t of
combining them together in a thousand ways, and of rendering even the
mineral kingdom subservient to its refinements.

EMILY.

Nor is this all; for our delicacies are collected from the various
climates of the earth, so that the four quarters of the globe are often
obliged to contribute to the preparation of our simplest dishes.

CAROLINE.

But the very complicated substances which constitute the nourishment of
animals, do not, I suppose, enter into their system in their actual
state of combination?

MRS. B.

So far from it, that they not only undergo a new arrangement of their
parts, but a selection is made of such as are most proper for the
nourishment of the body, and those only enter into the system, and are
animalised.

EMILY.

And by what organs is this process performed?

MRS. B.

Chiefly by the stomach, which is the organ of digestion, and the prime
regulator of the animal frame.

_Digestion_ is the first step towards nutrition. It consists in reducing
into one homogeneous mass the various substances that are taken as
nourishment; it is performed by first chewing and mixing the solid
aliment with the saliva, which reduces it to a soft mass, in which state
it is conveyed into the stomach, where it is more completely dissolved
by the _gastric juice_.

This fluid (which is secreted into the stomach by appropriate glands) is
so powerful a solvent that scarcely any substances will resist its
action.

EMILY.

The coats of the stomach, however, cannot be attacked by it, otherwise
we should be in danger of having them destroyed when the stomach was
empty.

MRS. B.

They are probably not subject to its action; as long, at least, as life
continues. But it appears, that when the gastric juice has no foreign
substance to act upon, it is capable of occasioning a degree of
irritation in the coats of the stomach, which produces the sensation of
hunger. The gastric juice, together with the heat and muscular action of
the stomach, converts the aliment into an uniform pulpy mass called
chyme. This passes into the intestines, where it meets with the bile and
some other fluids, by the agency of which, and by the operation of other
causes hitherto unknown, the chyme is changed into chyle, a much thinner
substance, somewhat resembling milk, which is pumped by immense numbers
of small absorbent vessels spread over the internal surface of the
intestines. These, after many circumvolutions, gradually meet an