TALKING OF PERFUMES AGAIN Lavender oil 40/42 % ...... 89.5 Bergamot oil ........ 10'0 Musk ketone ........ 0.5 100.0 This toilet water would give the true fresh note of the lavender and might, despite its simplicity of formulation, be regarded as an acceptable preparation. In creams or lotions its performance would be but moderate with the initial effect fairly good. However, the perfume would be fugitive and lacking in "body", with a tendency to become "stale." In powder, too, the effect would be disappointing, lacking in strength and depth, and would lose its initial freshness in a short time. In soaps the blend would be a dismal failure. When used at the rate of 1 per cent in a normal soap base the odour of the tablet would be but faintly lavender and the odour of soap would preponderate. Further, the life of the faint odour of perfume would be short. A new technique calling for more raw materials is needed for both cream and powder, but an even more drastic reformulation is required for a satisfying lavender perfume for soap. The light pleasing notes of French lavender oil, so effective in alcoholic media, are far less efficacious when used in soap. They require considerable modification and reinforcement. One might approach the problem in the following manner: Lavender oil 40/42 per cent Lavandin 20/22 per cent Lavender concrete Lavandin concrete Terpineol .. Bois de rose oil .. Linalyl acetate .. Terpinyl acetate Spike lavender Spanish Borneol .... Bornyl acetate .. Oakmoss resoine.. Labdanum resoine Coumarin .. Musk ambrette .. Musk xylol .. Musk ketone .. 20 30 5 5 5 5 5 7 10 4 4 2 1 6 2 4 2 117 193

JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Strength and body has been given to the lavender accord by the lavandin, lavandin and lavender concretes and spike. The ester notes have been modified by the use of linalyl, terpinyl and bornyl acetate and the alcohol notes by the use of terpineol and borneol. The spike and bornyl acetate give the necessary top lift so essential for the initial impression when the tablet is examined prior to use. The coumarin--a typical lavender note--performs almost throughout the whole range of evaporation and is an essential part of a lavender soap perfume. The oakmoss, labdanum and musks assure adequate back notes and fixation and generally sweeten the whole accord. FIXATION Earlier in this talk I mentioned fixation, a subject which has been some- what summarily dismissed by writers in the field of perfumery. Previously brief references to non-volatile solvents, solids and resinous products have been made, but the modern tendency appears to be to decry the use of fixa-. tives as unscientific, which is surprising, as the subject lends itself ideally to both theoretical and practical considerations. Just recently I read a pamphlet which absolutely scoffs at the existence of a fixative whilst, at the same time, talking of products which enhance the tenacity of a given odour. This could be dismissed as a confusion in terminology if it were not for the fact that the paper states quite definitely that benzyl benzoate, when added to a perfume, will have no effect on the rate of evaporation of the constitu- ents of the perfume. At least one writer has suggested that fixation actually takes place within the nose. If this effect did in fact occur perfumers and, indeed, all users of perfumes might well have cause to regret the very existence of such products. What exactly do we mean by fixation ? It is simply a retarding of the rate of evaporation of the constituents of a mixture of volatile substances. Call it "tenacity," "length of life" or any name you choose, it comes simply to the fact that we desire to maintain as far as possible a constant rate of evaporation of the individual constituents and certainly to inhibit the loss of the more volatile members. Ideally, we should select a range of ingredi- ents, all strong in odour and possessing identical and low vapour pressures. Such a mixture would obviously require no additional fixative. In actual fact we must use, in one blend, many substances varying in vapour pressure over a considerable range, and our problem is to make sure that the more volatile ingredients are not lost too readily, thus upsetting the balance of the perfume. Actually, the very mixing of two or more substances may produce some degree of fixation or lowering of the individual rates of evaporation. Before the molecules of a pure liquid can leave the surface they must overcome the forces of attraction of the other molecules, and this attraction is great, as the molecules of the liquid are much more closely packed than when in the vaporous state. In an ideal system the effect of dissolving a substance 194