Quantum tunneling, perfumes, and the sense of smell

Also: the inadequate equilibria of academic publishing and which luxury brands you shouldn't trust

Chandler Burr’s The Emperor of Scent is a story about science, in all its glory and shame. It’s about perfumes, with a number of delightful descriptions and pointers as to quality and effect. It’s about which luxury brands you can trust. It’s about a larger-than-life scientist and aesthete who sounds like a pretty fun person, Luca Turin.

It’s also one of a genre which I enjoy, which I will call “skeptics who convert,” or “authors who can’t maintain journalistic neutrality and distance.” As in, the authors start out with some either neutral or even slight negative bias towards the idea or person in question, then convert somewhere along the way, and end up wholehearted believers and advocates. Scott Carney’s book on Wim Hof, What Doesn’t Kill Us, is similar, as is Pollan’s How to Change Your Mind. I hear Krakauer’s Under the Banner of Heaven is too, although it hasn’t made it’s way to the top of my queue and been read yet.

It encompasses such tidbits as rocket propellant chemist interview techniques,¹ the creation story and characteristics of a number of perfumes (with more anon), and the story of how a perfume gave away Louis XVI and Marie Antoinette as they tried to escape in disguise and incognito.²

But overall, it is the story of the mechanism behind our sense of smell.

On the glory side, we have the protagonist, Luca Turin - a polymathic interdisciplinary dabbler, an iconoclast, an aesthete, a recreational perfume expert, and a scientist more interested in truth than reputation.

On the shame side, we have the journal Nature, broken peer review, a rigid and hidebound Establishment, and a bunch of so called “scientists” disparaging a paper they haven’t read purely on vibes and reactions in their social sphere.

Surprisingly, even twenty years later, according to Wikipedia, there has been no vindication either way, from the traditionalists (smell as shape) or the iconoclast (Turin’s smell as vibration theory).

The essential debate is about the mechanism behind smell sensing. The established position maintains that the G proteins in our nasal passages lock onto and detect different shapes on molecules, or perhaps different parts of shapes, and assembles this information into the different smells we perceive.

But this model has many problems - the even and odd esters used in Chanel no 5 smelling different,³ rocket fuel with no sulfur atom smelling like sulfur, deuterated molecules smelling different than molecules with regular hydrogen despite having identical shapes, sila compounds with silicons in place of carbons, and thus exactly the same shapes - but different atomic weights - smelling different, and more.

What would explain all these disparate facts that give the lie to “smell as shape?” If smell was detected by vibration, by the frequency of the electron shells in what is being smelled. Basically, the nose would be doing spectroscopy, which is crazy if you’re thinking of optical spectroscopy, but makes more sense if you’re thinking of electron tunneling voltage drop spectroscopy.

Turin himself proved that proteins can be conductive, he even patented an albumin diode. If vibration rather than shape is how smell works, it explains a number of other mysteries as well. Why we can detect specific atoms in a molecular compound via smelling, as in metal carbonyls, carbon cages with a different atom in the middle - ferrocene, nickelocene, and the like- which smell different even though they have the same external shape. Why even small molecules can have very intense smells, whereas if the shape theory were true, they should be diffuse and difficult to pin down due to being able to attach to a wide array of potential shape chemoreceptors. How every “shape class” of smells like sandalwood, ambergris, or camphor has a flagrant exception that smells like the reference scent, but has a completely different shape.

The funniest thing is that the “shape” paradigm is so bad, it’s only barely predictive. The seven big scent houses⁴ spend millions on labs and scientists annually that stab in the dark for various molecules (starting from previously successful bases, then adding ethyls and aldehydes and methyl groups), ultimately getting hundreds to low thousands of potential molecule candidates. Then you smell each one, and toss the 95% that don’t smell interesting or good. Then of the remaining ones, you toss another 95% that don’t smell strongly enough to be economical. You end with maybe 20 you send to the parfumiers, who reject the vast majority of *those.* ultimately, you’re lucky to get 1-3 economically and aesthetically useful new scents for your millions of dollars and year spent of many chemists toiling.

“In the end, the very, very rare molecule that smelled strong, was cheap to make, had tested biologically safe and environmentally sound, was patentable, and had a useful odor—that one became a new product in the Big Boys’ commercial catalogs. A single decent smell molecule that hit all the right marks could bring money flooding in.

