Claude Auguste Lamy (; 15 June 1820 – 20 March 1878) was a French

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

and

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...

chemist who discovered the element

thallium Thallium is a chemical element; it has Symbol (chemistry), symbol Tl and atomic number 81. It is a silvery-white post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Che ...

independently from

William Crookes Sir William Crookes (; 17 June 1832 – 4 April 1919) was an English chemist and physicist who attended the Royal College of Chemistry, now part of Imperial College London, and worked on spectroscopy. He was a pioneer of vacuum tubes, inventing ...

in 1862; as a result, they are considered co-discoverers, although they did not collaborate.

Early life and education

Lamy was born in the commune of Ney in the department of Jura,

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

in 1820. Lamy's father-in-law was Frédéric Kuhlmann. After secondary school in Poligny, Dole and finally

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

, Auguste Lamy entered the

École Normale Supérieure École or Ecole may refer to: * an elementary school in the French educational stages normally followed by Secondary education in France, secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing i ...

and was a fellow student of

Louis Pasteur Louis Pasteur (, ; 27 December 1822 – 28 September 1895) was a French chemist, pharmacist, and microbiologist renowned for his discoveries of the principles of vaccination, Fermentation, microbial fermentation, and pasteurization, the la ...

; he graduated in 1842. He became a teacher at and again in Lille. In 1845, he was awarded the agrégation in physics and the licencié in natural sciences.

Working life

From 1848 to 1850, he began his career as a physics teacher at a college in

Lille Lille (, ; ; ; ; ) is a city in the northern part of France, within French Flanders. Positioned along the Deûle river, near France's border with Belgium, it is the capital of the Hauts-de-France Regions of France, region, the Prefectures in F ...

(following

there), then at

Limoges Limoges ( , , ; , locally ) is a city and Communes of France, commune, and the prefecture of the Haute-Vienne Departments of France, department in west-central France. It was the administrative capital of the former Limousin region. Situated o ...

, then at the Écoles académiques de Lille from 1852. He defended his doctoral thesis in Paris in 1851. He taught about thermodynamics, industrial physics and hydraulic presses, distillation and explosions. In 1854 he became a professor at the faculty of sciences of Lille ( Université Lille Nord de France). He taught at École des arts industriels et des mines ( École centrale de Lille). In 1866 he changed to the École Centrale des Arts et Manufactures (École centrale de Paris).was awarded the chair of physics at the faculté des sciences de Lille in 1854. He also taught at the École des arts industriels et des mines in Lille ( École centrale de Lille) for 11 years before moving to

, where in 1865 he was awarded the Chair of Industrial Chemistry at the École centrale des arts et manufactures, as successor to Anselme Payen. A member of the Société des sciences, de l'agriculture et des arts de Lille, he became president of the Société française de chimie in 1873.

Discovery of thallium

upright=1.5, New chemical element thallium isolated and identified spectrometrically in 1861-1862 in Lille by Lamy In 1862, in Lille, Claude Auguste Lamy identifies and isolates 14 grams of the element

using the spectroscope loaned by his brother-in-law, the chemist Jules Frédéric Kuhlmann. In 1861, however, this

chemical element A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its ...

had been previously described by

who was studying by

spectroscopy Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Spectro ...

the light emitted by a heated

selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...

ore.

Later life

He was a member of the board of directors of établissements Kuhlmann from 1870 to 1878, founded by his father-in-law. Lamy died in 1878.

References

1820 births 1878 deaths 19th-century French physicists 19th-century French chemists Academic staff of the Lille University of Science and Technology Discoverers of chemical elements Thallium {{france-chemist-stub