SOME CURRENT PROBLEMS IN came into being through the of Chevreul, another French of Leblanc, who raised the of soapmaking from the rule of method to something that be predicted from the specific ,.action that actually takes place. from this period onwards to have been fairly rapid and ?•ffiany new fats, oils and additives .iWere introduced. i?It must be admitted, however, that ?søapmaking remained a relatively ii:Backward industry until about half ?a century ago, for the so-called •- .... . •i:• prachcal bus•ness man" remained •i:Supreme, scorning the aid of science •ii'.!!0r even the assistance of a works ?•...:!!:chemist. A classic example 'of i(}:•:.'inefficiency due to such ignorance :• •.was the. failure for many years to ,•,•-' recover all or even part of the avail- ::i':•!:able glycerin. Many other wasteful ¾.,procedures were common practice •i• at this epoch. It is fortunate that ?)managerial and technical staff now }Work in much greater harmony, :i':il although a few factory owners still ½iexist (notably in undeveloped coun- :: :tries) who cannot refrain from ß ß (attempting false economies in plant :):land process control, technical investi- ?. :'gation and research. , SOME CURRENT PROBLEMS :11:: A subject of particular interest to manufacturers of toilet soaps at the •! present time is what may conveni- ::'ently be termed "the economics of soap perfuming." The devising of an attractively odorous perfume compound for soaps is much more difficult than is gener- TOILET SOAP MANUFACTURE ally supposed and the pitfalls are many. Of course, all perfume com- pounds call for skill in their invention and production, but more contribu- tory causes produce failures when one is dealing with soaps. Stability and fixation are the two main features to consider. To choose any floral compound and "hope for the best" when incorporating into a soap base is both illogical and most uneconomical, many such compounds giving disappointing results, with a veritable disaster upon ageing. One of the main causes is the erroneous view taken about perfume base costs, it being far cheaper to use less of a relatively expensive base than much more of a cheap base. In many cases the use of cheap perfume bases may be regarded as the direct cause of unsuccessful results, and a final product that has no popular appeal. Cheap soap base perfumery com- pounds frequently contain various residual terpenes these may, how- ever, from an odour point of view, be regarded merely as diluents of no value. This general, although incorrect, method of compounding a soap perfume, should be discarded in lavour of the method which requires that a base is first s•lected, which contains a definite odour value with a known stability in soaps, and that to this base other ingredients are added to build up a suitable odorous compound that is not affected when incorporated in the soap base. Volatility, stability and boiling range are the three main points to con- sider when choosing your ingredients, 227

JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS whether they are to be natural or synthetic. The use of a cheap perfume compound calls for a much higher ratio to obtain a reasonable odour than when a compound is employed containing, say, a blend of absolutes or concretes, together with judicious blending of natural essential oils or high-grade synthetics, but containing no diluent such as the residual terpenes. In the one case, one pound or more is used to perfume 1 cwt. of soap, while two to six ounces of the more expensive blend would suffice. And if an odour comparison be made with the two compounds of like tonal value, it will be clearly appreciated that it is false economy to employ the cheaper compound. Also, odour value is in many cases a much stronger selling point than actual lathering properties, and must of necessity influence repeat sales of any toilet soap of well-liked odour. An'almost Universal Base of exce/)tional value for every type of soap, from which an individual compound can be made, consists of: Ionone 10 per cent, Linalol 5 'per cent, Terpineol, anhydrous, 85 per cent.. A proportion of this base serves as a foundation upon which the final perfume is built. Terpineol is strongly resistant to any alkaline reaction as encountered in a soap .base, and is of almost universal usage on the Continent, where soaps must in general possess a good, strong, .likeable odour, or the dis- criminating public will not deign to try them. For all high-class toilet soaps, those containing a compound blend of absolutes and concretes, together with selected essential oils, are the best compounds to employ. •' The results obtained are excellent and the fragrance imparted is lasting. Ordinary distilled oils in judicious combination with isolates or syn- thetics, cannot compare with these compounds based upon absolutes and concretes. The latter have, of course, a much higher initial cost, but there is no justification for the soap manufacturer's reluctance to employ them, when one considers that the use of only 0'25 per cent of. a natural Jasmin can give a more fragrant lasting odour than, say, 10 to 15 per cent of a high-class Jasmin synthetic. Often it is super- :. i ficial economy that is being practised, '. quite apart from the fact that the i substitute can never impart the::: finesse of the nattiral product, how2 ever good it may be. One must:: also bear in mind that, with compound based upon the more i expensive ingredients, a ratio of • 12'5 per cent to 30 per cent can b e ':(} used as against 100 per cent of cheaper base. DETERIORATION IN TOILET classified under the following headji!! (a) that due to the compositionøf•i the soap base ß (b) that caused by the process manufacture ß ' and :': :: (c) that which can be trac'ed::t6?i additions to the finished duct and to impurities 228