Kundt, August Adolph

(b. Schwerin, Germany, 18 November 1839; d, Israelsdort, near Lübeck, Germany, 21 May 1894

physics.

Kundt was a leading experimental physicist in the nineteenth century. He studied at the University of Berlin, where he received his doctorate under G. Magnus in 1864 and qualified for lecturing in 1867. He obtained a professorship of physics in 1868 at the Polytechikum in Zenrich, at the University of Würzburg in 1869, and at accepted the latter’s chair at Berlin in 1888.

Kundt worked primarily in optics, acoustics, and gas theory; he became famous mainly for his method of determining the speed of sound in gases. By means of standing waves, which were produced in a tube closed at one end, the “Kundt tube,” and made visible thorough finely divided lycopodium seeds—in what were known as “Kundt’s dust figures” —he could determine the speed of sound in gases and compare it with that in solid bodies, In collaboration with E. G. Warburg, Kundt investigated friction and heat conduction in gases and established their pressure independents for certain regions,. In 1876 Lundt and Warburg published their determining, which became famous, of the ration of the specific heats of monatomic gases, such as mercury gas.

Kundt was, in addition, an expert on anomalous dispersion in fluids and thin metal layers. He demonstrated that this physical phenomenon appears in materials which absorb certain colors to a high degree, With W. C. Roenthgen he demonstrated the Faraday effect—the magnetic rotation of the plane of polarization of light—for gases. Kundt also published investigation on the spectra of lightning and on procedure for determining the thermo,-—actino—, and piezoelectricity of crystals.

BIBLIOGRAPHY

I. Original Works Biblogrphies of Kundt’s works are in Poggendroff, III, 757—758; abd IV, 818; and A. Harnack, Geschicker der königlichen Preussischen Akademie der Wissenschaften zu Berlin, III (Berlin, 1900), 162 (kundt’s academie writings only). He wrote more than 50 scientific papers, including the following, published in Annalen der Physic und Chemie;“Ueber eine besondere Art der Bewegung elastischer Körper auf toönenden Roöhren und Staöben,” 126 (1865), 513–527; “Ueber neue akustische Staubfigure und Anwendung derselben zur Bestmmung der Schallgeswindigeit in festen Köpern und Gasen” 127 (1866), 497–523; “Unterssuhung uöber die Schallge schwindigkit der Luft in Röhren,” 135 (1868), 337–372, 527–561; “Ueber anomale Dispersion der Körper mit Oberflaöchenfarben,” 142 (1872); 163–171; 143 (1871);“Reibubg und Waörmweleitung verduö Gase,” 155 (1875), 337–365, 525–550; 156 (1876), 177–211, written with E. G. Warburg; “Ueber die specifische Waörme des Quecksillbergases,” 157 (1876). 353–369, written with E. G. Warburg; and “Ueber die electromotoische Drehung der Polarisationsebene des Lichtes in Gasen,” n.s. 8 (1879), 278–298; n.s. 10 (1880) 257–265, written with W. C. Roengen. He also wrote “Antrittsrede” (after his election as a member of the Prussian Academy of Sciences), in Sitzungsberichte der Presussischen Akademie der Wissenscaften zu Berlin, II (1889), 679–683; and “Gedaöchtnisrede auf Werner von Siemens,” in Abhandlungen der Preussischen der Wissenschaften (1893), no. 2, 1-21.

II. Secondary Literature See W, Von Bezold, August Kundi, Gedaöchtnisrede, gehalten in dwer Sitzung der Physika lishen Gesellschaft zu Berlin an 15. juni1894 (Leipzig, 1894); and E. du Boise–Reymond, “Antwort auf kundts Antrittsrede,” in Sitzungsberichte der Preussischen Akademie der Wissenschaften zu Berlin (1889), no. 2, 683–685.

Hans-GÜnther KÖrber