C 37 r 3 
with mercury before-mention ’d ; fo that the whole 
of this apparatus without inconvenience might be 
moved together. The Torricellian vacuum then occu- 
pied a fpace of about thirty inches. In making the 
experiment, when the room was darkened, a wire 
from the prime conductor of the common electrical 
machine communicated with one of the bafons of 
mercury, and any non-eleCtric touching the other 
bafon, while the machine was in motion, the electri- 
city pervaded the vacuum in a continued arch of 
lambent flame, and as far as the eye could follow it, 
without the leaft divergency. 
That the electricity was not furniflied from the 
glafles employed in thefe operations, nor from the 
circumambient air, I have heretofore, in my com- 
munications to you upon this fubjeCt, endeavoured to 
evince. I have fhewn, that eleCtricity is the effeCt of 
a very fubtil and elaftic fluid, occupying all bodies 
in contact with the terraqueous globe ; and that 
every-where, in its natural flate, it is of the fame 
degree of denflty ; and that glafs and other bodies, 
which we denominate eleCtrics per fe , have the power, 
by certain known operations, of taking this fluid 
from one body, and conveying it to another, in a 
quantity lufficient to be obvious to all our fenfes : 
and that, under certain circumftances, it was poflible 
to render the eleCtricity in fome bodies more rare 
than it naturally is, and, by communicating this to 
other bodies, to give them an additional quantity, 
and make their eleCtricity more denie : and that thefe 
bodies will thus continue until their natural quantity 
is reftored to each ; that is, by thofe, which have 
loft part of theirs, acquiring what they have loft; 
A a a 2 and 
