would brave with impunity in their active
and waking state. Insufficient food, in point
of quantity, both in men and animals,
produces a decided diminution of temperature
and of power to resist cold. M. Chossat was
cruel enough to starve pigeons, guinea-pigs,
and other innocent creatures, to death; and
he found that their temperature gradually
diminished until the moment when their
sufferings were at end; the greatest and most
rapid diminution of their vital heat occurred
on the last day of their life, both with birds
and mammifers. In fact, they really died of
cold—as M. Chossat coolly remarks.

Living animals have the power of resisting
extreme temperatures, for a certain time,
until their powers give way under continued
adverse influences, and death ensues. Heat
is resisted by the cooling effects of evaporation
from the skin. Thus, reapers support
the fierceness of an August sun by imbibing
an abundance of liquid, which furnishes the
material of perspiration. In the same way,
copious draughts—to an amount of gallons
per day, incredible to persons who sit quietly
at home in their parlours—alone enables
glass-workers, copper-smelters, iron-founders,
and the like, to bear the scorching glare, the
radiated heat, and the burning atmosphere
in which they are enveloped during their
hours of toil. Blagden, who took a fancy
to making personal experiments inside a
heated stove, felt excessively uncomfortable
at his first entrance, but was all right
as soon as a profuse sweat broke forth
throughout the entire surface of his skin.
Heat, which is very bearable in a dry
atmosphere (that is in an atmosphere which
readily absorbs evaporation), becomes oppressive
when the air is saturated with moisture,
and is unbearable if endured in the form of
a hot bath, which necessarily precludes, all
perspiration. Cold, we have seen, is defied
by warm-blooded animals, so long as they are
animals and not dead bodies, by maintaining
an ever-burning fire within themselves.

There are certain creatures, however, such
as dormice, loirs, and marmots, which
approach the condition of the inferior races;
instead of keeping up their active functions
by respiration, they yield to the benumbing
influence of winter, become torpid, and fall
into a hibernal lethargy. The circulation in
hibernating animals is languid and retarded,
but still it continues to a slight degree.
Mangili saw with the microscope the blood
circulating in the capillaries of a torpid bat's
wing. Hibernating mammifers, in a lethargic
state, although they apparently behave like
dead bodies, are dead only in appearance.
Under the influence of a temperature several
degrees above the freezing point, their
sensibility, their usual circulation, and the
mechanical and chemical phenomena of
respiration, are re-established. If the air
around them becomes warmer still, they
awake completely, and recover the full
exercise of all their functions. If, on the
other hand, they are kept too long under the
influence of a too low temperature, as they
no longer absorb oxygen, so they no longer
generate heat; they then cool like inert
bodies, but slowly, because their tissues are
bad conductors. Their extremities are the
first to freeze; little by little congelation
gains ground, till it reaches the organic
centres. To natural lethargy succeeds death
by cold, accompanied by all the anatomical
disorders which take place in all animals
under similar circumstances.

By the very reason of the imperfectness,
or rather the simplicity of their organisation,
the inferior animals resist much longer and
better than hibernating mammifers, the
effects of very low temperatures. Facts
have been observed which demonstrate that
not only insects, but even vertebrate
animals, are able to support a veritable congelation,
without its resulting in death. The
eggs of insects adhering to the twigs of trees,
often bear uninjured the severest frosts.
Caterpillars have been frozen stiff and hard,
so that they caused a glass to ring when let
fall into it, and yet have come to life again
by being brought into a warm chamber.
Monsieur Gavarret, one of the Professors at
the Faculty of Medicine of Paris—to whose
able work we are indebted for the substance
of this article—states an additional case,
which we cannot read without a dubitating
shake of the head. For some time past, it
appears, it has been the practice in Russia
and the northern part of the United States,
to transport to a distance certain fish frozen
as stiff as stakes, and in a veritable state of
thorough congelation; nevertheless, it suffices
to plunge them into water at a temperature
a little above the freezing-point, to restore
these much enduring fish to the full enjoyment
of all their faculties. We know that
toads have been frozen till they were hard
and stiff like frozen meat; all their limbs
were inflexible and brittle; and, when
broken, there issued not one droplet of blood
from the wound. Nevertheless, when put
into slightly-warmed water, in ten minutes
they completely came to life again. Toads
are undoubtedly gifted with wonderful
tenaciousness of life; in respect to the fish,
the great difficulty is the absence of the
specific names of the Russian and American
frost-bitten, but, in spite of that, resuscitated
patients.

A WESTERN CAMPAIGN.

ON an April morning, in the year last
ended, cannon were fired thrice from the
ramparts of Fort Snelling, and re echoed a
hundred times from the rocks of the Mississippi
valley. It was the signal for all soldiers on
leave of absence to repair to quarters. The
wind being west, the guns could be heard in
the streets of Saint Paul, and obedient bands of