PAUL DIED OF an aneurysm. When my mother’s neighbor told me on the phone, I remember trying to picture how it must have happened. It’s quick, they say. A lot of people who have one never know until the end. Maybe not even then, especially if, as with my brother, it’s low in the aorta.
He woke one morning at four A.M. with a numbness in his leg. The doctor told me later that was because blood had begun leaking through a fissure in the aneurysm, then trickled down and moistened the nerves. They took him to the hospital and performed extensive tests, thinking maybe a thrombus, or blood clot, had dislodged, a loose cannon in his circulatory system. His EKG was normal. They gave him a stress test. The numbness got worse—he had no feeling in his leg. They decided to ship him to another hospital, one specializing in vascular disorders, and wheeled him to an ambulance and sent him on his way.
They were pulling into that hospital’s parking lot when the aneurysm burst and the heart emptied of blood. It had nowhere to go but his inner cavities, his fissures and canyons, slots and little craters. Bleeding to death inside one’s body must be the worst form of claustrophobia. It had to feel like a great sinkhole in his body, the horizon of the world draining inside him. He was caught in a spiral of dizziness, I’m sure, so the crisis of panic— What’s happening? Oh my God —most likely drained out as soon as he felt it, like those seemingly crucial things we forget the moment we think them as sleep overtakes us.
On the other hand, perhaps it took longer. And how long is long when you’re dying, anyway? Falling from a roof might take only a second, yet it lasts forever. The reason for this is that time balloons, as arteries do—it swells with the surge. Of course, Paul was wired to monitors that must have shown what was happening, and maybe the medics were shouting “Paul, hang on!” as he faded, and pumping him full of electric current, and his body was jerking—“Are you with me, Paul?”—and all became a part of the spiraling dizziness, adding to the panic yet scattering it too.
When the sensation of spinning unclogged his brain, it also dislodged and cut loose his consciousness. His brain died first, starved of blood and oxygen.
Two weeks later, after the funeral, after I’d seen his house and learned what was in it, I woke up one morning feeling pains in my chest; they felt like heartburn, so I took some antacid. But they wouldn’t go away. I taught a seminar on my campus, feeling increasingly short of breath. After the class, I had difficulty walking. I jog regularly and, in the summer, climb mountains on routes ten or twenty miles long. But I could hardly make it to the parking lot.
Halfway there, I turned back, and with my newly hatched festinating walk—stopping every few minutes to catch my fading breath—made it to the science library and looked up aneurysms. Severe heartburn feels like how I’d imagined an aneurysm would feel if it were pressing on the trachea or esophagus. However, I learned that most aneurysms were asymptomatic. Most? I sagged across campus to my car and drove to the closest ER.
In the hospital that night, the doctor told me that one of my lungs had collapsed. It might occur again in a week or two, perhaps in a year or two, or maybe never again. To reinflate the lung, he inserted a tube in my chest, which drained out the air caught in the chest cavity. One way that a lung collapses is by springing a leak—caused by a cyst or other weakness in its wall—and the more air that escapes into the chest cavity, the less the lung can inflate against the pressure. The lung leaks and air accumulates slowly, so it may take a while for it to fully collapse. Mine was fully collapsed.
The tube, going in, felt like being stabbed. As the doctor shoved, I felt it scrape a rib, felt each millimeter of tissue and nerve it divided. Once the air was released, my lung inflated as predicted, all at once, like an air bag. And that sensation is impossible to describe—something like an umbrella popping open inside you.
I lay there squirming, feeling little adhesive pains here and there, like new stars being born. Those, I was assured, were the result of the lung’s readhering to the sticky pleura. Pleura? I was learning such interesting things about the body on whose shoulders I’d traveled all my life.
It does make you wonder about the various ways, while your body sleeps, that all its inner cauldrons can percolate and bubble, stirring plots to cause trouble, chaos, and confusion, planting seeds of death.
In 1945, in the village of al-Qasr in Upper Egypt, a night watchman named ‘All killed a thief attempting to steal irrigation equipment from his clan’s fields. The next morning, he in turn was murdered, by a member of the thief’s family, a man named Ahmad. Six months later, ‘All’s son, Muhammad ‘All, was digging above the Nile Valley cliffs for talus rich with nitrates, to fertilize the same fields. He came across a jar at the base of a boulder whose lid was probably sealed with bitumen, although we’ll never know because he smashed it with his mattock. He did this with reluctance—it might contain a jinni, he thought. Then again, it might also contain gold, and in fact when he broke open the jar, yellow particles swirled out. They turned out to be fragments of papyrus. Inside the jar were books of the type made in late antiquity, when scrolls had only recently been abandoned in favor of stacks of flat sheets bound in leather. He wrapped them in his coat, hopped on his camel, and carried them home.
