified form of starch 
 found in some parts of plants. It is more readily 
 soluble than starch. Dextrine has the same composi- 
 tion as starch and inulin, but is readily soluble. Starch 
 is converted into dextrine by the application of heat. 
 
 121. Gums are a class of substances found in most 
 plants. They are similar to starch in composition 
 and general properties, but are mostly soluble. 
 
 122. Sugars. There are quite a number of vege- 
 table substances possessing the general characters of 
 sugar, and differing but little in composition. The 
 most important are : cane sugar (sacharose) C 12 H 22 
 O xl ; fruit sugar (laevulose) 6 H 12 O 6 , and grape 
 sugar (glucose) 6 H 12 6 .f Cane sugar is found in 
 
 *The exact formula for these organic substances is not in all 
 cases fully determined. Some authorities give starch as Oj 2 
 H 2 o O i o • It will be observed that the proportions of the ele- 
 ments are the same in either case. There is no question as to 
 the percentage composition of these substances. 
 
 tStrictly speaking, grape sugar is called dextrose, and the 
 term glucose includes both lsevulose and dextrose, but in prac- 
 tice the term glucose is principally used to describe dextrose 
 artificially produced. 
 
54 sciencb'in farming. 
 
 the juice of the sugar cane, in the sugar beet, and in 
 many other plants. Fruit sugar is as sweet as cane 
 sugar, but differs from it in that it does not granulate. 
 It exists in honey and in many fruits. Grape sugar 
 (glucose) has the same composition as fruit sugar, 
 but differs from it in being only one-third as sweet. It 
 can be granulated. 
 
 Grape sugar differs in composition from starch only 
 by the elements of a molecule of water. If we take 
 
 1 molecule of starch C 6 Hi 6 
 
 Add 1 molecule water H 2 Oi* 
 
 We have 1 molecule glucose O fi H12 Or 
 
 As the proportionate weights of the molecules of 
 starch and water are 162 and 18, it follows that if we 
 could take 162 lbs. starch and 18 lbs. water and cause 
 them to unite, we should have 180 lbs. glucose. 
 
 By boiling starch or cellulose with water and an 
 acid, it is caused to combine with the water, produc- 
 ing glucose. The acid does not enter into the combi- 
 nation, and at the close of the process remains un- 
 changed in quantity and quality. The combination 
 of the starch and water is effected by the presence of 
 the acid, only. How some substances thus induce 
 changes in others by their presence is not understood. 
 The property is called catalysis. 
 
 Glucose is now made on a great scale, and used for 
 adulteration of sugars and syrups and the manufac- 
 ture of candies and alcohol. Starch, sulphuric acid 
 and water are mixed in the proportions of 1,000 lbs. 
 starch, 21 lbs. acid and 150 gallons water. The mix- 
 ture is boiled until the starch has been converted into 
 
 *When one atom of an element is intended, it is not usual to 
 place the figure 1 after the symbol, as that stands for one atom. 
 We do so in this case to make the addition more clear. 
 
CHEMISTRY. 55 
 
 glucose. Chalk is then added, which combines with 
 the acid, forming sulphate of lime or gypsum, which 
 is separated by settling and straining. 
 
 When pure, glucose is not unwholesome, but it is 
 often carelessly made, and contaminated with the sul- 
 phuric acid and chalk used in its manufacture. 
 
 123. The Fectose Group. — These comprise a large 
 number of substances that are found in plants and 
 especially fruits. They are called pectin, pectose, 
 pectic acid, etc. Their exact chemical composition 
 has not been definitely determined, but they are not 
 true carbohydrates, as the oxygen they contain bears 
 a larger proportion to the hydrogen than it does in 
 water! This group of substances forms the vegetable 
 jellies — which differ from the animal jellies in not 
 containing nitrogen. 
 
 124. Vegetable Acids. — These are a very numerous 
 class of substances, and differ from carbohydrates in 
 containing a larger amount of oxygen. In analyses of 
 foods, both the pectose group and the vegetable acids 
 are frequently included in the estimate of the soluble 
 carbohydrates. 
 
 125. Fats. — The various oily, fatty and waxy sub- 
 stances found in organic matter are divided into two 
 classes : " volatile" oils, such^as oil of peppermint, 
 which give the fragrance to plant and flower, and 
 which will evaporate like water ; and " fixed " oils, 
 which will not evaporate, but leave a greasespot. The 
 latter class are the only ones we need to consider in 
 this work. 
 
 Animal and vegetable fats are of the same gen- 
 eral character, and consist principally of mixtures in 
 varying proportions of three fatty principles : stearin 
 — contained largely in tallow and the firmer fats; pal- 
 
56 SCIENCE IN FARMING. 
 
 mitin, contained in palm oil, butter, beeswax, etc., 
 and olein, which forms the liquid substance in fats 
 and oils. The striking difference between fats and 
 carbohydrates is the much larger proportion of carbon 
 and hydrogen, and the much smaller proportion of 
 oxygen contained in the fats. This is illustrated in 
 the following table, giving the amount of each ele- 
 ment contained in 10,000 parts of starch, pectin and 
 olein : 
 
 Starch Pectin Olein 
 
 Carbon 4,444 4,067 7,740 
 
 Hydrogen 617 508 1,180 
 
 Oxygen 4,939 5,425 1,080 
 
 10,000 10,000 10,000 
 
 It will be remembered that starch fairly represents 
 the carbohydrates, pectin the vegetable jellies, and 
 olein the fats and oils. 
 
 126. Albuminoids. — This term is applied to a large 
 number of important substances, including all nitro- 
 genous organic compounds except the amides and 
 alkaloids. Most, if not all of them contain a small 
 quantity of sulphur. Animal and vegetable albumin- 
 oids differ but little in composition. Their exact 
 chemical formula has not been positively determined, 
 but their composition, in 10,000 parts, is about as fol- 
 lows: 
 
 Carbon 5,350 
 
 Hydrogen 700 
 
 Oxygen 2,240 
 
 Nitrogen 1,550 
 
 Sulphur 160 
 
 10,000 
 
 By comparison with the table in paragraph 125, it 
 will be seen that they contain a larger proportion of 
 carbon and hydrogen than the carbohydrates and less 
 
CHEMISTBY. 57 
 
 oxygen, holding an intermediate position between 
 them and fats. 
 
 127. Animal albumin is found nearly pure in the 
 white of an egg. In its natural state it is soluble ; but 
 heat, alcohol or acids change it into an insoluble 
 form, or "coagulate" it. This is the change that 
 takes place in cooking an egg. Musculirie constitutes 
 the substance of the muscles. Fibrine forms the "clot" 
 in blood. Gelatine is obtained from the skin and 
 bones of animals by the application of hot water. It 
 is commonly seen in glue, and the finer and purer 
 forms are sold as gelatine, isinglass, etc. Gluten is 
 contained in wheat and most grains. It is not a sim- 
 ple albuminoid, but a mixture of several. Keratin 
 is the general name applied to the substances of 
 which horn, hair and wool are formed. Animal 
 casein is found in milk, and forms the substance of 
 cheese. Vegetable casein, which closely resembles 
 it, is found in peas, beans and other leguminous plants. 
 
 128. Amides. — These vegetable nitrogenous com- 
 pounds are not well understood. They exist princi- 
 pally in roots and immature plants. In the plant 
 they are convertible into albuminoids, but animals 
 have not the power to effect this transformation. 
 
 129. Alkaloids are a class of nitrogenous vegetable 
 substances that exist in the plant in but small quan- 
 tities. Tobacco owes its effects to an alkaloid called 
 nicotine ; opium to an alkaloid called morphine ; tea 
 and coffee derive their stimulating effects from an al- 
 kaloid called theine, or caffeine. These substances, 
 though of much general interest, are of little practical 
 importance to the farmer. 
 
 130. Transformation of Organic Substances. — The gen- 
 eral similarity of organic substances renders their 
 
58 SCIENCE IN FARMING. 
 
 change from one form into another very simple. In 
 the natural laboratories of the plant and animal this 
 is constantly being done. Carbohydrates are changed 
 into each other, either- by a rearrangement 01 
 their atoms, or by the addition or removal of the 
 elements of water. By the removal of oxygen, carbo- 
 hydrates are converted into fats, and fats again by 
 the addition of oxygen, are changed back into carbo- 
 hydrates. Out of carbohydrates and nitrates the 
 plant manufactures albuminoids, and the animal can 
 remove the nitrogen and part of the oxygen from the 
 albuminoid and produce fat. These transformations 
 will be more fully considered in the chapters on Plant 
 Growth and Animal Life. 
 
 § 8. Cqmbustion and Decay. 
 
 131. The rapid union of any substance with the 
 oxygen of the air, producing light and heat, is called 
 combustion. In common language, it is said the sub- 
 stance burns. The light and heat are produced by the 
 union of the atoms of oxygen with the atoms of the 
 substance, the force that had before been keeping them 
 apart being converted into heat. Substances that will 
 burn are called combustible ; those that will not are 
 called incombustible. 
 
 "When a carbohydrate such as cellulose burns, the 
 hydrogen and oxygen being in the proportions to form 
 water, pass off as watery vapor, while the carbon 
 combines with oxygen from the air, forming carbonic 
 dioxide. As there are 12 atoms of carbon in a mol- 
 ecule of cellulose, and as one atom of carbon unites 
 with two atoms of oxygen in forming carbonic dioxide, 
 it follows that in the combustion of a molecule of cellu- 
 lose it unites with 24 atoms of oxygen from the air. 
 
CHEMISTRY. 59 
 
 The process and its results may be thus shown: 
 Cellulose Oxygen Result. 
 
 12 / 12(00 ) 
 
 §*° ° 2 H 10(H 2 6) 
 
 The student will quickly see that there are the 
 same number of atoms of each element on each side 
 of the brace. The proportions by weight would be 
 
 1 molecule cellulose, weighing '. 324 
 
 24 atoms oxygen, weighing 16 each 384 
 
 Total material 708 
 
 Resulting in 
 
 12 molecules carbonic dioxide, weighing 44 each 528 
 
 10 molecules water, 18 each , 180 
 
 Total product 708 
 
 That is, when 324 parts of cellulose are burned, 
 there is a combination of 144 parts of carbon with 384 
 parts of oxygen ; or, when 1,000 lbs. of cellulose are 
 burned, there is a union of 444 lbs. carbon with 1,269 
 lbs. oxygen, making 1,713 Jibs, of the two elements. 
 
 When fat is burned, the proportions are somewhat 
 different. Instead of the hydrogen and oxygen in the 
 fat being in the proportion to form water, there is a 
 great excess of hydrogen, so that not only does a 
 thousand lbs. of fat contain more carbon than a thou- 
 sand lbs. of cellulose, but when it burns, a large part 
 of the hydrogen it contains also unites with oxygen 
 from the air. In burning 1,000 lbs. olein, there would 
 be a union of 
 
 Carbon 771 lbs. 
 
 Hydrogen 105 lbs. 
 
 With oxygen 2,929 lbs. 
 
 Total elements uniting 3,805 lbs. 
 
 So that in the combustion of 1,000 lbs. of oil, the 
 weight of the elements that enter into combination 
 
60 SCIENCE UNARMING. 
 
 is more than twice as great as in the combustion of 
 1,000 lbs. of cellulose. Hence the much greater 
 amount of heat produced. 
 
 132. Decay. — When organic matters are exposed to 
 warmth, air and moisture, the same chemical changes 
 that take place rapidly in combustion, occur slowly, 
 the result being the same in the end. This process of 
 decay is called by chemists " eremacausis," which 
 means slow combustion. During decay heat is pro- 
 duced, as in combustion, but being developed much 
 more slowly, is less noticeable. The products of 
 the decay of non-nitrogenous organic matter are car- 
 bonic dioxide and water. If the substance contains 
 nitrogen, either nitric acid or ammonia will also be 
 produced. 
 
 The chemistry of respiration will be explained in 
 the chapter on Animal Life. 
 
CHAPTER V 
 
 SCIENCE IN AIR. 
 
 § 1. Its Composition and Characteristics. 
 
 133. Composition. — The atmosphere is a mixture of 
 oxygen and nitrogen, with a variable quantity of 
 watery vapor, and a small amount of carbonic diox- 
 ide. Its average composition, by weight, in 100,000 
 parts is as follows : 
 
 Nitrogen 78,492 
 
 Oxygen 20,627 
 
 Watery vanor 840 
 
 Carbonic dioxide 41 
 
 100,000 
 This composition is commonly expressed as four parts 
 nitrogen and one of oxygen. 
 
 In addition to these substances the atmosphere al- 
 ways contains a small amount of ammonia, dust, and 
 other impurities. The proportions in which these 
 exist are so minute that although their presence can 
 be detected, it is extremely difficult to estimate the 
 amount. 
 
 134. The proportion of oxygen and nitrogen in the 
 air in the open country never varies. In a close room 
 where many persons are gathered, or in the crowded 
 streets of large cities, the proportion of oxygen may 
 be slightly reduced. The proportion of carbonic diox- 
 ide is also nearly uniform except in places where 
 from local influences this gas is produced more rapid- 
 
62 SCIENCE IN FARMING. 
 
 ly than it can be diffused. The proportion of watery 
 vapor varies greatly. It may be said therefore, that 
 with the exception of water, the composition of the 
 great bulk of the atmosphere is the same at all places 
 and all seasons. 
 
 The different gases of which the atmosphere is com- 
 posed are simply mixed together, and are not in 
 chemical combination (57). 
 
 135. Diffusion of Gases. — If a jar containing hydro- 
 gen is placed above one containing carbonic dioxide, 
 and the two are connected by a small tube, the car- 
 bonic dioxide gradually rises through the tube and 
 diffuses itself through ,the hydrogen, which at the 
 same time descends diffusing itself through the car- 
 bonic dioxide, and although the latter gas is twenty 
 times as heavy as the hydrogen this process will con- 
 tinue — the heavy gas ascending and the light one de- 
 scending, until both jars contain a mixture of the two 
 gases in exactly the same proportion. "Whenever two 
 gases are mixed, in any proportion, they will diffuse 
 through each other until in time the composition of 
 all parts of the mixture is the same. If the specific 
 gravity* of one of the gases composing the mixture is 
 
 ♦Specific gravity is the proportionate weight of a substance 
 — that is the relation that the weight of a given bulk of one 
 substance bears to the weight of an equal bulk of some other 
 substance taken as a standard. Thus a pint of oil weighs less 
 than a pint of water, and so we say that the specific gravity of 
 oil is less than that of water. A cubic foot of oxygen weighs 
 more than a cubic foot of nitrogen, and we say that its specific 
 gravity is greater. In practice, solids and liquids are com- 
 pared with water as a standard, and gases with air. Thus the 
 specific gravity of lead is 11.44, by which is meant that a given 
 bulk of lead weighs eleven and forty-four one-hundredths times 
 as much as an equal bulk of water. The specific gravity of 
 hydrogen is .069, by which is meant that a given bulk of hydro- 
 gen weighs sixty-nine one4housandths as much as an equal 
 bulk of air, 
 
SCIENCE IN AIR. 63 
 
 greater than the other, more time will be required to 
 effect the diffusion, but it will be as thoroughly ef- 
 fected. When different gases have thus been mixed, 
 they do not again separate, however great may 
 be the difference in specific gravity. This is called 
 the Law of Diffusion of gases. 
 
 It is this law that secures the uniformity of com- 
 position of the atmosphere. Although the specific 
 gravity of oxygen is greater than that of nitrogen, 
 yet through the working of this law, the lower 
 portions of the atmosphere contain no more oxygen 
 than the upper portions. Although the specific grav- 
 ity of carbonic dioxide is much greater than that of 
 the other constituents of the atmosphere, yet it never 
 separates, and settles into the low places and valleyf, 
 but the air on the highest mountain peaks contains 
 as much as that at the level of the ocean. Owing to 
 this law also, injurious gases poured into the air are 
 soon diffused through the whole bulk of the atmos- 
 phere, and by their great dilution become harmless. 
 If it were not for this, cities would soon become unin- 
 habitable by the accumulation of carbonic dioxide 
 and other injurious gases, and every low place would 
 be filled with poisonous gas. 
 
 136. Apparent Exceptions. — Occasionally there is 
 such an accumulation of carbonic dioxide in cellars, 
 dry wells and old pits that persons entering them in- 
 cautiously, lose their lives. In the island of Java 
 there is said to be a place called the Valley of Poison, 
 containing an accumulation of this gas. The ground 
 is covered with the bones of animals which have 
 been suffocated while passing through. These ex- 
 ceptions are only apparent. In such cases the 
 gas is being produced in the well, pit or valley, 
 
64 SCIENCE IN FARMING. 
 
 more rapidly than it can be diffused through the air. 
 
 When there is reason to suspect that carbonic diox- 
 ide — or " choke damp," as it is popularly called, 
 exists in dangerous quantities, a lighted candle should 
 be lowered into it. If the gas is present in sufficient 
 quantity to be dangerous the candle will be extin- 
 guished. The best method of removing this gas from 
 pits and cellars is by the -use of quicklime. One 
 hundred pounds of quicklime will absorb about 675 
 cubic feet of-the gas. 
 
 The air near a large city contains a larger propor- 
 tion of ammonia than that in the country, but this 
 also is owing to the fact that the ammonia is produced 
 in the city more rapidly than it can be spread through 
 the surrounding atmosphere by diffusion. The winds 
 assist in securing the uniform diffusion through the 
 atmosphere of gases developed in special localities. 
 § 2. Importance of Each Constituent. 
 
 No estimate can be made of the comparative value 
 of the different constituents of the atmosphere, as each 
 one is essential. 
 
 137. Oxygen sustains life and combustion. It is 
 essential to germination. Sfc unites with organic mat- 
 ter in the soil, giving rise to new compounds that can 
 be used as food by plants. It combines with impuri- 
 ties and poisonous gases in the atmosphere, changing 
 them into harmless forms. It acts upon the rocks 
 and rocky particles of the soil and reduces them to 
 such a condition that plants can use them. It is 
 the great purifier and disinfectant, as it converts dan- 
 gerous organic compounds into harmless -inorganic 
 ones. Without oxygen neither plant nor animal 
 could live ; and'the action of oxygen on the soil is 
 essential to maintain its fertility. 
 
SCIENCE IN Alft. 65 
 
 138. The nitrogen of the air serves to dilute the 
 oxygen, and prevent its too energetic action. Being 
 itself perfectly harmless, and in many respects inert, 
 it is excellently adapted for this purpose. Although 
 it is essential to plant growth, the plant lias no power 
 
 'to use the free nitrogen of the air ; it must be in com- 
 bination' with some other element before it can be ap- 
 propriated by the plant. There is a probability that 
 under certain circumstances the nitrogen of the air 
 contained in the pores of the soil is oxidized and made 
 available for plant food. The free nitrogen of the air 
 is oxidized to a small extent through the influence of 
 electricity, forming nitric acid, which combines with 
 the ammonia in the air, forming nitrate of ammonia, 
 which is washed out by the rains. The quantity 
 supplied to the soil in this way varies, but probably 
 the average does not exceed from 6 to 9 lbs. of nitro- 
 gen per acre in a year, 
 
 139. Although the proportion of carbonic dioxide 
 in the atmosphere is small, (only one part in twenty- 
 five hundred,) yet the volume of air is so great that 
 the actual amount of this gas is very considerable. It 
 is calculated the air over an acre of ground contains 
 28 tons of this gas. This is a sufficient quantity to 
 supply the needs of vegetation for many years, even 
 were there no more produced ; but the processes of 
 combustion, respiration and decay are constantly 
 pouring this gas into the atmosphere.* 
 
 The carbonic dioxide contained in the air supplies 
 all the carbon for the plant. Careful experiments 
 have shown that plants cannot grow and increase in 
 
 *The amount of this gas absorbed by the leaves of plants 
 equals that produced, and the balance is thus constantly main- 
 tained. 
 5 
 
66 SCIENCE IN FARMING. 
 
 weight in an atmosphere containing none of this gas. 
 The constant motion of the winds causes an immense 
 amount of air to touch the leaves of plants, thus 
 enabling them to obtain an abundant supply of car- 
 bon. The farmer, therefore, need have no anxiety 
 about providing carbon or carbonaceous manures to 
 the roots of plants. 
 
 140. Water vapor is always present in the air, but 
 the amount varies greatly. The warmer the air the 
 greater amount of water it is able to retain. When 
 the air contains all the water it can hold at that tem- 
 perature, it is said to be saturated. When air that is 
 partly saturated is cooled, a temperature will be 
 reached at which it will be saturated, and any fur- 
 ther decrease of temperature will cause the formation 
 of mist or dew. The temperature at which mist or dew 
 begins to form is called the " dew point." Suppose 
 the temperature of the air in a room was 70 degrees, 
 and it contained enough water to saturate it at 60 de- 
 grees ; if then the temperature was reduced to 60 de- 
 grees, any further reduction would result in the form- 
 ation of mist or dew, and 60 would be the dew point. 
 The nearer the air is to saturation the closer will the 
 dew point approach to the temperature of the air. 
 Therefore a high dew point shows that the atmos- 
 phere is nearly saturated. When a pitcher is filled 
 with ice-water in summer, drops of dew soon begin to 
 collect on the outside, and, in popular language the 
 pitcher is said to " sweat." The expression is incor- 
 rect. The drops of water do not come through the 
 pores of the pitcher, but the cold surface reduces 
 the temperature of the air touching it below the dew 
 point, and the water contained in the air is condensed 
 on the sides of the pitcher. On a clear night the 
 
SCIENCE IN AIR. 67 
 
 leaves of plants, the surface of the soil and other ob- 
 jects radiate into space the heat they have absorbed 
 from the sun during the day. As soon as they are 
 by this process cooled below the dew point, the mois- 
 ture of the air is condensed on them, and we say the 
 " dew falls." Strictly speaking, the dew does not fall, 
 as it collects as readily on the under surface of an ob- 
 ject as on its upper surface. As clouds check this 
 radiation of heat into space (54), we rarely have dew 
 on cloudy nights. 
 
 141. As air is warmed, its capacity for water is in- 
 creased, it feels dry, and will absorb water from what- 
 ever it touches, although the actual amount contained 
 is the same as before. This is the reason why the air 
 of a " stove room" is injurious to the lungs, and de- 
 structive to house plants, unless provision is made for 
 increasing the amount of moisture in the air. 
 
 The vapor of water in the air is not usually ab- 
 sorbed by the plant, but an increase in the amount 
 present refreshes the plant by checking evaporation 
 from th# leaves. The soil absorbs a considerable 
 amount of moisture from the air, and in this way it 
 becomes of use to the plant. 
 
 142. The quantity of ammonia in the air is very 
 small. A portion of this is absorbed directly by the 
 leaves of plants, a portion is washed out by the rains, 
 and a portion is absorbed by the soil. The amount of 
 nitrogen brought down by the rains in nitricfacid and 
 ammonia has been given (138). What amount is 
 absorbed by the leaves of plants and by the soil has 
 not yet been determined, and varies so much under 
 different circumstances, that it will be difficult to se- 
 cure an average. The amount absorbed is greatly in- 
 fluenced by the character and condition of the soil. 
 
68 SCIENCE IN FARMING. 
 
 The source of ammonia in the air has not been pos- 
 itively ascertained. Some of it is produced by the 
 decomposition of organic matter ; some by the burn- 
 ing of coal. There is always a larger amount brought 
 down by rains in the neighborhood of cities than in 
 country districts. 
 
 § 3. Summary. 
 
 143. The farmer therefore gets from the air : 
 
 Oxygen, to cause the germination of seed, the de- 
 composition of organic matter, and the reduction of 
 the mineral portions of the soil to a form in which 
 they can be used as food for plants. 
 
 Nitrogen in the form of ammonia, absorbed by the 
 leaves of plants and by the soil, and brought down by 
 the rains, and in the form of nitric acid brought down 
 by the rains. Also, probably, free nitrogen, to be ox- 
 idized in the soil under proper conditions into nitric 
 acid. 
 
 Carbon, in the form of carbonic dioxide. The 
 farmer can use the plant for the purpose of collecting 
 carbon from the air and supplying it to the soil, for 
 the improvement of its condition. 
 
CHAPTER VI. 
 
 SCIENCE IN SOILS. 
 
 § 1. Origin of Soils. 
 
 144. Soil consists of the broken fragments of rock 
 mixed with partially decayed organic matter. The 
 character of the soil, therefore, varies with the kind 
 of rock from which it was produced, the extent of the 
 decomposition it has undergone, and the kind and 
 amount of organic matter that is mixed with the de- 
 composed rock. 
 
 145. Rock has been reduced £to the condition of 
 soil by various natural agencies. When the conti- 
 nents_were under the ocean, the force of the water 
 broke off fragments of rock, and by grinding these to- 
 gether, reduced them to powder. During the ages 
 when glaciers — great rivers of ice — covered much of 
 the earth's surface, the rocks were ground to powder. 
 After the continents took the form they now have, 
 other agencies continued the work. Water penetrated 
 the crevices of rock, and, freezing, broke and crum- 
 bled it. It also gradually dissolved part of the rock. 
 The air and water together caused the elements in 
 the rock to separate and enter into new combinations. 
 Thus by degrees a soil of inorganic material was . 
 
70 SCIENCE IN FARMING. 
 
 formed. The rains brought down and added to it ni- 
 tric acid and ammonia from the air, and on this primi- 
 tive soil low orders of plants, at first, began to grow; 
 and as they decayed upon the soil, returned to it all 
 they had gathered from both soil and air. Fresh sup- 
 plies of nitrogen were constantly brought down by the 
 rains, and this the vegetation changed into organic 
 forms and restored to the soil again. Thus, through 
 long ages, the work of preparing the soil went on, 
 and where the hand of man has not interfered, is still 
 going on. 
 
 § 2. Composition and Classification of Soils. 
 
 146. Soils are composed of three principal constit- 
 uents — sand, clay, and humus. 
 
 Sand is rock reduced to a powder. The composi- 
 tion of each grain is that of the original rock. 
 
 Clay is the product of the chemical decomposition 
 of rock. When perfectly pure it is a silicate of alu- 
 mina. It is seldom a pure silicate, however, usually 
 containing potash, soda, magnesia, iron, and other 
 substances. 
 
 Humus is partially decayed organic matter. When 
 organic matter reaches a certain stage of decay, it 
 forms a dark colored mass, and decomposition pro- 
 ceeds but slowly. This dark mass is humus. 
 
 147. According to the proportion of these three in- 
 gredients, soils are known as sandy, loamy, clayey 
 and peats. 
 
 Mixtures of sand and clay are usually classified 
 thus: 
 
SOILS. 71 
 
 Name of Per cent of Per cent of 
 
 Soil. Sand. Clay. 
 
 Sand 100 — 
 
 Sandy loam 75 25 
 
 Loam 50 50 
 
 Clay loam 25 75 
 
 Clay 100 
 
 Soils that do not exactly agree with any of these, 
 are classed with the one to which they approach most 
 closely. Thus, a soil containing 60 per cent sand 
 and 40 per cent clay, or 60 per cent clay and 40 per 
 cent sand, is called a loam ; while one containing 35 
 per cent clay and 65 per cent sand is called a sandy 
 loam, and one containing 35 per cent sand and 65 per 
 cent clay, is called a clay loam. 
 
 In swamps where a rank growth of vegetable mat- 
 ter is produced every year, and decay is checked by 
 excess of water, humus accumulates in great quantity, 
 so that the soil consists almost entirely of partially 
 decayed vegetable matter. Such soils are called peats 
 or swamp muck. 
 
 § 3. Properties of Soils. 
 
 The characteristics of soils vary according to their 
 chemical composition and their mechanical condition. 
 
 148. Retention of Water. — If a portion of soil is 
 soaked with water and then allowed to drain until 
 no more will flow from it, a considerable amount of 
 capillary water (97) will remain. Soils differ, not 
 only in the amount of water they can retain within 
 their pores, but also in the readiness with which they 
 part with this water by evaporation. In the follow- 
 ing table the first column of figures gives the number 
 of pounds of water retained by 100 lbs. dry soil, and 
 the second column the percentage of this water lost 
 
72 SCIENCE IN FARMING. 
 
 by evaporation in a given time, the soils being all 
 spread out and treated alike : 
 
 Kind of Water Per cent lost by 
 
 soil. retained evaporation. 
 
 Quartz sand 25 88.4 
 
 Clay loam 40 52 
 
 Heavy clay 61 34.9 
 
 Loam 51 45.7 
 
 Garden mould 89 24.3 
 
 Humus 181 25.5 
 
 It will be seen that while pure sand retained only 
 one-fourth of its weight of water, and lost nearly all 
 of that by evaporation, in the short time (four hours) 
 used in the experiment, humus retained nearly dou- 
 ble its weight, and lost but one-fourth of this by evap- 
 oration in the same time. The retentive power of 
 the garden mould was due to the large amount of hu- 
 mus it contained. 
 
 In general, it may be said that the larger the pro- 
 portion of sand in a soil, the less power it has to 
 retain water, and the more readily it will part by 
 evaporation with what it contains ; and the larger the 
 proportion of humus in the soil, the more water it 
 will be able to retain and the more slowly will it part 
 with it by evaporation. 
 
 The coarseness or fineness of the particles of a soil 
 has a great influence on its power to retain water. 
 The finer the particles, the more water it can retain. 
 A very fine sand is greatly superior to a very coarse 
 sand. 
 
 149. Absorption of Water from Air. — Soils possess to 
 a greater or less degree the power of absorbing mois- 
 ture from the air. In this, as in the retention of wa- 
 ter, soils differ greatly. The following table shows 
 the number of pounds of water absorbed by 1,000 lbs. 
 
soils. 73 
 
 of perfectly dry soil exposed to moist air for 24 hours, 
 the result of one experiment : 
 
 Quartz sand 
 
 Heavy clay 41 
 
 Garden mould 52 
 
 Clay loam 28 
 
 Loam 35 
 
 Humus" 120 
 
 Sand, especially coarse sand, has little p(jwer of ab- 
 sorbing moisture from the air. Clay has more power, 
 and humus most of all. 
 
