Sur la constitution des substances aromatiques

Kekulé’s 1865 Sur la constitution des substances aromatiques, published in Bulletin de la Société Chimique de Paris, is one of the program’s working technical references. Cited in Book IV (Categorical Microcosm), Part 6, Chapter Organic Chemistry and Aromatic Systems, where the program draws on it in the context of “Kekulé’s proposal (1865) of alternating single and double bonds (C_6H_6 as a hexagonal ring) was a breakthrough, but it predicted two distinct C–C bond lengths.”