A month after that, a neighbor spotted Ahmad, the man who’d murdered Muhammad ‘All’s father, asleep by the side of a road outside their village. Beside him was a jar of unsold sugarcane molasses. The neighbor alerted Muhammad ‘All’s family, who’d been urged by their mother to keep their mattocks sharp. They fell on Ahmad while he was sleeping, hacked off his limbs, chopped him into pieces, ripped out his heart and ate it raw, sharing it among them—the supreme blood revenge.
Muhammad ‘Ali gave his books to the local Coptic priest, after being told they were Christian texts. His mother had already burned at least one when she ran out of firewood, and others had been distributed to neighbors. Some found their way to Cairo, where they fetched high prices, but when collectors and scholars asked their discoverer where he’d found them, Muhammad ‘All, afraid of an ambush by Ahmad’s family, only agreed to take them to the site under government escort and in disguise.
Ten years later, Ahmad’s teenage son opened fire during a funeral procession for a member of Muhammad ‘All’s family, killing or wounding twenty people. Muhammad ‘All himself was shot above the heart, and displayed the wound with pride the rest of his life, since, being intact, he was living proof of unsuccessful vengeance.
The books turned out to be a large group of Gnostic texts from the first several centuries of the Christian era, now best known as the Nag Hammadi Library. In one of them, The Apocryphon of John, the creation of Adam is described as a kind of choral assemblage of factory parts, with a different angel or demon assigned to each limb and organ. So: “Eteraphaope-Abron created his head; Meniggesstroeth created the brain; Asterechme created the right eye; Thaspomocha created the left eye; Yeronumos created the right ear; Bissoum created the left ear; Akioreim created the nose; Banen-Ephroum created the lips; Amen created the teeth; Ibikan created the molars; Basiliademe created the tonsils; Achcha created the uvula. . . . ” This goes on for several pages of the original codex. Angels and demons are appointed as guardians over each item, as well as over the bone-soul, the sinew-soul, the flesh-soul, the marrow-soul, the blood-soul, the skin-soul, and the hair-soul. By the end of the passage, Adam’s body contains enough guardian powers to run a football stadium, each assigned to a fragment of the whole. There are demons to reign over heat, cold, and wetness, and others assigned to the senses, the imagination, the passions and emotions. Someone named Oummaa is in charge of “composition”—presumably a sort of batter taster.
The resulting soft machine called Adam has been literally articulated as a collection of parts inside a bag of skin, also a part. This was in the text a man had found before chopping his enemy into pieces.
What was the body for those late ancients? What secrets did it hide? One difficulty was that finding out—by dissection, for example—might release a swarm of demons. “He that toucheth the dead body of any man shall be unclean seven days” (Numbers 19:11). In 1300, the Pope issued a bull excommunicating those who cut up dead bodies. Dissection by then had come to be regarded as a sinful prying into nature’s secrets.
The more ancient ancients were not as squeamish about body parts, as anyone who has read The Iliad can attest. Yet Homer’s descriptions—“Idomeneus stabbed Erymas in the mouth with the pitiless/bronze, so that the brazen spearhead smashed its way clean through/below the brain in an upward stroke and the white bones splintered,/and the teeth were shaken out with the stroke and both eyes filled up/with blood, and gaping he blew a spray of blood through the nostrils/and through his mouth, and death in a dark mist closed in about him”—while graphic, are curiously detached. They have a sort of stillness, like separate snapshots arranged to make a series. One feels, in Homer, that there’s not much difference between the inside and the outside of the body. Inside, outside, public, private—the ancients saw them as continuous. Maybe that’s why they regarded those mysterious human innards shrouded in darkness—the pipes and cisterns of the body, wrapped in bloody spaghetti—as hardly mysterious at all, being part of the world every bit as much as stones, birds, olives, and urns.
