Colonial North America: Countway Library of Medicine

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