Jean-Baptiste Dumas

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Jean-Baptiste Dumas

Jean-Baptiste André Dumas (born July 14, 1800 in Alais / Département Gard , † April 11, 1884 in Cannes ) was a French chemist . The name " chloroform " comes from him .

Life

Duma's father was an artistically gifted man, he was a secretary in the town of Alais (the old name of the town of Alès). In 1815 the young Jean-Baptiste Dumas, who had previously attended a local private preparatory school , where he received a humanistic education, became an apprentice in a pharmacy in Alais. In 1816 he got the offer to work in a larger pharmacy in Geneva . Lectures in botany, physics and chemistry were held in this pharmacy, and there was also a well-equipped laboratory. In Geneva he wrote his first book on pharmaceutical plants, and a little later a book on physiological chemistry . At the suggestion of Jean-Francois Coindet (1774–1834), Dumas had carried out studies from 1818 on iodine in charred sponges and as a possible remedy for goiter and proposed iodine tincture and potassium iodide as medicines. In the pharmacy's laboratory, he made various chemical devices from books. He shared the results of his research efforts with the Geneva university professor Charles-Gaspard de la Rive . Around this time he also worked with Prévost (see below).

When Dumas was 22 years old, the scholar Alexander von Humboldt visited him in Geneva. Humboldt encouraged him to seek proximity to the great natural scientists ( Claude-Louis Berthollet , Joseph Louis Gay-Lussac , Louis Jacques Thénard ) in Paris. In 1823 Dumas moved to Paris and was offered a position for evening lectures at the École polytechnique . Dumas, who worked in Paris with the younger physiologists and made the acquaintance of the leading experimental physicians of the time, first became a repetitionist in chemistry at the École polytechnique in 1823 , then professor at the Athénée ( Athenaeum ), where he received the chair of chemistry, at the von he co-founded École centrale des arts et manufactures in 1829 and finally, at the age of 28, successor to Gay-Lussac at the Sorbonne . In 1824 Dumas also appeared as a co-founder of the journal the Annales des Sciences Naturelles . He was also co-editor of the Annales de Chimie et de Physique .

In 1826 he married Hermine Brongniart (1803-1890), the older daughter of the French chemist, geologist and naturalist Alexandre Brongniart (1770-1847).

In 1840 he became a teacher at the École de Médicine de Paris , where he received the chair of chemistry. Since that time he delivered a long series of chemical works, most of which were of significant influence on the formation of chemical views.

During the July Monarchy , Dumas was a member of the Public Education Council and from 1849 to 1851 Minister of Agriculture and Trade. After the February Revolution in 1848 he joined the Commission consultative and then became a senator and member of the councilor for public education and, in 1856, its vice-president. Since 1849 he was a member of the Göttingen Academy of Sciences , since 1858 a foreign member of the Bavarian Academy of Sciences , since 1875 a member of the Académie française and since 1872 of the Accademia dei Lincei . At the age of 32 he was a member of the Paris Academy, and honors and appointments from numerous other institutes around the world soon followed. After health problems had set in in 1883, Dumas died on April 11, 1884.

Grave of JB Dumas (Paris)

Scientific achievements

Avogadro and Ampère improved the volume law of Alexander von Humboldt and Gay-Lussac, that the same number of atoms are contained in a gas at the same pressure and the same temperature, and thus the atomic mass can be calculated from the gas density , by expanding the gas concept of molecules (Particles made up of compound atoms). Dumas was the first to point out that gas molecules with the same particles can split and so gases with dissimilar atoms can arise. Dumas developed a method for the exact determination of the density of gases in certain temperature ranges. With this method he was able to determine the exact atomic mass of the elements for inorganic chlorides of phosphorus , arsenic , boron , tin and silicon from the vapor densities.

In collaboration with Jean Servais Stas , Dumas determined the atomic mass of carbon to be 12. The very precise determination of the atomic mass of carbon was of great importance for organic elemental analysis. Exact determinations of the atomic masses of 30 other elements followed. The determination of the atomic mass according to Jöns Jakob Berzelius could be further refined. Dumas found that 22 atomic masses are integer multiples of the hydrogen atom. This work by Dumas paved the way for a very precise determination of atomic mass.

