52 THE ATOMIC WEIGHTS. 



bility of silver chloride. Such data are given in Stas' paper of 1882,* 

 and four results are as follows : 



54.2065 



54.20676 



54.2091 



54-2054 



Mean, 54.20694, db .00045 



Corrected for a trace of silica in the sodium chloride, this mean becomes 

 54.2046, it .O0045.t Combining all four series, we have for the NaCl 

 equivalent to 100 parts of Ag 



Pelouze 54- HI, .0063 



Dumas 54- 1 7 2 , .0096 



Stas, early series 54.2078, .0002 



Stas, late " 54.2046,^.00045 



General mean 54.2071, .00018 



Here the work of Stas is of such superior excellence that the other de- 

 terminations might be completely rejected without appreciably affecting 

 our final results. 



In their research upon the atomic weight of boron, Ramsay and Aston J 

 converted borax into sodium chloride. In the latter the chlorine was 

 afterwards estimated gravimetrically by weighing as silver chloride on a 

 Gooch filter. Hence the ratio, AgCl : NaCl : : 100 : x, as follows : 



3.0761 grm. NaCl gave 7.5259 AgCl. Ratio, 40.874 



2.7700 6.7794 " " 40.859 



2.8930 " 7.0804 " " 40-859 



2.7360 " 6.6960 " 40.860 



1.9187 " 46931 " " 40.863 



Mean, 40.867, .0033 



Finally, for the ratios between silver and sodium bromide we have one 

 set of measurements by Stas. The bromide was prepared by saturating 

 Na. 2 C0 3 with HBr. The NaBr proportional to 100 parts of silver was 



95.4420 



95-4383 

 95.4426 



95-4392 



Mean, 95.4405, .0007 



We have now before us the data for computing, with greater or less 

 accuracy, the atomic weights of the six elements under discussion. In 



*Mmoires Acad. Roy. de Beige., 43. 1882. 



fSee Van der Plaats, Ann. Chim. Phys. (6), 7, 16. 1886. 



% Chem. News, 66, 92. 1892. 



I Memoires Acad. Roy. Beige., 43. 1882. 



