Book review DISPERSION OF POWDERS IN LIQUIDS--With Special Reference to Pigments. 2nd Edition. Editor: G. D. Parfitt. Pp. 418 (1973). Applied Science Publishers. London. oe8.00. Although the cosmetic chemist is very much concerned with the prac- tical problems associated with the dispersion of pigments in a wide variety of media, there is little pub- lished work on the technology in- volved. For this reason, the experience gained in allied industries is the only real source of information, particu- larly the paint and printing ink indus- tries. The book reviewed represents an up-to-date exposition of both the theoretical and practical aspects of pigment dispersion in paints and printing inks and these are very much relevant to our problems in make-up formulation. For the more practically minded formulator the first important chapter is Chapter 4 which deals at great length with the role of surface active agents in the dispersion of pigments in both aqueous and non-aqueous media. Chapter 6 deals with the equipment used for making satisfactory pigment dispersions--very useful in that it shows the wide range of equipment available in addition to the well known triple roller and colloid mills. Assessment of state of pigment dis- persion is often not carried out in the cosmetics industry but Chapter 7 not only states how to do this but why it should be done. These are some of the more prac- tically important sections of a book which also contains some excellent chapters on the fundamental physical chemistry involved in the pigment wetting-out process. T. J. ELLIOTT 735