It is self-evident that diseased persons, of either sex, should not marry.

By parity of reasoning, it is equally evident that they should deny themselves sexual intercourse. By diseased persons I of course mean those with communicable blood diseases, the virus, seed or susceptibility of which is liable to be transmitted in the act of copulation; and here I think it highly proper to direct attention to a fact too often slighted in medical literature, and absolutely unthought of by the general public. I mean the greater relative liability to venereal contagion of the woman than the man.

It is not desirable, in a medico-literary work of this character, to burden the reader with masses of dry, clinical testimony, unless it be in those matters which by reason of the involvement of their relations and aetiology make a somewhat greater demand upon our mental powers of analysis. But to show the greater liability of the female to venereal contagion, it is only necessary to point out that the spermatic fluid, injected into the female, must cause infection through absorption; while, unless in the acute stage, the mate, undergoing only a brief period of contact, may escape entirely. In one case the diseased fluid is actually injected into the female body, producing certain inoculation, while in the other, through failure of the absorptive mechanism, by prompt disinfection, or even by ordinary cleanliness, no contagion may follow. Thus, except during the initial lesion, a syphilitic woman is not likely to infect the male, while at any stage the male is almost certain to infect the female.

Blood disease, then, should always prohibit marriage; for scrofulous, consumptive, or syphilitic parents, even though seemingly strong and healthy, cannot possibly bear other than sickly or deformed children, which, in vindication of Darwin's now fully recognized and generally beneficent law, are invariably puny and short lived.