imagined, but by stimulating the
torpid vessels into their usual action; and thence increasing the action
and consequent warmth of the whole skin, and of all the parts which are
associated with it.

II. 1. _Sialagogues._ The preparations of mercury consist of a solution or
corrosion of that metal by some acid; and, when the dose is known, it is
probable that they are all equally efficacious. As their principal use is
in the cure of the venereal disease, they will be mentioned in the
catalogue amongst the sorbentia. Where salivation is intended, it is much
forwarded by a warm room and warm clothes; and prevented by exposing the
patient to his usual habits of cool air and dress, as the mercury is then
more liable to go off by the bowels.

2. Any acrid drug, as pyrethrum, held in the mouth acts as a sialagogue
externally by stimulating the excretory ducts of the salivary glands; and
the siliqua hirsuta applied externally to the parotid gland, and even hard
substances in the ear, are said to have the same effect. Mastich chewed in
the mouth emulges the salivary glands.

3. The unwise custom of chewing and smoking tobacco for many hours in a day
not only injures the salivary glands, producing dryness in the mouth when
this drug is not used, but I suspect that it also produces schirrhus of the
pancreas. The use of tobacco in this immoderate degree injures the power of
digestion, by occasioning the patient to spit out that saliva, which he
ought to swallow; and hence produces that flatulency, which the vulgar
unfortunately take it to prevent. The mucus, which is brought from the
fauces by hawking, should be spit out, as well as that coughed up from the
lungs; but that which comes spontaneously into the mouth from the salivary
glands, should be swallowed mixed with our food or alone for the purposes
of digestion. See Class I. 2. 2. 7.

III. 1. Expectorants are supposed to increase the secretion of mucus in the
branches of the windpipe, or to increase the perspiration of the lungs
secreted at the terminations of the bronchial artery.

2. If any thing promotes expectoration toward the end of peripneumonies,
when the inflammation is reduced by bleeding and gentle cathartics, small
repeated blisters about the chest, with tepid aqueous and mucilaginous or
oily liquids, are more advantageous than the medicines generally enumerated
under this head; the blisters by stimulating into action the vessels of the
skin produce by associa