His father, Anthony Gay, son of a doctor, was a lawyer and prosecutor and worked as a judge in Noblat Bridge.[6] Father of two sons and three daughters, he owned much of the Lussac village and began to add the name of this hamlet to his name, following a custom of the Ancien Régime. Towards the year 1803, father and son formally adopted the name Gay-Lussac.[7] During the Revolution, under the Law of Suspects, his father, former king's attorney, was imprisoned in Saint Léonard from 1793 to 1794.
Gay-Lussac received his early education at the hands of the Catholic Abbey of Bourdeix.[8] In the care of the Abbot of Dumonteil, he began his education in Paris, finally entering the École Polytechnique in 1798.
Three years later, Gay-Lussac transferred to the École des Ponts et Chaussées, and shortly afterward was assigned to C. L. Berthollet as his assistant. In 1804 he was appointed répétiteur (demonstrator) to Antoine François Fourcroy at the École Polytechnique, whom he succeeded in 1809 as professor of chemistry. From 1809 to 1832, he was also the professor of physics at the Sorbonne, a post which he only resigned for the chair of chemistry at the Jardin des Plantes. In 1821, he was elected a foreign member of the Royal Swedish Academy of Sciences. In 1831 he was elected to represent Haute-Vienne in the chamber of deputies, and in 1839 he entered the chamber of peers. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1832.[9]
Gay-Lussac married Geneviève-Marie-Joseph Rojot in 1809. He had first met her when she worked as a linen draper's shop assistant; he noticed she was studying a chemistry textbook under the counter, which led to their acquaintance. The couple had five children, of whom the eldest (Jules) became a student of Justus Liebig in Giessen. Some publications by Jules are mistaken as his father's today since they share the same first initial (J. Gay-Lussac).
Gay-Lussac had a reputation as one of the greatest European scientists of his day, well justified by his innumerable discoveries in both chemistry and physics. The restored royalty made him a Peer of France, although he worked politically with the anti-clerical party. He was closely associated with François Arago.
Gay-Lussac and Biot ascend in a hydrogen balloon, 1804. Illustration from the late 19th century.
1802 – Gay-Lussac first published the law that at constant pressure, the volume of any gas increases in proportion to its absolute temperature. Since in his paper announcing the law he cited earlier unpublished work on this subject by Jacques Charles, the law is usually called Charles's Law, though some sources use the expression Gay-Lussac's Law. This law was independently and nearly simultaneously stated by John Dalton.
1804 – He and Jean-Baptiste Biot made a hydrogen-balloon ascent; a second ascent the same year by Gay-Lussac alone attained a height of 7,016 metres (23,018 ft) in an early investigation of the Earth's atmosphere. He wanted to collect air samples at different heights to record differences in temperature and moisture.
1805 – Together with his friend and scientific collaborator Alexander von Humboldt, he discovered that the composition of the atmosphere does not change with decreasing pressure (increasing altitude). They also discovered that water is formed by two parts of hydrogen and one part of oxygen (by volume).
1810 – In collaboration with Louis Jacques Thénard, he developed a method for quantitative elemental organic combustion analysis by measuring the CO2 and H2O evolved when an organic compound is fully oxidized by potassium chlorate. He also summarised the equation of alcoholic fermentation.
1811 – He recognized iodine as a new element, described its properties, and suggested the name iode.[10]
1815 – He synthesized cyanogen, determined its empirical formula, and named it.
1824 – He developed an improved version of the burette that included a side arm, and coined the terms "pipette" and "burette" in an 1824 paper about the standardization of indigo solutions.[11]
Gay-Lussac, L. J.; von Humboldt, A. (1805). "Expériences sur les moyens eudiométriques et sur la proportion des principes constituans de l'atmosphère". Journal de Physique. 60.
Gay-Lussac's article (1809) "On the combination of gaseous substances", online and analyzed on BibNumArchived 2019-06-16 at the Wayback Machine (for English, click 'à télécharger').
