54- THE OCEAN WORLD. 



drawn within their orbits, while the other parts of the body remained 

 immovable. 



If only one of the two organs of the torpedo is touched it happens 

 that, in place of a strong and sudden shock, only a slight sensation is 

 experienced — a numbness, or start, rather than a shock. The same 

 result followed with every experiment tried. The animal was tried 

 with a non-conducting rod, and no shock followed ; glass, or a 

 rod covered with wax, produced no effect ; touched with a metallic 

 wire, a violent shock followed. Melloni, Matteucci, Becquerel, and 

 Breschet have all made the same experiments, with the same results ; 

 Matteucci having ascertained that the shock produced by the tor- 

 pedo is comparable to that given by a voltaic pile of loo to 150 pairs 

 of plates. 



The organ which produces this curious result is formed like a half- 

 moon ; it is double, and placed on each side of the head occupying 

 the space between it and the base of the pectoral fins. It consists of 

 a multitude of small prisms arranged parallel the one to the other 

 and perpendicularly to the surface ; 1,262 of these prisms have been 

 counted in one of the two organs of a torpedo, three feet in length. 

 Without entering into the anatomical descriptions which have been 

 given by Stannius, Max Schultze, Breschet, and others, we may 

 mention here that all the small parallelopipedes, which enter into its 

 structure, are separated one from the other by walls of cellular tissue, 

 in which are distributed the vessels and nerves. The nervous threads 

 wliich each apparatus receives are divided into four principal trunks. 

 According to modern authors, the electricity is elaborated in the 

 brain under the influence of the will. It is afterwards transferred by 

 means of the nervous threads into the principal organ, where it serves 

 the purpose of charging the numerous little voltaic piles which con- 

 stitute the organ of commotion. 



It is, nevertheless, necessary to receive our comparisons of the 

 apparatus of the torpedo with the voltaic pile of our laboratories with 

 caution. The apparatus resembles a good conducting body, which 

 is capable of being strongly electrified ; it is sufficient to touch one of 

 the surfaces in order to receive the shock. But if the little prisms 

 composing it were charged like our voltaic piles, it would be necessary 

 to touch both their surfaces in order to receive the shock. No perfect 

 analogy can therefore exist between this natural apparatus and the 

 scientific instrument named after Volta. 



It is possible by the aid of heat to restore the extinct or suspended 

 electrical functions of the torpedo. Retained in a tank of sea- water 

 a yard in height by a third of that in diameter, and at 22° Centi- 



