By Robert Hazen, Ph.D., George Mason University
Luigi Galvani and his fellow countryman, Alessandro Volta, were two amazing characters in the history of science, whose careers were linked in a curious way. Their findings and controversies were related to the behavior of frogs. Read on to find more on their interesting theories.
Early Years of Luigi Galvani
Anatomist Luigi Galvani (1737 to 1798) was born in the northern Italian city of Bologna, where he was raised and educated all the way through a medical degree. He went on to become a faculty member at the University of Bologna and President of the Bologna Academy of Sciences. He spent his entire career there and died in the same house where he was born.
Galvani’s Experiments on Frogs
Luigi Galvani was an authority in his times on physiology, especially on dissection. He was fascinated by the interaction of tissues with electricity. Galvani focused much of his work on the subject of animal electricity.
Galvani’s most famous experiments involved studying the effects of electric sparks on the muscular legs of frogs. He discovered the remarkable effects of static electricity, which caused their legs to twitch and convulse spontaneously, even from a dissected frog.
While performing these experiments, Galvani noticed something rather new and unexpected. He had attached a brass wire to a frog’s leg and was preparing to induce a spark by touching the leg with a steel scalpel. When the internal crural nerves of the frog were touched, suddenly all the muscles of the frog’s limbs seemed to contract and fall into tonic convulsions. However, these convulsions were not caused by a spark. An entirely new phenomenon had occurred because of a brass hook and a steel scalpel touching the frog at the same time.
Learn more about electromagnetism.
Galvani Interpretation of Animal Electricity
Galvani conducted different set of experiments to study the effects of lightning on severed limbs of various kinds of animals.
Two different metals, brass and iron, were stuck into the severed limbs of a frog. When Galvani placed the wire outside during an electrical storm, the various limbs would jump and twitch as he expected. However, the twitching sometimes also occurred on dry and sunny days as long as the brass and the iron were both attached to the limbs.
A lot many experiments were still required to clarify and define this phenomenon. Galvani showed that when copper and iron wires were inserted into different parts of these dead frogs’ legs, The legs convulsed when the wires touched. There was no spark and no other sort of electrical current was required.
All that was needed was two pieces of metal. Galvani interpreted this new electrical phenomenon in terms of animal electricity. He interpreted that this type of electricity was intrinsic to biological tissues.
Alessandro Volta and Metallic Electricity
Alessandro Volta, the famous Italian physicist upon hearing Galvani’s experiments directed his attention to the same phenomena. He tried the same kinds of experiments, but focused more on the metallic elements of Galvani’s experiment than the biological components.
Being a physicist, Volta was interested in the physical world and so metals seemed to be the more basic thing to study. He was soon convinced that it was the juxtaposition of these two different metals that led to the electrical phenomenon, which he called metallic electricity.
Learn more about the first law of thermodynamics.
Conflict between Animal and Metallic Electricity
At this point, a very unfortunate conflict developed between supporters of Galvani’s animal electricity and Volta’s metallic electricity. An extension of this conflict was between biology and physics. And as so often happens in science, the physicist seemed to win over the biologist.
Volta’s view soon prevailed because his electrical effects could be produced independently of frog’s legs or any other biological material for that matter. He found that if two rods of different metals were put into an acidic bath, an electric potential would form between those two rods.
This is a transcript from the video series The Joy of Science. Watch it now, Wondrium.
Invention of the Battery
This was the beginning of the study of electricity, the study of moving electrons. For Volta, the next step was a very logical one. He devised arrangements in which different metals were kept in contact and studied various configurations.
Volta found that electricity could be produced by just stacking alternate layers or discs of metals zinc and silver in a saltwater bath that would allow current to flow. This was the invention of the battery, the device that was described in Volta’s article on electricity in 1800.
Learn more about magnetism and static electricity.
Common Questions About How Galvani’s Animal Electricity Theory Led to the Invention of the Battery
The supporters of metallic electricity were convinced that the juxtaposition of two different metals was enough to create an electrical phenomenon while the ones supporting animal electricity proposed that electricity was intrinsic to biological tissues.
Galvani’s experiments studied the effects of electric sparks on the muscular legs of frogs. He discovered the remarkable effects of static electricity, which caused the frog’s legs to twitch and convulse spontaneously, even in a dissected frog.
Alessandro Giuseppe Antonio Anastasio Volta was the famous Italian physicist who invented the electric battery. He is also considered to be the pioneer of electrical sciences and electricity.
When two rods of different metals were put into an acidic bath, Volta found that an electric potential formed between those two rods.
