matters exist most largely). The
starchy matter in the interior of the grain, which is the least capable
of giving strength to the animal, is carefully separated, and used as
food for man, while the better portions, not being ground so finely, are
rejected. This one thing alone may be sufficient to account for the
fact, that the lives of men have become shorter and less blessed with
health and strength, than they were in the good old days when a stone
mortar and a coarse sieve made a respectable flour mill.

Another important fact concerning the ashes of plants is the difference
of their composition in different plants. Thus, the most prominent
ingredient in the ash of the potato is _potash_; of wheat and other
grains, _phosphoric acid_; of meadow hay, _silica_; of clover, _lime_;
of beans, _potash_, etc. In grain, _potash_ (or _soda_), etc., are among
the important ingredients.

[Of what advantage are these differences to the farmer?

Of what are plants composed?]

These differences are of great importance to the practical farmer, as by
understanding what kind of plants use the most of one ingredient, and
what kind requires another in large proportion, he can regulate his
crops so as to prevent his soil from being exhausted more in one
ingredient than in the others, and can also manure his land with
reference to the crop which he intends to grow. The tables of analyses
in the fifth section will point out these differences accurately.

FOOTNOTES:

[J] This pectic acid gelatinizes food in the stomach, and thus renders
it more digestible.

[K] See Johnston's Elements, page 41.

[L] Sifted through a fine cloth called a bolting cloth.

CHAPTER VIII.

RECAPITULATION.

We have now learned as much about the plant as is required for our
immediate uses, and we will carefully reconsider the various points with
a view to fixing them permanently in the mind.

Plants are composed of _organic_ and _inorganic_ matter.

[What is organic matter? Inorganic?

Of what does organic matter consist? Inorganic?

How do plants obtain their organic food?

How their inorganic?

How is ammonia supplied? Carbonic acid?]

Organic matter is that which burns away in the fire. Inorganic matter is
the ash left after burning.

The organic matter of plants consists of three gases, oxygen, hydrogen
and nitrogen, and one solid substance carbon (or charcoal). The
inorganic matter of plants consists of potash, soda, lime, mag