154 



THE ATOMIC WEIGHTS. 



was weighed as U3O4, and the carbon as CO.,. From the 

 ratio between the CO. and U3O4 the atomic weight of 

 uranium may be calculated without involving any error 

 due to traces of moisture possibly present in the oxalate. 

 I subjoin Peligot's weighings, and give, in the third column, 

 the UgO^ proportional to 100 parts of CO.: 



1.456 grm. 

 1.369 

 2.209 

 .1.019 

 1.069 

 1.052 



-338 



Hence U3O, = 423.342, ± .451. 



From the acetate, C2H3(UO)0,.H20, the following per- 

 centages of U3O4 were obtained : 



5.061 grm. acetate gave 3.354 



4.601 " 3.057 



1.869 " 1.238 



3.817 " 2.541 



10.182 " 6.757 



4-393 " 2.920 



2.868 " 1.897 



rrm. U.,0.j. 



66.2715 per cent. 



66.4421 



66.2386 



66.5706 



66.3622 



66.4694 



66.1437 



Mean, 66.3569, ± .038 



The acetate also yielded the subjoined percentages of 

 carbon and of water. Assuming that the figures for carbon 

 were calculated from known weights of dioxide, with C = 12 

 and O = 16, I have added a third column, in which the 

 carbon percentages are converted into percentages of CO.: 



Mean, 21.265. rb .187 11.24 



41.222, 



.092 



