Chancel, Gustav Charles Bonaven-Ture

(b. Loriol, France. 18 January 1822; d. Montpellier, France, 5 August 1890),

chemistry.

After studying at the École Centrale in Paris, Chancel worked in the laboratory of Jules Pelouze. In 1846 he was an assistant in chemistry at the École des Mines, and when Charles Gerhardt left Montpellier. Chancel replaced him as professor of chemistry (1851). He became dean of the faculty of sciences in 1865 and rector of the Montpellier Academy in 1879. He was a corresponding member of the Académie des Sciences from 1880 and received its Jecker Prize in 1884 for his work in organic chemistry.

Chancel’s researches were primarily in analytical and organic chemistry. His analytical studies dealt with the separation and analysis of metals in solution. In 1858 he introduced a new method of precipitation. Instead of adding the precipitating agent to a solution, Chancel slowly generated it in the solution itself. The principal advantage lay in the formation of a dense crystalline precipitate of high purity. By means of this method he precipitated aluminum as the hydroxide by means of sodium thiosulfate in the presence of iron.

Chancel investigated ketones in his first organic chemical researches. In 1844 he obtained butyrone from butyric acid and proved that it was analogous to acetone; he also discovered butyral and butyramide. The following year he isolated valerone and valeral from valeric acid. By 1845 several unsuccessful attempts had been made to clarify the nature of ketones and their relation to other organic classes. Chancel set the stage for the establishment of their constitution by proposing that they were combinations of an aldehyde and a hydrocarbon. Gerhardt adopted this idea in 1853, proposing four types of inorganic molecules from which all organic compounds could be derived by substitution of radicals for hydrogen atoms. One such type was the hydrogen type . It included all hydrocarbons:

It also included aldehydes and ketones:

Chancel collaborated often with Gerhardt. In 1852 they proposed that the sulfonyl group could replace the carbonyl group and announced the preparation of benzenesulfonyl chloride from benzoyl chloride. Chancel helped to confirm Gerhardt’s homologous series for alcohols. After noting that the alcohol series had missing links between ethyl and amyl alcohols, he succeeded in preparing propyl alcohol (1853).

Chancel also collaborated with Auguste Laurent. They discovered butyronitrile in 1847 and phenylurea and diphenylurea in 1849. Chancel confirmed Laurent’s proposal of alcohol and ether as members of the water type (1850). Most chemists followed Liebig in regarding ether and alcohol as ethyl oxide and hydrated ethyl oxide, respectively. Laurent in 1846 proposed the water type:

The experiments of Chancel and independently those of Alexander Williamson, decided the issue in favor of Laurent. Chancel prepared ether from potassium ethylate and ethyl sulfate. He also prepared methylethyl ether from potassium methylate and ethyl sulfate. In the latter case Liebig’s theory predicted a mixture of dimethyl and diethyl ethers, whereas Laurent’s theory predicted methylethyl ether. Chancel claimed no priority of discovery but simply stated that he had reached the same results as Williamson and that these discoveries confirmed the ideas of Gerhardt and Laurent on the constitution of alcohol and ether.

BIBLIOGRAPHY

I. Original Works. Chancel wrote a guide for his students: Cours élémentaire d’analyse chimique (Montpellier, 1851). He collaborated with Gerhardt on Pré cisd’analyse chimique qualitative (Paris, 1855: 3rd ed., 1874) and Précis d’analyse chimique quantitative (Paris, 1859; 3rd ed., 1875). His important papers include “Mémoire sur la butyrone,” in Comptes rendus hebdomadaires des séances de l’Académie des sciences, 18 (1844), 1023–1028; “Théorie de la formation et de la constitution des produits pyrogénés,” ibid., 20 (1845), 1580–1587; “Recherches sur l’acide valérique,” ibid., 21 (1845), 905–911: “Sur l’éthertfication et sur une nouvelle classe d’éthers.” ibid., 31 (1850). 521 –523, and 32 (1851), 587–589; “Recherches sur les combinaisons de l’acide sulfurique avec les matières organiques,” ibid., 35 (1852), 690–694, written with Gerhardt; “Recherches sur l’alcool propionique.” ibid., 37 (1853), 410–412; and “Del’emploi des hyposulfites dans l’analyse.” ibid., 46 (1858), 987–990.

II. Secondary Literature. There is a bibliography of Chancel’s papers with an account of his life and work by M. R. Forcrand: “Notice sur la vie et les travaux de G. Chancel,” in Bulletin de la Société chimique de Paris. 5 (1891), i–xx. See also the notice by P. Hamon, in Dictionnaire de biographie française, VIII (Paris, 1959), 363–364.

Albert B. Costa