 The amount of water absorbed from the air depends 
 on the temperature ; the higher the temperature the 
 less the absorption. The rapidity with which the ab- 
 sorption takes place depends on the amount of mois- 
 ture in the atmosphere. A given soil at a given tem- 
 perature will absorb the same amount of water from 
 the air, whether it contain a larger or smaller amount 
 of moisture, but a longer time will be required in pro- 
 portion to the dryness of the air. 
 
 As a result of this property, soils — especially those 
 rich in humus — that may become comparatively dry 
 during a hot day, will absorb a considerable amount 
 of water during the night. 
 
 150. Capillary Attraction. — When a lamp-wick, or 
 any other porous substance, is dipped into a liquid, 
 the liquid will ascend through the pores of the sub- 
 stance, and the force that causes it to ascend is called 
 capillary attraction. The law governing the opera- 
 tions of this force is that the smaller the pores of the 
 substance, the greater hight the liquid will be raised. 
 Soil being a porous substance, possesses the property 
 of capillarity, to a greater or less degree, according to 
 the number and fineness of the pores. In a soil com- 
 posed largely of coarse sand, the pores are large and 
 few, and the upper part of the soil may be quite dry 
 while there may be abundance of water but a short 
 
74 SCIENCE IN FARMING. 
 
 distance below the surface. A soil composed of fine 
 particles contains a large number of small pores, and 
 can draw water from considerable depths. Humus 
 possesses this property in the highest degree ; coarse 
 sand in the lowest. Soils composed of a mixture of 
 fine sand^lay and humus, often possess it in a very 
 high degree. 
 
 151. Retention of Fertilizing Elements. — If the dark 
 colored, offensive liquor from a manure he^p is al- 
 lowed to filter through a portion of good soil, the of- 
 fensive and coloring matter will be retained by the 
 soil, and the water that passes through' will be free 
 from color and odor. All soils possess this property 
 to some degree, but certain soils possess it to a much 
 greater degree than others. 
 
 The effect is partly mechanical. The matters in so- 
 lution adhere to the surface of the particles of the 
 soil, and are thus retained. The more porous the soil, 
 and the greater amount of surface is thus exposed to 
 the liquid, the greater its power in this way. 
 
 The effect is also partly chemical. Phosphoric acid, 
 when in solution, unites with lime, alumina, and 
 ferric oxide, forming insoluble compounds. Ammo- 
 nia and potash enter into combination with the silica 
 and alumina of clay soils, forming what are called dou- 
 ble silicates. Calcic carbonate in some cases enables 
 a soil to retain potash and ammonia. Humus has 
 this retentive power in a great degree, acting both 
 chemically and mechanically. 
 
 In general, sandy soils have the least power of re- 
 taining fertilizing elements, and the coarser the sand 
 the less its power. Clay and humus have this power 
 to a great degree. The power of clay is increased 
 when it containsjferric oxide, the presence of which 
 
SOILS. 75 
 
 can be recognized by the red color it imparts to 
 the soil. 
 
 152. Temperature of the Soil. — The warmth of the 
 soil is derived from the rays of the sun, and is in- 
 fluenced by the character and color of the soil and 
 the amount of water it contains. 
 
 Other things being equal, a dark soil absorbs 
 warmth from the sun more rapidly than one of a 
 lighter color (46). 
 
 Sandy soil acquires heat more rapidly than a clay, 
 as it is a better conductor (42), and the heat received 
 from the sun is carried down into the soil. Such a 
 soil, therefore, gains warmth more rapidly in the 
 spring, and is also more likely to " burn out" during 
 a hot season. 
 
 A dry soil acquires heat more rapidly than a wet 
 one, for the double reason that the specific heat (39) 
 of water is much greater than that of soil, and that so 
 large a portion of the heat received by a wet soil is 
 expended in evaporating the water (34). It requires 
 more than twenty times as much heat to raise the 
 temperature of a wet soil to a point at which seed 
 will germinate as would be required by a dry one. 
 A well drained sandy loam, containing sufficient hu- 
 mus to make it dark in color, is best adapted to secure 
 favorable results in temperature. 
 
 153. Absorption of Ammonia. — The soil possesses 
 the property of absorbing and condensing gases 
 within its pores, and when exposed to the air 
 under favorable conditions will absorb ammonia. 
 If substances are present in the soil with which 
 this ammonia can combine, the soil can then 
 take up a further portion from the air. If the soil 
 contains nothing to fix the ammonia, it is liable to be 
 
76 SCIENCE IN EARMING. 
 
 again given off in the air and lost. Clay and humus 
 possess to a greater degree than any other substance 
 the property of absorbing and retaining ammonia. A 
 moist soil absorbs more than one that is entirely dry. 
 The rate of absorption depends on the amount of sur- 
 face exposed to the air. 
 
 154. Adhesiveness of Soils. — The common terms 
 " light " and " heavy " as applied to soil, have refer- 
 ence to its adhesiveness, or " stickiness," and not to 
 its actual weight. A cubic foot of pure sand weighs 
 about 35 lbs. more than a cubic foot of clay, yet a 
 sandy soil is called " light," and a clay soil " heavy." 
 Clay is the most adhesive of all soils, and consequently 
 the most difficult to work. The addition of sand re- 
 duces its adhesiveness. Humus has the same effect. 
 
 155. Weight of Soil. — The following table gives the 
 
 weight of the dry soil on an acre taken to the depth 
 
 of one foot : 
 
 Sand 4,792,000 lbs. 
 
 Loam 4,182,000 lbs. 
 
 Common plow land 3,485,000 lbs. 
 
 Heavy clay 3,267,000 lbs. 
 
 Garden mould 3,049,000 lbs. 
 
 Sand is the heaviest and humus the lightest con- 
 stituent of soils, consequently those rich in humus, 
 such as old pastures and rich black lands, weigh less 
 to the acre than sandy or loamy soils. 
 
 156. Wastes by Drainage.— The water that falls 
 upon the soil and filters through it dissolves a portion 
 of the soluble constituents, and analysis of drainage 
 water shows that it contains nearly every element of 
 fertility contained by the soil through which it has 
 passed, with the exception of phosphoric acid. The 
 amount of most substances removed by drainage is 
 not, however, sufficient to be of practical importance. 
 
soils. 77 
 
 Most of the important soil constituents are retained 
 in the manner already explained (151). Nitric acid 
 is the important exception to this rule. Nearly all 
 its salts being soluble it is freely carried away by the 
 drainage water. The Nile pours 1,100 tons of salt- 
 peter into the sea every 24 hours, the result of the 
 drainage of the soil. 
 
 About the only means by which the waste of 
 nitrates by drainage can be prevented, is to keep the 
 soil covered with a crop during the season when nitric 
 acid is formed in the soil. The roots of the growing 
 crops take up the nitrates as they are formed, and 
 convert them into insoluble organic compounds. 
 
 As will be seen (163), the nitrates are produced 
 most rapidly during the warmer months. Cereal 
 crops, wheat, etc., — leave the soil bare much of this 
 time, and hence are exhaustive because they allow a 
 waste of fertility. When clover is sown with wheat 
 it remains after the latter has been cut, favors nitri- 
 fication and saves the nitrates that are produced, by 
 changing them into organic forms. 
 
 § 4. Chemical Characteristics of Soils. 
 
 157. No two soils have exactly the same composi- 
 tion chemically, and it would be difficult even to get 
 two samples of soil from different parts of the same 
 field that would be exactly alike. All chemical anal- 
 yses of soils are therefore approximate, only. 
 
 The value of chemical analysis in determining the 
 present fertility of a soil is but small. A soil may 
 contain, as shown by analysis, an abundance of every 
 element of plant food, and yet be unproductive, owing 
 to the plant food being in insoluble combinations. A 
 soil, however, that shows by analysis a large propor- 
 tion of plant food, is usually one that can be made 
 
78 SCIENCE IN FARMING. 
 
 productive by proper treatment. The following anal- 
 ysis is of an excellent wheat soil : 
 
 Silica 71.552 
 
 Alumina 6.935 
 
 Ferric oxide 5.173 
 
 Lime 1.229 
 
 Magnesia 1.082 
 
 Potash 0.354 
 
 Soda 0.433 
 
 Sulphuric acid 0.044 
 
 Phosphoric acid 0.430 
 
 Organic matter 10.198 
 
 ' Water 2.684 
 
 158. Plant Food. — The greater part of even the 
 
 most fertile soils is of no value as plant food. Silica, 
 
 though often found in plants, is not essential to their 
 
 growth, and alumina does not enter the plant. Of 
 
 the organic matter in the soil, only a small per 
 
 cent is of value as plant food. It is necessary that a 
 
 soil should contain all the elements found in the plant, 
 
 except carbon, hydrogen and oxygen ; but as some of 
 
 these elements are used by the plant in such minute 
 
 quantity and are so universally present in the soil, 
 
 they may in practice be disregarded. The substances 
 
 usually considered as plant food are : 
 
 Nitrogen 
 Phosphoric acid 
 Sulphuric acid* 
 
 Potash 
 Lime* 
 
 An acre of the soil, the analysis of which has just 
 
 been given, would weigh, taken to the depth of one 
 
 foot, about 3,500,000 lbs., and would contain of these 
 
 substances-: 
 
 Nitrogen (probahly) 8,000 lbs. 
 
 Phosphoric acid 15,050 lbs. 
 
 Sulphuric acid 1,540 lbs; 
 
 Potash 12,390 lbs. 
 
 Lime 43,015 lbs. 
 
 *Lime and sulphuric acid are usually present in sufficient 
 
SOILS. 79 
 
 Few soils are as rich in phosphoric acid as the one 
 above given, and many are much richer in sulphuric 
 acid. 
 
 159. Exhaustion of Soils. — When crops are contin- 
 uously grown and carried away, nothing being re- 
 turned to the soil, the amount of plant food undergoes 
 a steady diminution. A crop of 30 bushels of wheat 
 and the straw will take from the land, of 
 
 Nitrogen 45 lbs. 
 
 Phosphoric acid 22.7 lbs. 
 
 Sulphuric acid 19.5 lbs. 
 
 Potash 27.9 lbs. 
 
 Lime 10.2 lbs. 
 
 If a crop of 30 bushels of wheat to the acre were 
 grown every year, and both grain and straw carried 
 away, nothing being restored to the land, it would ex- 
 haust the soil, the analysis of which has just been 
 given, of these constituents as follows : 
 
 Of nitrogen in 177 years. 
 
 Of phosphoric acid in 766 years. 
 
 Of sulphuric acid in 80 years. 
 
 Of potash in 444- years. 
 
 Of lime in 4,217 years. 
 
 Practically it would be impossible to exhaust the 
 soil of these substances, as, before it was exhausted, 
 crops would cease to grow. 
 
 160. Rotation. — The exhaustion of the soil by a ro- 
 tation of crops, especially where a large portion of the 
 crop is fed on the farm, is much slower. Take, for 
 illustration, a farm of eighty acres. Suppose that the 
 crops grown are Indian corn, wheat, clover and grass; 
 that such a rotation is adopted that twenty acres 
 are each year devoted to each crop. Suppose nothing 
 
 quantity, and are therfore frequently disregarded in estimating 
 tiie quality and needs of soils. 
 
80 SCIENCE IN FARMING. 
 
 is sold but wheat and animal products. We will esti- 
 mate the annual average crops to be, 
 
 Wheat (400 bushels) 24,000 lbs. 
 
 Straw 48,000 lbs. 
 
 Clover hay 100,000 lbs. 
 
 Hay 80,000 lbs. 
 
 Corn (1,000 bushels) 56,000 lbs. 
 
 Corn fodder 168,000 lbs. 
 
 Calculating that in feeding the straw, hay, corn, 
 and fodder, 10 per cent of the nitrogen, phosphoric 
 acid and potash are taken by the animal, and 90 per 
 cent returned in the manure, the loss of these constit- 
 uents each year would be: 
 
 Nitrogen. Phosphoric Acid Potash. 
 
 Wheat* 440 lbs. 191 lbs. 129 lbs. 
 
 Strawt 23 lbs. 12 lbs. 29 lbs. 
 
 Cloverf 197 lbs. 56 lbs. 195 lbs. 
 
 Hayt 124 lbs. 30 lbs. 134 lbs. 
 
 Cornt 93 lbs. 34 lbs. 20 lbs. 
 
 Cornfoddert 80 lbs. 89 lbs. 161 lbs. 
 
 Total loss 957 lbs. 412 lbs. 668 lbs. 
 
 Dividing these amounts by 80 — the number of acres 
 — we get the loss per acre per annum on a farm so con- 
 ducted : 
 
 Nitrogen 11.96'lbs. 
 
 Phosphoric acid 5.15 lbs. 
 
 Potash 8.35 lbs. 
 
 With this rotation, it wodld require, to exhaust the 
 soil described in paragraph 158 : 
 
 Of nitrogen : 668 years. 
 
 Of phosphoric acid 2,922 years. 
 
 Of potash 1,484 years. 
 
 Under a proper rotation there need therefore be no 
 apprehension of exhaujting, or even of materially re- 
 ducing, the amount of 'plant food in a fertile soil in 
 any ordinary life time. In fact, except by allowing 
 
 * Amount contained in entire crop, t One-tenth amount con- 
 tained in entire crop. 
 
Bolts. 81 
 
 ifctb'wash away, it would be impossible to exhaust 
 the plant food in any fertile soil in a hundred years. 
 
 181. Condition of Plant Food in Soil.— The greater 
 port of the plant food in the soil exists in forms of 
 combination that cannot be used by the plant until 
 they have undergone some chemical change. The 
 same causes that prevent the exhaustion of the plant 
 food by drainage, also prevent it from being imme- 
 diately used by a crop. Nitrogen usually exists in in- 
 soluble organic compounds ; phosphoric acid ih insolu- 
 ble phosphates of lime or iron ; potash m-combination 
 with silica and alumina. A soil may contain enough of 
 these constituents to produce 30 bushels of wheat per 
 acre for five hundred years, and yet not contain 
 enough of them in a form the plant can use to pro- 
 duce a single crop of 10 bushels to the acre. Some 
 soils that are called " exhausted " or " run down " 
 contain a great deal more plant food in an acre than 
 others that are called extremely fertile. In the one 
 case the plant food is available, in the other it is not. 
 A large part of the science of farming consists in 
 knowing how to render the plant food in the soil 
 available, and how to secure it with a crop before it 
 is wasted by drainage. 
 
 162. Chemical Changes in the Soil. — In order that 
 the plant food in the soil may be rendered available, 
 chemical action must be constantly maintained. The 
 principal agents by which the chemical changes are 
 effected, are the oxygen of the air, and the carbonic 
 dioxide in the water of the soil. 
 
 By the action of the carbonic dioxide, the tricalcic 
 phosphate is gradually changed into bicalcic phos- 
 phate, the nature of the change being similar to that 
 deseribqd on page 49, carbonic dioxide taking the 1 
 
82 SCIENCE XS FARMING. 
 
 place of sulphuric acid. The same agency also 
 changes the potash into a soluble form. 
 
 By the action of the oxygen of the air, the organic 
 matter in the soil is changed into ammonia, water, 
 and carbonic dioxide — and the ammonia is alsq 
 oxydized producing nitric acid and water. 
 
 163. Nitrification. — By this is meant the conversion 
 of the nitrogen contained in organic matters and am- 
 monia into nitric acid. It is one of the most impor- 
 tant chemical operations in the soil — as it is in the 
 form of nitric acid — or its compounds with bases — 
 that nitrogen becomes available for the use of a crop. 
 The conditions necessary for nitrification are : 
 
 A porous soil. 
 
 The presence of the carbonates of potash, lime or 
 soda in the soil; 
 
 Warmth. 
 
 Moisture. 
 
 Under these conditions and through the influence 
 of a minute fungus plant called bacterium, the nitro- 
 gen of the organic compounds unites with the oxygen 
 of the air, producing nitric acid, which as rapidly as 
 formed combines with the lime, potash or soda pres- 
 ent, forming nitrates. 
 
 Nitrification proceeds more rapidly the higher the 
 temperature, and ceases altogether at the freezing 
 point. When the soil contains an excess of water, 
 nitrification ceases, and nitrates are sometimes decom- 
 posed with the escape of free nitrogen. 
 
 In order that nitrification may proceed rapidly and 
 keep the growing crop supplied with available nitro- 
 gen, it is necessary that the soil be kept porous so 
 that it presents a large amount of surface to the air, 
 and that it be moist but not wet. These conditions 
 
SOILS. 83 
 
 axe secured by drainage and cultivation. Mulching 
 the ground favors nitrification by keeping the soil in 
 a moist, porous condition. Part of the value of clover 
 and other crops that shade and cover the ground is 
 due to the fact that they thus provide the conditions 
 favorable for nitrification. 
 
 § 5. Mechanical Conditions of Soils. 
 
 164. Meets of Division. — A cube 1 inch each way, 
 has 6 square inches surface. If it is divided once in 
 each direction, and reduced to 8 cubes, each ^ inch 
 each way, these smaller cubes will have 1£ square 
 inches surface — or 12 square inches in all. By the di- 
 vision the total amount of surface has been doubled. 
 If the division is continued until the original cube has 
 been divided into a million cubes, the surface will be 
 increased six hundred times. Thus the smaller the 
 particles of the soil, the greater the amount of surface 
 will be exposed to the air which penetrates it, to the 
 water, and to the roots of plants. 
 
 The retention of water and of fertilizing material is 
 due largely to adhesion to the surface of the particles 
 of the soil; hence the smaller these particles the 
 greater the amount of this retention. The absorption 
 of moisture and ammonia from the air is in propor- 
 tion to the surface exposed. The chemical action of 
 air upon the soil is in proportion to the amount of 
 surface exposed. The smaller the particles of soil the 
 smaller and more numerous will be the pores, and 
 hence the greater will be its capillarity. 
 
 For all these reasons, the fertility of the soil de- 
 pends greatly on the fineness of its particles, and soil 
 that in its ordinary condition is almost sterile is some- 
 times rendered quite productive' by thorough pulver- 
 ization. 
 
84 SCIENCE IN FARMING. 
 
 165 . Some softs, especially heavy clays, are so com- 
 pact that the air cannot penetrate them, and the roots 
 of plants find difficulty in doing so. Such soils " bake" 
 into compact masses, and in that condition they are 
 of little value. It is necessary to mix sand or hu- 
 mus with such soils to make them sufficiently open 
 and porous to admit the air, and to separate their 
 particles so as to prevent " baking." 
 
 166. Drainage. — Soil may contain water in three 
 conditions: hygroscopic, capillary, and hydrostatic 
 (97). When it contains hydrostatic water the parti- 
 cles of the soil are wet, and the pores between them 
 are filled with water. The water prevents the air frpm 
 penetrating the soil, and renders it unfit for the growth 
 of agricultural plants,* and the chemical changes nec- 
 cessary to make the plant food' in the soil available can 
 not take place. 
 
 167. When soil containing hydrostatic water dries, 
 it shrinks and hardens into compact masses. The 
 shrinkage causes the soil to crack, often breaking the 
 roots of plants. This is particularly the case with 
 clay soils. The compact masses thus formed offer 
 great resistance to the roots of plants, and as they can 
 not readily be penetrated by the air, but little mois- 
 ture can be absorbed frpm it. The cracks caused. by 
 the shrinkage are too large to favor capillary attrac- 
 tion, and moisture is not drawn up from below. 
 
 Water falling on soil in such a condition is absorbed 
 slowly, and much of it may flow off, leaving the 
 
 *Theterm "agricultural plants" is used to describe those 
 which are cultivated by the farmer. There are some others 
 which grow under very .different circumstances and obtain 
 their food in a different manner, such as aquatics, (plants which 
 grow in water), parasites, (those which grow on others), and, 
 fungi. 
 
soils. 85 
 
 ground at the depth of a few inches unmoistened. 
 Therefore an undrained soil, particularly if it be a 
 heavy clay, suffers greatly in a drought. 
 
 168. When, by means of ditches or underdrains, 
 the hydrostatic water is removed, the soil remains 
 moist, as the capillary water cannot thus be removed. 
 The roots of plants find sufficient moisture in the par- 
 ticles of the soil, and as the pores are filled with air, 
 this supplies the oxygen necessary for their growth 
 and health. 
 
 When a well drained soil becomes dry, it does not 
 harden into compact masses, nor shrinkf and crack, 
 but remains in a loose and porous condition. During 
 the night the temperature of the soil is reduced by 
 radiation, (44), and moisture is condensed from the 
 air. If the soil is compact and imperviousjto air, this 
 moisture will be condensed upon the surface only ; 
 but if by drainage it has been left porous, the mois- 
 ture will also be condensed within its pores, often to 
 a considerable depth. Drainage also favors capillary 
 attraction in the soil, thus enabling it to draw water 
 from below. A light rain falling on such a soil is im- 
 mediately absorbed. For these reasons drainage ena- 
 bles the soil to withstand drought. 
 
 A loose, porous soil presents to the air many times 
 as much surface as a hard and compact one, thus se- 
 curing a larger absorption of ammonia, and providing 
 conditions favorable for nitrification (163). In this 
 way drainage increases the fertility of the soil. 
 
 In some parts of Minnesota the soil consists of a 
 deep sandy loam, containing a large amount of hu- 
 mus. The sand is exceedingly fine. This soil seems 
 of almost inexhaustible fertility. It is moist a few 
 jnches beneath the surface during the dryest weather, 
 
86 SCIENCE IN FARMING. 
 
 and can be worked immediately after the heaviest 
 
 rain. 
 
 § 6. Value of Sand, Clay and Humus. 
 
 169. Sand. — The value of sand in the soil depends 
 on the kind of rock from which it has been reduced, 
 and the size of its particles. White quartz sand con- 
 tains no plant food, and soils containing it in large 
 quantity are not usually fertile. 
 
 To determine the character of the sand, mix a por- 
 tion of the soil with a large amount of water. After 
 allowing time for the sand to settle, pour off the wa- 
 ter, which will contain most of the clay and humus. 
 By repeatedly washing the sand which remains, it 
 may be obtained pure. If it is white, " sharp" and 
 coarse, it is of little value in the soil. Sand from 
 granite or limestone contains a considerable amount 
 of plant food, which, under the influence of air 
 and cultivation, will be slowly given up in avail- 
 able form for the plant. If the portion of soil used in 
 the experiment is first dried and weighed, and the 
 sand that remains also dried and weighed, the propor- 
 tion of sand in the soil will be known. 
 
 The mechanical uses of sand in the soil are to make 
 it loose and porous, facilitate drainage and prevent 
 " baking." Sand alone does not absorb moisture or 
 ammonia from the atmosphere, nor has it the power 
 of retaining plant food. Manures applied to sand 
 have little effect beyond the immediate crop. Sand 
 becomes warm early in the spring, and soils contain- 
 ing it in excess are liable to " burn out" in hot wea- 
 ther. When mixed with a due proportion of clay and 
 humus, the advantages of sand are secured without 
 its disadvantages. The finer the sand the more value 
 it is in the soil. 
 
SOILS. 87 
 
 170. Clay. — Pure silicate of alumina (146), -sup- 
 plies no food to the plant, but clay in the soil usually 
 contains potash, magnesia, lime, and other substances 
 of value. Red clays contain ferric oxide, valuable 
 not only as plant food, but also because it promotes 
 nitrification and aids in retaining nitrates in the soil. 
 
 Clay possesses, in a high degree, the properties of 
 absorbing ammonia from the air, and of retaining fer- 
 tilizers, lime, potash and ammonia combine with it, 
 forming double silicates. Clay thus not:only absorbs 
 ammonia from the air, but retains it when absorbed 
 (153). It has also in a considerable degree the power 
 of retaining water, of absorbing moisture from the air, 
 and of capillarity. 
 
 Clay soils are called " retentive." Manures applied 
 to them waste but little, and often continue to pro- 
 duce marked effects for years. 
 
 The disadvantages of clay are its adhesiveness, mak- 
 ing it a " heavy" soil to work, and its tendency to 
 "bake." The addition of lime renders it less adhe- 
 sive, the fine particles of calcic carbonate formed in 
 the soil, separating the particles of clay. Burn- 
 ing clay entirely destroys its adhesiveness, and if the 
 burnt clay is mixed with the soil, it has an effect similar 
 to the addition of sand. This plan is sometimes re- 
 sorted to in dealing with very " stubborn" clay lands. 
 
 171. Humus (146). — The proportion of humus in 
 the soil varies from 2 or 3 per cent to as much as 97. 
 To ascertain the per cent of humus, weigh a portion 
 of the soil that has been thoroughly dried in an oven, 
 and heat it to a dull redness, until all the organic 
 matter is consumed. Weigh what remains, and the 
 loss in weight will show the amount of humus. 
 
 Humus contains carbon, hydrogen and oxygen, but 
 
88 SCIENCE IN FARMING. 
 
 the plant does not obtain these from this source. It 
 also contains nitrogen in organic combination, which 
 cannot be directly used by the plant, but which is 
 gradually converted into ammonia and nitric acid by 
 the action of the air. The amount of nitrogen con- 
 tained in a soil is usually in proportion to the amount 
 of humus it contains. Humus also contains some 
 phosphoric acid, potash, and other mineral elements 
 of plant food. 
 
 Humus has other value in the soil besides supply- 
 ing plant food. Its dark color makes the soil warmer. 
 It has great power of retaining water and of absorbing 
 moisture and ammonia from the air. Being very 
 porous it possesses capillarity in a greater degree than 
 any other soil constituent. The decomposition of 
 humus in the soil produces carbonic dioxide which, 
 being dissolved in the water of the soil, assists in the 
 decomposition and solution of mineral matters. 
 
 Humus overcomes the adhesiveness of clay soils, 
 and remedies the deficiencies of sand. 
 
 The addition of lime to humus hastens its decom- 
 position by favoring the conversion of the nitrogen it 
 contains into nitric acid. 
 
 § 7. Practical Application. 
 
 172. The soil best adapted for most agricultural 
 purposes is composed of fine sand, clay and humus. 
 No one of these ingredients should be in great excess. 
 
 173. Correcting Defects in Soil. — Soils may be good 
 in many respects and contain an abundance of most 
 of the elements of plant food, and yet from deficiency 
 of some one constituent, or defective mechanical con- 
 dition, be unproductive. Such soils may often be 
 rendered valuable at moderate expense by proper 
 treatment, which can be determined by a considera- 
 
SOILS. 89 
 
 tion of their character and of the principles already 
 given. 
 
 174, . A soil may contain an excess of humus and 
 yet be unproductive. The plan to pursue is to secure 
 the decomposition of the humus, and the conversion 
 of the plant food it contains into available forms. 
 This can be accomplished by drainage and thorough 
 cultivation, by which the soil is exposed to the air, 
 and by the addition of lime. Soils of this kind are 
 sometimes " sour " owing to the presence of organic 
 acids produced by the slow decomposition of humus, 
 and which are injurious to plants. Lime combines 
 with these acids forming harmless compounds. The 
 addition of phosphates or potash may sometimes be 
 beneficial.* When phosphates are needed, rock 
 phosphate— which contains no nitrogen— -would be 
 suitable, as the. soil already contains an abundance of 
 nitrogen which only needs to be rendered available. 
 Green manuring on such a soil would be injurious 
 rather than beneficial. 
 
 175. A sandy "leachy " soil may be improved by 
 growing a succession of green crops, rye, buckwheat, 
 sowed corn, clover, etc., and plowing them under. 
 The humus thus furnished will supply those charac- 
 teristics of the soil lacking in the sand. Nitrogenous 
 manures may be used with profit, but they should be 
 applied on the surface and at the season when the 
 plant can make immediate use of them. After a suf- 
 
 *Whether phosphate and potash are needed can only be de- 
 termined by experiment. Four portions of the field should be 
 marked off. To one portion phosphate should be applied, to 
 another potash, to the third both, and the fourth should re- 
 ceive no manure. The cultivation, drainage and liming of the 
 four portions should be the same, and the results carefully 
 noted. 
 
90 SCIENCE IN FARMING. 
 
 ficient amount of humus has. accumulated in the soil, 
 the crops may be fed off and the manure produced 
 returned. 
 
 176. A " retentive " clay is often a difficult soil to 
 deal with, but can usually be rendered valuable by 
 proper treatment, and as it has great capacity for 
 retaining manures, those which are applied and not 
 immediately used by the crop will accumulate in the 
 soil. The first treatment indicated is thorough drain- 
 age — which will make the next step — thorough culti- 
 vation, possible. The adhesiveness may be overcome 
 by the use of lime, by plowing under long barn-yard 
 manure, and by green manuring. Nitrogenous 
 manures, such as bone phosphates and guano can be 
 used with advantage — but should not be applied at 
 the same time with the lime, or a waste of nitrogen 
 may be occasioned. After the condition of the clay 
 has been sufficiently improved, the plowing under of 
 green crops may be discontinued. 
 
 177. Thus by drainage, cultivation, green manur- 
 ing and the use of lime, the farmer can to a great ex- 
 tent remedy natural deficiencies in the soil. Of the 
 three great soil constituents, humus is the only one 
 over which control can be exercised. By the use of 
 lime and cultivation it can be reduced in quantity 
 when in excess ; and by plowing under green crops 
 it can be increased when needed. 
 
CHAPTER VII. 
 
 science nsr plant growth. 
 
 § 1. Composition of Plants. 
 
