The Secret of Scent: Adventures in Perfume and the Science of Smell [Englisch] [Gebundene Ausgabe]

I wrote a longer review of "The Emperor of Scent."

The Good: Turin definitely has an interesting, original theory of olfaction. As I said in my earlier review, I think there's some chance that he may be right, even though many other olfactory experts dismiss the theory. I'm ready to believe that he could be a creative genius. Turin has a curious writing style that is worth noticing. At his best, he discusses scientific issues in a manner that will make intuitive sense to laypeople. He weaves in some intriguing nouns, metaphors, images, and colorful descriptions. He provides (mostly) generous descriptions of the theorists who proceeded him. Sometimes, he creates a surreal descriptive world in which perfumes seem to become dramatic sculptures, or plays. At first, I found myself dismissive of his grand and perverse expressiveness. But as I sampled colognes and other scents, I had to admit that there was a method to the author's descriptive madness.

The Good, Part 2: My sense of Turin and his work was enhanced by material available on the web. NPR has a series of radio reports on Turin, including some featuring Turin, and some featuring Chandler Burr. There's an interview with Chandler Burr on "To the Best of our Knowledge" (available via the Wisconsin Public Radio website). Turin's Flexitral website (science section) is worth a look. Some new work on electron flow in the presence of odor, by Brookes et al (University College, London), is consistent with the theory.

The Bad: Turin hasn't done the sorts of experiments that will persuade the scientific community that his theory is correct. In fact, there's a strongly worded essay in the journal Nature that suggests that the theory is as wrong as it is popular with the uneducated masses. I believe that Turin's theory remains viable... but I'm not an expert on olfaction per se.

The Ugly: Turin seems to have antagonized a fair number of sensory scientists. If you read this book, or "The Emperor of Scent," you'll see why. Turin sometimes descends into a gossipy and highly critical style. He rips into scientists the way that the tabloids rip into celebrities. He seems to antagonize and villify the people who might be most interested in testing his model. For instance, I'm a sensory scientist, experimental psychologist, and a psychophysicst (among other things). Turin doesn't have kind words for people in my line of work, suggesting that we are flat, uninteresting, and too interested in quantitative measurement (I can't remember the exact words. It wasn't pretty).

The Ugly, Part 2: Turin points out the ugly side of science, including the various cliques and petty squabbles that rule the day. He points out conflicts of interest and close-minded groupthink. If you aren't familiar with the scientific world, or if you've never had a creative idea, you might conclude that Turin is simply bitter and self-absorbed. But Turin is often on target, I must say. I don't know much about the world of olfactory scientists, but I've watched the group dynamics among scientists for years. A creative, temperamental person like Turin will have difficulty being accepted and appreciated by the scientific mainstream, even if his ideas find their way into mainstream theories. You might come away with the idea that Turin is the good guy and that the scientific establishment is inhabited by the bad guys. LOL. It isn't that simple!

The Ugly, Part 3: I enjoyed the book and would even recommend it. It was fun to read. But I'm amazed at the public's uncritical reaction to books like this one. Beware of the reviewers or media types who say that books like this one should be "required reading." Most reviewers enjoy Turin's drama but are not in a position to evaluate the scientific merits of Turin's work.

We have a pretty good idea about how eyes work to bring light inputs into our brains, and the same is true for ears bringing in sound. We rely on those two senses for a great deal of our information about the world, well above the sense of smell, whose operation is still largely mysterious. It is fun to think that this is quite possibly because smell is an ancient detection system; even one-celled animals can somehow sense molecules floating around them, and approach or avoid. Also, it may be because smell is intimately part of the brain itself; the smell sensors are extended bundles of brain neurons. Anyone who cracks the code to know just how molecules of a certain formation produce a certain smell is liable, not only to advance basic human knowledge, but also to gain a great deal of money. Everyone knows how big the market for perfumes is, and there are also industrial scents put into soap and detergent at no small price. Luca Turin thinks he knows how smell works. He'd be the last to say that the system is fully worked out, but his is the latest explanation, and he is gainfully employed in using it, which would seem to indicate that it works in a practical way. He has written about his theory, and the economic world of odors, in _The Secret of Scent: Adventures in Perfume and the Science of Smell_ (Ecco), a look into a singular world of economic and scientific ambitions.

