Alessandro Volta invented the voltaic pile—the first electric battery.
Alessandro Giuseppi Volta became one of the best-known scientific celebrities of his day for his work with electrical currents. One of his most influential findings was the fact that electricity can be generated from metals. Before his time, the only source of electricity that scientists were familiar with was that produced by friction--what is commonly known as static electricity. Volta was also a gifted inventor, and one of his greatest creations was based on the concept of metal-generated electricity--the voltaic pile. For his many achievements in the study of electricity, the unit of force in electrical current--the volt--was named in Volta's honor.
Comes from a religious family
Volta was born on February 18, 1745, in Como, Lombardy, Italy. He was one of the seven children who survived to adulthood of Filippo and Maddelena de' conti Inzaghi Volta. Filippo, like his three brothers, had entered a religious order of the Catholic church; but in order to make sure the family line did not die out, Filippo left his career in the Church, married, and had a family. But the family tradition of intense devotion to the Church was carried on by his children. Most of Volta's brothers and sisters entered the Church as well.
Decides on a career in physics
After Volta's father died around 1752, the boy's education was handled by his father's brothers. They enrolled him in a religious school run by the Jesuit order, where he, too, was nearly drafted for the priesthood by his teachers. His uncles, who wanted Volta to become an attorney, removed him from the influence of the Jesuits, and sent him to the Seminario Benzi when he was 16. But Volta soon developed his own ideas about what kind of profession he would follow. After reading a history of electricity written by English chemist Joseph Priestley (1733-1804), Volta became very interested in the subject and announced his intention of becoming a physicist.
Begins experiments with electricity
During the 1760s, Volta devoted himself to the study of electricity. With a friend, Giulio Cesare Gattoni, Volta carried out some early experiments; one of their projects involved studying the electricity brought down by a lightning rod. Volta also began corresponding with the two leading experts on electricity at the time: French physicist Jean Antoine Nollet (1700-1770) and Italian physicist Giovanni Batista Beccaria (1716-1781). Volta would write to the scientists when he thought of questions or suggestions that related to the work and theories of the two men. Beccaria, somewhat annoyed by the many comments of the young man, suggested that Volta read his writings on the subject of electricity and begin his own serious experimentation. Volta eagerly followed the older scientist's advice, but because he did not have access to the equipment he needed, he was forced to invent his own. This talent for creating inexpensive but useful instruments would play a large role in Volta's career.
Invents the electrophorous
In 1774, Volta began his academic career when he was appointed professor of physics at the high school in Como. In the same year, he created one of his most significant inventions; the electrophorous. This device had the ability to store significant electrical charges, and replaced the Leyden jar which, up until that time, had been used for storing smaller charges.
Volta's invention of the electrophorous actually began with the work of French physicist Charles-Augustine Coulomb (1736-1806). Until the late 1700s, scientists were mainly concerned with the type of electrical charge produced by friction (rubbing objects together), also known as static electricity. Coulomb had discovered that electrical charges were located on the surface of a charged body, not inside of it. Volta's electrophorous used two metal discs; one was rubbed to produce a negative electrical charge, the second disc was brought close enough to the first to establish a positive charge on the one side, leaving a negative charge on the other. Volta used Coulomb's discovery to draw off the negative charge from one side of his charged disc, leaving just a positive charge on the opposite side. The electrophorous provided scientists with a useful source of electric charge that could be used to charge other objects without losing its power. Some other scientists argued that Volta should not be given credit for the new invention because it was based on ideas developed by others. Most people, however, recognized that Volta had made a great contribution by taking these ideas and turning them into a useful instrument.
Makes discoveries in chemistry research
While his scientific reputation began to grow as a result of his creation of the electrophorous, Volta became involved with some experiments in chemistry. He found that when he exploded hydrogen gas in a closed container of air, he could measure the amount of oxygen that the hydrogen released from the air. In this way, he was able to make the first accurate measurement of the proportion of oxygen in the air. In 1776, he began applying the same technique to the study of marsh gas, the gas released by decomposing matter in a marsh or swamp. When he exploded hydrogen in the marsh gas, he discovered a new gas, methane.
