CountA count is a nobleman in European countries; his wife is a countess. The word count came into English from the French comte, itself from Latin comes—in its accusative comitem—meaning "companion", and later "companion of the emperor, delegate of the emperor". The British equivalent is an earl...
Alessandro Giuseppe Antonio Anastasio Volta (February 18, 1745 – March 5, 1827) was an
ItalianThe Italian people are an ethnic group, in the sense of sharing a common Italian culture, descent, and speaking the Italian language as a mother tongue...
physicistPhysics is a natural science; it is the study of matter and its motion through spacetime and all that derives from these, such as energy and force...
known especially for the development of the first electric cell in 1800.
Early life and works
Volta was born in Como, Italy and was taught in the public schools there. In 1774 he became a professor of physics at the Royal School in Como. A year later, he improved and popularized the
electrophorusAn electrophorus is a capacitive generator used to produce electrostatic charge via the process of electrostatic induction. A first version of it was invented in 1762 by Swedish professor Johan Carl Wilcke,...
, a device that produces a static electric charge. His promotion of it was so extensive that he is often credited with its invention, even though a machine operating in the same principle was described in 1762 by Swedish professor Johan Carl Wilcke.
In 1776-77 Volta studied the
chemistryChemistry is the science concerned with the composition, behavior, structure, and properties of matter, as well as the changes it undergoes during chemical reactions...
of
gasThis page is about the physical properties of gas as a state of matter. For the uses of gases, and other meanings, see Gas .A gas is one of four states of matter. Near absolute zero, a substance exists as a solid...
es, and discovered
methaneMethane is a chemical compound with the chemical formula . It is the simplest alkane, and the principal component of natural gas. Methane's bond angles are 109.5 degrees. Burning methane in the presence of oxygen produces carbon dioxide and water. The relative abundance of methane and its clean...
by collecting the gas from marshes. He devised experiments such as the
ignitionCombustion or burning is a complex sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames, appearance of light flickering.Direct combustion by atmospheric oxygen is a reaction...
of methane by an electric
sparkA spark is a small airborne ember or particle of red-hot matter.Spark may also refer to:
In science:* An electric spark, usually with a flash and a sharp noise, may be:** A momentary electrostatic discharge...
in a closed vessel. Volta also studied what we now call electrical
capacitanceIn electromagnetism and electronics, capacitance is the ability of a body to hold an electrical charge.Capacitance is also a measure of the amount of electric charge stored for a given electric potential. A common form of charge storage device is a parallel-plate capacitor...
, developing separate means to study both electrical potential (V) and charge (Q), and discovering that for a given object they are proportional. This may be called Volta's Law of capacitance, and likely for this work the unit of electrical potential has been named the
voltThe volt is the SI derived unit of electromotive force, commonly called "voltage". It is also the unit for the related but slightly different quantity electric potential difference...
.
In 1779 he became professor of experimental physics at the
University of PaviaThe University of Pavia is a university located in Pavia, Lombardy, Italy. It was founded in 1361 and is organized in 9 Faculties.-History:...
, a chair he occupied for almost 25 years. In 1794, Volta married the daughter of Count Ludovico Peregrini, Teresa, with whom he raised three sons, Giovanni, Zannino, and Flaminio.
Volta and Galvani
Volta began to study, around 1791, the "animal electricity" noted by
Luigi Galvani Luigi Galvani was an Italian physician and physicist who lived and died in Bologna. In 1771, he discovered that the muscles of dead frogs twitched when struck by a spark.ref> – Eric Weisstein’s World of Scientific Biolgraph. This was one of the first forays into the study of...
when two different metals were connected in series with the frog's leg and to one another. Volta realized that the frog's leg served as both a conductor of electricity (we would now call it an
electrolyteIn chemistry, an electrolyte is any substance containing free ions that behaves as an electrically conductive medium, usually when in a solution...
) and as a detector of electricity. He replaced the frog's leg by brine-soaked paper, and detected the flow of electricity by other means familiar to him from his previous studies. In this way he discovered the electrochemical series, and the law that the
electromotive forceIn physics, electromotive force, or most commonly emf , or electromotance is "that which tends to cause current to flow."...
