WINKLER, CLEMENS

(b. Freiberg, Germany, 26 December 1838; d. Dresden, Germany, 8 October 1904)

technical chemistry, analytical chemistry.

Winkler was the son of Kurt Winkler, a pupil of Berzelius, N. G. Sefstrom, and Gahn, who managed a large cobalt works. Before entering the School of Mines at Freiberg. he spent his school vacations in his father’s laboratory, where he learned accuracy and cleanliness in the Berzelius tradition.

Winkler entered the cobalt trade and soon became interested in the use of sulfur gases from the smelting furnaces as a raw material in preparing sulfuric acid. This involved refining the methods of industrial gas analysis, and to this end he developed the Winkler gas burette; he also published the first comprehensive book on the subject (1876). Extending his work on sulfuric acid. Winkler prepared oleum (required by dyestuff makers) from chamber acid by means of a contact process. Chamber acid was decomposed at red heat to yield oxygen and sulfur dioxide, which were converted to sulfur trioxide over platinized asbestos. This was a significant advance, since previous workers had attempted to use finely divided metals or oxides without the asbestos support. The weakness of Winkler’s process lay in the gases being formed and used in stoichiometric proportions; his paper, however, was published in 1875, four years before the law of mass action was enunciated in its final form.

In 1885 a rich vein of argyrodite was discovered, and the mineral was submitted to Winkler for complete analysis. In repeated experiments his totals were consistent at 93 percent, and his early training in mineral analysis under his father convinced him that some hitherto unrecognized element must be present. In 1886 he showed that the substance was Mendeleev’s predicted ekasilicon, which he named germanium.

Winkler was professor of analytical and technical chemistry at the Freiberg School of Mines from 1873 to 1902. At a time when most German chemical effort was concentrated in the organic field, he made many contributions to inorganic and analytical chemistry through his patient teaching and his prolific writing.

BIBLIOGRAPHY

I. Original Works. The Royal Society Catalogue of Scientific Papers. VI, 396. VIII, 1251–1252, XI, 824–825, and XIX, 662, lists 91 publications. The following are relevant to the present article: “Versuche fiber die Ueberftihrung der schwefligen Saure in Schwefelsaureanhydrid durch Contact wirkung behufs Darstel–lung von rauchender Schwefelsaure,” in Dinglers polytechnisclres Journal,218 (1875), 128, on the contact process for sulfuric acid: and “Germaniun, Ge, ein neues, nichtmetal Iisehes Element,” in Berichte der Deutschen chemischen Gesellschgft,19 (1886), 210, on germanium. The book on gas analysis is Anleitung –at–chemischen Unterstrchung der I ndustrie-gale (Freiberg, 1876), which is supplemented by “Beitrage zur technischen Gasanalyse,” in Zeitschrift fiir anal vtische Chemie28 (1889), 269–289. Those who wish to savor Winkler’s literary style should read “Uber die Entdeckung neuer Elemente,” in Berichte der Deutschen cheinischen Gc.rellschcgft,28 (1897), 6–21.

II. Secondary Literature. There is no complete biography in English. The definitive life is Otto Brunck, in Berichte der Deutschen chemischen Gesellschaft,39 (1906), pt. 4, 4491 –4548. A shorter version by Brunck is in G. Bugge, Das Bach der grossen Chemiker, II (Berlin, 1930, 336–350.

The best English account of the sulfuric acid process is in G. Lunge, Sulphuric Acid and Alkali, 4th ed., I (London, 1913), in which 46 index references, are given. Winkler’s work on gas analysis has 25 index references in G. Lunge, Technical Gas Analysis (London, 1914). The discovery of germanium is described in M. E. Weekes. Discovery of the Elements, 4th ed. (Easton, Pa., 1939), 319–323.

W. A. Campbell