Gay-Lussac, Joseph Louis, 1778-1850, French chemist and physicist. He was professor in Paris at the Sorbonne, at the Polytechnic School, and at the Jardin des Plantes. Gay-Lussac made two balloon ascensions in 1804, attaining on the second a height of about 7,016 m (23,000 ft), to test the variation of the earth's magnetic field and the composition of the atmosphere at varying altitudes. He made advances in industrial chemistry; in the field of analytical chemistry he improved the methods of analyzing gas mixtures, studied prussic acid and iodine, and isolated cyanogen. With L. J. Thénard he improved Davy's method of isolating alkali metals, showed chlorine to be an element, and isolated boron. In physics he is known especially for his work on gases. In 1802 he discovered independently that a gas at constant pressure expands, for each degree of temperature, by a constant fraction of its volume at 0°C;. This law, first discovered (1787) by J. A. C. Charles, is known as Charles's law or as Gay-Lussac's law (see gas laws). However, Gay-Lussac's name is more commonly associated with another law of gases, the law of combining volumes, which Gay-Lussac was the first to formulate (c.1808). This law states that the volumes of gases that interact to give a gaseous product are in the ratio of small whole numbers to each other and that each bears a similar relation to the volume of the product.

Joseph Louis Gay-Lussac (December 6, 1778 – May 9, 1850) was a French chemist and physicist. He is known mostly for two laws related to gases, and for his work on alcohol-water mixtures, which led to the degrees Gay-Lussac used to measure alcoholic beverages in many countries.

Biography

Gay-Lussac was born at Saint-Léonard-de-Noblat in the department of Haute-Vienne. He received his early education at home and in 1794 was sent to Paris to prepare for the École Polytechnique after his father was arrested, into which he was admitted at the end of 1797. Three years later he transferred to the École des Ponts et Chaussées, and shortly afterwards was assigned to C. L. Berthollet as his assistant. In 1802 he was appointed demonstrator to A. F. Fourcroy at the École Polytechnique, where subsequently (1809) he became professor of chemistry. From 1808 to 1832 he was professor of physics at the Sorbonne, a post which he only resigned for the chair of chemistry at the Jardin des Plantes. In 1831 he was elected to represent Haute-Vienne in the chamber of deputies, and in 1839 he entered the chamber of peers.

In 1809 Gay-Lussac married Geneviève-Marie-Joseph Rojot. He had first met her when she worked as a linen draper's shop assistant and was studying a chemistry textbook under the counter. He was father of five children, of whom the eldest (Jules) became assistant to 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). Some of his descendants live in Brazil, South America (de Salusse Lussac/Lussac Do Coutto/Do Coutto Monni) and in Ontario, Canada.

Achievements

In 1802, Gay-Lussac first formulated the law that a gas expands linearly with a fixed pressure and rising temperature.

In 1804 he made a hot-air balloon ascent with Jean-Baptiste Biot to a height of 6.4 kilometres in an early investigation of the Earth's atmosphere. He wanted to collect samples of the air at different heights to record differences in temperature and moisture.

In 1805, together with his friend and scientific collaborator Alexander von Humboldt, he discovered that the basic 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).

In 1808, he was the co-discoverer of boron.

In 1810, in collaboration with Louis Thenard, he developed a method for quantitative elemental analysis by measuring the carbonic acid and oxygen evolved by reaction with potassium chlorate.

in 1811, Gay-Lussac recognized iodine as a new element, described its properties, and suggested the name iode.

In 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.

In Paris, a street and a hotel near the Sorbonne are named after him as are a square and a street in his birthplace, St Leonard de Noblat. His grave is at the Père Lachaise cemetery in Paris.

Academic lineage

References

• Gay-Lussac, L. J. and A. von Humboldt (1805) Expérience sur les moyens oediométriques et sur la proportion des principes constituents de l'atmosphère. J. Phys.-Paris LX.
• Maurice Crosland. Gay-Lussac, Scientist and Burgeois, Cambridge University Press, Cambridge, 1978, 333p., ISBN 0521219795