Jean Baptiste André Dumas (; 14 July 180010 April 1884) 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 ...
, best known for his works on organic analysis and synthesis, as well as the determination of
atomic weights (relative atomic masses) and
molecular weights by measuring
vapor
In physics, a vapor (American English) or vapour (Commonwealth English; American and British English spelling differences#-our, -or, see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,R ...
densities. He also developed a method for the analysis of
nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...
in compounds.
Biography
Dumas was born 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 ...
(
Gard
Gard () is a department in Southern France, located in the region of Occitanie. It had a population of 748,437 as of 2019;[apothecary
''Apothecary'' () is an Early Modern English, archaic English term for a medicine, medical professional who formulates and dispenses ''materia medica'' (medicine) to physicians, surgeons and patients. The modern terms ''pharmacist'' and, in Brit ...]
in his native town.
In 1816, he moved to
Geneva
Geneva ( , ; ) ; ; . is the List of cities in Switzerland, second-most populous city in Switzerland and the most populous in French-speaking Romandy. Situated in the southwest of the country, where the Rhône exits Lake Geneva, it is the ca ...
, where he attended lectures by
M. A. Pictet in
physics
Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...
,
C. G. de la Rive in
chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...
, and
A. P. de Candolle in
botany
Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...
, and before he had reached his majority, he was engaged with
Pierre Prévost in original work on problems of
physiological chemistry and
embryology
Embryology (from Ancient Greek, Greek ἔμβρυον, ''embryon'', "the unborn, embryo"; and -λογία, ''-logy, -logia'') is the branch of animal biology that studies the Prenatal development (biology), prenatal development of gametes (sex ...
.
In 1822, he moved to Paris, acting on the advice of
Alexander von Humboldt
Friedrich Wilhelm Heinrich Alexander von Humboldt (14 September 1769 – 6 May 1859) was a German polymath, geographer, natural history, naturalist, List of explorers, explorer, and proponent of Romanticism, Romantic philosophy and Romanticism ...
, where he became professor of chemistry, initially at the
Lyceum, later (1835) 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 ...
. He was one of the founders of the École centrale des arts et manufactures (later named
École centrale Paris
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 ...
) in 1829.
In 1832 Dumas became a member of the
French Academy of Sciences
The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...
. From 1868 until his death in 1884 he would serve the academy as the permanent secretary for its department of Physical Sciences. In 1838, Dumas 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 ...
. The same year he became correspondent of the Royal Institute of the Netherlands and, when that became the
Royal Netherlands Academy of Arts and Sciences in 1851, he joined as a foreign member. Dumas was president of
Société d'encouragement pour l'industrie nationale from 1845 to 1864. He was elected to the
American Philosophical Society
The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...
in 1860.
After 1848, he exchanged much of his scientific work for ministerial posts under
Napoléon III
Napoleon III (Charles-Louis Napoléon Bonaparte; 20 April 18089 January 1873) was President of France from 1848 to 1852 and then Emperor of the French from 1852 until his deposition in 1870. He was the first president, second emperor, and last ...
. He became a member of the National Legislative Assembly. He acted as minister of agriculture and commerce for a few months in 1850–1851, and subsequently became a senator, president of the municipal council of Paris, and master of the French mint, but his official career came to a sudden end with the fall of the
Second Empire.

Dumas was a devout Catholic who would often defend Christian views against critics.
Dumas died at
Cannes
Cannes (, ; , ; ) is a city located on the French Riviera. It is a communes of France, commune located in the Alpes-Maritimes departments of France, department, and host city of the annual Cannes Film Festival, Midem, and Cannes Lions Internatio ...
in 1884, and is buried at the
Montparnasse Cemetery in Paris, in a large tomb near the back wall. His is one of the
72 names inscribed on the Eiffel tower.
Scientific work
Dumas was one of the first to criticise the electro-chemical doctrines of
Jöns Jakob Berzelius, which, at the time his work began, were widely accepted as the true theory of the constitution of compound bodies, and opposed a unitary view to the dualistic conception of the Swedish chemist. In a paper on the atomic theory, published in 1826, he anticipated to a remarkable extent some ideas which are frequently supposed to belong to a later period; and the continuation of these studies led him to the ideas about substitution (metalepsis) which were developed about 1839 into the theory (Older Style Theory) that in
organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...
there are certain types which remain unchanged even when their
hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
is replaced by an equivalent quantity of a
halide element. The classification of organic compounds into homologous series was advanced as one consequence of his researches into the acids generated by the
oxidation
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...
of the alcohols.
