A Holt’s Divulsor as described in Tiemann’s American Armamentarium Chirurgicum page 358 which is in effect a urethral dilator designed to stretch and release a stricture or narrowing of the urethra. The cannula without the bougie would be inserted through the tip of the penis up to or through the point of narrowing.
The hollow bougie is then introduced over a central conducting rod, dilating the bore of the cannula as it passes, so releasing any stricture. The plates securing either side of the protective cannula are made from crosshatched ivory as is the end of the introducing rod. The ivory plate on one side is marked ‘Maw London’