Volta battery

This is one of the earliest electric batteries ever made. It was invented by Alessandro Volta in 1799 and consists of discs of two different metals, such as copper and zinc, separated by cardboard soaked in brine.

In the early 1900s, the study of electricity was an exciting new subject and there were different theories on what electricity was and how it was generated. One idea, by Luigi Galvani, was that there was a special electricity in animals, demonstrated by connecting two different metals with a frog's leg. Volta realised that it was the liquid in the frog's leg which was important rather than the frog itself. He replaced it with paper soaked in brine and got the same effect.

This particular battery was given by Volta to Michael Faraday when he and Humphry Davy visited Milan in June 1814. Davy was inspired by Volta's ideas and built his own batteries to experiment with. He created the process now called electrolysis, and made several important discoveries. Faraday followed up this work and went on to alter Davy's ideas about the relationship between electricity and chemistry. Scientists today continue to revise, refine and expand existing ideas in the same way.