ATOMIC WEIGHTS 



113 



Mean, 40.7797, ± .00028 



This mean, combined with that of Ramsay and Aston, gives a general 

 mean of 40. 7803, ±.00028, which falls within the limits of variation of 

 Richards and "Wells' series. 



For the ratio between silver and sodium bromide we have one set of 

 measurements by Stas." The bromide was prepared by saturating IsTaoCOa 

 with HBr. The NaBr proportional to 100 parts of silver was — 



95.4420 

 95.4383 

 95.4426 

 95.4392 



Mean, 95.4405, ± .0007 



The second bromide ratio, AgBr : NaBr, is represented by two experi- 

 ments, made by Richards and Wells ^ in a research upon the transition 

 temperature of sodium bromide. With vacuum weights the figures are — ■ 

 NaBr. AgBr. Ratio. 



5.49797 10.03253 54.8014 



3.64559 6.65248 54.8005 



Mean, 54.8010, ± .0005 

 THE AMMONIUM HALIDE-SILVEK KATIOS. 



Ratios connecting silver with the chloride and bromide of ammonium 

 have been repeatedly determined, by methods essentially the same as 

 those adopted in the similar analyses of potassium and sodium halides. 



For the ammonium chloride equivalent to 100 parts of silver, Pelouze ' 

 found : 49.556 



49.517 



Mean, 49.5365, ± .013 



^ Oeuvres Completes, 1, 796. 

 - Proc. Amer. Acad., 41, 443. 

 scoinpt. Rend., 20, 1047. 1845. 



