as a political instrument, and for the difficulties which attend the career of Prophet-statesman, the life of Joseph Smith (the founder of Mormonism) furnishes illustrations of the most instructive character; only the biographer of Mohammed must envy the wealth and authenticity of the material at Dr. Riley's disposal, without which the formulæ of modern psychology could not have been applied to the interpretation of Smith's career so successfully as Dr. Riley has applied them.

A second class of works are those in which savage life is described at first hand: and among these the Autobiography of James P. Beckwourth deserves special notice. There are chapters in that work where by substituting camel for horse we might find a reproduction of Bedouin manners and institutions; and the question of Beckwourth's veracity does not affect the general truth of his descriptions.

Finally, I have to thank various persons from whom I have derived assistance. I am indebted for many suggestions and improvements to the Editor of the Series, to J. P. Margoliouth, and to the Rev. W. J. Foxell, who have read and re-read the proofs; to Mr. A. E. Cowley, Fellow of Magdalen College, for advice in the selection of coins; to Dr. J. Ritchie, Fellow of New College, and Mr. R. B. Townshend for guidance with regard to medical and anthropological works; and to Mr. G. Zaidan, editor of the Cairene journal Hilal, for leave to reproduce certain plates that have appeared in his magazine, and also for the names of certain Arabic works with which I

was not previously acquainted. Mr. Zaidan is well known in Arabic-speaking countries as a historian, novelist, and journalist; and I hope that ere long I may have the pleasure of introducing some of his works to English readers.