Page:Contraception; 1st ed. (IA in.ernet.dli.2015.94163).pdf/152

London the condom was in use." They are still often advocated for the double purpose of prevention both of pregnancy and venereal contamination.

Present day "sheaths" are made in a great variety of thicknesses and quality, either of the cæcal membranes of animals or from various grades of prepared rubber. Their object is to collect the seminal fluid and prevent it coming in contact with the vagina. By the use of sheaths this object is generally achieved unless the condom breaks or is perforated. Owing to the fact that thinness of texture is very much desired (as even the thinnest condom interferes with the full sensory excitation) the very thin forms are in greater demand than those of stouter manufacture, and accidents or ruptures at the critical time are not infrequent.

Entirely similar in its physiological action in so far as it deprives the woman of contact with the glans is the short sheath, made to cover the glans penis only. It is less reliable and more difficult to adjust than the condom. The essential feature of the method, viz., the collection of the whole of the semen, is the same as the large sheath.

The sheath method in general, although a complete contraceptive if no rupture or perforation occurs, is very liable to unex