On Looking: Eleven Walks With Expert Eyes (31 page)

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Indeed, some research using fMRIs found that two areas—the amygdala and the ventral prefrontal cortex—in the brains of parents grow more active at the sound of an infant crying. Not so nonparents, whose brains showed a bigger response to laughter than to crying.

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Sound is always the same kind of stuff: compression waves propagating through a medium, causing particles to hand off the vibration to their neighbors. We hear these waves as pitched higher or lower, or as being more or less intense—but they can also travel faster or slower. Counterintuitively, while sound moves at around 1,100 feet per second in the air, it races along at somewhere on the order of 5,000 feet per second in water. Though water is denser than air, which slows down the passing of the waves through the water molecules, it is also stiffer than air, which speeds up the sound. Sound passes through solids, which are stiffer still, at fifteen times the rate as through water.

“The only true voyage . . . would be not to visit strange lands

but to possess other eyes, to see the universe through the eyes

of another, of a hundred others, to see the hundred universes

that each of them sees, that each of them is.”

(Marcel Proust)

“A beagle pulling on a long leash trotted by and unceremoniously defined the corner of the trash pile by urinating on it.”

This entire project sprang from a walk with a dog; it seemed apt that it end with one. I spent sixteen years walking with (and informally studying) Pumpernickel, a curly haired, sage mixed breed. Through her choices, the subjects of her attention, what she balked at or lunged toward, I began to see her world. By minding her attention,
seeing what she saw from two feet off the ground, and observing how much she seemed to
smell
her way through the world, my own perception was changed. I began to see how horrible a long block with no trees or lampposts was: where could one receive word, through the markings of other dogs, who has been around? Where could one leave word oneself? Despite my never once attempting to communicate with others by peeing on the street, I picked up Pump’s aesthetic preference for streets with a lively set of street furniture, trees, and other curbside paraphernalia.

During her life, we developed a wide variety of walks together geared to what I imagined her view of the world to be. There were
into-the-wind
walks, during which she kept her eyes closed into slits and her nose in the air, nostrils working mightily. We took
smell walks
: instead of racing to take a walk defined by me for its length or its destination, we loitered at every place she wanted to smell, as she inhaled her view with her nose. As she grew older, we took walks that were largely episodes of sitting, in a field with ample olfactory vistas and plenty of dogs upwind. Most dog walks are done to allow the animal to pee or to get exercise. While those are sound reasons for a walk, what about walks to see the world? To interact with other dogs? What about walks to smell new smells?

Because humans are not smell-centered, we have difficulty imagining how rich in odors the world is. That is a constraint of our eyes: the picture they paint is so vivid that we assume there is no other way to make sense of the world but as a series of things to see. For most other terrestrial mammals, though, on four legs and with their noses near the ground, the world is perceived through odors. Kenneth Grahame, in
The Wind in the Willows,
introduces the genial Mole to school us: “We others,” he writes, “who have long lost the more subtle of the physical senses, have not even proper terms to express an animal’s inter-communications with his surroundings . . . and have only the word ‘smell,’ for instance,
to include the whole range of delicate thrills which murmur in the nose of the animal night and day, summoning, warning, inciting, repelling . . . those caressing appeals, those soft touches wafted through the air.”

Mole must lead us stump-nosed, blunt-seeing humans to imagine what it might be like to “see” in this way through metaphors: metaphors from sound (murmur), tactile sense (appeals, touches), and evocations of emotion (thrills, inciting, warning). We can come up with a vivid description of how a place we visited
looked
; but how it
smelled
? We are left with vague comparisons (“like a summer’s day”) that are evocative but not specific; names that tell us nothing about the quality of the scent (the smell of garlic or fresh bread); or superficial quality words (foul, lovely, delicious, spicy). What smells are very good at is beckoning memories forth: a whiff of pipe tobacco reminds me of the smell of the inside of my father’s desk when I was a child and he was still a smoker, of the sound of his footfalls and the jangle of the change in his pants pockets, of what it felt like to have him listen to me and smile. The smell, like the memory, is entirely personal. It cannot be shared with the ease that an image, rendered in ink or oils, can be experienced by hundreds or millions of viewers.

By now, it is well known that dogs are “good” at smelling. As we humans open our eyes and see the world, dogs come out of sleep with both nostrils working. A dog’s nose is remarkably well made for this task. The inside of the nose is a labyrinth of tunnels lined with specialized olfactory receptors waiting for an odorant molecule—a
smell
—to land on them. In the back of the nose is an “olfactory recess” separated from the main respiratory pathway by a bony plate, allowing smelling to be distinct from breathing, and letting odors loiter for a long time to be considered. Though we tend to think that only some things are smelly—a spring bloom, a trash can, a new car, a bus’s exhaust—just about everything has
a scent. Anything with molecules that can be “volatile,” that can evaporate into the air and travel toward a receptor in someone’s nose, smells.

The dog nose has
hundreds of millions
of receptors in that nose; they even have a second kind of nose above the hard palate of their mouth, called a vomeronasal or Jacobson’s organ. Molecules such as hormones that do not stir the receptors of the nose to fire may find a rousing welcome here. All animals house hormones, which are involved in bodily and brain activities, and those hormones we emit, called pheromones, are detected by the vomeronasal organ. This is how a dog could detect another dog’s stress or sexual readiness in a spray of her urine left on the ground.

