198 THE ATOMIC WEIGHTS. 



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

 joined ratios : 



(l.) Percentage ZrO.^ in Zr(SOJ.^, 43.317, ± .0051 



(2.) Percentage ZrO,j in Zr(SeOJ2, 32.558, =b .0192 



(3.) Percentage Zr02 from K^ZrFg, 43.200, zb .043 



(4.) Percentage K2S0^ from KjZrFg, 61.365, i .094 



(5.) K^SO^ : ZrOg : : 100 : 70.396, ± .079 



Tlie antecedent atomic weights are — 



o = 15.879, =b .0003 K = 38.817, ± .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.^= 121.454, ± .0182 



From (2) " = 121.708, ±.0798 



From (5) " = 121.770, ±: .1370 



General mean ZrO.^ = 121. 471, ± .0176 



Finally, there are three independent estimates for the atomic weight 

 of zirconium : 



From molecular weight ZrO, Zr ^ 89.713, zh .0177 



From ratio (3) " = 89.437, ± .2390 



From ratio (4) " = 90.778, ± .4326 



General mean Zr = 89.716, zb .0175 



If = 16, Zr = 90.400. 



Here the first value alone carries appreciable weight. 



