ATOMIC WEIGHTS 



187 



The two bromide ratios combined give Ag: Br: : 100 : 74.077, ±.0067. 

 Third. The ratio 2 Ag : SrCl„ : 



SrCL. 

 1.64759 

 1.66352 

 1.53462 

 1.64619 

 1.76006 

 1.56224 



Ag. 



2.24203 

 2.26356 

 2.08817 

 2.24011 

 2.39486 

 2.12572 



Ratio. 

 73.486 

 73.491 

 73.491 

 73.487 

 73.493 

 73.492 



Mean, 73.490, ± .0008 



Hence Sr = 87.645. 



Fourth. The ratio 2AgCl : SrCI. 



SrCl^. 

 1.64764 

 1.66357 

 1.53467 

 1.64624 

 1.76010 



Mean, 55.311, ± .0009 



Hence Sr = 87.610. 



The two chloride ratios combined give Ag: CI: : 100 : 32. 867, ±.0026. 



Fifth. Eatio SrBr, : SrSO^ : 



SrBr.. 8r80i. Ratio. 



7.14570 5.30466 74.236 



7.64281 5.67326 74.230 



9.86072 7.32047 74.239 



Mean, 74.235, 



.0018 



Hence Sr = 87.677. 

 Sixth. Eatio SrCL 



SrSO, 



Mean, 115.859, ± .0010 



Hence Sr = 87.668. 



The arithmetic mean of the six vakies obtained by Thorpe and Francis 

 is 87.649, a little higher than the value fonnd by Eichards. A general 

 combination of all the fignres for strontium, however, would fall very 

 near Eichards' determinations. 



