Considerations of health, and uncertainty as to the rearing of her children, or any other personal cause may urge the mother of a family to avoid frequent births. For this purpose precautions are required by the married partners; and these means may be employed by the wife as well as by the husband. These methods are not absolutely infallible. (The only infallible methods are operations: viz., the obstructing by a ligature or by compression of the Fallopian tubes; the extirpation of the uterus or the ovaries in the female, and of the testes in the male.) They must be made use of very carefully and perseveringly if the couple wish to reduce to a minimum the chances of increasing the number of children. We shall give the minutest details about each of the methods known at the present day, insisting, last of all, upon the _injections_, for the essential part of every preventive method consists in cleanliness. It is in the case of women who have had children that the methods about which we have to speak are most easily applied; for the narrower the female passage, the greater is the difficulty in making use of them. Of course, we shall not speak here of sexual satisfaction such as masturbation, which may be dangerous to health, consisting in an artificial excitation rather than in the appeasing of a physiological need. When the accoucheur or midwife who examines a woman in labour pushes the finger, moistened with a little soap, as far as possible into the vagina, a small protuberance is felt like the tip of the finger, which is the lower end of the womb. The womb, the mouth of which is felt with some difficulty in the centre of the protuberance, is the little nest in which the human egg is hatched. As soon as the male fluid (sperm) has arrived within the orifice of the womb the woman can no longer prevent impregnation, even if she immediately use vaginal injections with the most sedulous care; and to inject fluid into the womb or to make any other attempt to destroy the ovulum within the womb is more or less dangerous, as it may produce fever or hæmorrhage. These operations are in the department of medicine or surgery, and are only permissible for the prevention of some dangerous disease, or danger of sudden death. The medicines or poisons recommended for re-establishing menstruation are rarely of any effect, and are dangerous to life. The following methods have simply the aim of preventing the male fluid from entering into the mouth of the womb; they in nowise injure the health, and are not forbidden in any civilised country either by moral codes or by law. MEANS TO BE EMPLOYED BY THE HUSBAND.