1904 — 5 .] Mr J. Fraser on Electricity based on Bubble Atom. 695 
upon the negative as a positive would do, only not so power- 
fully. If the neutral body were a good conductor, the attraction 
between them would approximate to that between a positive and 
negative, for the side next the negative would become positive by 
the induction of the latter, and they would “ attract ” one another 
as positive and negative. If the neutral were a bad conductor 
it would become less positive at the near end, consequently there 
would be less “ attraction.” 
The foregoing principles will be further illustrated as we 
advance. 
*20. In electrostatics the electricity always resides on the surface 
of bodies. Why 1 ? Because confined motion always flies to the 
region of least restraint. Confined steam tries to make its way 
outwards. So the new motion of positive electricity flies to the 
surface of bodies, because there the atoms have a greater power of 
expansion, and it is there that the lack of motion constituting 
negative electricity would be first felt, i.e. the atoms at the surface 
would be the first to suffer, since a greater quantity of electricity, 
or motion, alivays resides at the surface, owing to the atoms there 
only being half in contact with their fellows, their upper surface 
being free. 
21. The Action of Points on Electricity. 
From the foregoing it will be readily seen why electricity 
resides more on pointed surfaces, and on corners, than on plane 
surfaces. Electricity, like every other confined motion, tends to 
fly to the weakest spot, and break out there ; so, in the static 
state, it resides almost entirely on the surface atoms of bodies, 
because they, at their upper surfaces, offer least resistance to 
expansion, and, in the case of negative electricity, will be the 
first to lose their motion, since they contain most of it. Well, 
then, when we try to realise what a pointed or conical surface 
must be, we must see that in such a surface a greater proportion 
of the free surface of each atom must be exposed. If the 
reader resides in Edinburgh let him go to the Castle and look at 
the pyramids of cannon balls which he will see there at the first 
battery to which he will come, and he will see my meaning. 
He will see that a far larger proportion of the surface of each 
