Start with the deepest mystery of smell. 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 thingsanything, crushed raspberry and mint, the subway at West Fourteenth and Eighth, a newborn infantremains a mystery. Luca Turin began with that mystery.
Or perhaps he began further back, with the perfumes. "The reason I got into this," Turin will say, "is that I started collecting perfume. I've loved perfume from when I was a kid in Paris and Italy."
Or maybe (he'll tell you another day, considering it from a different angle), maybe it was "because I'm French, at least by upbringing.
Frenchmen will do things Anglo men won't, and France is a country of smells. There's something called pourriture noble. Noble rot. It's a fungus. It grows on grapes, draws the water out, concentrates the juice wonderfully, adds its own fungal flavor, and then you make wines like the sweet Sauternes. Paradise. From rotten grapes. The idea that things should be slightly dirty, overripe, slightly fecal is everywhere in France. They like rotten cheese and dirty sheets and unwashed women. Guy Robert is about seventy, a third-generation perfumer, lives in the south of France, used to work for International Flavors & Fragrances, created Calèche for Hermès. One day he asked me, 'Est-ce que vous avez senti some molecule or other?' And I said no, I'd never smelled it, what'd it smell like? And he considered this gravely and replied, 'ça sent la femme qui se néglige.' " (It smells of the woman who neglects herself.)
This makes him remember something, and he leans forward enthusiastically. "One of the stories I heard when I started meeting the perfumers and was let into their tightly closed world involves Jean Carles, one of the greatest perfume makers in Parishe used to work for Roure in Grasse, near Nice, where all perfumes used to be made. He became anosmic, lost his sense of smell, and he simply carried on from memory, creating perfumes. Like Beethoven after his deafness. Jean Carles went on to create the great Ma Griffe for Carven, a result of pure imagination in the complete absence of the relevant physical sense. Carles's condition was known only to him and his son. When a client came in, he'd go through the motions, make a big show of smelling various ingredients and, finally, the perfume he had created, which he would present with great gravity to the client, smelling it and waving its odor around the room. And he couldn't smell anything!" Turin smiles, thinking about it.
The perfume obsession led Turin to write the perfume guide, which out of the blue cracked open for him doors into the vast, secret world in which perfumes are created, and there he started noticing little things that didn't make sense. A weird warp in official reality. Plus there were the other clues, the small pockets of strangeness he bumped into in the scientific literature, carefully fitting these into the puzzle without even realizing it, without (as he'd be the first to admit) really understanding what he was doing. And somewhere along the line, between scouring the French Riviera for bottles of buried fragrances, pursuing (in his own very particular way) the strange triplets of biology and chemistry and physics, and prowling the library's remotest stacks, randomly sliding into things he found theresomething that due to his intellectual promiscuity he does a lot ofsomewhere Luca Turin got the idea of cracking smell. But it started with the mystery at smell's heart, which is not only that we don't know how we do it. We actually shouldn't be able to smell at all.
From everything we know about evolution and molecular biology, smell does the impossible. Look at two other systems inside your body, and you'll understand.
First, digestion. Human beings have evolved over millennia while eating certain moleculeslipids and carbohydrates and proteins in the roots and berries and various unlucky animals we've gotten our hands on. The tiny carbs and proteins are made of tinier atoms and molecules, and for your body to burn them as various fuels, evolution has engineered a digestive system for you. The system's first task is to recognize which raw fuel it's dealing with, so it can send out the right enzymes to break that fuel down, process it for us. (Enzymes are catalysts, molecule wranglers, and every enzyme in every one of our cellsand there are tens of thousands of different enzymesbinds to a molecule and processes it. Some break molecules down, scrapping them to use their dismantled parts, some zip them together, and some rearrange them for the body's own purposes.) But in every case the enzyme "recognizes" its molecule by that molecule's particular shape. Fat, thin, lumpy, rounded, oblong, rectangular. The enzyme feels some cleft in some molecule, fits its special fingers into it like a key fits into a lock. And if the shape of the lock and the shape of the key conform, bingo: Recognition! By shape.
And what gives a molecule its shape? We think of atoms as these perfectly symmetrical spheres, shining and frozen on labels of "Super-Strong!" kitchen cleaners, their electrons zipping around their nuclei like perfectly spherical stainless-steel bracelets. Since electrons move at close to the speed of light, if you filmed those cartoon atoms in motion you'd see a round electron membrane, a solid, buzzing sphere made of blisteringly fast-moving electrons.
But that's kitchen-cleaner labels. The skins of atoms are actually made of the paths of their outermost electrons, but not only don't they zip around in perfectly circular orbits, they carve an almost infinite variety of 3-D orbital grooves around their nuclei. If that's not enough, atoms get shoved against and glued to one another in molecules, forming bulbous structures, or nonspherical structures with disks and oblongs. Imagine taking the giant inflatable balloons in the Macy's parade, each one shaped differently, and pushing them against one another; their skins smoosh and warp, their bulbs and crevices contract and expand. So the electrons zip along in these new configurations, in elongated ellipses and valleys and sharp peaks and strange arcs. Which means that each molecule creates a unique shape that an enzyme can recognize as precisely as a retinal scan.
In fact, molecular recognition is arguably the fundamental mechanism of all life, and it is based on this single, universal principle: Shape. Receptor cells from your head to your glands and skin recognize enzymes, hormones, and neurotransmitters by their molecular shapes. The only variable is time.
