Wells on the Soils of the Scioto Valley, Ohio, 331 
which we might suppose would be barren, without the usual 
proportions of silicious and aluminous matter, is, on account 
of its great fineness, and the remaining ten per cent. of 
organic and inorganic constituents, enabled to yield the best 
crops upon the Island. 
These advantages derived from the fineness of the elementary 
particles, it is evident the Ohio soils will always possess, as it 
cannot be exhausted by any system of culture; and if due 
regard be paid to supplying them with sufficient quantities of 
organic and inorganic nutriment, they must and always will be 
unrivaled for fertility. 
An examination of the silicious, insoluble constituents of 
these soils, leads to the belief, that they have not been derived 
from the disintegration or decay of any underlying, or con- 
tiguous rocks, but from materials brought from a distance. 
The rocks of Ohio are for the most part carbonate of lime ; 
and yet in only one of the soils examined by me, namely, a 
subsoil, could the slightest trace of carbonic acid be detected. 
The method adopted for testing was by placing the soil in a 
favorable light upon a watch-glass, covering it with dilute warm 
acid and watching carefully for the appearance of efferves- 
cence. In this way the slightest trace of carbonic acid could 
not fail of being recognized. In the examination of the soils of 
Massachusetts by President Hitchcock, the same remarkable 
deficiency of carbonates, even in soils resting upon carbonate 
of lime rocks, was noticed. ‘The same conclusions have also, 
l understand, been arrived at by Dr. D. D. Owen from an 
examination of the soils of Iowa and Wisconsin. From these 
facts, I am led to believe, that the alkaline and earthy carbo- 
nates are to a much greater extent wanting in arable soils 
than is generally supposed. This supposition may perhaps 
be restricted to the northern portions of this country, wine 
have soils. resulting mainly from materials distributed by the 
drift agency. Where a soil containing considerable quan- 
tities of organic matter is tested for carbonates after ignition, 
they will generally be found; the crenates and apocrenates 
