Auguste Laurent and the Prehistory of Valence (The History of Science and Technology, V. 1)

This study focuses on the French chemists of 1830-1858, and their roles in the development of organic chemistry and its eventual connectin with atomic and valence-bond theory, and uncovers new complexities in the thought processes that led to the concept of valence. The exploration of Laurent's early career reveals that this French chemist had proposed a hyposthesis to explain phenomena due to valence fifteen years before August Kekulé's Exposition of the classic valence-bond theory in 1858. Laurent put forward a hypothesis supposing the dividibility of atoms at a time when such a theory was far removed from the possiblity of experimentation. Within the positivist philosophy which prevailed at the time, few besides him would have dared to advance such a hypothesis. Laurent's hypothesis influenced certain advances in his chemistry, and that of his close associate, Charles Gerhardt, and eventually these advances helped turn most chemists to atomism.