C 335 ] 
thirty feet From the ground (the fame experiment that 
was made by my friend the Abbe Mazeas , and com- 
municated, with feveral others, to the Royal So- 
ciety *), in order to obferve the electric effects during 
thunder ft or ms and cloudy weather. Thefe wires he 
frequently found electrified in a f mall degree , when 
the day was clear , and without the leaf appearance of 
a cloud. Might not this effeCt therefore arife from 
the friction of the air againft the wires ? 
From confidering all thefe things, and what thefe 
laft experiments have taught us concerning the dif- 
ferent effects produced by hot and cold air , it feems 
probable, that many of the curious operations in na- 
ture arife from a conflant flux and reflux of the elec- 
tric fluid. And if the obfervation be true, that air, 
free from moifture, during tempefts and hurricanes 
in the night, frequently affords a faint kind of light, 
refembling what is feen in an exhaufted receiver, 
through which the eleCtric fluid is caufed to flow, 
as alfo it occaflons a more general clearnefs in the 
heavens, than would appear were there no fuch violent 
agitations ; it is reafonable to imagine, that a flux of 
the eleCtric fluid in the air , is the caufe of fuch ap- 
pearances ; for the fame reafon that our artificial blafls 
produced the electrical effects I have juft now men- 
tioned. 
But it remains to be inquired into, whether the 
Tourmalin is fo difpofed by nature, as to fuffer the 
eleCtric fluid to pafs through it only in one direction, 
like ?nagnetifm through the loadflone , or is indifferent 
which way it flows. 
* See the Tranfa&ions of Ihe Royal Society, Vol. XLVIII. 
Exp. 
