EPOCH OF DAVY AND FARADAY. 195 



mical combinations the elements may be consi- 

 dered as electro-positive and electro-negative ; and 

 made this opposition the basis of his chemical doc- 

 trines; in which he was followed by a large body 

 of the chemists of Germany. He held too that the 

 heat and light, evolved during cases of powerful 

 combination, are the consequence of the electric 

 discharge which is at that moment taking place : a 

 conjecture which Faraday at first spoke of with 

 praise 46 . But at a later period he more sagely says 47 , 

 that the flame which is produced in such cases 

 exhibits but a small portion of the electric power 

 which really acts. " These therefore may not, cannot, 

 be taken as evidences of the nature of the action ; 

 but are merely incidental results, incomparably 

 small in relation to the forces concerned, and sup- 

 plying no information of the way in which the par- 

 ticles are active on each other, or in which their 

 forces are finally arranged." And comparing the 

 evidence which he himself had given of the prin- 

 ciple on which Berzelius's speculations rested, with 

 the speculations themselves, Faraday justly con- 

 ceived, that he had transferred the doctrine from 

 the domain of what he calls doubtful knowledge, to 

 that of inductive certainty. 



Now that we are arrived at the starting-place, 



from which this well-proved truth, the identity of 



electric and chemical forces, must make its future 



advances, it would be trifling to dwell longer on 



46 Researches, Art. 870. 47 960. 



02 



