[ 6oi ] 
natural quantity of fluid. And, 4thly, The fpaces 
Be and FG will be faturated in all parts. 
For, firfl, If the fluid is difpofed in this manner, 
no particle of it can have any tendency to move : 
for a particle placed anyw'here in the fpaces B C and 
F G, is attradted with jufl; as much force by E F, as 
it is repelled by C D i and it is repelled or attracted 
with juft as much force by A B, as it is in a con- 
trary diiedtion by G td, and, confequently, has no 
tendency to move. A particle placed anywhere in 
the fpace C D, or in the fpaces A B and G H, if 
they are overcharged, is indeed repelled with more 
force towards the planes D d, A a, and FI h, than it 
is in the contrary diredion ; but as the fluid in thofe 
fpaces is already as much comprefled as poflible, the 
particle will have no tendency to move. 
2dly, It feems impoflible that the fluid fliould be 
at reft, if it is difpofed in any other manner : but as 
this part of the demonftration is exadly fimilar to 
the latter part of that of Problem the flrft, I fhali 
omit it. 
C 0 R O L. I. 
If the two fpaces A D and E H are both over- 
charged, the redundant fluid in CD is half the dif- 
ference of the redundant fluid in thofe fpaces : for 
half the difference of the redundant fluid in thofe 
fpaces, added to the quantity in A B, which is half 
the fum, is equal to the whole quantity in A D. For 
a like reafon, if A D and E FI are both undercharged, 
the redundant matter in E F is half the difference of 
the redundant matter in thofe fpaces j and if A D is 
VoL, LXl* 4 ff over- 
