HISTORY OF GALVANISM. 47 



as his decided conviction, that the action of one of 

 the metals upon the other is the sole cause of the 

 excitation of the electricity, and that the only 

 use of the interposed fluid is to convey the ex- 

 cited electricity from one pair of plates to the 

 other.* 



Many papers were written on the subject of this Cuthbert- 

 controversy, some of them containing illustrations ri 

 or modifications of the electric hypothesis, while 

 others proceeded entirely upon the opposite opi- 

 nion, endeavouring to prove, either that the phe- 

 nomena could not be explained on this principle, 

 or that the data on which it was attempted to be 

 founded were incorrect. Of this latter description 

 is an examination of the experiments which Volta 

 had himself brought forwards as the basis of his 

 reasoning, by Mr. Cuthbertson, an able practical 

 electrician, who, after repeating the experiments 

 with every precaution, could not obtain the results 

 which had been announced ; a circumstance which 

 he attributes to a defect in Volta's apparatus.f 

 It was about that time that I published the outline 

 ,of a chemical theory of galvanism, which was after- 

 wards given more in detail, the further consi- 

 deration of which will be deferred to the second 

 part of the essay. 



Professor Simon, of Berlin, repeated on a large 



* Nicholson's Journ. 8vo. i. 135. t !*>"* 281. 

 J Ibid. iii. 69 ; and Thomson's Ann. iil 32. 



