ELECTRICITY, &c. 



DERIVED from the Greek word rjAgxrpov (elec- 

 tron), amber, in which substance the electric 

 phenomena were first observed. 



Nature of Electricity. 



Different opinions are entertained among scientific 

 men regarding the nature of electricity. By some 

 the phenomena are supposed to depend on a single 

 subtle fluid, in excess in the bodies said to be posi- 

 tively electrified ; but deficient in the bodies said to 

 be negatively electrified. 



A second class suppose the effects to be produced 

 by two different fluids, called the vitreous and resinous 

 fluids. Others regard them as affections or motions 

 of matter, or an exhibition of attractive powers, 

 similar to those that produce chemical combination 

 and decomposition ; but usually exerting their action 

 on masses. 



General Properties of Electric Matter. 



It penetrates bodies and traverses their substance 

 with unequal degrees of velocity. The electric fluid 

 always tends to spread itself over conductors, and to 

 assume a state of equilibrium in them. It tends to 

 escape from one body to another, but never wholly 

 abandons even the smallest. A current of electric 

 matter, whether luminous or not, is always accom- 

 panied with heat, the intensity of which depends on 

 E 



