Another work ascribed to the pen of Michael Scot, and one which seems likely to be authentic, is that contained in the Speciale Manuscript. This volume is one of those collections of alchemical tracts made in the fourteenth century to which we have already alluded. It belonged to the library of the Speciale family in Palermo, and has been made the subject of an interesting monograph by Carini.[119] No. 44 of this manuscript is entitled _Liber Magistri Miccaelis Scotti in quo continetur Magisterium_. The term _Magisterium_, or supreme secret of art, would seem to carry with it a certain reference to Aristotle, ‘Il _Maestro_ di color che sanno,’ as Dante calls him.[120] Curious as the appearance of such a name in connection with alchemy may seem to us, it is certain that Aristotle held a high place in the chemical traditions of the Middle Ages. The _Meteora_ afforded a text which lent itself readily to large commentaries by the Arabian chemists. The tract _De Mineralibus_, which we noticed when speaking of Al Kindi, was one of these commentaries, and it is easy to see how it became confused with the text which it illustrated so as in time to be considered the work of Aristotle himself. This, we may believe, was the ground on which so many alchemical works were afterwards published under the same mighty name.[121] An interesting example appears in the Speciale collection itself which contains the following title: _Liber perfecti Magisterii Aristotelis qui incipit cum studii solertis indigere_.[122] The treatise _Cum studii_ is also found in the Paris manuscript,[123] where it is ascribed to Rases. To the school of Rases then we are inclined to attribute the works on the _Magisterium_, and among the rest therefore, this treatise in the Speciale Manuscript, which bears the name of Michael Scot, seemingly because he translated it from the Arabic. This conclusion is confirmed when we notice the character of some of the chapter headings as given by Carini; for example: ‘Qualiter _Venus_ mutatur in _Solem_’; and again, ‘Transformatio _Mercurii_ in _Lunam_.’ These show beyond all doubt that the doctrine which Michael Scot published by means of this version was that held by the school of Rases.