58 JOURNAL OP THK 



The crucible was then heated with the blow pipe until 

 the weig"ht was constant. This required at least an 

 hour if a porcelain crucible was used. 



The method was carried out by the writer as g^iven 

 above and accurate results, as noted, obtained, when 

 the iron was no more than hve per cent of the two 

 metals present. The iron was not determined. The 

 g'reat amount of time required was the only objection 

 to be noted. 



//. By Ainnioiiiuni Hydroxide, Aiumoiiiiini Sulphide 

 (Did SulpJiurous Acid. 



Berthier^' said that if a mixture of the salts of iron 

 and zirconium in solution be precipitated by an excess 

 of ammonium hydroxide and then an excess of ammoni- 

 um sulphide be added, that the ferrous sulphide formed 

 could be dissolved out with a sulphurous acid solution. 

 Several experiments were carried out. The solution 

 was precipitated by an excess of ammonium hydroxide, 

 — in one the excess was boiled away^then an excess of 

 freshly made ammonium sulphide was added and the 

 whole allowed to settle. (Experiments were made with 

 both the colorless and yellow ammonium sulphide). 

 The supernatant liquid was drawn off, or the whole 

 filtered, and the precipitate boiled with a strong- sul- 

 phurous acid solution. Most of the black sulphide be- 

 came immediately decolorized. After a five or ten 

 minutes boiling", the solution was filtered and washed 

 with hot water and a weak sulphur dioxide solution. 

 The precipitate remained ' brown however, strongh^ 

 colored by the iron which had not been dissolved. In 

 one experiment this impure precipitate was redissolved 



15. Booth's Enc3'cl. Chem. 



