ce in the intestinal canal,
even its simple passage through the canal; conserves the electrical
activity of the intestinal nerves and thus influences the whole
sympathetic nervous system.

This brief review, cursory as it is, of the function of the minerals in
the renewal of substances undergoing tissue change, makes it clear that
our daily food must contain a sufficient quantity of them if healthy
metabolism is to be maintained.

Chemically considered the human body is one individual whole, its
characteristic chemical basis being gelatine. Lieut. C.E. McDonald,
U.S.A. Medical Corps, recognized this when he recently wrote: "The
similarity of chemical compositions explains why, when any particular
region falls a prey to chemical decomposition, others quickly become
affected."

Oxygen gas is the medium through which chemical combustion is carried on
in the body for the purpose of preparing materials to enter into its
composition. The mineral salts already named not only form the solid
basis of the various tissue but also serve as conductors or insulators
of electricity in the body. The absence of one of them for a protracted
period is sufficient to explain widespread degeneration in the system.

In view of the fact that these various minerals play an indispensable
part in healthy metabolism it is imperative that a sufficiency of them
should be supplied in proper proportion in our daily food. It is
imperative, if we desire to retain or to restore health to the body.

These mineral elements are to be found in the first instance in the
earth, but they are of no use to the body in that form. We cannot digest
and assimilate inorganic matter no matter how finely it may be
pulverized. But plants can assimilate them from the earth and organize
them in such form as to make them easily assimilable by animals and man.

If the soil on which our food is produced is itself deficient in some of
these elements, our food must also lack them. If, moreover, we cannot
for any reason add the missing elements to the soil, we must supply them
to the human system in the shape of prepared nutritive salts. It is
preferable, of course, that our food should contain all of the elements
necessary for the proper nourishment of the body.

Thus we are forced to return to consideration of the soil. It is an
established fact that our fields were originally formed from decayed
rock, and analysis shows that this primitive rock contains the same
miner