12 E. W. Hilgard—=Silt Analyses of Soils and Subsoils. 
indeed, the ioe process be exceedingly slow. It is not, 
therefore, as difficult to cultivate as would be supposed from 
the sum of its fine ingredients. Nor is it nearly as much sub- 
ject to denudation as “the two preceding soils, the mass formed 
by its contact with water being too tough and coherent to be 
readily moved by flowing water. But being very little per- 
vious, it is liable to injury in wet seasons; while in dry ones, 
the cracks formed by the contraction of the subsoil prove dis- 
astrou 
No. 330 i is the soil prevalent in the Flatwoods (see above), and 
is the direct result of the disintegration of the old Tertiary clays. 
It is a very heavy, intractable soil, yielding good crops only in 
very favorable years, as it is exte eedingly liable to injury both 
from wet and dry seasons, and can be tilled only within a very 
limited range of condition as to moisture. Water will stagnate 
on it for weeks, and a late, wet spring will, sometimes, altogether 
prevent the pitching of crops. But it is not at all liable to 
— 
246 is likewise the direct result of the disintegration of 
(highly ferruginous) Tertiary clays. Notwithstanding its high 
percentage of ‘‘ clay,” it is more easily tilled than the preceding 
one, although acquiring a stony hardness when dried slowly. 
The fact that among its 40°25 per cent of “clay” there are 10°6 
of ferric oxide, and that it contains ‘8 per cent of lime, explains 
both its easier tillage and greater thriftiness, as com ared with 
the preceding. It is a pretty “safe” soil, and quite productive ; 
not at all subject to denudation. 
O. is the extreme of a clay soil, so as to be almost unfit 
for tillage, and directly available for the potter’s lathe. It bears, 
nevertheless, a pretty good growth of timber, chiefly pine. _ Its 
popular name is derived from the peculiar aspect assumed by 
its surface, when after a drought which has caused fissures (as 
much as an inch wide) to be formed, a rain causes the edges 
first to crumble off into the open cracks, and then swell; which, 
with the subsequent swelling of the mass itself, compels it to 
bulge up. The result is a hillocky surface, which is popularly 
likened to ‘hog wallows.” ‘The soil is, at present, practically 
worthless. 
The next, No. 390, is very similar in its (ostensible) physical 
composition to the preceding, Yet while the “hog-wallow ” soil 
is among the most worthless of the wails of Mississippi, shit 
the celebrated “buckshot” soil of the Mississippi bottom, is 
among the most valuable. True, the chemical composition o 
the buckshot soil is greatly superior to that of the other yet 
it could not rank as highly as it does, as a cotton soil especially, 
but for the fact sree (in = with the prairie soil, 173, 
above described) it possesses the property of crumbling or 
