The determination of 10-100 wmg. quantities of hexosamine.

1. A dextran synthesized by Leuconoatoc mesenteroides (strainNRRL B-512) has been partly hydrolysed with acid and the products were fractionated on charcoal-Celite. 2. Glucose was the only monosaccharide product and the dito hexa-saccharide fractions each contained a single component. 3. The oligosaccharides have been characterized as the lower members of the isomaltodextrin series and new crystalline derivatives of the triand tetra-saccharides have been prepared. 4. Some observations on the copper-reducing powers of glucose oligosaccharides are recorded.