The invasion of New York by cerebro-spinal fever in the winter and spring of 1904-5, when some 4,000 cases occurred,1 and the more recent appearance of the disease in Glasgow (March, 1906), in Belfast, and some other districts, invite attention to its causation and prophylaxis. It is generally recognised that a cerebro-spinal meningitis may be set up by various causes, such as disease of the mi...