FERTILIZERS. 
233 
When those matters haveTeen combined in the bodies of vegetables they are fitted to become 
the food of animals; they are not absolutely changed into any thing else ; there is a recombi¬ 
nation of some bodies, and certain additions to the mineral substances which are derived from 
the vegetable kingdom. These organic bodies are formed by the union of oxygen, carbon, 
nitrogen and hydrogeif^ elements which play an important part in all organized bodies. Though 
these elements form constituent parts of the earth’s crust, yet it would seem, from certain 
facts, that the vegetable kingdom is the field in which they are combined and prepared, and 
putin a proper state to become nutriment for animals; yet it is not by any means certain 
but the combinations may take place in the interior and exterior of the earth. First, there 
is an immense supply of carbon, from the carbonates of the earths and alkalies. The primi¬ 
tive limestone, Avhich I have described in the volume containing a description of the rocks 
of the Second Geological District of New T -York, and which was first brought to the notice 
of geologists by myself, in the reports for that district, is a rock occupying a position simi¬ 
lar to granite, and hence must exist deep in the earth. Hence it is exposed to all those 
chemical agencies which are competent to decompose the rock and set free the carbonic acid, 
which in escaping can hardly fail to be brought to the surface. It will also form new combi¬ 
nations ; it will be absorbed by water, soils, etc. Carbonic acid then may be supplied in the 
earliest states of the earth, and as carbon constitutes, in all vegetables, a very large propor¬ 
tion of their solid parts, it is essential to them ; and however much may be required for this 
purpose, it appears from observation that the supply from the source I have named, must 
equal the wants of a kingdom. Carbonic acid, too, is continually escaping from the earth in 
some districts, showing clearly the probability of the position I have taken in regard to the 
carbonates in general, and the primary limestone in particular. Of nitrogen it may be said, 
too, that there is really no necessity for maintaining that its only supply is from organized bo¬ 
dies, inasmuch as ammonia, too, is a product of volcanic action, or of the chemical reactions 
which are constantly taking place in the interior of the earth. 
Of oxygen and hydrogen it is scarcely necessary to attempt to point out the sources of 
supply, in any state of the earth’s crust, inasmuch as oxygen forms a very large proportion of 
the crust itself, forming with all bodies combinations from which a supply for the vegetable 
kingdom might be derived. Water is one of the great sources of hydrogen ; it is also a con¬ 
stituent of many other bodies, and hence the supply of the four organic elements, those which 
seem to be required to constitute an organ, could have been furnished directly from the interior 
of the earth, or from its surface, prior to the growth of a single vegetable ; and the supply 
was great. Hence, too, it seems that the hypotheses of some chemists, in regard to the supply 
of vegetation in its first beginning upon the earth, of these bodies, are unnecessary : it is not 
necessary at least, to maintain that vegetation was scanty, and confined to a few of the lower 
tribes of plants, because fertilizers, those especially which constitute the main bulk of organs, 
could not be obtained. Other causes were in operation, which restrained the growth of vege¬ 
tables ot the highest order; for if we may form an opinion of the character of the vegetation 
of the early periods, it was mostly marine. Rocks of the Taconic System contain the first 
[Agricultural Report — Vol. iii.] 30 
