August Kundt

August Adolf Eduard Eberhard Kundt (1839 to 1894) was a German physicist, born in Schwerin in Mecklenburg, known for developing Kundt's tube, an apparatus for measuring the speed of sound in gases and solids. He began his studies at Leipzig and moved to Berlin, where Heinrich Magnus turned him from astronomy to physics and he graduated in 1864 with a thesis on the depolarization of light. In 1866 he devised the dust-figure method, in which fine lycopodium powder collects at the nodes of a vibrating air column in a tube. He became professor of physics at the Federal Polytechnic Institute in Zurich in 1868, where he taught Wilhelm Rontgen, and in 1872 at the newly re-established University of Strassburg, where in 1876 he and Emil Warburg proved that mercury vapour is monatomic. He also studied anomalous dispersion and magneto-optics, and in 1888 he returned to Berlin as successor to Hermann von Helmholtz.