ELISHA MITCHELL SCIENTIFIC SOCIETY. 21 



zirconium chloride solution be neutralized by sodium 

 carbonate in the cold and sodium thiosulphite added 

 until the solution was decolorized and then boiled as 

 long- as sulphur dioxide came off, the zirconium would 

 be precipitated as oxide ^meaning* doubtless hydroxide;. 

 To test these observations a solution of zirconium 

 chloride was neutralized bv ammonia and an excess of 

 sodium thiosulphite was added in crystals. A precipi- 

 tate began to be formed directly. This was washed 

 eigfht or ten times by decantation, filtered, the precipi- 

 tate dried b}' absorption paper, and analyzed. It gave: 



Zirconium dioxide 19.66 20.50 .... .... 



Sulphur dioxide .... 4.03 4.14 



Water (blast-lamp) 16.05 16.41 



Water, at 95- C 60.11 58.58 



99.85 99.61 

 Perceiitar.,'-e of zirconium on a water-free basis is 75. 

 Perce nta.Lfe of zirconium calculated in ZriSo O3 ).2 is 21.95. 



A second experiment was carried out with an acid 

 solution of zirconium chloride. The sodium thiosul- 

 phite crystals were added in the cold and when com- 

 pletely dissolved the solution was heated to boiling*. 

 This precipitate, on analysis, gave: 



Zirconium dioxide 21.74 20.73 .... .... 



Sulphur dioxide .... 5.33 5.4L 



Water (blast-lamp) 9.72 8.64 



Water, at 95 ■ C 63.23 65.37 



100.07 100.15 



Finally another portion was taken, precipitated with 

 an excess of sodium thiosulphite, and boiled until there 

 was no long-er any odor of sulphur dioxide. This pre- 

 cipitate was anah'zed: 



Zirconium dioxide 47.01 47.19 .... .... 



Sulphur dioxide 6.90 6.95 



Water (blast-lamp^ 21.41 21.14 



Water, at 95- C 24.16 24.72 



99.48 100.01 



