(b. Bologna, ltaly,.9 September 1737; d. Bologna. 4 December 1798)
anatomy, physiology, physics.
Galvani, who is most famous for his work relating to the discovery of current electricity, received his professional training in medicine. He studied at Bologna with several leading medical teachers of his time, including Jacopo Bartolomeo Beccari and Domenico Galeazzi. After receiving his degree in medicine and philosophy on 15 July 1759, Galvani divided the first years of his professional career, between medical and surgical practice, anatomical research, and lecturing on medicine. After spending several years as an honorary lecturer, on 22 June 1768 he became a paid lecturer at the college he had attended, and on 12 December 1775 he became Galeazzi’s adjunct in anatomy at the University of Bologna. The Senate of Bologna had installed Galvani as curator and demonstrator of the anatomical museum in March 1766, and on 26 February 1782 it elected him professor of obstetric arts at the Istituto delle Scienze. During the last years of his life Galvani suffered several personal misfortunes. In 1790 his beloved wife, Lucia Galeazzi, daughter of his anatomical preceptor, died; and a few years later he was deprived of his offices at the university and the Istituto delle Scienze because of his refusal to swear allegiance to Napoleon’s Cisalpine Republic. He died in poverty and sorrow.
Galvani devoted most of his early scientific efforts to important but rather straightforward anatomical topics. His first publication, in 1762, was a dissertation on the structure, function, and pathology of bones. He described the chemical and anatomical elements from which bones are constructed, their pattern of growth, and various diseases to which they are subject. In 1767 he published an essay on the kidneys of birds, in which he described, among other things, the three-layered ureteral wall and its peristaltic and antiperistaltic movement upon irritation. Galvani also devoted several papers to the anatomy of the ear in birds, just before Antonio Scarpa published on this subject. He recounted with particular precision the comparative anatomy of the auditory canal in several species of birds, devoting some attention to the distribution of blood vessels, muscles, and nerves in the middle and inner ear.
Galvani addressed his most important and bestremembered investigations to problems of animal electricity. During the 1770’s his research interests shifted to a considerable extent from largely anatomical to more strictly physiological studies, specifically on nerves and muscles. In 1772 Galvani read a paper on Hallerian irritability to the Istituto delle Scienze, and in 1773 he discussed the muscle movement of frogs before the same body. In 1774 he read a paper on the effect of opiates on frog nerves. These researches fused in his mind with slightly earlier eighteenth-century studies, several of them by Italians, on the electrical stimulation of nerves and muscles. Picking up where Beccaria, Leopoldo Caldani, Felice Fontana, and Tommaso Laghi had recently left off, Galvani began in late 1780 an extensive and meticulous series of investigations into the irritable responses elicited by static electricity in properly prepared frogs.
Galvani’s frog preparations consisted of the spinal cords, crural nerves, and lower limbs dissected as a unit. Using these preparations, he at first touched the conductor of a static electrical machine directly to the spinal cord (kept on a pane of glass) and watched the convulsive contractions of the muscles in the lower limbs, which rested on a so-called “magin square,” a flat plate condenser made by attaching a sheet of metal foil to both sides of a single pane of glass. Galvani was apparently trying to arrive at general laws relating the forcefulness of muscle contraction directly to the quantity of electric fluid applied and inversely to the distance of the nerve and muscle from the conductor. After much repetition and sometimes complex variation of this basic procedure, Galvani was faced with one quite unanticipated result: the lower limbs contracted even when the frog was completely insulated from the machine and removed some distance from it. As long as the crural nerves were touched by a grounded conductor, the muscles contracted whenever a spark was drawn from an electrical machine, even though the spark did not directly strike the frog preparation.
