420 



ZINC, CADMIUM, LEAD, &C. 



not made any attempts to analyze it, because the 

 previous analysis of Dr. Davy is perfectly accu- 

 rate. He found it composed of 



atoms copper 

 atom chlorine 



8 

 4-5 



12-5 



The constituents of the chlorides and sulphuret 

 of copper, compared with those of the oxides, 

 leave no room for doubt that the true atomic 

 weight of this metal is 4.* 



* It is hardly necessary to remark, that the atom of copper might be 

 represented by 8, as well as by 4-. In that case, red oxide of copper 

 would be composed of 



1 atom copper = 8 

 1 atom oxygen = 1 



ind black oxide of 



The chlorides would be : 

 protochloride 



I atom copper = 8 

 2 atoms oxygen = 2 



10 



1 atom copper = 8 

 1 atom chlorine = 4*5 



12-5 



perchloride 1 atom copper = 8 



2 atoms copper = 9 



17 



