Wise Parenthood (15th edition)/Appendix

Rubber caps on the lines recommended on p. 37 have long had the approval of the chief authorities in various countries. They are made by different firms, but unfortunately often in an unsatisfactory form. Since the first edition of this book was published, I have followed up various complaints of failure, or of inability to obtain exactly the article demanded, and have been surprised and disappointed at the variability of the article which is sold as the small check pessary. The relative size and proportion of the cap to its rim have a significance which it may be worth stating. In the accompanying diagrams, A₁ and A₂ are drawings of a satisfactory cap; B₁ and B₂ drawings of a type frequently sold, and in my opinion not only unsatisfactory on general principles, but liable to lead to those failures which have made some people distrust this most valuable method. The points to be noted in the drawings are primarily as follows: The spring ring S and the conical portion C should be in such relative proportions towards each other as is indicated in A, and not as in B, where the rim is too thick and heavy and the conical portion C is too flat and small. There is an interesting physiological reason against so flat a cap, which it would perhaps be out of place here to elaborate. A further point to be noted is ​that the whole appliance, both rim and cap, should be of very pliable and soft rubber, and should not be withered or wrinkled in the slightest degree. Also the line of junction, indicated down the fine line in the drawings of C, should be entirely secure, and without the smallest thin area or perforation. I have had sent to me a cap, otherwise perfect, in which a minute bubble in the rubber just at this junction had

developed into a hole more than large enough for the entry of the sperm. To ascertain that the line of junction is secure, the cap should be held up to the light and examined, preferably by a magnifying glass.

In figures A, and B, the caps are reversed and shown from underneath, and the line of junction between the soft cap C and the surrounding ring S is apparent. In A it will be noted that the junction is smooth and that the cap and ring merge into one another. But in B there is a comparatively rough ​welding of the thick raw edge of the cap C, which is—or may be—a very dangerous source of failure. No cap which is offered with such a rough interior should be accepted by a would-be purchaser.

A great variety of shapes and makes of caps are on the market, and those who require further information should study the photographic plates and text of my larger work, "Contraception (Birth Control), Its Theory, History and Practice: A Manual for the Medical and Legal Professions."

It should be remembered that rubber tends to perish, even when not in use, and that to put away a cap dry for months or more, and then bring it into use may mean serious failure, owing to the development of small cracks. Rubber which is not in use is best kept under water, as it is in scientific laboratories. A small china or celluloid pot or jar with a lid should be available, filled with water, under which the cap is submerged after it has been washed out and dipped into a simple non-corrosive disinfectant solution. Time under water may discolour the cap somewhat, but should tend to preserve its essential pliability and usefulness.