﻿396 Methods for Separating Uranium X from Uranium. 



by means of acetone. The j3 activity was measured by 

 covering the sample with two thicknesses of paper which had 

 previously been tested and shown to cut off all a. radiation. 

 The activity due to the a rays was obtained by subtracting 

 the /3 activity from the total activity. 



The separation bj means o£ ammonium carbonate does not 

 work well unless there is a considerable amount of undissolved 

 impurity. The presence' of ferric hydroxide, either added to 

 or precipitated in the solution, materially aids the separation. 

 The results obtained by us with ammonium carbonate, how- 

 ever, were not nearly so satisfactory as those with acetone 

 and the other solvents mentioned. 



In order to see whether the decay curves of Ur X, obtained 

 by means of ammonium carbonate, were similar to those of 

 UrX obtained by means of aeetone &c, the following expe- 

 riment was performed : — 12 grms. of Kahlbaum's uranium 

 nitrate was dissolved in 60 c.c. of water. A few drops of 

 dilute ferric chloride solution were then added, followed by 

 ammonium carbonate solution in excess. After filtering, the 

 precipitate w*as washed with ammonium carbonate solution. 

 It was then reclissolved in dilute nitric acid, and reprecipitated 

 with excess of ammonium carbonate in order to get rid of 

 traces of uranium. A few T drops of ferric chloride were again 

 added to the first uranium filtrate, and the precipitate thus 

 obtained filtered off and washed with ammonium carbonate. 

 The filter-papers with their precipitates were then incinerated 

 together, and the ferric oxide and ash ground up in alcohol 

 and spread in a very thin layer on a metal tray. The alcohol 

 was burnt off, and after cooling the total activity, as well as 

 that due to the a and (3 radiations, was measured at intervals 

 of several days in the manner described above. The ihree 

 curves representing these activities fell to half value in from 

 21 to 22 days, and were in every way comparable to those 

 obtained by means of acetone. 



We have thus shown, first, that UrX may be separated 

 from uranium by means of a number of solvents in which 

 UrX is insoluble, these new methods being more satisfactory 

 than those already in use, and secondly that Ur X emits not 

 only /3 but also a. rays. 



Butler College, Indianapolis, Inti. 

 University of Missouri, Columbia, Mo. 



