A sample of cellulose nitrate was to be fractionated into a series of fractions differing from each other with respect to the degree of polymerization. The method chosen was to be one which would give a large number of fractions, each one attaining as high a degree of homogeneity with respect to chain length as could be reached without too great refinement of procedure. The degree of polymerization of the fractions was to be determined by viscosity measurements using the Staudinger viscosity equation (109) and then using a suitable solvent, a quantitative determination of the solubility of each fraction was to be attempted. From any solubility data obtained an attempt was to be made to determine if any relationship existed between the degree of polymerization and the solubility. Solubility is dependent upon the nitrogen content of the nitrate. Therefore, the nitrogen content of each fraction was to be determined, in order to draw valid conclusions from the solubility data. / M.S.