Michael Scot, as we know, had become familiar with the works of Rases while still in Sicily, and thought so highly of the _De Medicina_ as to borrow thence for his treatise on physiognomy no fewer than thirty-one chapters relating to that subject.[106] It is a natural conjecture then which leads us to find in his acquaintance with this author’s writings the starting-point of Scot’s interest both in medicine and in alchemy. Leaving for the present what may hereafter be said of his name and fame as a physician, let us examine the origin and nature of his work as a student of the Arabian chemistry. We have reached what would seem to be the proper moment for such an inquiry. The treatises of Michael Scot on this subject are not dated indeed, but their form shows them to belong to the epoch of his work as a translator. They were therefore probably produced during the period of his residence at Toledo, and as there is a long interval, otherwise unaccounted for, between 1210, when the _Abbreviatio Avicenna_ appeared, and the date of his next publication some seven years later, this blank cannot be better filled than by supposing that it was during these years he found time for the study of alchemy, and for the translation or composition of the writings in that branch of science which still bear his name. In this, as in almost all his other studies, Michael Scot sat at the feet of Eastern masters. But the Arabians themselves had derived their chemical science, at least in its first principles and primitive processes, from still older peoples. If we are to understand the progress of human thought in this science we must trace it from the beginning, following again that beaten track of tradition by which not physiognomy and alchemy alone, but almost all the secrets of early times, have reached the modern world. Primitive chemistry was closely connected with the still older art of metallurgy, out of which it arose by a natural process of development. Those who worked with ores soon discovered the secret of alloys, whereby a considerable quantity of baser metal, such as copper, lead or tin, could be added to gold or silver, so as greatly to increase the bulk of the whole without injuring either its appearance or usefulness. The problem of the crown set before Archimedes, and happily solved by that philosopher in the bath, shows how dexterously alloys were used by the Greeks, and what subtle means were necessary for their detection.