Weapon salve

A weapon salve is an ointment which aims to heal a wound caused by a bladed weapon. Method: apply an herbal preparation -, not to the abrasion itself but to the blade of the weapon that caused it. You can see how this won't work.

Belief in action at a distance was common among practitioners of Paracelsian medicine (Paracelsus, incidentally, coined the concept of "the dose makes the poison"). Typically the salve would include blood from the wound caused by the weapon.

Paracelsus's recipe for such a salve: Take of moss growing on the head of a thief who has been hanged and left in the air; of a mummy; of human blood, still warm – of each one ounce; of human suet, two ounces; of linseed oil, turpentine, and Armenian bole – of each two drachms. Mix all well in a mortar, and keep the salve in an oblong, narrow urn.

The use of a weapon salve involved a form of sympathetic magic. The weapon and the wound joined magically, as one caused the other. The ingredients for the salve itself all have magical properties associated with healing, with the alignment of the stars, or with other magical processes. The human blood is a form of life magic, common in any sacrificial ritual.