LIBRARY 
 
 UNIVERSITY OF CALIFORNIA. 
 
 GIFT OK" 
 
 Mrs. SARAH P. WALS WORTH. 
 
 Received October, 1894. 
 Accessions Afo.LftT Cfes M). 
 


 ?lrsr*$s 
 
 foftJTIESITT] 
 
 
SCIENTIFIC AGRICULTURE, 
 
 OR THE ELEMENTS OF 
 
 CHEMISTRY, GEOLOGY, 
 
 BOTANY AND METEOROLOGY, 
 
 . ; o t 
 
 PRACTICAL AGRICULTURE 
 
 BY M. M. RODGERS, M. D., 
 AUTHOR OF "AGRICULTURAL CHEMISTRY," "PHYSICAL EDUCATION 
 
 AND MEDICAL MANAGEMENT OF CHILDREN," &C. 
 
 ILLUSTRATED BY NUMEROUS ENGRAVINGS, & A COPIOUS GLOSSARY. 
 
 Nature maintains uniformity in the operation of all her laws, and produces nothing 
 by chance : whenever, th- refore, we observe an apparent exception to this prin- 
 ciple, it is due to deficiency of knowledge or error in conclusion. And who- 
 tver pi'actically disregards this truth, and rests his hopes upon contingent 
 events, will be compelled to correct his error at his own cost. 
 
 ROCHESTER: 
 
 PUBLISHED BY ERASTUS DARROW, 
 
 CORNER OF MAIN & ST. PAUL STREETS. 
 
 1848. 
 
;l/J^ 
 
 JOEHUC: 
 
 Entered according to Act of Congress, in the year of our Lord 
 one thousand eight hundred and forty-eight, 
 
 BY ERASTUS D ARROW, 
 
 in the Clerk's Office of the District Court of the Northern District 
 of New York. 
 
 BESTON & FISHER, PRINTERS, 
 Reynolds' Arcade, Rochester. 
 
TO 
 
 HON. ZADOC PRATT, 
 
 THIS VOLUME IS RESPECTFULLY DEDICATED BY 
 
 THE AUTHOR. 
 
PREFACE 
 
 No apology ought to be required for the appearance of a work like 
 this : the importance of the subjects discussed should secure at least an 
 impartial examination. 
 
 But from the humiliating consciousness which the author feels of his 
 own inability to do justice to so difficult a task, he is induced to say 
 something by way of explanation, in order if possible, to put himself 
 upon friendly terms with his readers. The importance of an enter- 
 prise, however, furnishes no reason to an incompetent person for at- 
 tempting its prosecution. 
 
 If, after the book has passed the trial of the public prosecutors in be- 
 half of science, the critics, they shall decide against it, the author has 
 no alternative, but must plead guilty: neither will he claim indulgence 
 on the ground of its being the first offence, or plead, in extenuation of 
 his fault, his ignorance of the law in relation to the case. 
 
 But a sincere desire, (augmented by personal considerations,) to aid in 
 the diffusion and cultivation of science, has induced him to make au 
 effort, which may not be regarded by liberal minds as altogether in- 
 excusable. 
 
 The practice of issuing crude and imperfect books, is a fault quite 
 too prevalent at the present day : there are already too many mere 
 alphabets of science, abridgements, and books of learning made easy ; 
 their tendency is to make conceited and superficial scholars, without 
 the labor of personal observation and patient study. 
 
 But the elements of any science may be so explained and arranged, 
 as to give a synopsis which may be of much service to the student ; 
 and when these elements are learned, he has laid the foundation for 
 future advancement by his own observation. Plainness and brevity have 
 been studied, and technical language avoided as much as possible ; a 
 glossary has been appended which explains such technical terms as 
 
 1* 
 
VI PREFACE. 
 
 .were indispeusible. It is needless to say, that a treatise on science 
 cannot be entirely divested of all difficulties, and couched in language 
 which is at once simple and expressive. 
 
 It was deemed better to give the rudiments of each sciencej in a 
 separate systematic treatise, than to intersperse them through the whole 
 book without order or method. A reader will profit more to have the 
 principles given in this way, that he may apply them himself, than he 
 will to have a perfect system of agriculture made up of them all, with- 
 out systematic arrangement. 
 
 Another advantage of such a book is that the general reader may ob- 
 tain the first principles of Chemistry, Geology, Botany or Meteorology, 
 without reading a large amount of agricultural science, which, to him, 
 may be of little use. 
 
 The author is aware that an amount of matter is embodied in thi.s 
 book sufficient to make, when extended and amplified, several such 
 volumes: but nearly all books contain much by way of explanation 
 and speculation, that could well be omitted. Some things may be found 
 in the book which do not appear to have any direct connection with 
 practical agriculture; but a little observation shows that the science* 
 discussed all have such a connection and relation, that to omit any prin- 
 ciple would destroy the harmony of the whole system. 
 
 The best authorities have been consulted, so that whatever may be 
 open to criticism must be judged by their testimony. It is desirable 
 that the agricultural community, for whose more special use the book 
 is designed, may be disposed to favor the enterprise: with all its faults, 
 therefore, it is respectfully committed to them and the public; with 
 no claims except to their forbearance, and no means of propitiating 
 their favor, beyond its own merits. 
 
 M. M. RODGERS 
 
 Rochester. August. 1848. 
 
AUTHORITIES CONSULTED, 
 
 KANE'S CHEMISTRY, 
 
 FOWNE'S 
 
 SILLIMAN'S " 
 
 TURNER'S " 
 
 LIEBIG'S AGRICULTURAL " 
 
 LYELL'S GEOLOGY, 
 
 HITCHCOCK'S " 
 
 COMSTOCK'S " 
 
 GRAY'S BOTANY, 
 
 WOOD'S " 
 
 EATON'S " 
 
 MULLER'S ELEMENTS OF PHYSICS AND METEOROLOGY,. 
 
 BOUSSINGAULT'S METEOROLOGY, 
 
 BRANDE'S ENCYCLOPEDIA, 
 
 LARDNER'S LECTURES ON SCIENCE, 
 
 ENCYCLOPEDIA BRITTANICA, 
 
 JOHNSTON'S AGRICULTURAL CHEMISTRY, 
 
 BOUSSINGAULT'S RURAL ECONOMY, 
 
 THAER'S PRINCIPLES OF AGRICULTURE, 
 
 PETZHOLDT'S LECTURES ON AGRICULTURE, 
 
 COLMAN'S EUROPEAN AGRICULTURE, 
 
 GARDNER'S FARMER'S DICTIONARY, 
 
 REPORT OF THE REGENTS OF THE UNIVERSITY OF N. YORK, 
 
 TRANSACTIONS OF THE N, Y, STATE AGRICULTURAL SOCIETY, 
 
ACKNOWLEDGEMENTS. 
 
 THE Author acknowledges with pleasure, the valuable assist- 
 ance of several scientific and practical gentlemen, to whose 
 names he is permitted to refer viz: 
 
 CHESTER DEWEY, M. D., Professor Chemistry, Geology, &c- 
 JOHN J. THOMAS, Esq. 
 
 L. WlTHEREL, A. M. 
 
 P. BARRY, Esq. 
 L. B. LANGWORTHY, Esq. 
 AARON ERICKSON, Esq. 
 D. D. T. MOORE, Esq. 
 
 1C., GOODSELL, Esq. 
 
 Several of the above named gentlemen have examined por- 
 tions of the manuscript of this book, and made such sugges- 
 tions and corrections as they thought necessary. 
 
 They should not, however, be held responsible for any state- 
 ment which may appear to be erroneous, or for the selection* 
 and arrangement of the topics discussed. M.. M. E. 
 
INTRODUCTION. 
 
 AGRICULTURE is doubtless one of the oldest, most honorable 
 and important pursuits among civilized nations. Without it 
 the food of man must have been limited to the flesh of wild 
 animals and the spontaneous productions of the earth : Com- 
 merce could not exist to any extent; the arts and sciences 
 would be almost unknown ; and society could not advance in 
 improvement beyond a refined state of barbarism. But the 
 culture of the soil enables men to produce more of the neces- 
 sary food than they require, so that a part only are required 
 in this pursuit, while the remainder are enabled to turn their 
 talents and ingenuity to some other useful calling, the products 
 or services of which are given to the agriculturist in exchange 
 for food. 
 
 This is the origin of the division of labor, which is at the 
 foundation of all political economy and true governmental 
 policy : this division and subdivision of labor is adopted more 
 extensively the more a nation becomes enlightened and pros- 
 perous. Without such distribution of pursuits, little wealth 
 could be accumulated by nations or individuals. In order 
 that every man should be independent of the services of all 
 
12 INTRODUCTION. 
 
 others, he must manufacture and produce every thing with 
 his own hands which in the social and civilized state of society, 
 he receives from them : this would so occupy his time and 
 talents that he could only produce the bare necessities of a 
 primitive life: his food must be obtained by hunting, fishing 
 and digging roots, his clothing, the skins of animals, his 
 shelter, a rude hut, and his only beverage" water. 
 
 From this mode of living, also, the earth must soon contain 
 more inhabitants than could subsist on its spontaneous food, 
 and part must die of starvation. 
 
 The art of agriculture has been known and successfully 
 practiced by some of the oriental nations from remote ages. 
 
 The Chinese appear to have a good practical knowledge of 
 soils, and have, by industry and skill in agriculture, sustained 
 a population of an almost incredible number: and, although 
 they are supposed to be but little removed from barbarism, 
 they are said to excel all other nations in the amount of food 
 which they produce from a given space of soil. 
 
 That the ancient Romans had an amount of practical know- 
 ledge equal to most nations of the present day, is evident from 
 the following passages from Virgil's Georgics. Thus in his 
 first Georgic he alludes to the rotation of crops, the art of 
 manuring and burning land. 
 
 " Yet shall thy lands through easier labor rear 
 Fresh crops by changeful produce year by year, 
 If rich manure new life and nurture yield, 
 And ashes renovate the exhausted field. 
 Thus interchanging harvests, earth repair; 
 Nor lands unplowed, meantime no profit bear. 
 Much it avails to burn the sterile lands, 
 And stubble, crackling as the flame expands; 
 Whether earth gain fresh strength or richer food, 
 Or noxious moisture, forced by fire exude; 
 Whether it draw through many an opening vein, 
 Juice to fresh plants that clothe anew the plain, 
 Or brace the pores, that pervious to the day, 
 Felt the prone sun's intolerable ray, 
 To piercing showers the expanded fissure close, 
 And the chill north that blisters as it blows." 
 
INTRODUCTION. 13 
 
 Again in the second Georgic we have evidence that they 
 studied the nature of, and adapted various crops to different 
 qualities of soils. 
 
 " Now learn the soils, the nature of each field, 
 
 What fruits their varying strength and virtue yield; 
 Know first, the ungenial hill and barren land, 
 Where sterile beds of hungry clay expand, 
 And thorns and flints deface the rugged earth, 
 Demand the long lived plants palladian birth." 
 
 In the other three Georgics we learn that the Romans 
 understood horticulture, gardening, the management of do- 
 mestic animals and bees, and the extermination of noxious 
 weeds and insects. Limited as were their mechanical means, 
 and their knowledge of chemistry, geology and botany, still 
 their skill and success would seem to exceed that of agricultu- 
 rists of the present day ; and in fact we may almost believe 
 that the practical knowledge of farming has retrograded since 
 that time. If this is the case, it cannot be because science 
 has been detrimental to modern practice, but is rather owing 
 to their close observation of nature, and their attentive indus- 
 try. It is no argument against the art of culture being 
 conducted on scientific principles : the success of practical men 
 is due to the discovery and carrying out of these principles, 
 although they may be ignorant of them, and may not recog- 
 nize them as such. The idea that the farmer requires nothing 
 but practice and experience to ensure success, is as erroneous 
 as to suppose the school teacher requires no knowledge of 
 arithmetic or grammar. Not a blade of grass can be made to 
 grow without perfect conformity to the laws of nature, and 
 still the farmer arrogates to himself the credit of success in an 
 operation, the philosophy of which he neither does, nor desires 
 to understand. 
 
 The failures of practical men in attempting to apply some 
 new principle, are owing to want of knowledge and skill in 
 combining science with practice, and not to any discrepancy 
 
 2 
 
14 INTRODUCTION. 
 
 in facts. It must be admitted that many of the processes of 
 successful farming are not yet explained, and many things, 
 true in theory, are not, as yet, demonstrated in practice, but 
 this does not justify the conclusion that nature is not entirely 
 consistent with herself. Men have been too much disposed to 
 consider certain phenomena as " mysterious and past finding 
 out," and thus have ended their investigations. 
 
 But the time has arrived when the application of science is 
 the only means of any great success in agriculture ; and those 
 who reject this light must be content to plod their way 
 through life like one groping in darkness, be considered as 
 wanting in intelligence and enterprize, to accomplish but 
 little and barely subsist, while the scientific farmer reaps 
 abundant harvests. However strong the prejudice may be 
 against what is absurdly called "book farming," the old 
 empyrical system cannot, in a country where the population is 
 dense, the soil becoming exhausted, and manures scarce, 
 maintain a successful competition with one which is conducted 
 upon scientific principles. 
 
 No art or profession presents more points of contact with the 
 various branches of natural science than that of agriculture ; 
 and in no pursuit is education regarded as of less importance. 
 While in all the learned professions and many mechanical 
 arts, education is considered indispensible, the farmer whose 
 knowledge consists of reading, writing, and a few empyrical 
 dogmas of his ancestors, is supposed to be abundantly quali- 
 fied for his calling. Trained and educated in all the old and 
 established practices of his fathers, he is sceptical upon all 
 that is written, and slow to adopt any new improvement in 
 practice. 
 
 An ancient philosopher being asked what things were most 
 propei for boys to learn, replied, " Those things which they 
 intend to practice when they become men." Now inasmuch 
 as agriculture involves the same branches of knowledge as 
 
INTRODUCTION. 15 
 
 most other arts and professions, it follows of necessity that the 
 farmer requires the same education and discipline of mind as 
 those do who practice law, medicine, engineering, and the 
 mechanical arts. 
 
 Agriculture should not be looked upon as the end of life, 
 but only as a means of securing the necessary food for subsis- 
 tence: this, as well as all other pursuits, should be adopted 
 with the view of enabling men not only to improve and 
 beautify the earth, but to cultivate the moral, intellectual and 
 social powers, and to fulfil according to their capacity, their 
 proper station among their fellow men. It should not tend to 
 make men mere machines, who toil for the sole purpose of 
 gratifying grovelling and depraved appetites ; but it should 
 elevate and refine to the highest degree of perfection, all the 
 better faculties of our nature. 
 
 A large part of the farming community already recognize 
 the utility of the natural sciences in the cultivation of the soil. 
 
 Some elementary books have been written which have 
 been favorably received by the farming public. Among 
 the natural sciences, Geology has received more attention than 
 any other among this class of men. The connection of this 
 science with agriculture is so apparent to every one who 
 learns but the rudiments of it, that it needs only to be intro- 
 duced, (in treatises which are plain and well arranged,) to be 
 studied and applied in practice. It teaches the origin and 
 nature of all the various soils and rocks, and all great physical 
 changes which are taking place from natural causes on the 
 earth, and beneath its surface. 
 
 Botany is also of much importance: and indeed the agricul- 
 turist and horticulturist are the only persons to whom the 
 study and practical application of its principles are indispen- 
 fitble. It teaches the characters, habits and localities of nearly 
 one hundred thousand different species of plants; it treats 
 
T.6 INTRODUCTION. 
 
 also of their physiology, and explains many of the most 
 interesting processes of vegetation. 
 
 Chemistry is the key which unlocks the great laboratory of 
 nature, and shows us how she performs her complicated 
 processes, and produces all her wonderful phenomena. 
 
 Meteorology investigates all the facts and phenomena per- 
 taining to weather, climate, seasons, temperature, storms, lati- 
 tude, altitude, winds, &c. 
 
 Zoology treats of the habits, localities, depredations and 
 uses of all the objects of the animal kingdom. Comparative 
 anatomy and physiology constitute a branch of zoology which 
 treats of the form, structure, functions, differences and pecu- 
 liarities of all the organs of animal bodies. It is the -basis of 
 all knowledge relative to breeding, rearing, feeding, and 
 curing the diseases of animals. 
 
 Natural Philosophy treats of the properties and dynamic 
 forces of light, air, water, and the mechanical powers, and 
 their application to machinery and other practical purposes of 
 life. Besides these, many other branches of knowledge are 
 indispensible to the education of the accomplished agricultu- 
 rist. The study of astronomy, geography, architecture, politi- 
 cal economy, algebra, geometry, a knowledge of the lan- 
 guages, general literature, and the fine arts to some extent, 
 and in fact we might say, a complete collegiate course, belongs 
 as much to the farmer as to the professional man. 
 
 But the means by which this amount of preparatory educa- 
 tion is to be attained by farmers' sons, are not yet provided. 
 Various plans for agricultural schools have been proposed, 
 none of which have been successful in this country. Where 
 such schools have been established and endowed with compe- 
 tent instructors, library and apparatus, the number of pupils 
 have been a mere fraction of the young men who were 
 destined for agricultural pursuits. While a few are ambitious 
 of high attainments, the great mass are indifferent, or preju- 
 
INTRODUCTION. 17 
 
 diced against what they suppose to be only an innovation. In 
 this way the schools fail for want of patronage, and young 
 are deprived of their education for want of schools. 
 
 But if we are not yet prepared to sustain agricultural 
 schools, some other plan may be available. The teachers of 
 common schools may be educated in scientific agriculture, so 
 as to be able to instruct all such pupils as are designed for 
 this pursuit, in at least the elements of the most necessary 
 branches. In this way the germs of science will be planted 
 and a taste excited, which will lead ultimately to a thorough 
 and systematic course of study. 
 
 This plan, though limited and imperfect in its operation, has 
 the ad/antage of giving to boys, early impressions, and a 
 preference for those studies, which, if proper books are acces- 
 sible, may be pursued in connection with practice in after life. 
 A plan has been proposed for securing the agricultural educa- 
 tion of teachers, which is to establish a professorship of agri- 
 cultural science in the State Normal School. By this means 
 teachers could be educated, who would be competent to teach 
 the science to the extent required in the schools of farming 
 communities. 
 
 Every farm should be considered a chemical laboratory, 
 and every farmer a practical chemist and philosopher : farming 
 would then be honorable and lucrative. Education would 
 give to the cultivator of the soil that dignified confidence and 
 polish which he has a right to possess, and which he now " 
 too often ridicules or envies in men in other pursuits. No- 
 reason exists why rural pursuits should alienate their votaries 
 from the rest of mankind, and give rise to those jealousies and 
 suspicions with which they look upon men of other occupa- 
 tions, or fill the mind with that dogged arrogance which is 
 
 always the offspring of ignorance. 
 
 ' 
 
 The profits of productive farming would, when conducted 
 2* 
 
IO INTRODUCTION. 
 
 scientifically, enable the farmer to accumulate wealth, and 
 enjoy all the comforts and luxuries of refined life. Every 
 community could be made up of the best society, every 
 family could have its fine library and its accomplished sons 
 and daughters: farmers' sons need not leave the favorite 
 pursuit of their fathers, and go into the learned professions, 
 from the erroneous conclusion that they were more honorable 
 or profitable. Farmers' daughters need not despise the 
 delightful and healthful employments of the dairy, the 
 kitchen, or the loom, and seek elevation in the miserable 
 pursuits and fashions of the city. 
 
 Nothing conduces more to the elevation and refinement of 
 the mind than the study of nature ; the man who holds fre- 
 quent communion with nature, and studies and obeys her 
 laws, is always made a better and happier man. 
 
 The more we explore the mysteries of nature, the more are 
 we humbled with the reflection, that to our finite view, only a 
 small part of her works are comprehensible. And when, after 
 years of patient toil, we fancy we have learned most of her 
 laws, we still find the great Author has only opened to our 
 view new vistas to more extensive and unexplored fields of 
 knowledge. 
 
 " Nature is always perfect and unvarying, but man's 
 knowledge is progressive ; consequently in every advance he 
 arrives nearer the truth, yet as far from knowing all nature 
 and her laws as he is from infinity. Exact knowledge consists 
 in those things which can be seen and demonstrated, while 
 in all knowledge of inference there is progression. Opinions, 
 which are often the result of imperfect knowledge, are liable 
 to change, and the mind is never advanced by adopting the 
 opinions of others; for by that means man is never made a 
 thinking being, but rests upon authority In all sciences, the 
 acquisition of new truths exhibits in a new light, the beautiful 
 and harmonious operation of the laws of nature." 
 
INTRODUCTION. 19 
 
 Besides the benefit of mental discipline derived from the 
 study of nature, for which agriculture opens as wide a field 
 as any other pursuit, the charms of rural life are unalloyed 
 by the reflection of ill-gotten gain, and uncontaminated by 
 immoral influences. The farmer has no occasion to review 
 with remorse, a life of injustice to his fellow men, or mourn 
 the loss of fortunes accumulated by an occupation almost 
 necessarily dishonest. The lawyer looks upon his briefs pre- 
 pared for unjust causes, the physician upon the emaciated 
 forms of his patients, and the speculator upon the wealth 
 amassed from the ruined fortunes of others, with the humilia- 
 ting consciousness that they have not, in all cases, returned an 
 equivalent for what they have received. But the cultivator 
 of the soil may pursue his calling with the cheering reflection, 
 that an all bounteous Providence has rewarded his efforts, and 
 through him bestowed means of happiness upon his fellow 
 men. 
 
 The reminiscenses of rural life and scenes are always 
 pleasant: who would not wish to return to the bounding and 
 joyous days of youth, which were spent among woodland 
 scenes, green fields, along the river's shore, on the sunny hill's 
 side, or in the silence of the cool ravine, where every object 
 lent enchantment to the scene, afforded pleasure without 
 alloy, and prepared the mind for the admiration of nature and 
 study of her laws in maturer years. What haunts so sacred, 
 what objects so linked to our affections, as those associated 
 with rural life in childhood. Who that appreciates the 
 quietude and smiling plenty, the balmy air and variegated 
 landscape of the country, would not prefer it to the crowded 
 noisy streets, the pestiferous atmosphere and demoralizing 
 influences of the city. It is in the country alone that man 
 enjoys the beauties of nature, as she spreads them out before 
 him in all their wild luxuriance, or as she patiently smiles 
 beneath the improving hand of cultivation. 
 
20 INTRODUCTION. 
 
 Agriculture is an honorable, a delightful and a glorious 
 pursuit: the first man who lived on earth was an agriculturist, 
 -and agriculture must exist till the last man leaves it. 
 
 But all labor is honorable: the GREAT FIRST CAUSE 
 works, nature works, and every man who enjoys her 
 fruits, ought to hold it honorable to work. When shall the 
 glorious time dawn, that intelligence and true philanthropy 
 shall annihilate the selfish distinction which pride has made 
 between labour and idleness? May that auspicious day soon 
 arrive when the worthless distinctions between mental and 
 physical labour shall cease to exist, which separates man from 
 his fellow man, and all the tenants of earth meet as equal 
 sovreigns of our common inheritance. 
 
NATURAL SCIENCE. 
 
 NATURAL SCIENCE embraces all the objects of the material 
 creation, from the minutest insect, plant or particle of dust, to 
 the most vast of the celestial spheres. This great field of 
 knowledge is divided into Natural Philosophy and Natural 
 History. Natural Philosophy elucidates the laws which gov- 
 ern the phenomena of the material world, and is divided 
 into Chemistry and Physics. Chemistry treats of phenomena 
 which depend upon a change in the constitution of bodies: 
 Physics treats of the dynamical properties and phenomena of 
 bodies, which do not depend on a change in constitution or 
 elements. 
 
 Natural History treats of the character and properties of 
 individual objects : these are divided into three great natural 
 groups called kingdoms, viz. the animal, the vegetable and 
 the mineral kingdom. Natural objects are distinguished also 
 into two great classes termed animate- organic and inanimate- 
 inorganic. All the individuals of each of the primary divi- 
 sions, are again divided or grouped into Classes, Orders, Ge- 
 nera and Species. 
 
 The dividing line between organic life and inanimate mat- 
 ter, is not well defined; between the lowest form of organic 
 life and the most perfect and symmetrical crystal of the mine- 
 
22 NATURAL SCIENCE. 
 
 ral kingdom, however, the distance must be almost immeasura- 
 bly great. Passive motion or change, is the peculiar attribute 
 of inorganic matter: it can neither enjoy life, nor be subject 
 to death : but life and organization are inseparable, to this 
 combination, birth and death, are the necessary and invaria- 
 ble terms of existence. 
 
PART I. 
 
 CHEMISTRY 
 
 CHAPTER I. 
 
 THE science of Chemistry has for its object the investigation 
 of the properties of all elementary and compound substances, 
 their relations and combinations, the agencies by which their 
 changes are effected, and the laws which govern them. The 
 basis on which this science rests, is facts and experiment; and 
 as it is purely a demonstrative physical science, no hypotheti- 
 cal or speculative views can be practically made of any ser- 
 vice to its advancement and application. 
 
 Every change which takes place in the elementary consti- 
 tution of matter in the universe, whether effected by natural 
 causes or by the operations of art, involves a fixed chemical 
 law, and is due to chemical action. 
 
 Chemistry consists of two distinct branches, viz. Analysis 
 and Synthesis. Analysis consists in decomposing a compound 
 body and separating its elements. Synthesis consists in uni- 
 ting simple bodies so as to form a compound substance. The 
 forces which preside over and cause all chemical changes, are, 
 attraction, light, caloric, electricity and magnetism. The rela- 
 tive importance of these several forces cannot be exactly esti- 
 mated in the present state of the science : the question as to 
 
24 SCIENTIFIC AGRICULTURE. 
 
 their individual nature, or identity with electricity, remains 
 unsettled. 
 
 The science of chemistry, which has achieved greater tri- 
 umphs over matter, and conferred more practical knowledge 
 of nature upon civilized man than all other sciences com- 
 bined, has gradually grown out of the superstitious art of 
 Alchemy. 
 
 Modern chemistry, instead of alluring its votaries into a 
 fruitless search after the "philosopher's stone," crowns their 
 investigations with results which tend to the advancement of 
 civilization and the increase of human comforts and happi- 
 ness. Its objects are not limited to the study of abstract laws 
 alone ; but also to the improvement of the useful arts, the 
 cure of disease, the production and preparation of food, the 
 study of the laws of organic life, and finally to every thing- 
 affecting our physical relations to the material universe. 
 
 PROPERTIES OF BODIES. 
 
 CAPILLARITY. 
 
 Capillarity is the force by which small tubes and porous 
 substances absorb and raise fluids above the surface of that in 
 which they are immersed. This force depends upon the cohe- 
 sion of the molecules, or ultimate atoms of the fluid for each 
 other, and the attraction of the solid body for those of the 
 fluid. If we dip the end of a small tube open at both ex- 
 tremities, into a fluid, it will be observed to rise slowly above 
 the surface of the surrounding mass : if one corner of a sponge 
 be dipped into water and allowed to remain, it will by virtue 
 of its capillarity in a little time be saturated ; the water hav- 
 ing been raised by this force against the antagonizing force of 
 gravity. 
 
CHEMISTRY. 25 
 
 COHESION. 
 
 Cohesion is the force by which the particles of a homogene- 
 ous body are held together and resist separation. Caloric is 
 the opposing or antagonizing force of cohesion. " The three 
 different forms which matter assumes, viz. solid, liquid and 
 gaseous, are determined by the degree of the cohesive force 
 existing among the elementary particles." This force is great- 
 est in solids, less in fluids, and least in gases. In gases this 
 force is negative or absent, the particles having a tendency to 
 repel each other. The globular form of the drops of liquids 
 depends upon this force. 
 
 It is easy to conceive that if cohesion were to be suspended, 
 all solids as well as fluids would assume the gaseous form ; 
 the repulsive tendency beingt henu ncontrolled. This can be 
 effected to a certain extent by means of heat : heat overcomes 
 the cohesive power of solids and changes them to liquids : but 
 when the heat is removed, they are again changed to solids by 
 cohesion, as in the case of melted iron : bodies naturally 
 liquid, as water and mercury, are volatilized by heat, and as- 
 sume the gaseous form. The cohesive force acts at insensible 
 distances. 
 
 DIVISIBILITY. 
 
 Matter is capable of being divided into inconceivably small 
 particles. We have, however, no means of determining the 
 question of its infinite divisibility. We can easily imagine that 
 the minutest particle which can be produced by mechanical 
 means, must still have extension, form and weight, and would 
 be divisible, (had we instruments sufficiently delicate,) into 
 other particles, and these again into others, and so on until 
 they totally disappeared from the limit of our conceptions. 
 But we cannot by any process whatever annihilate or destroy 
 the least particle of matter. 
 
 The particles of hydrogen gas, which is itself fourteen times 
 lighter than common air, would, individually present an idea 
 
 3 
 
26 SCIENTIFIC AGRICULTURE. 
 
 almost inconceivable. And still this gas is material, and must 
 be made up of an aggregate of particles. A single grain of 
 gold used in gilding silver wire, is made to cover a surface of 
 1400 square inches, and still the gold upon the millionth of a 
 square inch when examined by the microscope, is distinctly 
 visible. A square inch of gold leaf may be divided into one 
 billion and four hundred millions of particles, and still retain 
 all the characters and color of a large mass. 
 
 Chemical action may be supposed to carry the process of 
 division to a much higher attenuation than mechanical means. 
 A single drop of solution of indigo colors 1000 cubic inches of 
 water, and yet this coloring matter is an aggregate of distinct 
 particles. The fineness of particles has an important effect 
 on the chemical action of one body upon another. Perhaps a 
 more definite idea may be given by the following example. 
 The author had the pleasure of examining with Professor 
 Dewey's improved microscope, some fossil infusoria, which 
 were so small that they appeared like perfectly impalpable 
 powder, and not the least gritty between the teeth. These 
 minute particles of dust when subject to the greatest magni- 
 fying power of the instrument, proved to be the shells of in- 
 fusoria resembling in shape the sow-lug and trilobite, and ap- 
 parently from three to four inches in length and one inch in 
 width. And still, minute as they were, they must have had 
 when living, all the organs and machinery of animals of large 
 size. 
 
 GRAVITY. 
 
 The term gravity, in natural philosophy, signifies weight : it 
 is that force or attraction in nature which causes all bodies to 
 move towards the earth when not prevented by some other 
 force. The gravitating force of a body is in proportion to the 
 quantity of matter which it contains. The force of gravity in- 
 creases in falling bodies, in proportion as they approach the 
 earth. Bodies of the same bulk, do not always possess the 
 
CHEMISTRY. 27 
 
 same gravity or weight, owing to difference in density : thus 
 lead weighs about twelve times as much as cork, bulk for 
 bulk, that is, it contains twelve times as much matter, and 
 hence it has twelve times the gravitating force. 
 
 What this gravitating force is, has not been determined ; all 
 we know in relation to it is, its effects. Specific gravity, de- 
 notes the weight of any body, compared with some other body 
 of equal bulk, which is taken as a standard and is reckoned at 
 unity. Water is taken as the standard of specific gravity for 
 solids and fluids, while atmospheric ah- is the standard from 
 which the weight of the gases is estimated. 
 
 DENSITY. 
 
 By density, is understood, the compactness of bodies, or the 
 number of ultimate particles contained in a given bulk : bodies 
 which contain the most particles are most dense, that is, their 
 particles are in the closest proximity to each other. Rarity, or 
 porosity is opposed to density. Density does not depend upon 
 the peculiar kind of matter of which a body is composed, but 
 only upon the proximity of its particles. This is apparent, 
 from the fact that the lava ejected from volcanoes, if cooled 
 on the surface of the earth, produces a stone sufficiently light 
 and porous to float upon water, while if cooled under great 
 pressure at a distance below the surface, it forms a dense 
 heavy rock like granite. 
 
 ELASTICITY. 
 
 Elasticity is the property in bodies, which causes them to 
 resume their original form and bulk, after being bent, com- 
 pressed or condensed. Most solid and hard bodies possess 
 this quality in some degree : glass, ice, ivory, <fec. are elastic 
 solids : india-rubber is an exceedingly elastic body, while wet 
 clay is entirely destitute of this property. The gases are far 
 the most elastic of all bodies. 
 
23 SCIENTIFIC AGRICULTURE. 
 
 TENACITY. 
 
 By tenacity, we understand the degree of force or cohesion 
 with which the particles of a body are held together, in other 
 words tenacity means toughness. Some substances, as some 
 of the metals, are extremely tenacious, while others want this 
 quality almost totally. The tenacity of the metals varies great- 
 ly, cast steel being the most tenacious of them all, while lead 
 is the least so. The tenacity of the woods varies as does also 
 that of soils : clay soil is tenacious, while sand soil is destitute 
 of this property. 
 
 CHEMICAL ATTRACTION, OR AFFINITY. 
 
 This is a peculiar power in bodies, which disposes them to 
 unite with other bodies and form compounds. It is the power 
 by which chemical phenomena are produced: it is different 
 from cohesion and all other forces in nature: it acts with 
 various degrees of energy in different elementary bodies, 
 showing a preference for some, and refusing to act on others 
 at all. Chemical affinity is influenced by many other agents, 
 as heat, electricity, gravity, cohesion, moisture, elasticity and 
 light. An affinity originally weak, may by some of these 
 agencies be made strong, while an affinity originally strong 
 may be rendered weak or, destroyed altogether. 
 
 When common salt is thrown in water, it unites with it, 
 (dissolves,) by means of a weak affinity or chemical attraction, 
 but if oil be thrown into water, it does not unite with it, 
 because it has no affinity for it Some substances unite in all 
 proportions, as, for example, vinegar and water; while others 
 unite only in definite and fixed proportions, as sulphuric acid 
 and lime, &c. When two substances of opposite natures are 
 brought together, as, vinegar and pearlash, they readily unite, 
 by means of simple affinity, and form a third substance dif- 
 ferent from either of the other two. If now a third substance 
 be added, which has a stronger affinity for one of these two 
 than they have for each other, the two first separate, or are 
 
CHEMISTRY. 29 
 
 decomposed, and one of them goes to unite with the new 
 substance, and form a compound, by means of elective affinity. 
 Two bodies which have no affinity for each other, may 
 sometimes be made to unite by means of a third : thus, oil and 
 water will not unite alone, but by the medium of the alkali 
 potash, which has an affinity for both, they unite and form the 
 well known compound, soap.* Chemical union is usually 
 attended with the evolution of heat. Some substances unite 
 without any apparent action, while others have an affinity so 
 strong that union takes place with an explosion. Chemical 
 affinity manifests itself iu a more complex form under the 
 name of double elective affinity. 
 
 When nitrate of ammonia and carbonate of potash are 
 mixed together in solution, a double decomposition and reunion, 
 take place : the potash leaves the carbonic acid to go to the 
 nitric acid, and the nitric acid leaves the ammonia to go to 
 the potash, the carbonic acid and ammonia, finding them- 
 selves deserted and alone, unite and form carbonate of ammo- 
 nia. Thus nitrate of ammonia and carbonate of potash are 
 decomposed, and nitrate of potash and carbonate of ammonia 
 formed. This may be more clearly shown by arranging the 
 four elements thus : 
 
 Nitrate of ( 1. Nitric Acid. 3. Potash. ) Carbonate 
 
 Ammonia. ( 2? Ammonia. 4. Carbonic Acid. ) of Potash. 
 
 This change of elements took place because a stronger 
 affinity existed between 1 and 3, than between 1 and 2, and 
 a stronger affinity existed between 2 and 4, than between 3 
 and 4. These compounds might again be decomposed by 
 others, having affinities sufficiently powerful to overcome that 
 which holds them together. In order that bodies may be 
 
 * This example is taken from Comstock's Chemistry on account of 
 its plainness; but is nevertheless not strictly true, as the idea of an 
 intermediate substance is now abandoned by chemists. The truth is, 
 that the alkali and oil unite and form soap, which it itself dissolved in 
 the water. 
 
30 SCIENTIFIC AGRICULTURE. 
 
 united by affinity, they must possess different chemical proper- 
 ties: thus acids and alkalies are chemically opposed, and are 
 consequently drawn together, while they rarely, if ever, unite 
 with each other. "We might [says Dr. Fownes] define 
 chemical affinity to be a force by which new substances are 
 generated." 
 
 LAWS OF COMBINATION. 
 
 The elements of chemical compounds are -generally limited 
 to fixed and invariable proportions on both sides. It is this 
 constancy of proportions alone, which gives to chemistry its 
 title to the character of an exact science ; for had all bodies 
 the property of combining in every possible proportion under 
 every variety of circumstances, no definite or certain knowledge 
 could be obtained in relation to the constitution, properties or 
 chemical uses of bodies: experiments would give results so 
 different and variable, at different times, and under various 
 circumstances, that the votaries of this sublime and useful 
 science would long since have abandoned it in despair. 
 
 The elements of a given chemical compound are always in 
 the same proportions : thus, green oxide of iron is composed 
 of 27 parts, by weight, of iron, and 8 parts of oxygen: com- 
 mon salt is a compound of 23 parts sodium and 35 parts 
 chlorine; and these are the smallest proportions in which 
 those elements can be made to unite. When two elements 
 unite in more than one proportion on either side, the additional 
 proportions are just double, triple, quadruple, &c., or 1 to $ 
 that is 2 to 3, 3 to 5, the amount of the first : that is, they 
 increase in exact multiple proportions. To illustrate this 
 principle we may allude to the five compounds of oxygen and 
 nitrogen. 
 
 Protoxide of nitrogen consists of 
 
 Nitrogen, 14.06 Oxygen, 8 
 
 Deutoxide " 14.06 " 16 
 
 Hyponitrous acid " 14.06 " 24 
 
 Nitrous add 14.06 32 
 
 Nitric acid 14.06 40 
 
CHEMISTRY. 31 
 
 It will be seen that while the nitrogen remains the same, the 
 oxygen increases by multiples of 8, which is its equivalent 
 number. The nitrogen, although willing to unite with several 
 whole proportions of oxygen, would reject a quarter or half 
 of an equivalent, and not unite with it : so, in the preparation 
 of any compound, if an excess of either element be used, it is 
 not combined, but left alone in its original state. 
 
 The equivalent or combining number of a body is that which 
 represents the smallest in which it is known to combine with 
 other bodies. The representative number of a compound, is 
 the sum of the combining equivalents of its components. Com- 
 bining proportions are reckoned by weight and by volume ; in 
 these two estimations of course different equivalent numbers 
 are used. 
 
CHAPTER II. 
 
 LIGHT. 
 
 IN order to understand the relations of light to vegetation, a 
 short description of its properties is necessary. There are two 
 theories respecting the nature of light : one supposes it to be 
 particles of luminous matter emitted, or thrown off by luminous 
 bodies. The other supposes the existence of a substance 
 called ether, which pervades all nature, and is put into a 
 vibrating or wave-like motion by all luminous bodies. 
 
 Rays of light proceed in straight lines from luminous bodies, 
 unless interrupted by some intervening medium. Light moves 
 with the astonishing velocity of 200,000 miles in a second of 
 time. When a ray of light falls on a plane surface, it is 
 disposed of in one of three ways : when the plane is black, the 
 ray is all absorbed: when it is polished, the ray is partly 
 absorbed and partly reflected : when the plane is transparent, 
 as glass or water, it may be partly absorbed, partly transmitted 
 and partly reflected. The law of reflection of light is the same 
 as that of sound: when a ray of light falls obliquely on a 
 reflecting surface, it is reflected in the same angle as the one 
 in which it approached the surface ; thus the angles of reflec- 
 tion and incidence are equal. 
 
 "When a ray of light passes from a rarer to a denser medium, 
 it is refracted, or turned out of its course : when it passes from 
 a rare to a denser medium, as from the air into water, it is 
 
CHEM-J6TRY. 
 
 33 
 
 bent towards the perpendicular: when it passes from a dense 
 to a rarer medium, it is turned from the perpendicular. 
 
 Light is a compound of seven colors, viz : violet, indigo, blue, 
 green, yellow, orange and red. The colors can be separated 
 by a triangular piece of glass, called a prism : they possess 
 different degrees of refrangibility, as will be seen by the 
 
 Fig. 1. Solar Spectrum. 
 
 figure. 
 
 Violet 
 
 Indigo 
 
 Blue 
 
 Green 
 
 Yellow 
 
 Orange 
 
 Red 
 
 [This cut shows the solar spectrum in the order of its seven colors : 
 the violet appears most, and the red least refracted.] 
 
 There are also heating rays, which attend the luminous 
 ones: the calorific, or heating powers of the red rays, are the 
 greatest : these powers diminish in the order of the spectrum, 
 from the red to the violet, which possesses the least of all. 
 Light is a powerful decomposing agent : many chemical com- 
 pounds, as the salts of silver, are decomposed by the agency 
 of light alone. The influence of light on vegetation is very 
 important, and will be noticed hereafter. The process of 
 taking phtographic and Daguerreotype pictures, depends upon 
 the action of light on a sensitive metallic surface. 
 
 There are several sources of light : the great source of light 
 which produces the day to our earth, is the sun, the moon's 
 light is only a reflected light which it receives from the sun. 
 The combustion of bodies is another source of light : another 
 form of light is called phosphoresence, which is emitted by 
 certain bodies, as phosphorus, decayed wood, putrid flesh, 
 
34 SCIENTIFIC AGRICULTURE. 
 
 certain gases, &c. : this is a feeble light, and is only visible in 
 darkness. 
 
 CALORIC. 
 
 Caloric is the substance or agent which is thrown off by 
 heated or burning bodies, and which produces the sensation 
 of heat : in common language it is the word used to express 
 both the cause and the effect. This agent possesses no appre- 
 ciable weight. Although it must be substance^ or material 
 in its nature, still a body when highly heated or charged 
 with caloric, is not sensibly heavier raan when cold. 
 
 Caloric appears to exist in all bodies. Heat and cold are 
 only relative terms ; when a body is so cold as to produce the 
 sensation of coldness to our touch, we call it cold; on the 
 contrary, when it produces the sensation of warmth, we call it 
 warm, although the absolute temperature may be the same 
 in both cases. Caloric always tends to seek an equilibrium: 
 that is, it constantly passes from the hotter to the colder 
 bodies: if a piece of ice at 32 be carried into an atmosphere 
 where the temperature is 60 below 32, it will, in changing 
 its temperature to that of the surrounding air, give off 60 of 
 heat : this illustration is sufficient to prove that the ice really 
 contains heat. 
 
 The expansive power of heat is another property which 
 involves many important facts : when caloric enters a body, it 
 is supposed that a mutual repulsion of its particles takes place, 
 so as to partially overcome their cohesive power, and render 
 the body less dense. All bodies expand by heat, the degree 
 of this expansion, however, differs widely in different bodies. 
 The expansibility of fluids is greater than that of solids, with 
 equal degrees of heat. 
 
 All gases expand nearly equally with the same degrees of 
 heat : this is not the case, however, with the solids and liquids. 
 Some bodies are much better conductors of caloric than others : 
 
CHEMISTRT. 
 
 35 
 
 dense bodies are generally the best conductors of caloric: 
 the metals are better conductors than wood or glass ; porous 
 bodies conduct with less facility than dense ones. Snow is 
 porous, and therefore a poor conductor of caloric, this is why 
 the ground freezes less when covered with snow, than when it 
 is naked. 
 
 The 'different conducting power of bodies is illustrated by a 
 familiar example: on a cold winter morning we find the 
 hearthstone intensely cold to the feet, while the woolen carpet 
 is warm : now as as they are both exposed to the same tem- 
 perature, the different sensation produced must depend on the 
 different conducting power of the two bodies, the one con- 
 ducting off the heat of the body so rapidly as to produce 
 the feeling of coldness, and the other conducting but very 
 slightly. 
 
 By specific caloric is understood, that quantity which is 
 peculiar to each body : when one body is found to possess a 
 greater amount of caloric than another of equal weight, it is 
 said to possess a greater capacity for caloric. The reason 
 why different substances possess different capacities for caloric, 
 is not precisely known. Bodies least dense appear generally 
 to possess the greatest capacity for caloric, while those more 
 dense possess the least. Hydrogen gas, the lightest of all 
 known bodies, is said to possess this capacity in the greatest 
 degree. 
 
 When a piece of cold iron is hammered for a few minutes, 
 it becomes hot: when sulphuric acid is mixed with a liquid 
 less heavy and dense, as water or alcohol, the mixture becomes 
 hot; when ice melts and becomes water, it absorbs heat, or 
 becomes colder, as is shown by a thermometer. The heat 
 which is developed in the last case, and which was before 
 inappreciable to the senses, is called latent heat. 
 
 All heated bodies are constantly emitting or throwing off 
 caloric; this is called radiant caloric, because it is radiated 
 
36 SCIENTIFIC AGRICULTURE. 
 
 in all directions like the rays of light. This effect is not 
 produced by the gradual conduction of caloric by the ain 
 because the same effect takes place in a vacuum, and in a 
 direction opposite to the wind. When rays of heat fall upon 
 any body, they are, like the rays of light, either absorbed, 
 reflected, or transmitted. Highly .polished substances reflect 
 the heat, while rough surfaces absorb it The angles of 
 incidence and reflection are equal in radiant caloric, as well as 
 in light and sound. The color of bodies has an important 
 influence on their radiating power: dark colors radiate better 
 than light ones. 
 
 The transmission of heat through the air takes place 
 without any obstruction, as is the case with light; but with 
 respect to other transparent media it is different " If a para- 
 bolic or concave mirror be taken, and its axis directed towards 
 the sun, the rays of both heat and light will be reflected to 
 the focus, which will exhibit a temperature sufficiently high to 
 fuse a piece of metal, or fire a combustible body. If a plate 
 of glass be now placed between the mirror and the sun, the 
 effect will be but little diminished. Now let the same experi- 
 ment be made with the heat and light of a common fire ; both 
 will be concentrated by reflection as before, but on inter- 
 posing the glass the heating effect of the focus will be reduced 
 to almost nothing, while the light will not" have undergone 
 perceptible diminution. 
 
 " Thus the rays of heat coming from the sun traverse glass 
 with great facility, which is not the case with those emanating 
 from an ordinary red hot body." Rays of heat are not 
 transmitted equally through different bodies of equal trans- 
 parency: for example, of 100 rays falling on a crystal of rock 
 salt, 8 were intercepted: of the same number, glass inter- 
 cepted 61, and alum 91. Color also varies the power of 
 bodies to transmit heating rays. Black and opake bodies stop 
 the rays completely. Rays of heat from different sources 
 
CHEMISTRY. 37 
 
 differ in their properties: those proceeding from red hot 
 copper and fluor spar, differ from those from an oil lamp or 
 the sun. Cold is merely a negative condition depending on 
 the absence of heat. 
 
 There are several sources of caloric, of which the sun is the 
 principal, and compared with which all others are insignificant. 
 The sun radiates heating as well as luminous rays, which 
 reach the earth, and are partly absorbed and partly reflected. 
 The combustion of bodies is another source, electricity, gal- 
 vanism, friction, condensation, animal vital action, and chemical 
 action, are all sources of caloric. The earth is supposed to 
 contain in its interior a vast amount of heat. The relations 
 of heat to the growth of vegetation are important, and will be 
 noticed in another place. 
 
 ELECTRICITY. 
 
 Electricity is a fluid or principle pervading all nature, so far 
 as we kno\v. The first full investigation of this extensive and 
 interesting branch of science was made by Dr. Franklin ; and 
 although it is only a few years since, yet it has become iden- 
 tified with almost every branch of physical science, and has 
 already had an immense influence on the moral and social, 
 as well as commercial condition of the civilized world. We 
 still know little of the nature of electricity ; although many of 
 its properties and effects are somewhat well understood, still 
 all investigation and discovery has only tended to render its 
 true nature and phenomena more mysterious, and its origin 
 more questionable. We see its effects, but what it is, or 
 whence it originates, we know not 
 
 But for the sake of convenience, philosophers have applied 
 certain terms to its peculiar properties : these terms in some 
 cases indicate particular effects and conditions, and in others 
 they may be said to be little more than names for our 
 ignorance. Electricity is supposed to be a fluid which exists 
 
 4 
 
38 SCIENTIFIC AGRICULTURE, 
 
 in two opposite states, viz : positive and negative. The terms 
 vitreous and resinous have also been used to designate these 
 t\vo states. 
 
 The simplest manner of exciting or producing electricity is 
 by rubbing a piece of amber or sealing wax on dry cloth* 
 when it will be found capable of attracting light bodies, such 
 as feathers, bits of thread, paper, &c. The body so affected is 
 called an electric, and is said to be in a state of, .electrical 
 excitation. The sealing wax or amb^r in this case is in the 
 positive state, or is positively electrified, while the feather or 
 other substance attracted to it is in the negative state, or is 
 negatively electrified. It is impossible to develop one of these 
 states or phenomena without at the same time developing the 
 other also. After adhering to the electrical body for a few 
 seconds it will fall off, it being charged with electricity and in 
 the positive state like the electric : if the electric be excited 
 again, and the feather presented to it, it will be strongly 
 repelled and tend to fly off this is called electrical repulsion. 
 
 The passage of the electric spark is instantaneous: it appears 
 also to be confined to the surface of bodies in its passage. 
 Bodies which allow electricity to pass over them are called 
 conductors: these are non-electrics, that is, they cannot be 
 excited by friction so as to produce electricity: on the con- 
 trary, those bodies which can be electrically excited will not 
 conduct the fluid; so that non-conductors are electrics, and 
 non-electrics are conductors. 
 
 The electric spark fires gaseous mixtures, and is capable of 
 producing intense heat: electricity also decomposes solutions 
 of metallic oxides and salts. Some fishes, as the torpedo and 
 electrical eel, possess an electrical apparatus within their 
 bodies, which is capable of producing severe shocks upon 
 other animals ; and this is done, too, at the will of the fish. It 
 has been satisfactorily settled by Prof. Matteitcci, that electri- 
 city has nothing to do with the action of the nervous system 
 
CHEMISTRY. 39 
 
 of animals, and that life and all the vital functions are not 
 dependent upon it for their existence and action. Electricity 
 gives polarity to iron, and is supposed to be the cause of, or 
 identical with magnetism. 
 
 The polarity of the earth is supposed to depend upon the 
 passage of electrical currents around it. Electricity is desig- 
 nated according to its different states, by the terms statical 
 and dynamical. Statical electricity treats of the properties of 
 the fluid at rest or in a state of equilibrium. Dynamical 
 electricity treats of the fluid in motion, or as it displays its 
 phenomena while under experiment. The upper regions of 
 the atmosphere are generally in a positive state; in cloudy 
 weather, the distribution of the fluid is disturbed, and this 
 gives rise to the phenomena of thunder and lightning. Gal- 
 vanism, as well as magnetism, is supposed to be identical 
 with, or a modification of, electricity. 
 
 Electricity is developed in various ways, by different kinds 
 of apparatus which cannot be described in this place. All the 
 forms of electricity are applied to useful purposes, to con- 
 siderable extent, in the arts and sciences. It remains an 
 unsettled problem as yet, whether electricity in any form can 
 be made available to the growth of. vegetation : its efficacy, 
 also, in the healing art, is not as much relied upon as in 
 former years ; this, like all newly discovered remedial agents, 
 has had its day of glory, and has, probably, by means of 
 correct observation and careful experiment, fallen to about its 
 proper standard. 
 
 NOTE. The term PVROGEX has been proposed instead of 
 Electricity : the term signifies generator of heat or fire. 
 
CHAPTER III. 
 
 GENERAL PROPERTIES OF GASES. 
 
 GA& is an elastic fluid or air, formerly, but not now, supposed 
 to be produced by the union of some body with caloric: most 
 gases are inappreciable by the senses, except that of feeling, 
 having neither taste, color nor odor. Some have a specific 
 gravity greater, and others less than common or atmospheric 
 air. Several gases have been liquified by the conjoined action 
 of cold and pressure : several have also been solidified by the 
 conjoined action of intense cold and the pressure of from two 
 to fifty atmospheres. The product of this experiment is in 
 most cases an exceedingly transparent crystaline substance. 
 Gases, like, liquids, have but a slight power of conducting 
 caloric: their conducting power is so slight as to be imper- 
 ceptible, and they are therefore called non-conductors of 
 caloric. 
 
 AH gases possess a certain amount of specific caloric, the 
 precise quantity which they respectively contain has not been 
 determined. Gases exist throughout nature, and may be 
 produced by artificial means. Some of them are capable of 
 being respired, without injury to health, while others cannot, 
 without producing deleterious or fatal effects. Some are, in 
 common language, supporters of combustion, while others are 
 not. Those gases only which are necessary to be known in 
 their relations to agriculture, will bo described in this work, 
 
CHEMISTRY. 41 
 
 OXYGEN ITS PROPERTIES AND RELATIONS. 
 
