Alchemy
AlchemyAlchemy, 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
chemistry.
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 Empedocles—that all things are composed of air, earth,
fire, and water—was 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
mercury.
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
processes.
>From the Arabs, alchemy...
To view the complete essay, you be registered.