This was why the Big Boys and their stockholders optimally wanted to produce three or so molecules a year. The reality was that each was spending millions every year to create thousands and thousands of molecules, synthesize hundreds, test dozens, and get maybe one onto the shelves. This was what Turin found strange.”

Versus if you actually knew what you were doing, if you had a predictive theory of smell, you could dial to order. Instead of testing thousands, and throwing away the 95% that didn’t smell like anything good or interesting, you could explicitly dial for molecules you think would smell good or interesting, and get a much lower discard rate than 95%, and might be able to lower the second “intensity” 95% attrition rate too, if you found an amplitude equivalent in the vibrational model.

“Measuring the loudness of a molecular vibration (the amplitude, how strongly the vibe will be felt by the nasal spectroscope) is virtually impossible, and the reason for that couldn’t be simpler: we just don’t have the technology yet, either to replicate the measurement in the lab or to calculate it accurately. The amplitude is determined by the “partial charges” on each atom of the molecule, and at the moment we have no way to measure partial charges. Or rather the technology we do have to do this is ridiculously primitive and notoriously inaccurate. That is mostly a physics problem.”

Turin backs his smelling-via-vibration hypothesis as exhaustively as he can - he tracks down functional domains in the nose that can serve as the energy source (and that has the right energy capacity) and zinc receptor region needed for a conductive docking point within smell receptors via which the electrons can transfer. He writes up all of the many shape exceptions he’s found that give pretty solid evidence that shape can’t be the sole means we detect smells, and finally submits it all to Nature. It languishes for an entire year. He gets terrible peer reviewers who are both biased and dumb, in the sense they object to parts of the physics, chemistry, or biology when that’s not their domain and they simply misunderstand parts of the picture. He refutes the objections easily, and requests different reviewers. High level colleagues suggest multiple reviewers who would be better, but Nature goes back to the original three. Eventually a year later they undergo an editorial change and the new editor kills it.

He publishes in some no-name journal, and then a recurring theme through the remainder of the novel is other smell scientists disparaging his theory without ever having read the paper or its arguments, while still being unable to explain the many inconsistencies Turin points out.

Sadly, a fairly typical outcome for an iconoclast, given how much of science is driven by tradition and primate dominance games rather than genuine searches for truth.

Criticisms

The largest criticism I could think of is that although “shape” is relatively noisy, even if vibration is true, shape is almost certainly *correlated,* even if noisy. This is because the vibration of different atomic bonds is also reflected at least in part by shape, because molecules follow the same quantum mechanical laws that drive vibration in the ways and angles that they can bond as well. The degree of correlation would be interesting to know - there is after all a significant difference and a lot of arbitrage opportunity between a 0.5 correlation and a 0.8 correlation. But to build models with shape is almost certainly correlated with the underlying desired properties, even if it’s not the cleanest possible signal.

Current state of the scent houses and literature

A lot has changed since twenty years ago when the book was published - computers are vastly faster and more capable, the ML revolution means that any of the Big Boys could create models much more easily with their data (whether shape or vibration driven), quantum chemistry and atomic bond precision calculations would have both made very significant advances - so what does the landscape look like today?

Richard Axel, a prominent smell lab PI mentioned a few times in the book, won the Nobel prize for identifying the roughly ~1k human olfaction receptors and tracing the neurological wiring of smell.

Did the Big Boys revolutionize scent molecule production with more computer power, smarter models, or some revolution in understanding? It’s difficult to tell, but I lean towards “no.”

This is because many of them have gone out of business or been acquired since then:

1. Quest (Britain) - merged with Givaudan in 2007.

2. Firmenich (Switzerland) - merged with DSM 2023 - DSM is mainly a food flavorings and materials conglomerate with no mention of fragrances that I could find.

3. IFF (USA) - stock price seems fine but operating income is negative 2B and lots of private equity and reverse mergers going on in the company’s history.

4. Haarmann & Reimer (Germany) and Dragoco (Germany) - merged in 2003 to form Symrise; Symrise is doing well, it went public in 2006, and has acquired a number of other fragrance companies since then.

