104 



THE ATOMIC WEIGHTS. 



weightjof KBr was taken by difference. The ratio Au:KBr: : 100 : x 



appears in a third column. 



An. KBr. Ratio. 



6.19001 3-73440 60.329 



4.76957 2.87715 60.32? 



4.14050 2.49822 60.336 



3.60344 2.17440 60.342 



3.67963 2.21978 60.326 



4-57757 2.76195 60.337 



5-36659 3-23821 60.326 



5.16406 3. 11533 60.327 



Mean, 60.331, .0016 



This mean combines with Krtiss' thus: 



Kriiss 60.390, .0059 



Thorpe and Laurie 60.331, d= .0016 



General mean 60.338, d= .0015 



The potassium bromide of the previous experiments was next titrated 

 with a solution of pure silver by Stas' method, the operation being 

 performed in red light. Thus we get the following data for the ratio 

 Ag : Au : : 100 : :c, using the weights of gold already obtained : 



Ag. Au. Ratio. 



3.38451 6.19001 182.893 



2.60896 4.76957 182.813 



2.28830 4.18266 182.786 



2.26415 4.14050 182.868 



1.97147 3-60344 182.775 



2.01292 3-67963 182.801 



2.50334 4-57757 182.863 



2.93608 5.36659 182.780 



2.82401 5.16406 182.865 



Mean, 182.827, .0101 



Finally, in eight of these experiments, the silver bromide formed 

 during titration was collected and weighed, giving values for the ratio 

 Au: AgBr: 



100 : x, as follows : 



An. AgBr. 



6.19001 5.89199 



4.76957 4-54261 



4.18266 3.98288 



4.14050 3-94309 



3-60344 3-43 i5 



3.67963 3-50207 



4.57757 4.35736 



5.36659 5-11045 



Ratio. 



95.186 

 95.242 



95-224 

 95.232 , 



95.i9i 

 95-175 

 95-189 

 95.227 



Mean, 95.208, .0061 

 Kriiss found, 95.255, dr .0142 



General mean, 95.222, .0056 



