the Decomposition of the Earths , &c. 203 



having the same whiteness and lustre as the other metals of 

 the earths. It sunk rapidly in 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 

 earths, containing only a small quantity of mercury were 

 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 oxygen, ^nd 

 bases, in barytes and strontites, by heating amalgams of 

 Jthem in tubes filled with oxygen, but without success. £ 

 satisfied myself, however, that when the metals of the earth* 

 were burned in a small quantity of air they absorbed oxygen, 

 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 effervesce during their solution 

 in acids. 



The evidence for the composition of the alkaline earths is 

 then of the same kind as that for the composition of th6 

 common metallic oxides ; and the principles of their decern* 

 position are precisely similar, the inflammable matters in all 

 cases separating at the negative surface in the Voltaic cir-> 

 cuit, and the oxygen at the positive surface. 



These new substances will demand names.; and on the 

 same principles as I have named the bases of the fixed alka- 

 lis, 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 Decom 'posit, ion of Alumine % 

 Silex, Zircone, and Glucine. 



I tried the methods of electrization and combination with 

 * Bergman. Opusc. torn. ii. p- 200. 



quicksilver, 



