Since tuberculosis had not been known either in its nature or in its proper therapeutics for thousands of years, Robert Koch (1843-1910) 1882 discovered its germs and 1890 recommended its treatment with tuberculin, i.e. an extract of its bacterial cultures. During the "Tuberkulin-sturm" which ensued from the publication of Koch, the substance was at once proved in numerous clinics in many countries. But in spite of sophisticated procedures of production it could not become standard therapy because of its considerable side-effects when not being applied accurately. In selected cases therapy with tuberculin is still applied even today. However, the effort of treating tuberculosis with tuberculin had already been made before its propagation by Robert Koch. Yet the forerunners of Koch's therapy with tuberculin had not been recognized by scientific medicine at the time because of lacking plausibility of its fundamental principles--not before Emil von Behring (1854-1917) within his scientific researches came to an explicit recognition of the homeo- and isopathetic principle of treatment.