BOOK REVIEWS 353 The new edition is produced to the usual high standard. Remarkably the revisers have managed to compress this new edition into over one hundred fewer pages than the previous edition but this has not prevented a one-third increase in cost. Nevertheless, at the price this volume repre- sents good value and will undoubtedly be found a worthy addition to every cosmetic chemist's bookshelf. R.P. REEVES. The Principles and Practice of Modern Cosmetics. Volume 2. R. G. Harry. COSMETIC MATERIALS. Second Edition. Revised by W. W. Myddleton. Pp. xv + 803 q- Ill. (1963). Leonard Hill (Books), Ltd., London. 84s. This second edition is presented in an essentially similar manner to the first, i.e. an alphabetical listing of materials with details of synonyms, formula, molecular weight, occurrence or manufacture, physical and chemical properties, B.P. standard, use in toilet preparations and dermatological action. A little over four hundred monographs are included in the main section and, in addition, the Standards and Methods of both the TGA and TPF are reproduced which appear to be complete up to mid-1962. An appendix includes monographs on the FDA approved colours. A!most one third of this volume is devoted to reproduction of these specifications and methods and one wonders whether this is justifiable. The selection of materials for inclusion in this new volume leaves some- thing to be desired. More than thirty monographs deal with materials which the authors state are not used, little used or should not be used in cosmetics. Surely this is sufficient reason for excluding them. To these I would add at least another forty materials which means that more than one in six of the monographs are on materials which are of neg!igible interest to the modem cosmetic chemist. Some of these are perfume and flavour materials and are better left to the specialist works such as Arctander's recent volume but most are adequately, and more aptly, dealt with in the pharmaceutical texts, B.P., U.S.P., B.P.C., N.F., 'Martindale', etc. Some materials omitted are equally perplexing for instance, PCMC and PCMX are included but not DCMX U.S. permitted colours but no mention of British permitted food colours methyl--and benzethonium chloride but not benzalkonium chloride, cetyl and stearyl dimethyl benzyl ammonium chloride nor alkyl pyridinium compounds sodium but not stannous fluoride stearic and palmitic but not other fatty acids hairspray resin Devlex A.515 but not Ciba 325, Resyn 28-1310, Gantrez AN, etc. (the use of ethyl cellulose in hairsprays is not mentioned) menthyl salicy!ate but not its common cheaper alternatives homomenthyl and benzyl salicylates phenylmercuric benzoate and nitrate but not the borate a.s.o.

354 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS There is also a certain amount of unnecessary duplication. For instance, adjacent monographs describe acetic acid and glacial acetic acid separate monographs describe ethyl alcohol and I.M.S. sodium carbonate anhydrous, monohydrate and decahydrate calcium hydroxide and lime water chalk and calcium carbonate. The monograph on I.M.S. is particularly disappoint- ing and gives a completely erroneous picture of a material the use of which is made complex enough by Excise regulations information on denaturi- sation requirements could usefully have been included. Probably the most important group of modern cosmetic materials are the surface-active agents and their treatment in this volume is very sketchy and inadequate in contrast to the lengthy discussion of some materials of comparatively minor importance. Errors and misleading statements are all too frequent in this volume, making the reviewefts task the more difficult. The formula for D.D.T. (p. 165) is wrong the old numbering for the Arctons (p. 196) is used the Isceons and Ucons are not mentioned and the derivation of the present propellant numbering system is not given the formula for sodium perborate (p. 442) is wrong but the correct formulas for the two "hydrates" are given in the TPF standard on the adjacent page! (its main use as a cold wave neutraliser is not quoted) is propenyl alcoho! a synonym for glycerol (p. 202) ? The monograph on the Carbopols appears on page 113 but the TGA specification follows Polyvinyl alcohols on page 369 with no cross- reference. The monograph on cetyltrimethyl ammonium bromide incor- rectly ascribes this constitution to Cetrimide and Cetavlon the latter are, of course, the mixed alkyl (average C•4) derivative. I cannot agree with the definitive statement (p. 27 referring to aluminium chloride as a deodorant) "... it is the aluminium ion which reacts with and precipitates the skin proteins with consequent obstruction of the sweat pore". Perhaps the most spectacular error however refers to the use of thioglycollic acid in cold waving (p. 502), "... it severs the S-S link in hair and forms an S-H group. An oxidizing agent is then applied to the hair and a sulphenic group is produced R-S-OH, which combines with another amino group in the hair molecula to give the 'set' "• I found particularly irritating the inconsistent and sometimes quite erroneous presentation of references, and the extraordinary number of typographical errors indicate that the proof-reading leaves very much to be desired. The presentation, binding and paper of this new edition are excellent but regrettably I cannot say that this volume is either a worthy successor to the first edition, or a worthy companion to the filth edition of Volume 1. R. P. REEVES.