[ 670 ] 
and the refiftance to its motion is the fame in both 
canals, the fluid fhould move with the fame rapi- 
dity in both : and I fee no reafon to think that the 
cafe will be different, if the communication is 
made by canals of real fluid. 
Therefore what was laid in the beginning of this 
feclion, namely, that as great a fliock would be 
produced by making a communication between 
tlie conductor and the ground, as between tlie two 
fides of the I^eyden vial, by canals of the fame 
length and lame kind, fecms a necefiary confe- 
quence of this theory ; as the quantity of fluiil 
' which pafles through the canal is, by the fuppo- 
fltion, the fame in both; and there is the greateft 
reafon to think, that the rapidity wdth which it 
pafles will be nearly if not quite the fame in- both. 
1 hope foon to be able to fay whether this agree* 
with experiment as well as theory. 
It may be worth obferving, that the longer the 
canal N R S is, by which the communication is 
made, the lefs will be the rapidity with which the 
fluid moves along it; for the longer tlie canal is, 
the greater is the refiflance to the motion of the 
fluid in it ; whereas the force with which the 
whole quantity of fluid in it is impelled, is the 
fame whatever be the length of the canal. Ac- 
cordingly, it is found in melting fmall wires, by 
diredling a Ihock through them, that the longer 
the wire the greater charge it requires to melt it. 
As the fluid in B$, is attra£ted with great force 
by the redundant matter in E<p, it is plain that if 
the fluid is able to penetrate at all into the glafs, 
great part of the redundant fluid will be lodged in 
b I 
I 
