NATURAL SCIENCE IN THE MIDDLE AGES 283 



Berthelot found 160 tracts by Greek alchemists. Also, various dis- 

 tinguished scientists continued to believe in the transmutation of metals 

 as late as the seventeenth century. Second, thirteenth century alchemy 

 was less superstitious and more scientific than in previous periods, 

 whether among the Greeks or more recently among the Arabs. This 

 fact has been rather obscured because the editors and publishers of books 

 on alchemy in the sixteenth century preferred to print such treatises as 

 made great pretensions and were full of mystic language. Thus the 

 productions of charlatans got into print and the more sober works of 

 rational investigators remained for the most part neglected in manu- 

 scripts. These, however, have now been studied by Berthelot with the 

 following results. 



Whereas Greek tracts on alchemy are all in an archaic enigmatic 

 style, " combining in one undecipherable medley terms of obscure mean- 

 ing, magical formulas, astrological notions, citations from mystic 

 authors, and cryptic allusions to a philosophy long since buried too deep 

 for present resurrection " ; on the contrary, the thirteenth century trea- 

 tises are full of positive details and rational argument. Moreover, the 

 medieval alchemists are careful to refute those who deny the possibility 

 of transmuting metals, while it does not seem to have entered the heads 

 of the Greek alchemists that any one should doubt the truth of their art. 

 Third, this progress is not due to the Arabs. Berthelot discovered only 

 one treatise in Arabic which contained precise and minute details about 

 chemical substances and operations. As a rule the Arabian alchemists 

 wrote "theoretical works full of allegories and declamations." For a 

 long time several works important in the history of chemistry as well as 

 of alchemy were regarded as Latin translations from the Arab Geber, 

 who was consequently regarded as a pioneer in the history of science. 

 Berthelot discovered the Arabic manuscripts which turned out to be of 

 little value and largely copied from Greek sources. On the other hand, 

 the Latin works which had gone under Geber's name were produced in 

 the thirteenth and fourteenth centuries by men who seem, like Adelard 

 of Bath, to have preferred to attribute their own ideas to the Arabs. 



Let us examine for a moment with Berthelot the chief of these 

 treatises. It is " a systematic work, very well arranged." " Its modest 

 method of exposition" differs greatly from "the excessive and vague 

 promises of the real Geber." It refutes scepticism as to alchemy in a 

 long scholastic discussion typical of the thirteenth century. But this is no 

 mere scholastic treatise. Parts of it possess " a truly scientific character " 

 and show "the state of chemical knowledge and theory with a precision 

 of thought and expression unknown to previous authors." The writer 

 "defines carefully silver, lead and the other metals, and traces the 

 characteristic features of their chemical history as far as it was then 

 known. If you leave out a few incorrect details connected with trans- 



