Physician, philosopher, alchemist, musician, and mathematician, born in Rayy, Persia; called Rhazes in the West. He was born in the year 865 in the Persian city of Rayy, near present-day Tehran, and died in the same town about 925. Before learning medicine, he studied philosophy, alchemy, and music. At an early age he gained eminence as an expert in medicine and alchemy, and patients and students flocked to him from distant parts of Asia.
He was first placed in charge of the first Royal Hospital at Rayy, from where he soon moved to a similar position in Baghdad and became head of its famous Muqtadari Hospital. He moved from time to time to various cities, especially between Rayy and Baghdad, but finally returned to Rayy, where he died around 930 C.E. His name is commemorated in the Razi Institute near Tehran. He also served as physician at the Samanid court in Central Asia.
Razi wrote on many different subjects. His general medical textbook, Kitab al-Mansuri fi al-tibb (The Book of Medicine for Mansur) was written for the Samanid ruler of Rayy, Abu Salih al-Mansur. His voluminous working files of readings and personal observations were assembled posthumously by his students and circulated under the name Kitab al-Hawi fi al-tibb (The Comprehensive Book on Medicine). Over 1,000 of his case histories are also preserved today, and they provide an important insight into the working life of the greatest medieval clinician. Kitab al-Mansuri, which was translated into Latin in the 15th century C.E., comprised ten volumes and dealt exhaustively with Greco-Arab medicine. Some of its volumes were published separately in Europe. His al-Judari wal Hasabah was the first treatise on smallpox and chicken-pox, and was the first to draw clear comparisons between smallpox and chicken-pox. Al-Hawi was the largest medical encyclopaedia ever composed at the time, containing on each medical subject all important information that was available from Greek and Arab sources.
A special feature of his medical system was that he encouraged cure through healthy and regulated food. This regiment was combined with his emphasis on the influence of psychological factors on health. Razi was an expert surgeon, and was the first to use opium as anaesthesia.
In addiiton to his clinical work, Razi was also a researcher. He portrayed in great detail several chemical reactions and also given full descriptions of and designs for about twenty instruments used in chemical investigations. His description of chemical knowledge was translated into Latin and used for many years as the source for chemistry. He was the first to produce sulfuric acid together with some other acids, and he also prepared alcohol by fermenting sweet products. In the biology area, Razi developed a primitive classification system; dividing substances into plants, animals and minerals, thus in a way opening the way for inorganic and organic chemistry.