Thermodynamics: The 2016 advent calendar
Day 15

When Faraday kept frogs

Hop back in time and visit the Ri froggery.

How do you measure electricity before you’ve invented the voltammeter? This was the problem facing Michael Faraday and Humphry Davy, working on early experiments with electricity in the labs of the Royal Institution.

The solution was to use frogs. Luigi Galvani had famously discovered that passing a current through a frog’s leg muscles would cause them to twitch. For a long time, this was the only reliable and economical way of testing whether electric current was flowing, so the Ri kept an active froggery, jumping with live frogs. These frogs, unfortunately, reached an abrupt end when their services were required for an experiment.

Fortunately, it didn’t take long for technology to catch up, and soon the frogs were replaced with something a little more humane. 

  • Photo of frog specimen in the Ri archives

    This specimen remains in our archive today. Note its smashed head, and the metal plates that have been slotted under the leg muscles for the experiment.

    Credit: Royal Institution

More from the advent calendar