Frictional Electricity is that produced by the friction of one substance against another.
Resinous Electricity.—The kind of electricity produced upon a resinous substances such as sealing wax, resin, shellac, rubber or amber when rubbed with wool or fur. Resinous electricity is negative electricity.
Vitreous Electricity.—A term applied to the positive electricity developed in a glass rod by rubbing it with silk. This electric charge will attract to itself bits of pith or paper which have been repelled from a rod of sealing wax or other resinous substance which had been rubbed with wool or fur.
CHAPTER II
STATIC ELECTRICITY
Static electricity may be defined simply as electricity at rest; the term properly applies to an isolated charge of electricity produced by friction. The presence of static electricity manifests itself by attraction or repulsion.
Electrical Attraction and Repulsion.—When a glass rod, or a stick of sealing wax or shellac is held in the hand and rubbed with a piece of flannel or cat skin, the parts will be found to have the property of attracting bodies, such as pieces of silk, wool, feathers, gold leaf, etc.; they are then said to be electrified. In order to ascertain whether bodies are electrified or not, instruments called electroscopes are used.
There are two opposite kinds of electrification:
1. Positive; 2. Negative.