 178. Water. — The largest constituent of all living 
 plants is water. The following table gives the aver- 
 age percentage of water in various fresh plants : 
 
 Meadow grass 72 
 
 Red clover 79 
 
 Corn fodder 81 
 
 Cabbage 90 
 
 Potatos (tubers) 75 
 
 Beets 82 
 
 Turnips 91 
 
 Pumpkins 94.5 
 
 The per cent of water is not always the same. It 
 is greater in plants grown in a wet season than in 
 those grown in a dry one. The ranker the growth 
 of plants the more water they contain, hence the in- 
 creased weight of crop caused by heavy manuring is 
 often chiefly water. In some cases the amount of dry 
 matter contained in a crop grown on a manured soil 
 may be less than that in a crop produced without 
 manure. The following table gives the weight (fresh 
 and dried) of two crops of clover grown on an acre of 
 ground each, one with, and one without manure. 
 
 Fresh Clover. Clover Hay. 
 
 Manured acre 22,256 lbs. 4,800 lbs. 
 
 Unmanured acre 18,815 lbs. 5,190 lbs. 
 
92 SCIENCE IN FARMING. 
 
 It will be seen that while the crop on the manured 
 acre was ranker and weighed more when fresh than 
 that on the unmanured acre, it contained so much 
 more water that the amount of hay was less. 
 
 179. Even dried plants and the seeds and grains 
 contain a considerable amount of hygroscopic water 
 (97). The following table gives the per cent of water 
 contained in various plants and grains that are usually 
 considered dry : 
 
 Meadow hay 15 
 
 Clover hay 17 
 
 Straw 15 
 
 Wheat (grain) 14 
 
 Indian corn (grain) 12 
 
 Wheat bran 14 
 
 The amount of hygroscopic water varies a little 
 with the temperature and the condition of the atmos- 
 phere. 
 
 The term " dry substance " is used to describe all 
 the plant except the water. Thus, fresh meadow 
 grass contains about 28 per cent dry substance; 
 meadow hay 85 per cent ; Indian corn 88 per cent, 
 and so on. That is, 100 lbs. meadow grass if dried at 
 a temperature of 212, so as to drive off all the water 
 would weigh 15 lbs. ; 100 lbs. Indian corn would 
 weigh after being dried in this manner 88 lbs. As the 
 craantity of water in different plants varies so greatly 
 it is often necessary in making comparisons to con- 
 sider only the dry substance each contains. 
 
 180. Ash. — When a plant is burned, part passes off 
 in gas and vapor, but a part remains unconsumed: 
 This is called the ash, and the amount of it varies in 
 different plants, and in "the same plants grown under 
 different circumstances. Plants grown on a soil rich 
 in available ash constituents will contain more, ash. 
 
PLANT GROWTH. 93 
 
 than the same plants grown on soil in which these 
 substances are deficient. The following table gives 
 the percentage of ash in the dry substance of various 
 plants : 
 
 Wheat (grain) , 2 
 
 Oats (grain) 3.3 
 
 Indian corn (grain) 1.5 
 
 Timothy 7.1 
 
 Bed clover 6.7 
 
 Turnip (roots) 12 
 
 That is, if turnips were thoroughly dried at the 
 temperature of 212> and 100 lbs, of this dried turnip 
 burned, 12 lbs,, of ash would be left. The following 
 table gives the number of pounds of ash in a ton of 
 various vegetable substances in their natural con- 
 dition : 
 
 Name of Substance. Ash in One Ton. 
 
 Oats. (grain) , 70 lbs. 
 
 Wheat (grain) 34 lbs. 
 
 Indian corn (grain) ,. 32 lbs, 
 
 Wheat bran 122 lbs. 
 
 Clover Hay 106 lbs. 
 
 Meadow hay 124 lbs. 
 
 Wheat straw 92 lbs. 
 
 Meadow grass 40 lbs. 
 
 Green clover 30 lbs. 
 
 Potatos 20 lbs. 
 
 Turnip , 14 lbs. 
 
 The ash of plants consists principally of lime, pot- 
 ash, phosphoric acid, sulphuric acid, soda, magnesia 
 and iron. Chlorine is occasionally present, and silica 
 quite frequently (158). Minute portions of other sub- 
 stances are frequently found, but do not seem essen- 
 tial to the plant. 
 
 181. Other Substances . — The remainder of the plant 
 is composed of cellulose (119) and other carbohy- 
 drates (117), lignose (119), albuminoids (126), pentose 
 
94 SCIENCE IN FARMING. 
 
 substances (123), amides (128), vegetable acids (124), 
 fats (125) and alkaloids (129). 
 
 § 2. Germination. 
 
 182. A Seed is composed of two parts — the embryo 
 and the endosperm. The embryo, commonly called 
 the "chit," is the undeveloped plant. The en- 
 dosperm forms the bulk of the seed, and is the pro- 
 vision made by Nature for the nourishment of the 
 young plant. 
 
 183 . Chemistry of Germination . — When a seed is sub- 
 jected to favorable conditions of moisture, air and tem- 
 perature, water and oxygen are absorbed, and certain 
 chemical changes occur. The starch in the endosperm 
 is converted into glucose and other soluble substances; 
 fats, by combination with the elements of water, are 
 changed into soluble carbohydrates; and albuminoids 
 also become soluble. The nutriment in the seed is 
 thus prepared for the use of the plant. 
 
 Two stems are now thrown out from the embryo ; 
 one, called the radical, turns downward into the soil, 
 the other, called the plumule, turns upward and seeks 
 the light. The substances in the endosperm that 
 have been rendered soluble, are dissolved by the wa- 
 ter absorbed, and carried through the growing plant, 
 and in the proper places changed into cellulose and 
 other insoluble substances. 
 
 This process continues, the young plant being sup- 
 ported by the nutriment stored in the seed, until that 
 is exhausted, as it has no power to obtain any other 
 food until the leaves are formed and exposed to the 
 light. If the nutriment in the parent seed is exhaust- 
 ed before the leaves reach the light, the young plant 
 dies of starvation. 
 
PLANT GROWTH. 95 
 
 184. Necessities of Germination. — These are oxygen, 
 water and a proper temperature. The 'Boil performs 
 no part in the work except to furnish the proper con- 
 ditions. Oxygen and water are both needed to effect 
 the chemical changes by which the substances in the 
 seed are rendered soluble, and water is necessary to 
 dissolve them and convey them to the different parts 
 of the growing plant. 
 
 Numerous experiments have been made to deter- 
 mine the lowest and highest temperatures at which 
 germination is possible, and that at which it proceeds 
 most rapidly. The following table gives the results 
 with certain seeds : 
 
 Lowest Highest Most Rapid 
 
 Temperature. Temperature. Germination. 
 Wheat and Barley 41 deg. 104 deg. 84 deg. 
 
 Peas 44.5 " 102 " 84 " 
 
 Indian corn 48 " 115 " 93 " 
 
 Squash 54 " 115 " 93 " 
 
 Some other seeds will germinate at much lower 
 temperatures. It is said that rye will germinate at 
 any temperature above the freezing point. 
 
 § 3. Mow the Plant (trows. 
 
 185. Plant Food. — The plant has no power to create 
 any substance. It can therefore only grow by col- 
 lecting certain elements from the soil and air and 
 forming out of these the various organic compounds. 
 The elements used by the plant are carbon, hydrogen, 
 oxygen, nitrogen, phosphorus, sulphur, calcium, pot- 
 assium, magnesium and iron. Without these ten, no 
 agricultural plant can be formed, and deficiency in 
 one cannot be made up by an over-supply of another. 
 After germination, the plant obtains its food by means 
 of its roots and leaves. 
 
% SCIENCE W FARMING. 
 
 186. The Roots gather from the soil all those- sub- 
 stances which form the ash of the plant, and also ni- 
 trogen, usually in the form of a nitrate. These sub- 
 stances are taken up in solution. The roots have 
 power, however, to attack some substances that are 
 not ordinarily soluble. This is due to the acid sap 
 which they contain, and which dissolves some sub- 
 stances when they are in direct contact with the roots. 
 It is in this manner that plants obtain phosphoric acid 
 — a substance that rarely exists in the soil in a solu- 
 ble condition. The roots also obtain from the soil the 
 water necessary for the growth of the plant. Solu- 
 ble substances in the soil not essential to the plant, 
 are often taken up by the roots. These are usually 
 deposited in the older tissues, or as a crust upon the 
 stem of the plant, and often serve a useful purpose 
 by hardening the tissues and protecting them from 
 injury. Carbonic dioxide is also taken up by the 
 roots, but the amount is so small that the fact is of 
 scientific interest, only. 
 
 187. The Leaves absorb carbonic dioxide from the 
 air. This is taken up by the minute pores of the 
 leaves. These pores are called stomata, and are very 
 numerous. An ordinary apple leaf has about 100,000 
 to the square inch. The carbonic dioxide is decom- 
 posed in the leaf, the oxygen being given off and the 
 carbon uniting with the elements of water to form 
 carbohydrates. The decomposition of the carbonic 
 dioxide in the leaf is performed in what are called the 
 chlorophyl cells. These cells contain a green liquid 
 called chlorophyl, and to which the green color of the 
 plant is due.* All green portions of the plant have 
 
 *Plants which have no green color cannot obtain carbon 
 from the air. These are chiefly parasites — which obtain their 
 
PLANT GROWTH. 97 
 
 the power of decomposing carbonic dioxide, but the 
 work is principally performed by the leaves. 
 
 The plant obtains the power by which this decom- 
 position of carbonic dioxide is accomplished, from the 
 sunlight. The process ceases entirely in the darkness. 
 
 All green plants are thus during the day-time con- 
 stantly taking carbonic dioxide from the air and re- 
 turning oxygen. 
 
 Albuminoids and amides are formed from, the solu- 
 ble carbohydrates in connection with nitrogen and 
 sulphur obtained from, nitrates and sulphates in the 
 sap. Fats are produced by the removal of a part of 
 the oxygen and hydrogen of carbohydrates, and veger 
 table acids by their oxidation. 
 
 The leaves absorb from the air a very small amount 
 of ammonia, which is used by the plant in the forma- 
 tion of albuminoids and amides. 
 
 188. The soluble carbohydrates and other sub- 
 stances when formed are carried in the sap to every 
 portion of the plant, and its tissues are built up by 
 the conversion of these soluble substances into cellu- 
 lose, lignose, and other insoluble forms. Thus every 
 part of the plant, including the roots, is built from the 
 carbon obtained by the leaves. 
 
 189. The plant has the power of rendering soluble 
 substances that have been deposited in one part, con- 
 veying them to another, and changing them into new 
 forms. If a tree is stript of its leaves, it can no longer 
 obtain carbon from the air, but carbohydrates already 
 dej^ited in other parts of the tree will be taken up 
 by tne sap and used for the production of new leaves. 
 If these are removed as rapidly as they are produced, 
 
 carbon from the juices of the plants they live upon — or fungi, 
 which obtain it from decaying organic matter. 
 7 
 
98 SCIENCE m FARMING. 
 
 the tree will continue putting forth leaves until the 
 available supply of material is exhausted, when it 
 dies. 
 
 During the fall the carbohydrates, albuminoids, 
 phosphoric acid and potash contained in the leaves 
 are largely re-absorbed and deposited in the trunk. 
 With the coming of warm weather the sap begins to 
 circulate, these substances are converted into soluble 
 forms and used for the production of new leaves. The 
 sugar in maple sap is produced from the starch stored 
 up the previous fall. 
 
 190. Respiration. — The plant is continually absorb- 
 ing oxygen through the bark and leaves. This com- 
 bines with carbon in the plant forming carbonic diox- 
 ide, which is thrown off. This process continues both 
 in daylight and darkness, and so closely resembles 
 the respiration of animals that it has been given that 
 name. 
 
 During the daytime the amount of carbonic dioxide 
 absorbed is many times greater than that given off, 
 and consequently the process of respiration is not 
 noticeable, but in darkness when the absorption of 
 carbonic dioxide ceases, the effect of respiration be- 
 comes perceptible. Hence it is sometimes said that 
 plants absorb carbonic dioxide during the day, and 
 give it off during the night. The statement is. not 
 scientifically correct as respiration continues at all 
 times, but its effects are hidden, in daylight, by the 
 larger amount of carbonic dioxide absorbed, and of 
 oxygen given off.* ^ 
 
 *From the fact that plants give off carbonic dioxide in the 
 night, the theory has been advanced that they are injurious in 
 bed-rooms. The amount of this gas given off is so minute that 
 it could have no appreciable effect on the air of any ordinary 
 
PLANT GROWTH. 99 
 
 § 4. Formation of Seed. 
 
 191. The Seed.— As we have seen (182), the seed 
 contains nutritive matter in the most concentrated 
 form, it being Nature's provision for the nourishment 
 of the young plant until the time when it shall be 
 able to collect food for itself. We therefore find in the 
 seed every element needed for the life and growth of 
 the plant. The composition of seed is more uniform 
 than that of any other portion of the plant, and they 
 never contain any of the unessential ash constituents 
 sometimes taken up by the roots. 
 
 192. Annuals. — These are plants which germinate, 
 attain maturity, and produce their seed wMiin a 
 single season of growth. During the early part of the 
 life of an annual, its energies are entirely devoted to 
 the formation and development of the organs of nutri- 
 tion, the leaves and roots. When the flower is put 
 forth this process is checked, and as the formation of" 
 the seed progresses, less and less food is gathered 
 from the soil and air, and the energies of the plant 
 are devoted to gathering up the nutritive matter 
 already formed within its tissues, changing them into 
 more concentrated forms and depositing them in the 
 seed. The final work of storing food in the seed is 
 done after the plant has entirely ceased to collect 
 food from without. 
 
 Thus as seed formation in an annual progresses, 
 the whole plant undergoes exhaustion, and, if the 
 season is favorable, this exhaustion is very great. 
 Consequently the straw of a crop is more valuable in 
 a season unfavorable for the maturing of the grain. 
 
 room. A growing plant absorbs during daylight a great deal 
 more carbonic dioxide than ij; jgives off in 24 hours. 
 
100 SCIENCE IN FARMING. 
 
 The extent to which this exhaustion of the plant is 
 carried is shown in the following tables giving the 
 percentage of soluble carbohydrates,* albuminoids, 
 and crude fibref in the dry substance of various plants, 
 before and after the formation of seed : 
 
 RED CLOVER. 
 
 Cut in Bloom. Cut When Ripe. 
 
 Soluble carbohydrates 36.0 24.4 
 
 Albuminoids 16.0 11.3 
 
 Crude fibre 43.0 57.6 
 
 RYE FODDER. 
 
 Cut in Bloom. Ripe Straw. 
 
 Soluble carbohydrates 55.0 31.5 
 
 Albuminoids 12.2 1.8 
 
 Crude fibre 26.9 63.0 
 
 INDIAN CORN FODDER. 
 
 Cut in August. Cut after Grain 
 has ripened. 
 
 Soluble carbohydrates 61.2 45.3 
 
 Albuminoids 6.2 3.5 
 
 Crude fibre 26.4 46.5 
 
 The decrease in proportion of the nutritive sub- 
 stances — especially albuminoids, is very noticeable in 
 each case. 
 
 It must be remembered that these tables give the 
 percentage composition of the dry substance only, the 
 purpose being to illustrate the exhaustion of the plant 
 in the formation of seed. They cannot be used to 
 compare the value of a ton of green rye fodder with a 
 ton of rye straw, on account of the different amount 
 of water. This part of the subject will be considered 
 elswhere. 
 
 193. Biennials. — These are plants which grow 
 
 *Theterm "soluble carbohydrates" is frequently used in 
 analyses of foods to represent not only the true carbohydrates, 
 but also the pectose substances (228). 
 
 tCrude fibre consists of cellulose, and lignose in such forms 
 that they cannot readily be dissolved. 
 
PLANT GROWTH. 101 
 
 through one season, producing only leaves and roots, 
 and the next season throw up a flower stalk and pro- 
 duce seed. Beets and cabbages are biennials. In 
 these plants the first year's growth is devoted to col- 
 lecting nutritive matters from the soil and air and 
 storing them, either in a fleshy root, as in the beet, 
 parsnip and carrot, or in a leafy head, as in the cab- 
 bage. In the second season the flower stalk is thrown 
 up and seed produced from the material that had 
 been stored up during the first season.* 
 
 194. The tuber of the potato and the bulb of the 
 onion are similar storehouses of food. Men and ani- 
 mals take advantage of these characteristics of vege- 
 table life, and find much of the best and most concen- 
 trated food in the seeds of annuals, and the roots of 
 biennials — gathered at the close of the first season— 
 or if they use the whole plant do so before the pro- 
 duction of seed begins. 
 
 § 5. Summary and Practical Application. 
 
 195. Germination. — The necessities of germination 
 are water, air, and a suitable temperature. When the 
 pores of the soil are filled with water, germination is 
 greatly retarded, as the water excludes the air. Too 
 deep planting retards germination for the same rea- 
 son. As moisture is essential, it is necessary that the 
 soil should be well pulverized, otherwise the seed 
 may fall into cavities between the lumps of soil and 
 be unable to obtain sufficient moisture ; or if damp- 
 ness oi 1 the weather at the time of sowing the seed en- 
 ables it to germinate, a few dry days following may 
 
 *A plant cannot take up by its roots and use organic matter 
 in the soil, but it can take organic matter from one part of its 
 own structure and use it for building up some other portion. 
 
102 SCIENCE IN FARMING. 
 
 cause the young plant to perish before its roots can 
 penetrate the soil far enough to obtain a supply of 
 moisture. As warmth is necessary, seed sown before 
 the ground has become sufficiently warm is liable to 
 rot instead of germinating. Indian corn, especially, 
 requires a considerable degree of warmth, and a " bad 
 stand " is often the result of planting in cold ground. 
 
 As the parent seed is the only source from which 
 the young plant can draw nourishment until its leaves 
 reach the light, when seeds are too deeply planted, 
 the young plant may exhaust this nutriment and die 
 from starvation before its leaves reach the light. 
 Hence, also, if the leaves are torn from a young plant 
 just as germination is completed, it dies, being de- 
 prived of means of obtaining food from soil and air, 
 and having no source of supply within itself. If the 
 plant is allowed to grow for a time after germination, 
 a supply of material is laid up within its own tissues 
 which can be used for the production of new leaves. 
 A practical knowledge among farmers of the working 
 of this principle has given rise to the expression that 
 " the best time to kill weeds is before they come up," 
 by which is meant just as the process of germination 
 is completed. 
 
 196. Plant Food. — As the plant cannot use the ni- 
 trogen contained in organic matter in the soil until it 
 has been oxydized into nitric acid, it is necessary to 
 expose the soil thoroughly to the action of the air, in 
 order to secure a sufficiency of available plant food. 
 The nitrogen in urea being available for the* use of 
 the plant without first being oxydized, urine acts very 
 rapidly as a fertilizer. As, when one element of plant 
 food is deficient, the plant is incapable of using other 
 food, however abundant it may be, it is necessary to 
 
PLANT GROWTH. 103 
 
 see that all the elements of plant food needed are con- 
 tained in the soil and in an available condition. As 
 the carbon in the plant is obtained wholly from the 
 air, carbonaceous matters in manures are without 
 value as plant food. 
 
 197. The Growing Plant. — As the whole plant, in- 
 cluding the roots, is built up from carbon obtained by 
 the leaves, no growth can be made after the leaves 
 have been removed, and hence, if insects are allowed 
 to continually destroy the leaves of trees, the trees 
 themselves will ultimately die. Hence, also, if weeds 
 are constantly cut down and not permitted to put 
 forth leaves, the roots will ultimately perish. In 
 order to kill a weed in this way, however, the leaves 
 must be removed as rapidly as produced, for if they 
 are allowed to remain even for a short time, they will 
 lay up another store of surplus material. 
 
CHAPTER VIII. 
 
 SCIENCE IN ANIMAL LIFE. 
 
 § 1. Composition of the Animal. 
 
 198. General Composition. — Animal substances are 
 composed of the same ten elements as vegetables (185) 
 with cholorine and sodium in addition. These two 
 last elements form in combination common table salt 
 (106), and though not essential to plant life, are usu- 
 ally present in vegetable substances. 
 
 199. Organic Compounds. — These are principally 
 Albumnoids Gelatinoids, Keratin (127) and fats. Car- 
 bohydrates do not exist in the animal body except in 
 the form Of partially consumed food. 
 
 200. Ash. — The ash consituents are principally 
 found in the bones, of which about 55 per cent, is 
 tricalcic phosphate. Iron and potash are also found 
 in all parts of the system. 
 
 201. Water. — As in the plant, the larger part of the 
 living animal is water. The following table shows the 
 average composition of* a half fat ox, weighing 1,000 
 lbs. exclusive of stomach and intestines: 
 
 Water k 560 
 
 Nitrogenous matter 181 
 
 Fat 208 
 
 Ash 51 
 
 1,000 
 
ANIMAL LIFE. 105 
 
 Comparison with Vegetable Matter.— The ani- 
 mal contains less carbon, hydrogen, and oxygen than 
 the plant and more nitrogen, phosphoric acid and lime. 
 The following table shows the number of pounds of 
 these contained in 1,000 lbs. of a fat ox, (exclusive 
 of stomach and intestines) and in an equal weight of 
 fresh clover in bloom: 
 
 Fat Ox. Fresh Clover. 
 
 Nitrogen 28.18 5.10 
 
 Phosphoric acid 16.52 1.40 
 
 Lime 19.20 4.80 
 
 § 2. Animal Nutrition. 
 
 203. We have seen that the food of plants consists 
 of gasses, mineral salts, and water, out of which it 
 forms all of its various organic compounds. The 
 power by which these transformations are accom- 
 plished is obtained from a source outside of the plant 
 — the light of the sun. , 
 
 The animal is unable to construct organic matter 
 out of inorganic, nor can it obtain power for carrying 
 on the functions of life, from any outward source. It 
 must therefore find in its food, in forms that will re- 
 quire but little change, the materials it needs, for 
 growth; and, also the source of animal heat and en- 
 ergy. The plant is therefore the machine by which 
 inorganic matter is prepared for the use of the animal 
 and the medium through which the energy derived 
 from the light and heat of the sun is made available 
 for the purposes of animal life. 
 
 204. Digestion. — The food of animals consists of 
 carbohydrates, albuminoids, fat and mineral salts con- 
 tained in the plant. These are fitted for animal nu- 
 trition by the process of digestion. Some of the car- 
 bohydrates, such as sugar require but little change. 
 
106 science in farming. 
 
 Others, such as starch and cellulose must be converted 
 into glucose. This change is begun by the action 
 of the saliva, and is completed in the intestines. The 
 albuminoids are rendered soluble by the action of the 
 gastric juice secreted by the stomach, and also by the 
 pancreatic juice. The digestion of fats is accomplished 
 by the bile and pancreatic juice. 
 
 205. Assimilation. — After the food has been ren- 
 dered soluble, or digested, it is absorbed by the mi- 
 nute blood vessels lining the intestines and by vessels 
 called the lacteals, and carried by the blood to every 
 part of the body. Each part takes from the blood 
 the needed material for its own growth or repair, and 
 changes it into substance like itself. This is called 
 assimilation. Thus all parts of the body are nour- 
 ished by the blood. How the tissues make the selec- 
 tion from the blood, of the particular materials they 
 need, is not understood. 
 
 206. Waste of the Body.— The tissues of the body 
 are continually undergoing oxidation and decay. The 
 waste matter thus produced is taken up by the blood, 
 and removed from the system through the excretory 
 organs. This waste is repaired by the blood which 
 serves both to bring the new material and remove that 
 which is worn out. 
 
 207. Respiration. — By the action of the heart, the 
 blood is forced through the lungs. Owing to the pe- 
 culiar structure of these organs, it is here very thor- 
 oughly exposed to the air, and absorbs oxygen, 
 which gives it a bright scarlet color. In the circula- 
 tion of the blood the oxygen thus absorbed, combines 
 with the carbon of the food, the process being similar 
 to combustion (131). The carbonic dioxide formed 
 by this process is given off by the lungs. When car- 
 
ANIMAL htm. 107 
 
 bohydrates suffer oxidation in the blood the products 
 are carbonic dioxide and water. When albuminoids 
 or amides are oxidized the nitrogen is separated in the 
 form of urea (OON 2 H 4 ) a substance containing 46.67 
 per cent of nitrogen, and which is removed from the 
 blood by the kidneys. 
 
 208. Excretion is the process by which waste or 
 useless material is removed from the body. The prin- 
 cipal organs of excretion are the lungs, kidneys and 
 skin. Carbonic dioxide, water and small portions of 
 waste organic matter are thrown of by the lungs, and 
 skin. The kidney removes the urea produced by the 
 oxidation of nitrogenous substances, and the mineral 
 salts. The solid excrement is composed of the undi- 
 gested portions of the food, with a small amount of 
 bile, and secretions of the intestines. 
 
 § 3. Uses of Food in the Body. 
 
 209. The principal uses of food are : 
 
 1. To furnish material which can be burned in the 
 body for the production of heat and energy. 
 
 2. To supply material for growth. 
 
 3. To repair the waste of the body (206). 
 
 4. To produce fat. 
 
 5. The production of milk. 
 
 210. In the construction of fat, flesh, or milk, the 
 animal must find in the food all the elements which 
 the substances to be formed Will contain. From a 
 carbohydrate it can produce fat, because they contain 
 the same elements, the difference being only in the 
 proportions in which they are combined. It can also 
 produce fat from an albuminoid, by the removal of the 
 nitrogen, but it cannot produce an albuminoid from 
 
108 SCIENCE IN FARMING. 
 
 fat or a carbohydrate, as neither of these substances 
 contains nitrogen, which is an essential element in 
 the albuminoid. 
 
 Albuminoids are therefore capable of meeting all 
 the requirements of the body, and can support life 
 without any other food. Fats and carbohydrates can 
 be used for the production of fat, and to furnish car- 
 bon for combustion in the blood. 
 
 The respective values of these different classes of 
 foods will be considered in the next chapter. 
 
 211. Source of Animal Heat and Energy. — We have 
 seen (37) that in the locomotive, energy- that had been 
 obtained from the sun by plants long ages ago, is set 
 free, by the combustion in the fire-box, of the carbon 
 of the coal, and that this energy is applied to useful 
 work by the machinery of the engine. In the animal 
 the energy derived from the sun by agricultural plants 
 is set free by the combustion, in the blood, of the car- 
 bon of the food, and the muscles and organs of the 
 body are the machinery by which this energy is ap- 
 plied to useful work. Part of it is expended in main- 
 taining the heat of the body, part in carrying on the 
 processes of respiration, digestion, circulation, etc., 
 and part may be used by the animal in physical exer- 
 cise or useful work. The combustion of a given 
 amount of carbon from the food, will produce a given 
 amount of energy and no more. If more of this en- 
 ergy is used for maintaining the heat of the body, less 
 can be used in the performance of work, and if an in- 
 creased amount of heat and work is needed, there 
 must be an increased consumption of food. 
 
 § 4. Disposition Made of the Food. 
 
 212. Heat and Energy. — By far the greater portion 
 
ANIMAL LIFE. 109 
 
 of the food consumed by the animal is used in the 
 production of heat and energy. The heat of the body 
 must be maintained, and even when the animal is at 
 rest a large amount of energy is used in the processes 
 of digestion, respiration, circulation, etc. In a fatten- 
 ing animal, the amount of food used in this manner 
 is from three to ten times as great as the amount used 
 in the production of increase. In animals that are 
 not growing or laying on fat, the proportion of food 
 used for the production of heat and energy is still 
 greater. If the food contains a due proportion of car- 
 bohydrates and fat, these will be used for this purpose 
 rather than the albuminoids. 
 
 213. Growth and Repair. — The albuminoids in the 
 food are used for producing new tissues, and also for 
 repairing the necessary waste. The amount required 
 for this latter purpose is but small. An ox weighing 
 1,000 lbs. will require only five- or six-tenths of a 
 pound of albuminoids per day to repair the waste of 
 tissue. Albuminoids consumed in excess of the 
 amount required for growth and waste, are either 
 burned for production of heat and energy, or convert- 
 ed into fat. In either case the nitrogen is separated 
 in the form of urea* 
 
 214. Production of Fat. — When more food is con- 
 sumed and digested by the animal than is required 
 for growth, the repair of waste, and production of heat 
 and energy, the surplus will be converted into fat, 
 and stored up to meet future demands of the system. 
 The production of fat is in fact the one method by 
 which the animal can dispose of food consumed in ex- 
 cess of immediate needs. 
 
 215. Milk. — When an animal is giving milk, a 
 large amount of the food consumed is used in its pro- 
 
110 SCIENCE IN FARMING. 
 
 duction. Fats and carbohydrates are used in form- 
 ing the fat and sugar, and albuminoids for the casein. 
 A large amount of mineral salts are also used in milk 
 production. 
 
 216. The mineral salts obtained in the food are 
 largely used in the production of the bones. Those 
 not used are removed by the kindeys. 
 
 217. Undigested Food. — The animal never digests 
 all the food it consumes. The amount left undigested 
 varies with the kind of food and the animal. It is 
 seldom less than five, and sometimes as much as sixty 
 per cent of the dry matter of the food consumed. , 
 This undigested food passes oif in the solid excrement. 
 
 § 5. Effects of Insufficient Food. 
 
 218. Insufficient Albuminoids. — When the albumin- 
 oids supplied to an animal in its food are but just 
 suflicient to repair the waste of tissue, muscular growth 
 will necessarily cease. If the amount of albuminoids 
 in the food is insufficient to repair the waste, the ani- 
 mal will gradually shrink in weight, and finally die of 
 starvation, even though abundantly supplied with non- 
 nitrogenous food constituents. Instances are on re- 
 cord of children who have died from starvation while 
 being fed on a purely farrinaceous (starchy) diet. In- 
 jury to children raised by hand, from insufficient al- 
 buminoids in their diet is more common than is usu- 
 ally known. 
 
