174 Prof. G. Wiedemann on the Laics of the 



electricity with the molecules proceeding in streams from their 

 centres of equilibrium, which would then communicate it to 

 the succeeding molecules, and so on. 



In all probability electrolytes are conductors in conse- 

 quence of the electricity being carried by the atoms with 

 which it is connected. Whilst the atoms of each molecule in 

 their movement come into friction with each other, with the 

 dissolving medium, &c, they lose their electrolytic movement 

 in the direction of the current, and their vis viva is converted 

 into heat-motion. This frictional resistance therefore answers 

 to the resistance to conduction. On account of its complexity, 

 especially when the electrolyte is in solution, we cannot ex- 

 pect to find a simple relation between the resistance of the 

 electrolyte and its otherwise mechanical constants. On this 

 account also, a simple law cannot be expected, for instance, 

 from the comparison of the resistance of the fluid solutions of 

 chlorides with their specific volumes. The conductive capacity 

 calculated upon the supposition of an inverse proportion be- 

 tween two values differs, for instance, according to F. Kohl- 

 rausch, nearly 10 per cent, in quantity. 



The gas molecules then, as above stated, will be propelled 

 from the electrodes with a certain charge in directions which 

 correspond to the greatest diminution of the potential ; they 

 thus come into contact with other molecules, with which they 

 share their electricity or (if electricity consists in oscillations 

 of the ether surrounding each molecule) their vibrations, and 

 so on. 



The process, therefore, would be exactly similar to that 

 of electrolysis, only that the vis viva of the gas molecules 

 does not, like that of the atoms, so far as produced by the 

 electromotive force acting at each point, change completely 

 into heat by friction on the neighbouring medium, but it 

 propagates itself from the electrodes through the whole inter- 

 val of the discharge, and a small aliquot part of it is also 

 conveyed about equally all along the sides of the tube in the 

 form of heat. 



Besides the general characteristics of discharge, there is 

 another series of separate points to be noticed — for example, 

 the unequal extension of the positive and negative discharge, 

 the spot at which the vis viva contained in the moving bodies 

 of gas ultimately appears in the form of heat, the dark space 

 near the negative electrode, and the disposition of the light 

 of the discharge. 



The unequal extension of the positive and negative discharge 

 has already been referred, in a former memoir, to the greater 

 initial velochVv in the positive as compared with the negative 



