330 Wells on the Soils of the Scioto Valley, Ohio. 
measurement, did not exceed one sixtieth of an inch in 
diameter. The soil was then broken in a porcelain mortar, 
care being taken that the dried particles only were crushed, 
without triturating any of the silicates, or earthy matter. One 
hundred parts of six samples of soil, representing a particular 
district, so treated, left upon the sieve before described 
the following small quantities of coarse residue; of which it 
should be stated, that it was made up in part of vegetable 
fibre and undecomposed organic matter. Of soil No. 1, seven 
parts in one hundred remained upon the sieve ; of No. 2, one 
and six tenths; of No. 3, a subsoil, from twenty to thirty 
parts ; of No. 4, six and three tenths ; of No. 5, one and five 
tenths; of No. 6, eight parts in one hundred. 
The remarkable comminution of the particles of these 
soils, gives us at once a clue to the secret of their great fer- 
tility. With this fineness, an increased power is at once 
given to a soil for the absorption, retention, and condensation 
of moisture, carbonic acid, and ammonia ; an opportunity for 
the free permeation of atmospheric air; a facility to the root- 
lets of plants for extension, and a consequently increased 
facility for receiving and appropriating nourishment. Indeed 
a soil but scantily provided with the inorganic constituents 
deemed necessary for the support of vegetable life, but gifted 
with this’ fineness of the elementary particles, must possess 
great elements of fertility. In fact, I consider the existence 
of a large proportion of finely divided matter in a soil o 
almost as much importance, so far as regards its fertility, as 
its chemical constitution. It must be also evident that a so! 
composed in great part of silicious matter, (as many of the 
fertile western soils are,) may, if the particles possess sufficient 
fineness, assume to a considerable extent the good properties 
and character of an aluminous soil, without its bad ones. AS 
an illustration of this, I would state, that one of the best 
tobacco soils upon the Island of Cuba, some time since exa- 
mined by Dr. A. A. Hayes, of Boston, was found to contain 
ninety per cent. of the peroxide of iron. And yet this soil, 
