Five Quarts: A Personal and Natural History of Blood Read online

  The earliest and most influential surviving texts on bloodletting were written by a Greek doctor named Galen (A.D. 129–200), who began his career tending to wounded gladiators and rose to become the Western world’s supreme authority on medicine. Galen’s views were considered medical gospel for fourteen hundred years, and I can understand why. He makes an illogical practice sound downright reasonable. His writing voice is so clear and commanding, it is almost a summons.

  Galen first made a name for himself at the Coliseum in Pergamum, a small kingdom in what’s now western Turkey. There, as the chief physician to the gladiators, Galen was the ancient equivalent of an ER doctor, treating the freshly butchered in his trauma ward in the basement of the stadium. Just as a modern physician might hear the distant wail of an ambulance and know a body was on its way, Galen may have had his own alarm system in the collective gasps and muffled yelps of the crowds overhead. This gifted twenty-eight-year-old, who’d begun studying the healing arts at fourteen, had an impressive first year on the job: Not a single gladiator died of injuries, which was unheard of, given that the combatants fought with brutal-looking tridents and two-foot-long swords. The position also gave him an unprecedented scientific advantage: rare, close-up views inside still-living bodies.

  Neither of Galen’s most distinguished predecessors, Aristotle (384–322 B.C.) and the Greek physician Hippocrates (460–375 B.C.), had ever dissected a human body. And those who had performed dissections noted that the corpse’s arteries were empty (because, as a modern pathologist would explain, blood drains back into the veins once the heart stops). This led the great thinkers to the false conclusion that the arteries contained only an air-like substance. Hence artery, derived from a Greek word meaning “air duct.” Galen, with virtual human vivisections at his disposal, was able to correct this error. Clearly, the arteries were filled with blood. Further, he accurately traced the course of blood from the right side of the heart to the left via the pulmonary artery and lungs. The most crucial discovery, however—that the arteries, veins, and heart work together as a circulatory system—would not be made until the 1600s.

  Despite his new insights, the foundation of Galen’s medical philosophy did not change. He embraced the ancient Hippocratic theory that a person’s state of health was determined by four fluids, or humors—blood, phlegm, yellow bile, and black bile—which had to be in perfect balance within the body for good health to prevail. When one or more of these fluids was overabundant or insufficient, the body’s inner scales tipped and disease resulted. The humor called black bile deserves special mention because, as modern medical historians point out, it is a fictitious substance, though Galen firmly believed it existed. Conceptually, there had to be four humors—not three, not five—because the body was seen as a microcosm of the universe, which was organized in patterns of four: the basic elements (earth, air, fire, water) and their cosmological correlates (the Earth, sky, sun, sea); the four seasons; and what were known as the Aristotelian “qualities” (cold, damp, hot, and dry). All of these aspects were interrelated, sometimes overlapping, in an elaborate system that Galen would later codify in his medical books. Phlegm, for example, was cold, damp, watery, and wintry, while blood was hot, damp, air-, and spring-like. That the microcosm mirrored the macrocosm was a defining part of Galen’s diagnoses. After patching up a gladiator who’d lost a large amount of blood, for instance, he would likely have prescribed a huge increase in the man’s dietary intake. In the doctor’s view, the liver—the body’s hot, damp organ—was “the principal instrument of sanguification”; it converted digested food into blood. The patient, by gorging himself, would restore his humoral balance. Were another gladiator unable to fight because of, say, a high fever, Galen would have diagnosed “plethora,” an excess of humors in his body. As treatment, Galen would have turned to copious bloodletting.

  With only a slight shift in thinking, I can understand Galen’s rationale. Since physical appearance was one of the few diagnostic tools available to him, it’s not wholly absurd that Galen would’ve concluded from a flushed, fevered face that the patient was suffering from superfluous blood. Or, similarly, that a sallow complexion meant that the gallbladder—the hot, dry organ—was producing too much yellow bile. To have explained to Galen that things floating in the blood actually caused disease would’ve made as much sense to him in his day as saying his fax needed paper. In second-century medicine it wasn’t the quality of blood that was at issue, but the quantity. One could have too much of a good thing.

  Doctors in Galen’s time had other methods for cutting off the body’s production of fresh blood: getting the patient to stop eating for several days or inducing vomiting (after all, who doesn’t look a bit bloodless after throwing up?). But Galen preferred the immediacy of venesection, opening a vein. He used a pointed, double-edged metal scalpel, an instrument of the period called a phlebotom (from the Greek phlebos, for “vein,” and tome, meaning “to cut”), from which came the medical term for drawing blood, phlebotomy. Few of these original devices survive to the present day, but one found in the ruins of Pompeii was probably typical: a slim, three-inch-long bronze blade mounted in a decorative handle.

