More than most other organs, the kidneys lose function as you age. Between the ages of forty and seventy, their filtration capacity drops by about 50 percent. Kidney stones become more common, as do more life-threatening illnesses. The death rate from chronic kidney disease has jumped by more than 70 percent since 1990 in the United States and by even more in some third world countries. Diabetes is the commonest cause of kidney failure, with obesity and high blood pressure as important contributory factors.

  What the kidneys don’t return to the body via the bloodstream, they pass on to the second and more familiar of our bladders, the urinary one, for disposal. Each kidney is connected to the bladder by a tube called a ureter. Unlike the other organs discussed here, the urinary bladder doesn’t produce hormones (at least none yet found) or have a role in body chemistry, but it does at least possess a kind of venerability. “Bladder” is one of the oldest words in the body, dating from Anglo-Saxon times and predating both “kidney” and “urine” by more than six hundred years. Most other words in Old English with a median d sound morphed into a softer th sound, so that “feder” became “feather” and “fader” became “father,” but “bladder” for some reason resisted the gravitational pull of common usage and has stayed true to its original pronunciation for well over a thousand years, something few other parts of the body could claim.

  The urinary bladder is rather like a balloon in that it is designed to swell as we fill it. (In an average-sized man it holds about a British pint, or about six-tenths of a quart; in a woman, rather less.) As we age, the bladder loses elasticity and can’t expand as it once did, which is part of the reason old people spend much of their lives scouting for restrooms, according to Sherwin Nuland in How We Die. Until very recently, it was thought that the urine and bladder are normally sterile. Occasionally bacteria might sneak in and give us a urinary tract infection, but there were no permanent colonies of bacteria in there. For that reason when the Human Microbiome Project was launched in 2008, with the intention of tracking down and cataloging all the microbes within us, the bladder was excluded from investigation. We now know that the urinary world is at least somewhat microbial, too, if not apparently vastly so.

  One unfortunate feature the bladder has in common with both the gallbladder and the kidneys is a tendency to form stones—hardened balls of calcium and salts. For centuries, stones plagued people to a degree almost unimaginable now. Because they were so difficult to deal with, they often grew to a most prodigious size before the victim finally accepted the necessity—and very high risk—of surgery. It was a horrible procedure, combining unsurpassed levels of pain, danger, and indignity in a single mortifying operation. Patients were calmed, to the extent possible, with infusions of opiates and mandragora (a form of mandrake), then placed on their backs on a table with their legs pushed back over their heads, their knees bound to their chests, and their arms bound to the table. Usually four strong men were called upon to hold the patient still while the surgeon scavenged about for stones. Not surprisingly, surgeons who performed the procedure were celebrated for their speed more than any other quality.

  Probably history’s most famous lithotomy, or stone removal, was that experienced by the diarist Samuel Pepys in 1658, when he was twenty-five years old. This was two years before Pepys started his diary, so we don’t have a firsthand account of the experience, but he mentioned it frequently and vividly thereafter (including in the diary’s very first entry when he finally started it) and lived in loquacious dread of ever having to undergo anything like it again.

  It’s not hard to see why. Pepys’s stone was the size of a tennis ball (albeit a seventeenth-century tennis ball, which was slightly smaller than a modern tennis ball, though the distinction could fairly be called academic to anyone carrying one). While four men held Pepys down, the surgeon, Thomas Hollyer, inserted an instrument called an itinerarium up his penis and into the bladder to fix the stone in place. Then he took a scalpel and quickly and deftly—but excruciatingly—cut a three-inch-long incision through the perineum (the area between the scrotum and the anus). Peeling back the opening, he gently cut into the exposed and quivering bladder, thrust a pair of duck-billed forceps through the opening, captured the stone, and extracted it. The entire procedure from beginning to end took just fifty seconds but left Pepys bedridden for weeks and traumatized for life.*

  Hollyer charged Pepys twenty-four shillings for the operation, but it was money well spent. Hollyer was famous not just for his speed but also for the fact that his patients very generally survived. In one year, he performed forty lithotomies and lost not a single subject—an extraordinary achievement. Doctors in the past were not always anything like as dangerous and incompetent as we are sometimes led to think them. They might have known nothing of antisepsis, but the best of them did not lack for skill and intelligence.

  Pepys for his part marked the anniversary of his survival for some years thereafter with prayers and a special dinner. He kept the stone in a lacquered box, and for the rest of his life showed it off at every opportunity to anyone willing to marvel at it. And who could possibly blame him?

  * Pepys’s complaint is often wrongly described as kidney stones. I regret to say I repeated that error in my book At Home: A Short History of Private Life. Pepys had kidney stones aplenty, too—he passed them regularly throughout life—but Dr. Hollyer (sometimes spelled Hollier in other accounts) would not have been able to extract such a large stone from the kidneys without killing him. The experience is recorded fully and memorably in Claire Tomalin’s esteemed biography, Samuel Pepys: The Unequalled Self.

  9 IN THE DISSECTING ROOM: THE SKELETON

  Heaven take my soul, and England keep my bones!

