G. Thomson
Encyclopedia
G. Thomson was an English geologist
Geologist
A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes and history that has shaped it. Geologists usually engage in studying geology. Geologists, studying more of an applied science than a theoretical one, must approach Geology using...

. He died in Palermo
Palermo
Palermo is a city in Southern Italy, the capital of both the autonomous region of Sicily and the Province of Palermo. The city is noted for its history, culture, architecture and gastronomy, playing an important role throughout much of its existence; it is over 2,700 years old...

 at the early age of 46 years.

Name

His name is indicated only with G. because the full name is unknown. In several secondary sources he is called William Thomson or William Thompson, and sometimes is even confused with Lord Kelvin (1824-1907)
William Thomson, 1st Baron Kelvin
William Thomson, 1st Baron Kelvin OM, GCVO, PC, PRS, PRSE, was a mathematical physicist and engineer. At the University of Glasgow he did important work in the mathematical analysis of electricity and formulation of the first and second laws of thermodynamics, and did much to unify the emerging...

. However in his own work published on Atti dell'Accademia Delle Scienze di Siena and on the article of Paneth he is indicated as G. Thomson. On some other sources is also called W. G. Thomson.

Discovery of Widmanstätten pattern

Thomson at the time was living in 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...

. One day he decided to treat with nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...

 a Krasnojarsk
Krasnojarsk (meteorite)
-History:A mass of about 700 kg was detected in 1749 about 145 miles south of Krasnoyarsk. It was seen by P.S. Pallas in 1772 and then on his orders transported to Saint Petersburg....

 meteorite
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...

 with the purpose of cleaning it from rust
Rust
Rust is a general term for a series of iron oxides. In colloquial usage, the term is applied to red oxides, formed by the reaction of iron and oxygen in the presence of water or air moisture...

. Shortly after the contact with acid he noticed on the surface of the metal a strange never seen before figures: it was the later-called Widmanstätten pattern
Widmanstätten pattern
Widmanstätten patterns, also called Thomson structures, are unique figures of long nickel-iron crystals, found in the octahedrite iron meteorites and some pallasites. They consist of a fine interleaving of kamacite and taenite bands or ribbons called lamellæ...

.

In 1804 he published his discovery in French on the Bibliothèque Britannique. In 1808 his work was published post-mortem also in Italian language (translated from the original English manuscript) on Atti dell'Accademia Delle Scienze di Siena.

The discovery is commonly credited to Count Alois von Beckh Widmanstätten
Count Alois von Beckh Widmanstätten
Count Alois von Beckh Widmanstätten was an Austrian printer and scientist. His name is sometimes given as Alois von Beckh-Widmannstätten or Aloys Beck, Edler von Widmannstätten.-Working life:...

 probably due the early death of Thomson and the lack of an English publication. The discovery of Widmanstätten was independent, but it dates 1808 and it lacks publication.
So the full credit of the discovery should be assigned to G. Thomson due chronological priority. For this reason, several authors suggested to call the pattern also Thomson structure.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK