SCIENCE OF THE SIXTEENTH CENTURY. 



103 



nomena must have been first observed, many new processes invented, 

 many compounds formed of which nature had presented no example. 

 But the race of alchemists has left behind no great general principles 

 as permanent acquisitions to science. Their views of the composition 

 of bodies united the ancient theory of the four elements with certain 

 doctrines of their own, the most prominent of which was that metals 

 and minerals were constituted by combinations of "salt," ' c sulphur," 

 and " mercury." These terms, as used by the alchemists, bear a wider 

 sense than that which we now attach to them ; " mercury," for instance, 

 appears to include any volatile liquid whatever. In the search for the 

 means of transmuting metals, the separation from the metals of their 

 constituent " mercury" was a great object, since it was believed that 

 if this basis of the metals could, but be isolated and studied apart, the 

 clue to the process of transmutation would be obtained. After all, the 

 proof of the existence of a common base in all metals, and the dis- 

 covery of methods of transforming one metal into another, are not 

 beyond the possibilities of chemical science. 



