The text analyses metaphors of bacteriology which were extensively used in Germany during the era of William II. These display--in a vivid exchange with the scientific concepts of the age--a specific popular understanding of disease based on bacteriology. Disease is essentially seen as a war of physicians against microbes. While popularizing science bacteriological metaphors became part of the political language of their age. At the same time the prestige of bacteriology was in turn employed to lend credibility to pictures of assumed enemies--by portraying them as infectious diseases. Although the political language of bacteriology differed from the social darwinism of the age in important structural and semantic aspects, it nevertheless influenced the political language of its time, for example by becoming a blueprint of antisemitic rhetorics.