_Impeditio conceptionis._—The most frequent method employed conceptum impeditare is that of coitus interruptus, or onanism at the moment when it is felt that ejaculation of the semen is about to take place. The male orgasm then occurs outside the vagina, and the female orgasm is, as a rule, not induced at all. This practice is very injurious to both mates. Although the male act is allowed to reach its acme, still the ejaculation occurring outside the natural place, the proper satisfaction is missing, and there remains a constant hankering after the repetition concubitus which leads to excesses. Besides, this constant feeling of dissatisfaction causes in the long run a number of serious symptoms in both mates. The weakness of the brain is manifested by phobias and psychic effects, as ill humor, headaches, vertigo, syncope, insomnia, spasms of laughter or crying, irritability, fatigue and spinal pains. The affections of the gastro-intestinal canal are, spasm in swallowing, nausea, ravenous appetite or loss of appetite and constipation. The affection of the lungs is shown by nervous asthma. The heart shows palpitation and tachycardia. The genito-urinary system shows the following symptoms: impotence, frequent urination, hyperaesthesia in urethra, pressure in perineum, neuralgia of the testicles and spermatorrhoea. The muscles and skin show their affection by a certain tremor, paraesthesia in the legs and perspiration at the least exertion. Besides these symptoms, found in men and women alike, the female shows serious local symptoms. In the woman congressus interruptus prevents the inducing of the orgasm. In this way the tumefaction of the female genitals is not removed. The genital organs become engorged and are not allowed to enjoy the relaxation, consequent upon the completion congressus. If these interrupted sexual meetings are often repeated, serious diseases of uterus and ovaries develop. The uterine walls become dense and thickened and the menstruation is disturbed. The woman suffers from pains, tenderness and the sense of bearing down. In the course of time the absence of the detumescence causes real chronic disturbances, such as vulvitis, vaginitis, erosions of the cervix, endometritis, retroposition of uterus, salpingitis, oöphoritis and even fibroids or cancers.