asses into the weakness of partial paralysis; then
suddenly or gradually, with or without convulsions, stupor sets in,
deepening into coma, and death from arrested respiration is the final
result. If the temperature of the animal be tested from time to time
during the exposure, it will be found to rise steadily, and the severity
of the symptoms will be directly, and in any one species constantly,
proportional to the intensity of the bodily heat.

The nervous system of man apparently resists the action of heat, but in
reality it does not do so. Man, it is true, is the only animal that can
thrive almost equally amidst arctic snows and in tropical jungles. This
is not, however, because his nervous system lacks sensitiveness, but
because he has the power of heating or cooling his body in such a manner
that its temperature is comparatively unaffected by that of the
surrounding air. Man might be well defined as the naked sweating animal.
In the north he strips the bear and the fox of their coat to keep him
warm; in the south his own skin acts as a refrigerator. The dog has a
few sweat-glands about the mouth--man has two millions densely covering
his body. In the horse exposed to heat the hair soon becomes wet and
matted, interfering very greatly with evaporation; in man the bare skin
offers an excellent surface, from which the perspiration passes off
almost as fast as formed. Evaporation, conversion of a liquid into a
vapor, means a steady conversion of sensible heat into what was
formerly called latent heat, but what we now know to be repulsive force:
the heat-energy of the body is lost in driving the particles of sweat
asunder in the form of vapor.

It is possible, however, to have a temperature which even a Hindoo
cannot resist. When a man is exposed to such a heat his bodily
temperature rises, and as it rises the symptoms of fever develop
precisely as they do in the lower animals--sometimes slowly, sometimes
suddenly--with disturbances of the respiration, circulation and
innervation precisely similar to those already noticed as occurring in
the dog, the cat and the rabbit. Sunstroke, or thermic fever, is
generally believed to be instantaneous in its onset, but the wide
experience of the English in India has shown that whilst in some cases
it is thus sudden in its development, in others it is a slow process,
and probably in almost all cases close observation would have revealed
the existence of premonitions.

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