THE ALCHEMICAL STUDIES OF SCOT 67 



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. 



M. Berthelot has reminded us^ that the trans- 

 mission of receipts for such processes from early 

 times to our own has been naturally and inevitably 

 secured by the unbroken continuity of practice in 

 the arts which gave them birth, and that they thus 

 passed safely from generation to generation, and 

 even spread from the tribes that originated them to 

 other and distant peoples. He cites in support of 

 this observation a papyrus of the third century, 

 preserved at Leyden, which, he says, contains what 

 are substantially the same directions as those of the 

 chief mediseval authorities in such matters : the 

 Mappae Clavicula and the Compositiones ad Tin- . 

 genda.'^ These receipts are not unnaturally en- 

 titled ' How to make Gold,' and it is curious to 

 find in them the veritable starting-point of the 



^ La Cliimie au Moijen Age, Paris, 1893. One cannot praise too 

 highly the interest and value of this monumental work. I am greatly 

 indebted to it for many of the facts and conclusions here repeated. 



2 The Mappae Clavicula (Key to Painting) belongs to the tenth 

 century ; the Compositiones ad Tingenda is of the age 'of Charlemagne. 

 A MS. of the eighth century (not the ninth as Berthelot says) is extant 

 at Lucca (Bibl. Capit. Can. I. L.). Muratori has printed it in his 

 Antiquitates Italicae, ii. 364-87. It contains receipts for the colours 

 used in making tesserae for mosaic, for dyeing skins, cloth, bone, horn 

 and wood ; for making parchment ; for various processes such as^old 

 and silver beating and drawing, and the gilding of iron ; for chryso- 

 grapliy and the gilding of leather ; ' quomodo eramen in colore avhiCX,^ 

 transmutetur,' 'operatio Cinnaberim,' a perfume for tlie hands called 

 lulaldn, and for certain amalgams of gold and silver called glutina. 



