EXPERIMENTS ON MOLYBDENA. 131 



ing thrcKvn into water, this fluid entered its interstices with sorbed water,, 

 avidity. 



Exps. 14 and 15. To know whether the molybdic acid Molybdic acid 

 were capable of being reduced b}^ the action of tire alone, stronff\eat^ - 

 without being mixed with any carbonaceous matter, I took imbedded in 

 a piece of the acid, which had been melted, and weighed 55 

 grains. This I placed in the midst of charcoal powder in a 

 crucible, and exposed it for an hour and half to the same de- 

 gree of heat as in the preceding experiment. The result was 

 a tumid mass, which had not any moie consistency than that 

 of experiments 12 and 13. It was like that of an ash gray 

 colour, and had lost eighteen grains of its weight, or in the 

 proportion of 3273 per cent. In nitric acid it comported 

 Itself in the same manner as the masses obtained in the pre- 

 ceding experiments. Two hundred and seventy grains of 

 the matter obtained from the molybdate of ammonia roasted 

 in experiments 9 and 10, being treated in the same manner, 

 and kept a quarter of an hour at a white heat, gave a similar 

 product to that of experiments 12 and 13. They had lost 

 7^ grains, or 28'89 per cent. 



In a second trial 264 grains of the viulet brown oxide, Attempt to re- 

 having been kept only half an hour at a moderately strong ^"o^noxide.^ 

 red heat, the result was amass but imperfectly reduced. The 

 interior was no way changed; the surface only was gray. Re- 

 placed in the fire, and kept at a white heat for half an hour, 

 it was entirely reduced, and lost 74 grains, amounting to 28'03 

 per cent. Hence it follows, that the substance obtained from 

 the molybdate of ammonia is very far from being in the 

 metallic stale. 



These experiments show, that oxigen may be separated Oxigen separa- 



from molybdena by the action of fire alone when in contact , u,il^™°^°' 

 -' •' lybdena in con» 



with charcoal. They prove, that the reduction of the oxide tact with char- 

 and of the acid of molybdena may be effected without great ^"o^g^ 

 difficulty. It remains to be seen, whether this reduction can 

 be effected with larger quantities, and whether the molybdena 

 cannot be obtained in a button. 



Exps. \6 a»d 17. I took ten drachms of molybdate of Molybdate of 

 ammonia; put them into a glass which I placed in a cruci- ammonisiheat* 

 ble, and exposed to a red heat for half an hour; and obtained ^he brown 

 K 2 .a muss 



