Grumpy RN has pointed out that there is a link from the picture identifying the object as an Ecraseur. However the Wiki entry is not quite correct for this object which is a chain ecraseur.
The shiny strip to the left is not a blade or a wire but a fine chain, designed to crush rather than cut.
It was used, among other things to treat haemorrhoids. The chain was looped around the piles and tightened using the screw device to deliberately strangulate. Bearing in mind this is a 19th century instrument there would have been no anaesthetic.