“People who lose their sense of smell are usually astounded at how much pleasure it takes out of their lives,” says Beauchamp. “We depend on smell for interpreting the world but also, no less crucially, for getting pleasure from it.”
This is especially true of food, and for that very important subject we need another chapter.
*1 Craniometry is also sometimes referred to as craniology, in which case it needs to be distinguished from the modern, perfectly respectable discipline of the same name. Modern craniology is used by anthropologists and paleontologists to study anatomical differences in ancient peoples, and by forensic scientists to make determinations about the age, sex, and race of recovered skulls.
*2 Surely, however, any figure must be largely notional. How on earth would you distinguish, let us say, expression No. 1,013 from No. 1,012 or 1,014? Any such differences would have to be practically microscopic. Even some basic expressions are almost impossible to distinguish. Fear and surprise cannot usually be told apart without knowing the context that prompted the emotion.
*3 Incidentally, twenty-twenty vision means only that you see as well from twenty feet what any other reasonably well-sighted person would see. It doesn’t mean that your vision is perfect.
6 DOWN THE HATCH: THE MOUTH AND THROAT
To lengthen thy life, lessen thy meals.
—BENJAMIN FRANKLIN
IN THE SPRING of 1843, the great British engineer Isambard Kingdom Brunel took a rare break from his labors—at the time he was building the SS Great Britain, the largest and most challenging ship ever to come off a drawing board to that time—to amuse his children with a magic trick. Things didn’t go quite to plan, however. Midway through the entertainment, Brunel accidentally swallowed a gold half-sovereign coin that he had secreted under his tongue. We may reasonably imagine Brunel’s look of surprise followed by consternation and perhaps slight panic as he felt the coin slide down his throat and lodge at the base of his trachea. It caused him no great pain, but it was uncomfortable and unnerving because he knew that if it shifted even slightly it could choke him.
Over the next few days, Brunel, his friends, colleagues, family, and doctors attempted every obvious remedy, from slapping him hard on the back to holding him aloft by the ankles (he was a small man and easily lofted) and shaking him vigorously, but nothing worked. Seeking an engineered solution, Brunel designed a contraption from which he could hang upside down and be swung in wide arcs in the hope that motion and gravity together would make the coin fall out. That didn’t work either.
Brunel’s plight became the talk of the nation. Suggestions poured in from every quarter of the country and from abroad, but every attempted remedy failed. At length, the eminent physician Sir Benjamin Brodie decided to attempt a tracheotomy, a risky and disagreeable procedure. Without benefit of anesthetic—the first use of anesthetic in Britain was still three years off—Brodie made an incision in Brunel’s throat and tried to extract the coin by reaching into his airway with long forceps, but Brunel couldn’t breathe, and coughed so violently that the attempt had to be abandoned.
Finally, on May 16, more than six weeks after his ordeal began, Brunel had himself strapped into his swinging contraption once again and set in motion. Almost immediately, the coin fell out and rolled across the floor.
Very shortly afterward, the eminent historian Thomas Babington Macaulay burst into the Athenaeum Club in Pall Mall and shouted, “It’s out!” and everyone knew at once what he meant. Brunel lived the rest of his life without complications from the incident and, as far as is known, never put a coin in his mouth again.
I mention all this here to make the point, if it needed making, that the mouth is a place of peril. We choke to death more easily than any other mammal. Indeed, it can reasonably be said that we are built to choke, which is clearly an odd attribute to go through life with—with or without a coin in your trachea.
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Look inside your mouth and a good deal of what you find is familiar—tongue, teeth, gums, dark hole at the back presided over by that curious little flap known as the uvula. But behind the scenes, as it were, are lots and lots of very important apparatus that most of us have never heard of: palatoglossus, geniohyoid, vallecula, levator veli palatini. As with every other part of your head, the mouth is a realm of complexity and mystery.
Take the tonsils. We are all familiar with them, but how many of us know quite what they do? In fact, nobody knows quite what they do. They are the two fleshy hummocks that stand sentinel on either side of the throat at the back. (Confusingly, in the nineteenth century they were often called amygdalae, even though that name was already applied to structures in the brain.) Adenoids are similar but lurk out of sight within the nasal cavity. Both are part of the immune system, but not a particularly impressive part, it must be said. Adenoids often shrink away to virtually nothing in adolescence, and both they and tonsils can be removed without making any discernible difference to your overall well-being. The tonsils are part of a somewhat grander structure known as Waldeyer’s tonsillar ring, named for the German anatomist Heinrich Wilhelm Gottfried von Waldeyer-Hartz (1836–1921), who is better remembered for coining the term “chromosome” in 1888 and the term “neuron” in 1891. He was, anatomically speaking, all over the place. Among much else, he was the person who first postulated, way back in 1870, that a woman is born with all her eggs, or ova, fully formed and ready to go.*1
The anatomist’s word for swallowing is “deglutition,” and it is something we do quite a lot—about two thousand times a day, or once every thirty seconds on average. When you swallow, food doesn’t just drop into your stomach by means of gravity, but is pushed down by muscular contractions. That’s why you can eat and drink while upside down if you choose to. Swallowing is a trickier business than you might think. Altogether, fifty muscles can be called into play just to get a piece of food from your lips to your stomach, and they must snap to attention in exactly the right order to ensure that whatever you dispatch into the alimentary system doesn’t go down the wrong way and end up lodged in an airway, like Brunel’s coin.
The complexity of human swallowing is largely because our larynx is low in the throat compared with other primates. To accommodate our upright posture when we became bipedal, our necks became longer and straighter and moved to a more central position beneath the skull rather than toward the rear as in other apes. By chance, these changes gave us greater aptitude for speech but also the danger of “tracheal obstruction,” in the words of Daniel Lieberman. Uniquely among mammals, we send our air and food down the same tunnel. Only a small structure called the epiglottis, a kind of trapdoor for the throat, stands between us and catastrophe. The epiglottis opens when we breathe and closes when we swallow, sending food in one direction and air in another, but occasionally it errs and the results are sometimes dire.