1904 - 5 .] Mr J. Fraser on Electricity based on Bubble Atom. 709 
constituted bodies there must be differences, and in some cases 
great differences, in the size of the spaces existing between the 
atoms and molecules ; and especially will this be so in the case 
of compound bodies, for the latter are made up of atoms of 
different sizes and weights. It would follow from this that the 
ether which fills these spaces will have a greater difficulty or 
facility of passing from space to space, according to their constitu- 
tion, so as to readily admit of their heat-vibrations. In cases 
where there is a difficulty of passage, owing to pockets and corners, 
the ether, during the inward phase of the vibration, will be under 
great pressure, which will react on the atoms, increasing the 
speed of their particles enormously, and so preventing their, 
acceptance of new motion, such as that of electricity, and greatly 
increasing the subsequent outward rebound and loss of potential 
energy of the particles. In the cooler portions of bodies of this 
nature the spaces will be narrower, thus increasing the difficulty 
of the escape of the ether during the inward phase of vibration 
and increasing the pressure on the particles of the cooler portion, 
or at any rate tending to make up the difference in speed which 
the lessened amplitude would cause. This would prevent the 
conduction of heat to the cooler portions, for as the speed of the 
particles of the cooler portion would be nearly equal to that of the 
hotter, there would be little difference in the exchange between 
them, and thus the heat, instead of spreading, would be radiated in 
the locality where it was generated.* 
We can now account for the fact that insulators conduct 
electricity better when they are hot. They do so because the 
spaces between the atoms are wider ; there is greater facility for 
the passage of the ether from space to space, and consequently 
less pressure on the atoms and less particle-speed. 
34. It requires only a superficial study of the subject, in view 
of the present theory, to arrive at the conclusion that heat must 
resist the passage of electricity through — all bodies, I was going 
to say — at any rate through most ; and even in the case of 
insulators, if there was no heat — that is at the zero temperature — 
and if the molecular contact was good, and the electrical potential 
This property of bodies I propose to call by the name of “Self- 
Compression. ” 