(emf) of a
galvanic cellThe Galvanic cell, named after Luigi Galvani, is a part of a battery consisting of an electrochemical cell with two different metals connected by a salt bridge or a porous disk between the individual half-cells...
, consisting of a pair of metal
electrodeAn electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit...
s separated by electrolyte, is the difference between their two electrode potentials. That is, if the electrodes have emfs , then the net emf is . (Thus, two identical electrodes and a common electrolyte give zero net emf.) This may be called Volta's Law of the electrochemical series.
In 1800, as the result of a professional disagreement over the galvanic response advocated by Galvani, he invented the
voltaic pileA voltaic pile is a set of individual Galvanic cells placed in series. The voltaic pile, invented by Alessandro Volta in 1800, was the first electric battery...
, an early
electric batteryAn electrical battery is a combination of one or more electrochemical cells, used to convert stored chemical energy into electrical energy. Since the invention of the first Voltaic pile in 1800 by Alessandro Volta, the battery has become a common power source for many household and industrial...
, which produced a steady electric current. Volta had determined that the most effective pair of dissimilar metals to produce electricity was
zincZinc , also known as spelter, is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
and
silverSilver is a chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
. Initially he experimented with individual cells in series, each cell being a wine goblet filled with
brineBrine is water saturated or nearly saturated with a salt .It is used to preserve vegetables, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses.Brine is a common fluid used in large refrigeration installations for the transport of heat from...
into which the two dissimilar electrodes were dipped. The electric pile replaced the goblets with cardboard soaked in brine. (The number of cells, and thus the voltage it could produce, was limited by the pressure, exerted by the upper cells, that would squeeze all of the brine out of the cardboard of the bottom cell.)
First Battery
In announcing his discovery of the pile, Volta paid tribute to the influences of
William NicholsonWilliam Nicholson was a renowned English chemist and writer on "natural philosophy" and chemistry, as well as a translator, journalist, publisher, scientist, and inventor....
,
Tiberius CavalloTiberius Cavallo was an Italian physicist and natural philosopher.-Life:He was born at Naples, where his father was a physician....
and
Abraham BennetAbraham Bennet FRS was an English clergyman and physicist, the inventor of the gold-leaf electroscope and developer of an improved magnetometer...
.
An additional invention pioneered by Volta, was the remotely operated pistol. He made use of a
Leyden jarThe Leyden jar, or Leiden jar, is a device that "stores" static electricity between two electrodes on the inside and outside of a jar. It was invented independently by Ewald Georg von Kleist in 11 October 1744 and by Pieter van Musschenbroek in 1745—1746. The latter place of invention, Leiden,...
to send an electric current from
ComoComo is a city in Lombardy, Italy, north of Milan. Situated at the southern tip of the south-west arm of Lake Como, it is the capital of the province of Como and directly borders the comunes of Blevio, Brunate, Capiago Intimiano, Casnate con Bernate, Cavallasca, Cernobbio, Grandate, Lipomo,...
to
MilanMilan in Italy, is the capital of the region of Lombardia and of the province of Milan. The city proper has a population of about 1.3 million, while the urban area is the fifth largest in the E.U. with an estimated population of 4.3 million...
(~50 km or ~30 miles), which in turn, set off the pistol. The current was sent along a wire that was insulated from the ground by wooden boards. This invention was a significant forerunner of the idea of the telegraph which also makes use of a current to communicate.
The battery made by Volta is credited as the first electrochemical cell. It consists of two electrodes: one made of
zincZinc , also known as spelter, is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, the other of
copperCopper is a chemical element with the symbol Cu and atomic number 29.It is a ductile metal with very high thermal and electrical conductivity. Pure copper is rather soft and malleable and a freshly-exposed surface has a pinkish or peachy color...
. The
electrolyteIn chemistry, an electrolyte is any substance containing free ions that behaves as an electrically conductive medium, usually when in a solution...
is sulphuric acid or a brine mixture of salt and water. The electrolyte exists in the form 2H
+ and SO
42-. The zinc, which is higher than both copper and hydrogen in the electrochemical series, reacts with the negatively charged sulphate. ( SO
42- ) The positively charged hydrogen bubbles start depositing around the copper and take away some of its
electronAn electron is a subatomic particle that carries a negative electric charge. It has no known substructure and is believed to be a point particle. An electron has a mass that is approximately 1836 times less than that of the proton. The intrinsic angular momentum of the electron is a half integer...
s. This makes the zinc rod the negative electrode and the copper rod the positive electrode.
