Electricity is not stopped, not the least Power will be exerted, and the Gold will lie still. I must here remark likewise, that this Law of Electricity is so constant and regular, that I have not found one Deviation from it; so that even the Quicksilver, spread thin as it usually is at the Back of a Plate of a Looking-glass, will prevent the passing through of the electrical Attraction, unless stopped by an Originally-electric. This Penetration of the electrical Power through originally-electrics is much greater than has hitherto been imagined, and has caused the Want of Success to great Numbers of Experiments. I have been at no small Pains to determine, how far this Power can penetrate through a dry Originally-electric; and have found by repeated Trials, that either in a Cake of Wax alone, or of Wax and Resin mixed, when the Electricity is very powerful, it has passed, I say, in straight Lines through these Cakes of the Thickness of 2 Inches and 4/10; but I never could make it act through one of 2 Inches 8/10, for in this it was perfectly stopped. So that the Cakes commonly made use of to stop the Electricity, by being too thin, suffer a considerable Quantity of the electrical Power to pervade them, and be lost in the Floor. I make no Doubt, if the electrical Power could be more increased, it would penetrate much further through these Originally-electric Bodies. PROPOSITION III. ELECTRICITY, in common with Light likewise, when its Forces are collected and a proper Direction given thereto upon a proper Object, produces Fire and Flame. COROLLARY.