AlPHA-CELLULOSE is an insoluble fibrous residue obtained by extraction of wood, straw pulps and holocelluloses with strong alkali under carefully controlled conditions. Since the procedures used are arbitrary, the yield and composition of the alpha-cellulose prepared from any specific source may vary within rather narrow limits. Although alpha-cellulose from structural celluloses consists largely of β-1,4 glucopyranose chains, it contains also some non-glucose units. Xylan appears to be associated with most alpha-celluloses, with mannan being present also in those from gymnosperms1,2. Recent evidence by Leech3 indicates that a chemical union exists between the glucose and mannose units. Analytical data on wood alpha-celluloses suggest that uronic acid residues are also contained in the alpha-cellulose fraction, although positive identification of the specific acid has not been made2.