Jabir ibn Hayyan (Geber)

c. 721-c. 815

Arab Alchemist and Physician

Jabir ibn Hayyan, often known as Geber, is sometimes confused with a fourteenth-century Spanish mystic who also called himself Geber. In fact the latter deliberately took on the name of his distinguished predecessor, and thus is typically known as "the false Geber." As for the true Jabir, he is widely credited as the Father of Chemistry, the first alchemist to take his studies beyond superstition and into the realm of pure science. Among his many practical discoveries were arsenic, sulphur, and mercury.

Born Abu Musa Jabir ibn Hayyan, Jabir practiced alchemy and medicine professionally in the town of Kufa, now in Iraq, beginning around 776. Little else is known of his biography, except the fact that at one point he worked under the patronage of a vizier from the Barmakid dynasty, and that he was in Kufa when he died. Far more is known concerning Jabir's work, including the fact that he produced some 100 writings, of which 22 were on the subjects of chemistry and alchemy.

By recognizing that it was necessary to use specific amounts of a given substance to produce a particular reaction, and by emphasizing experimentation, observation, and reproducible methods, Jabir laid the groundwork for chemistry as a science. He identified three basic types of chemical substances: spirits such as arsenic and ammonium chloride, which vaporize with heat; metals; and compounds that may be crushed into powder. Today this distinction between volatile substances, metals, and nonmetals remains in use. In addition to his discoveries of specific chemicals—which include nitric, hydrochloric, citric, and tartaric acids—Jabir contributed to knowledge concerning distillation, sublimation, crystallization, calcination, and evaporation.

He also discovered the fact that heating a metal adds to its weight, and his experiments with the darkening effects of light on silver nitrate provided a forerunner for the idea of photographic negative images. Among the instruments developed by Jabir was the alembic, a vessel used in distillation. He also was the first to use manganese dioxide for making glass, and developed aqua regia as a means of dissolving gold. In addition, he created a number of practical applications for chemistry in areas such as steelmaking, rust-prevention, gold lettering, cloth-dyeing, leather-tanning, and waterproofing.

Finally, evidence of Jabir's lasting impact can be discerned from the many Arabic terms—most notably, alkali—that made their way into European languages through his writings. Of Jabir's many books, among the most influential in the West have been Kitab al-Kimya, translated in 1144 by Robert of Chester as "The Book of the Composition of Alchemy," and Kitab al'-Sab'een, which Gerard of Cremona (1114-1187) translated. Numerous other translations appeared in Latin, and during later centuries works of the false Geber were mixed in with those of the true Jabir.

JUDSON KNIGHT