Scot as a mathematician, alchemist, and astrologer, had this been his sole life’s work, would have merited no insignificant niche in the temple of Science; but in addition to this, he exercised, though in an entirely indirect manner, a marked influence on the history of Europe. His talents and learning commended him for the position of tutor to Frederick II., at that time king only of Sicily, but afterwards “Emperor of the Romans.” Frederick was an orphan, having lost both his parents in early childhood, and the receptive mind of the ardent boy responded sympathetically to the instructions of his broad-minded and accomplished tutor, who was destined subsequently to become his confidant and friend. Michael Scot’s first efforts as an author had for their aim the education of his royal pupil. For this purpose he first wrote the _Liber Introductorius_, and afterwards the _Liber Particularis_ and the _Physionomia_. The first two of these books dealt with astronomy and astrology, and the latter with physiognomy and the reading of character from the physical appearance. Marriages were arranged early in those days, and Frederick, when a boy of but fourteen, was united in wedlock, at the Pope’s desire, with Constance, daughter of the King of Aragon, and widow of the King of Hungary, who was some ten years his senior. This brought the attendance of Michael Scot at the court at Palermo, temporarily at least, to an end, and led to his setting sail, as already narrated, for the coasts of Spain. It appears that the _Physionomia_ was his parting gift on his marriage to his illustrious pupil. On his arrival in Spain, Scot betook himself to the headquarters of the scientific activities of those days, the renowned city of Toledo. Here, towards the middle of the twelfth century, a regular school for translations from the Arabic had been established, and it was work of this kind on which Scot himself embarked. Here he translated the _Abbreviatio Avicennæ_ with a dedication to the Emperor Frederick in the following terms: “O! Frederick, Lord of the World, and Emperor, receive with devotion this book of Michael Scot, that it may be a grace unto thy head and a chain about thy neck”—no empty compliment as such phrases generally are, nor one unappreciated by its distinguished recipient. Here, too, he pursued his studies in alchemy, chemistry, medicine, and astrology. Alchemy in those days was a special bone of contention, one school maintaining its feasibility, and the other denouncing it, after the manner of nineteenth century scientists, as a mere will-o’-the-wisp. The belief in it which later on took hold of Mediæval Europe had not yet met with any general sort of acceptance, though the Arabian school in the main adopted it, and there seems little doubt that it was held by Michael Scot himself. One book indeed on this particular subject, _De Alchimia_, is attributed to his pen. The book is contained in a manuscript in possession of Corpus Christi College, Oxford.