John Leo Afer, de Medicis et Philosophus Arabibus, c. 14, apud Fabric. Bibliot. Graec. tom. xiii. p. 278, 279. This philosopher is named Esseriph Essachalli, and he died in Africa, A. H. 516, A.D. 1122. Yet this story bears a strange resemblance to the Sherif al Edrissi, who presented his book (Geographia Nubiensis, see preface p. 88, 90, 170) to Roger, king of Sicily, A. H. 541, A.D. 1153, (D'Herbelot, Bibliotheque Orientale, p. 786. Prideaux's Life of Mahomet, p. 188. Petit de la Croix, Hist. de Gengiscan, p. 535, 536. Casiri, Bibliot. Arab. Hispan. tom. ii. p. 9 - 13); and I am afraid of some mistake.