Skip ahead to Robert Fludd. In 1633, the same “Trismegistian-Platonick-Rosy-crucian Doctor” and “cacomagus” we met earlier, the coinventor of the thermometer, described looking over a physician’s shoulder as he dissected a cadaver in London. The place was most likely the College of Physicians’ house at the end of Paternoster Row, on Amen Corner, in the shadow of St. Paul’s Cathedral, although Fludd doesn’t specify. Both Fludd and the dissector were members of the London College of Physicians, and both were anatomists, so let’s say Amen Corner.
The physician was attempting to prove that no passageways existed in the muscular wall between the right and left ventricles of the heart. Belief in such “intraventricular pores of the septum” went back at least to Galen, and probably resulted from dissections of miscarried or aborted fetuses. The fetus does possess an opening between the two sides of its heart, since its circulating blood is its mother’s, and this blood bypasses its lungs, which of course can’t function in the womb. When a child is born, the lungs inflate, and blood from the right atrium begins to flow through the pulmonary trunk into the lungs, from which it returns to the left atrium; and gradually the passageway between the two sides of the heart closes.
Four years earlier, the French philosopher Pierre Gassendi claimed to have witnessed, in a dissection at Aix, a surgeon named Payanus who probed with a spatula for such openings or pores in the septum of an adult—and found them. “Taking the spatula, he approached the septum of the heart to try the penetration. He attempted this not straight on as others do, but he first made the approach most lightly with the edge of the iron entered in beneath . . . and he explored the approach always further by twisting the iron up and down, and to the side, most patiently.” Fludd, in his description of the dissection Tie witnessed, mentions this passage and upbraids Gassendi for failing to conclude the obvious: that the surgeon produced the openings he was searching for in the very act of searching. Those who have examined the heart with care, like the physician whose shoulder he peered over, says Fludd, have never found a septum with “pores.” “Not in any one out of the many cadavers that he examined did he find such a septum; and neither I nor any others who with most acute and almost lynx-like eyes saw this when we examined the septum of the heart.”
Lynx-like eyes to be sure. Fludd would have needed keenness of sight at such a dissection, or, as they were called, at the “mysteries” of an anatomy. In the house on Amen Corner, the dissecting table probably had a curtain around it, hung on a metal frame, to ensure the cadaver’s decency before the cutting began. The physician wore white aprons and sleeves and a large white bonnet that probably dwarfed him, since this man was short. Light was surely a problem; wax candles were always provided, to peer into the body cavity. In this case, perhaps the heart was removed and carried to a window. Or maybe the physician simply plopped it on the table next to a candle and touched it with his silver-tipped rod—made of white whalebone—and let the others turn their lynx eyes upon it.
The cadavers at such anatomies were malefactors executed for felonies in London. Queen Elizabeth granted the College of Physicians four such bodies a year, a number James I increased to six.
Why would such mythical openings in the heart concern a man like Fludd? Because the doctor whose shoulder he was peering over was William Harvey, who had demonstrated to the world that blood circulates in the body, and in so doing had asserted that it moves from the veins to the arteries by means of the lungs. But according to the ancients, the lungs drew air into the body to cool off the heart, and the pulmonary vein carried that air into the heart. Therefore the blood passed from the right to the left side of the heart through pores in its septum. “I should like to be informed why,” asked Harvey, “if the pulmonary vein were destined for conveying air, it has the structure of a blood vessel?” In fact, as he knew, the pulmonary vein conveys blood, not air, and the lungs close the loop of circulation by making a link from the veins to the arteries.
As for the other link, from the arteries to the veins, Harvey had to presume that it existed, since what we today know as the capillaries were too small to be seen without a microscope. And Harvey’s work, says Steven Vogel, “antedated practical microscopes.” Thirty years after Harvey published his findings, Marcello Malpighi provided the finishing touch, becoming the first to see capillaries with a microscope. But I’m getting ahead of myself.
Fludd, who liked to give his name as de Fluctibus, was Harvey’s colleague and friend. As Fellows and Censors of the College of Physicians, they had the power to examine and license new doctors. Fludd was one of the first to acclaim Harvey’s discovery of blood circulation, and he helped Harvey find the publisher for his book announcing the discovery: William Fitzer in Holland, who specialized in Rosicrucian texts. Yet Fludd was an enthusiast and a mystic, whereas Harvey, according to Geoffrey Keynes, with “a somewhat cold and secluded mind,” was “eager for knowledge, but not burning to share it with others.” Harvey thought that human beings were mischievous baboons and modern writers were “shitt-breeches.” He was very short, with a brownish complexion, round face, small eyes, a little pointed beard, and a pudgy body. His temper was quick—he carried a dagger—and he had trouble sleeping, either because of the continual flux of ideas racing through his head or because he was one of the first Englishmen, says Keynes, to form an addiction to coffee.
