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Rhasis (or Rhazes) (ca. 825-925)

Rhasis (or Rhazes) (ca. 825-925)

Name given to the famous Arabian physician, chemist, and alchemist Abu Bekr Muhammed Ben Zakeriyah er-Rasi. His popular name "Al-Rhasis" (Man of Ray) derives from his birthplace of Ray, near Teheran, on the frontiers of Khorassan. He first studied philosophy, logic, metaphysics, poetry, and music, and became a skilled player on the lute. At the age of thirty, he began to study medicine and soon became one of the most famous physicians of his time. He was director of the famous hospital of Bhagdad, and a great many books on medicine, chemistry, and philosophy are ascribed to him.

He also wrote treatises on alchemy and the transmutation of metals. Some commentators have compared his intellectual attainments with those of Galileo and Robert Boyle. He had a great reputation for his insistence upon the importance of practical experiment over theory. He was one of the first experimenters to mention borax, orpiment, realgar, and other chemical compounds.

There is a probably apocryphal story that he dedicated an alchemical work to the Emir El Mansur, prince of Khorassan, who rewarded him with a thousand pieces of gold, but desired to witness a transmutation. Rhasis was by now an elderly man and his experiment was unfortunately unsuccessful.

El Mansur was enraged, and struck him with a whip, saying "I have rewarded you richly for your trouble, and now I must punish you for your affirmation of lies!" As a result, Rhasis was blinded. However, other explanations have been offered for his failing eyesight, including the claim that it resulted from an inordinate appetite for eating beans.

In his studies in chemistry he left some results of real value, notwithstanding the time and trouble he spent in the pursuit of the philosophers' stone. Another theory which he held in common with Geber and others was that the planets influenced metallic formation under the earth's surface.


Barrett, Francis. The Lives of the Alchemystical Philosophers. 1815. Rev. ed. as Alchemists Through the Ages. Blauvelt, N.Y.: Rudolf Steiner Publications, 1970.

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