HISTORY OF GALVANISM. 77 



apparatus, and perhaps repelled by the positive ; 

 while the oxygen, which reduces it to the state 

 of an oxide, follows the contrary order. In the 

 recomposition of the alkalies, the substances exert 

 their natural affinities ; according to circumstances, 

 either simple oxidation is produced, or a more 

 rapid combination, attended with the extrication 

 of heat and light. 



Sir H. Davy next proceeded, in an elaborate Properties 

 train of experiments, to ascertain the physical metals, 

 properties of these metals, to which he gave 

 the names of potassium and sodium, and their 

 chemical relations to other bodies. He examined 

 their fusibility, the power which they possess of 

 conducting electricity and caloric, and their speci- 

 fic gravity. He afterwards observed their action 

 on water, the acids, sulphur, phosphorus, the 

 metals, oils, and metallic oxides. It is scarcely 

 necessary to remark, that the examination was 

 conducted with the address and dexterity which 

 characterizes all the operations of this distin- 

 guished experimentalist. A minute detail of the 

 particulars would be foreign to the object of 

 this work, and strictly belongs to the science of 

 chemistry ; galvanism being no farther connected 

 with these bodies, than as the instrument by which 

 they are produced. On this account it will not fall 

 under my province to notice the discussions which 

 ensued respecting the nature of these new metals ; 

 for although it was generally admitted that the 

 substances were the bases of the fixed alkalies, 



