The patients of this class have always been normal in their sex-life. Suddenly, one day, they find themselves impotent. The cause of this kind of impotence is, in the majority of cases, sexual excesses, and four different kinds of excesses may be taken into consideration, excesses in copulation, in masturbation, in mental erethism, or commonly called day-dreaming, and finally excesses in tactile eroticism, or the common sexual dalliance or caresses of young lovers. _Copulation excesses._—During coition all the parts of the genital apparatus are in a state of extreme congestion. If such congestions are too often provoked they have a more or less deleterious effect upon the organs. Especially the colliculus and the prostatic portion of the urethra are affected by such repeated congestions. While the other parts assume their normal state soon after ejaculation and the cessation of erection, the colliculus remains still in a state of turgescence for some time. Now, the prostatic urethra is very rich in sensible nerves, and by its congestion all the generative organs are kept in a state of erethism. The irritation of this area is also capable of deranging the spinal genital centres. It either increases excitability and causes ejaculatio praecox, or it decreases excitability, and erections are no longer evoked. Besides affecting the special nerves, the repeated orgasm, through the mental vertigo, the muscular convulsion, the cardiac and respiratory excitement, must lead to nervous disorders. As a matter of fact, venereal excesses are followed by malaise, nervousness, mental depression, lassitude, fatigue, satiety, heaviness in the head, disposition to sleep, dulness of intellect, indisposition to exercise, want of decision, regrets and ill humor, and the other symptoms of general neurasthenia. _Masturbatic excesses._—Still excesses in copulation are not so harmful as excesses in masturbation. In the first place excesses in copulation are self-limited. Indulgence in intercourse requires the consent of the partner, and where a second person is needed, there is always a limit put to the will of the first party. Furthermore, excesses in coition require each time a complete erection, and abused nature will finally deny erections. If the young and vigorous individual should in the beginning be able to command quite a number of erections in one night, after a certain time, he will be glad if he could have one complete erection during a night, or even once a week. In this way Nature herself regulates such excesses and takes care that “the trees should not sweep the stars down.” The case is different with masturbation. No limit is set here to the excesses. Self-abuse does not require cooperation of a second person, and what is of more importance, erection is not requisite. Thus even Nature is here powerless. Hence when there is a propensity to masturbatory excesses, there is nothing to prevent the individual from abusing its favorite pastime.