 219. Insufficient Non-Nitrogenous Constituents. — 
 When carbohydrates and fat in the food are insuffici- 
 ent to meet the demands for the production of heat and 
 energy, the albuminoids will be burned for this pur- 
 pose, even though growth is stopped and the wastes of 
 the body gd unrepaired. In this manner, deficiency 
 
ANIMAL LIFE. Ill 
 
 of non-nitrogenous matter in the food may cause loss" 
 of muscular weight, although these substances are not 
 capable of conversion into muscle. Owing to the 
 same principle, an increase of non-nitrogenous matter 
 in food may cause an increase of muscular develop- 
 ment, provided the food already contains a due pro- 
 portion of albuminoids. The increase in such a case 
 is not due to the conversion of the non-nitrogenous 
 substance into muscle, but to the fact that they sup- 
 ply carbon for the production of heat and energy, and 
 thus prevent the albuminoids from being used for this 
 purpose. 
 
 220. Starvation. — When the food is insufficient to 
 meet the needs of the animal, not only is waste left 
 unrepaired, but fat that had previously been de- 
 posited is re-absorbed into the blood and burned in 
 place of food. If the deficiency of food continues, 
 the muscular substances will also be attacked and 
 absorbed. This process will continue until the ani- 
 mal can no longer obtain from its own tissues 
 material to produce, by its combustion, sufficient heat 
 and energy to maintain the vital processes, and the 
 animal dies. 
 
 § 6. Effects of Exercise and Exposure to Cold. 
 
 221. As we have already seen, the first use of food 
 is for the production of heat and energy. When an 
 animal is exposed to cold, the amount of heat re- 
 quired to maintain the temperature of the body will 
 be increased, and a larger proportion of the food con- 
 sumed by the , animal must be used in its produc- 
 tion. 
 
 222. Physical work can only be performed by 
 means of the energy derived from the combustion of 
 
112 SCIENCE IN FARMING. 
 
 food in the system. Consequently every increase of 
 physical exercise increases the amount of food that 
 must be used in the production of energy. 
 
 223. The first effect, therefore, of exposure to cold, 
 or of exercise, is an increased appetite, by which Na- 
 ture indicates that more food is needed. If the in- 
 creased food is not provided, the effect on the animal 
 will be re-absorption of fat, and, in extreme cases, 
 waste of muscular substance. 
 
CHAPTER IX. 
 
 SCIENCE IN FOODS. 
 
 § 1. Food Constituents: 
 
 224. Food is composed of various organic sub- 
 stances combined in varying proportions. Vegetable 
 substances will vary in composition according to the 
 soil and season, and the treatment they have received. 
 All statements of the composition of food are there- 
 fore approximate only. The nutritive constituents of 
 foods are usually classed as : 
 
 Albuminoids. 
 
 Amides. 
 
 Fats. 
 
 Soluble carbohydrates. 
 
 Crude fibre. 
 
 Ash. 
 
 225. The term albuminoids is used to include all 
 
 nitrogenous matters in food that can be used for the 
 
 formation of albuminoids in the animal system. In 
 
 a great many analyses all the nitrogenous substances 
 
 in the food are classed as albuminoids. In many 
 
 substances this is unavoidable, as the proportion of 
 
 the nitrogen contained in the amides has not yet been 
 
 determined in all cases. 
 8 
 
114 SCIENCE IN FARMING. 
 
 226. Amides cannot be used by the animal for the 
 production of albuminoids, but can be burned in the 
 system as a source of heat and energy. They exist 
 principally in roots and immature substances. 
 
 227. The term " soluble carbohydrates " in analy- 
 ses of foods includes all non-nitrogenous substances 
 (excepting ash and fats) that can readily be dissolved 
 by weak acids or the juices of the stomach. 
 
 228. Crude fibre includes the coarser and harder 
 portions of cellulose and lignose that are not readily 
 dissolved by weak acids or the juices of the stomach 
 
 229. In many analyses of foods the division is 
 made into flesh formers, heat producers and ash. Un- 
 der the term " flesh formers " are included all nitro- 
 genous substances, and under " heat producers " all 
 that do not contain nitrogen. The terms, however, 
 are incorrect and misleading. 
 
 § 2. Com/position of Foods. 
 
 230. The figures in the following table give the 
 average results of a number of analyses. They repre- 
 sent about the composition of any ordinary lot of 
 food, but cannot be relied on as positively accurate, 
 as the composition of different samples of the same 
 kind of food is rarely the same. The variation in com- 
 position is but small in seeds and grains, but in roots, 
 straw and fodder is often quite considerable. The 
 column of " Total nitrogenous matter" may, in most 
 cases, be considered reasonably near the truth, but 
 some doubt exists as to the figures in the column of 
 " True albuminoids," owing to the uncertainty with 
 regard to some foods, particularly roots and fodder, as 
 to the proportion of the nitrogen that exists in the 
 
FOODS. 
 
 115 
 
 form of amides and nitrates.* In many cases it has 
 
 POUNDS OP EACH CONSTITUENT IN ONE TON OF VAKIOUS POODS. 
 
 Name of Foood. 
 
 ig* 
 
 "bod 
 
 ga 
 
 la 
 
 
 GRAINS, CAKES, ETC. 
 
 Cotton cake, decorticated 
 
 Cotton cake, undecorticated. . 
 
 Linseed cake 
 
 Beans .• 
 
 Peas 
 
 Oats 
 
 Wheat 
 
 Barley 
 
 Bye 
 
 Indian corn 
 
 Wheat bran 
 
 Corn cobs _ 
 
 HAY AND STRAW. 
 
 Meadow hay 
 
 Clover hay 
 
 Lucerne hay, cut in bloom . . . 
 
 Wheat straw 
 
 Oat straw 
 
 Corn fodder, 
 
 GREEN FODDER. 
 
 Meadow grass 
 
 Clover 
 
 Eye 
 
 Lucerne, in blossom 
 
 Peas 
 
 Hungarian grass in blossom . 
 
 Sorgum 
 
 Indian corn 
 
 ROOTS, ETC 
 
 Potatos 
 
 Mangel wurzel . . „ 
 
 Turnips 
 
 Pumpkins 
 
 Sugar beets, small 
 
 Carrots 
 
 not been possible to give the amount of true albumi- 
 noids. 
 
 200 
 230 
 240 
 290 
 286 
 260 
 288 
 280 
 286 
 228 
 280 
 206 
 
 824 
 492 
 562 
 510 
 448 
 258 
 226 
 212 
 220 
 208 
 284 
 28 
 
 286 
 
 194 
 
 320 
 
 246 
 
 334 
 
 288 
 
 286 
 
 60 
 
 286 
 
 50 
 
 280 
 
 60 
 
 1600 
 
 70 
 
 1660 
 
 66 
 
 1458 
 
 66 
 
 1480 
 
 90 
 
 1630 
 
 64 
 
 1312 
 
 118 
 
 1480 
 
 50 
 
 1644 
 
 22 
 
 1500 
 
 ' 42 
 
 1770 
 
 24 
 
 1834 
 
 22 
 
 1890 
 
 26 
 
 1630 
 
 20 
 
 1700 
 
 30 
 
 740 
 443 
 506 
 459 
 404 
 232 
 203 
 191 
 198 
 187 
 200 
 ? 
 
 155 
 196 
 230 
 
 ? 
 
 ? 
 
 ? 
 
 ? 
 ? 
 1 
 ? 
 ? 
 ? 
 1 
 ? 
 
 25 
 6 
 10 
 ? 
 ? 
 
 ? 
 
 280 
 
 124 
 
 240 
 
 32 
 
 40 
 
 120 
 
 30 
 
 40 
 
 40 
 
 102 
 
 84 
 
 28 
 
 50 
 44 
 50 
 30 
 40 
 22 
 
 360 
 
 604 
 
 606 
 
 918 
 
 1050 
 
 1076 
 
 1362 
 
 1274 
 
 1384 
 
 1370 
 
 1008 
 
 880 
 
 820 
 764 
 450 
 652 
 
 764 
 780 
 
 384 
 140 
 298 
 140 
 164 
 300 
 306 
 218 
 
 410 
 164 
 106 
 56 
 308 
 216 
 
 *It was formerly supposed that all the nitrogen contained in 
 
116 SCIENCE IN FARMING. 
 
 231. The composition of straw depends very much 
 on the season. In seasons that have been unfavora- 
 ble for maturing the grain, the straw contains consid- 
 erably more soluble carbohydrates and albuminoids 
 than indicated in the table (192). Only a small por- 
 tion — probably less than half — of the nitrogen in straw 
 exists in true albuminoids. 
 
 232. The composition of hay depends greatly on 
 the date of cutting. The following table gives the 
 number of pounds of nutritive substances in a ton of 
 hay made from grass cut at three different periods. 
 The first date represents grass younger than it would 
 usually be cut for hay, but such as cattle get on a 
 good spring pasture. The second date represents 
 good early cut, well cured hay. The third date rep- 
 resents a quality of hay cut rather late, and rather 
 
 coarse and stemmy : 
 
 May 14. June 9. June 26. 
 
 Nitrogenous matter 303 191 145 
 
 Fat' 55 47 46 
 
 Soluble carbohydrates 700 742 743 
 
 Crude fibre 394 598 654 
 
 It will be seen from this table that grass in early 
 spring contains a larger proportion of nitrogenous 
 matter and fat than it does later in the season. In 
 the more mature crop, however, a larger proportion of 
 the nitrogen is contained in true albuminoids. 
 
 233. Root crops, as they approach maturity, con- 
 tain more valuable nutritive constituents than when 
 
 foods was available for the use of the animal, and the albumi- 
 noids were reckoned by first ascertaining the amount of ni- 
 trogen contained in the food and multiplying this by 6.25. 
 Many errors have arisen from this method, as in some foods 
 as much as 75 per cent of the nitrogen exists in amides and ni- 
 trates. Foods have thus been supposed to have a high albu- 
 minoid ratio (255), when in fact they were very deficient in al- 
 buminoids. 
 
FOODS. 117 
 
 immature, a portion of the fibre being converted into 
 starch and sugar. 
 
 234. Water in Foods. — It will be noticed that pota- 
 tos, the*dryest of the roots, contain three-fourths of 
 their weight of water, while turnips are nine-tenths 
 water. This is a matter that is of considerable im- 
 portance in determining the proper mixture of foods, 
 and will be more fully considered in the next chapter. 
 
 235. Variations Caused by Soil and Season. — Foods 
 grown in wet seasons and on heavily manured soil, 
 usually contain more than the average per cent of 
 water (178). Root crops grown on rather poor soil 
 contain a larger per cent of nutritive ■ matter than 
 those grown on soil that has been heavily manured. 
 The dry substance in a crop grown on soil that has 
 been heavily manured, usually contains a larger per 
 cent of ash and of nitrogen than the dry substance of 
 a crop grown without manure. A larger portion of 
 the nitrogen in the manured crop will be in the form 
 of amides and nitrates. 
 
 236. Effect of Methods of Preparing Foods.— Hay 
 that has been roughly handled contains a smaller pro- 
 portion of valuable constituents than that which has 
 been more carefully treated, as the finer portions of 
 the blades and leaves, which contain more albumi- 
 noids and less crude fibre than the stems, are crum- 
 bled and broken off. Clover, especially, is liable to 
 deterioration in this way, as the leaves, which are 
 rich in albuminoids, crumble readily when too dry. 
 The chemical composition of a ton of clover which 
 had been roughly treated, would be quite different 
 from that of a ton which had been properly cured; 
 If grass, after cutting, is exposed to drenching rains, 
 part of the soluble constituents will be washed out, 
 
118 SCIENCE IN FARMING. 
 
 and its composition will therefore show a larger per- 
 centage of crude fibre. Hay that has undergone fer- 
 mentation in the field will have suffered a further loss 
 of soluble carbohydrates by their conversion into car- 
 bonic dioxide and water. 
 
 When properly handled and cured, the composition 
 of hay does not differ materially from that of the grass 
 from which it was made. 
 
 § 3. Digestibility of Foods. 
 
 237. The composition of a food cannot be taken, 
 alone, as a trustworthy indication of its feeding value, 
 as this will depend largely on its digestibility. Some 
 foods are almost entirely digested, while of others 
 more than half is sometimes rejected (217). 
 
 238. An animal does not always digest the same 
 proportion of each constituent in a food, nor the same 
 proportion of the same constituent in different foods. 
 Thus, a cow will digest a much larger proportion of 
 the albuminoids in lucerne hay than of those in clover 
 hay, and will digest a larger proportion of the fat in 
 clover hay than of that in lucerne hay. The digesti- 
 bility of foods thus influences not only their compara- 
 tive feeding value, but also their relative character. 
 Thus the difference as an albuminoid food in favor of 
 lucerne hay over clover is greater than indicated in 
 the table on page 115. Likewise the table shows lu- 
 cerne hay as containing a larger proportion of fat than 
 clover ; yet so much more of the fat contained in clo- 
 ver is digested, that as a food it is really richer in fat 
 than lucerne. It will thus be seen that while such a 
 table as given on page 115 is very useful for many 
 purposes, yet, taken alone, it cannot be depended on 
 
FOODS. 119 
 
 to determine either the value of a food, or its char- 
 acter.* 
 
 239. The following table gives the number of 
 pounds of digestible constituents in a ton of several 
 different foods as determined by experiments with 
 cattle and sheep. It will be noticed that in many re- 
 spects^it differs materially from the last table : 
 
 Name of Nitrogenous ■&. Soluble Car- WK „ Q 
 
 Food. Matter. * at ' bohydrates. * 1Dre - 
 
 Linseed cake 472 216 473 ? 
 
 Beans 449 30 854 ? 
 
 Oats 204 101 818 52 
 
 Barley 163 40 1108 ? 
 
 Indian corn 164 87 1247 ? 
 
 Wheat bran 213 42 706 82 
 
 Meadow hay 109 23 508 300 
 
 Clover hay 135 25 527 229 
 
 Lucerne hay 219 19 301 320 
 
 Oat straw 19 12 329 488 
 
 Wheat straw 12 11 254 494 
 
 240. In this table it was impossible to make any 
 accurate calculation of the amount of true albumin- 
 oids in the digested portion of the food. It will prob- 
 ably be safe to assume, however, that true albumin- 
 oids formed 90 per cent of the digested nitrogenous 
 matter in the cakes and grains — 80 per cent in hay 
 and 50 per cent in straw. Roots appear to be almost 
 completely digested. 
 
 241. The horse digests a smaller proportion of 
 coarse foods than ruminating animals, but on grains 
 and concentrated food his digestion is equal or 
 superior to theirs. 
 
 242. Pigs have great powers of digesting concen- 
 trated food, and can digest a good proportion of green 
 foods when supplied in moderate amount, but they 
 
 *By the "character" of a food is meant its richness in any 
 particular constituent, as albuminoids or fat. 
 
120 SCIENCE IN FARMING. 
 
 do not successfully digest large quantities of coarse 
 food. 
 
 243. The degree of maturity of a crop has much 
 to do with its digestibility. Young grass is more di- 
 gestible than that which is older. The number of 
 pounds of food constituents in a ton of hay cut at 
 different dates was given in paragraph 232. We now 
 give the number of pounds of digestible food constitu- 
 ents in a ton of hay cut at the same three dates : 
 
 May 14. June 9. June 26. 
 
 Nitrogenous matter 222 138 80 
 
 Fat 36 24 20 
 
 Soluble carbohydrates 530 459 414 
 
 Crude fibre 313 393 400 
 
 By comparison with the preceeding table, the great 
 depreciation in the value of the crop, as it approached 
 maturity will be noticed. Not only does the older 
 grass contain a smaller proportion of the more valu- 
 able constituents, but a smaller proportion of what it 
 does contain is digested. 
 
 For this reason, young grass or clover pastured, or 
 cut and fed green gives greater returns in beef or 
 milk than the same amount of grass allowed to ma- 
 ture and made into hay. This also explains why cat- 
 tle do so well on spring pastures. 
 
 244. Digestibility of Food as Affected by Mixing. — 
 To secure the most complete digestion of food, a cer- 
 tain proportion between the nitrogenous and non-ni- 
 trogenous constituents must be secured. 
 
 245. If, to a diet of hay or straw, a food rich in al- 
 buminoids is added, the digestibility of the whole ra- 
 tion is not impaired, but if to such a diet a food de- 
 ficient in albuminoids is added, the proportion of the 
 hay or straw digested will be diminished. Potatos, 
 and other foods rich in starch, have a greater effect 
 
FOODS. 121 
 
 in reducing the digestibility of a diet with which they 
 are mixed than mangels or other roots rich in sugar. 
 
 246. If to a diet of hay or straw, potatos or some 
 similar food is added, and also some food rich in albu- 
 minoids, such as peas, beans, or linseed cake, the di- 
 gestibility of the diet will not be reduced. 
 
 247. The results of experiments in this direction 
 show that in order to secure the most perfect diges- 
 tion of food, the diet must contain a certain propor- 
 tion of albuminoids. If a diet is mixed in such a 
 manner that it does not contain a sufficient proportion 
 of albuminoids, a larger percentage of all the nutri- 
 tive constituents in the diet will remain undigested. 
 It is therefore important in determining on a mixed 
 diet to consider what its albuminoid ratio (255) will 
 be, and to so proportion the food that this ratio (cal- 
 culated from the whole food) will not fall below that 
 which secures the most perfect digestion of all the 
 food constituents. The proper albuminoid ratio will 
 be considered in the next chapter. 
 
 § 4. Valuation of Foods. 
 
 248. For development of muscle no comparisons 
 can be made between albuminoids and non-nitrogen- 
 ous substances, as only the albuminoids in the food 
 can be used for this purpose. If a diet is deficient in 
 albuminoids, the addition of a sufficient quantity of 
 them will have an effect out of all proportion to the 
 actual value of the albuminoids. 
 
 249. As albuminoids, carbohydrates and fats can 
 all be used for laying on fat, or can be consumed in 
 the system for the production of heat and energy, it 
 is easy to make a comparison of their respective 
 values for these purposes. By careful experiments 
 
122 SCIENCE IN FABMING. 
 
 these values have been determined, as follows: 
 
 Fat 100 
 
 Albuminoids 47.4 
 
 Carbohydrates* 43.1 
 
 These figures refer to the value of the digested por- 
 tions of the food. A given weight of a very digesti- 
 ble carbohydrate might be of more value than an equal 
 weight of an indigestible fat, but the proportion be- 
 tween the value of 1 lb. of digested fat and 1 lb. of di- 
 gested carbohydrate is that of 100 to 43.1. That is if a 
 given weight of fat in a food were worth $1.00, an equal 
 weight of albuminoids would be worth 47^ths cents, 
 and an equal weight of carbohydrates, 43^11 cents. 
 
 250. The rule usually adopted in comparing the 
 value of fats with carbohydrates is to multiply the 
 amount of fat by 2.44. That is, if one lot of food con- 
 tained 100 lbs. fat and another 244 lbs. carbohydrates, 
 they would be estimated of equal feeding value. 
 
 251. To illustrate. By reference to the table in 
 paragraph 239 it will be seen that a ton of linseed 
 cake contains 216 lbs. digestible fat, and 473 lbs di- 
 gestible carbohydrates. To estimate the feeding value 
 of the digestible constituents in a ton of linseed cake, 
 we multiply the fat by 2.44 and add to this the carbo- 
 hydrates. Thus : 
 
 Number of pounds 216 
 
 Multiply by 2A± 
 
 864 
 864 
 432 
 
 Equal in carbohydrates to 5 2 7.0 4 
 
 Add carbohydrates 473 
 
 1000.04 
 
 *This includes all digestible non-nitrogenous food constitu- 
 ents except fats. 
 
FOODS. 123 
 
 By which we see that the feeding value of the 
 digestible non-nitrogenous constituents in a ton of 
 linseed cake is equal to ljOOO^ths lbs. of starch or 
 other digestible carbohydrates. 
 
 252. The rule for reducing fat to its equivalent 
 value in starch, or other digestible carbohydrates, is : 
 Multiply the number of pounds of fat by 244 and 
 point off the last two figures in the product for deci- 
 mals. 
 
 253. As already stated, the value of a food, pro- 
 viding it contains a sufficient amount of albuminoids 
 to meet animal requirements, depends on its capacity 
 for the production of heat and energy. By taking 
 the digestible constituents of different foods and re- 
 ducing them all to their value in carbohydrates, their 
 respective values have been approximately deter- 
 mined. 
 
 254. The following table gives the result of these 
 calculations, Indian corn being taken as the standard 
 with which the others are compared. The first column 
 gives the respective values of foods in their ordinary 
 condition, the second column the respective values of 
 the dry substance in these foods : 
 
 Name of Food. 
 
 Indian corn 
 
 Linseed cake* 
 
 Beans 
 
 Barley 
 
 Oats 
 
 Wheat bran 
 
 Meadow hay 
 
 "Wheat straw 
 
 Potatos 
 
 Mangels 
 
 Ordinary Con- 
 dition. 
 100 
 
 Dry Sub- 
 stance. 
 100 
 
 95 
 
 96 
 
 93 
 
 96 
 
 85 
 
 88 
 
 80 
 
 81 
 
 67 
 
 69 
 
 59 
 
 61 
 
 47 
 
 49 
 
 30 
 
 105 
 
 13 
 
 100 
 
 *It may appear strange that linseed cake is given a position 
 as a food inferior to Indian corn. It must be remembered that 
 
124 SCIENCE IN FARMING. 
 
 The figures for the last five articles are probably too 
 high, owing to the fact that proper deduction has not 
 been made for the amides and nitrates. 
 
 § 5. Albuminoid Ratio. 
 
 255. The " albuminoid ratio" of a food is the pro- 
 portion that exists between the albuminoids and the 
 non-nitrogenous constituents. 
 
 It is customary in calculating the albuminoid ratio 
 of a food to take into consideration the digestible por- 
 tion only, as the portion undigested of course has no 
 feeding value. When the digestibility of the different 
 constituents of a food is not known, the albuminoid 
 ratio must be calculated from its total constituents. 
 A food will usually appear richer in albuminoids 
 when the estimate is made from the table of digesti- 
 ble constituents than when calculated from the table 
 of total constituents, as there is usually a larger per- 
 centage of carbohydrates, fat and fibre rejected, undi- 
 gested, than of albuminoids. 
 
 256. To secure strict accuracy in the determina- 
 tion of the albuminoid ratio, the calculation should 
 be made from the amount of true albuminoids only, 
 as the amides and nitrates are without value in the 
 production of muscle. Nearly all the older calcula- 
 tions are erroneous from this cause, as it is only lately 
 that the distinction between amides and true albu- 
 minoids has been learned. It is still sometimes nec- 
 essary to make calculations in this way, as, with 
 some foods, the proportion of nitrogen which exists 
 in true albuminoids has not been ascertained with 
 
 this table is calculated only on the capacity of the food for pro- 
 ducing heat and energy. Linseed cake mixed with other foods 
 may, by increasing the albuminoid ratio of the mixed diet, 
 have a value many times greater than that of corn, 
 
FOODS. 125 
 
 J*- 
 
 certainty. Calculations made in this manner will be 
 reasonably correct with respect to grains and concen- 
 trated foods ; but with roots and immature substances 
 such calculations are liable to be seriously incorrect. 
 Thus, mangels were formerly supposed to contain suf- 
 ficient albuminoids to form a complete ration, their 
 albuminoid ratio being 1 : 8, when calculated on the 
 supposition that all the nitrogenous matter they con- 
 tained was in albuminoids ; but when only the true 
 albuminoids were reckoned, the ratio was found to 
 be 1 : 31.8 (263). 
 
 257. To determine the albuminoid ratio of a food, 
 the feeding value of the digestible non-nitrogenous 
 constituents is ascertained, and this is divided by the 
 amount of albuminoids. The product is the proportion 
 of non-nitrogenous to one of nitrogenous constituents. 
 
 258. Illustration. — Suppose the albuminoid ratio of 
 wheat bran is desired. By reference to the table in 
 paragraph 239, we find that a ton of wheat bran con- 
 tains the following amounts of digestible constituents : 
 
 Albuminoids* 213 lbs. 
 
 Fat 42 lbs. 
 
 Carbohydrates 706 lbs. 
 
 Fibre 82 lbs. 
 
 First reduce the fat to its equivalent in starch (250) : 
 
 Fat 42 lbs. 
 
 Multiply by 2^44 
 
 168 
 168 
 84 
 
 The fat is equal in starch 1 2.4 8 lbs. 
 
 Add digestible carbohydrates . . 7 6 lbs. 
 
 And digestible fibre 8 2 lbs. 
 
 8 9 0.4 8 lbs, 
 
 *In this instance it is necessary to reckon all the nitrogenous 
 
126 SCIENCE W FARMING. 
 
 Which gives us the feeding value of the digestible 
 non-nitrogenous constituents of a ton of bran as equal 
 to 890.48 lbs. To get the proportion between this and 
 the albuminoid, we divide it by the number of pounds 
 of albuminoids. Thus : 
 
 213)8 90.4 8(4.18 
 852 
 
 384 
 213 
 
 1718 
 1704 
 
 We thus get the proportion of one to four and eighteen 
 one-hundreths, which is written thus : 1 : 4.18. 
 
 259 . When the proportion of albuminoids in a food 
 is large, it is said to have a high albuminoid ratio. 
 When the proportion is small, that food is said to 
 have a low albuminoid ratio. Thus the albuminoid 
 ratio of decorticated cotton cake is 1 : 1.5 ; that of 
 wheat straw 1 : 64.4 ; cotton cake is said to have a 
 high, and wheat straw a very low, albuminoid ratio. 
 
 260. To Determine the Albuminoid Ratio of a Mixed 
 Diet. — This is a matter of great importance, as it ena- 
 bles the farmer to know whether a mixed diet is prop- 
 erly proportioned to meet the desired object. 
 
 261. Bole. — Ascertain the number of pounds of 
 each digestible constituent in the amount of each food 
 used in the mixture ; add these and calculate the al- 
 buminoid ratio of the product, the same as in any 
 other case. 
 
 262. Illustration. — Suppose a farmer wishes to use 
 
 matter in the bran as albuminoid, as the per cent of amides 
 contained in the digested portion of bran has not been fully de- 
 termined. 
 
FOODS. 127 
 
 a mixed diet arranged in the following proportion : 
 
 Meadow hay 100 lbs. 
 
 Corn meal 20 lbs. 
 
 Bran 20 lbs. 
 
 By reference to the table in paragraph 239, we learn 
 the amount of each digestible constituent in one ton 
 of each food named, and by a simple calculation we 
 obtain the number of pounds of digestible substance in: 
 
 Nitrogenous p . Carbohy- ™ 
 
 Matter. * at ' drates. JnDre - 
 
 100 lbs. meadow hay... 5.45 1.15 25.40 15.00 
 
 20 lbs. corn meal 1.64 .87 12.47 ..... 
 
 20 lbs. bran 2.13 .42 7.06 .82 
 
 Total in whole ration... 9.22 2.44 44.93 ■ 15.82 
 
 Keducing the fat to' its value in starch (250), we 
 get the value of the digestible non-nitrogenous con- 
 stituents in the diet : 
 
 fat, 2.44 lbs. equal to 5.95 lbs. 
 
 Carbohydrates 44.93 lbs. 
 
 Fibre 15.82 lbs. 
 
 Total value equal to. 66.70 lbs. 
 
 From which we find by the usual rule (257) that the 
 albuminoid ratio of the mixed diet is 1 : 7.23.* 
 
 263. The following table gives the albuminoid ra- 
 tio of various foods, calculated from the digested por- 
 tions only. The first column gives the ratio as deter- 
 mined by calculations made on the supposition that 
 all the nitrogenous substances in the food are true al- 
 buminoids. The second column gives the ratio as de- 
 termined by estimating only the true albuminoids. 
 The figures given in the first column for cakes and 
 grains are nearly correct. The true ratio for turnips 
 
 *It will be noticed that this calculation is made on the sup- 
 position that all the nitrogen is in albuminoids, and the ratio 
 thus obtained is therefore rather above the truth. 
 
128 
 
 SCIENCE IN FARMING. 
 
 would probably be about 1 : 12, and of wheat straw 
 not more than 1 : 100; for clover hay about 1 : 9. 
 
 ALBUMINOID RATIO OF THE DIGESTED POKTION OP POODS. 
 
 Reckoning all Ni- Reckoning on- 
 Name of Food' trogehous matter ly the true 
 
 as albuminoids. albuminoids. 
 
 Cotton cake decorticated 1 : 1.5 
 
 Cotton cake undecorticated 1 : 1.8 
 
 Linseed cake 1 : 2.3 
 
 Beans 1 : 2.4 
 
 Peas 1 : 2.9 
 
 Wheat bran 1 : 4.2 1 : 7 
 
 Oats 1 : 5.5 
 
 Barley 1 . 7.6 
 
 Indian corn 1 : 9 
 
 Clover hay 1 : 5.9 
 
 Meadow hay 1: 8 1 : 12.4 
 
 Turnips 1 : 6.2 
 
 Mangels 1 : 8 ] : 31 .8 
 
 Potatos 1 : 10.6 1 : 17.7 
 
 Wheat straw 1 : 64.4 
 
 264. The same food may have a different albumi- 
 noid ratio when fed to-diiferent animals, as one may 
 digest a larger proportion of the albuminoids, and the 
 other a larger proportion of the carbohydrates. In 
 one experiment a horse and a sheep were fed on the 
 same meadow hay. The portion of the hay digested 
 by the horse had an albuminoid ratio of 1 : 6.7, while 
 the portion digested by the sheep had a ratio of 1 : 9.1. 
 This difference was due to the fact that the horse di- 
 gested as large a proportion of the albuminoids in the 
 hay as the sheep, but the latter animal digested a 
 larger proportion of the carbohydrates and crude fibre. 
 
CHAPTER X. 
 
 SCIENCE IN FEEDING. 
 
 § 1. General Principles. 
 
 265. The practical objects to be attained in feeding 
 are: 
 
 1. To cause growth— development of bone and mus- 
 cle — in the young animal. 
 
 2. The production of milk. 
 
 3. The production of fat. 
 
 4. To furnish material from which the animal can 
 derive energy to be employed in useful work. 
 
 A fifth might be added — namely, the production of 
 manure, but this will be considered in the next 
 chapter. 
 
