Turin published his electron-tunneling mechanism in 1996 in Chemical Senses. Some parts of the theory were, and remain, unproved. Isotopes, for example, are identical in shape but should smell different from one another because their slightly different weights should produce slightly different vibrations. Turin reported that they did. But his finding proved hard to reproduce in studies involving naïve subjects: differences in smell are subtle, and perception varies from subject to subject. The failure to confirm odor differences between isotopes, which seemed to disprove the theory, was reported in a paper in a 2004 issue of Nature Neuroscience, accompanied by a harsh editorial. But recent studies are turning the tide Turin’s way. A 2007 paper in Physical Review Letters showed that his mechanism was physically plausible; and Greek researchers are preparing to publish a paper showing that fruit flies can, in fact, smell the difference between isotopes. (In 2003, Turin’s trials in forwarding his theory were the subject of The Emperor of Scent by Chandler Burr, who now writes about perfume for the New York Times.)
While his theory was under attack, Turin consoled himself, as Noël Coward would say, with the bitter palliative of commercial success. From 2000 to 2007 he was chief scientist for Flexitral, whose main business was creating replacements for 26 fragrances that the European Union had restricted or banned as possible allergens. He was using vibrational theory to design molecules every day “and getting a tremendously high success rate,” he says. “I could calculate whether a smell would be right or not.”
All very practical, and potentially very profitable–but not madly artistic. “One would like to invent new smells, but business is business,” Turin says. Yet at the company he did achieve what he calls a long-held dream: a “drop-dead lily of the valley.” Muguet, the lovely French word for the flower, is the mountain any fragrance chemist hopes to scale. There has been no truly accurate rendition of its all-white scent, which combines soapy rose and cut grass. Edmond Roudnitska’s Diorissimo, created in 1956, came the closest; it established Roudnitska, Turin writes, as the “Mozart of postwar French perfumery.” Two of the chemicals Roudnitska discovered to be key components were later identified as potential allergens, and their use has been restricted. On a mountain on a skiing holiday, Turin got the idea for a molecule he guessed would smell right. That night he faxed a sketch of it to chemists at his lab and asked if they could make it. Two days later, they reported that the whole laboratory smelled of lily of the valley. It was “an epiphany,” Turin says. “Like a Roman emperor, I can die now.”
Instead, he left the business for what he calls a “science break”: at MIT he is working on an artificial nose.
a matter of taste
Could I outgrow Eau Sauvage and embrace the new? In a long smelling session at the New York offices of Robertet, an international fragrance firm, I discovered one reason I used Eau Sauvage in the first place: it contains a novel synthetic, and one I like. To historians of fragrance, Eau Sauvage is famous because it was the first perfume to use hedione, an “effect aroma” that, Turin says, “lubricates” a fragrance, as if one were licking one’s lips. Discovered in 1961 and put to use by Roudnitska five years later, hedione gives Eau Sauvage what Turin describes as a “strange, glittering freshness.” The fragrance could cut through a 1960s smoke-filled room (cigarette smoke has become the great missing ingredient in older perfumes) with its mixture of citrus, pine, and rosemary.