256 THE HAKMONIES OF NATURE. 



long, it is equal to fifty-eight square feet, and in an electrical 

 eel four feet in length, it is at least 123 square feet in extent. 



In both these fishes the electricity generated by the action 

 of these wonderful batteries, besides its benumbing and stun- 

 ning effects on living animals, renders the needle magnetic, 

 decomposes chemical compounds, emits the spark, and in short 

 exercises all the other known powers of the ordinary electricity 

 developed in inorganic matter, or by the artificial apparatus of 

 the laboratory. 



Electrical fishes exert their peculiar power only occasionally and 

 at irregular intervals, and chiefly when excited by the approach 

 of some animal, or by the irritation of their surface by some 

 foreign body. The discharge, both with regard to time and 

 intensity, seems to be dependent on an exertion of the will. 

 Sometimes the torpedo buries itself in the sand left dry at ebb- 

 tide, and it has occasionally happened, according to some natu- 

 ralists, that persons walking across the sand and treading upon 

 the spot beneath which the electrical fish lay concealed, have 

 received a discharge strong enough to throw them down. 



The effects produced by the gymnotus are more severe, for 

 those eels are able when in full vigour to kill the largest animals, 

 when they suddenly unload their electrical organs in a favoura- 

 ble direction. All other fishes, aware of their power, fly at the 

 sight of the formidable gymnotus. They stun even the angler 

 on the high river-bank, the moist line serving as a conductor 

 for the electric fluid. 



The capture of these eels affords a highly entertaining and 

 animated scene. Mules and horses are driven by the Indians 

 into the streams or marshes which they infest, until the un- 

 wonted noise and splashing of the waters rouse the fishes to an 

 attack. Gliding along they creep under the belly of the horses, 

 many of whom die from the shock of their strokes ; while others, 

 with head erect and dilated nostrils, endeavour to flee from the 

 electric storm which they have aroused. But the Indians, armed 

 with long poles and uttering wild cries, drive them back again into 

 the pool. Gradually the unequal contest subsides. Like spent 

 thunderclouds the exhausted fishes disperse, for they require a 

 long rest and plentiful food to repair the loss of their galvanic 

 powers. Their shocks grow weaker aud weaker. Terrified by 

 the noise of the horses, they timidly approach the banks, when, 



