ATOMIC WEIGHTS 



475 



mean percentage of platinum becomes 43.953, ±.0078. Hence Pt = 

 195.14. Upon comparing the work witli that done later b.y Halberstadt, 

 and by Archibald, the latter mean seems the fairer one to adopt. 



For the chlorine estimations in the ammonium salt, Seubert gives the 

 subjoined data. I add in the last column the weight of salt proportional 

 to 100 i^arts of silver chloride : 



.041 



Hence Pt= 197.22. 



The potassium salt, KoPtClg, was also analyzed by ignition in hydro- 

 gen, treatment with w^ater, and w^eighing both the platinum and the 

 potassium chloride. The weights given are as follows : 



Hence we have these percentages, reckoned on the original salt : 



Pt. 



40.119 

 40.120 

 40.076 

 40.070 

 40.107 

 40.120 

 40.114 

 40.130 



KGl. 



30.706 

 30.728 

 30.698 

 30.666 

 30.700 

 30.627 

 30.710 

 30.621 



Mean, 40.107, it .005 



Mean, 30.682, ± .009 



Hence Pt= 194.83. Hence Pt= 195.0(5. 



As with the ammonium salt, three experiments were made upon the 

 potassium compound to determine the amount of chlorine (four atoms 



