1F359, 360] 



INGREDIENTS OF SOILS AND PLANTS. 



207 



under the above head, any thing more than the merest outline of the doc- 

 trine of Agricultural Chemistry. In the final Report, it might be proper to treat 

 of the subject more at length ; for the present, I shall confine myself to what is 

 absolutely necessary for the useful understanding of the matter contained in the 

 present pages. 



359. Scientific and Technical Terms.— It may be justly expected that in 

 writing for the benefit of the mass of the people, the use of technical terms 

 should be avoided as much as possible. On the other hand, it is vain to expect, 

 in entering upon any new field of knowledge whatsoever, to escape the necessity 

 of learning some new words or expressions. This is unavoidable, and in the 

 very nature of things ; for whenever we direct our special attention to any olject, 

 we find it to consist of distinct parts, which a merely general, cursory glance 

 failed to detect. These parts are so many new conceptions or ideas, and new 

 ideas, as a matter of course, require new luords for their expression. 



This is quite as true of the arts and crafts of every day, as of the exact sciences. 

 The language which the sailor uses in describing his vessel, is not more intelli- 

 gible to the uninitiated "landsman." than a chemical formula would be to the 

 sailor himself; the printer, the tailor, the shoemaker, the blacksmith — all have 

 their peculiar terms of trade. If the majority of men, while perfectly at ease 

 with reference to what the tailor styles his "goose," stand appalled at the "big 

 words" of chemical or geological terminology, it is not because the former term 

 is more expressive of its object than the latter, but simply because tailors are 

 more numerous than chemists, and their calling more ancient. 



In this respect, agriculturists enjoy an advantage over all other occupations ; 

 their technical terms are known and understood by an overwhelming majority 

 of mankind, not only because they themselves form so numerous a class, but 

 also because the products o'' their labor are t e prime necessities of life, which 

 all feel deeply interested in, and with wh eh, a*- well as with the means employed 

 to produce them, all are consequently conversant 



360. In t G!Ikhii<:nts ok Soils — Ki^kmknts. — Anciently, no separate ingredients 

 were distinguished in so Is ; "earth" was regarded as a simple, an element, which 

 might, to he sure, be slightly modified here and there, yet was essentially the 

 same everywhere. Later researches have gradually resolved soils, rocks and 

 whi proceeds from them, into a number of substances, which as yet have 

 resisted all etforts at a further decomposition. These substances, most of which, 

 as well as their combinations, are unknown to common life, have received new 

 names, so fur as tins was necessary ; we call them elements, supposing that they 

 are incapable of being resolved into any simpler constituents. 



Ch mists are, at the present tune, acquainted with sixty-four elements; but 

 among this multitude, only sixteen or sevemeen claim the attention of the 

 agriculturist, as being ingredients of his soils as well as of the products which 

 They are the following : 



he draws therelrom. 

 f 

 Oxygen. 

 II 'i 'rogen. 

 Nitrogen. 

 Carbon. 

 Silicon. 

 £ j Sulphur. 

 -g Chlorine. 

 S j Lluorine. 

 g j Phosphorus. 



©:3 

 to <l 





Potassium. 

 Sodium. 

 { Calaum. 

 Magnesium. 

 Aluminium, 



Heavy Metals. 



5 Manganese. 

 (Iron. 



To the first class of this list may b« added Iodine, and to the last, Copper ; 

 since these substances are found to be very generally present, though in very 

 minute quantities. 



