Abu Bakr Muhammad Ibn Zakariyah Ar-razi, Latin Rhazes, born 864 A.D., Rayy, died 930 A.D., Rayy, in Iran, celebrated alchemist and Muslim philosopher who is also considered to have been the greatest physician of the Islamic world. He studied medicine, mathematics, astronomy, chemistry and philosophy. At the age of 30, the practical experience gained at the well-known “Muqtadari” Hospital helped him in his chosen profession of medicine. He was first placed in charge of the first Royal Hospital at Ray, from where he soon moved to a similar position in Baghdad, where he remained the head of its famous “Muqtadari” Hospital for many years. He moved from time to time to various cities, especially between Ray and Baghdad, and finally returned to Ray, where he died around 930 A.D. Razi was a Hakim, an alchemist and a philosopher. In medicine, his contribution was so significant that it can only be compared to that of Ibn Sina. Some of his works in medicine e.g. Kitab al- Mansoori, Al-Hawi, Kitab al-Mulooki and Kitab al-Judari wa al- Hasabah earned everlasting fame. Kitab al-Mansoori, was translated into Latin in the 15th century A.D. . Some of its volumes were published separately in Europe. His al-Judari wal Hasabah was the first treatise on smallpox and chicken pox, and is largely based on Razi's original contribution: It was translated into various European languages. Through this treatise he became the first to draw clear comparisons between smallpox and chickenpox. Al-Hawi was the largest medical encyclopedia composed by then. It contained on each medical subject all important information that was available from Greek and Islamic sources, along with Razi’s own remarks based on his experience and views. A special feature of his medical system was that he greatly favored cure through correct and regulated food. This was combined with his emphasis on the influence of psychological factors on health. He also tried proposed remedies first on animals in order to evaluate their effects and side effects. He was also an expert surgeon and was the first to use opium as an anesthetic.

In addition to being a physician, he compounded medicines and, in his later years, gave himself over to experimental and theoretical sciences. It seems possible that he developed his chemistry independently of Jabir Ibn Hayyan. He portrayed in great detail several chemical reactions and also gave full descriptions of and designs for about twenty instruments used in chemical experiments.

His description of chemical knowledge is in plain and plausible language. One of his books called Kitab-al-Asrar deals with the preparation of chemical materials and their utilization. Another one was translated into Latin under the name Liber Experiment rum, He went beyond his predecessors in dividing substances into plants, animals and minerals, thus in a way opening the way for inorganic and organic chemistry. By and large, this classification of the three kingdoms still holds. As a chemist, he was the first to produce sulfuric acid together with some other acids, and he also prepared alcohol by fermenting sweet products.