Luigi Galvani was an Italian anatomist who, through his discovery that the legs of frogs would move when touched by two different metals, essentially founded the study of current electricity, also contributing significantly to the field of animal physiology. He was born in Bologna, in the Papal States (now Italy) on September 9, 1737. Galvani received a medical degree from the University of Bologna in 1762, where he was named Professor of Anatomy and Gynecology in 1775. In 1797, when Bologna fell to the French, Galvani lost his professorship because he refused to become a sworn supporter of Napoleon. He died the following year, in poverty.
Scientists had been experimenting with static electricity for more than a century by the time Galvani conducted his frog leg experiments. Knowing that an electric spark could provoke movement in live muscle tissue, Galvani noticed, while dissecting a frog, that nerve action/muscle movement was induced by electrical phenomena. For example, in one experiment, Galvani used silver and brass rods, one touching the spinal cord, the other touching the foot. When the opposite ends of the rods made contact, the leg muscle contracted.
Another experiment required the placement of the legs and spinal cord, respectively, upon brass and copper foil. A muscle contraction would occur when the ends of a metal rods would simultaneously touch both pieces of foil. In a third experiment, the legs and spinal cord were immersed in fluid. When the fluid came in contact with metal, a muscle contraction would result. A key element in these experiments was the fact that two different types of metal were needed to provoke a contraction and that electricity could be produced by chemical action. Electricity was definitely involved, but Galvani did not know whether the electricity was coming from the metal or from the muscle. Galvani, along with other scientists, referred to this phenomenon as "animal electricity" and eventually as "galvanism." The concept of galvanism was challenged by the Italian physicist Alessandro Volta (1745-1827), whose electrical experiments demonstrated that the electrical current originated in the metals.
Galvani's frog experiments may have encouraged assumptions that were eventually invalidated, but his contributions to physiological and electrical science initiated subsequent discoveries and spurring research in a variety of fields, including electric currents and electrotherapy. Processes and devices named after him include the galvanometer, which measures the current in a conductor, galvanic skin response a change in the skin's electrical conductivity due to any stimulus, and galvanization, the process whereby an electric current is used to apply a layer of zinc crystals to any other metal, usually iron and steel. The many terms derived from his name include galvanotaxis, which denotes movement in response to an electrical stimulus. In everyday language, the verb denotes the operation of providing an impetus for an action.
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