Dogs are called macrosomatic, or keen-scented, while humans are called microsomatic, or feeble-scented. It is not for lack of equipment, though: almost 2 percent of our genome, the entire blueprint for making a human being, is dedicated to coding for olfactory receptors. Think of it! One out of every fifty genes is committed to making cells that can detect smells. So smells are important to us. Without smells in our lives, we become desperately unhappy—foods are not enjoyable, the environment is flattened—while some smells bother us excessively.
¹

But for much of the day, we go about our business un-smellily: we do not smell overmuch. For humans, odors tend to be either enticing or repugnant, alluring or foul, evocative or evaded. To a dog, the world is terrifically smelly—but not in the way we think of smelliness. To the dog, smells are simply information. Their world has a topography wrought of odors; the landscape is brightly colored with aromas.

Biologically, the human nose works in the same way as the dog’s. Odors are swept into the far reaches of the nose and land in receptors—a few million of them. But that is hundreds of millions fewer than the dog bears.
²
The difference in number of cells translates into a difference in kind. Dogs detect odors at one or two parts per trillion, unimaginably more sensitive than we are. One part mustard, one trillion parts hot dog: dogs can detect the mustard.

To begin to understand what a city block really smells like, there seemed to be one clear course of action: ask a dog. So it happened that one day I set to taking a walk around the block for this book with Finnegan, the earnest, playful black dog in our home now. I began by asking Finnegan about his interest in accompanying me, in showing me the odors of our block. From the way he was plopped languidly on the sofa, head relaxing off its edge, he did not look inclined. But on my second request, he leapt up, consented to having his leash snapped on, and trotted out our door alongside me.

Finn pushed out into the fresh air with enthusiasm. I followed him. Then we . . . stopped. It had occurred to me to ask
his
preference in our walking route, so instead of pulling him left (parkward) or right (cityward) when we exited the building, I stopped on the steps. Finn, ever cooperative, stopped as well. He perched on the top step, projecting his snout proudly ahead of him. As a steady, light stream of people walked by, they pushed air out of the way as they passed, occasioning plenty of sniffing by Finn. If someone so much as turned in his direction, he ducked
his head and let his tail wiggle his body with anticipation and excitement.

I waited for him to make a move. Between passersby, his body was still, only his head reacting to the activity on the street. The day was especially windy, and a sad old flag on a building across the way whipped around its pole. Finn perked his ears at the snap of the cloth, the bang of the flag rope against the pole. A sound Scott Lehrer could use for a shot of a seaside New England cottage hit by an ocean breeze, I thought. Our urban wind carried the sounds of someone hollering down the block, and tumble-weeded a plastic bag, belly full of air, along the tops of the parked cars.

We stood on the steps for several minutes. At last, I realized that should I not start us moving, we would not be having a walk at all, but a rousing “stand.” Were Finn any other kind of animal, he might have bolted as soon as we got outside. So I chose a direction and began walking. As we set off, I watched Finn’s attention. My audio recorder was again useless here, as it had been with my son. Instead, I would have to let Finn tell me what he saw by observing where he went, where he loitered, how his ears bent into focus, and how his tail measured his mood.

Straightaway, he sneezed, then licked his nose. I had to think that this was not significant, a reflexive reaction to a pollen tickling him. Later, I would rethink this. Finn pranced along by my side. He held his head high, and it gently bounced up and down with his stride. His gaze lightly touched the wall to our left, a garage door closing, a dog passing on our right. A driver honked a loud honk; Finn did not pause, but his eyes narrowed and his ears flattened against his head. Pressing down his ears should make the sound quieter, if not absent—the canid equivalent of our covering our immobile ears with our hands.

It was not long before he stopped outright. He licked his
nose again. A squat, unimpressive baluster caught his interest. It appeared to be made of poured concrete and held up an iron railing: a short skirt worn by the building to protect it from us. Finn peered at it, nose millimeters away from the surface. He even touched the surface, moistening it with small nose prints. I tried to follow his nose-gaze. I could see a palimpsest of messy splashes of drying liquid, some more messy or more dry than others.

This was, of course, the motherlode for dogs: other dogs’ urine. Visible generations of urine splotches lay one (roughly) atop the other. After some satisfying-looking sniffing, he moved to the next urine post. And the next. I noticed with some chagrin that there appeared to be a half dozen balusters ahead of us before we reached the corner. Given his renewed attention at each, I got the distinct impression that to him they were not at all alike. Each told tales of different visitors, some well fed, some ready for sex, some aggressive, some ill. Maybe some sad, longing, suspicious, or delighted.

I began to imagine the sidewalk as a place that conceivably held traces of other people’s passage—of their mood and health and habit. In what form I might see those traces was another question.
Other people’s trash
was the first thing that came to mind, unhappily: in a city, there is always evidence of others’ passage by the things they let drop through their fingers. But there are many more subtle cues. The fog of warm air that hits me as I pass a parked car tells me that someone quite recently turned off the ignition and left. The disruption of fallen petals or leaves on the sidewalk works like reverse tea leaves to tell the story of how many people have swept by. Look up when you see a flurry of cigarette butts on the ground and you are bound to see the entrance to a commercial building. (And it is likely after lunch break.) Some years ago I began noticing, then collecting, stray single gloves or mittens lying forlornly on the ground, displaced from the hands they had been warming.
These melancholy creatures, always frozen in an awkward or pleading pose, indicated recent passage of someone busily doing something requiring a free hand. I found more right gloves than left, probably a reflection of the overwhelming right-handedness of people, and the inclination to remove a right glove to do something requiring dexterity: take out one’s wallet, punch in a phone number, retie a shoe.