afterwards he published his “Lectures on the Mosaic Cosmogony.” This was followed by his “Cosmography of Peritsol,” a work displaying such erudition that it gained a wide circulation in Europe and was reprinted there in several languages. His next work, “A Commentary upon Samuel Hannagid’s Introduction to the Talmud,” was a book which deservedly attracted much attention, owing to the light which it threw upon an interesting portion of rabbinical literature and to its depth of Talmudic knowledge. In 1853 he published, conjointly with the Rev. J. J. Lyons, of New York, a work on the Jewish Calendar System, chiefly valuable on account of its excellent prefatory treatise upon the Jewish system of calculating time. Dr. de Sola’s mastery of Semitic languages and literature early attracted the notice of our learned bodies, and, after first acting as lecturer, he was, in 1853, appointed professor of Hebrew and Oriental literature at McGill University. The high abilities which he displayed as occupant of this chair proved the wisdom of the appointment, and he continued to hold the position during the rest of his life. For some time Dr. de Sola had been engaged in the preparation of one of his most important productions, “The Sanatory Institutions of the Hebrews.” The work was published in two parts and was an exhaustive exposition of the hygienic laws of the Hebrews, as exhibited in both Scriptural and rabbinical writings, critically examined in the light of modern scientific knowledge. It was a production which evinced how deeply the author had penetrated into scientific as well as rabbinical paths of learning. Shortly afterwards he published a supplemental work to it, entitled “Behemoth Hatemeoth.” The prominence to which Dr. de Sola had now reached among men of letters led McGill University to confer upon him the degree of LL. D. in 1858. In 1860, Dr. Hall, the editor of The British American Journal, devoted to physical and medical science, induced Dr. de Sola to assist that publication with his pen, and, among other contributions, his series of articles “Upon the Employment of Anaesthetics in Cases of Labor, in Connection with Jewish Law,” call for particular mention.