produce such an influence on the body by sudden extraction of its heat
as to destroy it at once by the mere act. If a man could be surrounded
with frozen mercury he would die instantaneously, as from shock, by
the immediate extraction of his heat. But in ordinary cases, and under
ordinary circumstances, the mere rapid extraction of waste heat is not
sufficient to account for all the mischief produced by a low
temperature; for by artificial warmth and non-conducting garments, we
counteract the influence, and that, too, in a manner which proves
pretty successful. We may, therefore, leave this element of extraction
of heat as a most important, but not as the sole, agent of evil.


SUPPRESSED OXIDATION.

The second element is the effect on the process of oxidation of blood
under the influence of cold. We all are aware that if a portion of
dead animal or vegetable matter be placed at a low temperature, it
keeps for a considerable time; and we have evidence of dead animals
which, clothed in thick ribbed ice, have been retained from
putrefaction for centuries. Hence we say that cold is an antiseptic as
alcohol is, and chloroform, and ammonia, and other similar bodies.
Cold is an antiseptic then, but why? Because it prevents, even in the
presence of a ferment, the union of oxygen gas with combustible
matter. The molecules of oxygen, in order that they shall combine, and
in their combination evolve heat, require to be distributed, and to be
distributed by the form of motion known as heat; deprive them of this
activity, and they come into communion with themselves, are attracted
to each other, and lose to the extent of this attraction their power
of combining with the molecules of other bodies for which they have an
affinity. In an analogous, but more obvious way, we may see the same