ELECTRICITY IN THE PHENOMENA OF ANIMAL LIFE. 447 



When the circuit is completed by means of a nonoxidizable or less 

 oxidizable substance this equilibrium is made an end of by doing 

 away with the counter electro-motive force, as a path of escape is offered 

 to the electricity; but the electric flow or current thus established 

 constitntes an available form of energy, which may be used to liberate 

 zinc if we cause such current to act by a suitable arrangement upon an 

 easily decomposable zinc salt. 



• On condition, then, that we provide by a supply of supplementary 

 energy for the inevitable losses of effect resulting from these succes- 

 sive operations, we see that it is possible to form a cycle of reactions 

 corresponding at all points to our definition of vitality. 



If, then, this definition give a true statement of the facts, must we 

 not come to recognize in the vital cycle the image of that which we 

 have just sketched. - - - 



Let us consider a culture medium capable of maintaining the life of 

 a given cell by furnishing it with all the constituent material it recpiires, 

 and let us observe that in order to suitability of the medium for the 

 cell the former must contain at least the chemical elements which occur 

 as constituents of the latter. 



As long as the cell is absent this medium may be compared to the 

 voltaic battery with circuit unclosed, which we have taken as an 

 example by analogy. Like this latter, and by virtue of the same nat- 

 ural hiws, it will present a state of equilibrium, due to the existence of 

 two opposite electrical forces — a kiiul of state of virtual combination 

 between the electro-positive and electro-negative constituents — but no 

 chemical change will disturb its original homogeneity. 



Let us now supi)Ose that the living cell is introduced. As soon as 

 equilibrium is overthrown disi)lacement8 of electricity are set up, com- 

 binations and decompositions take place, and the vital circulation of 

 energy and matter is established. 



To explain what has thus occurred we must assume, it seems to me, 

 that the first result of the introduction of the living germ or cell has 

 been to offer to the electricity conducting paths, or in other words, to 

 bring about what I will call odogenesis.^ The first effect of vitality 

 would seem to bo that of a contact action, allowing of cliemical change 

 being energetically prodnced by favor of the short circuits ottered to 

 the electrical energy engendered. 



III. — OF THE PART PLAYED BY THE LIVING CELL. 



Nevertheless, how can this take place, since the medinm we have 

 under consideration continues inactive, the cell introduced reacting 

 only with the stratum of this medium with which it is in immediate 

 contact! 



To explain this it is essential to remark that from the quite special 

 point of view at which we are just now j^lacing ourselves we must 



' Odogenesis, the creation of a jiatL, from o(Wf aiid jtvecic. 