He was always alert, skeptical and quizzical, and did not suffer fools. Is it possible to conclude from this description that Robert Fludd was not a fool?
Or was he patronized by Harvey?
We know that Fludd was there that day because he later published a book defending himself and Harvey against the attacks of Pierre Gassendi, who’d witnessed that butcher Payanus digging into a heart with, of all things, a spatula—and in it he cites Harvey’s dissection. Later, after Fludd’s death, Harvey went even further in demonstrating the impermeability of the heart septum: he tied off the pulmonary artery of a “throttled human being” (a highwayman) and pumped the right ventricle and atrium with water until they were larger than a football and ready to burst; no water passed from the right to the left side of the heart.
What went through Fludd’s mind while looking over Harvey’s shoulder? Perhaps the flickering candle, the pulley and hook hanging from the ceiling, the fire in the hearth, the smell of blood and body tissue, not to mention the heady odor of his fellow physicians crowding around, since no one in seventeenth-century England bathed very often—perhaps all this made him think of better things, of escaping that close, poorly lit room. The human body was a glory to Fludd, as it would be to William Blake two hundred years later. “The Head sublime, the heart Pathos, the genitals Beauty, the hands & feet Proportion” was the way Blake expressed it. Fludd would have concurred. In his book A Philosophicall Key, our old friend Pan—Fludd’s Principle of Universal Nature—creates the human body out of “grosser elements” to house the “supernaturall splendour” of the “Aethereall spirit.” I’ve modernized the spelling in the following long quotation. Pan is reporting the instructions he received from Demogorgon, the god of the earth:
Then in his middle sphere shall thou erect a pavilion called the heart, which, like the sun in the greater world, shall send forth his essential beams circularly from his center, that thereby they may animate and vivify every member of this so well-erected a microcosm. Then also will I command, that Chronos or Time . . . shall justly guide and proportion the minutes of his life and days, observing carefully that the motion of his pulses be obedient to just measure and harmonical proportion, and that their Systole and Diastole do live together in peace and concord as man and wife. . . . In the which therefore thou shalt set to thy helping hand first to transmute by thy natural motion the chilly substance and cloudy vapors of the airy ventricle into crimson and ready blood, which thou shall conduct by the doubleguarded channels of the veins through every region of this earthly edifice, that thereby it may produce unto itself a universal fertility by successive and hourly nourishment, even as thy rainy influence make the whole earth of the macrocosm passing fruitful. . . . Moreover the brackish torrents and wheyey streams shall trickle down from the mountains of the stomach, liver, and spleen, and kissing first in their current the scarlet and reeking billows of the greater veins, shall penetrate by a double conduit or channel quite through the stony and rocky caverns of the kidneys, as through the gravelly veins and sandy passages of the earth’s mountain, and so by Time’s direction shall fall soberly into the salt sea of the bladder.
The gray body Fludd observed over Harvey’s shoulder may have possessed such a marvelous geography, but to see it would require more than lynx eyes—it would require, in Blake’s words, looking through, rather than with, one’s senses.
One can hardly imagine an odder couple than these doctor friends, the rational Harvey and the mystical Fludd. Yet A Philosophicall Key was written in 1619, the year Harvey says he formulated his notion of the blood’s circulation. And as this passage shows, Fludd was simultaneously forming a similar concept: that the heart, like the sun, sends forth his beams—that is, the blood—“circularly from his center.” In his De motu cordis, when Harvey places his discovery in the center of a chapter at the center of his book, in uppercase letters—“I began to think whether there might not be A MOTION, AS IT WERE, IN A CIRCLE”—he offers not as evidence but as bolstering atmospherics a series of Fluddian metaphors:
This motion we may be allowed to call circular, in the same way as Aristotle says that the air and the rain emulate the circular motion of the superior bodies; for the moist earth, warmed by the sun, evaporates; the vapours drawn upwards are condensed, and descending in the form of rain, moisten the earth again. By this arrangement are generations of living things produced; and in like manner are tempests and meteors engendered by the circular motion, and by the approach and recession of the sun.
