John Tyndall, the rhetorician of molecularity. Part one. Crossing the boundary towards the invisible

Abstract

This paper highlights the way in which Tyndall achieved his broad understanding of the molecular character of physical nature through an examination of the various molecular explanations he put forward in his papers and lectures, and argues that, in Tyndall's writings, one can find a most articulate version of nineteenth-century British molecular discourse. The exploration of those molecular conditions which underlay physical phenomena was central to his research throughout the years, and for this exploration he utilized his imagination, which he believed to be an innate faculty of the human mind. According to Tyndall, the imaginative dimension of science consisted of the creation of mental images of the unseen which enabled scientists to cross the boundary that separated the realm of phenomena from those of causal mechanisms. In his writings he expressed these mental images of the unseen in the distinctive molecular language of his age.