We now have two terminals, and the current will flow if we connect them. The reactions in this cell are as follows:
- zinc
- Zn → Zn2+ + 2e-
- sulfuric acid
- 2H+ + 2e- → H2
The copper does not react, functioning as an electrode for the reaction.
However, this cell also has some disadvantages. It is unsafe to handle, as sulfuric acid, even if dilute, is dangerous. Also, the power of the cell diminishes over time because the hydrogen gas is not released, accumulating instead on the surface of the electrode and forming a barrier between the metal and the electrolyte solution.
The primitive cell is widely used in schools to demonstrate the laws of electricity and is known as the
Lemon batteryA lemon battery is a device used in experiments proposed in many science textbooks around the world. It is made by inserting two different metallic objects, for example a galvanized nail and a copper coin, into a lemon. The copper coin serves as the positive electrode or cathode and the galvanized...
.
Last years and retirement
In honor of his work, Volta was made a count by Napoleon in 1810.
Volta retired in 1819 in his estate in Camnago, a
frazioneA frazione , in Italy, is the name given in administrative law to a type of territorial subdivision of a comune; for other administrative divisions, see municipio, circoscrizione, quartiere...
of
ComoComo is a city in Lombardy, Italy, north of Milan. Situated at the southern tip of the south-west arm of Lake Como, it is the capital of the province of Como and directly borders the comunes of Blevio, Brunate, Capiago Intimiano, Casnate con Bernate, Cavallasca, Cernobbio, Grandate, Lipomo,...
now called Camnago Volta after him, where he died on March 5, 1827. He is buried in Camnago Volta.
Volta's legacy is celebrated by a Temple on the shore of Lake Como in the centre of the town. A museum in Como, the Voltian Temple, has been built in his honor and exhibits some of the original equipment he used to conduct experiments. Near
Lake ComoLake Como is a lake of glacial origin in Lombardy, Italy. It has an area of 146 km², making it the third largest lake in Italy, after Lake Garda and Lake Maggiore...
stands the
Villa OlmoVilla Olmo is a neoclassic villa located in the city of Como, Italy.-History:The construction began in 1797 and was commissioned by marquis Innocenzo Odescalchi to the swiss architect Simone Cantoni....
, which houses the Voltian Foundation, an organization which promotes scientific activities. Volta carried out his experimental studies and made his first inventions in Como.
See also
- Volta Prize
The Volta Prize was established by Napoleon Bonaparte in 1803 to honor Alessandro Volta, an Italian physicist noted for developing the battery. In 1801, Alessandro Volta was summoned to Paris to demonstrate his great discovery before the French Academy of Sciences. Bonaparte declared his...
- Luigi Galvani
Luigi Galvani was an Italian physician and physicist who lived and died in Bologna. In 1771, he discovered that the muscles of dead frogs twitched when struck by a spark.ref> – Eric Weisstein’s World of Scientific Biolgraph. This was one of the first forays into the study of...
- Eudiometer
A eudiometer is a laboratory device that measures the change in volume of a gas mixture following a physical or chemical change.- Description :...
- History of the battery
The history of the development of electrochemical cells is crucial to the scientific study and industrial applications of electricity, for prior to the rise of electrical grids around the end of the 19th century, they were the main source of electricity...
- Volta (lunar crater)
Volta is a lunar crater near the northwest limb of the Moon. It is located south-southeast of the crater Xenophanes, and due north of the smaller Galvani. The crater Regnault lies across the western rim of Volta. Attached to the southwest rim of Volta and the southern rim of Regnault is Stokes...
- History of the internal combustion engine
Although various forms of internal combustion engines were developed before the 19th century, application was hindered until the commercial drilling and production of petroleum began in the mid-1850s...
- Lemon battery
A lemon battery is a device used in experiments proposed in many science textbooks around the world. It is made by inserting two different metallic objects, for example a galvanized nail and a copper coin, into a lemon. The copper coin serves as the positive electrode or cathode and the galvanized...
External links