SHOULD CHILDREN UNDER TEN LEARN TO READ AND WRITE?

By Prof. G. T. W. PATRICK.

There are certain propositions about education so evidently true that probably no parent or teacher would question them. For instance, the best school is one in which the course of study is progressively adapted to the mental development of the children. Again, certain subjects are adapted to children of certain ages or stages of development, and others are not. One would not recommend the study of logic or of the calculus to the average child of ten, nor would the teaching of English be wisely deferred until the age of fifteen. Finally, if the courses of study in our present school system shall be found to be arranged without regard to the order of mental development, they will sooner or later be modified in accordance with it.

Now the educational system in practice in the two or three hundred thousand public schools in the United States is a somewhat definite one, with a somewhat fixed order of studies through the different years or grades. In a majority of the States children are admitted to the schools at the age of six; in more than one third of the States children of five are admitted. In a general way we may say that during the first four years of school life the principal subjects occupying the time of the children are reading, writing, and arithmetic. To be more exact, we may cite, for instance, the city schools of Chicago.[45] Exclusive of recesses and opening exercises, there are in these schools thirteen hundred and fifty minutes of school work per week. Of this time, in the first and second grades, six hundred and seventy-five minutes are devoted to reading, seventy-five minutes to writing, and two hundred and twenty-five minutes to mathematics. Seventy-two per cent of the total time is therefore consumed by these subjects. In the third grade the proportion is the same; in the fourth grade it is somewhat more than fifty per cent. I have mentioned the Chicago schools because this is one of those school systems where a liberal introduction of other subjects, such as Nature study, physical culture, singing, and oral English, has somewhat lessened the time given to reading, writing, and arithmetic. Other cities, with few exceptions, will be found to give more rather than less time to these subjects. In the country schools, and indeed in a vast number of town and city schools, practically all the time during these early years is given to reading, writing, and arithmetic.

We must conclude, therefore, if our educational system is a rational one, that reading, writing, and arithmetic are the subjects peculiarly adapted to the mind of the child between the ages of five and ten. It is worth while to inquire from the standpoint of child psychology whether this be true. It should be observed, in the first place, that the manner in which our educational system has grown up is no guarantee that it rests upon a psychological basis. Our schools are exceedingly conservative. Any innovations or radical changes are resisted by the parents of the children even more strenuously than by school boards, superintendents, and teachers. Notwithstanding numerous and important minor improvements, the school system as a whole remains unchanged. Our children of seven and eight years are learning to read and write because our grandfathers were so doing at that age.

We can not here discuss the origin of our present school curriculum, but, as explaining the prominence given to reading, writing, and arithmetic, it is worthy of notice that originally the elementary school existed to teach just these three subjects. The primitive schoolmaster was not superior to the parents of the child, usually not their equal, in anything except his knowledge of "letters." So the child was sent to school for a short time to learn letters. It was not at all the function of the school to educate the child in all that was necessary to fit him for the duties of life. Afterward, as the scope of the school was enlarged, other subjects were added, and these were put after the original ones, and the schoolmaster, furthermore, came rather to take the place of an educator than a mere teacher of letters. It is conceivable, therefore, that the present accepted order of studies in our elementary schools rests upon an accidental rather than upon a psychological basis. It is true that modern educators have expressly considered the subject of the order and correlation of studies, as, for instance, in the case of the Committee of Fifteen, and that, while recommending minor changes in the school curriculum, they have not usually thought of questioning the position so long held by reading, writing, and arithmetic. In the report of the committee just referred to we find this expression: "The conclusion is reached that learning to read and write should be the leading study of the pupil in his first four years of school." But, again, it was not the function of this committee to suggest sweeping changes, nor to raise the inquiry whether the system itself rests upon a psychological basis. Even if it did not rest upon such a basis, expressions like the above would not be unnatural on the part of committees appointed by bodies representing the system as a whole.

We may not, then, conclude a priori that our system of primary education is a sound one. There have indeed been other wholly different systems giving excellent results in their time, as, for instance, that of the ancient Greeks, where music and gymnastics, not reading, writing, and arithmetic, were the principal subjects occupying the time of the pupils.

Much attention has recently been given to the subjects of the physiology and psychology of children. These studies have been systematic, painstaking, and exact. It seems, indeed, to many people improbable that anything very new or very remarkable should just at this time be found out about children, and there have not been wanting either prominent educators or psychologists who have given public expression to warnings against the new "child study." But this, again, is not conclusive, for students of history may recall that every advance in science has met just such opposition—for instance, bacteriology, organic evolution, chemistry, and astronomy. Furthermore, when we reflect that scientific advance in this century has ever been, and inevitably, from the simple to the complex, and, further, that the brain of the child is the most complex thing in the whole range of natural history which science will ever have to attempt, it is not difficult to understand that scientific knowledge of it with its pedagogical implications has not belonged, at any rate, to the past. It will belong to the future, having, perhaps, its beginnings in the present. An educational system which has not reckoned with an accurate knowledge of the brain of the child may by accident be a correct one, but until such reckoning is made we can not be sure.

