August Kekulé

I was sitting, writing at my textbook, but the work did not progress; my thoughts were elsewhere. I turned my chair to the fire and dozed. Again the atoms were juggling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by repeated visions of this kind, could now distinguish larger structures of manifold conformation: long rows, sometimes more closely fitted together; all twining and twisting in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke; and this time I spent the rest of the night in working out the consequences of the hypothesis.

Let us learn to dream, gentlemen, then perhaps we shall find the truth. But let us beware of publishing our dreams before they have been put to the proof by the waking understanding.

The benzene ring was not discovered, it was dreamt.

The theory of the constitution of organic compounds is, in its present form, the most important and fruitful generalization in organic chemistry.

The atoms are not simple points, but are extended in space and possess a definite volume.

Chemistry is the science of the transformations of matter.

The number of atoms which can combine with one atom of carbon is four.

The atoms of carbon are tetravalent.

The atoms are in constant motion.

The constitution of a chemical compound is the arrangement of its atoms in space.

The benzene formula is a closed chain of six carbon atoms, each united to one hydrogen atom.

The idea of the benzene ring came to me in a dream.

The chemist must be an artist, a philosopher, and a craftsman.

The progress of science depends on the free exchange of ideas.

The most important discoveries are often made by accident.

Imagination is more important than knowledge.

The true scientist is always a skeptic.

The pursuit of knowledge is an endless journey.

Science is a human endeavor, full of triumphs and failures.

The beauty of chemistry lies in its ability to explain the world around us.