 Oxygen is an invisible, transparent fluid, without taste or 
 odor ; respirable and necessary to organic life, with a specific 
 gravity of 1.2G, air being 1. It has the most extensive 
 affinity of all known substances. It combines with metals, 
 forming oxides and acids : it combines also with other gases, 
 and is an important element in water and the atmosphere: it 
 js usually called a supporter of combustion, it exists in great 
 abundance in nature, and may be obtained by chemical process 
 from several substances, most easily, perhaps, from black 
 oxide of manganese. It is said that nearly one-third of the 
 weight of all the solid matter of the globe consists of this 
 gas. The combustion of all fires depends on the presence of 
 oxygen, a lighted taper burns with greatly increased bril- 
 liancy in pure oxygen gas. 
 
 No plant can vegetate without it, although no plant will 
 long survive after being placed in this gas alone. No animal 
 can respire for a single minute without oxygen, but when 
 immersed in a jar of it, the vital processes are all increased 
 until fever succeeds, and the animal dies. "According to 
 Dr. Henry, 100 volumes of water absord only 3j of oxygen.'' 
 The combining number of oxygen is 8. 
 
 HYDROGEN ITS PROPERTIES AND RELATIONS. 
 
 Hydrogen gas is the lightest of all known substances, being 
 fourteen times lighter than common air, destitute of taste, 
 color or odor : it is combustible, but not a supporter of com- 
 bustion; it is incapable of sustaining animal life, though it 
 is destitute of poisonous properties, an animal dies when 
 immersed in it from want of oxygen, the death results from 
 its negative condition, rather than from any positive injury 
 which is sustained by breathing the gas. It exists in nature 
 in less abundance than carbon or oxygen, and is not known to 
 occur in a free or uncombined state. It forms a small part of 
 all animal and vegetable substances, and constitutes one-ninth 
 
 *4 
 
42 SCIENTIFIC AGRICULTURE. 
 
 part of the weight of water : it does not occur in combination 
 witli any of the mineral masses of the globe, except coal, and 
 this is itself of vegetable origin. This gas burns with a pale 
 yellow flame, its combustion is attended by the formation of 
 water. 
 
 Plants do not grow in this gas, but gradually wither and 
 die. Its specific gravity is 0.0687: 100 gallons of water 
 absorb 1-i- gallons of this gas. It is the gas used' for inflating 
 balloons. Hydrogen is readily obtained by the action of sul- 
 phuric acid on zinc or iron. It is necessary to the growth of 
 vegetation, but not in a free or uncombined state. The com- 
 bining number of hydrogen is 1. 
 
 CARBON ITS PROPERTIES AND RELATIONS. 
 
 Carbon exists in a pure and crystaline form in the diamond ; 
 graphite, or black lead, and common charcoal, are examples of 
 carbon of impure varieties. It constitutes a large proportion 
 of all animal and vegetable substances: nearly all plants in a 
 dried state, contain from 40 to 50 per cent, by weight, of 
 carbon. This substance is of great importance in the art of 
 culture, on account of its power of absorbing large quantities 
 of the gases and vapors of the atmosphere, this is especially 
 true of charcoal, or carbon in a light and porous form. Char- 
 coal is used for filtering impure water, which it cleanses f om 
 decayed animal or vegetable substances, and coloring matters 
 which are held in solution: it is used also in clarifying syrups 
 and oils: it has the power of absorbing noxious vapors and 
 gases, which result from the decomposition of animal and 
 vegetable matters, and of preventing or retarding the decay 
 of all organic substances. 
 
 The gases and moisture which are arrested and retained by 
 carbon in the soil, are again readily yielded up to the roots of 
 plants, during the process of growth. Several important ends 
 are subserved by carbon in the soil : it purifies impure air and 
 
CHEMISTRY. 43 
 
 water, which would not nourish plants, but on the contrary 
 prove destructive to their tender germs and roots : it absorbs 
 gases from the air as before stated ; prevents putrefaction (and 
 acidity to some extent,) in the soil, and is itself an indispen- 
 sable element in vegetation. 
 
 Carbonic acid is a gas or air, which results from the com- 
 bustion of charcoal, when charcoal is burned, it nearly all 
 disappears in the form of gas, leaving only a small residue of 
 ash behind. Carbonic-acid-gas is heavier than common air, 
 colorless, invisible, having an agreeable pungent taste and 
 odor, but cannot be respired without poisonous effects resulting 
 from it. Carbonic acid may be obtained for experiment from 
 white marble, which is a carbonate of lime, or from common 
 limestone. The combining number of carbon is 6. 
 
 It is neither combustible nor a supporter of combustion, a 
 lighted taper dipt into a jar this gas is instantly extinguished ; 
 it often exists in deep wells, mines, caverns and pits, and 
 proves fatal to those who enter them, the precaution should 
 therefore always be taken to let down a lighted candle, which 
 will determine the presence or absence of the gas. It is this 
 gas also which proves so deleterious in ill ventilated rooms 
 heated by coal fires. It is formed during the combustion of 
 all wood, coal and oil fires, it is generated by the respiration 
 of animals and the growth and decay of vegetation: it is 
 produced also, together with alcohol, during the fermentation 
 of sugar. It is evolved in vast quantities from the ground in 
 volcanic countries, and exists in combination with metallic 
 oxides in the earth : these compounds are called carbonates, 
 the most important of which is carbonate of lime. This gas 
 has an acid reaction : water dissolves its own volume of it, and 
 forms an agreeable sparkling solution: it is this gas which 
 escapes during the effervesence of soda water and various 
 kinds of beer. 
 
 It is apparent that the excessive accumulation of so poi- 
 

 ... 
 
 SCIENTIFIC AGRICULTURE. 
 
 ra gas must prove destructive to all animal and vegeta- 
 e, if some means were not provided by which it could be 
 removed as fast as it is generated by natural causes : growing- 
 vegetables, although they could not live in this gas alone, 
 require a constant supply of it as an element of food, and 
 this is just sufficient to preserve a wonderful balance in this 
 respect throughout all nature. 
 
 According to Liebig, a healthy man expires from his lungs 
 5 ounces a day, or 100 pounds a year, of carbon: a horse, or 
 cow, expires six times this amount, or 600 pounds a year. 
 ISTow if the crops of an acre of land require 2 tons of carbon in 
 a year, (which is Johnston's estimate,) a farm of 25 acres 
 would require, if all cultivated, 50 tons of carbon. If the 
 family of the farm be reckoned at 5 adults, and the stock at 2 
 horses, 5 cattle, 40 sheep, 5 hogs, including the poultry, the 
 amount of carbon they would all expire would be not far from 
 10 tons in a year. They would then supply from this source 
 alone one-fifth of all the carbon requisite to grow the crops of 
 the farm. 
 
 Coal which is dug from the earth and burned as fuel, adds 
 to the carbon of the atmosphere a new portion, which had 
 been buried in the earth, and consequently lost to vegetation 
 for many centuries. The coal consumed annually in Great 
 Britain, contains 14 millions of tons of carbon, which would 
 supply this element to the crops of twenty-eight millions of 
 acres. [Johnston.] Decay of vegetation, when extensive, as 
 in the peat bogs of Europe, the jungles of India, and the 
 tropical forests of Africa and South America, furnishes im- 
 measurable quantities of carbon. 
 
 The final result of this eremacausis, (slow combustion,) or 
 slow decay, is the same as that of ordinary combustion: the 
 immediate result, however, is different: decay furnishes much 
 less carbon in proportion to the matter consumed than com- 
 bustion; decay produces, also, light carburetted hydrogen, 
 
CHEMISTRY. 45 
 
 which combustion does not. The latter gas is changed by the 
 electricity of the air to carbonic acid and water. 
 
 The evolution of carbon from volcanoes, and fissures in the 
 earth in volcanic regions, is immense. In the ancient volcanic 
 region Eifel, on the bank of the Rhine, an annual evolution 
 takes place, according to Bischoff, of 27,000 tons of carbon. 
 Some carbon is absorbed by the waters of seas and oceans, 
 which is not, as far as we know, restored to the atmosphere. 
 Vegetable matters carried away by water, deposited and em- 
 bedded in beds of sand and clay, are thus prevented from 
 decaying, and their carbon is consequently lost. These are 
 two sources of loss of carbon: and although the balance 
 between its production and consumption is nearly equal, "still, 
 according to Prof. Johnston, there is supposed to be a slight, 
 permanent loss to the entire mass of our atmosphere. 
 
 NITROGEN ITS PROPERTIES AND RELATIONS. 
 
 Nitrogen is widely diffused through nature, constituting 
 nearly four-fifths of the atmosphere, and existing in many 
 vegetable, and most animal substances. It is destitute of 
 color, taste or odor, and is a little lighter than common atr ; it 
 is incapable of supporting combustion or animal life, but, like 
 hydrogen, it has no positively poisonous properties. Water 
 absorbs it in very small quantity: it is in fact distinguished for 
 negative properties, the reason why it does not sustain com- 
 bustion and animal life, appears to be merely the Absence of 
 oxygen. Its use in the atmosphere seems to be only to dilute 
 the oxygen sufficiently to render it fit for respiration. 
 
 Nitrogen combines with oxygen and forms acids and oxides. 
 Its combining number is 14. Nitrogen may be obtained by 
 burning phosphorus under a bell glass over water. It does 
 not enter into the composition of any of the mineral con- 
 stituents of the earth's crust, except coal, which is of vegetable 
 origin. Nitrogen forms an important part in the growth of 
 both animals and plants. 
 
46 SCIENTIFIC AGRICULTURE, 
 
 GASEOUS COMPOUNDS. 
 
 WATER ITS PROPERTIES AXD RELATIONS. 
 
 Pure water is transparent, colorless, tasteless, and inodor- 
 ous: it is a compound of the gases oxygen and hydrogen, in 
 the proportion of 8 parts of the former to 1 of the latter, by 
 weight, or by volume, 1 of oxygen to 2 of hydrogen. It 
 boils, under ordinary circumstances, at 212 and freezes at 
 82o, Fall. : its greatest density is at about 40, at 212, it 
 takes the form of vapor or steam, and is thus increased to 
 1700 times its former bulk, and is about two-fifths lighter than 
 common air, it consequently rises and becomes diffused 
 through the air. 
 
 Water evaporates at all temperatures above freezing: it is 
 780 times heavier than common air, a cubic foot weighs six- 
 ty-two and a half pounds. It is the standard of specific gravity 
 for all bodies, its number in this respect is unity or 1. 
 
 The purest water, except that which has been distilled, falls 
 from the clouds in the form of rain and snow at the close of a 
 shower: all other natural waters contain various soluble and 
 insoluble gaseous, mineral and organic matters, among which 
 are, carbonic acid, carbonate of lime, ammonia, salts of iron, 
 soda, iodine, bromine, magnesia, silica, sulphur and others. 
 "Water possesses the most extensive solvent power of all known 
 liquids : it absorbs gases from the air to a considerable amount : 
 these are again expelled by boiling, and are altered in their 
 proportions from those which constitute the atmosphere. 
 
 Water mixes with, or dissolves all liquids except those of an 
 oily nature : it dissolves also most salts, many gums, coloring 
 matters, and slowly dissolves many rocks and earths: water 
 has a wide range of affinities for animal, vegetable and mine- 
 ral elements, which it exercises without being itself decom- 
 posed, It is the most universally diffused through the three 
 
CHEMISTRY 47 
 
 kingdoms of nature, of any substance: it enters largely into 
 the composition of living animal bodies, and constitutes, ac- 
 cording to Johnston, half the weight of all green or newly 
 gathered vegetables which are cultivated for the use of man. 
 
 Without water, neither animals nor plants could exist, (with 
 their present organization,) the earth would become a scorched 
 and sterile waste : many compounds resulting from chemical 
 affinities which require the presence of water, would be un- 
 known : the varieties of climate which now exist would also 
 to a great extent be unknown. Water in its relations to vege- 
 table life, and also its meteorological influences, will be more 
 particularly discussed in a subsequent part of this book. 
 
 THE ATMOSPHERE ITS PROPERTIES AXD RELATIONS. 
 
 The atmosphere which we breathe is an immense ocean of 
 gaseous fluid : the depth of this ocean is about 45 miles, at 
 the bottom of which we live, or rather, it extends about 45 
 miles above the surface of the earth, which it entirely sur- 
 rounds. It is composed of the two gases oxygen and nitro- 
 gen, in volume in the proportions of about 21 of the former 
 to T9 of the latter in 100. It contains also, according to 
 Sausseur, ^ jV ^ f ^s bulk of carbonic acid. 
 
 The quantity of this gas is greater in cities than in the coun- 
 try, slightly less in the air over the seas and great lakes, it 
 is less over a wet than a diy soil, and by day than by night. 
 The air is imbued with watery vapor which varies in different 
 climates : it holds in suspension, traces of various animal and 
 vegetable matters and ammonia. Heat and electricity also 
 exist more or less at all times in the atmosphere. Air diffuses 
 itself everywhere, penetrates the minutest recesses of every 
 porous body, and presses with the almost incredible weight of 
 15 pounds to every square inch of the earth's surface: it is 
 transparent, colorless, invisible, elastic, tasteless and inodorous. 
 The two essential elements of the atmosphere, viz. oxygen and 
 
48 SCIENTIFIC AGRICULTURE. 
 
 nitrogen, arc not, according to Dr. Kane and others, in a state 
 of chemical union, but only a mixture. 
 
 The specific gravity of air is about 7 SO times less than that 
 of water; 100 cubic inches weigh about 31 grains. A column 
 of air 45 miles high just balances a column of water of the 
 same diameter, 33 feet high, or a column of mercury 29 
 inches high : hence water cannot be raised in a pump on the 
 principle of atmospheric pressure, more than about 33 feet, 
 hence also the mercury in the barometer tube is about 29 
 inches high. The air expands and becomes less dense by 
 heat ; hence warm air always rises, and cold air descends : the 
 composition of the air is everywhere nearly uniform, its com- 
 plete and beautiful adaptation to the wants of animal and 
 vegetable life will be more apparent the more we become 
 acquainted with its nature and laws : without it no animal or 
 plant could exist for a single day. Its relations to vegetation 
 more especially, will be described hereafter. 
 
 CARBONIC OXIDE. 
 
 Carbonic oxide is a colorless, inodorous gas, composed of 
 one equivalent of carbon, united to one of oxygen : it extin- 
 guishes a lighted taper, takes fire at the same time itself, and 
 burns with a pale blue flame, forming carbonic acid. It is 
 lighter than common air, nearly insoluble in water, and does 
 not support animal life. It is produced, together with car- 
 bonic acid, by the combustion of coal fires. " It is not known 
 to occur in nature, or to minister directly to the growth of 
 plants." 
 
 OXALIC ACID. 
 
 This is another compound of carbon and oxygen, in the 
 proportions of two of the former to three of the latter. It is 
 found in the interior of many plants, as the sorrel, rhubarb, 
 bistort, gentian, chick pea, and several lichens : it is not known 
 to contribute to their growth, but appears to be the result of a 
 
CHEMISTRY 49 
 
 gaseous combustion consequent upon their growth. It is 
 found combined with potash and lime in the form of salts 
 called oxalate of potash and lime : it is one of the most impor- 
 tant of the organic bodies. 
 
 Crystalized oxalic acid is, in transparent bodies, intensely- 
 sour, and very poisonous. This acid is not found in the soil, 
 nor in the waters which reach the roots of plants : the simple 
 process by which it is elaborated in the interior of plants will 
 be described hereafter. Oxalic acid neutralizes alkalies per- 
 fectly, and forms several important salts. There exists a rela- 
 tion between carbonic acid, carbonic oxide and oxalic acid, 
 which will be described under the head of vegetable physi- 
 ology, 
 
 LIGHT CARBURETTED HYDROGEN. 
 
 This is a light, inflammable gas, which is formed by the 
 decomposition of organic substances at high temperature : in 
 warm weather it may be seen rising in bubbles from marshy 
 places and stagnant pools, when vegetables are in process of 
 decomposition. This gas is colorless, destitute of taste or odor, 
 about half the weight of common air: a lighted taper is 
 extinguished by it, while the gas ignites and burns with a pale 
 yellow flame : animals immersed in this gas cease to breathe 
 almost instantly. This is the gas which exists in marshes 
 under the name of marsh (fas, and also in coal mines under 
 the name of fire damp: violent explosions sometimes took 
 place in coal mines by the ignition of this gas mixed with 
 oxygen, from the miners' lamps, previous to the invention of 
 the safety lamp by Dr. Davy. It consists of one equivalent 
 of carbon and two of hydrogen. 
 
 This gas, together with carbonic acid, is given off during 
 the fermentation of compost, and all large collections of vege- 
 table matter. " It is supposed, [says Johnston,] by many, to 
 minister to the nourishment of plants: it is, however, very 
 
 o 
 
50 SCIENTIFIC AGRICULTURE. 
 
 sparingly soluble in water, so that in a state of solution, it 
 cannot enter largely into the pores of the roots, even though it 
 be abundantly present in the soil:" it probably exists in all 
 well manured soils; "but the extent to which it really acts as 
 food to living vegetables is entirely unknown." 
 
 NITRIC ACID ITS PROPERTIES AND RELATIONS. 
 
 Nitric acid is a compound of one part nitrogen and five of 
 oxygen: liquid nitric acid, when pure, is colorless, intensely 
 sour and corrosive, heavier than water, and boils at 187 Fah- 
 renheit. If exposed to the air, it gives off white fumes with 
 the disengagement of part of its oxygen, becomes yellow, and 
 is converted into nitrous acid. 
 
 " True nitric acid [says Dr. Kane] has never been isolated ; 
 that substance generally spoken of as nitric acid, is a compound 
 of it with water ; it is a nitrate of water, or, as it is popularly 
 termed, liquid nitric acid, or aquafortis." This acid decom- 
 poses all organic substances rapidly, neutralizes the alkalies, 
 and oxidizes the metals, for which it has a strong affinity. 
 
 This acid is not found in nature in an uncombined state; but 
 it occurs in combination with soda, lime and potash, in the 
 form of nitrates, in many tropical countries. In the West 
 Indies, vast quantities of nitrate of potash (salt petre) are 
 formed by nature : in Chili and Peru, immense beds of nitrate 
 of soda are also found. The origin of these salts is as follows : 
 rain water, particularly that which falls during a thunder 
 shower, contains nitrate of ammonia, when the water comes in 
 contact with the potash, soda and lime of the soil, having a 
 stronger affinity for them than for the ammonia, it unites with 
 them and forms the salts, while the ammonia is again set free 
 and escapes into the air. These salts are soluble in water, and 
 are important agents in promoting the growth of cultivated 
 plants. 
 
CHEMISTRY. 51 
 
 AMMONIA ITS PROPERTIES AND RELATIONS. 
 
 Ammonia is a colorless gas, having a strong, pungent odor 
 and alkaline taste: it is composed of one proportion of nitro- 
 gen and three of hydrogen: its equivalent number then is 17. 
 It is slightly combustible, but does not support combustion. 
 " Ammunia is rapidly absorbed by water, which takes up 780 
 times its volume at 32:" this is called water of ammonia, or 
 spirits of hartshorn, it has a specific gravity about one-tenth 
 less than water, and boils at 120. In its power of neutrali- 
 zing acids, it ranks next to lime, being a powerful base: it 
 forms, with the metallic salts and with acids, many compounds. 
 Ammoniacal gas does not support respiration, animals are 
 speedily suffocated by it, and living plants confined in it soon 
 wither and die. It is absorbed largely by porous bodies, such 
 as charcoal, burnt brick, burnt clay, &c., charcoal is said to 
 absorb 95 times its own bulk. 
 
 Ammonia is sufficiently caustic to destroy both animal and 
 vegetable substances. It is remarkable that the two gases 
 which form ammonia, having neither taste nor odor when 
 separate, produce, when united in certain proportions, a gas so 
 intensely strong, pungent, and acrid. Ammonia being only 
 about three-fifths the weight of common air, it rises and 
 mingles with the air when it is set free, unless it is retained 
 by some substance with which it will unite and form a solid 
 substance not volatile. The salts of ammonia are easily soluble 
 in water. 
 
 Ammonia exists in considerable abundance in nature, it is 
 almost universally diffused, but does not enter as a constituent 
 into any of the mineral masses of the earth's crust. It is found 
 mostly in a state of combination with acids, in the form of 
 nitrate, muriate and carbonate of ammonia. It is evolved 
 largely by the decay of animal and vegetable matters, and 
 does not remain long in a free state in the air, but combines 
 
52 SCIENTIFIC AGRICULTURE. 
 
 with acid vapors which it meets in the atmosphere, and forms 
 other compounds. 
 
 The salts of ammonia are decomposed by lime, magnesia, 
 potash and soda, and the ammonia is set free in the gaseous 
 state : the ease with which compounds of ammonia are decom- 
 posed, constitutes one of its most valuable properties, and 
 renders it peculiarly adapted to the various offices it performs 
 in the processes of vegetation. In the air, the, soil, or the 
 interior of plants, it is easily decomposed by electricity and the 
 alkaline bases before named. 
 
 " The hydrogen it contains in so large quantity, [says Prof. 
 Johnston,] is ready to separate itself from the nitrogen in the 
 interior of the plant, and, in concert with the other organic 
 elements introduced by the roots or the leaves, to aid in pro- 
 ducing the different solid bodies of which the several parts of 
 plants are made up. The nitrogen also becomes fixed in the 
 colored petals of the flowers, in the seeds, and in other parts, 
 of which it appears to constitute a necessary ingredient, passes 
 off in the form of new compounds, in the insensible perspira- 
 tion or odoriferous exhalations of the plant, or returning with 
 the downward circulation, is thrown off by the root into the 
 soil from which it was originally derived." The transforma- 
 tions which actually take place in the interior of plants, is not 
 yet perfectly understood, although many of them can be 
 clearly explained. The agency of ammonia and its various 
 compounds, in the promotion of vegetation, is both powerful 
 and important, and will be explained more fully in a subse- 
 quent chapter, as will also its formation and sources. 
 

 CHAPTER IV. 
 
 ELEMENTARY BODIES. 
 
 ELEMENTARY or simple bodies, are those which consist of a 
 single substance, and cannot be decomposed, or reduced to a 
 more simple form. They are such as have hitherto resisted 
 all attempts at decomposing them; but still, new methods of 
 analysis may yet enable the chemist to prove them to be of a 
 compound nature, and indeed this has already been the case 
 with some which were formerly considered elementary. These 
 simple bodies are about sixty in number, so far as yet known ; 
 but chemical analysis will doubtless make us acquainted with 
 others. Several attempts at classification of these bodies have 
 been made ; but none, as yet, has been on all accounts unob- 
 jectionable. 
 
 One division is, into metallic and non-metallic substances: 
 this division, although entirely arbitrary and less philosophical 
 than some others, is still the most convenient, and sufficiently 
 explicit for our present purpose. It is the one adopted by 
 Doct. Fownes. 
 
 Non-Metallic Elements. 
 
 Oxygen, Chlorine, Silicon, 
 
 Hydrogen, Iodine, Boron, 
 
 Nitrogen, Bromine, Sulphur, 
 
 Carbon, ' Fluorine, Selenium. 
 
 *5 
 
04 SCIENTIFIC AGRICULTURE. 
 
 Elements of Intermediate Characters. 
 Phosphorus, Arsenic, Tellurium. 
 
 Metals. 
 
 Antimony, Uranium, 
 
 Chromium, Cerium, 
 
 Vanadium, Lantanum, 
 
 Tungsten, Platinum, 
 
 Rhodium, Palladium, 
 
 Iridium, Yttrium, 
 
 Osmium, Bismuth, 
 
 Gold, Tin, 
 
 Alumnium, Mercury, 
 
 Glucinum, Silver, 
 
 Zirconium, Lead, 
 
 Thorium, Barium, 
 
 Cadmium, Strontium, 
 
 Copper, Calcium, 
 
 Iron, Magnesium, 
 
 Manganese, Zinc, 
 
 Lithium, Nickel, 
 
 Sodium, Cobalt, 
 
 Pelopium, Potassium, 
 
 Niobium. Ruthenium, 
 
 Molybdenum, Erbium, 
 
 Columbium, Terbium. 
 
 Titanium, 
 
 These sixty simple elements combine with each other in 
 such manner as to form the innumerable compounds which 
 make up the whole animal, vegetable and mineral kingdoms. 
 So far as we know, all ponderable bodies in the universe are 
 only the varied compounds of these few substances. The 
 imponderable agents, light, caloric, electricity, galvanism, and 
 magnetism, and the vital principle, are not well understood in 
 their natures and composition ; so that nothing can be predi- 
 
CHEMISTRY. 5o 
 
 catcd as to their relation in composition to the simple bodies. 
 Such, only, of these bodies will be described, as are necessary 
 to be known in their relations to Agricultural Science. 
 
 ACIDS. 
 
 Acids are chemical compounds whioh are capable of uniting 
 in different proportions with alkalies, to form a third class 
 called salts : by this union the properties of both the acids and 
 alkalies are destroyed, or neutralized. Most acids have a sour 
 taste, there are, however, some exceptions: they change 
 vegetable blues to red ; they are electro-negative, and there- 
 fore have a strong affinity for the electro-positive compounds, 
 such as alkalies, alkaline earths and oxides. Nearly all of 
 them contain oxygen; when the oxygen is not present, it is 
 replaced by hydrogen: they are therefore called by some 
 writers, oxacids and hydracids. 
 
 Acids are divided again into mineral and vegetable; the 
 mineral are, nitric, sulphuric, muriatic, &c. : the vegetable acids 
 are very numerous, acetic, citric and tartaric are examples. 
 Most vegetable acids contain both oxygen and hydrogen. The 
 mineral acids are heavier than water, exceedingly caustic and 
 corrosive, destroying both animal and vegetable textures. 
 Some acids are in a fluid, and others in a dry, solid or crys- 
 taline form. They unite with water in all proportions. They 
 absorb water from the atmosphere, if exposed, and become 
 weaker in strength, diminished in weight, and increased in 
 bulk. 
 
 ALKALIES. 
 
 Alkalies are a class of bodies possessing properties opposite 
 to those of acids, having a strong affinity for, and uniting with 
 them in different proportions, to form salts, as before stated. 
 They are incombustible, caustic and acrid, very soluble in 
 water, and change vegetable blues and red to green, and yellow 
 to brown, in fact they destroy or change the vegetable colors 
 
50 SCIENTIFIC AGRICULTURE. 
 
 generally. They are divided into fixed and volatile, the 
 fixed alkalies are potash and soda: these do not evaporate, like 
 ammonia, which is therefore called a volatile alkali. They 
 have a sharp, pungent taste, destitute of acidity, and, with the 
 exception of ammonia, have but little odor. They unite with 
 the oils and fats, and form the well known compound, soap. 
 There is also a class of compounds called alkaline earths, as 
 lime, barytes, magnesia and strontium. The alkalies and alka- 
 line earths are electro-positive in their affinities. 
 
 SALTS. 
 
 Salts constitute a numerous class of compounds, which 
 result from the chemical union of acids and alkalies. They 
 are of three kinds, viz : acid, basic and neutral. 
 
 Acid salts contain an excess of acid ; most of them are not 
 really acid salts, but double salts, of which one base is water ; 
 bi-carbonate of potash is an example. [Kane.] The sub- 
 stance which unites with an acid to form a salt, is called a 
 lase, 
 
 Basic salts are those in whicli there is more than one 
 equivalent of base for one of acid, as in sulphate and nitrate 
 of copper. 
 
 Neutral salts do not manifest either acid or alkaline proper- 
 ties on vegetable colors, they have neither an acid nor an 
 alkaline taste, and generally consist of one equivalent of acid 
 and one of base. 
 
 Double salts are formed by the union of two simple salts; 
 in general both salts contain the same acid, but different bases. 
 Salts usually crystalize in regular determinate forms; some 
 being in prisms or crystals, having three, four, five, six, 
 &c., sides, and as many angles. Most salts contain some 
 water in a loose state of combination : this is called their water 
 of crystalization. This water evaporates from some salts, and 
 they become a dry powder, such are called effervescent salts: 
 
CHEMISTRY. 57 
 
 others absorb more water from the atmosphere, and are dis- 
 solved in it, these are called deliquescent salts. 
 
 Salts may effervesce or deliquesce without destroying their 
 peculiar qualities or the chemical union between the acid and 
 base. Salts dissolved by water again crystalize when the 
 water is evaporated. The crystals of some salts are very 
 small, as in epsom salts, in others they are large, as in chro- 
 mate of potash. 
 
 ORGANIC ELEMENTS OF PLANTS. 
 
 Organic bodies possess a much greater complexity of com- 
 position, than substances of mineral origin. The organic 
 bodies are distinguished from the inorganic by the nature of 
 their elements : the products of the vegetable kingdom surpass 
 in number and variety those of the mineral, but still those of 
 the former consist almost exclusively of six elements, viz : car- 
 bon, oxygen, hydrogen, nitrogen, sulphur, and pkospkortt?: of 
 these six, carbon alone exists in all bodies of both animal and 
 vegetable origin. Sulphur and phosphorus are met with but 
 seldom : iodine and bromine exist in marine plants and 
 sponges; besides these, plants contain in most cases, iron, 
 silicon, calcium, potassium, magnesium, manganese, and some- 
 times fluorine. These are called the ultimate elements of 
 plants, because they are the final result of analysis, and 
 cannot themselves be reduced to a more simple form, or sepa- 
 rated into other elements. 
 
 These combine in such a manner as to form the various 
 substances, such as starch, gum, sugar, and an almost endless 
 variety of others found in plants. These latter are called 
 organic products, or immediate or proximate elements, because 
 they are more easily separated and obtained without a rigid 
 analysis. As a general rule, bodies most complex in their 
 number of elements and simplicity of equivalent relations, are 
 the weakest, and least capable of resisting those disturbing 
 
58 SCIENTIFIC AGRICULTURE. 
 
 forces which tend to produce decomposition, or transformation 
 of their elements. Substances of different properties, but 
 identical in composition, are called isomeric bodies. 
 
 These bodies, although containing the same ultimate ele- 
 ments, may be as widely different in their chemical relations 
 as bodies which have no elements in common. Oil of turpen- 
 tine and oil of citron are isomeric compounds, each being 
 composed of carbon 5 hydrogen 4. 
 
 LIGNINE. 
 
 The proper wood of plants, when separated by chemical 
 means from all soluble substances, is called lignine. It is 
 composed of carbon, hydrogen and oxygen, these are its 
 constant elements, whether it be obtained from the porous 
 willow, dense boxwood, or the fibres of linen and cotton. The 
 hydrogen and oxygen exist in the same proportions as in 
 water; so that lignine is apparently only carbon and water: 
 but distillation does not prove this to be the case. 
 
 Pure lignine is white: it undergoes no decomposition in dry 
 air, or under water which contains no air; but by the joint 
 action of heat and air it undergoes changes which produce 
 another series of compounds, very different from itself. Woody 
 fibre is arranged in cells and tubes : the walls of these cells 
 and tubes are composed of cellular woody fibre, and covered 
 by a solid substance called incrusting matter. It is difficult to 
 separate the two, so as to determine by analysis the precise 
 difference in their composition. It is evident that woody fibre 
 constitutes the great mass of all forest trees, and also of the 
 dried stalks and roots of most plants. 
 
 STARCH. 
 
 Starch is probably the most abundant product of vegeta- 
 tion, with the exception of woody fibre. It is obtained from 
 the flower of all the grains, many roots, the .pith and seeds of 
 many other plants. Starch is obtained in the form of a fine 
 
CHEMISTRY. oU 
 
 powder, consisting of rounded, shining white particles. They 
 are tasteless and inodorous, and when kept dry undergo no 
 change in any length of time. Starch is insoluble in cold 
 water or alcohol, but dissolves readily in hot water, and forms 
 a jelly. Starch, like lignine, is composed of carbon, hydrogen 
 and oxygen. Starch is a delicate test for the presence of 
 iodine. 
 
 Arroiv root, sago, tapioca, inulme and lichenine are varieties 
 of starch. It is frequently deposited among the woody fibres 
 and in the inner bark of trees, as the willow, beech and pine. 
 This is the reason, [says Prof. Johnston,] that the branch of a 
 willow takes root so readily, and also, that the bark of trees is 
 used in some countries as food. 
 
 GUM. 
 
 Gum arabic is a familiar example of this class of substances ; 
 the gum from peach and plumb trees is similar in constitution. 
 Pure gum is light colored, having a sweetish taste, destitute of 
 odor, insoluble in alcohol, soluble in water, with which it forms 
 an adhesive mucilage. Gum is composed of carbon, hydrogen 
 and oxygen : it exists in the seeds and other parts of many 
 plants. Arabine, carasine, bassorine, dextrine, and traga- 
 canthine are all varieties of gum: this, as well as starch, is 
 highly nutricious as food. 
 
 SUGAR. 
 
 Sugar exists in many plants, but is obtained principally 
 from sugar cane, sugar maple, and beet root. Pure sugar is 
 in large transparent crystals, having a pure sweet taste, desti- 
 tute of odor, soluble in water, highly nutricious. Its constit- 
 uent elements are carbon, hydrogen and oxygen. Grape 
 sugar, sugar of milk, and sugar of mushrooms, are all va- 
 rieties. 
 
60 SCIENTIFIC AGRICULTURE. 
 
 MUTUAL RELATIONS OF LIGNINE, STARCH, GUM AND SUGAR. 
 
 It is a remarkable fact, that these four substances, though 
 possessing properties so entirely different, are composed of the 
 same elements in the same proportions. This fact, so evident 
 to the analytical chemist, is still little more comprehensible to 
 him, after his most profound investigations, than to the most 
 unlearned. And, although we can readily separate the ele- 
 ments of these bodies, we cannot combine the same elements 
 so as to form any one of them. The formulae below show 
 their constitution. 
 
 Woody fibre is composed of C. 12, H. 10, 0. 10. 
 
 Starch " " C. 12, H. 10, 0. 10. 
 
 Gum " ' " C. 12, H. 10, 0. 10. 
 
 Cane sugar " C. 12, H. 10, 0. 10. 
 These four substances are capable of being transformed ono 
 into another, as woody fibre into starch, starch into sugar, gum 
 into sugar, &c., as will be hereafter described. 
 
 GLUTEN. 
 
 Gluten exists in the flour of wheat, rye, barley and oats, 
 from which it may be obtained by washing the paste or dough 
 for a long time in water. It is a soft, tenacious, elastic, grayish 
 substance, with very little taste or odor. It is nearly insoluble 
 in water, but easily dissolved by alcohol, acids and alkalies : 
 when moist gluten is dried at 212; it becomes a semi-trans- 
 parent, yellowish, brittle mass, resembling glue. Wheat con- 
 tains more gluten than any of the other grains: it contains, 
 according to its quality, from 8 to 35 per cent. Gluten is 
 highly nutricious: it is composed of carbon, hydrogen, oxygen 
 and nitrogen. 
 
 ALBUMEN. 
 
 Albumen is a gelantinous, colorless substance, without taste 
 or smell, dissolved by acids and alkalies, but insoluble in 
 
CHEMISTRY. 61 
 
 alcohol and water. Albumen resembles the white of eggs, 
 which is animal albumen; it abounds in the juices of many 
 plants, as cabbage, turnips, <fec. : its composition is identical 
 with that of gluten, which is as follows: 
 
 Carbon, 54.76 
 Hydrogen, 7.06 
 Oxygen, 20.06 
 Nitrogen, 18.12 
 
 100 
 
 When exposed to air and moisture it undergoes decomposi- 
 tion, which is attended by the formation of vinegar and ammo- 
 nia. It possesses highly nutrient properties. 
 
 WAX. 
 
 Wax is found in many plants : beeswax may be taken as 
 the type of this class of bodies. It is insoluble in water or 
 cold alcohol, but dissolved by boiling alcohol, which separates 
 it into two proximate principles, viz: cerine and myridne. 
 Beeswax melts at 144, and when freed from its yellow 
 coloring matter, has a white crystaline appearance, Cerine, 
 boiled with a solution of potash, forms soap. Wax is supposed 
 to be derived from the oils of plants. 
 
 RESIN. 
 
 Resin is obtained from the pitch of various of the coniferous 
 family, such as the pine, hemlock, fir, &c. Resin is highly 
 inflammable, insoluble in water, but readily dissolved by 
 alcohol and essential oils: the principal resins are, common 
 rosin, copal, mastic and elemi. Common rosin is what remains 
 after the distillation of pitch to obtain spirits of turpentine. 
 
 CAMPHOR. 
 
 Camphor is a gum-like, white, brittle, semi-transparent sub- 
 stance, having a strong peculiar odor and an acrid bitter taste. 
 
 6 
 
62 SCIENTIFIC AGRICULTURE. 
 
 It exists in several plants, but is found in most abundance in 
 the camphor tree. It is highly inflammable, and resembles in 
 some respects the resins : it is nearly insoluble in water, but 
 dissolved by alcohol and oils. 
 
 CAOUTCHOUC. 
 
 Caoutchouc, or India Rubber, is the product of several 
 trees in tropical countries, from which it exudes in tlie form of 
 a milky juice which hardens by contact with the air. It is 
 insoluble in water or alcohol, and dissolves but imperfectly in 
 ether; its proper solvent is volatile oils: oil of turpentine dis- 
 solves it, but it dries imperfectly afterwards. At a tempera- 
 ture a little above that of boiling water it melts and never 
 resumes its elasticity : in its properties, it possesses considera- 
 ble resemblance to the resins: it may be^converted into a 
 volatile oil by distillation. 
 
 FIXED OILS. 
 
 Oils are divided into two classes, viz: fixed and volatile: 
 the former are capable of being distilled without decomposi- 
 tion, the latter are not. The animal and vegetable oils agree 
 in their properties very nearly in every respect. The fixed 
 oils are obtained by pressure, from the seeds of various plants, 
 as the castor bean, flax seed, <fcc. 
 
 They have little taste or odor, are lighter than water, con- 
 geal at a lower temperature, and require a higher heat than 
 that of boih'ng water to evaporate them. They are highly 
 nutricious, and combine with soda to form soap: by contact 
 with air they become rancid and gummy : they are all inso- 
 luble in water, and, with the exception of castor oil, but 
 slightly so in alcohol: they dissolve easily in ether and the 
 volatile oils. 
 
 VOLATILE OILS. 
 
 Volatile or essential oils are numerous in the vegetable 
 kingdom, and give to plants their peculiar odors: they are 
 
CHEMISTRY. 63 
 
 obtained by distillation. Most of them are lighter than water, 
 highly combustible, and dissolve in alcohol to form essences: 
 when pure, they are colorless, and evaporate from paper 
 without leaving a greasy stain, as fixed oils do: they do not 
 form soap with alkalies, 
 
 VEGETABLE ACIDS. 
 
 Acids are numerous in the vegetable kingdom, and possess 
 much interest and importance ; but the limits of this book will 
 not admit of a detailed account of them : they constitute but a 
 small part of the plants from which they are derived. The 
 most important are the acetic, oxalic, tartaric, citric and malic 
 acids. The general properties of acids have already been 
 described. 
 
 VEGETABLE ALKALIES. 
 
 Alkalies exist in all plants, and always in the form of salts, 
 or in combination with an acid. Potash, lime and soda, 
 although found in plants in greater abundance than the 
 others, are not vegetable alkalies : the true vegetable alkalies 
 are, morphia, quinia, strychnia, <fec. 
 
 METALLIC OXIDES AND EARTHS found in plants have already 
 been named, and their properties will be described in another 
 chapter. The few organic proximate elements of plants which 
 have been briefly described, are but a comparatively small 
 part of the whole number: only such as possess most interest, 
 and are most common and necessary to be understood, have 
 been selected. 
 
 DIASTASE. 
 
 Diastase is a white, tasteless powder, formed during the 
 process of malting barley, and also during the germination of 
 plants. The properties of diastase are not well understood, 
 it is supposed to be the first product of the putrefactive fer- 
 mentation of vegetable gluten and albumen. 
 
64 SCIENTIFIC AGRICULTURE. 
 
 EXTRACTIVE MATTER. 
 
 Extractive matter (apotheme) exists in vegetables, and may 
 be obtained by steeping them in hot water, and then evapo- 
 rating the water, when a brown powder will remain, which is 
 but slightly soluble in water or alcohol, but soluble in alkalies. 
 Its nature is not well understood ; Dr. Kane, however, supposes 
 it may be identical with ulmic or hamic acid. It is not nutri- 
 cious. 
 
 TANNIN. 
 
 Tannin exists in the bark of most trees, but most abun- 
 dantly in the bark of the oak, horse chestnut and hemlock. It 
 is an astringent brownish powder, soluble in alcohol and water. 
 It has an astringent taste and is destitute of odor : it combines 
 with animal gelatine and forms an insoluble precipitate ; hence 
 by soaking the skins of animals in a solution containing tannin, 
 it is converted into leather, which is no longer subject to 
 putrefaction. It is composed of carbon, hydrogen and oxygen : 
 it is not nutricious : it precipitates most metallic solutions, and 
 is hence used in practical chemistry as a re-agent. 
 
 COLORING MATTER. 
 
 The matter which constitutes the basis of vegetable colors 
 is found in most plants. "The organic coloring principles, 
 [says Dr. Fownes,] with the exception of one red dye, cochi- 
 neal, are all of vegetable origin." The art of coloring is based 
 upon the affinity which exists between the coloring matter and 
 the fibres of the different fabrics to be colored. This is 
 stronger in woolen than in cotton and linen ; hence in dyeing 
 the two latter a third substance, called a, mordant, is used, 
 which strengthens their affinity: for this purpose, salts of 
 alumina, iron and tin are used. 
 
 The coloring principle of vegetable blues is indigo: that of 
 madder red is alizarine: of madder yellow, xanthine: the 
 green color of plants depends upon a substance called chloro- 
 
CHEMISTRY. 65 
 
 phylle. The coloring principle of logwood is hcematoxyline : 
 carmine is a beautiful pink color derived from the cochineal 
 insect: several substances produce yellow and brown. 
 
 Nearly all vegetable colors are destroyed by the action of 
 solar light, and all of them, without exception, by the action 
 of chlorine gas : acids and alkalies destroy or change them. 
 No coloring principle has yet been found in plants, capable of 
 being transferred to other bodies so as to produce a green: 
 greens are therefore produced by the action of blues upon a 
 base of yellow. Substantive colors are those which combine 
 directly with the fibres of cloth without the intervention of a 
 mordant : adjective colors require the assistance of a mordant 
 to make them permanent, 
 
 INORGANIC ELEMENTS OF PLANTS. 
 
 Besides the organic elements which enter into the compo- 
 sition of plants, and which, as before stated, are themselves in 
 most cases composed of the four principal elements, carbon, 
 oxygen, hydrogen and nitrogen, there are several inorganic 
 substances, which are constantly present in all plants, and in 
 about the same relative proportions in the same plant in all 
 cases. These are in combination with the gases and with one 
 another. Chlorine, iodine, sulphur, phosphorus, potassium, 
 sodium, calcium, magnesium, aluminum, silicon, iron and man- 
 ganese, 
 
 CHLORINE. 
 
 Chlorine is a yellowish green gas, having a pungent, suffo- 
 cating odor ; it is soluble in water, extinguishes a lighted taper, 
 has a specific gravity of 2.47, and when submitted to the 
 pressure of four atmospheres, is condensed into a limpid, 
 yellow liquid. This gas is a supporter of combustion, but not 
 of animal life : a piece of phosphorus, gold leaf, potassium or 
 sodium, introduced into it, inflame and burn spontaneously. 
 Chlorine has but little affinity for oxygen, its chemical pre- 
 
 e* 
 
66 SCIENTIFIC AGRICULTURE. 
 
 ferences being principally hydrogen and the metals : it is not 
 found in an uncombined state in nature. The most charac- 
 teristic property of this gas is its bleaching power ; it decom- 
 poses readily the most permanent organic coloring principles ; 
 the presence of water is necessary to develop the bleaching 
 properties of chlorine. 'This gas is a highly disinfecting agent. 
 Common salt is a compound of chlorine and sodium. 
 
 IODINE. 
 
 Iodine is a solid substance, in shining lead-colored scales. 
 It is volatilized or converted into vapor by a moderate haat, 
 the vapor has a beautiful violet color, and an odor resembling 
 chlorine. It is soluble in water, and more perfectly so in 
 alcohol. It is obtained from the ashes of marine plants, but 
 has not as yet been detected in any of the plants cultivated 
 for food. Both plants and animals confined in the vapor of 
 iodine soon perish. 
 
 SULPHUR. 
 
 Sulphur exists in considerable abundance in nature; the 
 most common source of the sulphur of commerce is volcanic 
 action : it is sublimed and thrown out in large quantities from 
 the earth, it exists also in natural waters. It is a yellowish 
 green powder, having little taste or smell, it is but slightly 
 soluble in water. When heated it exhales white fumes of an 
 intensely suffocating odor, these fumes are called sulphurous 
 add. This gas is destructive to both animal and vegetable 
 life: it possesses bleaching properties. There are several 
 compounds of sulphur which are essential to the growth of 
 vegetation. 
 
 PHOSPHORUS. 
 
 Phosphorus is a solid substance, having the consistence of 
 wax, and of a pale yellow color: when exposed to the air, it 
 takes fire spontaneously and burns with a pale blue flame, 
 scarcely visible except in the dark. When heated, however, 
 
CHEMISTRY. 
 
 67 
 
 it takes fire and burns with a brilliant flame and intense light, 
 with the evolution of dense white fumes. 
 
 It is not found in nature in an uncombined state, "and is 
 not known [says Johnston,] to be susceptible of any useful 
 application in practical agriculture." Phosphoric acid results 
 from the combination of 'the fumes of burning phosphorus 
 with the oxygen of the atmosphere. It has the characteristic 
 properties of acids, and unites with lime, soda and potash, to 
 form phosphates. This acid is not found in nature in a free 
 state, but the compounds of phosphorus are extensively dif- 
 fused throughout nature, and are essential to the growth of 
 all cultivated plants. 
 
 CATALOGUE OF THE COMPOUNDS DERIVED FROM THE INORGANIC 
 ELEMENTS OF PLANTS. 
 
 Sulphurous acid, 
 
 Sulphuric " 
 
 Phosphoric " 
 
 Potash, 
 
 Soda, 
 
 Lime, 
 
 Magnesia, 
 
 Chloride of Potassium, 
 " Sodium, 
 
 " Calcium, 
 
 " Magnesium, 
 
 First Chloride of Iron, 
 
 Second " " " 
 
 Carbonate of Soda, 
 
 Bi-carbonate " 
 
 Nitrate " 
 
 Sulphate 
 
 Phosphate " 
 
 Bi-phosphate " 
 
 Alumina, 
 Silica, 
 
 Protoxide of Iron, 
 Peroxide " 
 Protoxide of Magnesia, 
 Sesquioxide " 
 
 Peroxide " 
 
 Sulphuret of Potassium, 
 Sodium, 
 Calcium, 
 Iron, 
 
 Bi-sulphuret " 
 Carbonate of Potash, 
 Bi-carbonate " 
 Sulphate " 
 
 Nitrate " 
 
 Binoxalate " 
 
 Bitartrate " 
 
 Phosphate 
 
SCIENTIFIC AGRICULTURE. 
 
 Carbonate of Lime, Bi-p'uospliate of Potash, 
 
 Sulphate " Carbonate of Magnesia, 
 
 Nitrate " Bi-carbonate " 
 
 Phosphate " Sulphate 
 
 Bi-phosphate " Nitrate *' 
 
 Silicate of Potash, Phosphate " 
 
 Bi-silicate " Sulphate of Alumina, 
 
 Silicate of Soda, Phosphate " 
 
 Bi-silicate " Silicate " 
 
 Silicate of Lime, Carbonate of Iron, 
 
 " Magnesia, Sulphate " 
 
 Carbonate of Magnesia, 
 Sulphate 
 
 These are not all the compounds found in plants; but they 
 are those which exist in most plants, and which are more or 
 less essential, in some quantity, to the healthy growth and 
 maturity of the various parts of the vegetable organization. 
 
CHAPTER V. 
 
 FERMENTATION. 
 
 Fermentation is a peculiar decomposition or transformation of the ele- 
 ments of a complex organic substance, by the agency of some 
 external disturbing force different from ordinary chemical attraction, 
 as heat, air, or contact with some other body similarly affected. 
 
 Liebig. 
 
 THE compounds which are capable of fermentation, or any 
 similar change, are those in which a weak affinity or equilib- 
 rium exists, and is consequently easily disturbed and overcome, 
 by several different agencies, such as heat, acids, oxygen, 
 chlorine, &c. If we add to a solution of sugar and water a 
 small quantity of any organic substance which is itself in the 
 act of slow decomposition, the sugar becomes affected in the 
 same way, and is changed to carbonic acid and alcohol 
 
 This is called vinous fermentation: another form of vinous 
 fermentation is that which takes place in the transformation of 
 must into wine: when the expressed juice of the grape is 
 exposed to a temperature of about 70 F., its own temperature 
 is raised, carbonic acid is given off, a scum rises to the surface* 
 and a sediment subsides to the bottom, and the must is changed 
 to wine. This is the simplest case of fermentation : yeast is 
 peculiarly effective in producing this kind of fermation. Yeast 
 is the product of the vegetable gluten or albumen in fermen- 
 
SCIENTIFIC AGRICULTURE. 
 
 tation. Tiie fermenting power of yeast is destroyed by boiling, 
 by alcohol, by many salts and acids, and generally by all those 
 agencies which render albimnn and gluten insoluble. 
 
 Besides yeast, there are several vegetable substances, as 
 gluten, albumen, caseine and fibrine, which, when in a state of 
 decomposition, act as ferments on a solution of sugar. The 
 same effect is produced, also, by animal gluten, albumen, flesh 
 and blood, after putrefaction has commenced. When wine 
 and cider are exposed to the air at a certain temperature, a 
 second fermentation, called the acetous, takes place, and they 
 are changed to vinegar: during this change oxygen is absorbed 
 from the air, and carbonic acid is evolved : " but the apparent 
 cause of the formation of vinegar is the abstraction of hydrogen 
 from the alcohol, so as to leave the remaining elements in such 
 proportions as to constitute acetic acid. The presence of nitro- 
 gen seems to be necessary to the composition of all ferments. 
 The precise nature of the changes which take place during 
 fermentation are not yet precisely understood or explained. 
 
 " We can offer no other explanation of these facts of fermen- 
 tation than this, that when a body in a state of progressive 
 change, the particles of which are in a state of motion, is 
 placed in contact with another body, the particles of which 
 are in a state of unstable equilibirum, the amount of motion 
 mechanically communicated to the particles of the latter from 
 those of the former is sufficient to overturn the existing equi- 
 librium, and by the formation of a new compound, establish a 
 new equiblirum more stable under the given circumstances." 
 
 [Turner. 
 
 METAMORPHOSIS OF ORGANIC ELEMENTS. 
 
 There are certain organic compounds which, from the com- 
 plexity of their constitution and consequent weakness of affinity, 
 are peculiarly disposed to decomposition and change of elemen- 
 tary form. Among these are starch, gum, sugar and lignine, 
 the first three of which are composed of the same elements in 
 the same proportions. 
 
CHEMISTRY. 71 
 
 These are disposed to change of elementary form whenever 
 the balance of opposing forces is destroyed: that is, whenever 
 by the agency of some external disturbing force, as heat, air or 
 water, the affinity which holds these elements together is over- 
 come, the elements are separated entirely, or one element is 
 replaced by another ; and thus lignine is changed into starch, 
 starch into sugar, &c. 
 
 This intimate relation of composition among these substances 
 renders it plain that they may all occur together in the same 
 plant, and that when one occasionally disappears from the 
 plant, it may be replaced entirely or in part by another; and 
 this is really the case. Lignine or woody fibre may be changed 
 to starch by boiling sawdust in water so as to separate all 
 soluble matters, then drying it in an oven and fermenting with 
 yeast. In this way the author has made bread of beech wood, 
 which was but little inferior to that made from unbolted wheat 
 flour. 
 
 Woody fibre may be transformed to starch, also, by the 
 action of sulphuric acid or caustic potash. 
 
 Starch, when gradually heated to a temperature not ex- 
 ceeding 300 F., acquires a brownish tint, and is changed to 
 gum. Starch may be changed to gum by dissolving it in hot 
 water, and allowing it to remain in a cold place for a few 
 months ; or it may be changed more rapidly by boiling it in 
 water for a length of time. By the action of sulphuric acid, 
 also, starch may be changed to gum, and this gum again into 
 grape sugar. 
 
 Gum arable may be changed to sugar by the agency of 
 chalk and sulphuric acid. [Berzelius. 
 
 Cane sugar which is crystalized, if heated to a temperature 
 of 360 F., gives off two atoms of water and is changed to 
 caramel: this is an uncrystallizable sugar, containing one pro- 
 portion of oxygen and one of hydrogen less than cane sugar. 
 Cane sugar may be changed to grape sugar by digesting it in 
 
V2 SCIENTIFIC AGRICULTURE. 
 
 dilute sulphuric acid at a gentle heat. The formula for these 
 two varieties of sugar is as follows : 
 
 Cane Sugar. Dry Grape Sugar. 
 
 Carbon, 12, Carbon, 12, 
 
 Hydrogen, 10, Hydrogen, 12, 
 
 Oxygen, 10. Oxygen, 12. 
 
