some Experiments on the Torpedo. 83 



my body several times a part of it, holding the silver spoon, 

 by which the shock was taken, in one hand, wetted in salt and 

 water, and keeping the wire connected with the electrometer 

 in the other wet hand ; the shocks which passed through the 

 reduplications of the electrometer were sufficiently powerful 

 to be felt in both elbows, and once even in the shoulders. 



These negative results may be explained by supposing that 

 the motion of the electricity in the torpedinal organ is in no 

 measurable time, and that a current of some continuance is 

 necessary to produce the deviation of the magnetic needle ; 

 and I found that the magnetic electrometer was equally insen- 

 sible to the weak discharge of a Leyden jar as to that of the 

 torpedinal organ ; though whenever there was a continuous 

 current from the smallest surfaces in voltaic combinations of 

 the weakest power, but in which some chemical action was 

 going on, it was instantly and powerfully affected. Two series 

 of zinc and silver, and paper moistened in salt and water, caused 

 the permanent deviation of the needle several degrees, though 

 the plates of zinc were only ^th of an inch in diameter. 



It would be desirable to pursue these inquiries with the elec- 

 tricity of the gymnotus, which is so much more powerful than 

 that of the torpedo : but if they are now to be reasoned upon, 

 they seem to show a stronger analogy betAveen common and 

 animal electricity, than between voltaic and animal electricity: 

 it is however I think more probable that animal electricity will 

 be found of a distinctive and peculiar kind. 



Common electricity is excited upon non-conductors, and is 

 readily carried off by conductors and imperfect conductors. 

 Voltaic electricity is excited upon combinations of perfect and 

 imperfect conductors, and is only transmitted by perfect con- 

 ductors or imperfect conductors of the best kind. 



Magnetism, if it be a form of electricity, belongs only to 

 perfect conductors ; and, in its modifications, to a peculiar 

 class of them. 



The animal electricity resides only in the imperfect conduc- 

 tors forming the organs of living animals, and its object in the 

 ceconomy of nature is to act on living animals. 



Distinctions might be established in pursuing the various 

 modifications or properties of electricity in these dillcrcnt forms; 

 but it is scarcely possible to avoid being struck by another re- 

 lation of this subject. The torpedinal organ depends for its 

 f)owcrs upon the will of the animal. John Hunter has shown 

 low co])iously it is furnished with nerves. In examining the 

 cohimiiar structure of the organ of the torpedo, I have never 

 been ul)lc to discover arrangements of difli3rcnt conductors si- 

 milar to those in galvanic combinations, and it seems not im- 

 M 2 probable 



