In further work on the vacuum pyrolysis of cotton cellulose, alone or with flame‐retardants, at temperatures usually near 420°, products have been identified and determined. In the tar, laevoglucosan has been determined by an infra‐red absorption method, and by gas‐liquid chromatography of its trimethylsilyl ether; 5‐(hydroxymethyl)furfural and 1,6‐anhydro‐β‐D‐glucofuranose have been identified and determined similarly by gas‐liquid chromatography. By thin‐layer chromatography of the 2,4‐dinitrophenylhydrazones, 19 carbonyl compounds have been identified in the products from pure cotton; fewer were found from cotton treated with flame‐retardants. The distribution of boron, nitrogen, phosphorus and chlorine from appropriate flame‐retardants has been determined among the products of pyrolysis of cotton. It is concluded that borax/boric acid, and APO‐THPC, act predominantly in the solid phase; Proban appears to act partly in the vapour phase. Mechanisms of pyrolysis are proposed. In a pure cotton cellulose, 1,2‐anhydroglucoses are regarded as important intermediates.

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The variation of stress and birefringence occurring during the relaxation of elongated samples of polyisobutylene at constant length was observed at temperatures between −40° and +50°C. It is found that stress and birefringence relax in the same way throughout this region, and that the quantity (stress/birefringence × temperature) is a constant. This indicates that this material behaves in a manner consistent with the kinetic theories of elasticity and birefringence for an ideal rubber, and that the statistical segment size is fairly independent of temperature in this range. A value of 3.5 × 10−24 cm.3 is obtained for the difference between the principal polarizabilities of the statistical segment.

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The investigation of the equilibrium absorption of Chrysophenine G by cotton has been extended to a wide range of salt/dye ratios in the dyebath. The results do not agree with the predictions of a current quantitative theory of the direct dyeing of cellulose.The substantivity ratio appears to increase indefinitely with increase of the salt/dye ratio, while the theory predicts that it should approach a finite limit ; and, contrary to the theory, the relation between the substantivity ratio and the salt/dye ratio depends on the salt concentration. '' Internal " adsorption isotherms have been calculated from the results.They approximate to the Freundlich type, differing considerably from the linear form assumed in the formulation of the theory, and depend on the salt concentration. The failure of the theory to fit the experimental results may be caused principally by the unavoidable use of concentrations in place of activities in its formulation.