Earns respect and honors for scientific work
By 1779, Volta had earned a reputation as an important scientist in the field of electricity, mainly due to his invention of the electrophorous. Because of his place in the scientific world, he was appointed professor of experimental physics at the University of Pavia, a position he would hold for nearly 40 years. Volta was a popular teacher, and the university eventually built a new lecture hall to hold all the students who came to hear him, as well as all the scientific equipment that Volta purchased during his travels to scientific centers in Europe. A few years after beginning his position at Pavia, Volta announced another invention; he had improved upon the electrometers used by other scientists to measure electrical charges. His new condensing electroscope was a much more sensitive instrument that allowed for the detection of very small charges. Even though Volta's greatest achievement still was to come, he began to receive many honors for his scientific work. In 1791, he was named a fellow of the Royal Society of London, and three years later the society awarded him the prestigious Copley Medal.
Scientific community splits over "animal electricity"
In 1791, Volta was drawn into a controversy that divided scientific thought about the nature of electricity. An Italian anatomist, Luigi Galvani (1737-1798), announced that year that he had discovered the existence of "animal electricity." Galvani had noticed that when he touched the muscles in a frog's legs with probes made of two different metals, the legs would twitch. He concluded that the frog tissue was the source of an "electrical fluid" that released a charge in the presence of the metal probes, causing the contraction in the frog muscles. The concept that there was another kind of electricity other than static electricity was completely new to scientists.
Finds that metal produces electricity
Volta did not believe that the "animal electricity" described by Galvani was possible, and he began a series of experiments on the topic himself. He conducted tests on numerous animals, including himself, and ultimately discovered there was no such thing as "animal electricity." Instead, he found that the two different types of metal probes used in Galvani's experiments were actually the source of the current, not the frog tissue. Volta had come up with a different, but equally new idea: that placing different metals near each other could produce electricity.
Creates first electric battery
The controversy raged on until 1800. In that year, Volta built a device that produced a large flow of electricity. He filled bowls with a saline (salt) solution and "connected" them with strips of different metals. One end of the strip was copper; the other end was tin or zinc. By bending his strips from one bowl into another, Volta was able to create a constant flow of electrical current; the world's first electric battery had been invented. Volta had proven that the metal was the source of the electricity and that animal electricity did not exist.
Later, in order to make his battery smaller, Volta used round discs of copper, zinc, and cardboard that had been soaked in a saline solution. He stacked his discs one on top of the other. Attaching a wire to the top and bottom of his pile allowed the electric current to flow. This invention, known as the voltaic pile, was the greatest achievement of Volta's career.
Voltaic pile leads to important discoveries
While Volta himself did not fully see the potential uses of his invention, the value of the voltaic pile was quickly recognized by other scientists. It provided, for the first time, a continuous source of electricity. One of the first scientists to make use of the voltaic pile was the English chemist William Nicholson (1753-1815), who built his own pile when he heard about Volta's invention in 1800. Nicholson placed the ends of his wires in water and discovered the flowing current "electrolyzed" the water, breaking it up into hydrogen and oxygen. English physicist and chemist Henry Cavendish (1731-1810) had shown those two elements could be combined to form water; Nicholson reversed the procedure. Nicholson's discoveries would later lead to the work of English chemist Humphry Davy (1778-1829), who used electrolysis to identify a number of new elements, including potassium, sodium, calcium, and magnesium.
Receives honors from Napoleon
Volta was highly celebrated for his last and greatest scientific contribution. The French leader Napoleon Bonaparte (1769-1821) was particularly impressed with the scientist's achievement and brought Volta to Paris in 1801 to give a special series of lectures on electricity at the National Institute of France (later known as the Academy of Sciences); to honor the occasion he was awarded a special gold medal. Napoleon also granted Volta a pension, gave him the title of count, and made him a senator of the kingdom of Lombardy. Volta continued to hold his post at the University of Pavia, eventually becoming the director of the philosophy department there. He retired to his family home in Como in 1819 and died there on March 5, 1827, at the age of 82. One the greatest recognitions of Volta's work came from the world scientific community in 1873: in Volta's honor, the unit of force that moves electric current was named the volt.
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