What is Electricity?
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What is Electricity? book
The universal antecedent to the production of electricity is the immediate/mediate contact of heterogeneous substances—substances that are heterogeneous either in their molecular constitutions, or in their molecular states. The production of what are called “beats” in acoustics, will best illustrate this. It is a familiar fact that two strings vibrating at different rates, from time to time concur in sending off aerial waves in the same direction at the same instant: that then, their vibrations getting more and more out of correspondence, they send off their aerial waves in the same direction at exactly intermediate instants. The residual positive and negative waves will then neutralize each other along any conductor that is placed between them, seeing that the plus waves communicated from the one mass to the conductor, meeting with the minus waves communicated from the other, and being mutually cancelled as they meet, the conductor will become a line of least resistance to the waves of each mass.