Sscrr. XXIX. ELECTRICAL FISH. 299 



in general, when a solid which is not a metal becomes 

 fluid, it almost entirely loses its power of conducting 

 heat, while it acquires a capacity for conducting elec- 

 tricity in a high degree. 



The galvanic fluid affects all the senses. Nothing can 

 be more disagreeable than the shock, which may even 

 be fatal if the battery be very powerful. A bright flash 

 of light is perceived with the eyes shut, when one of 

 the wires touches the face and the other the hand. By 

 touching the ear with one wire and holding the other, 

 strange noises are heard, and an acid taste is perceived 

 when the positive wire is applied to the tip of the tongue 

 and the negative wire touches some other part of it. 

 By reversing the poles the taste becomes alkaline. It 

 renders the pale light of the glow-worm more intense. 

 Dead animals are roused by it, as if they started again 

 into life, and it may ultimately prove to be the cause of 

 muscular action in the living. 



Several fish possess the faculty of producing electrical 

 effects. The most remarkable are the gymnotus elec- 

 tricus, found in South America ; and the torpedo, a 

 species of ray, frequent in the Mediterranean. The 

 electrical action of the torpedo depends upon an appa- 

 ratus apparently analogous to the Voltaic pile, which the 

 animal has the power of charging at will, consisting of 

 membranous columns filled throughout with laminae, sep- 

 arated from one another by a fluid. The absolute quan- 

 tity of electricity brought into circulation by the torpedo 

 is so great, that it affects the decomposition of water, 

 has power sufficient to make magnets^ gives very severe 

 shocks and the electric spark. It is identical in kind 

 with that of the galvanic battery, the electricity of the 

 under surface of the fish being the same with the neg- 

 ative pole, and that in the upper surface the same with 

 the positive pole. Its manner of action is, however, 

 somewhat different ; for although the evolution of the 

 electricity is continued for a sensible time, it is inter- 

 rupted, being communicated by a succession of dis- 

 charges. 