Dumas also showed that
kidney
In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...
s remove
urea
Urea, also called carbamide (because it is a diamide of carbonic acid), is an organic compound with chemical formula . This amide has two Amine, amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest am ...
from the blood.
Vapour densities and atomic masses
Dumas perfected the
method of measuring vapor densities which was also important in determining atomic weights (see below). A known amount of the substance being analyzed was put into a previously weighed glass bulb, which was then sealed and heated in water to vaporize the substance. The pressure was recorded with a
barometer
A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis ...
, and the bulb is allowed to cool to determine the mass of the vapor. The universal gas law was then used to determine the moles of gas within the bulb.
In an 1826 paper, he described his method for ascertaining vapour densities, and the redeterminations which he undertook by its aid of the
atomic weights of
carbon
Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...
and
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 ...
proved the forerunners of a long series which included some thirty of the elements, the results being mostly published in 1858–1860.
He showed "in all elastic fluids observed under the same conditions, the molecules are placed at equal distances".
He also determined the atomic weight of
samarium, one of the
rare earth elements.
Dumas established new values for the
atomic mass of thirty elements, setting the value for
hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
to 1.
Determination of nitrogen
In 1833, Dumas developed a
method for estimating the amount of
nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...
in an
organic compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...
, founding modern analysis methods. He made important revisions to the existing combustion methods with a sophisticated
pneumatic trough. These revisions were the flushing of the combustion tube with
carbon dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...
and the addition of
potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash.
Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...
in the pneumatic trough. Flushing with carbon dioxide eliminated the nitrogen present in the air that previously occupied the combustion tube, eliminating the need for correction due to nitrogen in the air. The potassium hydroxide dissolved the passing carbon dioxide gas, which left nitrogen as the only gas in the collection tube.
Theory of substitution and theory of chemical types
At the Tuileries palace in Paris, guests at a soirée began reacting adversely to a gas suddenly emitted by the candles. Alexandre Brongniart asked his son-in-law, Dumas, to investigate. Dumas found that the coughing and dangerous fumes were caused by chlorine present in the candle wax. Chlorine had been used to whiten the candles, and Dumas concluded that it must have combined during the candle-making process. This led Dumas to investigate the behavior of chlorine substitution in other chemical compounds.
One of the most important research projects of Dumas was that on the action of
chlorine
Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...
on
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 ...
to form
trichloroacetic acid – a derivative of essentially the same character as the acetic acid itself, though a stronger acid. Dumas extended this to a theory (sometimes considered a law) which states that in an organic compound, a hydrogen atom may be substituted for any
halogen.
In his published paper on the subject, Dumas introduces his theory of types. Since the trichloracetic acid retained similar properties to acetic acid, Dumas reasoned that there were certain chemical structures that remained comparatively unchanged even if one atom were changed within them. The basis of this theory rests in the
natural history
Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...
of organism classification, which Dumas learned under the botanist
de Candolle. This new theory challenged Berzelius's previous theory of
electrochemical dualism and was also a competitor of
radical theory.
Family
He married Herminie Brongniart, daughter of
Alexandre Brongniart, in 1826.
See also
*
Dumas method
*
Dumas method of molecular weight determination
References
Further reading
*
*
*
*
Tiffeneau, Marc (1934). ''Jean-Baptiste Dumas (1800–1884)'', Paris, Laboratoires G. Beytout.
External links
*
Jean-Baptiste Dumas Biography Pasteur Brewing
An essay by Josiah Parsons Cooke ''Reprinted from the Proceedings of the American Academy of Arts and Sciences, vol. xix, 1883–'84''
Jean-Baptiste-André Dumas ''Science ''Science'' Vol. III No.72 Published by the American Association for the Advancement of Science''
{{DEFAULTSORT:Dumas, Jean-Baptiste
19th-century French chemists
Ministers of agriculture and commerce of France
1800 births
1884 deaths
Members of the Académie Française
Members of the Royal Netherlands Academy of Arts and Sciences
Members of the Royal Swedish Academy of Sciences
Foreign members of the Royal Society
Foreign associates of the National Academy of Sciences
Officers of the French Academy of Sciences
Recipients of the Copley Medal
Recipients of the Pour le Mérite (civil class)
People from Alès
French Roman Catholics
Burials at Montparnasse Cemetery
People involved with the periodic table
International members of the American Philosophical Society