Tuesday 18 June 2013

Inventor of the day: Alessandro Volta and the fight about the frog’s legs

I’ll wager you have one of Alessandro Volta’s devices either in your pocket right now, or very close at hand. I”d win my bet, because it’s there in virtually every electronic device you type on, talk on or text on—and without it, it wouldn’t work.

Alessandro Volta was the inventor of the “electric pile”—the forerunner of the modern battery.  It came about because of a debate over frogs’ legs

In 1780, Volta had become engaged in a debate with Italian physician and scientist Luigi Galvani that would inspire his development of a device which would solve that problem and seal his place in history. Galvani had been experimenting with dissected frogs’ legs, still attached to their spinal cords and hung on brass or iron hooks. He noted that when touched with a piece of another metal the frog legs would twitch; he believed he had discovered a new form of electricity, generated by those legs. He called this “animal electricity.”
    Volta refuted this theory and insisted that the animals’ legs were not producing the electricity, only reacting to it. He believed that the metals used in Galvani’s experiments were generating the current and set out to prove Galvani wrong.
 

Their debate offers an interesting example of how a scientist’s philosophical outlook can either cloud or inform their work. Galvani subscribed to the philosophical notion then current of “Vitalism,” which suggested a “life force” could be found in many things, even dead frogs.  Basing his own ideas on a firmer and more rational footing, Volta would have none of this—and in proving his own convictions correct, he delivered to the world the means by which to power the portable modern world.

    Volta unveiled on March 20, 1800, via a letter to the president of the Royal Society of London, the first-ever electric pile. He built the device in an effort to show that generating electrical current did not require any animal tissue. Rather, his model included a stack of alternating silver and zinc wafers, with pieces of brine-soaked cloth in between. When a wire was connected to both ends of the pile at once, a current flowed.
    Different types of metal affected the volume of current produced [zinc and copper being the two he eventually settled on], and adding more wafers could increase the intensity. This, essentially, was the world’s first battery. It was an instant success and helped lead to further research and development in electrochemistry, electromagnetism, and practical applications for electricity.

Top effort, that.

4 comments:

Anonymous said...

There's apparently clay pots in Egypt that are much older (5000yrs) that appear to have pitch in them with a copper centre - like an electrode. These may generate current and be an early battery but I can't remember where I read this. There's also drawings of what look like big light bulbs as well but I'm not aware anyone has made one to see if that's correct.

History gets lost pretty quickly.

Dolf said...

Anonymous

Are you talking about:

http://en.wikipedia.org/wiki/Baghdad_Battery

Saw it on Mythbusters, and they could get 4 volts out of it.

Anonymous said...

So his name became the Volt, and his companion's name was used for the Galvanometer.

Peter Cresswell said...

** Baghdad battery looks fascinating. I can see that being a great McGuffin for a historical novel.

** Yep, Volta = Volt, Galvani = galvanised, Galvanic Series, Galvanometer etc.