Our increasing knowledge of the child's mind, his muscular and nervous system, and his special senses, points indubitably to the conclusion that reading and writing are subjects which do not belong to the early years of school life, but to a later period, and that other subjects now studied later are better adapted to this early stage of development. What is thus indicated of reading and writing may be affirmed also of drawing and arithmetic. The reasons leading to this conclusion can be only very briefly summarized here.

As regards reading, writing, and drawing, they involve, in the first place, a high degree of motor specialization, which is not only unnatural but dangerous for young children. Studies in motor ability have shown that the order of muscular development is from the larger and coarser to the finer and more delicate muscles. The movements of the child are the large, free movements of the body, legs, and arms, such as he exhibits in spontaneous play. The movements requiring fine co-ordination, such as those of the fingers and the eyes, are the movements of maturer life. If we reverse this order and compel the child to hold his body, legs, and arms still, while he engages the delicate muscles of the eyes and fingers with minute written or printed symbols, we induce a nervous overtension, and incur the evils incident to all violation of natural order. The increasing frequency of nervous disorders among school children, particularly in the older countries, is probably due in part to these circumstances. If we consider the brain of the child of seven or eight years, our conclusions are strengthened that he should not be engaged in reading and writing. At this age the brain has attained almost its full weight, and is therefore large in proportion to the body. Its development is, however, very incomplete, particularly as regards its associative elements—that is, the so-called association fibers and apperception centers. Such a brain constantly produces and must expend a large amount of nervous energy, which can not be used centrally—that is, psychologically speaking—in comparison, analysis, thought, reflection. It must flow out through the motor channels, becoming muscular movement. The healthy child is therefore incessantly active in waking hours, the action being of the vigorous kind involving the larger members. Hence we can understand that, of all the ways in which a young child may receive instruction, the method through the printed book is pre-eminently the one ill fitted to him.

The evil of this method is aggravated by the fact that, before the child can receive instruction through the book, a long time—several years, in fact—is spent in the confining task of learning to read. It comes about, therefore, that the child, at the very age when he should be leading a free and expansive life, is obliged to fix his eyes upon the narrow page of a book and decipher small printed symbols, in themselves devoid of life and interest. With respect to writing and learning to write the case is worse. A considerable amount of motor specialization is involved in forming letters upon the blackboard, but when the pencil and pen are used it becomes of an extreme kind. In the whole life history of the man there are no movements requiring finer co-ordination than those of writing with pencil or pen, yet our school system requires these of the child of six or seven years, makes them, indeed, a prominent part of elementary school life. In addition to the motor specialization of reading and writing is the physical confinement in the narrow seat and desk which is necessarily connected with them. The child of six or seven has not reached the age when such confinement is natural or safe.

The injuries which I have mentioned relate to the nervous system as a whole. There are other injuries resulting from the reading habit in young children which concern the eyes directly. So much has been said and written lately about the increase of myopia and other defects of the eye among school children, that I shall merely refer to this subject here. Upon entering school, children are practically free from these defects. Upon leaving school, a strikingly large percentage are suffering from them, more, however, as yet, in European countries than in America. The causes are many, but it is scarcely doubted that the chief cause is found in bending over finely printed books and maps, and fine writing, pencil work, and drawing. If pencils, pens, paper, and books could be kept away from children until they are at least ten years of age, and their instruction come directly from objects and from the voice of the teacher, this evil could be greatly lessened.

If the above reasons for not teaching reading and writing to young children were the only ones, the objections could to a certain extent be overcome. Writing might, for instance, be practiced only on the blackboard with large free-hand movements, and letters could be taught from large forms upon charts. But we have to consider the questions whether reading and writing are in themselves branches of instruction which belong to the early years of school life, whether they may not be acquired at a great disadvantage at this period, and whether more time is not spent upon them than is necessary. It is a well-known fact that a child's powers, whether physical or mental, ripen in a certain rather definite order. There is, for instance, a certain time in the life of the infant when the motor mechanism of the legs ripens, before which the child can not be taught to walk, while after that time he can not be kept from walking. Again, at the age of seven, for instance, there is a mental readiness for some things and an unreadiness for others. The brain is then very impressionable and retentive, and a store of useful material, both motor and sensory, may be permanently acquired with great economy of effort. The imagination is active, and the child loves to listen to narration, whether historical or mythical, which plays without effort of his will upon his relatively small store of memory images. The powers of analysis, comparison, and abstraction are little developed, and the child has only a limited ability to detect mathematical or logical relations. The power of voluntary attention is slight, and can be exerted for only a short time. All this may be stated physiologically by saying that the brain activity is sensory and motor, but not central. The sensory and motor mechanism has ripened, but not the associative. The brain is hardly more than a receiving, recording, and reacting apparatus. It would be inaccurate, however, to express this psychologically by saying that perception, memory, and will are the mental powers that have ripened at the age of seven. This would be true only if by perception we mean not apperception, which involves a considerable development of associative readiness, but mere passive apprehension through the senses, and if by memory we mean not recollection, but mere retentiveness for that which interests, and if by will we mean not volition, but only spontaneous movement and readiness to form habits of action, including a large number of instinctive movement psychoses, such as imitation, play, and language in its spoken form.

