[ 586 '] 
repels that particle ; otherwife the body would ap- 
pear electrical, as will be fliewn herealter. 
^ To explain this hypothdis more fully, fuppofe that 
I grain of eleCtric fluid attraCls a particle of matter, 
at a given diftance, with as much force as n grains 
of any matter, lead for inltance, repel it : then will 
I grain of eleCtric fluid repel a particle of eleCtric fluid 
with as much force as n grains of lead attraCl it ; and 
I grain of eleCtric fluid will repel i grain of eleCtriq 
fluid with as much force as n grains of lead repel n 
grains of lead. 
All bodies in their natural ftate, with regard to 
electricity, contain fuch a quantity of eleCtric fluid 
interfperfed between their particles, that the attraction 
of the eleCtric fluid in any fmall part of the body on 
a given particle of matter lhall be equal to the re- 
pulfion of the matter in the fame fmall part on the 
fame particle. A body in this Hate I call faturated 
with eleCtric fluid : if the body contains more than 
this quantity of eleCtric fluid, I call it overcharged : 
if lefs, I call it undercharged. This is the hypothe- 
fls ; I now proceed to examine the confequences 
which will flow from it. 
I 
f % 
Lemma I. 
Let EA£’(TAB.XX.fig.i.)reprefent a cone continued 
infinitelyj let A be the vertex, and 'Qb and Y)d planes 
parallel to the bafe j and let the cone be filled with 
uniform matter, whofe particles repel each other 
with a force inverfely as the n power of the diftance. 
If n is greater than 3, the force with which a particle 
at 
