August Kekulé

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Friedrich August Kekulé, later Friedrich August Kekule von Stradonitz (7 September 1829 – 13 July 1896) was a German organic chemist.

Life

From the 1850s until his death, Kekulé was one of the most prominent chemists in Europe, especially in theoretical chemistry. He was the principal founder of the theory of chemical structure.

The Ouroboros dream

The new understanding of benzene, and hence of all aromatic compounds, proved to be so important for both pure and applied chemistry after 1865 that in 1890 the German Chemical Society organized an elaborate appreciation in Kekulé's honor, celebrating the twenty-fifth anniversary of his first benzene paper. Here Kekulé spoke of the creation of the theory.

He said that he had discovered the ring shape of the benzene molecule after having a reverie or day-dream of a snake seizing its own tail, forming a circle (an ancient symbol known as the Ouroboros). This vision, he said, came to him after years of studying the nature of carbon-carbon bonds.

A similar humorous depiction of benzene had appeared in 1886 in the Berichte der Durstigen Chemischen Gesellschaft (Journal of the Thirsty Chemical Society), a parody of the Berichte der Deutschen Chemischen Gesellschaft, only the parody had monkeys seizing each other in a circle, rather than snakes as in Kekulé's anecdote. Some historians have suggested that the parody was a lampoon of the snake anecdote, possibly already well-known through oral transmission even if it had not yet appeared in print. Others have speculated that Kekulé's story in 1890 was a re-parody of the monkey spoof, and was a mere invention rather than a recollection of an event in his life. Kekulé's 1890 speech, in which these anecdotes appeared, has been translated into English. If one takes the anecdote as the memory of a real event, circumstances mentioned in the story suggest that it must have happened early in 1862.

He told yet another anecdote in 1890, of a vision of dancing atoms and molecules that led to his theory of structure. This happened, he claimed, while he was riding on the upper deck of a horse-drawn omnibus in London. This probably occurred in the late summer of 1855.

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