1897 introductions

Vasectomy is an elective surgical procedure that results in male sterilization, often as a means of permanent contraception. During the procedure, the vasa deferentia are cut and tied or sealed so as to prevent sperm from entering into the urethra and thereby prevent fertilization of ova through sexual intercourse. Vasectomies are usually performed in a physician's office, medical clinic, or, when performed on a non-human animal, in a veterinary clinic. Hospitalization is not normally required as the procedure is not complicated, the incisions are small, and the necessary equipment routine.

thumb|right|Silencer (silver) and exhaust pipe on a [[Ducati motorcycle]] thumb|right|A silencer cut open to show the insulation, chambers and piping inside the shell

bicycle tube valve

fictional castle in Bram Stoker's 1897 novel Dracula