Louis Jacques Thénard (4 May 177721 June 1857) was a French

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 ...

Life

He was born in a farm cottage near Nogent-sur-Seine in the Champagne district the son of a farm worker. In the post-Revolution French educational system, most boys received scholarships for education up to age 14, and this allowed him to be educated at the academy at

Sens Sens () is a Communes of France, commune in the Yonne Departments of France, department in Bourgogne-Franche-Comté in north-central France, 120 km southeast from Paris. Sens is a Subprefectures in France, sub-prefecture and the second la ...

. He then went at the age of sixteen to study

pharmacy Pharmacy is the science and practice of discovering, producing, preparing, dispensing, reviewing and monitoring medications, aiming to ensure the safe, effective, and affordable use of medication, medicines. It is a miscellaneous science as it ...

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 ...

. There he attended the lectures of Antoine François Fourcroy and

Louis Nicolas Vauquelin Louis Nicolas Vauquelin FRS(For) HFRSE (; 16 May 1763 – 14 November 1829) was a French pharmacist and chemist. He was the discoverer of chromium and beryllium. Early life Vauquelin was born at Saint-André-d'Hébertot in Normandy, France, th ...

. He was allowed into Vauquelin's laboratory even though he was unable to pay the monthly fee of 20 francs, due to the requests of Vauquelin's sisters. But his progress was so rapid that in two or three years he was able to take his master's place at the lecture-table, and Fourcroy and Vauquelin were so satisfied with his performance that they procured for him a school appointment in 1797 as a teacher of chemistry, and in 1798 one as at the

École Polytechnique (, ; also known as Polytechnique or l'X ) is a ''grande école'' located in Palaiseau, France. It specializes in science and engineering and is a founding member of the Polytechnic Institute of Paris. The school was founded in 1794 by mat ...

Career

In 1804 Vauquelin resigned his professorship at the

Collège de France The (), formerly known as the or as the ''Collège impérial'' founded in 1530 by François I, is a higher education and research establishment () in France. It is located in Paris near La Sorbonne. The has been considered to be France's most ...

and successfully used his influence to obtain the appointment for Thénard, who six years later, after Fourcroy's death, was further elected to the chairs of chemistry at the

and the Faculté des Sciences. He also succeeded Fourcroy as member of the academy. In 1821, he was elected a foreign member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences () is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for promoting nat ...

. In 1825 he received the title of baron from

Charles X Charles X may refer to: * Charles X of France (1757–1836) * Charles X Gustav (1622–1660), King of Sweden * Charles, Cardinal de Bourbon (1523–1590), recognized as Charles X of France but renounced the royal title See also * * King Charle ...

, and in 1832 Louis Philippe made him a peer of France. From 1827 to 1830 he represented the ''

département In the administrative divisions of France, the department (, ) is one of the three levels of government under the national level (" territorial collectivities"), between the administrative regions and the communes. There are a total of 101 ...

'' of

Yonne Yonne (, in Burgundian: ''Ghienne'') is a department in the Bourgogne-Franche-Comté region in France. It is named after the river Yonne, which flows through it, in the country's north-central part. One of Bourgogne-Franche-Comté's eight con ...

in the chamber of deputies, and as vice-president of the , he exercised a great influence on scientific education in France. He died in Paris on 21 June 1857. A statue was erected to his memory at Sens in 1861, and in 1865 the name of his native village was changed to La Louptière-Thénard. Above all things Thénard was a teacher; as he himself said, the professor, the assistants, the laboratory — everything must be sacrificed to the students. Like most great teachers he published a textbook, and his (4 vols., Paris, 1813–16), which served as a standard for a quarter of a century, perhaps did even more for the advance of chemistry than his numerous original discoveries.

Research

Soon after his appointment as at the École Polytechnique he began a lifelong friendship with

Joseph Louis Gay-Lussac Joseph Louis Gay-Lussac ( , ; ; 6 December 1778 – 9 May 1850) was a French chemist and physicist. He is known mostly for his discovery that water is made of two parts hydrogen and one part oxygen by volume (with Alexander von Humboldt), f ...

, and the two carried out many research projects together. For their research, Gay-Lussac and Thénard would receive 30,000 francs from

Napoleon Napoleon Bonaparte (born Napoleone di Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French general and statesman who rose to prominence during the French Revolution and led Military career ...

in the third and last installment of the Galvanism Prize. Careful analysis led him to dispute some of

Claude Louis Berthollet Claude Louis Berthollet (, 9 December 1748 – 6 November 1822) was a Savoyard-French chemist who became vice president of the French Senate in 1804. He is known for his scientific contributions to the theory of chemical equilibria via the ...

's theoretical views regarding the composition of the metallic

oxide An oxide () is a chemical compound containing at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion (anion bearing a net charge of −2) of oxygen, an O2− ion with oxygen in the oxidation st ...

s, and he also showed Berthollet's "zoonic acid" to be impure

acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main compone ...

(1802). In response, Berthollet invited him to become a member of the

Society of Arcueil The Society of Arcueil was a circle of French scientists who met regularly on summer weekends between 1806 and 1822 at the country houses of Claude Louis Berthollet and Pierre Simon Laplace at Arcueil, then a village 3 miles south of Paris. Members ...

. In 1806 he analysed the chemical composition of the Alais meteorite, which fell in

Alès Alès () is a Communes of France, commune and Subprefectures in France, subprefecture in the Gard Departments of France, department in the Occitania (administrative region), Occitania Regions of France, region in Southern France. Until 1926, i ...

on 15 March 1806. This was the first

carbonaceous chondrite Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 8 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites. The C chondrites represent only a small propo ...

to be discovered. Thénard found a high carbon content of 2.5 per cent. His first original paper (1799) was on the compounds of

arsenic Arsenic is a chemical element; it has Symbol (chemistry), symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is not ...

and

antimony Antimony is a chemical element; it has chemical symbol, symbol Sb () and atomic number 51. A lustrous grey metal or metalloid, it is found in nature mainly as the sulfide mineral stibnite (). Antimony compounds have been known since ancient t ...

with

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

and

sulphur Sulfur (American spelling and the preferred IUPAC name) or sulphur (English in the Commonwealth of Nations, Commonwealth spelling) is a chemical element; it has Symbol (chemistry), symbol S and atomic number 16. It is abundance of the chemical ...

. In 1807, he began important research into

ether In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl). They have the general formula , where R and R� ...

s. His researches on

sebacic acid Sebacic acid is a naturally occurring dicarboxylic acid with the chemical formula . It is a white flake or powdered solid. ''Sebaceus'' is Latin for tallow candle, ''sebum'' is Latin for tallow, and refers to its use in the manufacture of candles. ...

(1802) and on

bile Bile (from Latin ''bilis''), also known as gall, is a yellow-green/misty green fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is primarily composed of water, is pro ...

(1807) deserve mention as well, as does his discovery of

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usua ...

(1818).L. J. Thénard (1818
"Observations sur des nouvelles combinaisons entre l’oxigène et divers acides,"
''Annales de chimie et de physique'', 2nd series, vol. 8, pages 306-312; see especially page 308. In 1799 he developed the pigment known as Thénard's blue in response to a request by Jean-Antoine-Claude Chaptal for a cheap colouring matter. His name is one of the 72 names inscribed on the Eiffel Tower.

Works

* ** **

References

Attribution: * {{DEFAULTSORT:Thenard, Louis Jacques 1777 births 1857 deaths 18th-century French chemists French Roman Catholics Members of the French Academy of Sciences Members of the Royal Swedish Academy of Sciences Foreign members of the Royal Society 19th-century French chemists