ATOMIC WEIGHTS 



39r 



Hence Te= 127.53. All of Gallo's weights are on a vacuum basis. 

 Gallo also made a series of electrolytic analyses of tellurium dioxide as 

 follows. The precipitation was effected in a hydrofluoric acid solution : 



.0220 



Hence Te= 127.053. . ^ • 



Two determinations by Lenher/ although not next in chronological 



order, may be conveniently inserted here. One was by reduction of 



TeOo, the other bv oxidation of Te : 



Mean, 79.938, ± .0037 



Hence Te = 127.50. 



The percentage of tellurium in the dioxide is now fixed by 15 serie? 

 of determinations, which, arranged in the order of ascending magnitude 

 may be combined, as usual, into a general mean: 



Brauner, oxidation 79.711, ± .0239 



Heberlein 79.8745, ± .0034 



Gallo 79.881, ± .0220 



Brauner, reduction 79.932, ± .0534 



Lenher 79.938, ± .0037 



Gutbier, 1902 79.948, ± .0031 



Staudenmaier 79.950, ± .0043 



Gutbier, 1905, 1 79.951, ± .0015 



Gutbier, 1905, 2 79.952, ± .0031 



Pellini, reduction 79.953, ± .0171 



Pellini, oxidation 79.957, ±: .0071 



Metzner 80.004, ± .0165 



Wills, 1 80.015, ±: .0410 



Wills. 2 80.028, ± .0040 



Berzelius 80.042, ±: .0050 



General mean, 79.9498, 



.0010 



The determinations by Staudenmaier, Pellini and Outbier are in close 

 agreement, and very near the general mean of all. 



.Tourn. Amer. C'hem. Soc, 30. 741. 1908. 



26 



