AN ATTEMPT 



TO ESTABLISH 



THE FIRST PRINCIPLES OF CHEMISTRY 

 BY EXPERIMENT. 



CHAP. I. 



HISTORICAL INTRODUCTION. 



CHEMISTS appear at all times to have admitted 

 that the constituents of compound bodies are 

 constant, whether we consider the elements 

 themselves, or their proportions. But it was not 

 till Chemistry had made considerable progress, 

 that any thing like an analysis of the salts could 

 be attempted. Homberg, so far as I know, was 

 the first person who thought of determining the 

 composition of these bodies. He contrived a 

 hydrometer for ascertaining the specific gravity 

 of acids. This instrument was similar to the 

 weighing bottle at present in common use for 

 the same purpose. It enabled him to judge, from 

 the specific gravity, how much stronger one acid 



VOL. I. A 



