_Incidents――Observation――Historical Data, and Sexual Hygiene._――Nature furnishes us a vast field for speculation and inquiry, when even confined within the domain of certainties; and there is an occult line beyond which everything is speculative and imaginary; but there are facts enough in common view to enlighten the seeker after knowledge by simply collecting commonplace occurrences and gleaning therefrom their rich lessons. Observation, by association and comparison, and correct judgment will teach us many things not in the least hypothetical――facts. To comprehend the obscure relations of the sexual function and the varieties of morbid changes, we must first systematically inquire into a few of nature’s designs, and ascertain thereby the true purpose of the sexual organs. What purpose? is the first point at issue in any observation, and must be answered by the physiologist and Physician in this investigation, as he _only_ has the results of abuse, or wrong application, to investigate and correct. The production of healthy offspring must be nature’s only design for the sexual organs. How to accomplish this end, is the great question of scientific observers. It seems quite axiomatic to remark, that maturity and perfect development _only_ can assure perfect reproduction of the species. Again, that pleasure should always attend the act of copulation, otherwise the pain of parturition and the care of rearing the young would always militate against the perpetuation of the race. With the normal condition of the sexual organs and functions the physician has comparatively little to do; but with their abuses he has all to do. To comprehend the abnormal, he must be familiar with the normal condition of structure and function. Masturbation is a small part of the indiscretions and evils of the sexual; and the lesions growing out of such evils are too numerous to mention. There is no doubt venereal diseases grew out of the evils of repetition of sexual congress, with certain unknown violations of nature’s laws, by depraved human beings. I am credibly informed of an occasion: “A prostitute received the embraces of eleven men in immediate succession: the ninth and eleventh took gonorrhœa, and again gave it; but the prostitute remained free from the disease until two months after, when she took the disease from one to whom she had given it, on the above-mentioned occasion, after which she spread it through a small town in which she lived and also in which she was in the habit of plying her vocation. She was free from disease before this occasion.” It is no more doubted that a male will contract a purulent urethritis from contact with a woman during her menstrual crisis, or if she be afflicted with an infective leucorrhœa; but such a discharge in the male is not generally contagious, and he may indulge freely without giving the disease. Uncleanliness may be considered a common cause of sexual disease in both sexes.