[ 104 3 
immediately j though it Js capable of fcccivittg that 
Virtue from an Ele 6 irical per fe» 
Observations. 
1. When the Air is full of moift Vapours, Electri- 
cals per fe are excited to Eled.ricity with very great 
Difficulty, requiring to be often warm’d, and much 
rubb’d ; as appears in exciting that Virtue in Glafs, 
Amber, Wax, 
2. In dry Weather, efpecially in frofty Weather, 
the Electricals per fe will have their Virtue excited 
with very little Action upon them; as appears by 
warming a Glafs Receiver, which, without any rub- 
bing, will caufe the Threads of a Down Feather, tied 
to an upright Skewer, to extend themfelves as foon 
as it is put over the Feather. Sometimes Refin and 
Wax exert their Eledricity by only being expos’d to 
the open Air. 
j. EleCtr teals per fe retain the Virtue longeft 
when kept near to, or inclos’d by, other EleCtricals 
per fe. Thus the rubb’d Tube will retain its Virtue 
pretty long in dry Air, as^ appears by chafing a fea- 
ther about the Room very long without new rub- 
bing; as alfo by Lumps of Refin and Sulphur, 
which have been melted and poured into dry Drinfc- 
ing-glaffes, keeping their Virtue long, if kept in 
thofe Glaflfes, and wrapp’d in dry :Silk, or fuch fort 
of Paper as will become eledrical by rubbing ; fo-r 
as often as they are expos’d to the Air, they will at^ 
trad. 
4. EleCtricals per fe communicate their Virtue to 
any of thz Non~eleCirical, brought near them ; 
in which Cafe Non-ehct'rkals repel 
like 
