new "Experiments in Electricity, See. 25 
from the glafs, and tin-foil {tuck upon it, and which 
was crouded upon the cap, becaufe the negative atmo- 
fphere of the wax now diffufes itfelf equally through 
the cap, the wires, the corks, See . ; and, therefore, the 
corks repel each other with pofitive electricity. 
If, inftead of the fealing wax excited negatively, an 
eleCtric pofFeffed of pofitive electricity be ufed, the elec- 
trometer acquires the negative electricity, and the expla- 
nation, mutatis mutandis , is the fame as above. 
By conlidering this remark it will appear, that when 
this electrometer is electrified, either pofitively or nega- 
tively, and an electrified body is brought towards the 
brafs cap; the electricity of that body will be of the 
fame kind with that of the electrometer, if the corks in- 
creafe their divergency ; but it will be of the contrary 
kind, if the corks approach one another. 
When this instrument is to be ufed to try the electri- 
city of the fogs, the air, the clouds, See. the obferver is to 
do nothing more than to unferew it from its cafe, and, 
holding it by the bottom ab, to prefent it to the open air 
a little above his head, fo that he may conveniently fee 
the corks p, which will immediately diverge if there is 
any electricity ; the kind of which, that is, whether pofitive 
or negative, may be afeertained by bringing an excited 
Vol. LXX. E piece 