5. Takasago (Japan) - seemingly doing well according to the stock price, but still the smallest of the scent houses.

6. Givaudan Roure (Switzerland) - doing well according to stock price and various acquisitions, however on March 7, 2023, Givaudan confirmed that it was the target of an industry-wide investigation by European and Swiss authorities. Investigators were looking into a possible cartel in the supply of fragrances and fragrance ingredients. Companies face fines as much as 10% of their global turnover for violating EU antitrust rules.

Overall, it’s difficult to tell how the fragrance parts of the remaining Big Boys are doing, since the bulk of all of their businesses seems to be food flavors and additives (which has been booming as an economic segment), and thus their stock price is likely primarily driven by those things, and they are all relatively small companies by revenue and income.

And what about the literature?

The most recent sallies from either side seems to have been in 2015.

Block, et al. Implausibility of the vibrational theory of olfaction (2015): Basically, they take some of the deuterated vs normal hydrogen compounds that smell different, and at the olfactory receptor level, try to find a difference in receptor triggering / response, and don’t find it. They maintain that the different smells that flies and humans reliably report (with statistical significance) is a result of impurities in the non-deuterated compounds, because the deuterated compounds are much more expensive and have been subject to much stricter purity standards.

Turin’s response, Plausibility of the vibrational theory of olfaction (2015), says that Block ignored two receptors that did have statistically significant different responses, complains they didn’t describe any differences or lack of differences in smell in the compounds tested, and that the indicated impurity doesn’t coelute with the musk, and that they controlled for this specific impurity with a sham deuteration protocol in their last paper.

Block et al. respond in Reply to Turin et al.: Vibrational theory of olfaction is implausible (2015): they test the two receptors with different responses with varying concentrations of the compounds and find no dose response, and write it off as random noise that goes away if you Bonferroni correct across the ~300 odor receptors tested (ie the p value isn’t low enough with Bonferroni correction). They then aver that they’re serious scientists, sirrah, testing molecular mechanisms, and will have no truck with random smellings of compounds. Finally they say that flies and humans could smell differences between the compounds via other processes, specifically calling out that “perireceptor processes involving nasal mucus are susceptible to secondary deuterium isotope effects.”

There’s no more responses in this specific chain, but in 2016 Turin comes out with:

Drimyli et al. Differential Electrophysiological Responses to Odorant Isotopologues in Drosophilid Antennae (2016), where they find physiological differences in responses to deuterated vs regular compounds in electroantennogram amplitudes, and that perireceptor mechanisms aren’t involved:

“Here we interrogate electrophysiologically the antennae of four Drosophilids and demonstrate conserved differential response amplitudes to aldehydes, alcohols, ketones, nitriles, and their deuterated isotopologues. Certain deuterated odorants evoked larger electroantennogram (EAG) amplitudes, while the response to the normal odorant was elevated in others. Significantly, benzonitrile isotopologues were not distinguishable as predicted. This suggests that isotopologue-specific EAG amplitudes result from differential activation of specific olfactory receptors. In support of this, odorants with as few as two deuteria evoke distinct EAG amplitudes from their normal isotopologues, and this is independent of the size of the deuterated molecule. Importantly, we find no evidence that these isotopologue-specific amplitudes depend on perireceptor mechanisms or other pertinent physical property of the deuterated odorants. Rather, our results strongly suggest that Drosophilid olfactory receptors are activated by molecular vibrations differentiating similarly sized and shaped odorants in vivo, yielding sufficient differential information to drive behavioral choices.”

So where does that leave vibration vs shape? Still unresolved, as near as I can tell.

Smell is as objective as vision or hearing

One of Turin’s recurring conceits in the book is that smell is as objective as any other sense. Sure, people can disagree on what they’re smelling, or how much they enjoy it - but people can disagree on what they see or hear too (eyewitness accounts being famously unreliable), and can disagree about how much they enjoy what they’re seeing or hearing. Remember blue / black / gold / white dress? Remember the Yanny / Laurel aural illusion equivalent?

“The Dress” circa 2015

He points out that if smell were truly subjective, then billion dollar industries like perfume and scented candles couldn’t even *exist,* because there wouldn’t be a common enough market for people to agree on what scents are good and worth paying for. But obviously, they do exist, and people broadly agree on what apple pie, sulfur, flowers, leather, and the ocean (among many other things) smells like.

