WURTZ, CHARLES-ADOLPHE

(b. Wolfisheim, near Strasbourg, France, 26 November 1817; d. Paris, France, 12 May 1884)

chemistry.

Wurtz spent the earliest years of his life in Wolfisheim, a small village near Strasbourg, where his father, Jean–Jacques Wurtz, was Lutheran pastor. He grew up in a rather modest but cultured home that was intellectually stimulating and part of a healthy agricultural community. His mother, the former Sophie Kreiss, came from a well–educated family and she appears to have enjoyed a more good–humored disposition than her husband. Their son was intelligent and gifted with an artistic nature; but he attended the Protestant school in Strasbourg, from July 1826, without showing exceptional promise. By the age of seventeen, however, he had developed a sufficiently strong interest in chemistry to offend his father with experiments in the house. The idea of a career in the ministry appealed less and less to young Wurtz, who eventually was allowed to embark on a medical course at the University of Strasbourg. This promised both security and an opportunity to cultivate his interest in chemistry.

Such was his preoccupation with chemistry that for his doctorate in medicine (1843) Wurtz wrote a thesis on fibrin and albumin, in which he described a method for the purification of soluble albumin and argued for a difference between albumin of blood and the albumin of an egg. After graduating from Strasbourg it was a natural step to move to Giessen, where he could study with Liebig and where he soon met A. W. Hofmann, who later complemented his work on the amines and became his biographer. At Giessen, Wurtz began his research with a study of hypophosphorous acid in an attempt to decide between the conflicting formulas of Dulong and Rose. He found time to translate Liebig’s papers into French for the Aunnales de chimiehis generation. There never was a school of chemists in France, work that brought him into contact with the leading chemists in Paris. In 1844 he moved to that city, where he soon joined Dumas at the laboratory associated with the Faculty of Medicine.

It was there that Wurtz succeeded Dumas as lecturer in organic chemistry (1849), as professor (1853), and as dean (1866). In the last, more administrative, role he did much to improve the scientific education of medical students and to ensure that clinical professors in the hospitals had better laboratory facilities. From the Faculty of Medicine, Wurtz transferred to a chair of organic chemistry which had been specially created for him at the Sorbonne in 1874. Henceforth he could leave behind his heavy administrative responsibilities and enjoy his real vocation as a teacher.

Throughout his life Wurtz remained true to his Lutheran heritage. He displayed no trace of anticlericalism and found little difficulty in harmonizing his science with his faith. A staunch defender of the atomic theory against the skeptical positivism of Berthelot, he gave the theory a teleological interpretation in perfect accord with his natural theology. He was greatly respected for the diplomacy he demonstrated while dean of the Faculty of Medicine and for the liberalism that enabled him to defend his socialist colleagues, Alfred Naquet and Robin, with whom he had few political sympathies. His liberalism also manifested itself in his campaign for the admission of women students to the Faculty of Medicine. Intensely patriotic, he was deeply affected by the capture of his native Alsace during the Franco–Prussian War. He helped to found a society for the protection of the refugees who crowded into Paris from Alsace, and he was active when the capital fell under siege.

In 1852 Wurtz married a well–to–do childhood friend; they had four children, only one of whom pursued a scientific career. Wurtz became one of the most enthusiastic and outstanding teachers of his generation. There never was a school at Giessen, but Wurtz probably came closest to realizing one. Since he spoke French, German, and English, he was able to surround himself with the most distinguished chemists of the day. Both Couper and Butlerov–pioneers of structural organic chemistry–studied in his laboratory; around him, during the 1870’s, there gathered such giants as LeBel, van’t Hoff, and charles Friedel; and it was in his laboratory that Boisbaudran discovered gallium in 1875.

