Alchemy, ancient art practiced especially in the Middle Ages, devoted chiefly
to discovering a substance that would transmute the more common metals into
gold or silver and to finding a means of indefinitely prolonging human life.
Although its purposes and techniques were dubious and often illusory, alchemy
was in many ways the predecessor of modern science, especially the science of
The birthplace of alchemy was ancient Egypt, where, in Alexandria, it began to
flourish in the Hellenistic period; simultaneously, a school of alchemy was
developing in China. The writings of some of the early Greek philosophers might
be considered to contain the first chemical theories; and the theory advanced
in the 5th century BC by Empedoclesóthat all things are composed of air, earth,
fire, and waterówas influential in alchemy. The Roman emperor Caligula is said
to have instituted experiments for producing gold from orpiment, a sulfide of
arsenic, and the emperor Diocletian is said to have ordered all Egyptian works
concerning the chemistry of gold and silver to be burned in order to stop such
experiments. Zosimus the Theban (about AD 250-300) discovered that sulfuric
acid is a solvent of metals, and he liberated oxygen from the red oxide of
The fundamental concept of alchemy stemmed from the Aristotelian doctrine that
all things tend to reach perfection. Because other metals were thought to be
less "perfect" than gold, it was reasonable to assume that nature formed gold
out of other metals deep within the earth and that with sufficient skill and
diligence an artisan could duplicate this process in the workshop. Efforts
toward this goal were empirical and practical at first, but by the 4th century
AD, astrology, magic, and ritual had begun to gain prominence.
A school of pharmacy flourished in Arabia during the caliphates of the Abbasids
from 750 to 1258. The earliest known work of this school is the Summa
Perfectionis (Summit of Perfection), attributed to the Arabian scientist and
philosopher Geber; the work is consequently the oldest book on chemistry proper
in the world and is a collection of all that was then known and believed. The
Arabian alchemists worked with gold and mercury, arsenic and sulfur, and salts
and acids, and they became familiar with a wide range of what are now called
chemical reagents. They believed that metals are compound bodies, made up of
mercury and sulfur in different proportions. Their scientific creed was the
potentiality of transmutation, and their methods were mostly blind gropings;
yet, in this way, they found many new substances and invented many useful
>From the Arabs, alchemy generally found its way through Spain into Europe. The
earliest authentic works extant on European alchemy are those of the English
monk Roger Bacon and the German philosopher Albertus Magnus; both believed in
the possibility of transmuting inferior metals into gold. This idea excited the
imagination, and later the avarice, of many persons during the Middle Ages.
They believed gold to be the perfect metal and that baser metals were more
imperfect 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 could
be 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. The
Italian Scholastic philosopher St. Thomas Aquinas, the Catalan churchman
Raymond Lully, and the Benedictine monk Basil Valentine (flourished 15th
century) also did much to further the progress of chemistry, although along
alchemical lines, in discovering the uses of antimony, the manufacture of
amalgams, and the isolation of spirits of wine, or ethyl alcohol.
Important compilations of recipes and techniques in this period include The
Pirotechnia (1540; trans. 1943), by the Italian metallurgist Vannoccio
Biringuccio; Concerning Metals (1556; trans. 1912), by the German mineralogist
Georgius Agricola; and Alchemia (1597), by Andreas Libavius, a German
naturalist 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, and
mercury, representing, respectively, earth, air, and water; fire he regarded as
imponderable, or nonmaterial. He believed, however, in the existence of one
undiscovered element common to all, of which the four elements of the ancients
were merely derivative forms. This prime element of creation Paracelsus termed
alkahest, and he maintained that if it were found, it would prove to be the
philosopher\'s stone, the universal medicine, and the irresistible solvent.
After Paracelsus, the alchemists of Europe became divided into two groups. One
group was composed of those who earnestly devoted themselves to the