1901 - 2 .] Mr J. Fraser on Constitution of Matter and Ether. 55 
oxygen attacks iron ; all depending, I have no doubt, on the strength 
of the “affinities.” 
It is evident that bubbles, or atoms, of the kind postulated, will 
be more or less compressible as they are more or less open-grained ; 
and which, in their turn, depends on the greater or less speed of the 
ethereal particles forming the skin of the bubbles. It will be 
evident, also, that the greater the speed of the particles, the more will 
the bubbles resist compression, as centrifugal tendency varies as 
the square of the speed for orbits of the same size. These two 
statements seem to contradict one another, but really there is no 
contradiction, for the close-grained atoms resist compressions because 
they cannot be further compressed, as there must be a limit, owing 
to being in touch all round. But the open-grained kind can be 
compressed, if sufficient force be applied, to a very great extent. 
Of course it will be understood that the compression I am speaking 
of must be brought about by the close contact of the atoms shielding 
off portions of one another’s surfaces from pressure, whereby an 
increase of pressure is applied to other portions of their surfaces, 
otherwise an increase of pressure applied equally all round would 
generate a repulsive force equal to the increase in the pressure. 
(See p. 47.) Well, then, the open-grained kind will be the most 
compressible, and the close-grained kind the least compressible. 
This leads me to conduction and valency. The best conductors 
will, of course, be the most rigid kinds, and these will be found 
amongst the close-grained. A close-grained atom, if pushed against 
another one, being more rigid, would transfer the energy of the 
push more completely to its neighbour than an open-grained one. 
An open-grained one would retain a large proportion of the energy 
amongst its own particles by springing in and out on its own centre, 
and would, by so springing in and out, radiate a goodly proportion 
away. As an example : if a man wanted to push a heavy weight 
in front of him by means of a rod, he would use a stiff, rigid rod, 
and not a thin, flexible cane, because in the former case he would be 
practically applying all his strength to the moving of the load, 
while in the latter he would be applying it to the bending of the 
cane. The more rigid the atom, other things being equal, the 
better the conductor ; and the more springy, the worse the con- 
ductor. 
But a good deal depends on whether the molecules of the bodies 
