ation of sensorial power; as its production in these organs, which
are subject to perpetual activity, is continued during their quiescence,
and is in consequence accumulated.

While, on the contrary, where those vital organs act too forcibly by
increase of stimulus without a proportionally-increased production of
sensorial power in the brain, it is evident, that a great deficiency of
action, that is torpor, must soon follow, as in fevers; whereas the
locomotive muscles, which act only by intervals, are neither liable to so
great accumulation of sensorial power during their times of inactivity, nor
to so great an exhaustion of it during their times of action.

Thus, on going into a very cold bath, suppose at 33 degrees of heat on
Fahrenheit's scale, the action of the subcutaneous capillaries, or glands,
and of the mouths of the cutaneous absorbents is diminished, or ceases for
a time. Hence less or no blood passes these capillaries, and paleness
succeeds. But soon after emerging from the bath, a more florid colour and a
greater degree of heat is generated on the skin than was possessed before
immersion; for the capillary glands, after this quiescent state, occasioned
by the want of stimulus, become more irritable than usual to their natural
stimuli, owing to the accumulation of sensorial power, and hence a greater
quantity of blood is transmitted through them, and a greater secretion of
perspirable matter; and, in consequence, a greater degree of heat succeeds.
During the continuance in cold water the breath is cold, and the act of
respiration quick and laborious; which have generally been ascribed to the
obstruction of the circulating fluid by a spasm of the cutaneous vessels,
and by a consequent accumulation of blood in the lungs, occasioned by the
pressure as well as by the coldness of the water. This is not a
satisfactory account of this curious phaenomenon, since at this time the
whole circulation is less, as appears from the smallness of the pulse and
coldness of the breath; which shew that less blood passes through the lungs
in a given time; the same laborious breathing immediately occurs when the
paleness of the skin is produced by fear, where no external cold or
pressure are applied.

The minute vessels of the bronchia, through which the blood passes from the
arterial to the venal system, and which correspond with the cutaneous
capillaries, have frequently been exposed to cold air, and become quiescent
along wi