Nearly all the roots of England's maturest science run back into the deepest mediæval night. A worthy associate with Thomas Aquinas, Albert the Great, and Michael Scot, was the celebrated Roger Bacon, a native of Somersetshire, who flourished in the thirteenth century. This Franciscan monk seems to have been a "Phœnix of intellects" in the fundamental education of the English race, "an old and new library of all that was good in science." He greatly established and extended the natural sciences, by means of mathematics, and the production of phenomena in the way of experiments. To him especially credit is due, that the influence which he exercised upon the mode of treating natural studies, was more beneficial and of more lasting effect than the discoveries themselves which have been attributed to him. Says Humboldt, "He roused himself to independent thought, and strongly blamed the blind trust in the authority of the schools: yet he was so far from neglecting to search into Grecian antiquity, that he prizes the study of comparative philology, the application of mathematics, and the 'Scientia Experimentalis,' to which he devotes a particular section in his great work. One of the popes, Clement IV., defended and patronized him; but two others, Nicholas II. and IV., accused him of magic, and cast him into prison, and thus he experienced the reverses of fortune which have been felt by great men of all times. He was acquainted with the Optics of Ptolemæus and the Almagest. As he always calls Hipparchus 'Abraxis,' like the Arabs, we may conclude that he had only made use of a Latin translation of the Arabic work. Besides Bacon's chemical investigations respecting combustible and explosive mixtures, his theoretical optical works upon Perspective, and the position of the focus in a concave mirror, are the most important."