OF AN ELECTRIC DISCHARGE. JT 



According to this it will not be necessary for us to consider 

 the varying condition which exists during a discharge, but only 

 to consider the constant conditions existing before and after the 

 discharge ; and as in these two states the electricity is at rest, 

 the question whether the electricity possess vis viva or not may 

 remain unnoticed. 



In like manner it is unnecessary to decide whether there are 

 two kinds or only a single kind of electricity; for, that the at- 

 tractions and repulsions take place as if there were two elec- 

 tricities is sufficiently proved; and we can therefore, in the 

 present instance, where we have only to do with the Jbrces, 

 always speak of two electricities as the carriers of these forces, 

 without therefore attributing to them an actual existence. 



Besides the work already mentioned as produced by the 

 attractive and repulsive forces of the electricity, and which is 

 measured by the increase of the potential, we find in the case 

 of discharge many additional effects in which other forces come 

 into play, and of which a few of the most common may be 

 introduced here. 



At one or more places electric sparks spring over, by which a 

 stratum of air or other non-conducting body is broken through. 

 When the electric current passes in one place through a thin 

 wire, the latter undergoes mechanical changes which may vary 

 between the limits of small indentations impressed on the wire 

 and the complete reduction of the latter to powder. When the 

 current passes through electrolytic bodies, chemical decompo- 

 sitions take place. In bodies which lie in the immediate neigh- 

 bourhood of the current, induced currents or magnetic effects 

 may be excited, &c. 



These actions must, in reference to the forces under con- 

 sideration, be regarded as negative work, inasmuch as the 

 nature of the actions is, that the corresponding forces, as for 

 example in the first case, the resistance of the layer of air or 

 other body penetrated by the spark, in the second case, the 

 solidity of the wire, &c., are overcome, and therefore motions 

 take place which are opposed to the forces. If all these quan- 



reckons the potential of a mass upon itself double what it really is. In other 

 cases, where, instead of the potential, he introduces quantities corresponding to 

 the potential function, his formulas and mine are coincident. 



