Case 13. For three years the generally respected farmer D., married, aged 35, has manifested states of sexual excitement, with increasing frequency and severity, which, during the past year, have become true paroxysms of satyriasis. It was impossible to discover hereditary or other organic cause. D. was compelled, at times when his sexual excitement was excessive, to perform the sexual act from ten to fifteen times in twenty-four hours, without deriving any feeling of satisfaction. Gradually he developed a condition of general nervous hyper-irritability (_éréthisme général_) with increased emotional irritability to the extent of pathological outbreaks of anger, and impulse to over-indulgence in alcohol, which induced symptoms of alcoholism. His attacks of satyriasis became so violent that consciousness was interfered with, and the patient raged about in blind impulse to sexual acts. He demanded that his wife give herself to other men or to animals in his presence; that she allow copulation with him, _presentibus filiabus_, because this would afford him greater enjoyment. Memory for the events at the height of these attacks, in which the extreme irritability even led to outbreaks of maniacal rage, was entirely wanting. D. himself thought that he must have had moments in which he no longer had control of his senses, and without satisfaction from his wife would have been compelled to seize the next best female. After an attack of violent emotion, these attacks of sexual excitement suddenly disappeared entirely. The two following cases show how powerful, dangerous, and painful sexual hyperæsthesia may become in those afflicted with this anomaly:— Case 14. _Hyperæsthesia Sexualis_—_Delirium Acutum ex Abstinentia._—On May 29, 1882, F., aged 29, single, shoemaker, was received at the clinic. Father was of passionate temper; mother neuropathic, and had an insane brother. Patient had never been seriously ill previously, and was not a drinker, but had always been sexually very passionate. Five days before, he was taken acutely ill mentally. He made two attempts at rape in broad daylight, before witnesses, and when arrested talked in delirium only of obscene things, and masturbated without stint, and for three days had been raving mad. On admission he presented the picture of a severe acute delirium, with violent motor symptoms of irritation, and fever. Under treatment with ergotin a cure was effected. On January 5, 1888, second admission, in a state of violent mania. On January 4, he had become morose, irritable, whining, and sleepless; and then, after vain assaults on women, had manifested symptoms of increasing angry excitement.