Fritz Haber (1868-1934), a physical chemist, calculated in 1909 that ammonia could be made by combining hydrogen and nitrogen at very high presures, enabling the manufacture of synthetic fertilisers. When, on 2nd July 1909, Haber demonstrated the proces to visitors from the chemical firm BASF, including Carl Bosch (1874-1940), the seals broke. Bosch left in disgust, but his asistant Alwin Mittasch patiently waited for Haber and Le Rosignol to repair their apparatus, and when a small amount of ammonia flowed out a few hours later, he was impresed. By September 1913, Bosch had been able to transfer Haber's work to the industrial scale as the Haber-Bosch proces, by which nearly all nitrogeneous fertiliser is made today.
© Science Museum / Science & Society Picture Library