EXPERIMENTS OX MOLYBDSXA. ^^^ 



scarcely lost an eighth of a grain. This experiment shows, 

 1st, that the molybdena contained no excess of sulphur: 

 2dly, that the heat applied was not sufficient to expel the 

 sulphur ftom it: 3dly, that there was no oxigen combined 

 with it. 



Exp. 2. The molybdena of the preceding experiment Treated xvitk 

 was put into half an ounce of pure nitric acid, the specific "'^'^'^ ^'^^ * 

 gravity of which was 1'22, and made to boil on a sand heat. 

 The acid attacked the molybdena pretty briskly, but not so 

 much as I should have supposed. To accelerate the ope- 

 ration, and prevent the sulphur from passing to the state of 

 sulphurous acid, I added a drachm and half of pure muri- murialic acid 

 atic acid, of the weight of l*13o, and a drachm of nitric'^ ^ * 

 acid. After boiling for an hour the whole was converted 

 into a homogeneous mass of a milky whiteness, which was 

 diluted with eight times its -weight of water; the solution 

 was filtered; and the sulphuric acid, that had been formed, and sulplnmc 

 was separated, by washing well both the residuum and the '^"'^ ^'^'^"^'^^' 

 filter. Into the liquor, that had passed through the filter, a 

 isolution of muriate of barytes was poured. This occasioned which wis prs- 

 a precipitate, which, being carefully collected, dried, and ^'I'ltated by 

 heated red hot, weighed seventy-two grains, and comported 

 itself as pure sulphate of barytes. To determine the cir- 

 cumstances, in which this precipitate is possible, I made the 

 two following experiments. 



Exp. 3. Five grains of molybdic acid were mixed with Molybdic aoJi 

 two ounces of distilled water ; twenty drops of muriatic acid, ^^ bvin'^ar^te' 

 of the strength mentioned above, were added ; the whole was of barytes- 

 boiled for half an hour, and the liquor was filtered. The 

 solution had a very rough metallic taste ; and solution of 

 muriate of barytes did not render it turbid, though a little 

 sulphuric acid produced this elfect immediately. 



Exp. 4. Five grains of molybdic acid and twenty grains Molybdata of 

 of pure liquid ammonia were put into two ounces of water, ^'"'"^"''^ 

 and the mixture shaken, till the whole was perfectly dis- 

 solved. A solution of muriate of barytes being added, a and muii;iteof 

 copious fiocculent precipitate immediately formed, which b.-vrytcs udde<i. 

 was afterward redissolved on adding a few drops of muriatic 

 or nitric acid, and shaking the mixture. 



These experiments show: ], that no indissoluble molyb- inferences. 



dat 



