[ 669 1 
able to enter a little way into the glafs, but not to 
pals through it, or unable to enter it at all ; and 
if it is able to enter a little way into it, let 
or b as I fhall call it, reprcfent that part of the 
glafs into which the fluid can enter from the plate 
and that which the fluid from Ey' can 
enter. By the abovementioned propofition, if b 
the thicknefs of the glafs, is very fmall in relpeff 
of bd^ the diameter of the plates, the quantity of 
redundant fluid forced into the fpace or B 
(that is, into the plate B^ if the fluid is unable to ' 
penetrate at all into the glafs, or into the plate B^/, 
and the fpace together, if the fluid is able to 
penetrate into the glafs') will be many times greater 
than w’hat would be forced into it by the fame de- 
gree of eleclrification if it had been placed by 
itlelf; and the quantity of fluid driven out of E tp, 
will be nearly equal to the redundant fluid in BX 
If a communication be now made between B 5 
and E (p, by the canal N R S, the redundant fluid 
will run from B^ to E cp ; and if in its way it pafles 
through the body of any animal, it will by the ra- 
pidity of its motion produce in it that fenfation 
called a fliock. 
It appears from the 26th propofition, that if a 
body of any fize was eledtrified in the fame degree 
as the plate B^/, and a communication was made 
between that body and the ground, by a canal of 
the fame length, breadth and thicknefs as N RS; 
that then the fluid in that canal would be impelled 
with tlie lame force as that in N RS, fiippofing 
the fluid in both canals to he incompreflible ; and 
conftquently, as the quantity of fluid to be moved. 
