Luigi Galvani
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Luigi Galvani (September 9, 1737 – December 4, 1798) was an Italian physician and physicist who lived and died in Bologna. In 1771, he discovered that the muscles of dead frogs twitched when struck by a spark.[1] He was a pioneer in modern obstetrics, and discovered that muscle and nerve cells produce electricity.
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[edit] Early life
Galvani attended Bologna's medicine school and became a medical doctor just like his father. In 1764 he married the only daughter of the professor at the University of Bologna. In 1772 Galvani became president of the university.
[edit] Frog legs
![The electrochemical behavior of two dissimilar metals [(zinc (Z) and copper (C)] in a bimetallic arch, in contact with the electrolytes of tissue, produces an electric stimulating current that elicits muscular contraction.](../../../upload/thumb/3/3c/Galvani%27s_legs.gif/250px-Galvani%27s_legs.gif)
In about 1766, Galvani began investigating the action of electricity upon the muscles of frogs. By observing the twitching in the muscles of frog legs suspended by copper hooks on an iron rail, Galvani was led to the invention of the metallic arc. The arc was made of two different metals, such than when one metal was placed in contact with a frog’s nerve and the other in contact with a muscle, a contraction would occur.[3]
In 1783, according to popular version of the story, Galvani dissected a frog at a table where he had been conducting experiments with static electricity, Galvani's assistant touched an exposed sciatic nerve of the frog with a metal scalpel, which had picked up a charge.[citation needed] At that moment, they saw sparks in an electricity machine and the dead frog's leg kick as if in life. The observation made Galvani the first investigator to appreciate the relationship between electricity and animation — or life. This finding provided a basis for the current understanding that electrical energy (carried by ions), and not air or fluid as in earlier balloonist theories, is the impetus behind muscle movement. He is typically credited with the discovery of bioelectricity.
Galvani coined the term animal electricity to describe whatever it was that activated the muscles of his specimens. Along with contemporaries, he regarded their activation as being generated by an electrical fluid that is carried to the muscles by the nerves. The phenomenon was dubbed "galvanism", after Galvani, on the suggestion of his peer and sometime intellectual adversary Alessandro Volta.
[edit] Animal electricity vs. heat electricity
Galvani's investigations led shortly to the invention of an early battery, but not by Galvani, who did not perceive electricity as separable from biology. Galvani did not see electricity as the essence of life, which he regarded vitalistically. Galvani believed that the animal electricity came from the muscle. Galvani's associate Alessandro Volta, in opposition, reasoned that the animal electricity was a physical phenomenon, i.e. a metallic electricity.
While, as Galvani believed, all life is indeed electrical, specifically that all living things are made of cells and every cell has a cell potential, biological electricity has the same chemical underpinnings as the flow of current between electrochemical cells, and thus can be recapitulated in a way outside the body. Volta's intuition was correct. Volta, essentially, objected to Galvani’s conclusions about “animal electric fluid,” but the two scientists disagreed respectfully and Volta coined the term galvanism for a direct current of electricity produced by chemical action.[4]
Thus, owing to an argument between the two, in regards to the source or cause of the electricity, Volta built the first battery in order to specifically disprove his associate's theory. Volta's "pile" became known therefore as a voltaic pile
[edit] Later life
Lucia, Galvani's wife died in 1790 at age 47. Luigi died eight years later at the age of 61.
[edit] Miscellaneous
- Galvani's report of his investigations were mentioned specifically by Mary Shelley as part of the summer reading list leading up to an ad hoc ghost story contest on a rainy day in Switzerland—and the resultant novel "Frankenstein"—and its electrically reanimated construct.
- Galvani's name also survives in the Galvanic cell, the galvanometer and galvanization.
- Galvani crater, on the Moon, is also named after him.
[edit] References
- ^ Luigi Galvani (1737-1798) – Eric Weisstein’s World of Scientific Biolgraph.
- ^ Malmivuo, J., & Plonsey, R. (1995). Bioelectromagnatism: Principles and applications of bioelectric and biomagnetic fields. New York: Oxford University Press., Ch.1
- ^ Luigi Galvani – NNDB
- ^ Luigi Galvini – IEEE Virtual Museum.
[edit] See Also
[edit] Further reading
- Kandel E.R., Schwartz, J.H., Jessell, T.M. (2000). Principles of Neural Science, 4th ed., p.6. McGraw-Hill, New York.
[edit] External links
- Luigi Galvani (Overview) - Corrosion Doctors
- Luigi Galvani - Theory of Animal Electricity
- Luigi Galvani - About.com
