The object of this paper is to present in concise form recent views upon the influence of Reflex Stimulation and Toxic Agencies upon Insanity and Epilepsy. For the most part these will be dealt with together, although the influence of reflex irritation will of necessity be chiefly confined to epilepsy. With regard to both insanity and epilepsy, cases will occur in which it is impossible to decide whether a reflex or toxic condition originates the mischief. It must not be supposed that these views are novel, except in their development. Both Abercrombie and Henry Monro long ago discussed these theories. The latter acute observer, in his “Remarks on Insanity” (1851), dwells at length on both toxic and auto-toxic origins of insanity, and his views even at the present day may be considered with interest and advantage. Since this time there has been a continual increase of experimental and clinical evidence lending support to the theories advanced. It is the purpose of this paper to state dispassionately the accumulated observations upon this subject. Some apparent contradictions arise at the outset; amongst these are—
(1) Any given disorder may survive the removal of its supposed cause.
(2) Given in two different cases the operation of precisely similar morbid conditions, the same results are certainly not invariably met with.