128 PROGRESS OF SCIENCE IN THE CENTURY. 



alkalis are the oxides. This important step, 

 checked by the French chemists, seems to have led 

 many for a time to a false expectation. " The idea 

 was arrived at that the substances hitherto known 

 were only compounds, and that the aim of chemistry 

 was now to discover the true elements, which it was 

 supposed would resemble potassium and sodium. 

 . . . The galvanic current, at that period an en- 

 tirely new agent, had accomplished this marvel, and 

 it was itself a marvellous thing. By its aid it had 

 become possible to decompose compounds into their 

 true elements; hence it is not surprising that this 

 agency was regarded as identical with the one which 

 gave rise to combinations ; i.e., with affinity." * 



Berzelius. — The ingenious suggestions of Davy 

 were soon developed by Berzelius into a consistent 

 theory which was then used as the foundation idea 

 of a chemical system. 



He believed, with Davy, that all chemical reac- 

 tions are produced by electricity, which " thus seems 

 to be the first cause of the activity all around us in 

 nature." But he differed from Davy in his mode 

 of conceiving of the electrical distribution. In his 

 own words, ^^ If the electro-chemical views are ac- 

 curate, it follows that every chemical combination 

 depends wholly and only upon two opposite forces, 

 namely, the positive and negative electricities, and 

 that every compound must be composed of two parts, 

 united by the effects of their electro-chemical reac- 

 tions, since there is not any third force. From this 

 it follows that every compound substance, whatever 

 the number of its constituents may be, can be divided 

 into two parts, of which the one is positively and the 

 other is negatively electrical." 



* Ladenburg, 1900, p. 67. 



