365 



When two persons, insulated or not insulated, 

 hold each other s hands, and one of these per- 

 sons only touches the fish with the hand, either 

 naked or armed with metal, the shock is most 

 commonly felt by both at once. It happens 

 however also, that, in the most painful shocks, 

 the person who comes into immediate contact 

 with the fish alone feels the shock. When the 

 gymnotus is exhausted, or in a very weak state 

 of excitability, and will no longer emit strokes 

 on being irritated with one hand ; the shocks are 

 felt, in a very vivid manner, on forming the 

 chain, and employing both hands. Even then 

 however, the electric shock takes place only at 

 the will of the animal. Two persons, one of 

 whom holds the tail, and the other the head, 

 cannot, by joining hands and forming a chain, 

 force the gymnotus to dart his stroke. 



In employing very delicate electrometers in 

 a thousand ways, insulating them on a plate of 

 glass, and receiving very strong shocks which 

 passed through the electrometer, I could never 

 discover any phenomenon of attraction or repul- 

 sion. The same observation was made by Mr. 

 Fahlberg at Stockholm. This philosopher how- 

 ever has seen an electric spark, as Walsh and 

 Ingenhousz had done before him at London, by 

 placing the gymnotus in the air, and interrupt- 

 ing the conducting chain by two gold leaves 

 pasted upon glass, and a line distant from each 



