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redandant fluid in the fpace therefore, unlefs 
the fpace Qb is undercharged, the particle will move 
towards the furface. 
Corollary. 
For the fame realbn, if the globe is undercharged, 
there will be a Ipace Bby in which the matter will be 
intirely deprived of fluid, the quantity of matter 
therein being more than the whole redundant matter 
in the globe; and, confequently, the fpace C^, 
taken all together, will be overcharged. 
Lemma VI. 
Let the whole fpace comprehended between two 
parallel planes, infinitely extended each way, be 
filled with uniform matter, the repulfion of whofe 
particles is inverfely as tne fquare of the diftance ; 
the plate of matter formed thereby will repel a par* 
ticie of matter with exadtly the lame force, at what- - 
ever diftance from it, it be placed. 
For, fuppofe that there are two fuch plates, of 
equal thicknefs, placed parallel to each other, let 
^ 3‘) point not placed in or between 
the two plates : let B C D reprefent any part of the 
-neareft plate : draw the lines AB, AC, and AD, 
cutting the^ furtheft plate in b, €, and for it is 
plain, that if they cut one plate, they muft, if pro- 
duced, cut the other : the triangle BCD is to the 
tiiangle bcj^ as AB^ toA^*; therefore a particle 
of matter at A will be repelled with the fame force 
by the matter in the triangle BCD, as by that in 
bed. Whence it appears, that a particle at A will 
be ' 
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