the
sensation of pain constitute convulsions and madness; and are distinguished
from the muscular actions owing to increased sensation, as in sneezing, or
coughing, or parturition, or ejectio feminis, because they do not
contribute to dislodge the cause, but only to prevent the sensation of it.
In two cases of parturition, both of young women with their first child, I
have seen general convulsions occur from excess of voluntary exertion, as
above described, instead of the actions of particular muscles, which ought
to have been excited by sensation for the exclusion of the fetus. They both
became insensible, and died after some hours; from one of them the fetus
was extracted in vain. I have heard also of general convulsions being
excited instead of the actions of the musculi acceleratores in the ejectio
feminis, which terminated fatally. See Class III. 1. 1. 7.

These violent exertions are most frequently excited in consequence of those
pains, which originate from defect of the action of the part. See Sect.
XXXIV. 1. and 2. The pains from excess and defect of the action of the part
are distinguishable from each other by the former being attended with
increase of heat in the pained part, or of the whole body; while the latter
not only exist without increase of heat in the pained part, but are
generally attended with coldness of the extremities of the body.

As soon as these violent actions of our muscular or sensual fibres for the
purpose of relieving pain cease to be exerted, the pain recurs; whence the
reciprocal contraction and relaxation of the muscles in convulsion, and the
intervals of madness. Otherwise these violent exertions continue, till so
great a part of the sensorial power is exhausted, that no more of it is
excitable by the faculty of volition; and a temporary apoplexy succeeds,
with snoring as in profound sleep; which so generally terminates epileptic
fits.

When these voluntary exertions become so connected with certain
disagreeable sensations, or with irritations, that the effort of the will
cannot restrain them, they can no longer in common language be termed
voluntary; but nevertheless belong to this class, as they are produced by
excess of volition, and may still not improperly be called depraved
voluntary actions. See Sect. XXXIV. 1. where many motions in common
language termed involuntary are shewn to depend on excess of volition.

When these exertions from excess of volition, which in common lan