The carbohydrates of the Jerusalem artichoke and other Compositae.

more easily prepared from the dahlia tuber (cf. McDonald, 1946). ('Artichoke' is used to indicate Jerusalem artichoke throughout this paper.) It has long been evident (cf. Tanret, 1893a, b) that inulin may constitute only a small fraction of the total carbohydrate present in the artichoke tuber, the remainder resembling inulin in being composed essentially of fructofuranose units, but having a greater solubility in water and in aqueous ethanol. The term 'inulide' has been used by French workers (Wolff & Geslin, 1918) to describe substances of this type, which occur also in the tissues of many other Compositae (cf. Colin, 1919). Lemoigne (1941a, 1942) has published a comprehensive review of existing knowledge of the carbohydrates of the artichoke. In the course of an investigation into the transformations of fructose polysaccharides in the tubers we have made a survey ofthe carbohydrates present, using new methods, in particular paper partition chromatography. Although it was not our main intention to investigate the composition ofthe tubers, and some of the techniques employed are perhaps not the most suitable for that purpose, it is clear from the results presented here that existing ideas about the tuber carbohydrates must be modified. A preliminary account of this work has been given (Bacon & Edelman, 1949).