‎"KEKULÉ, AUGUST - THE REVOLUTION IN ORGANIC CHEMISTRY.‎
‎Ueber die Constitution und die metamorphosen der chemischen Verbindungen und über die chemische Natur des Kohlenstoffs.‎

‎Leipzig und Heidelberg, C.F. Winter'sche Verlagshandlung, 1858. 8vo. Later hcloth. Spine with gilt lettering. In: ""Annalen der Chemie und Pharmacie. hrsg. von Friedrich Wöhler, justus Liebig und hermann Kopp"", Band CVI. With both titlepages. (8),392 pp. a. 1 litographed plate (shaved in outer margin, ut not belonging to Kekule's paper). (Entire volume offered). Kekule's paper: pp. 129-159. Internally clean.‎

Reference : 48805

‎First appearance of this milestone paper in organic chemistry in which he demonstrated the mutual linking together of carbon atoms, developed the idea of affinity units, later called ""valence bonds"", and thus making it possible to explain the formation of organic compounds containing large numbers of carbon atoms. This was ""the final step in the development of modern structural formulas for organic compounds..."" (Leicester & Klickstein, p. 417)""It was not till 1858 that a satisfactory theory of molecular constitution was advanced, simultaneously and independently, by thwo young chemists, Friedrich August Kekulé and Archibald Scott Couper. The theory of molecular constitution put foreward....by Couper and Kekulé rested on two main postulates, the quadriivalency of carbon,....and the capacity of the carbon atom for mutual linking or combining together to form a carbon ""chain"". By this hypothesis of the mutual linking together of carbon atoms - which waslater confirmed by experiment - it was possible to explain the formation of organic compounds containing a large number of carbon atoms. On the foundation of their postulates two postulates, moreover, (they) showed how the molecular constitution or mutual linking together of the atoms of a compound could be represented diagrammatically and the relstions between different compounds made readily intelligible. In his classic paper ""On a New Chemical Theory"" (the paper offered here in its first appearance) advanced beyond Kekulé by representing the constitutions of the compounds by means of GRAPHIC FORMULA in which, as at the present day, the valencies pf the atoms are represented by lines....his formulae are similar to those at present in use...""(Findlay pp. 34 ff)""The theory of Kekulé and Couper gave the chemists the means of solving the problems of chemical constitution"" and by means of the graphic or constitutional formulae it became possible to represent the molecular constitution of known compounds and to foresee the possible existence of isomeric compounds.""(Findlay).Parkinson ""Breakthroughs"" 1858 C. - Ostwald's Klassiker No. 183. - Leicester & Klickstein ""A Source Book in Chemistry"", pp. 417-425. - Exhibition of First Editions of Epochal Achievements in the History of Science, Berkeley 1934. No 57.‎