Nature's requirements. It is enough for all the brute creation. As men,
and as thinkers, we need something more.

In all the lower orders of creation the normal state is preserved.
Health is the rule, and sickness the rare exception. Demand and supply
are exactly balanced. The contraction of the voluntary muscles, and the
expenditure of nervous power consequent on locomotion, the temperate
use of the five senses, and the quiet, regular performance of the great
organic processes, limit the life and the waste of the creature. But
when the brain expands in the dome-like cranium of the human being, a
new and incessant call is made on the reparative forces. The nervous
system has its demands increased a hundred-fold. We think, and we
exhaust; we scheme, imagine, study, worry, and enjoy, and
proportionately we waste.

In the rude and primitive nations this holds good much less than among
civilized people. Yet even among them, the faculties whose possession
involves this loss have been ever exercised to repair it by artificial
means. In the busy life of to-day how much more is this the case!
Overworked brains and stomachs, underworked muscles and limbs, soon
derange the balance of supply and demand. We waste faster than
enfeebled digestion can well repair. We feel always a little depressed;
we restore the equilibrium temporarily by stimulation,--some with
alcohol and tobacco, others with coffee and tea. Now it is to these
last means of supply that the name has been given of "accessory foods."

"Accessories are those by whose use the moulting and renewing (that is,
the metamorphosis) of the organic structures are modified, so as best
to accommodate themselves to required circumstances. They may be
subdivided into those which _arrest_ and those which _increase_