JOURNAL OF THE SOCIETY OF COSi•IETIC CHEMISTS' Mr. Erhard S. Alterthum, Dermacult, Limited, 30 Adderly Street, P.O. Box 2362, Cape Town, South Africa. Mr. John C. James, United - Rexall Drug Co., Ltd., 68 Broadview Av.enue, Toronto 8, Ontario, Canada. Mr. Cecil C. Clark, The Anglo. Canadian Drug Co., Ltd., 99 Simcoe Street, South, Oshawa, Ontario, Canada. Mr. Alec Rimer, 17 Belmont Court, Banket Street, Hillbrow, Johannesburg, South Africa. Mr. Alberto E. L. Codina, Pond's Argentina S.R.L., Tucuman 2341, Buenos Aires, Argentina. Dr. Sadgopal, c/o Chemistry Branch, Forest Research Institute, P.O. New Forest, Dehra Dun, India. Mr. Stanley Gurland, P.O. Box 1751, Cape Town, South Africa. Mr. Herbert E. Szama, Avertida Santa Fe 3091, Buenos Aires, Argentina. STABILITY OF COSMETIC EMULSION5 (Concluded from page 197) as part of such a test. Finally, the possibility of a spon- taneous phase inversion occuring at some future time should be guarded against. Whether a given emulsion will be of the oil-in-water or the water-in-oil type depends on the type of emulsifier, the emulsion ingredients, the proportions of the two phases, and other factors. Any given emulsion may be near enough to instability so that some change in storage conditions may result in a phase inversion. Once a formula has been tenta• t. ively adopted, its stability against this type of change can be tested by making a series of small alterations in the formula. These alterations should include 'changes in the proportions of emulsifier, con- tinuous phase, and disperse phase. If the product is to be stable in re- gard to inversion all the altered samples should turn out to be of the same phase type. If some of the samples show inversions, their com- positions will indicate the change to be made in the original formula to avoid this change. It is hoped that this description of emulsion testing and testing theory will prove to be helpful to others who work with emulsions. The author gra.tefully acknowl- edges the helpful suggestions ooe Mr. E. J. Latos of Colburn Labora- tories, Inc. and of Dr. Herbert Sanders of Ninol Laboratories. (Paper presented at the' September, 1950, meeting of the Chicago Section, Society of Cosmetic Chemists, U.S.A.) 208

SOGIETY OF COSMETIC CHEMISTS, (U.S.A.) DIRECTORY OF MEMBERSHIP Dr. Philip D. Adams, Andrew Jergens Company, 2535 Spring Street, Cincinnati 5• Ohio. Dr. Jan,es Baker, 33-35 75th Strecl, Jackson Heights, Long Island, New York. Mr. Joseph A. Alexander, 315 West End Avenue, New York 23, New York. Mi'. tierman J. Amsterdam, 587 Montgomery Street, Brooklyn 25, New York. Dr. Carl N. Anderson, Pine Road, Briarcliff Manor, New York. Dr. Louis Appel, 3.1 West 85 Street, New York, N.Y. Ms'.- William 'F, dwin ArehSmeyer, 1278 Campbellton Road, S.W., Atlanta, Georgia. Mr. Douglas Atlas, 4443 S. Greenwood Street, Chicago, Illinois. ß , Mr. Edward F. Arnold, Commercial Solvents Corp., .t..7 East 42nd Street, 'New. York, New York. 'Mr,:.. Win.. S. 'Arnold, ._ '706 N. Patton Avenue, krling{on Heights, Illinois. 198 Mr. H. J. Bannon, Grove Labs., 2630 Pine Street, St. Louis 3, Missouri. Dr Louis C. Barail, 8 XVest 66th Street, New York 23, New York. Mr. Gabriel Barnett, 241 West 97th Street, New York, New York. Mr. William D. Barry, 241-17 Church Street, Douglaston, New York. Mr. Fred C. Beardsley, Packers Tar Soap Co., Inc.,. Mystic, Connecticut. Dr. Paul Z. Bedoukian, 511 West 232nd Street'. New York 63, New York. Dr. Arthur Behr, 406 East Grove Street, Midland, Michigan. .. Howard' T. Behrrnari, M.D..½ " 1125 Park Avenue ..... New York, New York.