luigi galvani


September 9th 1737: Luigi Galvani born

On this day in 1737, the Italian scientist Luigi Galvani was born in Bologna. Galvani is best known for his 1771 experiment where he made the muscles of dread frog legs twitch when touched with a spark. He is thus considered a pioneer of the study of bioelectricity. Galvani died in December 1798. His work was an inspiration for Mary Shelley when she was writing ‘Frankenstein’. The word 'galvanise’ is based on his name due to his famous experiments into the process.

The Electrification of Human Corpses

In 1780 the Italian anatomy professor Luigi Galvani discovered that a spark of electricity could cause the limbs of a dead frog to twitch. Soon men of science throughout Europe were repeating his experiment, but it didn’t take them long to bore of frogs and turn their attention to more interesting animals. What would happen, they wondered, if you electrified a human corpse?

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The electrical currents generated by and through the neurons or nerve cells were the means by which the Italian anatomist Luigi Galvani discovered electricity. Galvani had found that electrical impulses could be conducted to the legs of frogs, which dutifully twitched; and the idea became popular that animal motion (“animation”) was in its deepest sense caused by electricity. This is at best a partial truth; electrical impulses transmitted along nerve fibers do, through neurochemical intermediaries, initiate such movements as the articulation of limbs, but the impulses are generated in the brain. Nevertheless, the modern science of electricity and the electrical and electronic industries all trace their origins to eighteenth-century experiments on the electrical stimulation of twitches in frogs.
—  Carl Sagan, The Dragons of Eden: Speculations on the Evolution of Human Intelligence

Giovanni Aldini was an Italian physicist and the nephew of Luigi Galvani. Aldini might be best known for his public demonstration on galvanism, the stimulation of muscle tissue with an electrical current, pioneered by his uncle. His public demonstration in London in 1803 used the corpse of the executed criminal George Forster.

It wasn’t until the summer of 1816 when Aldini and Galvani’s science and the world of fiction would converge when a young Mary Godwin, along with (among many others) Percy Shelley, Lord Byron, and John Polidori, conceived a competition to create the best horror story. Inspired by the night’s discussions on the occult and, yes, galvanism, and possibly more than a little insomnia, the future Mary Shelley was gripped by a “waking dream” that would inspire her to begin writing the horror story we now know as Frankenstein, or The Modern Promethius.

Delve into more on such literary crossovers in The Body Electric, our newly released chapter of Fantastic Worlds, Science & Fiction 1780-1910. I hope you don’t find it too shocking.

Google’s Doodle celebrating Alessandro Volta is misleading, and The Guardian’s Charlotte Connelly jumped at the chance to set it straight:

In 1799 Volta was experimenting with some curious phenomena that had been discovered by fellow Italian Luigi Galvani in the 1780s. Galvani had found that the muscles of dead frog’s legs could be made to twitch by touching the nerves with two pieces of metal. After several years work, and isolating the experiment from outside forces as well as he could, Galvani concluded that there was an “animal electricity” that came from within the frog. His work was intriguing, and easy to repeat. Interested natural philosophers from across Europe began experimenting and debating the new electricity.

Volta was one of those interested experimenters and, although initially agreeing with Galvani’s assessment, over time he began to consider that the electrical fluid, as it was then conceived, did not originate in the frog. He began to see the frogs’ legs as sensitive instruments, rather than the cause of the phenomena. To test his idea Volta sought ways to remove the frog from the experiment. He knew that the excitation of the leg muscles was more pronounced when two different metals were used to touch the nerves, and he suspected that metals were the key to understanding.

Volta’s breakthrough came in 1799 when he took two different metals, zinc and silver, and experimented with placing them together. A zinc disc was put down, then a silver disc, and finally a disc of damp cardboard. This was repeated several times to create a pile of discs, which if large enough was indeed capable of giving Volta an electric shock. Volta’s electrical pile was the first device that was able to produce a reasonably consistent source of electricity.

News of Volta’s invention spread incredibly quickly within scientific circles, and through reports in newspapers of impressive public displays. Within weeks William Nicholson and Anthony Carlisle in London used a similar pile to decompose water into oxygen and hydrogen. A new discipline of electro-chemistry proved very fruitful in the coming years, enabling Humphry Davy to discover and isolate several new elements with the enormous pile he’d had built for his lab at the Royal Institution. By 1820 variations on Volta’s pile were common in scientific laboratories, giving the Danish scholar Hans Christian Oersted the tools he needed to discover the link between electricity and magnetism. His discovery paved the way for the electric telegraph, which revolutionised communication technologies.

Charlotte Connelly is PhD student at the University of Cambridge and will be reproducing Volta’s pile for the Naked Scientists radio show on Wednesday.

Well done, Charlotte! 

Ch 117 review: battery

I dare say this is a voltaic pile. It’s probably providing power to the electric lights over the beds, and to the centrifuges.

The voltaic pile was the first electrical battery that could continuously provide an electric current to a circuit. It was invented by Alessandro Volta, who published his experiments in 1800. […] The entire 19th century electrical industry was powered by batteries related to Volta’s (e.g. the Daniell cell and Grove cell) until the advent of the dynamo (the electrical generator) in the 1870s.

Volta’s invention built on Luigi Galvani’s 1780s discovery of how a circuit of two metals and a frog’s leg can cause the frog’s leg to respond. Volta demonstrated in 1794 that when two metals and brine-soaked cloth or cardboard are arranged in a circuit they produce an electric current. In 1800, Volta stacked several pairs of alternating copper (or silver) and zincdiscs (electrodes) separated by cloth or cardboard soaked in brine(electrolyte) to increase the electrolyte conductivity. When the top and bottom contacts were connected by a wire, an electric current flowed through the voltaic pile and the connecting wire.

source: wikipedia

Today’s Google Doodle honors Alessandro Volta, the Italian physicist who is credited with creating the first electric battery in 1799. As TIME writes:

Volta’s invention was the result of a professional competition with Luigi Galvani, who discovered that dissected frogs’ legs would twitch when probed with a wire.

Galvani believed the frogs’ muscles generated the electricity, while Volta thought the animal tissue was only a conductor.