﻿28 The Electron Theory of Matter* 



electrons of opposite sign to attract each other more than 

 those of like sign repel each other. The gravitation between 

 atoms is proportional to the number of electrons in each, 

 while their masses depend on the masses of the electrons, and 

 therefore on their velocities as well. 



§ 10. While we may admit that the hypothesis of the 

 expanding electron affords a qualitative explanation of the 

 law of gravitation, yet we can hardly rest satisfied unless it 

 gives for the gravitation constant a value of the right order. 

 After many trials I have not succeeded in devising a 

 mechanical model of the electron which shall do this in a 

 satisfactory manner. When we treat the problem as that of 

 a source in an incompressible liquid with the pressure at 

 infinity equal to a given constant, we find that a is an elliptic 

 function of the time which varies between two definite limits. 



a 



Since - must be small, a must be very close to one of the two 



limits ; thus there are possible two electrons of different 

 sizes, each varying very slowly in size ; their radii being 

 different, so also are their electromagnetic masses ; by 

 identifying them with the negative and positive electrons we 

 can account for the difference in mass of the two kinds of 



electrons. In order to account for the smallness of — we 



a 



must suppose the density /jl of the aether to be very large. In 

 order to get the proper value of the gravitation constant, we 

 must suppose //, to be of the order 10 100 , whether we assume 

 gravitation to be due to one or both kinds of electrons. 



In itself a large value of fi is not an objection. But it 

 leads to a difficulty, which however is not peculiar to the 

 present view, but is shared by every theory which assumes a 

 mechanical action between the electron and the aether. A 

 sphere moving through a liquid has an effective mass, greater 

 than its true mass, by one half the mass of liquid displaced. 

 If this were true of the electron, its effective mass would be 

 enormously greater than its electromagnetic mass. For the 

 negative electron this is not the case ; it moves through the 

 aether without experiencing any appreciable resistance beyond 

 that due to electromagnetic radiation. Yet we require it to 

 force back the aether while it expands. 



§ 11. The conclusions of this investigation are as follows : — 



(1) In order to account for the definiteness of atomic 



structure, as evidenced by the fineness of the spectrum lines, 



on an electron theory without the assumption of forces 



between electrons other than electromagnetic, it is necessary 



