CATH′ETERS

Small tubes introduced into the bladder for the purpose of drawing off its contents. They may be regarded as hollow bougies. Prep. 1. A piece of smooth catgut, or steel wire, bent to the proper shape, is coated with melted wax. When cold it is dipped repeatedly into an ethereal solution of india rubber, until a sufficient thickne is obtained, after which it is dried by a gentle heat, and then boiled in water to melt out the wax, and to allow the catgut to be withdrawn. A solution of india rubber in bisulphide of carbon is now generally employed instead of an ethereal solution. 2. From slips of india rubber, as directed under Bougies . 3. A smooth ti ue of silk is woven over a bent wire, and then coated with a surface of india rubber, or elastic varnish, and finished off as before. See Bougies .