12 ART. 16. — M. OGAWA : 



ferric oxide and the unknown oxide in the residue, after ex- 

 tracting the fused mass with water, this unknown oxide dissolving 

 in nitric acid to form a bluish green solution, and the oxide of 

 the new element in the aqueous extract. It must be here remarked 

 that, although the nitric acid extracts, both green and brown, 

 undeniably contain iron, as is shown by their subsequent treat- 

 ment, they give no reactions with potassium ferrocyanide. 



With regard to the unknown oxide, which dissolves in nitric 

 acid with a bluish green colour, above referred to, no further 

 observation has been made than that it is radioactive, and it is 

 likely that the radioactivity of the sulphide residue from thorianite 

 is due to the presence of this substance. It can be definitely 

 stated that it does not contain any uranium. Since the brown 

 coloured nitric acid extracts also give the same unknown oxide, 

 dissolving in nitric acid with a bluish green colour, after fusion 

 with potassium nitrate, it is possible that the difference in colour 

 may be due to the existence of two ditïerent oxides of one and 

 the same unknown element. 



Conclusions. 



1. Both molybdenite and thorianite contain a new element, 

 which is closely allied to molybdenum. 



2. It forms a complex salt (?) with ammonium molybdate, 

 precij)i table, from its aqueous solution, in a crystalline form on 

 saturation with ammonium chloride. 



3. It appears to form two different oxides, the higher oxide 

 boing similar in its properties to molybdenum trioxide and acting 

 as an acidic oxide. The salts of barium, lead and silver, formed 



