otruded into the neck of the gall-bladder, when the disease is not very
great, produce pain at the other extremity of the bile-duct, which enters
the duodenum immediately under the pit of the stomach; but, when the
disease is great from the largeness of the bile-stone, the pain is felt in
the region of the liver at the neck of the gall-bladder.

It appears from hence, that the pains enumerated in this genus are
consequences of the inactivity of the organ; and, as they do not occasion
other diseases, should be classed according to their proximate cause, which
is defective irritation; there are nevertheless other pains from defect of
stimulus, which produce convulsions, and belong to Class III. 1. 1.; and
others, which produce pains of some distant part by association, and belong
to Class IV. 2. 2.

SPECIES.

1. _Sitis._ Thirst. The senses of thirst and of hunger seem to have this
connection, that the former is situated at the upper end, and the latter at
the lower end of the same canal. One about the pharinx, where the
oesophagus opens into the mouth, and the other about the cardia ventriculi,
where it opens into the stomach. The extremities of other canals have been
shewn to possess correspondent sensibilities, or irritabilities, as the two
ends of the urethra, and of the common gall-duct. See IV. 2. 2. 2. and 4.

The membrane of the upper end of the gullet becomes torpid, and
consequently painful, when there is a deficiency of aqueous fluid in the
general system; it then wants its proper stimulus. In the same manner a
want of the stimulus of more solid materials at the other end of the canal,
which terminates in the stomach, produces hunger; as mentioned in Sect.
XIV. 8. The proximate causes of both of them therefore consist in deficient
irritation, when they are considered as pains; because these pains are in
consequence of the inactivity of the organ, according to the fifth law of
animal causation. Sect. IV. 5. But when they are considered as desires,
namely of liquid or solid aliment, their proximate cause consists in the
pain of them, according to the sixth law of animal causation. So the
proximate cause of the pain of coldness is the inactivity of the organ, and
perhaps the consequent accumulation of sensorial power in it; but the pain
itself, or the consequent volition, is the proximate cause of the
shuddering and gnashing the teeth in cold fits of intermittent fevers. See
Class I. 2. 2. 1.

Thirst may be div