He was born at Cordova A.D. 1135, and, while yet young, wrote commentaries on the Talmuds both of Babylon and Jerusalem, and also a work on the Calendar; but, embracing Mohammedanism, he emigrated to Egypt, and there became physician to the celebrated Sultan Saladin. Among his works are medical aphorisms, derived from former Greek, Latin, Hebrew, and Arabic sources; an abridgment of Galen; and of his original treatises, which were very numerous, may be mentioned those "On Hemorrhoids," "On Poisons and Antidotes," "On Asthma," "On the Preservation of Health,"--the latter being written for the benefit of the son of Saladin--"On the Bites of Venomous Animals"--written by order of the sultan--"On Natural History." His "Moreh Nevochim," or "Teacher of the Perplexed," was an attempt to reconcile the doctrines of the Old Testament with reason. In addition to these, he had a book on Idolatry, and one on Christ. Besides Maimonides, the sultan had another physician, Ebn Djani, the author of a work on the medical topography of the city of Alexandria. From the biographies of these learned men of the twelfth century it would seem that their religious creed hung lightly upon them. Not unfrequently they became converted to Mohammedanism. [Sidenote: Later Jewish physicians.] It might be tedious if I should record the names and writings of the learned European Jews of the twelfth and thirteenth centuries, a period more prolific of these great men than even the preceding ages. But I cannot pass these later centuries without mentioning the Alphonsine Tables, calculated for Alphonso, the King of Castile, by Mascha, his Hebrew physician. The irreligious tendency of the times is illustrated by the well-known sarcasm uttered by that Spanish monarch respecting the imperfect construction of the heavens, according to the Ptolemaic hypothesis. For long, however, the Jews had been dabbling in free-thinking speculations. Thus Aben Tybbon, above-mentioned, anticipating that branch of science which has drawn upon itself, in later years, so much opprobrium, wrote a work containing a discussion of the causes which prevent the waters of the sea from encroaching on the land. Abba Mari, a Marseillese Jew, translated the Almagest of Ptolemy and the Commentary of Averroes upon it. The school of Salerno was still sending forth its doctors. In Rome, Jewish physicians were very numerous, the popes themselves employing them. Boniface VIII. had for his medical adviser Rabbi Isaac. At this period Spain and France were full of learned Jews; and perhaps partly by their exerting upon the higher classes with whom they came in contact too much influence, for the physician of a Christian prince was very often the rival of his confessor, and partly because the practice of medicine, as they pursued it, interfered with the gains of the Church, the clergy took alarm, and caused to be re-enacted or enforced the ancient laws. The Council of Beziers, A.D. 1246, and the Council of Alby, A.D.