One interesting argument he makes in the book is that fully 1% of all genes are dedicated to smell, making it one of the largest things coded for in the genome, in line with the immune system, and indicating that it was impossibly important / adaptive in the EEA and we’re not giving smell nearly its due in our modern societies.

However, this turns out to be an artifact of poor genetic understanding circa 20 years ago (it’s actually up to 3% of all genes now, and defining this olfaction receptor family and the attendant neurological wiring is why Richard Axel won the Nobel prize) and mammalian gene conservation - if you dig into it, something like 2/3 of those genes are pseudogenes that don’t actually code for any protein by now, as they’ve steadily atrophied as primates have relied more on vision than smell.⁵

Another interesting tidbit, he points out that we know of ten thousand distinct smells, and there is no theoretical upper bound on the number of distinct smellable things yet, because our understanding and theory of the sense of smell is so bad.

All fun and interesting, but of course, what we’re REALLY here for is perfumes - the making of them, their characteristics, which brands dilute and cost cut and which don’t - or so the book seems to demonstrate, given the page count dedicated to them. The perfume evaluations and the inside baseball around how perfumes are created was actually one of the more fun and entertaining parts of the book for me.

How are perfumes made?

It starts with a brief from one of the major fashion houses, which then goes to the parfumiers at the Big Boys, the seven “fragrance” firms that have large labs and herds of chemists creating new scent chemicals every year.

Fun fact about the parfumiers - many are smokers, contrary to expectation. Turin explains it in the book as driven by the fact that the carbon monoxide blocks the enzyme cytochrome P450, which is involved in breaking down scent molecules. If they’re not broken down, they are stronger and last longer, and allow you to hold them in your sensorium longer for evaluation.

“It is the perfumers who transform the confidential briefs from the religious visions and aesthetic hallucinations at the houses of Dior and Calvin Klein and Givenchy—obsessions and poisons and envies and joys; “We want the smell of old melting candles in ballrooms of Italian marble during a Chinese winter,” “Give us the fragrance surrendered by a young blue flower crushed under the heated, ivory back of a woman with chocolate eyes,” “We must have the scent lightning makes the instant it strikes a platinum rose.” The perfumers turn these visions into structures of neutrons and protons and electrons welded together that make our eyes suddenly open, make us sit up, turn and inhale, molecules that blossom and flame, molecules that spin stories.”

“Tom Ford was dreaming of a perfume that smelled like fresh cherry wood licked by a green-hot oxygen fire in a Balinese temple, Marc Jacobs absolutely demanding a blossoming daffodil floating on an ocean of smoky Siberian snows—would these molecules work? (The perfumers sifted through their bags.) Was there a smoky metallic here? A wood in green flame? And the answer, statistically, was probably no. In basements beneath the perfumers, gathering dust, were vast, ever expanding glass-vial graveyards of molecules the chemists down below had proffered to them and which they had discarded.”

Perfumes are one of the industries with the most expensive ingredients, and at the same time, one of the industries with the highest margins.

“The hands of the perfumer are tied by the economics of perfume raw materials. Thousands of ingredients, thousands of different prices. The prices of raw materials in perfumery can vary by a factor of ten thousand. There’s stuff at £3 a kilo, like Iso E Super, a kind of nondescript woody-lemony. Then there’s iris-root butter from Florence: £30,000 per kilo. Like the best Turkish rose extract. Oudh wood from India is in that stratospheric league. It costs around £33,000 (about $50,000) per kilo. It’s the wood of a certain Indian tree that has been eaten by a fungus. You carve out the rotten wood that has taken on the smell of the fungus and extract the fragrance. There’s only one supplier to the West. It’s a drop-dead smell, very complex, honey, fresh tobacco, spices, amber, cream. You do not use a lot of this stuff in perfumes unless you are financially suicidal.”

These are both true at the same time, because perfumes start out expensive, as the flamboyant and visionary creations of artists, and then the accountants get a hold of them, and wring everything unique or compelling out of them by substituting inferior and cheaper ingredients.

