190 HALL AND SMITH— COLUMBIUM. [May 19, 



in a receiver, and this was then heated until all of the sulphur 

 monochloride was distilled out. This sulphur monochloride and 

 any other chlorides which it might contain was again distilled to 

 remove the last of the columbium chloride which might have been 

 carried over mechanically. It was then treated with water and 

 oxalic acid, the sulphur filtered off, and any oxide dissolved in the 

 oxalic acid precipitated with ammonium hydroxide. This hydrate 

 was changed to potassium double fluoride. 

 Analysis : 



0.5444 gram of sample gave o. 1952 gram of oxide and 



0.3850 gram of potassium sulphate 

 0.1952 : 0.3850 :: x/2 : 174 x = 175.9. 



Calculated. 

 K 2 CbOF 6 H 2 0. Calculated. Found. 



Oxide 44.52 33.33 35.85 



K.SO^ 57.S1 72.50 70.72 



0.0310 gram of the oxide was found to contain 0.244 gram Ti0 2 , 

 or 78.7 per cent. 



A solution of the oxide in hydrochloric acid reduced with zinc 

 to an amethyst or violet color ; the oxide also gave a violet titanium 

 bead in the reducing flame with salt of phosphorus. 



It would seem that about 80 per cent, of the oxide from this 

 double fluoride was Ti0 2 . 



The remainder of the double fluoride, about .5 gram, was dis- 

 solved in the mother liquor from which it came by heating, and 

 an excess of sodium hydrate added. A fiocculent precipitate 

 formed. After cooling, this was filtered off and the filtrate acidi- 

 fied with hydrochloric acid and tested for metallic acids with am- 

 monium hydroxide. A precipitate was obtained, which was filtered 

 out and, after washing thoroughly, dissolved in hydrochloric acid. 



Upon passing hydrogen sulphide through this solution a heavy 

 precipitate of yellow stannic sulphide was obtained, showing that 

 tin had been carried over with the titanium by the sulphur mono- 

 chloride. 



The precipitate formed by the excess of sodium hydroxide was 

 drained thoroughly and boiled up with water. Nothing went into 

 solution, as would have happened had there been any sodium 

 columbate in the precipitate. This well washed precipitate was 



