The reactivity series for metals was born in 1771 when Luigi Galvani touched two different metals to a frogs legs and it involuntarily jumped. He found the greater the difference in the metals, the larger the effect. Alessandro Volta expanded on Galvani’s work and created the reactivity series.
Here is a link to a video of what appears to be someone replicating the Galvani experiment on their kitchen counter next to their tooth brush. Eew.