84 smithsoniajSt miscellaneous collections vol. 54 



Combining the three groups of determinations, the final value for the 

 ratio Ag : CI : : 100 : x is obtained. 



Direct determinations 32.8582, ± .00042 



Incidental determinations 32.8562, ± .00071 



Indirect determinations 32.8684, ± .00060 



General mean 32.8606, ± .00031 



This value is almost identical with tliat found by Eichards and Wells 

 in their preliminary series of determinations, namely, 32.8G10. 



Addenda. The following indirect determinations of the silver-chlorine 

 ratio appeared too late to be used in the general discussion of the funda- 

 mental ratios. 



In Archibald's work on the atomic weight of platinum the subjoined 

 ratios appear : 



Ag:Pt: :100:180.965, ± .0034 

 AgCl:Pt: : 100:136.203, ± .0031 



Hence Ag : CI : : 100 : 33.864, ± .0039. 



The final series of determinations by Eichards and Willard of the 

 atomic weight of lithium, give these data : 



Ag:LiCl: : 100: 39.2992, ± .00014 

 AgCl:LiCl: : 100: 29.5786, ± .00014 



Hence Ag : CI : : 100 : 32.8637, ± .00077. 



From the strontium chloride ratios of Thorpe and Francis I find: 



2Ag:SrCl2: :100:73.400, ± .0008 

 2AgCl:SrCL: : 100: 55.311, ± .0009 



Hence Ag : CI : : 100 : 32.867, ± .0026. 



THE SILVER-BROMINE RATIO. 



The measurements of the silver-bromine ratio resemble those of the 

 ratio between silver and chlorine, and fall into three groups. First in 

 order are the direct determinations. 



Marignac,^ to effect the synthesis of silver bromide, dissolved the metal 

 in nitric acid, precipitated the solution with potassium bromide, washed, 

 dried, fused and weighed the product. The ratio Ag: Br : : 100 : a; is 

 given in the third column : 



' Oeuvres Completes, 1, S3. 



