ABSTRACT
Stereochemists believed that the groups around the carbon atom were arranged in a tetrahedron, and that stereoformulas represented in some fashion the molecule as a physical object. For Johannes Wislicenus, the importance of stereochemistry lay in its ability to uncover the underlying structure of the atom. Wislicenus proposed the least sophisticated of the atomic models, in which the carbon atom was 'probably' a tetrahedron whose corners possessed a concentration of chemical affinity. For J. H. Van 't Hoff, the tetrahedron gave organic chemistry a mathematical or geometrical foundation that could allow a more precise prediction of the number of possible isomers and provide an explanation for existing cases of isomerism. Van 't Hoff's suggestion that chemical formulas could represent the microscopic world of the molecule initiated the last major addition to the development of chemistry's visual language. Chemical formulas represent microscopic entities in macrocosmic from, while geological diagrams represent macrocosmic entities in microcosmic form.
