Ferdinand Frédéric Henri Moissan was a French chemist and pharmacist. He was born on September 28, 1852, and died on February 20, 1907. He won the 1906 Nobel Prize in Chemistry for separating fluorine from its compounds. He also discovered moissanite and helped create the electric arc furnace. Moissan was one of the first members of the International Atomic Weights Committee.
Biography
Henri Moissan was born in Paris on September 28, 1852. He was the son of Francis Ferdinand Moissan, a low-ranking officer for the Eastern Railway Company, and Joséphine Améraldine (née Mitel), a seamstress. In 1864, the family moved to Meaux, where Moissan attended a local school. During this time, he worked as an apprentice clockmaker. However, in 1870, due to war with Prussia, Moissan and his family returned to Paris. He was unable to earn the grade universitaire, which was required to attend university. After spending a year in the army, he enrolled at the École Supérieure de Pharmacie in Paris. He was of Jewish descent and practiced the Catholic faith.
In 1871, Moissan became a trainee in pharmacy. In 1872, he began working for a chemist in Paris, where he saved a person poisoned with arsenic. This experience inspired him to study chemistry. He first worked in the laboratory of Edmond Frémy at the Musée d’Histoire Naturelle and later in the laboratory of Pierre Paul Dehérain at the École Pratique des Haute Études. Dehérain encouraged Moissan to pursue an academic career. Moissan passed the baccalauréat, a required exam for university study, in 1874 after failing earlier. In 1879, he became qualified as a first-class pharmacist at the École Supérieure de Pharmacie, and he earned his doctoral degree there in 1880.
Moissan quickly advanced in his career at the School of Pharmacy, eventually becoming Assistant Lecturer, Senior Demonstrator, and finally Professor of Toxicology by 1886. In 1899, he took the Chair of Inorganic Chemistry. The following year, he became Professor of Inorganic Chemistry at the Sorbonne, succeeding Louis Joseph Troost. During his time in Paris, Moissan became friends with chemist Alexandre Léon Étard and botanist Vasque. He married Léonie Lugan in 1882, and they had a son, Louis Ferdinand Henri, in 1885.
Moissan died suddenly in Paris in February 1907, shortly after returning from receiving the Nobel Prize in Stockholm. His death was attributed to a sudden case of appendicitis, though some believe repeated exposure to fluorine and carbon monoxide may have contributed.
Throughout his career, Moissan published over 300 works. He won the 1906 Nobel Prize in Chemistry for isolating fluorine for the first time. He also received the Prix Lucaze, Davy Medal, Hofmann Medal, and Elliott Cresson Medal. He was elected a fellow of the Royal Society and The Chemical Society of London, served on the International Atomic Weights Committee, and was made a commandeur in the Légion d’honneur. He was honored with honorary membership in the Manchester Literary and Philosophical Society and was described as a professor at the École Supérieure de Pharmacie, 7, Rue Vauguelin, Paris.
Research
In 1874, Moissan published his first scientific paper with Dehérain, describing how plants use carbon dioxide and oxygen. Later, he shifted his focus from plant physiology to inorganic chemistry. His research on pyrophoric iron, a substance that reacts strongly with water, was praised by two leading French chemists of the time, Henri Étienne Sainte-Claire Deville and Jules Henri Debray. After earning his Ph.D. in 1880 for studying cyanogen and its reactions to form cyanures, Moissan accepted a job at an analytical laboratory, offered by his friend Landrine.
During the 1880s, Moissan studied fluorine chemistry, particularly how to isolate the element. Fluorine had been known for years, but no one had successfully separated it, and some scientists had died trying. Without his own laboratory, Moissan used space borrowed from others, including Charles Friedel. There, he used a powerful battery of 90 Bunsen cells to observe a gas produced by the electrolysis of molten arsenic trichloride. However, the gas was reabsorbed by the arsenic trichloride, making further study difficult.
In 1886, Moissan successfully isolated fluorine by using electrolysis on a solution of potassium hydrogen difluoride (KHF₂) in liquid hydrogen fluoride (HF). This mixture was needed because hydrogen fluoride does not conduct electricity. His apparatus used platinum-iridium electrodes in a platinum holder and was cooled to −50 °C. This process separated hydrogen and fluorine gases for the first time on June 26, 1886. This method remains the standard for producing fluorine today. The French Academy of Sciences sent three scientists—Marcellin Berthelot, Henri Debray, and Edmond Frémy—to confirm his results. However, Moissan initially failed to reproduce them because the hydrogen fluoride lacked traces of potassium fluoride, which had been present in earlier experiments. After fixing this issue and demonstrating fluorine’s isolation multiple times, he received a prize of 10,000 francs. He later won the 1906 Nobel Prize in Chemistry for this achievement. Following this, Moissan studied fluorine’s chemical properties and discovered many fluorine compounds, including sulfur hexafluoride with Paul Lebeau in 1901.
Moissan also helped develop the electric arc furnace, which enabled the creation of new chemical compounds. He experimented with using pressure to make synthetic diamonds from carbon. Additionally, he used the furnace to produce borides and carbides of various elements. Calcium carbide was a significant discovery, as it advanced the study of acetylene. In 1893, Moissan analyzed fragments from a meteorite found near Meteor Crater in Arizona. He identified a new mineral made of silicon carbide, which was later named moissanite in his honor in 1905. In 1903, Moissan was elected to the International Atomic Weights Committee, a position he held until his death.