In the course of investigating this strange result, Galvani in the mid-1780’s uncovered an even stranger one. He and his research associates had begun to explore the effects of atmospheric electricity on frog preparations, on the assumption that some analogy existed between convulsions induced by distant electrical machines and those sometimes induced by static discharge in the atmosphere. The expected analogous results were obtained. But then Galvani made the unanticipated observation that muscle contractions occurred even without discharge of atmospheric electricity. As he explained later in his De viribus electrictricitatis in motu musculari commentarius (1791), Galvani at one point fastened some prepared frogs by “brass hooks in their spinal cord to an iron railing which surrounded a certain hanging garden of my house.” He noticed that these frogs went into contractions “not only when lightning flashed but even at times when the sky was quiet and serene,” and he was able to intensify these effects by deliberately pressing the brass hooks in the spinal cord to the iron railing. He obtained similar results indoors by placing the frog on an iron plate and pushing the brass hook against it. Contractions resulted indoors only when metals, rather than glass or resin, were used; and these contractions seemed stronger with certain metals than with others. In a follow-up series of investigations, Galvani experimented with metallic arcs. He tried various bent metal conductors, touching one end to the hooks in the spinal cord and the other to the muscles in the frog’s leg. Contractions resulted, their strength depending on the metals used for the hook and the arc. Contractions did not result when a nonconductor replaced the metal in the arc.
Galvani had here hit upon the central phenomenon of galvanism: the production of electric current from the contact of two different metals in a moist environment. He did not, however, interpret his own discovery this way. Instead, Galvani thought that he had finally obtained confirmation for the suspicion, entertained from time to time during the eighteenth century, that animals possess in their nerves and muscles a subtle fluid quite analogous to ordinary electricity. He himself had occasionally flirted with this idea but had never previously made much of it. But his experiments with the metallic arcs seemed to provide clear and unmistakable proof of a special “animal electricity,” and he spent considerable effort in specifying and elaborating his theory.
Galvani’s fullest statement is in part IV of his Commentarius. He explains that the muscle can be compared to a small Leyden jar charged with a dual electrical charge, and the nerve to the jar’s conductor. Animal electrical fluid is generated from the blood in the brain and passes via the nerves into the core of the muscles, which thus become positively charged while the outside becomes negative. Electrical equilibrium in the muscle, as in a Leyden jar, can be disrupted by applying an arc between conductor and core or by drawing a spark from an electrical machine. When the muscle discharges in either of these ways, its fibers are stimulated to violent, irritable contraction. Both the original anomaly of convulsive contraction upon distant sparking and the subsequent observation of contractions provoked by the metallic arc were thus explained in terms of “animal electricity” and its special discharge pathways.
Reaction to Galvani’s published reflections was vigorous although somewhat confused. Alessandro Volta, the noted Italian electrician, was among the first to take up the new theory of animal electricity, but by 1792/1793 his original support turned to skeptical reserve. In papers published in the Philosophical Transactions of the Royal Society, Volta professed belief in Galvani’s theory but simultaneously advanced the thesis that the “metals used in the experiments, being applied to the moist bodies of animals, can by themselves...excite and dislodge the electric fluid from its state of rest; so that the organs of the animal act only passively.” By the end of 1793 Volta had discarded Galvani’s animal electricity for his own theory of “contact,” according to which conducting bodies of certain kinds, especially metals, can by their mere contact excite electrical fluid, which can in turn stimulate various irritable responses. Galvani was not prepared to concede defeat, and he and his nephew Giovanni Aldini mounted a campaign in the mid-1790’s to establish beyond doubt the existence of a special animal electricity. In 1794 and 1797 he announced experiments employing only frog nerve-muscle preparations (without metals) and showed that convulsive contractions could be produced merely by touching nerves to muscles.
At the same time, Galvani extensively examined the electrical properties of marine torpedoes. He found that the strong electrical discharge is generated in these animals in structures analogous to ordinary nerves and muscles, and this seemed to supply additional support for the theory of animal electricity. Volta’s counterattack led in 1799 to his invention of the pile, a stack of metal-metal-moist-conductor elements which was, in fact, the first primitive wet-cell battery. When Galvani died, prospects for the survival of his theory were very uncertain. Nevertheless, support for the concept of animal electricity survived into the nineteenth century and ultimately led in the 1840’s to the basic work of Emil du Bois-Reymond.
