104 THEORY OF GALVANISM. 



tion, it must, upon the whole, be regarded as 

 being decisively proved, that all the phenomena 

 which we style galvanic depend merely upon the 

 action of electricity, modified by the manner in 

 which it is produced or excited. 



what is Hence arises an interesting question, and one 

 which lies at the very foundation of all our future 

 inquiries, How does galvanism differ from common 

 electricity ? This question may refer both to the 

 nature of the phenomena themselves, and to the 



Remarks means employed for their production. We may 



on thedefi- , - , . . Al , 



define galvanism, either by enumerating the spe- 

 cific characteristics of those events which we class 

 together under this title ; or we may show how 

 they have all a reference to each other, from the 

 similarity of the processes that are employed for 

 their development. The definition that was given 

 at the commencement of the essay, may be re- 

 garded as sufficiently correct and comprehensive, 

 without exceeding the limits to which a definition 

 ought to be restricted. It appears to include every 

 action of bodies upon each other which is usually 

 considered as belonging to this particular branch 

 of natural philosophy ; while it excludes those that 

 are, by common consent, referred to a different 

 department. It is, however, in some cases, difficult 

 to draw the exact line of distinction between elec- 

 tricity and galvanism ; and indeed we may doubt 

 whether any precise distinction actually exists. 

 For as it is conceived that they both depend upon 

 the same agent, having merely experienced some 



