104 



THE ATOMIC WEIGHTS 



■weight of KBr was taken by difference. The ratio Au:,KBr: : 100 : x 



appears in a third column. 



Ah. KBr. Ratio. 



6.19001 3-73440 60.329 



4.7^957 2.S7715 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 



I 5-16406 3- I '533 60.327 



Mean, 60.331, =b .0016 



This mean combines with Kriiss' thus: 



Kriiss 60.390, ± .0059 



Thorpe and Laurie 60.331, ± .0016 



General mean 60.338, ± .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 : .r, using the weights of gold already obtained : 



Ag. Au. Ratio. 



3.38451 6.19001 182.893 



2.60S96 4.76957 182.813 



2.28830 4.18266 182.786 



2.26-1.I5 4.14050 182.868 



I. 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, =b .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 : a:, as follows : 



An. AgBr. Ratio. 



6. 19001 5.89199 95.186 



4.76957 4.54261 95-242 



4.18266 3.98288 95.224 



4.14050 3-94309 95-232 



3-60344 3-43015 95-191 



3-67963 3-50207 95.175 



4-57757 4.35736 95-189 



5-36659 5-11045 95-227 



Mean, 95.208, zh .0061 

 Kriiss found, 95.255, ±z .0142 



General mean, 95.222, ± .0056 



