The discovery of thiamin.

Thiamin deficiency was long known as 'beriberi' in English and 'kakké' in Japan and China. The cause of beriberi was attributed to miasmas rising from wet soil and later to an unknown infectious organism. Systematic studies of beriberi began in the Dutch East Indies in the 1880s. Cornelis Pekelharing and Cornelis Winkler investigated beriberi in the Dutch East Indies and thought that they had isolated a micrococcus that was responsible for the disease. Christiaan Eijkman observed that chickens fed white rice developed a leg paralysis or 'polyneuritis', whereas chickens fed brown (unpolished) rice did not. Gerrit Grijns succeeded Eijkman in the beriberi studies in Java and concluded correctly that there were unknown substances in foods that were needed for the peripheral nervous system. In 1926, Barend Jansen and Willem Donath isolated and crystallized a substance that cured polyneuritis in pigeons. Robert Williams synthesized thiamin in 1936.