721?-815?

Arab alchemist who pioneered the development of many chemical processes. He prepared steel and other metals, used manganese dioxide in glassmaking, and devised dying and tanning techniques. He also prepared hydrochloric, citric, and tartaric acids, as well as ammonium chloride and aqua regia. Jabir is best known for modifying the Greek doctrine of four elements, maintaining that they combine to form sulfur (idealized principle of combustibility) and mercury (idealized principle of metallic properties), from whence all metals are formed. Jabir believed that, in principle, it was possible to transmute one metal into another, an idea widely believed until the rise of the phlogiston theory in the late seventeenth century.