ELISHA MITCHELL SCIENTIFIC SOCIETY. 55 



try a method commonly used with titanium, viz.: pro- 

 long-ed boiling- of a potassium hydrog^en sulphate fusion 

 in dilute solution with sulphur dioxide in excess. On 

 application of this method, however, on the prepared 

 sulphate (see above), I failed even after boiling* four 

 hours with an excess of sulphur dioxide, to obtain a 

 precipitate, if the solution was acid. If the solution 

 was nearly neutralized with ammonium h^^droxide, and 

 then boiled with an excess of sulphur dioxide, after 

 being- greatly diluted a precipitate was produced. This 

 precipitation, however, was incomplete, even after boil- 

 ing- six hours or passing- steam through the same for 

 two or three hours. The precipitate too was very 

 finely divided, running through the closest filter 

 papers at m}^ command. Therefore this method could 

 not be used. 



But on addition of sulphur dioxide to the chloride 

 solution, even in the cold, and if it was acid, a dense 

 white precipitate was immediately^ noted. On boiling- 

 with an excess of sulphur dioxide in a neutralized solu- 

 tion, /. 6\, the chloride solution, neutralized by ammo- 

 nium hydroxide until the slight precipitate was no 

 longer dissolved by boiling-, and this precipitate then 

 taken up with tAvo or three drops of dilute dydrochloric 

 acid, the separation of the zirconium was complete. 



The accuracy of this method is shown b}^ the follow- 

 ing- results : — 



