Electric Origin of Molecular Attraction. 629 



If the electric properties of matter are to be explained in 

 terms of electrons, so also must the electric and magnetic 

 properties of the aether. I have proposed to call the molecule 

 of electricity formed in the aether by the union of the atoms 

 % and b of electricity the neutron, and to denote it by 13. In 

 an electrostatic field we must suppose the electric axes of the 

 neutrons so turned in the direction of the field that each has a 

 positive component of electric moment in that direction. This 

 acquisition of a common direction by the axes of the neutrons 

 constitutes what is called the polarization of the aether 

 regarded as a dielectric. The amount of the component 

 electric moment is proportional to what Maxwell calls the 

 electric displacement, which we can thus realize as a veritable 

 displacement to be specified by an actual distance, namely, the 

 component of the vector joining the centres of the two 

 electrons in a neutron in the direction of the electric field. 

 We thus come into contact with an important point in the 

 dynamics of the aether bearing also on the subject in hand. 

 We shall therefore glance at the problem : What is the virial 

 of the forcive of a set of doublets uniformly distributed with 

 parallel axes through any space ? 



Take a spherical shell of radius r and thickness dr, and take 

 the ring cut out by cones whose axis passes through the centre 

 parallel to the axes of the doublets, and whose semivertical 

 angles are 6 and 9 + d6\ then if there are n doublets per 

 unit volume, and if B, denotes the central force between a 

 doublet at the centre and any doublet in the shell, we have 

 for the part of jXRr due to the doublets in the ring and at 

 the centre, using the value of It given by (]), the expression 



n > 3/%^ (2 cog2 g _ sin 20) 27 rr 2 s i n Q dQ dr =/(0) dd, say ; 

 — r 



and for the whole shell 



2^ 2 f(0)d0=0. 



Thus the tendency is for the virial \ . ^22Rr for all the 

 doublets in a large space to vanish. Neither attractive nor 

 repulsive forces predominate in the virial ; and thus we see 

 how it would not be correct to argue from elementary con- 

 siderations that in parallel doublets uniformly distributed 

 attractive forces could be assumed to preponderate. 



Moreover, we see that if to the neutrons of the aether we 

 apply Clausius's equation of the virial, as in the kinetic theory 

 of matter, the production of an electrostatic field does not 

 cause any variation of the virial of the internal forces. Now 