Let’s consider a perfume’s creation story:

On the creation of the Dior perfume “Dioressence”

“The whale eats indigestible stuff, and every once in a while it belches a pack of it back up. It’s mostly oily stuff, so it floats, and ambergris isn’t considered any good unless it’s floated around on the ocean for ten years or so. It starts out white and the sun creates the odorant properties by photochemistry, which means that it’s become rancid, the molecules are breaking up, and you get an incredibly complex olfactory result. So Guy gets on a plane and flies up to see the dealer, and they bring out the chunk of ambergris. It looks like black butter. This chunk was about two feet square, thirty kilos or something. Huge. A brick like that can power Chanel’s ambergris needs for twenty years. This chunk is worth a half million pounds.

“The way you test ambergris is to rub it with both hands and then rub your hands together and smell them. It’s a very peculiar smell, marine, sealike, slightly sweet, and ultrasmooth. So there he is, he rubs his hands in this black oily mess and smells them, and it’s terrific ambergris. He says, Great, sold. He goes to the bathroom to wash his hands ‘cause he’s got to get on an airplane. He picks up some little sliver of dirty soap that’s lying around there and washes his hands. He leaves. He gets on the plane, and he’s sitting there, and that’s when he happens to smell his hands. The combination of the soap and ambergris has somehow created exactly the animalic Dior he’s been desperately looking for. But what the hell does that soap smell like? He’s got to have that goddamn piece of soap. The second he lands in France, he sprints to a phone, his heart pounding, and calls the dealer in England and says, ‘Do exactly as I say: go to your bathroom, take the piece of soap that’s in there, put it in an envelope, and mail it to me.’ And the guy says, ‘No problem.’ And then he adds, ‘By the way, that soap? You know, it was perfumed with some Miss Dior knockoff.’

“So Guy put them together, and got the commission, and made, literally, an animalic Dior. Dioressence was created from a cheap Miss Dior soap knockoff base, chypric, fruity aldehydic, plus a giant cube of rancid whale vomit. And it is one of the greatest perfumes ever made.”

This is the peak from which great perfumes start - but they quickly become enshittified, as the accountants have their way, here described for Nina Ricci’s L’Air du Temps:

“When the big fragrance firms take L’Air du Temps and wreck it by having an accountant redraw the formula to take out the expensive ingredients and substitute cheap ones, what they are doing, among other things, is depriving thousands of people throughout the world of the thrill of the memories that are infused with L’Air du Temps because unless it is the same smell, it won’t trigger. The pale new reflection may be, intellectually, objectively, a reflection. It may carry sort of the same top notes, that musk in the base, and rationally you can identify the similarity—but your brain stem isn’t electrified. Memory isn’t triggered. L’Air du Temps used to be much more intense, raunchy, strange. And they kept everything that it had in common with its contemporaries and removed everything that was different. There’s a lot less benzyl salicylate. It’s a very peculiar note, almost a wintergreen oil. So now it’s just like a dozen other fragrances.”

Turin would also steer you away from Dioressence (and indeed, ANY Dior perfume⁶):

“Dioressence is still being manufactured, and sold everywhere, and everyone buys it, and it’s now a total lie, a total lie to the original, to what it was. Miss Dior is also still around, and it’s only half a lie. Dior have continuously cheapened their fragrances and substituted less expensive materials till the gods departed and all that’s left is a gorgeous, empty, lamented name.”

Leading to the enduring high margins of most end-state perfumes:

“In general, perfume raw materials cost at most £100 per kilo, and because perfume is about 80 percent dilution—alcohol, which costs nothing—that real cost is 80 percent diluted too, down to about £20 per kilo of actual fragrance. A kilo has thirty-five ounces in it, so every ounce of perfume costs, generously, under £1 in raw materials to make and sells for at least £50, though of course you have to allow for costs of bottling, marketing, advertising, and so on. It is generally recognized that only about 3 to 5 percent of a perfume’s price tag goes for its smell.”

What perfume brands would Turin actually recommend as faithful and non-dilution prone? Guerlain, Chanel,⁷ and Jean Patou.

“It’s why Guerlain and Chanel and Jean Patou are so great. Not necessarily expensive perfumes. Just great ones that are never, ever diluted. No tricks, no cheating, no cutting corners.”

So how did Turin, a biophysicist, get to be so involved in perfume, to the extent he’s being consulted by multiple perfume houses, and being invited into some of the Big Boys in consulting roles?

