244 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS advise that they are incorporated. The choice of absolute oil will, of course, be governed by the complex, and one, two or three absolutes can be incor- porated. It is helpful if the floral absolute of the same odour complex is used, such as a jasmin for a jasmin complex or a rose for a rose complex, but this is not a hard-and-fast rule, for the addition of rose absolute will improve a jasmin complex but the addition of jasmin absolute w/ll not benefit a rose complex to the same extent. Otto of rose benefits most complexes, and one must decide from experience whether this rose would be better in a perfume than Rose de Mai, or vice versa. Most of these absolute oils possess a deep coloration, and that is one thing to guard against. They are inclined to over-colour a finished product and, as this is not always deskable, care should be exercised. There are those absolutes which possess a low price value such as Mimosa, Lavender and Oakmoss which can be used in higher proportions, though obviously one does not expect to include the expensive absolutes in compounds of the low price bracket, and there are absolutes of reasonable price value which can be used in fair proportion such as Genet, Immortelle, Jonquil and Tuberose. The expensive absolutes are Jasmin, Orange Flower, Cassie, Rose de Mai, Clary Sage, Violet, and I should include Otto Rose in the category of absolutes for this purpose. (Although a figure of 1 per cent has been mentioned previously, it is not intended that only 1 per cent should be used, but considerably more if the price allows.) The value of essential oils cannot be overestimated, and although good use is made of the more well-known oils, more use could be made of the lesser-used oils. I will not describe them as lesser known as they kre all known even if not used, but trace amounts of these essential oils could be and should be used to a great advantage, and many subtle effects are obtained. The oils I have in mind are such as Ambrette, Angelica, Basil, Carrot, Celery, Chamomile, Costus, Cumin, Elemi, Estragon, Ginger, Hops, Hyssup, Juniper, Lovage, Mace and Myrtle. An oil such as Ambrette must be used very cautiously, not only because of its high price, but because of its very powerful odour. In minute traces, however, it can have a very pleasing influence on perfume compounds, particularly on those of a heavy tonality. Oil of Celery can be very helpful to a jasmin complex, and Costus will give warmth to many compositions, especially those with a Violet complex. It is not necessary, however, to keep within conventional lines, and the perfumer should be imaginative and a little bold in his use of these oils. Many interesting tonalities can be obtained by their judicious use, though care should be taken not to make their presence obvious. The many aromatic gums which are obtainable, such as Galbanum, Labdanum, Benzoin, Olibanum, etc., yield very interesting oils in distillation, and they can be used together with the resinoid of the gum or alone to give a characteristic note. The value of these oils lies in the fact that they are

THE ART OF THE ?ERFUMER 245 more volatile than their resinoid counterparts, have more influence over the perfume during its earlier stage of evaporation and do not influence the residual note quite as much. There are many occasions in perfumery when this is desirable. Overdosing of a compound must be guarded agairmt, as the influence of these oils is very powerful. The use of these oils is growing and they are contained in many of the modem compositions. Their obvious presence in some compositions unfortunately detracts from the •esthetic value of the perfume. Mention must also be made of the few animal products used in perfumery and the tremendous influence they have over a perfume. Most perfumes are improved by a careful addition of one or more of the animal products. To even out the variation in odour value experienced with different consign- ments it is advisable to prepare solutions of these animal products. The best method is the addition of an alcoholic tincture to the finished perfume at the time of compounding. These tinctures should be at least six months old before use and the perfume with the added tinctures must be allowed to mature for a further six to twelve months' period. For a non-alchoholic product an extract in a solvent such as benzyl benzoate is advised and this can be added to the compound. The influences of these animal products are not felt until a suitable maturing time has elapsed, and this also applies when the substituted or synthetic animal products are used. These synthetically prepared bodies are not complete substitutes for the natural products but have frequently to be used for reasons of economy. Specialities should be used by the perfumer if they give him the assistance he needs for developing a complex. A speciality is a basic compound and is used to impart a special note to a perfume, whilst a compound is a finished product of such concentration that it can be used to perfume powders, creams, soaps, toilet waters, handkerchief perfumes, etc. Many specialities have been prepared by chemists after extensive research, and invariably they are stable products giving little odour variation from batch to batch. Several of the great perfumes of yesterday and to-day contain special/ties, and indeed the success of some can be attributed to these products, without which the perfumer would find it even more difficult to obtain a note of distinction. Some of these specialities are blends of several bodies and when they are included in a perfume they give the perfumer an opportunity of using some of the tremendous number of new aromatics of which he might not be aware or perhaps has forgotten. This is not intended to convey that each and every composition should contain a quota of specialities, nor do I consider that a perfumer should prepare a perfume just by mixing a few specialities, but it is advisable to examine the specialities very carefully and to choose wisely the correct type in order to produce the necessary warmth or tonality of depth or other note which the perfumer feels necessary for rounding off his creation. I do not hold the view that expert and experi-