This branch of Michael Scot’s activity relates itself easily and naturally to what we already know of his acquirements and familiarity with the Arabian authors. It was from the _De Medicina_ of Rases that he borrowed so much material for his _Physionomia_. The _Abbreviatio Avicennae_ too, which he translated for Frederick in 1210, was in no small part a treatise on comparative anatomy and physiology, nor is it likely that he can have missed reading the famous _canon_ of the same author, in which Avicenna expounds a complete body of practical medicine. We need not wonder then to find that, on Scot’s return to court, his work on Averroës done, he added the practice of physic to his duties as Imperial Astrologer. This new profession must have offered itself to him as another means of securing a general forgetfulness of the questionable direction in which his philosophical studies had lately carried him. He seems in fact to have won almost as much fame in medicine as he had made for himself in the study of mathematics. Lesley says ‘he gained much praise as a philosopher, astronomer, and physician.’ Dempster speaks of his ‘singular skill,’ calling him ‘one of the first physicians for learning’[221] and adding that Camperius[222] had the highest opinion of him. An anonymous writer, _De claris Doctrina Scotis_, is even more precise, telling us that Scot was noted for the cures he effected in difficult cases, and that he excelled in the treatment of leprosy, gout, and dropsy.[223] Some slight remains of this skill are to be found in the libraries of Europe; for Michael Scot was a writer on the science of his art as well as a practising physician. The chief of these relics is a considerable work on the urine. This subject had been widely, if not deeply, studied by the more ancient medical authorities, whose investigations appear in the _Ketab Albaul_ of Al Kairouani,[224] and in a book to which we have already more than once referred: the _De Urinis_ compiled for Frederick in 1212.[225] The same title belongs to one of the treatises by Avicenna, which has been reprinted in the present century.[226] The _De Urinis_ of Michael Scot seems now extant in the form of an Italian translation alone. The exact title is as follows: ‘Della notitia e prognosticatione dell’orine, secondo Michele Scoto, così de’ sani, come delli infermi,’ or, more briefly, ‘El trattato de le urine secondo Michaele Scoto.’[227] The author enumerates no less than nineteen divisions of his subject, which he seems to have studied very exactly. This work long remained an authority in the medical schools, as appears, not only from the two translations we have noticed, but also in the fact that large use was made of it in a later collection which commences thus: ‘In the name of the Lord, Amen. These are certain recipes taken from the book of Master Michael Scot, Physician to the Emperor Frederick, and from the works of other Doctors.’[228]