Cutting instruments, including scalpels, saws and knives, needles, forceps, hand drills, probes and trepanning tools (made to cut or drill holes in the scull) are among the oldest medical instruments, dating to the 1600s and earlier. Catheters, usually made of silver, date to the time of the Romans. Cased, fitted, surgical, midwifery, lithotomy and post mortem kits dating from the late 1700s well into the 1900s are highly collectable.