alchemy

Supposed technique of transmuting base metals, such as lead and mercury, into silver and gold by the philosopher's stone, a hypothetical substance, to which was also attributed the power to give eternal life.

This aspect of alchemy constituted much of the chemistry of the Middle Ages. More broadly, however, alchemy was a system of philosophy that dealt both with the mystery of life and the formation of inanimate substances. Alchemy was a complex and indefinite conglomeration of chemistry, astrology, occultism, and magic, blended with obscure and abstruse ideas derived from various religious systems and other sources. It was practised in Europe from ancient times to the Middle Ages but later fell into disrepute when chemistry and physics developed.

Alchemy probably began in Egypt, where it is mentioned in very early records. Legend after legend developed regarding the origin of this mystical science, which is variously attributed to Hermes Trismegistus, to the fallen angels of the Book of Genesis, and yet again by revelation to Moses and Aaron. The origin through Hermes was most generally accepted, and has affected chemical language down to the present day (for example, ‘hermetically sealed’).

During the 4th and 5th centuries the writings of the alchemists continued increasing until by the end of the 5th century speculative alchemy had reached its highest point in the Alexandrian schools. During the Islamic conquests, many Arabs and Persians became notable alchemists. One of the best known was Jabir ibn Hayyan, known to Western Europe as Geber. His ideas were very similar to those of the old Alexandrian philosophers, and he also believed in the influence of the planets on metals.

The theory of transmutation, which can be traced quite easily in the writings of the Greek philosophers, continued to exist amongst the alchemists of the Middle Ages and men such as St Albertus Magnus, Roger Bacon, and Vincent of Beauvais all believed in it. Even well into the 17th century alchemistic ideas were still held, at least from the academic point of view, by the chemists of the period. Among them may be mentioned Johann Glauber, Robert Boyle, and, for some time Isaac Newton and Gottfried Leibniz, and even Dr Johnson, who was interested in chemistry.