s
with them; and the irritations, sensations, and volition, ceased to be
necessary to their production. As the actions of the muscles of the lower
limbs in fencing are associated with those of the arms; and the ideas of
suggestion are associated with other ideas, which precede or accompany
them; as in repeating carelessly the alphabet in its usual order after
having began it.

II. We shall give the following names to these four classes of fibrous
motions, and subjoin their definitions.

1. Irritative motions. That exertion or change of the sensorium, which is
caused by the appulses of external bodies, either simply subsides, or is
succeeded by sensation, or it produces fibrous motions; it is termed
irritation, and irritative motions are those contractions of the muscular
fibres, or of the organs of sense, that are immediately consequent to this
exertion or change of the sensorium.

2. Sensitive motions. That exertion or change of the sensorium, which
constitutes pleasure or pain, either simply subsides, or is succeeded by
volition, or it produces fibrous motions; it is termed sensation, and the
sensitive motions are those contractions of the muscular fibres, or of the
organs of sense, that are immediately consequent to this exertion or change
of the sensorium.

3. Voluntary motions. That exertion or change of the sensorium, which
constitutes desire or aversion, either simply subsides, or is succeeded by
fibrous motions; it is then termed volition, and voluntary motions are
those contractions of the muscular fibres, or of the organs of sense, that
are immediately consequent to this exertion or change of the sensorium.

4. Associate motions. That exertion or change of the sensorium, which
accompanies fibrous motions, either simply subsides, or is succeeded by
sensation or volition, or it produces other fibrous motions; it is then
termed association, and the associate motions are those contractions of the
muscular fibres, or of the organs of sense, that are immediately consequent
to this exertion or change of the sensorium.

* * * * *

SECT. VII.

OF IRRITATIVE MOTIONS.

I. 1. _Some muscular motions are excited by perpetual irritations._ 2.
_Others more frequently by sensations._ 3. _Others by volition. Case of
involuntary stretchings in paralytic limbs._ 4. _Some sensual motions
are excited by perpetual irritations._ 5. _Others more frequently by
sensation or v