For twenty years, from 1852, Wurtz was responsible for the section devoted to foreign literature in the Annales de chimie. He became a member of the Academy of Medicine in 1856, vice–president in 1869, and president in 1871. He was elected a foreign member of the Royal Society in 1864 and subsequently won the Copley Medal. Twice he was awarded the Jecker Prize by the Institut de France: and after having been admitted to the chemical section of the Academie des Sciences in 1867, he was its president in 1881. Although the idea for the Societe Chimique de France may not have originated with wurtz, he became its secretary, its guiding spirit, and several times its president (1864, 1874, 1878). It was during his presidency (1864) that a number of separate publications, including Wurtz’s own Repertoire de chimie pure, were amalgamated to produce the official bulletin of the society. Wurtz was equally active in establishing the Association Francaise pour l’Avancement des Sciences, a new organization designed to foster science in the provinces. Modeled on the British Association, with which Wurtz was impressed, the French Association held its first meeting at Bordeaux in 1872. When it met at Lille in 1874, Wurtz delivered the presidential address. He was greatly honored in public as well as in academic life; he was elected mayor of the seventh arrondissement of Paris, and a member of the Senate.

Wurtz began his career at a time of great crisis in organic chemistry. The dualistic approach of Berzelius appeared to be collapsing under the attacks of Dumas, Laurent, and Gerhardt, who favored a unitary conception of organic molecules based on their novel concepts of substitution and double decomposition. Wurtz had no hesitation in aligning himself with Laurent and Gerhardt; he was the first teacher in France to champion their ideas, and became the architect of a new chemical system that embraced their antidualist concepts as well as the emerging concepts of atomicity (valence) and chemical types.

Remarkable among Wurtz’s earliest discoveries was his fulfillment of Liebig’s prediction that there might be organic compounds analogous to ammonia and derivable from it by the replacement of hydrogen. Having prepared substituted ureas from derivatives of cyanogen, Wurtz investigated the action of potassium hydroxide on his products and thus obtained the primary amines (1849). This outstanding discovery was soon extended by his friend Hofmann, who demonstrated that the remaining two equivalents of hydrogen in ammonia could be replaced by alkyl groups. This provided support for the thesis that Gerhardt was developing: that it might be possible to regard all organic compounds as derivable from a small number of inorganic types, such as water or hydrogen chloride. The value of ammonia as a primitive type was now revealed:

It was thus clear to Wurtz that organic radicals could replace hydrogen without destroying the basic structure or type. There remained, however, at least one serious bone of contention between the dualist school, now represented by Kolbe in Germany, and the new French school. Could the hydrocarbon radicals, postulated by the dualists as constituents of organic acides and alcohols, actually be isolated in the free state? Kolbe and the English chemist Frankland thought they had succeeded in isolating the methy1 and ethy1 radicals, thereby corroborating the conservative view that acetic acid, for example,contained the methy1 radical, then written as (C₄H₆), in precisely the same way that sulfuric acid contained sulfur:

(C₄H₆) · O₃ + H₂O and S · O₃ + H₂O.

Laurent and Gerhardt, however, argued that the supposed verification was circular, and that what Kolbe and Frankland had isolated were dimers of the hypothetical radicals. The stability, vapor density, and boiling point of these controversial hydrocarbons favored the dimerization thesis, but a strictly chemical proof was required. It was Wurtz who provided this proof when he applied sodium to a mixture of alkyl iodides (1854). When the iodides were those of ethy1 and buty1, he obtained some ethy1 buty1; when they were those of buty1 and amyl, he obtained some buty1 amy1, thereby confirming that what was isolated contained two equivalents of the radicals, and was not a free radical itself.

Wurtz ingeniously had not only found a new method for synthesizing alkanes but also had embarrassed the dualism of Kolbe, with whom, as with Berthelot, he was frequently at loggerheads. Earlier in his career (1844), Wurtz had observed the curious fact that a hydride of copper,when treated with hydrochloric acid, generated a quantity of hydrogen double that contained by the hydride alone. This clearly suggested the possibility that each molecule of hydrogen might comprise two equivalents or atoms of hydrogen–one from the hydride and one from the acid. His work on the controversial hydrocarbons now endorsed this interpretation, which in turn ratified Avogadro’s molecular hypothesis, so long neglected. Consequently, Wurtz became a leading advocate of the presuppositions underlying the atommolecule distinction and, by examining the dissociation of anomalous vapors such as phosphorus pentachloride, he was able to rehabilitate the use of vapor density measurements for the determination of molecular weights.

