Carl Bosch, German chemist, c 1930s.

GERMANY - MAY 24: The chemical engineer Carl Bosch (1874-1940) developed industrial ammonia synthesis. He worked with Friedrich Bergius (1884-1949) on the invention and development of chemical high-pressure methods, for which they shared the Nobel Prize for chemistry in 1931. Their Haber-Bosch process for synthesising ammonia meant that fertilisers and explosives could be made from air, water, and coal which were readily available natural resources. Previously, the nitrites and other chemicals necessary for making fertilisers and explosives had had to be imported and were expensive. (Photo by SSPL/Getty Images)