A scent, a whiff and we’re transported once again

I wish I had a little bottle of Rocky Mountain National Park boulder-in-the-sun-covered-with-pine-needles or Old Delhi anise-in-a-copper-pot or Inside Passage sunrise- on- the-bow-of- the-Alaska- State-Ferry. To return to Colorado or India or Alaska, I’d have only to unstop the top.

The pictures we bring back from trips address our visual sense, helping us recall where we went and what we saw. But smells summon the memory of places on a deeper, more emotional level, which makes them precious perfume to a traveler.

“Stumbling on new smells is one of the delights of travel,” Diane Ackerman wrote in “A Natural History of the Senses.”

My mother grew dreamy whenever she got a whiff of plumeria because its heavenly scent never failed to remind her of her first visit to Hawaii.

The smell of tiare blossoms is as good as a ticket to French Polynesia for Frank Voelkl, a scent creator who developed a perfume named for the flower for Symrise, a New Jersey-based fragrance company.

Christopher Brosius, founder of the Demeter Fragrance Library, also has a nose finely tuned to the way places smell. His company produces such unusual scents as Holy Water, inspired by the smell of an old Norman church in England. Recently he thought he had assembled the perfect ingredients for a wet Manhattan pavement scent but realized it smelled like London, not New York.

To William Cain, a professor of surgery at UC San Diego who has researched olfactory functions, nothing smells like Paris in the morning, a rich, complicated blend of coffee, baked goods, alcohol and vegetables. “Every single place has a unique combination of ingredients that gives it a signature smell,” Cain says.

Together with touch and taste, smell is usually considered one of the baser senses, Cain says, relied upon by creatures at the lower end of the evolutionary scale. It’s thought that prehistoric man used his nose to tell him where he was, thereby helping him survive. In this way, the senses of smell and place have long been intimately tied.

To support the point, Cain observes that his dog returns to the place where it licked a broken egg off the sidewalk weeks before, puts its nose down and sniffs in hopes of finding another reward.

“But dogs have no interest in the smell of flowers,” Cain says. “I don’t know why people find them so pleasant.” What makes us decide an odor is fair or foul remains a mystery. And although scientists have begun making important discoveries about olfactory chemistry and physiology, questions persist about how we process and remember smells.

Cain says it’s now understood that smelling involves the conversion of chemical energy from molecules that enter the nasal passages to the electrochemical energy of the nervous system. But scientists still don’t know how receptor cells in the nostrils recognize the smells of particular molecules, whether they’re rotten eggs or plumeria.

Nathan Lewis, a Caltech chemistry professor, has created an artificial smell detector, which could be used to identify explosives. But it can recognize only the digital patterns of those smells for which it has been programmed.

It takes a human to smell something altogether new and different, then file it away in the memory. It lodges there until the nose receives the same odor later and consults the memory to tell us what it is and how to feel about it.

The links between smell and memory are strong, “a route that carries us nimbly across time and distance,” writes Ackerman, who, in her book, recalls that the scent of eucalyptus in Santa Barbara reminds her of being a child “tucked in bed, safe and cosseted, feeling my mother massage my chest with Vicks VapoRub.”

Smell-generated memories seem to me singularly emotional. Rocky Mountain pine is all about happiness. The smell of artificial air freshener in a hotel room makes me lonely and sad, although I don’t know why. It’s as though smells bypass the intellect and go directly to the heart.

Perfumer Brosius says the most popular scent in the Demeter Fragrance Library is Dirt, which evokes the smell of digging in the garden. “Every child has played there,” he says. “It’s a comforting smell.”

After Sept. 11, several classic old perfumes, such as patchouli- and vanilla-scented Shalimar, were reintroduced. Rochelle Bloom, president of the Fragrance Foundation in New York City, says these scents seem to succor baby boom women by reminding them of happier, more innocent times.

I fear I have an unrefined nose; I seem to notice only strong, generally distasteful smells, such as trashy city streets and latrines at campsites, especially in warm weather. That’s when the molecules that pique nasal receptors are most easily vaporized, making it possible for us to breathe them in, starting the whole mysterious process of smelling. Maybe this has its benefits, given the number of vile odors one encounters on the road.

But researcher Cain says that travel is about collecting experiences, including odors. So I’d rather have a sharp nose and take the good with the bad. Besides, it delights me to think of smells oozing out of all the places in the world, waiting to encounter receptors in my nose and then somehow become my most intense travel memories.