Purification of Gallium. 



597 





Gallium. 





Lead. 



18', 18" 



2294 n, R. 



23' 



2802-01 



19', 19" 



2338 n, E. 





3639-57 



20', 20" 



2371 n, r. 



10 



3683-47 



21', 21" 



2418 », r. 





374000 



I, 1', 1" 



2450-10 -R. 







2, 2', 2" 



2500-18 J?. 





Zinc. 



3, 3' 



2659-84 r. 



23' 



2800-9 



4,4' 



2719-66 r. 





f 3282-28 



5, 5' 



2874-24 JR. 





| 3302-56 ) 



6, 6' 



2943-66 M. 



9, 9 



' <( 3302-91 j 



11 



3778 n, II 





j 3344-99 | 

 (^ 3345-51 j 



12 



3889 n, H. 





13 



4033-03 B. 



24 



6362-346 



15 



4172-05 B. 









j 5353-81 

 "j 5359-8 





Calcium. 





16 



4226-72 



25 



j 6396-84 

 I 6413-74 













Indium. 







22' 



2560-22 







V, 7' 



3039-36 r. 







8, 8' 



3256-03 r. 







14 



4101-82 







17 



4511-37 







The reasonably complete separation obtained by the frac- 

 tional crystallization of the ammonium alums of gallium and 

 indium from water solution, as previously described,* suggested 

 the substitution of caesium for ammonium. Accordingly, a 

 portion of a gallium-indium alloy weighing 2'3 grms., and con- 

 taining 10 per cent of indium, small amounts of zinc and lead, 

 and traces of copper, was converted into the sulphates, and 

 a calculated amount of caesium sulphate was added. The 

 caesium-gallium alum crystallized readily,f and after ten 

 crystallizations a spectroscopic examination of the product 

 showed practically pure gallium; the indium, zinc, copper, 

 and lead having been almost entirely removed (tig. 46). The 

 mother liquor gave evidence of a considerable amount of 

 indium and also indubitable evidence of the presence of zinc 

 and lead, showing that indium, zinc, and lead may be removed 

 from gallium by this method (tig. 4«). 



The examination of some gallium deposited electrolytically 

 from an alkaline solution showed the presence of traces of zinc 

 (fig. 4c), and the following process was tried to separate the 

 zinc : a weighed porcelain boat containing 0'15 grms. of the 

 element was placed in a combustion tube so connected with a 



* This Journal, vol. xli, p. 351, April, 1916. 



f These crystals lend themselves well to a microchemical test for gallium. 



