C 613 ] 
whole together, will be repelled with^ as much force 
one way as the other ; and the fluid in F G is all of 
it repelled from C : therefore in both cafes the fluid 
in the canal, taking the whole together, is repelled 
from C ; confequently fome fluid will run out of D 
and the canal, till the attradion of the unfaturated 
matter therein is fuflicient to balance the repulfion 
of the redundant fluid in ABC. 
PROP. XV. 
If we now fuppofe that the fluid on the outfide of 
ABC is moveable i the matter adjacent to ABC 
on the outfide, will become undercharged. I 
fee no reafon however to think that that will 
prevent the body D from being undercharged j 
but I cannot fay exadly what effed it will have, 
except when ABC is fpherical and the repuHion 
is inverfely as the fquare of the diflance ; in this 
cafe it appears by Prob. 1. that the fluid in the 
part D B of the canal will be repelled from C, 
with juft as much force as in the laft propo- 
fition ; but the fluid in the part BG will not be 
repelled at all : confequently D will be under- 
charged, but not fo much as in the laft pro- 
pofuion. 
Corollary. 
If ABC is now fuppofed to be undercharged, it is 
certain that D will be overcharged, provided the 
master near A BC on the outfide is laturated witii im- 
moveable 
