Alkindi, Or Alchindus, an Arabian physician and philosopher, born in Bassorah at the end of the 8th century, died in the middle of the 9th. Some, however, place his life two or three centuries later. He wrote more than 200 different treatises on logic, music, geometry, arithmetic, astronomy, medicine, etc. His treatise known under the Latin title I)e Theoria Magicarum Artium has secured for him the fame of a magician. ' Various other works of his were translated into Latin during the middle ages, and published at Paris, Stras-burg, and Venice. His theories are distinguished by great ingenuity, so much so that Cardan ranked him among the twelve subtle spirits of the world.