108 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS and the resulting activated state is resistant to oxidation. These Schiff bases are the newest development in commercially available cosmetic sun screens. Thus, ethyl-p-glucosylimidobenzoate is a screen (Escalol- 206*) which is highly selective in its activity. To a greater extent than even the p-aminobenzoate esters, such compounds absorb selectively in the erythematogenic range while they are nearly completely transparent in the higher ultraviolet. They permit the most complete transmission of the tanning radiation while providing efficient protection against erythemal radiation. z 2['0 aoeO 360 400 WAVELENGTH Thus a 2.7 per cent concentration of Escalol 206 in a clear or emulsified lotion transmits only 7.4 per cent of the erythematogenic radiation of sunlight, and 95.6 per cent of the radiation in the so-called tanning range, above 315 millimicrons. REFERENCE (1) Braude, E. H., "Chemistry of Carbon Compounds," Vol. 1A, Elsevier Publishing Princeton, N.J. (1951), pp. 71-93. * Van Dyk & Co., Inc.

THE EFFECT OF COSMETIC EMULSIONS ON THE STRATUM CORNEUM By DONALD H. Pow•.v.s and CHAV. L•.S Fox* Presented September 18, 1958, International Symposium, Gesellschaft Deutscher Kosmetik Chemiker, Bonn, Germany IN DEVELOPING cosmetic creams and lotions the cosmetic chemist is faced with t•he task of preparing not only a stable product but one that will have good consumer acceptance. Preparing a new emulsion for the application to the skin with acceptable shelf life may be a difficult task especially when one attempts to incorporate the promotional "plusses" that marketing must have but this could very well be child's play compared to the decision as to what characteristics the consumer would like to see in the product and how to evaluate the efficacy of the product. What is still more of a challenge is the fact that many emulsion properties are discussed daily among cosmetic chemists with no means at hand for measuring these characteristics. For example, experts in cosmetic product development will agree that an outstanding product should (1) possess a certain degree of "slip," (2) dry quickly, (3) leave just the merest trace of oiliness, (4) leave a velvety "feel," (5) leave a smooth finish, etc. But all these characteristics are purely subjective--the end result desired, of course, is a soft, smooth skin. In trying to arrive at what properties the consumer looks for, one may resort to panel testings but the authors have found them of little value in arriving at an answer. True, panel tests are effective in detecting serious flaws in the product, such as evidence of irritation, but they are of little help in actually determining the efficacy of the product. Many of you have, undoubtedly, experienced the situation where two creams identical in every respect except for odor are panel tested. Yet, the results obtained would indicate that the products are poles apart as regards "feel, .... finish, .... slip, .... stickiness, .... skin smoothness," or "greasiness." What is more disturbing is the case where the identical product is tested by a panel of cosmetic chemists on the one hand and by a panel of ad- vertising and marketing personnel on the other with opinions as to "feel," * Warner-Lambert Research Institute, Morris Plains, N.J. 109