that time they have a taste for oxygen. This
effete air, which men and animals exhale, so charged with carbonic acid,
the plants drink in through every pore. They take it from the mouth of
man, appropriate it to their daily uses, and in time render it back to
him mingled with other ingredients in wholesome fruit. Carbonic acid is
death when it combines with the blood,--as it does when we inhale
it; but not so when it enters the stomach in small quantities. One
inspiration of it is enough to make us dizzy,--as when we enter an old
well or stoop over a charcoal fire; but a draught of water fully
charged with it is exhilarating and refreshing, as we know by repeated
experiences at marble fountains that meet us on so many city-corners.

If plants had souls, they would be pure ones, since they can bear such
contamination and not be harmed,--nay, since even from such foul food
as we give them they can evolve results so beautiful. We give them our
cast-off and worn-out materials, and they return us the most beautiful
flowers and the most luscious fruits.

Beside carbonic acid, there are two other principal materials, which
are every day passing off in an effete state, though capable of being
transferred to the uses of plants. But when an animal dies, the whole
substance is then at Nature's disposal. We must set aside a great deal
of it for the ants and flies, who will help themselves in spite of us.
If any one has never seen a carcass rapidly disappearing under the
steady operations of the larvae of the flesh-fly, he has yet to learn
why some flies were made. The ants, too, carry it off in loads larger,
if not heavier, than themselves. But carcasses of animals may go to
decay, undisturbed by the ravages of these useful insects. That is, the
limited partnership of Oxygen, Hydrogen, & Co., under which they agreed
to carry on the operations of sheep, fox, or fish, having terminated
by the death of the animal, the partners make immediate use of their
liberty and go off in inorganic form in search of new engagements,
leaving sulphur, phosphorus, and the other subordinate elements of the
animal, to shift for themselves. They were in the employ of a sheep;
they will now carry on a man or an oak-tree, a colony of insects,
or something else. Under the form of carbonate of ammonia, the four
elements diffuse themselves through the air, or are absorbed by the
earth, and offer themselves at once to the roots and leaves of the
trees, as re