CAKTILAGINOUS FISHES. 515 



elbow against a hard substance." Eedi remarks, besides, that the pain 

 and trembling sensation resulting from the touch diminishes as the 

 death of the Torpedo approaches, and that it ceases altogether when 

 the animal dies. 



In the seventeenth century, the fishermen affirmed that the sensa- 

 tion was even communicated through the line by which it was caught, 

 and even by the w r ater. Eedi does not deny this phenomenon, neither 

 does he confirm it. He states that the action of the animal is never 

 more energetic than when it is strongly pressed by the hand, and 

 makes violent efforts to escape. Neither Eedi nor Eeaumur, however, 

 could explain the cause of the strange phenomenon. It was reserved 

 for Dr. Walsh, a fellow of the Eoyal Society of London, to demon- 

 strate the fact that the power was electrical in its nature. This he 

 did by numerous experiments, which he made in the Isle of Ee. The 

 following are some of his experiments. 



He placed a living torpedo upon a clean wet towel ; from a plate he 

 suspended two pieces of brass wire by means of silken cord, which 

 served to isolate them. Eound the torpedo were eight persons, stand- 

 ing on isolating substances. One end of the brass wire was sup- 

 ported by the wet towel, the other end being placed in a basin full of 

 water. The first person had a finger of one hand in this basin, and a 

 finger of the other in a second basin, also full of water. The second 

 person placed a finger of one hand in this second basin, and a finger 

 of the other hand in a third basin. The third person did the same, 

 and so on, until a complete chain was established between the eight 

 persons and nine basins. Into the ninth basin the end of the second 

 brass wire was plunged, while Dr. Walsh applied the other end to the 

 back of the torpedo, thus establishing a complete conducting circle. 

 At the moment when the experimenter touched the torpedo, the eight 

 actors in the experiment felt a sudden shock, similar in all respects to 

 that communicated by the shock of a Leyden jar, only less intense. 



When the torpedo was placed on an isolated supporter, it com- 

 municated to many persons similarly placed from forty to fifty shocks 

 in a minute and a half. Each effort made by the animal, in order to 

 give them, was accompanied by the depression of its eyes, which were 

 slightly projecting in their natural state, and seemed to be drawn within 

 their orbits, while the other parts of the body remained immovable. 



If only one of the two organs of the torpedo is touched it happens 



2 L 2 



