Mohammad bin Zakaria Razi

 Mohammad bin Zakaria Razi is one of the great Iranian scholars of the third century AH. George Sarton has called the second half of the third century (AH) in the history of science, the age of Mohammad bin Zakaria Razi (251-313 AH) (865-925 BC). Razi is the greatest clinical physician of Islam and the Middle Ages, the physicist, the chemist, and the philosopher with his own independent thinking. Apparently, he studied mathematics, philosophy, astronomy and literature. He was probably engaged in studying chemistry in his youth, and later due to his eye disease, he studies medicine and became famous in this science and prominent in this area of ​​study. At the service of Abu Saleh Mansur ibn Ishaq Samani, the ruler of Ray, Razi was chosen as the head of the new hospital founded there. Later he became the head of the hospital in Baghdad. Because of his great reputation, various rulers invited him to their court. Razi had a good moral and behavior, and treated patients with kindness and affection, and endowed the poor the people in need. Some have counted his publications up to 198 and others attributed 237 books to him. None of his works about nature, mathematics, astronomy, and the recognition of light are left today. Razi did not limit himself to the scientific aspects of medicine, but in every sense he was a great physician, and was a master in the science and practice of medicine. His memoir, in which he has described his patients' improvement procedure completely, is available today. His most famous work is in Al Hawi book of medicine. His other works in this field are Al-Tebe al-Muluki and Mansoori's book. In addition, there are reports on some diseases, the most famous of which are al-Jedri and al-Hassbeh books, which have been appraised and acclaimed by the Europeans and are considered to be the best medical treatises of the past. There is also a treatise on bladder and kidney stones published in French in London. Moreover, Razi has written a book on philosophy and theology and supernatural and religious and philosophical controversy. He became blind at the end of his life as a result of a continuous study of alchemy, and eventually passed away in 313 AH.