CATIONIC SURFACE-ACTIVE AGENTS 231 ammonium compounds continue to attract interest. For example, L'Oreal •? have claimed shampoo compositions containing cationic (c. 10 per cent), nonionic detergent (c. 2 per cent), carboxymethyl cellulose (1 per cent) and lactic acid (5 per cent). It would appear, however, that the preferred technique is to use a cationic as a separate treatment, perhaps largely because the cationics cannot compete economically with anionics as ordinary detergents. In closing, a few remarks may be made concerning formulation of a new quaternary ammonium compound based product. This is simple so long as the quaternary ammonium compounds are not expected to behave like anionics. Except where common sense and experience guide, one should not be put off by the numerous statements in the literature about incompatibili- ties the latter are sometimes most advantageous TM and several compositions containing these incompatibilities have been mentioned in the literature. For example one patent • claims the employment of the reaction product of equimolecular quantities of anionics and cationics in the preparation of ointments and skin creams. A further example has already been quoted." Viscosity can be increased in quaternary ammonium compound solutions or creams by the addition of gums, cellulose ethers, non-ionics, fatty alcohols, lipids, or by simple inorganic salts. Clear, watery solutions of some quarter- nary ammonium compounds may be gelled by the addition o• a suitable salt. This effect is due to the normal salting-out caused by the electrolyte together with the conversion of part or whole of the quaternary ammonium compound to a new salt. All other formulation problems are of the type applicable to all cosmetic products. Acknowledgement The author thanks the directors of Milton Antiseptic Ltd. for permission to publish this paper. REFERENCES Lincoln, P. A., g/Ianufacturing Chemist, 27, 353 (1956). Rohm and Haas Company, U.S.A., Technical Bulletin. Lawrence, C. A., Soap, _Perfumery and Cosmetics, 27, 369 (1954). Lincoln, P. A., British Patent 735,631. Sinnova, French Patent, 1,000,869. Valko, E. I., and Dubois, A. S., J. l•act., 47, 15 (1944). Shelton, R. S., Van Campen, M. G., Tilford, C. H., Lang, I-t. C., l•isonger, L., I3andelin, F. ]., and Rubenkoenig, H. L., J. •lmer. Chem. Soc., 68,753 (1946). Valko, E. I., and Dubois, A. S., J. •act., 50, 481 (1945). Celia, J. A., Harriman, L. A., Eggenberger, D. lXl., and Ilarwood, H. J., J. •lmer. Chem. Soc., 77, 4264 (1955). Hugo, W. B., J. Pharm. Pharmacol., 9, 145 (1957). Lincoln, P. A., _Pharmaceutical Jnl., 177, 1956, 251.

232 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Lawrence, C. A., Surface-active Quaternary Ammonium' Germicides. Academic Press Inc., N.Y., 1950. Reddish, G. F. (ed.), Antiseptics, Disinfectants, Fungicides, and Physical and Chemical Sterilisation, Henry Kimpton, Lond., 1954. Mills, C. M., Ester, V. C., and Henkin, H., Journal of the Society of Cosmetic Chemists, 7, (5), 466 (1956). Hilfer, H., Drug and Cosmetic Industry, 73, 766 (1953). I-Iiloeer, t-I., Ibid., 77, 180,279 (1955). Monsavon-L'Oreal, British Patent 741,307. Kempson-Jones, G., Export Review, p. 40 (Oct. 1955). Barber, A., Chinnick, C. C. T., and Lincoln, P. A., J. appl. Chem., 5,594 (1955). Chinnick, C. C. T., and Lincoln, P. A., 1st Worm Congress on Surface ,4ctive Agents, 1, Sect. 2. 209, Paris, 1954. Barber, A., Chinnick, C. C. T., and Lincoln, P. A., Analyst, 81, 18 (1956). Lincoln, P. A., and Chinnick, C. C. T., Analyst, 81, 100 (1956). Lincoln, P. A., 1st World Congress on Surface Active Agents, 2, Sect. 9,761, Paris, 1954. Lincoln, P. A., Sanitarian, 64, 4, 1955. Lincoln, P. A., Brit. g/led. Jnl., No. 4971, 874 (1956). Richard Hudnut, French Patent 1,098,369. Monsavon-L'Oreal, British Patent 730,279. Dehydag Deutsche Hydrierwerke, British Patent 767,840.