And, lastly, with the increased actions of the excretory duct of
this gland are associated those of the other end of it by their frequently
acting together; in the same manner as the extremities of other canals are
associated; and thus a greater flow of tears is poured into the eye.

When a flow of tears is produced in grief, it is believed to relieve the
violence of it, which is worthy a further inquiry. Painful sensations, when
great, excite the faculty of volition; and the person continues voluntarily
to call up or perform those ideas, which occasion the painful sensation;
that is, the afflicted person becomes so far insane or melancholy; but
tears are produced by the sensorial faculty of association, and shew that
the pain is so far relieved as not to excite the excessive power of
volition, or insanity, and are therefore a sign of the abatement of the
painful state of grief, rather than a cause of that abatement. See Class
III. 1. 2. 10.

2. _Sternutatio a lumine._ Some persons sneeze from looking up at the light
sky in a morning after coming out of a dark bedroom. The olfactory nerves
are brought into too great action by their sympathy with the optic nerves,
or by their respective sympathies with some intervening parts, as probably
with the two extremities of the lacrymal sac; that is, with the puncta
lacrymalia and the nasal duct. See Class II. 1. 1. 3.

3. _Dolor dentium Stridore._ Tooth-edge from grating sounds, and from the
touch of certain substances, and even from imagination alone, is described
and explained in Sect. XVI. 10. The increased actions of the alveolar
vessels or membranes are associated with the ideas, or sensual motions of
the auditory nerves in the first case; and of those of the sense of touch,
in the second case; and by imagination, or ideas exerted of painful
sensation alone, in the last.

4. _Risus sardonicus._ A disagreeable smile attends inflammations of the
diaphragm arising from the associations of the reiterated exertions of that
muscle with those of the lips and cheeks in laughing. See Diaphragmitis,
Class II. 1. 2. 6.

5. _Salivae fluxus cibo viso._ The flow of saliva into the mouths of hungry
animals at the sight or smell of food is seen in dogs standing round a
dinner-table. The increased actions of the salivary glands have been
usually produced by the stimulus of agreeable food on their excretory ducts
during the mastication of it; and with this increased action of their
excr