  —WILLIAM SHAKESPEARE, THE LIFE AND DEATH OF KING JOHN

  I

  THE MOST POWERFUL impression you get in a dissecting room is that the human body is not a wondrous piece of precision engineering. It’s meat. It is nothing like the plastic teaching models of torsos lined up on shelves around the perimeter of the room. Those are colorful and shiny, like children’s toys. An actual human body in a dissecting room isn’t toylike at all. It is just dull flesh and sinew and lifeless organs drained of color. It is slightly mortifying to realize that the only raw flesh we normally see is the meat of animals that we are about to cook and eat. The flesh of a human arm, once the outer skin is removed, looks surprisingly like chicken or turkey. It’s only when you see that it ends in a hand with fingers and fingernails that you realize it’s human. This is when you think you might be sick.

  “Feel this,” Dr. Ben Ollivere is saying to me. We are in the dissecting room at the University of Nottingham Medical School in England, and he is directing my attention to a piece of detached tubing in the upper chest of a male body. The tube has been sliced through, evidently for demonstration purposes. Ben instructs me to stick my gloved finger into its interior and feel it. It is stiff, like uncooked pasta—like a cannelloni shell. I have no idea what it is.

  “The aorta,” Ben says with what seems like pride.

  I am frankly amazed. “So that’s the heart?” I say, indicating the shapeless lump beside it.

  Ben nods. “And the liver, pancreas, kidneys, spleen,” he says, pointing out the other organs of the abdomen in turn, sometimes nudging one aside to expose another behind or beneath it. They are not fixed and hard like the plastic teaching models, but move about easily. I am vaguely reminded of water balloons. There is a lot of other stuff in there, too—threaded blood vessels and nerves and tendons, and lots and lots of intestines, all of it just kind of tipped in, as if this poor, anonymous, former person had had to pack himself in a hurry. It was impossible to visualize how any of this disordered interior could ever have conducted the tasks that would allow the very inert body before us to sit up and think and laugh and live.

  “You can’t mistake death,” Ben says to me. “Live people look alive—and even more so on the inside than on the surface. When you open them up in surgery, the organs throb and glisten. They are clearly living things. But in death they lose that.”

  Ben is an old friend and a distinguished academic and surgeon. He is clinical associate professor of trauma surgery at the University of Nottingham and a consultant trauma surgeon at Queen’s Medical Centre in the city. There isn’t anything in the human body that doesn’t fascinate him. We rather race around this one as he tries to tell me everything about it that interests him, which is everything.

  “Just consider all that the hand and wrist do,” he says. He tugs gently on an exposed tendon in the cadaver’s forearm up near the elbow, and to my surprise the little finger moves. Ben smiles at my startlement and explains that we have so much packed into a small space in the hand that a lot of the work has to be done remotely, like strings on a marionette. “If you make a tight fist, you feel the strain in your forearm. That’s because it’s the arm muscles that are doing most of the work.”

  With a blue-gloved hand, he gently swivels the cadaver’s wrist, as if conducting an examination. “The wrist is just a thing of beauty,” he goes on. “Everything has to go through there—muscles, nerves, blood vessels, everything—and yet it has to be completely mobile at the same time. Think of all the things your wrist has to do—take a lid off a jam jar, wave good-bye, turn a key in a lock, change a lightbulb. It’s a magnificent piece of engineering.”

  Ben’s field is orthopedics, so he loves bones and tendons and cartilage—the living infrastructure of the body—the way other people love expensive cars or excellent wines. “See that?” he says, tapping a small, smooth very white obtrusion at the base of the thumb, which I take to be a bit of exposed bone. “No, it’s cartilage,” he says. “Cartilage is remarkable, too. It is many times smoother than glass: it has a friction coefficient five times less than ice. Imagine playing ice hockey on a surface so smooth that the skaters went sixteen times as fast. That’s cartilage. But unlike ice, it isn’t brittle. It doesn’t crack under pressure as ice would. And you grow it yourself. It’s a living thing. None of this has been equaled in engineering or science. Most of the best technology that exists on Earth is right here inside us. And everybody takes it almost completely for granted.”

  Before we move on, Ben examines the wrist more closely for a moment. “You shouldn’t ever try to kill yourself by cutting your wrists, by the way,” he says. “All of those things going in are wrapped in a protective band called a fascial sheath, which makes it really hard to get to the arteries. Most people who cut their wrists fail to kill themselves, which is no doubt a good thing.” He is briefly thoughtful. “It’s also really hard to kill yourself by jumping from a height,” he adds. “The legs become a kind of crumple zone. You can make a real mess of yourself, but you are very likely to survive. Killing yourself is actually difficult. We are designed not to die.”

  This seems a slightly ironic thing to say in a big room full of dead bodies, but I take his point.

  * * *

  —

  Most of the time the dissecting room at Nottingham is filled with medical students, but it is the summer holidays when Ben Ollivere shows me around. Two other people join us from time to time, Siobhan Loughna, a lecturer in anatomy at the university, and Margaret “Margy” Pratten, head of the anatomy teaching section and associate professor of anatomy.

  The dissecting room is a large, well-lit room, clinically clean and slightly chilly, with a dozen anatomical workstations ranged around it. A liniment-like smell of embalming fluid hangs in the air. “We have just changed formulations,” Siobhan explains. “It preserves better, but smells a bit more. Embalming fluid is mostly formaldehyde and alcohol.”