Basically, as a lark, he wrote the definitive guide to perfumes by reviewing a bunch of them and then publishing the resulting manuscript. He had always been an aficionado, and had amassed quite a collection of perfumes of all vintages. His descriptions were so apropos, so incisive, and so popular that many of the industry professionals who read it assumed he was one of their own breaking ranks, and writing under a nom de guerre.

Some of Turin’s reviews follow:

Perfume reviews:

Paradox (Jacomo)

“Beauty itself, as with faces, is not simple: perfumes can be handsome (Mitsouko), graceful (Calandre), gorgeous (Joy), comely (Shalimar), radiant (Tommy Girl), exquisite (Après l’Ondée), stunning (Angel). Reader beware: Paradox is, to paraphrase something once said about Scriabin’s music, a perfume of “almost unbearable loveliness.” One of the properties of loveliness is that it disarms all attempts to be serious, and turns all critical machinery into a pile of whirring junk. What I find all the more irritating is that Paradox isn’t even “my type.” It is, after all, yet another fruit salad of the type that has kept perfumers gainfully employed since Deci-Delà. But this fruit salad does something that it has no right to do: break hearts. If this were music, it would be Bizet’s Symphony in C. If it were a car, it would be a Facel-Vega Facellia. If it were an aircraft it would be a 1959 Caravelle in Air France livery. Anyway, go smell it.”

Rive Gauche (Yves Saint Laurent)

“Thanks to Rive Gauche, mortals can at last know the scent of the goddess Diana’s bath soap. A true emblem of the ‘70s, this sumptuous reinterpretation of the innovative metallic note found in the less fortunate Calandre (Paco Rabanne) belongs to the uncrowded category of sculpture-perfumes. Its seamless silvery form, initially hidden by white, powdery notes, soon pierces the clouds and gains height by the hour. Like Chamade (Guerlain), Rive Gauche enjoys a peculiar relationship with intensity: the more time passes, the stronger its grace becomes, as if fading allowed its inner light to radiate more easily. A masterpiece. A notable example of the perfect agreement between container and content, its atomizer of metal and blue stripes, at once precious and whimsically “industrial,” is itself an item of undying chic.”

Python (Trussardi)

“The absurdly named Python is a poverty-stricken sweet-powdery affair, a very distant relative of the wonderful Habanita (Molinard). It belongs in a tree-shaped diffuser dangling from the rearview mirror of a Moscow taxi.”

Après l’Ondée (Guerlain)

“Divinely named [“After the Rainshower”], a prototype of the cold and melancholy fragrance, this stunning creation is the counterpart—the brighter, fresher younger brother—of the mysterious L’Heure Bleue (Guerlain). Après l’Ondée evolves only slightly with time: its central white note, caressing and slightly venomous, like the odor of a peach stone, imposes itself immediately and retains its mystery forever. Its simplicity, its keen nostalgia, and its unadorned beauty make this an anomaly for Guerlain.”

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.”

Rush (Gucci):

“The first sniff gave me a shock of recognition, like a long-forgotten but familiar face, and I spent a few busy minutes dredging my memory for the original impression . . . Dioressence! Not all of it, mind you, just a bit I loved, which in the original happened two or three hours into the story and felt like a warm breath whispering crazy things in my ear. That breath is back, now strong, loud, irresistible, a sultry wind fit to keep everyone stark awake and plotting indiscretions. . . . The charm of this perfume is entirely man-made, no mention of Nature, e.g. flowers, etc. This thing smells like a person. To be exact, thanks to the milky lactone note, it smells like an infant’s breath mixed with his mother’s hair spray. . . . What Rush can do, as all great art does, is create a yearning, then fill it with false memories of an invented past . . .”

What else would you get from reading the book yourself?

