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 >If
it hadn't been for Alessandro Volta, you might have frogs in your radios
and flashlights instead of batteries. Back in 1771, Luigi Galvani,
one of Volta's friends and fellow-Italians, noticed a strange reaction
when a frog's leg came into contact with a spark from a machine — it
twitched. Believing that the twitch originated in the frogs leg itself,
Galvani devised an "animal electricity" experiment by setting a frogs
leg between two different metals. Sure enough, the muscles in the frogs
leg twitched. Being a man of science, when Volta heard of his friend's
experiment, he decided to put it to the test. In his own experiments
he also saw that the frogs leg twitched when set between two metals,
but he did not share in Galvani's conclusion that the electrical current
came from the muscles in the frogs leg. And thus began the invention
of the first battery.
When Volta saw the muscle twitching, instead of changing around the types
of metal at each end of the frog leg, he decided to do away with the
leg. To achieve the same effect, Volta first set up a couple bowls
of salt water. He then fashioned a metal arc with tin at one end and
copper at the other. By setting one end of the arc in one bowl, and
the other in another bowl, Volta was able to replicate the "animal
electricity" experiment without having to ruin his appetizer (providing
he had a taste for frogs legs, that is). By setting up over three sets
of 20 bowls and running different patterns of metal arcs through them,
Volta was able to test the possibilities of a closed circuit.
Eventually, by 1799, Volta would simplify his experiment by using spongy paper
soaked in salt water and set between smaller discs
of copper, silver or brass and tin or zinc. He would pair up the two metals
and set the salted paper on top. By connecting a wire on the top and
bottom of this little pile, Volta was able to produce a closed circuit.
Volta found that the best metals for his experiment were silver and
zinc, and he would try to keep the pattern of silver, zinc, and paper
piled as high as possible — leading Volta to call his early battery
a "column." These days, Volta's column of metals and paper is known
as the Voltaic Pile, and is almost universally considered the forerunner
of the modern batteries we use today.
So now you also know where we get the term "volt" — yup, it's in
honor of Volta. If you'd like to read about Volta's experiments in
his own words, you can find a brief translation of his notes here:
http://dbhs.wvusd.k12.ca.us/webdocs/Chem-History/Volta-1800.html.
If you do not use rechargeable batteries, but you are interested,
you may want to visit the Batteries
and Chargers section of our Web site.
To view our past articles, please visit our What's
in the News Archives.
As always, please e-mail me with any comments or
article suggestions you might have. If you have a customer service or technical question,
please send to ccraneco@aol.com or call 1-800-522-8863.
If you are interested in using C. Crane’s articles on your own Web site,
please let me know. I’d be happy to take a look at your Web site and
see what we can do. Good-bye for now, Carlos. About
the author.
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