1 94 Faraday. 



occasioned a comment from Faraday on the number of sugges- 

 tions which were continually being laid before him. He re- 

 marked that although at different times a large number of 

 authors had presented him with their ideas, this case of 

 Jenkin was the only one in which any result had followed. 

 " The volunteers are serious embarrassments generally to the 

 experienced philosopher."* 



The discoveries of Oersted, Ampere, and Faraday had shown 

 the close connexion of magnetic with electric science. But the 

 connexion of the different branches of electric science with 

 each other was still not altogether clear. Although Wollaston's 

 experiments of 1801 had in effect proved the identity in kind 

 of the currents derived from frictional and voltaic sources, the 

 question was still regarded as open thirty years afterwards,f no 

 satisfactory explanation being forthcoming of the fact that 

 frictional electricity appeared to be a surface-phenomenon, 

 whereas voltaic electricity was conducted within the interior 

 substance of bodies. To this question Faraday now applied him- 

 self; and in 1833 he succeeded* in showing that every known 

 effect of electricity physiological, magnetic, luminous, calorific, 

 chemical, and mechanical may be obtained indifferently either 

 with the electricity which is obtained by friction or with that 

 obtained from a voltaic battery. Henceforth the identity of the 

 two was beyond dispute. 



Some misapprehension, however, has existed among later 

 writers as to the conclusions which may be drawn from this 

 identification. What Faraday proved is that the process which 

 goes on in a wire connecting the terminals of a voltaic cell is of 

 the same nature as the process which for a short time goes on in 

 a wire by which a condenser is discharged. He did not prove, 



* Bence Jones's Life of Faraday, ii, p. 45. 



t Cf. John Davy, Phil. Trans., 1832, p. 259 ; W. Ritchie, ibid., p. 279. Davy 

 suggested that the electrical power, " according to the analogy of the solar ray," 

 might be " not a simple power, but a combination of powers, which may occur 

 variously associated, and produce all the varieties of electricity with which we are 

 acquainted." 



J Exp. Jies. 9 Series iii. 



