440) Mr. W. Sutherland on the 
“The Fundamental Atomic Laws of Thermochemistry ” 
(Phil. Mag. [5] xl.) 1 have shown that (RS) is of secondary 
importance to (R). It appears then that Lodge’s principle 
concerning the Volta Contact H.M.F. is the outcome of 
certain laws in the mutual energetics of matter and electricity. 
It should be noticed that although (RS) was originally defined 
as the work of bringing R and its attached doublet into 
combination with S and its attached doublet, it is possible 
that it may contain parts depending on R alone and on 8 
alone, these merging into (R) and (S) and leaving a com- 
paratively small part depending on both R andS._ This part, 
which in the thermochemical paper is denoted by /(RS8), is 
what is of secondary importance, and not the complete (RS). 
The further investigation of the energetics of matter and 
electricity would carry us too far into thermochemistry, 
which must be left for separate treatment. The object of 
this section has been mainly to show the relation of the Volta 
Contact H.M.F. to atomic energies. 
6. The Neutron Structure of the Aither used for Calculation 
of its Density and Rigidity, and Deduction of the Velocity 
of Light. aT 
The electric doublet must be the basis of the electric and 
magnetic properties of the ether. The doublet of the ether, 
which I have proposed te call the neutron, may be represented 
as f and b in contact in the form of spherical shells of 
electricity of radius a. ‘The electric moment of the neutron 
is 2ae. The inertia of electricity, contemplated by Maxwell 
and first calculated by J. J. Thomson, necessitates the 
existence of a definite amount of inertia in each neutron, and 
so necessitates a definite density of the ether. Moreover, if 
the neutrons are packed closely enough like the iolecules 
of solid bodies, they will confer rigidity on the ether. An 
ether is conceivable having its neutrons free like the molecules 
of a gas, but exercising strong mutual directive influences 
through their polarities. For rapid shears this would act 
like a solid, for slow displacements like a gas. Thus from 
the electromagnetic properties of the electron we have de- 
duced density and rigidity as essential properties of the ether. 
The postulates of the elastic and of the electric theories of 
light are but different expressions of the same things. Now 
the magnitude of « was estimated in ‘‘ Cathode, Lenard, and 
.Réntgen Rays”’ (Phil. Mag. [5] xlvii.) as 10-™ ems. on the 
assumption that the ratio I/e of the inertia I of a cathode 
projectile to its charge e, determined by J. J. Thomson, was 