For organic elemental analysis, Dumas developed an improved method for determining the nitrogen of combustible molecules, the nitrogen determination according to Dumas, named after him . He also developed a method for the determination of gas densities or molar masses of vaporizable substances. This procedure, the molar mass determination according to Dumas , is named after him.

In organic chemistry, Dumas developed the substitution theory. Berzelius derived the reaction process from electrolysis and assumed electropositive and electronegative areas in every particle. In an organic compound - according to Berzelius' idea - carbon was the electronegative particle, hydrogen the electropositive particle. He imagined it was impossible that an electropositive particle like hydrogen could be displaced by an electronegative particle like chlorine. Dumas, however, demonstrated the substitution of hydrogen by chlorine in the action of chlorine on candle wax and also presented a theory of radical substitution (1830) for the conversion of ethanol with chlorine to chloral (a reaction that Justus Liebig , a colleague and competitor of Dumas in Paris, discovered). One hydrogen atom of each organic molecule could be replaced by a chlorine, bromine, iodine atom or by half an oxygen atom. The theory of substitution also contributed to the understanding of the molecular formula and structure of diethyl ether and the formation of ethers from potassium ethoxide and ethyl iodide ( Williamson's ether synthesis ).

On April 5, 1834, Dumas had published the correct empirical formula of chloroform , which was discovered independently by Liebig, Guthrie and Soubeiran in 1831 and to which Dumas had given its current name, and presented it to the Academy of Sciences in Paris on December 24, 1834.

From 1840 Dumas developed the type theory (chemistry) in conjunction with Charles Frédéric Gerhardt . Dumas found that by replacing a hydrogen atom with a chlorine atom, the properties of the organic compounds were retained. Acetic acid can be converted into trichloroacetic acid with chlorine ; like acetic acid, trichloroacetic acid is an acid. With this theory, organic structures could be better classified according to the elemental analysis. The type theory was a unitarian theory, it broke with the dualistic view of the molecules (radical theory) of Berzelius, according to which molecules consist of a positive and a negative segment. Every chemical compound forms a closed whole, i.e. does not consist of two parts .

Dumas identified propionic acid by elemental analysis and gave it the corresponding name; the acid was previously called metacetic acid. Dumas was able to predict that between formic acid and palmitic acid there would have to be 14 intermediate links (estimation based on physical properties: melting and boiling points). Dumas found in 1837 together with Peligot the methanol as a by-product of the wood distillation ( wood alcohol ) and could by the elemental analysis to determine oxidation to formic acid and molecular mass determination the identity. In addition to methanol, Dumas found two other alcohols ( amyl alcohol , cetyl alcohol ) and was able to use the boiling and melting points of these compounds to infer the number of other alcohols between these members. He is considered to be the founder of the homologous series.

He was able to represent nitriles by the action of phosphorus pentoxide on amides and ammonium salts of carboxylic acids.

Dumas discovered chlorocarbonic acid ester through the action of phosgene on an alcohol and, after reaction with ammonia, the carbamic acids , urethanes .

His main achievements concern the alkaloids , the ethyl and amide compounds , the discovery of methanol ( wood spirit ) and a homologous compound of ethanol (fusel oil), indigo , tartaric acid , the composition of fatty acids and the effects of alkalis on organic bodies. He developed a method to determine the nitrogen content in organic compounds (known today as the "Dumas method"), and thus laid the basis for modern analysis methods. His work on the determination of molar masses of liquids was just as important . Dumas was also very active in the field of physiological chemistry . For the theoretical chemistry his works are notably on the substitution was epoch-making.

With the physiologist, chemist and embryologist Jean Louis Prévost (1790-1850), with whom he worked on many scientific questions of a medical nature around 1820, he carried out a successful blood transfusion using non-coagulable blood in animals and described this with him in 1821. Dumas and Prévost demonstrated the presence of urea in the blood of animals whose kidneys had been removed and worked on fertility, particularly on the formation of eggs in mammals. They also recognized the fertilization process in frog eggs.

Others

Jean-Baptiste Dumas is immortalized by name on the Eiffel Tower, see: The 72 names on the Eiffel Tower .