Following out, then, somewhat as above, the psychology of the child, what kind of education would be particularly adapted to his stage of development? We ask not what can the child be taught, but what studies are for him most natural and therefore most economical. In the first place, from the development of the senses and the perceptive power above described, we infer that the child is ready to acquire a knowledge of the world of objects around him through the senses of sight, hearing, touch, temperature, taste, and smell. His education will have to do with real things and their qualities, rather than with symbols which stand for things. If we wish a general term for this branch of instruction, we may call it natural science, or, to distinguish it from science in its more mature form as the study of laws and causes, we may call it natural history, or, more briefly, Nature study. Although the appropriateness and economy of this study for young children has been known and proclaimed for more than a century, it is still in practice the study of later years, while young children study letters.

In the second place, from the development of the retentive powers of the child we infer that he is qualified to gain acquaintance not only with the real world around him, but with the real world of the past. We may call this history. History is now studied later by means of text-books. It may be studied with far greater economy during earlier years by means of direct narration by parent or teacher. It is wonderful how eagerly a child will listen to historical narration, and how easily he will retain it. This method of teaching history forms a striking contrast to the perfunctory manner in which it is often studied in the upper school grades, with the text-book "lesson," "recitation," and the "final examination." Upon the minds of many young people the study of history has a deadening effect when the history epoch is passed and the mathematical epoch has arrived. It has already been proposed, at a conference of educators lately held in Chicago, to extend the study of history downward into the lower grades, a proposition fully sanctioned by psychological pedagogy. In what I have here said about history for young people I refer not to the philosophy of history, which comes much later in the life of the student, but to history as a mere record of facts and events, the kind of history which is now studied in the grammar and high schools, the kind which many educators who would make all children philosophers are now saying should not be studied at all.

In the third place, what studies correspond to the development of the will in the child from five to ten? It is the habit-forming epoch. It is the time when a large and useful store of motor memory images may be acquired, and when permanent reflex tracts may be formed in the spinal cord and lower brain centers. This is the time to teach the child to do easily and habitually a large number of useful things. If we use the term in its broadest sense, we may call this branch of instruction morals, but it will also include, besides habits of conduct, various bodily activities, certain manual dexterities, and correct habits of speech, expression, and singing. But here some restrictions must be observed. The habit-forming period begins at birth and continues far beyond the age of ten, and the period from five to ten is not the time for the formation of all habits. The order of muscular development must be observed, and all dexterities involving finely co-ordinated movements of the fingers, or strain of the eyes, should be deferred beyond this period, or at most begun only in the latter part of it; such, for instance, as writing, drawing, modeling, sewing, knitting, playing upon musical instruments, and minute mechanical work, as well, of course, as the plaiting, pricking, stitching, weaving, and other finger work still practiced in some kindergartens and primary schools.

We have thus seen that there are certain branches of instruction for which the mind of the child from five to ten has ripened, and which may therefore be taught most economically and safely during this period. Concerning the teaching of language I shall speak presently, but thus far we have found that from the psychological standpoint there are at any rate three subjects which are strikingly adapted to this period, namely, natural science, history, and morals, using these terms with the latitude and restriction already explained. Certain branches of Nature study and one branch of what we have called morals—namely, manual training—have in recent years been introduced into our best elementary city schools, and in a few schools history is taught systematically in the lower grades by means of stories. They have not, however, crowded out reading, writing, and arithmetic so much as crowded into them. But if we consider the great mass of schools in city, town, and country throughout the land, the subjects which practically complete the elementary school curriculum—reading, writing, arithmetic, and geography—are, with the exception of the latter, found to be subjects which do not naturally belong to this period at all. Mathematics in every form is a subject conspicuously ill fitted to the child mind. It deals not with real things, but with abstractions. When referred to concrete objects, it concerns not the objects themselves, but their relations to each other. It involves comparison, analysis, abstraction. It calls for a fuller development of the association tracts and fibers of the cerebral hemispheres. The grotesque "number forms" which so many children have, and which originate in this period, are evidence of the necessity which the child feels of giving some kind of bodily shape to these abstractions which he is compelled to study. Under mathematics I do not of course include the mere mentioning or learning a number series, such as in the process called "counting," or the committing to memory of a multiplication table. Furthermore, in this and in all discussions of this kind it must be remembered that there are exceptional children in whom the mathematical faculty, or musical faculty, or literary faculty, develops much earlier than with the average child. If possible, they should have instruction suited to their peculiarities. But it is evident that, so long as children are educated in "schools," there must be a general plan of education, and that it can not be based upon exceptional children.

