Joseph Louis Gay-Lussac

Joseph Louis Gay-Lussac was a French chemist and physicist, born in 1778 at Saint-Léonard-de-Noblat. He trained at the École Polytechnique and the École des Ponts et Chaussées, worked as an assistant to Claude Louis Berthollet, and later held the chair of chemistry at the École Polytechnique and a physics post at the Sorbonne. He is known for two laws on gases, including the law of combining volumes published in 1809, for finding with Alexander von Humboldt that water forms from two parts of hydrogen and one of oxygen by volume, and for his work on alcohol and water mixtures that led to the Gay-Lussac degrees used to measure alcoholic strength. He co-discovered boron, recognised iodine as an element and synthesised cyanogen. He died in Paris in 1850.