42 TWO NEW WORLDS. 



made great strides in the infra-world. Both the 

 permeability and the dielectric constant are in- 

 creased 10 22 times, i.e., as much as the lengths are 

 reduced. In the case of the latter (the "specific 

 inductive capacity "), the increase may be interpreted 

 as an increase in the density and mobility of the 

 infra-electrons. 



It is seen then, so far, that we can describe the 

 physical constitution of the infra-world with con- 

 siderable confidence. An attempt can also be made 

 to arrive at some idea of the astronomical, 

 chemical, and biological conditions prevailing 

 there, and such an attempt shall be made in what 

 follows. 



NOTE. 



Kaufmann's experiments have made it extremely 

 probable that the whole of the mass of an elec- 

 tron is " electromagnetic," i.e., due to the electric 

 charge it carries. J. J. Thomson has calculated the 

 " apparent mass " of an electron from its charge, e, 

 and its radius, r, and finds it to be proportional 



to - If m denotes the mass, we have e 2 =mr, a 



numerical coefficient being understood. 



Now, if all masses were due to free electric charges, 

 we should expect every ponderable body to be 

 charged, and the magnitude of the charge would be 

 expressed by e Vrar. 



One charged body might revolve about another of 

 opposite sign, the attraction being, by Coulomb's law, 



