Alchemy was an early system of thinking about nature that contributed to the development of the modern science of chemistry. It was popular in ancient China, Persia, and western Europe throughout antiquity and the Middle Ages (400–1450). A combination of philosophy, metallurgical arts (the science of metals), and magic, alchemy was based on a distinctive world-view—that an essential correspondence exists between the microcosm and the macrocosm (the smallest and largest parts of the universe). Its objectives were: (1) to find ways of accelerating the rates at which metals were thought to "grow" within Earth in their development toward perfection (gold) and (2) to accomplish a similar perfection in humans by achieving eternal life.
Scholars do not know when or where alchemy originated. However, historians agree that alchemistic ideas and practices flourished in the ancient world within several cultural traditions. Even the term alchemy has remained mysterious; scholars have identified al as an Arabic article and proposed various possible meanings for the word chem, but a clear explanation of the term is still lacking.
The earliest alchemical practices are believed to have arisen in China in the fourth century B.C. The main emphasis in Chinese alchemy, it seems, was not on transmutation—the changing of one metal into another—but on the search for human immortality. In their search for an elixir (special liquid) of immortality, court alchemists experimented with mercury, sulfur, and arsenic. They sometimes created poisonous potions; several emperors died after drinking them. Such spectacular failures eventually led to the disappearance of alchemy in China.
Elixir: In alchemy, a substance that is supposed to have the power to change base metals into gold or to bring about human immortality.
Macrocosm: The whole extent of the universe.
Microcosm: A small part of the whole universe, as, for example, an individual human life.
Philosopher's stone: A material thought by alchemists to have the power to bring about the transmutation of metals.
Transmutation: The conversion of one substance into another, as in the conversion of lead or iron into gold.
Alchemy flourished in parts of Islam in the eighth and ninth centuries. Court scientists, encouraged by their rulers, began studying and translating Greek philosophical and scientific works to aid them in their quest. The greatest practitioner of Arabic alchemy was ar-Razi (also known as Rhazes; c. 850–c. 925), who worked in Baghdad.
This dogged pursuit of a recipe for gold led Arabic alchemists to study and classify chemical elements and chemicals. Ar-Razi speculated about the possibility of using "strong waters," which were in reality corrosive salt solutions, as the critical ingredient for the creation of gold. Experimentation with salt solutions led to the discovery of mineral acids, but scholars are not sure if Arabic alchemy should be credited with this discovery.
The history of Western alchemy probably begins in the Egyptian city of Alexandria. Among the most prominent Alexandrian alchemists was Zosimos of Panopolis, Egypt, who may have lived in the third or fourth century A.D. In accordance with older traditions, Zosimos believed that a magical ingredient was needed for the creation of gold. Greek alchemists called this ingredient xerion, which is Greek for "powder." This word came into Latin and modern European languages as elixir and later became known as the elusive philosopher's stone.
After the fall of the Western Roman empire in the fifth century, Greek science and philosophy—as well as alchemy—sank into oblivion. In was not until the eleventh century that scholars rediscovered Greek learning, translating Greek scientific and philosophical works into Latin. The pioneers of medieval science, such as Roger Bacon (c. 1219–c. 1292), viewed alchemy as a worthwhile intellectual pursuit, and alchemy continued to exert a powerful influence on intellectual life throughout the Middle Ages. However, as in ancient China, alchemists' continued failure to produce gold eventually provoked skepticism and led to its decline.
In the sixteenth century, alchemists turned to more practical matters, such as the use of alchemy to create medicines. The greatest practitioner of this type of alchemy was Swiss physician and alchemist Philippus Aureolus Paracelsus (1493–1541), who successfully used chemical drugs to treat disease. Although a believer in magic, astrology, and alchemy, Paracelsus was also an empirical scientist (one who relies on observation and experimental methods); he contributed significantly to the development of medicine.
While alchemy is often considered to be unscientific, some great scientists, including Isaac Newton (1643–1727), took the subject seriously enough to conduct alchemical experiments. In addition, alchemy is credited with laying the foundation for the study of chemistry. Not only did alchemists systematize and classify the knowledge of elements and chemicals, they also made a number of important discoveries, including sal ammoniac (ammonium chloride, which is used in batteries), saltpeter (potassium nitrate, which is used in gunpowder and the manufacture of glass; or sodium nitrate, which is used in rocket propellants and explosives), alcohol, and mineral acids. In addition, they developed a number of laboratory techniques, including distillation (a method of purifying a liquid) and crystallization (solidifying substances into crystals).
[ See also Chemistry ]