On January 6, progress of the condition to severe acute delirium (great disturbance of consciousness, jactation, grinding of the teeth, grimacing, and other motor symptoms of irritation; temperature as high as 40.7° C.); impulsive masturbation. Recovery was complete by January 11, under energetic treatment with ergotin. After his recovery the patient gives an interesting account of the cause of his illness. Always very passionate sexually; first coitus at the age of sixteen. Continence caused headache, great psychical irritability, lassitude, great loss of pleasure in work, and sleeplessness. Since he had few opportunities in the country to satisfy his desire, he had recourse to masturbation. It was necessary for him to masturbate once or twice daily. No coitus in two months. Increasing sexual excitement; could think of nothing save means for the gratification of his impulse. Masturbation was not sufficient to banish the constantly increasing torment _ex abstinentia_. During the last four days violent impulse to coitus; increasing sleeplessness and irritability. There was only a summary recollection of the height of the illness. Patient recovered in December. A very respectable man; he considers his inordinate desire decidedly pathological, and is anxious about his future. Case 15. On July 11, 1884, R., aged 33, servant, was admitted suffering with paranoia persecutoria and neurasthenia sexualis. Mother was neuropathic; father died of spinal disease. From childhood he had an intense sexual desire, of which he became conscious as early as his sixth year. From this age, masturbation; from fifteenth year, _faute de mieux_, pederasty; occasionally, sodomitic indulgences. Later, abusus coitus in marriage cum uxore. Now and then even perverse impulse to commit cunnilingus and to administer cantharides to his wife, because her libido did not equal his own. His wife died after a short period of married life. Patient’s circumstances became straightened, and he had no means to indulge himself sexually. Then masturbation again; employment of lingua canis to induce ejaculation. At times, priapism and conditions approaching satyriasis. He was then driven to masturbate, in order not to become stuporous. Beneficial diminution of the libido nimia, with the gradually predominating sexual neurasthenia and hypochondria. The following case, valuable for an understanding of many Messalinas, some of whom are historically celebrated, is a classical example of pure hyperæsthesia sexualis, which I take from Trelat’s “Folie lucide”:—