Frog Pile

The story of the modern chemical battery is full of neurotic Italians and loads of dead frogs. Most notably, an experimental feud between Luigi Galvani and Alessandro Volta defined our earliest understandings of electricity.

 

Galvani believed in “animal electricity” based on an accident he allegedly witnessed with Lucia Galeazzi, his wife. A static spark jumped from the tip of a dissection scalpel to the exposed sciatic nerve of a butchered frog leg the couple was examining. At this moment, the legs kicked as if alive. Galvani, fascinated, dedicated the rest of his life to stringing frog legs together into rudimentary circuits—these creations were lovingly called “frog piles”. He even began wiring the legs to lightning rods during electrical storms to force more power through the legs.

 

Volta was impressed, but didn’t quite believe the phenomenon was unique to living things (as Galvani claimed). Volta set out to prove Galvani wrong by constructing a “frog pile” with no frogs at all. He found that he could create a circuit of electricity by simply placing two different metals together with a saltwater electrolyte in-between. Effectively, this is how modern chemical batteries work. Volta specifically used zinc and copper to prove that electricity could be generated chemically and was not inherently tied to life.

 

Volta’s “voltaic pile” was built to specifically discredit Galvani’s frog pile, however that didn’t stop the fever of electric animal experimentation in the 19th century. Carlo Matteucci invented a highly sensitive device called the frog galvanoscope that measured the presence of voltage. It was 56,000 times more sensitive than other measures of electricity. It consisted of a frog leg placed in a glass tube with wires connecting to the exposed nerves; when electricity is present, the leg gives a small kick. While extremely sensitive, the frog galvanoscope needs frequent replacing—only working for a day or two before needing a fresh leg.

 

This piece is a little homage to frogs everywhere for helping us learn to power everything from toys to cars on chemical batteries. The work is entirely self-powered on 8 saltwater copper-zinc battery cells using Volta’s ultimately correct hypothesis. The blue tint in the jars of frog legs is due to a chemical reaction between copper, water, and formaldehyde.