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, zb .00045 



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

 54.2046, =h .00045.1 Combining all four series, we have for the NaCl 

 equivalent to 100 parts of Ag — 



Pelouze 54. 141, ± .0063 



Dumas 54. 172, zh .0096 



Stas, early series 54.2078, dr .0002 



Stas, late " 54.2046, =b .00045 



General mean 54.2071, zfc .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 X 

 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, zh .0033 



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

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

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



95.4420 



95-4383 

 95.4426 



95-4392 

 Mean, 95.4405, rt .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 



*Meraoires Acad. Roy. de Beige., 43. 18S2. 



tSee Van der Plaats, Ann. Chira. Phys. (6), 7, 16. 1S86. 



JChem. News, 66, 92. 1892. 



g M6nioires Acad. Roy. Beige., 43. 1SS2. 