 From the fact that we can produce these metamorphoses at 
 pleasure, it is easy to conceive that they may take place even 
 more readily and perfectly in the vegetable organization, than 
 by the comparatively clumsy operations of the chemical labor- 
 atory. This is one of an infinite number of the beautiful 
 processes of nature which modern chemistry has discovered. 
 
PART II, 
 
 GEOLOGY. 
 
 CHAPTER I. 
 
 GEOLOGY investigates the nature, composition, origin, struc- 
 ture, and arrangement of the materials of which the earth 
 is composed. Geology may be divided into three parts, viz: 
 1. Chemical Geology, which investigates the chemical nature 
 and composition of the various materials of which the earth 
 is made up. 2. Mechanical Geology, which treats of the 
 arrangement, structure and relative position of these various 
 materials. 3. Historical Geology, which treats of then: relative 
 ages and origin, and the changes which they are undergoing.* 
 
 Every part of the earth, including air and water, except 
 undecomposed animal or vegetable matters, is regarded as 
 mineral. 
 
 The term rock, in geological language, includes besides the 
 solid parts of the globe, the loose materials, such as sand, 
 
 * This division is proposed by the author, and is, like all the othe rs 
 which have been proposed, imperfect, and, in some respects, objec- 
 tionable. It has the advantage of being plain and convenient: such a 
 division, however, whether perfect or imperfect, is not indispensable to 
 the successful study of Geology. 
 
74 SCIENTIFIC AGRICULTURE. 
 
 gravel, clay, soils, <fec., which constitue a part of its crust 
 " Taken as a whole, the earth is about five times heavier than 
 water, and two and a half times heavier than common rocks." 
 The density of the earth increases from the surface towards 
 the centre. The surface of the earth beneath the ocean, as 
 well as the dry land, is elevated into hills, with plains and 
 Tallies intervening. The mean depth of the ocean is estimated 
 at between two and three miles; from the phenomena of tides, 
 the Atlantic, in its middle part, is supposed to be over nine 
 miles deep. 
 
 DEFINITION OF TERMS. 
 
 Rocks are divided into two great classes, viz: stratified and 
 unstratified. 
 
 Stratification consists of the division of a rock into regular 
 parallel planes or leaves, varying in thickness from that of thin 
 paper, to several yards. Strata are often tortuous and variable 
 in thickness in different parts of the same lamina or layer; 
 "nevertheless, the fundamental idea of stratification, is that of 
 parallelism in the layers." "The term stratum is sometimes 
 employed to designate the whole mass of a rock, while its 
 parallel subdivisions are called beds, or layers." So, also, of 
 sand, clay, gravel, &c. 
 
 The term bed is used to designate a layer or mass of rock 
 more or less irregular, lenticular or wedge shaped, lying 
 between the layers of another rock, such as beds of coal, 
 gypsum or iron. 
 
 Fig. 1. 
 
 - - - - "Without lamina. 
 
 - With waved lamina. 
 
 Finely laminated. 
 
 - Coarsely laminated. 
 
 - - - Obliquely laminated 
 
 - - - - Parallel lamina. 
 
GEOLOGY. 
 
 " A seam is a thin layer of rock that separates the beds or 
 strata of another rock, as a seam of coal, limestone, <fec." 
 
 A joint is a separation of rocks, both stratified and unstrati- 
 fied, into masses of some determinate shape : joints are more 
 or less parallel, and usually cross the beds obliquely. 
 
 Cleavage planes are divisions in rocks, which do not coincide 
 with those of stratification, lamination or joints. They are 
 supposed to result from a crystaline arrangement of the par- 
 ticles of the rock. 
 
 Fig 2 Cleavage Planes. 
 
 d A A 
 
 A A a B 
 
 [Fig. 2 exhibits the planes of stratification, B, B, the joints, A, A, A, 
 A, and the slaty cleavage, d, d.] 
 
 Horizontal strata are those which have little or no inclina - 
 tion, but lie parallel Fig " 3 ' Horizontal *** 
 
 with the horizon: this 
 position, however, 
 rare, almost all strata being more or less inclined. 
 
 The Dip of strata signifies the angle which they form with 
 
 the horizon. Fig. 4. Dip and Outcrop. 
 
 utcrop. When 
 strata are uncovered 
 above the surface, or 
 protrude from the side of a hill so as to be visible, they are 
 said to crop out. 
 
 An Escarpment is formed when strata terminate abruptly, 
 so as to form a precipice. 
 
76 SCIENTIFIC AGRICULTURE. 
 
 A Fault in a rock is the dislocation of strata, so that their 
 continuity is destroyed, and a series of strata on one or both 
 sides of the fracture are forced from their original position, 
 and raised one above another, or moved laterally. Faults are 
 generally filled with clay, sand and fragments of other rocks. 
 
 A Gorge is a wide and open fissure or fault: when still 
 wider, with sloping sides and rounded at the bottom, it is 
 called a valley. 
 
 Fig. 5. Dyke. 
 
 A Dyke is a mass or wall of 
 rock interposed between the 
 ends of a dislocation, so as to 
 break their continutity: dykes 
 rarely send off branches. 
 
 Veins are portions of rocks smaller than dykes, proceeding 
 from some large mass, and ramifying through a rock of a 
 different kind. Metallic veins were originally melted metals, 
 which were injected into the fissures and crevices of rocks by 
 some subterranean force. 
 
 Fossil. This term includes those petrified remains of plants 
 and animals which are found in alluvium, or imbedded in solid 
 rock, and constituting part of its structure. 
 
 Formations. The term formation is used to designate a 
 group of rocks having some character in common, either in 
 relation to age, origin or composition. JSvery formation con- 
 sists of several varieties of rock, all agreeing in certain qualities, 
 and occupying such relative situations as to indicate that they 
 were formed during the same period and under similar circum- 
 stances. Thus we speak of graywacke formation, gneiss for- 
 mation, coal formation, &c. 
 
 CLASSIFICATION OF ROCKS. 
 
 Many different classifications of rocks have been proposed, 
 none of which is entirely unexceptionable : the present state of 
 Geological science will admit of our adopting any one of them* 
 
GEOLOGY. 
 
 77 
 
 without the risk of incurring much inaccuracy. It is not 
 designed in this treatise to give a full classification of all the 
 rocks, with a detailed description of their characters, but only 
 the outlines of classification, and a brief description of such as 
 are deemed most important to our present purpose. 
 
 Notwithstanding the apparent discrepancies among the 
 systems of classification, " in all the essential principles, geolo- 
 gists are nearly agreed : they all admit one class to be stratified 
 and another unstratified: one portion of the stratified rocks 
 to be fossiliferous and another portion not fossiliferous : and 
 they generally agree also as to the extent of the different 
 distinct formations. Now these three principles are all that 
 are essential for classification ; and some of the best geologists 
 limit themselves to these." [Hitchcock.] 
 
 One very common and natural classification of rocks is, into 
 two great families, viz : stratified and unstratified. We shall 
 give the outlines of two others, viz : the improved Wernerian 
 and that of Mr. Lyell. 
 
 IMPROVED WERNERIAN CLASSIFICATION. 
 
 ( Alluvium, 
 ALLUVIAL. 
 
 TERTIARY. <J Tertiary strata. 
 
 ChalTc, 
 
 Green sand, 
 
 Wealden, 
 
 Oolitic system, 
 
 Lias, 
 
 New red sandstone, 
 
 Coal formation, 
 
 Carboniferous limestone, 
 
 Old red sandstone. 
 
 SECONDARY. 
 
 TEANSIT.ON. 
 
 Silurian system, 
 ywt 
 
 *7 
 
PRIMARY. 
 
 78 . SCIENTIFIC AGRICULTURE. 
 
 f Clay slate, 
 
 Quartz rock, 
 
 Hornblende slate, 
 
 Talcose slate, 
 j Primary limestone, 
 
 Serpentine, 
 
 Mica slate, 
 
 Gneiss. 
 
 Alluvium. If we commence at the surface of a soil which 
 has been formed by the successive deposits of annual floods, or 
 the freshets of rivers, and descend to the lowest class of rocks, 
 vi Zj the primary, we shall pass through the different classes 
 of rocks in the following order. The first few feet, usually 
 less than one hundred, is composed of vegetable and earthy 
 matters, loam, sand and fine gravel, deposited in horizontal 
 beds. 
 
 Drift. The second formation is made up of coarse and fine 
 sand, gravel, and. sometimes clay, containing rounded masses 
 of rock called boulders. This mixture is often horizontally 
 stratified. 
 
 Tertiary. The third series is composed of clay, sand, gravel 
 and marl, with occasional beds of quartzose and calcareous 
 rock, which have been deposited from water in a quiet state. 
 This series also contains many organic remains : the strata are 
 usually horizontal, but sometimes they have a small dip. 
 
 Secondary. The next series below the tertiary is composed 
 mostly of solid rocks : these rocks are made up mainly of sand, 
 clay and pebbles cemented together : these are interstratified 
 by organic remains and several varieties of limestone, they 
 usually dip at various angles. The older fossiliferous rocks 
 included in this series are sometimes called transition rocks. 
 
 Primary Transition. This class includes both stratified 
 and unstratified crystaline rocks, which are destitute of organic 
 remains. The unstratified rocks lie below the stratified ones 
 wherever they have been found : hence it is inferred that the 
 interior of the globe consists of unstratified crystaline rocks. 
 
80 SCIENTIFIC AGRICULTURE. 
 
 L YELL'S CLASSIFICATION. 
 
 Mr. Lyell comprehends all the various rocks which compose 
 the crust of the earth in four great classes, depending for their 
 distinctive characters on their origin and age. These are 
 named as follows. 
 
 f AQUEOUS, 
 J VOLCANIC, 
 j PLUTONIC, 
 ^ METAMORPHIC. 
 
 Aqueous Rocks. This class, called also, the sedimentary 
 rocks, covers a larger portion of the earth's surface than any 
 of the other three classes. They are stratified, and supposed 
 to have been deposited by water, both running and quiescent: 
 they contain fossils, shells and coals. 
 
 Volcanic Roclcs. This class of rocks has been produced, 
 both in ancient and modern times, by the action of volcanic 
 fires or subterranean heat. "They are for the most part 
 unstratified, and devoid of fossils:" they are more partially 
 distributed than aqueous formations, at least in respect to 
 horizontal extension. 
 
 Plutonic Rocks. This class of rocks has been formed, " at 
 great depths in the earth, and they have cooled and crystalized 
 slowly, under enormous pressure, where the contained gases 
 could not expand." They are more crystaline than the others, 
 have no cavities, and contain no organic remains. They lie 
 below, and are older than all others. 
 
 Metamorphic Rocks* These rocks, according to Mr. Lyell, 
 were originally deposited from water in regular strata, and 
 afterwards metamorphosed or changed by subterranean heat, 
 so as to assume a new and different texture. They contain no 
 pebbles, pieces of imbedded rock, nor organic remains, and are 
 often crystaline, as granite. They vary in color and compo- 
 
 * This class is considered as merely a hypothetical division by many 
 of the best Geologists. 
 
GEOLOOT. 81 
 
 sition. The degree of heat which produced the change in 
 those rocks was less intense than that which produced the 
 plutonic class, and was doubtless assisted by gaseous agency. 
 
 We have thus given a brief outline of two systems of classi- 
 fication, without, however, giving the reasons in favor of the 
 propriety of any theory or classification. Our limits will not 
 admit of a subdivision of the classes into orders, genera and 
 species, much other useful matter must also be excluded. 
 A few of the most important rocks and the metalloids have 
 been described, being thought indispensable to a proper under- 
 standing of the principles of geology and the constitution of 
 soils. 
 
CHAPTER II. 
 
 GRANITE. 
 
 GRANITE is a compound of three minerals, viz: quartz, 
 feldspar and mica : the different ingredients are sometimes in 
 coarse crystaline fragments, and in other cases so fine as to 
 be scarcely distinguishable by the naked eye. Granite is 
 most usually of a whitish or flesh color, it has, however, other 
 tints. Feldspar predominates in the composition of granite, 
 while the mica is in the smallest quantity. "These three 
 minerals are united in what is termed confused crystallization: 
 that is, there is no regular arrangement of the crystals in 
 granite as in gneiss." The coarse grained granites contain 
 the most interesting specimens of simple minerals, while the 
 finer kinds are best for architectural purposes. 
 
 Granite often preserves a uniform character through a great 
 extent of country, forming rounded hills: it is sometimes, 
 though not generally, subdivided by fissures into masses of a 
 cuboidal and columnar form. Where it is naked at the 
 surface, and exposed to atmospheric changes and action, it is 
 in a crumbling state, and covered with a scanty vegetation. It 
 is remarked by Lyell, that all granitic rocks are frequently 
 observed to contain metals, at or near their junction with 
 stratified rocks. 
 
 Granite is supposed to be the oldest, most abundant and 
 important of all the unstratified rocks. There are several 
 
GEOLOGY. 83 
 
 varieties of granite, viz: graphic granite, syenitic granite, 
 talcose granite, porphyritic granite, eurite and pegmatite: 
 these varieties have various proportions of each element, and 
 also various colors and crystaline arrangement. 
 
 SYENITE. 
 
 Syenite is composed of quartz, feldspar and hornblende : it 
 is sometimes called syenitic granite, it has received this name 
 from the ancient quarries at Syene in Egypt. It has the 
 appearance of granite, but its composition is different, horn- 
 blende being substituted for the mica in granite. Syenite, 
 according to Lyell, frequently loses its quartz and passes insen- 
 sibly into syenitic greenstone. 
 
 PORPHYRY. 
 
 Rocks of a homogeneous, compact structure, containing some 
 other crystaline mineral, of the same age with the base, are 
 called porphyry. The base, or principal mass of the rock, may 
 be greenstone, claystone, basalt, or other rock containing crys- 
 tals of feldspar, augite, olivine, <fec. 
 
 " True classical porphyry, [says Dr. Hitchcock,] such as was 
 most commonly employed by the ancients, has a base of com- 
 pact feldspar, with embedded crystals of feldspar." The term 
 porphyry is indefinite, and does not belong to any particular 
 rock. The term is of Greek origin, and signifies purple, but 
 this rock is of a variety of colors, and is the hardest and most 
 durable of all rocks. 
 
 GREENSTOXE. 
 
 This is a granular rock composed of feldspar and hornblende ; 
 the felsdpar is imperfectly crystalized : greenstone sometimes 
 contains augite and iron also. The hornblende predominates 
 in quantity over the other ingredients. 
 
 TRACHYTE. 
 
 Trachyte is a porphyritic rock of a grayish or whitish color, 
 
84 SCIENTIFIC AGRICULTURE* 
 
 composed principally of glassy feldspar, containing also crystals 
 of feldspar, mica, hornblende, and sometimes iron. It is rough 
 and harsh to the touch, hence its name from the Greek word 
 trachus, (rough:) it occurs in vast quantities in Europe and 
 South America, in volcanic regions, but is not found in the 
 United States. 
 
 BASALT. 
 
 " Basalt consists of an intimate mixture of augite, felspar 
 and iron, to which a mineral of an olive green color called 
 olivinc, is often superadded in distinct grains or nondular 
 masses." The iron is usually magnetic, and is sometimes 
 accompanied by the metal titanium, hence the name, "titani- 
 ferous iron." Augite is the predominant element in this rock: 
 basatt presses insensibly into most other varieties of trap rock. 
 True basalt does not occur in the United States. 
 
 AMYGDALOID. 
 
 Any rock containing almond shaped pieces of some other 
 mineral, as quartz, chalcedony, agate, calcareous spar, or zeo- 
 lite, may be denominated amygdaloid: the base may be wacke, 
 basalt, greenstone, or any other trap rock. Some amygdaloid 
 rocks have the almond shaped cells or cavities, which are 
 empty, and glazed on their sides by a glassy coating, showing 
 their igneous origin. 
 
 SERPENTINE. 
 
 This is a greenish colored rock, containing, according to Dr. 
 Hitchcock, 40 per cent, of magnesia, it is a hydrated silicate 
 of magnesia. Serpentine sometimes contains diallage, steatite, 
 talc, and some iron. It is classed by most authors among 
 unstratified rocks. Comparatively it is not a rock of great 
 extent: it is often associated with talcose slate. 
 
 LAVA. 
 
 Under the term lava, are embraced all the varieties of 
 
GEOLOGY. 85 
 
 melted matter thrown out by volcanoes: these are composed 
 almos't entirely of feldspar and augite. Some lavas are por- 
 phrytic, and contain imperfect crystals, "derived from some 
 older rocks, in which the crystals pre-existed, but were not 
 melted, as being more infusible in their nature." 
 
 When lava is cooled in the open air, it is light, porous and 
 spongy, and floats on water, as is the case with pumice stone ; 
 but when cooled under great pressure, at considerable depths 
 below the surface, solid rock is the result 
 
 There are several varieties of lava, varying in composition, 
 and also of different colors, as gray, whitish, greenish and dark: 
 fragments of granite and other rocks, several metals and 
 gases, water, sulphur, mud, glass, and various salts and acids, 
 are ejected from the craters of active volcanoes. 
 GNEISS. 
 
 Gneiss is composed of quartz, feldspar and mica, and some 
 specimens contain hornblende. This rock is essentially the 
 same as granite, except it is stratified. The laminated struc- 
 ture becomes obscure where the gneiss passes into granite: 
 its stratification is remarkably regular in some specimens, and 
 in others tortuous and irregular. This rock is said to be very 
 extensive in the United States, particularly in New England. 
 QUARTZ. 
 
 This rock is composed either of an aggregate of fine grains 
 or crystals compacted together, or of a solid homogeneous 
 mass of quartz, sometimes containing feldspar, mica, horn- 
 blende, talc or clay slate. " In these compound varieties, [says 
 Hitchcock,] the stratification is remarkably regular; but in 
 pure granular quartz, it is often difficult to discover the planes 
 of stratification." 
 
 It is alternated or interstratified with all the primary rocks, 
 in which case its structure is regular. Some quartz is capable 
 of sustaining a powerful heat without cracking or other 
 change, hence it makes an excellent fire stone. 
 
 8 
 
86 SCIENTIFIC AGRICULTURE. 
 
 HORNBLENDE SLATE. 
 
 Hornblende predominates in this rock, over the various 
 quantities of quartz, feldspar and mica which it sometimes 
 contains. ' When it contains much feldspar, it is not slaty, but 
 resembles greenstone. It is of a dark color, commonly asso- 
 ciated with, and passes insensibly into clay slate, mica slate 
 and gneiss. 
 
 CLAY SLATE. 
 
 This rock is composed mostly of fine clay, and is usually 
 more or less dark and shining from the mixture of chlorite and 
 black lead which it contains. " It may [says Lyell,] consist of 
 the ingredients of gneiss, or of an extremely fine mixture of 
 mica and quartz, or talc and quartz." It passes insensibly 
 into mica slate, talcose slate, or hornblende slate : on the other 
 hand it passes into unconsolidated clay. 
 
 Clay slate is the kind used for roofing: it varies in color 
 according to its composition, from greenish or bluish gray to 
 lead color. This rock, as well as the following, is used for 
 whetstones: the best hones are compact feldspar, and are 
 erroneously supposed to be petrified wood. 
 
 MICA SLATE. 
 
 This rock is a compound of quartz and mica, the mica being 
 in the greatest quantity. This is one of the most common 
 and abundant of the stratified rocks. It sometimes contains 
 beautiful twelve-sided crystals of garnet in considerable abun- 
 dance : beds of pure quartz also occur in this rock. 
 
 PRIMARY LIMESTONE. 
 
 This rock is sometimes in thick beds of white, bluish, 
 greenish or gray granular marble, such as is used in sculpture : 
 it sometimes contains, mica, quartz, hornblende, feldspar and 
 talc. It is both stratified and unstratified; sometimes being in 
 thick beds without any marks of mechanical arrangement, and 
 
GEOLOGY. 
 
 87 
 
 at others it is in laminated leaves or scales like slate, of various 
 thickness. 
 
 TALCOSE SLATE. 
 
 Talc is the principal ingredient in this variety of slate, it 
 is sometimes in a pure state and sometimes mixed with quartz, 
 feldspar, mica, hornblende or limestone : it is a softish stone, 
 valuable for building purposes. There are several varieties. 
 
 Composition of Feldspar. 
 Silica, - - 65.21 
 
 Alumina, - - 18.13 
 
 Potash, 16.66 
 
 100.00 
 
 Composition of Basaltic Hornblende. 
 Silica, - 42.24 
 
 Alumina, - - 13.92 
 
 Lime, - 12.24 
 
 Magnesia, - 13.74 
 
 Protoxide of Iron, - 14.59 
 
 Oxide of Manganese, - - - p. 3 3 
 
 Composition of Mica. 
 Silica, - 
 
 Alumina, - - 
 
 Protoxide of Iron, - 
 Potash, - 
 Oxide of Magnesia, 
 Fluoric Aeid, - 
 Water, - 
 
 CHALK. 
 
 97.06 
 
 46.10 
 31.60 
 8.65 
 8.39 
 1.40 
 1.12 
 1.00 
 
 98.26 
 
 Chalk is similar in composition to carbonate of lime, viz: 
 
88 SCIENTIFIC AGRICULTURE. 
 
 carbonic acid, 44, lime, 56, 100. It is a pulverizable rock, 
 of several varieties, which have resulted from the impurities 
 which were deposited with it. The chalk beds contain great 
 quantities of flint, which is dispersed through them in small 
 masses. Chalk also contains organic remains: it is a durable 
 building stone, and is used for docks, &c. ; some ancient 
 buildings are of chalk : no chalk has been found in America. 
 
 ROCK SALT. 
 
 This cannot be considered a rock, but yet it occurs in vast 
 beds, and in connection with rocks, at great depths in the 
 earth. In its pure form it is a transparent crystaline salt, 
 having the appearance of flint glass : the impure specimens are 
 reddish or bluish, and mixed with sulphate of soda and muriate 
 of magnesia. Its origin is not exactly known ; it is supposed, 
 however, to have resulted from the evaporation of sea water. 
 It is found in Spain, Poland, Hungaiy, Germany, and in some 
 parts of Asia and America. 
 
 COAL 
 
 Mineral or fossil coal is of several varieties, differing in 
 density and weight, and of a dark color, varying from brown to 
 jet black. It is composed of carbon and bitumen, and usually 
 contains some other matters. Coal is undoubtedly of vegetable 
 origin : as evidence of this, the organic structure of coal can be 
 seen in some specimens so distinctly that about three hundred 
 species of plants have been discovered in the various kinds. It 
 contains also many species of fossil animals. 
 
 Coal beds vary in thickness, from a few feet to three thou- 
 sand or more, and are often several miles in length. The 
 manner in which such immense masses of vegetable matter 
 have accumulated during the lapse of ages, may be conceived 
 by reference to a single example. 
 
 "According to Bringier, the quantity of timber which 
 drifted into the Atchafalaya, an arm of the Mississippi, during 
 
GEOLOGY. 
 
 89 
 
 an overflow in 1812, amounted to 8,000 cubic feet per minute. 
 The raft thus collected at the mouth of the Red River, is sixty 
 miles long*, and in some parts fifteen miles wide." The quan- 
 tity which descends the Mississippi in a few years might 
 furnish sufficient matter for the largest coal bed known. 
 
 The varieties of coal are brown coal, or lignite, bituminous 
 coal, anthracite coal, and graphite, or black lead : this consists 
 of carbon and iron, and, according to Dr. Hitchcock, "appears 
 to be anthracite which has undergone a still further minerali- 
 zation." All these varieties of coal occur in seams or beds, 
 interstratified by sandstone and shales: brown coal is found 
 mostly in the tertiary, bituminous in the secondary series, and 
 also with new red sandstone and clay. 
 
 Anthracite is found in graywacke, mica slate, limestone, 
 gneiss, plastic clay, and almost all stratified rocks. 
 
 [Fig. 7 is a sketch of the great coal basin of South Wales, in Great 
 Britain, which contains seventy-three beds of coal, whose united 
 thickness is ninety-three feet.] Hitchcock. 
 
 *8 
 
PART III. 
 
 BOTANY. 
 
 CHAPTER I. 
 
 BOTANY is that branch of natural science which investigates 
 the nature and character of, and includes all knowledge in 
 relation to the vegetable kingdom. It treats of the structure, 
 habits, locality, uses, classification and nomenclature of every 
 species of plant known on the globe. 
 
 Botany is divided, for the sake of convenience and method, 
 into PHYSIOLOGICAL and SYSTEMATIC: Physiological Botany 
 resolves itself into Anatomy, Morphology and Vegetable Phy- 
 siology. 
 
 Anatomy treats of the organic structure and relations of all 
 the various parts of plants. 
 
 Morphology treats of their form, symmetry, and arrange- 
 ment. 
 
 Vegetable physiology treats of all the phenomena of the 
 vital functions, as absorption, exhalation, digestion, respiration, 
 circulation, germination, &c. 
 
 Systematic botany is divided into botanical classification, 
 special descriptive botany, glossology, and geographical botany. 
 
92 SCIENTIFIC AGRICULTURE. 
 
 Classification treats of the proper grouping and arrangement 
 of plants according to their natural affinities and characters. 
 
 Special descriptive botany consists in applying correctly the 
 generic and specific botanical names to parts. 
 
 Glossology consists in the explanation and application of 
 names to all the various organs of plants. 
 
 Geographical botany treats of the climate, country, zone 
 and locality to which the various species belong. 
 
 Finally, botany comprehends, in its most extended sense, a 
 knowledge of the relations of the vegetable kingdom to other 
 departments of natural objects, and the development of the 
 limitless resources of this part of the CREATOR'S vast plan for 
 the sustenance and happiness of his creatures. 
 
 PRIMARY DIVISIONS OF PLANTS. 
 
 The vegetable kingdom is divided into two great natural 
 families, viz : PHENOGAMIA, or that division which includes all 
 flowering plants, and CRYPTOGAMIA, or that which includes all 
 floioerless plants. 
 
 These two divisions are further distinguished by the dif- 
 ference in their elementary structure. The phenogamous, or 
 flowering plants, abound with the woody and vascular tissues ; 
 while the cryptogamous, or flowerless plants, consist almost 
 entirely of the cellular tissue. The phenogamia produce seeds 
 having the cotyledon and embryo, while the cryptogamia 
 produce minute organs called spores, having no such distinc- 
 tion of organs. The phenogamia are therefore called cotyle- 
 donous, and the cryptogamia, acotyledonous. In the former, 
 also, we find a system of compound organs, regularly and suc- 
 cessively developed, in the order of root, stem, leaf, flower and 
 seed, while the latter appear to be "simple expansions of 
 cellular tissue, without order, symmetry or proportion." 
 
 CLASSIFICATION OF PLANTS. 
 
 All natural sciences classify their respective objects under 
 
BOTANY. 93 
 
 certain fundamental divisions. The first of these divisions is 
 into CLASSES, the second divides classes into ORDERS, the 
 third divides orders into GENERA, the fourth divides genera 
 into SPECIES, and these are again divided into varieties. 
 
 The number now known on the whole earth, is between 
 80,000 and 100,000 distinct species of plants. The classifica- 
 tion of plants, and all other natural objects, is founded on the 
 resemblance and differences, in some one or more points, of the 
 individuals of each class, order, <fec. 
 
 A CLASS, in natural history, comprises an assemblage of 
 objects or individuals, having one or more common charac- 
 teristics. Thus the whale, the hog and the cow all belong to 
 the class mammalia, because they all have red blood, breathe 
 by means of lungs, and nourish their young by means of milk : 
 the whitewood, rose and locust all belong to the division phe- 
 nogainia and class angeiosperma, because they all produce 
 flowers and woody stems, and bear fruit in capsular vessels. 
 
 An ORDER is a subdivision of a class, and divides objects 
 into groups, which are distinguished by more minute and 
 peculiar points of resemblance than those on which a class is 
 based, but still possessing all the peculiar characteristics of 
 that class. The lion, tiger, dog and cat, all belong to the class 
 mammalia and order carnivora, because they live, in their 
 native state, on flesh: the water-cress, turnip and mustard all 
 belong to the order cruel/era, because they all produce flowers 
 having four petals, arranged in the form of a cross. 
 
 " A GENUS is an assemblage of species with more points of 
 agreement than difference, and more closely resembling each 
 other than they resemble any species of other groups." This 
 is a subdivision of an order. The dog, wolf, lion and cat, all 
 belong to the same order, but, on account of certain dif- 
 ferences, the lion and cat belong to one genus, and the dog 
 and wolf to another: the apple, cherry, rose and almond, all 
 
94 SCIENTIFIC AGRICULTURE. 
 
 belong to the order rosacea, but they belong to different 
 genera, according to some peculiarity in the organs of each. 
 
 A SPECIES "embraces all such individuals as may have 
 originated from a common stock: such individuals bear an 
 essential resemblance to each other, as well as to their common 
 parent, in all their parts." This is a subdivision of a genus. 
 The white and red clover both belong to the genus trifolium; 
 but they differ in some minor points sufficiently to place them 
 in different species. 
 
 A variety is a subdivision of a species, and is the last 
 distinction made in any system of classification : varieties in the 
 vegetable kingdom occur principally in the cultivated species; 
 they depend only upon slight differences, as, for instance, the 
 same apple tree, rose bush, or potato vine, may produce fruit, 
 tubers and flowers of different colors, but still alike in all essen- 
 tial characteristics. 
 
 We see through the whole vegetable kingdom, a most 
 marked analogy and connection, from the minutest organized 
 microscopic plant, to the largest forest tree: there are also 
 differences so obvious that there can be no doubt of the pro- 
 priety of arranging them into different groups according to 
 their peculiar characters. 
 
 ELEMENTARY ORGANS OF PLANTS. 
 
 The most simple and elementary form of a plant is that of 
 the embryo, which is produced by, and contained in the seed. 
 This consists of two parts, viz : the plumula and radicle. The 
 plumula is the part which is afterwards developed into the 
 ascending part of the plant, the stem, branches and leaves- 
 The radicle is that which becomes the root, and descends into 
 the earth in search of food and moisture. The ascending part 
 of the young plant is at first merely a minute growing point, 
 enveloped in delicate rudimental leaves, which constitute a 
 lud. 
 
95 
 
 fed c 
 
 [Fig. 1, Forms of tissue; a, cutting of elder pith, cellular; b, cells 
 from the gritty centre of the pear; c, from the stone of the plum both 
 strengthened by solid matter; d, woody fibre; e, spiral vessel with a 
 single fibre partly drawn out; f, vessel with a quadruple fibre. Wood.~\ 
 
 The several elementary structures of which the various 
 parts of plants are made up, are called elementary tissues: 
 they are five in number, viz: the cellular, woody, vasiform, 
 vascular, and laticiferous. The chemical elements of which 
 these tissues are composed, are enumerated and described in 
 works on chemistry. 
 
 Cellular tissue is composed of a series of minute cells 
 attached together, and having a more or less regular form. 
 Fig. 1, a. 
 
 Woody tissue consists of minute tubes, tapering to a point 
 at both ends, and adhering by their sides, the end of one tube 
 overlapping that of another so as to" form continuous threads. 
 Fig. 1, d. 
 
 The vasiform tissue consists of tubes, large enough to be 
 seen by the naked eye in some plants, as, for example, in a 
 transverse section of the oak. In some plants these tubes are 
 jointed, or divided by partitions, and in others they arc con- 
 tinuous. It is through these that the sap rises, and they are 
 the largest vessels in the vegetable organization. Fig. 2, a. 
 Vascular tissue consists of spiral vessels, resembling some- 
 
96 
 
 SCIENTIFIC AGRICULTURE. 
 
 what the woody fibre; they contain air, and their internal 
 structure differs in various plants. Fig. 2, b. 
 
 The laticiferous tissue is that through which is circulated 
 the latex, or nutricious sap. It consists of minute, irregular 
 branching tubes opening into each other, and situated mostly 
 in the bark and under side of the leaves. Fig. 2, c. 
 
 The epidermis, or outside bark, is formed of celluar tissue, 
 and envelopes the entire plant, except the stigma of the flower, 
 and the spongioles of the roots. In plants whose bark is rough 
 and ragged, as in the walnut and oak, it is not distinguishable. 
 
 The delicate membrane which may be stripped from the 
 iris, or house leek, is the epidermis ; this covering of plants is 
 perforated by minute orifices or mouths, which open and close 
 by the presence or absence of light The epidermis and leaves 
 have several appendages, as glands, hairs, prickles, thorns* 
 receptacles and stings, which it is not necessary to describe in 
 this treatise. 
 
 Fig. 2. 
 
 [Fig. 2, Fornn of tissue, &c.; a, annular ducts; b, spiral and annu- 
 lar at intervals; c, laticiferous tissues; e, stomata of iris, vertical section; 
 d, d, green cells at the orifice; f, f, cells of the parenchyma; e, air cham- 
 ber; g, g, epidermis and stomata of yucca; h. stomata closed; the dots 
 represent small luminous bodies in the cells. Wood.~\ 
 
CHAPTER II. 
 
 ORGANS AND STRUCTURE OF THE FLOWER. 
 
 TIIE essential organs of a flower are three, viz : the stamens, 
 the pistils, and the receptacle. These are all the parts neces- 
 sary to the perfection of the seed, they therefore constitute a 
 perfect flower: to these, however, is added in most flowers, 
 the perianth, consisting of the calyx and corrolla. 
 
 The STAMENS are slender, thread-like organs within the 
 "flower" or perianth, around the pistils: their most common 
 number is five : but this varies from one to a hundred. Their 
 office is said to be the fertilization of the seed. 
 
 The PISTILS are usually slender, larger than the stamens, 
 and occupy the centre of the flower : " they are destined to 
 bear the seed." They are sometimes numerous, but in many 
 cases there is only a single one. 
 
 The RECEPTACLE is placed at the end of the flower stalk, and 
 constitutes the basis upon which the organs of fructification are 
 usually placed, in such manner as to encircle it. 
 Fig. 3. The CORROLLA is the interior Fi - ' 
 
 i part of the perianth, consisting 
 k of one or more circles of colored 
 leaves of various hues and deli- 
 cate texture, situated upon the 
 receptacle : these leaves are called 
 petals, (Fig. 4, a, a,) and they may be 
 
98 
 
 SCIENTIFIC AGRICULTURE. 
 
 united at the edges, constituting a bell-form flower, (Fig. 3,) 
 or they may be separate, constituting a wheel-form flower. 
 Fig. e. 
 
 Tig. 4. 
 
 a 
 
 The CALYX is the external part of the 
 perianth, consisting of a circle of leaves, 
 the same in number as those of the 
 corrolla, in some cases distinct, and in 
 others united: they are usually green: 
 these leaves are called sepals. Fig. 5, a. 
 
 We see now, that a complete flower is 
 made up of four regular sets of organs, 
 viz : the stamens, pistils, receptacle and 
 perianth: these organs are arranged in 
 concsntric whorls, or rings: some of them may be absent, or 
 suppressed, some superfluous ones may be developed and some 
 
BOTANY. 
 
 09 
 
 degenerated into those of a different set, as petals into stamens, 
 flowers into leafy branches, &c. 
 
 The stamen consists of three distinct parts, viz: the filament, 
 (Fig. 6, a,) the anther, (Fig. 6, b) and the pollen. The filament 
 Fis> 6 - is the thread-like part which sup- 
 
 ports the anther at its summit: 
 the pollen is a fine yellow dust 
 of various forms contained within 
 the cells of the anther, until dis- 
 charged through its pores into 
 the air. 
 
 The pistil consists also of three 
 parts, viz: the ovary, the style, 
 and the stigma. 
 
 The ovary is the base of the 
 pistil which contains the young 
 seeds, and which ultimately be- 
 comes the fruit Fig. 6, d. 
 The style is a prolonged column arising from the ovary, and 
 supporting the stigma at its top. Fig. 6, e. 
 
 The stigma is the upper extremity of the style, usually of a 
 globular form: ii may be either simple or compound, according 
 to the structure of the ovary and style. Fig 6, f. 
 
 The ovules are minute globular bodies in the cells of the 
 ovary, which become the seeds of the matured fruit 
 
 The placenta is a fleshy ridge within the cells of the ovary, 
 from which the ovules are developed, and to which they are 
 attached. 
 
 There are several other secondary and minute parts, be- 
 longing to the flower, which it is not necessary or practicable 
 to describe here, as it would only burthen the memory with 
 technical terms which would convey but little useful know- 
 ledge. 
 
100 
 
 SCIENTIFIC AGRICULTURE. 
 
 Fig. 7. 
 
 THE FRUIT. 
 
 The ultimate object of the whole vegetable organization 
 appears to be the production of fruit; which is the agent 
 through which the reproduction of the species is accomplished. 
 After the seed is perfected in annual plants, they soon wither 
 and die : the flower always precedes the fruit, and is neces- 
 sary to its development and perfection. The fruit consists of 
 two parts, viz: &e pericarp and the seed, or the seed-covering 
 and the seed: the pericarp is wanting in some plants, but the 
 seed is essential in all. In the coniferous plants, as the pine, 
 spruce, &c., the seed is naked and destitute of the pericarp. 
 
 The PERICARP is the part which envelops 
 the seed, whatever be its substance or struc- 
 ture. Fig. 7. In the peach and plum, this is 
 a fleshy, pulpy substance, in the oak and 
 Fi S' 8 - walnut, a dense hard shell : (fig. 8.) 
 thus the structure and composi- 
 tion of the pericarp varies in dif- 
 ferent plants, from a soft watery 
 pulp to a dense shell. The pro- 
 cess of the ripening of fruit con- 
 sists of certain chemical changes produced 
 by the action of light, heat and air, and 
 perhaps other agents. Pericarps have 
 received specific names, according to their 
 
 Fig. 9. form and structure: that of the pea and bean 
 is called a pod, that of the walnut and but- 
 ternut is called a nut, that of the apple and 
 pear, a pome, that of the currant and whor- 
 tleberry, a berry, &c. Fig. 9. 
 
 This figure represents the pericarp, or seed 
 capsule of the cenothera. 
 
BOTANY. 101 
 
 THE SEED. 
 
 The seed contains the rudiments of a new plant, and is the 
 final product of all the complicated and beautiful processes of 
 vegetation. The essential parts of the seed are, the integu- 
 ment a, the albumen and the embryo. 
 
 The integuments are composed of several distinct layers, 
 which constitute the immediate coverings of the other parts. 
 
 The albumen lies next to the integuments, constituting the 
 principal bulk of some seeds ; it is a whitish substance, com- 
 posed mainly of starch, which, by the chemical changes which 
 it undergoes during the process of germination, serves to 
 nourish the embryo plant. 
 
 The embryo comprises all the rudiments of the new plant: 
 it consists of three parts, viz : the radicle, the plumule, and the 
 cotyledon. 
 
 The radicle is the part which forms the root, the plumule 
 Fig. 10. forms the ascending portion of the plant, 
 
 the cotyledon is the bulky part of seeds, and 
 forms the first leaves of young plants, which 
 lin the garden bean, cucumber, &c., are 
 I thick, fleshy and oval, when they first rise 
 above the surface of the ground: these 
 ! support the plant and perform the function 
 of leaves until the proper leaves are formed. 
 
 [This figure shows an embryo with its plumule 
 and radicle developed from the cotyledon: a, radi- 
 cle; b, plumule; c, cotyledon.] 
 
 GERMINATION OF SEEDS. 
 
 Germination consists of the first chemical changes and vital 
 action, which take place when a new plant is about to be 
 produced. 
 
 " When the seed is planted in a moist soil, at a moderate 
 temperature, the integuments gradually absorb water, soften 
 
 *9 
 
102 
 
 SCIENTIFIC AGRICULTURE. 
 
 and expand. The water is decomposed, its oxygen combines 
 with the carbon of the starch which has been stored up in the 
 tissues. Thus, losing a part of its carbon, the starch is con- 
 verted into sugar for the nourishment of the embryo, which now 
 begins to dilate and develop its parts. Soon the integuments 
 burst, the radicle descends, seeking the damp and dark bosom 
 of the earth, and the plumule rises with expanding leaves, to 
 the air and light. The conditions requisite for the germination 
 of the seed are, heat, moisture, oxygen, air and darkness." 
 
 [Wood. 
 
 Fig. A. 
 
 [Fig, A. This cut represents a young dicotyledonous plant, with its 
 radicle, a, developed; its cotyledons, c, c, appear in the form of large 
 succulent leaves; the plumule is just appearing as a minute point 
 between the cotyledon*.] 
 
 THE ROOT. 
 
 The root constitutes the basis of the plant : it serves two 
 purposes in the vegetable economy, first to fix the plant 
 
BOTANY. 
 
 103 
 
 mechanically in the soil and retain it in its position, secondly 
 to absorb from the soil those inorganic elements which are 
 necessary for its food. The general direction of the root is 
 downwards ; but the roots of various plants grow at all angles 
 from the horizontal to the perpendicular : the principal perpen- 
 dicular axis is called the tap root. The number and extent of 
 the roots must correspond with those of the stalk and leaves 
 of the plants, in order to supply their demand of food from the 
 soil. 
 
 Roots do not usually extend to great depths, but keep 
 within the limit of that portion of soil which supplies their 
 proper nutriment. Roots are distinguished from stems and 
 branches by the absence of stomata, buds and pith, and by 
 the presence of absorbing fibres. 
 
 The stock, or main body of the root, sends off i\\Q fibrils, or 
 minute, slender branches of the root, the delicate, tender 
 extremities of the fibrils are called spongioles: these arc the 
 growing points, and the organs which absorb from the soil the 
 earthy part of the food of all plants. If some trees, as the 
 willow or currant, be inverted in the soil, the branches are 
 changed to roots, while the roots put forth leaves in the air, 
 and the plant grows. 
 
 Roots are of several different forms, which have received 
 Fi s- llt specific names for the sake 
 
 of convenience. 
 
 Ramose, or branching 
 roots, are those which send 
 :off many ramifications in 
 various directions, like the 
 branches of a tree: such 
 are the roots of the oak 
 and elm. Fig. 1 1 . 
 
104 
 
 SCIENTIFIC AGRICULTURE. 
 
 Fig. 12. Fusiform, or spindle shaped roots, consist of a 
 fleshy stock, tapering downwards to its extremity, 
 sending off fibrils, which are its true roots: such 
 are the raddish, carrot and parsnep. Fig. 12. 
 
 The napiform root is a variety of 
 the fusiform, in which the neck or, 
 upper part swells out, so that its' 
 diameter equals or exceeds its 
 length. The turnip and turnip- 
 raddish are examples. Fig. 13. 
 
 Fibrous roots are made up 
 of numerous small thread-like 
 roots, attached directly to the 
 stalk, without any neck or main 
 root : such are the roots of most 
 grasses. Fig. 14. 
 
 Fasciculated roots differ from 
 the fibrous in having some of their fibres thickened and fleshy, 
 as in the dahlia and peony. 
 
 Tuberous roots consist of fleshy, roundish knobs or tumors, 
 Fi s 15 - at or near the extremity of the stalk, as in 
 
 the orchis : " the potato was formerly classed 
 among tubers, but as it uniformly bears 
 buds, it is classed among stems." Fig 15. 
 
 Granulated roots consist of many small 
 rounded bulbs connected together by fibres, 
 as in the common wood sorrel. 
 
 Fig 16. 
 
 Fig. 16. 
 
BOTANY. 105 
 
 Besides these varieties of roots, there are several others 
 which are peculiar, and distinguished by not being necessa- 
 rily fixed in the soil. 
 
 Aerial roots are those which grow from some part of the 
 plant above the surface of the soil in the open air. Some 
 creeping plants, as the ground ivy, send forth these roots from 
 their joints. The screw-pine also sends off roots which are 
 several feet in length before they reach the ground. Such 
 roots are often seen in the common maize. 
 
 Floating roots belong to plants which float upon the surface 
 of water. The water-starwort is said to float upon the surface 
 until flowering, when it sinks and takes root in the mud till its 
 seeds ripen. 
 
 The epiphytes, or plants fixed upon the branches of other 
 species, derive their nourishment mostly from the air: such 
 are some species of moss. 
 
 Parasites are those plants which grow upon other plants ; 
 and some of whose roots are said to penetrate their tissues 
 and subsist upon their juices; while the roots of others are 
 aerial, and derive their food from the air : such are the mistle- 
 toe and dodder. 
 
 Roots are divided again into three varieties, viz: annual, 
 biennial and perennial, according to their duration. 
 
 Annual roots are those which live only one year, and must 
 be raised from the seed, sown every spring, as beans, peas 
 and cucumbers. 
 
 Biennial roote_are those which live two years and do not 
 blossom the first season, but they produce flowers, fruit and 
 seeds the second year, and then die : such are the beet, cab- 
 bage and carrot. 
 
 Perennial roots live several years, some of them, as forest 
 trees, live to a very great age: the grasses, dandelion and 
 asparagus are other examples. 
 
106 SCIENTIFIC AGRICULTURE. 
 
 STRUCTURE AND FUNCTIONS OF THE ROOT. 
 
 The internal structure of the root and stem are similar : the 
 fibrils are composed of vascular tissue, inclosed in a cellular 
 epidermis, which, however, does not extend to the ends of the 
 fibrils; these ends are naked and spongy, hence they are 
 called spongioles, and have the power of absorbing large quan- 
 tities of water. 
 
 The growth of the root takes place by layers upon its 
 surface and the addition of matter at the extremities. The 
 fact is considered established, [Johnston,] that the spuigioles 
 absorb gaseous as well as aqueous matters, when in contact 
 with them. The root absorbs only from its spongioles ;-> from 
 these it is carried by the vessels of the fibrils to those of the 
 main roots, and thence into the stem and to all parts of the 
 plant. 1. Both organic and inorganic substances, in a state of 
 solution in water, enter the circulation of plants. 2. The roots 
 have the power of selecting such substances as are necessary 
 for their food, and of rejecting those that are^njurious to their 
 healthy growth. 3. Roots possess the power of excreting 
 certain matters which are in excess, or are unnecessary or 
 injurious to them. 4. Roots have the power of modifying the 
 fluids as they pass through them. [Johnston.] 
 
 THE STALK OR STEM. 
 
 The part of a plant which rises above the surface of the 
 soil, which constitutes the principal axis, and is intermediate 
 between the roots and branches, is called the stem. The 
 direction of the stem is generally vertical, but in some plants 
 it is oblique or horizontal. Stems, like roots, may be annual, 
 biennial or perennial. Plants are divided into kerbs, shrubs, 
 and trees, according to the size and duration of the stem. 
 
 Herbs are plants with annual roots and annual stems, which 
 do not become woody: such are the grasses, mints, most 
 flowers, <&e. 
 
 Shrubs have perennial, woody stems and roots, divided into 
 
BOTAN1T. 107 
 
 numerous branches near the ground, and do not attain the 
 size of trees : such are the alder, whortlebeny, lilac and haw- 
 thorn. 
 
 Trees have perennial, woody stems and roots, do not 
 branch off near the ground, and attain a great size : examples, 
 elm, oak and pine. The distinguishing property of the stem 
 is the production and development of luds. 
 
 Buds are of two kinds, viz: the leaf -bud and the flower-bud. 
 
 The leaf-bud consists of delicate layers of cellular tissue, or 
 embryo leaves, covered by hardened crusty scales. 
 
 The "flower-bud consists of the rudiments of the new flower. 
 
 There are several subordinate organs, which are little more 
 than appendages to the stem, and which it is unnecessary to 
 describe. 
 
 STRUCTURE AND FUNCTIONS OF THE STEM. 
 
 Plants are divided into exogenous and endogenous. 
 The exogenous are those which grow by accumulation, or 
 layers of matter from the outside. This class includes nearly 
 all forest trees and most shrubs and herbaceous plants of tem- 
 perate climates. 
 
 The endogenous plants are those which grow from the inside, 
 or by accretion of matter within that already developed. Most 
 of the bulbous plants of temperate regions, all the grasses, and 
 the palms, cane, <fec., of tropical countries, are endogenous. 
 The exogenous stem consists of bark, wood and pitL 
 The pith is a light spongy substance, at the centre of the 
 stem : it is composed of cellular tissue, and seems to exercise 
 its peculiar functions only during the earlier growth of plants. 
 
 [Wood. 
 
 The icood is composed of cylindrical or concentric layers, in- 
 tersected by medullary rays, which are those thin dense plates 
 of wood dividing the "grains," and are large and easily seen 
 in a piece of beech or oak wood which has been split. The 
 pith, together with the first layer which incloses it, are the 
 
108 
 
 SCIENTIFIC AGRICULTURE. 
 
 Fig. 17. 
 
 product of the first year's growth; 
 one new layer is formed every suc- 
 ceeding year, so that the number 
 of rings or "grains" at the base of 
 the stem indicate correctly the age 
 of the tree. Each layer is composed 
 of woody fibres, vasiform tissue and 
 
 ducts. 
 
 Fig. 17. 
 
 [Fig. 17. 1, represents an erogenous 
 stem of one year's growth; a, pith; b, 
 bark; c. medullary rays; d, woody bun- 
 dles of fibre; 2, laticiferous vessels of the 
 bark.] 
 
 The outside, lighter colored lay- 
 ers constitute the allurmnn or "sap 
 wood:" the brownish layers inside are harder than the sap 
 wood, and are hence called the duramen. 
 
 The bark forms the external covering or integuments of the 
 stem and root. The bark consists of three distinct layers : the 
 outside covering is called the epidermis, this layer is some- 
 times covered with a coating of gummy, oily or resinous matter. 
 The middle layer is the cellular integument; and the inner coat 
 the liber. The two outer layers are of cellular structure, "while 
 the inner one is both cellular and woody. 
 
 The sap is carried by the vessels through the alburnum to 
 the leaves, with the vessels of which they communicate: while 
 in the leaves, the sap undergoes some changes, (not well 
 understood,) by moans of the air and light, by which it is 
 converted into a fluid called latex. From the vessels of the 
 under side of the leaf, it descends by the vessels of the inner 
 bark ; part of it is carried inwards by the pores of the medul- 
 lary rays, and diffused through the stem, while the remainder 
 descends to the roots, and is distributed through them. Sap 
 is milky, gummy, saccharine bitter, &c., in various plants. 
 
 At the end of spring a portion of the descending sap, which 
 
BOTANY. 
 
 100 
 
 is now transformed into a viscid glutinous matter called cam- 
 bium, is deposited between the liber and the wood, becomes 
 organized into cells, ajid forms a new layer upon each. Soon 
 afterwards, the new layers are pervaded by woody tubes and 
 fibres, which commence at the leaves and grow downwards. 
 " The number of layers in the bark and wood will always be 
 equal." (Wood.) The outer bark of young twigs seems to 
 perform the same function as the leaves : in the cactus, sta- 
 pheliu, and other plants which produce no leaves, the bark must 
 perform the same office as the leaves do in plants which pro- 
 duce them. (Johnston.) 
 
 ^ Fig. is. 
 
 4 
 
 C C 
 
 [Fig. 18. 3, horizontal section of an endogenous stem, exhibiting the 
 bundles of woody fibre, spiral vessels and ducts, irregularly disposed in 
 the cellular tissue : 5, a, a, cellular tissue ; b, spiral vessels on inner side 
 of dotted ducts, c, c; d, woody fibre on the exterior side: 4, stem of 
 three year's growth; a, pith; e, bark; b, c, d, successive annual layers: 
 6 a, pith; b, spiral vessels of the medullary sheath; c, dotted ducts; d, 
 woody fibre; e, bark.] 
 
 The endogenous stem exhibits no distinction of bark, wood 
 and pith, and no concentric annual layers or grains. It is 
 composed of cellular tissue, woody fibres, spiral vessels and 
 
 10 
 
110 
 
 SCIENTIFIC AGRICULTURE. 
 
 ducts, the same as that of exogens. The cellular tissue exists 
 equally in all parts of the plant; the rest are in bundles, im- 
 bedded in the stem: "each bundle consists of one or more 
 ducts, with spiral vessels adjoining their inner side next to the 
 centre of the stem, and woody fibres on the outside, as in the 
 exogen. 
 
 " A new set of these bundles is formed annually, or oftener, 
 proceeding from the leaves, and passing downwards in the 
 central parts of the stem, where the cellular tissue is most 
 abundant and soft After descending awhile in tliis manner, 
 they turn outwards and interlace themselves with those which 
 were previously formed." 
 
 Oryptogamons or Flowerless Planta. 
 
CHAPTER III. 
 
 STRUCTURE AND FUNCTIONS OF THE LSAF. 
 
 THE leaf is an extension of the two outer layers of the bark 
 expanded into a broad thin net work: leaves constitute the 
 verdure of nearly all plants; their color is almost universally 
 green, which color they derive from a substance called chloro- 
 phylle, deposited just beneath the cuticle. Towards the end 
 of autumn, after the verdure of plants has matured, their color 
 is changed to various hues, as yellow, orange, red, <fec., by the 
 action of oxygen on their elements. 
 
 Deciduous leaves are those which fade and fall off at the end 
 of autumn, annually. 
 
