Dr. Rognetta, in a memoir on the causes of amaurosis, insists on the opinion that onanism produces this disease, by exhausting the sensibility of the body. He compares this habit to decay. “Nothing,” says he, “enervates the body so much as too frequent emissions of semen, especially when they are caused by the hand: the spasm which attends them throws the body into all the infirmities of old age. The retina and optic nerve then gradually lose their sensitive faculty, which finally becomes extinct. Those who masturbate are affected with amaurosis, like decrepit old men.” Rognetta adds, that he has the notes of several cases of amaurosis, which had resisted all remedies, and which were caused entirely by the _luxuria manuensis_. He relates the history of a young ecclesiastic, nineteen years old, a native of Palermo, whose sight became very weak. This unfortunate young man had been in the habit of masturbating seven times a-day: he was also prone to sodomy. Rognetta advised him to leave off this bad habit, and to return to his native place and take cold baths. Sanson, also, places voluntary and involuntary pollutions among the asthenic causes of amaurosis: he, however, regards these pollutions as sometimes causing irritation of the retina. He assimilates them, as do many other authors, to all abundant discharges of fluids. The following case has been considered by him as one of asthenic amaurosis, produced in this manner:--A notary’s clerk, twenty-four years old, experienced for a year a progressive debility in his sight. He had labored much at night, by lamp-light, and attributed his disease to this cause; but another, which had contributed to the development of the amaurosis, was the excesses of this young man, in onanism and coition. Venereal disease, which he had contracted, might also contribute to this bad result. The pupil was dilated; the iris was immoveable; the eye was perfectly clear; and the retina, of a dull color, could be seen through the pupil. An antivenereal treatment, purgatives, emetics, and blisters around the organ, &c., produced no effect.