The History of Electricity
Luigi Galvani (1737-1798) was an Italian physician and physicist. He
was one of the first to investigate the phenomenon of what came to be
named as 'bioelectrogenesis'. Galvani reported a series of experiments
he had been conducting since 1780 where fog's legs violently
contracted if a metal scalpel accidentally touched a certain leg nerve
during dissection. He showed that contractions occurred when the
operator made contact with the nerve by means of an electric conductor
connected to the ground, when the electrostatic machine was working or
when there was a lighting strike in the vicinity. There were also
produced if the frogs were placed on an iron plate while a brass hook
simultaneously pressed against the iron. The use of two dissimilar
metals saw the effects being most profound. (Asimov's new Guide to
Further experiments confirmed this effect, which convinced Galvani
that he was observing the effects of what he called "animal
electricity", i.e., the life force within the muscles of the frog.
Galvani discovered that the electric current delivered by a Leyden jar
or rotating static electricity generator would cause the contraction
of the muscles in the frog's leg and many other animals, either by
applying a charge to the nerve or by touching the exposed muscle of
one frog with the nerve of another. He thought 'animal electricity'
was generated in the tissue of the frog and distinguished this kind of
electricity from 'artificial electricity' generated by friction
(static electricity) and from 'natural electricity' such as lightning.
He caused great controversy within the scientific society by proposing
that this flow of fluid (animal electricity) secreted by the brain
activated muscles. He discovered the physiological action of
electricity and demonstrated the existence of bioelectric forces in
animal tissues. Galvani's experiments helped to establish the basis
for biological study of neurophysiology and neurology.
1. Source: Corrosion Doctors. The prepared frog's leg hangs from the
spinal stub by the nerves. When the electrostatic machine
revolved, or Leyden jar discharged, Galvani observed that the legs
jerked when a scalpel touched the nerve.
2. Source: Corrosion Doctors. To test the possible influence of
lightning on frog's legs Galvani experimented outdoors. Found that
legs moved under certain conditions even when the air was serene.
However another Italian physicist called Alessandro Volta (1745-1827)
disagreed with Galvani's explanation of the phenomenon and began
experiments that led him to theorise that animal tissue was not
necessary for conduction of electricity.
Proof of this theory was the battery, which he invented in 1800. He
built the first...