(seq. 531)

524

Materia Medica

Cathartics

are produced by the same cause, those states of the mind are removed
by purging. Operations of the purgatives are diminished or even prevented
by intense applications of the mind Bonaparte would doubtless feel
no inconvenience from a cathartic when at the head of an army
prepared for battle or in moments when he is planning the distruction
of his Enemies. It is a disputable point among Physicians whether
or not cathartics are taken up into the circulation. I suspect that
some of them are taken up, some of them are the mild substances
so mild as to form an article of diet, the colouring matter of
rheubarb is peceptable in the urine and even in the sweat, it may
be said that the colouring matter is not the purgative quality, but
I do not think they are different since if we obtain the colour in
water it will purge from the action of purgation of sucking children
through the medium of milk we seem to derive proofs of their
absorption, besides if a purgative be apply’d to an open issue it will have the
effect of puging the patient, these however are not certain proofs, since
the quantity of the cathartic absorbed could not I should suppose be
sufficient to act on the intestines, the doses of purgatives are different at
different times or in the same person at different times, in different
climates and even in different states of Society. I know one or two