The catalytic decomposition of undegraded cellulose in the form of cotton fibres is described with hydrogen peroxide at 0.4-0.04% (w/v) concentration in the presence of ferrous salts at pH3-5. 2. Complete solubilization of 5mg. of cotton fibres occurred in about 7 days in the presence of 0.4% hydrogen peroxide and 0.2mm-ferrous sulphate at the optimum pH4.2-4.3. 3. With 0.4% hydrogen peroxide the most rapid decomposition of cellulose was confined to ferrous sulphate concentrations of approx. 2-0.02mm. If the concentrations of the reagents were decreased in proportion extensive breakdown occurred but much more slowly. 4. In the primary stages of breakdown cotton fibres were disintegrated to very short fibres. These were subsequently solubilized, but there was little accumulation of soluble material. Organic matter was lost from solution as the reaction progressed. 5. Other naturally occurring cellulose-containing materials, such as grass, straw, hay and sawdust, were also disintegrated and solubilized by hydrogen peroxide and ferrous sulphate.
