Radioactive Properties of Uranium. 

 Table I. 



49 



Ether 



portion. 





Water 



portion. 









First crystal plate. 



Plate of crystal 

 from mother liquor. 



T. 



! 



3 Activity. 



T. 



j3 Activity. 



T. 



j3 Activity. 



0-25 



19 



010 



366 



012 



2190 



1 



57 



0-32 



281 



033 



1370 



2 



84 



75 



210 



075 



1270 



3 



131 



112 



219 



112 



1125 



5-3 



190 



1-64 



236 



1-68 



1090 



63 



220 



29 



285 



29 



1090 



73 



260 



4-9 



344 



4-9 



1100 



8-3 



273 



5-9 



368 



00 



1120 



93 



311 



70 



399 



7-0 



1180 



133 



420 



8-1 



427 



8-1 



1210 



143 



446 



91 



440 



9-1 



1210 



153 



460 



12-8 



529 



12-9 



1200 



165 



480 



138 



545 



13-8 



1210 







14-8 



572 



157 



1190 







16-4 



598 



18-7 



1200 



1 



It is seen that the activity of the ether portion increases 

 with the time according to the theoretical curve, reaching 

 half final value in twenty-two days. The activity of the first 

 part of aqueous solution, which contained the first crystals,, 

 falls to about half value in about one day, this value being 

 almost the minimum, and then increases slowly with the time. 

 As we see from fig. 1, the second part of curve II is parallel 

 to curve I, which shows that the activity of the first plate 

 of crystal increases at the same rate as that of the ether 

 portion. 



The plate obtained from mother liquor (curve III) lost 

 its activity during the first few days after crystallization. 

 Its activity after reaching a minimum and after a small 

 increase remained practically constant. After two months it 

 was observed to have decreased only 10 per cent. 



Disregarding for a moment the first rapid decrease of 

 activity of both aqueous portions, which is exactly of the 

 same nature as observed by Meyer and ISchweidler, we see 

 that we have the ft activity in two cases increasing at the 

 same rate, i. e. the increase of activity of the ether portion 

 and of the plate of crystal first obtained. This points to the 

 fact, that UrX was removed not only from the ether portion, 

 but also in some degree from the first obtained crystals. 



Phil. Mag. S. 6. Yol. 10. No. 55. July 1905. E 



