A gorget with four angled detachable blades on an ebony handle dating to circa 1813.

This instrument was used as a guide during lithotomy. The patient having had his bowel purged with a clyster was secured  in the lithotomy position with leather restraints. A per urethral grooved sound was first inserted to act as a guide for the gorget which would meet it via a lateral perineal incision and from there be guided into the bladder. The sound was then removed and  instruments to break and remove stones could be inserted into the bladder along the groove of the gorget. It was not until 1850 that ether and chloroform afforded patients the respite of an anaesthetic so this procedure must have been a riot of agonies. Yet this was the scientific surgical method arrived at after years of experimentation with alternative approaches which traumatised the rectum, bladder, urethra and prostate and had paltry survival rates.

The identical instrument is illustrated on P 150 of the earliest systematic textbook of surgery in America, Elements of Surgery by John Syng Dorsey.

• From the Phisick collection