The thing about enzymes is that evolution has learned over millennia that you're going to need to digest (break down, make up, or molecularly rearrange) certain thingswild almonds and crab apples and dead squirrels (sugars, fats, and proteins)and not othersraw petroleum or sand or silicate (fluorocarbons and borazines). So evolution has by now selected for you a complete, fixed genetic library of enzymes that will bind to and deal with a fixed list of molecules. (It's not an exact one-to-one enzyme-to-foodstuff ratio, but it's precise enough that it's why your dog famously can't digest chocolate, a culinary product his wolf ancestors never ate: evolution never selected for dogs an enzyme that recognized the shape of chocolate's molecules, so if you feed them these molecules, they get sick.) And if just one enzyme is missing, you end up with nasty, sometimes lethal, diseases and disorders. You can dump the squirrels for terrine de lapin et petits légumes, it doesn't matter: it's the same lipids and proteins in your library, and as long as you don't eat, say, plastic, for which you have no enzyme, your digestive system happily recognizes the molecules you consume, be it McDonald's or the fifth course at the Clifton Inn. The thing to remember here, however, is time: enzymes stand ready to identify the right molecule instantly.
For contrast, take the immune system. Antibodies are designed (they have to be) to bind to things that weren't around our ancestors, unknown bacteria and foreign parasites and each year's new, nastier, mutated viruses we've never seen before. Your visual system can recognize things that weren't in Homo sapiens's evolutionary environment, like Ferraris and Star Wars and Barbra Streisand, and so can your immune system, but your visual system deciphers photon wavelengths while your immune system is feeling out molecules' shapes. Here's the difference. When it encounters a new virus, the immune system starts rapidly rearranging genes at random, spewing out antibodies until it hits on one that fits the invader's shape, binds to it, and destroys it. (It's the exact opposite of a "fixed library" idea; Susumu Tonegawa of MIT won a 1987Nobel Prize for figuring this out.) So that's why you're at home for a few days with the flu. Your immune system needs time to break them, invader's shape code and produce the shape weapon to fight it. Where the digestive system is limited but instant, the immune system is unlimitedit "takes all comers"; but it also takes time.
But here is the problem. Someone hands you a molecule called a borane. You lift it to your nose. And without fail, you smell it. There's just one catch: boranes were created by inorganic chemists at the beginning of the twentieth century and never existed in the ancestral environment of any human being. Yet we smell them. This is impossible.
The fact is that we have never found any molecule in the smellable size range that we could not smell instantly. This is the mystery of smell.
You smell boranes instantly, not in a few days or weeks, even though you cannot have an evolutionarily selected receptor molecule for their unique shape. Smell is unlimited, like the immune system, and yet it is instant, like the digestive system. And everything we know about Shape and molecular recognition says this should be impossible.
We understand the human sense of vision intimately, down to exactly which vibration of a particle of light caught in the vision receptor in the retina will make us see exactly which color (a 1967 Nobel given for vision). We know hearing in exquisite detail, can predict with absolute accuracy which air vibration in the cochlea will create what tone (a 1961 Nobel for hearing). But of smell, we do not know, cannot predict.
This is why smell is the object of two cut-throat races. The first is scientific. This all-out race is being run in some of the most powerful labs (by the most competitive researchers with the biggest egos). The prize is the unscrambling of one of the most important secrets of biology, not to mention (everyone is betting on this) a Nobel Prize. An astounding 1 percent of human genes, we recently discovered, are devoted to olfaction. "So smell must be incredibly important for us," notes NIH geneticist Dean Hamer, "to devote so much of our DNA to it. The only comparable systemand this was the big surprise to everyoneis the immune system, and we all know why it's important to fight off invaders. This says smell was central in our evolution in a way that, presently, we don't really understand."
The other race is for money. Approximately $20 billion is generated every year by industrially manufactured smells, and virtually all these smells are made by only seven companies, the Big Boys, which split the billions among themselves. The Big Boys shroud themselves in secrecy to protect the public brand image of their clients. They make the molecules that you associate with the smells of Tide laundry detergent, Clorox bleach, and Palmolive soap, but they are also the actual creators of the superexpensive fragrances sold under the rarefied labels Calvin Klein and Chanel and L'Oréal, Miyake and Armani. The creation of a single commercially successful fragrance molecule represents tens of millions of dollars, and the Big Boys employ an army of chemists tasked with creating them. The way to create them is the magic formula.
This is why Luca Turin's theory is as important as it is unknown. It is not only a new theory of smell. Financially, it implies a technology that threatens thousands of engineers and corporate executives, the investment of billions of dollars, and the industrial structures of massive corporations in North America, Europe, and Japan.
Scientifically, it is a wildly revolutionary proposal contradicting a universal, bedrock assumption of biologyShapeand positing an astounding, microscopic electrical mechanism that operates inside the human body and is made of human flesh. You might as well, fumed one furious scientist who heard about Turin's idea, propose a new theory of digestion through tiny nuclear reactors in people's stomachs. Perhaps the only thing odder than the theory is the story of how Turin actually came up with it, and then of what happened to him when he did, which is what this book is about.
Excerpted from The Emperor of Scent by Chandler Burr. Copyright © 2003 by Chandler Burr. Excerpted by permission of Random House. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.