 Evergreens are those which remain green throughout the 
 year. . % 
 
 Leaves are arranged in various ways upon the stem and 
 branches of plants : in some, as in the potato, they are scattered 
 along the stem irregularly: in others, as the pea, they aie 
 alternate, or one above another on opposite sides of the stem : 
 when two are against each other at the same joint or node, 
 they are called opposite: when more than two are arranged 
 in a circle at the same node, as in the meadow lily, they are 
 verticillate : in the pepper and some others, they are arranged 
 spirally around the stem. 
 
 The prolongation of the leaf-stalk, through the middle of 
 the leaf, is called the midrib; the smaller divisions, or ribs, 
 which radiate or go off from this, are called nerves. 
 
112 
 
 SCIENTIFIC AGRICULTURE. 
 
 The hair-like lines sent off from the midrib and nerves are 
 called veins. This distinction is arbitrary, as there is no dif- 
 ference in the structure or function. The various distributions 
 of the veins have received distinctive names, and these are all 
 included under the generic term venation. 
 
 FORMS OF LEAVES. 
 
 Tlieforjns of leaves have also subjected them to an arrange- 
 ment under specific heads. The forms of leaves are said by 
 De Candolle to depend upon the length of the midrib and the 
 relative length of the veins. 
 
 rig. IP. Orbicular leaves are roundish, as in the 
 
 pyrola rotundifolia, or round leaf wintergreen, 
 and nasturtion. Fig. 19. 
 
 Elliptical leaves, as their name Fig. 20. 
 implies, are elliptical or oval in 
 form, as in the whortleberry and 
 wintergreen. Fig. 20. 
 
 Lanceoate leaves are long and tapering at the< 
 point like the blade of a lancet, as in the willow and peach. 
 Fig. 21, a. 
 
BOTANY. 
 
 113 
 
 Pig. 22 
 
 rig. 23. 
 
 Cordate leaves are heart-shaped, as in the lilac and aster 
 cordifolium. Fig. 22. 
 
 Sagittate leaves have the form of an arrow-head, as in the 
 sagittaria. Fig. 23, #. 
 
 Reniform leaves are kidney-shaped, as in the wild ginger 
 and ground ivy. Fig 24. 
 
 Linear leaves are narrow, long and straight, as in the grasses 
 and grains. Fig. 21, c. 
 
 Deltoid leaves are in the form of the Greek letter delta,- or 
 nearly triangular, as in the Lombardy poplar. Fig. 21, e. 
 
 Acerose leaves are long, narrow and needle-shaped, and 
 clustered together, as in the pine. Fig. 23, b. 
 
 Piimatified, or feather-cleft leaves, have deep clefts between 
 all their veins, separating the leaf into parallel segments, as in 
 the lepidium. Fig 25, d. 
 
 *10 
 
114 
 
 SCIENTIFIC AGRICULTURE. 
 Fig. 25. Fig 20. 
 
 Lyrate leaves have several deep rounded notches between 
 their veins, as in the water-cress. Fig. 25, c. 
 
 Connate leaves have the bases of opposite leaves united so 
 As to appear like one entire leaf, as in the boneset and sapo- 
 naria*. Fig. 26. 
 
 Digittate leaves have narrow, deep clefts between the veins, 
 with long segments radiating from the end of the leaf-stalk, as 
 in the common hemp. Fig. 27. 
 
 Fig 28. 
 
 Stellate leaves are arranged around 
 the stem in such a manner as to form a 
 star, as in the red lily. Fig. 28. 
 
 Loled leaves are deeply indented or 
 cleft at their margins, so as to divide 
 them into lobes, as in the liverwort. Fig. 
 .29, a. 
 
BOTANY. 
 
 115 
 
 Sinuate leaves have their margins divided by deep roundish 
 clefts, as in the white oak. Fig. 29, b. 
 
 Fig 29. 
 
 Emarginate leaves are irregular, having but slight indenta- 
 tions in the margin. Fig. 29, c. 
 
 Tubulate leaves have the sides or margins united so as to 
 form a cup, as in the side-saddle and pitcher plant. Fig. 30. 
 
 Fig 30. 
 
 Fig 31. 
 
 Compound leaves consist of 
 several small leaves on separate 
 leaf-stalks, and arranged along 
 the opposite sides of the same 
 stem, as in the hedysarum. Fig. 31 . 
 
 Ternate leaves rig. 32. 
 arise in threes from 
 the same leaf- stalk. 
 Fig. 32. 
 
 Alternate is a se- 
 cond division by 
 threes. 
 
116 
 
 SCIENTIFIC AGRICULTURE. 
 
 Fig. 33. Leaves are opposite when placed at equal 
 
 distances in pairs on opposite sides of the stem. 
 Fig. 33. 
 
 These are the principal forms of leaves; 
 still, many other names are given by botanists 
 to the various modifications of these. Specific 
 terms are employed also in describing the 
 stem, margin, base, point and surfaces of leaves. 
 There are also various appendages to the 
 leaves, which have distinctive names,- in sys- 
 tematic works on botany. To describe all the 
 minor points in the organography of plants 
 would exceed our limits, and, besides, it would render this 
 brief outline of botany too complex to be interesting to the 
 general reader. 
 
 MINUTE STRUCTURE OF THE LEAF. 
 
 The frame work of the leaf is an extension and expansion of 
 the medullary sheath, which is composed of woody fibre and 
 vessels. The integument, or outer covering of the leaf, is 
 the same as that of the bark, of which it is a continuation. 
 
 The cellular tissue peculiar to the leaf is called its paren- 
 chyma. This parenchyma exists in two layers of cells, which 
 differ somewhat in structure. Within the cells, and adhering 
 to their walls, are the minute green particles of cklorophylle, 
 F*g 34. which give color to the leaf: the empty 
 
 spaces between the cells communicate 
 with the external air by means of sto~ 
 mata, or mouths, which, in most plants, 
 are found only on the lower surface. 
 In all those plants whose leaves are 
 vertical, as the iris, they are on both 
 
 [Fig. 34. Magnified sides equally: in the water lily, they 
 section of the epidermis . , . ., /. * ,-, 
 
 of the m y> showing tte exist only in the upper surface, the 
 
 storoata, c, >c. 
 
 lower surface being in contact with the 
 
BOTANY. 
 
 117 
 
 Tlio veins which carry the latex, or nutricious fluid of 
 the leaf, "having reached the edge of the leaf, double back 
 upon themselves," spread through the lower surface, and are 
 again collected, and returned through the leaf-stalk into the 
 bark. 
 
 Fig. 35. 
 
 [Fig. 35 shows a magnified section of the leaf of the lily: the upper 
 surface, a, consists of flattened cells of the epidermis, arranged in a 
 single layer; beneath this, b, is the more compact part of the paren- 
 chyma, consisting of a layer of oblong cells placed in such a position 
 that their longer axis is perpendicular to the leaf's surface. Next 
 below is the parenchyma of the lower surface, c, composed of oblong 
 cells arranged longitudinally, and so loosely compacted as to leave 
 larger spaces between. Lastly, d, is the epidermis of the lower sur- 
 face, with stomata, e, e, opening into air chambers, f.] 
 
 FUNCTIONS OF THE LEAF. 
 
 The functions of the leaf are, exhalation, absorption, respi- 
 ration and digestion. The ultimate end of these functions is 
 to produce the necessary changes on the crude sap brought 
 up from the roots, and to convert it into the latex, which is the 
 proper nutrition of the growing plant : this ftuid is to the plant 
 what the arterial blood is to the animal system. 
 
 Exhalation in plants is the throwing off of the excess of 
 water in the sap, so as to leave it in a more concentrated form, 
 and consequently better adapted to nutrition : exhalation takes 
 place through the stomata, and is different from mere evapo- 
 ration, which depends upon the state of temperature and air. 
 Exhalation is supposed to cease during darkness. 
 
 Absorption is performed mainly by the roots, in nearly all 
 plants : when, however, these are defective or wanting, the leaf 
 
118 SCIENTIFIC AGRICULTURE. 
 
 assumes the vicarious office of absorption. The invigorating 
 effect of a shower of rain oil the leaves of parched and wilted 
 plants, is seen long before the water could have reached the 
 roots and have been carried up to the leaves : this effect must 
 be produced, therefore, by the absorption of moisture by the 
 leaf. This action takes place mostly from the lower surface of 
 the leaf. 
 
 Respiration in plants consists, as in animals, in the absorp- 
 tion of oxygen from the air, and the giving off of carbonic 
 acid. It is performed mainly by the leaves, but is performed 
 to some extent by other parts also : it continues without inter- 
 mission by day as well as by night, during the life of the plant 
 Respiration is most active during the processes of germination 
 and flowering: a constant supply of oxygen, and the daily 
 presence of light, are indispensable to the growth and vitality 
 of the plant 
 
 Digestion comprises all those changes which the mineral, 
 aqueous and gaseous matters undergo after entering the plant, 
 until they are assimilated and become a part of the organism. 
 " It consists in the decomposition of carbonic acid by the green 
 tissues of the leaves, under the stimulus of the light, the fixa- 
 tion of the solid carbon, and the evolution of pure oxygen." 
 
 [Wood. 
 
 INFLORESCENCE. 
 
 Inflorescence is the term used to indicate the peculiar 
 arrangement of flowers upon the stem and branches of plants ; 
 also their successive development in different parts of the same 
 plant Flowers are said to be terminal and axillary, in regard 
 to their position on the stem. 
 
 Terminal flowers are placed at the end or summit of the 
 branch or flower stalk. 
 
 Axillary flowers are placed in the angle formed by the 
 branch or leaf-stalk, and the primary central stem, or larger 
 lateral braaches. 
 
BOTANY. 119 
 
 The peduncle is the flower-stalk, or that part of the stem 
 which is attached to and supports the flowers : it may be simple 
 or branching, and it may be entirely absent, 
 rig 36 
 
 [Fig. 36 shows a papilionaceous flower with its peduncles-3 
 
 A scape is a flower-stalk, or peduncle, which springs imme- 
 diately from the root, in those plants which are called stemless, 
 as the sarracenia, hyacynthus, &c. 
 
 A rachis is the main axis, or stem, of a compound peduncle, 
 along which are arranged the flowers, as in the currant, grape, 
 grasses, plantain, &c. 
 
 A flower is said to be solitary, when a single terminal or 
 axillary flower is developed, as in the erythronium and con- 
 volvulus. The successive evolution of flowers is distinguished 
 into two varieties, viz : the centripetal and centrifugal. 
 
 In centripetal inflorescence, the blooming of the flower com- 
 mences at the circumference and proceeds towards the centre, 
 as in the mustard, carrot, &c. 
 
 In centrifugal inflorescence, the blossoming commences at 
 the terminal or central flower, and advances laterally to the 
 circumference, as in the elder, pink and sweet-william. These 
 two modes of inflorescence are sometimes combined in the 
 same plant. [Gray.] 
 
 There are several varieties of centripetal inflorescence, which 
 
120 
 
 SCIENTIFIC AGRICUJLTURE. 
 
 arc designated by specific terms ; as the spike, raceme, amcnt, 
 spadix, corymb, umbel, head, panicle and thyrse. 
 
 Of centrifugal inflorescence, there are also several varieties, 
 as the cyme, fascicle, whorl, or verticil, &c. 
 
 Fig 37. 
 
 [Fig. 37 represents a head of oats showing an example of a panicled 
 flower.] 
 
 Tendrils, 
 
CHAPTER" IV. 
 
 GENERAL REMARKS. 
 
 THE dissemination of seeds is a subject not unworthy o* 
 allusion. It is known to botanists, that nearly all plants have 
 particular localities to which they are indigenous. But, by 
 various means, they have become more or less distributed over 
 different and distant parts of the earth. Some seeds, as those 
 of the thistle and dandelion, are furnished with a little plume 
 or wing, by means of which they are wafted by winds to great 
 distances, and thus sown in a soil and locality where the 
 species was never before known. Some seeds are furnished 
 with hooks or burs, by means of which they attach themselves 
 to the clothing of men and animals : seeds are also eaten by 
 animals and birds, carried to great distances, voided undigested 
 and without injury to their vitality, germinate wherever they 
 are deposited. 
 
 Many seeds are so protected by a thick dense pericarp, that 
 they make long voyages, being carried along by the current 
 of streams, or the ebbing and flowing of tides, until they reach 
 a distant country, and perhaps even another continent, and 
 there propagate and establish their species. They are carried 
 also by ships and other conveyances engaged in commercial 
 transportations, as well by accident as by design for the 
 purpose of cultivation. Many seeds retain their vitality after 
 boiling, digestion in alcohol, and being buried in the earth for 
 
 11 
 
122 SCIENTIFIC AGRICULTURE. 
 
 centuries. Dr. Lindley mentions a remarkable instance of the 
 longevity of raspberry seeds, which, as proven by circum- 
 stances, must have been 1,600 years old, and were found 
 thirty feet below the surface of the earth. Oily seeds are 
 more liable to putrify and lose their vitality than others. 
 
 The blooming of flowers was thought, during the dark and 
 middle ages, when the human mind was blinded by the 
 grossest superstition, to be emblematical of something con- 
 nected with religion: thus when the time of the blossoming 
 of a flower fell on the birthday of a saint, or on the day of a 
 martyrdom, that flower was consecrated or dedicated to such 
 saint or martyr. 
 
 Plants exhibit many phenomena which seem to be connec- 
 ted with atmospheric conditions and changes : thus it is said 
 a storm may be predicted by the folding or opening of certain 
 flowers ; also that a clear sky, thunder, wind, &c, may be fore- 
 told by the various other phenomena observed to take place 
 in the different organs of plants. Some plants are capable of 
 enduring a high degree of heat: those of the tropics sustain 
 a temperature which would be intolerable to animals for a 
 great length of time : others are found immersed in the waters 
 of boiling springs, and in a state of thrifty vegetation. 
 
 Every country exhibits a flora, or botanical character, pecu- 
 liar to itself. The influence of light and heat on the growth 
 of plants is seen to be powerful and important. In the polar 
 regions, where almost perpetual winter reigns, the vegetation 
 is rigid, scanty and stinted : the centre of the frigid zone, in 
 fact, is totally destitute of vegetable life. After passing the 
 arctic circle, we find a few species of mosses, lichens and ferns, 
 and a few shrubs. The only country in this zone where the 
 grains can be successfully cultivated, is Lapland. The tem- 
 perate zone produces most species of useful nutrient plants, 
 such as the grains, berries, fruits and grasses, as well as valu- 
 able timber trees. The torrid zone produces every variety of 
 
BOTANY. 123 
 
 vegetation from the equator to the poles: this variety depends 
 upon the altitude at which they are found; the low land pro- 
 duces the most luscious fruits and stately trees, with a vast 
 variety of flowers and spices. 
 
 As vegetation ascends the mountain heights, even under 
 the equator, it assimilates, according as the climate becomes 
 less congenial, to that of the colder regions, in the same way 
 as when receding from the equator towards the poles. Plants, 
 like animals, are liable to various diseases : no inorganic body 
 can be said to suffer from disease, although they are subject 
 to decomposition and disintegration, they are not capable of 
 diseased action, because destitute of vitality, which i^ indispen- 
 sable to such a process. Plants may become diseased from 
 a deficiency or excess of food, air, light, water, heat, or from 
 cold, noxious vapors, external injuries, insects, parasites and 
 hereditary organic or functional debility. They are also 
 liable to diseases peculiar to old age and excessive action, in 
 the same manner as animals. Thus they suffer from anemia,* 
 or want of fluids, like aged persons: they sometimes labor 
 under dropsy, from deficiency of light, and from other causes 
 they suffer and die from dry mortification* 
 
 Lastly, plants are liable to disease and death from poisoning 
 and contagion. The economical uses of plants are well known, 
 and require only a passing notice : forest trees, and some parts 
 of other plants, are indispensable in the arts: cereals, fruits 
 and roots, are used as food for both man and beast : the grasses, 
 lichens, mosses and herbs serve as food for animals: various 
 plants, and the substances derived from them, are also used as 
 medicines. Plants designed for medicinal purposes should be 
 collected at a time when the whole vitality and forces are not 
 engaged in the growth of the plant and maturity of the flower 
 and seed : herbs should be gathered soon after flowering, or 
 when the seed is nearly ripened : roots, if annual, should be 
 
 * Terms proposed by the author. 
 
124 SCIENTIFIC AGRICULTURE. 
 
 gathered after the stem and foliage are withered in autumn, 
 or before the old root begins to decay in the spring: barks 
 possess more strength if taken after the descent of the sap has 
 ceased, and the cambium has become hardened into wood and 
 bark. 
 
 Some remarks on the collection and preparation of plants 
 for herbariums, and upon botanical analysis, classification and 
 nomenclature, might be made; but they would be of little 
 service, as they would anticipate a step in the science which 
 lies beyond the limits of this treatise. 
 
 * 
 
PART IV. 
 
 METEOROLOGY. 
 
 CHAPTER I. 
 
 METEOROLOGY is the science which treats of all the various 
 phenomena which take place in the atmosphere. " Under the 
 term meteorology, it is now usual to include, not merely the 
 accidental phenomena to which the name of meteor is applied, 
 but every terrestrial as well as atmospherical phenomenon, 
 whether accidental or permanent, depending on the action of 
 heat, light, electricity, and magnetism. In this extended 
 signification, meteorology comprehends climatology and the 
 greater part of physical geography ; and its object is to deter- 
 mine the diversified and incessantly changing influences of the 
 four great agents of nature now named, on land, in the sea, 
 and in the atmosphere." [Brande.] 
 
 A meteor is any phenomenon of a transitory nature, which 
 appears in the atmosphere. The various conditions and changes 
 which take place in the air incessantly, with respect to heat, 
 cold, moisture, dryness, &c., are called weather. Observations 
 have been made in all ages of the world upon these phenomena, 
 in order to explain their causes and foretell the changes of 
 weather. But there are so many conditions to be considered, 
 and so many influences which probably can never be under- 
 
126 SCIENTIFIC AGRICULTURE. 
 
 4 
 
 stood, that there is little certainty in all the theories and 
 weather tables which have been formed. Although many of 
 the meteorological phenomena are somewhat well understood 
 in their individual nature, still, when they are combined, their 
 operation is exceedingly complex, and the number of their 
 changes almost infinite. 
 
 Records of past changes of weather have long been kept, 
 but it has been found by observation and comparison of the 
 results of different seasons and years, that few data are 
 obtained, on which to ground any prognostications of the 
 future. Some individuals have, by long and close observation, 
 attained some apparent accuracy of judgment in relation to the 
 phases of the weather; but their conclusions were not of a 
 nature to be systemized and transmitted to posterity ; so that, 
 if any real attainment has been made in this way, it has 
 always been lost with the observer. 
 
 "The registers which are kept in different observatories, 
 prove, contrary to popular belief that the changes of weather 
 are in no way whatever dependent on the phases of the moon." 
 Although the ever varying and endless changes of weather 
 are all the necessary results of fixed laws, yet it is doubtful 
 whether these laws will ever be sufficiently understood to 
 enable us to reduce our knowledge respecting them to demon- 
 strative ccertainty. 
 
 CLIMATE. 
 
 Climate, in its most extended signification, embraces all the 
 modifications of atmospheric temperature and conditions, and 
 the principal causes on which they are dependent: besides 
 temperature, it includes humidity, dryness, winds, barometrical 
 conditions, purity of air, &c. The principal causes which tend 
 to modify climate are, latitude, altitude, direction in which the 
 sun' sprays fall upon the earth, configuration and aspect of the 
 land, its proximity and relation to the sea, direction of the 
 wind, density of the atmosphere, number of rays of the sun 
 
METEOROLOGY. 127 
 
 which are absorbed, amount of vegetation, character of the 
 soil, and state of agriculture. 
 
 But among all these causes none have so important an 
 influence on determining the climate of a country as latitude 
 and altitude. The degrees of heat are not always equal for 
 the same latitude; thus at Rome, in latitude 63 north, the 
 mean temperature is the same as that of Raleigh, North 
 Carolina, in latitude 36 north. 
 
 Lines passing through points on the surface of the earth at 
 which the mean annual temperature is the same, are called 
 isothermal lines. These lines do not pass round the earth in 
 a direct course like the parallels of latitude, but they vary so 
 as to assume a tortuous direction. 
 
 The isochimenal lines, or lines of equal cold, or equal 
 winter, vary much more than the lines of equal summer. 
 The reason why latitude affects the temperature of a climate, 
 is because it varies the obliquity of the sun's rays in relation to 
 the earth. This, however, is not the cause of the difference in 
 the length of day and night at different places. 
 
 The following table from Muller shows the length of the 
 longest day for the different latitudes. 
 
 Polar Elevation. Length of longest day. 
 
 12 hours. 
 
 1644 / 13 
 
 3048' 14 
 
 4922' 16 
 
 6323' 20 " 
 
 6632' 24 " 
 
 6723' 1 month. 
 
 7339' 3 
 
 90 6 " 
 
 Altitude has an important effect on determining the mean 
 temperature on all places, whatever may be their latitude. 
 The temperature diminishes from the surface upwards as far 
 
128 SCIENTIFIC AGRICULTURE. 
 
 as man has ever ascended, and probably beyond this point to 
 the very limit of the atmosphere. The interior of the earth is 
 supposed to be yet in a fluid state from the effects of heat ; 
 the solid outside crust constituting only y^ part of its whole 
 diameter: at 50 to 40 feet below the surface, invariable tem- 
 perature prevails; that is, there is always an equilibrium, so 
 that the mercury in a thermometer would remain stationary 
 at this depth, whatever might be the temperature above in 
 the open air. This point would be at the surface if the tem- 
 perature of the air was always the same. The increase of 
 cold upwards from the earth is at the rate of 1 F. for every 
 100 yards. The snow line, or line of perpetual congelation, 
 varies less in proportion to latitude than altitude : thus it will 
 be seen by the table below, that this line is much lower at the 
 equator than in higher latitudes in proportion. 
 
 Table of Snow Lines from Mutter. 
 
 Coast of Norway, 2,340 feet above sea level. 
 
 Iceland, 3,042 " " 
 
 Alps, 8,801 " " " " 
 
 MtEtna, 9,441 
 
 Himmalayas, 14,625 " x 
 
 Mexico, 14,625 " " " " 
 
 Quito, 15,600 " " " " 
 
 There are three reasons given by Dr. Brande, why the cold 
 increases as we ascend, viz: 1. The absorption of the sun's 
 rays in the denser strata of the atmosphere near the surface 
 of the earth. 2. Radiation of caloric from the earth. 3. The 
 ascending current of air. 
 
 Configuration of the land varies the climate of a country : 
 a plain is hotter than an uneven surface, all other conditions 
 being equal. The sand on the desert plains of Africa some- 
 times attains a temperature of 122 F. The side of a moun- 
 tain or hill, which faces the sun, is warmer than the opposite 
 
METEOROLOGY. 129 
 
 side, for the plain reason that its rays strike upon it more 
 vertically. 
 
 Proximity or distance from the ocean is another cause 
 which varies climate. Small islands and peninsulas have 
 milder winters and fresher summers than the interior of conti- 
 nents in the same latitude. 
 
 The refrigerating effect of winds blowing from the polar 
 seas is felt in countries at great distances : the reverberation of 
 winds among mountains also increases the cold and heat of 
 certain localities. The other causes upon which climate is 
 dependent, are considered in another place. The - following 
 table from Muller, shows the mean temperature of several 
 different places. 
 
130 
 
 SCIENTIFIC AGRICULTURE. 
 
 Table showing the mean temperature of several places during 
 several years, part of one from Mutter's Phys. and Me'ty. 
 
 ** 
 
 OOi l 
 
 4 
 
 
 * 
 
 00^ *O^ CO_ O^ ^ fO^ O^ 00^ CC^ C^ CO^ ir^ CO^ ^ ^ 
 
 CO I r-H I I rH r-l <>l 
 
 tuunjny 
 
 T I IO 
 
 O -t- OD OO 
 
 i I CO i I O5 i ( r-(OOO5COiO 
 
 co o <M oc co 
 
 CD GOJ^OO 
 
 <N<Mi lOOCOCOCOCOCO-^iO^O 
 
 'UV9/1 
 
 a^rH<NCDCOr-HO5CO CJ i-l CO <M i-l 
 
 O OO-t^OO 
 
 93 ui 
 V3S daoqv 
 
 <O J>. i- O5 00 "^ 
 GO OO O O5 O CO 
 
 fe: . M 
 
 ^ COlOJ>.iOOi COCO-^Ci 00 CD iO i t 
 
 
 r- lOSlOCOOOi IOOO5i-HOiO r ScO(:?-C^a>'CO 
 J^lCO^^lO^CO'^f-HOO lV ^CO^ H (Mr-lr-t 
 
 1 rf * ' . 
 
 S 
 
 ,0 o g j. rf g | 
 
 
 o 
 
 . 
 
 
 
132 SCIENTIFIC AGRICULTURE. 
 
 EXPLANATION OF THE CUT. 
 
 This cut is designed to show the latitude and altitude at 
 which some of the most important plants flourish in the 
 greatest perfection. It shows also the latitude in which various 
 winds prevail, the latitude where there is little or no rain 
 and also where there is almost constant rain. The scale of 
 miles on the left hand of the cut shows the height of the 
 mountains, the elevation at which plants grow on their sides, 
 and the line of perpetual snow. On the right hand are the 
 degrees of latitude. The locality of plants, as shown by the 
 table, nrj not perhaps strictly accurate in all cases; but they 
 approximate correctness sufficiently near for all ordinary calcu- 
 lations. 
 
METEOROLOGY. 133 
 
 INFLUENCE OF AGRICULTURE ON THE CLIMATE AND THE ANNUAL 
 FALL OF RAIN, 
 
 The question, wlietlier the clearing away of forests and the 
 labors of the agriculturalist have had any influence in lessening 
 the annual quantity of rain and the quantity of water in streams, 
 as well as in modifying the climate, is one of considerable 
 interest and importance. The clearing away of forests, so as 
 to allow^of free evaporation of water from marshes, and per- 
 mit the access of the sun's rays to the soil, most certainly has 
 a tendency to equalize the distribution of heat, if it does not 
 actually raise the mean annual temperature. The mean tem- 
 perature of the whole earth, however, was much higher 
 formerly than at present. The tillage of the soil, by rendering- 
 it loose, and exposing a greater surface to the action of heat 
 and air, favors evaporation, and in this way makes a cold, wet 
 soil, dry and warm. It also increases the capacity of the soil 
 for heat, and favors nocturnal radiation and the formation of 
 dew : but perhaps this fact goes about as far to sustain one 
 side of the question as the other. 
 
 It is a fact universally admitted by geologists, that the level 
 of the waters of the earth have every where undergone a 
 change. The instances are numerous, in which rivers, lakes, 
 seas and marshes, have been greatly diminished or totally 
 dried up; this may be one of those phenomena which is 
 evident to all, but which is nevertheless difficult clearly to 
 explain. Islands have risen out of the sea, coasts have been 
 left dry by the receding of the waters, and the beds of large 
 rivers have become dry arable soil. This has of course been 
 in some instances owing to the actual elevation of portions of 
 land by some subterranean force: and it is also true that 
 portions have been submerged by similar causes. But these 
 causes are insufficient to account for the general drying of 
 streams and diminution of rains in cleared agricultural dis- 
 tricts. " In felling the trees which covered the crowns and 
 slopes of mountains, men in all climates seem to be bringing 
 
 12 
 
134 SCIENTIFIC AGRICULTURE. 
 
 upon future generations two calamities at once, a want of 
 fuel and a scarcity of water." [Humboldt.] 
 
 The rainy season is less regular in countries where the soil 
 is dry and naked, than where it is moist and covered with 
 dense forests or luxuriant vegetation. In some parts of South 
 America, which are clothed with ancient and large forests, rain 
 is falling almost incessantly : but in the same country, where 
 there are wide extended plains and little vegetation, it seldom 
 or never rains. Boussingault states, that when he was in 
 Payta, in South America, the inhabitants informed him it had 
 not rained there in seventeen years. The conclusions to which 
 he arrived on this subject, part of them sustained also by 
 Humboldt and Dr. Hitchcock, are as follows. 
 
 1. "That extensive destruction of forests lessens the quan- 
 tity of running water in a country. 
 
 2. " That it is impossible to say precisely whether this dimi- 
 nution is due to a less mean annual quantity of rain, or to 
 more active evaporation, or to these two effects combined. 
 
 3. " That the quantity of running water does not appear to 
 have suffered any diminution or change in countries which 
 have known nothing of agricultural improvement. 
 
 4. "That independent of preserving running streams, by 
 opposing an obstacle to evaporation, forests economize and 
 regulate their flow. 
 
 5. "That agriculture established in a dry country, not 
 covered with forests, dissipates an additional portion of its 
 running water. 
 
 6. "That clearings of forest land of limited extent may 
 cause the disappearance of particular springs, -without our 
 being therefore authorised to conclude that the mean annual 
 quantity of rain has been diminished. 
 
 7. " That in assuming the meteorological data collected in 
 intertropical countries, it may be presumed that clearing off 
 the forests does actually dimmish the mean annual quantity 
 of rain which falls." 
 
CHAJPTER IL 
 
 THE philosophical principles upon which the phenomena of 
 rain are immediately dependent, are not yet well settled : rain. 
 is supposed, however, by many of the best writers, to depend 
 upon the action of electricity for its origin. All causes which 
 have a tendency to reduce the temperature of the air, cause a 
 precipitation of moisture. When the aqueous vapor which is 
 held in suspension by the air becomes condensed by cold, the 
 minute vesicles coalesce and form drops, which by their gravity 
 descend through the air, which is no longer capable of sus- 
 taining them. 
 
 The drops of rain are said to be from one twenty fifth to 
 one third of an inch in diameter : when they descend through 
 a stratum of dry air, they are partly dissipated by evaporation. 
 This accounts in part for the fact that there is less rain on 
 plains than on mountains. 
 
 The same latitudes have not the same quantity of rain! 
 this, like climate, is modified by various local circumstances, 
 as altitude, proximity to the sea, direction and prevalence of 
 winds, agricultural condition, forests, &c. The quantity of 
 rain which falls during the year is greatest at the equator, and 
 diminishes as we leave this point and approach the poles. 
 
 The quantity also which falls during the night and during 
 the day, varies at different places : in Europe more rain falls 
 during the day than during the night time; while in South 
 
136 SCIENTIFIC AGRICULTURE. 
 
 America more falls during night thaji during day. The mean 
 quantity of rain is less as we ascend above the sea level : it is 
 more in the same latitudes where the mean temperature is 
 68 F., than at any point above or below this. 
 
 Rains become less periodical and regular as we leave the 
 equator. The mean annual quantity of rain in Europe, between 
 latitudes 35 and 50 north, (and probably the same would be 
 nearly true of similar latitudes in the United States,) is from 
 25 to 45 inches. 
 
 The mean quantity, as shown by the report of the Regents 
 of the University of New York to the Legislature, for the last 
 ten or fifteen years, as measured at thirty different places in 
 this state, is 35.84 inches. Of these various estimates, 43.65 
 was the greatest number of inches, which fell at " Erasmus 
 Hall," Long Island: the smallest number was 28.14, which 
 fell in St. Lawrence county. We see from tables in Bous- 
 singault's work, that most falls in autumn and least in spring: 
 we see also that most falls in July and least in March of any 
 months in the year. 
 
 This table is from the record kept ly L. Wetherell, Esq., at 
 the Rochester Collegiate Institute. 
 Greatest annual mean temperature for 13 years, ending 
 
 with 1847, 3999 
 
 Least do. - 25 46 
 
 Greatest mean temperature of one year, - - 48 60 
 Least " " " - - 43 71 
 
 Highest heat, July, 1845, - - 102 
 
 Lowest " Feb., 1836, 8 below zero. 
 Most rain in one month, Oct., 1846, 6.79 inches. 
 
 Least " " " Jan., 1837, 0.16 
 
 DEW AND FROST. 
 
 All bodies in nature are constantly undergoing a change of 
 temperature : however hot or cold a body may be, it is eon- 
 
METEOROLOGY. 
 
 tinually giving out heat,^ither by radiation or by contact, or 
 it is receiving and absorbing heat from other bodies. Upon 
 the principle that heat tends to seek an equilibrium, by means 
 of radiation and absorption among bodies, the production of 
 dew and frost may be accounted for. 
 
 During the absence of the sun, a great quantity of heat is 
 dissipated from the surface of the earth by ladiation: by this 
 means, when the night is clear, the temperature is considerably 
 lowered : when, however, the earth is overhung by a canopy 
 of clouds, they radiate in return, or reflect, and thus maintain 
 an almost uniform temperature. When the clouds are absent, 
 all the heat radiated by the earth is lost in the upper regions 
 of space, and the surface is reduced in temperature many 
 degrees below the atmosphere. 
 
 " The stratum of air which lies in contact with the surface 
 of the ground is then cooled by contact, and a portion of the 
 watery vapor which it had possessed in the elastic form, is 
 deposited as liquid water. If the temperature of the air be 
 itself low, and the night very clear, the cooling may proceed 
 so far that the drops of dew at the moment of their deposition 
 shall be frozen, and thus form frost." [Kane.] The fact is 
 familiar to most observers, that dew and frost are formed only 
 in clear starlight and still nights, and then only on the 
 surface of good radiators. 
 
 The cooling of the earth's surface by the loss of radiant 
 heat, is prevented by a covering of snow or any other sub- 
 stance which intercepts its passage, and no dew or frost is 
 formed. Thus plants may be protected against frost by 
 covering them with a blanket or layer of straw : the same end 
 may be attained by raising large fires by means of damp straw, 
 brush, <fec., so as to destroy the transparency of the air by a 
 cloud of smoke and watery vapor. This mode is practiced by 
 the Incas of South America, who seem to understand the 
 conditions under which dew and frost are formed. When 
 
 *12 
 
138 SCIENTIFIC AGRICULTURE. 
 
 there is a current of air, there will be no condensation of 
 watery vapor so as to form dew or frost: hence they are 
 seldom or never seen on a windy night. 
 
 In some parts of the world, as in sections of South America 
 and Mexico, dews are so copious as to supply the place of 
 rains. The cold ascribed by many persons to the light of the 
 moon, is nothing but the consequence of nocturnal radiation. 
 JMists, fogs, and clouds, are only floating vesicles of watery 
 vapor, which obscure the transparency of the atmosphere; 
 they differ only in the degree of their density. " A fog, [says 
 a celebrated naturalist,] is a cloud in which one is, a cloud is 
 a fog in which one is not" Fogs are not common in hot 
 countries, they rise to a small height, and are prevented by 
 winds. In Peru dense fogs continue for half the year. Day 
 fogs are volcanic ashes and vapors diffused through the air by 
 wind. The appearances of clouds may be changed according 
 to their height, density, distance, and the angles at which the 
 sun's light strikes upon them, &c. They are moved about 
 and broken apart by winds, and assume various and beautiful 
 hues, according to the different colors of the sun's rays which 
 they reflect 
 
 Clouds, then, are merely floating, distant fogs, and arc most 
 frequently formed over some body of water or wet soil, 
 sxow. 
 
 Snow is congealed water, which descends from the upper 
 regions of the atmosphere. The precise conditions of atmos- 
 phere requisite for its formation, or the manner in which it 
 takes place, is not yet well understood. The most that is 
 known respecting it, is in relation to the form of its flakes: 
 these are stellate, and composed often of hexagonal prisms, 
 arranged at an angle of 60, from each of which others fre- 
 quently shoot out at the same angle. The whiteness of snow 
 is said to depend on the minuteness of its crystals. In some 
 cases snow presents no appearance of crystalization. 
 
METEOROLOGY. 
 
 139 
 
 Snow recently fallen has a bulk ten or twelve times that of 
 the water from which it is formed ; while common ice has a 
 bulk only about one-ninth greater than the water of which it 
 is formed. The temperature of the air in which snow is 
 formed, must be below freezing, that is, 32 Fah. ; and if it 
 falls through a warmer temperature in its descent to the earth, 
 it is melted, hence there is no snow in warm weather, nor in 
 the torrid zone, except on the summits of mountains which 
 reach above the line of perpetual congelation. It may there 
 snow above and rain below. 
 
 The snow line, or line of perpetual snow, varies greatly in 
 altitude, according to location and circumstances. On the 
 Himmalaya chain, according to Humboldt, the snow line on 
 the south side is 4,4000 feet below that on the north side ; so 
 that this line cannot be depended upon as a point by which to 
 estimate the altitude O f mountains. 
 
 [This figure from Muller shows a few of the forms of snow flakes or 
 crystals, all of which belong to the hexagonal system.] 
 
SCIENTIFIC AGRICULTURE. 
 HAIL. 
 
 Hail is a well known meteor, which occurs most commonly 
 in spring and summer, and is often accompanied with thunder. 
 It is formed by the congelation of rain or vapor in the upper 
 regions of the atmosphere. Hail storms are of rare occurrence, 
 and seldom continue more than a quarter of an hour. Hail 
 clouds always float lower than rain clouds. Hail stones appear 
 to be composed of several spherules adhered together; those 
 of the centre being soft, sometimes nearly fluid water, and 
 those of the circumference solid and opake. 
 
 They are also occasionally laminated or radiated. Hail 
 stones are sometimes enormously large : the largest of which 
 we have seen any account, according to Dr. Brande, measured 
 14 inches in circumference, and weighed from 5 to 13 ounces. 
 Many ingenious speculations have been made to account for 
 the formation of hail, but none of them sufficiently satisfactory 
 to be entitled to implicit belief. The most probable cause of 
 this phenomenon now is, that " hail is produced by the mixture 
 of exceedingly cold air with a body of hot and humid air." 
 
 [Olmstead. 
 
 Whether a cold wind comes suddenly from the regions of 
 perpetual congelation, in contact with a body of hot air charged 
 with vapor, blows suddenly into the regions of perpetual frost, 
 and thus, by condensation of the vapor, produces hail, we can- 
 not determine. It is sufficient for this theory, that hot moist 
 air meets with intensely cold air in any way whatever. 
 
 LIGHTNING. 
 
 " This is an electric phenomenon produced by the passage 
 of electricity between one cloud and another, or between a 
 cloud and the earth." The zigzag form of the flash, the fre- 
 quency of its repetition, and the great length, or extent of sky 
 which it embraces, are not yet well understood or accounted 
 for. 
 
METEOROLOGY. 141 
 
 The phenomena of lightning are best observed from the tops 
 of mountains which extend above the clouds; from such a 
 position the flashes have been obsevered to extend for several 
 miles in length. The frequency of succession, and length of 
 the luminous streaks, are supposed to depend upon the imper- 
 fect conducting power of the clouds and vapor between them. 
 
 The question is now settled, that lightning rods, by con- 
 ducting off the fluid, serve as a protection to buildings. The 
 rod protects a circle, the diameter of which is four times the 
 length it extends above the highest point of the building: 
 hence the failures of lightning rods have been owing to their 
 not extending sufficiently high. 
 
 THUNDER. 
 
 The noise produced by the passage of lightning or electricity 
 through the air, from one cloud to another, or from a cloud to 
 the ground, is termed in common language, thunder. The 
 .loudness of thunder depends upon the magnitude and prox- 
 imity of the explosion, the .relative position of the clouds, the 
 character of the surrounding country, and the position of the 
 observer. 
 
 The sharp crashing noise sometimes heard, is caused by 
 lightning striking near us : the low rumbling noise is the effect 
 of distant thunder : the rattling sound is occasioned by a quick 
 succession of explosions from a highly charged cloud. The 
 same species of snapping noise attends the discharge of sparks 
 from the prime conductor of a charged electrical machine. 
 "And when we consider how trifling a portion of electric 
 matter is put in action by the most powerful means of artifi- 
 cial excitement, compared with* the quantity stored up in a 
 full charged thunder cloud, the discrepancy between the 
 appalling crash of the one and the insignificant snap of the 
 other, it will appear surprising that both should originate in 
 the same cause." [Brande.] 
 
 Lightning is the light attendant upon electrical action, and 
 
142 SCIENTIFIC AGRICULTURE. 
 
 thunder the noise which succeeds it: the difference in time 
 between the two phenomena depends upon the distance of the 
 explosion from the observer, allowing the velocity of sound to 
 be 1,125 feet, and that of light about 200,000 miles in a 
 second of time. We give below an extract from the " Ency- 
 clopedia Brittanica," showing the various conditions under 
 which electricity appears in the atmosphere. 
 "1. In regular thunder clouds. 
 " 2. During fog with small rain. 
 " 3. During a brisk snow or hail storm. 
 " 4. During a smart shower on a hot day. 
 " 5. During a shower on a cold day. 
 " 6. In hot weather after wet days. 
 " 7. In wet weather after dry days. 
 " 8. In clear and frosty weather. 
 " 9. In clear warm weather. 
 " 10. During a cloudy sky. 
 "11. During a mottled sky. 
 " 12. In sultry weather with light hazy clouds. 
 " 13. In cold, damp nights. 
 
 " 14. During a north-west wind, which produces a sensation 
 of dryness and coldness, not indicated by the thermometer." 
 
 WINDS. 
 
 Wind is air put in motion. Rarefaction of one portion of 
 the atmosphere by heat, and condensation of another portion 
 by cold, are the principal causes of wind. Some local causes 
 of limited extent may produce wind, such as large fires, &c ; 
 but these winds are limited to the locality where they origi- 
 nate. There, is no known cause, besides heat and cold, which 
 is capable of producing any general or extensive current in the 
 air. 
 
 A wind may be merely relative or apparent, and proceed 
 from the passage of the observer through the air, as by a 
 steam car or balloon. If the speed of his vehicle be twenty 
 
METEOROLOGY. 143 
 
 miles an hour, he feels a current of air equal in velocity to his 
 own ; the wind appears to blow at that rate. The direction of 
 winds may be modified by various causes: when two or more 
 currents meet from different directions, the general direction 
 will be a resultant one, the consequence of the several forces, 
 as in the case of trade winds. 
 
 Winds have received various distinctive appellations accord- 
 ing to the phenomena which they present : thus we have the 
 trade winds, the land and sea breezes* the harmattan, the 
 monsoon, the simoon, the sirocco, whirlwind, hurricane and 
 tornado. A brief description only of each of these varieties 
 can here be given. 
 
 Land and sea breezes. These winds prevail mostly among 
 the islands of the torrid zone ; but more or less in all maritime 
 countries. They are mild, balmy breezes, which blow towards 
 the shores during the day, and from off the land towards the 
 sea during the night time. Their phenomena is explained as 
 follows : during the day the land becomes heated by the rays 
 of the sun, the heat of the ground rarifies the air, which 
 consequently rises to the higher regions, while the cold air 
 from off the ocean rushes in to supply its place ; thus producing 
 a breeze inland as long as the sun continues to warm the earth. 
 This is called the sea breeze. 
 
 During the absence of the sun, the earth, which radiates its 
 accumulated heat faster than the sea, becomes cooler, and the 
 direction of the breeze is changed : the air from off the ocean 
 rises, while the colder air from the land rushes in to supply its 
 place, just as in the case of the sea breeze. This night wind 
 which blows off the land is called the land breeze. As the 
 central part of an island becomes warmer than its shores, the 
 breeze will be the strongest in the midland : " its current will 
 also be performed in a constant gyration; so that the air which 
 flows in upon the land by day, rises, flows out above, and 
 returns again in the same current : and the process is similar 
 
144 SCIENTIFIC AGRICULTURE. 
 
 by night, only the current is reversed." At the time when a 
 perfect equilibrium exists between the temperature of the land 
 and sea, the wind ceases, and there is for a time a dead calm. 
 
 Trade winds are produced by the same causes operating 
 upon a larger scale, and the revolution of the earth on its own 
 axis. These are tropical winds, which prevail only within the 
 limit of about 30 each side of the equator. Their general 
 course on the north side of the equator, is from north-east to 
 south-west, and on the south side, from south-east to north- 
 west. The upward current of the air at the equator, in conse- 
 quence of its higher temperature, causes the colder air to rush 
 in from the north and south towards the point of greater rare- 
 faction; this produces the northward and southward currents. 
 These currents have now a westerly tendency given them by 
 the diurnal rotation of the earth on its axis towards the cast; 
 thus producing their general directions as above described. 
 When not changed by local causes, their direction is the same 
 throughout the year : but however they may be modified, they 
 always blow towards the point of greatest rarefaction, and 
 receive a relative motion from the earth's diurnal revolution. 
 Their velocity is greatest at the equator, where the earth's 
 motion is the most rapid, and diminishes towards the poles in 
 proportion as the circumference of the earth diminishes, and 
 the motion is less rapid. 
 
 The harmattan wind is a periodical easterly wind, which 
 olows irregulary in Africa: it occurs three or four times 
 yearly, and continues for a longer or shorter period, according 
 to circumstances. It blows with only a moderate velocity, 
 is peculiarly dry and unpleasant : it is attended by a haziness 
 of the atmosphere, which often obscures the sun most of the 
 day. During this wind there is no moisture in the air, and no 
 dew or fog; vegetation becomes parched, and droops. Not- 
 withstanding the depressing and disagreeable effects of the 
 harmattan, it is said to be a salubrious wind. 
 
METEOROLOGY. 145 
 
 Monsoons are a modification of the trade winds, which occur 
 mostly in the Indian ocean, and north of 10 south latitude. 
 The south-east winds blow from April to October, and are 
 frequently attended by rain : from October to April they blow 
 from the north-east, and are dry. The change from one 
 monsoon to another is usually attended by violent storms. 
 
 The simoon is a hot, pestilential wind, which, during certain 
 seasons of the year, blows northward from the deserts of Africa 
 and Arabia. This wind, after being modified by passing over 
 the Mediterranean sea, is called in the south of Italy, the 
 sirocco; its poisonous effects are supposed to depend on its 
 dry ness. 
 
 Whirlwinds are such as have a rapid gyratory, as well as 
 progressive motion. Hurricanes are generally whirlwinds con- 
 fined to a narrow path, with a forward motion, sometimes not 
 exceeding 15 miles an hour. 
 
 A wind which moves at the rate of 4 or 5 miles an hour is 
 called a gentle breeze; when its velocity is 15 or 20 miles an 
 hour, it is a gale; when 30 to 40 miles an hour, a high wind; 
 and when 100 miles an hour, a hurricane or tornado, Hurri- 
 canes are more frequent on the shores of China and the Indies 
 than in any other part of the world. 
 
 13 
 
CHAPTER III. 
 
 AURORA BOREALIS. 
 
 "Tins is a luminous meteor usually appearing in tlie northern 
 part of the sky, and presenting a light somewhat resembling 
 the dawn or break of day." The aurora exhibits such a variety 
 of forms at different times, that no general description can give 
 any definite idea of its appearance: this, however, may be 
 easily attained by observation of the meteor itsel It appears 
 to be a horizontal cloud extending towards the east and west, 
 and rising a few, degrees above the horizon. The lower part 
 of the cloud is often darkish,, and the upper part lu.minous and 
 whitish: from this part, streams or columns of light shoot 
 upwards with an unsteady, wave-like motion, reaching some- 
 times to the zenith, and at others only a few degrees above the- 
 horizon. 
 
 The "Northern Lights" usually appear two or three hours,, 
 or soon after sunset, and continue a few hours, and occasionally 
 the whole night : they, also sometimes appear for several sue- - 
 cessive nights, but are rarely seen after midnight or in the 
 morning. [Brande.] They often succeed a change of weather 
 from heat and rain to cold and clear. They are sometimes 
 tinged with .green ; or orange, but more commonly with various 
 shades of red.; The aurora is sometimes seen in the southern \ 
 hemisphere. The mean height of the luminous sheet has been 
 variously estimated a^ from : 100 to 400 miles. No satisfactory. 
 
MKTEOROLOGr. 147 
 
 explanation of this phenomenon has yet been given; many 
 ingenious theories have been proposed, but as we have not 
 space to detail them for the gratification of the curious, we 
 must refer them to larger and more scientific treatises. The 
 probable cause, however, is electricity. 
 
 IGNUS FATUUS, OR "WILL O* THE WISP." 
 
 This is a nocturnal light, commonly known in this country 
 by the name of " Jack- Lantern:" it is seen floating over 
 marshy grounds, moors, grave yards, and along the margins 
 of rivers, and sometimes has a progressive motion, which is 
 probably given it by the passing breezes. The origin and 
 nature of this meteor have been the subject of many supersti- 
 tious theories and absurd speculations; it has often been 
 ascribed to supernatural causes. The most probable explana 
 tion of it is that given by Muller : he supposes it to be hydro- 
 gen gas which is mixed with phosphorus; and that conse- 
 quently it is nothing more than a phosphorescent light. 
 
 A HALO, 
 
 Is a luminous circle, usually of various and beautiful hues, 
 surrounding the sun or moon during certain conditions of the 
 atmosphere. There are two kinds of halo, depending upon 
 different physical causes. The first are small, their diameter, 
 according to Dr. Brande, not exceeding from 5 to 10, and 
 composed of three or more concentric rings of different colors. 
 " These are usually called coronce; and they appear either 
 when a small quantity of aqueous vapor is diffused through 
 the atmosphere, or when light fleecy clouds pass over the sun 
 or moon." The second kind consists of a single luminous 
 circle whose diameter is about 45. 
 
 A halo of the moon is usually a white circle with its inner 
 edge sometimes tinged with pale red. There is much truth 
 in the remark, that a dense halo close to the moon portends 
 rain. Lunar halos are most frequent, because the sun's rays 
 
148 SCIENTIFIC AGRICULTURE. 
 
 arc too dazzling to admit of their being seen. The most 
 probable cause of this phenomena is, that it depends on the 
 refraction of light in passing through small transparent prisms 
 of ice, floating in the higher regions of the atmosphere. 
 
 PARHELIA. 
 
 Parhelia, or mock suns, consist of the simultaneous appear- 
 ance of several images of the true sun. They are at the same 
 height above the horizon as the sun, and are connected by a 
 horizontal circle, which is sometimes colored, but usually white- 
 The cause of these suns is not satisfactorily explained : they 
 are supposed, however, to depend in some way upon the reflec- 
 tion and refraction of the sun's rays. There may be parhelia 
 without rings, and rings without parhelia. They never appear 
 in an unclouded sky, sometimes occur opposite to the sun. 
 
 FIRE BALLS. 
 
 These are "luminous bodies which suddenly appear in the 
 sky, usually at a great height above the earth, and shoot 
 through the heavens with immense velocity, and are sometimes 
 accompanied by the fall of an aerolite." Various hypotheses 
 have been proposed to account for these meteors : limit does 
 not admit of a detail of these opinions ; and it is perhaps suffi- 
 cient to say, that the true explanation of this phenomenon has 
 not, so far as we can ascertain, been given. 
 
 RAINBOW. 
 
 This well known and beautiful meteor consists of two con- 
 centric arches, formed of the colors of the solar spectrum. It 
 is caused by the refraction and reflection of the sun's rays 
 while falling on drops. of rain. The size of a rainbow depends 
 upon the height of the sun above the horizon. Inverted bows 
 are sometimes seen on the ground; they are formed by the 
 rays of the sun falling on the drops of dew or rain which are 
 suspended from the tops, of grass, or from spider' webs : they 
 
METEOROLOGY. 149 
 
 are also seen about waterfalls and ship masts, forming a perfect 
 circle. Lunar rainbows are sometimes seen in the night time ; 
 but their colors are faint and indistinct In order to see a 
 rainbow, we must face a cloud and turn our back to the sun 
 or moon. The philosophical explanation of rainbows will be 
 found in works on natural philosophy and meteorology. 
 
 MIRAGE. 
 
 Mirage is an optical illusion often observed at sea, especially 
 in high latitudes ; it sometimes also appears on the land, par- 
 ticularly in Egypt and Persia: it is seen also on the margins 
 of rivers and lakes. It consists in the appearance in the air 
 over the surface of the sea, of multiplied images of objects on 
 the surrounding coast 
 
 " It arises from unequal refraction in the lower strata of the 
 atmosphere, and causes remote objects to be seen double, as if 
 suspended in the air." These images are sometimes inverted: 
 ships, whale fisheries, and other objects, are sometimes descried 
 by means of mirage at considerable distances. The mathe- 
 matical theory of this phenomenon will be found in works on 
 optics, &c. 
 
 SHOOTING STARS. 
 
 These are common and well known meteors, some of which 
 resemble fire balls in every respect. We shall not attempt 
 any description or explanation of them, as their origin and 
 nature are involved in great obscurity and uncertainty. 
 
 AEROLITES. 
 
 These are mineral masses which fall to the earth apparently 
 from the upper regions of the atmosphere. They have a dark 
 or blackish color externally and a grayish hue internally. 
 They have a specific gravity more than three times that of 
 water : chemical analysis of one specimen shows its constituent 
 elements to be, iron, sulphur, silex, nickel, magnesia, and some- 
 times chromium. These meteors have, with some probability, 
 
 *13 
 
150 SCIENTIFIC AGRICULTURE. 
 
 been supposed to come from volcanoes in the moon : but there 
 is still great obscurity hanging about the whole subject 
 
 COLOR OF THE SKY. 
 
