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Summary and Conclusions Systematic physical chemical data on the solventwinterization behavior of cottonseed and peanut oils with acetone have been obtained which should serve as a basis for selecting the conditions necessary for the effective solvent winterization of these oils in acetone. Cottonseed and peanut oils are only partially miscible with acetone below certain temperatures which have been determined. In peanut oil this phenomenon may interfere with the winterization process within a certain range of concentrations. For cottonseed oil however the separation into two liquid phases does not occur until some 5°C. below the temperature required for adequate winterization. Complete data for a 3‐hour holding‐time have been obtained for three cottonseed oils ranging in iodine value from 106.1 to 116.4. Tables and graphs have been constructed to show the effect of oil‐solvent ratio, chilling temperature, holding‐time, agitation, and iodine value of the original oil on the percentage of solid removed and on the degree of winterization and iodine value of the winterized oil. Similar data have been obtained for a refined peanut oil insofar as possible without interference from separation into two liquid phases. It seems probable that if acetone were used as the winterization solvent for peanut oil, the separation into two liquid layers and the sensitivity of this phenomenon to moisture might be a source of processing difficulties especially if filtration instead of centrifugation were used to separate the solid from the supernatant.

RECENT advances in the science of high polymers have resulted in the development of theories which permit interpretation of textile properties in terms of molecular quantities. These theories make possible evaluation of some of the molecular constants required to correlate satisfactorily the physical and chemical behavior of a textile fiber with the properties of the molecules of which it is composed. The present paper demonstrates the application of stress-relaxation data to the Tobolsky-Eyring [26] theory of mechanical properties of high-polymeric. materials for the purpose of determining certain molecular constants characteristic of cellulose fibers.The investigation of stress relaxation at constant deformation of textile materials has been seriously neglected despite the advantages of such a study in adding to our knowledge of textile behavior. Experimental data which have been reported for glass filaments [9], rubber [2, 15, 21, 25, 27], gelatin gels [4], lead [28], steel [29], and polyvinyl acetate [17] have only limited application to the problem of textiles. Smith and Eisenschitz [24] investigated stress relaxations of viscose rayon, cellulose acetate, and silk. They attempted to interpret their results in terms of the Boltzmann &dquo;after-effect theory,&dquo; which they found permits only an &dquo;approximation to the actual behavior of rayon.&dquo; On the other hand, the reviews by Press [ 23 ] , Leaderman [ 10] , and Lyons [11]] indicate a wealth of flow and creeprecovery data which, because of the complexity of the phenomena involved, cannot be used in evaluating molecular constants as readily as stress-relaxation data. As Lyons points out, stress relaxation eliminates strain as a variable and permits investigation of &dquo;the adjustments taking place at the micellar and molecular levels, without the complication of concomitant deformation in the fiber substance.&dquo;The present report is of just such an investigation. . In it a new method for evaluating stress relaxation is described, and the results obtained are interpreted in terms of current molecular concepts of the structure of cellulose fibers.Theory Three types of motion in a fiber are postulated in the reaction-rate theory of elasto-viscous behavior as outlined by Tobolsky and Eyring [25,26] : motion due to decay of the primary structural elements of the fiber network; motion due to relaxation of secondary cross bonds permitting units of the network structure to slip on the application of stress; and motion of the mobile segments of the long molecules or groups of molecules. Equations based on a modi-