.[ 6o7 ] ■ 
communicate with each other by a canal, I mean 
that the fluid fliall be able to pafs readily from one 
body to the other by that canal. 
PROP. IX. 
If any body at a .diflance from any over or under- 
charged body be overcharged, the fluid within 
it will be lodged in greater quantity near the 
furface of the body than near the center. For, 
if you fuppofe it to be fpread uniformly all over 
the body, a particle of fluid in it, near the furface, 
will be repelled towards the furface, by a greater 
quantity of fluid than* that by which it is re- 
pelled from it; confequently, the fluid will 
flow towards the furface, and make it denfer 
there : moreover, the particles of fluid clofe to 
the furface will be prefled clofe together ; for 
otherwife, a particle placed fo near it, that the 
quantity of redundant fluid between it and the 
furface Ihould be very fmall, would move to- 
wards it ; as the fmall quantity of redundant 
fluid between it and the furface would be un- 
able to balance the repulfion of that on the 
other fide. 
From the four foregoing, problems it feems likely,, 
that if. the eledlric attraction or repulfion is inverfely 
as the fquare of the diftance, almofl: all the redun- 
dant fluid in the body will be lodged clofe to the 
furface, and there prefled clofe together, and the 
reft of the body will be faturated. If the repulfion 
is inverfely as fome power of the diftance between 
7 the 
