ils,
depends on the kind of sand. On some sand they rot very badly, on others
hardly at all. Sandy soils differ very materially: some are almost pure
silex; while others are filled with a fine dust, and, although
apparently loose, are much more nearly impervious to the air than
heavier soils; on the former, nearly all will decay, and on the latter,
most will be preserved.

Look at the immense potato crops near Rochester, N. Y., on sandy land.
We have personally examined it, and find it to be filled with dust, that
excludes the air, and saves the potato from rot. Why, then, is a heavy
clay useless for potatoes? Is not clay a very tight soil? Unbroken it
is; but, when plowed, it is always left in larger particles than other
land--it is but seldom pulverized. The spaces between the particles are
all open to the free action of the air; hence, instead of being close,
it is one of the most open of all our soils. This confirms the theory.

The influence of manuring land is still another confirmation. We are
directed not to manure our land for potatoes when the disease prevails.
It is said we can raise no sound potatoes on rich land when the rot is
abroad. This is an error. The richness of the soil does not promote the
disease; but if any kind of manure be applied that, from its bulk and
coarseness, keeps the soil open to the air, the potatoes will rot. But
fertilize to the highest extent, in any way that does not make the soil
too open, and let in the air, and the crop will be greatly increased
with perfect safety. Thus, this theory, like every truth, perfectly fits
in all its bearings.

There is, then, no perfect remedy for the disease but in the power of
Him who can purify the atmosphere. Numerous remedies and preventives
have been recommended, by those who suppose they have tried them with
success. But in other localities and soils, all their remedies have
failed, as will all others that will yet be discovered. A careful
examination of the texture of the soils, upon the principles here
indicated, and a repetition of their experiments, will show the
discoverers that their success depended upon their soils, while others
failed in using the same remedies on other soils. The practical uses of
this theory are obvious. When the disease is abroad, we should select
soil that excludes, as much as possible, the atmosphere, and plant
_deep_; on all land not liable to have water stand on the subsoil. Do
not be deceived into the beli