551 SUPPLEMENT ON 



organs to a battery composed of a multitude of electric pieces, 

 or a numerous series of small fulminating squares or plates. 

 As the force of a battery of this kind is estimated by the ex- 

 tent of the surface of the squares or plates which form it, he 

 calculated what might be the measurement of all the united 

 surfaces of the vertical and horizontal membranes in the four 

 torporific organs of a gymnotus four feet long, and found it to 

 be at least one hundred and twenty-three square feet. The 

 two organs in the torpedo are only fifty-eight. When we 

 recollect the terrible effects produced by plates whose 

 surface is but a few feet square, we shall not be surprised 

 that an animal which possesses, and can use at will an electric 

 instrument of a hundred and twenty-three square feet of sur- 

 face can produce such astounding shocks as we have now 

 described. 



We shall conclude with a few brief extracts from M. de 

 Humboldt respecting the mode of taking these fish. 



" Having remained for three days to no purpose in the 

 town of Calabozo, and received but a single living eel, and 

 that rather weak, we resolved to proceed to the banks of those 

 pools in which the gymnoti abound, and make our experi- 

 ments in the open air. We first came to a small village 

 named Rastro de Abaxo. The Indians conducted us thence 

 to Cano de Bera, a reservoir of miry and stagnant water, but 

 surrounded with rich vegetation. We were greatly surprised 

 when they informed us that they were going to catch about 

 thirty half-wild horses in the neighbouring savannahs, to em- 

 ploy them in fishing for these electric eels. The idea of this 

 sort of fishing, which they call embarbascar concaballos 1 , is 

 singular enough. The word barbasco designates the roots of 

 any poisonous plant, by the contact of which a great mass 

 of water receives in an instant the property of killing, or at 



1 To make drunk by means of horses. 



