With the exception of the condition of a person labouring under acute mania, no phase of insanity so thoroughly arrests the attention of even an uneducated observer as that which has been styled stupor in late years. Painful as it is to see the vagaries and extravagances of the former, hardly less so is it to contemplate in the latter the great impairment of mental power, which may reach even to almost total obliteration. But while on the one hand acute mania has been elaborately described from every point of view—indeed, the very nature of its symptoms force a recognition, and demand prompt treatment—yet stupor has received but little attention, considering what an important element it may become in a case. In fact, it is only comparatively recently that it has been looked upon as anything more than mere “depression.” For more than a casual mention of it, we must chiefly refer to French psychological literature, to the writings of such men as Baillarger, Esquirol, Brierre de Boismont, Dagonet, etc. But these authorities differ much in their opinions, even as to the fundamental nature or natures of the sets of mental phenomena which are included under this comprehensive term.