(seq. 489)

482

Materia Medica

Emetics

health, that emetics had better be omitted, but when the stomach
is in a morbid state they are certainly usefull, except when they would
be injurious from the straining &c. Dr Cullen thinks that the
heart burn, acid eructations, and head ache, indicate the necessity of
emetics as also nausea and loathing of food, and the increase of
mucous in the stomach,* [footnote back 3 pages] but their operation does not stop here, it
extends to the duodenum and perhaps to the jejunum, but this is not the
case with the mild emetics, it is by the paristatic [peristaltic] motion of the small
intestines that the contents are thrown up, bile which does not exist
naturally in the stomach is frequently thrown up by active emetics,
by some fevers, mania, nausea, or by other causes, in
vomiting the diaphragm and abdominal muscles contract and
compress the abdominal viscera, and among others the gall bladder
and duodenum, this circumstance takes place chiefly in fishes and evinces
that this circumstance is adapted to some purpose in animal economy,
and is not merely an exertion. Vomiting excites the force of the circulation
in different parts of the body, but this increase is not perminant and
sinks proportionably low, after the emetic has operated. Dr Cullen
thinks there exists a sympathy between the stomach and excretory vessels
over the surface of the body thereby causing a diaphoresis an effect of