Managing Scientific Information and Research Data

The first time I heard about the “Kekulé Riddle” was during a lecture that Dr. Alfred Bader, the founder of the Aldrich Chemical Company (now Sigma-Aldrich), gave at the Department of Chemistry and Biochemistry of the University of Maryland, College Park. Dr. Bader presented evidence that when the German chemist Friedrich August Kekulé published his paper on the benzene ring, he had already seen similar models proposed by an Austrian chemist, Josef Loschmidt. According to the legend, Kekulé came to the idea of this particular (ring) structure of benzene after dreaming of a snake eating its own tail. His theory was published in 1865—four years after Loschmidt had already proposed a similar structure, which he published in a little-known book. Archibald Scott Couper was the first to propose the theory of the tetravalence of carbon, but it was Kekulé who published it just a month earlier (in May of 1858) than Couper. After the lecture, I had the opportunity to interview Dr. Bader for the Chemical Information Bulletin (Baykoucheva, 2007) and asked him this question: