StMU Research Scholars

Thank Frogs for Volta’s Battery

Can you imagine a day without a battery? All our devices from smartphones to pacemakers use the power of batteries to harness electricity. These devices play a pivotal role in our society and it is important to give credit where credit is due. You can thank the great Italian scientist Alessandro Volta for his discovery of the first ever battery coined the voltaic pile. If his name sounds a bit familiar it is because the volt (unit for electric potential) is named after him.

Portrait of Alessandro Volta | Courtesy of Wikimedia Commons|

Alessandro Volta was born to an aristocratic family in Como, Italy on February 18th, 1745.1 Volta excelled in math and science at a very young age. Even as a school boy he showed a keen interest in electricity. In the eighteenth century, the phenomenon of electricity was an intellectual curiosity, and not much was known about its properties. Volta excelled in school, and in 1774 he became a professor of physics at the Royal School of Como.2 During his time as professor, his interest in electricity remained a focus of his work. He created the electrophorus, which was a device used to generate static electricity.

Volta never set out to invent the battery. His experiments on electricity were in response to the claims of a scientist and friend of his, who claimed to have found electricity in animals.3 This scientist was Luigi Galvani, a professor of anatomy at the University of Bologna. One day as Galvani was performing an experiment on frogs, he began to cut the legs so that they would be exposed. When he touched his steel scalpel with a brass hook holding the frog’s legs in place, he saw the legs twitch. Galvani was convinced that what was going on was the presence of animal electricity. Galvani thought the muscles of the frog stored its life force. When Volta learned about Galvani’s discovery of animal electricity, he went right away to try to replicate Galvani’s experiment. Volta wanted to see for his own eyes what Galvani had published to the scientific community about his new discovery. After completing the experiment dozens of times, Volta disagreed with Galvani. Volta believed that the movement of the frog legs were because of the electric stimulation that was provided by the steel scalpel and the brass hook.4 Volta concluded that the frog’s legs were merely a vessel for the electric stimulation.

Luigi Galvani’s Twitching Frog’s Leg | Courtesy of Wikimedia Commons|

Once Volta recreated Galvani’s experiment, he knew the key to producing electricity was by using two metals that were not the same and not the actual frog legs themselves. The frog legs could not produce any sort of electricity. The reason the frog legs would move was because of the charge which was sent through the frog legs and into the nerves inside the legs which in turn resulted in a twitch. This was an indication that electricity was present. Volta recreated the experiment but would later conclude the frog legs were not the only electricity indicators but so were other materials such as moist cards of brine, or cardboard soaked in salt water. This was when Galvani concluded that the electric charge came from the rods of metal themselves and had nothing to do with frog legs. For the first experiment he used five cups with brine or salt water in them. Then, by adding pieces of silver and zinc, he attached the cups by metal strips where he placed them into the cups of brine. He would then put one finger at each end of the cups to feel the slight electric shock. Impressed with his work, he wanted to see if he could recreate his experiment, but without all the brine water. He then created a circuit consisting of copper and zinc discs that were separated by a cardboard soaked in brine. Just by adding more copper, cardboard soaked in brine, and zinc, Volta was able to adjust the amount of electricity that was being produced by the circuit. This became the voltaic pile, the first battery with a reliable source of electricity. Once Volta realized what he had done, he was able to refute the idea Galvani proposed about animal electricity.

Volta’s description of the Voltaic Pile | Courtesy of Wikimedia Commons

Volta published his experiment and findings to the scientific community and later was honored for his invention of the voltaic pile. Today it is now almost impossible to not be in constant contact with a battery. You can thank Alessandro Volta for his discovery of the battery, which became a template for our modern dry-cell batteries. We might also thank Luigi Galvani for his role in stimulating Volta’s experiments, and maybe even thank the many nameless frogs for their contributions.

  1. Oliver J. Thatcher, The Library of Original Sources (New York, Chicago: University Research Extension, 1907), 395.
  2. Encyclopedia of World Biography, 2004, s.v. “Alessandro Volta,” by Paula K. Byers.
  3. Joost Mertens, “Shocks and Sparks: The Voltaic Pile as a Demonstration Device,” The History of Science Society 89, no. 2 (June 1998): 303.
  4. Giuliano Pancaldi, Volta: Science and Culture in the Age of Enlightenment (Princeton University Press, May 1, 2005), 110.

51 Responses

  1. It is amazing to think that the discovery of batteries can be traced back to the humble frog. Given what we know about electricity now, it is curious that Luigi Galvani thought that thought that the frog’s legs stored their own sort of electricity. Alessandro Volta probably had no idea what would eventually become of his discoveries: now we are almost always using batteries. This was a very interesting article!

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