What we learn from physiology and psychology about the ripening of the child's mind is confirmed by the theory of the "culture epochs." I can not discuss here the doctrine of "recapitulation," with its great truths and its minor exceptions, but it is well known that in a general way the development of the child, both physical and mental, is an epitome of the development of the race. If we compare the physical and mental activities of the modern civilized man with those of the more primitive member of the race, we may learn what forms of physical and mental activity are natural in the different periods of child life. Some of the things which are characteristic of the modern as contrasted with the primitive man are sedentary habits, manual dexterities requiring finely co-ordinated movements both of the eyes and fingers, increasing devotion to written language and books as contrasted with spoken language, the lessened dependence upon the memory, the increasing subjectivity of mental life as contrasted with the purely objective life of the savage, and the increased importance of reflection, deliberation, and reasoning, with decrease of impulsive and habitual action. These things, then, we should expect to belong to the later period of child life, and studied which involve these activities will not be economically pursued in the elementary school grades. These laws are wholly overlooked in our traditional school curriculum. In practice we are saying to the young child: "Man is a sedentary, reading, writing, thinking, reasoning being, possessing the power of voluntary attention. I am to educate you to be a man. Therefore you must learn to sit still, to read, write, think, reason, and give attention to your work." The child of six or eight years is therefore given a book or pen, and put into a closely fitting seat and left to give attention to his work. This is precisely as if the mother should say to the infant at the beginning of the period of creeping: "You are a man, not a brute. Men go upright, not on all fours. You must walk, not creep."

I wish to call especial attention to the fact that it is only late in the history of the race that language has passed to its written form. Man is indeed now a reading and writing animal, but only recently has he become so. It is only since the invention of printing and the wide dissemination of books, magazines, and newspapers that reading has become a real determining factor in the life of the people. Even now the human organism is engaged in adapting itself to the new strain brought upon the eyes and fingers in reading and writing. We can understand, therefore, that it will demand a considerable maturity in the child before he is ready for that which has developed so late in the history of the race. The language of the child, like that of the primitive man, is the language of the ear and tongue. The child is a talking and hearing animal. He is ear-minded. There has been in the history of civilization a steady development toward the preponderating use of the higher senses, culminating with the eye. The average adult civilized man is now strongly eye-minded, but it is necessary to go back only to the time of the ancient Greeks to find a decided relative ear-mindedness. Few laboratory researches have been made upon the relative rapidity of development of the special senses in children, but such as have been made tend to confirm the indications of the "culture epochs" theory, and to show that the auditory centers develop earlier than the visual.

More and more attention is given in our elementary schools to the subject of language—more, as some think, than the relative importance of the subject warrants; but without discussing this question, it is indubitably shown by child psychology that it is the spoken language which belongs to the elementary school. The ear is the natural medium of instruction for young children, and all the second-hand knowledge which it is necessary that the child should receive should come to him in this way. It should come from the living words of the living teacher or parent, not through the cold medium of the printed book. In the elementary school, then, the child may be instructed in language as it relates to the ear and the tongue, and this is the real language. He may be taught to speak accurately and elegantly, and he may be taught to listen and remember. He may study in this way the best literature of his mother tongue, and get a living sympathetic knowledge of it, such as can never come through the indirect medium of the book. Indeed, this language study need not be limited to the mother tongue. There is no age when a child may with so great economy of effort gain a lasting knowledge of a foreign language as when he is from seven to eleven years old.

When the spoken language has been mastered in this way, and when the child has arrived at the reading and writing age, language in its written form may be acquired in a very short time, and that which now fills so many weary years of school life will sink into the position of comparative insignificance in which it rightfully belongs. Reading and writing have usurped altogether too much time. In the schools of to-day there is a worship of the reading book, spelling book, copy book, and dictionary not rightfully due them. By dropping the study of letters from the lower grades much needed time may be found for other timely and important subjects, such as Nature study, morals, history, oral language, singing, physical training, and play.

One of the greatest goods which would follow the banishing of the book from the primary and elementary schools would be the cultivation of better mental habits. Children suffer lasting injury by being left with a book in their seats and directed to "study" at an age when the power of voluntary attention has not developed. They then acquire habits of listlessness and mind-wandering afterward difficult to overcome. They read over many times that which does not hold their attention and is not remembered. Lax habits of study are thus acquired, with the serious incidental result of weakening the retentive power which depends so much upon interest and concentration. With the substitution of the oral for the book method, reliance upon the memory during the memory period will permanently strengthen the child's power of retention.

The period between the ages of five and ten years is an important one in the child's life. It is the time when the "let-alone" plan of education is of most value, for the reason that nearly all our educational devices beyond the kindergarten are more or less attempts to make men and women out of children. If the child at this age must be put into the harness of an educational system, his course of study will not be impoverished by the omission of reading and writing. To teach him to speak and to listen, to observe and to remember, to know something of the world around him, and instinctively to do the right thing, will furnish more than enough material for the most ambitious elementary school curriculum.

