OM THE DECOMPOSITION OF THE EARTHS. 375 



When exposed to air, it rapidly tarnished, and fell into a 

 white powder, which was barytes. When this process was 

 conducted in a small portion of air, the oxigen was found 



absorbed, 



I have tried a number of experiments on the action of potassium Base of potaik 

 on bodies supposed simple and on the undecornpounded acids. »PPl»««i 'o 

 From the affinity of the metal for oxigen, and of the acid for the 

 substance formed, I had entertained the greatest hopes of success. 

 U would be inconsistent with the object of this paper to enter into a 

 fi)ll 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 elu- 

 cidated by fartiier researches ; I shall now merely mention the ge- 

 neral results, to show that I have not been tardy in employing tiie 

 means which were in my power, towards effecting these important 

 objects. 



When potassium was heated in muriatic acid gas, as dry as it muriatic acid 

 could be obtained by common chemical means, there was a violent K^S 

 chemical action with ignition ; and wiien the potassium was in suf- 

 iicienc quantity, the muriatic acid gas wholly disappeared, and from 

 one third to one fourth of its volume of hidrogen was evolved, and 

 muriate of potash was formed. 



On fluoric acid gas, which had been in contact with glass, the fluoric add ga<;, 

 potassium produced a similar effect; but the quantity of hidrogen 

 generated was only one sixth or one seventh of the volume of gas, 

 and a white mass was formed, which principally consisted of fluate 

 of potash and silex, but which emitted fumes of fluoric acid when 

 exposed to air. 



When boracic acid, prepared in the usual manner, that had been and boracic 

 ignited, was heated in a gold tube with potassium, a very niinute:^*^'"^* 

 flinantity of gas only was liberated, which was hidrogen, mixed with 

 nitrogen, (the last probably from the common air in the tube) ; bo- 

 rate 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 hi- The results no t 

 drogen was produced from the water adhering to the acids; and the c^'^'^^"*''®- 

 different proportions of it in the different cases are a strong proof 

 of this opinion. Admitting this idea, it seems, that muriatic acid 

 gas must contain at least one eighth or one tenth of its weight of 

 water; and that the water oxigenates in the experiment a quantity 

 p( potassium, sufficient to absorb the whole of the acid. 



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

 composition of these bodies ; the black substance produced from 

 the boraeic acid is similar to that which I had obtained from it by 

 electricity. The quantities that I have operated upon have been as 



yet 



