Abol-Hasan Ali Ben Hnsoin Ben All Masidi, an Arabian scholar, born in Bagdad about 890, died probably in Cairo in 956. He belonged to a family illustrious from the time of Mohammed. From childhood he exhibited remarkable talents and fondness for study, and attained a universality of erudition which has been equalled by no other Arab. On some important questions he expressed ingenious and novel views, which were in advance of his successors for several centuries. Not content with the information contained in books, he undertook several long journeys. About 914 he visited the ancient Persepolie, and passed thence to India, Ceylon, the coast of China, Madagascar, and southern Arabia, and explored the region of the Caspian sea. About 926 he was in Palestine, and he subsequently dwelt in Svria and in Egypt. He says he travelled so far to the east that he forgot the west, and so far to the west that he forgot the east. His most important work is the Akhbar al-zeman, or "History of the lunes, an immense general history, which has never been printed; no copy of it exists in Europe. His second work, entitled Kitab al-wasat, or "Book of the Middle," treated curious question- in history, geography, philosophy, and the sciences; but copies of it are very rare, and unknown in Europe. Perceiving that these works were too voluminous to be popular, he wrote a smaller history, entitled Moritj al-dheheb ve-maadin al-jewdhir, or "Meadows of Gold and Mines of Gems," which is not rare in the libraries of Europe. The first volume has been translated into English by Dr. Aloys Sprenger (London, 1841); there is a French translation by Derenbourg, and an edition of the original with a translation by Barbier de Meynard (7 vols., Paris, 1861-73). He is the author of a variety of other works on religion, morals, medicine, and the sciences, some of which are extant in manuscript, and others are known only by their titles.