TALKING OF PERFUMES AGAIN citral and lemongrass turned your skin yellow and anisaldehyde oxidised to a white solid, and how phenyl acetaldehyde polymerised to a viscous liquid ? These and a hundred more experiences one remembers and forever associates with the appropriate odour. But to return to our selected ingredients, our perfumer-to-be, lacking the background outlined above, sets out to memorise each odour, making what association he can and by continu- ous effort perfecting his olfactory memory. From the few ingredients already mentioned he may produce a crude but identifiable range of floral or other mixtures. There are four typical floral odours which occur repeat- edly in our bouquet or fancy perfumes--rose, jasmin, lilac, muguet and, in addition, perhaps violet. The rose odour may be made basically from phenyl ethyl alcohol, geraniol and geranium oil. The latter oil was specially included in our limited range as it contains the indispensable alcohols rhodinol and citronellol and certain esters which possess the intense rose odour. The lilac impression is given by phenyl ethyl alcohol, hydroxycitron- ellal and terpineoi. The muguet by hydroxycitronellal, terpineol, phenyl ethyl alcohol and geranium, the latter used for its rhodinol notes. Jasmin is less easy to define in terms of a few selected items, but is typified by amyl cinnamic aidehyde, benzyl acetate, linalool and linalyl acetate and, perhaps, hydroxycitronellal, together with small amounts of the ever-present phenyl ethyl alcohol. Sweetening effects to any of these four basic odour types may be achieved by traces of musk ketone. Below in tabular form is shown the four floral formulae, making use of eight synthetics (or isolates) and one essential oil. Rose .Lilac Muguet Jasmin Phenyl ethyl alcohol .. 40 20 10 10 Hydroxycitronellal .. 5 35 40 5 Geraniol .... 45 - 15 - Geranium Oil .... 5 - 5 - Terpineol .... - 25 15 - Amyl cinnamic aidehyde - 5 5 35 Benzyl Acetate .. 5 5 5 40 Linalool .... - 5 - 5 Linalyl Acetate .. - 5 5 5 Musk ketone .... traces traces traces traces Violet may be built in simple fashion from alpha ionone. The formulae shown are, of course, crude and only in rough proportions. Geraniol, for instance, is given only as a representative of the rose-alcohol group. In rose it would be supplemented by citronellol and rhodinol accord- ing to type and cost. Further, many refinements and more attention to blending proportion would be necessary, but the table is helpful if only to 187

JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS indicate how certain ingredients occur in each type. Thus phenyl ethyl alcohol, hydroxycitronellal and benzyl acetate are present in all four per- fumes, and amyl cinnamic aidehyde and linalyl acetate in three and the remainder in two. By making simple mixtures of the four basic types many "blends" or bouquets may be formulated. These mixtures may be further modified by ringing the changes with bergamot oil, vetivert, sandalwood, alpha ionone, musk ketone and musk ambrette, from the ingredients origin- ally given to our trainee. Final sophistication will eventually be achieved by careful use of methyl nonyl acetaldehyde. Without doubt, a second perfumer would approach the subject on very different lines and may well consider that important basic raw materials have been neglected or that unnecessary complications have been introduced at an early stage. However, many trainees passing through our perfumery laboratories have benefited from this particular approach. Having reached a stage where he is reasonably well acquainted with the selected raw materials and with an approximate idea of how his four basic floral odours are built up, he now widens his range of raw matehals. He will come to understand the basic odours of other floral perfumes, e.g., carnation typified by clove oil, iso eugenol and eugenol, modified by the rose complex. It will be advisable also to attempt to imitate or modify certain essential oils and in this case lavender is a good example. Lavender oil, offered in many grades, and lavandin are in themselves excellent basic raw materials, especially for soap perfumes, but by themselves they are but indifferent performers. They require "building up," supporting and greatly modifying before they may be considered adequate in soap. At the same time it must always be remembered that the presentation of a perfume in whatever the medium should aim for an individual character: for something that differs from the next preparation. Before passing from the types with which our trainee will become familiar, Colognes should be mentioned. Quite apart from the popular toilet water, the Cologne idiom is used to give the fresh citrus note to many creations. Colognes are essentially based on bergamot, lemon, orange, mandarin, lime and, inevitably, neroli. One of the finest training techniques and, indeed, a necessary qualifica- tion of the perfumer is the matching or imitating of an existing perfume. Quite apart from commercial necessities or training, the olfactory examina- tion of a perfume is a satisfying and exciting business. It is an exercise in the knowledge of raw materials, a test of memory, a battle of wits and, above all, a test of patience. From the trainee's point of view, he starts with simple mixtures, initially of two synthetics or oils in stated proportions, his problem being simply to identify the two ingredients. Gradually more complicated mixtures are presented, complicated in number, type, and proportions. Perhaps no work in perfumery sharpens the wits more effectively than this 188