Rhazes

Rhazes (rā`zēz) or Rasis (rā`sĭs,–zĭs), 860–932, Persian physician. He was chief physician at the Baghdad hospital. An observant clinician, he formulated the first known description of smallpox as distinguished from measles in a work known as Liber de pestilentia (tr. A Treatise on Smallpox and Measles, 1848). His works were widely circulated in Arabic, and Greek versions and were published in Latin in the 15th cent. They include a textbook of medicine called Almansor and an encyclopedia of medicine compiled posthumously from his papers and known as Liber continens.

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Razi, al-

 in full Abu Bakr Muhammad ibn Zakariyya' al-Razi Latin Rhazes

(born c. 865, Rayy, Persia—died 925 or 935, Rayy) Persian alchemist and philosopher. He saw himself as the Islamic heir of Socrates in philosophy and of Hippocrates in medicine. In The Comprehensive Book, he surveyed Greek, Syrian, early Arabic, and some Indian medical knowledge, adding his own comments. A number of his works were translated into Latin and other languages. One such, The Spiritual Physick of Rhazes, is a popular ethical treatise and major alchemical study. He called himself a follower of Plato but disagreed with Arabic interpreters of Plato. His theory of the composition of matter is similar to that of Democritus. He was considered one of the greatest physicians of the early Islamic world.