Fifth-Century Greek philosopher Democritus, the putative founder of modern science and atomic theory, who laughed constantly and lived more than one hundred years, once had occasion to ponder our sense of smell. It was, he theorized, the result of our nose reading the shape of airborne particles. Democritus called these particles “atoms,” and he thought sweet atoms were “round and of a good size,” while sour ones were “bulky, jagged, and many angled.”
This “shapist” theory of smell, or olfaction, continues to this day. It boils down to the essential concept of tiny pieces of things being “read” by receptors in our nose. Democritus called these pieces “atoms,” but he had no sense of atomic theory in the modern sense, which asserts that these pieces are, in fact, molecules. But that’s just a theory, and the truth is that no one really knows how our sense of smell works. The shapist theory has many inconsistencies and demonstrated limitations. Molecules with the same shape produce different smells; inversely, two molecules with completely different shapes can produce the same smell (sandalwood).
On August 6, 1945, at 8:15am, miles away from the site of the Hiroshima bombing, people reported an impossibly bright light and the smell of burning rubber. This posed a problem for the shape theory of smell: If smell was the result of particulate matter – molecules – landing on receptors in the nose, how then to explain the instantaneous travel of molecules from the blast site to noses miles away?
Enter Luca Turin and his vibratory theory of olfaction. A flamboyant polymath, perfume enthusiast-turned-authority, with a keen nose and Ph.D.’s in physiology and biophysics, Turin was interested in inconsistencies in the shapist theory of smell. He also had an unusual set of interests and training. “The thing is, the problem of smell wasn’t that hard to crack,” says Turin. “[And you] had to know a huge number of disparate facts… How many people would be aware simultaneously of the recipe for Chanel No. 5, the vibrational numbers of boranes…and Malcolm Dyson…?” (Dyson was the first to propose a vibrational theory of olfaction, in 1937, but technology was too limited then to test it, and the theory was abandoned in favor of shape theory until Turin picked it back up in 1996).
Another factor weighing uniquely in Turin’s favor was the access he was given to the large and notoriously secretive scent labs of the “Big Boys,” seven companies responsible for virtually all perfumes and scented products in the world. He was given this access largely based on having written Perfumes: The Guide, widely regarded as the definitive text in the field, and containing such gems as this:
Sacrebleu (Parfums de Nicolaï) **** dusky oriental
If you travel at night on Europe’s railways, near big stations you can sometimes see lights the size of a teacup nestled between the rails, shining the deepest mystical blue-purple light through a filthy Fresnel glass. They appear to be permanently on, suggesting that the message they convey to the train driver is an eternal truth. Since childhood I have fancied the notion it may not be a trivial one like “buffers ahead” but something numinous and unrelated to duty, perhaps “life is beautiful” or some such. Sacrebleu has the exact feel of those lights, a low hum that may be eclipsed by diurnal clamor but rules supreme when, at 3 a.m., you know you are looking into your true love’s eyes even though you can’t see them
The “Big Boys” found it hard to turn away a luminary of their industry, especially one whose popularity, olfactory precision and rapier pen had the power to buoy or sink the critical and commercial success of their new perfumes. That he was inquisitive and nettlesome-bordering-on-imperious was not lost on them, but their fear of his written wrath caused them to relent and Turin was let into the inner scientific sanctum of the industry.
The Big Boys employ thousands of people and generate roughly $20-billion-a-year in revenue. All of that revenue and all of those jobs are tied, intellectually and economically, to shape theory.
So imagine the shock and recoil when, after several years of investigation and documentation, Turin reported his findings, and proposed that the vibrational frequency, rather than the shape of molecules, determined their scent. Turin was proposing that our sense of smell arises through quantum mechanics, not biology or chemistry. Turin was also proposing, by extension, that all of the scientists and experts in the industry were operating on false premises.
So there was resistance, but no one around was qualified to review or validate Turin’s theory. Nature rejected Turin’s findings after a year and an unusual two peer reviews. “The biologists said the chemistry was wrong, the chemists said the problem was the physics, and the physicists said the fault lay with the biology,” is how Turin described the rejection. Since Turin’s initial report of his findings, several subsequent studies have produced conflicting results, and the scientific community remains agnostic to Turin’s theory. Turin has also since written his own book on the subject, entitled The Secret of Scent.
The almost complete lack of multidisciplinary scientists qualified to fully review the vibrational theory of olfaction poses a major barrier to solving the mystery of scent. Chandler Burr, Scent Editor for the New York Times (yes, Scent Editor) and author of a book about Turin entitled The Emperor of Scent, characterizes the resistance to vibrational theory as a “problem of calcified minds and vested interests.”
Smell governs a greater portion of human interaction than most people realize, and the widespread use of artificial and manufactured scents represents a qualitative alteration and denaturing of human experience. Subtle yet powerful aspects of human attraction key on smell: think of pheromones, and what people speak of when they point to having “chemistry” with someone. In most cases, whether they realize it or not, they’re talking about having exchanged coded scent messages with someone, communiques dispatched between primal, distinctly pre-cognitive parts of our brains.
Perfumers, artists of human scent attraction, have long known of and exploited the primal powers of scent, and the key ingredients of some of the more enduring fragrances manufactured in modern times underscore their understanding of our creature selves. One widely used perfume ingredient, civet, is actually cat anus gland, and inhaled on its own, is capable of producing shock, horror, and involuntary recoil. Yet hidden inside a cloud of floral and musk overtones, civet delivers a potent animalian calling card. Other little-known but popular perfume ingredients, like ambergris—whale vomit—and zebu grease—human infant feces—also point to the perfumer’s understanding of how to call and manipulate our more creature selves.
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The battle over how our sense of smell works continues to rage, and may well result in a renaissance in scent manufacturing (not to mention a Nobel prize for Turin). If the vibrational theory of olfaction carries the day, you might expect the realm of human scent manufacturing to take a mighty leap forward.
But one nagging question about all of this stays in my mind: When we’re talking about a deeply primal, deeply important thing like our sense of smell, is the advance of artificial scent manufacturing necessarily good for the human experience? Scent reigns over hunger, recessed memory and human attraction. Scent belongs to our animal natures.
Smell evokes; it whets. Perhaps its manipulation in certain playful settings is a fine thing, but when an artificially-rendered scentscape becomes ubiquitous—think of deodorants, perfumes, detergents, scented creams and hair products—what is lost in the bargain?