GYMNOTUS, OR ELECTRICAL EEL. J9 



that the electric organ ceases to perform its functions when 

 fatigued by too long usage, the eels, after a certain time, re- 

 semble discharged batteries. Their muscular motions con- 

 tinue equally lively, but they have no longer the power of 

 discharging very energetic shocks. When the conflict had 

 lasted a quarter of an hour, the mules and horses seemed less 

 alarmed ; they did not erect the mane, their eye expressed 

 less pain and terror ; we saw them no longer fall over. On 

 the other hand the eels, swimming half out of the water, and 

 endeavouring to avoid the horses in place of attacking them, 

 in their turn approached towards the bank. The Indians as- 

 sured us, that no horse is killed when driven two days after- 

 wards into the pool. These electric fishes require rest and 

 abundant nourishment to produce and to accumulate a great 

 quantity of the galvanic electricity. We know, by the expe- 

 riments that have been made upon the torpedos (electric rays) 

 of Italy, that on cutting or tying the nerves which go to the 

 electric organs, the functions of these parts cease as the move- 

 ment of a muscle is suspended, as long as the ligature of the 

 main artery or nerve remains. The organs of the torpedo or 

 gymnotus depend upon the nervous system and the vital func- 

 tions : they are not mere electro-motive apparatuses, which 

 attract from the surrounding bed of water the electricity they 

 have lost. One cannot, therefore, be surprised that the 

 power of the electric shocks of the gymnoti depends upon 

 their health, and consequently upon rest, nourishment, age, 

 and probably a great assemblage of physical and moral con- 

 ditions. 



The eels, making towards the bank, are taken with great 

 facility. Small harpoons, attached to cords, are cast at them; 

 the harpoon sometimes brings up two at a time. By this 

 means they are drawn out of the water without the cord, 

 which is very dry and of some length, communicating the 

 shock to the person who holds it. In a few minutes five 

 large eels were on dry land. One might have caught twenty, 

 if as many had been wanted for our experiments. Many 

 were only slightly wounded in the tail; others severely in the 

 head. We were enabled to observe the natural electricity of 

 these fishes, modified by the different degrees of the vital 

 force which they enjoyed. I shall describe in this Memoir 

 not only the experiments made, in conjunction with M. Bon- 

 pland, on the gymnoti taken in our presence, but also those 

 which we had an opportunity of making upon an eel of an 

 enormous size, which we found in our house on our return 

 from Rastro to Calabozo. This latter had been caught in a 

 net ; it had not received any wound. Immediately on being 