 The general color of the unclouded sky is azure or blue: 
 this is explained on the supposition that the particles of the 
 atmosphere, when illuminated, reflect mostly the blue rays. 
 Whenever the prevailing color of the sky is anything but a 
 pure blue, it is discolored by smoke, vapor and clouds; the 
 more dense these clouds, the nearer the color -of the sky 
 approaches to black. The deep red of the morning and 
 evening sky is explained by supposing the atmosphere permits 
 only the red and yellow rays to pass, and reflects the blue 
 rays. [Muller.] 
 
 The fiery red of morning is caused by an excess of moisture, 
 which, notwithstanding the tendency of the sun's rays to 
 disperse it, forms clouds in the atmosphere, and hence indi- 
 cates rain. A gray sky at morning and a red sky at evening, 
 on the contrary, foretell fine weather. The various other 
 beautiful hues which tint the sky and fringe the massive 
 clouds, so as to produce all the varied gorgeous drapery of 
 the heavens, are caused by the absorption, refraction and 
 reflection of the different rays of the solar spectrum. 
 
 TWILIGHT. 
 
 Twilight is the diminished light of day, which is seen from 
 the setting of the sun on its sinking below the western hori- 
 zon, till the last faint gleaming of day has disappeared. The 
 time at which twilight begins and ends, is altogether arbi- 
 trary, and must depend very much on the acuteness of the 
 vision of the observer. It has been said to commence at the 
 moment of sunset, and terminate when the first small stars 
 are visible. Twilight is short in countries having a pure sky : 
 in Chili, it lasts only a few minutes. In high latitudes it is 
 
METEOROLOGY. 151 
 
 of longer duration, on account of the sun's orbit being much 
 inclined to the horizon. In countries lying in the vicinity of 
 50 of latitude, twilight continues until the sun has descended 
 from 15 to 20 below the horizon. 
 
 The moon's light is only the reflected light of the sun, and 
 is estimated to be, when in its greatest intensity, only 
 part as much as the light of that vast luminary. 
 
i 
 
PART V. 
 
 AGRICULTURE 
 
 CHAPTER I. 
 
 FORMATION AND ELEMENTS OF SOILS. 
 
 THE soil is composed of disintegrated rocks, animal and 
 vegetable matters : most soils are made up of successive layers 
 of fine sand and organic matters, loam, fine gravel, clay, coarse 
 gravel, and occasional masses of rock of various sizes. Various 
 causes have concurred to produce the alluvial deposit on the 
 surface of the earth, which must ultimately have been formed 
 entirely of the rocks which constitute the solid basis and prin- 
 cipal bulk of the globe. 
 
 The running water of rivers and the great ocean current 
 which sweeps across the earth had denuded the rocks which 
 it washed in its course from the high Lpds to the plains and 
 valleys : in this way, ravines have been excavated, valleys filled 
 up, and vast level plains formed. The floods formed by rains, 
 and the torrents resulting from melted snow and ice, which 
 flow down the mountains' sides, wash away all loose matters, 
 and often undermine and tear away fragments of rock : these 
 
154 SCIENTIFIC AGRICULTURE. 
 
 are swept along by the impetuous stream, tlieir corners worn 
 off, and they, together with the finer particles, are deposited 
 on the plains or in the valleys, in the form of sand, gravel and 
 "boulders." 
 
 The action of the air contributes powerfully to the decompo- 
 sition and crumbling of rocks. Water, also, which falls into 
 the cleavage or crevices of rocks, and becomes frozen, often 
 cleaves large masses asunder by its expansion in passing into 
 ice : these masses are again subdivided in the same manner* 
 until entire hills of marble, slate, and other rocks, 'are com- 
 pletely pulverized. The affinity of the gases of the air and 
 water for these elements of the various rocks produce the same 
 effect. The combined action of ice and water in transporting 
 masses of rock is another powerful agency in the formation 
 and distribution of soils. Immense blocks of rocks are fre- 
 quently frozen into ice, which is subsequently broken up and 
 floated by streams and freshets to great distances from their 
 original locality : these, in process of time, become pulverized, 
 and add their elements to the soil. 
 
 The action of fire in volcanic districts produces immense 
 effects in chaging the character of rocks, leveling hills, and 
 filling up valleys with ashes and lava: so vast is the quantity 
 sometimes thrown out at a single eruption, that the whole 
 country for many miles around is covered with the melted 
 rocks, scoria, ashes and cinders. 
 
 In this way Pompeii, Herculaneum and Stabia were inhumed 
 A. D. 79, by a single eruption of Vesuvius. Whole strata of 
 rocks are sometimes broken up by earthquakes, and are after- 
 wards disintegrated and mingled with the soil. The agency 
 of winds in wafting fine particles of alluvium and sand has in 
 many places entirely changed the character of the soil; in 
 some places vast barren plains have keen formed, " dunes " or 
 sand hills raised, fertile fields stript of alluvium, and others 
 coveted by sand containing no other elements of a fertile soil. 
 
SCIENTIFIC AGRICULTURE. 155 
 
 It is apparent now, that the soil bears no necessary resem- 
 blance in all cases to the rocks on which it lies, except when 
 derived directly from them ; then it partakes of their nature. 
 
 After the surface of rocks has by these agencies become 
 sufficiently pulverized and decomposed to form a thin layer of 
 soil, lichens and mosses succeed in fixing their roots in it, 
 causing at the same time further disintegration of the rocks, , 
 and increase of the soil" by their annual decay. When the- 
 soil becomes in this way of sufficient depth and fertility to 
 nourish other, larger, and more perfect species of plants, vegetai- 
 tion becomes more abundant: the decay of this, together with; 
 the organic and earthy matters of animals, which are returned 
 to the soil, combined with the art. and industry of man, a 
 soil sufficiently deep and fertile for successful cultivation, is in 
 process of time produced. 
 
 A general knowledge of the rocks, metals and earths, is of 
 great value to the agriculturist, in enabling him, by the indi-- 
 cations which they afford, to discover springs, mineral waters, 
 ores, mines of coal or metal, marl, lime, valuable stones, &c. ; 
 and also to direct him. to the best locations for lime kilns, glass- 
 houses, brick kilns, potteries, foundries,; salt works, bath houses 
 and stone quarries. Modern chemistry has shown that almost 
 every substance is a compound of several others, and future- 
 experiment may yet show us the compound nature of many 
 bodies which are now considered elementary. There would be 
 little difficulty in determining the character of any soil, had we 
 only to consider the constitution of the rock from which it was 
 originally derived. 
 
 But, during the lapse of ages, the various causes which have 
 been in operation have so changed them that their primitive 
 character has almost disappeared, and they must be considered 
 in thehvpresent actual conditions. Arable soils consist mainly 
 of silex and alumina, with some lime, iron,, sodium, potassium. 
 
156 SCIENTIFIC AGRICULTURE. 
 
 manganese, magnesia, animal and vegetable remains in various 
 proportions and different stages of decomposition. The ele- 
 ments of the soil must exist in different proportions, in order 
 to render them available for agricultural purposes. 
 
CHAPTER II. 
 
 METALS, METALLOIDS, AND ORGANIC ELEMENTS OF 
 SOILS. 
 
 SILICON.* 
 
 SILICON is one of the most abundant and widely distributed 
 substances, constituting probably one sixth of the entire mineral 
 weight of the globe. It is never found pure or in an uncom- 
 bined state, but always combined with oxygen, forming oxide 
 of silicon, or silicic acid. The vast mountains of granite, gneiss, 
 porphyry and sandstone, mica, feldspar, crystal quartz, nearly 
 all precious stones, -the sands of the sea shore and desert, and 
 all stones that emit sparks on being struck by steel, are mainly 
 silicon. 
 
 It is contained in a crystaline state in the outside bark of 
 many plants, particularly in cane, bamboos and the grasses. It 
 is with difficulty separated from its oxygen, but when sepa- 
 rated and pure, it is a fine whitish powder, destitute of taste 
 or odor: it undergoes no change, except becoming darker and 
 denser, by any common degree of heat, but melts before the 
 blow pipe into colorless glass ; it has no affinity for pure water, 
 so that it is not dissolved in it in the smallest degree ; it absorbs 
 
 * Recent investigations appear to show that silicon is neither a metal 
 nor a metalloid. 
 
 14 
 
158 SCIENTIFIC AGRICULTURE. 
 
 water slowly, and allows it to escape easily. It is neither dis- 
 solved nor acted upon by any acid except the fluoric, with 
 which it unites find forms a fluoride of silicon. 
 
 The equivalent number of silicon is 22.22, its specific 
 gravity 2.GG. The fixed alkalies easily unite with silicon, and 
 form silicates, as the silicate of potash, lime, <fcc. It forms an 
 important ingredient in porcelain, glass, and the enamel or 
 glazing of stone ware. The salts of silicon are not numerous; 
 they are all insoluble in water, (according to Prof. Johnston,) 
 except those of potash and soda. 
 
 As silicon is so important an element in plants, and so inva- 
 riably present in all productive soils, a knowledge of its chemi- 
 cal character, and the best means of rendering it available to 
 the roots of growing vegetation, is indispensable. 
 
 ALUMINUM. 
 
 This metallic earth is found in greater abundance in nature 
 than lime, being one of the principal ingredients in nearly all 
 rocks, except the purest limestone : it is the principal element 
 of clay, and exists largely in garnet, albite and mica: it is found 
 also in the ashes of most plants. In its native state it is usually 
 found in combination with silica, and sometimes with sulphuric 
 or phosphoric acid: it is also found nearly pure, or uncombined, 
 in the ruby and sapphire, two beautiful precious stones. Alu- 
 mina is an oxide, and the only one known of the earth alumi- 
 num ; it is white, tasteless and inodorous ; its equivalent num- 
 ber is 13.7. 
 
 It dissolves in acids and in solutions of caustic alkalies; it 
 has a strong tendency to unite with organic matters, and has 
 fcbo a greater affinity for water than any of the other elemen- 
 tary earths. "When mixed with silica in the proportion to 
 form clay, it is easily molded into any form, as in stone and 
 earthen ware: it loses part of its tenacity by fire,. hence the 
 benefit of burning clay soils. Alum is a salt formed by the 
 union of potash, alumina and sulphuiic acid, this salt is 
 
SCIENTIFIC AGRICULTURE. 159 
 
 extensively used as a mordant in calico printing. Alumina is 
 supposed to contribute but little to the nourishment of plants: 
 it is said by Liebig to be an absorbent of ammonia: this, 
 however, is doubted by Prof. Johnston. Its principal agency 
 as ji.i element of soils, is of a mechanical kind. The salts of 
 alumina are few; they have not been sufficiently tested as 
 fertilizers to determine precisely their value in this respect: 
 Sprengol considers them highly deserving of trial in practical 
 agriculture. 
 
 MANGANESE, 
 
 This mjtal is diffused widely through nature, although not 
 in great abundance: it is found mostly in the mineral, but 
 traces of it also exist in the animal and vegetable kingdoms. 
 It has a very strong affinity for oxygen, and is therefore with 
 difficulty reduced from its oxides and ores, which, however, 
 may be done by a long continued and intense heat 
 
 It is hard, brittle, granular, grayish white, and has a specific 
 gravity of 8 : it is very infusible, soon tarnishes by the absorp- 
 tion of oxygon, and after a while falls into a black powder. 
 There are several oxides, two acids, and many salts of manga- 
 nese, some of which are soluble and others insoluble in water. 
 It is used in the arts, and is probably a necessary ingredient 
 in soils. Its equivalent is 27.G7. 
 
 IRON. 
 
 This is the most important of all the metals, and is the most 
 extensively distributed over the earth. It is sometimes found 
 in loose blocks of pure metal on the surface ; but mostly in 
 veins and mines, combined with sulphur, forming a gold 
 colored ore, called sulphuret of iron, and with oxygen in the 
 form of the black and red oxides : it is also extensively com- 
 bined with carbonic acid, constituting the clay iron ore. Native 
 arsenites, phosphates, sulphates and other salts have been, 
 found. 
 
 Nearly all reddish soils and stones are colored by oxide of 
 
160 SCIENTIFIC AGRICULTURE. 
 
 iron. Pure iron is bluish white, brilliant malleable and ductile, 
 the strongest of all metals, and has a specific gravity of 7.8 ; 
 its equivalent is 27.14. 
 
 Iron oxidizes readily when in contact with moisture, and 
 also by heat. Only two of the oxides are of any interest to 
 the agriculturist, viz: the black and the red. The black oxide 
 rarely occurs in the soil, except in combination with some acid ; 
 and this, when exposed to the air, absorbs oxygen and changes 
 to the red oxide. When the black oxide or sulphate is present 
 in moist boggy soils, it proves injurious to vegetation: the red 
 is less injurious. Both are insoluble in pure water, and both 
 are soluble in acids. The red oxide is said to absorb ammonia 
 from the atmosphere, and by thus bringing it within the reach 
 of plants, it is in this way useful, when the soil contains any 
 considerable quantity. 
 
 A red soil containing much iron should be turned over fre- 
 
 iD 
 
 quently, so as to keep it pervious to the air ; and, according to 
 Johnston, such soil "may occasionally be summer fallowed with 
 advantage, in order that the oxide may absorb from the air 
 those volatile substances which are likely to prove beneficial 
 to the growth of future crops." 
 
 The sulphate of iron (green vitriol,) is often found in soils, 
 particularly in bogs and marshy places, and it is said to be 
 very injurious to vegetation: these effects are counteracted by 
 lime, marl, and plaster, which decompose the sulphate and 
 unite with the sulphuric acid and form gypsum. In this way 
 it is beneficial to soils containing lime, and may be used as a 
 manure. Iron is found in the ashes of nearly all plants, and 
 to a small extent in animal bodies. It is probable that some 
 of the soluble salts of iron are requisite to the growth of most 
 plants. 
 
 SODIUM. 
 
 Sodium exists in vast quantities, and is widely diffused 
 through nature : it is found combined with chlorine, forming 
 
SCIENTIFIC AGRICULTURE. 1G1 
 
 common salt, of which great quantities are found in Poland, 
 England and elsewhere. It is the principal saline ingredient 
 in the waters of salt lakes and the ocean. It is found in many 
 minerals, most plants, and in all the animal fluids. Sodium is 
 found in vast quantities in South America in the form of a 
 nitrate. 
 
 The pure metal -sodium is lighter than water, its specific 
 gravity being 0.972; its equivalent number is 23.3. It is a 
 silvery white metal, resembling potassium closely in its appear- 
 ance. The compounds of sodium are numerous and important 
 This metal is soft at common temperatures, melts at 194 F., 
 and oxidizes rapidly in the open air. 
 
 As soda exists in most soils, and is found in some form in 
 most if not all plants, it is probably a necessaay ingredient in 
 soils ; many of its salts, particularly the nitrate, sulphate, chlo- 
 ride and phosphate, are valuable fertilizers. 
 
 POTASSIUM. 
 
 This is the metallic basis of potash : it is bluish white when 
 not exposed to the air, but by the contact of ajr it instantly 
 oxidizes and becomes covered by a crust of the alkali, potash: 
 when thrown in water, it takes fire and burns, with a violet 
 flame. At common temperatures it is soft and may be 
 molded into any form, like wax: "at 32 it is quite brittle, 
 and crytalizes in cubes;, at 70 it is pasty, and at 150, per- 
 fectly liquid. At a dull, red heat, it boils, forming a green 
 vapor, and may be distilled." 
 
 Like sodium, it is lighter than water; its specific gravity 
 being 0.655. Potassium has a remarkable affinity for oxygen, 
 which it abstracts from almost all other bodies. Its equiva- 
 lent number is 39.3. Potash is a strong fixed alkali: it neu- 
 tralizes the strongest acids, and its salts are numerous and 
 important Potassium is not found in an uncombincd and 
 pure state in nature, but in the form of an oxide : it exists in 
 
 *H 
 
162 SCIENTIFIC AGRICULTURE. 
 
 many minerals, nearly all plants, and in animal bodies. It is 
 most abundant in the green and tender parts of plants, the 
 timber of forest trees contains comparatively little. 
 
 Its powerful action on other metals and earths, its caustic 
 action on vegetable substances, and its almost universal pre- 
 sence in soils and vegetation, show it to be an indispensable 
 element of good soils, and a powerful fertilizer. Potash is 
 rendered more caustic by mixture with quick lime, in this 
 way it is beneficial in compost by facilitating the decomposition 
 of vegetable matters. 
 
 MAGNESIUM. 
 
 Magnesium is found in the minerals, serpentine, talc, steatite, 
 asbestos, augite, chrysolite and hornblende: it is always found 
 combined with acids, or other earths, it is found also in marl, 
 and in small quantities in animal substances. It is a white, 
 silver-like metal when pure, malleable, and fusible at a red heat, 
 not changed by dry air, but slowly oxidized by damp air: it 
 dissolves in dilute acids, giving off hydrogen gas, and forming 
 a salt of magnesia. 
 
 Its equivalent number is 12.7. When heated to redness in 
 the air, or in oxygen, it burns with brilliancy, and forms mag- 
 nesia, or oxide of magnesium: it inflames spontaneously in 
 chlorine. It exists in considerable quantity in nature, par- 
 ticularly in magnesian limestone. 
 
 Magnesia slowly but entirely neutralizes acids ; it is inodorous, 
 white, has a slightly alkaline taste, absorbs and retains water 
 to nearly the same degree as lime, but is less caustic and 
 alkaline. There are several important salts of magnesia, some 
 of which are valuable as fertilizers, and indispensable to the 
 growth of vegetation. 
 
 CALCIUM. 
 
 Calcium is a white silvery metal, heavier than water, 
 having a strong affinity for oxygen, with which it combines 
 
SCIENTIFIC AGRICULTURE. 103 
 
 only in one proportion, forming lime. The equivalent number 
 of calcium is 20.5. 
 
 Lime is the most important and abundant of all the earths, 
 being extensively distributed through the mineral kingdom, 
 and constituting the principal earthy ingredient in the shells 
 and bones of animals, and also existing in all plants. It is 
 found in nature combined with carbonic acid, as in marble, 
 limestone and chalk, in quantities so large as to form entire 
 mountains. It is found combined with sulphuric acid, consti- 
 tuting gypsum or plaster of paris: it is also combined with 
 phosphoric, fluoric and arsenic acids. 
 
 The minerals, calcareous spar, gypseous spar, arragonite, and 
 many others, are composed of lime. All natural waters con- 
 tain more or less of this earth. Lime is a pure, white, alkaline 
 earth: when burned lime is exposed to the air, it rapidly 
 absorbs water, and falls into a line powder, which is called 
 "slaked lime," or hydrate of lime. This earth has a strong 
 affinity for acids, with which it forms several salts. It is only 
 sparingly soluble in water, and less so in hot than in cold 
 water : when completely dissolved in clear water, it is called 
 lime water: this, when exposed to the air, unites with the 
 carbonic acid of the air, and a thin pellicle or layer of carbon- 
 ate of lime is formed on the surface, this soon falls to the 
 bottom, and another layer is formed ; and so the process con- 
 tinues until the lime ail becomes a carbonate, and is thus 
 precipitated from the water. 
 
 Lime attacks and destroys both animal tissues and vegetable 
 substances with rapidity, and without the exhalation of those 
 noxious gases and offensive odors, which result when putre- 
 faction goes on without the presence of lime. Lime is valua- 
 ble as a manure in soils destitute of this earth, by supplying 
 an indispensable element to plants, and also by neutralizing 
 r.cidity, dissolving silica, and decomposing insoluble organic 
 
16-i SCIENTIFIC AGRICULTURE. 
 
 m liters, such as woody fibre, humus, peat, ulmine, <kc. The 
 salts of lime arc also of great value as fertilizers. 
 
 MARL. 
 
 Marl is a compound of lime and clay, so intimately mixed 
 that their respective particles cannot be distinguished. The 
 exact process by which nature combines the two elements is 
 not known; for if clay and lime -be mixed together artificially, 
 they form a substance quite different from natural marl: &nd, 
 according to Timer, "it does not possess the faculty of losing 
 its aggregation when exposed to the influence of the atmos- 
 phere, and crumbling to dust like natural marl." 
 
 The proportions of the two elements are various: sometimes 
 the lime predominates, sometimes the clay, and in some speci- 
 mens they are equal. When the clay predominates greatly, it 
 is called clay marl: when the lime predominates, it is called 
 Iim2 ra ii-1. M irl is found in considerable variety, both of com- 
 position and color: it assumes a blue, red, yellowish or whitish 
 hue, according to the oxides of iron, or other matters which it 
 may contain : it is found in greater or less quantities in almost 
 all countries, sometimes on or near the surface, and in other 
 cases at considerable depths in the earth. 
 
 "It is confined [says Dr. Hitchcock,] to the alluvial and 
 tertiary strata, and differs from many varieties of limestone, 
 only in not being consolidated." It often contains salts of 
 potash and soda, fragments of shells, bones, and some vegeta- 
 ble matter: that which contains a large quantity of shells is 
 called shell marl: several other species of marl are described, 
 the most important and valuable of which is greenstone marl 
 
 Nearly all the varieties, except stone marl, are easily pene- 
 trated and their particles separated by water: frost is also an 
 active agent in pulverizing it, it is therefore often laid on 
 land at the beginning of winter. Marl may be detected by 
 the acids, with which it effervesces and forms salts. It is 
 evident from the character and composition of marl, that it is. 
 
SCIENTIFIC AGRICULTURE. 
 
 a valuable fertilizer, especially on lands deficient in clay and 
 
 lime. 
 
 GYPSUM. 
 
 Gypsum is a compound of sulphuric acid, lime and water: 
 it is sometimes found in the form of a soft yellowish white rock, 
 with a texture resembling that of loaf sugar ; " but sometimes 
 [says Lyell,] it is entirely composed of lenticular crystals." It 
 is insoluble in acids, and does not effervesce, for the reason 
 that it is already combined with sulphuric acid, for which it 
 has a stronger affinity than for any other. A variety called 
 anhydrous gypsum sometimes occurs, which contains no water. 
 
 Gypsum is nearly insoluble in pure water; when deprived 
 of its water by heat, it is called calcined gypsum, or " plaster 
 of paris," in this state, if mixed with water, it may be formed 
 into molds or casts, and it soon solidifies into a hard, white, 
 compact mass. When calcined gypsum is long exposed to the 
 air, it absorbs moisture, and is no longer fit for casts and stucco 
 work, until calcined afresh. Gypsum can only be fused by a 
 high degree of heat, it does not then part with its sulphuric 
 acid, but only loses its water. The origin of this rock is diffi- 
 cult to explain ; its found mostly among the new red sandstone, 
 but occurs also among other rocks. 
 
 It is found in most countries in great abundance, and in 
 various forms, as gypseous spar, gypseous stalactites and sta- 
 lagmites, compact gypsum, &c., and in combination with clay 
 and lime. Gypsum cannot be formed artificially. Water con- 
 taining gypsum is called hard water. The decomposition of 
 gypsum can be easily effected by the alkaline carbonates: if 
 powdered gypsum be boiled in a solution of carbonate of 
 potash, a double decomposition, and also reunion, takes palce ; 
 the sulphuric acid of the gypsum unites with the potash, and 
 forms sulphate of potash, while the carbonic acid unites with 
 the lime of the gypsum and forms carbonate of lime. Gypsum 
 is one of the most valuable fertilizers known. 
 
106 SCIENTIFIC AGRICULTURE. 
 
 CLAY. 
 
 Clay is a compound of the t\vo earths, silica and alumina, in a 
 state of chemical union: it usually contains, also, an excess of 
 uncombined silica in the form of sand. Proper clay is formed 
 by nature alone, for no chemical process is known by which 
 silica and alumina can be made to unite so as to form real clay. 
 It is usually colored by some of the oxides of iron, so as to 
 present a bluish, yellow, red or brown hue. 
 
 The two elements of clay are rarely contained in equal 
 quantity ; the silica almost always predominates, sometimes 
 to the amount of 93 per cent. Clay sometimes contains an 
 insoluble carbonate or phosphate of iron, which are both 
 thought to be injurious to vegetation. It sometimes contains 
 also manganese and sulphate of iron, the last of which, unless 
 in a limy soil, is injurious to plants: organic matters are often 
 found in clay, giving it a blackish hue and astringent properties. 
 Clay has been form ad by the decomposition of rocks, such as 
 granite, feldspar, clay slate and argillaceous schist. 
 
 Clay which contains neither iron nor vegetable matter, does 
 not change color by heat: if it contains vegetable matter, it 
 becomes lighter colored by heat; if colored dark by oxide of 
 ircn, it may become lighter by burning, on account of the iron 
 changing its proportion of oxygen. White clay, which does 
 not change color by heat, is nearly or quite pure. When clay 
 is dry, it absorbs water rapidly, becomes tenacious and adhe- 
 sive, so as to retain any form or impression given to it: when 
 saturated with water, it no longer allows that fluid to pass 
 through it: it is from this cause that water stands long on the 
 surface of the ground in swamps having a clay_ subsoil, and 
 this is why we find springs and water veins before we come to 
 solid rock. 
 
 When wet clay is exposed to frost, it is cracked or fissured, 
 and sometimes completely pulverized, by the expansion of the 
 water it contains, during freezing. It retains water with more 
 
X 
 
 SCIENTIFIC AGRICULTURE. 107 - 
 
 tenacity than any other earth, and after being deprived of its 
 water by- heat, becomes hard. After being heated to red 
 clay loses its ductile properties, is insoluble in water, and is of 
 no use in the soil, urtil, by long action of the atmosphere, 
 moisture, and animal manure, it is changed to its former con- 
 dition. Clay does not effervesce with acids, unless it contains 
 lime or carbonate of iron : it requires a high degree of heat for 
 its fusion. Clay is often found in combination with gypsum. 
 There are several varieties of clay, of which we notice only a 
 few. 
 
 Kaolin, or porcelain clay, is the purest and finest, and is 
 used in the manufacture of porcelain ware: it is of a yellowish 
 or grayish white hue, and is supposed to be formed by the 
 decomposition of feldspar. 
 
 Pipe day ranks next to kaolin in fineness, and is of various 
 hues. 
 
 B^le is a species of red clay, used in the manufacture of 
 brown earthern ware. 
 
 Potter's clay is used for bricks and stone ware. 
 CLi'j iron ore contains carbonate and phosphate of iron, and 
 has been described under the head of iron. 
 
 TEAT. 
 
 "Peat usually consists of soluble and insoluble geine, with 
 a mixture of undecomposed vegetable matter and some earths." 
 It is usually limited to the colder parts of the globe: it results 
 mostly from the accumulation and decomposition of mosses, 
 but also from any other vegetable matters which become 
 mixed with it 
 
 The lower stratum of peat beds decays, while the plants on 
 the surface continue to grow, thus adding new matter annually 
 until they attain the thickness, in some cases, of thirty or forty 
 feet. In tropical climates, the heat produces decomposition so 
 speedily that vegetables are resolved into their elements before 
 peat can be formed. 
 
. 
 
 1G8 SCIENTIFIC AGRICULTURE. 
 
 Pe.it is usually found also in low boggy or marshy districts. 
 According to Dr. McCulloch, "by the long continued action of 
 water and other agents, the geine of peat is changed into bitu- 
 men and carbon, which constitute lignite and bituminous coal : 
 in a few instances the process of bitumenization has been found 
 considerably advanced in beds of peat." 
 
 Peat is remarkable for its power of preserving animal mat- 
 ters from putrefaction. 
 
 The following is an analysis of a specimen of peat from 
 Massachusetts. 
 
 Soluble geine, - 26.00 
 
 Insoluble do. - - 59.60 
 
 Sulphate of Lime, - - 4.48 
 
 Phosphate of do. - - - - 0.72 
 
 Silicates, - 9.20 
 
 100.00 
 
 When the decay is far advanced, the peat is a dark colored 
 and sometimes solid mass; when less advanped in decomposi- 
 tion, it is light brown, spongy, and contains pieces of vegeta- 
 bles not yet disorganized, in this state it is used in some 
 countries as fuel. Peat is sometimes sour, from the presence 
 of phosphoric and acetic acids : it sometimes also contains am- 
 monia; it decomposes slowly in the open air. When mixed 
 with lime or potash and fermenting barn-yard manure, it 
 becomes a valuable fertilizing agent, and may be used on any 
 soil which requires the addition of vegetable matter. 
 
 HUMUS. 
 
 Humus is a brown or blackish colored substance, composed 
 of vegetable matter in a state of decay. " Humus [says Bous- 
 singault,] is the last stage in the putrefaction of vegetable 
 organic matter : its elements have acquired a stability which 
 enables them to resist all fermentation." It is of a spongy 
 texture, easily pulverized, and nearly insoluble in water: it 
 
SCIENTIFIC AGRICULTURE. 169 
 
 absorbs water with such avidity as to contain three fourths of 
 its own weight without being moist 
 
 Weak acids have little effect on humus, except to dissolve 
 the alkaline and metallic or earthy matters which are usually 
 mixed with it Potash and soda dissolve humus entirely, with 
 the evolution of ammonia: from this solution, acids cause a 
 precipitate of a brown inflammable powder resembling ulmine. 
 Humus contains more carbon and nitrogen than the vegetables 
 from which it is derived : the nitrogen may be partly formed 
 from the excrements of insects which live in the humus. 
 
 Humus contains, besides some mineral elements, carbon, 
 oxygen, hydrogen and nitrogen, phosphoric, sulphuric and 
 humic acids. Humus is dissipated when exposed to the air by 
 a slow combustion, with the disengagement of carbonic acid. 
 This, and all vegetable earths, are entirely destructible. Salts 
 are formed during the decomposition of humus, by the union 
 of bases with the humic acid, these are called humates. 
 
 Besides the above elements, humus contains, according to 
 Berzelius, humic, crenic and apocrenic acids, and traces of 
 glairin. Humus is an indispensable ingredient in all fertile 
 soils, hence the necessity of replacing it in the soil as fast as it 
 is exhausted. 
 
 Agriculturists who think to supply the place of manure by 
 frequent and deep ploughing, have been disappointed, and 
 their fields have been gradually impoverished by crops, until 
 they became barren. When humus is put on a clay soil, it is 
 retained with such tenacity by the clay, that the free contact 
 of air is prevented, and it decomposes more slowly, for this 
 reason clay requires a larger quantity, other things being 
 equal, to produce the same effects, than other soils. 
 
 Sand allows free access of air to the humus, which is incor- 
 porated with it, and thereby favors its decomposition and 
 consequent fertilizing power. Lime and potash destroy the 
 acidity of sour humus, and favor its decomposition: sour 
 
 15 
 
170 SCIENTIFIC AGRICULTURE. 
 
 humus contains an insoluble extractive matter, which is inju- 
 rious to vegetation. A soil which abounds in sour humus 
 produces little but reeds, rushes, flags, sedge, and other poor 
 and unpalatable plants: such soils are rendered fertile by 
 draining, burning and alkalies, 
 
CHAPTER III. 
 
 PHYSICAL PROPERTIES OF SOILS. 
 
 THE physical properties of soils necessary to be considered 
 are, density, weight, state of division, firmness and adhesive- 
 ness, power of imbibing moisture, power of containing water, 
 power of retaining water, capillary power, contractibility on 
 drying, power of absorbing gaseous matters, power of absorb- 
 ing heat, power of containing heat, and power of radiating 
 heat. 
 
 The weight of a soil depends upon its density, or the 
 proximity and density of its particles. Dense soils retain heat 
 longer than light ones, and afford a firmer support to the roots 
 of plants. 
 
 The following table, from Johnston, shows the relative 
 weight of several soils. 
 
 A cubic foot of dry silicious or calcareous sand weighs 180 Ibs. 
 
 " " Half sand and half clay " 95 
 
 " " Of common arable land " 80 to 90 
 
 " " Of pure agricultural clay " 75 
 
 " " Of rich garden mold " 70 
 
 " " Of a peaty soil "39 to 50 
 
 The state of division of the particles composing the soil has 
 
 an effectvupon its weight, as well as money value. A soil 
 
 eomposecTof clay, sand, coarse and fine gravel and vegetable 
 
172 SCIENTIFIC AGRICULTURE. 
 
 mold, is superior in all respects to to one composed of either of 
 these ingredients alone. 
 
 Firmness and adhesiveness. Most soils become hard and 
 stiff in some degree, by the cohesion of their particles after 
 being thoroughly wet. Clay soils become hard and difficult to 
 pulverize when thoroughly dried, while pure sand soils scarcely 
 cohere at all. This varies according to the relative amount of 
 sand and clay or lime in the soil. The practical inference is, 
 that a sandy soil is improved by clay, and a stiff clay soil is 
 ameliorated by sand. 
 
 The power of imbibing moisture is possessed by all fertile 
 soils. In dry weather, this quality in soils is highly important, 
 in order that moisture may be absorbed from the dews of the 
 night, to compensate to the roots of plants what they had lost 
 by exhalations from their leaves and evaporation from the soil, 
 during the day. 
 
 During a night of twelve hours, when the air is moist, 
 according to Schubler, 
 
 1000 pounds of perfectly dry quartz sand will gain Ibs. 
 " " Calcareous " " 2 
 
 " " Loamy soil " 21 
 
 " " Pure agricultural clay " 27 
 
 " " Rich peaty soils, still more. 
 
 Power of containing water, in dry climates, constitutes one 
 of the most important characteristics of arable soils. A good 
 soil for ploughing or tilling must be capable of containing from 
 30 to 70 per cent, of its weight of water: soils which allow 
 their moisture to sink down immediately after rains, below the 
 reach of the roots of plants, are valuable only " for pine plan- 
 tations or laying down to grass." [Johnston.] 
 
 The following table from Schubler shows the relative capacity 
 of soils for containing water. By this, we mean, the amount 
 of water which a given quantity of earth will imbibe and 
 
SCIENTIFIC AGRICULTURE. 173 
 
 contain, before it is saturated or full, so as to allow the water 
 to drop or run out 
 
 From 106 Ibs. of dry soil, the water will begin to drop, if it 
 be a quartz sand, when it has absorbed 25 Ibs. 
 
 Calcareous sand, " " " " 29 
 
 Loamy soil, " " " 40 
 
 English chalk, " 45 
 
 Clay loam, " 50 
 
 Pure clay, " " 70 
 
 Power of retaining water. Evaporation is constantly going 
 on from the surface of the earth, except when the atmosphere 
 is saturated, or rain or dew is falling. The rapidity with which 
 soils become dry after rains, depends upon the tenacity with 
 which chey retain water : as a general rule, those soils which 
 are capable of containing the most water, also retain it with 
 the greatest tenacity. Thus a sand soil will lose as much 
 water in one hour as a clay in three, or peat soil in four hours. 
 On this property depends in a great degree the warmth or 
 coldness of a soil. 
 
 The capillary power of the soil is exhibited by pouring 
 water into the bottom of a flower pot, when it will be seen 
 that the earth gradually takes up the water, and the moisture 
 soon appears on the surface. In the same way the surface 
 soil absorbs moisture from the subsoil ; and when this contains 
 an excess of water, the surface is also too wet and cold. Open, 
 porous soils, -such as sand, peat and humus, possess greater 
 capillary power than stiff clay. Upon this action the soil is 
 dependent for its supply of moisture during dry weather: 
 upon this, also, the roots of plants are dependent for a supply 
 of soluble saline matters, which, during rains, have been 
 washed down into the subsoil beyond their reach. This is the 
 principal means by which, in hot, dry climates, where rains 
 seldom or never fall, the soil obtains sufficient moisture to 
 produce vegetation. This capillary action explains the exis- 
 
 *15 
 
174 . SCIENTIFIC AGRICULTURE. 
 
 tence of the thick crusts of nitrate, carbonate and chloride of 
 soda, which are met with in Peru and other parts of South 
 America, India and Egypt These salts are brought to the 
 surface by capillary action, in a state of solution, and deposited 
 as the water evaporates. 
 
 Contractibility on drying. Some soils contract or shrink 
 on becoming dried after rains, much more than others; and 
 this appears to be in proportion to their power of retaining 
 water. Thus clay and peat diminish in bulk one fifth on being 
 perfectly dried after saturation, while sand maintains the same 
 bulk in either state. [Johnston.] This contraction in clay 
 soils has a tendency to tear and injure the small and tender 
 roots of plants. 
 
 Power of absorbing gaseous matters. rThe necessity of free 
 access of air to the soil has already been noticed; and in 
 proportion to the amount of air which is admitted into the soil, 
 will be the oxygen and other gases absorbed and made avail- 
 able to the roots of vegetation. Clays, peat and humus absorb 
 more oxygen than sandy soils ; this is due partly to difference 
 in porosity, and partly to the chemical character of each. Be- 
 sides oxygen, soils absorb carbonic acid, ammonia, nitric acid, 
 and other vapors which contribute to fertility. All soils absorb 
 gaseous substances the most readily when in a moist state ; so 
 that dews and showers are of great benefit, in bringing the soil 
 into a condition to extract from the air fresh supplies of the 
 gases. 
 
 Power of absorbing heat. The earth is capable of absorbing 
 lieat during sunshine, so as to attain a temperature above the 
 surrounding air. Dark colored, brown and reddish soils absorb 
 heat most rapidly, and become warm the soonest They also 
 become from three to eight degrees warmer than other colored 
 soils, and by this means they promote the growth of vegetation 
 better than those of other colors. This property gives an 
 additional value to dark soils over light ones, in countries 
 
SCIENTIFIC AGRICULTURE. 17-"> 
 
 where sunshine is deficient, and in fields which bavo a northern 
 aspect 
 
 Power of retaining heat. As heat always tends to seek an 
 equilibrium, it follows that after the sun has disappeared, and 
 his rays cease to shine on a particular part of the earth, the 
 amount of heat which it has absorbed above that of the air is 
 gradually given off again to the latter, until their temperature 
 is equal, or until the air becomes the coldest, as in frosty 
 nights. A peat soil cools more quickly than clay, and clay 
 more quickly than sand. This difference must have an influ- 
 ence on the growth of crops. In cold, wet soils, the property 
 of radiating heat slowly compensates in some degree for the 
 injury done (o plants by these conditions. It also prevents the 
 formation of dew and frost, as soon as would otherwise be the 
 case. On the contrary, soils which radiate heat faster promote 
 the formation of dew by becoming cooled below the dew point 
 sooner, and in this way compensate in some small degree, for 
 deficiency of rain. 
 
 The absorbing, as well as radiating power of the soil, may 
 be increased by a top dressing of soot, charcoal, muck, or some 
 dark colored manure. The principle of absorption and radia- 
 tion as dependent upon color, holds true in relation to plants, 
 as well as to soils: and, if all other conditions are favorable, 
 the light colored, (white straw,) crops should be cultivated on 
 dark colored soils, and the dark colored, (green straw,) crops 
 on the light colored soils* 
 
 The study of the mechanical and physical properties of 
 soils is of more importance than has generally been supposed. 
 These have now been discussed as fully as limits would admit, 
 and we conclude the subject by stating finally, what are the 
 ultimate uses and relations of the soil to plants. 
 
 * This idea is original with the author, so far as he knows : whether 
 of any value or not, others may judge and decide. 
 
176 SCIENTIFIC AGRICULTURE. 
 
 First, the soil serves as the foundation for upholding and 
 giving mechanical support to the vegetable structure. 
 
 Secondly, it absorbs light, heat, air and moisture, which are 
 indispensable to healthy vegetation. 
 
 Thirdly, it supplies both the organic and inorganic elements 
 required by the plant as food. 
 
 Fourthly, it is a chemical laboratory, in which these ele- 
 ments are constantly being prepared to be taken into the plant 
 by its roots. 
 
CHAPTER IV. 
 
 TILLAGE. 
 
 ALL operations upon the soil for its improvement and prepa- 
 ration for crops, may be included under the two heads of 
 tillage and stercology, or manuring. Tillage includes the 
 operations of draining, irrigation, paring and burning, rotation 
 of crops, fallow, extirpation of weeds and insects, ploughing, 
 ribbing, lapping, laying in beds, scarifying or grubbing, subsoil 
 ploughing, trenching, rolling, harrowing, hoeing, spading, &c. 
 
 The objects of tillage are, 1. To loosen the soil and render 
 it permeable to air, water and the roots of plants. 2. To bring 
 up the subsoil and mix it with the surface. 3. To incorpo- 
 rate manures with the soil. 4. To allow free access of the 
 heat and light of the sun. 5. To pulverize the coarse and 
 compact portions. 6. To destroy weeds and insects. V. To 
 bury green crops designed for manures. 8. To render wet 
 soils dry and arable. .9. To supply a sufficiency of water to 
 dry soils. 10. Tojix movcable and light blowing soils. 11. To 
 clear the soil of roots ami stones. 12. To cover seeds with 
 soil "after sowing. t -. .5^%*$**" ^. 
 
 The following operations are described by Colman, and are, 
 part of them, peculiar to the agriculture of Europe. 
 
 Lapping consists in turning a furrow upon an unploughed 
 surface, so that when the field is finished, it is only half 
 ploughed. 
 
178 SCIENTIFIC AGRICULTURE. 
 
 Ribbing resembles lapping, except that two furrows, instead 
 of one/ are turned upon the same unploughed space. 
 
 Stitching or laying in beds consists in turning two furrows* 
 back to back, and then ploughing alternately on either side, 
 until the bed is from 5 to 60 feet wide, and leaving deep fur- 
 rows between all the beds. 
 
 Trench ploughing consists in making a deep furrow, by 
 ploughing one furrow directly in another. 
 
 Subsoil ploughing consists in breaking up and loosening the 
 subsoil with a plow for that purpose, and without inverting the 
 surface. 
 
 Scarifying or grubbing differs from harrowing only by being 
 performed with a cultivator or similar instrument, which goes 
 deeper into the earth than the common harrow, for the purpose 
 of pulverizing the soil, and bringing up roots and stones to the 
 surface. 
 
 The other operations of tillage need not be described, as 
 they are common and well understood. There can be no 
 question that much of the success of productive agriculture 
 depends upon the perfection of tillage. A perfect tillage 
 requires the combination of patient labor, mechanical imple- 
 ments of the best construction, and skill in the operations. 
 
 A poor soil well tilled may produce better crops than a good 
 soil without tillage. Thorough tillage, by mixing and pulveri- 
 zing the soil sufficiently, is a means of saving manures and 
 greatly increasing the return of the harvest: it is not, however, 
 true, as once supposed, that tillage will supercede the neces- 
 sity of all manures ; it only compensates for part of the manure 
 requisite, and facilitates the operation of that which is applied. 
 The Chinese, and some nations of Europe, have, by a perfect 
 svstem of tillage, rendered barren soils fertile, and caused 
 fertile soils to vield harvests of almost incredible amount. 
 
flCIENTIFIC AGRICULTURE. 179 
 
 IRRIGATION. 
 
 Irrigation has been practiced by the Chinese and Egyptians 
 from the remotest antiquity. In countries where rains seldom 
 fall, and the ground becomes dry and parched, irrigation is of 
 immense value. It consists in taking water from lakes, sewers, 
 running streams or reservoirs, and causing it to flow over the 
 land by means of small canals or furrows, then by proper out- 
 lets to carry it off again. It is confined, according to Colman 
 and Johnston, almost exclusively to meadow lands. 
 
 The benefits of irrigation in a country where rain falls fre- 
 quently and abundantly, are the same as those of manuring. 
 When the water used holds in suspension any organic matters, 
 they subside while the water remains on the fields, and leave 
 a visible layer of manure on the surface, after the water is 
 drained off. An example of the fertilizing effects of irrigation 
 is seen in the lands along the banks of the Nile and Ganges. 
 But the effects of irrigation with water that contains no organic 
 sediments, must be considered the same as that of rains. Run- 
 ning water furnishes to plants some gasses, which are absorb- 
 ed, and in this way are beneficial. Crops of young and ten- 
 der plants should be irrigated by pure water : it may be re- 
 peated every two or three weeks when there is any want of 
 rain, and the water be allowed to lie on the field only three or 
 four days. It is thought by English Agriculturists to be inju- 
 rious to meadows to flood them immediately after mowing. 
 
 Warping is a process similar to irrigation: the object of 
 this, however, is more especially to obtain the sediments of 
 muddy streams, &c. ; the water should never be allowed in 
 either process to remain on the field until stagnated. Irriga- 
 tion is most beneficial on land which is well drained beneath, 
 so as to allow the water to penetrate the subsoil, and not stand 
 too long on the surface. Meadow lands are sometimes water" 
 ed in the winter to prevent the injurious effects of frost upon 
 the roots of the grass. Irrigation is not practiced to much ex- 
 
180 
 
 SCIENTIFIC AGRICULTURE, 
 
 tent in the United States; and the remoteness of many farms 
 from streams, as well as the expense attending the operation, 
 will prevent its universal application, even where it would be 
 beneficial. 
 
 PARING AND BURNING.* 
 
 Paring and Burning is much practiced in many parts of 
 Europe, particularly in Great Britain; but, so far as we are 
 informed, it is but little practiced in the United States. It is 
 done mostly upon sward, peat and turf soils. The operation 
 consists in removing, with a plow or spade, a slice from the 
 surface, from one- to three inches thick : this is piled up in 
 small heaps along with other combustible matters, such as 
 brush, weeds and decayed wood ; these, when sufficiently dry, 
 are fired and allowed to smoulder and burn slowly until the 
 whole is reduced to ashes. The ashes are then spread evenly 
 over the surface of the soil. The quantity of ashes which is 
 sometimes obtained in this way at a single burning, is stated 
 by Colman to be 2660 bushels, or about 77 tons per acre. 
 
 The benefits of paring and burning are, 1. It disentegrates 
 and reduces to fineness, some stones and hard clay. 2. It de- 
 stroys insects, with their eggs and larvae. 3. It reduces vege- 
 table matter to ashes and gases, which are available for the 
 immediate food of a crop of plants. There are some objec- 
 tions to this process, which ought to be stated, as it involves 
 some principles not wholly understood. 
 
 One objection is that it consumes too much of the vegeta- 
 ble and organic matters of the soil: another is the amount of 
 labor required in the operation. The benefit however, of par- 
 ing and burning upon cold, moist, sour, peat and turf soils, is 
 unquestionable. The lime and potash produced, serve to neu- 
 tralize acids in the soil, and the iron, if it contain any, is brought 
 to a higher degree of oxydation. 
 
 On light, sandy, gravelly soils, where vegetation is thin and 
 
 * This operation is very little practiced in America. 
 
SCIENTIFIC AGRICULTURE. 181 
 
 there is little organic matter present, this practice is injurious. 
 The process of burning, according to Boussingault, ought to 
 cease after the organic matters are reduced to a blackish ash ; 
 for when carried beyond this, so that incineration is complete 
 and a red ash is left, it may materially injure, if not render 
 the soil barren. 
 
 DRAINING. 
 
 The draining of wet lands has become one of the most im- 
 portant branches of mechanical agriculture. An excess of 
 water in the soil prevents the access of air, reduces the tem- 
 perature, favors the formation of frost, fogs and mildew, and 
 renders tillage difficult or impossible. Soils may be rendered 
 too wet in various ways, as, by the tides of the sea, by the 
 setting back of rivers, by permanent springs in the soil, by 
 small subterranean streams, and by the compact and retentive 
 nature of the soil or subsoil. The advantages of draining, and 
 the various modes by which it is best accomplished, are well 
 described by Johnston and Colman, from whose works the fol- 
 lowing facts in relation to the operation are derived. 
 
 1. It carries off all stagnant water, and gives a ready escape 
 to the excess of what falls in rain. 2. It prevents the ascent 
 of water from below, either by capillary attraction, or springs. 
 3. It allows the water of rains to penetrate, and find a ready 
 passage from the soil, instead of washing the surface. 4. The 
 descent of water through the soil is followed by fresh air, which 
 occupies the space just left by the water. 5. The soil after 
 thorough draining becomes looser, more friable and easily 
 broken ; this is especially true of stubborn clays, which in 
 practice become altogether another soil. 6. By freeing the 
 soil from the excess of water, it becomes warmer, and thereby 
 advances the crop to an earlier harvest: thus it is "equivalent 
 to a change of climate" 7. When the autumn is wet, drain- 
 ing carries off the superabundance of water, and prepares the 
 land for sowing fall crops, which would otherwise be retarded, 
 
 16 
 
182 SCIENTIFIC AGRICULTURE. 
 
 or altogether prevented. 8. In its consequences it is equiva- 
 lent to an actual deepening of the soil. 0. In wet soils, bone?, 
 wood-ashes, rape dust, nitrate of soda, and other artificial ma- 
 nures are almost thrown away. 10. He who drains confers a 
 benefit upon his neighbors also. 11. It produces a more salu- 
 brious climate, and conduces greatly to the health and moral 
 happiness of the whole population. 
 
 Several different modes of draining are practiced in Great 
 Britain, which are worthy of notice some of them arc also 
 known and practiced in the United States. The, process of 
 draining by open ditches is the rudest, and was doubtless the 
 first form of draining. Covered drains were next substituted, 
 of various construction. One form of these is made by dig- 
 ging a ditch, and then filling it with straw or faggots, and cov- 
 ering it over with the earth which was thrown out. Another 
 form is excavated so as to taper to a point at the bottom, and 
 having a shoulder left at the height from the bottom which it 
 is desirable to cover the waier-course. This is then covered 
 by an inverted sod, which rests on the shoulders; after which 
 the earth thrown out in excavating is returned, and the surface 
 levelled. Another process is by the mole plow : another by 
 filling the bottom of a ditch with small stones of uniform size. 
 Two other forms, called in England tile and pipe drains, are 
 constructed by means of tile and pipes made of brick clay, 
 and are said to form water-courses which are both cheap and 
 durable. 
 
 FALLOWING. 
 
 "By fallowing, it has been known in all ages that the produce 
 of the land was capable of being increased. How is this in- 
 crease to be accounted for t We speak of leaving the land to 
 rest, but it can really never become wearied of bearing crops. 
 It cannot, through fatigue, lie in need of repose. In what, then, 
 does the efficacy of naked fallowing consist?" (Johnston.) 
 
 Some agriculturists reject the practice of fallowing as use- 
 
SCIENTIFIC AGRICULTURE. 188 
 
 less, upon the supposition that all the objects accomplished by 
 it, may be also by the application of manures. The proposal 
 to substitute manures, is of course equivalent to an admission 
 that fallow is beneficial to the soil. Now if any change takes 
 place in the soil while lying in fallow, we must first know what 
 that change is before we can determine whether manures will 
 affect the same change : and in order to know this, we must 
 have an exact analysis of the soil, before the fallowing begins, 
 and at the end of its term ; this will show what new elements 
 are formed, and what old ones are decomposed. 
 
 If, tlven, we have a manure which will furnish to the soil all 
 the elements which were formed by chemical action during fal- 
 low ing, it will fulfil the same indication. But in either case, 
 an analysis of the soil is requisite before the fact can be estab- 
 lished : and inasmuch as those who discard fallowing, have 
 made no such analysis, they have made no demonstration of 
 the truth of their position. And until farther facts are de- 
 veloped by chemical experiment, it may be fairly questioned, 
 whether, on all soils, and under all circumstances, fallow can be 
 dispensed with. The benefits to be derived from allowing land 
 to lie in naked fallow are enumerated by Johnston as follows : 
 
 1. In strong clay soils, fallow affords opportunity for destroy- 
 ing weeds, which it is difficult to extirpate while the land is 
 continually bearing crops. 2. The weeds and herbage which 
 spring up during summer, afford an abundant crop for green 
 manure : they should be ploughed under before their seeds 
 ripen. 3. Land which is continually cropped, becomes ex- 
 hausted of certain elements within the depth to which their 
 roots extend. By leaving the soil at rest, the rains which fall 
 and circulate through it, equalize the distribution of the solu- 
 ble substances which it contains. The water which in dry 
 weather, ascends by capillary attraction from below, brings up 
 Baline compounds and deposits them as it evaporates. 4. Some 
 subsoils require to be turned up and exposed to the action of 
 
184 SCIENTIFIC AGRICULTURE. 
 
 the air for some time, before they can be safely mixed with 
 the surface soil. 5. The soil often contains more or less 
 organic matter which is inert, or decays so slowly as to be 
 almost unavailable to vegetation : by leaving this to decompose 
 and become fitted for the food of plants, the crop which fol- 
 lows will grow more luxuriantly and yield more abundantly. 
 6. The nitrates, which are very favorable to vegetable growth, 
 are more rapidly formed when the land lies in naked fallow 
 than when covered with crops. 7. The fragments of rocks of 
 various kinds are disintegrated and decomposed faster during 
 fallow than during cropping. 8. The saline and other sub- 
 stances, such as ammonia, magnesia, the nitrates, &c., which 
 are brought down by rains, accumulate in the soil during fal- 
 low. 9. The clay, oxide of iron, and organic matter of the 
 soil, have the power of extracting ammonia from the air; and 
 this is the more rapid, the greater the extent of surface which 
 is uncovered and exposed to the passing air. 10. The light 
 soils sometimes become too loose to afford sufficient mechani- 
 cal support to the roots of crops, and require time to settle 
 together and resume their cohesion and compactness. 
 
 No doubt the period usually allowed to land to lie in fallow 
 may in many cases be very much abridged, and in some cases 
 altogether dispensed with. Whenever follow is beneficial, it 
 must be ascribed to some one or more, if not all the above 
 causes combined. 
 
