XOTE OX A XEW ELEMENT IN THORIANITE. 7 



the reprecipitated hydroxides \Yere filtered and ignited. The 

 ignited oxides were then heated in a cnrrent of chlorine gas 

 and carbon tetrachloride vapour. A difficultly volatile chloride, 

 apparently identical with tliat obtained from thorianite, was 

 thus produced. Its spectrum, also, was exactly the same as 

 before. The yield of the oxide was, however, very much better, 

 about one decigram having been obtained from 200 gr. of the 

 mineral. 



Examination of Molybdenite. 



The powdered mineral was roasted in air, until sulphurous 

 acid gas was no longer given off. The residue, which was yellow 

 when hot and pale greenish yellow when cold, was digested with 

 a dilute solution of ammonia. The portion insoluble in ammonia 

 was then digested with dilute hydrochloric acid, and the solution 

 filtered from some undecomposed portion of the mineral. The 

 acid solution was nearly neutralised with ammonia and, after 

 saturation with ammonium chloride and on standing, a pale 

 yellow precipitate was formed. The precipitate, apparently am- 

 monium vanadate, was removed by filtration. To the yellowish 

 green filtrate, hydrogen sulphide was passed to saturation, and 

 the black precipitate thereby formed was filtered off. The filtrate 

 was freed from hydrogen sulphide by boiling, and then ammonia 

 and hydrogen peroxide were added. The precipitated hydroxides 

 were redissolved in dilute hydrochloric acid and boiled, as before, 

 with sodium tliiosulphate in order to remove iron. 



The reprecipitated hydroxides were filtered, ignited and fused 

 with a mixture of sodium carbonate and potassium nitrate, and 

 the fused mass dissolved in water. After decomposing the solution 