Turin has to tell us about some basic chemistry, and his analogies are good, although some of the chemistry is so fundamental he even has to delve into a bit of quantum physics; in other words, don't expect to understand the details because nobody does. He is excellent at introducing us to the tools of his trade, like the gas chromatograph: "This machine is to smell what a prism is to light... and without it the life of the fragrance chemist would be hell." Molecules in smells are able to get to our noses because they are loosened by heat (body heat in the case of perfumes); cold things have little smell. Molecules are all tiny, but it is the small, simple ones that smell, while our noses usually can't pick up the big, complicated ones. The aldehyde family of molecules if they have an odd number of carbons smell mostly waxy, while if they have an even number they smell mostly of citrus; it is as if our noses have carbon counters in them. Perfumes often have expensive ingredients, but that isn't what makes perfumes expensive, since only 3% of the price goes to the smell itself; the rest is packaging, advertising, and margins. "Functional fragrances" rather than perfumes are what goes into soap powder, fabric softeners, and so on. They basically cover the smell of the working ingredients, and have to be cheap, but they bring in as much money to the fragrance-maker because there are so many of them, used in such large quantities. But they are not to be sniffed at, except literally; Turin writes, "Some functional perfumes are true works of art: I would pay real money for a bottle of the 1972 fabric softener Stergene which smelled sensational." Musks are a foundation for such scents, but they could not be so used before they were cheap. They used to come from face glands of oxen, sex glands of deer, excrement of pine martens, or urine of badgers, so getting a gallon of the stuff was not cheap. It was in 1887 that an explosives chemist, Dr. Baur, invented what is now known as Musk Bauer; he was tinkering with TNT. Since then, all perfumers have used synthetic musks.

Turin says that solving the structure-odor problem required of him knowledge of biology and chemical structure, which he knew about from his professional training as do many others, but then also a special interest in odor, which was just a hobby that a friend said he should write about. He wrote a guide on perfumes, and although he was paid peanuts for it, "this ugly little book" got him into the best perfumery labs. When he started writing up his ideas of smells caused by molecular vibration, other researchers got interested. There was a media buzz that has not hurt his cause, including a BBC documentary on his work. When his understanding of molecular vibration enabled him to stick an extra carbon into a molecule to make a lemon smell that was stable, and he told a friend who was a businesswoman about it, they started the fragrance company Flexitral. Soon he not only had ideas for fragrances but bottles of the real thing. It is interesting that in a recent audit, Flexitral's success rate in making an aimed-at fragrance was one in ten, which sounds low, but for the industry based on shapes of molecules rather than vibrations, it used to be one in a thousand. Cut-throat competition has given evidence that Turin's explanations are on the right track. It has not been easy. He has some interesting remarks here on the peer-review process that is the basis of modern scientific research; something is basically wrong with a system which, in his case, calls on peers from the small pool of a specialized field, all of whom would have conflicts of interest in judging the work. He is also scathing on the university system: "Universities are businesses these days, and every square metre of lab space must be made to sweat cash." Bitterness is not the tone here, however; as an amateur (literally, one who is pursing a goal for love, not money), Turin writes with a jolly enthusiasm about a subject which is inherently interesting and whose science is still in its beginnings.

I am delighted with this book! Finally I can take a really good, long look at all the structures of molecules with familiar smells and try to sort it all out for myself. This is what Turin tries to do, along with a continuously dry, irreverant humor that just makes it so much fun to read.

Even if you don't have a background in chemistry, you might be able to give this book a try, though it will take some willingness to sit down and try to mentally fit together all the jargon, which he defines nicely. But it this book will be more fun for someone with a tiny smattering of knowledge of organic, like knowing the definition of a functional group.

But this isn't just a book about smell, he could be onto something big in general, about how receptors really work. Of course it still needs proof, but his theory is that molecular vibration, rather than shape (although vibration and shape are related) may be better predictors for receptor activation by a molecule. If that is so, think of the pharmacological implications. That's big!