3O8 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS forty year old smoker and a seventy year old non-smoker. This is even more apparent when neither subject has been extensively exposed to sunlight. The premature aging of women's facial skin is mainly the con- sequence of three basic factors: 1. The physiological process of aging of the entire integument, characterized by the folds resulting from habitual facial movements such as smiling and frowning. 2. Those chronic changes on the outermost skin layers which are caused by long exposure to sunlight. Such changes, as a rule, are not found on the skin of the rest of the body except on the neck, forearms, and hands. 3. Combined with the first two factors are those changes in the circulation and the quality of the deeper connective tissue which follow long years of smoking and which are mainly noticeable on the face and on the neck.

J. Soc. Cosmetic Chemists, 16, 309-315 (1965) The Action of Hair Sprays on Hair MARTIN G. BROOKINS, M.S.* Presented before the New England Chapter, April 23, 196•, Framingham, Mass. Synopsis--Observations are made concerning the mechanism of hair spray application and holding. Indirect evidence leads to the author's hypothesis that wetting by alcohol per se is not responsible for curl rclaxation. INTRODUCTION Since holding in a hair spray is due mainly to the mechanical rigidity of the resin deposit formed on hair fibers, its application becomes important. By studying how the resin deposit is formed on hair fibers, the degree of holding of different types of film formers and the effect of resin distribution throughout the entire mass of hairs can be assessed. The application also depends upon the wetting properties of the solvent vehicle on hair. In most commercial aerosol hair sprays today, the main solvent is alcohol, with halogenated hydrocarbons used as solvents and propellants. By the time the liquid hair spray droplet strikes the hair, most of the propellant has evaporated, leaving only a residual amount present in the droplet. The amount of "flow-out" of the droplet on the hair fiber depends upon the degree to which the droplet wets the hair fiber and also depends upon the mobility of the droplet after it strikes the hair fiber. It is known, for instance, that a hair spray container packed with 50% alcoholic concentrate and 50% propellant provides a much wetter spray than one packed with 70% propellant and 30% alcoholic concentrate. A wet spray, 50f50 type /assuming that the * John H. Breck, Inc., Springfield, Mass. 309