Gay-Lussac rode a hydrogen balloon over 7 kilometres up to sample the sky
In 1804 Joseph Louis Gay-Lussac floated alone to 7,016 metres in a hydrogen balloon, collecting air to see whether the atmosphere changes with height. The same chemist named iodine, co-discovered boron, coined the words pipette and burette, and met his wife when he caught her reading chemistry under a shop counter.
He was born on 6 December 1778 at Saint-Léonard-de-Noblat in what is now Haute-Vienne. His father, a lawyer and royal prosecutor who owned much of the hamlet of Lussac, was jailed for a year during the Revolution; around 1803 father and son formally took the double surname. After schooling with Catholic clergy, Gay-Lussac entered the École Polytechnique in 1798 and soon became assistant to the chemist Claude-Louis Berthollet.
His gas work made his name. In 1802 he published the rule that a gas at constant pressure expands in proportion to its absolute temperature; because he credited unpublished work by Jacques Charles, it is usually called Charles's law, and John Dalton found it independently at almost the same moment. After the balloon flights, he and Alexander von Humboldt showed in 1805 that the air's composition stays the same at lower pressure, and that water forms from two volumes of hydrogen to one of oxygen. In 1808 he announced that gases combine in simple whole-number ratios by volume.
The discoveries kept coming. With Louis Jacques Thénard he devised a way to analyse organic compounds by burning them with potassium chlorate and measuring the carbon dioxide and water released, and the pair shared a 30,000-franc prize from Napoleon in 1809. He identified iodine as an element in 1811 and proposed its name, made and named cyanogen in 1815, and improved the burette with a side arm. His studies of alcohol and water gave rise to the degrees Gay-Lussac once used to label drinks in many countries.
Professor of chemistry at the Polytechnique from 1809 and of physics at the Sorbonne until 1832, he later sat as a deputy for Haute-Vienne and was made a peer of France. His wife, Geneviève Rojot, bore five children; the eldest, Jules, studied with Justus Liebig, and some of his papers are still wrongly attributed to his father. Gay-Lussac died in Paris on 9 May 1850 and is one of 72 scientists named on the Eiffel Tower.
Source: Joseph Louis Gay-Lussac
