Science AlchemyAlchemy, ancient art practiced especially in the Middle Ages, devoted chieflyto discovering a substance that would transmute the more common metals intogold or silver and to finding a means of indefinitely prolonging human life. Although its purposes and techniques were dubious and often illusory, alchemywas in many ways the predecessor of modern science, especially the science ofchemistry. The birthplace of alchemy was ancient Egypt, where, in Alexandria, it began toflourish in the Hellenistic period; simultaneously, a school of alchemy wasdeveloping in China. The writings of some of the early Greek philosophers mightbe considered to contain the first chemical theories; and the theory advancedin the 5th century BC by Empedocles that all things are composed of air, earth,fire, and water was influential in alchemy. The Roman emperor Caligula is saidto have instituted experiments for producing gold from orpiment, a sulfide ofarsenic, and the emperor Diocletian is said to have ordered all Egyptian worksconcerning the chemistry of gold and silver to be burned in order to stop suchexperiments. Zosimus the Theban (about AD 250-300) discovered that sulfuricacid is a solvent of metals, and he liberated oxygen from the red oxide ofmercury. The fundamental concept of alchemy stemmed from the Aristotelian doctrine thatall things tend to reach perfection. Because other metals were thought to beless "perfect" than gold, it was reasonable to assume that nature formed goldout of other metals deep within the earth and that with sufficient skill anddiligence an artisan could duplicate this process in the workshop. Effortstoward this goal were empirical and practical at first, but by the 4th centuryAD, astrology, magic, and ritual had begun to gain prominence. A school of pharmacy flourished in Arabia during the caliphates of the Abbasidsfrom 750 to 1258. The earliest known work of this school is the SummaPerfectionis (Summit of Perfection), attributed to the Arabian scientist andphilosopher Geber; the work is consequently the oldest book on chemistry properin the world and is a collection of all that was then known and believed. TheArabian alchemists worked with gold and mercury, arsenic and sulfur, and saltsand acids, and they became familiar with a wide range of what are now calledchemical reagents. They believed that metals are compound bodies, made up ofmercury and sulfur in different proportions. Their scientific creed was thepotentiality of transmutation, and their methods were mostly blind gropings;yet, in this way, they found many new substances and invented many usefulprocesses.

>From the Arabs, alchemy generally found its way through Spain into Europe. Theearliest authentic works extant on European alchemy are those of the Englishmonk Roger Bacon and the German philosopher Albertus Magnus; both believed inthe possibility of transmuting inferior metals into gold. This idea excited theimagination, and later the avarice, of many persons during the Middle Ages. They believed gold to be the perfect metal and that baser metals were moreimperfect than gold. Thus, they sought to fabricate or discover a substance,the so-called philosopher's stone, so much more perfect than gold that it couldbe used to bring the baser metals up to the perfection of gold. Roger Bacon believed that gold dissolved in aqua regia was the elixir of life. Albertus Magnus had a great mastery of the practical chemistry of his time. TheItalian Scholastic philosopher St. Thomas Aquinas, the Catalan churchmanRaymond Lully, and the Benedictine monk Basil Valentine (flourished 15thcentury) also did much to further the progress of chemistry, although alongalchemical lines, in discovering the uses of antimony, the manufacture ofamalgams, and the isolation of spirits of wine, or ethyl alcohol. Important compilations of recipes and techniques in this period include ThePirotechnia (1540; trans. 1943), by the Italian metallurgist VannoccioBiringuccio; Concerning Metals (1556; trans. 1912), by the German mineralogistGeorgius Agricola; and Alchemia (1597), by Andreas Libavius, a Germannaturalist and chemist. Most famous of all was the 16th-century Swiss alchemist Philippus Paracelsus. Paracelsus held that the elements of compound bodies were salt, sulfur, andmercury, representing, respectively, earth, air, and water; fire he regarded asimponderable, or nonmaterial. He believed, however, in the existence of oneundiscovered element common to all, of which the four elements of the ancientswere merely derivative forms. This prime element of creation Paracelsus termedalkahest, and he maintained that if it were found, it would prove to be thephilosopher's stone, the universal medicine, and the irresistible solvent. After Paracelsus, the alchemists of Europe became divided into two groups. Onegroup was composed of those who earnestly devoted themselves to the scientificdiscovery of new compounds and reactions; these scientists were the legitimateancestors of modern chemistry as ushered in by the work of the French chemistAntoine Lavoisier. The other group took up the visionary, metaphysical side ofthe older alchemy and developed it into a practice based on imposture,necromancy, and fraud, from which the prevailing notion of alchemy is derived. "Alchemy," Microsoft (R) Encarta. Copyright (c) 1994 Microsoft Corporation. Copyright (c) 1994 Funk & Wagnall's Corporation.