Shortly before the end of the last century, Eijkman observed that fowl receiving a diet of polished rice developed a disease which he believed to be of the same nature as human beri-beri. It was subsequently shown that this condition in fowl (polyneuritis gallinarum), and beri-beri in man, could both be cured by the addition to the diet of rice polishings or an extract prepared from them. In 1911, Funk obtained from rice polishings a crystalline substance capable of preventing or curing beri-beri, which he named “vitamine” in view of its evident importance to life, and in the erroneous belief that it had the chemical structure of an amine. Four years later, McCollum and Davis demonstrated that at least two such dietary factors were necessary for growth in rats—“fat-soluble A” and “water-soluble B”. Before long it was recognized that the latter factor had the properties of the antineuritic “vitamine“, and a number of similar organic compounds were discovered, which were essential constituents of the diet in minute quantities, and for which the general term “vitamin”, was agreed upon. For several years it was assumed that water-soluble vitamin B (contained in yeast, rice polish, liver, etc.) was a single entity, but in 1919 Mitchell noted that certain vegetables rich in the antineuritic principle had little power to promote growth, and in 1926 two fractions were distinguished, each essential for growth—thermolabile vitamin B
1, containing the antineuritic principle (thiamin), and thermostable vitamin B2.