The Electric Current around the Gymnotus. 367 



necessity of touching the fish, several persons received shocks 

 independently of each other; thus A was at 4,6; B at 10, 

 11 ; C at 16, 17; and^D at 18, 19; all were shocked at once, 

 A and B very strongly, C and D feebly. It is very useful 

 whilst experimenting with the galvanometer or other instru- 

 mental arrangements, for one person to keep his hands in the 

 water at a moderate distance from the animal, that he may 

 know and give information when a discharge has taken place. 



1778. When B had both hands at 10, 11, or at 14., 15, 

 whilst A had but one hand at 1, or 3, or 6, the former felt 

 a strong shock, whilst the latter had but a weak one, though 

 in contact with the fish. Or if A had both hands in at 1, 2, 

 or 3, 4, or 5, 6, the effect was the same. 



1779. If A had the hands at 3, 5, B at 14, 15, and C at 

 16, 17, A received the most powerful shock, B the next 

 powerful, and C the feeblest. 



1780. When A excited the gymnotus by his hands at 8, 9, 

 whilst B was at 10, 11, the latter had a much stronger shock 

 than the former, though the former touched and excited the 

 animal. 



1781. A excited the fish by one hand at 3, whilst B had 

 both hands at 10, 11, (or along), and C had the hands at 12, 

 13 (or across) ; A had the pricking shock in the immersed 

 hand only (1774.); B had a strong shock up the arms; C 

 felt but a slight effect in the immersed parts. 



1782. The experiments I have just described are of such 

 a nature as to require many repetitions before the general re- 

 sults drawn from them can be considered as established ; nor 

 do I pretend to say that they are anything more than indica- 

 tions of the direction of the force. It is not at all impossible 

 that the fish may have the power of throwing each of its four 

 electric organs separately into action, and so to a certain de- 

 gree direct the shock, i. e. he may have the capability of cau- 

 sing the electric current to emanate from one side, and at the 

 same time bring the other side of his body into such a con- 

 dition, that it shall be as a non-conductor in that direction. 

 But I think the appearances and results are such as to forbid 

 the supposition, that he has any control over the direction of 

 the currents after they have entered the fluid and substances 

 around him, 



1783. The statements also have reference to the fish when 

 in a straight form ; if it assume a bent shape, then the lines 

 of force around it vary in their intensity in a manner that 

 may be anticipated theoretically. Thus if the hands were 

 applied at 1,7, a feebler shock in the arms would be ex- 

 pected if the animal were curved with that side inwards, than 

 if it were straight, because the distance between the parts 



