Koch

Koch Robert (Robert Koch, 1843-1910), a world scientist, alongside Pasteur one of the founders of modern bacteriology. After graduating in 1866 from the medical faculty of the University of Göttingen, K. first engaged in private practice, and then according to

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"^^tusch Bacillus anthracis», Cohns Beiträge z. Morphologie der Pflanzen, B. II, 1876-77; also separate ed.-Lpz., 1876; 2. Aufl., Lpz., 1910). As a medium for the multiplication of bacteria, K. used the fluid from the anterior chamber of bull's eyes, which he placed as a hanging drop on cover slips. His thermostat consisted of plates filled with wet sand, covered with other plates and heated by a kerosene lamp. He took the inoculation material from the spleens of anthrax-infected mice. With the help of these simple devices, K. succeeded in discovering that bacteria are capable of forming a special form of dormant life-the spore, and K. traced under the microscope both the appearance of spores in bacteria and the development of new generations from these spores. These researches finally elucidated the etiology of anthrax. The existence of extremely resistant spores illuminated the methods of spread of this disease and eliminated all the contradictions that had perplexed previous researchers. At the same time, the role of bacteria as causative agents of infection was irrefutably proven for the first time.-The second work of K., in the same home setting, was devoted to the etiology of wound infections («Untersuchungen über die Aetiologie der Wundinfektionskrankheiten», Lpz., 1878). In it were established the famous requirements («Koch's triad»), without which the connection of diseases with certain microbes cannot be proven. «Parasitic microorganisms must be found in all cases of a given disease; their number and distribution must be able to explain all the phenomena of the disease, and finally in each individual wound infection a specific causative agent must be determined in the form of a well-morphologically characterized microorganism». To fulfill the established requirements, K. created a whole series of new methods for preparing specimens, staining bacteria with aniline dyes, illuminating with the Abbe apparatus and examining through a system of lenses immersed in cedar oil, methods that became a permanent possession of science and an essential aid to all further research. K. first applied these new methods to experimental diseases artificially induced in laboratory animals, in the bodies of which microbes were present in pure cultures. Given the state of bacteriological technique at that time, the bodies of animals seemed to K. the only apparatus that made it possible to maintain perfectly pure cultures of one specific type of microorganism. K.'s outstanding works did not fail to attract attention, and he was given the opportunity to continue his research in appropriate conditions-in the highest health institution (Berlin, Imperial Health Office). Here K. developed his activity to the fullest and over several years gave the world a series of remarkable discoveries and research. Quickly (from 1880 to 1885) followed K.'s classical works on disinfection, on the etiology of tuberculosis («Beitrag z. Aetiologie der Tuberkulose», Berl. klin. Wochenschr., 1882, № 15), on the etiology of cholera («Bericht über die Thätigkeit z. Erforschung d. Cholera in Aegypten u. Indien», Deutscher Reichsanzeiger, 1883), as well as a number of discoveries by K.'s students and collaborators (diphtheria-Loffler, typhoid fever-Gaffky and others). The work on tuberculosis is undoubtedly K.'s greatest discovery both in terms of the importance of the question itself and the difficulties that K. overcame to resolve it. To find the tuberculosis microbe, it was necessary to invent special staining methods, for its isolation and multiplication-special culture methods. K. brilliantly solved all these tasks and fulfilled all the requirements mentioned above in relation to tuberculosis. Then in the study of cholera, K. invented the remarkable method of isolating pure cultures from a mixture of microbes by streaking the mixture on gelatin plates. By this method, K. easily isolated the causative agent of cholera-the Indian vibrio and proved in international competition the superiority of his technique over Pasteur's.-In the further course, K. directed his efforts to solving the practical problem: to find a means of combating the tuberculosis bacillus he had discovered. Despite 30 years of persistent struggle, K. failed, however, to find a radical and specific treatment for tuberculosis. The most important discovery in this direction-tuberculin-was not properly evaluated and analyzed by him, and the action of tuberculin remained mysterious for a long time. However, from this most important task of his life, K. sometimes turned to other works, of which should be noted first the works concerning the establishment of principles for combating infectious diseases, and in particular cholera, typhoid fever, malaria (investigation of foci, isolation of patients, disinfection). The particular originality and at the same time merit of K. in this fight against infections lies in the fact that it is not defensive, but so to speak offensive. K. demanded the creation of special fighting units-epidemic detachments. Thus, K. organized expeditions to the Italian islands and large permanent organizations in the areas of typhoid epidemic spread in the Rhine provinces and in Alsace-Lorraine. On the same essentially offensive principle are based K.'s famous expeditions to Africa to elucidate the etiology and organize the fight against a whole series of tropical infections: cattle plague, piroplasmosis, malaria, relapsing fever and sleeping sickness. These expeditions provided a mass of valuable material and led, as is known, to many important discoveries that are still at the center of general interest. For the work of Koch and his students, in 1891 a special institute of infectious diseases (Berlin) was created, which now bears K.'s name and to this day remains the most important scientific center in this field. Together with Flügge (C. Flügge), Koch in 1886 founded the journal «Zeitschrift für Hygiene u. Infektionskrankheiten» (Leipzig-Berlin), which is still being published. Being by nature a researcher, K. did not like teaching and soon refused the chair offered to him. But his students were professors of hygiene in all German universities. K. as a scientist represents a brilliant example of an analytical mind. All of K.'s efforts were directed toward the exact characterization of each individual microbe as a separate species and toward establishing certain, even the smallest and escaping other observers, differences of this microbe from neighboring ones. Therefore, all the significance and meaning of K.'s works lie not in any theories and generalizations, but in the discovery of ever new and decisive distinguishing features of microbes and in finding new methods for establishing these distinguishing features.-Among the numerous signs of recognition and distinction received by K. from various scientific institutions and states, should be mentioned the Nobel Prize (1905).-A collection of K.'s works was published posthumously (Robert Kochs gesammelte Werke, Band I - II, Leipzig, 1912).