202 ELECTRIC FISHES. L.ECT. X. 



In water, heated to about + 30 centig. [= 86 Fahr.;] 

 the torpedo soon ceases to live, and dies while giving a 

 great number of violent discharges. 



When it is frequently irritated while in water, especially 

 by compressing it about the eyes, it gives numerous shocks ; 

 and then ceases to do so, even though we continue to excite 

 it. After a certain period of repose its faculties return. 



Narcotic poisons, strychnia, and morphia, administered 

 to these animals in large doses, quickly kill them, after ex- 

 citing a great number of violent and rapid discharges. In 

 small doses these poisons over-excite the torpedo, and in 

 this state the slightest irritation procures shocks. I have 

 known a shock produced by giving a blow to the table on* 

 which the animal was placed. Touched at the tail, it is 

 immediately obtained; but if we divide the spinal marrow, 

 the parts situated below the section are no longer able to 

 give it : it is then a discharge produced by a reflex action 

 on the spinal marrow. 



The analogies between muscular contractions and the 

 discharge of the torpedo are complete : what destroys, aug- 

 ments, and modifies the one, acts equally upon the other. 



Electric Phenomena of the Gymnotus. Respecting the 

 gymnotus, another electric fish found in some of the lakes 

 of South America, I have but a few words to say, as the 

 animal has been but little studied. I regret I cannot here 

 quote a long passage from the work of the celebrated Hum- 

 boldt, in which he describes the method of capturing the 

 electric eels as adopted by the South American Indians. 

 They drive their horses and mules into the muddy lakes 

 where these fishes live. These commence the contest by 

 giving very violent and very numerous discharges to the 

 horses and mules ; and not unfrequently kill them. After a 

 long fight, the gymnoti, exhausted by fatigue, float on the 