 ROTATION OF CROPS. 
 
 By rotation of crops, is implied, the alternate production of 
 different plants in regular succession on the same land. Expe- 
 rience has shown that the same crop cannot be produced 
 successively on the same field for an indefinite period of time. 
 
 The grasses and forest trees seem to present an exception 
 to this principle : but it must be observed that the grasses are 
 mowed or pastured down before arriving at maturity, for, if 
 they were allowed to perfect their growth and ripen their 
 
SCIENTIFIC AGRICULTURE. 185 
 
 seeds, tho same result would follow as in other crops. And 
 with regard to forest trees, it has been observed that where an 
 oak forest has been cut down, a growth of pine will succeed; 
 and where a pine forest has been cleared away, a growth of 
 oak will spring up in its place : where beech and maple are 
 cut, poplar and basswood often succeed them. Thus it appears 
 that the soft and hard woods alternate with each other. 
 
 The reasun formerly given for the necessity of rotation was, 
 that all plants throw off certain matters or excrements by their 
 roots, which prove injurious to another crop of the same kind 
 of plants j but which are beneficial rather than injurious to 
 crops of a different kind. 
 
 This beautiful theory originated with the distinguished bota- 
 nist, Decandolle, and explains, apparently, in an easy and satis- 
 factory manner, all the reasons for the necessity of rotation 
 of crops. The simplicity and high authority of this theory 
 obtained for it, for many years, an unquestioned assent; and 
 the only objection which lies against it now is, that it is not 
 supported by a. single fact 
 
 The objections to it are, 1. That plants do not excrete so 
 great an amount of noxious matters as supposed by Decan- 
 dolle. 2. No evidence exists of their injurious effects upon 
 the plants from which they are excreted. 3. There has been 
 no demonstration of their nutritive effects on other plants. 
 
 This theory, then, must be abandoned, and we must look 
 for one which is supported by facts: and if one cause be found 
 adequate to explain all the effects produced, we are not bound 
 to seek for another. 
 
 The necessity of rotation does not depend upon there being 
 too much, but too little, of some particular elements in the 
 soil. (Johnston.) All plants require certain elements for food, 
 and these are indispensible to their growth and maturity : one 
 plant requires them in certain proportions and another requires 
 these and others besides, in quite different proportions. 
 
 *16 
 
186 SCIENTIFIC AGRICULTURE. 
 
 "If we assume, [says Petzholdt,] that the utility of the rota- 
 tion of crops depends exclusively upon the circumstance that 
 all cultivated plants withdraw from the soil unequal amounts 
 of certain ingredients for their nutrition, all the observed facts 
 are at once satisfactorily explained, and the possibility of deter- 
 mining the rotation of crops, or of avoiding it altogether, if 
 desirable, made evident." 
 
 It is useless to remark, that no plant can vegetate in a soil 
 which does not contain all the elements which it requires for 
 its food. Some species of grass contain, and therefore require 
 for their growth, a large amount of silica : a soil which contains 
 no silica cannot produce them. A soil may contain just enough 
 silica for one crop, but not enough for a second, so that a second 
 could not be produced; but a crop of some other plant requiring 
 much less silica, might be grown upon it as successfully as the 
 grass before. 
 
 " A single crop of wheat may deprive the soil so completely 
 of one of its mineral constituents, that another crop of wheat 
 could not grow upon it; and yet this soil may contain abundant 
 mineral constituents for the production of a good crop of clover 
 or turnips." An analysis of a soil and the ashes of plants 
 desired to be produced upon it, will determine negatively, 
 whether it is eligible to their growth: but the only positive 
 proof is a trial of the crop upon the soil. 
 
 All plants draw certain mineral elements from the soil, but 
 do not all equally exhaust its fertility. All knowledge respect- 
 ing the application of manures, and the adaptation of certain 
 plants to particular soils, is based upon these facts. The 
 necessity for rotation may sometimes be obviated by allowing 
 the land to lie in fallow for a year, after which the crop 
 may be successfully repeated. Manuring may also sometimes 
 answer the same purpose; but as a general rule in practice, 
 however it may be explained in theory, a judicious rotation is 
 beneficial. 
 
SCIENTIFIC AGRICULTURE. 18 
 
 Boussinganlt states that ho saw in South America, fields on 
 which good crops of wheat were said to have been produced 
 annually for more than two centuries ; and also that potatoes 
 arc cultivated continually on the same soil. It is stated also 
 by Colman, that onions yield more and more abundantly the 
 oftener they are grown on the same field. These statements 
 either contain some hidden fallacy, or they prove that the fields 
 in question contained an inexhaustible amount of the elements 
 necessary to the plants produced ; for they do not, nor were 
 they designed to prove, that rotation is unnecessary. 
 
 It is unquestionable that a perfect system of agriculture, 
 and the maximum production of all crops, requires a system 
 of alternation, regulated according to circumstances, and in 
 accordance with the principles of Chemistry. A valuable end 
 to be obtained by rotation is the destruction of certain weeds 
 and the insects which inhabit them. 
 
 The following table shows a system of rotation which is 
 practiced in Pennsylvania. 
 
 First year Grass or clover. 
 
 Second " Pasture. 
 
 Third " Indian corn. 
 
 Fourth " Oats or barley (manured.) 
 
 Fifth Wheat. 
 
 Sixth " Grass (plastered.) 
 
 The tables below are from Colman, and show some courses 
 of rotation practiced in England. 
 First year Turnips (manured.) 
 Second " Barley. 
 Third " Clover. 
 Fourth Wheat. 
 
 0)i a Clay Soil. 
 
 First year Swedes turnips and Mangel Wurtzel. 
 Second " Wheat and beans, (i. e., part of land in each.) 
 
188 SCIENTIFIC AGRICULTURE. 
 
 Oil a Clay Soil continued. 
 Third year Clover. 
 Fourth " Wheat and oats. 
 Fifth " Vetches, rye and turnips. 
 Sixth Wheat. 
 
 On a Sandy Soil. 
 
 First year Swedes and Mangel Wurtzel. 
 Second " Barley. 
 Third " Clover. 
 Fourth " Oats. 
 
 Fifth " Cabbage and potatoes. 
 Sixth " Wheat. 
 
 On a Limestone Soil. 
 First year Rye and turnips. 
 Second " Barley. 
 Third " Clover. 
 Fourth Oats. 
 Fifth " Turnips. 
 Sixth " Wheat 
 
 The table below is from Mr. J. J. Thomas' Prize Essay : it 
 gives three courses, which are said to be well adapted to the 
 State of New York. 
 
 First Course. 
 
 First year Corn and roots, well manured. 
 Second " Wheat sown with 15 Ibs. clover seed per acre. 
 Third " Clover one or more years, according to fertility 
 and amount of manure at hand. 
 
 Second Course. 
 
 First year Corn and roots with manure. 
 Second " Barley and Peas. 
 Third " Wheat, sown with clover. 
 Fourth " Clover, one or more years. 
 
SCIENTIFIC AGRICULTURE. 189 
 
 Third Course. 
 
 First year Corn and roots, with manure. 
 
 Second " Barley. 
 
 Third " Wheat, sown with clover. 
 
 Fourth " Pasture. 
 
 Fifth " Meadow. 
 
 Sixth " Fallow. 
 
 Seventh " Wheat. 
 
 Eighth " Oats sown with clover. 
 
 Ninth " Pasture or meadow. 
 
 It will be evident, on a little reflection, that no definite rules 
 can be given, and no set of tables devised which shall apply to 
 all soils and under all circumstances. The frequency of any 
 crop in the course of rotation, must, therefore, be determined 
 by a consideration of the character of the soil and subsoil, the 
 amount of manure applied, and the other crops which come 
 in the course.* 
 
 * " In wheat farming districts and with the wheat farmer, who depends 
 for his sales and profits solely upon wheat and wool, the following rota- 
 tion with slight variation, is often adopted. 
 
 Divide all the available land into three, six or nine enclosures: let 
 one-third be always in wheat, one-third in pasture and meadow, and 
 one-third in summer crops well manured, which may be followed with 
 wheat the same fall, or may be put in barley the next spring, and fol- 
 lowed with wheat and well clovered in all cases. The general practice 
 is, to summer fallow the clover after spring pasturing. There should 
 be about one sheep to the acre of all the available land ; the manner of 
 cropping the fallow is important. 
 
 Others make a four years' rotation, letting the clover lay two years, 
 one for pasture and one for meadow. On this system no more ealtle 
 should be kept, or butter and cheese made, or corn, oats or potatoes 
 grown, than is required for the farm use; everything is made subser- 
 vient to the wheat crop." L. B. Langworthy. 
 
CHAPTER V. 
 
 STERCOLOGY.* MANURES. 
 
 ALL agents used by the Agriculturist to preserve or restore 
 the productiveness of the soil, are properly called manures. 
 All soils, after being long cultivated and subjected to the ex- 
 hausting- influence of continual harvests, become deficient in 
 mineral and organic elements, which must be replaced artifi- 
 cially or total barrenness will ensue. Manuring is the process 
 by which this end is accomplished, and for it, there is no 
 substitute. 
 
 If the supply be less than the crops require, the soil increases 
 in barrenness : if it just replaces what lias been removed by 
 the crops, the fertility remains the same: if more be added 
 than the crops require, the fertility of the land is increased. 
 
 *A NKW TERM STERCOLOGY, Mr. Editor: I wish to propose, 
 through your paper a new term, which I think will supply a deficiency 
 in agricultural language. We have no generic term which embraces in 
 its signification, the science or art of enriching the soil. 1 therefore 
 propose the term STERCOLOGY, which is compounded from the word 
 stercus, which means manure, and logos, a discourse. 
 
 Although hardly general enough in its strict meaning, this word may, 
 by a little extension, be understood to embrace everything under the 
 head of manuring, enriching, ameliorating or amending the soil. And 
 although words are only the signs of ideas, and technical language 
 should not be used unnecessarily, still a systematic division of any 
 branch of science into parts embraced under generic heads is always 
 convenient. 
 
 Yours, respectfully, 
 
 M. M. RODGERS." 
 
 Genesee Farmer, August, 1847. 
 
SCIENTIFIC AGRICULTURE. 191 
 
 The remains of plants, together with the excrements and car- 
 m of animals, if returned to the soil before decomposition, 
 must contain all the mineral, organic and gaseous elements,, 
 which the plants derived from the soil or the atmosphere. 
 These must pass through the different processes of decompo- 
 sition, before they assume their original gaseous and earthy 
 forms, and become again available for the food of plants. 
 
 The whole science of manuring consists in supplying to the 
 soil, those indispensible elements which have become exhaust- 
 ed. The richest manure may be applied to a failing soil, and 
 if it lacks a particular element which the crops require, and 
 which the soil does not contain, the soil grows barren notwith- 
 standing the manuring. Farm-yard manure, probably contains 
 the greatest number of elements necessary to fertility ; but par- 
 ticular plants require special manures. 
 
 Manures operate beneficially on the soil in several ways. 
 
 1. By serving directly in some instances as the food of plants. 
 
 2. By causing chemical changes in the soil, by which other 
 substances are prepared to be taken up as nutriment by their 
 roots. 3. By neutralizing noxious substances in the soil which 
 prevent the growth of vegetation. The operation of lime on a 
 cold, sour, peat soil, or one which abounds in sulphate of iron, 
 is an example of this principle. 4. Manures change, accord- 
 ing to their bulk and texture, the mechanical properties of 
 soils, 5. They may change more or less, according to their 
 various properties, the physico chemical character of a soil, in 
 relation to light, heat, air and water. Sand, used upon a clay 
 soil, for the purpose of rendering it more loose and friable, 
 would be as properly a manure, as farm yard, or any other 
 variety. Clay used to ameliorate a sandy soil, is also in effect 
 a manure. 
 
 Manures have been classified in various ways, according to 
 their supposed operation and nature. The most simple and 
 convenient division, and one which is usually adopted at pre- 
 
192 SCIENTIFIC AGRICULTURE. 
 
 sent, is that which arranges all of them into three classes, viz: 
 animal, vegetable and mineral manures. The first class includes 
 all substances of animal origin : the second includes all those 
 of vegetable origin; and the third, all those derived directly 
 from the mineral kingdom. 
 
 O 
 
 ANIMAL MANURES.* 
 
 Animal substances are better fertilizers than those of veget- 
 able origin, on account of their chemical constitution and the 
 facility with which they decompose : they furnish more manure 
 in proportion to their bulk, and act more promptly and rapidly. 
 The properties and value of these substances are given mostly 
 on the authority of Johnston and Boussingault. 
 
 The flesh of animals, after and during its decomposition, is a 
 rich and active manure: the lean flesh acts more energetically 
 than the/a. 
 
 Blood is similar in its properties to lean flesh ; it is sometimes 
 applied as a top dressing in the form of dried powder, and 
 sometimes mixed with other matters, to form composts. The 
 scraps of skin among 1 the refuse of curriers' shops are also 
 used as manure. 
 
 Wool, hair, horns and hoofs found in large quantities among 
 the refuse of various manufactories, contain large proportions 
 of carbon and nitrogen, as do most animal substances, and are 
 therefore highly concentrated manures. The refuse of fisheries, 
 soap and candle factories, slaughter houses, kitchens, sugar 
 manufactories, &c., all contain matters rich in those elements 
 which characterize good fertilizers. 
 
 Animal charcoal, which is to be obtained in considerable 
 quantities at sugar refiners' shops, in a state of mixture with 
 blood and lime, is a manure of considerable value. 
 
 Bones are valuable on account of both the organic an.d 
 mineral matters which they contain, The bones of different 
 
 * See tables at the end of the chapter. 
 
SCIENTIFIC AGRICULTURE. 193 
 
 animals differ somewhat in composition: phosphate of lime 
 constitutes the largest proportion of the matter of dry bones ; 
 the amount is from forty to sixty per cent of their weight 
 Eight pounds of bone dust are equal in phosphates to 1000 
 pounds of hay or wheat straw. 
 
 The value of bones is not dependent alone on the phos- 
 phates, but partly upon the gelatine and other organic matters 
 which enter into their composition : these latter operate in the 
 same way as the other organic tissues of animals. Bones are 
 prepared for manure by boiling, by maceration in sulphuric 
 acid and water, and by grinding; the last of which methods is 
 thought on all accounts to be preferable. In soils deficient in 
 phosphates, bones are of great value ; and from the compara- 
 tively small quantity of phosphates which most crops require, 
 the effect of a large manuring with bone dust is manifest upon 
 the land for. many years: " 260 pounds of bone dust, (less than 
 six bushels,) are sufficient to supply all the phosphates con- 
 tained in the crops which are reaped from an acre during an 
 entire fourshift rotation of turnips, barley, clover and wheat 
 Some lands remember a single dressing for fifteen or twenty 
 years.'* (Johnston.) 
 
 The prolonged effect of bones is due to the organic as well 
 as mineral matters. Bones should not be ground too fine: 
 they are particularly applicable to turnip crops and pasture 
 lands : the milk of cows contains about half a pound of phos- 
 phates to every ten gallons ; hence the necessity of these salts 
 in the soil of pastures. Animal tissues, when used as manures, 
 ought to be well covered with earth, or ploughed under, in 
 order to facilitate their decomposition, and at the same time 
 prevent the escape of the gases formed during this process. 
 
 Solid excrements of animals, Night soil, or human ordure, 
 is a highly valuable fertilizer. It is best prepared for use by 
 mixture with powdered charcoal, half burnt peat, or scil which 
 is rich in vegetable matter : quick lime has been used for the 
 
194 SCIENTIFIC AGRICULTURE. 
 
 same purpose ; but, although it destroys the odor, it dissipates 
 at the same time a large portion of its ammonia. During the 
 decomposition of night soil, an evolution of carbonic acid, 
 ammonia, sulphuretted and phosphuretted hydrogen takes 
 place. After the escape of these gases, the odor ceases, and 
 the remainder, when dried, constitutes what is sold in large 
 cities under the name of poudrette. The odor of recent night 
 soil may be destroyed, and the volatile elements retained, by 
 adding to it gypsum or dilute sulphuric acid. This manure is 
 used in the form of compost, and as a top dressing in the form 
 of poudrette. 
 
 The excrements of horned cattle are more valuable and 
 enduring in their operation than those of the horse and sheep. 
 It ferments more slowly on account of its smaller quantity of 
 nitrogen; hence it retains its virtue longer, and produces a 
 more lasting effect on the soil. It is colder in its nature than 
 that of the horse, which is owing partly to the amount of water 
 it contains, and partly to its peculiar constitution. 
 
 The excrements of the horse abound more in nitrogen com- 
 pounds than those of cattle. Even where both are fed upon 
 the same food, those of the horse are more valuable than those 
 of the cow. It begins to heat and ferment in a short time, and 
 in two or three weeks, according to Johnston, loses nearly half 
 its original weight. On account of this rapid fermentation and 
 the consequent loss of volatile matters, it should be mixed as 
 soon as possible with charcoal, peat, sawdust, or earth rich in 
 vegetable matters, or be sprinkled with gypsum or dilute 
 sulphuric acid. For the same reason, this kind of manure 
 ought, contrary to popular opinion, to be spread upon and 
 ploughed into the soil before any signs of fermentation take 
 place ; unless it is mixed with some other matters to form com- 
 posts. Erom its tendency to ferment and develop heat, it is 
 . admirably adapted to enter into all composts. An additional 
 
SCIENTIFIC AGRICULTURE. 105 
 
 quantity of water prevents too rapid fermentation and pre- 
 serves the virtues of this manure to a considerable extent 
 
 The excrements of the hog are said to be a rich manure ; but 
 they have a strong and unpleasant odor, and often impart a 
 rank taste to the crops upon which they are used: for this 
 reason it has been advised not to use them on crops, particu- 
 larly of roots, which are designed for food. They are colder 
 and less inclined to ferment than those of the cow, and should 
 be combined with other manures or made into composts. 
 
 The excrements of sheep form a richer and more fermentable 
 manure than those of the cow : they are said to be most bene- 
 ficial on soils which contain much vegetable matter, which 
 absorbs the volatile matters which would otherwise pass off 
 during fermentation. 
 
 The value of all animal manures depends much upon cir- 
 cumstances, viz : the food upon which the animal is fed ; the 
 age and condition of the animal ; the amount of labor he per- 
 forms; the length of time and manner in which the manure is 
 kept Since, then, their value is affected by so many condi- 
 tions, it is evident that no general conclusions can be drawn, 
 which shall not be liable to exceptions; and no set of analyses 
 can furnish tables which shall in all eases agree. The following 
 tables may be relied upon as being as nearly correct as can be 
 obtained, and sufficiently so for all practical purposes. 
 
 Excrements of birds. These are among the most powerful 
 fertilizers. The excrement of pigeons is said to be particularly 
 valuable to flax crops, for which it is held in high esteem in 
 some parts of Europe. This, like most other manures, loses 
 much of its value by being allowed to ferment without the 
 admixture of some other matters to retain its volatile elements. 
 The principal value of this, as well as the excrements of all 
 birds, which have been analyzed and used as manures, is 
 dependent mainly on the large proportions of ammonia and 
 phosphates which they contain. The excrements of hens, 
 
196 SCIENTIFIC AGRICULTURE. 
 
 geeso, turkeys and ducks, are of less value than those of the 
 pigeon. 
 
 Guano is the excrements of sea fowls, and is an earthy sub- 
 stance of a grayish brown color: it is mostly found in Africa 
 and South America. It is found on the islands and coasts of 
 those countries, in latitudes where the weather is so dry that 
 decomposition has proceeded slowly, and it has consequently 
 accumulated in large quantities. Guano is said to be efficacious 
 as a manure, applied to almost any crop : it is, however, accord- 
 ing to Johnston, more advantageous to root crops than to grain 
 or grass crops. It is conveniently applied as a top dressing, 
 mixed with gypsum, wood ashes or powdered charcoal. Two 
 or three hundred pounds to an acre is sufficient for a single 
 dressing. 
 
 The urine of men and animals is the most valuable and the 
 most neglected of all manures. That of the cow and hog is 
 said to be more valuable, because it contains more solid soluble 
 matter than that of any other domestic animal. The efficacy 
 of urine as a manure is due to the large quantity of urea, 
 ammonia and phosphates, and consequently of nitrogen, which 
 it contains. Recent urine generally exerts an unfavorable 
 influence on growing vegetation ; it is most beneficially applied 
 after fermentation has fairly commenced, and before it reaches 
 the final stage of the process. (Johnston.) 
 
 Decomposition is attended with a diminution of urea, and an 
 increase of ammonia. It is important that the urine collected 
 should be fermented in tightly covered cisterns to prevent the 
 escape of volatile matters : it has been proposed to add gyp- 
 sura, sulphate of iron, or sulphuric acid, to the fermenting 
 urine, in order to fix the ammonia; the mixture of vegetable 
 mold with it has been also recommended as equally effective 
 and more economical. The loss of manure in waste urine in 
 densely populated countries and large cities, is immense, as is 
 shown by the following calculation. 
 
SCIENTIFIC AGRICULTURE. 197 
 
 [If we allow the quantity of urine voided by each indvidual to be 
 COO pounds yearly, the city of Rochester, which contains 30,000 inhabi- 
 tants, would furnish yearly 1,200,000 pounds, or 540 tons. This, esti- 
 mated at the price of guano would be worth $21,600. Now if we esti- 
 mate the number of horses and cows of the city to 500 of each, and 
 that each animal voids as much urine as two persons, the amount would 
 be 80,000 pounds, or 40 tons, which would be worth $1,600. Here 
 then is a loss, if we reckon guano at $40 per ton of $23,200: or of 
 manure enough to produce, in addition to the ordinary crop, over 
 16,000 bushels of wheat in a single year. These calculations may not 
 be correct, but they approximate this point sufficiently for our purpose.] 
 
 VEGETABLE MANURES. 
 
 Organic vegetable matters in various conditions, constitute 
 the largest part of manure in use. The form in which they 
 are prepared and applied has an important influence on their 
 fertilizing effect. The principal difference between dry and 
 green vegetable matter is, that the latter decomposes more 
 rapidly and therefore acts more promptly. Unripe plants fur- 
 nish a more valuable manure than ripe ones. 
 
 Straw and chaff, when ploughed into the soil dry, are slow 
 in decomposing, and act more slowly than when previously 
 fermented. The question of applying straw without previous 
 decomposition, is, in practice, only a question of time. It is 
 doubtless true that it furnishes about the same amount of 
 manure in both cases ; but in the one case it has a more 
 speedy and powerful, and in the other a more prolonged effect 
 
 Saw dust, is a cheap, and on some accounts a valuable ma- 
 nure : it ferments slowly in the soil, and cannot, therefore, be 
 much relied upon the first year or two. It is beneficial in ab- 
 sorbing gases and liquid manures, and its effect is felt gradually 
 by the soil as decomposition proceeds : . it is also beneficial to 
 stiff clay land by rendering it more loose and light 
 
 Dry leaves and decayed wood, operate as manures in a man- 
 ner similar to saw dust ; they are however better fitted by 
 decomposition in compost heaps. 
 *17 
 
198 SCIENTIFIC AGRICULTURE. 
 
 Oil calces, from cotton and linseed exhausted of their oils, 
 are valuable as fertilizers ; but their value for fattening animals 
 perhaps exceeds that as a manure, and may prevent their 
 direct use for this purpose. 
 
 Peat, is used with benefit on soils which are deficient in 
 organic matters : it decomposes slowly, especially if sour or 
 applied alone to a wet soil containing little lime. Its action, 
 when properly decomposed and prepared, is the same as that 
 of other vegetable matters : it usually contains more or less 
 mineral and gaseous matters, which have their own peculiar 
 operation ; but these are not to be considered as affecting the 
 vegetable character of peat as a manure. On account of the 
 slowness with which it decays, it should be mixed with lime, 
 gypsum, wood ashes, or some vegetable matter which decom- 
 poses rapidly, such as farm-yard manure : swamp muck and 
 humus are similar in properties to peat. 
 
 Tanners' bark, is used as a manure, but is liable to the 
 same objection as peat 'in respect to its slow decay: it is bes^ 
 brought into a state of fermentation by mixture with lime and 
 farm-yard manure in composts. 
 
 Soot, is a complicated substance, as will be seen by refer- 
 ence to the table : it contains many things necessary to vegeta- 
 tion, and is a manure of some value ; but experiment has not 
 yet determined its precise character and operation. 
 
 Charcoal, on account of its power of absorbing gases and 
 destroying offensive odors, is a valuable addition to the soil : 
 its operation is not so direct as that of some other manures; 
 that is, it is not so useful on account of any element which it 
 furnishes to plants, as by the intermediate office which it per- 
 forms of absorbing and retaining in the soil those volatile mat- 
 ters which plants require, and which would otherwise escape 
 and be lost. It is beneficial as a top dressing, and as an in- 
 gredient in composts : it evolves carbonic acid in its decompo- 
 sition, and is in this way directly useful to plants. Its power- 
 
SCIENTIFIC AGRICULTURE. 199 
 
 ful antiseptic properties render it very beneficial to young and 
 tender plants ; by keeping the soil free of putrefying sub- 
 stances which would otherwise destroy their spongiolos and 
 prevent their growth. 
 
 Farm-yard manure. The manner and state in which farm- 
 yard manure should be applied, has been a subject of much 
 experiment and controversy. The conclusions of Johnston ia 
 relation to this subject, appear rational and satisfactory. This 
 kind of manure is made up of the solid and liquid excrements 
 of animals together with straw and hay, some of which are in 
 a state of decomposition, and the remainder fresh and un- 
 changed. The question as to which condition these manures 
 should be used in, must depend upon circumstances. If the 
 object is to furnish the greatest amount of organic matter to 
 the soil, the sooner the manure is applied after it is made, the 
 better this object is accomplished. On compact clays, the 
 mixture of straw and coarse manure is beneficial, as it renders 
 them looser and lighter, while the products of decomposition 
 are more completely retained in the soil than they would be in 
 a loose one. But coarse manures render loose soils more loose, 
 and lose more of their elements in decomposing : for these 
 reasons, compact fermented manures are preferable in such 
 soils. For manuring crops which grow rapidly and attain 
 maturity in a short time, well fermented manures and fine 
 composts are felt more immediately and powerfully than re- 
 cent ones. Such crops as turnips, buckwheat, clover, and 
 many garden vegetables, might nearly attain maturity before 
 decomposition would be sufficiently advanced in new and coarse 
 manures to render them beneficial. When it is desired to force 
 and quicken the growth of a crop, a well fermented, or fine 
 heating manure should be used; such as rich compost, bone 
 dust, or the excrements of the horse and sheep. 
 
 Top dressing for pastures, meadows and turnip crops, should 
 usually be of the same kind as these just named. But farm. 
 
200 SCIENTIFIC AGRICULTURE. 
 
 yard manure is not subject to any special law, but is to be used 
 according* to its quality and condition, and adapted to circum- 
 stances. Vegetable substances are all similar in their nature 
 and operation, and are modified by conditions and circum- 
 stances. They are all subject to the same laws, and their 
 relative value depends on their constitution and adaptation to 
 each particular case. 
 
 GREEN MANURES. 
 
 By green manures, is understood those plants which are 
 grown for the purpose of being ploughed in and mixed with the 
 soil before being harvested or used as food for animals. This 
 plan of manuring is by no means of recent origin ; it was 
 known and practiced among the Romans. The plants most in 
 use for this purpose in the United States are red clover, buck- 
 wheat and grass in the form of green sward. Several other 
 plants are used in Europe, viz., rape, lupine, vetches, rye, tur- 
 nip, carrot and beet tops, borage, spurry, sea weeds and fresh 
 water plants. 
 
 The advantages of green manures, according to Johnston, 
 are, 1. They undergo decomposition sooner than dry vegeta- 
 ble matter, and consequently become sooner available for the 
 food of succeeding crops. 2. The nitrogen and carbon which 
 they contain, if allowed to decay in the open air, are lost ; 
 while if the plants had been buried, before decay, these gases 
 would have been mostly retained in the soil for the use of suc- 
 ceeding crops. 3. By ploughing in a crop of plants, the or- 
 ganic matter is more equally distributed through the soil than 
 could be done by any other means. 4. Green manures are 
 available where other manures are scarce, and in soils deficient 
 in organic matter. 5. The plants used as green manures, bring- 
 up towards the surface by their roots, matters which had sunk 
 into the soil too deep to be of much service. 6. It restores to 
 the soil all it took from it, in a more soluble and available con- 
 
SCIENTIFIC AGRICULTURE. 201 
 
 dilion ; and in addition to this, those gases also which the plants 
 extracted from the air during growth. 7. A green crop yields 
 more manure than the same crop could do in any other form. 
 8. A grain crop is greater on the same field when green, than 
 when fermented manures are used. The best plants for 
 green manures are those which grow the fastest, produce the 
 most vegetable matter, and with the smallest expense. 
 
 Sufficient seed should be sown, that the plants may coyer 
 the ground completely; the crop should be ploughed in before 
 the time of full blowing, because the flowers give off nitrogen, 
 which is wasted in the air. Agriculturists agree that a seconJ 
 and third crop of green plants still continue to improve the 
 soil; but there must be a limit, beyond which this practice 
 cannot be carried with benefit and profit Green manuring 
 might perhaps secure a field against barrenness for an indefi- 
 nite period of time, providing nothing was ta!*en off: but if a 
 crop was occasionally carried away, in must of course be im- 
 poverished to the amount of what is taken off in mineral 
 matters. It is probably true that lands in a state of nature, 
 which are covered with forest trees or other vegetation, never 
 become barren. 
 
 The soil may in time become deficient in a particular mineral 
 element which the incumbent plants require ; but when these 
 die out, others immediately spring up by a natural rotation, 
 and, requiring elements slightly different from the first, grow 
 as luxuriantly as they did. Thus one race of plants succeeds 
 another, each in turn exhausting the soil of certain elements, 
 and leaving it richer in others. The question may arise, What 
 becomes of the mineral elements, which are lost, if nothing is 
 taken off the soil, since they do not escape into the air? The 
 probability is, they sink down deeper and deeper into the soil 
 in the form of soluble salts, until beyond the resell of the 
 roots of plants. 
 
202 SCIENTIFIC AGRICULTURE. 
 
 IMPROVEMENT OF THE SOIL BY PASTURE. 
 
 Pasture may be either temporary or permanent Tempo- 
 rary pasture consists in laying down a field to pasture for one, 
 two or three years, or more. The soil is benefitted by pasture 
 in several different ways. The roots of the grass which remain 
 furnish a large amount of organic matter, which, to a soil poor 
 in this constituent, is of great benefit. Land which lies several 
 years will be more benefitted than when it lies but a single 
 year; but the first year enriches it more than any succeeding 
 one. The result to the land will be nearly the same, whether 
 the grass be mown or eaten off by the stock, " That farming 
 is the most economical, where the land will admit of it, which 
 permits the clover or grass to occupy the land for a single 
 year only." 
 
 Permanent pasture consists in the suspension of grain crops, 
 and the occupation of the land by grass or clover, for an indefi- 
 nite period of time. Besides the benefit which the soil derives 
 from the organic matters left in it, some of its mineral con- 
 stituents are, by the action of air, moisture, and the roots of 
 the grass, brought into a more soluble state to be used by 
 succeeding crops. Another advantage of pasture, especially 
 on stiff clay soil, is that it renders it more loose and friable. 
 On dry, sandy soils, pasture is beneficial, by retaining the 
 moisture longer, and also the dry organic matters and fine 
 sand upon the surface, which would otherwise be blown away 
 by the winds. Insects perform a part in improving pasture 
 lands, which is by no means insignificant. 
 
 They subsist upon the organic matters of the soil, which, 
 they bring into a minute state of division and deposit on the 
 surface as they ascend by night through their holes. They 
 furnish also, considerable organic matter, which is rich in 
 nitrogen, by the death and decay of their own bodies. Thus 
 these earth worms and insects, in the lapse of a few years, 
 furnish a vast amount of the richest manure without the 
 
SCIENTIFIC AGRICULTURE. 203 
 
 smallest expense. The time which land may lay in pasture 
 and still increase in richness, must have a limit, and this 
 depends upon the quality of the soil and the kinds of grass 
 which occupy it. 
 
 The soil will require an occasional top dressing, or the pas- 
 ture will deteriorate: on account of the exhaustion of certain 
 elements in the soil, grasses, as well as forest trees and other 
 plants, tend to a natural rotation; one species, after flourishing 
 a few years, begins to decline and finally dies out, and is 
 replaced by another, and this, in time by another, and so on, 
 indefinitely. All pasture lands whatever, which are arable, 
 can, after a series of years, be subjected to grain crops; and 
 this in most cases would doubtless be expedient. This how- 
 ever, must be determined in each particular case, by an appre- 
 ciation of all the circumstances and conditions. 
 
CHAPTER VI. 
 
 MINERAL MANURES. 
 
 MINERAL manures are divided, for the sake of convenience? 
 into saline and earthy ; the former including pure salts whose 
 composition is exactly known, such as common salt and car- 
 bonate of soda ; and the latter including the various earthy 
 matters used to ameliorate the soil, such as lime, wood ashes, 
 and marl. The mineral manures are all supposed to have a 
 specific mode of action, which is "peculiar to each respectively: 
 the theory of their action, however, as fertilizers, cannot, for 
 want of space, except in a few cases, be detailed. But few, 
 comparatively, of the known mineral fertilizers are in common 
 use, and those only will be described. 
 
 SALINE MANURES. 
 
 Carbonate of soda. This salt, according to Johnston, is 
 beneficial on lands abounding in sulphate of iron, or overgrown 
 with mosses and other noxious vegetation ; and also as a top 
 dressing to fields of young grain, and wherever wood ashes 
 would be useful. It is said to be peculiarly beneficial to the 
 strawberry. From forty to sixty pounds may be applied to 
 an acre, either in powder mixed with other manure, or in 
 solution. 
 
 Sulphate of soda, or Glauber's sail, has been used with 
 much benefit on fruit trees, rye, beans, beets, and some other 
 crops. The quantity used should be at least one hundred 
 
SCIENTIFIC AGRICULTURE. 203 
 
 pounds per acre, cither in solution or in powder just before a 
 rain. [It must not be inferred, that this, or any other manure, 
 because it is recommended for a particular species of plants, is 
 not therefore adapted to the growth of others; but those only 
 are mentioned, upon which they have been tried sufficiently to 
 warrant a conclusion as to their efficacy.] 
 
 Sulphate of magnesia, or epsom salts, is said to be useful to 
 young crops of wheat, clover, peas and beans: one or two 
 hundred pounds to an acre should be used. 
 
 Sulphate of lime, or gypsum. This salt of lime, usually 
 called "plaster," has been long known and much employed as 
 a fertilizer on almost all crops and soils. It requires much 
 water for its solution. The beneficial operation of gypsum is 
 supposed to depend upon several circumstances. This, like all 
 the sulphates, furnishes sulphur, which is important in the 
 nutrition of plants, especially those of the liguminous order. 
 Gypsum prevents the escape of ammonia which is deposited 
 in the soil by rain, and evolved by the decomposition of ani- 
 mal and vegetable matters. In soils deficient in lime, it supplies 
 this element in an available state for their nutrition. It has 
 been thought to operate most beneficially on red clover and 
 Indian corn. 
 
 Nitrate of soda is on some accounts a good fertilizer; it has 
 not come into general use, and is not as well understood in its 
 relations to soils and to plants as it should be. Several results 
 are theoretically attributed by Johnston to the action of the 
 nitrates on vegetation. 1. They give a dark green color to 
 the leaves. 2. They hasten and sometimes prolong the growth 
 of vegetation. 3. They increase both the straw and the grain 
 of the cereals. 4. They impart a saline taste to hay and 
 straw, which causes cattle to eat them with more avidity. 
 5. Grain which has been manured with the nitrates yields 
 more bran and less flour than those manured with other salts 
 The nitrates increase the oat crop ; they should not, however, 
 
 18 
 
206 SCIENTIFIC AGRICULTURE. 
 
 be used for any crop on land which is already disposed to 
 produce too much straw. They are exceedingly soluble, and 
 are for this reason not so beneficial on loose, light soils, because 
 more easily washed away than on close, compact soils : for the 
 same reason they produce little effect after the first year. 
 They furnish a large amount of nitrogen, and are most bene- 
 ficial to poor soils which are deficient in organic matters. 
 
 Chloride of sodium, or common salt, has been used with 
 yarious results as a fertilizer. Plants require for their growth 
 both of the elements of common salt, viz, chlorine and soda ; 
 and in soils which are deficient in one or both of these ele- 
 ments, there can be no doubt as to its efficacy ; but in a soil 
 which contains them in sufficient quantity in a soluble state, it 
 cannot be expected that this salt will be of any service. It is 
 most likely to prove beneficial on lands lying remote from the 
 sea, and which, consequently, would be more apt to require it. 
 This salt is of more benefit to green crops than cereals; and 
 also to hasten and increase the growth of the herbage of plants 
 than the seeds. 
 
 The chlorides of lime and magnesia contained among the 
 refuse of chemical manufactories, are also used as manures 
 with good effects. The chlorides are destructive to both ani- 
 mal and vegetable life, when used in large quantity; they 
 have consequently been used to destroy weeds, worms and 
 insects in the soil. 
 
 The silicate of potash and soda, and the various salts of 
 ammonia, are, without question, powerful fertilizers, particu- 
 larly on the grasses; but they are not in general use, on 
 account of their high price, as well as doubtful reputation 
 among those practical men who have not tested them. 
 
 EARTHY MANURES. 
 
 Wood ashes. The ashes of wood and all other vegetable 
 matter, contain various proportions of several different salts, all 
 of which are necessary to the growth of plants. The following 
 
SCIENTIFIC AGRICULTURE. 207 
 
 table presents an analysis of the ashes of the red beech and 
 oak, by SprengeL 
 
 Red Beech. 
 
 Oak. 
 
 Silica, 
 
 5.52 
 
 26.95 
 
 Alumina, 
 
 2,33 
 
 
 Oxide of Iron, 
 
 3.77 
 
 8.14 
 
 Oxide of Manganese, 
 
 3.65 
 
 
 Lime, 
 
 2o.OO 
 
 17.38 
 
 Magnesia, 
 
 5.00 
 
 1.44 
 
 Potash, 
 
 22.11 
 
 16.20 
 
 SooX 
 
 3.32 
 
 6.73 
 
 Sulphuric Acid, 
 
 7.64 
 
 3.36 
 
 Phosphoric Acid, 
 
 5.62 
 
 1.92 
 
 Chlorine, 
 
 1.84 
 
 2.41 
 
 Carbonic Acid, 
 
 14.00 
 
 15.47 
 
 100. 100. 
 
 It will be seen by the table, that one kind of ash is richer 
 in one element, and another in some other element : the value 
 of each must be estimated accordingly. The ashes of the oak 
 and beech, both contain more lime than they do potash, and 
 would therefore be as efficacious on a soil deficient in lime, as 
 on one deficient in potash. We see, then, that, contrary to 
 popular opinion, the ucility of this manure does not depend 
 solely upon the action of potash, but on several other elements 
 also. 
 
 Ashes, as a general rule, are used with benefit on the 
 grasses, lugurninous and Indian corn crops. They may be 
 mixed with an equal quantity of gypsum or bone dust, and 
 applied to the amount of ten to thirty bushels to an acre; or, 
 if the ashes have been leached, fifty, sixty, or a hundred 
 bushels may be used to an acre. According to Johnston, only 
 about one fifteenth part of the weight of ashes are immediately 
 soluble ; their effects are therefore more permanent than those 
 
208 SCIENTIFIC AGRICULTURE. 
 
 of any of the soluble saline manures, being felt by the land for 
 more than ten years. 
 
 The following mixture is said to be nearly equal in efficacy 
 for a year or two, to one ton of wood ashes. 
 
 Crude potash, 60 pounds. 
 
 Grystalized carbonate of soda, 60 " 
 
 Sulphate of soda^ 20 
 
 Common salt, 20 " 
 
 160 
 
 Leached ashes are nearly destitute of potash, and cannot, of 
 course, supply this substance to vegetation; they are said, 
 however, to be of service to oat crops in particular, and are 
 beneficial to clay soils. The ashes of coal, peat, turf, straw 
 and cane are also valuable as fertilizers, according to their 
 constitution and the crops to which they are applied. 
 
 Crushed or pulverized rocks of various kinds could be used 
 with the same benefit and in the same cases, according to their 
 elementary composition, as other mineral manures: crushed 
 granite would furnish a considerable amount of potash ; it is 
 easily ground after being heated to a red heat. Crushed trap 
 contains much lime, and is a good manure : crushed lavas are 
 also valuable on most soils. 
 
 Marl. The composition and other chemical characters of 
 marl have been described : it consists of lime, clay, and often 
 sand, shells, and other matters. The object and effect of 
 marling are similar to those of liming land. Marl should be 
 used according to its constitution ; clay marl should usually be 
 put on sandy soils, and lime or sandy marl on clay soils. The 
 best time for laying on marl is at the end of autumn, so that 
 it may be pulverized by frosts during the winter Boussin- 
 gault says, land which contains ten per cent, of carbonate of 
 lime can dispense with marl. 
 
 The effect of marl is not unlimited, but, like lime, requires 
 
SCIENTIFIC AGRICULTURE. 209 
 
 to be repeated once in 10 or 12 years. With regard to the 
 quantity of marl which should be used to an acre, we must be 
 governed by the same rational considerations as the use of all 
 other manures ; viz., it should be applied where it is required, 
 and in quantity equal to the demand of the soil. The opin- 
 ions of practical men vary greatly on this subject : according 
 to Johnston, ten or fifteen, to one hundred and twenty tons 
 are used to an acre ; while Boussingault says, " allowing the 
 broadest margin, and judging from the composition of the ashes 
 of the plants of ordinary crops, we can see that the quantity 
 of three and a half bushels of marl of the usual composition 
 per acre, which is assumed as the average quantity to be laid 
 on, is vastly more than can be absolutely necessary." 
 
 This discrepancy has arisen partly from the extravagant 
 notions about the virtues of marl, and partly from the nature 
 of the marl and the soils to which it has been applied by dif- 
 ferent experimenters. 
 
 Chalk is much used as a fertilizer in some parts of Europe 
 where it is cheap and abundant ; but, from its scarcity and 
 price, it can never be expedient to use it in this country while 
 we have such an abundance of lime in various other forms. 
 When used, it is subject to nearly the same laws as lime and 
 marl. Its composition varies ; some specimens contain more 
 phosphate of lime, magnesia and silicates, than others. Ehren- 
 berg has made the remarkable discovery, that chalk to a con- 
 siderable extent, is composed of the shells or skeletons of ma- 
 rine microscopic animals. 
 
 Lime. The chemical and physical properties of lime have 
 already been described, and it remains for us to examine briefly 
 the principles of its adaptation to the soil as a fertilizer. Much 
 discussion has been had, and many long essays written on this 
 subject; but no chemist claims for this substance any excep- 
 tion to general chemical laws, or attributes to it any action 
 more specific than that of any other manure. There is no 
 
 18* 
 
210 SCIENTIFIC AGRICULTURE. 
 
 doubt that all our present knowledge of lime as a manure, 
 can be expressed in a few known and plain principles: we do 
 not assume that all is known about lime that may be known at 
 some future time, but that the facts can be much more briefly 
 and perhaps more clearly set forth than is done by most wri- 
 ters on agriculture. 
 
 Lime is perhaps the most important mineral used as a ma- 
 nure. When applied to a soil entirely destitute of lime, the 
 quantity will necessarily be larger than at subsequent periods. 
 
 The quantity used must be determined, as in all other cases, 
 by circumstances. No general rule can be given for its use, 
 but each one must judge from the facts in the case and pro- 
 ceed accordingly. Johnston says, "if we suppose one per cent 
 to be necessary, then upwards of 300 bushels of slaked lime 
 must be mixed with a soil six inches in depth, -to impart to an 
 acre this proportion." On wet, peaty, marshy, or clay soils, 
 more lime will be necessary than on dry, sandy and loose soils : 
 on soils which contain much organic matters also, more may be 
 used than on those nearly destitute of them. It is consider- 
 ed better economy to apply lime in smaller quantities and at 
 shorter intervals, than to use it in large quantities at more dis- 
 tant period?. 
 
 Caustic lime should be applied to marshy and clay soils im- 
 mediately after slaking: when allowed to slake in the open air 
 spontaneously, without the use of water, it is more mild, and 
 better adapted to grass lands and young crops; but W 7 hen ap- 
 plied to naked fallow and mixed with the soil, it may be used 
 in either state. Burned lime is well adapted to the compost 
 form of manures. As quick lime dissipates the ammonia of 
 fermenting manures in the soil, it ought not to be applied at 
 the same time, nor to come in immediate contact with them : 
 it is best applied usually in the fall, or as long as possible be- 
 fore the next crop is sown. 
 
 These principles apply only to caustic lime : unburned lime, 
 
SCIENTIFIC AGRICULTURE. 211 
 
 marl, gypsum, chalk, and composts containing Urn?, may be 
 applied at any time. Lime, in order that it may produce its 
 full effect and most lasting benefit, should bo kept near the 
 surface. This may be done by sub-soil ploughing, by which 
 the lime is thrown up to the surface; and also by sowing deep 
 rooted crops, which will reach it after it has sunk too deep to 
 benefit others of shorter roots. The amount of lime in the 
 soil gradually diminishes from several causes, when it is not 
 occasionally replenished : it is removed to a small extent with 
 the annual harvests, and by assuming new forms by chemical 
 action ; a portion is also carried away in solution with the 
 water which falls by rain and filters through both the surface 
 and subsoil. 
 
 The beneficial effects of lime, although more permanent, are 
 not felt as soon as those of some other mineral manures : it is 
 of little service on soils deficient in organic matter. The length 
 of time which lime shows its effects upon the crops and soil, is, 
 according to circumstances, from ten to thirty years. Its use 
 is sometimes attended by unfavorable results when not judi- 
 ciously used: light, loose soils are rendered too loose; and the 
 growth of certain noxious weeds favored by its-presence : an 
 ov(r-doso destroys too much organic matter, hardens certain 
 soils, ^id injures the spongioles of young plants. It is said to 
 operate injuriously upon flax, by causing tenderness of its cor- 
 tical fibre. 
 
 These remarks on the use of lime as a manure, are conden- 
 sed from Johnston, who has given perhaps the best treatise on 
 lime extant. As the subject is both important and interesting, 
 it may be well to recapitulate briefly. 
 Recapitulation. 
 
 1. Lime increases the fertility of soils deficient in this element. 
 
 2. It causes the soil to produce grain which yields more flour 
 and less bran, and improves the quality of all other crops. 
 
212 
 
 SCIENTIFIC AGRICULTURE. 
 
 3. It increases the effect of other manures by hastening de- 
 composition. " 
 
 4. It destroys noxious insects and worms. 
 
 5. It destroys noxious weeds and mosses, and gives rise to 
 sweet grasses and herbage. 
 
 6. It prevents smut in wheat and other crops. 
 
 7. It hastens the maturity of the crop. 
 
 8. It neutralizes the acidity of sour soils and renders them 
 productive. 
 
 9. It makes cold wet soils dryer and warmer. 
 
 10. It renders tight stiff clays loose and friable 
 
 11. It destroys noxious gases and promotes health. 
 
 12. It stiffens loose sandy soils. 
 
 13. It brings inert organic matters into a state of fermen- 
 tation. 
 
 14. It causes the evolution of carbonic acid. 
 
 15. It serves directly as the food of plants. 
 
 16. It causes the formation of several salts in the soil. 
 
 COMPOSTS. 
 
 It was formerly supposed, that great advantage was derived 
 from the combination of several different substances together, 
 and forming what are called composts. The recipes for these 
 compounds are numerous, and go to prove that the diswvcry 
 of a good compost requires but little scientific or practical skill. 
 AVhen a compost heap is made up of several materials which 
 are all separately good manures, it follows of necessity that 
 the resulting compound must be a good fertilizer. But it is 
 impossible to supply any more in this way than if these seve- 
 ral ingredients were applied to the soil separately. And a 
 little knowledge of chemistry w^ill show that by this means, 
 no new elements can be generated. Neither can any new pro- 
 perty be developed which could not be done by their separate 
 action. -We see that whenever a substance which has little or 
 no fertilizing power, is in this way manufactured into a good 
 
SCIENTIFIC AGRICULTURE. 213 
 
 manure, it is done at the expense of some powerful fertilizer 
 which is diluted by the mixture, and consequently loses just 
 as much of its efficacy as the other gaiss. Thus, although 
 this process serves to dilute and extend manures which are 
 too powerful or too expensive, it absolutely supplies none. 
 
 Now, although it is evident that this method does not aug- 
 ment in the slightest degree, our quantity of available ma- 
 nure, yet it has several advantages. Caustic lime and wqpd 
 ashes are sometimes too strong for young and tender vegeta- 
 tion ; and when this is the case, the object of their use is 
 much better attained by mixing and diffusing them through 
 some other substance, such as saw-dust, sand, barn manure or 
 humus, or allowing them to lie in a heap together with any 
 vegetable matters, such as leaves, straw, chaff, rotten wood or 
 turf; or with animal matters; until decomposition is completed. 
 
 Another advantage is, that a manure which is valuable and 
 scarce, as guano, poudrette, and some chemical salts, may be 
 extended by mixture so as to be applied to a much larger space 
 than would be practicable if used singly. Thirdly, this mode 
 enables the agriculturist to spread his manure on the soil more 
 even and uniformly. And lastly, by making compost we are 
 enabled to hasten the final decay of animal and vegetable 
 matters, so as to gain considerable time. By mixing quicklime 
 with barn manure, straw, leaves, &c., decomposition goes on 
 more rapidly, and these substances are transformed to availa- 
 ble manures in a comparatively short space of time. But 
 much discretion is necessary in this respect, otherwise some 
 valuable elements are wasted ; the object is to fix and retain 
 the volatile elements and not to dissipate them. A great 
 objection to composts is, the amount of labor retired in ma- 
 king, turning, and transporting them to the fields. 
 
 No definite formula can with any propriety be given for 
 making composts, as the agriculturist must determine for him- 
 self in each particular case, as to what elements his fields most 
 
214 SCIENTIFIC AGRICULTURE. 
 
 require, and also his time and the resources at his command. 
 With these considerations, and an adequate knowledge of his 
 business, he will be able to make a more judicious disposition 
 of his manures than by the aid of any prescribed rules which 
 can be laid down in books. 
 
CHAPTER VII. 
 
 TABLE OF THE COMPARATIVE VALUE OF MANURES, 
 
 FROM ANALYSES BY MESSRS. PAYEN AND BOUSSINGAULT. 
 
 Kind of Manure. 
 
 M 
 
 ~ /: 
 
 i- - 
 
 fi 
 
 > i i 
 
 Nitrog 
 00 of ir 
 
 Dry. 
 
 en in 
 
 latter. 
 
 Wet. 
 
 Q,ual'y 
 ding to 
 
 Dry. 
 
 accor- 
 state. 
 
 Wet. 
 
 Squival'nt 
 ccord.do. 
 
 Dry. i Wet 
 
 Farm-yard manure, 
 
 79.3 
 
 1.05 0.41 
 
 100 
 
 100 
 
 100 
 
 100 
 
 Water from do. 
 
 99.6 
 
 1.54 0.06 
 
 78 
 
 2 
 
 127 
 
 68 
 
 Wheat straw, 
 
 19.3 
 
 0.30 0.24 
 
 15 
 
 60 
 
 650 
 
 167 
 
 Rye straw, 
 
 12.2 
 
 0.20 0.17 
 
 10 
 
 42.5 
 
 975 235 
 
 Oat straw, 
 
 21.0 
 
 0.36 
 
 0.28 
 
 18 
 
 70 
 
 542 
 
 143 
 
 Barley straw, 
 
 11.0 
 
 0.26 
 
 0.23 
 
 13 
 
 57.5 
 
 750 
 
 174 
 
 Wheat chaff, 
 
 7.6 
 
 0.94 
 
 0.85 
 
 48 
 
 212.5 
 
 207 
 
 47 
 
 Pea straw, 
 
 8.5 
 
 1.95 
 
 1.79 
 
 1001447.5 
 
 100 
 
 22 
 
 Buckwheat straw, 
 
 11.6 
 
 0.54 
 
 0.48 
 
 27 
 
 120 
 
 301 
 
 83 
 
 Dried potato tops, 
 
 12.9 
 
 0.43 
 
 0.37 
 
 22 
 
 92.5 
 
 453 
 
 108 
 
 Oak leaves, 
 
 25.0 
 
 1.57 
 
 1.18 
 
 80 
 
 293 
 
 125 
 
 34 
 
 Beech leaves, 
 
 39.3 
 
 1.91 
 
 1.18 
 
 78 
 
 294 
 
 102 34 
 
 Burnt sea weed, 
 
 3.8 
 
 0.40 
 
 0.38 
 
 20 95 
 
 488| 105 
 
 Oyster shells, 
 
 17.9 
 
 0.40 
 
 0.32 
 
 20 
 
 80 
 
 488J 125 
 
 Sea-side marl, 
 
 1.0 
 
 0.52 
 
 0.51 
 
 26.5 
 
 128 
 
 377 
 
 78 
 
 Oak saw-dust, 
 
 26.0 
 
 0.72 
 
 0.54 
 
 36 
 
 135 
 
 250 
 
 74 
 
 Oil cake of linseed, 
 
 13.4 
 
 6.00 
 
 5.20 
 
 307 
 
 1300 
 
 33 
 
 8 
 
 Refuse of cider apples 
 
 6.4 
 
 0.63 
 
 0.59 
 
 32 
 
 147 
 
 309 
 
 68 
 
 Cow's ordure, 
 
 85.9 
 
 2.30 
 
 0.32 
 
 117 
 
 80 
 
 84 
 
 125 
 
 Cow's urine, 
 
 88.3 
 
 3.80 
 
 0.44 
 
 194 
 
 110 
 
 51 1 91 
 
 Excrements of horse, 
 
 75.3 
 
 2.21 
 
 0.55 
 
 113 137.5 
 
 88 
 
 73 
 
 Urine of do. 
 