So Harvey too used macrocosmic pictures to describe microcosmic realities, not unlike what I’m doing in tracing Paul’s story. In Harvey’s case, this method enabled him to emphasize two things. One, that blood, like rain, is preserved in its circuit—it’s always the same blood. The old view was that blood, continually manufactured, was continually being absorbed by the body, since it was the “virtue” that nourished and warmed the whole body.
The other, that blood circulated, turned out to be one of the great paradigm shifts in science. It didn’t depend just on lynx eyes and a scalpel-edged mind; it also required a new picture and model, that of the circle. Fludd was not the only one ever to say the blood moved in a circle, nor was his notion of circularity exactly that of Harvey. But he was there with his “well-erected microcosm” when Harvey needed a model. As Walter Pagel asks, “Could [Fludd’s] idea about the circular motion of the spirit in the blood and its imitation of the movement of the Sun have left an impression in Harvey’s mind and have in some way ‘sensitised’ him to the association of ‘circularity’ with the blood and the heart?”
Geoffrey Keynes reports that Sir Richard Quain visited the Harvey family vault in 1868. William Harvey’s coffin was a wrapping made of lead roughly shaped to the body, with a face carved on top. Other members of his family had similar leaden shells, some of which had sagged and contracted, so that their skeletons showed through. In Harvey’s case, the lead had cracked, and Quain writes of being horrified when a large frog jumped out.
Maybe this frog was a descendant of those seventeenth-century martyrs to science who were tied down, stabbed, cut open, chopped up, injected with fluids, and boiled to demonstrate the blood’s circulation. As one of Harvey’s biographers points out, it isn’t possible to demonstrate the circulation of the blood by dissecting cadavers, whose hearts have stopped beating. Living animals must be used. Harvey’s great successor, Marcello Malpighi, said that in discovering the capillaries “I have almost destroyed the entire race of frogs.” Harvey also cut open live frogs, as well as fish, pigeons, dogs, snakes, and chickens. “The examination of bodies of animals has always been my delight,” he said. He once removed the heart from a frog and observed that the creature still skipped around. Another time, he chopped up the heart of a salmon and watched all the pieces continue to beat. He studied them closely; they were contracting, not dilating.
One of the most compelling passages of De motu cordis is Harvey’s description of a dying heart. He’d already established that the heart is a muscle that pumps by contracting. The old view was that the heart and arteries both dilate and contract, and that the arteries, with muscles in their walls, pump as well.
Last of all, drawing towards death, it [the heart] ceases to answer by its motion, and only by nodding its head seems to give consent, and moves so insensibly, that it seems only to give a sign of motion to the ears: So the heart first leaves beating before the ears, so that the ears are said to out-live it: the left ventricle leaves beating first of all, then its ear, then the right ventricle, last of all . . . the rest giving off and dying, the right ear beats still: so that life seems to remain last of all in the right. And whilst by little and little the heart is dying, you may see after two or three beatings of the ear, the heart will, being as it were rowsed, and very slowly and reluctantly, endeavour and frame a motion.
“Ear” in this translation (Harvey wrote in Latin) means auricle, Latin for ear—and auricle is another word for atrium. Harvey also describes moistening his finger after a pigeon’s heart had stopped beating, then touching the heart. The warmth of his finger, he reports, encouraged the heart to recommence beating, “recalled as it were from death to life.”
He describes experiments with live fish, in which he cut them open, tied off the aorta, and watched the heart fill to near bursting. Then he tied off the inferior vena cava, and the opposite happened: the heart became flat, almost empty, though still stubbornly beating. The aorta went flat too, receiving less and less blood, and soon none at all. What became of all that blood? After filling the veins it poured into the main vein and stretched it until it almost exploded. This proved the theory of circulation. The stream of blood went around in a circle, and no matter where he tied a vessel, an accumulation took place.