 266. While food is being supplied for these pur- 
 poses, a sufficient amount must also be furnished to 
 repair the wastes of animal substance (206), maintain 
 the heat of the body, and furnish the energy required 
 in the vital processes (212). 
 
 267. We have seen (203) that the plant is the ma- 
 chine by which inorganic substances are converted, 
 into forms that can be used by the animal. To the 
 farmer, the animal is only a machine for the conver- 
 sion of vegetable substances into flesh, fat, milk, wool 
 
 etc., and for the development into useful work of the 
 9 
 
130 SCIENCE IN FARMING. 
 
 energy which the plant has obtained from the sun 
 and stored in the food. 
 
 268. If a steam engine attached to a mill requires 
 20 lbs. of coal per hour to overcome the resistance of 
 the machinery and only that amount is supplied, no 
 useful work can be accomplished. If the supply of 
 coal is increased to 30 lbs. per hour, the energy de- 
 rived from the 10 lbs. added would be available for 
 grinding. If 40 lbs. per hour is supplied, the available 
 power will be that of 20 lbs. of coal. Thus by the last 
 increase of 10 lbs. the work which can be accom- 
 plished is doubled. 
 
 269. The same principle applies to the science of 
 feeding. If an animal which requires 20 lbs. of food 
 per day to repair the waste of tissue and carry on the 
 vital processes receives only that amount, no part of 
 this food can be applied to growth, production of fat 
 or milk, or in useful work. If a larger quantity of 
 food is supplied, the additional food can be used for 
 profitable increase. 
 
 270. The animal is, in fact, engine and mill com- 
 bined. Into the same hopper is put the grist to be 
 ground and the fuel to drive the engine. Only that 
 which is furnished in excess of the amount required 
 
 . to keep mill and engine running and in repair pays 
 any profit to the owner. Of this excess part is ground 
 up and worked over into profitable forms, and part is 
 used to supply the additional energy needed for the 
 purpose. 
 Underfeeding is therefore extravagance. . 
 
 271. Adaptation of Foods. — It is not only necessary 
 that the animal should have sufficient food, but it 
 must be adapted to the object desired. If the food 
 supplied to a growing animal is composed chiefly of 
 
FEEDING. 131 
 
 non-nitrogenous matters, these cannot be converted 
 into muscle, and either growth will be checked or an 
 excess of food must be supplied — and a portion of the 
 carbohydrates be wasted. If on the other hand the 
 food contains a larger proportion of albuminoids than 
 is needed, while the animal will not suffer, as the al- 
 buminoids will meet all its needs (210), yet as they 
 are much more expensive than carbohydrates, the 
 farmer's profits will be greatly diminished. 
 
 272. Effects of Exercise. — We have seen that the 
 physical energy in the animal is derived from the 
 combustion of the carbon of the food in the blood 
 ( 211 ) . The greater amount of physical effort required 
 the greater amount of the food consumed will be used 
 for this purpose. 
 
 It has been ascertained by experiment that a man 
 when doing a fair day's work, gives off from his lungs 
 one-third more carbonic dioxide than in an equal time 
 when at rest, which proves that when at work one- 
 third more food was burned in the system. 
 
 Hence all unnecessary exercise on the part of an 
 animal causes a waste of food. When cows are 
 driven long distances to and from pasture, are com- 
 pelled to roam over closely cropped fields in search 
 of food, or worried by flies, or chased by dogs and 
 boys, the farmer may know that the energy'thus ex- 
 pended is obtained by the combustion of food that 
 would otherwise be converted into milk andjbutter.* 
 
 *The greatly increased production of butter and cheese 
 claimed by the advocates of soiling, is partially explained by 
 the fact just given. The cows kept in a quiet and'comfortable 
 stable, protected from annoyance by flies and spared all un- 
 necessary exertion, can put into the pail a quantity of butter, 
 that, were they roaming over a large pasture and fighting flies, 
 they would be obliged to burn for the production of physical 
 
132 SCIENCE IN FABMTNG. 
 
 273. Effects of Cold. — Exposure to cold results in 
 loss to the farmer in much the same manner as excess 
 of exercise. The animal heat must be maintained 
 and food will be burned in the system in proportion 
 to the demand for this purpose. Food which the an- 
 imal should be manufacturing into fat, flesh or milk, 
 is burned to keep the animal warm. A farmer would 
 be considered extravagant who would put up a stove 
 to warm his stable and feed the fire with butter, but 
 when he leaves his cows exposed to cold and storms, 
 they have to keep warm by burning the butter which 
 would otherwise go into the milk pail. 
 
 274. In some experiments with sheep made to as- 
 certain the amount of food required to produce one 
 pound increase of live weight, it was found that 150 
 lbs. of turnips were required to produce this amount 
 of increase when fed to sheep which had no protec- 
 tion from storms and cold, but that the same result 
 was obtained by feeding 100 lbs. when the sheep were 
 protected. 
 
 275. The Kansas State Board of Agriculture re- 
 cently made some experiments in fattening pigs. A 
 number were put in pens and fed and treated alike, 
 with the exception that part of the pens were in the 
 basement of a barn and part were out of doors. It 
 was found that one pound of increase was made from 
 5.15 lbs. of corn fed to the pigs in the barn, but that 
 
 energy. Men who have had no experience in soiling, often 
 wonder how it is possible that the food grown on an acre 
 should produce any more milk and butter when cut and fed to 
 animals in the stable, than when the same animals gather it 
 for themselves. They do not see the butter burned to enable 
 the cow to wander after her food, and fail to appreciate that it 
 is burned as truly as if put into the fire-box of an engine. 
 
FEEDING. 133 
 
 5.48 lbs. corn were required to make one pound of 
 increase in the pigs fed outside. 
 
 Too great heat is also wasteful, as it occasions per- 
 sp'iration and food must be consumed in its evapora- 
 tion. 
 
 276. Effect of Water in Food.— A certain amount of 
 water is necessary to the life of the animal, but if an 
 excess is contained in the food waste will be oc- 
 casioned, as the water must all be warmed to the 
 temperature of the animal and a part must be evapo- 
 rated through the skin. Considerable food must be 
 burned to produce the heat 'thus required. 
 
 277. The proper proportion of water is, for sheep 
 about two parts to one of dry substance j for cattle, 
 four parts to one. Cows giving milk require a still 
 larger proportion of water. 
 
 278. In feeding grains and dry fodder'there is lit- 
 tle probability of supplying too much water, but in 
 feeding roots alone the quantity of water is liable to 
 be greatly in excess of the animal's requirements. 
 When an animal is fed exclusively on turnips, a large 
 part of the dry substance consumed will be used in 
 raising the temperature and evaporating the surplus 
 water. 
 
 279. Hence, roots should usually be fed in connec- 
 tion with dry food, and when fed in this manner, will 
 give much better results than when fed alone. 
 
 § 2. Proper Food for the Young Animal. 
 
 280. The chief object of the food supplied to the 
 young animal is to produce bone and muscle, as the 
 production of a large amount of fat is not desirable. 
 The food, therefore, should be rich in albuminoids, 
 phosphoric acid and lime. The milk — called colos- 
 
134 SCIENCE IN FARMING. 
 
 trum— which Nature furnishes for the young animal 
 at birth, is exactly fitted for the purpose designed. 
 The following table gives the analysis of the colos- 
 trum of the cow : 
 
 Water 716 
 
 Albuminoids 207 
 
 Fat 34 
 
 Sugar 25 
 
 Ash 18 
 
 1,000 
 
 The albuminoid ratio is about 1 : 0.5. The ash, 
 which is also in large proportion, is principally calcic 
 phosphate. This food is therefore specially adapted 
 for producing bone and muscle. During the first 
 few days of its life the animal takes but little ex- 
 ercise ; consequently the amount of carbonaceous 
 food required is not large. The character of the milk 
 soon changes, as the needs of the animal change. The 
 milk contains more fat and sugar, and less albumi- 
 noids and ash. The following is the average compo- 
 sition of cow's milk : " 
 
 Water 870 
 
 Albuminoids 40 
 
 Fat 37 
 
 Sugar 46 
 
 Ash 7 
 
 1,000 
 
 The albuminoid ratio is now only 1 : 3.3. 
 
 The composition of milk gives the key to the proper 
 food for the growing animal. 
 
 281. It should be readily digestible and contain a 
 fair proportion of fat. Carbohydrates can take the 
 place of fat; but as 2.44 lbs. carbohydrates are re- 
 quired to equal 1 lb. of fat, a less bulk of carbona- 
 ceous food will be required when fat is provided, and 
 the animal will thus be able to consume more albu- 
 
SEEDING. 135 
 
 minoids, which are essential for the development of 
 bone and muscle. The food must also contain a due 
 proportion of phosphoric acid and lime. 
 
 282. By reference to the table of foods (230), it 
 will be seen that young clover and grass are rich in 
 albuminoids. They also contain a considerable per- 
 centage of phosphates, and therefore form a suitable 
 diet for the growing animal. Bran makes a good ad- 
 dition to such a diet, and a little linseed cake will 
 supply the fat and albuminoids. 
 
 283. Many of our best farmers have adopted the 
 plan of putting their growing pigs on grass or clover 
 pastures, and feeding but moderately with corn. 
 This enables the pig to grow and develop a large, 
 bony and muscular carcass, with capacious digestive 
 organs. When the time arrives for fattening such an 
 animal, it can consume large quantities of food, and 
 produce a proportionately large amount of fat. 
 
 284. The proper albuminoid ratio for a growing 
 animal is 1 : 5 to 1:7. When all the nitrogenous 
 matter has been reckoned as albuminoid, in determin- 
 ing the ratio, it should not be less than 1 : 5. 
 
 § 3. Proper Food for Producing Milk. 
 
 285. As milk contains a large proportion of albu- 
 minoids and phosphates, the food must contain enough 
 of these substances to meet the demands for milk in 
 addition to what is required to supply the wastes of 
 tissue. If the food does not contain enough of these 
 substances, the flow of milk will be diminished, or 
 the cow must use her own tissues for its production. 
 The food should also contain some readily digestible 
 fat, as we have seen that this is contained in milk in 
 considerable quantity (280). 
 
136 SCIENCE IN FARMING. 
 
 286. If a food is deficient in albuminoids, the cow 
 may be fed all she can eat, and yet be unable to yield 
 a liberal supply of milk. 
 
 287. As the bulk which a cow can eat is limited, 
 the food should be tolerably concentrated ; otherwise 
 it will not be possible for her to obtain a sufficient 
 amount of nutritive substances in the quantity she is 
 able to eat 
 
 288. For example. By reference to the table in 
 paragraph 239, it will be seen that a ton of wheat 
 straw contains only 12 lbs. of digestible nitrogenous 
 matter. Not more than half of this is in the form of 
 true albuminoids. As 25 lbs. of milk contain about 1 
 
 ' lb. albuminoid, it would be necessary for a cow fed 
 on wheat straw alone, to consume (in addition to the 
 amount required to repair the wastes of her tissues) 
 333£ lbs. straw in order to produce 25 lbs. of milk. It 
 is true that a cow could not eat such a quantity ,of 
 straw in a day, but it would be as possible for her to 
 do so as it would be for her to give a liberal flow of 
 milk on such a diet. This explains why farmers who 
 winter their cattle at the straw stack find it impossi- 
 ble to make butter in winter.* 
 
 289. Pea and bean meal, linseed and cotton cake 
 are rich in albuminoids. Bran and clover are also ni- 
 trogenous foods and contain a considerable proportion 
 of phosphates, Mangels supply valuable carbohy- 
 drates. A diet of good clover or meadow hay, with 
 
 *A cow could hardly keep alive, much less give milk, fed on 
 pure wheat straw. Practically a straw pile always contains a 
 little grain and some other substances, and the cattle " pick 
 up" a little food besides. The usual condition in spring of 
 cattle wintered at the straw stack, is, however, a sufficient evi- 
 dence of the correctness of the scientific principles that have 
 been laid down. 
 
FEEDING. 1*37 
 
 mangels, bran and a small amount of linseed or cot- 
 ton cake, bean or pea meal would be a good milk 
 diet from a scientific stand-point, and practical expe- 
 rience has approved it. 
 
 290. The value of young meadow grass as a milk 
 diet is well known. The fact that cows on pasture 
 decrease in flow of milk as the season advances, is 
 also a familiar one. This is caused by the decrease 
 of albuminoids in the older grass. By reference to 
 the table in paragraph 243, it will be seen that 100 
 lbs. of hay, cut May 14th, contained a little over 
 11 lbs. of digestible albuminoids, while the same 
 quantity cut June 26th,- contained but 4 lbs. The 
 cow cannot eat more grass in summer than in spring, 
 and therefore if at each period she has all the grass 
 she can eat, she will by June 25th get but four- 
 elevenths as much albuminoids as she would May 
 14th.* 
 
 291. Wolf gives the albuminoid ratio of a milk 
 diet as 1 : 5, reckoning all the nitrogenous matter as 
 albuminoids. Reckoning only the true albuminoids', 
 a ratio of 1 : 6 or 1 : 7 will be sufficient. 
 
 292. Meadow grass cut May 14th has a ratio of 
 1 : 4.14 (reckoning all nitrogenous matter). That cut 
 June 26th has a ratio of only 1 : 10.76. The first, there- 
 fore is a rich milk diet, while the latter falls far below 
 the requirement. 
 
 293. Analysis of aftermath hay shows that while 
 it is no richer in albuminoids than the first crop, it is 
 very considerable richer in fat. The following table 
 
 *This further explains the advantages claimed by the advo- 
 cates of soiling. Under this system the cattle are kept con- 
 stantly supplied with fresh young grass and fodder, cut at the 
 time when it is richest in nitrogenous constituents. 
 
138 SCIENCE IN FARMING. 
 
 gives the number of pounds of food constituents in a 
 ton of aftermath hay : 
 
 Water 237.4 lbs. 
 
 Nitrogenous matter 196.8 lbs. 
 
 Soluble carbohydrates 845.0 lbs. 
 
 Fat 136.8 lbs. 
 
 Crude fibre 395.4 lbs. 
 
 Ash 188.6 lbs. 
 
 2,000.0 lbs. 
 
 Such hay if fed with sufficient nitrogenous food to 
 secure a proper albuminoid ratio, would make a bet- 
 ter milk diet than the first crop. 
 
 294. Mr. T. Horsfall, of England, made some of 
 the most complete experiments on the diet of milk 
 cows. He first calculated a diet from scientific prin- 
 ciples, and then applied to this the test of practical 
 experiment. The ration for each cow per day con- 
 sisted of: 
 
 Meadow hay 9.33 lbs. 
 
 Rape cake 5. lbs. 
 
 Malt combs 1.5 lbs. 
 
 Wheat bran 1.5 lbs. 
 
 Beans 1.5 lbV 
 
 Green fodder 34. lbs. 
 
 Oat straw 8.33 lbs. 
 
 Bean straw 2. lbs. 
 
 Total 63.16 lbs. 
 
 The rape cake, malt combs, wheat bran, beans and 
 bean straw made this a highly nitrogenous diet, the 
 albuminoid ratio being 1 : 5.4. The rape cake fur- 
 nished a considerable quantity of fat. In some parts 
 of the country rape cake and malt combs cannot be 
 obtained. Linseed or cotton cake can be substituted, 
 and a diet fully equal to Horsfall's be obtained. If 
 neither of these can be had, an approach to the ration 
 could be made by increasing the proportion of bran 
 — using clover or Hungarian grass and some corn 
 meal. 
 
FEEDING. 139 
 
 Mr. Horsfall's cows on this diet gave a large quan- 
 tity of milk, of which 16 quarts yielded from 24 to 28 
 ounces of butter. And the cows gained in weight. 
 
 § 3. The Fattening Animal. 
 
 295. The chief constituent in the increase in a fat- 
 tening animal is fat. In experiments at Kothamsted 
 it was found that the increase of weight in a fattening 
 sheep consisted of: 
 
 Water 22.0 
 
 Nitrogenous matter 7.2 
 
 Fat 68.8 
 
 Ash : 2.0 
 
 The increase contained nearly ten times as much 
 fat as muscle. 
 
 296. Theoretically, therefore, the fattening animal 
 requires a diet containing but a small proportion of 
 albuminoids. Practically, however, it is found that 
 when the ratio falls as low as theory would indicate 
 could be used, the digestibility of the food is im- 
 paired and the health of the animal suffers (247). 
 
 297. The albuminoid ratio* of food for a fattening 
 animal has been ascertained to be : 
 
 For cattle 1 
 
 For sheep 1 
 
 For pigs 1 
 
 10 
 9 
 
 7 
 
 298. A diet richer in albuminoids may often be 
 used with advantage when not too expensive. Food 
 excessively rich in albuminoids, as cotton cake, is 
 liable to produce disease if fed in large quantities. 
 Such substances should always be fed moderately 
 and in connection with other foods. 
 
 299. Experiments in Fattening. — The following ta- 
 ble shows the result of some experiments made by 
 
 *Reckoning only the true albuminoids. 
 
140 SCIBNCE IN FARMING. 
 
 Messrs. Lawes & Gilbert, of Kothamsted, England, 
 for the purpose of determining the amount of food 
 required to produce an increase of a pound of live 
 weight, and the relative capabilities of different ani- 
 mals for converting food into meat. In the experi- 
 ment, the oxen and sheep were fed on linseed cake, 
 clover hay and sweedes ; the pigs on barley meal : 
 
 RESULTS OBTAINED PER HUNDRED POUNDS LIVE WEIGHT PER WEEK. 
 
 Oxen. Sheep. Pigs. 
 
 Dry food received per week per 
 hundred pounds hve weight. . . . 12.5 16.0 27.0 
 
 Which contained of digestible sub- 
 stance 8.9 12.3 22.0 
 
 Amount of food expended per week 
 in production of heat and energy 
 for each 100 lbs. live weight.... 6.86 9.06 12.58 
 
 Gain in hve weight per week for 
 each 100 lbs. of live weight of 
 animal 1.13 1.76 6.43 
 
 The student will understand from the above table 
 that an ox weighing 1,000 lbs. consumed per week 
 food containing 125 lbs. of dry substance, of which he 
 digested 89 lbs. 68.6 lbs. of this was used in the pro- 
 duction of heat and energy, and 11.3 lbs. stored as in- 
 crease in live weight. The remainder of the digested 
 matter was expended in repairing the wastes of the 
 body. 
 
 300. The table also shows that a sufficient number 
 of pigs to weigh 1,000 lbs consumed per week food 
 containing 270 lbs. dry substance, of which they di- 
 gested 220 lbs. 125.8 lbs. of the digested matter was 
 used in the production of heat and energy, 64.3 lbs. 
 stored up as increase, and the remainder expended in 
 repairing waste of tissue. 
 
 301. These experiments show that the pig eats more 
 in proportion to his weight than the ox, but he also 
 
FEEDING. 141 
 
 makes a larger amount of increase in proportion to 
 food consumed. 
 
 RESULTS OBTAINED PEK HUNDRED POUNDS DRY FOOD USED. 
 
 Ox. Sheep. Pig. 
 Received by animal 100 100 100 
 
 Digested 72.2 76.9 81.5 
 
 Used for heat and energy 54.9 56.6 46.6 
 
 Laid up in increase 9 11 23.8 
 
 By the term 100 lbs. dry food is meant an amount of 
 food containing 100 lbs. dry substance. 
 
 302. It will be noticed that the pig digested a 
 larger proportion of his food than the ox. This was 
 not due to the better digestive powers of the pig, but 
 to the fact that his food contained a larger proportion 
 of digestible material. Calculating therefore only on 
 the digestible portion of the food, we get the follow- 
 ing table, showing the amount of increase in live 
 weight produced from 100 lbs. digested dry substance 
 — that is, from an amount of food containing 100 lbs. 
 of digestible dry substance : 
 
 Ox. Sheep. Pig. 
 Increase in live weight per 100 lbs. 
 digested food 12.7 14.3* 29.2* 
 
 It will be seen that the pig produced a far greater 
 amount of increase from a given amount of digestible 
 food than either the sheep or the ox, showing that he 
 is the most profitable machine which the farmer can 
 use for the conversion of his crops into meat. 
 
 303. The table in paragraph 299 shows that even 
 in these experiments, where the animals were care- 
 fully treated, and no unnecessary food expended in 
 the production of heat and energy, the amount of 
 food consumed for this purpose was far greater than 
 that stored in the increase. 
 
 304. The fact that the pig uses a larger proportion 
 
142 SCIENCE IN FABMINGL 
 
 of the food he consumes in production of increase 
 than the ox, and less for heat and energy, explains 
 the reason why he requires a diet richer in albumin- 
 oids. 
 
 305. The fattening animal does not make the same 
 rate of increase,' nor yield the same profit on food 
 consumed during the whole fattening period. As the 
 animal increases in size and weight, it can eat less 
 food in proportion to its weight, and probably digests 
 a smaller proportion of what it does eat. It also uses 
 a larger proportion of the digested food for production 
 of heat and energy and repair of waste. 
 
 306. An experiment was made at Rothamsted with 
 16 pigs, averaging 135.8 lbs. at the commencement of 
 the fattening period, and 276.3 lbs. at its completion. 
 The food consisted of 7 lbs. pea meal per day for each 
 pig, with all the barley meal in addition that they 
 would eat. The pigs were fed for ten weeks and 
 weighed every two weeks. The following table gives 
 the result. The number of pounds of food refers to the 
 food^in its ordinary condition — not to the dry sub- 
 stance: 
 
 Food con- Pood consum'd Foodconsum'd 
 
 sumed per per 100 lbs live to produce 100 
 
 head. weight. lbs increase. 
 
 60.1 lbs. 39.7 lbs. 386 lbs. 
 
 67.5 lbs. 36.7 lbs. 388 lbs. 
 66.4 lbs. 30.9 lbs. 502 lbs. 
 66.0 lbs. 27.4 lbs. 511 lbs. 
 
 69.6 lbs. 26.3 lbs. 618 lbs. 
 
 First two weeks . . 
 Second two weeks 
 Third two weeks . 
 Fourth two weeks 
 Fifth two weeks . . 
 
 Average for ten w'ks 65.9 lbs. 32.0 lbs. 469 lbs. 
 
 307. During the first two weeks 3.86 lbs. food pro- 
 duced 1 lb. increase ; but during the last two weeks 
 it required 6.18 lbs. to produce that amount. Calcu- 
 lating that 90 per cent of the increase was butcher's 
 parcass, it required during the first two weeks only 
 
FEEDING. 143 
 
 4.29 lbs. food to produce a pound of pork ; but during 
 the last two weeks 6.88 lbs. to produce that amount. 
 The pork made during the last two weeks therefore 
 cost 60 per cent more than that made the first two. 
 
 308. In experiments made in feeding pigs in the 
 United States, it was found that 5.33 lbs. corn was re- 
 quired to make 1 lb. increase in live weight, while in 
 the English experiment just given, the average for 
 the whole period was 1 lb. increase from 4.69 lbs, food. 
 The difference in favor of the English experiment 
 was probably due to the fact that the food used — a 
 mixture of pea and barley meal — had a much higher 
 albuminoid ratio than corn. 
 
 309. Corn does not contain a sufficient proportion 
 of albuminoids to make a perfect diet for fattening 
 pigs. Consequently the addition to a corn-diet of a 
 small amount of some highly nitrogenous food, as 
 linseed cake,* or bean or pea meal, greatly increases 
 the value of the whole food. 
 
 310. Skim milk is a highly nitrogenous food. Its 
 percentage composition is about : 
 
 Water 90. 
 
 Albuminoidst 3.7 
 
 Fat 0.8 
 
 Sugar 4.8 
 
 Ash 0.7 
 
 157.4 lbs. skim milk contains as large an amount of 
 albuminoids as a bushel of corn. We have seen that 
 a pig requires a diet having an albuminoid ratio of 
 1 : 7, and that the ratio of corn is only 1:9. If a 
 pound of skim milk is fed with every pound of corn, 
 
 *Linseed cake can only be fed in small quantity, or it will 
 injure the flavor of the pork. 
 +The nitrogenous matters in milk are all true albuminoids 
 
144 SCIENCE IN FARMING. 
 
 the albuminoid ratio of the whole diet would be 1 : 6.4 
 — a ratio sufficient to secure the best results.* 
 
 311. The entire increase of live weight in a fatten- 
 ing animal is not useful carcass. As the animal grows 
 the digestive organs also grow. The increase of offal 
 is not as great proportionally as the increase of butch- 
 er's carcass, and consequently the highly fattened 
 animal contains a larger percentage of carcass and 
 less percentage of offal than the animal in " store " 
 condition only. 
 
 312. In fattening a sheep, from 68 to 77 per cent of 
 the increase is carcass. 
 
 313. Of the fatted animal, about 60 per cent of the 
 fasted live weight is carcass in the ox, 58 per cent in 
 the sheep and 83 per cent in the pig. 
 
 § 4. The Working Animal. 
 
 314. A working animal, if it has been properly 
 grown, will contain a large amount of muscular sub- 
 stance and a comparatively small proportion of fat. 
 To replace the waste of this muscular tissue will re- 
 quire a fair amount of albuminoids in the food. Be- 
 yond this, carbohydrates and fat meet the require- 
 ments of the working animal. It has been found that 
 an albuminoid ratio of 1 : 9 is sufficient for an adult 
 horse at work. 
 
 315. It would seem that a horse not at work would 
 require about as large an amount of albuminoids as a 
 working horse, but a smaller amount of carbohy 
 
 *This explains why persons who have but one or two pigs 
 and give them the skim milk and scraps from the table, are so 
 successful. The small quantity of food rich in albuminoids 
 added to the corn, raises the character of the whole diet, and 
 better results are obtained from all the food given. 
 
FEEDING. 145 
 
 drates, and that therefore the albuminoid ratio of his 
 diet should be higher. 
 
 316. In growing an animal intended for work, the 
 object is to produce the largest possible development 
 of muscle, and but a small development of fat. There- 
 fore the food for the young animal intended for work 
 should be rich in albuminoids — bran, oats, peas, beans, 
 clover, etc. 
 
 §6 . Summary. 
 
 The only profit which the farmer can secure in 
 feeding, is that from food supplied in excess of the 
 amount required to keep the animal alive and in 
 health. 
 
 It is not only necessary that the food be sufficient 
 in quantity, but its character must also be adapted to 
 the purpose desired. Lack of care and judgment in 
 this respect is likely to result in injury to the animal, 
 waste of some of the food constituents supplied, or the 
 use of unnecessarily expensive foods. 
 
 In arranging a mixed diet, the effect of the mixing 
 upon the digestibility of the food must be carefully 
 considered, otherwise, much of the food supplied may 
 remain undigested, causing waste and loss. 
 
 The greater the amount of food, a fattening animal 
 can be induced to eat and digest, the greater will be 
 the profit obtained in proportion to the amount of food 
 consumed. Therefore the flavor of the food, and the 
 degree in which it is relished by the stock, have an 
 important influence on the profits of feeding. 
 
 Exertion, and exposure to cold require a large 
 consumption of food which gives no returns in flesh 
 or fat, therefore, economy requires that fattening stock 
 be protected from the weather, and spared a ^ un " 
 necessary exercise. 
 10 
 
146 SCIENCE IN FARMING. 
 
 The increase of weight produced from a given 
 amount of food is greater in the young animal than in 
 the old, and greater in the beginning of fattening than 
 towards its close. Therefore, a careful estimate should 
 be made of the cost of the food and the value of the 
 meat produced, so that the farmer may know at what 
 time to sell his stock in order to secure the largest 
 profit on food used. 
 
 In fattening pigs, improvement in their health, and, 
 therefore, in the profit of the farmer, has been secured 
 by keeping them supplied with a mixture of 20 lbs. 
 sifted coal ashes, 4 lbs. salt, and 1 lb. superphos- 
 phate of lime. 
 
CHAPTER XL 
 
 SCIENCE IN FERTILIZERS, 
 
 § 1. General Principles. 
 
 317. A fertilizer is a substance which, if added to 
 the soil, will increase its capacity for the production 
 of a crop. The science of fertilization includes all 
 methods of rendering the soil more productive. 
 
 318. The production of a good crop depends on the 
 soil and the season. Over the former, only, the farmer 
 has control, and it is his business to provide a condi- 
 tion of* soil that will secure the largest crop the sea- 
 son is capable of producing. 
 
 The conditions of soil necessary for this are : A 
 sufficient amount of plant food, in a form that can be 
 used by the crop; 
 
 Such a mechanical condition of the soil as will en- 
 able the roots of the plants to reach and use the avail- 
 able plant food present. 
 
 319. Nature and Cultivation. — We have seen (145) 
 that in a state of nature the amount of plant food in 
 the soil tends continually to increase. Under cultiva- 
 tion where crops are carried away, the amount must 
 
14S SCIENCE IN FARStlNG. 
 
 decrease, unless in some manner the plant food taken 
 away from the soil is restored. 
 
 320. Favorable mechanical conditions of the soil 
 are obtained by cultivation, drainage, and sometimes 
 by plowing under green crops (See " Soils," sections 
 5, 6, and 7). 
 
 321. Plant food in the soil'is rendered available by 
 drainage, cultivation, the use of lime, bare fallow, 
 and by plowing under green crops (See " Soils," par- 
 agraphs 161-163). 
 
 322. The amount of plant food in the soil is in- 
 creased by the addition of manures. 
 
 323. The methods necessary to secure favorable 
 mechanical conditions of the soil also tend to increase 
 the amount of plant food by favoring absorption from 
 the air, and to render that which is present available, 
 by favoring nitrification and the solution of mineral 
 substances. 
 
 324. The methods necessary to render plant food 
 available, also usually improve the mechanical condi- 
 tion of the soil, and by favoring absorption, tend to 
 increase the total amount of plant food in the soil. 
 
