SYNTHETIC PERFUME MATERIALS FROM PINENE 171 According to our analyst, the amount of isopulegol in the traditional product which we have been manufacturing ranges from 0-01•0.1% . The figures for the synthetic hydroxycitronellal are within those limits, in fact rather on the lower side. On the basis of recent olfactive tests on the purity of hydroxycitronel!al, I am inclined to state that isopulegol is not quite the villain it is commonly thought to be. •!R. A.D. CHESHIRE: IS it in any way possible that the observed odour differences between the natural and synthetic citronellols is due to the differ- ent proportions of a- and/%forms ? T•E L•½TUR•R: I have smelt different products, containing both or one of the isomers, and in my opinion the differences of odour have no connec- tion with the a- and/•-forms. DR. R. FAvR•: As users we have something to say about these new developments in the perfumery industry, which are opening up new avenues for the industry, and we ourselves welcome the advent of these new chemicals, which will help to avoid dependence on essential oils so difficult to obtain nowadays. As Dr. Naves rightly said, they should not be regarded as replacements of the old but must be considered as entirely new products. Is it really necessary for us to try always to reproduce exactly some perfumery materials which have been produced for many years in the past ? I believe that the advent of these new materials, from fresh sources, will create a revolution in the industry. Large users of perfumery materials will welcome the opportunity of obtaining supplies independently of natural sources, with the difficulties of the political situation, transport, etc. I would like to hear the opinion of the people who use these materials, but not necessarily on the question of odour, because I do not think we should always try to simulate the odours of traditional raw materials. We must be progressive and forward looking, and see exactly what other people feel about it. •!R. J. G. E. HACKFoRT•-Jo•s: Other speakers have emphasized the differences which must always exist between terpene alcohols produced by the pinerie process, and those produced by conventional methods. These differences will make it difficult to change over to pinene products in existing established formulations, but as new products the pinene-process alcohols present great interest and the nerol in particular is very fine. Considering that ionones and methyl ionones produced by the pinerie process will be made from citral which has been already substantially purified, does the lecturer feel that the end products will more closely approach ionones produced by conventional methods ? T•E L•CTUR•R: Yes, the ionones are much further distant from the first

172 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS natural raw material. In the traditional ionones, processed from lemongrass oil, one normally does not find much of the lemongrass terpenes. I am therefore of the opinion that the new ionones will very much fall in line with the traditional ones. MR. G. L. GARDEL: As a perfumer, I would state that when comparing with products derived from natural sources, it does not matter how good the chemistry of the synthesis really is--you can never mistake a natural product for a synthesized one. But if that fact is realised, and the perfumer keeps his mind free from any outside stimul•e, commercial or otherwise, then he is fulfilling his role. In other words, he makes use of anything that has a smell, and maybe will give him a solution to the problem he is engaged upon. Surely this is his function, the rest is more or less incidental. That is my opinion on the use of synthetic materials. The perfumer is always con- fronted with economic considerations, and I agree that one should not change the horse in mid-stream, because like everything else the position is subject to commercialism. Hydroxycitronellal depends a great deal on the process involved. If you knew the manufacturing processes involved, you would find they all differed, and no matter where hydroxycitronellal is obtained from, there are no two Mike. This is entirely due to the manufacturing conditions.