An educated gentleman of middle age--without epileptic antecedents--had exhausted himself by many years of over-strenuous mental work. Without other prodromal symptoms (such as depression, etc.) he attempted suicide during a holiday; in a peculiar twilight state he suddenly threw himself into the water from a bank, in sight of many persons. He was at once pulled out and retained but a fleeting remembrance of the occurrence. Bearing these observations in mind, neurasthenia must be allowed to account for a considerable share in the attacks of our patient, Miss E. K. The headaches and the teno-synovitis point to the existence of a relatively mild hysteria, generally latent, but becoming manifest under the influence of exhaustion. The genesis of this peculiar illness explains the relationship which has been described between epilepsy, hysteria and neurasthenia. _Summary._--Miss Elise K. is a psychopathic defective with a tendency to hysteria. Under the influence of nervous exhaustion she suffers from attacks of epileptoid giddiness whose interpretation is uncertain at first sight. Under the influence of an unusually large dose of alcohol the attacks develop into definite somnambulism with hallucinations, which are limited in the same way as dreams to accidental external perceptions. When the nervous exhaustion is cured the hysterical manifestations disappear. In the region of psychopathic deficiency with hysterical colouring, we encounter numerous phenomena which show, as in this case, symptoms of diverse defined diseases, which cannot be attributed with certainty to any one of them. These phenomena are partially recognised to be independent; for instance, pathological lying, pathological reveries, etc. Many of these states, however, still await thorough scientific investigation; at present they belong more or less to the domain of scientific gossip. Persons with habitual hallucinations, and also the inspired, exhibit these states; they draw the attention of the crowd to themselves, now as poet or artist, now as saviour, prophet or founder of a new sect.