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THE NATURE OF ELECTRICITY

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The only way to charge a body negatively is to add electrons
to it, and the only way to charge it positively is to take electrons
away from leaving an excess of positive electricity.
The ancient Greeks knew that when a piece of amber is
rubbed with wool or fur it achieves the power of attracting light
objects. Later оn phenomenon was studied, and, the word electric,
after the Greek word “electron”, meaning amber was used. Many
scientists investigated electric phenomena, and during the
nineteenth century many discoveries about the nature of electricity,
and of magnetism, which is closely related to electricity, were
made. It was found that if a sealing-wax rod is rubbed with woolen
cloth, and a rod of glass is rubbed with a silken cloth, an electric
spark will pass between the sealing-wax rod and the glass rod
when they brought near one another. Moreover, it was found that a
force of attraction operates between them. An electrified sealing
wax is repel let however, by a wax rod, and also an electrified
glass rod is repelled, by similar glass rod.
The ideas were developed that there are two kinds of
electricity, which were called resinous electricity, and that
opposite kinds of electricity attract one another, whereas similar
kinds repel one another. Although these simple electric and
magnetic phenomena have been known since ancient times, most
of the basic quantitative laws of electricity and magnetism were
discovered between 1784, when Charles Coulomb investigated the
forces between charged objects, and 1831, when M. Faraday
discovered magnetic induction. Prior to this 50-year period of
discovery, the only practical electric invention was the lightning
rod of Benjamin Franklin (1752).
After this period, the practical utilization electricity increased
rapidly with the development of the telegraph (1844), the
telephone (1877), incandescent lighting (1880) and electric motors
(1887). Uses of electricity have continued to expand to this day,
with the current revolution in microelectronics giving us ever-
increasing control over the machines.

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