Abstract
In this article, I argue that chemical lectures at universities played a crucial role in the establishment of chemistry as a well-defined science in Germany around 1800. In particular, lecture demonstrations served to secure the facticity of facts. This was important, because the concept of the chemical fact was at the centre of the prevailing epistemology, which itself partly reflected the social order of chemistry as a science in Germany, and partly served to foster it. In the dialectic constellation of research and teaching, professor-chemists took the lead in the social and epistemological definition of chemistry.