It is easily seen, that if coition and masturbation may cause all these inflammations, so, too, they may sustain and increase them. The pleasures of love, therefore, should be strictly forbidden to persons affected with diseases of the genito-urinary passages. Acute inflammation of the urethra, blenorrhagia, has often been known to pass to a chronic state by a single act of venery; which, says Lewedrain, may even cause this change several months after the apparent termination of acute blenorrhagia.
May an incontinence of urine be produced by excesses in coition or masturbation? We have more than once seen this disease in young onanists. Sainte Marie, also, places it among the symptoms of daily involuntary pollution; and Lallemand has remarked, that most individuals affected with this pollution had been subject, in their infancy, to incontinence of urine. May not the relations between these two affections extend to the causes which determine them?
One of the most common causes of excesses in venery is, the _involuntary loss of semen_. This disease, which has been termed _spermatorrhœa_, _involuntary pollution_, may also arise from other causes; but as it results most frequently from excesses in masturbation or coition, we shall devote particular attention to it.
Let us consider the mode in which the excretion of semen takes place in the normal state. It is the remote consequence of a voluntary action, and the immediate result of involuntary contractions. The venereal sense is excited voluntarily, either by copulation, or by applying the hand: this excitement is carried to as great an extent as possible; and then a crisis, entirely independent of the will, terminates it. This crisis occurs sooner or later. It may even be quickened or retarded by the will, which may excite or modify the venereal sense; but when it does take place, it is always by involuntary contractions--that is, by a true convulsion.
This last action has two well marked periods. In the first, the semen passes from the seminal vesicles into the urethra; in the second, this liquid is violently expelled. The contraction of the seminal vesicles--and perhaps, also, that of the levatores ani muscles--are the powers by which the semen comes into the urethra. The ejaculation is caused by the muscles of the perinœum, and particularly by the bulbo-cavernosus muscle. The swelling and hardness of the corpus cavernosum furnish this muscle with a point of resistance, which enables it to compress more efficiently the semen with which the urethra is filled; and the straightening of this canal, by the erection, renders the expulsion of this fluid more easy. All these motions take place by jerks; and, we repeat it, convulsively, without the aid of the will.