FARADAY. 41 1 



emerged from his researches with the great principle of 

 Definite Electro -chemical Decomposition in his hands. 

 If his discovery of Magneto-electricity may be ranked 

 with that of the pile by Volta, this new discovery 

 may almost stand beside that of Definite Combining 

 Proportions in Chemistry. He passed on to Static 

 Electricity its Conduction, Induction, and Mode of 

 Propagation. He discovered and illustrated the prin- 

 ciple of Inductive Capacity ; and, turning to theory, he 

 asked himself how electrical attractions and repulsions 

 are transmitted. Are they, like gravity, actions at a 

 distance, or do they require a medium ? If the former, 

 then, like gravity, they will act in straight lines ; if 

 the latter, then, like sound or light, they may turn a 

 corner. Faraday held and his views are gaining 

 ground that his experiments proved the fact of curvi- 

 linear propagation, and hence the operation of a medium. 

 Others denied this ; but none can deny the profound 

 and philosophic character of his leading thought. 1 The 

 first volume of the Researches contains all the papers 

 here referred to. 



Faraday had heard it stated that henceforth physical 

 discoveries would be made solely by the aid of mathe- 

 matics ; that we had our data, and needed only to work 

 deductively. Statements of a similar character crop 

 out from time to time in our day. They arise from 

 an imperfect acquaintance with the nature, present 

 condition, and prospective vastness of the field ol 

 physical enquiry. The tendency of natural science 

 doubtless is to bring all physical phenomena under the 

 dominion of mechanical laws ; to give them, in other 

 words, mathematical expression. But our approach to 



1 In a very remarkable paper published in Poggendorff's 

 Annalen ' for 1857, Werner Siemens accepts and develops Faraday's 

 theory of Molecular Induction. 



