the Decomposition of the Earths, &c. 201 



the amalgam of barytes, the residuum appeared as a white 

 metal of the colour of silver. It was fixed at all common 

 temperatures, hut became fluid at a heat below redness, and 

 did not rise in vapour when heated to redness, in a tube of 

 plate glass, but acted violently upon the glass, producing a 

 black mass, which seemed to contain barytes, and a fixed 

 alkaline basis, in the first degree of oxygenation*. 



When 



* From this fact, compared with other facts that have been stated, p. 195, 

 it may be conjectured, that the basis of barytes has a higher affinity for oxy- 

 gen than sodium ; and hence, probably, the bases of the earths will be more 

 powerful instruments for detecting oxygen, than the bases of the alkalis. 



I have tried a number of experiments on the action of potassium on bodies 

 supposed simple, and on the undecempounded acids. From the affinity of 

 the metal for oxygen, and of the acid for the substance formed, I had enter- 

 tained the greatest hopes of succes*. ft would be inconsistent with the object 

 of this paper to enter into a full detail of the methods of operation; I hope 

 to be able to state them fully to the Society at a future time, when they shall 

 be elucidated by further researches ; I shall now merely mention the general 

 results, to show that I have not been tardy in employing the means which 

 were in my power, towards effecting these important objects. 



When potassium was heated in muriatic acid gas, as dry as it could be ob- 

 tained by common chemical means, there was a violent chemical action with 

 ignition ; and when the potassium was in sufficient quantity, the muriatic 

 acid gas wholly disappeared, and from one-third to one-fourth of its volume 

 of hydrogen was evolved, and muriate of potash was formed. 



On fluoric acid gas, which had been in contact with glass., the potassium 

 produced a similar elFect ; but the quantity of hydrogen generated was only 

 one-sixth or one-seventh of the volume of gas, and a white mass was formed, 

 which principally consisted of fiuate of potash and silex, but which emitted 

 fumes of fluoric acid when exposed to air. 



When bnracic acid, prepared in the usual manner, that had been ignited, 

 was he-ued in a gold tube with potassium, a very minute quantity of gas only 

 was liberated, which was hydrogen, mixed with nitrogen (the last probably 

 from the common air in the tube); borate of potash was formed, and a black 

 substance, which became white by exposure to air. 



In all these instances there is great reason to believe that the hydrogen was 

 produced from the water adhering to the acids ; and the different proportions 

 of it in the different cases, are a strong proof of this opinion. Admitting this 

 idea, it 6e«ms that muriatic acid gas must contain at least one-eighth or one- 

 tenth cf its weight of water ; and that the water oxygenates in the experi- 

 ment a quantity of potassium, sufficient to absorb the whole of the acid. 



In the cases of fluoric and boracic acids, there is probably a decomposition 

 of these bodies ; the black substance produced from the boracic acid is similar 

 to that which I had obtained from it by electricity. The quantities that I 

 have operated upon, have. been as yet too small to enable me to separate and 



examine 



