The Emperor of Scent

(Above: The book and its dilettante subject, perfumer Luca Turin)

Milo's post on fragrances reminded me of the seminar on a new theory of smell that I had given a few years ago, which initiated my interest in perfumery. The real impetus was a book named "The Emperor of Scent", about a maverick scientist named Luca Turin, who developed a new theory of smell based on vibrations of molecules instead of their shape, the traditional approach which does a pretty poor job at explaining SOR (Structure Odor Relationships).

Over the course of my seminar, I had an opportunity to communicate both with Luca Turin and Chandler Burr, the book's author. I remain interested in the area, and would sometime like to think of serious computational approaches that one could undertake to understand SOR.

I thought I would post my review of the book. For an introduction to the fascinating world of perfumery and smell alone, it's a fascinating read.

"Start with the deepest mystery of smell" says author Chandler Burr in the opening stanza. "No one knows how we do it. Despite everything, despite the billions the secretive giant corporations of smell have riding on it and the powerful computers they throw at it, despite the most powerful sorcery of their legions of chemists and the years of toiling in the labs and all the famous neurowizardry aimed at mastering it, the exact way we smell things–anything, crushed raspberry and mint, the subway at West Fourteenth and Eighth, a newborn infant–remains a mystery".

In this gripping and entrancing book, Chandler Burr tackles the life story of Luca Turin, a man with an unusually sensitive nose,and a man obsessed by perfume and smell, a sense that commands a 20 billion dollar enthralling industry of flavour and odors. I was bowled over by Turin, at least the way Burr has described him; a brilliant, feisty, passionate, uniquely creative and completely non-conformist scientist trying to decipher a deep puzzle. Strangely, we still don't know how exactly we smell, and Turin set about to find out just how. Collecting together bits and pieces of biology, chemistry and physics, recent and past, he resurrected a fifty year old theory of smell in an astoundingly novel way. Burr also chronicles the intense interactions Turin had with other scientists, prima donnas in the field, big perfumery company scientists and executives, and the editors of the prestigious journal Nature. Turin was as much of a public person as a private one. In the end, Turin fails to convince most of them of the value of his theory, and ends up publishing his theory in a reasonably good but not blockbuster journal.

I was so impressed by this book that it became the basis for a graduate seminar on olfaction and perfume that I am going to give soon, and I have to really thank Burr for that. These days, I am engaged in thrusting bottles of chemicals under people's noses, and asking them to describe the smell. The book also introduced me to the dazzling and unique world of perfumery and smell in general, a bizzarely interesting mixture of art and science. The exotic sources for perfumery raw materials kept me glued to it and other perfumery books. Whether it was oudh, that lavish material that is obtained from rotten wood eaten by a fungus in Assam, or ambergris, the mesmerising ingredient originating in the stomach of a sperm whale, the world of perfumery abounds with facts which made me gravitate toward learning more. Most of these perfumery materials are fantastically expensive (typically costing more than their weight in gold) and hence the search for synthetic substitutes is an expedient one. Before I made a foray into this world, I was unaware of the fact that perfumers can smell perfume the way a music maestro or composer listens to a symphony. There are 'notes' in every perfume, and a good perfumer can literally dissect each note and characterize it when he smells a new creation. (For example, 'spicy', 'woody', 'minty' and 'green')

The book makes it clear that the perfumery industry is shrouded in secrecy, sophistication, and glamour. This very fact indicates that the creation of new smells is both an unpredictably creative process, and also a matter of trial and error. Because there is no 'objective' way to judge whether a perfume will be wildly popular or not, seductive advertising, big money, and big names are the name of the perfumery game. I remember, that when I got off on the Charles De Gaulle airport in Paris for a transit flight, the first thing I saw was Nicole Kidman's face staring at me from an enormous poster advertisement for Chanel 5., one of the most successful perfumes ever. Unlike the drug industry, where a drug succeeds if it succeeds, the appeal of perfumes is essentially created by the 'commodification of desire', as Noam Chomsky would probably call it! High society, penthouse cocktail parties, and extravaganza are the engines which fuel the perfumery industry. The perfumery capital of the world is surely Grasse in France. In fact, the French are totally obsessed with perfume. After defense and aerospace, it is their third largest money maker.

All this makes perfumery very much an art, and there is definitely a need for a convincing general scientific framework with which one could relate smell to the structure of molecules that constitute it. My uncle works as a perfumer in International Flavours and Fragrances, one of the biggest perfumery companies in the world, and this book served to enhance my appreciation and fascination of the state of affairs, as I recalled intriguing tidbits about smell and chemistry that my uncle has told me many times. Before Turin came on the scene, there was essentially a general paradigm of smell that drove studies in perfumery. It was a mixture of empirical chemistry and a hodgepodge of art and intuition. However, there were gaping cracks in this framework, and Turin decided to come up with a theory that could remedy this situation. Without going into the details, let me say that Turin's theory is very interesting and innovative, and promises possible new understanding in our study of smell. That the science/art of smell has come of age is indicated by the awarding of last year's Nobel Prize to two researchers who worked out the biology of olfaction.

