ON THE DECOMPOSITION OF THE EARTHS^ §77 



the earths. It sunk rapidly ia water, though surrounded 



by globules of gas producing magnesia, and quickly changed 



in air, becoming covered with a white crust, and falling into 



a fine powder, which proved to be magnesia. 



In several cases in which amalgams of the metals of the Amalgams of 



earths, containing only a small quantity of mercury, were ^^j^^ "!^,^* ° 



obtained, I exposed them to air on a delicate balance, and 



always found, that, during the conversion of metal into earth, 



there was a considerable increase of weight. 



I endeavoured to ascertain the proportions of oxigen and ^ ttempts to 

 ,.., , .,1. , /., ascertain the 



oasis m barytes and strontites, by heating amalgams of them proportion of 



in tubes filled with oxigen, but without success. I satisfied '^^^• 

 myself, however, that when the metals of the earths were 

 burned in a small quantity of air they absorbed oxigen, 

 gained weight in the process, and were in the highly caustic 

 or unslacked state; for they produced strong heat by the 

 contact of water, and did not eff"ervesce during their solu- 

 tion in acids. 



The evidence for the compostion of the alkaline earths is 

 then of the same kind as that for the composition of the com- 

 mon metallic oxides; and the principles of their decomposi- 

 tion are precisely similar, the inflammable matters in all cases 

 separating at the negative surface in the Voltaic circuit, and 

 the oxigen at the positive surface. 



These new substances will demand names ; and on the same New names, 

 principles as I have named the bases of the fixed alkalis 

 potassium and sodium, I shall venture to denominate the 

 metals from the alkaline earths barium, strontium, calcium, 

 and magnium ; the last of these words is undoubtedly ob- 

 jectionable, but magnesium * has been already applied to 

 metallic manganese, and would consequently have been an 

 equivocal term. 



'IV. Inquiries relative to the Decomposilion of Alumine, 

 Silex, Zircone, and Glucine. 

 I tried the methods of electrization and combination with Alumine and 

 quicksilver, and the common metals, by which I had suc-^f^g'^A 

 cecdcd in decomposing the alkaline earths, on alumine and earth?. 



* Bergman. Opusc. torn, ii, p. COO. 



silex; 



