42 THE ATOMIC WEIGHTS. 



69.099 



69.1034 



69.104 



69.103 



69.102 



69.104 



69.104 



69.105 



69.103 



69.101 



69.105 



Mean, 69.1033, =b .0003 



In these determinations Stas did not take into account the slight solu- 

 bility of precipitated silver chloride in the menstrua employed in the 

 experiments. Accordingly, in 1882* he published a. new series, in which 

 by two methods he remeasured the ratio, guarding against the indicated 

 error, and finding the following values : 



69.1198 

 69.11965 

 69.121 

 69.123 



Mean, 69.1209, .0003 



Corrected for a minute trace of silica contained in the potassium 

 chloride, this mean becomes 



69.11903, . 0003. f 



Still later, in order to establish the absolute constancy of the ratio in 

 question, Stas made yet another series of determinations,^ in which he 

 employed potassium chloride prepared from four different sources. 

 One lot of silver was used throughout. The values obtained were as- 



follows : 



69.1227 

 69.1236 

 69.1234 

 69.1244 

 69.1235 

 69.1228 

 69.1222 

 69.1211 

 69.1219 

 69.1249 

 69.1238 

 69.1225 

 69.1211 



* Memoires Acad. Roy. de Beige, t. 43. 1882. 

 fSee Van der Plaats, Ann. Chim. Phys. (6), 7, 15. 

 I Oeuvres Posthumes, edited by W, Spring. 