One of Wurtz’s most popular works was Latheorie atomique (1879). Its title denoted more than the atomic‐molecular theory of Avogadro or Ampere; it designated a theory that incorporated the idea of combining power or atomicity of the atoms–a new concept for which Wurtz had helped to clear the ground. He had done so by contributing to the notion of polyatomic organic radicals and by clarifying the distinctions between affinity, basicity, and atomicity. It was one of his outstanding contributions to chemistry that he succeeded in the preparation of the first dihydroxy alcohol, ethylene glycol, by the hydrolysis of ethylene diiodide (1856). It followed that the radicals of ethyl alcohol. glycol, and glycerin had ascending capacities of combination, and could be called monatomic, diatomic, and triatomic, respectively. This concept of characteristic combining power, when applied to the elements, precipitated the notion of valence, credit for which belongs to several of Wurtz’s contemporaries as well as to him. The carbon–carbon bond eluded Wurtz–perhaps because of his conviction that the elements (including carbon) might exhibit more than one valence. Although he was justified in this belief, he differed from Kekule, whose commitment to an exclusive tetravalence for carbon inexorably led to the vital carbon–carbon bond. The evidence suggests, moreover, that Wurtz simply found the structural formulas of Kekule and Couper too arbitrary and unnecessarily pretentious.

By dehydrating glycol, Wurtz procured ethylene oxide–a missing link that permitted him to construct a comprehensive series of analogies between organic and inorganic oxides that was based on the twin concepts of atomicity and type. Ethylene oxide was hailed as an analogue of the oxides of diatomic calcium and barium, just as glycery1 oxide could be represented as an analogue of the oxides of triatomic antimony and bismuth. On the basis of such analogical argument–and not, it should be noted, on the basis of organic synthesis–Wurtz proclaimed the unification of chemistry (1862).

Wurtz excelled as a practical chemist, and almost all his contributions were of lasting value. Among his many miscellaneous methods of synthesis were those for the production of phosphorous oxychloride, of neurine from ethylene oxide, of aldol from acetaldehyde, of phenol from benzene, and of esters from alkyl halides and the silver salts of acids.

BIBLIOGRAPHY

I. Original Works. Several of Wurtz’s major works were translated into English and German. The following references are to the original French eds.: Repertoire de chimie pure en France et à l’étranger, 4 vols. (Paris, 1858-1862); Chimie medicale (Paris, 1864); Leçons de chimie proféssees en 1863 par MM. A. Wurtz, A. Lamy, L. Grandeau (Paris, 1864); Leçons de philosophie chimique (Paris, 1864); Lecons élémentaires de chimie moderne (Paris, 1867-1868); Histoire des doctrines chimiques depuis Lavoisier (Paris, 1868), the intro. to Dictionnaire de chimie pure et appliquee, 14 vols. (Paris, 1868-1878); English trans. by H. Watts, A History of Chemical Theory (London, 1869); Les hautes éetudes pratiques dans les universités allemandes (Paris, 1870); La théorie atomique (Paris, 1879); and Traite de chimie biologique (Paris, 1880).

