at, electricity, aether, essential oils, friction, and
exercise.

2. These promote both the secretions and absorptions, increase the natural
heat, and remove those pains, which originate from the defect of irritative
motions, termed nervous pains; and prevent the convulsions consequent to
them. When given internally they induce costiveness, and deep coloured
urine; and by a greater dose intoxication, and its consequences.

II. OBSERVATIONS ON THE INCITANTIA.

I. 1. Opium and alcohol increase all the secretions and absorptions. The
increase of the secretion of sensorial power appears from the violent
exertions of drunken people; the secretion of sweat is more certainly
excited by opium or wine than by any other medicine; and the increase of
general heat, which these drugs produce, is an evidence of their effect in
promoting all the secretions; since an increase of secretion is always
attended with increase of heat in the part, as in hepatic and other
inflammations.

2. But as they at the same time promote absorption; those fluids, which are
secreted into receptacles, as the urine, bile, intestinal and pulmonary
mucus, have again their thinner parts absorbed; and hence, though the
quantity of secreted fluid was increased, yet as the absorption was also
increased, the excretion from these receptacles is lessened; at the same
time that it is deeper coloured or of thicker consistence, as the urine,
alvine feces, and pulmonary mucus. Whereas the perspiration being secreted
on the surface of the body is visible in its increased quantity, before it
can be reabsorbed; whence arises that erroneous opinion, that opium
increases the cutaneous secretion, and lessens all the others.

3. It must however be noted, that after evacuations opium seems to promote
the absorptions more than the secretions; if you except that of the
sensorial power in the brain, which probably suffers no absorption. Hence
its efficacy in restraining haemorrhages, after the vessels are emptied, by
promoting venous absorption.

4. In ulcers the matter is thickened by the exhibition of opium from the
increased absorption of the thinner parts of it; but it is probable, that
the whole secretion, including the part which is absorbed, is increased;
and hence new fibres are secreted along with the matter, and the ulcer
fills with new granulations of flesh. But as no ulcer can heal, till it
ceases to discharge; that is, till the absorption becomes as great as the