KOCH, ROBERT (1843—). A German physi cian and bacteriologist, born at Clausthal, Han over. He studied medicine at 06ttingen; then practiced medicine in Lang,enhagen, Raekwitz, and Wollstein. It was at \Vollstein, from 1872 to 1880, that he began the researches in bac teriology upon which his fame chiefly rests. Koch's researches on the history of anthrax were published in 1876, and two years later followed his study on the history of traumatic infective diseases. These works placed bacteriology upon a firm scientific basis. Appointed in 1880 a mem ber of the Imperial Board of Health in Berlin, he continued the unwearied study of the communi cable causes of anthrax, cholera, and tubercu losis, isolating the tubercle bacillus in 1882. To do this it was necessary to invent new appliances for microscopical work, and new methods of stain ing specimens to render visible these special mi ero;;rganisms. In this way Koch set on foot advances in bacteriology which are of inestimable value.
Koch and his supporters have shown that many diseases are caused by specific germs. In experi ments upon animals Koch discovered that the injection of diseased blood produced septicemia in house-mice, discovering also that the microor ganisms found in the blood of these animals were identical in form and character with those in the blood used for injection. At the site of tho injection of the infected fluid abscesses developed. The pus from these abscesses, full of the bacteria when injected in a diluted form into a healthy animal, invariably produced the disease. Koch produced erysipelas in the way. The infec tious character of tuberculosis of the lungs had been suspected for many years, but to him belonga the credit of discovering its specific germ. The tubercle bacilli are distinguished from others by marked characteristics, and are present in all cases of the disease. Koch demonstrated these bacteria in the sputum of those suffering from pulmonary tuberculosis. In 1S83 Koch became chief of the (Zermatt eommission sent to and India to investigate cholera. with the result of discovering the cholera spirillmn or comma bacillus. in the same year Koch published a method of inoculation to prevent anthrax. Re hulling to Germany in 1SS4, Koch received 100, 000 marks from the Government. In 1885 lie was appointed professor in the University of Ber lin and director of the new Hygienic Institute. In November. 1890, through the premature report by a student, it became generally known that Dr. Koch had discovered and tested, by a series of careful experiments, a compound substance which, when administered by injection hypoder mically, was destructive of the tubercle bacilli, and hence presumably a swift and certain cure for tuberculosis. The excitement throughout the world' attendant upon this announcement was very great. Physicians from all countries flocked
to Berlin, and consumptive patients traveled thither in the hope of certain cure. Amid all this Plantar, Koch remained for a long time silent as to the method of preparing the 'lymph,' and singular ly conservative in the claims that he made of its efficacy. In January. 1891. he put forth a state ment concerning the nature of his lymph, which, while not giving all the details of its preparation, made it evident that it was itself prepared from the bacilli. The essential parts of his statement will be found in the article TUBERCULIN. The lymph, or, as he preferred to call it, the para. toloid, is a poison and must be used with great caution. The reaction consequent upon its use is so marked as to lead many physicians to doubt its ultimate advantages. Professor Billroth stated that with three patients the reactions seemed so dangerous as to force him to discon tinue the treatment; and Sehrfitter of Vien na (January, 1891) and Crocq of Brussels con firm this statement from their own experience. The value of this discovery as a means of cure in the human race must therefore be regarded as yet in doubt, though the German Government be gan erecting the Koch Institute for Consumptives with an immense laboratory and 150 beds.
In 1901. before the British Congress on Tu berculosis held in London. Koch called attention to the fact that even at his first publication of the a•iologv of tuberculosis. he expressed himself with reserve regarding the identity of the dis ease in man and aniumls. announcing his belief that bovine tuberculosis and human tuberculosis were distinctly different diseases. These state ments, at the time characterized as sensational, gave rise to extensive disputation and experi ment. Among Koch's published works are: Zur Actiologie des llitzbrandes (1876) ; ratcrsuch ungen fiber die iletiologie der H'undinfrktions ucran•heiten (1878; Eng. trans. by Cheyue, 1880) ; Ueber die If ilzbeandimpf u ny, Eine Entgeynung a of dun von Pasteur in 1Jciif gehaltenen l'ortrag (1882) ; Beitrag zur :]etiologic der Tubereulose (1882; Eng. trans. by Boyd. 188G) ; Uebrr die Cholerabaklerien (1884; Eng. trans. by 'Aycock, 1886) ; Ueber Nalurbeilung und medizinische Kunst (1385; : On Disinfection, ab-tracted aria translated by Whitelegge (1886) Weiterr Icilungen fiber sin lIcilmittel gegen Tuberculose (1890) ; Uelar baktcriologisek, Porsehung (1890 ; trans. into English 1891) : Ergebnisse der rent Deutschen Belch ausgesand ten Jiularia-Expeditio nen (1900) ; Au Investigation of Pathogenic Or ganisms, translated by Horsley (1886) ; Arrzt lichr Brobachtungen in den Troprn (1398 ) ; Diagnosis, Treatment, and Prophylaxis of Tropi cal Malaria, translated by Shakespeare (1898). See the articles on TUBERCULOSIS and TUBER