Elected and ministerial functions
  • Deputy, Député (1849)
  • Senator, Senateur
  • Minister for Agriculture and Trade, Ministre de l'Agriculture et du Commerce (1850–1851)
More functions
  • Member of the Paris City Council, conseil municipal de Paris
  • Vice-President of the Paris City Council
  • Vice President of the Supreme Council and Public Education (1861–1863)
  • President of the High Commission against Phylloxera, C ommission Supérieure du Phylloxéra (1871–1885)

Fonts (selection)

  • Research relative à l'action du chlore sur l'alcool. In: L'Institut. Journal général des société et travaux scientifiques de la France et l'étranger. Volume 2, (April 5) 1834, pp. 106-108.
  • Investigation into the effect of chlorine on alcohol. In: Annals of Physics and Chemistry. New series, Volume 31, 1834, pp. 650-673.
  • Traité de chimie appliquée aux arts (Paris 1828–46, 8 volumes; German von Buchner, Nuremberg 1844–49, 8 volumes);
  • Leçons sur la philosophie chimique (Paris 1837; German by Carl Rammelsberg , Berlin 1839);
  • Thèse sur la question de l'action du calorique sur les corps organiques (Paris 1838);
  • Essai sur la statique chimique des êtres organisés (Paris 1841, 3rd edition 1844; German by Vieweg, Leipzig 1844).
  • The philosophy of chemistry: Lectures, go to the Collège de France / Jean-Baptiste Dumas. Collected by Amand Bieneau et al. in Dt. transfer by Carl Rammelsberg. - Berlin: Lüderitz, 1839. Digitized edition of the University and State Library Düsseldorf

literature

Web links

Individual evidence

  1. ^ Albert Faulconer, Thomas E. Keys: Jean Baptiste André Dumas. 1965, p. 459.
  2. ↑ Genealogy
  3. ↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 72.
  4. ^ Member entry by Jean-Baptiste Dumas (with a link to an obituary) at the Bavarian Academy of Sciences , accessed on January 29, 2017.
  5. ↑ Liebigs Annalen der Chemie, 38 , 141 (1841).
  6. ↑ Ann. d. chimie et de physique (3), 1 , 5 (1841).
  7. ^ Albert Faulconer, Thomas Edward Keys: Jean Baptiste André Dumas. 1965, p. 459.
  8. ^ Albert Faulconer, Thomas Edward Keys: Chloroform. In: Foundations of Anesthesiology. 2 volumes, Charles C Thomas, Springfield (Illinois) 1965, Volume 1, pp. 442-481, here: pp. 442 f. and 459-462.
  9. ↑ J. Dumas: About the law of substitution and the theory of types , Lieb. Ann., Vol. 33, Issue 3 (1840), pp. 259-300.
  10. ↑ J. Dumas: Ueber die Chem. Types , 35 , Issue 2 (1840), pp. 129-173.
  11. ↑ Short biography
  12. ↑ Barbara I. Tshisuaka: Prévost, Jean Louis. In: Werner E. Gerabek , Bernhard D. Haage, Gundolf Keil , Wolfgang Wegner (eds.): Enzyklopädie Medizingeschichte. De Gruyter, Berlin / New York 2005, ISBN 3-11-015714-4 , p. 1182.
  13. ↑ JL Prévost, J.-B. Dumas: Examen du sang et de son action dans les divers phénomènes de la vie. In: Ann. Chim. Volume 18, (Paris) 1821, pp. 280-297.
  14. ^ Albert Faulconer, Thomas Edward Keys: Jean Baptiste André Dumas. 1965, p. 459.
  15. ↑ List of members since 1666: Letter D. Académie des sciences, accessed on October 23, 2019 .
  16. ^ Foreign members of the Russian Academy of Sciences since 1724: Dumas, Jean-Baptiste André. Russian Academy of Sciences, accessed October 23, 2019 (Russian).
  17. ^ Science, Vine and Wine in Modern France Par Harry W. Paul, p. 40.
personal data
SURNAME Dumas, Jean-Baptiste
ALTERNATIVE NAMES Dumas, Jean-Baptiste André
BRIEF DESCRIPTION French chemist
DATE OF BIRTH July 14, 1800
PLACE OF BIRTH Alès
DATE OF DEATH April 11, 1884
Place of death Cannes