Courville (1945) remarks that: “It was almost a medical habit in England on the part of physicians with literary leanings in the first half of the nineteenth century to write an essay on ‘water on the brain’.” It was not, however, until the experimental work of Dandy (1917) was published that a dynamic and scientific approach to the problem became possible. To this day no generally effective and applicable method of treatment has been devised. This is possibly due in part to the tendency to lump together a variety of conditions of different aetiology and pathology under the one heading. To emphasize this point it is perhaps useful to publish the following case, which clinically seemed to be one of simple hydrocephalus, but post-mortem examination of which showed that the symptoms had quite a different origin.