SOILS AND FERTILIZERS.[46]

By CHARLES MINOR BLACKFORD, Jr., M. D.

The word "soil" is used in several arts and sciences to denote the material from which something derives nourishment. The meat broths and jellies on which bacteria are grown are soils for them, as the earth of a field is a soil for the ordinary farm crops; but in general we mean by soils the various mixtures of mineral and organic substances that make up the surface of the earth.

The object of this paper is to show as briefly as possible the way it was formed, of what it is composed, the manner in which it nourishes plants, and the rules that should guide us in replenishing its nutritious matter when exhausted. So broad a field can be but lightly touched, and the effort will be to give only hints from which rules for specific cases may be deduced.

When a sample of ordinary fertile soil is analyzed, it is found to consist of a number of minerals, of carbon, nitrogen, and phosphorus in various combinations, water, and certain other ingredients dependent on the locality. Among the minerals the most important are potassium, sodium, lime, iron, and silicon, and the history of these is of the greatest interest.

Scientific students are generally agreed that the surface of the earth is but a shell inclosing a liquid, or at all events a highly heated interior. Originally the whole mass was fluid, but the surface has cooled more rapidly than the interior, and so a firm crust has been formed. As the central mass cooled, it contracted, and the crust became wrinkled and folded, as does the skin of an apple as its pulp dries, and, by this folding, great ridges were thrown up in some places and vast depressions formed in others. When the crust became cool enough for water to remain on it, most of the depressions were filled by it, and the "dry land appeared," not only on the crests of the ridges, but on the elevated plateaus about them, and thus oceans and continents were formed.

Had one of us seen the earth at that time he would have been loath to select it as a residence. Rugged, rocky ranges of precipitous mountains surrounded by stretches of naked rock made the landscape. Dense clouds from the tepid oceans dashed against the icy peaks, and torrents of water rushed back to the sea. Where the slopes permitted, the glaciers spread over wide areas, for no vegetation checked the rapid radiation of heat, and night brought bitter cold. The crust waved and fluctuated over the liquid interior as does thin ice under a daring skater, and as it fell the sea rushed over the land, only to flow elsewhere as the depressed area rose again. The freezing and thawing and the effects of wind and water in time produced a change. The rocks were riven and broken to powder, their nearly vertical slopes became less steep, and instead of bare rock the earth showed dreary morasses and stretches of sand.

Over these marshes vegetation began to thrive. In the sea there lived then, as now, a teeming population, animal, vegetable, and living beings that can with difficulty be assigned to either of these classes. Each of them, however, contained carbon, and many had built lime, phosphorus, nitrogen, and other valuable substances into their bodies. Where food was abundant these grew in vast numbers, and though many are infinitely small singly, their aggregate mass is enormous. Among the tiny organisms is one called the Globigerina, a being so small as to require a microscope to study it, but in the past, as now, growing in great numbers in the sea. The animal is soft and jellylike, but it forms an outside skeleton of shell of carbonate of calcium or chalk, a structure that protects it living, but entombs it dead. When death comes, the little Globigerina sinks to the bottom, and its tiny shell helps to cover the sea floor.

In the days of long ago these lived as now, and when some convulsion of Nature lifted the bottom of prehistoric seas, the Globigerina ooze was lifted as well, and thus the "limestone" formed. In our land a bed of this kind extends from Alabama to Newfoundland; thence, as the "telegraphic plateau," it passes under the Atlantic, rising into the chalk downs and cliffs of England; then, again dipping under the sea, it passes through Europe, and finally furnishes the marble quarries of Greece. Heat, water, and chemical action give a ceaseless variety to the forms of the limestone, but wherever found it shows the former seat of an ocean.

As soon as the "ooze" was lifted from below the sea it began to change. Some has been exposed to heat and has crystallized into marble, but for our purposes the most interesting changes have been wrought by water. Chalk, limestone, and marble—for these are chemically the same—are almost insoluble in pure water. But water is rarely pure; it dissolves many things, and among them the carbonic-oxide gas that every fire, every animal, every decaying scrap of wood is pouring into the atmosphere. The rain, charged with this gas, dissolves the limestone, but when the gas escapes the lime falls, as you know happens when "hard" water is boiled, for the heat drives off the gas. By this solution, however, the lime is scattered widely through the soil, and is rarely lacking in untilled earth.

Besides lime, phosphorus is necessary in a good soil. This is widely spread in Nature, but its great reservoir is the ocean, that boundless mine of wealth. Many marine animals have the power of building it into their tissues, and the shells of oysters and other mollusks, the bones of nearly all animals, terrestrial and marine, and parts of other organisms, are composed of phosphates to a greater or less degree. In the ceaseless changes of level the primal oyster beds and coral reefs are raised to the surface or far above it, and the slow action of time begins to tear down the deposits and spread them wide-cast. Since that far-off time "in the beginning" no new matter has been put on earth save the small amounts of the meteorites, and the economy of Nature can allow not one atom to lie in idleness, but calls on each one to play its part ceaselessly, "without haste and without rest." A certain amount of a substance is disseminated through the earth; by rains it is washed into the streams, and thence to the sea. Here plants or animals eagerly await it, and by means of them it is again restored to the land, to begin again its endless round.