Then came Malpighi. He cut open frogs and observed the arteries running into the peritoneum (the membrane around the abdominal cavity) swell with each heartbeat and branch into smaller and smaller blood vessels. He filled the arteries in a dog’s lung with mercury and observed its fine branches, like moonlit antlers. Harvey had boiled livers, spleens, lungs, kidneys, and other organs until their tissues “could be shaken like dust from the fibres or picked away with a needle,” looking for the so-called anastomosis of the arteries and veins—the direct openings between them, posited by the ancients—with no success. There had to be what we call capillaries, he concluded, but they were too small to see. Malpighi saw them. He tied the artery running into a frog’s lung, cut out the lung, hung it up to dry, and holding it against the setting sun several days later, looked at it through a single-lens microscope and made out its intricate network of capillaries, each one containing a thread of dried blood. He placed it under his doublelens microscope with a lamp and could trace with his eyes their labyrinthine curves and countless branches.
Pinning down live frogs, he cut them open and looked at their lungs, peritonea, and bladders; with the microscope he could see where the arteries rooted down into fine stringy nets of billowing capillaries, which gathered in bunches then fanned out as veins.
Malpighi, by the way, performed these experiments while experiencing severe attacks of kidney stones. Once he even cut open a kidney and saw what we know as the glomeruli, hanging on the arteries, as he put it, like apples on a tree.
If any further confirmation is needed that human beings are no longer animals, it would be these explorations of the hidden body and of what used to be called forbidden knowledge. Harvey once demonstrated the heart’s powerful pulse by tying down a dog and opening a proximal artery so that the blood rhythmically spurt across a room. Those who cut up living animals know they aren’t human, of course. One can inflict disinterested pain only on that which isn’t oneself.
Still, a part of us remembers the time when we were animals. The memory is a vestige, like the tail on human fetuses. Harvey’s description of a dying heart, with its nodding head—as though falling asleep—eerily suggests a Victorian account of a fading pet’s last moments. The odd combination of precision, objectivity to the point of bloodlessness, and the word “ears” (we think of furry little envelopes) creates for us today, no matter who we are—biologist, poet, cynic, sentimentalist—an unresolved tension. We flow back and forth, as perhaps Harvey did, between a mind that knows and a body that suffers.
Both Harvey and Malpighi died of strokes, or heart attacks—the distinction then wasn’t always easy to make. So it turns out that both were animals after all. They were animals because their bodies could die, even if those bodies were a form of clockwork. Their contemporary Descartes, who called the body a machine, denied consciousness to animals, and his followers were said to make fun of those who pitied dogs for suffering pain. “They said the animals were clocks,” said one Frenchman, and “the cries they emitted when struck were only the noise of a little spring that had been touched.” Descartes supported Harvey’s theory, though with modifications. He especially applauded its mechanistic explanations. His followers were said by the same anonymous countryman to have nailed living dogs up on boards “by their four paws to vivisect them to see the circulation of the blood which was a great subject of controversy.”
Today we at least anesthetize laboratory animals before cutting them open, although some insist this doesn’t make any difference and we shouldn’t under any circumstances cut open animals. Most scientists I know try to avoid causing any animal to feel pain. But sometimes, they say, it can’t be avoided. Descartes was right in one respect: an animal isn’t “conscious of” pain. But Descartes was wrong too. The attention pain commands weighs far too much to talk about consciousness “of.” Both animals and humans become their pain. So pain, ironically, is one of those experiences that return us to our union with the animals.
This union, though, can be a two-edged sword. Consider my brother. He shared his house with a menagerie of pets and slowly reduced himself to their existence, to living in his own waste. He also abandoned those pets when he moved out, and the things I’d discovered in cleaning up his house told me what they’d suffered for that.
Meanwhile, poor Robert Fludd. He lost again. His notion of circular motion may have provided the model Harvey needed, but models are only models, and science isn’t metaphor. The body is not the luminous landscape of visionary delight whose brackish torrents and streams of whey trickle down the mountains of the stomach and spleen, kissing the veins and penetrating the caverns of the kidneys. No, it is rather Harvey’s soft machine of moving parts, of uniform substance, and of largely rational design, though just how rational is open to question. Evolution, for example, isn’t rational—and it jerry-builds our bodies.
Nearly one hundred years before Harvey, Andreas Vesalius, the first modern anatomist, got a lot of things right about our bodies and their basket of secrets, but not the heart and blood. That’s why we needed Harvey. Vesalius like Harvey was convinced that there were not intraventricular pores between the two sides of the heart, but as to where the blood went from the right ventricle, he confessed to being uncertain. His account of the pulse and the arteries and veins was pretty much Galenic. Galen had shown, by inserting a reed into a severed artery, that the heart transmitted its pulse along the walls of the arteries, and that these walls actually contracted.
