For years, Friedrich Kekulé, a German chemist, struggled to unlock the secrets of benzene, an organic compound with unique properties. In chemical reactions, other organic chemicals combined in predictable ways. But benzene was a renegade with odd and surprising properties. Its molecular structure was a mystery.
One evening, Kekulé fell asleep in front of a flickering fire. He began to dream. In his dream, atoms danced in midair. Some atoms linked up with others to form pairs. Some of the pairs joined other pairs. Chains of atoms joined other chains. The chains twisted and turned like snakes. Suddenly one of the snakes formed a circle, its head chasing its own tail. The head grabbed the tail, and the snake whirled around and around.
Kekulé awoke with a start, dazed by the still-fresh dream. He realized that the dancing snakes were the solution to the benzene problem. Rather than lining up in chains like other compounds, benzene’s atoms formed a circle. That was the only way to explain benzene’s peculiar and unpredictable ways.
Kekulé’s vivid dream revolutionized chemistry, giving us new understandings of chemicals and the ways that they combine.