Page:Contraception; 1st ed. (IA in.ernet.dli.2015.94163).pdf/46

destroy the life and activities of the spermatozoa in the semen without in any way injuring or destroying the accessory substances in the seminal fluid and without injuring the lining or the bacterial inhabitants of the vagina.

Theoretically, the second result should be as easy to obtain as the farmer, but in practice it has not yet been ascertained what substances, if any, are in practice available. for use to deal with the spermatozoa effectively without having some effect on any other cells or tissues. Quinine, which is widely and beneficially used at present, has certain detrimental effects on a small number of people, and does not, therefore, conform to 'the theoretically perfect contraceptive. substance. Other theoretically better substances depart still more from the desirable standard owing to difficulties of application.

The internal cervical cap or small occlusive pessary if properly adjusted by the woman over the cervix so that it closes the entrance of the os, but does not cover, or intercept contact between the penis and the vaginal walls, offers no chemical or destructive action to either the sperm or the vaginal capacity to absorb. After insertion it is entirely unobtrusive. It is considered more in detail on p. 138.