This artificial leech is plated brass. The plunger to the left is spring loaded to allow the creating of a vaccuum when depressed and the foot of the item is applied to the skin. When the plunger is released the draw is created. The right tube contains a spring driven blade that is released with the depression of the lever. The item is marked as Kidston & Co Manufacturers, 18 Bishopsgate, London, Reg. Feb 11th 1850.