The metals most necessary for plant life are potassium, sodium, and iron; indeed, the very name of the first shows its importance. If the ashes which contain all the mineral constituents of plants be put in a vessel and water poured on them, a solution of lye will percolate through the mass. The word lye is an abbreviation for alkali, and when chemistry became sufficiently advanced, a metal was discovered in this lye to which the name potassium—i. e., potash-metal—was given. If seaweeds be burned and leeched in the same way we can obtain from the lye another metal, sodium, that is much like potassium, and that is one of the most widely spread substances on earth as its chloride, or common salt.

Potassium and sodium enter into the composition of many rocks, and as these become eroded by weather they are scattered through the soil, whence their salts are extracted by rootlets and enter into the formation of vegetable tissue.

Behind these stands iron. The green coloring matter of plants is a very complex substance known as chlorophyll, the duty of which is to take carbonic oxide from the air, utilize the carbon, and restore the oxygen. Iron enters into the composition of chlorophyll, and to it is due the brown color of dead leaves. This metal is well-nigh universal, all the reds and browns in soils and rocks being made by it, and so it is rarely lacking anywhere.

So much for the metals in soils; but, important as they are, plants can not live on them alone. Among the nonmetallic bodies phosphorus stands high among essentials, and for it we are indebted to the sea and the interior of the earth. Many living creatures extract phosphorus from the sea water—combine it chiefly with lime, and use the phosphate for making skeletons or shells, as the case may be. After the death of the possessors the bones or shells sink to the bottom, as do the Globigerina, and in time are either lifted up, as were the limestones, and form "phosphate beds" like those of Georgia and Florida, or are dredged up and ground into powder with bones of land animals.

Much of the matter forced up from the interior of the earth contains phosphorus; indeed, it is the bane of Southern iron ores; but though iron masters dread it, farmers welcome it, as the rains and frosts crumble the phosphatic rocks and add them to the mass of débris that forms our soil.

Now let us take a test tube and put into it lime, potash, soda, iron, silicon, or sand, and phosphorus, add to it a grain of corn, and watch results. Under suitable conditions of warmth and moisture the grain will sprout, but when the store of food laid up in it is exhausted our little plant will die. It is obvious that something else is needed for a soil, and analysis shows that it is nitrogen, the gas that forms nearly four fifths of our atmosphere—a gas useless, as such, to animals, but essential to plants. Nitrogen is abundant in Nature. Besides being nearly four fifths of the air, it forms twenty-two per cent of nitric acid, forty-five per cent of saltpeter or niter, eighty-two per cent of ammonia, and about twenty-five per cent of sal ammoniac. Plants can not use nitrogen in its pure form, but one or another of these forms will be found in the soil, whence it may be extracted.

Now we have the chief articles of plant food, and it is necessary to know how they are to be used. A plant usually consists of two parts, one that appears above ground, bearing branches, twigs, and leaves, and another that remains below ground. It is this latter that concerns us now, and it is worth study. This lower part consists of a number of twigs called rhizomes, from which proceed a vast number of fine, threadlike rootlets, and these are the mouths of the plant, through which it draws nourishment from the earth about it.

Before any living thing can use nourishment from without, it must be dissolved, and this solution requires much preparation at times. Men, and other animals with a wide range of food stuffs, effect this by the secretions of the digestive organs; but most plants have no digestive apparatus, strictly speaking, and were they supplied with an abundance of the foods they most need, they would starve unless the food were in a suitable state for absorption.

The way in which Nature effects this solution is the key to many of her secrets, and it has been understood only within the past few years. If we have a piece of meat freshly taken from an animal we find it firm, coherent, and almost odorless. If it be put into a warm, moist chamber for a few days a great change comes over it, and it becomes soft, offensive in odor, and liable to fall to pieces. We say that it is rotten or putrid. If a bit of it be put under a microscope, it is seen to be teeming with bacteria, and these are responsible for the decay. Now, if a specimen of earth be examined, we find that it contains bacteria, that attack all kinds of organic matter, tearing it to pieces to get their food, and making many different things out of what is left. There is one sort of ferment that grows in apple juice and splits the sugar into alcohol and carbonic acid, forming "hard cider," and if the fermentation stops at this point the well-known drink results. However, there is another ferment called "mother of vinegar" that may get in, and, if so, a different kind of fermentation is started that forms acetic acid instead of alcohol; or the bacteria of decomposition may come in and the whole go back to its elements.

