The relation between the completion of the sex act and sleep in woman is well indicated in the case of Mrs. A., who is typical of a large class of wives. She married a man with whom she was passionately in love. Neither she nor her husband had ever had connection with anyone else, and, while they were both keen and intelligent people with some knowledge of biology, neither knew anything of the details of human sex union. For several years her husband had unions with her which gave him some satisfaction and left him ready at once to sleep. Neither he nor she knew that women should have an orgasm, and after every union she was left so "on edge" and sleepless that never less than several hours would elapse before she could sleep at all, and often she remained wakeful the whole night. After her husband's death her health improved, and in a year or two she entered into a new relation with a man who was aware of women's needs and spent sufficient time and attention to them to ensure a successful completion for her as well as for himself. The result was that she soon became a good sleeper, with the attendant benefits of restored nerves and health. Sleep is so complex a process, and sleeplessness the resultant of so many different maladjustments, that it is, of course, possible that the woman may sleep well enough, even if she be deprived of the relief and pleasure of perfect union. But in so many married women sleeplessness and a consequent nervous condition are coupled with a lack of the complete sex relation, that one of the first questions a physician _should_ put to those of his women patients who are worn and sleepless is: Whether her husband really fulfils his marital duty in their physical relation. From their published statements, and their admissions to me, it appears that many practising doctors are either almost unaware of the very existence of orgasm in women, or look upon it as a superfluous and accidental phenomenon. Yet to have had a moderate number of orgasms at some time at least is a necessity for the full development of a woman's health and all her powers. As this book is written for those who are married, I say nothing here about the lives of those who are still unmarried, though, particularly after the age of thirty has been reached, they may be very difficult and need much study and consideration. It is, however, worth noticing how prevalent sleeplessness is among a class of women who have never had any normal sex-life or allowed any relief to their desires. There is little doubt that the complete lack of a normal sex relation is one of the several factors which render many middle-aged unmarried women nervous and sleepless. Yet for the unmarried woman the lack is not so acute nor so localised as it is for the married woman who is thwarted in the natural completion of her sex-functions after they have been directly stimulated.