Henri Louis Le Chatelier

An influential French chemist of the late 19th and early 20th centuries. He is most famous for devising Le Châtelier's principle, used by chemists to predict the effect a changing condition has on a system in chemical equilibrium.

His father was an influential figure who played important roles in the birth of the French aluminium industry, the introduction of the Martin-Siemens processes into the iron and steel industries, and the rise of railway transportation. Le Châtelier’s father profoundly influenced his son's future. As a child, Le Châtelier attended the Collège Rollin in Paris. At the age of 19, after only one year of instruction in specialized engineering, he followed in his father's footsteps by enrolling in the École polytechnique on 25 October 1869. Like all the pupils of la polytechnique, in September 1870, Le Châtelier was named second lieutenant and later took part in the Siege of Paris. After brilliant successes in his technical schooling, he entered the École des Mines in Paris in 1871.

Despite training as an engineer, and even with his interests in industrial problems, Le Châtelier chose to teach chemistry rather than pursue a career in industry. In 1887, he was appointed head of the general chemistry to the preparatory course of the École des Mines in Paris. He tried unsuccessfully to get a position teaching chemistry at the École polytechnique in 1884 and again in 1897.

At the Collège de France, Le Châtelier succeeded Schützenberger as chair of inorganic chemistry. Later he taught at the Sorbonne university, where he replaced Henri Moissan.

After four unsuccessful campaigns (1884, 1897, 1898 and 1900), Le Châtelier was elected to the Académie des sciences (Academy of Science) in 1907. He was also elected to the Royal Swedish Academy of Sciences in 1907.