4 AKT. 10. — M. OGAWA : 



followed by the addition of one-tliird of the total volume of 90°/o 

 alcohol. A crystalline precipitate, apparently the same as that, 

 which had been previously obtained and set aside as ammonium 

 vanadate, was produced on standing for some time, and this was 

 washed, first, with a saturated solution of ammonium chloride 

 and, then, with dilute alcohol. 



Judging from the mode of procedure, no other known 

 substance but ammonium vanadate could have come down as a 

 crystalline precipitate under the conditions above detailed, but 

 the reactions described below clearly show that it is not 

 ammonium vanadate. Neither can it be ammonium molybdate, 

 for this salt is not known to be precipitated by ammonium 

 chloride. It is true that the compound gives some of the 

 reactions of molybdenum, which it undoubtedly contains in one 

 form or another, but the fact above alluded to that it has been 

 obtained under conditions, which exclude the possibility of am- 

 monium molybdate being precipitated pure and simple, makes it 

 exceedingly probable either that the comj^ound above obtained is 

 a complex salt containing molybdenum and the new element or 

 that it belongs to the class of mixed crystals. 



The yield of the compound was about 7 grams from 400 

 grams of molybdenite. It is remarkable that the existence, in 

 this mineral, of such a comparatively large amount of a new 

 element should have hitherto escaped observation, but this may 

 be explained by the fact that the element is very closely allied 

 to molybdenum and that its equivalent weight does not differ 

 much from that of the latter. 



Properiies of the compound. The compound, above obtained, 

 which is evidently an ammonium salt, crystallises in minute 



