become obedient sensation and to volition._ 2. _And the sensual
motions._

III. 1. _Other muscular motions are associated with the irritative
ones._ 2. _And other ideas with irritative ones. Of letters, language,
hieroglyphics. Irritative ideas exist without our attention to them._

I. 1. Many of our muscular motions are excited by perpetual irritations, as
those of the heart and arterial system by the circumfluent blood. Many
other of them are excited by intermitted irritations, as those of the
stomach and bowels by the aliment we swallow; of the bile-ducts by the
bile; of the kidneys, pancreas, and many other glands, by the peculiar
fluids they separate from the blood; and those of the lacteal and other
absorbent vessels by the chyle, lymph, and moisture of the atmosphere.
These motions are accelerated or retarded, as their correspondent
irritations are increased or diminished, without our attention or
consciousness, in the same manner as the various secretions of fruit, gum,
resin, wax, and, honey, are produced in the vegetable world, and as the
juices of the earth and the moisture of the atmosphere are absorbed by
their roots and foliage.

2. Other muscular motions, that are most frequently connected with our
sensations, as those of the sphincters of the bladder and anus, and the
musculi erectores penis, were originally excited into motion by irritation,
for young children make water, and have other evacuations without attention
to these circumstances; "et primis etiam ab incunabulis tenduntur sæpius
puerorum penes, amore nondum expergefacto." So the nipples of young women
are liable to become turgid by irritation, long before they are in a
situation to be excited by the pleasure of giving milk to the lips of a
child.