Search results
Results from the WOW.Com Content Network
Jean Baptiste André Dumas (French pronunciation: [ʒɑ̃ batist ɑ̃dʁe dyma]; 14 July 1800 – 10 April 1884) was a French chemist, 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 densities.
The Dumas method of molecular weight determination was historically a procedure used to determine the molecular weight of an unknown volatile substance. [ 1 ] [ 2 ] The method was designed by the French chemist Jean Baptiste André Dumas , after whom the procedure is now named.
On the Eiffel Tower, 72 names of French men (scientists, engineers, and mathematicians) are engraved in recognition of their contributions. [1] Gustave Eiffel chose this "invocation of science" because of his concern over the protests against the tower, and chose names of those who had distinguished themselves since 1789. [2]
The Dumas technique has been automated and instrumentalized, so that it is capable of rapidly measuring the crude protein concentration of food samples. This automatic Dumas technique has replaced the Kjeldahl method as the standard method of analysis for nutritional labelling of protein content of foods (except in high fat content foods where ...
He later switched to chemistry and worked at the École Polytechnique in Paris under the direction of Jean-Baptiste Dumas. Stas and Dumas established the atomic weight of carbon by weighing a sample of the pure material, burning it in pure oxygen , and then weighing the carbon dioxide produced.
Shunned by Dumas, he eked out a living teaching in the mineral engineering lab - where he taught a young Louis Pasteur how to crystalize tartaric acid. Laurent died in Paris from tuberculosis . Alexander Williamson in England read Laurent's writing, leading to the Williamson Ether Synthesis that confirmed the validity of Laurent's approach.
Jean-Baptiste Dumas used the terms "physical atoms" and "chemical atoms"; a "physical atom" was a particle that cannot be divided by physical means such as temperature and pressure, and a "chemical atom" was a particle that could not be divided by chemical reactions. [26]
Jean-Baptiste Dumas and Auguste Laurent (an early supporter of radical theory) challenged radical theory in 1840 with a Law of Substitution (or Theory of Substitution). [3] This law acknowledged that any hydrogen atom even as part of a radical could be substituted by a halogen .