1. Much more depth on each of these story arcs - Turin’s research, the Nature battle, the perfumes, his consultations for the Big Boys, and so on

2. A glimpse into a really fun and interesting aesthete and scientist’s life

3. Somewhere in there, they actually map the scent of vanilla and a couple of other things - using scent vibrational frequency maps translated into the audible range - into a symphony, which is performed live at a concert

4. A deep dive on our sense of smell and what we know about how it works (because surprisingly, we haven’t advanced all that much in understanding in 20 additional years, which is almost certainly a sign that the “shape” paradigm IS wrong and we’re waiting for some ‘scientific consensus’ silverbacks to die for things to change / advance once more)

UPDATE: Luca Turin has his own substack! Here’s a fun AMA, I’m sure many people who enjoyed this post / review would enjoy his ongoing perfume thoughts:

1. “The alternative to RFNA was WFNA, which had its own personality; Clark used to test the mettle of job seekers to his lab by having his assistant drop a bit of old rubber glove in some WFNA. The rubber would squirm and swell for a moment like some satanic worm and then erupt in a magnificent, shrieking jet of flame. “I could,” wrote Clark, “usually tell from the candidate’s demeanor whether he had the sort of nervous system desirable in a propellant chemist.”

2. “He once found, in a good antiques store in Moscow, an extremely rare perfume, Le Parfum Idéal by Houbigant, made in 1900. The formula had disappeared from the face of the earth, and no one knew how to make the stuff. The perfume was in an exquisite, unopened Baccarat crystal bottle, and it had lived through the revolution, two world wars, Lenin, Stalin, and Khrushchev. He paid a hundred dollars for it. The woman who sold it to him thought he was crazy to pay so much. It was probably worth a thousand. He donated it to the Perfume Museum, and they managed, through gas chromatograph smellers, to reconstruct Houbigant’s formula. They gave a bit of the perfume back to him. “If,” says Turin, “you ignored the first minutes because the top notes were slightly fatigued from the journey, the next three hours were absolutely sensational, three hours that showed you why this perfume made Houbigant.”

“The house is allotted by some a small, crucial role in changing French history. During the Revolution, Louis XVI and Marie Antoinette were trying to escape the guillotine, dressed as ordinary citizens, and were apprehended in Varennes. “The legend,” Turin says, “is that they exited the carriage, acting natural, and she descended in a breathtakingly heavenly cloud of Houbigant. That’s how they caught them and cut off their heads. No ordinary Citizen had that fabulous shit.”

3. “But, said Robert, what was strange was the bimodal, almost digital fluctuation. Why were the odds (C7, C9, C11) waxy and the evens (C8, C10, C12) citrus? Why, when the shapes of C8 through C12 changed progressively (and significantly), would you get not progressive smell changes from one point to another but rather this weird bimodal back-and-forth? If smell were Shape, you would expect one of two possibilities. Either there’d be no pattern and the smells would be random, or there would be a pattern but the smells would be incremental: nine would smell closest to ten, which would smell closest to eleven, which would then be closest to twelve, and so on. In fact, you got neither. The pattern wasn’t random. It wasn’t incremental. The pattern was alternating. Why would you get citrus with an even number and then go to waxy with the odd? And then back to citrus? Why would a receptor feeling Shape give you that? “It’s the strangest thing,” said Robert quite pointedly at Turin (it was a challenge), “because—what? the receptors are counting the atoms to see if they’re even or odd?”

4. Quest (Britain), Givaudan Roure (Switzerland), Firmenich (Switzerland), IFF (USA), Gaarmann & Reimer (Germany), Dragoco (Germany), Takasago (Japan)

5. “Compared to many other mammals, primates have a relatively small number of functional OR genes. For instance, since divergence from their most recent common ancestor (MRCA), mice have gained a total of 623 new OR genes, and lost 285 genes, whereas humans have gained only 83 genes, but lost 428 genes. Mice have a total of 1035 protein-coding OR genes, humans have 387 protein-coding OR genes. The vision priority hypothesis states that the evolution of color vision in primates may have decreased primate reliance on olfaction, which explains the relaxation of selective pressure that accounts for the accumulation of olfactory receptor pseudogenes in primates.”

6. “Dior is run by lower life-forms. It is run by second-rate accountants. These are people”—he gathered himself to deliver this, as if passing a microscopic gallstone—“who use a thing called ‘afffff-ter shave.’ First-rate accountants would see that it was to their advantage to keep the quality up.”

“At lunch near Tottenham Court Road, he explained, “The financial temptation to dilute perfumes is almost irresistible. I mean, if you can make your oudh go twice as far. . . . Instead of using ten kilos you use five, and given how much this stuff costs per gram, the temptation to futz is just irresistible.”

7. Another fun fact from the book - “Coco” Chanel was so called (according to Turin) “because she threw the most fabulous cocaine parties in all of Paris.”