The memory of Roger Bacon has received but scant justice. Although long since recognized as one of the chief lights of England during the Middle Ages, the clinging mist of popular tradition has obscured his real brightness and distorted its proportions, while even among scholars he has been more known by reputation than by actual acquaintance with his writings. His principal work, his "Opus Majus," was published for the first time in London in 1733, in folio, and afterwards at Venice in 1750, in the same form. Down to the publication of the volume before us, it was the only one of his writings of much importance which had been printed complete, if indeed it is to be called complete,--the Seventh Part having been omitted by the editor, Dr. Jebb, and never having since been published. The facts known concerning Roger Bacon's life are few, and are so intermingled with tradition that it is difficult wholly to separate them from it. Born of a good family at Ilchester, in Somersetshire, near the beginning of the thirteenth century, he was placed in early youth at Oxford, whence, after completing his studies in grammar and logic, "he proceeded to Paris," says Anthony Wood, "according to the fashion prevalent among English scholars of those times, especially among the members of the University of Oxford." Here, under the famous masters of the day, he devoted himself to study for some years, and made such progress that he received the degree of Doctor in Divinity. Returning to Oxford, he seems soon to have entered into the Franciscan Order, for the sake of securing a freedom from worldly cares, that he might the more exclusively give himself to his favorite pursuits. At various times he lectured at the University. He spent some later years out of England, probably again in Paris. His life was embittered by the suspicions felt in regard to his studies by the brethren of his order, and by their opposition, which proceeded to such lengths that it is said he was cast into prison, where, according to one report, he died wretchedly. However this may have been, his death took place before the beginning of the fourteenth century. The scientific and experimental studies which had brought him into ill-favor with his own order, and had excited the suspicion against him of dealing in magic and forbidden arts, seem to have sown the seed of the popular traditions which at once took root around his name. Friar Bacon soon became, and indeed has remained almost to the present day, a half-mythical character. To the imagination of the common people, he was a great necromancer; he had had dealings with the Evil One, who had revealed many of the secrets of Nature to him; he had made a head of brass that could speak and foretell future events; and to him were attributed other not less wonderful inventions, which seem to have formed a common stock for popular legends of this sort during the Middle Ages, and to have been ascribed indiscriminately to one