Methodus medendi

Insanity, more than any other complaint, seems to take entire possession of the whole system, and almost secures it from other morbid attacks. (...). From hence a degree of improvement has arisen in the methodus medendi, by the introduction of some new disease into the system of maniacs; as where the patient has not had small-pox, this complaint may be communicated by inoculation.

C***
Practical Observations on Insanity, p. 16f.