economy. It is clear that the gelatine must be expelled from
the body in a form different from that in which it was introduced as
food.

When we consider the transformation of the albumen of the blood into
a part of an organ composed of fibrine, the identity in composition
of the two substances renders the change easily conceivable. Indeed
we find the change of a dissolved substance into an insoluble organ
of vitality, chemically speaking, natural and easily explained, on
account of this very identity of composition. Hence the opinion is
not unworthy of a closer investigation, that gelatine, when taken in
the dissolved state, is again converted, in the body, into cellular
tissue, membrane and cartilage; that it may serve for the
reproduction of such parts of these tissues as have been wasted, and
for their growth.

And when the powers of nutrition in the whole body are affected by a
change of the health, then, even should the power of forming blood
remain the same, the organic force by which the constituents of the
blood are transformed into cellular tissue and membranes must
necessarily be enfeebled by sickness. In the sick man, the intensity
of the vital force, its power to produce metamorphoses, must be
diminished as well in the stomach as in all other parts of the body.
In this condition, the uniform experience of practical physicians
shows that gelatinous matters in a dissolved state exercise a most
decided influence on the state of the health. Given in a form
adapted for assimilation, they serve to husband the vital force,
just as may be done, in the case of the stomach, by due preparation
of the food in general.

Brittleness in the bones of graminivorous animals is clearly owing
to a weakness in those parts of the organism whose function it is to
convert the constituents of the blood into cellular tissue and
membrane; and if we can trust to the reports of physicians who have
resided in the East, the Turkish women, in their diet of rice, and
in the frequent use of enemata of strong soup, have united the
conditions necessary for the formation both of cellular tissue and
of fat.

LETTER XI

My dear Sir,

In the immense, yet limited expanse of the ocean, the animal and
vegetable kingdoms are mutually dependent upon, and successive to
each other. The animals obtain their constituent elements from the
plants, and restore them to the water in their original form, when
they again serve as nourishment t