122 HISTORY OF CHEMISTRY. 



might be the opinions and expectations which they 

 combined with their attempts. Alchemy is a step 

 in chemistry, so far as it implies the recognition of 

 the work of the cupel and the retort, as the pro- 

 duce of analysis and synthesis. How perplexed 

 and perverted were the forms in which this recog- 

 nition was clothed, how mixed up with mystical 

 follies and extravagancies, we have already seen^ 

 and the share which Alchemy had in the formation 

 of any sounder knowledge, is not such as to justify 

 any further notice of that pursuit. 



The result of the attempts to analyze bodies by 

 heat, mixture, and the like processes, was the doc- 

 trine that the first principles of things are three, 

 not four ; namely, salt, sulphur, and mercury ; and 

 that, of these three, all things are compounded. In 

 reality, the doctrine, as thus stated, contained no 

 truth which was of any value ; for, though the 

 chemist could extract from most bodies portions 

 which he called salt, and sulphur, and mercury, 

 these names were given, rather to save the hypo- 

 thesis, than because the substances were really those 

 usually so called: and thus the supposed analyses 

 proved nothing, as Boyle justly urged against them 1 .; 



The only real advance in chemical theory, there- 

 fore, which we can ascribe to the school of the 

 three principles, as compared with those who held 

 the ancient dogma of the four elements, is, the 

 acknowledgment of the changes produced by the 



1 Shaw's Boyle. Skeptical Chymist, pp. 312, 313, &c. 



