s preparation and concentration of
mineral food in the surface-soil.

"The clover on the hillside field, on the whole, turned out a very good
crop; and, as the plant stood the winter well, and this field was left
another season in clover, without being plowed up, I availed myself of
the opportunity of making, during the following season, a number of
experiments similar to those of the preceding year. This time, however,
I selected for examination, a square yard of soil, from a spot on the
brow of the hill, where the clover was thin, and the soil itself stony
at a depth of four inches; and another plot of one square yard at the
bottom of the hill, from a place where the clover was stronger than that
on the brow of the hill, and the soil at a depth of six inches contained
no large stones.

SOIL NO. 1. (CLOVER THIN), ON THE BROW OF THE HILL.

"The roots in a square yard, six inches deep, when picked out by hand,
and cleaned as much as possible, weighed, in their natural state, 2 lbs.
11 oz.; and when dried on the top of a water-bath, for the purpose of
getting them brittle and fit for reduction into fine powder, 1 lb. 12
oz. 31 grains. In this state they were submitted as before to analysis,
when they yielded in 100 parts:

Composition Of Clover-Roots, No. 1, (From Brow Of Hill).

Moisture 4.34
Organic matter[A] 26.53
Mineral matter 69.13
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[A] Containing nitrogen .816
Equal to ammonia .991

"According to these data, an acre of land will yield three tons 12 cwts.
of nearly dry clover-roots, and in this quantity there will be about 66
lbs. of nitrogen. The whole of the soil from which the roots have been
picked out, was passed through a half-inch sieve. The stones left in the
sieve weighed 141 lbs.; the soil which passed through weighing 218 lbs.

"The soil was next dried by artificial heat, when the 218 lbs. became
reduced to 185.487 lbs.

"In this partially dried state it contained:

Moisture 4.21
Organic matter[A] 9.78
Mineral matter[B] 86.01
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