Physicist and chemist — Joseph Louis Gay-Lussac (Saint-Léonard-de-Noblat 1778 – Paris 1850) was a French physicist and chemist, a pupil of the École Polytechnique and a leading figure of Napoleonic science. He studied the behaviour of gases, formulating the law that bears his name, according to which, at constant volume, the pressure of a gas grows linearly with temperature; he also measured with good precision the coefficient of thermal expansion of gases, equal for all of them, paving the way for the concept of absolute temperature. In chemistry he stated the law of combining volumes for reactions between gases, an essential contribution to atomic-molecular theory. He was also a bold experimenter, devoted to the study of the Earth’s atmosphere.
Trivia
In 1804 he went up in a hot-air balloon to about 7000 metres of altitude to measure the temperature, humidity and magnetic field of the upper atmosphere, setting an altitude record that remained unbeaten for decades.
Theories and contributions
- Gay-Lussac’s law — At constant volume the pressure of a gas is proportional to the absolute temperature: .
- Law of combining volumes — Gases react with one another in volume ratios expressible by simple whole numbers.
Featured in chapters
Linked atoms
1 linked atoms.