Moissan, an eminent French chemist and pharmacist, was the discoverer of fluorine, the inventor of calcium carbide and pf the acetylene lamp and a promoter of the use of the electric furnace in chemistry and sciences. He invented the electric arc furnace to achieve high temperatures (up to 3500 °C), with which he isolated more metals and manufactured several compounds such as carbides. The furnace paved the way for chemical syntheses at notably high temperatures. His research was of fundamental importance and opened new fields for scientific research and industrial activity. Moissan was a distinguished scientific mind, a great experimental talent and a teacher. He was defined by a high code of honor based on sacrifice and work.

Moissan, an eminent French chemist of unequalled brilliance and intellectual prowess, was the first French scientist to receive the Nobel Prize in chemistry, which he received in 1906. This year, 2016, the French Academy of Science is celebrating its 350th anniversary, which is the best occasion to remember Moissan, as he was appointed a member of the French Academy of Science in 1891.

1 Moissan – Life, death and life after death

Moissan was born in Paris on 28 September 1852, in a family with the high values of work and honor. His father was employed at the “Chemins de fer de l’Est”, and his mother was a seamstress. In 1864, his family left Paris to go to the town of Meaux. In October 1864, Moissan began to attend college in the city of Meaux. It was part of a special secondary education because his family was too modest to give him an opportunity to follow longer-term studies. In July 1870, he obtained his vocational certificate. At the college, he was remembered as a student with a keen intellect, open to mathematics and to physical sciences. Then, he was an apprentice to a clockmaker in Meaux. His professional life as an apprentice watchmaker was interrupted by the events of 1870, the siege of Paris, and the Franco-Prussian War of 1870/1871, and his family was forced to return to Paris. He was 18 during the siege of the capital; he was incorporated for a year in the army and participated in the commitment in Avron in December 1870.

After the capitulation and armistice, upon the advice of his father, he enrolled in pharmacy school to prepare for a second-class degree in pharmacy, which was only accessible to non-graduate students. In February 1871, he became a trainee at the pharmacy Baudry, rue Saint-Martin in Paris, where he continued his training until June 1874. Then, he followed the theoretical teaching for three years to complete his pharmaceutical studies. Because Moissan hesitated between Pharmacy and Chemistry for a long time, he enrolled in 1872 at the Experimental Chemistry School of Edmond Frémy at the Museum of Natural History. After a semester during which he learned practical chemistry, he joined Dehérain’s laboratory, where he undertook plant physiology research on the absorption of oxygen and carbon dioxide emission by plants in darkness. Encouraged by Dehérain, he continued the classical studies and obtained his baccalaureate in 1874. In November 1875, he completed his year of military service in a nursing section in Lille and obtained his “licence ès sciences” in 1877. On his return to civilian life, impressed by the mineral chemistry class of Professor Alfred Rich at the School of Pharmacy, he selected this branch of chemistry as a field of research. In 1879, he reported his research in his thesis to obtain a first-class degree in pharmacy. His first extensive work in chemistry, which he started in Lille, addressed the family of iron oxides, had been proposed by Henri Debray, professor at the Sorbonne, and would be the subject of his doctoral thesis of Science, which he defended in 1880.

As a lecturer and head of practical work at the Paris School of pharmacy since November 1880, he was appointed as an associate professor in 1882 with a thesis entitled “Cyanogen Series”. In 1887, Moissan became the holder of the professor chair at the School of Pharmacy of Paris in toxicology and, starting from November 1899, in inorganic/mineral chemistry. He remained there until July 1900, when he was appointed to the inorganic chemistry chair of the Faculty of Paris, succeeding Louis Troost. Therefore, he had two functions. In 1899, he was appointed the Director of Practice and Industrial Chemistry Laboratory (founded by Charles Friedel in 1896) and replaced Charles Friedel, who had died. He held this position until his death in 1907.

As a professor at the Sorbonne, he had more influence to reform the teaching procedures in a laboratory that he trained chemists for analysis and industry, but he did not train engineers. Moissan wanted to raise the level and train engineers. In 1901, the laboratory became the Applied Chemistry Institute (ICA). In 1906, he was allowed to deliver a chemical engineering degree. Education was accordingly reformed with a greater theoretical emphasis. The institute was named the National School of Chemistry of Paris (ENSCP) in 1948 and is currently ENSCP Paristech. Moissan also participated in the work of the Academy of Medicine and Health Council, the Aluminum Commission for the Ministry of War.

Everyone who had the pleasure of being in his company said that he was a great pedagogue. He was appreciated for his teaching skills and encouragement to young people. He wished that his students develop critical thinking, and he gave them the freedom to express opinions that were contrary to his own. He brought cheerfulness and enthusiasm, and he communicated it to those around. His presence in the laboratory was a joy for all. As a prestigious researcher, Moissan was also an outstanding teacher who aroused many vocations and had numerous French and foreign students.

