voluntary actions, and in the exertions of our organs of sense, in
consequence of the irritations occasioned by external objects had been
suspended, and a consequent accumulation had taken place.

In like manner the exertion of the sensorial power less than natural in one
part of the system, is liable to produce an increase of the exertion of it
in some other part. Thus by the action of vomiting, in which the natural
exertion of the motions of the stomach are destroyed or diminished, an
increased absorption of the pulmonary and cellular lymphatics is produced,
as is known by the increased absorption of the fluid deposited in them in
dropsical cases. But these partial quiescences of sensorial power are also
sometimes attended with other partial quiescences, which sympathize with
them, as cold and pale extremities from hunger. These therefore are to be
ascribed to the associations of sympathy explained in Sect. XXXV. and not
to the general accumulation of sensorial power.

2. A quantity of stimulus less than natural, applied to fibres previously
accustomed to perpetual stimulus, is succeeded by accumulation of sensorial
power in the affected organ. The truth of this proposition is evinced,
because a stimulus less than natural, if it be somewhat greater than that
above mentioned, will excite the organ so circumstanced into violent
activity. Thus on a frosty day with wind, the face of a person exposed to
the wind is at first pale and shrunk; but on turning the face from the
wind, it becomes soon of a glow with warmth and flushing. The glow of the
skin in emerging from the cold-bath is owing to the same cause.

It does not appear, that an accumulation of sensorial power above the
natural quantity is acquired by those muscles, which are not subject to
perpetual stimulus, as the locomotive muscles: these, after the greatest
fatigue, only acquire by rest their usual aptitude to motion; whereas the