THEORY OF GALVANISM 153 



facts in its support, but still the fundamental posi- 

 tion on which the whole rests, the transfer of che- 

 mical affinity, considered as a primary cause, is 

 not easy to comprehend, unless we ascribe it to 

 the agency of some principle that must possess 

 different qu ah' ties from those that we usually as- 

 cribe to chemical affinity. I apprehend that it 

 must be regarded as a verbal, rather than as an 

 actual explanation of the fact, and that, at all 

 events, we ought not to apply it as a means of ex- 

 plaining phenomena, until we have established its 

 existence by some independent evidence. 



With these remarks I shall conclude my account Concluding 

 of the theory of galvanism. It will be perceived, 

 that much discordance of opinion still exists upon 

 the subject, and that some strong objections attach 

 to every hypothesis which has yet been proposed. 

 The most important points to ascertain are, the 

 difference between electricity, as excited by the 

 friction of the common machine, and that modifi- 

 cation of it which is strictly called galvanism. 

 For this purpose, the nature of electric intensity 

 should be further investigated ; for it would appear 

 that if we were able to attach a more precise idea 

 to this term, a considerable insight would be gained 

 into the cause of this difference. Experiments 

 somewhat similar to those of De Luc should be 

 prosecuted, in which the electrical and chemical 

 effects of the pile are separated from each other, 

 and a more accurate measure of the proper galva- 

 nic power should, if possible, be obtained, than any 



