A panacea is an old word to describe a chemical or discovery that would cure all illnesses.
Alchemy is a term used to describe the historical study of elements and matter with the goal of creating an elixir for immortality or trying to change metals into more precious metals.
Alchemy whilst being the study of such wild theories as the transmutation of metals and prolonging of life also had many useful origins of chemistry today from drug design to experimental techniques we still use in the lab today.