ATOMIC WEIGHTS 



205 



PbCk. 

 4.67G91 

 3.67705 

 4.14110 

 4.56988 

 5.12287 

 3.85844 

 4.67244 

 3.10317 

 4.29613 



Ag. 



3.62987 

 2.85375 

 3.21408 

 3.54672 

 3.97568 

 2.99456 

 3.62628 

 2.40837 

 3.33407 



From Ag ratio, Pb = 307.088. 

 Prom AgCl ratio, Pb = 207.096. 

 And Ag:Cl:: 100:32.864. 



These ratios combine with otliers thus : 



Ratio 2Ag:PbCL. 



Marignac with Dumas 128.727, ± .0130 



Baxter and Wilson 128.849, ± .0010 



General mean 128.848, ± .0010 



Ratio 2AgCl:PbCL. 



Marignac 96.890, ± .0704 



Baxter and Wilson 96.978, ± .0039 



General mean 96.977, ± .0039 



The older determinations practicall}' reject themselves, leaving Baxter 

 and Wilson's figures alone. 



The work done upon the atomic weight of lead by Meaglia ' is con- 

 fessedly an approximation, and nothing more. Metallic lead was used 

 to precipitate silver from a nitrate solution, and in that way the ratio 

 Ag:Pb was determined. Two series of observations were made, with 

 diflPerent preparations of lead. Calculated with Ag= 107.93, the follow- 

 ing values for Pb were obtained : 



1. 



206.872 

 206.907 

 206.903 

 206.909 

 206.930 

 206.903 

 206.929 



2. 

 206.866 

 206.897 

 206.927 

 206.933 

 206.935 



Thesis, University of Grenoble, 1907 



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