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

SOCIETY OF COSMETIC CHEMISTS OF GREAT BRITAIN DIRECTORY OF MEMBERSHIP Dr. Arthur Anisoeeld, 34 High Road, Willesden Green, London, N.W.10. Mr. A. E. Bridle, 8 Ladbrook Close, Pinner, Middlesex. Mr. Frank Arkins, "Glan Hafren ", Bryntirion Hill, Bridgend, Glamorgan, South Wales. Mr. H. Wentworth Avis, 11 Royal Crescent, Holland Park, London, W. 11. Mr. M. P. Bailey, 115 ]?look Rise, Tolworth, Surrey. Mr. J. Bather, 53 Draycott Avenue, Northwick Park, Harrow, Middlesex. Mr. A. B. Bell, 9 Old Lodge Way, Stanmore, Middlesex. Mr. D. W. Bichen6, "Glenhazel ", Cleator Moor, Cumberland. Mr. Pierre Bongard, 50 Seaford Avenue, Nottingham. Mr. Ernest Brown, 31 Leaside Avenue, Muswell Hill, London, N. 10. Mr. George Burghall, 102 Cosrock Avenue, Sherwood, Nottingham. Mr. A. G. H. Clarke, 58 Holmwood Road, Freezywater, Enfield, Middlesex. Mr. E. W. Clark, 9 Ambleside Avenue, Smith Lane, Bradford, Yorkshire. Mr. W. A. Cole, 28a Derby Square, l,oughborough, I,eicestershire. Mr. S. Crystal, Flat 1, 40 Syd•enham Avenue, Sefton Park, Liverpool 17. Dr. H. I•. Dean, c/o Chemistry Department, Wigan Mining & Technical College, Wigan, I,ancashire. 2O9