DISCOVERY ADDS CLUES TO COMPOSITION OF LIGNIN — The sugar glucose is part of the answer to a biochemical riddle — the exact composition of lignin. Lignin, which together with cellulose comprises wood, is a highly complex carbohydrate whose complete structure is unknown. It is considered a waste product…. Experiments … have shown that in Norway spruce trees the lignin is derived from glucose. The discovery was made by feeding the trees with radioactive glucose.… By studying where the radioactivity was located in the lignin the scientists were able to find how the glucose molecules were converted into these units…. They may some day be able to find as many uses for lignin as they have for cellulose.