ABSTRACT
According to Johannes Wislicenus, the chemical and mechanical characteristics of molecules governed their behavior – he therefore envisioned an unprecedented molecular dynamics to explain chemical reactions. Whatever the origins of his use of residual affinity, it is clear that Wislicenus did not postulate a purely mechanical rotation about the axis of the carbon–carbon single bond, but a dynamic rotation mediated by the chemical attraction of non-bound atoms. With the combination of rotations, attractions, favored configurations and the influence of heat, Wislicenus considered the molecule as a complex object with a unique set of inner dynamics. Wislicenus' ardent enthusiasm for J.A. Van 't Hoff's principles illustrated in 'Spatial Arrangement' represents an important shift in Wislicenus' own views on atoms and molecules that is also reflective of the overall shift from a chemical to physical atomism inherent in the emergence of 'chemistry in space'.
