Copaux, Hippolyte Eugène

(b. Paris, France, 9 March 1872; d. Etampes, France, 28 August 1934),

Chemistry

His father died when Copaux was very young, and the boy was brought up by his mother. She sent him to a school run by th Marist Brothers, who encouraged his taste for literature. Nevertheless, Copaux was drawn to chemistry. He graduated first in his class at the École de physique et de chimie Industrielles de Paris and later returned to the school, first as head of the department of analytic chemistry (1900), then as professor of general chemistry (1910) and director of studies (1925). In the meantime Copaux was a special assistant to H. Moissan (1895–1897) and received the licence-ès-sciences physiques (1896) and the docteur-ès-sciences physiques (1905).

Copaux’s first studies dealt with the chemsitry and crystallography of mineral substances: determination of the physical properties of metallic cobalt (1), which were not accuratly known (1902); preparation and study of salts of cobalt sesquioxide: cobaltic selenate, cobaltiacetate of the protoxide of cobalt, cobalti-oxalates of alkaline metals (2); and preparation and study of molybdate and tungstate complexes: metallic silicomolybdates (3), including potassium and silver silicomolybdate (4) (triclini yellow crystals with 30 H₂O and triclinic red crystals with 14 H₂O), various silicotungstates (5), borotungstates, and metatungstates (6).

During World War I, Copaux was assigned to the Patent Office, as head of the Chemical Department. He developed a process for the rapid preparation of phosphoric acid (7). In 1919 Copaux perfected a method for obtaining beryllium oxide (8) from beryl that, since it greatly facilitates the separation of impurities, is still the basis for th industrial production of beryllium: by treating beryl with sodium fluosilicate at 850°C., one obtains sodium fluoberyllate, which is soluble to the extent of twenty-eight grams per liter in boiling water; sodium fluoaluminate is only slightly hydrolyzed.

From 1925, Copaux continued to direct the laboratory experiments of his young collaborators on active hydrogen (9), beryllium and the heat of formation of beryllium oxide (10), and beryllium chloride, while assuming his new pedagogical and administrative responsibilities.

Several chapters of the Traité de chimie minérale, edited by Moisson (1904), were written by Copaux, who also published two works intended especially for students: Introduction à la chimie générale (1919) and Chimie minérale (1925), the latter with the collaboration of M.H. Perperot.

Copaux belonged to several French chemical and mineralogical societies. He was made a knight of the Legion of Honor in 1923 and an officer in 1933.

BIBLIOGRAPHY

The following abbreviations are used in the listing of Copaux’s works cited in the text: ACP, Annales de chimie et de physique; BSC, Bulletin de la Sociétié chimique de France; BSM, Bulletine de la Société française de minéralogie; and CR. Comptes rendus hebdomadirs des séances de l’Académie des sciences.

1. “Analyse qualitative et quantitative des composés ducobalt,” in BSC, 29 (1903), 301; “Propriétés physiques comparatives du cobalt et du nickel purs,” in CR, 140 (1905), 657; and “Recherches expérimentales sur le cobalt et le nickel,” in ACP, 6 (1905), 508.

2. “Les cobaltioxalates alcalins,” in CR, 135 (1902), 1214; and “Oxydation des acéstates de cobalt et de manganèse par le chlore,” ibid., 136 (1903),373.

3. “Étude chimique et cristallographique des silicomolybdates,” in ACP, 7 (1906), 118; “De la nature des metatungstates et de l’existence du pouvoir rotatoire dnles cristaux de metatungstate de potassium,” in CR, 148 (1909), 633; and “Constitution des paramolybdates et des paratungstates,” in BSC, 13 (1913), 817.

4. “Étude chimique et cristallographique d’un silicomolybdate de potassium et d’argent,” in BSM, 30 (1907),292

5. “Préparation des acides silicotungstigues,: in BSC, 3 (1908), 101.

6. “Les acides borotungstigues,” in CR, 147 (1908), 973; “Nouveaux’ documents sur le dosage du bore,” in BSC, 5 (1909), 217; and “Recherches sur les tungstates complexes, en particulier sur les borotungstates et les métatungstates,” in ACP, 17 (1909), 217.

7. “Procédé rapide pour doser l’acide phosphorique,” in CR, 173 (1921),656.

8. “Méthode de traitement du béryl pour en extraire o’oxyde du béryllium,” in CR, 168 (1919), 610.

9. “Qulques expériences sur la production de l’hydrogène actif,” in BSC, 37 (1925),141.

10. “Chaleur d’oxydation du béryllium,” in CR, 171 (1920), 630, and 176 (1923), 579.

AndrÉ Copaux