373 



the vial is discharged in such a manner, that the 

 cloth makes part of the chain ; prepared frogs, 

 placed at different distances, indicate by their 

 contractions, that the current spreads itself over 

 the (whole cloth in a thousand different ways. 

 According to this analogy, the most violent 

 shock given by the gymnotus at a distance 

 would be but a feeble part of the stroke, that 

 reestablishes the equilibrium in the interior of 

 the fish*. As the gymnotus directs it's fluid 

 where it pleases, it must also be admitted, that 

 the discharge is not made by the whole skin at 

 once ; but that the animal, excited perhaps by 

 means of the motion of a fluid poured into one 

 part of the cellular membrane, establishes at 

 will the communication between it's organs and 



* The heterogeneous poles of the double electrical organs 

 must be found in each organ. Mr. Todd has recently proved, 

 by experiments made on torpedoes of the Cape of Good 

 Hope, that the animal continues to give violent shocks, when 

 one of these organs is extirpated. On the contrary, all 

 electrical action is stopped, and this point, already elucidated 

 by Galvani, is of the greatest importance, if a great injury be 

 done to the brain, or if the nerves, which supply the plates of 

 the electrical organs, be divided. In the latter case, the 

 nerves being cut, and the brain left untouched, the torpedo 

 continues to live, and perform every muscular movement. 

 A fish, exhausted by too numerous electrical discharges, suf- 

 fered much more than another fish, deprived, by dividing the 

 nerves, of any communication between the brain and the elec- 

 tromotive apparatus. Phil. Trans. , 1816, part I, p. 120. 



