198 THE ATOMIC WEIGHTS. 



For computing the atomic weight of zirconium we now have the sub- 

 joined ratios : 



(i.) Percentage ZrO 2 in Zr(SO 4 ) 2 , 43.317, .0051 



(2.) Percentage ZrO 2 in Zr(SeO 4 ) 2 , 32.558, .0192 



(3.) Percentage ZrO 2 from K 2 ZrF 6 , 43.200, .043 



(4.) Percentage K 2 SO 4 from K 2 ZrF 6 , 61.365, .094 



(5.) K 2 S0 4 : Zr0 2 : : 100 : 70.396, .079 



Tlie antecedent atomic weights are 



O = 15.879, .0003 K = 38.817, dt .0051 



S =31.828, .0015 F = 18.912, .0029 



Se = 78.419, .0042 



With these data we first get three values for the molecular weight of 

 zirconia : 



From (i) ZrO 2 121.454, .0182 



From (2) " = 121.708, .0798 



From (5) " = 121.770, .1370 



General mean ZrO 2 121.471, .0176 



Finally, there are three independent estimates for the atomic weight 

 of zirconium : 



From molecular weight ZrO 2 Zr = 89.713, d= .0177 



From ratio (3) " = 89.437, .2390 



From ratio (4) " 90.778, .4326 



General mean Zr = 89.716, .0175 



If = 16, Zr 90.400. 



Here the first value alone carries appreciable weight. 



