Electric Discharge in Gases. 91 



kathode has become so small that no interference could take 

 place any more; hence we find the end of the positive elec- 

 trode still covered by a cap of light, even where it has broken 

 through the last layer. 



We must not, however, conceive of the point at which 

 reflection takes place as an infinitely thin layer, but one of 

 perceptible breadth which extends from the boundary of the 

 bright kathode-layer on the side of the kathode to the positive 

 light. The broader this layer becomes, the broader must also 

 be the places of maximum motion, and conversely : thus we 

 find with high pressures and a narrow bright kathode -layer, 

 well-defined narrow stratifications; with low pressures and 

 broad kathode-layer, the stratifications are diffuse; the distri- 

 bution of light in the stratifications is also explained. 



If too large quantities of electricity accumulate on the 

 anode, or if the current is too rapid, then, in consequence of 

 the irregular motion, no stratifications are formed. 



The idea of Herr Goldstein that each separate layer behaves 

 as a conducting element with anode and kathode, seems to me 

 to be only a mode of describing certain phenomena observed 

 in the stratifications, but not to furnish an explanation of 

 them. The anode and kathode of a layer would, in this way of 

 regarding the matter, have to be considered as the points of 

 entrance and exit of electricity in layers of gas in a peculiar 

 condition of motion or of tension. 



It might be supposed that certain difficulties would present 

 themselves to this explanation, in cases where the positive 

 electrode is in connexion with the earth, and the negative 

 connected with the source of electricity. 



I am inclined to think that the phenomena in this case may 

 be explained as follows. Under the influence of the electricity 

 accumulated on the negative electrode, or of positive with- 

 drawn from it, there is produced a dielectric polarization start- 

 ing from the luminous kathode -layer surrounding it. The 

 high resistance which experiment shows to exist is opposed 

 by the dark kathode-layer to the neutralization of electricity 

 in the direction of the negative electrode. The dielectric 

 polarization therefore spreads out towards the positive elec- 

 trode, where occurs a condensation of free electricity. As 

 soon as its tension has risen sufficiently, the discharge occurs 

 in the manner described above. The much more regular for- 

 mation of stratifications observed in this case has its ground in 

 the small quantity of free electricity accumulated upon the 

 positive electrode, which flows off much more regularly than 

 when new quantities of electricity pass continually from the 

 source of electricity to the electrode. 



