ELISHA MITCHELL SCIENTIFIC SOCIETY. 59 



in dilute hydrochloric acid and the process repeated. 

 There was only a slight diminution in the amount, of 

 iron left. If the h^^drochloric acid solution of this pre- 

 cipitate was neutralized b}' ammonium hydroxide and 

 then an excess of sulphurous acid added, the zirconium 

 separated out perfectU' white and free from iron, 



Found. Used. 



ZrO.— 0.1070 0.1070 



The method of Berthier as I carried it out did not 

 g-ive satisfactory results. 



///. By Sodium Thiosulphite. 



With proper precautions zirconium was completely 

 separated from iron by means of sodium thiosulphite. 

 The directions given for this method were not always 

 specific.^** It was noted ihy the writer) that unless 

 the solution be neutralized, the precipitation would be 

 incomplete; also if it be neutral and the boiling long 

 continued, the precipitate might be ver}^ finely divided 

 and hard to catch on the filter paper; also if all or the 

 greater part of the sulphur dioxide be boiled away the 

 oxide of iron separated immediate!}^ on access of the air 

 after the removal of the clock glass used to cover the 

 beaker. Xo accurate separation was obtained if the 

 solution was rendered neutral with ammonium hydroxide 

 or the precipitation was made when the solution was hot. 



But the method of ChanceP' and Stromeyer^** gave 

 accurate results. B}^ this method the solution was 

 rendered neutral with sodium carbonate, the beaker 



16. Rose, and Schorl. II— si— 271., and Miller's Chem. II— p. 643. 



17. Ann. Ch. Pharm. CVIII 237. 



18. Ibid, CXIII-127. 



