Alchemists attempted to purify, mature, and perfect certain materials.[1][4][5][n 1] Common aims were chrysopoeia, the transmutation of "base metals" (e.g., lead) into "noble metals" (particularly gold);[2] the creation of an elixir of immortality;[2] the creation of panaceas able to cure any disease; and the development of an alkahest, a universal solvent.[6] The perfection of the human body and soul was thought to permit or result from the alchemical magnum opus[2] and, in the Hellenistic and Western mystery tradition, the achievement of gnosis.[5] In Europe, the creation of a philosopher's stone was variously connected with all of these projects.