[ 6 99 ] 
but alfo upon Originalfy-Eledrics, as Silk, dry Fea- 
thers, little Pieces of Glafs, and Refin : it attrads ail 
Bodies, that are not of the fame Standard of Eledri- 
city (if 1 may be allowed the Expreffion) as the ex- 
cited Body from which it proceeds. I have found no 
Body, however denfe, whofe Pores are not pervious 
to Eledricity by a proper Management, not even 
Gold itfelf. 
c Propojition II. 
In common with Light, Eledricity pervades Glafs, 
but fuffers no Refradion therefrom 5 I having, from 
the mod exad Obfervations, found its Diredion to 
be in right Lines, and that through Glaffes of differ- 
ent Forms, included one within the other, and large 
Spaces left between each Glafs. 
Corollary . 
This redilineal Direction is obfervable only as far 
as the Electricity can penetrate through unexcited 
Originally-Eledrics, and thofe perfectly dry * nor is 
it at all material, whether thefe Subftances are trans- 
parent, as Glafs 5 femidiaphanous, as Porcelain, 
or thin Cakes of Wax 5 or quite opaque, as thick 
woollen Cloth, as well as woven Silk of various 
Colours; it is only neceffary that they be Originally- 
Eledrics. Bur the Cafe is widely different with re- 
gard to Non-eledrics 3 wherein the Diredion, given 
to the Eledricity' by the excited Originally -Eledric, 
is alter’d as foon as it touches the Surface of a Non- 
eledric, and is propagated with a Degree of Swift- 
nefs fcarcely to be meafured in all poffibie Diredions 
to impregnate the whole non- eledric Mafs in Con- 
tad with it, or nearly fo, however different in itfelf, 
and which mult of ttaceffity be terminated by an 
. Originally- 
/ 
