PART I. 



SECTION I. 



Experiments before the Discovery of the Pile. 



IN reviewing the history of galvanism there are 

 two great eras, which especially arrest our notice, 

 the formation of the pile of Volta in the year 1791 * 

 1800, and the decompositions of the alkalies and 

 earths by Sir H. Davy in 1806 ; these discoveries 

 naturally divide the narrative into three periods, 

 during each of which a particular train of phe- 

 nomena was pursued, and the attention was 

 occupied by a different kind of investigation. 



The original discovery, to which I have already 

 alluded, took place from a singular accident. The 

 wife of Galvani, being in a declining state of 

 health, employed as a restorative, according to 

 the custom of the country, a soup made of frogs. 

 A number of these animals, ready skinned for 

 the purpose of cookery, chanced to lie in his 

 laboratory, on a table near an electrical machine. 

 While the machine was in action, an attendant 

 happened to touch, with the point of a scalpel, the 



