Spanish physician of the latter half of the thirteenth century; perhaps identical with Nathan of Montpellier, the teacher of the unknown author of the "Sefer ha-Yashar." He was the son of a physician, and early began the study of medicine. He was the author of "αΊ’ori ha-Guf" (Steinschneider, "Cat. Bodl." col. 2537; Neubauer, "Cat. Bodl. Hebr. MSS." Nos. 2130, 1; 2131; 2132, 1), in which he collected the opinions of Hippocrates, Galen, Averroes, Avicenna, and Maimonides on therapeutics and hygiene. In this work he uses all the medical and botanical terms he could find in the Talmud; otherwise he employs technical Arabic expressions, which he afterward translates into the vernacular. He is supposed to have been the author of a work on the celestial spheres.