  Most bodies are cut into pieces—or transected, to use the formal term—so that students can focus on a particular area: a leg or shoulder or neck, say. The unit gets through about fifty bodies a year, Margy tells me. I ask her if it is hard to find volunteers.

  “No, quite the opposite,” she replies. “More bodies are donated than we can accept. Some we have to reject—if the person had Creutzfeldt-Jakob disease, for instance, because there would still be a danger of infection, or if they were morbidly obese.” (Very large bodies can be physically challenging to deal with.)

  At Nottingham, they have an informal policy that they keep only one-third of a transected body, Margy adds. The retained parts may be kept for years. “The rest is returned to the family so that they can have a funeral service.” Whole bodies are generally kept for no more than three years before being sent off for cremation. Members of the staff and medical students often attend the ceremonies. Margy makes a point of always trying to go.

  It seems a little strange to say when talking about bodies that have been carefully quartered, then turned over to students to further incise and probe, but at Nottingham they are fastidious about treating the bodies with respect. Not all institutions are quite so rigorous. Not long after my visit to Nottingham, there was a brief scandal in America after an assistant professor and some graduate students from the University of Connecticut were photographed posing with two severed heads in a selfie taken in a dissecting room in New Haven. By law no photography is allowed in dissecting rooms in Britain. At Nottingham, you cannot bring a phone in.

  “These were real people with hopes and dreams and families and all the rest that makes us human, who have given their bodies to help others, and that’s incredibly noble, and we try very hard never to lose sight of that,” Margy told me.

  * * *

  —

  It took a surprisingly long time for medical science to take a very active interest in what fills the space inside us and how it all works. Up to the Renaissance, human dissection was widely forbidden, and even when it became tolerated, not many people had the stomach for it. A few intrepid souls—Leonardo da Vinci most famously—cut people up for the sake of knowledge, but even Leonardo observed in his notes that a decomposing body was pretty disgusting.

  Specimens were nearly always hard to come by. When the great anatomist Andreas Vesalius, as a young man, wanted human remains to study, he stole the body of an executed murderer off a gibbet outside his hometown of Leuven (French Louvain), just east of Brussels in Flanders. William Harvey, in England, was so desperate for subjects that he dissected his own father and sister. No less bizarrely, the Italian anatomist Gabriele Falloppio (after whom the Fallopian tubes are named) was given a criminal who was still alive with instructions to put him down in the manner that best suited his purposes. Falloppio and the criminal together appear to have opted for a comparatively humane overdose of opiates.

  In Britain, criminals hanged for murder were distributed to local medical schools for dissection, but there were never enough bodies to meet demand. Because of the shortages, a brisk trade arose in illicit bodies stolen from churchyards. Many people lived in severe dread of having their bodies dug up and violated. A well-known case was that of the celebrated Irish giant Charles Byrne (1761–83). At seven feet seven inches, Byrne was the tallest man in Europe. His skeleton was coveted by the anatomist and collector John Hunter. Terrified of being dissected, Byrne arranged that when he died his coffin would be taken out to sea and dropped in deep water, but Hunter managed to bribe the ship’s captain with whom Byrne had made the arrangement, and instead Byrne’s body was brought to Hunter’s residence in Earl’s Court, London, where it was dissected while practically still warm. For decades, Byrne’s lanky bones have hung in a display case in the Hunterian Museum of the Royal College of Surgeons in London. However, in 2018 the museum was closed for a three-year-long refurbishment, and there has been talk of allowing Byrne to be buried at sea in fulfillment of his final request.

  As medical schools proliferated, the problem of supply steadily worsened. In 1831, London had nine hundred medical students but just eleven executed bodies to share between them. The following year, Parliament passed the Anatomy Act, which made the punishments for grave robbing more severe but also allowed dissecting institutions to take anyone who died penniless in a workhouse, which made a lot of paupers very unhappy but increased the supply considerably.

  The rise of scholarly dissection coincided with an improvement in the standard of medical and anatomical textbooks. The most influential anatomical work of the period—and indeed ever since—was Anatomy: Descriptive and Surgical, first published in 1858 in London and known ever since as Gray’s Anatomy, after its author, Henry Gray.

  Henry Gray was a rising young demonstrator of anatomy at St. George’s Hospital at Hyde Park Corner in London (the building still stands but is now a luxury hotel) when he decided to produce a definitive and modern anatomical guide. Gray was still only in his twenties when he began work on the book in 1855. For the illustrations, he commissioned a medical student at St. George’s named Henry Vandyke Carter for a payment of £150 spread over fifteen months. Carter was painfully shy but highly gifted. All of his illustrations had to be drawn in reverse so that they would print the right way around on paper, which must have been an almost unimaginable challenge. Carter did not only all 363 drawings but also nearly all of the preparatory dissection. Although many other anatomy books were available, Gray’s, in the words of one biographer, “eclipsed all others, partly for its meticulous detail, partly for its emphasis on surgical anatomy, but most of all perhaps for the excellence of the illustrations.”