(b. Versailles, France, 13 December 1817; d. Boulogne-sur-Mer, France, 22 November 1870)
Barreswil studied chemistry in Paris under the guidance of Robiquet and Bussy, and later under Jules Pelouze, whose laboratory on the Rue Dauphine he directed. It was there, from 1844 to 1849, that Barreswil worked side by side with Claude Bernard and gave the young physiologist, then far from his future eminence, extremely valuable assistance. They conducted experiments on themselves, such as subsisting only on gelatin and attempting to discover the influence of food on the chemical reaction in the urine.
At first Barreswil was especially interested in the improvement of chemical analysis; starting in 1843 he published several articles in this field, notably on a new process for separating cobalt from manganese (1846) and on the cupropotassic solution as a reagent facilitating the detection of sugar (1844). Rayer introduced the “blue liquid of Barreswil” into the systematic clinical detection of diabetes; only slightly altered, it is the Fehling solution used today.
Barreswil participated in Bernard’s researches on digestion (1844); on the chemical composition of gastric juices, bile, and pancreatic juice (1844–1846); on the means of eliminating urea after the removal of the kidneys (1847); and especially on the role of sugar in the animal organism. Both Bernard and Barreswil signed the two basic communications on the presence of sugar in the liver (1848) and in egg whites (1849).
While carrying on his own research, Barreswil discovered a new chrome compound, blue chromic acid (1847), and prepared quinine tannate.
Having become professor of chemistry at the École Municipale Turgot, and later at the École Supérieure de Commerce in Paris, Barreswil abandoned physiological chemistry and became more interested in the problems of industrial chemistry, particularly those of coloring, of photographic chemistry, and of the manufacture of sulfuric acid. He also carried out useful and humanitarian work as inspector of child labor in the factories of the Department of the Seine and as secretary of a philanthropic organization for the protection of young workers.
I. Original Works. Barreswil’s books include Appendice à tous les traités dʾanalyse chimique (Paris, 1848), written with A. Sobrero; Chimie photographique (Paris, 1854; 4th ed., 1864), written with Davanne; Répertoire de chimie pure et appliquée, 6 vols. (Paris, 1858–1866); and Dictionnaire de chimie industrielle, 3 vols. (Paris, 1861–1864), written with A. Girard et al. For the bibliography of his articles see Royal Society of London, Catalogue of Scientific Papers, I, 191–192.
II. Secondary Literature. There is no proper biographical study of Barreswil. Short notices are in G. Vapereau, Dictionnaire universel des contemporains, 4th ed. (Paris, 1870), and Dictionnaire de biographie française, V (Paris, 1951).
M. D. Grmek