shall enable it, within given bounds, (1) to move its own machinery;
(2) to call forth, at will, a limited measure of extra force which has
been lying latent in its organism; and (3) to supply a fluctuating
loss that must be conveyed away by contact with the surrounding air,
by the earth, and by other bodies that it may touch, and which are
colder than itself. There is thus produced in the body, _applied_
force, _reserve_ force, and _waste_ force, and these distributions of
the whole force generated, when correctly applied, maintain the
perfect organism in such balance that life is true and steady. So much
active force carries with it the power to perform so much labor; so
much reserve force carries with it the power to perform a measure of
new or extra labor to meet emergencies; so much waste force enables
the body to resist the external vicissitudes without trenching on the
supply that is always wanted to keep the heart pulsating, the chest
breathing, the glands secreting or excreting, the digestive apparatus
moving, and the brain thinking or absorbing.

Let us, even in the prime of manhood, disturb the distribution of
force ever so little, and straightway our life, which is the resultant
of force, is disturbed. If we use the active force too long, we become
exhausted, and call on the reserve; if we continue the process, the
result is failure more or less perfect, sleep, and, in the end, the
last long sleep. Let us, instead of exhausting the force, cut it off
at the sources where it is generated; let us remove the carbon or coal
that should go in as fuel food, and we create prostration, and in
continuance a waning animal fire, sleep, and death; or let us, instead
of removing or withdrawing the supply of fuel, cut off the supply of
air, as by immersion of the body in water, or by making it breathe a
vapor that weakens the combination of oxygen with carbon--such a vapor
as chloroform--and again we produce, at once, prostration, sleep, or