I9°5-] 



HALL AND SMITH— COLUMBIUM. 197 



cated save the morphine test for titanium, which proved exceedingly 

 delicate, yet to have the color show definitely in columbium the 

 latter must contain .5 per cent, of Ti0 2 . Codeine gave no color 

 with columbium, nor did resorcinol with tantalum, therefore Levy 

 could not have had pure material for his tests. 



In our use of these reagents we failed to find satisfactory tests 

 except in the case of morphine for titanium. None answered for 

 columbium in the presence of titanium or for tantalum in the pres- 

 ence of columbium. Resorcinol proved to be a fairly delicate test 

 for titanium. It gave no color with columbium, tantalum or 

 tungsten. 



ACTION OF HYDROCHLORIC ACID GAS ON IGNITED 

 COLUMBIC OXIDE. 



0.25 gram of ignited columbic oxide was completely volatilized 

 in three hours in a current of dry hydrochloric acid gas. It vola- 

 tilized as a white powder with no indication of reduction by change 

 of color. The compound formed adhered to the walls of the glass 

 tube, was insoluble in oxalic acid, and only very slowly soluble in 

 concentrated sulphuric acid, requiring long boiling to dissolve a thin 

 layer. It contained hydrochloric acid, as was shown by washing 

 with ammonium hydroxide and testing the washings with silver 

 nitrate and nitric acid. It would be very difficult to collect in a 

 form convenient for analysis, yet this should be done, as the body 

 evidently contains no water, as is given in the formula of a similar 

 body obtained by Smith and Maas {Zeit. atiorg. Chem., 7, 96) by 

 passing moist hydrochloric acid gas over the hydrated oxide. It is 

 undoubtedly analogous to the body obtained on heating molybdic 

 acid in hydrochloric acid gas, namely, Mo0 3 2HCl. It is likely 

 Cb 2 0..xHCl. 



ACTION OF SULPHURIC ACID ON THE HYDRATES OF COLUMBIUM 



AND TITANIUM AFTER RECIPITATION BY AMMONIUM 



HYDROXIDE FROM SOLUTIONS OF THEIR 



DOUBLE FLUORIDES. 



The method used was to precipitate the hydrates from a weighed 

 amount of the double fluorides, filter and wash as thoroughly as 

 possible, then transfer to a weighed platinum dish, reweigh, the 

 difference being water, after which a weighed amount of sulphuric 



