RICHARDS AND ARCHIBALD. ATOMIC WEIGHT OF CAESIUM. 457 



could be found for eliminating the last traces of chlorplatinate ; for 

 since this latter salt yields a dissimilar anion, it is even more soluble in 

 strong hydrochloric acid than in water, while potassic chloride is almost 

 insoluble in concentrated hydrochloric acid. The successive precipitation 

 was repeated long after the last apparent traces of platinum had disap- 

 peared, and the last snow white crystals were washed with a little water 

 and thoroughly dried over potash in a desiccator. 



The Comparison of Potassic and Argentic Chlorides. 



Ag = 107.930; CI = 35.455. 



The Comparison of Potassic Chloride and Silver. 



The method of analysis was precisely similar to that used in the 

 earlier analyses of caesic chloride, and the same sample of silver was 

 used. The only difference worthy of note is in the fact that while dry- 

 ing the potassic chloride for analysis, fusion did not take place at the 

 Inchest temperature attainable in the hard glass tube ; but the salt was 

 finely powdered, and the heating was maintained for a considerable 

 length of time at about 700°, so as to afford as much opportunity as pos- 