 79.1 
 
 12.50 
 
 2.61 
 
 641 652.5 
 
 15.5 
 
 15.3 
 
 Excrements of pig, 
 
 8.14 
 
 3.37 
 
 0.63 
 
 172J157.5 
 
 58 
 
 63 
 
216 
 
 SCIENTIFIC AGRICULTURE. 
 
 Kind of Manure. 
 
 B. 
 
 . 
 
 |i 
 
 Nitrogen in 
 100 of matter. 
 
 dual')- accor- 
 ding to state. 
 
 Equivalent 
 accord. do. 
 
 Dry. 
 
 Wet. 
 
 Dry. 
 
 Wet. 
 
 Dry. 
 
 Wet 
 
 Excrements of sheep, 
 
 63.0 
 
 2.99 
 
 Lll 
 
 153 
 
 277.5 
 
 65 
 
 36 
 
 Do. of goat, 
 
 46.0 
 
 3.93 
 
 2.16 
 
 201 
 
 540 
 
 5018.5 
 
 Poudrette, 
 
 12.5 
 
 4.40 
 
 3.85 
 
 225 
 
 962 
 
 44*10.3 
 
 Urine of public vats, 
 
 9.6 
 
 17.56 
 
 16.83 
 
 900 
 
 4213 
 
 111 2.3 
 
 Excrements of pigeons, 
 
 9.6 
 
 9.02 
 
 8.30 
 
 462 
 
 2075 
 
 21.5 
 
 5.0 
 
 Guano, 
 
 19.6 
 
 6.20 
 
 5.00 
 
 323 
 
 1247 
 
 31.5 
 
 80 
 
 Dried muscular flesh, 
 
 8.5 
 
 14.25 
 
 13.04 
 
 730 
 
 3260 
 
 13.5 
 
 3 
 
 Liquid blood, ,81.0 
 
 
 2.95 
 
 795 
 
 736 
 
 
 13.3 
 
 Fresh bones, 
 
 30.0 
 
 
 6.22 
 
 
 1554 
 
 
 6.5 
 
 Dregs of glue, 
 
 33.6 
 
 5.63 
 
 3.73 
 
 288.4 
 
 933.5 
 
 35 
 
 11 
 
 Sugar refiners' scum, 
 
 67.0 
 
 1.58 
 
 0.54 
 
 81 
 
 134 
 
 127 
 
 75 
 
 Horn shavings, 
 
 9.0 15.78 14.36 
 
 809 
 
 3590 
 
 12.3 
 
 3.0 
 
 Wood soot, 
 
 5.6! 1.31 
 
 1.15 
 
 67 
 
 287.5 
 
 149 
 
 35 
 
 TABLES OF ANALYSIS. 
 
 Talks showing the relative proportions of inorganic com- 
 pounds In the ashes of several cultivated plants. 
 The tables are taken from Prof. Johnston's Agricultural 
 Chemistry, and are supposed to be nearly correct: analysis 
 of different varieties and qualities of the same plants, vary- 
 slightly ; but still, for all practical purposes, the tables here 
 given are sufficiently accurate, being probably as near the real 
 constitution of them, as it is possible to obtain. 
 
 ASH OF WHEAT. 
 
 According to Sprengel's analysis, 1000 Ibs. of wheat leave 
 11.77 Ibs. of ashes, and 1000 Ibs. of straw leave 35.18 Ibs. 
 of ash. after burning. 
 
 This ash consists of 
 
 Potash, 
 Soda, 
 Lime, 
 Magnesia, 
 
 Grain of Wheat. 
 2.25 Ibs. 
 2.40 
 0.96 
 0.90 
 
 Straw of Wheat. 
 0.20 -Ibs. 
 0.29 
 2.40 
 0.32 
 
SCIENTIFIC AGRICULTURE. 
 
 21T 
 
 ASH OF WHEAT Continued. 
 
 Grain of Wheat. Straw of Wheat. 
 
 Alumina and a trace of Iron, 0.26 Ibs. 
 
 Silica, 4.00 
 
 Sulphuric acid, 0.50 
 
 Phosphoric acid, 0.40 
 
 Chlorine, 0.10 
 
 11.77 Ibs. 
 
 0.90 Ibs. 
 28.70 
 0.37 
 
 1.70 
 0.30 
 
 35.18 Ibs. 
 
 ASH OF BARLEY. 
 
 100 of grain of barley leaves 23.49 Ibs, 1000 Ibs. of straw 
 52.42 of ash. 
 
 
 Grain. 
 
 Straw, 
 
 Potash, 
 
 2.78 
 
 1.80 
 
 Soda, 
 
 2.90 
 
 0.48 
 
 Lime, 
 
 1.06 
 
 5.54 
 
 Magnesia, 
 
 1.80 
 
 0.76 
 
 Alumina, 
 
 0.25 
 
 1.46 
 
 Oxide of iron, 
 
 a trace 
 
 0.14 
 
 Oxide of manganese, 
 
 
 0.20 
 
 Silica, 
 
 11.82 
 
 38.56 
 
 Sulphuric acid, 
 
 0.59 
 
 1.18 
 
 Phosphoric acid, 
 
 2.10 
 
 1.60 
 
 Chlorine, 
 
 0.19 
 
 0.70 
 
 23.49 Ibs. 52.42 Ibs. 
 
 ASH OF OATS. 
 
 1000 Ibs. of the grain of oats contain 25.80 Ibs. and of 
 
 straw, 57.40 Ibs. of ash. 
 
 Grain. 
 
 Potash, 1.50 
 
 Soda, 1.32 
 
 Lime, 0.86 
 
 Magnesia, 
 Alumina, 
 
 0.67 
 0.14 
 
 Straw. 
 8.70 
 0.02 
 1.52 
 0.22 
 0.06 
 
 19 
 
218 
 
 SCIENTIFIC AGRICULTURE. 
 
 ASH OP OATS Continued. 
 
 Oxide of iron 
 Oxide of manganese, 
 Silica, 
 
 Sulphuric acid, 
 Phosphoric acid, 
 Chlorine, 
 
 Grain. 
 
 Straw. 
 
 0.40 
 
 0.02 
 
 
 0,02 
 
 19.76 
 
 45.88 
 
 0.35 
 
 0,79 
 
 0.70 
 
 0.12 
 
 0.10 
 
 0.05 
 
 25.80 Ibs. 57.40 Ibs. 
 
 5.32 
 
 ASH OF RYE. 
 
 1000 Ibs. of rye straw contain 27.93 Ibs., and of grain 10.40 
 
 Ibs. of ash. 
 
 Grain. 
 Potash, 
 Soda, 
 
 1.22 
 
 1.78 
 
 0.24 
 
 0.42 
 
 0.34 
 
 1.64 
 
 Lime, 
 
 Magnesia, 
 
 Alumina, 
 
 Oxide of iron, 
 
 Oxide of manganese, 
 
 Silica, 
 
 ).24 ) 
 ).42 f 
 
 Straw. 
 0.32 
 0.11 
 1.78 
 0.12 
 
 0.25 
 
 Sulphuric acid, 
 Phosphoric acid, 
 Chlorine, 
 
 0.23 
 0.46 
 0.09 
 
 22.97 
 1.70 
 0.51 
 0.17 
 
 10.40 Ibs. 27.93 Ibs. 
 
 ANALYSIS OF PEAT BY BOUSSINGAULT. 
 
 Silica, 
 Alumina, 
 Lime, 
 Magnesia, 
 Oxide of iron, 
 Potash and Soda, 
 
 65.5 
 16.2 
 6.0 
 0.6 
 3.7 
 2.3 
 
SCIENTIFIC AGRICULTURE. 219 
 
 ANALYSIS OF PEAT, BY BGUSSINQAULT Continued. 
 
 Sulphuric acid, 5.4 
 
 Chlorine, 0.3 
 
 100.0 
 
 ANALYSIS OF COAL ASHES BY BOUSSINGAULT. 
 
 Argillaceous matter insoluble in acids, 62 
 
 Alumina, 5 
 
 Lime, 6 
 
 Magnesia, 8 
 
 Oxide of manganese, 3 
 
 Oxide and sulphuret of iron, 16 
 
 100 
 
 ASH OF THE BEAN AND PEA. 
 
 100Q Ibs. of seed and straw, dried, contain 
 
 
 Field Bean. 
 
 Field Pea. 
 
 
 Seed. Straw. 
 
 Seed. Straw. 
 
 Potash, 
 
 4.15 16.56 
 
 8,10 2.35 
 
 Soda, 
 
 8.16' 0.50 
 
 7.39 
 
 Lime, 
 
 1.65 6.24 
 
 0.58 27.30 
 
 Magnesia, 
 Alumina, 
 
 1.58 2.09 
 0.34 0.10 
 
 1.36 3.42 
 0.20 0.60 
 
 Oxide of iron, 
 
 0.07 
 
 0.10 0.20 
 
 Oxide of manganese, 
 Silica, 
 
 0.05 
 1.26 2.20 
 
 0.07 
 4.10 9.96 
 
 Sulphuric acid, 
 Phosphoric acid, 
 Chlorine, 
 
 0.89 0.34 
 2.92 2.26 
 0.41 0.80 
 
 0.53 3.37 
 1.90 2.40 
 0.38 0.04 
 
 21.36 31.21 24.64 49.71 
 
 ASH OF THE TURNIP AND POTATO. 
 
 10,000 Ibs. of the roots, stalks and leaves, when taken before 
 drying, contain 
 
220 
 
 SCIENTIFIC AGRICULTURE. 
 
 Potato. 
 
 Turnip. 
 
 
 Roots. 
 
 Tops. 
 
 Roots. 
 
 Leaves. 
 
 Potash, 
 
 40.28 
 
 81.9 
 
 23.86 
 
 32.3 
 
 Soda, 
 
 23.34 
 
 00.9 
 
 10.48 
 
 22.2 
 
 Lime, 
 
 3.31 
 
 129.7 
 
 7.52 
 
 62.0 
 
 Magnesia, 
 
 3.24 
 
 17.0 
 
 2.54 
 
 05.9 
 
 Alumina, 
 
 0.50 
 
 00.4 
 
 0.36 
 
 00.3 
 
 Oxide of iron, 
 
 0.32 
 
 00.2 
 
 0.32 
 
 01.7 
 
 Oxide of manganese, 
 
 
 
 
 
 Silica, 
 
 0.84 
 
 49.4 
 
 3.88 
 
 12.8 
 
 Sulphuric acid, 
 
 5.40 
 
 04.2 
 
 8.01 
 
 25.2 
 
 Phosphoric acid, 
 
 4.01 
 
 19.7 
 
 3.67 
 
 9.8 
 
 Chlorine, 
 
 1.60 
 
 05.0 
 
 2.39 
 
 8.7 
 
 82,83 308.4 63,03 180.9 
 
 ASH OF THE CARROT AND PARSNEP. 
 
 
 Carrot. 
 
 Parsnep. 
 
 Potash, 
 
 53.33 
 
 20.79 
 
 Soda, 
 
 9.22 
 
 7.02 
 
 Lime, 
 
 6.57 
 
 4.68 
 
 Magnesia, 
 
 3.84 
 
 2.70 
 
 Alumina, 
 
 0.39 
 
 0.24 
 
 Oxide of iron, 
 
 0.33 
 
 0.05 
 
 Oxide of manganese, 
 
 0.60 
 
 
 Silica, * 
 
 1.37 
 
 0.84 
 
 Sulphuric acid, 
 
 2.70 
 
 5.40 
 
 Phosphoric acid, 
 
 5.14 
 
 4.01 
 
 Chlorine, 
 
 0.70 
 
 1.60 
 
 66.19 82.83 
 
 ASH OF GRASS AND CLOVER. 
 
 100 Ibs. of dry hay and clover contain 
 
 Rye Grass. Red Clover. 
 
 Potash, 
 Soda, 
 
 8.81 
 3.94 
 
 19.95 
 5.29 
 
SCIENTIFIC AGRICULTURE. 
 
 221 
 
 ASH OF GRASS AND CLOVER Continued. 
 
 Lime, 
 
 Magnesia, 
 
 Alumina, 
 
 Oxide of iron, 
 
 Oxide of manganese, 
 
 Silica, 
 
 Sulphuric acid, 
 
 Phosphoric acid, 
 
 Chlorine, 
 
 7.34 
 0.90 
 0.31 
 
 27.72 
 3.53 
 0.25 
 0.06 
 
 27.80 
 3.33 
 0.14 
 
 3.61 
 4.47 
 6.57 
 3.62 
 
 52.86 74.78 
 
 The practical inferences from these tables are, first the 
 kind of soil in which each will grow best, second the kind 
 of inorganic matter necessaiy to be supplied artificially, 
 third their nutrient properties, and the kind of stock they 
 are best adapted to nourish. ;v 
 
 The following table from " Liebig's Agricultural Chemistry," 
 shows the relative proportions of potash, lime and silica in 
 several cultivated plants. 
 
 SILICA PLANTS. 
 
 Oat straw and seeds, 
 Wheat straw, 
 Barley straw and seeds, 
 Rye straw, 
 Good hay, 
 
 Tobacco, 
 Pea straw, 
 Potato tops, 
 Meadow Clover, 
 
 ills of Potash Salts of Magne- 
 and Soda. sia and Lime. 
 
 34.00 
 
 4.00 
 
 22.50 
 
 7.20 
 
 s, 19.00 
 
 25.70 
 
 18.65 
 
 16.52 
 
 6.00 
 
 34.00 
 
 LIME PLANTS. 
 
 
 24.34 
 
 67.44 
 
 27.82 
 
 63.74 
 
 4.20 
 
 51.40 
 
 39.20 
 
 56.00 
 
 19* 
 
 
 Silica. 
 62.00 
 61.50 
 55.30 
 63.89 
 60.00 
 
 8.30 
 
 7.31 
 
 63.40 
 
 4.90 
 
222 
 
 SCIENTIFIC AGRICULTURE. 
 
 Wheat. 
 37.72 
 
 Oats. 
 19.12 
 
 Barley. 
 20.70 
 
 Rye. 
 
 37.21 
 
 1.93 
 
 10.41 
 
 3.36 
 
 2.92 
 
 9.60 
 
 9.98 
 
 10.05 
 
 10.13 
 
 1.36 
 
 5.08 
 
 1.93 
 
 0.82 
 
 1.25 
 
 9 
 
 9 
 
 9 
 
 49.32 
 
 46.26 
 
 40.63 
 
 47.29 
 
 0.17 
 
 
 0.26 
 
 1.46 
 
 
 3.07 
 
 21.99 
 
 0.17 
 
 POTASH PLANTS Continued. 
 
 Corn stalks, 72.45 6.50 18.00 
 
 Turnips, 81.60 18.40 
 
 Beetroots, 88.00 12.00 
 
 Potatoes, 85.81 14.19 
 
 The following table from Johnston, shows the composition of 
 the ashes of several grains without the straw. 
 
 Potash and soda, 
 Lime, 
 Magnesia, 
 Oxide of iron, 
 Oxide of manganese, 
 Phosphoric acid, 
 Sulphuric acid, 
 Silica, 
 
 101.35 93.92 98.92 100 
 
 There appears to be some mistake in the figures of this 
 table, as will be seen on adding up the columns ; but still, for 
 want of a more accurate one we must take this as it is, being 
 sufficiently accurate for all practical purposes. 
 
 ASHES OF THE FAECES OF THE HORSE \ ANALYSIS OF JACKSON. 
 
 Phosphate of lime, 5.00 
 
 Carbonate of do., 18.75 
 
 Phosphate of magnesia, 36.25 
 
 Silicic acid/ 40.00 
 
 100. 
 
 URINE OF THE HORSE '. ANALYSIS OF YAUQUELIN. 
 
 Carbonate of lime, 1.1 
 
 Carbonate of soda, 
 Hippurate of do. 
 
 .9 
 2.4 
 
 Muriate of potash, 
 
 Urea, 
 
 Water, 
 
 .7 
 44-0 
 
 50.0 
 
SCIENTIFIC AGRICULTURE. 223 
 
 ASHES OF THE FAECES OF THE COW : ANALYSIS OF IIAIDLEN. 
 
 Phosphate of lime, 10.9 
 
 Phos. magnesia, 10.0 
 
 Phos. iron, 8.5 
 
 Carbonate of potash, 8.5 
 
 Sulphate of lime, 3.1 
 
 Silicic acid, 63.7 
 
 Loss, 2.3 
 
 107.0 
 
 URINE OF THE COW : ANALYSIS OF BRANDE. 
 
 Muriate of potash and ammonia, 1.5 
 Sulphate of potash, 0.6 
 
 Carbonate of potash, 0.4 
 
 Phosphate of lime, 0.3 
 
 Urea, 0.4 
 
 Water, 96.8 
 
 100 
 
 ASHES OF HUMAN FJ2CES ! ANALYSIS OF BERZELIUS. 
 
 Sulphate of lime and phosphate of lime and magnesia, 67 
 Sulphate of soda and potash and phos. of soda, 5 
 
 Carbonate of soda, 5 
 
 Silicic acid, 11 
 
 Carbon and loss, 12 
 
 100 
 
 HUMAN URINE : ANALYSIS OF BERZELIUS. 
 
 Urea, 30.10 
 Lactic acid ( ?) lactate of ammonia ( ?) extractive 
 
 animal matter, 17.14 
 
 Uric acid, 1.00 
 
 Mucus, 0.32 
 
 Sulphate of potash, 37.01 
 
 Sulphate of soda, 3.16 
 
 Phosphate of soda, 2.94 
 
224 SCIENTIFIC AGRICULTURE. 
 
 HUMAN URINE Continued. 
 Muriate of soda, 
 
 Phosphate of ammonia, 
 Phosphate of magnesia and lime, 
 Muriate of ammonia, 
 Silicic acid, 
 Water, 
 
 1000 
 
 GUANO : ANALYSIS OF VOLKEL. 
 
 Muriate of ammonia, 4.2 
 
 Oxalate, do. 10.6 
 
 Urate do. 9.0 
 
 Phosphate do. 6.0 
 
 Sulphate of potash, 5.5 
 
 Sulphate of soda, 3.8 
 
 Phosphate of ammonia and lime, 2.6 
 
 Phosphate of lime, 7.0 
 
 Oxalate of do. 14.3 
 
 Residue soluble in uric acid, 4.7 
 Loss, (water, ammonia and organized matter,) 32.3 
 
 100 
 
 BONES OF THE OX : ANALYSIS OF BERZELIUS. 
 
 Animal matter, (gelatine,) 33.30 
 
 Soda with common salt, 1.20 
 
 Carbonate of lime, 11.30 
 
 Phosphate of do. 51.04 
 
 Fluoride of calcium, (?) 2.00 
 
 Phosphate of magnesia, 1.16 
 
 100 
 
 COAL SOOT I ANALYSIS OF BRACONNOT. 
 
 Ulmic acid, 302.0 
 A reddish brown substance containing nitrogen, 
 
 and yielding ammonia when heated, 200.0 
 
 Asboline, 5.0 
 
SCIENTIFIC AGRICULTURE. 
 
 225 
 
 COAL SOOT Continued. 
 
 Carbonate of lime with a trace of magnesia, 146.6 
 
 Acetate of lime, 56.5 
 
 Sulphate of lime, 50.0 
 
 Acetate of magnesia, 5.3 
 
 Phosphate of lime, with a trace of iron, 15*0 
 
 Chloride of potassium, 3.6 
 
 Acetate of potash, 41.6 
 
 Acetate of ammonia, 2.0 
 
 Silica, 9.5 
 
 Charcoal powder, 38.5 
 
 Water, 125.0 
 
 100 
 
 WOOL, HAIR, HORN \ ANALYSIS OF JOHNSTON. 
 
 Carbon, 
 
 Hydrogen, 
 
 Nitrogen, 
 
 Oxygen and sulphur, 
 
 Wool. 
 
 Hair. 
 
 Horn. 
 
 50,65 
 
 51.53 
 
 51.99 
 
 7.03 
 
 6.69 
 
 6.72 
 
 17.71 
 
 17.94 
 
 17.28 
 
 24.61 
 
 23.84 
 
 24.01 
 
 100 
 
 100 
 
 100 
 
 DRY OX BLOOD AND MUSCULAR FLESH I ANALYSIS OF PLAYFAIR 
 AND BOECKMAN. 
 Dry Flesh. 
 
 Carbon, 51.83 
 
 * Hydrogen, 7.57 
 
 Nitrogen, 15.01 
 
 Oxygen, 21.37 
 
 Ashes, 4.23 
 
 100 
 
 Remark. We have, all through the course of this treatise, 
 adhered to the principle that nature preserves a uniformity in 
 
226 SCIENTIFIC AGRICULTURE. 
 
 the execution of all her laws, and that she does nothing by 
 accident. And whenever we find an apparent exception to 
 this principle, it is evident that our knowledge is deficient or 
 our conclusions erroneous. 
 
 Hence, although plants may be made to maintain a transi- 
 tory and sickly existence without all the usual elements, and 
 to absorb both by their leaves and roots, substances unneces- 
 sary and pernicious to their growth, still from the uniformity 
 of the elements and their proportions, as shown by analysis of 
 the plants and the soils in which they thrive best, we are com- 
 pelled to conclude, that each and all of these elements, are in- 
 dispensible to their healthy growth and maturity. And who- 
 ever practically disregards this principle, and hangs his hope 
 of success on some contingent circumstance, must correct his 
 error at his own cost. 
 
CHAPTER VIII. 
 
 ANALYSIS OF SOILS. 
 
 THE agriculturist may, by long experience and close obser- 
 vation of the character and productions of his lands, become 
 acquainted with their general character and fertility, and 
 also what plants are best adapted to them. But it is desirable 
 that a more accurate knowledge of the elementary constitution 
 and the relative proportions of those elements which constitute 
 the food of plants, should be attained. 
 
 The only direct and certain means of arriving at this result 
 is chemical analysis. Without this process, it could only be 
 known by a trial of various crops upon different soils, whether 
 they were adapted to them or not: and, in order to determine 
 the value of soils in this way, several crops and much labor 
 might be lost in unsuccessful experiments. 
 
 Analysis of plants shows with absolute certainty what sub- 
 stances they have drawn from the soil and atmosphere for 
 food; these substances vary in different plants, both in their 
 nature and proportions: the same is also true in relation to 
 the elementary composition of soils. No two plants and no 
 two soils have precisely the same chemical composition. The 
 absence of a single element in a soil may render it totally bar- 
 ren for a particular crop, while it may produce some others in 
 great abundance. 
 
 A chemical difference in two soils, which might appear 
 
228 SCIENTIFIC AGRICULTURE. 
 
 insignificant, would, by experiment, be found to alter entirely 
 their relative agricultural value. 
 
 By referring to tables of the analysis of plants, and then 
 analyzing the soil, we can see at once what plant the soil is 
 adapted to produce. A soil containing all the organic and 
 inorganic elements of a particular plant, may be supposed 
 capable of producing the plant: but a soil deficient in one or 
 more of these elements cannot be expected to yield a crop. 
 A soil containing very little silica could not yield grass, but 
 might still contain enough for a crop of turnips. . 
 
 An exact analysis of the quality of a soil, with the quantity 
 of each element, requires the skill of a practical chemist, and 
 the apparatus of a laboratory: but the most important qualities 
 of a soil may be determined by a few plain and simple experi- 
 ments, which are easily made by any one, whether acquainted 
 with chemistry or not 
 
 The soil is made up, as before said, of various proportions of 
 animal, vegetable, mineral, earthy and gaseous matters. As a 
 general rule, the earthy part of the soil is estimated at from 
 90 to 96 per cent The salts of these earthy matters are in 
 small quantities. The amount of vegetable matter varies 
 greatly in different soils: in some, as in peat and muck soils, it 
 constitutes from one half to three fourths of their entire 
 weight ; while in sand and clay soils, it amounts to only from 
 one to five per cent The principal bulk of all soils, (except 
 peat, humus and muck soils,) is sand, clay and lime ; and on 
 the proportions of these, their peculiar properties, both chemi- 
 cal and physical, depend. The fertility of a soil is not depen- 
 dent upon any one of these, but upon the proportions and 
 state of mechanical division of all the other necessary elements. 
 The mixture of sand and lime with the other elements, (except 
 the alumina,) is usually entirely mechanical: in the various 
 kinds of clay, the silex and alumina are often chemically com- 
 bined, constituting a silicate of alumina. 
 
SCIENTIFIC AGRICULTURE. 229 
 
 The first process in the analysis of a soil is to weigh a given 
 quantity with apothecaries' scales; it should then be spread 
 out on a piece of clean paper and subjected to a heat not suffi- 
 ciently high to burn the vegetable matters which it contains, 
 until thoroughly dried : after drying, the soil should be again 
 accurately weighed, and the second weight subtracted from 
 the first, when the remainder will show the amount of water 
 lost 
 
 To find the amount of organic matter which it contains, put 
 the dried soil into an earthen crucible and heat it over a fire 
 to "redness, till the organic matter is burned out and the ash 
 only remains ; after cooling, it should be again weighed, the 
 loss by burning shows the amount of organic matter it con- 
 tained, allowing a trifle for the charcoal which remains with 
 the earthy part If a black soil loses nothing by burning, it 
 probably derives it color from black oxide of iron or graphite. 
 
 To detect humic acid, boil a small quantity of peat or muck 
 in a solution of carbonate of soda, until it attains a brown 
 color, then add muriatic acid till the solution has a distinctly 
 sour taste, when brown flocks of humic acid will fall to the 
 bottom. 
 
 Ulmic acid may be obtained from the same soil, after the 
 humic acid is separated, by digesting it over a gentle heat in a 
 solution of caustic ammonia, and then adding muriatic acid as 
 before ; brown flocks are precipitated, which are ulmic acid. 
 
 To detect crenic and apocrenic acids, digest a quantity of 
 soil in hot water until organic matter is dissolved out sufficient 
 to give the water a yellow color. When this solution is evapo- 
 rated to dryness, there remains a brown residue, which con- 
 tains the soluble saline matters of the soil, some extractive 
 matter, humic and ulmic acids, and the crenic and apocrenic 
 acids: these four acids are all in combination with alumina 
 and other bases. When this residue is dried at 220 F., the 
 compounds of the humic and ulmic acids become insoluble, 
 
 20 
 
230 SCIENTIFIC AGRICULTURE. 
 
 while the compounds of the crenic and apocrenic acids remain 
 soluble, and may be separated by washing in water. (Johnston.) 
 To detect the presence of lime, take 100 grains of a soil and 
 mix well with half a pint of cold water, and then add half an 
 ounce of muriatic acid, stirring the mixture frequently : let it 
 stand a few hours to settle, then pour off the water and fill the 
 vessel with water to wash out the excess of acid ; when the 
 water is clear, pour it off, dry the soil and weigh it; the loss 
 from the first weight will show the quantity of lime sufficiently 
 near for all practical purposes. (Gaylord.) 
 
 To determine the amount of sand, take a given quantity of 
 soil and boil it in water till it is thoroughly incorporated with 
 it, then pour the whole into a glass vessel and leave it till the 
 sand subsides: the clay remains in a state of mixture with the 
 water, which should be poured off and the sand dried and 
 weighed. If the sand contains lime, it may be separated by 
 muriatic acid as above directed. 
 
 The amount of clay may be very nearly ascertained by 
 evaporating the water which was poured off of the said, 
 the residue will be mostly clay. 
 
 To detect the presence of oxide of iron, mix a quantity of 
 soil with water, pour on muriatic acid and stir the mixture ; 
 let it stand a few hours and dip a piece of oak bark into the 
 solution, if the bark is colored brown or black, iron is present. 
 " To detect the presence of other salts, boil a portion of soil 
 in water, pour off the water and evaporate it, when the salts 
 may be obtained in crystals. 
 
 If the salt is a nitrate, it has a cool pungent taste, and 
 ignites when thrown on coals of fire. 
 
 If it be common salt, (muriate of soda,) it burns with a 
 crackling noise, and is also known by its taste. 
 
 Sulphate of soda puffs up by heat, gives off a watery vapor 
 and leaves a dry white mass." 
 
 These directions are sufficient to enable any one to make a 
 
SCIENTIFIC AGRICULTURE. 231 
 
 rough analysis of a soil, which, although not strictly correct, 
 may be of much service in determining the general character 
 of a farm, when a rigid and exact analysis cannot be obtained. 
 We give below two tables, one showing the composition of a 
 barren, and the other of a fertile soil. Taking the mineral 
 constituents of plants as a basis on which to predicate our rea- 
 soning in relation to the productive value of soils, we see at 
 once, that one of these tables shows a soil rich in all the 
 elements of fertility, while the other exhibits one almost irre- 
 deemably barren. 
 
 ANALYSIS OF A NEW SOIL ON THE BANKS OF THE OHIO RIVER, 
 POSSESSING GREAT FERTILITY. 
 
 Quartz sand and silicates, 87.143 
 
 Alumina, 5.666 
 
 Oxides of iron, 2.220 
 
 Oxides of manganese, 0.360 
 
 Lime, 0.564 
 
 Magnesia, 0.312 
 
 Potash and soda, 0.145 
 
 Phosphoric acid, 0.060 
 
 Sulphuric acid, 0.027 
 
 Chlorine in common salt, 0.026 
 
 Humie acid, 1.304 
 
 Insoluble humus, 1.072 
 
 Organic matters containing nitrogen, 1.011 
 
 Carbonic acid united to the lime, 0.080 
 
 ANALYSIS OF A SANDY SOIL, UNFIT FOR CULTIVATION. 
 
 Silica and quartz sand, 96.000 
 
 Alumina, 0.500 
 
 Oxides of iron, 2.000 
 
 Oxides of manganese, trace. 
 
 Lime, 0.001 
 
 Magnesia, trace. 
 
232 SCIENTIFIC AGRICULTURE. 
 
 ANALYSIS Continued. 
 
 Potash, do. 
 
 Soda, do. 
 
 Phosphoric acid, do. 
 
 Sulphuric acid, do. 
 
 Carbonic acid, 
 
 Chlorine, trace. 
 
 Humic acid, 0.200 
 
 Insoluble humus, 1.299 
 Water, 
 
 100 
 
 Chemically considered, a soil must contain all the inorganic 
 elements which plants require, and none that are injurious to 
 them. If the addition of a certain manure render a soil more 
 fertile, it is evident that the soil was deficient in one or more 
 of those substances which it furnished. If the addition of a 
 given manure or salt to a defective soil, fail to improve its fer- 
 tility, it is because enough of this substance is already present, 
 or because some other substance is wanting to render this 
 application available. A soil may sometimes show more or 
 less fertility for certain crops than analysis would indicate, on 
 account of some mechanical and physical conditions : in this 
 way the supply of certain elements may be cut off, although 
 they are present in the soil : the deficiency of others may also 
 be partially compensated by the same causes. 
 
CHAPTER IX. 
 
 MECHANICAL PHILOSOPHY. 
 
 Mechanical philosophy treats of the equilibrium and motion 
 of bodies: its great object of inquiry is, into the causes which 
 produce or prevent motion, and the manner in which it takes 
 place. " That part of mechanics which relates to the action of - 
 forces producing equilibrium or rest, in bodies, is called statics; 
 that which relates to the action of forces producing motion is 
 called dynamics" 
 
 The practical value of this branch of science consists in the 
 application of a few simple mechanical powers, either single or 
 combined in some kind of machinery, in overcoming resistances, 
 and producing and applying motion to useful purposes. 
 
 " Power is the means by which a machine is moved and 
 force attained ; thus we have horse power, water power, steam 
 power, <fec. 
 
 Force is the means by which bodies are set in motion, kept 
 in motion, and when moving are brought to rest The force 
 of gunpowder sets a ball in motion and keeps it moving until 
 the resisting force of the air, and the force of gravity bring it 
 to rest" 
 
 A few simple instruments or machines variously combined, 
 produce all the complicated, powerful and beautiful pieces of 
 machinery which have ever been constructed. 
 
 20* 
 
234 SCIENTIFIC AGRICULTURE. 
 
 These few elementary powers are, the lever, the wheel and 
 axle, the pulley, the inclined plane, the wedge and the screw. 
 
 The lever is a straight bar placed upon a supporting point 
 called a fulcrum, with the resistance which i's to be overcome, 
 at one end, and the power applied, at the other. 
 
 The wheel and axle is somewhat more complex than the 
 lever ; it consists of two concentric wheels, one of which is 
 larger than the other, and both revolving on a common axis. 
 This power acts like a succession of levers, and is therefore a 
 a modification of the lever. 
 
 The pulley consists of a flat disc, with a groove on the edge, 
 through which a rope passes, and a hole in its centre, through 
 which a fixed axis passes, on which it revolves: when several 
 pulleys are combined, they constitute a system of pulleys, or a 
 compound pulley. The power of a system of pulleys increases 
 in proportion to the number of pulleys employed. 
 
 The inclined plane, as its name implies, consists merely of a 
 plane surface, with one of its ends higher than the other, so 
 that the plane forms an angle with the horizon. 
 
 The wedge may be considered as two inclined planes with 
 their bases placed together, and their apices forming an acute 
 point. The power of the wedge depends upon its relative 
 length compared with the width of its base, or upon the de- 
 gree of taper from the base to the point. 
 
 The screw is the sixth mechanical power, and may be con- 
 sidered a continuous spiral wedge, or a modification of the in- 
 clined plane. The power of the screw depends upon the rela- 
 tion between its circumference and the distance between its 
 threads. 
 
 OBJECTS AND ADVANTAGES OF MACHINERY. 
 
 No actual power is ever generated by machinery ; force and 
 velocity may be gained, but they are always gained at the 
 expense of the motive power applied to work the machine: 
 the power and force must always be in exact proportion to 
 
MECHANICAL PIIILOSOPII V. 235 
 
 each other, so that, if one is increased, the other is diminished 
 in the same proportion. Great velocity in a machine, or in any 
 of its. parts, is incompatible with great power also; for whatever 
 js gained in speed is lost in strength, that is, it is gained at 
 the expense of power or force. 
 
 It is not expected to gain power, force and velocity at the 
 same time by tho use of any mechanical contrivance whatever, 
 but, by taking a philosophical advantage of the few simple 
 mechanical powers, to obtain one or the other of them, accor- 
 ding to the labor to be performed. 
 
 The advantages of machinery are numerous. 
 
 1. By the aid of machinery we can apply force to much 
 better purpose than by our unassisted hands. 
 
 2. A man can perform a work by its aid, to which he would 
 be wholly incompetent without it 
 
 3. It often enables men to exert their whole force, where 
 without it they could exert only a small part of it. 
 
 4. It enables us to employ animals in the execution of many 
 kinds of work which must otherwise be performed by man 
 himself. 
 
 5. It enables us to employ several inanimate motive powers, 
 such as water, steam, wind," heat, electricity, &c. 
 
 6. Many manufacturing operations are performed with much 
 greater facility and exactness than they could be by hand. 
 
 7. Machinery saves a considerable part of the materials used 
 in the manufacture of many fabrics. 
 
 ON REGULATING THE MOTION OF MACHINERY. 
 
 The motion of machinery, to operate to the best advantage, 
 should be perfectly regular and uniform. Variations of motion 
 consist principally in variations of power, weight or resistances, 
 and changes of velocity in different parts of the machine itself. 
 The different instruments used to obviate these effects, and 
 secure uniform motion, are called regulators. There can be 
 little doubt that water, where it is abundant and available, 
 
236 SCIENTIFIC AGRICULTURE. 
 
 furnishes the most economical motive power, and one which 
 propels machinery with greater uniformity than any other 
 which we possess. 
 
 Among the instruments used fcr modifying and regulating 
 motion are, the fly wheel, governor, ratchet wheel, universal 
 joint, crank, eccentric wheel, arch head, pendulum, knee joint, 
 fusee, &c. 
 
 Every part of a machine ought to be proportioned to the 
 stress it is to bear, and the strength it requires, and should 
 be no heavier than necesssary: all parts should bear their 
 relative proportion of the work and wear, so that when the 
 machine fails, all parts shall be worn out. Every machine 
 should consist of as few parts as possible ; because, when parts 
 are multiplied, friction is increased in the same proportion, and 
 the machine is more liable to get out of repair. All mechanical 
 obstacles and errors have a less ratio to the motion in great 
 than in small machines ; the former, therefore, work with more 
 uniformity and exactness, but are proportionally weaker and 
 more liable to be broken. 
 
 Motion and rest are both equally accidental states of matter: 
 bodies are no more disposed to lie at rest than to put them- 
 selves in motion : they maintain a state of rest so long as there 
 is an equilibrium of all the furces acting upon them ; and when 
 they assume a state of motion, it is because they are acted 
 upon by some extrinsic force, which is stronger than the com- 
 bined action of all those which tend to keep them at rest. 
 When once in motion, bodies would continue moving forever, 
 if no force obstructed them to destroy the equiblirum between 
 accidental resistances and the propelling force : in other words, 
 they never would come to rest, unless brought to rest by some 
 power superior to that which set them moving. 
 
 Motion may be absolute or relative: absolute motion is a 
 change of place by a body, in relation to some fixed point: 
 
MECHANICAL PHILOSOPHY. 237 
 
 relative motion is a change of place by a body in relation to 
 some other body which is in absolute motion. 
 
 Simple motion results from the action of a single force upon 
 a body, while compound motion is produced by two or more 
 forces acting different directions. Motion, when once attained 
 would be onward in a straight line unless changed or destroy- 
 ed by some force secondary to the one by which it was pro- 
 duced : a ball projected from a cannon, assumes a curved line 
 towards the earth, because acted upon by the attraction of 
 gravity ; and this sufficiently strong to overpower the propel - 
 ling force of the powder which gave it motion, and finally bring 
 it to rest. 
 
 OBSTRUCTIONS TO THE ACTION OF MACHINERY. 
 
 Friction arises mostly from the elevations of one surface 
 entering into the depressions of another; but partly also from 
 the mutual cohesion of the surfaces. 
 
 Sliding friction is produced when pinions or axes revolve on 
 their support 
 
 Rolling friction occurs when a round ball or wheel rolls 
 along a surface. Friction is greater between two surfaces of 
 wood where their fibres lie parallel than where they run across 
 each other: it is also greater between two surfaces of the same 
 metal than between those of different metals : two surfaces of 
 iron would produce more friction than one of copper and one 
 of iron : cast steel is said to be an exception to this rule. 
 
 The ristance of friction may be diminished by the use of fine 
 smooth and oily substances ; the particles of which fill up the 
 cavities and lubricate the asperities of the surfaces. For this 
 purpose oil is best adapted to metals and tallow for wood. 
 
 Extent of surface makes no difference, in a given body, in 
 regard to the amount of friction developed. Friction is in- 
 creased between two bodies by their remaining some time in 
 contact; in some cases it does not attain the maximum in four 
 or five days. In the contact of two metals, the friction attains 
 
238 SCIENTIFIC AGRICULTURE. 
 
 its highest point in a few seconds: two pieces of wood attain 
 their utmost friction in one or two hours : when iron runs upon 
 oak the friction will increase for four or five days. 
 
 Friction is less after motion becomes well established and 
 rapid, than when it first commences. The whole efficacy of 
 the screw depends upon the friction between the threads of 
 the external and internal screw: the screw being an inclined 
 plane, if there was no friction, it would unscrew, or the inter- 
 nal screw would descend by its own gravity when placed ver- 
 tically. Query ? What relation has the development of fric- 
 tion to. electricity ? 
 
 The resistance of the atmosphere, which in some machines 
 must be considerable, is another obstruction to the action of 
 machinery. The weight or gravity of a machine itself, or of 
 some of its parts, is sufficient in some cases to require a consi- 
 derable part of its power to overcome it. 
 
 STRENGTH OF MATERIALS. 
 
 It is important, in the construction of all pieces of archi- 
 tecture and machinery, that the mechanic should know the 
 strength of the materials which he is to employ in the work. 
 By strength, we understand the power which a body has, by 
 the cohesive force of its particles to resist fracture : stress is 
 the power or tendency in a body to produce fracture by its 
 own weight. 
 
 A joist eight inches wide and two inches thick, is four times 
 as strong when laid on its edge as when laid on its side. 
 
 " A triangular beam is twice as strong when resting on its 
 broad base as when resting on its edge." 
 
 " The strength of a column in the direction of its length, is 
 directly proportional to the area of its transverse section." 
 
 " Half the length of a beam supported at both ends, will 
 bear four times as great a pressure as the whole beam ; and a 
 prop placed under the centre of a beam increases its strength 
 in the same ratio." 
 
MECHANICAL PHILOSOPHY. 
 
 The strength of a beam increases from the centre towards 
 the ends or points of support, and the stress increases from 
 the. ends towards the centre; hence, a beam to be equally 
 strong at every point, should be eliptical, or the largest in the 
 middle and taper regularly towards both ends. 
 
 The strongest form in which a given quantity of matter can 
 be disposed, is that of a hollow cylinder: this, however, is true 
 only when the transverse sections of the cylinder are perfectly 
 circular. In this way nature economizes material, avoids too 
 great weight, and at the same time augments strength. 
 
 "A great column is in greater danger of being broken than 
 a similar small one ; an insect can sustain a weight many times 
 greater than itself, whereas a much larger animal, as a horse, 
 eould scarcely carry another horse of his own size." 
 
 It is not regarded as safe to load a stone structure with more 
 than one-sixth the amount of pressure which it requires to 
 crush it: iron may be loaded to one-fourth that amount In 
 building bridges, <fec., which are to span considerable space 
 without as much support as might be desirable, it is important 
 to calculate accurately, both the strength and stress of the 
 beams : bridges apparently strong, and perfect in construction, 
 sometimes fall by their own weight: in such cases there is an 
 unnecessary violation of a philosophical principle of which no 
 mechanic should be ignorant For suspension bridges, the 
 strongest material for spanning a wide stream is cast steel 
 wire, the next strongest is malleable iron, and k-ast of all 
 metals, lead. A piece of cast steel wire one-eighth of an inch 
 in diameter will sustain a weight of 16,782 pounds; or 4,931 
 feet of its own length : malleable iron wire of the same size, 
 9,008, or 2,467 feet of its own length: lead wire of the same 
 size sustains only 228 pounds, or 42 feet of its own length. 
 
 Of the different kinds of wood, the strongest are, the ash, 
 oak, teak, beech and larch, the strongest of these is the ash. 
 We see by these few facts in relation to mechanical philoso- 
 
240 SCIENTIFIC AGRICULTURE. 
 
 phy, that almost every practical mechanical operation can be 
 reduced to scientific rules, and the result calculated with 
 mathematical certainty before the work is commenced. We 
 see also how much more easily and economically many opera- 
 tions might be performed, and how much disappointment and 
 money might be saved by a knowledge of this branch of sci- 
 ence, to the visionary inventors of patent rights, the only fault 
 of which is, that they refuse obstinately to perform any part 
 of the work designed for them, and the greatest misfortune of 
 whose inventors is their ignorance. A knowledge of mechani- 
 cal philosophy is indispensible to the accomplished mechanic or 
 agriculturist 
 
GLOSSARY. 
 
 Agriculture, the science and art of productive farming. 
 
 Affinity, attraction that force which causes two bodies of dif- 
 ferent properties to unite and form a compound. 
 
 Annual, yearly. 
 
 Aerial, pertaining to the air. 
 
 Axis, the centre or point on which a body does or may revolve. 
 
 Acotyledonous, without a colyledon. 
 
 Appendage, something added. 
 
 Albumen, an organic principle resembling white of eggs. 
 
 Altitude, height or elevation. 
 
 Arterial, pertaining to the arteries. 
 
 Acerose, needle shaped. 
 
 Axillary, growing in the angle between the stem and leaf. 
 
 Arragonite, a simple mineral composed of carbonate of lime. 
 
 Ament, flowers collected on chaff-like scales and arranged on a 
 slender stalk. 
 
 Assimilate, to become similar. 
 
 Anemia, want of blood in botany want of sap. 
 
 Absorption, the act of imbibing or absorbing. , 
 
 Anthracite, a species of mineral coal. 
 
 Aluminum, a metalic earth, the base of alum. 
 
 Albite, a species of feldspar. 
 
 Arseniate, a salt of arsenic. 
 
 21 
 
242 GLOSSARY. 
 
 Asbestos, a fibrous incombustible mineral. 
 
 Analysis, separating the elements of a compound. 
 
 Azure, sky blue. 
 
 Alluvium, the sediment of rivers such as sand, vegetable mat- 
 ter, mud, &c. 
 
 Augite, a simple mineral of a dark green or black color, found 
 as a constituent in many volcanic rocks. 
 
 Amygdaloid, one of the trap rocks through which are scatter- 
 ed agates and simple minerals. 
 
 Agate, a translucent silicious mineral of many varieties. 
 
 Apocrenic acid, an acid found in peat and humus soils. 
 
 Atmosphere, the air which we breathe. 
 
 Aggregate, the sum of several particulars. 
 
 Anhydrous, destitute of water. 
 
 Aurora Borealis, Northern Lights. 
 
 Aqueous, wateiy. 
 
 Aerolite, a meteoric stone falling through the air. 
 
 Alternate, leaves growing on opposite sides of the stem at dif- 
 ferent distances, but not opposite each other, are alternate. 
 
 Alburnum, sap-wood. 
 
 Accretion, increasing in size by the addition of new matter. 
 
 Alchemy, the pretended science from which chemistry origina- 
 ted : its operations consisted in trying to change the baser 
 metals into gold ; to find a universal solvent and a remedy 
 for all diseases. 
 
 Attenuation, the act of making fine, thin, minute. 
 
 Angle of incidence, the angle at which a moving body strikes 
 another. 
 
 Angle of reflection, the angle at which a moving body leaves 
 or bounds from another. 
 
 Aquafortis, nitric acid. 
 
 Aqua-ammonia, spirit of hartshorn. 
 
 Acrid, sharp, pungent, biting. 
 
 Acid, sour, having chemical properties opposite to alkalies. 
 
GLOSSARY. 243 
 
 Alkali, in common language, lye. 
 
 Apotheme, extractive matter. 
 
 Adjective colors, such as require a mordant 
 
 Alizarine, the basis of the red coloring principle. 
 
 Arable, fit for tillage or cultivation. 
 
 Avidity, greediness, eagerness. 
 
 Asboline, one of the elements of soot 
 
 Botany, the science of plants. 
 
 Boulder, a rounded fragment of rock lying on the surface. 
 
 Blowpipe, an instrument used in chemical experiments. 
 
 Bole, a species of reddish earth. 
 
 Bitwnenization, the process of furnishing bituminous coal 
 
 Biennial, once in two years. 
 
 Biternate, twice ternate, two petioles, each bearing three 
 
 leaves. 
 Barometer, an instrument for measuring the pressure of the 
 
 atmosphere. 
 Base, the substance which combines with an acid to form a 
 
 salt 
 Bed, a term used in Geology to denote the extent of a stratum 
 
 of coal or other rock 
 Basalt, a dark green rock divided in columnsL 
 
 Climatology, a treatise on climate. 
 
 Caloric, the agent which produces heat 
 
 Coalesce, to unite or run together. 
 
 Condense, to make more dense. 
 
 Clouds, floating particles of water or other matter. 
 
 Congeal, to freeze or harden. 
 
 Crystalization, the act of forming crystals. 
 
 Concentric, having a common centre. 
 
 Cohesion, the force which holds the particles of bodies together. 
 
 Corona, a luminous circle round the sun or moon. 
 
 Cleavage planes, the flat surface formed by the cleavage of 
 rocket. 
 
244 GLOSSART. 
 
 Continuity, unbroken, continuous texture. 
 
 Carboniferous, any bed or rock containing coal. 
 
 Coral, a maritime production composed of lime, and the habi- 
 tation of insects. 
 
 Cuboidal, in the form of a cube : square. 
 
 Columnar, having the form of columns. 
 
 Chalcedony, a species of quartz-like mineral. 
 
 Calcareous spar, crystalized carbonate of lime. 
 
 Crater, the opening of a volcano through which its eruptions 
 take place. 
 
 Chlorite, a simple mineral of a green color. 
 
 Crucible, an earthen or metallic po< in which ores are melted 
 and purified. 
 
 Crenic acid, an acid found in peat and humus soils. 
 
 Calcareous, limy, composed mostly of lime. 
 
 Caustic, corrosive, biting, burning. 
 
 Calcine, to burn. 
 
 Cuticle, the outside bark or skin. 
 
 Capillarity, the property of absorbing by capillary attraction. 
 
 Carbonate of potash, pearlash. 
 
 Chlorine, a simple substance. 
 
 Calorific, producing heat. 
 
 Capacity for caloric, power of containing latent heat. 
 
 Combustion, the act of burning. 
 
 Conductors, substances which conduct caloric or electricity. 
 
 Carbon, charcoal. 
 
 Clarify, to make clear or clqan. 
 
 Carbonic acid, a compound of carbon and oxygen. 
 
 Complex, having many component parts. 
 
 Coniferous, bearing seeds in cones, like the pine. 
 
 Carmine, a coloring matter of a pink color. 
 
 Casiene, an organic ekment the basis of cheese. 
 
 Caramel, a substance produced by heating sugar. 
 
 Carburetted hydrogen, a gas composed of carbon and hydrogen. 
 
GLOSSARY. 246 
 
 Carbonic oxide, a gas composed of carbon and oxygen. 
 
 Corrosive, having- the property of corroding and destroying. 
 
 Ce/htlar, composed of small cells. 
 
 Cryptogamous, having flowers too minute to be seen with the 
 naked eye. 
 
 Cotyledon, a seed lobe. 
 
 Carnivora, the class of animals which live on flesh. 
 
 Cruciform, having the form of a cross. 
 
 Calyx, a cup, the bottom part of a flower. 
 
 Corolla, the closed leaves of a flower. 
 
 Crude, raw, immature. 
 
 Cordate, heart shaped. 
 
 ChlorophyUe, the green coloring matter of plants. 
 
 Cambium, the descending sap which forms wood. 
 
 Centripetal, tending towards the centre. 
 
 Cereals, the white straw grains, as wheat and rye. 
 
 Chrysolite, a simple mineral, of gold color. 
 
 Centrifugal, tending to recede from the centre. 
 
 Corymb, a cluster of flowers whose stalks spring from different 
 heights, and form a flat top. 
 
 Cyme, a cluster of flowers whose stalks rise from a common 
 centre, and afterwards subdivide irregularly. 
 
 Contagion, an infectious or pestilential disease which is com- 
 municated by contact or through the atmosphere, from one 
 animal or plant to another. 
 
 Denude, to make naked or bare. 
 
 Dunes, hills of blown sand. 
 
 Disintegrate, to separate into integral parts. 
 
 Ductile, capable of being drawn into wire. 
 
 Dilute, to make thin or reduce in strength. 
 
 Deciduous, falling off in the usual season : not persistent. 
 
 Dissemination, the act of sowing or scattering. 
 
 Dilate, to expand, extend, enlarge. 
 
 Digestion, the act of assimilating food to the body. 
 *21 
 
546 GLOSSARY. 
 
 Digitate, divided like the fingers. 
 
 Dip, the inclination of a stratum of rock from the horizon. 
 
 Dyke, a mass of rock which appears to have been injected into 
 
 the fissures of other rocks. 
 Drift, masses of sand or other matters driven together by 
 
 water. 
 
 Deleterious, injurious, noxious. 
 
 Duramen, the inside, brown heart of wood of forest trees. 
 Decompose, to separate into parts or elements. 
 Data, known or admitted facts or principles. 
 Deutoxide, a chemical compound containing two proportions of 
 
 oxygen. 
 
 Daguerreotype, a process of taking pictures by means of light. 
 Dynamical, pertaining to strength or power. 
 Deliquiesce, to dissolve gradually by attracting and absorbing 
 
 moisture from the air. 
 Distillation, separating essential oils or alcohol from other 
 
 matters, by means of heat, 
 Diurnal, daily, occurring daily. 
 
