Macedonio Melloni
Encyclopedia
Macedonio Melloni was an Italian
physicist
, notable for demonstrating that radiant heat has similar physical properties to those of light
.
, in 1824 he was appointed professor at the local University
but was compelled to escape to France
after taking part in the revolution of 1831. In 1839 he went to Naples
and was soon appointed director of the Vesuvius Observatory
, a post that he held until 1848. In 1845, he was elected a foreign member of the Royal Swedish Academy of Sciences
.
He died at Portici
, near Naples, of cholera
, aged 56.
. In 1831, soon after the discovery of thermoelectricity by Thomas Johann Seebeck
, he and Leopoldo Nobili
employed the instrument in experiments especially concerned with characteristics of (in modern language) black body radiation transmitted by various materials.
He used an optical bench fitted with thermopiles, shields and light and heat sources, such as Locatelli's lamp and Leslie's cube, in order to show that radiant heat could be reflected
, refracted
and polarised in the same way as light.
His most important book, La thermocrose au la coloration calorifique (Vol. I., Naples, 1850), was unfinished at his death.
He also studied the magnetism
of rock
s, electrostatic induction
and photography
.
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
, notable for demonstrating that radiant heat has similar physical properties to those of light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
.
Life
Born at ParmaParma
Parma is a city in the Italian region of Emilia-Romagna famous for its ham, its cheese, its architecture and the fine countryside around it. This is the home of the University of Parma, one of the oldest universities in the world....
, in 1824 he was appointed professor at the local University
University of Parma
The University of Parma is one of the oldest universities in the world, founded in the 11th century. It is organised in twelve faculties. The University of Parma has currently about 30,000 students.-History:...
but was compelled to escape to France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
after taking part in the revolution of 1831. In 1839 he went to Naples
Naples
Naples is a city in Southern Italy, situated on the country's west coast by the Gulf of Naples. Lying between two notable volcanic regions, Mount Vesuvius and the Phlegraean Fields, it is the capital of the region of Campania and of the province of Naples...
and was soon appointed director of the Vesuvius Observatory
Vesuvius Observatory
The Vesuvius Observatory is the surveillance centre for monitoring the three volcanoes which threaten the Campanian region of Italy: Mount Vesuvius, Campi Flegrei and Ischia. Founded in 1841 on the slopes of Mount Vesuvius , it is the oldest volcanology institute in the world....
, a post that he held until 1848. In 1845, he was elected a foreign member of the Royal Swedish Academy of Sciences
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. The Academy is an independent, non-governmental scientific organization which acts to promote the sciences, primarily the natural sciences and mathematics.The Academy was founded on 2...
.
He died at Portici
Portici
Portici is a town and comune of the Province of Naples in the Campania region of southern Italy. It is the site of the Portici Royal Palace.-Geography:...
, near Naples, of cholera
Cholera
Cholera is an infection of the small intestine that is caused by the bacterium Vibrio cholerae. The main symptoms are profuse watery diarrhea and vomiting. Transmission occurs primarily by drinking or eating water or food that has been contaminated by the diarrhea of an infected person or the feces...
, aged 56.
Work
Melloni's reputation as a physicist rests principally on his discoveries in radiant heat, made with the aid of the thermomultiplier, a combination of thermopile and galvanometerGalvanometer
A galvanometer is a type of ammeter: an instrument for detecting and measuring electric current. It is an analog electromechanical transducer that produces a rotary deflection of some type of pointer in response to electric current flowing through its coil in a magnetic field. .Galvanometers were...
. In 1831, soon after the discovery of thermoelectricity by Thomas Johann Seebeck
Thomas Johann Seebeck
Thomas Johann Seebeck was a physicist who in 1821 discovered the thermoelectric effect.Seebeck was born in Reval to a wealthy Baltic German merchant family. He received a medical degree in 1802 from the University of Göttingen, but preferred to study physics...
, he and Leopoldo Nobili
Leopoldo Nobili
Leopoldo Nobili, born in 1784 in Trassilico and died 5 August 1835 in Florence, was an Italian physicist who invented a number of instruments critical to investigating thermodynamics and electrochemistry....
employed the instrument in experiments especially concerned with characteristics of (in modern language) black body radiation transmitted by various materials.
He used an optical bench fitted with thermopiles, shields and light and heat sources, such as Locatelli's lamp and Leslie's cube, in order to show that radiant heat could be reflected
Reflection (physics)
Reflection is the change in direction of a wavefront at an interface between two differentmedia so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves...
, refracted
Refraction
Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
and polarised in the same way as light.
His most important book, La thermocrose au la coloration calorifique (Vol. I., Naples, 1850), was unfinished at his death.
He also studied the magnetism
Magnetism
Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...
of rock
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
s, electrostatic induction
Electrostatic induction
Electrostatic induction is a redistribution of electrical charge in an object, caused by the influence of nearby charges. Induction was discovered by British scientist John Canton in 1753 and Swedish professor Johan Carl Wilcke in 1762. Electrostatic generators, such as the Wimshurst machine, the...
and photography
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
.
Honours
- Rumford MedalRumford MedalThe Rumford Medal is awarded by the Royal Society every alternating year for "an outstandingly important recent discovery in the field of thermal or optical properties of matter made by a scientist working in Europe". First awarded in 1800, it was created after a 1796 donation of $5000 by the...
of the Royal SocietyRoyal SocietyThe Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...
, (1834); - Correspondent of the Académie des Sciences, (1835);
- Foreign member of the Royal Society, (1839).