542 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 100 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 Stanntus, 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 
which 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 og 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- 
