On August 27, 854, celebrated alchemist, physician, philosopher and polymath Muhammad ibn Zakariyya al-Razi (Rhazes) was born in Ray, Iran. He is considered to have been the greatest doctor in the world during the Middle Ages.
In his book Arabian Medicine, E. G. Browne writes, Abu Bakr Muhammad ibn Zakariyya of Ray, hence called in Arabic ar-Razi, and by the medieval Latinists “Rhazes” was probably the greatest and most original of all the Muslim physicians, and one of the most prolific as an author.
Razi spent most of his life in Persia, because it was his native country, and because his brother and his kinsmen dwelt there. His interest in Medicine was aroused, when he was of mature age, by visits to the hospital and conversations with an old druggist or dispenser who served in it.
Of the hospital, at Ray, he ultimately became chief physician, and there he attended regularly, surrounded by his pupils and the pupils of his pupils. Every patient who presented himself was first examined by the latter — the clinical clerks, as we should say; and if the case proved too difficult for them it was passed on to the Master’s immediate pupils, and finally, if necessary, to himself.
Subsequently, Razi became physician-in-chief to the great hospital at Baghdad, about the foundation of which he is said to have been consulted. Being asked to select the most suitable site, he is said to have caused pieces of meat to be hung up in different quarters of the city, and to have chosen the place where they were slowest in showing signs of decomposition.
Al-Razi is credited with being the first to recognize the reaction of the eye’s pupil to light. He wrote more than 224 books on various subjects. His most important work is the medical encyclopedia known as Al-Hawi fi al-Tibb, known in Europe as Liber Continens. His books on medicine, philosophy, and alchemy greatly influenced human civilization, especially in Europe.
Source: Arabian Medicine, E. G. Browne