A discussion of the kinetics of cellulose degradation using results obtained from experimental work and published literature findings. The practical work compared heat and light ageing of oxidised and reduced cellulose samples. Degradation of the cellulose was followed using viscosity measurements. It would appear that the degradation of cellulose follows different stages: a rapid initial stage, the second phase of breakdown in the accessible regions and the final stage of attack on crystallites. At this stage the cellulose has lost all physical strength. Graphs, references.