URANIUM. 153 



A. 

 71.924 

 71 



787 103.949 



767 103.867 



621 103.920 



794 103.900 



793 



778 



790 103.930 



Mean, 71.782, db .019 Mean, 103.913, ± .009 



From column A, the molecular weight of UO = 134.523, zb .102 

 B, " " = 135-985. ± -326 



General mean UO = 134.652, ± .097 



From column A U = 118.560 



" B " = 120.022 



From general mean of both columns __" == 118.689, d= .097 



Wertheim's * experiments were even simpler in character 

 than those of Ebehiien. Sodio-uranic acetate, carefully 

 dried at 200°, was ignited, leaving the following percentages 



of sodium uranate : 



67.5150S 

 67-54558 

 67.50927 



Mean, 67.52331, rfc .0076 



Hence the molecular weight of NaaU^O, = 634.865, 

 ± .191. And U = 119.282, ± .048. 



The final results of Peligot's t investigations appeared in 

 1846. Both the oxalate and the acetate of uranium were 

 studied and subjected to combustion analysis. The oxalate 

 was scrupulously purified by repeated crystallizations, and 

 thirteen analyses, representing different fractions, were made. 

 Seven of these gave imperfect results, due to incomplete 

 purification of the material ; six only, from the later crys- 

 tallizations, need to be considered. In these the uranium 



* Joum. fiir Prakt. Chem., 29, 209. 1843. 

 t Compt. Rend., 22, 487. 



