ATOMIC WEIGHTS 333 



For 2AgBr:ZnBu: -.lOQ-.x. 



Series A 59.975, ± .0034 



Series B 59.967, ± .0027 



Series D 59.961, ± .0004 



General mean 59.962, ± .0004 



From the Ag ratio, Zn=:: 65.371. 



Prom the AgBr ratio, Zn = 65.378. 



And Ag: Br:: 100: 74.077. 



In order to determine the atomic weight of zinc, Meagiia ' measured 

 the direct ratios between that metal and silver or gold. The silver was 

 precipitated from a sulphate solution by zinc, and the gold from a solution 

 of sodium chloraurate. From the weights obtained the following values 

 for zinc were computed, when Ag= 107.93 and Au = 197.2. 



Silver Series. Gold Senes. 

 65.58 65.509 



65.45 65.424 



65.50 65.440 



65.41 65.470 



Mean, 65.485, ± .0247 Mean, 65.4;?6, ± .0087 



From the silver ratio, with Ag= 107.88, Zn = 65.455. 



From the gold ratio, with Au= 197.369, Zn= 65.459. 



For the ratio 2 Ag : Zn, Gladstone and Hibbert's data give the value 

 30.318, ±.0077. Meaglia's figures, reduced to the same basis, give 30.337, 

 ±.0115. The two series combined give 



2Ag:Zn: :100:30.324, ± .0064 



For computing the atomic weight of zinc we now have the subjoined 



ratios : 



(1). ZnO:Zn: : 100: 80.349, ± .00065 



(2). ZnSO.iZnO: : 100: 50.413, ± .0020 



(3). HoO:Zn: : 100: 366.319, ± .088 



(4). 2CO,:ZnO:: 100: 93.169, ±.012 



(5). H:Zn: :1: 65.079, ± .0036 



(6). 4Ag:KoZnCl,: :100:66.111, ± .0023 



(7). 2Ag:Zn: : 100: 30.324, ± .0060 



(8). Cu:Zn:: 100: 103.22, ±.0261 



(9). 2Ag:ZnBr„: : 100: 104.38, ± .0007 



(10). 2AgBr:ZnBr„: : 100: 59.962, ± .0004 



( 11 ) . Au : Zn : : 197.2 : 65.436, ± .0087 



1 Thesis, Univei-sity of Grenoble, 1907. 



