KOCH, Robert, German bacteriologist: b. Klausthal, Hanover, 11 Dec. 1843; d. 28 May 1910. He received a medical education at Göttingen (1862-66), was assistant surgeon in the Hamburg general hospital, was in private practice at Langenhagen, Rakwitz and Wollstein, and in 1872 was appointed to the Imperial board of health. In 1882 he succeeded in isolating the tubercle bacillus, in 1883 was made privy councillor and became director of the cholera commission to India and Egypt. He discovered in 1884 the cholera spirillum, or comma bacillus, regarded as a positive test of the presence of Asiatic cholera. For this service he received by legislative act a gift of 100,000 marks ($25,000). In 1885 he was appointed professor in the University of Berlin, director of the newly established Hygienic Institute of Berlin, and also director of the Prussian board of health. One of his pupils prematurely announced in 1890 the discovery of a substance called tuberculin, which, he asserted, would cause to cease the growth of the tubercle bacillus. Subsequent experiment failed in the judgment of scientists to confirm this claim. In 1905 he was awarded the Nobel prize in medicine. In 1906 the Gorman government sent Koch to investigate the “sleeping sickness” in West Africa. He had previously studied blood infections in East Africa in 1903, had found the spirochetæ of African relapsing fever in the ticks through whose bites it is transmitted. In the tick he found also the piroplasma which causes “Texas fever,” and proved that the tsetse fly transmits the trypanosomata at the moment of biting. Among his writings are ‘Untersuchungen über die Aetiologie der Wundinfektionskrankheiten’ (1878; Eng. trans., 1880); ‘Ueber die Milzbrandimpfung: Eine Entgegnung auf den von Pasteur in Genf gehaltenen Vortrag’ (1882); ‘Beitrag zur Aetiologie der Tuberculose’ (1882; 1886); ‘Ueber die Cholerabakterien’ (1884; 1886); ‘Ueber Naturheilung und medizinische Kunst’ (1885); ‘On Disinfection’ (1886); ‘Ueber bakteriologische Forschung’ (1890); ‘Ergebnisse der vom deutschen Reich ausgesandten Malaria-Expeditionen’ (1900); ‘Aerztliche Beobachtungen in den Tropen’ (1898); ‘Diagnosis, Treatment and Prophylaxis of Tropical Malaria’ (1898). Consult Biggs, H. M., ‘Robert Koch and his Work’ (in American Review of Reviews, Vol. XXIV, New York 1901); Fischer, Bernhard ‘Robert Koch’ (in Deutsche Rundschau, Vol. XXXVII, Berlin 1910); Wyeth, J. A., ‘Memorial Address’ (New York 1911).