Friedrich August Kekule von Stradonitz, German organic chemist, c 1880s.
© Science Museum / Science & Society Picture Library
Painting. Kekule von Stradonitz's (1829-1896) speculation about the structure of organic molecules led to his discovery that where several carbons occur together in a compound, they are joined to each other. This discovery, combined with other theories, enabled him to propose a molecular structure for benzene (the benzene ring) which is still in use today. Known as 'an intuitive genius', he is considered to be the originator of the structure theory of organic chemistry.