Frog galvanoscope

The frog galvanoscope was a sensitive electrical instrument used to detect voltage^[1] in the late 18th and 19th centuries. It consists of a skinned frog's leg with electrical connections to a nerve. The instrument was invented by Luigi Galvani and improved by Carlo Matteucci.

The frog galvanoscope, and other experiments with frogs, played a part in the dispute between Galvani and Alessandro Volta over the nature of electricity. The instrument is extremely sensitive and continued to be used well into the nineteenth century, even after electromechanical meters came into use.