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. 



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 



