HG Kern Spring Lancet
Four veterinary spring lancets.  Two of the pieces are made by HG Kern of Philadelphia, PA.  These items were all probably made c. 1850.  The unit on the far left is nickel plated.
Opening the back of the handles of these pieces reveals the storage compartment for extra blades.
A rotating bar fits into a slot on the bottom of the blade to hold it in place.
Brass Veterinary spring lancet by Samuel Jackson of Baltimore, c.1850Jackson worked in Baltimore from 1833-1866 as a cutler and surgical instrument maker.