PRACTICAL PERFUMERY AND INSTRUMENTATION 207 anything to do with our daily life, if it satisfies these conditions we are willing to accept any information, indeed, it is our job to know a little of everything that goes on around us concerning cosmetics, high class per- fumery, cheap perfumery, etc. That brings me to another concept of the perfumer. In the last few years the idea has gone around that the perfumer should be a chemist. I believe that this is the completely wrong outlook. The chemist's training is such that he is very orderly in his thinking and follows rules, whereas I, even when talking, do not follow any rules. I just treat the problem as it occurs to me. Order does not exist in my mind, except for odours. So when this does happen, when you appoint a chemist trained in chemical formulations to approach the problems of perfumery and he tries to relate them to structure, he will not get very far. You might just as well ask an artist (painter) to be a dyestuff chemist. When you are dealing with art and not science, mathematical rules do not apply. We have heard various opinions about the sensitisation of the skin, stabilities, instabilities, discolourations all these the perfumer must dis- regard when he creates something new. I have found, for instance, that a chemical incorporated into a piece of soap, together with traces of alkali, discolours, but in an admixture with other things this effect is not obtained. It is the same with irritation. Cinnamic aidehyde, benzaldehyde, hydroxy- citronella! and others, all irritate the skin, but when you are building up-- and a perfumer uses anything from 20 to 200 materials--these effects can completely disappear. So by being dogmatic on certain aspects the per- fumer handicaps himself, and achieves nothing in the end. One's mind may be cluttered up with considerations of things becoming discoloured, but if you use a material that is known to discolour and try it out it may not discolour at all. Stability is not a thing by itself. A material may possibly not be stable in a particular medium, but in association with others it is perfectly all right. I have tried for years to establish the reasons for this, but have never succeeded. On my shelves I have numerous perfumes, perfectly good on a strip of paper, but when incorporated into soap and left for a few days, the perfume completely disappears. So I return to the compound and try a new approach. Why has it happened ? I do not wish to give the impression that I oppose instrumentation. I am keenly interested in anything that furthers progress in the field of perfumery, but there are two sides to my mind: one is the interest I have in the hows, whys and wherefores, and the other is my job as perfumer. I try to make my mind a blank when I start a new project, and do not worry about cost. My first object is to produce something that is technically properly constituted and fulfils its purpose, the rest is dealt with afterwards.

208 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS This is when the troubles of the perfumer begin. We have heard of the cost of some aromatics, and this is a perfectly valid argument. In this age, when everyone wants the best value for little money it looms very large on the perfumer's horizon. The only time when he applies logic is after making something, he then starts dissecting, and perhaps even starts all over again to bring his "something" within the limits of the economics that operate. Most of us are dependent on the companies that employ us, and therefore have to conform to the aspects of the business that demand a reasonable return for the money expended. One can see what happens when things are pushed to extremes. Music is an example that naturally comes to mind. Every note, its duration and vibration, the exact pitch of any single instrument can be expressed in precise mathematical terms, but I have yet to hear a piece of music composed of mathematical values. The perfumer is in much the same position because he deals with intangibles. I can appreciate that any scientist, any research chemist, will hate to be con- fronted with something against which he cannot put an equation. In perfumery we deal with something entirely in a man's mind. We perfumers do not even agree amongst ourselves. If two perfumers are asked for a duplication of lavender, which is not too difficult, I feel sure, that between them they might possibly have four identical materials, and the rest will be different. Yet they will come up with the same answer, or reasonably so. We do not know what actuates odour. There are many theories, but nothing proven concerning what actually happens when we smell something. Yet twelve months afterwards our memory can say "I have smelt this before". What has happened ? The memory has been stored as knowledge, but how ? The technicians are doing a very good job, but should not try to tell the perfumer how to do his. It is the perfumer's job to use the materials they produce. DISCUSSION MR. J. D. CHESHIRE: After discussing the relative merits of instrumental methods of analysis and the art of perfumery, you have stated that "the perfumer is buying odour and not physical constants". I would like to ensure that there is no confusion between the information provided by physical constants, such as boiling point, refractive index, or specific gravity, and by physical methods of analysis such as gas chromato- graphy or spectroscopy. Relationships between chemical conditions and odour are at present purely empirical, as you have pointed out, but physical methods of analysis are constantly open to improvements and will eventually undoubtedly play an important role in understanding and defining odours. Physical constants,