URANIUM. 



265 



Wertlieim's* experiments were even simpler in character than those 

 of Ebehnen. Sodio-uranic acetate, carefully dried at 200°, was ignited, 

 leaving the following percentages of sodium uranate : 



67.51508 

 67.54558 

 67.50927 



Mean, 67.52331, ± .0076 



The final results of Peligot'sf investigations appeared in 1846. Botli 

 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 onl}', from the later crystallizations, 

 need to be considered. In these the uranium was weighed as UgOg, and 

 the carbon as CO.^. From the ratio between the CO., and U-jOg the atomic 

 weight of uranium may be calculated without involving any error due 

 to traces of moisture possibl}^ present in the oxalate. I subjoin Peligot's 

 weighings, and give, in the third column, the UgOg proportional to 100 

 parts of CO.^ : 



CO^. U^O^. ^ Ratio. 



1.456 grm. 4.649 gi-m. 3'9-299 



1.369 " 4.412 " 322.279 



2.209 " 7.084 " 320.688 



1. 019 " 3.279 " 321.786 



1.069 " 3-447 " 322.461 



1.052 " 3.389 " 322.148 



Mean, 321.443, i .338 

 From the acetate, UO./C^H30,,).^.2H,0, the following percentages of 



ILOo were obtained : 



5.061 grm. acetate gave 3.354 grm. Vi.p^ 



4.601 " 3.057 



1.869 " 1.238 " 



3.817 " 2.541 



10.182 " 6.757 " 



4.393 " 2.920 



2. 868 " 1.897 



66.2715 per cent. 



66.4421 



66.2386 



66.5706 



66.3622 



66.4694 



66.1437 



Mean, 66.3569, =b .038 



The acetate also yielded the subjoined percentages of carbon and of 

 water. Assuming that the fi2;ure3 for carbon were calculated from known 



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

 tCompt. Rend., 22, 487. 1846. 