I. Original Works. Galvani’s most famous work is De viribus electricitatis in motu musulari commentraius (Bologna, 1791). It has been published several times since, reproduced ion facsimile, and issued in several translations. A facsimile of the original Latin ed., together with an English trans., was issued by the Burndy Library (Norwalk, Conn., 1953). Fuller eds. of Galvani’s writings include Opere edite ed inedite (Bologna, 1841), which contains several of his early anatomical papers and a report on then known MSS; Memorie ed esperimenti inediti (Bologna, 1937), which includes a transcription of Galvani’s notes for his experiments in the early 1780’s and a few draft papers on animal electricity from the same period; and a facsimile of Taccuino (Bologna, 1937), a notebook of Galvani’s investigations into torpedoes in the mid-1790’s.
II. Secondary Liteature. There is no full-length modern biography of Galvani, but several older éloges, e.g., by J. L. Alibert (Paris, 1806), are still useful and are supplemented by some extremely useful monographic work. Hebbel E. Hoff, “Galvani and the Pre-Galvanian Electrophysiologists,” in Annals of Science, 1 (1936), 157-172, is a basic source, as is I. B. Cohen’s “Introduction” to the Burndy Library ed. of the Commentarius. Also of fundamental importance are Giulio C. Pupilli’s “Introduction” to the ed. of the Commentarius published by Richard Montraville Green (Cambridge, Mass., 1953); and John F. Fulton and Harvey Cushing, “A Bibliographic Study of the Galvani and Aldini Writings on Animal Electricity,” in Annals of Science, 1 (1936). 239-268. Also worth consulting is Marc Sirol, Galvani et le galvanisme (Paris, 1939).
Theodore M. Brown.
Luigi Galvani was the pioneer of electrophysiology. A skilled anatomist, obstetrician, physician, and surgeon, Galvani conducted several experiments with animal nervous and muscular systems. After an accidental discovery of the relationship between electricity and muscle movement while dissecting a frog, Galvani proposed a theory of "animal electricity." Although his theory incorrectly identified the electro-conducting medium in animals as fluid, his research opened new lines of inquiry about the structure and function of the nervous system in both animals and humans.
Galvani was born on September 9, 1737 in Bologna, Italy. His original intention was to study theology and later enter a monastic order. However, Galvani was discouraged from pursuing monastic life in favor of continuing his studies of philosophy or medicine. He devoted his academic career at the University of Bologna to both interests and in 1759 received his degree in letters and medicine on the same day. In 1762, Galvani was named Professor of Anatomy at the university, and remained there for most of his career. His early works were primarily concerned with comparative anatomy.
In 1764, Galvani married Lucia Galleazzi, the daughter of a prominent member of the Bologna Academy of Science. Galvani's wife encouraged his independent research, and served as a counselor and guide for his experiments until her death. Drawing from his extensive training in anatomy and obstetrics, Galvani focused his research on the nature of muscular movement. While dissecting frogs for study, Galvani noticed that contact between certain metal instruments and the specimen's nerves provoked muscular contractions in the frog. Believing the contractions to be caused by electrostatic impulses, Galvani acquired a crude electrostatic machine and Leyden jar (used together to create and store static electricity), and began to experiment with muscular stimulation. He also experimented with natural electro-static occurrences. In 1786 Galvani observed muscular contractions in the legs of a specimen while touching a pair of scissors to the frog's lumbar nerve during a lightening storm. He also noticed that a simple metallic arch which connected certain tissues could be substituted for the electrostatic machine in inducing muscular convulsions.
The detailed observations on Galvani's neurophysiological experiments on frogs, and his theories on muscular movement, were not published until a decade after their coincidental discovery. In 1792, Galvani published De Viribus Electricitatis in Motu Musculari (On Electrical Powers in the Movement of Muscles). The work set forth Galvani's theories on "animal electricity." He concluded that nerves were detectors of minute differences in external electrical potential, but that animal tissues and fluids must themselves possess electricity which is different from the "natural" electricity of lightening or an electrostatic machine. Galvani later proved the existence of bioelectricity by stimulating muscular contractions with the use of only one metallic contact—a pool of mercury.
