Data are presented showing flow and physical properties of cellulose acetate plastics made using five plasticizers (previously described by Kirkpatrick before the Society of Rheology) with cellulose acetates of 2.3 and 2.6 acetyl groups per C6unit. Single plasticizers exert specific effects on flow and physical properties of the plastics. Mixtures of such plasticizers give plastics with properties which may be predicted by a simple proportion based on the amount of each plasticizer used. Results of Rockwell hardness, elastic modulus, impact strength, and water absorption tests of molded plastics are discussed. No general relation is found between flow properties of the plastics at molding heats and physical properties at room temperatures. An attempt is made to relate these results to the criteria for high elasticity set up by Houwink.