i9°5 ] 



HALL AND SMITH— COLUMBIUM. 187 



Calculated 

 K 2 CbOF 6 H20. Found. 



Oxide 57-81 58.02 



K 2 S0 4 44-52 4I-58 



The sp. gr. of the oxide was found to be 4.667. 0.2930 gram 

 of oxide gave a color with hydrogen peroxide equivalent to .0322 

 gram of Ti0 2 =11 per cent. 



The crucible in which the oxide was ignited was deeply stained. 

 The analysis and the color test showed the presence of titanium, 

 while the stain on the crucible and the high sp. gr: of the oxide 

 could be due to tin in considerable amount, which is precipitated 

 in the last fractions on fractional precipitation with ammonium 

 hydroxide. 



The crystals and the mother liquor remaining from this salt 

 were dissolved in boiling water and an excess of sodium hydrate 

 added, when a heavy flocculent precipitate separated. This was 

 filtered, boiled with water and the insoluble portion changed to 

 double fluoride. It was again taken up in boiling water and an 

 excess of sodium hydroxide added. The precipitation was not 

 complete. The portion precipitated was treated with boiling 

 water, filtered, and the filtrate found to contain a large amount of 

 titanium. That portion of the precipitate insoluble in water was. 

 changed to double fluoride. 



Analysis : 



0.5570 gram of sample gave 0.2248 gram of oxide and 

 0.3468 gram of K 2 S0 4 

 0.2248 : 0.3468 :: x/2 : 174 x = 225.6. 



The sp. gr. of the oxide was found to be 4.2. The oxide gave a 

 color with hydrogen peroxide showing the presence of about 21 

 per cent. Ti0 2 . 



Crystals "A" (page 181) were changed to double fluoride and! 

 recrystallized. 



Analysts : 



0.7184 gram of sample gave 0.31 88 gram of oxide and 



0.4176 gram of potassium sul- 

 phate. 

 0.3188 : 0.4176 :: x/2 : 174 x = 265.7. 



PROC. AMER. PHILOS. SOC. XLIV. l8o. M. PRINTED AUGUST I, I905. 