There is a wonderful provision of Nature shown in these stages. The bacteria—the organisms that produce decay—can not live in a strong sugar solution, but the ferments, like common yeast, can live in it, and they split the sugar into alcohol, carbonic oxide, and other things. In these another set can live, and when the first have died of starvation or from the alcohol they form, the second set step in and turn the weak alcohol into acetic acid. Acetic acid is a preserving agent, as our sour pickles show, but if it is not too strong there are some organisms that can live in it, and the whole process ends in decay. Now, it should be noticed that each of these organisms paves the way for the next by converting an unsuitable food stuff into a suitable one.

This familiar example indicates the lines on which Nature works. It is the same everywhere, and shows the advantage of specialization, of allowing some one with peculiar facilities for performing an act to do that exclusively, that others may profit by his skill. So long as each man sought and killed his food, cooked his meals, made his own clothing, weapons, and implements—in a word, lived alone—advance was impossible. It was only when he who was most skillful with the needle made garments for the hunter in exchange for a haunch of venison, that the hunter could practice marksmanship, and the tailor design a new cut for the mantle with which the warrior might dazzle the daughter of the arrow maker. It is the same in Nature. Some organisms possess powers of elaborating certain materials of which others are quick to avail themselves. Plants can manufacture starch, an article needed by animals, but of which their own capacity, so far as producing it is concerned, is very limited, and thus animals find it advantageous to avail themselves of these stores instead of taxing their own resources. Similarly, plants need the organic matters of the animal bodies, and wise agriculture supplies carbon, nitrogen, and other articles of food in the shape of animal and vegetable refuse. But this matter requires digestion; it must be made soluble before it can be absorbed, and but few plants can effect this solution unaided. The "Venus's flytrap," the sundew, the wonderful "carrion plant," and others, are equipped with elaborate apparatus by which they are enabled to capture, kill, and literally digest the insects that supply them with nitrogeneous food, but these are exceptional cases. Nature usually employs other agents.

The action of bacteria in causing decay has been said to be in general similar to fermentation—that it is effected by the bacteria in seeking their food. If oxygen be abundant, putrefaction occurs; if it be scant or absent, then fermentation takes place, for the tiny organisms require oxygen, and, if the air fails them, they pull to pieces the organic matters near them to obtain it. In doing this they get the nitrogen into such shape that the plants can use it, and thus digest their food for them. All organic matter contains carbon, hydrogen, and oxygen as a general rule, and to these are often united phosphorus, sulphur, nitrogen, and others, making very complex arrangements, veritable houses of cards, in fact, only held together by the strange power of life. When a leaf falls or a bird dies, some of these combinations are broken, and then the bacteria and other lowly organisms have full sway, for living matter is impregnable to all save a few of them. As oxygen or something else is taken out of the complex molecules, the compound falls to pieces, but as in the kaleidoscope the bits of colored glass tumble into endless varieties of symmetrical figures, so do the atoms fall into new combinations. If the keystone of an arch be removed, the stones fall apart; but atoms, unlike bricks or stones, can not stand alone as a rule; they must be united to something, and so, as soon as old associations are dissolved, new ones are formed. These new ones are those needed by plants, and thus is plant food digested.

The term "plant food" has been frequently used, and should now be distinctly explained, for merely stating the chemical elements is not describing the food. When a physician tells a nurse to feed a patient he does not order so much carbon, nitrogen, phosphorus, and the like, but specifies a soup, certain vegetables, and so on, detailing every particular; and the same should be done for vegetable invalids.

In medical practice a condition is recognized that is called scurvy. It is not exactly starvation, but is produced by lack of some food materials usually supplied by fresh vegetables. If scurvy appears at sea, no amount of meat, bread, cakes, or pastry will stop it; vegetables, and they only, will stay it. Sometimes a similar condition prevails among crops: some ingredient in a soil is lacking, and the others may be supplied indefinitely without giving the desired relief. To this may be attributed much of the fault found with fertilizers; for if the soil does not need a particular compound it is useless to apply it, and an excellent fertilizer is often blamed for not producing a crop on land already overstocked with it and crying for something else.

Let us suppose a field on which cotton has been grown for many successive years until it has become exhausted. Analysis shows that a crop yielding one hundred pounds of lint to the acre removes from the soil:

Nitrogen20.71pounds;
Phosphoric acid8.17"
Potash13.06"
Lime12.60"
Magnesia4.75"
———
Total59.29 "

The weight of the whole crop from which these figures were taken was eight hundred and forty-seven pounds, so that cotton exhausts land less than any staple crop, if the roots, stems, leaves, etc., be turned under and only the lint and seed be removed. Of these the lint (one hundred pounds) takes 1.17 pound from the soil, and the seed 13.89 pounds, making 15.06 pounds net loss.[47] But ignoring returns that may be made in the shape of cotton-seed meal, etc., and lime, with which our soils are abundantly supplied, we see that nitrogen, phosphoric acid, and potash have been removed. Suppose the owner puts bone meal on his exhausted land: the phosphoric acid in the bone will supply one need, and an improvement results. On the strength of this, bone meal will be loaded into the soil again, and let us suppose the deficit not yet made up, the crop again shows improvement. Now, phosphoric acid abounds in the soil, though the deficiency in nitrogen and potash has become steadily greater; so, when the customary bone meal is applied, the crop falls back, because the plants are starving for potash and nitrogen. They are like scurvy-smitten sailors, but many thoughtless farmers would attribute the decline to the maker of the bone meal, and say that its quality was not so high as formerly—an opinion similar to that of a sea captain who would ascribe to the poor quality of salt beef an outbreak of scurvy on his vessel.

