THE ALCHEMICAL STUDIES OF SCOT 87 



kinds of alum, the third describes the vitriols, and 

 the fourth the powders or spirits, by which we are to 

 understand those minerals which are capable of 

 being sublimed or made volatile, such as sulphur, 

 arsenic, and mercury. Two supplementary chapters, 

 the one on the preparation of the salts, alums, and 

 vitriols, and the other on that of the remaining- 

 class of chemicals, complete the whole book. This 

 supplement seems genuinely such, as it is not men- 

 tioned in the general contents, as these appear in 

 the preface. Perhaps we do not err if we sup- 

 pose it to have embodied the result of Scot's own 

 experiments in alchemy. 



It is indeed the practical nature of the alchemical 

 doctrine taught in the Liher Luminis which strikes 

 us most strongly when we read this book. A large 

 part of it is taken up with exact descriptions of the 

 minerals, according to their various forms and the 

 countries from which they were derived. The rest 

 consists of receipts for their employment in refining 

 metals. Whatever we may think of the validity 

 and use of these processes, we cannot fail to notice 

 that they are described in a perfectly straightforward 

 and simple style. Here are none of the mysteries, 

 the riddles and ridiculous allegories so common in 

 chemical works written at a later time. The truth 

 of the matter may probably be that, in following 

 the doctrine here set forth, Michael Scot and the 

 alchemists of his time did obtain results which were 

 then so surprising, as to excuse a certain exaggera- 

 tion in those who described them. Tests that could 

 touch and reveal the real nature of the metals under 

 any change of outward appearance were not then so 

 well known as now. Copper that had been made to 



