Christian tradition produced many popular stories elaborating on canonical scripture. According to an English folk belief, certain herbs gained their current healing power from having been used to heal Christ's wounds on Mount Calvary. In this case, a non-canonical story has a connection to a non-narrative form of folklore — namely, folk medicine. Arthurian legend contains many elaborations upon canonical mythology. For example, Sir Balin discovers the Lance of Longinus, which had pierced the side of Christ. According to a tradition widely attested in early Christian writings, Adam's skull lay buried at Calvary; when Christ was crucified, his blood fell over Adam's skull, symbolizing humanity's redemption from Adam's sin.