128 THE ATOMIC WEIGHTS, 



Turner,* in three similar experiments, found as follows : 



146.430 

 146.398 

 146.375 



Mean, 146.401, .on 



In these results of Tamer's, absolute weights are implied. 

 The results of Stas' syntheses,t effected after the same general method, 

 but with variations in details, are as follows. Corrections for weighing 

 in air were applied : 



146.443 



146.427 



146.419 



146.432 



146.421 



146.423 



Mean, 146.4275, .0024 



Combining, we get the subjoined result: 



Berzelius 146.419, .012 



Turner 146.401, .01 1 



Stas 146.4275, .0024 



General mean 146.4262, .0023 



Turner, in the same paper, also gives a series of syntheses of lead sul- 

 phate, in which he starts from the oxide instead of from the metal. One 

 hundred parts of PbO, upon conversion into PbS0 4 , gained weight as 

 follows : 



35-84 



35-71 



35.84 



35-75 



35-79 



35.78 



35.92 



Mean, 35.804, .018 



These figures are not wholly reliable. Numbers one, two, and three 

 represent lead oxide contaminated with traces of nitrate. The oxide of 

 four, five, and six contained traces of minium. Number seven was free 

 from these sources of error, and, therefore, deserves more consideration. 

 The series as a whole undoubtedly gives too low a figure, and this error 

 would tend to slightly raise the atomic weight of lead. 



*Phil. Trans., 1833, 527-538. 

 t Aronstein's translation, 333. 



