

PART II. 



THEORY OF GALVANISM. 



ACCORDING to the plan which was laid down, General 

 I must now proceed to give an account of the the- 

 ories and hypotheses that have been formed to 

 explain the phenomena of galvanism. I have had 

 occasion to allude to many of these in the course of 

 the historical sketch ; and the reader will, in some 

 degree, have anticipated my opinion respecting 

 them. The subject divides itself into several 

 branches, partly corresponding with the progress 

 of our knowledge of the facts that were gradually 

 developed, and partly depending upon the sup- 

 posed relation of galvanism to the other depart- 

 ments of natural philosophy. 



In this concise view of the science, I shall not Gaivani'g 

 think it necessary to enter into the merits of the h yP othesi - 

 earlier speculations that have been superseded by 

 later discoveries. Of this nature is the original 

 hypothesis of Galvani himself, that the convul- 

 sions which he observed in the muscles of frogs 

 were produced by a new and peculiar agent, re- 

 siding in the body, to which he gave the name of 

 animal electricity. Although there are some few 

 cases which seem to militate against the supposi- 