 325. The addition of manures frequently improves 
 the mechanical condition of the soil, and may also, by 
 starting chemical action, render the plant food al- 
 ready present, more available. 
 
 It is therefore impossible to draw a strictly accu- 
 rate line between these different methods. The 
 farmer must usually employ all three, and in order to 
 attain the best results, their judicious combination is 
 necessary. 
 
 The methods of improving the mechanical condi- 
 
FERTILIZERS. 149 
 
 tion of soils have been considered in chapter six. 
 § 2. Rendering Plant Food Available. 
 
 326. Bare Fallow. — This is one of the oldest meth- 
 ods of improving the condition of soils. It is often 
 called " resting the land," but the term is unscientific 
 and misleading. In a bare fallow the land is allowed 
 to remain one season without a crop, and is contin- 
 ually cultivated in order to keep down weeds, and ex- 
 pose the soil to the action of the air. Except by fa- 
 voring the absorption of ammonia from the air, it does 
 not increase the amount of plant food, but by favor- 
 ing oxidation, a portion of the mineral substances is 
 rendered soluble, and by nitrification the nitrogen 
 contained in the humus of the soil is converted into 
 nitric acid. Under favorable circumstances, a large 
 amount of nitrogen — sometimes as much as 35 to 55 
 lbs. per acre — will be converted into nitric acid, and 
 the soil be able to produce a double crop the year suc- 
 ceeding the fallow. 
 
 In some experiments at Rothamsted, one part of a 
 field was cropped with wheat four years in succession; 
 another part was cropped and fallowed alternately. 
 The soil was the same and no manure was used. The 
 following table gives the yield per acre for the four 
 years, the field that was cropped continuously being 
 marked No. 1, and the field fallowed each alternate 
 
 year, No. 2 : 
 
 Field No. 1. Field No. 2. 
 
 First year 15.87 bu. Fallow 
 
 Second year 13/81 bu. 37 bu. 
 
 Third year 15.81 bu. Fallow 
 
 Fourth year 21.06 bu. 42 bu. 
 
 Total in four years . 66.55 bu. 79 bu. 
 
 In this experiment the field that was alternately 
 
150 SCIENCE IN FARMING. 
 
 cropped and fallowed, produced in the four years a 
 total of nearly 12| bushels per acre more than the 
 other. As, in this case, one-half the seed and nearly 
 one-half the labor of harvesting were saved, the fal- 
 lowed field was the more profitable. 
 
 Producing a heavy crop alternate years by means 
 of a bare fallow, simply draws on the supply of plant 
 food in the soil. 
 
 If heavy rains fall on a bare fallow, much, or in 
 some cases all, of the nitric acid formed may be 
 washed out. The constant use of the bare fallow as 
 a means of securing large crops therefore tends, un- 
 der ordinary conditions of soil and climate, to the ul- 
 timate exhaustion of the nitrogen in the soil. 
 
 327. Lime. — The principal effect of the application 
 of lime is to favor the decomposition of humus in the 
 soil. The amount of plant food furnished is unim- 
 portant, as nearly all soils contain sufficient to 
 supply the needs of any ordinary crop. The use of 
 lime is therefore classed among the methods adopted 
 for rendering plant food already present in the soil 
 available. Its principal value for this purpose is on 
 soils that are over-rich in humus (174). The persis- 
 tent use of lime without other manures, therefore, 
 tends to greatly reduce the total amount of nitrogen 
 in the soil. While valuable when properly used, 
 many farms have been almost ruined by its injudi- 
 cious application. Lime is also sometimes useful on 
 clay soils, by improving their mechanical condition 
 (170). In this manner it may not only render a clay 
 soil more easy to work, but also increase its capacity 
 for absorbing and retaining fertilizing elements. 
 
 328. Green Manuring. — Growing green crops and 
 plowing them under is properly classed as one of the 
 
FERTILIZERS. 151 
 
 methods of rendering plant food available. It is true 
 that a large portion of the crop was obtained from the 
 air, but that portion is not of value as plant food in 
 the soil. The nitrogen* and mineral elements in the 
 plant were obtained from the soil, and the actual 
 quantity of these elements in the soil is, therefore, 
 not increased. 
 
 329. Green manuring renders the plant food in the 
 soil available : 
 
 By gathering that which is already present, form- 
 ing it into organic substances which are left near the 
 surface, and as they decay, give up to the succeeding 
 crop that which they have gathered. 
 
 By taking up the nitric acid as rapidly as formed 
 by nitrification, and thus preventing it from washing 
 out in the drainage water. 
 
 By shading the soil, keeping it moist, and loose, and 
 thus providing the circumstances favorable for nitri- 
 fication.! 
 
 *The leaves of plants absorb from the atmosphere some am- 
 monia (142) , and the nitrogen contained in this is gained by 
 the soil when the crop is plowed under. The quantity thus 
 obtained is, however, so small and so uncertain that it cannot 
 be taken into consideration in practical estimates. 
 
 ■(•Numerous experiments appear to indicate that under cer- 
 tain circumstances the free nitrogen of the air which is con- 
 tained in the pores of the soil, maybe oxidized into nitric acid. 
 The circumstances necessary are, a porous soil, rich in humus, 
 a certain amount of moisture, warmth, and the presence of 
 some base with which the nitric acid can combine as rapidly 
 as formed. The presence of ferric oxide in considerable quan- 
 tity seems to aid the action by catalysis (122). Should future 
 experiments demonstrate that this oxidation of free nitrogen 
 can be accomplished to any considerable extent under the in- 
 fluences which the farmer can control, the present views of the 
 operation of green crops will require serious modification. It 
 will then appear possible, by green manuring, not only to 
 change the nitrogen in the soil into more ayailable forms, but 
 
152 SCIENCE IN FARMING. 
 
 By attacking plant food existing in the soil informs 
 of combination not available for other crops. Legu- 
 minous crops (clover, peas, beans, etc.) appear to 
 have the power of feeding on nitrogenous substances 
 in the soil in forms that are not available for cereal 
 crops. This nitrogen it leaves in forms of combina- 
 tion that readily undergo oxidation with production 
 of nitric acid. Hence clover, even when the crop is 
 cut for hay arid seed, leaves in the roots and stubble 
 a large amount of plant food that can be used by the 
 succeeding crop. 
 
 § 3. Manures. 
 
 330. The plant takes from the soil a large number 
 of substances, but in practice only three have to be 
 considered. These are : 
 
 Nitrogen. 
 
 Phosphoric acid. 
 
 Potash. 
 
 The other mineral elements of plant food are equally 
 essential, but they are usually contained in the soil 
 in sufficient quantity, and most manures that contain 
 nitrogen, phosphoric acid and potash, also contain 
 these other substances. These three are the ones to 
 be considered in estimates of the fertility and exhaus- 
 tion of soils and in the valuation of manuTes. 
 
 331. We have seen (158) the amount of these sub- 
 stances in a very fertile soil. The following table 
 
 also to add to its quantity. With our present knowledge on 
 this subject, however, it will not be safe for the farmer to de- 
 pend on increasing his store of nitrogen by this means ; what- 
 ever future discoveries may be made, the wise farmer will still 
 carefully save and return to his soil all waste plant food. 
 
FERTILIZERS. 153 
 
 shows the amount taken from an acre by an average 
 crop: 
 
 a 
 
 So 
 o 
 
 ■+3 
 
 20 bushels wheat 22 lbs. 
 
 2000 lbs. straw 9.6 lbs. 
 
 Total crop 31.6 lbs. 
 
 30 bushels barley 26.2 lbs. 
 
 18000 lbs. straw 9 lbs. 
 
 Total crop 35.2 lbs. 
 
 30 bushels oats 25.3 lbs. 
 
 1800 lbs. straw 9.0 lbs. 
 
 Total crop 34.3 lbs. 
 
 20 bushels rye 19.7 lbs. 
 
 3240 lbs straw 13.0 lbs. 
 
 Total crop 32.7 lbs. 
 
 50 bushels Indian, corn 41.4 lbs. 
 
 8000 lbs. cornstalks 38.4 lbs. 
 
 Total crop 79.8 lbs. 
 
 2 tons meadow hay 62 lbs. 
 
 2 tons clover hay 78.8 lbs. 
 
 15 tons turnips 54."0 lbs. 
 
 9000 lbs. tops 38 6 lbs. 
 
 Total crop 92.6 lbs. 
 
 20 tons mangels 76 lbs. 
 
 16000 lbs. tops 44.7 lbs. 
 
 Total crop 1 20.7 lbs, 
 
 100 bushels potatos 20.4 lbs. 
 
 2000 lbs haulm 9.3 lbs. 
 
 Total crop : 29.7 lbs. 
 
 332. It would require a great many years to re- 
 move all the nitrogen, phosphoric acid and potash 
 from a soil (even were it possible to continue to grow 
 crops until the whole amount was exhausted) but that 
 
 Q-d 
 
 .§•3 
 
 9.5 lbs. 
 5.2 lbs. 
 
 A 
 
 m 
 tS 
 
 o 
 
 P-i 
 
 6.4 lbs. 
 11.6 lbs. 
 
 14.7 lbs. 
 
 18. lbs. 
 
 12.1 lbs. 
 3.6 lbs. 
 
 7.3 lbs. 
 17.4 lbs. 
 
 15.7 lbs. 
 
 27.7 lbs. 
 
 7.9 lbs. 
 4.5 lbs. 
 
 5.7 lbs. 
 18.7 lbs. 
 
 12.4 lbs. 
 
 24.4 lbs. 
 
 9.4 lbs. 
 6.8 lbs. 
 
 6.3 lbs. 
 25.2 lbs. 
 
 16.2 lbs. 
 
 31.5 lbs. 
 
 12.8 lbs. 
 42 4 lbs. 
 
 10.8 lbs. 
 76.8 lbs. 
 
 55.2 lbs. 
 
 87.6- lbs. 
 
 15.2 lbs. 
 
 67.2 lbs. 
 
 22.4 lbs. 
 
 78 lbs. 
 
 18 lbs. 
 8.4 lbs. 
 
 87.0 lbs. 
 31.7 lbs. 
 
 26.4 lbs. 
 
 118.7 lbs. 
 
 28.0 lbs. 
 13 3 lbs.- 
 
 156.0 lbs. 
 62.7 lbs. 
 
 41.3 lbs. 
 
 218.7 lbs. 
 
 10,8 lbs. 
 3.0 lbs. 
 
 33.6 lbs. 
 8.1 lbs. 
 
 13.8 lbs. 
 
 41.7 lbs. 
 
154 SCIENCE IN FABMING. 
 
 which is in an available condition may be exhausted 
 in a few years. 
 
 333. It is also necessary in order to produce a full 
 crop, that the soil should contain considerably more 
 of these substances in an available form than the crop 
 will require, for no plant can gather all the available 
 plant food in the soil. Thus we see that a crop of 
 wheat of 20 bushels to the acre, contains only about 
 32 lbs. of nitrogen, but such a crop cannot be grown 
 unless the soil contains at least 65 lbs. available 
 nitrogen. 
 
 334. The means employed to supply the required 
 available plant food, and prevent the deterioration of 
 the soil by too heavy drafts on the supply it contains, 
 are the application of farm-yard manures and com- 
 mercial fertilizers. 
 
 335. Farm- Yard Manure consists of the excrements 
 of the animals fed upon the farm, mixed with the 
 straw used for litter, and other waste products of the 
 farm. 
 
 336. Commercial Fertilizers consist of various im- 
 ported and manufactured articles with the refuse from 
 slaughter houses, etc., worked up into a condensed 
 form ready for immediate application. 
 
 § 4. Farm-Yard Manure. 
 
 337. Composition. — This varies greatly, depending 
 on the kind and amount of litter used, the character 
 of the animals producing it, the food used, the length 
 of time the manure has been kept, and the treatment 
 it has received. 
 
 338 . Water forms the greater part. The remainder 
 consists of carbonaceous matter with a small amount 
 
FERTILIZERS. 155 
 
 of nitrogenous substances and mineral salts. The fol- 
 lowing table gives the composition of one ton of av- 
 erage fresh farm-yard manure. 
 
 Water 1,420 lbs. 
 
 Nitrogen 9 lbs. 
 
 Phosphoric acid. ..." 4.2 lbs. 
 
 Potash 10.4 lbs. 
 
 Carbonaceous matter, lime, sand, etc., 556.4 lbs. 
 
 Total 2,000 lbs. 
 
 This represents an average sample of fresh manure. 
 It will be seen that one ton contains only 23.6 lbs., of 
 valuable plant food. Farm-yard manure from ani- 
 mals fed on rich food may contain a much larger 
 amount. 
 
 339. Fermentation of Manure. — When fresh manure 
 is allowed to remain in a heap, decomposition soon 
 commences. The carbon combines with oxygen from 
 the air, producing carbonic dioxide which is given off. 
 The nitrogen combines with hydrogen of the water 
 forming ammonia. If the manure has become dry, 
 this ammonia combines with the carbonic dioxide 
 forming carbonate of ammonia (112), which escapes 
 in vapor. If the heap has been kept moist, it com- 
 bines with the organic acids formed by the decompo- 
 sition of carbohydrates, producing soluble but not vo- 
 latile salts. 
 
 340. Considerable heat is produced during this 
 process, which drives off much of the water in the 
 manure. By fermentation of the manure, the amount 
 of water and carbon in the heap is decreased, while 
 the amount of nitrogen and mineral salts (if the pro- 
 cess has been properly conducted,) remains un- 
 changed. The manure, therefore, contains a larger 
 proportion of these substances than before fermenta- 
 tion, and more of the nitrogen is in an available form. 
 
156 SCIENCE W FARMING. 
 
 341. Manure Fermented in a Heap in Open Yard. — 
 
 The following table shows the weight of a ton of ma- 
 nure fermented in a heap in an open yard, and the 
 amount of nitrogen contained in the heap at different 
 dates : 
 
 Total Weight Nitr0Ben 
 of Manure. nitrogen. 
 
 November 3rd 2,000 lbs. 12.9 lbs. 
 
 April 30th 1,428 lbs. 12.8 lbs. 
 
 August 23rd 1,405 lbs. 9.3 lbs. 
 
 November 15th 1,391 lbs. 9.2 lbs. 
 
 The manure used in this experiment contained con- 
 siderably more nitrogen than that of which the analy- 
 sis was given in paragraph 338. It will be noticed 
 that during the first six months the weight of the ma- 
 nure was reduced nearly 29 per cent, while the loss of 
 nitrogen was immaterial. A ton of the manure ana- 
 lyzed April 30th would have contained 20.2 lbs. of ni- 
 trogen. During the next 6 months the decrease of 
 weight was very small, but the loss of nitrogen was 
 quite serious. A ton of the manure on November 
 15th would only contain about 13 lbs. of nitrogen. By 
 fermenting for six months in winter the weight of 
 manure that would have to be handled to obtain a 
 given amount of nitrogen was decreased, but by fer- 
 menting six months longer nitrogen was wasted 
 and the amount of manure required to contain a given 
 weight of it was as great as at first. 
 
 342. Manure Fermented Under Shed. — The follow- 
 ing table shows the result of an experiment in fer- 
 menting manure under a shed : 
 
 Total Weight Nitro „ en 
 
 of Manure. JNitrogen. 
 
 November 3rd 2,000 lbs. 12.9 lbs. 
 
 April 30th 992 lbs. 10.2 lbs. 
 
 August 23rd 800 lbs. 10.2 lbs. 
 
 November 15th, 758 lbs. ;i.41bs, 
 
FEEDING. 15? 
 
 In this case the manure lost more than half its 
 weight in the first 6 months, but it also lost 2.7 lbs. 
 nitrogen per ton. This was probably due to the heap 
 having been allowed to become too dry. During the 
 next four months the heap lost in weight but not in 
 nitrogen. On August 23rd the heap contained nitro- 
 gen at the rate of 25.5 lbs. per ton. It will be noticed 
 that the last date shows an actual increase in nitrogen. 
 This must have been due to error in the analysis, un- 
 less sufficient free nitrogen was oxidized in the heap 
 to cause the increase. We have not sufficient facts at 
 present to warrant this last supposition. 
 
 343. Manure Spread in Barn-Yard. — The following 
 table gives the result of an experiment with manure 
 left spread in an open barn-yard : 
 
 Total Weight „,. „„ 
 
 of Manure. Nitrogen. 
 
 November 3rd 2,000 lbs. 12.9 lbs. 
 
 April 30th 1,730 lbs. 9.2 lbs. 
 
 August 23rd 1,226 lbs. 5 lbs. 
 
 November 15th 1,150 lbs. _ 4.5 lbs. 
 
 In this case nitrogen was constantly lost, so that at 
 the end of the year but little over one-third remained. 
 The loss of nitrogen was in greater proportion than 
 the loss of weight, so that the manure at the close of 
 the experiment contained a smaller proportion of ni- 
 trogen than at its commencement. 
 
 344. Leaching. — When manure is exposed so that 
 the rain which falls upon it leaches through, great 
 loss of its most soluble, and therefore most valuable 
 constituents is incurred. A heap of ordinary manure 
 containing a ton of dry substance contains only 31 
 lbs. of nitrogen and 35 lbs. potash, while sufficient of 
 the dark colored drainage from the manure heap to 
 contain one ton of dry substance would contain about 
 
158 Science! in farming. 
 
 166 lbs. nitrogen and 554 lbs. potash. The nitrogen 
 in the drainage is also entirely soluble, and hence 
 much more valuable than that which remains. 
 
 345. Evaporation of Ammonia. — We have seen (339) 
 that the evaporation of ammonia may be prevented 
 by keeping the heap sufficiently moist to insure the 
 production of organic acids. It can also be prevented 
 by the addition of gypsum or land plaster (109). 
 Sulphuric acid diluted with water and sprinkled over 
 the manure heap also prevents this waste by the for- 
 mation of sulphate of ammonia, but it is neither as 
 cheap nor as convenient as land plaster. 
 
 346 . Care of Manure . — From the facts already given 
 the following practical applications may be made : 
 
 By the fermentation of manure it loses carbon and 
 water, causing considerable loss of weight and bulk, 
 but if the fermentation is properly conducted there 
 will be little or no loss of valuable constituents. 
 
 If the manure while fermenting is allowed to Be- 
 come dry, serious loss of nitrogen will ensue. 
 
 If so much water is allowed to fall on the manure 
 that it leaches through and escapes by drainage, great 
 loss of all the valuable constituents will result, and 
 the exhaustion may be so complete that what re- 
 mains will not be worth hauling to the field. 
 
 By the use of gypsum loss of nitrogen by evapora- 
 tion can be avoided. 
 
 347. — Concentration. — It costs as much to haul and 
 spread- a ton of poor manure as a ton of the best ; con- 
 sequently there is economy in having manure as con- 
 centrated as possible. If a farmer has two heaps of 
 manure, one weighing five tons and containing plant 
 food worth $2.50, and another weighing only one ton 
 but containg the same amount of plant food — and if 
 
tfEfiDtNd. 159 
 
 the cost of hauling and spreading is 50 cents per ton, 
 the net value of the two heaps will be as follows : 
 
 Five-ton heap containing plant food worth $2 50 
 
 Less cost of hauling and spreading at 50 cents a ton 2 50 
 Net value of 5 tons $0 00 
 
 One-ton heap containing plant food worth $2 50 
 
 Less cost of hauling and spreading at 50 cents a ton 50 
 Net value of 1 ton $2 00 
 
 § 5. Manure from Different Animals. 
 
 348. There is quite a differenceiin the manure pro- 
 duced by different anim als. The following table gives 
 the average amount of water, nitrogen, phosphoric 
 acid and potash in a ton of the fresh manure from 
 different stock, the manure including solid and liquid 
 excrements mixed with litter : 
 
 Water. Nitrogen. Ph ^ P £ 0ric Potash. 
 
 Horse ..... 1,426 lbs. 11.6 lbs. 5.6 lbs. 10.6 lbs. 
 
 Cattle 1,550 lbs. 6.8 lbs. 3.2 lbs. 8 lbs. 
 
 Sheep 1,292 lbs. 16.6 lbs. 4.6 lbs. 13.4 lbs. 
 
 Swine 1,448 lbs. 9 lbs. 3.8 lbs. 12 lbs. 
 
 Poultry*... 1,120 lbs. 32.6 lbs. 30.8 lbs. 17 lbs. 
 
 The manure from cattle and swine contains much 
 more water than that of the horse and sheep, and con- 
 sequently ferments less rapidly. In popular language, 
 the one is said to be cold and the other warm. To se- 
 cure the best results in fermenting manure, it is well, 
 when possible, to have the manure of all the different 
 * animals mixed in one heap. This gives a composi- 
 tion that causes fermentation to progress favorably. 
 
 349. Solid and Liquid Manure. — There is a great dif- 
 ference in the composition of the solid and liquid ex 
 crement of animals. The former contains the greater 
 part of the phosphoric acid ; the latter usually con- 
 
 *Fresh, but without litter. 
 
160 SctEtfci: W tfAfcMfito. 
 
 tains more of the nitrogen and potash. The manurial 
 constituents in the solid excrement are mostly insolu- 
 ble ; those in the urine are entirely soluble. 
 
 The following table gives the amount of plant food 
 contained in one ton of the fresh solid and liquid ex- 
 crement of different animals : 
 
 Nitrogen. Fbo ^ ie Potash. 
 
 Horse, solid excrement. . . 8.8 lbs. 7 lbs. 7 lbs. 
 
 " Urine 31 lbs 30 lbs. 
 
 Cattle, solid excrement. . . 5.8 lbs. 3.4 lbs. 2 lbs. 
 
 " Urine — . . . . 11.6 lbs 9.8 lbs. 
 
 Sheep, solid excremem. . . 11 lbs. 6.2 lbs. 3 lbs. 
 
 ' *' Urine 39 lbs. .2 lbs. 45.2 lbs. 
 
 Swine, solid excrement. . . 12 lbs. 8.2 lbs. 5.2 lbs. 
 
 " Urine 8.6 lbs. 1.4 lbs. 16.6 lbs. 
 
 The respective values of the different manures will 
 be considered in a later portion of the chapter. 
 
 The composition of manure varies with the consti- 
 tution of the animal and its food. Analyses can there- 
 fore give averages only. 
 
 § 6. Relation of Food to Manure. 
 
 350. The plant food in the manure must come from 
 that contained in the food supplied to the animal. In 
 the animal body a portion of the carbonaceous matter 
 is burned up, and the product thrown off by the lungs 
 (207), but nitrogen, phosphoric acid and potash are 
 not disposed of in this manner. All of these sub- 
 stances except what is used by the animal in the pro- 
 duction of milk or increase, will be found in the ma- 
 nure. 
 
 351. If an ox is given food containing 100 lbs. dry 
 substance, he will produce manure containing about 
 36£ lbs. dry substance, and in this manure will be the 
 greater part of the nitrogen, phosphoric acid and pot- 
 ash that was contained in the food supplied. As the 
 
FEEDING. 161 
 
 quantity of dry substance in the manure is much 
 less than that in the food from which it was pro- 
 duced, while the quantity of plant food is nearly 
 the same, it follows that the dry substance in the ma- 
 nure will contain a larger proportion of plant food 
 than is contained in the dry substance of the food. 
 The amount of plant food in the manure, however, 
 cannot be greater than that contained in the food 
 from which it was produced. 
 
 352. Cause of Difference in Manure. — If a ton of 
 corn is fed to an ox, and another ton to a sheep,* and 
 all the manure collected, there will be exactly the 
 same amount of plant food in the manure produced 
 by each animal while feeding on the ton of corn ; but 
 as the ox will have produced the larger quantity, his 
 manure will contain the smaller proportion of plant 
 food. # 
 
 353. The difference, therefore, in the value of ma- 
 nure produced by different animals is due to the fact 
 that some remove more of the carbonaceous matter 
 from the food supplied, and leave the manure propor- 
 tionally richer. But no animal can furnish in the ma- 
 nure any more plant food than is contained in the 
 food it receives. 
 
 Manure produced by animals fed on poor food will 
 therefore be poor, while that produced by those fed 
 on rich food will be rich. A ton of clover hay con- 
 tains four times as much nitrogen as a ton of wheat 
 straw ; therefore, other things being equal, the ma- 
 nure made by feeding a ton of clover hay will con- 
 tain four times as much nitrogen as that made by 
 feeding a ton of wheat straw. 
 
 -*Inthis example it is supposed- that neither animal is in- 
 creasing in weight. 
 11 
 
162 SCIENCE IN FARMING. 
 
 354. Proportion of Manure to Food. — When an ani- 
 mal is neither increasing in weight nor giving milk, 
 the manure produced will contain exactly the same 
 amount of plant food that was contained in the food 
 consumed.* 
 
 This is evident from the fact that the solid excre- 
 ment contains all the nitrogen, phosphoric acid and 
 potash of the undigested portion of the food ; and all 
 of these substances contained in the digested portion, 
 except what is used in the production of milk, stored 
 up in increase of weight, and used for the repairs of 
 the waste, is carried off in the urine. If the animal 
 is neither growing nor giving milk, the urine will con- 
 tain all these constituents except the amount used 
 in repairing waste. The wasted substance is taken up 
 by the blood and removed by the kidneys, and ex- 
 actly balances the amount used in repair. 
 
 355. When the animal is giving milk a portion of 
 the nitrogen and phosphoric acid will be removed in 
 the milk, and the manure produced will not usually 
 contain more than from 50 to 75 per cent of the 
 amount of these substances supplied in the food. 
 
 356. When an animal is growing rapidly a consid- 
 erable portion of the nitrogen and phosphoric acid 
 contained in the food is used in the production of 
 bone and muscle, and the manure contains a propor- 
 tionally smaller amount of these substances than the 
 food. 
 
 357. The fattening animal takes comparatively 
 little valuable material from the food, as the greater 
 
 *This, of course, includes all the manure both solid and liquid. 
 In the manner in which manure is often saved, or rather wasted, 
 it would contain but a small portion of the plant food furnished 
 the animals. 
 
FEEDING. 163 
 
 part of the increase is fat, which contains no plant 
 food. The following table shows the proportion of 
 the nitrogen supplied in the food, that is stored up in 
 increase, the proportion voided in the solid and liquid 
 excrement, and in both, in fattening oxen, sheep and 
 pigs: 
 
 Oxen. Sheep. Pigs. 
 
 Per cent nitrogen stored in increase ... 3.9 4.3 14.7 
 
 Per cent nitrogen voided in solid excre- 
 ment 22.6 16.7 21 
 
 Per cent nitrogen voided in urine 73.5 79 64.3 
 
 Per cent nitrogen voided in total excre- 
 ment . . : 96.1 95.7 85.3 
 
 With the fattening ox and sheep the manure con- 
 tained about 96 per cent of the nitrogen Supplied in 
 the food. As the pig uses a larger proportion of the 
 food he receives in production of increase, and less 
 for heat and energy, the per cent of nitrogen supplied 
 that goes into the manure is less than with either of 
 the other animals. 
 
 358. Of the phosphoric acid and potash contained 
 in the food of a fattening* animal, from 95 to 100 per 
 cent will be found in the manure. 
 
 359. The proportion of nitrogen received in food 
 that is voided in solid and liquid excrement will vary 
 with the kind of food supplied, and the table just given 
 will therefore only be correct in this respect when 
 the diet is the same as that on which the table was 
 calculated. As the manurial ingredients in the di- 
 gested portion of the food are voided in the liquid ex- 
 crement and that in the undigested portion in the 
 solid, the more digestible the food the larger pro- 
 portion of manurial ingredients will be contained in 
 the liquid excrement. Thus, we have seen that a ton 
 of wheat straw contains 60 lbs. nitrogenous matter 
 (230), but that only 12 lbs. of this is digested|(239). 
 
164 SCIENCE IN FARMING. 
 
 If an animal were fed on wheat straw alone, there- 
 fore, the solid excrement would contain at least 80 
 per cent of the total nitrogen voided. By the same 
 tables it will be seen that of the nitrogenous matter 
 in beans, 88 per cent is digested, and therefore when 
 an animal is fed on beans, the greater part of the nitro- 
 gen voided will be in the urine. 
 
 360. As the plant food contained in the solid ex- 
 crement is mostly insoluble, while that in the urine is 
 soluble, a pound of nitrogen in urine is worth more 
 than the same amount in the solid excrement, and 
 therefore the more digestible the food the more valu- 
 able will be the plant food in the manure produced. 
 
 361. We obtain from the foregoing facts the fol- 
 lowing rules : 
 
 The proportion of plant food in the manure will 
 depend principally on the proportion in which it is 
 contained in the food supplied to the animal. 
 
 The plant food in the manure will be more valu- 
 able in proportion as the food supplied to the animal 
 is more digestible. 
 
 Manure produced from working or fattening ani- 
 mals will contain from 90 to 95 per cent of the manu- 
 rial constituents contained in the food. 
 
 Manure made from milk cows and young, growing 
 animals, will contain from 50 to 75 per cent of the ma- 
 nurial constituents contained in the food. 
 
 362. Animal Food as Manure. — At one time rape 
 cake was largely used in England as manure, it being 
 sown with the seed. In this country cotton seed meal 
 has been used for the same purpose, and some experi- 
 menters have tried bran as a manure. 
 
