46 THE ATOMIC WEIGHTS. 



In his paper on the atomic weight of cadmium,* Huntington gives 

 three syntheses and three analyses of silver bromide. The data are as 

 follows, with the usual ratio given in the last column : 



1.4852 grm. Ag gave 2.5855 AgBr. 74.084 



1.4080 2.4510 " 74-077 



1.4449 " 2.5150 " 74.060 



4.1450 grm. AgBr gave 2.3817 Ag. 74-35 



1.8172 " 1.0437 " 74-i" 



4.9601 2.84 9 7 74.057 



Mean, 74.071, .0072 



Similar synthetic data are also given by Richards, incidentally to his 

 work on copper.f There are two sets of three experiments each, which 

 can here be treated as one series, thus : 



:.H235 grm. Ag gave 1.93630 AgBr. 74-73 



2-74335 " 74-044 



3.77170 " 74.076 



" 1.68205 " 74.053 



" 1.6789 " 74.069 



1.6779 " 74-074 



Mean, 74.065, .0035 



Another set of data by Richards appears in his research upon the 

 atomic weight of barium ; J in which BaBr 2 was balanced against silver, 

 and the AgBr was also weighed. Richards gives from these data the 

 percentage of Ag in AgBr, which figures are easily restated in the usual 

 form as follows: 



Percentage. Ratio, 



57.460 74.034 



57-455 74.049 



57-447 74 073 



57-445 74-074 



57.448 74-070 



57.442 74-089 



57.451 74.061 



57-455 74-049 



57-443 74.086 



57-445 74-074 



57-445 74-074 



Mean, 74.067, rb .0034 



The same ratio can also be computed indirectly from Cooke's experi- 

 ments upon SbBr 3 , Huntington's on CdBr 2 , Thorpe's on TiBr 4 , and 



* Proc. Amer. Acad., 1881. 



fProc. Amer. Acad., 25, pp. 199, 210, 211. 1890. 



I Proc. Amer. Acad., vol. 28. 1893. 



