An 18th century bistoury cache by Savigny used for the extraction of bladder stones. This single bladed instrument is sometimes referred to as a lithotome of Come.
The polished steel lever which opens the blade is crosshatched, as is the spring loaded release button which secures the lever within the ebony handle. This limits the opening of the instrument as well as allowing the blade to be fixed in an open position. There is a second adjustment possible using the pivot screw which allows the blade to be moved forwards and backwards by a few mm. The stem is signed Zavigny [sic]. The case is made from fitted wood and sharkskin, lined with red velvet and silk and with original hinges and catches.