An Ode to Odors and the Noses That Detect Them

Our sense of smell is my all-time favorite sense.

The mechanics of it are pretty amazing. It works like this: Let's start from the origin of the odor. Fragrance molecules emanating from the source (pick your favorite source: freshly baked bread, coffee, etc.) are pretty light and volatile things and are subject to rapid evaporation. They head toward our waiting noses propelled on a current of air. Solid things (things that can't evaporate) have no smell.

These tiny but powerful molecules head for you like a NASCAR driver toward the checkered flag. Then, BOOM! Your nose perks up. It seems that the hair-like projections (cilia) sprouting from the neurons at the top of your nasal passages have noticed these critters, and it's love at first smell! The molecules have bound themselves to the cilia/neurons and are now closer than two teenagers going steady.

All that's left is for the brain to identify the odor, associate it with the source and decide if it's pleasant or unpleasant.

It's estimated that homo sapiens (us) can identify more than 10,000 different smells and that this is possible because of the hundreds of special receptors in the lining of our noses. Each of these receptors is encoded by a specific gene, and it's these genes that enable us to perceive certain smells. That means that if your specific DNA is missing a gene or the gene is damaged, it can prevent you from detecting or recognizing a particular smell.

A while back I wrote about hair care products and briefly touched on the many odors that industry infuses into its products. Now, the spotlight falls on fragrances. Let's imagine a world without natural fragrances like the woods after a rain, lilacs, spices and more. Now let's add to the blandness by removing all fragrances from our personal care products (like soaps, perfume, et. al.) and from specialty chemicals (making poisonous antifreeze smell bitter has saved hundreds of animal lives each year). Without fragrances, our world would lose an important dimension. Manufacturers know this and spend billions on making grandma's Eau de Porcine bath salts and Uncle Fred's Bay Rum appealing. Advertising extols the virtue of the "heavenly scent of (fill in the blank), a fragrance that will make you more attractive, more successful in your job, more popular in school, etc., etc."

Fragrance additives are everywhere, and the battle of odors has reached the workplace where some companies and even communities are creating air-quality standards to exclude the wearing of perfume. This is being done to protect those allergic to fragrances (maybe 1 percent of the population of an office at any given time) from the onslaught of thoughtless people wanting to make themselves smell better by buying $50 bottles of perfume. How could they be so callous? I don't know about you, but I would rather smell a cheap perfume once in a while than be exposed to a person whose personal hygiene hasn't benefitted from the inside of a shower stall in days.

There is something infinitely more important about the sense of smell than the smell itself … the associations we make to certain smells. Like a bookmark in a book, we link smells to events and situations that have occurred throughout our lives. My most vivid "fragrance mark" has to do with a library. As a child, I accompanied my grandmother to our small-town library. I remember that when the door of that 19th century building was opened, the smell of books hit me like a tsunami. It still does. I know, because I visited there a few years ago and nothing had changed.

The wonderful memories of my childhood linked to that smell are filed away forever thanks to our marvelous sense of smell.

Stephan Helgesen is a former diplomat and regular contributor to the Telegraph. He writes from his mountain retreat in Tijeras. He can be reached at stephanhelgesen@cs.com.