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In the same year, Volta released his discovery of a continuous
source of electricity to the Royal Society of London. No longer
were experiments limited to a brief display of sparks that
lasted a fraction of a second. A seemingly endless stream
of electric current was now available.
France was one of the first nations to officially recognize
Volta’s discoveries. At the time, France was approaching the
height of scientific advancements and new ideas were welcomed
with open arms to support the political agenda. By invitation,
Volta addressed the Institute of France in a series of lectures
at which Napoleon Bonaparte was present as a member of the
Institute.
Figure 1-3: Volta’s experimentations at the
French National Institute.
Volta’s discoveries so impressed
the world that in November 1800, he was invited by the French
National Institute to lectures in which Napoleon Bonaparte
participated. Later, Napoleon himself helped with the experiments,
drawing sparks from the battery, melting a steel wire, discharging
an electric pistol and decomposing water into its elements.
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New discoveries were made when Sir Humphry Davy, inventor
of the miner’s safety lamp, installed the largest and most
powerful electric battery in the vaults of the Royal Institution
of London. He connected the battery to charcoal electrodes
and produced the first electric light. As reported by witnesses,
his voltaic arc lamp produced “the most brilliant ascending
arch of light ever seen.”
Davy's most important investigations were devoted to electrochemistry.
Following Galvani's experiments and the discovery of the voltaic
cell, interest in galvanic electricity had become widespread.
Davy began to test the chemical effects of electricity in
1800. He soon found that by passing electrical current through
some substances, these substances decomposed, a process later
called electrolysis. The generated voltage was directly related
to the reactivity of the electrolyte with the metal. Evidently,
Davy understood that the actions of electrolysis and the voltaic
cell were the same.
In 1802, Dr. William Cruickshank designed the first electric
battery capable of mass production. Cruickshank had arranged
square sheets of copper, which he soldered at their ends,
together with sheets of zinc of equal size. These sheets were
placed into a long rectangular wooden box that was sealed
with cement. Grooves in the box held the metal plates in position.
The box was then filled with an electrolyte of brine, or watered
down acid.
The third method of generating electricity was discovered
relatively late — electricity through magnetism. In 1820,
André-Marie Ampère (1775-1836) had noticed that wires carrying
an electric current were at times attracted to one another
while at other times they were repelled.
In 1831, Michael Faraday (1791-1867) demonstrated how a copper
disc was able to provide a constant flow of electricity when
revolved in a strong magnetic field. Faraday, assisting Davy
and his research team, succeeded in generating an endless
electrical force as long as the movement between a coil and
magnet continued. The electric generator was invented. This
process was then reversed and the electric motor was discovered.
Shortly thereafter, transformers were developed that could
convert electricity to a desired voltage. In 1833, Faraday
established the foundation of electrochemistry with Faraday's
Law, which describes the amount of reduction that occurs in
an electrolytic cell.
In 1836, John F. Daniell, an English chemist, developed an
improved battery which produced a steadier current than Volta's
device. Until then, all batteries had been composed of primary
cells, meaning that they could not be recharged. In 1859,
the French physician Gaston Platé invented the first rechargeable
battery. This secondary battery was based on lead acid chemistry,
a system that is still used today.
Figure 1-4: Cruickshank and the first flooded
battery.
William Cruickshank, an English
chemist, built a battery of electric cells by joining zinc
and copper plates in a wooden box filled with electrolyte.
This flooded design had the advantage of not drying out with
use and provided more energy than Volta’s disc arrangement.
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