The only possible flaw in this book, is that Burr does only too well in a sense. His eloquent description of many scientific concepts somewhats clouds the real truth behind them in a dazzling display of words and rhetoric. Things are not as simple as they seem, especially in science. So does his description of top scientists' reaction to Turin, and Turin's futile attempts to solicit interest from big perfumery companies. While it is true that the scientific peer review process that evaluated Turin's theory and finally dismissed it can sometimes be quite unforgiving, Burr makes Turin sound like the hero and all others (including last years' Nobel Laureates) as villains, who have come together in a conspiracy clique to prohibit others from overthrowing their pet ideas. That is rather unfair to them. The fact is that with all its flaws, the scientific review process has its merits and it's probably the best we have right now. Most importantly, not all of Turin's results sound as spectacular and unambiguous as Burr makes them sound, and Turin does not provide overwhelming evidence for them. In fact, some of his results are thought to be almost certainly false by a number of distinguished perfumers. When he first proposed his theory, many were convinced that he would win the Nobel the next year. However, as time revealed the overambitious essence of his ideas (no pun intended), people became much more skeptical. After all, Turin has proposed a theory, but perfumery is still very much an applied and empirical science/art, and is the basis for essentially a consumer industry that owes more to mystique and advertising than it does to hard science. Theories are of no use if they are not predictive and cannot make money for the big perfume giants. Most importantly, smell is SUBJECTIVE, and this is a point which keeps hitting home. Unlike the efficacy of a drug, there is no way to judge the character of a new smell. It may smell of mint to one person, sandalwood to the other. A related problem is that our sense of smell is bound by language, by the way we describe odors, and these descriptions turn out to be completely different for similar odors (even seasoned perfumers face this problem). This is a major barrier that has to be surmounted, if there is to be a satisfactory theory of smell. In this respect, Turin turned out to be too ambitious and tried to devise a general theory, without a proper method of evaluation and measurement. In a way, experiments still have to catch up with his theory. He still has a long way to go (not that the other ones are any more predictive; in this sense, Turin is on the same stage as the old stalwarts). Burr does not enumerate the drawbacks of Turin and his theories as well as he should have. Interestingly, the only serious scientific conference that Turin was invited to was a conference in Bangalore organised by the Tata Institute of Fundamental Research (TIFR) (Burr calls it 'India's Los Alamos'). There, he had lively discussions, especially with students in the rustic 'coffee board' cafeteria of the Indian Institute of Science, a place where I myself have lazed about many times when I spent a summer there.

The one feature of this book that stands apart is the spellbinding and exquisite language that Burr uses, quite worthy of its subject, who is a connoiseur in every sense of the word. Scientific facts and theories, tales of perfumes and their creators, the capricious world of perfume marketing, the artificiality and sophistry that inundates the high profile clientele of perfumes, and finally the man behind the book himself; all of these submit before Burr's flourishing descriptions and make engrossing reading. Burr is a master of rhetoric, and his style is very gripping; this is one of the best page-turners that I have come across.
The only thing that can possibly surpass Burr's language are Turin's own descriptions of perfumes and smells in the best selling perfume guide which he wrote. He has an uncanny ability to nail down the smell of anything in the most interesting and unanticipated words. I had never, ever thought that one could describe perfumes this way.
For example, consider this account of a perfume that he wrote:

Feu d'Issey (Issey Miyake)
"The surprise of Feu d'Issey is total: smelling it is like a frantic videoclip of objects that fly past at warp speed: fresh baguette, lime peel, clean wet linen, shower soap, hot stone, salty skin, even a fleeting touch of vitamin B pills. Whoever created this has that rarest of qualities in perfumery, a sense of humour. A reminder that perfume is, among other things, the most portable form of intelligence."

Or this one:

Vetiver (Guerlain)
"One of the rare perfumes so named that do not betray the character of this uncompromising raw material, Vetiver is a temperament as much as it is a perfume, above all when it is worn by a woman. Stoic and discreet, Vetiver scorns all luxury save that of its own proud solitude. At the same time distant and perfectly clear, it must be worn muted and must never allow itself to be sensed except at the instant of a kiss."

Not surprisingly, this book became quite controversial. Scientists and journal editors alike were miffed because of the bad light that it cast some of the big names in smell research in. A group from Rockefeller University published experiments in the well-known journal Nature Neuroscience, that did not support Turin's theory. But they were bound as well by the problem of objectively evaluating smell, and so even their experiments are certainly not the final say on the matter. However, all this backlash is actually a tribute to Burr, who could make his book so attractive and compellingly convincing, that even scientific journal editors needed to take note and criticize it (a rare event indeed for a popular scientific book).

My advice; read the book and enjoy it. It could be a fantastic read. However, don't take Burr's words too seriously and literally. Science is a harsh world, and rhetoric cannot undermine the rough scrutiny that any theory undergoes. One thing is for sure; Turin will be remembered, whether his theory survives or not. It is clear that even if he had not invented his smell theory, he would have still been a very interesting character for a profile. If his theory can be used in a fruitful way, it will be a great and enduring one. If not, at least he should be thanked for inspiring a wonderfully written book. For me, both ways it would be a reward, since the book and Luca Turin introduced me to a new and fascinating world.