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. He also developed a method for the analysis of nitrogen in compounds. Source: Wikipedia (en)