[ 486 1 
The late Dr. ^Defaguliers has obferved, in his ex- 
cellent Dififertation concerning Eledricity, c That 
* there is a fort of Capricioufnefs attending thefe 
2 Experiments, or fomething unaccountable in their 
* ‘Phenomena, not to be reduced to any Rule. For 
g fometimes an Experiment, which has been made 
s feveral times fuccelTively, will all at once fail.' 
Now I imagine, that the greateft Parr, if not the 
Whole of this Matter, depends upon the Moifture 
or Drynefs of the Air a fudaen though flight Al- 
teration in which, perhaps not fufficient to be obvious 
to our Faculties, may be perceived by the very fub- 
tle Fire of Eledricity. For, 
i ft, I conceive, that the Air itfelf (as has been 
obferved by Dr. P)efaguliers ) is an Eledric per fe-> 
and of the vitreous Kindi therefore it repels the 
Eledricity ariftng from the giafsTube, and difpofes 
it to eledrify whatever non-eledrical Bodies receive 
the Effluvia from the Tube. 
adiy. That Water is a Non-eledric, and, of con- 
fequence, a Condudor of Eledricity. This is exem- 
plified by a Jett of Water being attraded by the Tube, 
from either Eledrics per fe conduding Eledricity, 
and Noiveledrics more readily when wetted i but 
what is more to my prefent Purpofe, is, that if you only 
blow through a dry giafs Tube, the Moifture from 
your Breath will caule.that Tube to be a Condudor 
of Eledricity. 
Thefe being premifed, in proportion as the Air is 
replete with watery Vapours, the Eledricity ariling 
from the Tube, inftead of being conduded, as pro- 
pofed, is, by means of thefe Vapours, communicated 
3 to 
