1<3() ZINC, CADMIUM, LEAD, &c. 



This result does not approach the truth so near- 

 ly by a great deal, as the synthetical experiments 

 of Berzelius and Vauquelin. 



In repeating these experiments, I found it 

 much more difficult than I expected to procure 

 absolutely pure silver. I found that silver 

 which I had reduced from well washed chloride 

 was not absolutely free from copper. The me- 

 thod which I ultimately adopted was to keep 

 crystallized nitrate of silver in a state of fusion 

 for some time. It was then dissolved in water, 

 and precipitated by common salt. The precipi- 

 tate was digested for some time in water acidu- 

 lated with nitric acid. It was then thrown on 

 a filter, and well washed with distilled water. 

 Silver reduced from this chloride, and heated 

 with sulphur, gave a sulphuret exceedingly near 

 the theoretic proportions. As far as I could 

 estimate the weight of sulphuret from 13-75 

 grains of silver, it amounted to 15'75 grains ; 

 certainly the weight was not so much as 15*7^ 

 grains. There can, therefore, be no doubt that 

 sulphuret of silver is composed of 



1 atom silver = 13-75 

 I atom sulphur = 2 



Sulphate of 3. I analyzed likewise the sulphate of silver, 

 which corresponds in its constituents with the 



