Joseph Louis Gay-Lussac

Joseph Louis Gay-Lussac was born on 6 December 1778 in France and trained as both a chemist and physicist at a time when the two were barely separate. Working alongside Alexander von Humboldt, he demonstrated that water forms from two parts hydrogen to one part oxygen by volume - a clarifying jolt for early atomic theory. He went on to establish two laws governing gas behavior, tightening the field's empirical backbone. His later investigations into alcohol-water mixtures yielded the degrees Gay-Lussac, a measurement standard that many countries still use to classify spirits. He died on 9 May 1850, having spent a career turning vague substance into number.