Galvani's great interest was "animal electricity," which he studied in his post as a teacher of medicine in Bologna. In 1780, he constructed a crude electric cell with two different metals and the natural fluids from a dissected frog. In another experiment he applied current to the nerves of a frog and observed the contractions of the muscles in their legs. This led to widespread speculation on the relationship of biology, chemistry, and electricity, and perhaps encouraged speculation on medical electricity, such as George Adams and Benjamin Franklin were exploring. His theoretical foundation was later corrected by Alessandro Volta. For a contemporary account, consult William Nicholson's entry in The British Encyclopedia (1809).