Adolf von Baeyer, German organic chemist, late 19th century.

GERMANY - MAY 20: Lithograph in glazed frame of Adolf von Baeyer (1835-1917), organic chemist, notable for his synthesis of indigo. Baeyer studied under Bunsen in Heidelberg and won the 1905 Nobel Prize for chemistry. His work covered the structure and synthisis of indigo (a blue dye); the synthesis of barbiturate drugs; the mechanism of photosynthesis; hydrobenzenes, terpenes, and polyalkynes. Baeyer wrote �I have never planned my experiments to find out if I was right, but to see how the compounds behave�. That is, he did not set out to prove a theory but experimented with an open mind. (Photo by SSPL/Getty Images)