156 NATURE AND LIFE. 
peculiar to animals, as Galvani declared. It decides also 
that electricity produced by external causes has an influ- 
ence over animals, as Volta taught. From profound study 
of the two orders of phenomena, it deduces a system of — 
procedure for the cure of very many maladies by electricity. 
Consequently, an exposition of the relations between elec- 
tricity and life must begin with examining the electricity 
that exists naturally, in the same way that heat does, in 
animals, and then go on to explain the action of the fluid 
on the organism, whether in a healthy or morbid state. 
Such a description will complete what has been written in 
the Revue respecting the relations of life with light and 
heat—relations that we may to-day consider as forming the 
features of a new science. 
i, 
The most authentic witnesses to the existence of animal 
electricity are fish. The torpedo, the silurus, the gymno- 
tus, the ray, and other fishes, develop spontaneously a 
more or less considerable quantity of electricity. This 
fluid, the production of which depends upon the animal’s 
will, is identical with that of common electrical machines; 
it gives the like shocks and sparks at a certain tension. 
The apparatus for its formation consists of a series of 
small disks of a peculiar substance, kept apart by cells of 
laminated tissue. Fine nerve-end fibres are scattered over 
the surface of these disks, and the whole represents a sort 
of membranous pile, usually placed in the region of the 
head, sometimes toward the tail. 
These fishes are the only animals provided with an ap- 
paratus specially devoted to the production of electricity ; 
but all animals are electric, in this sense, that a certain 
quantity of that fluid is constantly forming within their 
organs. The existence of electricity peculiar to the nerves 
and muscles, and independent of their special modes of 

