[ 2°4 ] 
particles of electrical matter do repel each other, they 
are ftrongly attracted by all other matter. 
From thefe three things, viz. the extreme fubtilty 
of the eleCtrical matter, the mutual repulfion of its 
parts, and the ftrong attraction between them and 
other matter, arifes this effeCt, that when a quantity 
of eleCtrical matter is applied to a mafs of common 
matter of any bignefs or length within our obferva- 
tion (which has not already got its quantity) it is 
immediately and equally diffufed thro’ the whole. 
Thus common matter is a kind of fponge to the 
eleCtrical fluid ; and as a fponge would receive no 
water, if the parts of water were not fmaller than the 
pores of the fponge j and even then but flowly, if 
there was not a mutual attraction between thofe parts 
and the parts of the fponge ; and would ftill imbibe 
it Fatter, if the mutual attraction among the parts of 
the water did not impede, fome force being required 
to feparate them ; and fafteft, if, inftead of attraction, 
there were a mutual repulfion among thofe parts, 
which would aCt in conjunction with the attraction 
of the fponge : fo is the cafe between the eleCtrical 
and common matter. In common matter indeed 
there is generally as much of the eleCtrical as it will 
contain within its fubftance : if more is added, it lies 
without upon the furface (|, and forms what we call 
an 
to the refinance of the atmofphere, than to any natural tendency 
in the electricity itfelf. IV. IV. 
|| The author of this account is of opinion, that what is here 
added, lies not only without upon the furface, but penetrates with 
the fame degree of denfity the whole mafs of common matter, 
upon which it is directed. 