 Disinfecting, purifying and preventing contagion or infection. 
 Extant, now in use. 
 Extirpate, to destroy or eradicate. 
 Excavate, to dig or wear out a hollow or cavity, 
 Excrements, matters voided or excreted by animals. 
 Endogens, plants which grow from the inside. 
 Electricity, a principle in nature usually called lightning. 
 Elasticity, power of resuming form after compression. 
 Elective affinity, that affinity which causes an acid or alkali to 
 
 abandon one with which it is already united, and unite with 
 
 another. 
 Ether, a subtil matter which is much lighter than air, and 
 
 supposed to exist beyond the limits of the atmosphere. 
 Emit, to send off, give out or discharge. 
 Expansion, the act of enlarging or increasing in bulk. 
 
GLOSSARY. 247 
 
 Equivalent number, the particular quantity of any substance 
 
 required to combine with or saturate another substance. 
 Emanate, to issue or flow from. 
 Electric, a substance capable of giving off electricity. 
 Electrical repulsion, that property which causes bodies in the 
 
 same state of electrical excitement to separate: opposite 
 
 attraction. 
 
 Exude, to run out or issue from. 
 Equilibrium, balance of forces or properties. 
 Epiphytes, plants growing- upon the trunk and branches of 
 
 other plants and deriving nourishment mostly from the air. 
 Epidermis outside skin or bark. 
 Excrete, to eject or throw out. 
 Embryo, the germ of a plant or animal. 
 Elliptical, an oval figure with pointed ends. 
 Exogens, plants which grow by layers on the outside. 
 Exhalation, breathing out, giving off, emitting. 
 Evolution, emission, giving off, discharging. 
 Element, a component part, first principle. 
 Equator, an imaginary line dividing the earth into two halves ; 
 
 the equinoctial line. 
 Effloresce, to become a dry powder. 
 Eremacausis, slow combustion or decay. 
 Evaporation, becoming volatile, flying off with the air, drying 
 
 up. 
 
 Escarpment, a steep ledge of rocks. 
 Eurite, a white mineral. 
 Eject, to throw out, discharge. 
 Effervesce, to foam, bubble, ferment. 
 Fasicle, a small bundle. 
 
 Flora, the goddess of flowers, a flower or book of flowers. 
 Functional, pertaining to the office or use of a part of any 
 
 organism. 
 Filament, the slender, thread-like part of the stamen. 
 
548 GLOSS Any. 
 
 Fibrils, minute branches of roots. 
 
 Fibrous, composed of fibres. 
 
 Fusiform, spindle- shaped, tapering. 
 
 Fasciculated, collected in heads or bundles. 
 
 Fundamental, original, elementary, first principle. 
 
 Fructification, the flower and fruit with their parts, the act of 
 making fruitful. 
 
 FAHRENHEIT, the inventor of the thermometer which bears 
 that name. 
 
 Fault, a cleft or fissure in a rock. 
 
 Fossil, the remains of animals and plants found buried in the 
 earth. 
 
 Formation, a group of any kind of rocks referred to a common 
 origin or period. 
 
 Fossiliferous, containing fossils. 
 
 Fissure, a crack or cleft. 
 
 Fuse, to melt, become fluid from heat. 
 
 Faggot, a bundle of sticks or brush. 
 
 Friable, easily crumbled or pulverized. 
 
 Fertilizers, substances used to enrich the soil. 
 
 Focus, the point at which rays of light or heat meet 
 
 Fluor spar, a mineral compound of lime and fluoric acid. 
 
 Fibre, a slender, thread-like organ or substance. 
 
 Fumes, vapor, gas or smoke. 
 
 Freezing point, this is placed at 32 Fahrenheit. 
 
 Feldspar, a simple mineral which constitutes a principal ingre- 
 dient of most rocks. 
 
 Fire damp, light carburetted hydrogen. 
 
 Fibrine, the colorless part of the blood which when separated 
 from it becomes jelly-like. 
 
 Geology, the science of the earth's structure, (fee. 
 
 Graphite, black lead. 
 
 Galvanism, a species or modification of electricity. 
 
 Glutinous, sticky, visced, having the characters of glue. 
 
GLOSSARY. 249 
 
 Generate, to produce or create. 
 
 Gelatine, a proximate principle in plants and the bodies of ani- 
 mals, usually called jelly. 
 
 Guano, a species of manure composed mostly of the excre- 
 ments of sea fowl. 
 
 Granite, an unstratified primary rock. 
 
 Greenstone, a variety of trap rock composed of hornblende 
 and feldspar. 
 
 Gneiss, a primary stratified rock composed of the same mate- 
 rials as granite. 
 
 Garnet, a simple crystalized mineral, generally of a deep red 
 color. 
 
 Gypsum, plaster of paris, sulphate of lime. 
 
 Graphic granite, is a species of granite in which the quartz is 
 so arranged as to give the surface the appearance of having 
 letters. 
 
 Gorge, a deep fissure or valley. 
 
 Gyration, turning in a circular or spiral direction. 
 
 Glossology, the application of names to the various organs of 
 plants. 
 
 Granulated, consisting of small grains, granules, or masses. 
 
 Genus, the subdivision of an order. 
 
 Gland, an organ in animals and vegetables which performs the 
 function of secreting a fluid. 
 
 Germination, the unfolding of the seed and development of 
 the embryo. 
 
 Geine, a substance obtained from decayed wood, and contain- 
 ing an acid called the geic acid. 
 
 Glanular, consisting of grains. 
 
 Grayivacke, an ancient fossiliferous rock, generally of a gray 
 color. 
 
 Gravity, weight : specific gravity, the weight of a particular 
 body compared with some standard. 
 
 Gas, an elastic fluid, or air. 
 
250 GLOSSARY. 
 
 Gelatinous, containing gelatine. 
 
 Homogeneous, of the same nature, consisting of similar parts, 
 all alike in structure. 
 
 Hornblende, a simple mineral of dark green or black color. 
 
 Humid, moist, wet 
 
 Harmattan, a dry easterly wind in Africa. 
 
 Haziness, foggy, smoky, misty. 
 
 Horizon, the line where the earth and sky appear to meet. 
 
 Hydrogen, a gas, the lightest of all known bodies. 
 
 Hues, tints, colors. 
 
 Hurricane, a violent storm or tempest. 
 
 Halo, a circle appearing around the sun, moon, or stars. 
 
 Hypothesis, a supposition or theory assumed but not proved : 
 used for the purpose of argument. 
 
 Hexagonal, six sided : having six sides and six angles. 
 
 Hydracid, an acid formed by the union of a substance with 
 hydrogen without oxygen. 
 
 Hematoxyline, the coloring principle of logwood. 
 
 Hydrate, a compound containing water. 
 
 Humic acid, an acid obtained from humus. 
 
 Herbaceous, herb-like, not woody. 
 
 Herbarium, a book in which dried plants are preserved. 
 
 Imbibe, to take in, absorb. 
 
 Irrigation, the act of watering, moistening. 
 
 Incineration, the act of reducing to ashes. 
 
 Intersect, to meet and cross each other. 
 
 Isoincric, bodies which differ in properties but agree in com- 
 position. 
 
 Inter stratified, stratified between or among other bodies. 
 
 Infusible, that cannot be fused or melted. 
 
 Incas, inhabitants of Peru and some other parts of S. America. 
 
 Inf. ate, to blow up, fill with wind. 
 
 Isothermal lines, lines which pass through points on the sur- 
 face of the earth at which the mean temperature is equal. 
 
GLOSS ARV. 251 
 
 laochlmencd lines, lines passing through points on the earth at 
 
 which the mean temperature of the winter is equal. 
 Intertropical, between the tropics. 
 Jf/ nis fatuus, Jack 0' Lantern. 
 Inverted, turned upside down. 
 Igneous, rocks, such as have been melted by fire or volcanic 
 
 heat 
 
 Infusoria, animalcules too minute to be seen by the naked eye. 
 Interlace, to tangle or lace together. 
 Inflorescence, the manner in which flowers are connected with 
 
 the plants. 
 
 Indigenous, native of, or growing wild in a country. 
 Joint, the parting lines in rocks, often at right angles with the 
 
 planes of stratification. 
 Kaolin, a species of potter's clay. 
 Lignite, wood converted into a kind of coal. 
 Lava, the melted stone which is thrown out of volcanoes. 
 Lichens, cryptogamic plants, of a crusty texture, growing on 
 
 rocks and the trunks and branches of trees. 
 Lenticular, having the form of a lens. 
 Longevity, length of life. 
 Laticiferous, the system of vessels in the bark of plants, which 
 
 circulates their fluids. 
 Latex, the fluid formed from the sap, and which nourishes all 
 
 parts of plants. 
 
 Lanceolate,- in the form of a lancet 
 
 Lyrate, pinnatified wiih a. large roundish leaflet at the end. 
 Linear, long and narrow with parallel sides, as in the leaves of 
 
 the grasses. 
 
 Leguminous, having legumes or pods, as the bean and pea. 
 Liber, the inner bark of plants. 
 Lamina, layers, thin plates or leaves. 
 Longitude, the distance of places on the globe in an east and 
 
 west direction. 
 
252 GLOSSARY. 
 
 Latitude, distance or degrees north and south. 
 
 Laminated, in lamina, layers or leaves. 
 
 Lunar, pertaining to the moon. 
 
 Limpid, pure, clear, transparent: thin when used in reference 
 to some fluids. 
 
 Marine, pertaining to the sea. 
 
 Microscopic, objects which are too small to be seen without the 
 aid of the microscope. 
 
 Macerate, to soak, dissolve. 
 
 Maximum, the greatest number or quantity attainable in any 
 given case. 
 
 Magnetism, the power or force which causes the magnetic 
 needle to point north and south. 
 
 Molecules, the ultimate or minute particles of matter. 
 
 Mirror, a looking-glass. 
 
 Mercury, quicksilver. 
 
 Mucilage, a slimy fluid, one of the proximate elements of plants. 
 
 Mordant, any substance used by dyers to set colors, or render 
 them permanent. 
 
 Must, the juice of grapes which has not fermented, new wine. 
 
 Metamorphosis, change, transformation. 
 
 Meteorology, the branch of science which treats of changes of 
 weather and other atmospheric phenomena. 
 
 Meteor, any appearance or phenomena observed in the atmos- 
 phere. 
 
 Mean temperature, that point which lies midway between the 
 two extremes of heat and cold. 
 
 Mist, fog, vapor. 
 
 Maritime, relating or pertaining to the sea. 
 
 Monsoon, a periodical wind which blows six months in one di- 
 rection, and then changes and blows six months in the op- 
 posite direction. 
 
 Moor, a marsh or fen, or land overgrown with heath and other 
 shrubs. 
 
GLOSSARY. 253 
 
 Mirage, an optical illusion described in meteorology. 
 Mineral, in common language, the metals and rocks. 
 Metalloid, a name applied to some of the metallic bases of the 
 
 earths. 
 Mica, a rock which is divided or laminated in its shining scales, 
 
 and of various colors. 
 Metamorphic, rocks which have been altered by the action of 
 
 fire. 
 Muriate of magnesia,, & salt formed by the union of magnesia 
 
 with muriatic or hydrochloric acid. 
 Mammalia, vertebrated animals, which have warm blood, 
 
 breathe by means of lungs, bring forth living young and 
 
 nourish them by milk. 
 Membrane, a thin delicate skin. 
 Midrib, the main or middle rib of a leaf, running from the base 
 
 to the point 
 
 Medullary, pertaining to the pith or marrow. 
 Morphology, that part of botany which treats of the formation 
 
 and metamorphosis of organs. 
 Malleable, a metal which can be hammered and drawn out 
 
 into various forms by the hammer, as iron. 
 Nutrient, nourishing, or pertaining to nutrition. 
 Noxious, hurtful, injurious, unwholesome. 
 Nomenclature, a system of naming or applying technical terms 
 
 in any art or science. 
 Nutrition, the act or process of supplying the proper matter 
 
 for the growth of animals and plants. 
 Nitric acid, aquafortis. 
 Nitrate of potash, salt petre. 
 Node, a knot or protuberance. 
 Nocturnal, nightly, occurring every night 
 Nickel, a grayish white brittle metal. 
 Nodular, having nodes or knots. 
 Napiform, resembling a turnip in form, 
 
 22 
 
254 GLOSSARY. 
 
 Ovary, a name in botany given to the outer covering of the 
 
 germ. 
 Ovules, little eggs, the rudiments of seeds which the germ 
 
 contains before its fertilization. 
 Orbicular, round, circular. 
 
 Organography, a description of the organs of plants. 
 Organic, composed of various parts or organs which perform 
 
 separate offices. 
 
 Oxidize, to become rusty or combine with oxygen. 
 Observatory, a place or building for making observations on 
 
 the heavenly bodies. 
 
 Opake, not transparent, not pervious to rays of light 
 Optical, pertaining the eye, to vision, or the science of optics. 
 Orbit, in astronomy, the path of a comet or planet. 
 Outcrop, the naked ends of strata of rock which protrude 
 
 above the surface of the earth, as on the side of a hill. 
 Oolite, a limestone composed of rounded particles like the eggs 
 
 of fish. 
 
 Organic remains, the fossil remains of plants and animals. 
 Olivme, an olive colored simple mineral often found in grains 
 
 and crystals in basalt and lava, 
 
 Oxide, a chemical compound of metals with oxygen, &c. 
 Oxygen, a gas. 
 
 Oxalute, a salt composed of oxalic acid and a base. 
 Oxalic acid, an acid obtained from sorrel. 
 Ordure, excrement, faeces, manure. 
 
 Permeate, to penetrate or pass through the pores of a body. 
 Phospkuretted Hydrogen, a compound of phosphorus and hy- 
 drogen. 
 
 Poudrette, a manure prepared from ordure. 
 Philosopher's stone, an imaginary mineral sought by the alchy- 
 
 mists, which was supposed to be capable by mixture with 
 the baser metals of transmuting them into gold. 
 Proximate, near; "proximate elements," those elements of 
 
GLOSSARY. 255 
 
 plants, such as starch, gum, &c., which are composed of the 
 
 immediate elements, viz : the gases and mineral matters. 
 Protoxide, a compound containing one proportion of oxygen. 
 Photographic, pertaining to light; photographic pictures are 
 
 taken by light. 
 Phosphorescence, a peculiar luminous matter without fire or 
 
 combustion, as the light given out by phosphorus, decayed 
 
 wood, putrifying flesh, <fec. 
 Parabola, a conic section arising from cutting a cone by a 
 
 plane parallel to one of its sides. 
 Prism, in optics, a triangular glass instrument for separating 
 
 the rays of light. 
 Polarity, that property which causes one end of a body to 
 
 repel and the other to attract, as in bodies magnetized or 
 
 electrified; pointing towards the poles. 
 Putrefaction, decomposition or decay of organic bodies. 
 Pungent, biting, hot, sharp. 
 Ponderable, possessing weight. 
 Precipitate, to throw down or separate. 
 Phosphates, compounds containing phosphorus. 
 Parallelism,, the state or quality of being parallel. 
 Petrify, to become stone. 
 Pebble, a small stone. 
 Plutonic, pertaining to subterranean heat 
 Porphyry, an unstratified igneous rock. 
 Pegmatite, primitive granite rock, 
 Pumice stone, a species of lava. 
 Plumbago, black lead, graphite. 
 Pulverulent, consisting of fine dust or powder. 
 Phenomena, an appearance. 
 Phase, an appearance, exhibited by the illumination of the 
 
 moon or other planets. 
 Polar elevation, height of latitude, or approach towards the 
 
 poles. 
 
256 GLOSSARY. 
 
 Pestilential, infectious, spreading pestilence. . 
 
 Phosphorus, a simple combustible body of a yellowish color, 
 
 and the consistence of beeswax. 
 Physical, pertaining* to matter or physics. 
 Parhelia, mock suns, or luminous spots near the sun. 
 Pistil, the central organ of most plants consisting of the 
 
 stigma, style and germ. 
 Perianth, a sort of calyx, the floral envelops, consisting of the 
 
 calyx and corolla, which are placed around the pistils and 
 
 stamens. 
 Pollen, the dust contained within the anthers of flowers, and 
 
 necessary to fructification. 
 
 Placenta, a part of the ovary to which the ovules are attached. 
 Pericarp, the seed covering. 
 
 Parasite, a plant or animal which grows on another. 
 Perennial, lasting more than two years, evergreen. 
 Phenogamia, plants which bear visible flowers. 
 Petal, a, flower leaf which is part of the corolla. 
 Plumule, the ascending part of a germinating plant. 
 Perforate, to make a hole, having holes, to pierce. 
 Parenchyma, the principal and proper substance of any organ 
 
 in a plant or animal. 
 
 Pervious, porous, or capable of being penetrated. 
 Pellicle, a thin skin, film or crust. 
 Pyrogen, the matter or generator of electricity. 
 Porcelain, a fine kind of earthen ware. 
 Peat, decayed and decaying vegetables, usually buried below 
 
 the surface of the ground. 
 
 Peduncle, the stem which bears the flower and fruit. 
 Panicle, a loose, irregular bunch of flowers, as in the oat 
 Propagate, to produce, or multiply by shoots, &c. 
 Physiology, the science which explains the laws o life and 
 "the uses and offices of all the various organs of plants and 
 
 animals. 
 
GLOSSARY. 257 
 
 Ptdp t the soft juicy part of fruits and berries. 
 
 Quartz, a simple mineral composed of silex or flint 
 
 Quartzose, containing quartz. 
 
 Quiescent, in a state of quietude or repose. 
 
 Quadruple, four times, four fold. 
 
 Radiate, to shine, to proceed in direct lines from a point, like 
 
 rays of light or heat. 
 Repulsion, the act of repelling or driving off, as in bodies in 
 
 the same electrical state : opposed to attraction. 
 Rarity, the opposite of density, thin, light. 
 Refrangibility, capable of being refracted. 
 Respire, to breath. 
 
 Residual, remaining after a part is taken, sediment which sub- 
 sides from a watery, mixture. 
 
 Reagent, a substance employed to precipitate another from solu- 
 tion, or to detect the presence of some other substance. 
 Rape, a plant of the genus brassica, allied to the cabbage. 
 Ramify, to branch off, divide. 
 Radiation, the act of radiating, throwing off rays. 
 Refrigerating, producing cold. 
 Reverberate, to return, rebound, resound, re-echo. 
 Rays of light, the brilliant luminous lines which proceed or 
 
 radiate from a luminous body. 
 Rarify, to make less dense, to make thin or light. 
 Rarifaction, the process of ratifying, making more porous by 
 
 expansion. 
 Refraction, the act of bending or breaking, diviating from a 
 
 direct course, as in rays of light 
 Receptacle, the end of the flower stalk to which the organs of 
 
 fructification are usually attached. 
 Ramous, branching, having lateral divisions. 
 Ramification, branching, minute division. 
 Ravine, a deep hollow or valley worn out by water. 
 22* 
 
258 GLOSSARY. 
 
 Ruby, a precious stone, a simple mineral of a carmine red color. 
 
 Rachis, the common stalk to which florets and spikelets are at- 
 tached, and in the grasses and wheat. 
 
 Raceme, a cluster, that variety of inflorescence in which the 
 flowers are arranged by simple pedicels on the sides of a 
 common peduncle, as the currant. 
 
 Respiration, breathing, or the act of absorbing or inhaling, and 
 exhaling carbonic acid and oxygen. 
 
 Rosacea, an order of plants, including the rose tribe. 
 
 Radicle, the descending part of a germinating plant, a small 
 root. 
 
 Rudimental, consisting of the first principles, or simple elemen- 
 tary parts. 
 
 Reniform, kidney shaped. 
 
 Silicate, a salt containing silica united to a base. 
 
 Silecious, containing silex. 
 
 STERCOLOGY, the science of manuring, enriching, or improving 
 the soil. 
 
 Smoulder, to burn and smoke without vent. 
 
 Sewer, a drain to convey off water underground. 
 
 Sulphate of iron, green vitriol, copperas. 
 
 Spurry, a plant of the genus spergula, allied to duckweed and 
 tares. 
 
 Spiral, in the form of a screw, gyratory like the thread of a 
 screw. 
 
 Subordinate, of minor importance, a secondary or inferior part. 
 
 Synthesis, the act of combining, contrary to analysis. 
 
 Spectrum, a visible image continuing after the eyes are closed: 
 the seven primary colors constitute the solar spectrum. 
 
 Statical, in a state of rest, the branch of mechanics which 
 treats of bodies at rest. 
 
 Sterile, barren, unproductive. 
 
 Solvent, a substance or fluid which dissolves other substances. 
 
GLOSSARY. 259 
 
 Safety lamp, a lamp surrounded by wire gauze, invented by 
 Dr. Davy to prevent explosions from the ignition of gas in 
 coal mines. 
 
 Solar, pertaining to the sun. 
 
 Sublimated, brought into a state of vapor by heat. 
 
 Stamen, a slender threadlike organ in the centre of flowers. 
 
 Summit, the apex or top. 
 
 Stigma, the summit or top of the pistil. 
 
 Style, the part of the pistil between the stigma and germ. 
 
 Stomata, mouths, or orifices. 
 
 Spongioles, the minute spongy suckers or extremities of roots. 
 
 Spores, the seeds of cryptogaraous plants, bodies analagous to 
 the pollen grains of flowering plants. 
 
 Sepal, a leaf of the calyx. 
 
 Sagittate, arrow form. 
 
 Segment, a part or principal division of a leaf, calyx, or corolla. 
 
 Stellate, star form. 
 
 Succulent, juicy. 
 
 Shale, a solid form of clay, which usually divides into lamina. 
 
 Saccharine, sweet, containing sugar. 
 
 Spadix, an elongated receptacle of flowers, commonly proceed- 
 ing from a spathe. 
 
 Scoria, volcanic cinders. 
 
 Silicon, the substance which combined with oxygen constitutes 
 silicic acid or flint 
 
 Sapphire, a hard mineral, consisting of crystalized alumina: it 
 is of various colors ; the Hue being generally called the sap- 
 phire ; the red, the oriental ruby ; the yellow, the oriental 
 topaz. 
 
 Saline, salt, containing some salt. 
 
 Sodium, the metallic base of soda. 
 
 Steatite, soapstone, a hydrated silicate of magnesia and alumina. 
 
 Snow-line, the lowest point on mountains at which there is per- 
 petual snow. 
 
260 GLOSSARY. 
 
 Subterranean, underground, below the earth's surface. 
 
 Submerge, to plunge under water, to overflow. 
 
 Strata, layers of rock. 
 
 Spherule, a little sphere, or ball. 
 
 Simoon, a hot suffocating wind, that blows occasionally in Af- 
 rica and South America. 
 
 Sirocco, a pernicious wind that blows from the south-east in 
 Italy. 
 
 Salubrious, healthful, favorable to health. 
 
 Supernatur al, miraculous, out of the usual course of nature. 
 
 Solar spectrum, the seven primary colors as seen in the rain- 
 bow. 
 
 Stratified, arranged in strata or layers. 
 
 Silurian, a series of rocks forming the upper subdivision of 
 the sedimentary strata found below the old red sandstone, 
 and formerly designated the graywacke series. 
 
 Scape, a stalk which springs from the root, and supports 
 flowers and fruit, but no leaves. 
 
 Saturate, to fill with a fluid, absorb, soak. 
 
 Sedimentary rocks, are those which have been formed by 
 their materials having been thrown down from a state of 
 suspension or solution in water. 
 
 Syenite, a kind of granite so called because it was formerly 
 brought from Syene in Egypt. 
 
 Serpentine, a rock usually unstratified, containing much mag- 
 nesia, and often speckled of various colors, like a serpent's 
 back. 
 
 Sculpture, the art of carving wood or stone into the images of 
 men or animals. 
 
 Stucco, a fine white plaster, to plaster with stucco. 
 
 Stalactite, a variety of carbonate of lime in the form of icicles, 
 produced by the filtration of water containing lime in solu- 
 tion, from the crevices of rocks in the roofs of caverns. 
 
 Stalagmites, are similar to stalactites, but formed by the drop- 
 
GLOSSARY. 
 
 261 
 
 ping of water on the floors of caverns, and having their 
 points upwards. 
 
 Twilight, the light at the close of day after sunset and before 
 dark. 
 
 Tortuous, crooked, convoluted. 
 
 Tertiary, a series of sedimentary rocks, lying above the pri- 
 mary and secondary, and having characters which distin- 
 guish them from these two classes. 
 
 Trachyte, a variety of lava essentially composed of greenstone : 
 it frequently contains detatched crystals of feldspar, and 
 sometimes hornblende and augite. 
 
 Titaniferous, an iron ore containing titanium. 
 
 Talc, a species of magnesian earth, consisting of smooth shining 
 lamina, translucent or transparent. * 
 
 Transparent, admitting rays of light to pass through. 
 
 Transverse, crosswise, across. 
 
 Terrestrial, belonging to, or pertaining to the earth. 
 
 Tillage, includes all mechanical operations on the soil. 
 
 Tropical, belonging to the tropics. 
 
 Torrid zone, the hot country included between the Tropic of 
 Cancer, and the Tropic of Capricorn. 
 
 Tornado, a high wind, a whirlwind. 
 
 Theory, an exposition of the principles of any science; the 
 science without the art or practice. 
 
 Tissue, connection or organization, the proper substance of an 
 organ. 
 
 Terminal, situated at the end. 
 
 Thyrse, a loose irregular bunch of flowers. 
 
 Tenacity, toughness, having strong cohesion, 
 
 Tap root, the main root, the axis. 
 
 Tuber, a fleshy knob or tumor on a rcot. 
 
 Trifolium, the genus of plants to which clover belongs. 
 
 Ternate, leaves which are arranged in threes are called ter- 
 nate. 
 
262 GLOSSARY. 
 
 Transmit, to permit to pass, to convey through. 
 
 Tint, shade, hue, color. 
 
 Transition, rocks which appear to have been formed while the 
 earth was in a state of transition, from a state of desolation 
 to a habitable condition. They have a texture partly me- 
 chanical and partly chemical. 
 
 Urea, the principal element, next to water, in the composition 
 of the urine. 
 
 Vhnic acid, a substance formed by the action of acids on 
 sugar. 
 
 Unconsolidated, soft, not consolidated. 
 
 Umbel, a kind of infloresence in which the flower stalks diverge 
 from one centre, as the wild parsnep. 
 
 Volcano, a burning mountain. 
 
 Vision, sight, the act of seeing. 
 
 Veins, cracks or fissures in rocks which are filled with sub- 
 stances different from the rock, either mineral or earthy. 
 
 Volcanic, pertaining to volcanoes, produced by volcanoes. 
 
 Vertical, perpendicular, overhead. 
 
 Vapor, mist, fog, small particles of water. 
 
 Vesicles, small particles or drops. 
 
 Verticil, whorled, having leaves or flowers in a circle round 
 the stem. 
 
 Volatile, evaporating or flying off easily. 
 
 Vascular, made up of vessels, or full of vessels. 
 
 Vasiform tissue, is made up of large tubes. 
 
 Venation, the arrangement of the ribs or veins in leaves. 
 
 Viscid, stringy, sticky, slimy. 
 
 VerticiUate, whorled. 
 
 Verdure, foliage, herbage. 
 
 Vibrate, to swing or oscillate. 
 
 Vacuum, an empty space, a space from which the air has all 
 been removed. 
 
 Vitality, life, the vital or living principle. 
 
GLOSSARY. 263 
 
 Vital functions, those functions or actions which arc indispen- 
 sable to organic life. 
 
 Vetches, a liguminous plant allied to the pea, bean, and lentil 
 
 Warping, a process in agriculture similar to irrigation. 
 
 Wealden, a fresh water group of rocks, composed of clay, lime 
 marl, &c. 
 
 Zigzag, in a crooked direction, forming short angles. 
 
 Zenith, that point in the sky or celestial hemisphere which, is 
 vertical to the spectator. 
 
 Zanthine, a substance found in urinary calculi 
 
 Zeolite, a mineral composed of silica, alumina and lime. 
 
INDEX. 
 
 ANALYSIS, - 23 
 
 Affinity, chemical 28 
 
 Affinity, simple 28 
 
 Affinity, elective - 29 
 
 Attraction, chemical - 28 
 
 Atmosphere, "" * 47 
 
 Acid, nitric - 50 
 
 Aquafortis, - 50 
 
 Ammonia, - - 51 
 
 Acids, properties of - 55 
 
 Alkalies, properties of 55 
 
 Albumen, - 60 
 
 Acids, vegetable, - 63 
 
 Alkalies, vegetable 63 
 
 Apotheme, - - 64 
 
 Alizarine, - 64 
 
 Alluvium, - 78 
 
 Amygdaloid, - 84 
 
 Appendages of plants, 96 
 
 Anther, " -' - 99 
 
 Albumen, - ". - 101 
 
 Aerial roots, 105 
 
 Annual roots, - 105 
 
 Alburnum, - 108 
 
 Absorption, - 117 
 
 Agriculture, influence of on climate and fall of rain, 133 
 
 Aerolites, - 149 
 
 Aluminum, - - - - - 158 
 
 23 
 
26G INDEX. 
 
 Alum, - 158 
 
 Analysis of soils, - 227 
 Analysis of soils to determine the quantity of vegetable 
 
 matter, . 228 
 Analysis of soils to determine the quantity of sand and 
 
 clay, - 228 
 
 Analysis of soils to determine the quantity of water, - 228 
 
 Analysis of soils to determine the quantity of humic acid, 229 
 
 Analysis of soils to determine the quantity of ulmic acid, 229 
 Analysis of soils to determine the quantity of crenic and 
 
 apocrenic acids, 229 
 
 Analysis of soils to determine the quantity of lime/ - 230 
 
 Analysis of soils to determine the quantity of silica, 230 
 Analysis of soils to determine the quantity of oxide of iron, 230 
 Analysis of soils to determine the quantity of different 
 
 salts, - 230 
 
 Analysis of a fertile soil, - 231 
 
 Analysis of a barren soil, 231 
 
 Aurora Borealis, 146 
 
 Analysis of beech and oak ashes, - 207 
 
 Ashes of coal, peat, <kc., as manures, - 208 
 
 Analyses, tables of 216 
 
 Analysis of wheat, - 216 
 
 Analysis of barley, 217 
 
 Analysis of oats, - 217 
 
 Analysis of rye, - 218 
 
 Analysis of peat, - - 218 
 
 Analysis of coal ashes, - 219 
 
 Analysis of bean and pea, - 219 
 
 Analysis of turnip and potato, - 219 
 
 Analysis of carrot and parsnep, - 220 
 
 Analysis of grass and clover, 220 
 
 Analysis of silica plants, - 221 
 
 Analysis of lime plants, - 221 
 
 Analysis of potash plants, - 222 
 
 Analysis of fseces of horse, 222 
 
 Analysis of urine of horse, - 222 
 
 Analysis of feces of cow, 223 
 
 Analysis of urine of cow, - 223 
 
 Analysis of human fseces, 223 
 
 Analysis of human urine, - 22B 
 
INDBX. 267 
 
 Analysis of guano, * 4 * - . . - 224 
 
 Analysis of bones of the ox, . - J, - 224 
 
 Analysis of coal soot, - 224 
 
 Analysis of wool, hair, horns, 225 
 
 Analysis of ox blood and muscle, . - , - - 225 
 
 B 
 
 Bed, .' - . - 74 
 
 Basalt, - 84 
 
 Botany, - 91 
 
 Botany, divisions of - , * *-''< - - 91 
 
 Breeze,- - 145 
 
 Bridges, > - - / .' *"*'. - - 239 
 
 Biennial roots, . - - 105 
 
 Buds, > - , if * ; * ,.. *v - 107 
 
 Bole, - * - 167 
 
 Blood, as manure, '*'' - * - 192 
 
 Bones, as manure, .... -..*>] 192 
 
 Calcium, - - - 162 
 
 Charcoal, animal * ; ' . - - 192 
 
 Chaff as manure, ' - ; - - - 197 
 
 Charcoal as manure, ' 198 
 
 Carbonate 'of soda* as manure, * ** 204 
 
 Chloride of sodium, or 'common salt, as manure, - 206 
 
 Chloride of lime and magilesia as manures, - - 206 
 
 Crushed rocks," as manure, - 208 
 
 Chalk as a' manure*, - - 209 
 
 Composts, - 212 
 
 Comparative value* of manures, table of - - 215 
 
 Chemistry, - * - ' - +' - 23 
 
 Capillarity, - ' 4; -.^J; * * - > * * iw** 24 
 
 Cohesfon, v 25 
 
 Combination, laws* of 'f - 80 
 
 Caloric, - - 84 
 
 Caloric, expansive power of - 34 
 
 Caloric, conductors of - 34 
 
 Caloric, specific, - 35 
 
 Caloric, capacity for 85 
 
 Caloric, radiant > ,' . *. - 9$ 
 
268 INDEX. 
 
 Caloric, latent, . . . . . 35- 
 
 Caloric, transmission of . . . .36 
 
 Cold, 37 
 
 Carbon, t % . . . . .42 
 
 Carbonic acid, ..... 43 
 
 Carbonic oxide, . . . . .48 
 
 Carburetted hydrogen, . . . . 49 
 
 Cerine, ...... 61 
 
 Camphor, . . . . . 61 
 
 Caoutchouc, . . . .62 
 
 Coloring matter, ..... 64 
 
 Chlorophylle, ... .64 
 
 Colors, adjective . . . . . 65 
 
 Colors, substantive, . . . . .65 
 
 Carmine, . . . . . 65 
 
 Chlorine, ...... 65 
 
 Compounds derived from the inorganic elements of plants, 67 
 Caramel, ...... 71 
 
 Cleavage planes, ..... 75 
 
 Clay slate, ...... 86 
 
 Chalk, ...... 87 
 
 Coal, . . . . . . .87 
 
 Coal, varieties and origin of ... 89 
 
 Coal basin in Wales, . * . . .89 
 
 Class denned, ..... 93 
 
 Corolla, ...... 97 
 
 Calyx, ...... 98 
 
 Cotyledon, ...... 101 
 
 Cellular integument, . . . . 108 
 
 Cambium, ...... 109 
 
 Cryptogamous plants, . . . . 110 
 
 Chlorophylle, . . . . .111 
 
 Climate, ...... 126 
 
 Clouds, ...... 138 
 
 Corona, ...... 147 
 
 Clay, 166 
 
 D 
 
 Divisibility, . . . . 25 
 
 Density, ...... 27 
 
 Diastase, . . . . . 68 
 
INDEX. 
 
 269 
 
 Dip 75 
 
 Dyke, 76 
 
 Drift, 
 
 Duramen, . . . . . .108 
 
 Dissemination of seeds, . . . . 120 
 
 Digestion, . . . . . .118 
 
 Day, longest in different latitudes, 
 
 Dry leaves as manure, . . . .197 
 
 Decayed wood as manure, . ' . 197 
 
 Draining, its objects . ' . . . . 181 
 
 Draining, varieties of . . . 182 
 Dynamics, ...... 233 
 
 Dew, ...... 136 
 
 E 
 
 Elasticity, . . . . . 27 
 
 Equivalent number, . . . . .31 
 
 Electricity, . . . \. *.* . ./*'. 3 ? 
 
 Electricity, negative . , ' . . 38 
 
 Electricity, positive . . . . 38 
 
 Electricity, conductors of. . . .38 
 
 Electrical excitation, . . . . 38 
 
 Electrical repulsion, . . - 
 
 Electricity, statical . . V;' 39 
 
 Electricity, dynamical . ,* . . 39 
 
 Eremacausis, . . . . . 44 
 
 Elementary bodies, . . . . .53 
 
 Elements, organic . . . . 57 
 
 Elements, proximate . . . .57 
 
 Elements, immediate . . . . 57 
 
 Extractive matter, . . . . .64 
 
 Escarpment, . . . ': -Jr ' . 75 
 
 Embryo, . . . v V- \.V . 94 
 
 Epidermis, . . * . . 96 
 
 Embryo, . . , . . .101 
 
 Epiphytes, . . . . . 105 
 
 Epidermis, . . . . . .108 
 
 Exhalation, . . . . . 117 
 
 Excrements of plants, theoiy of ... 185 
 
 Excrements as manure, . . . 193 
 
 Excrements, human . . .' .193 
 
 24 
 
270 INDEX. 
 
 Excrements of horned cattle, . . . 194 
 
 Excrements of the horse, . . . .194 
 
 Excrements of the hog, . . . . 195 
 
 Excrements of sheep, . . . .195 
 
 Excrements of birds, . . . . 195 
 Epsom salts as manure, .... 205 
 
 Earthy manures, ..... 206 
 
 Fire damp, . . . . . 49 
 
 Fermentation, . . . . .69 
 
 Fermentation, vinous, . 69 
 
 Fermentation, acetous . . . .70 
 
 Fault, 76 
 
 Formation, . . . . . .76 
 
 Fossil, ...... 76 
 
 Feldspar, composition of . . .87 
 
 Flower, . . . . . . 97 
 
 Filament, ...... 99 
 
 Fruit, ...... 100 
 
 Fibrils, . . . . . . 103 
 
 Fusiform roots, . . . . . 104 
 
 Fibrous roots, . . . . .104 
 
 Faciculated roots, . . . . 104 
 
 Floating roots, . . . . . .105 
 
 Flowers, terminal . . . . 118 
 
 Flowers, axillary . . . . .118 
 
 Flower, solitary . . . . . 119 
 
 Forests, their influence on climate and the fall of rain, 134 
 
 Frost, . . . * . . .136 
 
 Frost, cause of . . . . ^137 
 
 Fogs, . . . . . . ~ 138 
 
 Fire balls, ..... 148 
 
 Fallowing, . . . . . .182 
 
 Fallowing, benefits of . . . 183 
 
 Flesh as manure, . . . . . 192 
 
 Fat of animals as manure, . . . 192 
 
 Farm-yard manure, . . . . .199 
 
 Force defined, ..... 233 
 
 Friction, . . . . .237 
 
INDEX. 271 
 
 Gravity, . . . . . . 26 
 
 Gravity, specific .' 
 
 Galvanism, ..... 39 
 
 Gases, properties of . . . . .40 
 
 Gum, '.,.... 59 
 
 Gluten, .'..... 60 
 
 Geology, .... .73 
 
 Gorge, . .' . .76 
 Granite, . . J . . 
 
 Greenstone, . .' . . . 83 
 
 Gneiss, ...... 85 
 
 Graphite, .... 
 
 Genus, defined ..... 93 
 
 Germination, . . . . . .101 
 
 Granulated roots, . . . . . 104 
 
 Gale, . . 145 
 
 Gypsum, . ., ;. ^ ,_ . 165 
 
 Gelatine as manure, . *. . . .193 
 
 Guano, ...... 196 
 
 Green manures, ..... 200 
 
 Green manures, uses of . . 200 
 
 Glauber's salts as manure, . , jf .-; . 204 
 
 H 
 
 History, natural . . t . . 21 
 
 Hydrogen, . . . . . .41 
 
 Hartshorn, spirits of . . . 51 
 
 Haematoxyline, . . . . .65 
 
 Hornblende slate, ..... 86 
 
 Hornblende, basaltic, composition of . . A * " 87 
 
 Herbs, 106 
 
 Hail, .... ,; . - . . . 140 
 
 Harmattan, . . - -;. ' j.'>, . 1^4 
 
 Hurricane, . . . . . .145 
 
 Halo, . . . , \ . . 147 
 
 Humus, . . . . . .168 
 
 Humus, its composition . . . . 169 
 
 Hair as manure, . . . . .192 
 
 Horns as manure, . . ..'. . 192 
 
 Hoofs as manure, . . * . * . 192 
 
272 INDEX. 
 
 I 
 
 Isomeric bodies, ..... 58 
 
 India rubber, . . . . .62 
 
 Indigo, . . . . . . 64 
 
 Inorganic elements of plants, . . .65 
 
 Iodine, ...... 66 
 
 Idial section of the earth's crust, . . .79 
 
 Integument, . . . . . 101 
 
 Inflorescence, . . . . .118 
 
 Inflorescence, centripetal . . . . 119 
 
 Inflorescence, centrifugal . . . .119 
 
 Isothermal lines, . . . . . 127 
 
 Isochimenal lines, ..... 127 
 
 Ignis fatuus, . . . . . 147 
 
 Iron, ....... 159 
 
 Irrigation, . . . . . 179 
 
 Inclined plane, . . . . .234 
 
 j 
 
 Joint, - 75 
 
 K 
 
 Kaolin, . - 167 
 
 L 
 
 Light, - 32 
 
 Light, nature of - 32 
 
 Light, reflection and refraction of 32 
 
 Light, origin of - - 33 
 
 Light, heating rays of 33 
 
 Lignine, 58 
 
 Lava, - 84 
 
 Limestone, primary 86 
 
 Latex, - .... 108 
 
 Liber, - 108 
 
 Leaf, - - - 111 
 
 Leaves, deciduous - 111 
 
 Leaves, evergreen - 111 
 
 Leaves, scattered - 111 
 
 Leaves, alternate - 111 
 
 Leaves, opposite - 111 
 
INDEX. 278 
 
 Leaves, verticillate 111 
 
 Leaf, orbicular - 112 
 Leaf, eliptical 
 
 Leaf, lanceolate - - - 1 1 2 
 
 Leaf, cordate - - 113 
 
 Leaf, sagittate - - 113 
 
 Leaf, reniform - , 113 
 
 Leaf, linear - - - - -113 
 
 Leaf, deltoul - 113 
 
 Leaf, acerose - 113 
 
 Leaf, pinnatified - - 113 
 
 Leaf, lyrate - 114 
 
 Leaf, connate - - 114 
 
 Leaf, digittate - 114 
 
 Leaf, stellate 114 
 
 Leaf, lobed - - - - 114 
 
 Leaf, compound - - 115 
 
 Leaf, sinuate - 115 
 
 Leaf, emarginate -' 115 
 
 Leaf, tubulate, - 115 
 
 Leaves, biternate 115 
 
 Leaves, ternate - 115 
 
 Lightning, 140 
 
 Lighting rods, - - 141 
 
 Lightning, conditions under which it is developed, <fec. 142 
 
 Land and sea breezes, - * .._* - - 143 
 
 Lime, - * - 163 
 
 Lapping, - - - - - 177 
 
 Leached ashes as manure, ,'> - 208 
 
 Lime as manure, - - - - 209 
 
 Lime, mode of applying, - - - 210 
 
 Lever, - - - >. . 234 
 
 Latex, - - - - - - 117 
 
 M 
 
 Myricine, ...... 61 
 
 Mordant, ...... 64 
 
 Miea slate, . . . . . 86 
 
 Mica, composition of . . . . .87 
 
 Midrib, . . . . . v 111 
 
 Meteorology, . . . ' **', ' +* . 125 
 
 24* 
 
274 INDEX. 
 
 Meteor, ...... 125 
 
 Mirage, . . . . . .149 
 
 Mists, . . . . . . 138 
 
 Monsoons, . . . . . .145 
 
 Manganese, . . . . . 159 
 
 Magnesium, . . . . .102 
 
 Magnesia, . . . . . 162 
 
 Marl, ....... 164 
 
 Manures, . . . . ". 190 
 
 Manuring, objects of . . . . .191 
 
 Manures, animal . . . . . 192 
 
 Mineral manures, . . . . .204 
 
 Marl as manure, ..... 208 
 
 Mechanical philosophy, . . . .233 
 
 Machinery, objects of . . . 234 
 
 Machinery, on regulating motion of . .235 
 
 Motion, species of . . . . 236 
 
 Machinery, obstructions to the action of . .237 
 
 Materials, strength of . . . 238 
 Materials, beams and columns .... 238 
 
 Materials, cylinder . . . . 239 
 
 Materials, metals, . . . . . .239 
 
 Materials, woods . . . . . 239 
 
 Materials, stone . . . . .239 
 
 N 
 
 Nitrogen, ...... 45 
 
 Napiform roots, . . . . . 103 
 
 Nerves, . . . . . .111 
 
 Night soil, . . . . . 194 
 
 Nitrate of soda as manure, . . . .205 
 
 
 
 Oxygen, ...... 41 
 
 Oxalic acid, . . . . . .48 
 
 Organic bodies, mutual relation of . . 60 
 Oils, fixed ...... 62 
 
 Oils, volatile . . . . . 62 
 
 Organic elements, metamorphosis of . . . 70 
 
 Outcrop, ...... 75 
 
 Olivine, , . . 84 
 
INDEX. 275 
 
 Order defined, ..... 93 
 
 Ovary, ...... 
 
 Ovules, ...... 
 
 Oil cake as manure, . . . . .198 
 
 Philosophy, natural, ... . . 21 
 
 Physics, \ * .$ . .21 
 
 Prism, . f . ; >' . . 33 
 
 Pyrogen, . , * r . . . 39 
 
 Phosphorus, . . . . 66 
 
 Phosphoric acid, *^ .$ . . .67 
 
 Primary rock, . . . . . 78 
 
 .Porphyry, . . . . .83 
 
 Plants, divisions of _ *' ... 92 
 
 Plants, classification of . .92 
 
 Plumule, . ...*-. . 94 
 
 Pistils, *^ . ' . " ,. * .97 
 
 Perianth, . .' .' *' . / . 97 
 
 Petals, . .. ' ./ '';-.- * . 97 
 
 Pollen, . "." V'. ... 99 
 
 Placenta, . V . ." . .99 
 
 Pericarp, . "/ ;' * : . . . 100 
 
 Parasitel, .* ' ? -* ^ '.. . . . 105 
 
 Perennial roots, . " .* ;" . 105 
 
 Pith, . . ; v* . ^, ' . . 107 
 
 Parenchyma, . . . * . . 116 
 
 Peduncle, . . . / ', / . .119 
 
 Panicle, . . . ; ; , " , . 120 
 Plants, curious phenomena of . /; . ',' > . . 122 
 
 Plants, locality of . . . ' . * ^ , .. 123 
 
 Plants, diseases of . . -^, ' ^* , . 123 
 
 Parhelia, . . . l .V * -^* 148 
 
 Potassium, . . . .. * *7 . IQI 
 
 Peat, . . . . . * . ] . 167 
 
 Potter's clay, . . . : , ,* . 167 
 
 Pipeclay, . . . ^ . * ^, " . 167 
 
 Peat, composition of . . . -' . .168 
 
 Paring and burning, . . . . 180 
 
 Phosphate of lime, . . .. .193 
 
276 INDEX. 
 
 Peat as manure, . . . . .198 
 
 Pasture, improvement of the soil by . 202 
 Pasture, temporary ..... 202 
 
 Pasture, permanent .... 202 
 
 Power defined, . . . . .230 
 
 Pulley, ...... 234 
 
 Q 
 
 Quartz, . . . . . .85 
 
 B 
 
 Rarity, . . . . . .27 
 
 Resin, ...... 61 
 
 Rocks, classification of . . . .77 
 
 Rocks, aqueous ..... 80 
 
 Rocks, volcanic ... . . .80 
 
 Rocks, plutonic ..... 80 
 
 Rocks, rnetamorphic . . . . .80 
 
 Rock salt, ..... 88 
 
 Radicle, . . . ... .94 
 
 Rain tables, . . . . . 136 
 
 Rotation, courses from Colman, . . 187 
 
 Receptacle, . . . . . 97 
 
 Radicle, ...... 101 
 
 Root, 102 
 
 Ramose roots, . . . , .103 
 
 Root, functions of . . . . 106 
 
 Respiration, . . . . .118 
 
 Rachis, . . . . . 119 
 
 Rain, . . . . .135 
 
 Rain, its cause, . . . . . 125 
 
 Rain, its quantity, &c., . . . .135 
 
 Rainbow, . . . . . 148 
 
 Rainbow, inverted . . . . .148 
 
 Ribbing, . . . . . 178 
 
 Rotation of crops, . . . . .184 
 
 Rotation, objects of . . . . 185 
 
 Rotation, courses of . . . . .188 
 
INDEX. 277 
 
 s 
 
 Science, natural . . . . .21 
 
 Synthesis, ..... 
 
 Spectrum, solar . . . . .33 
 
 Salts, properties of . . . . 56 
 
 Salts, acid . . . . . .* 56 
 
 Salts, neutral ' . * * * . . 56 
 
 Salts, basic . * . " . "*" . . . 56 
 
 Salts, double . . . 56 
 
 Salts, deliquescent, , . . . .57 
 
 Salts, effervescent, .... 56 
 
 Starch, ...... 58 
 
 Sugar, ...... 29 
 
 Stratification, . . . . .74 
 
 Seam, . . . . 75 
 
 Sulphur, . . . .66 
 
 Syenite, ...... 83 
 
 Serpentine, . ' \ . * , . . 84 
 
 Slate, talcose, , , . . . . 87 
 
 Species defined, < .V . . .94 
 
 Stamens, , . . . . 97 
 
 Style, ,.'" . * >. 5 . . 99 
 
 Stigma, . . * ' . . . 99 
 
 Seed, , 4 * .101 
 
 Spongioles, # . . . 103 
 
 Shrubs, . . . . . .106 
 
 Stem, exogenous . . . . . 107 
 
 Sap, . . . , - . . .108 
 
 Scape, . . *; ; . % * , "-. _ 119 
 
 Seeds, longevity of . . . v - .122 
 
 Snow line, . . . 128 
 
 Snow lines, table of . * * + ' . 128 
 
 Snow, . . . v v- 138 
 
 Snow crystals, system of ?.' .v '* . 139 
 
 Simoon, . . .*. . ; * 4 . 145 
 
 Sirocco, . ; . * .'^ . 145 
 
 Shooting stars, . . V ./ . 149 
 
 Silicon, . ./> . .-.* . .157 
 
 Sodium, . . . . . 160 
 
 Stalactites, . . . . . .165 
 
 Stalagmites, . . * V" ; * 165 
 
278 
 
 INDEX. 
 
 Spar, gypseous, . . . . .165 
 
 Stitching, . . . . 1%8 
 
 Scarifying, . . . . . .178 
 
 Soils, physical properties of . . . 171 
 
 Soils, weight of . . . .171 
 
 Soils, state of division of . . . 171 
 
 Soils, firmness and adhesiveness of . . .172 
 
 Soils, power of imbibing water . . . 172 
 
 Soils, power of containing water . . .172 
 
 Soils, power of retaining water, . . . 173 
 
 Soils, capillary power of . . . .173 
 
 Soils, their contractibility on drying, . .' 174 
 
 Soils, their power of absorbing gaseous matters, . 174 
 
 Soils, their power of absorbing heat, . . 174 
 
 Soils, their power of retaining heat, . . .175 
 
 Soils, their power of radiating heat, . . 175 
 
 Soils, their ultimate uses to plants, . . .176 
 
 Subsoil ploughing, . . . . 178 
 
 Stercology, . . . . . .190 
 
 Skins of animals as manure, . . . 192 
 
 Straw as manure, . . . . .197 
 
 Saw dust as manure, . . . . 197 
 
 Soot as manure, . . . . .198 
 
 Saline manures, ..... 204 
 
 Sulphate of soda as manure, . . . 204- 
 
 Sulphate of lime, or gypsum, as manure, . . 205 
 
 Silicates of potash and soda as manures, . .206 
 
 Salts of ammonia as manure, . . . 206 
 
 Screw, . . . . . 234 
 
 T 
 
 Tenacity, . . . . . .28 
 
 Tannin, ...... 64 
 
 Tertiary strata, . . . . .78 
 
 Transition rocks, . . . . . 78 
 
 Tissue, cellular . . . . .95 
 
 Tissue, woody . . . ... 95 
 
 Tissue, vasiform . . . .95 
 
 Tissue, vascular ..... 95 
 
 Tissue, laticiferous . . ... .96 
 
 Tendrils, . 120 
 
INDEX. 279 
 
 Trade winds, -. . . ... . 144 
 
 Trachyte, ..... 83 
 
 Tap root, . . . . . .103 
 
 Tuberous roots, . . . . * 104 
 
 Trees, 107 
 
 Temperature, table of . . . . 130 
 
 Thunder, ...... 141 
 
 Thunder, cause of . . . . 141 
 
 Tornado, . . . . . .145 
 
 Tillage, varieties of . . . . 177 
 
 Tillage, objects of . . . .177 
 
 Trench ploughing, . . . . 178 
 
 Tanner's bark as manure, . . . .198 
 
 Top dressing for crops, . . . . 199 
 
 u 
 
 Urine as manure, . . . . .196 
 
 Urine, waste and value of . . . . 197 
 
 V 
 
 Vein, 76 
 
 Variety defined, ..... 94 
 
 Veins, ...... 112 
 
 Venation, . . . . . . 112 
 
 w 
 
 Water, . . . . . .46 
 
 Wax, ...... 61 
 
 Wood, 107 
 
 Weather, ...... 125 
 
 Whirlwind, . . . . . .145 
 
 Warping, . . . . . 179 
 
 Wood ashes as manure, .... 206 
 
 Wheel and axle, . . . . , 234 
 
 Wedge, ...... 234 
 
 Winds, .... . . 142 
 
 Wool as manure, . . . , .192 
 
 x 
 
 Xanthine, ..... 64 
 
 
 Yeast, .... 
 
 
 

67829 
 
 UNIVERSITY OF CALIFORNIA LIBRARY