Harvey proved him wrong. It is the contraction of the heart that forces blood through the whole closed system, although it needs the help of either gravity or muscles by the time it reaches the veins. So, when we stretch, we squeeze blood through the veins, whose valves, discovered by Harvey, keep it moving toward the heart.
Still, the old view had accounted for an obvious phenomenon: when the heart beats, in a sense so does the body. The heart, says Steven Vogel, is a pressurized vessel. Like water pumped through a system of pipes, the blood retains the pressure of the system and responds to it at once. As the heart contracts, expelling blood, the pressure surge is immediately felt from the brain to the feet. Vogel points out that if the tubes and pipes in which our blood circulates were as rigid as the pipes through which our drinking water flows, we’d spring a leak with each heartbeat. The heart when it beats squeezes almost shut, and as it does so, blood surges out. The blood’s movement through the system alone is not sufficient to absorb these repeated and powerful surges, since the system is closed and there are no pressure valves. Therefore the arteries have to swell or they’d burst.
Vogel asks why an aneurysm doesn’t develop with every heartbeat. Because arteries, he says—elastic enough to expand with each pressure surge—are also resilient enough not to balloon out of shape while doing so. The elasticity comes from elastin, the resilience from collagen, two fibrous proteins often used in skin creams. The ligament running along the top of a sheep’s neck is made of elastin. Without this substance in our arterial walls, the system would continually rupture at its joints.
Collagen, on the other hand, is less extensible than elastin and much more stiff. When the ancients used ballistae (slingshots) to throw ninety-pound rocks a fourth of a mile, they were using the collagen in a braid of cow tendons and relying on its powerful resilience. Without collagen, local expansions of blood vessels would appear like balloons up and down the artery walls—in other words, aneurysms.
As it is, the right mix of elastin and collagen enables our vessels to absorb the impact of constantly repeating pressure surges and reductions. That is, the system is designed to stretch to a certain point, then resist stretching—or increase stiffness—as distension increases.
Elastin is found only in vertebrates, as if one needed bones on which to hang this limp pasta. Cephalopods like octopi and squid have something analogous—an extensible protein—in their aortic walls. Their bodies are also elastic, with short muscle fibers running every which way across their mantles. Lacking bones, a squid makes its whole body a heart: it contracts to squeeze out water, then takes in more water when it reassumes its shape, and this is how it swims. How we swim is internally: we keep our salty ocean moving through our bodies. Squids keep their bodies moving through their salty ocean. The heart in human beings is the size of a squid.
When Harvey showed that the arteries expand not because of muscles in their walls but because they’re receiving the surge of the heart, his evidence came from a close friend to whom he refers twice in his writings on the heart and blood, though we never learn his name. He first came to Harvey with an aneurysm in his neck, “daily increasing in size.” Its pulsations corresponded to those of the heart—that is, it swelled rather than contracted with each contraction of the heart. Also, Harvey could feel, presumably with his fingers, “large forceful pulsations” squirting into the aneurysm, while below it the pulse was weak. After the death of this friend, Harvey cut out his aneurysm, which he describes in a letter as having turned into a “pipe-like bone.”
If he’d had a stethoscope (they hadn’t yet been invented), Harvey could have heard the blood squirting into the aneurysm. Steven Vogel quotes the Sherlock Holmes novel A Study in Scarlet, in which Watson holds his stethoscope to a convict’s chest, which seems “to thrill and quiver as a frail building.” Inside it, he hears a sort of humming and buzzing. “Why,” Watson cried, “you have an aortic aneurism!”
The American hero Kit Carson in his last years was diagnosed with an aortic aneurysm, which pressed against his trachea, causing spasms of the bronchial tubes and making him continually short of breath. He was told that when the aneurysm burst he’d die either of suffocation or from a hemorrhage. “He begged me not to let him suffer such tortures, insisting that death would be better by chloroform while attempting relief . . . than death by suffocation,” said his doctor, H. R. Tilton. Tilton told Carson that a “grave symptom” would be blood in the sputum—that would mean the aneurysm was breaking through the trachea.
He suddenly called out, “Doctor, Compadre, Adios.” I sprang to him and seeing a gush of blood pouring from his mouth, remarked, “This is the last of the general.” I supported his forehead on my hand, while death speedily closed the scene.
In other words, his heart drained and emptied, as had my brother Paul’s.