LAWS OF ELECTRIC PHENOMENA. 15 



in the Memoirs of the Academy. But we may easily 

 imagine what a new fame and interest this discovery 

 gave to the subject of electricity. It was repeated 

 in all parts of the world, with various modifications: 

 and the shock was passed through a line of several 

 persons holding hands; Nollet, in the presence of 

 the king of France, sent it through a circle of 180 

 men of the guards, and along a line of men and 

 wires of 900 toises 10 ; and experiments of the same 

 kind were made in England, principally under the 

 direction of Watson, on a scale so large as to excite 

 the admiration of Muschenbroek ; who says, in a 

 letter to Watson, " Magnificentissimis tuis experi- 

 mentis superasti conatus omnium." The result was, 

 that the transmission of electricity through a length 

 of 12,000 feet was, to sense, instantaneous. 



The essential circumstances of the electric shock 

 were gradually unravelled. Watson found that it 

 did not increase in proportion either to the contents 

 of the phial or the size of the globe by which the 

 electricity was excited ; that the outside coating of 

 the glass (which, in the first form of the experiment, 

 was only a film of water,) and its contents, might be 

 varied in different ways. To Franklin is due the 

 merit of clearly pointing out most of the circum- 

 stances on which the efficacy of the Leyden phial 

 depends. He showed, in 1747 11 , that the inside of 

 the bottle is electrized positively, the outside nega- 

 tively; and that the shock is produced by the 



10 Fischer, v. 512. u Letters, p. 13. 



