Page:Contraception; 1st ed. (IA in.ernet.dli.2015.94163).pdf/83

This "method" is available at any time, and its practice is certainly a "primitive form of birth control. Ploss^[1] quotes Riedel as saying that the women of Buru Island often have unions with strange men, but during such unions they keep themselves very passive so as to avoid fertilization. Its persistence ever among civilized women as a method of contraception, in spite of the existence of innumerable cases in which the most passive and cold type of woman is known to have become pregnant, is in my opinion explicable only on the assumption that there are individual women who find this method reliable. Such are probably of the type which I have described as undersexed (see p. 95). Such women probably also tend to have an excess of acid secretion in the vagina (see p. 61), and, therefore, naturally to destroy the motility of the spermatozoa without the use of accessory chemicals, so long as the spermatozoa do not actually get sucked into the uterus. Hence by controlling the orgasm the tendency would be for spermatozoa to be restricted to the vagina for a period long enough for the natural acid secretion to take effect upon them.