Galvani's work altered the study of neurophysiology. Before his experiments, the nervous system was thought to be a system of ducts or water pipes, as proposed by Descartes. Galvani proved that there was a relationship between muscle movement and electricity and proposed that nerves were electric conductors. However, the nature of a different "animal electricity" which Galvani proposed was disproved later by Italian physicist, Alessandro Volta. Galvani had experimented with using animal fluids and metallic conductors—hence the reference to his name in the term "galvanized"—to create an electric pile, or battery. However, in 1800, Volta created the first successful battery which could produce a sustained electrical current. Thus, Volta effectively rejected Galvani's theory of "animal electricity."
After the death of his wife, Galvani joined the Third Monastic Order of the Franciscans. He continued his academic research, but when Napoleon seized control of Bologna in 1796, Galvani refused to swear the oath of allegiance to the newly created Cisalpine Republic on the basis that it contradicted his political and religious beliefs. As a result, he was stripped of his professorship and pension. Galvani died on December 4, 1798.
BRENDA WILMOTH LERNER
The Italian physiologist Luigi Galvani (1737-1798) is noted for his discovery of animal electricity.
Luigi Galvani was born at Bologna on Sept. 9, 1737. He studied theology for a while and then medicine at the University of Bologna. In 1762, upon completion of his studies, he was appointed lecturer of anatomy and surgery at Bologna. His interest focused on the animal senses, which led him into deep theoretical interest in the action of the nervous system.
By the middle of the 18th century various books on electricity were available in Italian, and in 1744 Benjamin Franklin's famous book on electricity appeared in Italian translation. Galvani was influenced by Franklin's "one fluid theory," according to which electrical phenomena were caused by an electric fluid that results in so-called positive electricity, while so-called negative electricity was the absence of fluid. What seemed especially important to Galvani was Franklin's explanation of the Leyden jar, the early form of condenser. According to Franklin, positive electricity accumulated on the inner conductor while the outer conductor became negatively charged. The whole setup was similar to an accumulation of fluid on the inside of the bottle. Galvani drew an analogy between the Leyden jar and animal muscle and carried out his experiments with this thought in mind. He studied the effects of electricity from lightning on muscular contractions in a frog and proved that the electricity produced muscular convulsions.
Galvani's first announcement of his experiments appeared in a paper, "On the Effect of Electricity on Muscular Motion," published in 1791. He also gave an account of convulsions produced in a frog, in the absence of an electrical machine, when the frog formed part of a circuit containing one or more pieces of metal. Galvani had observed motion of the nerve juices during these convulsions and proposed the theory that the convulsions were caused by electricity within the animal's body; the muscle fiber and the nerve were acting like a Leyden jar.
Galvani's great Italian contemporary Alessandro Volta began working on animal electricity in 1792 and came out in direct opposition to Galvani's theory of an animal electrical fluid. It was then that the famous controversy between the two began. Volta proved that the nerves were nothing but electrical conductors and that it was possible to get electrical effects by placing any two metals in contact with an intervening piece of moistened cardboard. In this controversy Volta was correct in his physical interpretations, yet it was Galvani's influence which fostered the flourishing science of neurophysiology in the 19th century. However, the controversy between the two men spread into their personal relations and even into Italian politics of the time.
After the Cisalpine Republic was established in 1797, Galvani refused to swear allegiance to it on religious grounds and was dismissed from his university position. Volta swore allegiance and played a central role in the republic. Galvani was reinstated a year later, but by then he was a completely broken man. He died on Dec. 4, 1798.
Biographical material on Galvani is in Bern Dibner, Galvani-Volta: A Controversy That Led to the Discovery of Useful Electricity (1952). See also James R. Partington, A History of Chemistry, vol. 4 (1964). □