Claude Louis Berthollet
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Claude Louis Berthollet (9 December 1748 Talloires, France – 6 November 1822 Arcueil,France) was a Savoyard-French chemist who became vice president of the French Senate in 1804. He is known for his scientific contributions to theory of chemical equilibria via the mechanism of reverse chemical reactions, and for his contribution to modern chemical nomenclature. On a practical basis, Berthollet was the first to demonstrate the bleaching action of chlorine gas, and was first to develop a solution of sodium hypochlorite as a modern bleaching agent.
He started his studies at Chambery and then in Turin where he graduated in medicine. Berthollet great development in works regarding chemistry made him, in a short period of time, an active participant of the Academy of Science in 1780.
Berthollet, along with Antoine Lavoisier and others, devised a chemical nomenclature, or a system of names, which serves as the basis of the modern system of naming chemical compounds.
He also carried out research into dyes and bleaches, being first to introduce the use of chlorine gas as a commercial bleach in 1785. He first produced a modern bleaching liquid in 1789 in his laboratory on the quay Javel in Paris, France, by passing chlorine gas through a solution of sodium carbonate. The resulting liquid, known as "Eau de Javel" ("Javel water"), was a weak solution of sodium hypochlorite. Another strong chlorine oxidant and bleach which he investigated and was the first to produce, potassium chlorate (KClO3), is known as Berthollet's Salt.
Bertholett first determined the elemental composition of the gas ammonia, in 1785.
Berthollet was one of the first chemists to recognize the characteristics of a reverse reaction, and hence, chemical equilibrium.
Berthollet was engaged in a long-term battle with another French chemist Joseph Proust on the validity of the law of definite proportions. While Proust believed that chemical compounds are composed of a fixed ratio of their constituent elements irrespective of the methods of production, Berthollet believed that this ratio can change according to the ratio of the reactants initially taken. Although Proust proved his theory by accurate measurements, his theory was not immediately accepted partially due to Berthollet's authority. His law was finally accepted when Berzelius confirmed it in 1811. But it was found later that Berthollet was not completely wrong because there exists a class of compounds that do not obey the law of definite proportions. These non-stoichiometric compounds are also named berthollides in his honor.
In April, 1789 he was elected a Fellow of the Royal Society of London. In 1801, he was elected a foreign member of the Royal Swedish Academy of Sciences. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1822.
He died in Arcueil, France in 1822.
- Po-chia Hsia, R.; Lynn Hunt, Thomas R. Martin, Barbara H. Rosenwein and Bonnie G. Smith (2007). The Making of the West, Peoples and Culture, A Concise History, Volume II: Since 1340 (2nd ed.). New York: Bedford/St. Martin’s. p. 685.
- http://www.nndb.com/people/888/000100588/ NNDB. Retrieved 1 December 2012.
- "Library and Archive Catalogue". Royal Society. Retrieved 13 December 2010.
- "Book of Members, 1780–2010: Chapter B". American Academy of Arts and Sciences. Retrieved 24 June 2011.
Further reading 
- Satish, Kapoor (1970–80). "Berthollet, Claude Louis". Dictionary of Scientific Biography 2. New York: Charles Scribner's Sons. pp. 73–82. ISBN 0684101149.
- N. S. Kurnakow (1925). "Singuläre Punkte chemischer Diagramme. (Dem Andenken CLAUDE-LOUIS BERTHOLLET, 1748-1822". Zeitschrift für anorganische und allgemeine Chemie 146 (1): 69–102. doi:10.1002/zaac.19251460105.
- Barbara Whitney Keyser (1990). "Between science and craft: The case of berthollet and dyeing". Zeitschrift für anorganische und allgemeine Chemie 47 (3): 213–260. doi:10.1080/00033799000200211.
- Charles Coulston Gillispie (1989). "Scientific Aspects of the French Egyptian Expedition 1798-1801". Proceedings of the American Philosophical Society 133 (4): 447–474. JSTOR 986871.
- H. E. Le Grand (1976). "Berthollet's Essai de statique chimique and Acidity". Isis 67 (2): 229–238. doi:10.1086/351586. JSTOR 230924.
- Swain P. A. (2000). "Hypochlorite bleaches in the textile industry : a history". School science review 82 (299): 65–71.
See also