Communication, especially publication, in the natural sciences today takes place almost exclusively in English. This phenomenon is relatively recent, with a strong shift toward monoglot natural science taking place roughly half a century ago. This talk offers an account of the transformation of communication in the natural sciences from a primarily trilingual situation in 1850 (English, French, and German) to a bilingual situation after the Second World War (English primary, Russian secondary), to the essentially monoglot system of today. The perspective will be presented through the modern history of German. A century ago, German was on its way to becoming the dominant language in a polyglot environment. The significant and sudden decline of German, due to political upheaval during the twentieth century (especially the First World War) and cultural processes within the scientific community, was the primary condition for the transformation of a polyglot linguistic system in the natural sciences to a monoglot one.