194 



HALL AND SMITH— COLUMBIUM. 



[May 



Reagent. 



37. I lexylmethylenetetramine, 



3S. Bromaniline (ra), 



39. Chloraniline (o), 



Solution of K 2 TiF 6 . Solution of K 2 CbOF s . 



Slight prec. on standing, Free, heavy — in- 

 complete. 

 No precipitation, Slight prec. on standing. 



Frecipit. slow- 

 plete. 



Slight prec. on standing. 

 No precipitation. 



The behavior of the bases which react with the above solutions of 

 titanium and columbium may be divided into the following classes : 



1. Those which precipitate the titanium completely, and while 

 they precipitate the columbium dissolve it upon the addition of an 



