August KekuléReverie dated to the 1860s; told in 1890

Kekulé's snake biting its tail

A famous story about a dream that led to the ring structure of benzene. Historians disagree about how much of it to believe.

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The dream

Retold in our own words from the sources below, not quoted.

At a celebration in his honour in 1890, the chemist August Kekulé told his audience how some of his ideas had come to him. He described dozing in front of the fire while working on a textbook. Atoms danced before his eyes, long rows of them twisting like snakes, until one of the snakes seized its own tail.

He said he woke as if struck by lightning and spent the rest of the night working out the consequences. The ring of six carbon atoms he proposed for benzene in 1865 became one of the foundations of organic chemistry.

Kekulé 1890

Where the story comes from

Kekulé told the story about twenty-five years after the discovery, in an after-dinner speech. He also described an earlier daydream on a London bus, in which atoms linked into chains. In his own words the experience was a half-sleep or reverie rather than a dream in the full sense.

How it has been read

History

The snake image has become the standard example of a dream solving a scientific problem. Taken carefully, it shows something more ordinary: an expert who has been thinking about a problem for years, half-dozing, seeing the pieces rearrange.

Kekulé 1890

Questions for your own dreams

Is there a problem you have been turning over for a long time?
Have you noticed ideas arriving when you stop trying, just before sleep or on waking?
How do you tell the story of a good idea afterwards, and what do you leave out?

Had a dream that stayed with you?

Tell us your dream

Sources

Every reading on this page comes from these works. Page references have not all been checked yet; those still waiting are marked.

August Kekulé (1890). Speech at the Benzolfest, Berlin, 11 March 1890. Berichte der Deutschen Chemischen Gesellschaft 23.
public domaincontested theory
- Cited at: Benzolfest speech, Berlin, 11 March 1890 (reference not yet checked)
- Cited at: Benzolfest speech (reference not yet checked)
Kekulé's own after-dinner account, given about 25 years after his benzene paper. Historians debate how literally to take it.
Alan J. Rocke (2010). Image and Reality: Kekulé, Kopp, and the Scientific Imagination. Chicago: University of Chicago Press.
cited, not reproduced
- Cited at: chapters on Kekulé's reveries (reference not yet checked)
Historian of chemistry; discusses the reliability of Kekulé's reverie stories.