 363 ,||We have already seen that the greater part 
 of all vegetable substances is carbonaceous matter, 
 
FEEDING. 165 
 
 valuable as food for animals but not as food for plants. 
 For example, a ton of bran contains 1,044 lbs. of di- 
 gestible food for the animal (239), but it only contains 
 138.2 lbs. manurial constituents (372). If this ton of 
 bran is fed to fattening oxen, the manure, if all saved, 
 would contain about 132 lbs. of manurial constituents, 
 while the remainder of the food might produce an in- 
 crease of weight in the oxen of 130 lbs. There would 
 therefore be a gain of 130 lbs. of weight in the oxen 
 to compensate for the loss of six pounds plant food. 
 The plant food in the manure would also be in more 
 available forms than in the bran, and the actual value 
 of the 132 lbs. in the manure would probably be 
 greater than that of the 138.2 lbs. in the bran.* 
 
 364. Plow Tinder or Feed. — The same principle will 
 in some cases determine the question whether it will 
 pay better to plow -under a green crop or feed it to 
 stock and return the manure. If on an acre of land 
 there is a crop of clover that will make two tons of 
 hay, it will contain plant food worth $17.52. If the 
 clover is plowed under, this is all the value that will 
 be obtained. If it is cut and fed to fattening cattle 
 and the manure carefully saved and returned, the 
 loss of plant food will be only 88 cents. The ques- 
 tion of profit and loss will therefore be on the one 
 hand the value of clover as food ; on the other, the 
 cost of cutting, curing and feeding the clover, and of 
 saving, hauling and spreading the manure, and the 
 88 cents' worth of plant food lost. 
 
 *It must be remembered that all such calculations as these 
 are based on the supposition that all the manure is saved. 
 Where the liquid manure is allowed to escape and the solid 
 portion wasted by leaching and evaporation, such calculations 
 will be very wide of the truth. 
 
166 SCIENCE IK FARMING. 
 
 Any farmer, therefore, who can determine these 
 
 points, namely : 
 
 The feeding value of the clover, 
 The cost of cutting and curing, 
 The cost of hauling and spreading manure, 
 
 Can readily determine whether it will pay best to 
 
 plow under a crop of clover or feed it and return the 
 
 manure.* 
 
 § 7 Valuation of Manure. 
 
 365. The determination of the comparative values 
 of different makes^ of commercial manures can be ac- 
 complished with reasonable accuracy, but the com- 
 parative values of farm-yard manures can be deter- 
 mined approximately only. They not only vary 
 greatly in the amount of plant food contained, but the 
 value of that plant food differs according to the form 
 of combination in which it may exist. A pound of 
 nitrogen contained in urine is available for the plant, 
 and is as valuable as a pound of nitrogen in nitrate 
 of soda, or sulphate of ammonia. But nitrogen con- 
 tained in half-digested straw is but slowly available, 
 and may remain in the soil unused for years. 
 
 366. For convenience the experiment stations of 
 this country have adopted certain figures to represent 
 the market value of nitrogen, phosphoric acid and 
 potash.f 
 
 *We have seen (171) that clover when plowed under may by 
 the production of humus, serve other useful purposes in the 
 soil besides furnishing plant food. In all cases where more 
 humus is needed to improve the condition of the soil, a new 
 element enters into the calculation of the comparative profit of 
 feeding or plowing under. In such cases it will doubtless often 
 be more profitable to plow under until the improvement in the 
 condition of the soil has been accomplished. 
 
 +The mistake is sometimes made' of supposing that these 
 figures represent the value that these substances will be to the 
 
FEEDING. 167 
 
 367. The valuations adopted by the Ohio State 
 Board are : 
 
 Kind of Plant Food. Price per lb. 
 
 Ammonia ; 18 cts. 
 
 Which is equal to nitrogen 21.86 cts. 
 
 Phosphoric acid in soluble compounds 12 cts. 
 
 Phosphoric acid in compounds insoluble in wa- 
 ter but available as plant food 10 cts. 
 
 Phosphoric acid in insoluble compounds which 
 have to undergo decomposition in the soil be- 
 fore they can be used by the plant 5 cts. 
 
 Potash in soluble compounds 6 cts. 
 
 The phosphoric acid in soluble compounds is called 
 in the official analyses " soluble phosphoric acid." It 
 is principally in the form of monocalcic phosphate 
 (110). The phosphoric acid in compounds insoluble in 
 water, but which can be used as food by plants, is 
 called " reverted ;" it is principally contained in bi- 
 calcic phosphate (110). The phosphoric acid in in- 
 soluble compounds is called " insoluble phosphoric 
 acid," and is principally contained in tricalcic phos- 
 phate. 
 
 In the estimation of the value of manurial constit- 
 uents in farm-yard manures, we shall adopt the fol- 
 lowing standard : 
 
 PLANT POOD IN MIXED MANURES. 
 
 Nitrogen 15 cents. 
 
 Phosphoric acid f. 8 cents. 
 
 Potash 5 cents. 
 
 farmer when applied to his field. No general estimate of this 
 value can be made, as it depends on soil, season and circum- 
 stance. A hundred pounds of nitrogen applied to the soil 
 might in some cases be worth to the farmer a dollar a pound, 
 under other circumstances it might not be worth a dollar for 
 the hundred pounds, or might even prove a detriment. There- 
 fore when the statement is made that nitrogen is worth 22 
 cents a pound, the meaning is that it can usually be bought in 
 the market for that price in forms that are immediately and en- 
 tirely available for plant food. Whether the nitrogen will be 
 worth that amount to the farmer in every particular case must 
 be determined by other considerations. 
 
168 SCIENCE IN FARMING. 
 
 PLANT POOD IN SOLID EXCREMENT. 
 
 Nitrogen 10 cents. 
 
 Phosphoric acid 6 cents. 
 
 Potash 4 cents. 
 
 PLANT FOOD IN URINE. 
 
 Nitrogen 22 cents. 
 
 Phosphoric acid 12 cents. 
 
 Potash 6 cents. 
 
 PLANT FOOD IN FOODS. 
 
 Nitrogen 15 cents. 
 
 Phosphoric acid 8 cents. 
 
 Potash 5 cents. 
 
 368. Plant food in ordinary barn-yard manure is 
 not worth as much as in nitrate of soda, sulphate of 
 ammonia, superphosphate, etc., on account of being 
 in forms that are less readily available to the plant. 
 The constituents of urine being already in solution 
 are of the highest value. The determination of the 
 value of the manurial constituents in foods is a mat- 
 ter of difficulty and one in which strict accuracy is 
 impossible. The more digestible the food the more 
 valuable are the manurial constituents it contains. 
 Therefore in the table in paragraph 372 the estimated 
 value of poor and indigestible foods is liable to be too 
 high, while that of rich foods is probably below the 
 truth. 
 
 369 . Tables of Values of Farm- Yard Manures.— These 
 tables represent approximately what the same quan- 
 tities of nitrogen, phosphoric acid and potash in 
 equally available forms would cost in commercial 
 fertilizers : 
 
 VALUE OF 1 TON FRESH FARM-YARD MANURE.* 
 
 Nitrogen 9 lbs, @ 15 cents $1 35 
 
 Phosphoric acid 4.2 lbs. @ 8 cents 34 
 
 Potash 10.4 lbs. @ 5 cents 52 
 
 Total value 1 ton $2 21 
 
 *As usually found in the barn-yard ; composed of the mixed 
 excrements of different stock with the straw used as litter. 
 
FEEDING. 169 
 
 WELL ROTTED FARM-YARD MANURE.* 
 
 Nitrogen 11.6 lbs. @ 15 centst $1 74 
 
 Phosphoric acid 6 lbs. @ 8 cents 48 
 
 Potash 10 lbs. @ 5 cents 50 
 
 Total value 1 ton $2 72 
 
 FRESH HEN MANURE.} 
 
 Nitrogen * 32.6 lbs. @ 15 cents $4 89 
 
 Phosphoric acid 30.8 lbs. @ 8 cents 2 46 
 
 Potash 17 lbs. @ 5 cents 85 
 
 Total value of 1 ton $8 20 
 
 AIR DRIED HEN MANURE. 
 
 Nitrogen 65.2 lbs. @ 15 cents $9 78 
 
 Phosphoric acid 61.6 lbs. @ 8 cents 4 93 
 
 Potash 34 lbs. @ 5 cents 1 70 
 
 Total value 1 ton $16 41 
 
 FRESH SOLID EXCREMENT, HORSES. 
 
 Nitrogen 8.8 lbs. @ 10 cents $ 88 
 
 Phosphoric acid 3.4 lbs. @ 6 cents 20 
 
 Potash „ 7 lbs. @ 4 cents 28 
 
 Total value of 1 ton $1 36 
 
 FRESH SOLID EXCREMENT, CATTLE. 
 
 Nitrogen 5.8 lbs. @ 10 cents $ 58 
 
 Phosphoric acid 3.4 lbs. @ 6 cents 20 
 
 Potash 2 lbs. @ 4 cents 08 
 
 Total value of one ton $0 86 
 
 FRESH SOLID EXCREMENT, SHEEP. 
 
 Nitrogen 11 lbs. @ 10 cents $110 
 
 Phosphoric acid 6.2 lbs. @ 6 cents 37 
 
 Potash 3 lbs. @ 4 cents 12 
 
 Total value of one ton $1 59 
 
 *The manure from which this analysis was made must 
 have been rotted in an open yard, and exposed to waste both by 
 leaching and evaporation, otherwise it would show a higher 
 value in proportion to the fresh. It is however, probably a 
 fair representation of the rotted manure that will be found in 
 most barn-yards. 
 
 tlf the nitrogen in the fresh manure is worth 15 cents a pound 
 that in the rotted manure (if fermentation is properly con- 
 ducted) is worth more. 
 
 JManurial constituents in hen manure are probably more 
 soluble and therefore really worth more per pound than in the 
 mixed farm-yard manure. 
 
170 SCIENCE OliFABMING. 
 
 FRESH SOLID EXCREMENT, SWINE. .'•■. , '";■ > 
 
 Nitrogen 12 lbs. @ 10 ce"nts $*20 
 
 Phosphoric acid 8.2 lbs. @ 6 cents 49 
 
 Potash 2.6 lbs. @ 4 cents 10 
 
 Total value of one ton $1 79 
 
 PRESH URINE, HORSES. 
 
 Nitrogen 31 lbs. @ 22 cents $6 82 
 
 Potash 30 lbs. @ 6 cents 1 80 
 
 Total value of one ton $8 62 
 
 FRESH URINE, CATTLE. 
 
 Nitrogen 11.6 lbs. @ 22 cents $2 55 
 
 Potash : 9.8 lbs. @ 6 cents 59 
 
 Total value of one ton $3 14 
 
 FRESH URINE, SHEEP. 
 
 Nitrogen 39 lbs. @ 22 cents $8 58 
 
 Phosphoric acid 0.2 lbs. @ 12 cents 02 
 
 Potash 45.2 lbs. @ 6 cents 2 71 
 
 Total value of one ton $ 11 31 
 
 FRESH URINE, SWINE. 
 
 Nitrogen 8.6 lbs. @ 22 cents $189 
 
 Phosphoric acid 1.4 lbs. @ 12 cents 17 
 
 Potash 16.6 lbs. @ 6 cents 1 00 
 
 Total value of one ton $3 06 
 
 370. These tables should have careful study. 
 Farmers who allow their liquid manure to drain away 
 but carefully preserve the solid may be surprised to 
 learn that while a ton of the solid excrement of a 
 horse is worth only $1.36, a ton of urine is worth $8.62. 
 It is true that these figures represent only the com- 
 mercial value of these substances, and not their value 
 when applied to the soil, but the proportion will 
 be correct, even if the actual value differs. Thus if a 
 ton of solid horse manure under certain circumstances 
 is worth to the farmer one-half more than the figures 
 given, under the same circumstances a ton of the 
 urine will also be worth one-half more than the 
 figures given. If under certain circumstances the 
 ton of urine is not worth $8.62, then, under the same 
 
FEEDING. 171 
 
 circumstances a ton of solid will not be worth $1.36.* 
 Urine being rich in nitrogen in a form that is im- 
 mediately available, renders it specially valuable as a 
 top dressing for crops requiring this substance. 
 
 371. Valuation of Foods as Manures. — The knowledge 
 of the manurial constituents of foods and their value, 
 is of considerable practical importance, as it has 
 much to do with the profits of feeding and the choice 
 of foods. Two foods may have equal feeding value 
 and cost about the same, but the manure produced 
 from one be worth more than that produced from the 
 other. By knowing the feeding value of each food 
 and the value of the manure produced from it, a 
 farmer can often make a calculation whether it will 
 pay to sell some article of food and buy another. 
 
 The question is often asked whether it will pay to 
 sell straw, the opinion being held by many that a 
 farmer who sells straw will impoverish his farm. By 
 reference to the following table it will be seen that 
 the plant food in a ton of straw is worth $2.44, while 
 that in a ton of bran is worth $13.25. Then if a farmer 
 can sell straw for $2.44 per ton and buy bran at $13.25 
 a ton, there would be no loss as far as elements of 
 fertility are concerned. There would be in fact a 
 slight gain, as the plant food in the manure produced 
 by feeding the bran would be in a more available 
 condition than that in the straw, f 
 
 372. Sir J. B. Lawes, of England, many years ago 
 prepared a table giving the value in money of the 
 
 *An exception to this rule may arise from difference in the 
 character of the two manures. Urine is rich in nitrogen and 
 potash, but contains no phosphoric acid. When this latter 
 substance is the one needed by the soil, the solid manure will 
 have the greater proportional value. 
 
 tin this we have considered only the value of the plant food 
 
172 
 
 SCIENCE IN FARMING. 
 
 manurial constituents in different foods. Since its 
 publication this table has been the standard in this 
 country as well as England. The following table is 
 calculated on the basis of valuation given in para- 
 graph 367, and differs slightly from that of Lawes : 
 
 AMOUNT AND VALUE OF MANURIAL CONSTITUENTS CONTAINED IN 
 ONE TON OP DIFFERENT FOODS. 
 
 \Torr, Q ~t tt™,i Pounds Pounds Phos- Pounds -. 7 -„ 1 „„ 
 Name of Food Nitrogen phoric acid Potash Value. 
 
 Linseed cake 90.0 39.2 29.4 $18 10 
 
 Cotton cake, decorticat- 
 ed 132.0 62.4 30.0 26 29 
 
 Cotton cake, undecorti- 
 
 cated 78.0 45.8 40.2 17 37 
 
 Beans 82.0 23.2 24.0 15 36 
 
 Peas 72.0 17.6 19.6 13 18 
 
 Bran -. . . 44.0 64.6 29.6 13 25 
 
 Oats 41.2 12.4 9.0 7 62 
 
 Barley 34.0 14.6 9.8 6 76 
 
 Indian corn 33.2 12.2 7.2 6 32 
 
 HAY AND STRAW. 
 
 Clover hay 39.4 11.2 39.0 8 76 
 
 Meadow hay 31.0 7.6 33.6 6 94 
 
 Wheat straw 9.6 5.2 11.6 2 44 
 
 Barley straw 10.0 4.0 19.4 2 79 
 
 Oat Straw 10.0 5.0 20.8 2 94 
 
 Pea straw, cut in bloom 45.8 13.6 46.4 10 28 
 
 Pea straw, ripe 20.8 7.0 20.2 4 69 
 
 Cornstalks 9.6 10.6 19.2 3 25 
 
 GREEN FODDER. 
 
 Grass 10.8 3.0 9.2 2 32 
 
 Bed clover: 10.2 2.8 8.8 3 37 
 
 Peas 10.2 3.0 10.2 2 50 
 
 Oats 7.4 3.4 15.0 2 73 
 
 Bye 10.6 4.8 12.6 2 60 
 
 Corn 3.8 2.6 8.6 1 21 
 
 Hungarian 20.0 2.5 17.0 4 05 
 
 Sorgum 8.0 1.6 7.2 169 
 
 ROOTS. 
 
 Potatos 6.8 3.6 11.2 1 87 
 
 Mangels 3.8 1.4 7.8 1 07 
 
 Carrots 3.2 2.0 6.4 96 
 
 Turnips 3.6 1.2 5.8 5 77 
 
 373. From this table and the rules laid down in 
 contained in the straw. When straw is used as an absorbent, 
 
PEEPING. 173 
 
 paragraph 361, a farmer can calculate the value of 
 the manure produced by feeding a given quantity of 
 any kind of food to any class of stock. 
 
 Thus, a ton of hay with half a ton of corn meal, and 
 500 lbs. mangels contains plant food worth $10.62. If 
 this were fed to fattening oxen, 95 per cent of the 
 plant food would be contained in the manure produced, 
 which would therefore be worth $10.09. A ton of corn 
 meal fed to fattening cattle would produce manure 
 worth $6.00. Fed to fattening pigs the manure pro- 
 duced would be worth $5.37. Fed to milk cows the 
 manure produced would not be worth more than $4.74.* 
 
 § 8. Commercial Fertilizers. 
 
 374. The use of commercial fertilizers has greatly 
 increased during the past few years. Their composi- 
 tion is often very uncertain, and in localities where 
 there is no efficient fertilizer law in force, they should 
 be purchased with caution. In Ohio and some other 
 states the manufacturer is required to print the 
 analysis on every package, and a heavy penalty is im- 
 posed if the composition does not agree with the 
 printed analysis. 
 
 375. Bone Dust. — This is bones reduced to a powder, 
 
 and when pure the composition is the same as bones. 
 
 One ton contains : 
 
 Nitrogen 76 lbs. 
 
 Phosphoric acid 364 lbs. 
 
 The phosphoric acid is in the form of tricalcic phos- 
 
 and prevents the waste of liquid manure, it has a practical 
 value greatly in excess of the plant food it contains. Thus, if 
 a farmer sells a ton of straw, and in consequence of the lack of 
 sufficient absorbents allows a 'ton of horse urine to be wasted, 
 the total loss, direct and indirect, would be $11.06. 
 
 *A11 these calculations are made on the supposition that 
 none of the manure produced is wasted. 
 
174 SCIENCE IN FARMING. 
 
 phate, and is therefore not available as plant food 
 until it has undergone decomposition in the soil. 
 Grinding the bones by increasing the amount of sur- 
 face exposed (164) facilitates this decomposition, but 
 the action is comparatively slow, and the effect of a 
 dressing of bone dust is spread over several years. On 
 account of its insolubility, bone dust may sometimes 
 be used with advantage on soils that possess but 
 little power of retaining fertilizers. 
 
 376. Guano is the excrement of sea fowls, that has 
 in some places been accumulating for ages. It is 
 principally obtained from the islands of the Pacific. 
 The valuable constituents are phosphoric acid and 
 nitrogen. That which comes from countries where no 
 rain falls, contains a large amount of nitrogen, some- 
 times as much as 240 lbs. to the ton. Where it has 
 been exposed to rain the nitrogenous matter has been 
 mostly washed out, and little but the phosphoric acid 
 remains. Phosphatic guanos are often converted into 
 superphosphates by treatment with sulphuric acid. 
 
 Owing to the uncertainty of its composition no 
 analysis of guano can be given that would apply to 
 more than one sample. It should always Jbe bought 
 on the analysis of the particular brand. 
 
 377. Rock Phosphate . — Large deposits tricalcic phos- 
 phate are found in some places, (110) and are called 
 "rock phosphate." These deposits are the remains of 
 marine animals. The organic matter has wasted, 
 and the calcic phosphate of the bones become com- 
 pacted into a mass like rock. This is ground to a 
 powder, as fine as flour, and in this condition used 
 as a fertilizer. It is most Valuable on soils rich in 
 humus, as the organic acids they contain assist in its 
 decomposition and solution. It is also rendered more 
 
FEEDING. 175 
 
 soluble by composting with barn-yard manure. It 
 contains no plant food of value, except phosphoric 
 acid. Bock phosphate is often converted into super- 
 phosphate by treatment with sulphuric acid. 
 
 378. Salts Containing Nitrogen. — Those in common 
 use as fertilizers are the sulphate and chloride -of am- 
 monia, and nitrate of soda, (108, 109 and 113). They 
 are valuable only for the nitrogen they contain. Be- 
 ing entirely soluble they act very rapidly and will 
 give nearly all their effect the same year they are 
 applied. Lawes and Gilbert found that 45 to 50 per 
 cent of the nitrogen in these salts was recovered in 
 the increased crop the first year, when applied to wheat 
 and barley ; but that the following year showed very 
 little effect from their application. 
 
 Owing to their solubility these salts are very liable 
 to be washed out in the drainage water, if applied at 
 a season when the crop cannot make immediate use 
 of them. They are best applied as a top dressing in 
 the spring. 
 
 379. Superphosphate. — The composition of super- 
 phosphate and the principles of its manufacture have 
 already, been given (111). Commercial superphos- 
 phate is a mixture of monocalcic phosphate with 
 gypsum. It also usually contains some free phos- 
 phoric acid, and bicalcic, and tricalcic phosphate. 
 When prepared from bones it also contains a consid- 
 erable per cent of nitrogen. To increase the amount 
 of nitrogen, blood, shoddy, leather waste, and the 
 refuse of slaughter houses are frequently added. The 
 character and composition of any particular brand can 
 only be determined by analysis. 
 
 Many of the commercial superphosphates contain a 
 large per cent of nitrogen and potash, while others, 
 
176 SCIENCE IN FARMING. 
 
 especially those made from rock phosphate contain 
 only phosphoric acid. 
 
 The advantage of converting bones and rock phos- 
 phate into superphosphate is due to the greater solu- 
 bility of the monocalcic phosphate. No plant food is 
 added by the process. 
 
 380. Manufacture of Superphosphate. — The princi- 
 ples of the manufacture have already been given 
 (111). In practice it will rarely prove profitable for 
 the farmer to manufacture his own. The proportions 
 would be, theoretically : 
 
 Bones 100 lbs. 
 
 Sulphuric acid 35 lbs. 
 
 Water 13 lbs. 
 
 Which would produce 148 lbs. dry superphosphate. 
 In practice, several times as much water would be 
 needed to make it possible to mix the mass. The 
 bones should be put in a wooden vessel, and the water 
 poured over them. The acid should then be added, a 
 little at a time. If all the acid is added at once the 
 mixture will be so strong that it will be liable to de- 
 stroy the wooden vessel. Therefore time, between 
 each addition of acid, must be allowed for it to com- 
 bine with the bones. The decomffcisition of whole 
 bones by sulphuric acid is a slow and tedious process.* 
 
 - § 9. Adaptation of Manures to Crops. 
 
 381: Different crops require very different supplies 
 of food. The table in paragraph 331 shows the 
 amount of different manurial ingredients removed by 
 different crops, but the proper manure for each crop 
 cannot be determined by such a table. Thus, it will 
 be seen that a crop of clover removes from the soil 
 more than twice as much nitrogen as a crop of wheat, 
 and yet wheat specially needs nitrogenous manures, 
 
FERTILIZERS. Ill 
 
 While clover does not. The reason of this is that some 
 crops have greater ability to obtain certain substances 
 from the soil than others. 
 
 It was formerly taught that all the constituents of 
 plant food contained in a crop must be added in the 
 manure. This is no longer considered necessary. If 
 each crop is manured with the particular substance 
 most needed for its successful growth, and a judicious 
 system of rotation followed, the best results will be ob- 
 tained in proportion to the manures used, and no un- 
 due strain will be made on the capabilities of the soil. 
 
 382. Cereal Crops. — These crops, in general, are spe- 
 cially benefitted by nitrogenous manures. In the ex- 
 periments at Rothamsted it was found that from forty 
 to eighty pounds of available nitrogen to the acre se- 
 cured a maximum crop. Potash is usually of little 
 value. Phosphoric acid when used alone seldom pro- 
 duces much effect, but is beneficial in connection 
 with nitrogen.* 
 
 383. Indian Corn. — No satisfactory experiments 
 have yet been made to determine the best manures 
 for corn. Phosphoric acid appears to be beneficial in 
 many cases, and when combined with nitrogen, good 
 results are usually obtained. Land plaster is a fa- 
 vorite manure for this crop. 
 
 384. Grass — Requires all the elements of plant 
 food, and well rotted stable manure applied as a top 
 
 *It is the opinion in many parts of this country that phos- 
 phoric acid is the manure specially needed for wheat. This 
 opinion is probably due to the fact that throughout the West 
 the superphosphates used have been mostly prepared from 
 bones, and contain nitrogen, often in considerable quantity. 
 The general result of experiments with purely phosphatic ma- 
 nures are that, unless combined with nitrogen, they are seldom 
 of much value for cereals. 
 12 
 
1?8 SclEtfCS OJ PARMUfS. 
 
 dressing to old meadows or pastures supplies this 
 need. Bone-dust is also especially valuable for this 
 crop, and can be sown broadcast. 
 
 385. Clover. — Although clover contains a larger 
 amount of nitrogen than almost any other crop grown 
 on the farm, it does not seem to need nitrogenous 
 manures; Potash and lime are the most valuable 
 manures, the lime being best applied in the form of 
 land plaster. 
 
 386. Turnips — Require nitrogen and phosphoric 
 acid. They seem to have little ability to appropriate 
 the phosphoric acid existing in the soil in insoluble 
 combinations ; hence fresh applications of superphos- 
 phate in connection with farm-yard manure have a 
 remarkable effect. In England superphosphate is 
 chiefly used for turnips, which are one of the most im- 
 portant crops grown there. Nitrogen without phos- 
 phoric acid will not secure a full crop. 
 
 387. Mangels — Obtain much less benefit than tur- 
 nips from phosphoric acid, and require more nitrogen. 
 Mixed farm-yard manure is suitable. 
 
 388. Potatos — Are similar to turnips, giving best 
 results from use of phosphoric acid and nitrogen. In 
 soils deficient in potash this is an essential constit- 
 uent in the fertilizer used ; but soils that have been 
 manured with farm-yard manure usually contain 
 sufficient potash. 
 
 § 10. Summary. 
 
 .The problem of maintaining the fertility of the 
 farm can only be satisfactorily solved by a considera- 
 tion of all the principles taught in this chapter. 
 
 The farmer who drains and cultivates, but fails to 
 restore to his land, in a measure at least, the elements 
 
FERTILIZERS. 179 
 
 of fertility that have been removed in the crops, will, 
 sooner or later, reduce the amount of available plant 
 food in his soil to such a degree that the production 
 will be seriously decreased. 
 
 The farmer who carefully saves all his manure and 
 returns it to the soil, but pays no attention to drain- 
 ing, and but little to cultivation, who allows weeds to 
 grow and rob the plants, will probably complain that 
 manuring does not pay — for no amount of manuring 
 will secure good crops on soil that needs draining, or 
 where the proper mechanical conditions are not pro- 
 vided. 
 
 The farmer who builds his barns and stables on a 
 side-hill, allows all the liquid manure to escape into a 
 creek, and keeps the solid portion where the drip- 
 pings from the roofs will fall upon and leach through 
 it, will be very likely to reach the conclusion that 
 manure is of little value and will not pay for hauling 
 to the field. And his conclusion will probably be 
 correct with reference to the manure he uses. 
 
 It has been shown (160) that when a judicious rota- 
 tion is followed, a good proportion of the crops fed on 
 the farm, and all the manure carefully saved and re- 
 turned, that the drain upon the soil will be but small. 
 
 It would seem, in fact, that under such circum- 
 stances, there is no need, at least at present, for pro- 
 curing plant food from sources away from the farm. 
 The farmer is not required to make provision for con- 
 tingencies that may arise from seven hundred to three 
 thousand years hence. If he uses care and judgment, 
 he may not only produce on his farm the material 
 needed for maintaining the fertilitity of his soil, but, 
 by rendering soluble the plant food it already contains, 
 actually increase its fertility. It should be ever borne 
 
180 SCIENCE IN tfARtarNfJ. 
 
 in mind that it is not alone the amount of plant food 
 in the soil that determines its fertility, but also the 
 forms of combination in which that plant food exists. 
 
 Most soils contain a great amount of plant food, 
 and hence treatment such as drainage, cultivation, 
 lime, fallow, and green crops, which do not add plant 
 food, but only change the condition of that already 
 present, are often successful in changing a compara- 
 tively barren soil into a fertile one. And if, after fer- 
 tility has thus been obtained, the greater part of the 
 crops grown on such a soil are fed on the farm and 
 the manure produced returned to the soil, the fertility 
 may be long maintained without the addition of plant 
 food from sources outside the farm. 
 
 If, however, it is desirable to rapidly bring a poor 
 soil to a condition of fertility, there can be no doubt 
 of the value of commercial fertilizers, as these will 
 enable the farmer to grow large crops with which to 
 make much manure that can be brought back to 
 the soil. 
 
 When the farmer wishes to make the growing of 
 grain, to be sold off the farm, his principle business, 
 the use of imported fertilizers will sooner or later be- 
 come a necessity. 
 
 In many cases one of the most economical methods 
 of obtaining plant food from outside sources, is to buy 
 bran, linseed or cotton seed cake, etc., and feed it to 
 stock, carefully saving the manure. 
 
INDEX. 
 
 Numbers refer to Paragraphs, not to Pages. 
 
 A 
 
 Acid, nitric 101 
 
 '' exists in the air 138 
 
 phosphoric 100 
 
 silicic 103 
 
 sulphuric 102 
 
 " mixing with water 102 
 
 Acids and alkalies distinguished ... 63 
 
 Acids, definition of 62 
 
 vegetable : . . 124 
 
 Agricultural plants * 166 
 
 # Adhesiveness of soils 154 
 
 Affinity 39 
 
 Air, composition 133 
 
 uniformity of 134 
 
 dried in a stove room 141 
 
 how warmed 52 
 
 what the farmer gets from 143 
 
 Albumin 127 
 
 Albuminoid ratio 255-264 
 
 error in caused by amides 256 
 
 for fattening animals 297 
 
 formilk 291 
 
 for working animals 314 
 
 for young animals 284 
 
 of mixed diets 260-262 
 
 to determine 257-258 
 
 Albuminoids 126 
 
 decrease in plants as seed forms 192 
 
 effect of insufficient in food 218 
 
 high value in some cases 248 
 
 how formed 187 
 
 meet all needs of animals 210 
 
 oxydized in circulation 207 
 
 term how used 225 
 
 used for repairing animal waste 213 
 
 used in making new tissue 213 
 
 value of as food 249 
 
 Aftermath hay, analysis of 293 
 
 Alkaloids 129 
 
 •Will be found in foot note. 
 
