Archibald Scott Couper (1831–1892)

Born in Scotland, Archibald Scott Couper studied classical languages before turning to science. It is thought that his training with the complicated grammars of Latin and ancient Greek influenced how he looked at chemistry, for he compared atoms and molecules to letters and words in his writing.

Couper had revolutionary ideas about the way atoms joined to form molecules. He was the first person to form a concrete idea of molecular structure, proposing that atoms joined to each other like Tinkertoys in specific three-dimensional structures. He postulated rings of atoms as the structures of some molecules, and straight chains for others. Also of importance was his idea that each carbon atom could be joined to exactly four other atoms in the structure of a molecule. What’s more, Couper was the first person to draw molecular structures using elemental symbols for atoms and with lines drawn between the atoms to indicate the bonds between them.

Unfortunately, while Couper’s work was timely and original, his paper describing his ideas was delayed in publication through the procrastination of his supervisor, Charles Adolphe Wurtz. The delay gave another chemist, August Kekulé, time to publish a similar paper a few weeks earlier. Kekulé would be credited with the idea of molecular structure and carbon’s tetravalency. Couper suffered a mental breakdown shortly after this turn of events and never worked as a chemist again.