a new Eleftromeier. 29 
quick-lime, umber, lapis calaminaris, Spanifh brown, powdered 
fulphur, flowers of fulphur, iron filings, ruft of iron, land. 
Rofin and chalk, feparately alike, were changed by mixture ; 
this was often tried in dry weather, but did not lucceed in 
damp : white lead alio fometimes produced politive, and fome- 
times negative, when blown from a plate. 
If a metal cup be placed upon the cap, with a red-hot coal 
in it, a fpoonful of water thrown in eleCtrifies the cup nega- 
tively ; and if a bent wire be placed in the cap, with a piece of 
paper fattened to it to iticreafe its furface, the politive electri- 
city of the afcending vapour may be tried by introducing the 
paper into it. Perhaps the electrification of fogs and rain is 
well illuftrated by pouring water through an inlulated cullender, 
containing hot coals, where the afcending. vapour is politive, and 
falling drops negative. Fig. y. 
The fenfibility of this electrometer may be confiderably in- 
creafed by placing a candle upon the cap. By this means a 
cloud of chalk, which only juft opens the leaf gold, will caufe 
it to ftrike the fides for a long time together; and the electri- 
city, which was not before communicated, now pafles into the 
electrometer, caufing the leaf gold to repel, after it is carried 
away. Even fealing-wax by this means communicates its fire 
at the diftance of twelve inches at leaft, which it would 
fcarcely otherwife do by rubbing upon the cap. 
A cloud of chalk or wheat flour may be made in one room, 
and the electrometer, with its candle, be afterwards leifurely 
brought from another room, and the cloud will eleCtrify it 
before it comes very near. The air of a room, adjoining to 
that wherein the eleCtrical machine was ufed, was very fenlibly 
electrified, which was perceived by carrying the inftrument 
through it with its candle. Fig. 8, 
In 