 Aluminum 93 
 
 Amides , 128 
 
 cannot be changed to albumi- 
 noids 226 
 
 often classed as albuminoids. ... 225 
 proportion of in different food . . 240 
 
 Ammonia, absorbed by soils 153 
 
 chloride 378 
 
 composition 98 
 
 contained in air 133 
 
 cost of 98 
 
 evaporation of, how prevented . 345 
 
 for house plants 98 
 
 quantity of in air 142 
 
 retained in soils 153 
 
 source of in air 142 
 
 sulphate 378 
 
 uses in the household 98 
 
 Amnionic carbonate 112 
 
 chloride 113 
 
 Amyloids 117 
 
 Analysis of soils, value of...: 157 
 
 Animal cannot use inorganic mat- 
 ter 203 
 
 composition of 198-202 
 
 matter compared with vegetable 202 
 Animals, the farmer's machine. '267-270 
 Annual, process of forming seed. ... 192 
 
 Ash, amount in plant 180 
 
 constituent of animals 200 
 
 Assimilation ; 205 
 
 Atoms, definition of 18 
 
 Atomic theory 75 
 
 weight 76 
 
 ' ' application of 79 
 
 B 
 
 Bacterium 163 
 
 Bases, definition 62 
 
 Bicalcic phosphate 110 
 
 Biennials 193 
 
 Black lead, nature of 88 
 
 Bone dust 375 
 
182 
 
 SCIENCE IN FARMING. 
 
 Bulbs, storehouse of food 194 
 
 Burning butter 272-273 
 
 C 
 
 Calcareous soils, bow known 112 
 
 Calcic carbonate 112 
 
 oxide 107 
 
 Calcium 92 
 
 Capillary attraction 150 
 
 Carbohydrates 118 
 
 do not exist in animals 199 
 
 value of as food 249 
 
 Carbon 88 
 
 Carbonate of ammonia 112 
 
 of lime 112 
 
 Carbonates 112 
 
 Carbonic dioxide, amount in air. . . 99 
 
 composition 99 
 
 contained in spring water 99 
 
 how produced 99 
 
 in cellar or pit 136 
 
 in hard water 99 
 
 needed by plants 99 
 
 Poisonous 99 
 
 quantity of in air 139 
 
 removed by lungs 207-208 
 
 supplies carbon for plants 139 
 
 taken up by roots of plants 186 
 
 Carcass, proportion in increase .311, 312 
 " of live weight .. 313 
 
 Casein 127 
 
 Catalysis 122 
 
 Cellulose 119 
 
 Cereal crops, manure for 382 
 
 Character of food, meaning of term* 238 
 
 Charcoal, nature of 88 
 
 Chemical combination 57 
 
 force 59 
 
 symbols 80 
 
 Ohemisim 59 
 
 Chemistry, its nature 56 
 
 of carbon compounds 114 
 
 Chemistry, agricultural 11 
 
 value of to farmers . . . 10 
 
 Chili saltpetre 108 
 
 Chloride ammonia 113 
 
 Chlorphyl 187 
 
 Chlorine 87 
 
 Clay, character of 170 
 
 effect of lime on 170 
 
 origin and composition 146 
 
 soils, how improved 176 
 
 Clouds, protect from frost 54 
 
 Clover, injured in curing 336 
 
 manure for 385 
 
 plow under or feed 364 
 
 Cold, effect of 221, 223 
 
 effect of in feeding 273 
 
 Colostrum, analysis of 280 
 
 Combining proportions 72 
 
 Combustion 131 
 
 Compounds, how described 82 
 
 how represented 81 
 
 proportion of elements in 96 
 
 Conduction, difference in 42 
 
 CopperaB 109 
 
 Corn, not a complete diet for pigs. . 309 
 Crops, require different manures ... 381 
 Crude fibre, meaning of 228 
 
 Dark soils, absorb warmth 152 
 
 Decay 132 
 
 Decimals, definition of 30 
 
 Dew-point 140 
 
 Dew, why none on cloudy nights. ... 140 
 
 Dextrine 120 
 
 Dextrose f 122 
 
 Diamond, nature of 88 
 
 Diffusion of gases 135 
 
 Digestibility of food, affectB its char- 
 acter 238 
 
 of food affected by mixing. . . 244-247 
 
 " " " *' maturity 243 
 
 " " differs 237 
 
 Digestion 204 
 
 most perfect how secured 247 
 
 Disinfectant, copperas 109 
 
 Division, effect of 164 
 
 Drainage, effect of 166-168 
 
 warms the soil 5o 
 
 Drought, prevented by drainage ... 168 
 
 Dry soils, become warm quickly 152 
 
 Dry substance, meaning of 179 
 
 E 
 
 Element, definition of 21 
 
 Elements, list of agricultural 83 
 
 Energy, animal, source of 211 
 
 original source of 37 
 
 Equivalents 78 
 
 Eremacausis 132 
 
 Excrement, solid, undigested food. . 208 
 
 Excretion 208 
 
 Exercise, effect of 221-223 
 
 effect of in feeding 272 
 
 * tWlll be found In foot not©. 
 
 Numbers refer to paragraphs, not to pages , 
 
INDEX. 
 
 183 
 
 Exhaustion, of soils ' — 159 
 
 in rotation . 160 
 
 F 
 
 Fallow, bare 326 
 
 Parmer, a manufacturer 6 
 
 need of knowledge 7 
 
 may prove injurious 326 
 
 Fat, how digested 201 
 
 how produced in plants 187 
 
 not changed into albumin 210 
 
 produced from albuminoids - . . 213 
 
 production, of 214 
 
 rule for reducing to value in car- 
 bohydrates 250-232 
 
 used for production of fat . - - . 215 
 value of as food ... . . ,. . . 249 
 
 Fats 125 
 
 Fattening animal, composition of 
 
 increase 295 
 
 animals, variation in rate of in- 
 crease 306 
 
 experiments in 295-308 
 
 Fertilizers, commercial 374-380 
 
 definition 317 
 
 Feeding, effects of cold in 273-275 
 
 effect of exercise in 272 
 
 general principles of 265-279 
 
 objects to be attained in 265 
 
 Ferric oxide, retains fertilizers 151 
 
 Fertility of soil, affected by its fine- 
 ness 164 
 
 Fibrine .127 
 
 Fixed oils 125 
 
 Flesh formers, use of term 229 
 
 Food, adaptation of 271 
 
 best for young animals 280-284 
 
 comparative value of 254 
 
 composition affected by soil and 
 
 season 235 
 
 composition of 230-236 
 
 consumed for, heat and en- 
 ergy 299, 303 
 
 digestibility of 237-247 
 
 disposition of 212-217 
 
 for producing milk 285-294 
 
 for fattening animals 295-298 
 
 insufficient, effects of 218-320 
 
 must contain all elements used 
 
 by animal 210 
 
 of what composed 224 
 
 pounds of digestible constituents 
 in ton 239 
 
 Numbers refer to paragraphs, 
 
 Food required to make l pound 
 
 ' increase 299-302 
 
 surplus how disposed of 214 
 
 * table of composition 280 
 
 undigested how disposed of 217 
 
 used for production of heat and 
 
 energy 212 
 
 uses of in animal body 209-211 
 
 valuation, comparative 248-254 
 
 valuation of manurial cbnstitfh- 
 
 ents in 371-372 
 
 value of not determined by anal- 
 ysis 237 
 
 Force, definition of 19 
 
 Formula, chemical 82. 
 
 Free, meaning of term 70 
 
 Fungi, how they feed * 187 
 
 G 
 
 Gases 17-18 
 
 Gelatiu 127 
 
 Germination, chemistry of 183 
 
 general summary 195 
 
 necessities of 184 
 
 temperature required for 184 
 
 Glucose , 122 
 
 how made 122 
 
 Gluten 127 
 
 Grass, manure for 384 
 
 Green manuring 328 
 
 Guano 376 
 
 Gums 121 
 
 Gypsum ... 109 
 
 use in manure 109, 345 
 
 H 
 
 Hay, effects of methods of preparing 236 
 
 composition affected by date of 
 
 cutting.: 232 
 
 Heat, absorption of 46 
 
 animal, source of 211 
 
 cannot be destroyed 37 
 
 conduction of 41 
 
 convection of 43 
 
 excessive cause waste in feeding 275 
 
 needed for melting ice 34 
 
 needed to boil water 34 
 
 origin of 38 
 
 produced in freezing 36 
 
 produced in slaking lime 35 
 
 producers, use of term 229 
 
 protection from 48 
 
 radiation of 44 
 
 *Will be found in foot note. 
 
 not to pages , 
 
184 
 
 SCIENCE' IN FARMING. 
 
 Heat, same principle as energy 32-36 
 
 Bpecific 39 
 
 transference of 40-46 
 
 Horse, digestive power of 24f 
 
 Horsefall's experiments in] feeding 
 
 cows 294 
 
 How the plant grows 185-190 
 
 Humus, power of retaining water. . 148 
 
 to estimate quantity in soil 171 
 
 or%lnof ]46 
 
 retains fertilizers 151 
 
 value of in soil 171 
 
 Hydrogen 85 
 
 I 
 
 Indian corn, manure for 383 
 
 I null n 120 
 
 Iron 94 
 
 black oxide 94 
 
 in soils, how rendered harmless. 94 
 
 red oxide 94 
 
 when injurious in soils 94 
 
 Isomerism 116 
 
 I* 
 
 Laevulose 122 
 
 Land plaster 109 
 
 Leaves, effect of removal 189 
 
 exhaustion in fall 189 
 
 work of 187 
 
 Lime, as a manure 327 
 
 effect on ammonia 107 
 
 on clay soils 170 
 
 quick 107 
 
 slacked 107 
 
 Liquids 17-18 
 
 Loam 147 
 
 M 
 
 Magnesium 92 
 
 Manganese 95 
 
 Mangels, manure for 387 
 
 Manure, adaptation 381-388 
 
 affected by digestibility of 
 
 food 359-360 
 
 amount produced from food 351 
 
 animal food used for 362-363 
 
 becomes rich by fermentation - 340 
 
 cause of difference in 354-355 
 
 comes from food 330 
 
 composition of drainage from. . . 344 
 
 concentration of 347 
 
 farm-yard, composition 337-338 
 
 fermentation of 339 
 
 fermented in open barn -yard 341 
 
 fermented under shed 342 
 
 Numbers refer to paragraphs, 
 
 Manure, for cereal crops ... .382 
 
 for clover 385 
 
 for grass 384 
 
 for Indian corn 383 
 
 for mangels 387 
 
 for potatos 388 
 
 for turnips 386 
 
 from animal giving milk 355 
 
 from different animals 348-349 
 
 from fattening animals 357 
 
 from growing animals 356 
 
 improve mechanical condition of 
 
 soils 532 
 
 leaching of 344 
 
 left spread over the yard 343 
 
 poor from poor food 353 
 
 proportion of to food 354 
 
 relation of food to 350-364 
 
 rich from rich food 353 
 
 rules for care of 346 
 
 solid and liquid S49 
 
 tables of value 369 
 
 valuation of 365-37S 
 
 varies with food and constitu- 
 tion of animals 349 
 
 Manures, plant food required in — 330 
 
 Matter, can change its form 15 
 
 cannot be created 15 
 
 cannot be destroyed 16 
 
 definition of 15 
 
 forms in which it exists 17 
 
 properties of 20 
 
 Milk, analysis of 280, 310 
 
 best food for 285-294 
 
 food used in production 215 
 
 key to proper food for young an- 
 imals 280 
 
 Molecular weight 77 
 
 Musculine 127 
 
 N 
 
 Nature and cultivation 319 
 
 Nitrate of soda .'...108, 378 
 
 Nitrates 101, 108 
 
 how saved in soil 156 
 
 Nitrification 163 
 
 Nitrogen 86 
 
 amount brought down by rain. . 138 
 
 lost in fermenting manure 339 
 
 oxydized in soil •329, 378 
 
 proportion stored in increase 357 
 
 rendered,available by bare fallow 326 
 
 *Will be found in foot note, 
 
 not to pages , 
 
INDEX. 
 
 185 
 
 Nitrogen not used uncombined 138 
 
 Nitrogenous substances 117 
 
 Nutrition, animal 203-208 
 
 O 
 
 Open fires 51 
 
 Organic chemistry 114 
 
 matter oxydized in soil 162 
 
 substances, classes of 117 
 
 substances, definition 71 
 
 substances, of what composed . . 114 
 
 Oxygen 84 
 
 uses in air 137 
 
 P 
 
 Parasitic plants, food of * 187 
 
 Pectose group of substances 123 
 
 Per cent, definition of 27 
 
 practical use of 29 
 
 Percentage composition 28 
 
 Perspiration protects from heat 49 
 
 Pig, amount increase from food 299-304 
 
 clover for 283 
 
 digestive powers of 242 
 
 experiments in feeding 306 
 
 the farmer's most profitable 
 
 stock 302 
 
 Phosphates 110 
 
 preparation of Ill 
 
 rendered soluble in soil 162 
 
 Phosphoric acid, insoluble 367 
 
 proportion of in solid excrement 358 
 
 reverted 367 
 
 soluble 367 
 
 Phosphorus 89 
 
 Potatos, manure for 388 
 
 Plants composition of , 178-181 
 
 exhaustion with age 192 
 
 in bed-rooms * 190 
 
 prepare food for animals 203 
 
 supplied with carbon by leaves . . 188 
 
 Plant food, amount of in soils 160 
 
 available, au excess needed in 
 
 the soil 333 
 
 available, may be exhausted . . . 332 
 
 condition of in the soil 161 
 
 means for rendering available 326-329 
 
 of what composed 185 
 
 valuation 367-368 
 
 Potash, caustic 104 
 
 use of term in fertilizers 104 
 
 Potassic Hydrate 104 
 
 Potassium 92 
 
 •Will be found In foot note. 
 
 R 
 
 Respiration, of plants 190 
 
 of animals , 207 
 
 Eock, how reduced to soil 145 
 
 phosphate 377 
 
 Boots, best use in feeding 279 
 
 improve with maturity 233 
 
 work of 186 
 
 Rotation, exhaustion of soils in .... 160 
 S 
 
 Sacharose 122 
 
 Sal ammoniac 113 
 
 Saltpeter ios 
 
 amount in water of the Nile 156 
 
 Salts, con taming nitrogen ...... 378 
 
 definition of term 65 
 
 Sand 146 
 
 absorbs water but slightly 149 
 
 determination of character and 
 
 amount 169 
 
 retains fertilizer but little 151 
 
 retains water poorly 148 
 
 Sandy soils, how improved 175 
 
 liable to burn out 152 
 
 readily warmed .'. 152 
 
 Science, and practice 2 
 
 definition of 1 
 
 in common language 3 
 
 foundation of 22 
 
 knowledge of 25 
 
 Seed, composition uniform 191 
 
 contains all elements of plant 
 
 food 91 
 
 formation of 191-194 
 
 of what composed 182 
 
 Silicic dioxide 103 
 
 how .dissolved 103 
 
 Silicon 91 
 
 Skim milk, analysis of 310 
 
 value of for pigs 310 
 
 Smoke, as a protection from frost . . 55 
 
 Sodic chloride 106 
 
 hydrate, 105 
 
 Sodium 92 
 
 Soil, absorption of water from air . 149 
 
 analysis of 157 
 
 baking of 165 
 
 capillary attraction 150 
 
 chemical changes in 162 
 
 classification of 147 
 
 composition of 144 
 
 condition of, necessary for crop 318 
 correcting defects In 1?? 
 
 Numbers refer to paragraphs, not to pages , 
 
186 
 
 SCIENCE IN FARMING. 
 
 Soil, exhaustion of 159 
 
 exhaustion of under rotation . . 160 
 fertility of afifec ted by drainage 168 
 
 of Minnesota 168 
 
 retention of fertilizing elements 161 
 
 retention of water by 148 
 
 run down 161 
 
 temperature of 162 
 
 Soiling, how advantageous. - * 209,*272 
 
 Solid 17-18 
 
 Soluble carbohydrates, use of term 227 
 
 definition of word 67 
 
 Solubility, difference in 69 
 
 Solution 66 
 
 Starvation 220 
 
 Straw, best in bad season 192, 231 
 
 as a milk diet 288 
 
 Sugar, maple how produced 189 
 
 Sugars 122 
 
 Superphosphates 379 
 
 manufacture of 380 
 
 T 
 
 Table salt 108 
 
 Table, air, composition of 133 
 
 absorption of water by soils 149 
 
 albuminoid ratio of foods 263 
 
 albuminoids, composition of 126 
 
 digestible constituents in foods 230 
 
 comparative value of foods 263 
 
 comparison animal and vegeta- 
 ble substance 202 
 
 composition of colostrum 280 
 
 composition of farm-yard ma- 
 nure 338 
 
 composition of food 230 
 
 composition of hay at different 
 
 dates 232 
 
 composition of milk 280 
 
 composition of plants before 
 
 and after maturity 192 
 
 composition of solid and liquid 
 
 excrement 849 
 
 concentration of manures 347 
 
 elements 83 
 
 effects of fallow 326 
 
 germination, temperature of. . . 184 
 manure fermented in open 
 
 barn-yard 341 
 
 manure fermented under a shed 842 
 manure left spread over a yard 343 
 
 plants ash in one ton 180 
 
 plants dry, water in 179 
 
 Table, plants, fresh, water In 178 
 
 proportion of nitrogen in in- 
 crease and excrement 357 
 
 soils, classification of 147 
 
 soils, composition of 157 
 
 soils, exhaustion of by wheat . 159 
 soils, exhaustion of under rota- 
 tion 160 
 
 soils, retention of water in . ... 148 
 
 soils, weight of an acre 155 
 
 value of manures 369 
 
 value of manurial constituents 
 
 in food 372 
 
 value of plant food 367 
 
 value of rich and poor manure. 347 
 
 water In animal substance 301 
 
 Transformation of organic sub- 
 stances 130 
 
 Trlcalcic phosphate. 110 
 
 Tubers, storehouse of food . ..194 
 
 Turnips, manure for .386 
 
 V 
 
 Under-feeding extravagant 270 
 
 Urea, formed from albuminoids... 207 
 Urine more valuable than solid ex- 
 crement 370 
 
 rapid action as fertilizer . . .196 
 V 
 
 Valley of poison 136 
 
 Volatile oils 125 
 
 W 
 "Waste of fertility by drainage . 156 
 
 of the body 206 
 
 "Water 97 
 
 amount In plants 178, 179 
 
 capillary 97 
 
 effect of in food 276 
 
 hydrostatic 97 
 
 hygroscopic 97 
 
 in air 140 
 
 " not absorbed by plants . 141 
 
 " prevents radiation 53 
 
 in|animal|substances 201 
 
 in soils requires beat to remove 50 
 
 of combination 97 
 
 proportion to dry food 277 
 
 Weeds, best time to kill 195 
 
 Weightofsoils 155 
 
 Working animal, food for 314 
 
 Young animal, proper food for . 280-284 
 Young grass and clover, best for 
 
 milk 290 
 
 why they give good returns. ... 243 
 
 Numbers refer to paragraphs, not to pages . 
 
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 Improved machinery has reduced 
 the expense of this fenoe so that it 
 is now manufactured at a price that 
 puts it within the reach of all. 
 
 
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MIAMI VALLEY HEED OF 
 
 POLAND CHINA SWINE 
 
 the property of J. L. Van Doren, Glen- 
 dale, Hamilton county, O. Stock for 
 sale at all times. Breeders.aU recorded 
 In Ohio P. C. Record. A correct 
 pedigree furnished with all stock sold. 
 All correspondents promptly answer- 
 ed. Special rates by express. Ad- 
 dress as above. 
 
 Roses and Flowering Plants. 
 
 Sixteen forlSl— Your Selection. 
 
 Our descriptive catalogue, contain- 
 ing full list of NEW and desirable va- 
 rieties sent FREE on application. 
 
 Address, E. BONNER & Co., 
 Xenla, Ohio. 
 
 J. H DENHAM, 
 
 ST. CLAIRSVILLE, Belmont Co., O., 
 Breeds Registered 
 
 POLAND CHINA SWINE 
 
 Merino Sheep and Jersey Cattle. His- 
 tory of P. C. Hog 25c. Call and see me. 
 
 Latch string always out. 
 
 h. s. ROSS, 
 
 SEVILLE, MEDINA CO., OHIO, 
 Breeder and shipper Improved Ches- 
 ter White Swine, Plymouth Bock, W. 
 C. B. Polands, S. S. Polish, Pekin 
 Ducks, Toulouse Geese and Bronze 
 Turkeys. 
 
 Stock for Sale at all Times: 
 Eggs In Season: 
 
 J. L. WHITON, 
 
 NORTH AMHERST, Lorain Co., O., 
 Breeder of 
 
 — Thoroughbred — 
 SHORT-HORN CATTLE. 
 
 JERSEY RED SWINE. 
 
 I can now fill orders for single pigs 
 or pairs or trios, not akin. Also a 
 choice lot of Boars, old enough for 
 service, and Sows of all ages, bred or 
 not, as desired. I purchased my stock 
 from Petit, of New Jersey, the cele- 
 brated breeder of Jersey Reds, and it 
 is all thoroughbred. Inquiries prompt- 
 ly answered. SAM'L TAYLOR, 
 Grove City, Franklin county, O. 
 
 A. M. TORE, 
 
 BUCYRIJS, Crawford Co., OHIO, 
 Breeder and shipper of pure 
 
 POLAND CHINA HOGS, 
 
 Of the most fashionable strains. AH 
 Breeding stock recorded in the O. P. 
 
 C. Record. 
 Chickens. 
 
 Also Plymouth Rock 
 Correspondence solicited. 
 
 PAUL TOMLINSON, 
 
 CEDARVILLB, Greene Co., OHIO. 
 Breeder of 
 
 SHORT-HORN CATTLE, 
 
 Poland China Pigs, Bronze Turkeys, 
 Light Brahma, Buff Cochin and Ply- 
 mouth Rock Fowls. 
 
 D. J. WHITMOKE, 
 
 CASSTOWN, MIAMI CO., OHIO, 
 
 Makes a specialty of 
 Devon Cattle, Poland 
 China Hogs, Cotswold 
 
 Sheep, Bronze Turkeys, 
 
 Lighc Brahmas, Plymouth Rock and 
 Houdan Chickens, "White Guineas, 
 Bremen and Toulouse Geese. 
 
 BERKSHIRES 
 
 For Sale. 
 
 Boars fit for service. Sows 
 bred and young stock. If 
 stock is not as repre- 
 sented, will pay return 
 charges on it. Stock regis- 
 tered. 
 
 JOHN M. JAMISON, 
 
 Roxabell, Ross county, Ohio. 
 
 I 
 
 A. Z.&C. D.FORNEY, 
 
 Breeders and Shippers of 
 Pure 
 
 Poland China Swine 
 
 fi^*Make a specialty of 
 
 this breed. 
 
 Reliable pedigrees fur- 
 nished. 
 
 PLAINFIELD, OHIO. 
 
 Coshocton county. 
 
CHICAGO SCALE CO., 
 
 147, 149 & 151 South Jefferson street, 
 
 MANUFACTURERS OF EVERY VARIETY OF 
 
 UaS. Standard Scales. 
 
 IfVThe Best Quality at the Lowest Prices. jkI 
 
 -2-Ton Wagon Scales (platform 6x12) $40.00 
 
 3-Ton 7x13 - - - $50.00 | 4-Ton 8x14 - - $60.00 
 
 All other sizes in proportion. All scales perfect. 
 Iron Levers, Steel Bearings, Brass Beam, Beam Box, and 
 building directions with each Scale. 
 
 "Tfie Little Detective," For Family or Office, $3.00. 
 Family or Farm Scale 1-2 to 24 lbs., $5. 
 
 A $23 Farmer's Forge for $10. 
 
 Every Farmer His Own Blacksmith. 
 
 A Forge, Anvil and Kit of Tools, 
 
 So any Parmer can do his own Jobbing, ONLY $20. 
 
 Also, all sizes of Anvils, Wind Mills, Fanning Mills, Farm 
 and Family Grist Mills, Hay Presses, Corn Shellers, Farm 
 and Garden Wheelbarrows. . Save Money. Get the Best. 
 Send fov List. 
 
JUST WHAT YOU WANT! 
 
 THE RANDALL HARROW. 
 
 The most Convenient, 
 Effective, Durable and 
 Reliable Harrow made. 
 Economizes time, saves 
 labor and money; se- 
 cures the largest yield 
 of crops by the most 
 perfect tillage. It has 
 no equal as a Pulver- 
 izer, Cultivator, Sod 
 . Cutter, and for tilling 
 all tenacious and tough 
 soils. It is often a sub- 
 stitute for the plow, 
 cutting from six to ten 
 feet in breadth. Less 
 labor and increased crops are the certain results of the use of the Randall 
 Harrow. Half the time saved by using it to prepare the aoil for seed ; and it 
 adapts itself to every condition of surface and soil. Every one who has used 
 it or seen it used, speaks in its praise. 
 
 IT IS 50 EXPERIMENT, BUT A PROVED SUCCESS ! 
 
 Do Not Tramp After and Lift Your Useless Old Drag, Bide the 
 Randall, and Save Many a Weary Mile. 
 
 TESTIMOKTIALS. 
 
 From E. C. Ellis, one of the editors of the Farmers' Advance, and a prom- 
 inent Granger: 
 
 Last summer I saw an advertisement of the Bandall Harrow, and liking the 
 description, I opened a correspondence with the manufacturers, which re- 
 sulted in my procuring one from them. After removing the fodder from my 
 cornfield, I prepared the ground for wheat with the harrow alone, and I never 
 had a crop put In more satisfactorily. I then got Bro. Van Doren, of Wyom- 
 ing Grange— one of the best farmers— to try it, which he did successfully, and 
 on returning it pronounced it the "Boss Harrow." This spring he used it again 
 with the same marked success in pulverizing the soil. I also had a ten-acre 
 field of clover turned under, then placed the Randall Harrow on it, and I have 
 never before seen sod put in such perfect order for corn. At the last meeting 
 of Wyoming Grange, Bro. G. W. Baymond, our ex-Master, stated that he had 
 a clover field that he could do nothing with. He had tried all the harrows in 
 the neighborhood and none could cut it. Bro. Van Doren said to him : "Get 
 Bro. Ellis' 'Boss Harrow;' it will fetch it." He came, got the harrow, and I 
 learn from my son that It did the work well. After so thoroughly testing it 
 myself, and having two No. 1 farmers like our ex-Masters Van Doren and 
 Baymond subject it to seve ie tests, and getting their testimony in its favor, I 
 feel justified in saying that the Bandall Harrow will do all that the manufac- 
 turers claim, and do most cheerfully recommend it as the best harrow I have 
 ever seen. E. C. ELLIS, Glendale, Ohio. 
 
 From M. W. Dunham, the largest breeder and importer of Norman and 
 Fercheron horses in the United States : % 
 
 I never bought a machine I was so well satisfied to pay for as the Bandall 
 Harrow. I have thoroughly tested it on nearly all kinds of ground, corn stub- 
 ble, sod breaking and fall plowing. No other implement can approach It for 
 completeness or work ana economy of power in surface cultivation. I am 
 sure you will have success, for the harrow needs only to be used to commend 
 itself as the most valuable implement in use. All purchasers will find, as I 
 have, that you conferred a favor by placing the Bandall Harrow within their 
 reach. M. W. DTJNHAM, Oak Lawn Farm, Wayne, 111. 
 
 We would be pleased to mail descriptive circulars to any one applying. 
 Agents wanted in unoccupied territory. 
 
 J. W. STODDARD & CO., Dayton, Ohio, Manufacturers. 
 
THE BIG GIANT AND MOUND CITY 
 
 IFZBIEID 2v£TTJI- 
 
 OUR LATEST INVENTION. 
 
 The most rapid Grinder ever made. We 
 
 make the only Corn and Cob Mill with 
 
 , Cast Steel Grinders. If we fail to furnish 
 
 I proof, will give you a mill. Ten different 
 
 j styles and sizes. The only mill that sifts 
 
 the meal. Grinds shelled corn, makes good 
 
 family meal and grinds all kinds of small grain. 
 
 STAR CANE MILL. 
 
 Grinds twice as fast. Double the capacity. 
 
 CHEAPEST MILL MADE. 
 
 WARRANTED in every respect. We man- 
 ufacture TEN. DIFFERENT STYLES of 
 Cane Mills, and a full stock of Evaporators 
 and ' 
 
 SUGAR MAKERS' SUPPLIES. 
 
 STUBB'S EVAPORATOR. 
 
 A boy 14 Tears Old 
 Can Operate It. 
 
 Saves fuel and LABOR, 
 . makes double the quanti- 
 tty, a perfect defecator, 
 saves 90 per cent, of labor 
 in skimming, produces a 
 better quality of syrup. B^ This Evaporator made the 
 syrup that teas awarded the highest premium — viz. $75 — at the 
 great St. Louis Fair in 188%. 
 
 "Send for circulars and prices. 
 
 J. A. FIELD & Co., St. Loots, Mo., 
 1622 to 1628 N. Eighth St., and 714 to 724 Howard St. 
 
— shoul!) Subscribe fok the — 
 
 FARM and FIRESIDE, 
 
 The Leading Agricultural, and Home Journal 
 of America. 
 
 ONLY 50 CENTS A YEAR. 
 
 LIBERAL PREMIUMS ~B9 
 
 — AND — 
 
 M*- CASH COMMISSIONS 
 
 Given Those Who Get Up Clubs. 
 
 Sample Copy and Premium List SENT FREE 
 
 UPON APPLICATION. 
 
 Address, 
 
 MAST, CROWELL & KIRKPATRICK, 
 
 Springfield, Ohio, and Louisville, Ky. 
 
 — ALSO PUBLISHERS OP — 
 
 OUR YOUKG PEOPLE, 
 
 A Handsomely Illustrated Paper for Young People. 
 
 ONE DOLLAR PER YEAR. 
 
 Address, MAST, CROWELL & KIRKPATRICK, 
 
 Springfield, O., and Louisville, Ky.