But it is our more particular object now to inquire into the _causes of absolute sterility_ in individual cases, rather than to discuss the operation of general laws upon the fertility of the community at large, however inviting such a discussion may be. When marriages are fruitless, the wife is almost always blamed. It is not to be supposed that she is always in fault. Many husbands are absolutely sterile; for it is a mistake to consider that every man must be prolific who is vigorous and enjoys good health. Neither does it follow, because a woman has never given birth to a living child, that she has not conceived. About one marriage in eight is unproductive of living children, and therefore fails to add to the population. The seeds of life have, however, been more extensively sown among women than these figures would seem to indicate. If the life of an infant for a long time after birth is a frail one, before birth its existence is precarious in the extreme. It often perishes soon after conception. A sickness, unusually long and profuse, occurring in a young married woman a few days beyond the regular time, is often the only evidence she will ever have that a life she has communicated has been ended almost as soon as begun. A tendency to miscarriage may therefore be all that stands in the way of a family. This is generally remediable. It is a well-known fact that frigidity is a frequent cause of barrenness, as well as a barrier to matrimonial happiness. Its removal, so desirable, is in many cases possible by detecting and doing away with the cause. The causes are so various, that their enumeration here would be tedious and unprofitable, for most of them can only be discovered and remedied by a practical physician who has studied the particular case under consideration. So also in regard to the various displacements and diseases of the womb preventing conception. Proper medical treatment is usually followed by the best results. While the fact that pleasure is found in the marital relation is a favourable augury for impregnation, it has been long noticed that Messalinas are sterile. It was observed in Paris, that out of one thousand only six bore children in the course of a year, whereas the ordinary proportion in that city for that time is three and a half births for every one hundred of the population. In some women, nothing seems amiss but too intense passion. Such cases are much more rare than instances of the opposite extreme producing the same effect. A condition of debility, or the presence of certain special poisons in the blood, may prevent conception, or, what is to all intents the same thing, cause miscarriage. Many apparently feeble women have large families. But in numerous instances a tonic and sometimes an alternative constitutional treatment is required before pregnancy will take place. On the contrary, there are well-authenticated cases of women who were stout and barren in opulence becoming thin and prolific in poverty.