secretion of matter in them continues to be greater, than the absorption of
it; and the ulcers at the same time continue to enlarge, by the contagion
affecting the edges of them; that is, by the stimulus of the oxygenated
matter stimulating the capillary vessels in its vicinity into actions
similar to those of the ulcer, which produces it.

This effect of the oxydes of mercury occurs, whether salivation attends its
use or not. Salivation is much forwarded by external warmth, when mercury
is given to promote this secretion; but as the cure of venereal complaints
depends on its absorbent quality, the act of salivation is not necessary or
useful. A quarter of a grain of good corrosive sublimate twice a day will
seldom fail of curing the most confirmed pox; and will as seldom salivate,
if the patient be kept cool. A quarter of a grain thrice a day I believe to
be infallible, if it be good sublimate.

Mercury alone when swallowed does not act beyond the intestines, its active
preparations are the salts formed by its union with the various acids, as
mentioned in the catalogue. Its union with the vegetable acid, when
triturated with manna, is said to compose Keyser's Pill. Triturated with
gum arabic it is much recommended by Plenk; and triturated with sugar and a
little essential oil, as directed in a former Edinburgh Dispensatory, it
probably forms some of the syrups sold as nostrums.

United with sulphur it seldom enters the circulation, as when cinnabar, or
Aethiop's mineral, are taken inwardly. But united with fat and rubbed on
the skin, it is readily absorbed. I know not whether it can be united to
charcoal, nor whether it has been given internally when united with animal
fat.

VIII. 1. Absorptions in general are increased by inanition; hence the use
of evacuations in the cure of ulcers. Dr. Jurin absorbed in one night,
after a day's abstinence and exercise, eighteen ounces from the atmosphere
in his chamber; and every one must have observed, how soon his sheets
became dry, after having been moistened by sweat, if he throws off part of
the bed-clothes to cool himself; which is owing to the increased cutaneous
absorption after the evacuation by previous sweat.

2. Now as opium is an universal stimulant, as explained in the article on
Incitantia, it must stimulate into increased action both the secretory
system, and the absorbent one; but after repeated evacuation by
venesection, and cathartics, the absorbent system is