1901-2.] Mr J. Fraser on Constitution of Matter and Ether. 43 
The particles of the spongy kind are drawing on the store of 
pressure at a greater rate than those of the others, but also they 
are repaying at a proportionately greater rate, so that at any 
assigned instant they owe no more than the others, or have no 
more capital withdrawn from the bank than any of the others. 
In fact, each particle of every mass will, at any particular instant, 
have precisely the same amount of pressure or force withdrawn 
from the universal store, and at that precise moment being put to 
another use, viz., that of changing the direction of motion of the 
said particle. 
It ought not now to be very difficult to see what is the cause of 
gravity or the apparent attraction which one body has for another. 
Every body in the universe will have, at any instant of time, a 
quantity of force or pressure withdrawn from the medium, precisely 
proportional in amount to the number of particles of which its 
atoms consist. In other words, the quantity of force withdrawn 
and otherwise utilised will be precisely proportional to the mass. 
Well, then, from the sun, and from every other body in the 
universe, there will be a slope or incline of pressure, so to speak, 
radiating out in every direction through space. In the neighbour- 
hood of each body the slope will he steepest, and its steepness will 
be proportional to the mass of the body, and growing less and less 
steep as the square of the distance from it, or growing steeper and 
steeper inversely as the square of the distance. It is readily seen 
that this must be so ; for the body is taking toll of the pressure in 
the space around it, and as the areas of circles are proportional to 
the squares of their radii, it is evident that in any plane circular 
space, say at double the distance from the centre of the body, there 
will he four times the area from which to withdraw the pressure, 
and that consequently any particular portion of the space at this- 
distance will be deficient in only a quarter of the pressure. At 
three times the distance the space will he deficient in only ^th 
the pressure, and so on inversely as the square of the distance ; 
the slope or incline of pressure growing less and less steep as the 
square of the distance grows. 
Well, now, suppose two bodies to be placed in the vicinity of 
one another, under these conditions, what must happen? The 
one would screen the other from the radiations which presumably 