As crops of any description extract potash, nitrogen, and phosphoric acid from soils, the question how they are to be replaced is an important matter, and its answer may be most readily found by studying Nature's methods. In parts of the Old World there are fields that are fertile in the extreme after thousands of years of tillage, and it is apparent that mere cultivation does not prove injurious. The tropical forests have something growing wherever a plant can find foothold—a population in which the struggle for food is secondary to that for light and air, and yet the soil supporting this vegetation is marvelously rich. Every leaf that falls remains where it fell until in the warm, moist, half-lighted forest it becomes a little heap of mold. The bacteria of decomposition require warmth and moisture for their life; light is deleterious to them, but they thrive in the dense shade of the jungle. The tangled web of roots, weeds, and vines retains the rainfall, retarding evaporation, and preventing both droughts and freshets. Receiving dead and broken leaves, boughs, and other vegetable products, and spared the washing of violent torrents, the forest is inestimably fertile.

On a smaller scale this goes on universally. The annual weeds, deciduous leaves, and such matter, fall prey to molds and bacteria, by which they are made soluble. Snows and rains bear the products into the soil, and there other bacteria, clustering around the roots, form the acids needed to complete solution. Every one knows that "well-rotted" manure is better than that which is fresh, and many wonder at this, but the reason is apparent. In feeding delicate patients, physicians often prescribe predigested foods or the digestive ferments to aid enfeebled assimilation; and similarly the manures that have been thoroughly acted on by bacteria, or containing those capable of producing the matters that plants need, are of most value for nourishing vegetation.

In producing an article of any sort, the cheapness and ease with which it can be made is largely dependent on the shape in which the raw material reaches the factory. If a foundry can procure iron that needs only to be melted and cast, the owner can fill his orders more readily than would be possible if he had to reduce the metal from the ore; and Nature uses this principle over and over again. The importance of nitrogen to plants and its abundance in Nature have been mentioned, but it has also been said that plants can not use it directly, as most animals do with oxygen. The tiny bacteria intervene, and this they do in two ways: first, by causing decay of animal or vegetable matter containing nitrogen, and by this decay producing substances that plants can absorb; and, secondly, by producing little nodules or "tubercles" on the rootlets, through which the plant can take up nitrogen.[48] Now, when a plant is sated with nitrogen, it ceases to form these tubercles, and their formation is a sure sign that the plant is craving this article of food. When it is supplied, and its own life is ended, these form reservoirs from which other plants may be supplied, as new castings may be made from broken wheels. The great value of "green manuring" depends on the store of available nitrogen so laid up, but it is open to failure in one direction. The liability of fermentation to go to the acid stage from contamination with acid-forming ferments has been mentioned, an accident the possibility of which is impressed on us from time to time by sour bread; and similarly the organic matter turned under may undergo acid fermentation, rendering the ground "sour" and unfit for cultivation.

The limits of this paper forbid the consideration of special fertilizers, but from the general principles laid down the rules for any special case may be deduced. A soil should contain a sufficient amount of potash, soda, lime, iron, and a few other minerals; phosphoric acid, nitrogen, organic matter, and, for some special crops, some other ingredients may be needed. When the soil needs renewing, there are two ways of accomplishing it. One way is to guess at what is needed; to buy fertilizers at high prices, without inquiring whether the soil needs the substances in that particular brand or not. Though very common, this is not a good plan. It is as though a physician were to give a patient any drug that was convenient, without inquiring into the disorder or the needs of the system, and it is followed by much the same result. That acid phosphate gave Farmer A a good crop, is no reason that Farmer B's land is also deficient in phosphorus. The same reasoning would teach that a heart stimulant that rouses a patient from shock would benefit one in danger of apoplexy, where the least increase in heart force might be fatal. A physician using such reasoning as the basis of his practice would not be considered a master of his art; and were he to attribute the fatal outcome of his logic to the poor quality of his stimulant, he would display criminal ignorance of drugs as well as disease; yet it is very common to see farmers put guano on a soil begging for potash, and then heap execration on the head of the dealer who sold the guano when the crop failed. To revert to a simile used above, a captain must not blame the salt pork for scurvy.

The other way to buy and use fertilizers is to ascertain what a certain crop needs; then find out whether these be in the soil, and to what extent. With these data the deficiency may be made good without the wasteful cost of the former method. State and Federal Departments of Agriculture furnish their aid freely and gladly, and already the signs are seen of the day when agriculture will take its place among the semiexact sciences, and the present haphazard methods will become obsolete.