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XLIVc Some Neie Methods for Separating Uranium X from 



Uranium. By Richard B. Moore, B.Sc, Professor of 

 Chemistry, Butler College, Indianapolis, U.S.A., and Her- 

 man Schluxdt, Ph.D., Assistant Professor of Physical 

 Chemistry, University of Missouri, U.S.A.* 



IX 1900, by adding ammonium carbonate to solutions of 

 uranium salts until the precipitate which first formed 

 redissolved, Sir William Crookesf was able to separate that 

 portion of the uranium salt which was active to a photo- 

 graphic plate. He showed that the minute undissolved 

 residue, which was mostly due to impurities in the salt, was 

 one hundred times more active, weight for weight, than the 

 uranium from which it had been separated. He also showed 

 that a partial separation could be made by dissolving crys- 

 tallized uranium nitrate in ether. Under such conditions the 

 uranium divides itself between the ether and water in unequal 

 proportions. That portion in the water layer was intensely 

 active to the* photographic plate, whilst that in the ether, 

 although its activity had been only slightly reduced when 

 measured by the electrical method, was practically inactive 

 photographically. The explanation for these results was 

 given by SoddyJ, and by Rutherford and Grier§, who 

 showed that a radio-active constituent, to which (Yookes 

 gave the name uranium X, had been separated by the above 

 processes from the parent uranium, and that this Ur X gave 

 rise to all of the (3 rays but to none of the a. rays. 



Becquerel || obtained similar results by another method. 

 He found that when barium sulphate was precipitated in a 

 uranium nitrate solution a portion of the.UrXwas carried 

 down with the precipitate. By a number of precipitations the 

 uranium ultimately became almost inactive photographically. 



Recently we have confirmed the above methods of sepa- 

 ration of UrX from radium, and in addition have obtained 

 several new methods for making the separation, which give 

 still better results. The details of the experiments follow. 



Five grams of crystallized uranium nitrate (Kahlbaum's 

 best IT) was dissolved in about 60 c.c. of acetone. The solution 

 was slightly cloudy, probably in consequence of the presence of 



* Communicated bv the Authors. 

 t Proc. Roy. Soc, lxvi.p. 409 (1900). 

 X Trans. Cheni. Soc. lxxxi. p. 460 (1902V 

 § Phil. Mag. Sept. 1902. 



|| a R. cxxxi. p. 137 (1900) ; cxxxiii. p. 977 (1901). 

 ^] McCoy has shown that this does not contain radium. Phil. Mag. 

 Jan. 1906. 



