Alchemy is a philosophical and protoscientific tradition practiced throughout Europe, Egypt and Asia. It aimed to purify, mature, and perfect certain objects. Common aims were chrysopoeia, the transmutation of "base metals" (e.g., lead) into "noble metals" (particularly gold); the creation of an elixir of immortality; the creation of panaceas able to cure any disease; and the development of an alkahest, a universal solvent. The perfection of the human body and soul was thought to permit or result from the alchemical magnum opus and, in the Hellenistic and western tradition, the achievement of gnosis. In Europe, the creation of a philosopher's stone was variously connected with all of these projects.
In English, the term is often limited to descriptions of European alchemy, but similar practices existed in the Far East, the Indian subcontinent, and the Muslim world. In Europe, following the 12th-century Renaissance produced by the translation of Islamic works on science and the Recovery of Aristotle, alchemists played a significant role in early modern science (particularly chemistry and medicine). Islamic and European alchemists developed a structure of basic laboratory techniques, theory, terminology, and experimental method, some of which are still in use today. However, they continued antiquity's belief in four elements and guarded their work in secrecy including cyphers and cryptic symbolism. Their work was guided by Hermetic principles related to magic, mythology, and religion.