[ r 4i ] 
Having, on the contrary, obferved that bodies* 
inflated with dried (ilk, had loft their electricity in 
a very fhort time, I attempted to render it a non- 
conductor, by having varnifhed it over with oil of 
turpentine, balfam of fulphur, and fuch like, but 
did not fucceed ; for filks fo treated foon became a 
conductor, and increafed confiderably in weight, if 
the air happened not to be very * dry ; fo much 
indeed, that I think ordinary filk, from its power of 
abforbing moifture from the air, may well ferve as 
an occafional hygrometer, either by being put into 
a balance, or by having an electrified body infulated 
with it. 
When the denfity of fogs, floating near the earth, 
increafes confiderably, the balls always approach j, 
but when they are fituated high in air, the reverfe 
generally happens. I had an opportunity of remark- 
ing a ftruggle between breezes from the north-weft 
and fouth-eaft at the fame time, in which the one 
leemed fometimes to prevail, and afterwards the 
other. This contention was fucceeded by a fmoaky 
hazinefs, which, like a fog, occafioned the balls to 
open : as the hazinefs -f- thickened, they opened 
* Even glafs attracts moifture to its furface, which makes it 
a conductor of eleCtricity, and, confequently, not fo convenient 
as fealing-wax. 
f An eleCtrical body, when contracted in its dimenfion, will 
have its electricity increafed, as appears by Dr. Franklin’s cu- 
rious experiment with the chain and filver can. I alfo have dif- 
covered, from repeated trials, that a piece of flannel, filk, &c, 
excited, and fuddenly twifted, not only {truck at a greater di- 
ftance than before, but fometimes emitted pencils of fire into the 
air. May we not hence infer why the electricity of vapour, Sic. 
(when not in contaCt with the earth) increafes by condenfa- 
ti on ? 
wider, 
