A universal cure. Panacea was the daughter of Esculapios (god of medicine). The name is evidently composed of two Greek words panakeomai (all I cure). Of course the medicine that cures is the daughter or child of the healing art.
The Promethean unguent rendered the body invulnerable.
Aladdin's ring (q.v.) was a preservative against all the ills which flesh is heir to. Sir Gilbert's sword. Sir T. Malory, in his History of Prince Arthur (i. 116), says:-
“Sir Launcelot touched the wounds of Sir Meliot with Sir Gilbert's sword, and wiped them with the cerecloth, and anon a wholler man was he never in all his life.”
(See also Achilles' Spear, Medea's Kettle, Reynard's Ring [see Ring], Panthera, etc.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894