Besides these volumes, Wurtz published prolifically. His work included at least 140 papers, of which the following contain his most important contributions to the advance of chemistry: “Recherches sur la constitution de l’acide hypophosphoreux,” in Annales de chimie e de physique, 3rd ser., 7 (1843), 35–50; “Sur l’hydrure de cuivre,” ibid.,11 (1844), 250–252; “Recherches sur les ethers cyaniques et leurs derives,” in Comptes rendus…de l’Académie des sciences,27 (1848), 241–243; “Sur une série d’alcalis organiques homologues avec l’ammoniaque,” ibid.,28 (1849), 223–226; “Recherches sur les urees composées,” ibid.,32 (1851), 414–419; “Sur l’alcool butylique,” ibid.,35 (1852),310–312; “Sur la théorie des amides,” ibid.,37 (1853), 246–250 and 357–361: “Sur une nouvelle classe de radicaux organiques,” in Annales de chimie et de physique, 3rd ser., 44 (1855), 275–313; “Sur le glycol ou alcool diatomique,” in Comptes rendus…de l’Académie des sciences,43 (1856), 199–204; “Sur l’acétal et sur les glycols,” ibid., 478–481; “Sur la formation artificielle de la glycérine,” in Annales de chimie et de physique, 3rd ser ., 51 (1857). 94–101; “Recherches sur Íacide lactique” Comptes rendus…de l’Academie des sciences,46 (1858), 1228-1232; and “Sur l’oxyde d’ethylene,” inbid.,48 (1859), 101–105. Also see “Observatiuons sur la theorie des types,” in Répertoire de chimie pure,2 (1860), 354–359; “On Oxide of Ethyléne, Considered as a Link Between Organic and Mineral Chemistry,” in Journal of the Chemical Society,15 (1862), 387–406; “Sur l’oxyde d’ethylene et les alcools polyethyleniques,” in Annales de chiemie et de physique, 3rd ser., 69 (1863), 317–355; “Nouveau mode de formation de quelques hydrogenes carbones,” in Comptes rendus…de l’Academie des sciences,54 (1862), 387–390; “Sur l’atomicite des elements,” in Bulletin de la Societe chimique de Paris,2 (1864), 247–253; “Sur les densites de vapeur anomales,” in Comptes rendus…del’Academie des sciences,60 (1865), 728–732, and 62 (1866), 1182-1186; “Transformation des carbures aromatiques en phénols,” ibid.,64 (1867), 749–751; “synthese de la nevrine,” ibid.,65 (1867), 1015-1018; “Sur la densite de vapeur du perchlorure de phosphore,” in Comptes rendus de l’Association francaise pour l’avancement des sciences,1 (1872), 426–445; “Nouvelles recherches sur l’aldol,” in Comptes rendus…de l’Academie des sciences,76 (1873), 1165-1171; “Recherches sur la loi d’Avogadro et d’Ampére,” ibid.,84 (1877), 977–983; “Sur la notation atomique,” ibid., 1264-1268; “sur les densites de vapeur,” ibid., 1347-1349; “Sur le ferment digestif du Carica papaya,” ibid.,89 (1879), 425–429; “Sur la papaine; contribution a l’histoire des ferments solubles,” ibid.,90 (1880), 1379–1385; and “Sur la preparation de Íaldol,” 92(1880) 1438-1439.

The above selection is taken and corrected from the bibliography appended to C. Friedel, “Notice sur la vie et les travaux de Charles–Adolphe Wurtz,” in Bulletin de la Societe chimique,43 (1885), i–lxxx, which also was published in the introduction to the 1886 ed. of Wurtz’s La theorie atomique.

II. Secondary Literature. Besides Friedel’s, biographies incldue A. W. Hofmann, in Berichte der Deutschen chemischen Gesellschaft,17 no. 1 (1884), 1207-1211, and 20, no. 3 (1887), 815–996; A. Gautier, in Revue scientifique,55 (1917), 769–770; M.Tiffeneau et al., ibid.,59 (1921), 573–602: and A. Williamson, in Proceedings of the Royal Socéiéty,38 (1885), xxiii–xxxiv.

The following works contain invaluable information for an accurate appraisal of Wurtz’s contributions to chemistry: R. Ansch∧entity;tz, August Kekule (Berlin, 1929); J. H. Brooke, “Organic Synthesis and the Unification of Chemistry–a Reappraisal,” in British Journal for the History of Science,5 (1971), 363–392; G. V. Bykov and J. Jacques, “Deux pionniers de la chimie moderne, Adolphe Wurtz et Alexandre M. Boutlerov, d’aores une correspondance inedite,” in Revue d’histoire des sciences,13 (1960), 115–134; E. Farber, “The Glycol Centenary,” in Journal of Chemical Education,33 (1956), 117; H. Hartley, Studies in the History of Chemistry (Oxford, 1971), ch. 8; D. Larder, “A Dialectical Consideration of Butlerov’s Théory of Chemical Structure,” in Ambix,18 (1971), 26–48; A. Metz, “Lanotation atomique et la theorie atomique en France a lafin du XlX^e siécle,” in Revue d’histoire des sciences,16 (1963), 233–239; J. R. Partington, “The Chemical Society of France, 1857-1957,” in Nature,180 (1957), 1165; and A History of Chemisty, IV (London, 1964), 477–488; C. A. Russell, The History of Valency (Leicester, 1971); and G. Urbain, “J. B. Dumas and C. A. Wurtz–leur role dans l’histoire des theories atomiques et moleculaires,” in Bulletin de la Societe chimique, 5th ser., 1 (1934), 1425-1447.

John Hedley Brooke