Bacteriological Researches in Acute Delirium.—The question of the relation of certain forms of acute mania to bacterial infection is one that has lately been brought prominently forward in this country. A recent paper by Ceni (Rivista Sperimentale di Freniatria, 1897, Fasc. iv, p. 796), in which the observations that have been made upon the subject on the Continent are somewhat fully reviewed, may therefore merit notice here at some length.