In 1882, he married Meaux Marie Léonie Lugan, the daughter of a pharmacist in the city. From this union, a son, Henri Louis Ferdinand, was born, who was their only child. Henri Louis Ferdinand became a chemist and pharmacist engineer, assistant to the School of Pharmacy, and second lieutenant of the infantry reserve. He was killed in the war in the Meuse on 10 August 1914.

2 Research activities: primus inter pares

His first studies, which were conducted at Dehérain’s lab, focused on oxygen absorption and carbon dioxide emission by plants that were kept in the dark. In 1874, he published his first results with Dehérain. In 1878–1879, he published two other memoirs and his first-class pharmaceutical thesis. Then, he abandoned plant physiology for inorganic chemistry. His first study in this area focused on oxides of the iron family, which was the subject of his doctoral thesis in sciences. The results led him to study various other metal oxides, particularly those of chromium, and he first discovered a method for obtaining pure chromium in 1879. As early as 1883, Moissan had turned his efforts toward fluorine isolation. On 26 June 1886, he passed an electric current through a solution of potassium fluoride in hydrofluoric acid in a platinum equipment; it cooled to –50 °C to reduce the activity of fluoride. He isolated a gas in the platinum environment and obtained a pale yellow gas that degraded anything except plastic. It was the desired fluorine!

Moissan also worked on the production of artificial diamond. Diamond synthesis was announced at the Academy of Sciences on 6 February 1893, and was fully confirmed a year later on 12 February 1894. The experiments on diamond synthesis were achieved due to the use of very high temperatures. To achieve this synthesis, Moissan primarily considered the use of very high temperatures. Moissan invented the electric oven. He described his oven for the first time on 12 December 1892, in a note to the Academy of Sciences, and he constantly perfected it thereafter. Moissan obtained temperatures of approximately 3500 °C, where the highest temperatures that had previously been obtained did not exceed 2000 °C. With an intense source of energy, Moissan paved the way for a new and important chapter in inorganic chemistry: that of high temperatures. As a result, he could melt and crystallize certain metal oxides that were considered infusible, obtain some refractory metals in pure form and large quantities by reducing their carbon oxides, and prepare often unknown metal carbides, nitrides, borides, silicides, distilled metals, and refractory materials. An important point of his work was obtaining calcium carbide, which paved the way for the chemistry of acetylene, which had two important applications at the time: gas lighting and oxyacetylene welding. Moreover, the preparation of pure calcium enabled him to study their properties and compounds, and obtaining calcium hydride led him to become interested in metal hydrides, which were a class of unknown compounds at the time.

A later study by Moissan involved the isolation of the ammonium radical. His studies in this area were based on metal ammonium, and he thought to reduce the temperature or use an electrolyzer, but he faced failures. However, by decomposing sodium amalgam at –80 °C with a liquid ammonium iodide solution, he obtained a solid ammonium amalgam whose state of purity he could study. He had promised to complete his study when death overtook him! The extensions of Moissan’s work remain important today both in the field of fluorine and its inorganic and organic compounds and in the high-temperature and industrial diamond synthesis, where production is based on his principle of recrystallizing amorphous carbon at very high temperature and very high pressure.

In 1906, Moissan received the Nobel Prize in Chemistry for the isolation of fluorine in 1886 and the development of the electric furnace, which was described for the first time in 1892 and opened the path to high-temperature chemistry.

Moissan published more than three hundred articles, two books of notes (one on fluoride and the other on the oven), and a mineral chemistry treatise in five volumes. Various brochures still describe his active participation in the university and academic life and the town planning problems in the city of Meaux, to which he always remained attached.

In 1896 and 1902, Moissan became the President of the Chemical Society. Elected vice president in 1907, he would have led a third time in 1908, but he died in early 1907. He was appointed a member of the Academy of Medicine in 1888 and a member of the Academy of Sciences in 1891. In 1883, he was elected a member of the Pharmacy Society of Paris. He was a commander of the Legion of Honor and received many other French and foreign awards.

Moissan had a special relationship with the industry. This link between university and industry was one of his main concerns.

Moissan he was a fine man with a mischievous mood and great culture and was a great collector of paintings, works of art, and autographs. Moissan, with his encyclopedic spirit, wrote the comedy An unexpected marriage, which he proposed to the Odeon Theatre in November 1879.

On 20 February 1907, two months after receiving the prize, he died at the age of fifty-four. The great respect expressed in these words not only pays tribute to a visionary scholar who has earned an honorable place in the history of science for eternal life, but also honors the man who loved his work and forged his star, which will continue to shine for centuries. The work of Moissan charms the souls of generations of chemists. Throughout his 54 years of existence, Moissan—dignitas dignitatum—showed how work was his code of life!