212 HALL AND SMITH— COLUMBIUM. [May 19, 



dehyde, sodium carbonate, and hydroxylamine hydrochloride. 

 The resulting solution gave no precipitate when added to a solu- 

 tion of titanium as double fluoride, zirconium as double fluoride, or 

 to a solution of columbium double fluoride. Further, after the 

 addition of the formoxime solution, ammonium hydroxide failed 

 to give a precipitate with any of the solutions noted above. It 

 did, however, give a precipitate with tantalum double fluoride, but 

 this was only partial. 



The statement of Geisow that titanium and zirconium can be 

 separated from columbium by means of an alkaline formoxime solu- 

 tion was not verified. The precipitation with tantalum is only 

 partial, and not complete as stated by him. 



It was noted {/our. Amer. Chem. Soc, 26, 1248) that potas- 

 sium iodate gave a complete precipitation in a solution of potassium 

 titanium fluoride, and no precipitate with a solution of columbium 

 double fluoride. Potassium iodate, free from periodate, was pre- 

 pared, and it was found to give no precipitate with either colum- 

 bium or titanium, except in acid solution, when both were 

 precipitated. A solution of a periodate was not tried. 



University of Pennsylvania. 



