Joseph Louis Gay-Lussac French chemist and physicist Date of Birth: 06.12.1778 Country: France

Biography of Joseph Louis Gay-Lussac

Joseph Louis Gay-Lussac was a French chemist and physicist, born in Saint-Léonard. He was a member of the Paris Academy of Sciences from 1806 and served as its president in 1822 and 1834. Gay-Lussac graduated from the Polytechnic School in Paris in 1800, where he studied under C. Berthollet. He worked as Berthollet's assistant from 1800 to 1802.

In 1805 and 1806, Gay-Lussac embarked on a European journey with the renowned German naturalist A. Humboldt. He became a professor of chemistry at the Polytechnic School and physics at the Sorbonne in 1809. In 1832, he became a professor of chemistry at the Botanical Garden in Paris.

Gay-Lussac's scientific works spanned various areas of chemistry. He independently discovered the law in 1802, which established the quantitative relationship between the expansion of gases and temperature at constant pressure. He also formulated the law of combining volumes in 1808, stating that the volumes of gases involved in a reaction are related to each other and to the volumes of the gaseous reaction products by simple whole-number ratios (Gay-Lussac's laws). He determined the direction of temperature change during the compression and expansion of gases (air) without heat exchange.

In his research on hydrochloric acid and hydrogen cyanide, Gay-Lussac demonstrated that the presence of oxygen is not a necessary criterion for defining a substance as an acid. He established an analogy between chlorine and iodine, preparing hydrogen iodide, iodic acid, and iodine monochloride. He also studied hydrofluoric acid.

Working with L.J. Thénard, Gay-Lussac isolated free boron from boron anhydride and developed methods for obtaining potassium and sodium by reducing their hydroxides. He investigated their peroxides, as well as the peroxides of calcium and barium, in 1810. Alongside H. Davy, he showed in 1813-1814 that iodine is a chemical element.

In 1815, Gay-Lussac determined the quantitative composition of hydrocyanic acid and established an analogy between it, hydrohalic acids, and hydrogen sulfide. He obtained and studied "cyan" (now known as dicyan), which played a role in the development of the theory of complex radicals and substitution theory.

One of Gay-Lussac's notable accomplishments was the construction of temperature-dependent solubility curves for salts in water in 1819. He also improved methods for volumetric analysis, including chlorometry (1824), alkali and acidimetry (1827), and the determination of silver and chlorine by precipitation (1832).

In collaboration with M.E. Chevreul, Gay-Lussac obtained a patent in 1825 for the production of stearin candles, marking a new era in the history of lighting. He invented a tower for trapping nitrogen oxides in the industrial production of sulfuric acid in 1827 (the use of such towers began in 1842). He developed an industrial method for obtaining oxalic acid from wood chips in 1829.

Gay-Lussac also invented the thermograph and the mercury siphon barometer in 1816. He, along with T.J. Pelouze, obtained lactic acid by heating milk in 1833.

Gay-Lussac was an honorary foreign member of the St. Petersburg Academy of Sciences from 1829.