While the great majority of married couples are actually suffering, or would suffer, without the exertion of definite control, from too many pregnancies there are still--particularly in the middle and upper classes--many would-be parents who long for children but seem to be mysteriously deprived of them. Doctors may have examined both the man and the woman, and pronounced them perfectly normal, perfectly healthy, and perfectly capable of having children together, and yet children do not come. Sometimes this is caused by an undue activity of a slightly acid secretion on the part of the woman, a secretion doing her no harm and of which she is quite unconscious, but which may be sufficient to render the active sperm impotent. Sometimes, therefore, it is sufficient to ensure conception for the woman to syringe the vagina with a little weak neutralising solution such as sodium carbonate shortly before sex union. Another cause which sometimes operates against the vital sperm penetrating to the waiting ovum is an excess of mucus at the mouth of the womb. In such a case it is important that a really complete and muscularly energetic orgasm should be achieved by the woman, not before but coincident with or after the sperm has been ejaculated. It is often argued that it makes no difference whether or not the woman has a complete orgasm, for so many cases are recorded in which women who have never experienced an orgasm have had many children; but it is generally forgotten that women are of many different types, and while one type of woman, the very fruitful mother with a wide vagina and but slight internal mucus, may conceive a dozen times without an orgasm, the more highly nervous, equally perfect, woman may only conceive on the occasion when she experiences an orgasm whilst the sperm are actually in the vagina. Another slight obstacle to conception on the part of a woman which is not infrequent is the position of the mouth of the womb and the relation of the vaginal canal, which may be such that the spermatic fluid tends to be lost without any of it penetrating the orifice of the womb itself. To overcome this it is often sufficient for the woman to turn over directly the act of union is complete and lie face downwards for a few hours.