56 JOURNAL OF THE 



The precipitation took place immediately an addition 

 of sulphur dioxide and after two minutes boiling- the 

 precipitate settled quickly and was easily filtered. 



This method then is applicable to the chloride only 

 and a sulphate would have to be first chang-ed to chlo- 

 ride by precipitation with ammonium hyhroxide and 

 resolution in hydrochloric acid. Th's was done and 

 0.2815 g-. Zr02 was found when 0.2812 g. was used. 



The presence of largfe amounts of such salts as am- 

 monium chloride did not aid the precipitation of the 

 sulphate. The presence of free hydrochloric acid must 

 be avoided and it is best to use a fresh solution of sul- 

 phur dioxide or the g-as direct. 



SEPARATION OE ZIRCONIUM FROM IRON. 



/. By Ariii}io)iini)i SulpJiidc i)i an Annnouiacal Tar- 

 trate Solution of their Salts. 



Rose" knew the property tartaric acid possesses of' 

 rendering- solutions of a number of metallic oxides inca- 

 pable of precipitation by alkalies. However he made 

 use of just such a solution, b}^ adding- to it an excess of 

 ammonium sulphide, to separate iron from zirconium. He 

 said, "If to the solution of these two bases a sufficient 

 quantity of tartaric acid has been added, the addition of 

 an excess of ammonia produces no precipitate. "I 

 found five times as much tartaric acid as iron present 

 was a "sufficient quantity," but an excess, five per cent, 

 of the whole solution, had no ill effect, althoug-h such a 

 larg-e excess is not necessary. If the iron was present 

 in the same amount as the zirconium, the separation 

 was found to be incomplete, if only one precipitation of 



14. Analyt. Chem. translated by Griffin, p. 58. 



