Jean-Baptiste Dumas facts for kids
Quick facts for kids
Jean-Baptiste Dumas
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| Born | 14 July 1800 Alès, France
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| Died | 10 April 1884 (aged 83) Cannes, France
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| Nationality | French |
| Known for | Atomic weights |
| Awards | Copley Medal (1843) Faraday Lectureship Prize (1869) Albert Medal (1877) |
| Scientific career | |
| Fields | Chemistry |
| Notable students | Eugène-Anatole Demarçay, Auguste Laurent |
Jean-Baptiste André Dumas (born 14 July 1800 – died 10 April 1884) was a famous French chemist. He is best known for his work on how to analyze and create organic chemicals. He also found ways to figure out the atomic weights (how heavy atoms are) and molecular weights (how heavy molecules are) of substances. He did this by measuring how dense their vapors were. Dumas also created a special method to find out how much nitrogen was in different chemical compounds.
A Chemist's Life
Early Life and Education
Jean-Baptiste Dumas was born in Alès, a town in France. When he was young, he started working as an apprentice for an apothecary (like a pharmacist) in his hometown.
In 1816, he moved to Geneva, a city in Switzerland. There, he went to lectures to learn about physics, chemistry, and botany (the study of plants). Even before he was 21, he was already doing his own research with another scientist, Pierre Prévost. They studied physiological chemistry (the chemistry of living things) and embryology (how embryos develop).
Moving to Paris and Becoming a Professor
In 1822, Dumas moved to Paris, the capital of France. He became a chemistry professor, first at the Lyceum, and later at the École polytechnique in 1835. He also helped start a new school called the École centrale des arts et manufactures in 1829. This school is now known as École centrale Paris.
Joining Important Groups
Dumas became a member of the French Academy of Sciences in 1832. This is a very important group of scientists in France. From 1868 until he died in 1884, he was the permanent secretary for the Physical Sciences department of the Academy.
He was also chosen as a foreign member of the Royal Swedish Academy of Sciences in 1838. Later, he joined the Royal Netherlands Academy of Arts and Sciences. From 1845 to 1864, he was the president of a group called the Société d'encouragement pour l'industrie nationale, which encouraged national industry. In 1860, he was elected to the American Philosophical Society.
Public Service and Later Life
After 1848, Dumas spent less time on science and more time working for the government. He served under Napoléon III. He became a member of the National Legislative Assembly. For a few months in 1850–1851, he was the minister of agriculture and commerce. Later, he became a senator, the head of the Paris city council, and even the master of the French mint (where money is made). However, his government career ended when the Second French Empire fell.
Dumas was a strong Catholic and often defended Christian beliefs. He died in Cannes, France, in 1884. He is buried in the Montparnasse Cemetery in Paris. His name is one of the 72 names written on the Eiffel Tower.
Discoveries in Chemistry
Challenging Old Ideas
Dumas was one of the first scientists to disagree with the ideas of Jöns Jakob Berzelius. Berzelius had a theory that chemical compounds were made of two parts. Dumas, however, believed in a "unitary view," meaning he thought compounds were more like one whole unit.
In 1826, Dumas wrote a paper about atomic theory. In this paper, he shared ideas that were very advanced for his time. These studies led him to develop ideas about "substitution." This theory, developed around 1839, suggested that in organic chemistry, certain basic structures stay the same. Even if a hydrogen atom is replaced by a halide element (like chlorine), the main type of the compound remains.
Dumas also found a way to group organic compounds into "homologous series." This was based on his research into acids that are formed when alcohols are oxidized. He also showed that kidneys remove urea from the blood.
Measuring Vapors and Atomic Masses
Dumas improved a method for measuring the density of vapors. This was very important for figuring out atomic weights. Here's how his method worked:
- He put a known amount of a substance into a glass bulb that had been weighed.
- He sealed the bulb and heated it in water to turn the substance into a vapor (gas).
- He recorded the pressure.
- Then, he let the bulb cool down to find the mass of the vapor.
- Using a scientific rule called the universal gas law, he could then figure out how many moles of gas were in the bulb.
In his 1826 paper, he explained this method. He used it to re-measure the atomic weights of carbon and oxygen. This led to a long series of measurements for about thirty different elements, with most results published between 1858 and 1860. He showed that "in all elastic fluids observed under the same conditions, the molecules are placed at equal distances." He also determined the atomic weight of samarium, which is one of the rare earth elements.
Dumas set new values for the atomic mass of thirty elements. He set the value for hydrogen as 1.
Finding Nitrogen in Compounds
In 1833, Dumas created a special method to estimate how much nitrogen was in an organic compound. This method became the basis for modern ways of analyzing chemicals. He made important changes to older methods that used burning. He used a special device called a pneumatic trough. His improvements included:
- Flushing the burning tube with carbon dioxide. This removed any nitrogen from the air that was already in the tube.
- Adding potassium hydroxide to the pneumatic trough. This chemical dissolved the carbon dioxide gas that passed through, leaving only nitrogen gas to be collected.
The Theory of Substitution and Chemical Types
One night at a party in Paris, guests started coughing because of a strange gas coming from the candles. Alexandre Brongniart asked his son-in-law, Dumas, to find out why. Dumas discovered that the dangerous fumes were caused by chlorine in the candle wax. Chlorine had been used to make the candles whiter. Dumas realized that the chlorine must have combined with the wax during the candle-making process. This made Dumas want to study how chlorine could replace other atoms in different chemical compounds.
One of Dumas's most important research projects was on how chlorine reacted with acetic acid to form trichloroacetic acid. This new acid was very similar to acetic acid, but it was stronger. Dumas expanded this idea into a theory (sometimes called a law). It states that in an organic compound, a hydrogen atom can be replaced by any halogen atom (like chlorine).
In his paper about this, Dumas introduced his "theory of types." Since trichloroacetic acid kept similar properties to acetic acid, Dumas believed that some chemical structures stayed mostly the same. This was true even if one atom inside them was changed. This idea was based on how living things are classified in natural history, which Dumas learned from the botanist de Candolle. This new theory challenged Berzelius's older theory of electrochemical dualism. It was also different from another idea called radical theory.
Family Life
Jean-Baptiste Dumas married Herminie Brongniart in 1826. She was the daughter of Alexandre Brongniart, who was also a famous scientist.
See also
In Spanish: Jean-Baptiste Dumas para niños
- Dumas method
- Dumas method of molecular weight determination
Images for kids
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Jean-Baptiste Dumas
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Grave of Dumas in Paris
