was followed by “A History of the Jews of Persia,” and within the same year he published his “Lectures on Scripture Zoology” which was succeeded by his “Lectures on the Mosaic Cosmogony.” Shortly afterwards he gave to the world “The Cosmography of Peritsol,” a work which at once attracted great attention and brought its author prominently to the front. It received such favourable notice from leading reviews as to be republished in part by the _Occident_ and other magazines, and translations in various languages were brought out by publishers in foreign countries. As late as 1881 we find it attracting the attention of the learned Chevalier Pesaro, of Italy, in the columns of an Italian review. His next important work “A Commentary on Samuel Hannagid’s Introduction to the Talmud,” displayed a deep and broad acquaintance with rabbinical literature, and was received with marked approbation by the _literati_ of this continent and Europe. His literary labours had now made him a prominent figure among the learned bodies of Montreal, and in 1853 he was appointed Professor of Hebrew and Oriental literature at McGill University, Montreal, a position which he continued to fill with marked ability during the rest of his life, and for which his deep knowledge of Semitic tongues particularly adapted him. He was also a co-labourer of Sir William Dawson in the Natural History Society, as well as at McGill, and did much towards vitalizing and extending the usefulness of that body. In 1853, in conjunction with the Rev. J. J. Lyons, of New York, he published his work on “The Jewish Calendar System,” containing a very exhaustive and abstruse treatise upon the Jewish mode of calculating time by the lunar system. Some years after this he completed one of his greatest and most learned productions, “The Sanitory Institutions of the Hebrews;” a work containing a most elaborate and critical consideration of the rabbinical dietary and hygienic laws, as based upon the Jewish traditional exposition of the hygienic statutes of the Bible, viewed in the light of modern scientific discoveries. The work excited alike the applause of scientists and of rabbinical scholars, and the eminence to which its author had now attained resulted in his having the degree of LL.D. conferred upon him in 1858. Shortly after the publication of “The Sanitory Institutions of the Hebrews,” Dr. de Sola published a supplemental work to it, entitled, “Behemoth Hatemeoth;” and in 1860, when Dr. Hall founded the _British American Journal_, devoted to the advancement of medical and physical sciences, Dr. de Sola accepted an invitation to assist the publication, and among many others of his writings that appeared in this journal his articles “Upon the Employment of Anæsthetics in cases of Labour, in connection with Jewish Law,” is specially worthy of notice. During the succeeding decade he was particularly active with his pen, bringing out