  When Galen put a phlebotom to a vein, he was continuing a medical tradition that had existed since at least 2500 B.C., the approximate date of an Egyptian tomb painting showing a noble being bled at the foot and neck, the earliest-known depiction of phlebotomy. Of course, this is not meant to suggest that there hadn’t been two and a half millennia of naysayers, just that scant records survive. What is known is that, from Hippocrates’s day forward, the critics of bloodletting were as passionate as the advocates. Galen discovered this firsthand when he moved to Rome, the big city, in the year 162. A local celebrity in Pergamum, the thirty-three-year-old found that his specialty made him an outsider here, and he immediately butted heads with the Roman medical establishment. His biggest opponent, strangely enough, was a man five hundred years dead, the Greek physician Erasistratus (300–260 B.C.), who’d taught at the celebrated medical center in Alexandria and had been vehement in condemning venesection. He had a legion of vocal followers, known as Erasistrateans.

  In a colonnaded hall opposite the Forum, Galen joined others in giving public lectures during his first year in Rome. In the spirit of self-promotion, he held forth on a range of topics, including, notoriously, his enthusiasm for bloodletting and his disdain for the teachings of Erasistratus. The Erasistrateans in attendance were not pleased, although their heckling probably just drew larger crowds. Galen relished stirring up controversy. He was also eager to drum up business. Unlike the majority of Roman physicians, he proclaimed himself to be above all sects, the leader of his own school of thought. He ingratiated himself to the audience, which swelled over time as word spread of the brash, charismatic healer. Bored with chariot races at the nearby Circus Maximus, dignitaries dropped by to see the theatrical young man who, for example, demonstrated vivisection with a squealing pig. Shorthand writers transcribed his speeches and, within months of his arrival, Galen’s views on bloodletting were published in the book Against Erasistratus, the title alone like a gauntlet thrown down.

  A modern reader of the book and its sequel, Against the Erasistrateans Dwelling in Rome, gets a vivid sense of this renegade doctor, a man whom one nineteenth-century historian described as a “quarrelsome, self-willed spiteful brawler, who goes for his adversary foaming at the mouth.” Nonetheless, Galen’s words lift from the page and, like a gentlemanly participant in a cross-time debate, he reiterates his opponent’s positions before dissecting them, even quoting the dead Erasistratus verbatim. This is fortunate since Erasistratus’s words survive only within the works of others.

  Galen starts off on a conciliatory note: The two physicians would not have disagreed, he admits, about what causes illness—humoral imbalance—or about the final goal of treatment, the “evacuation” of the plethos. They parted ways when it came to the means. “The easiest and promptest course of action is to open a
vein,” Galen states. “In this way, we evacuate the actual inflammatory materials themselves. And nothing else.” It’s a remedy that was “esteemed by the ancients.” By contrast, the main Erasistratean solution, starvation, “apart from the long time it requires, evacuates the whole system indiscriminately.” Even now, I can almost hear Galen’s tsk-tsk, as well as the grumbling of the Erasistrateans gathering at the back of the crowd.

  In addition, starvation, Galen warns, is accompanied by a host of evils: severe fatigue, nausea, heartburn, constipation, and perhaps the most serious side effect, turning the other humors “bilious and painful,” thereby exacerbating rather than alleviating the imbalance. Pausing, I imagine, to let the crowd absorb these grim facts and to allow the stenographers to catch up, Galen then adds, “Yet Erasistratus sees none of these.” He and his adherents are “like blind men, who although a smooth, broad, and direct road is near, often take a narrow, rough, and long one, and go by a circuitous route.”

  A surgeon by training and temperament, Galen next attacks their use of powerful laxatives and purgatives as a foolhardy reliance on fate. “The flow to the stomach cannot be stopped in the way you can immediately put an end to the bleeding by putting your finger to the divided vein.” He then brings this argument home: A “grave disturbance of the entire body [may occur] as a result of being evacuated either insufficiently or to excess,” whether it be loss of consciousness or “pulselessness.” Indeed—pause for dramatic effect—“the ultimate misfortune often ensues in this state.”

  What’s fascinating is that Galen’s own last remarks could equally have been used to denounce his beloved bloodletting. Erasistratus held that it was impossible to determine precisely how much excess blood a patient had and therefore how much should be let. Further, he had seen the handiwork of incompetents who’d slashed through tendons, nerves, and arteries in their hunt for a vein, leaving behind lifelong damage if not death. The practice was so fraught with risk that Erasistratus viewed bloodletting as tantamount to committing murder. But Galen felt himself beyond reproach. He well understood that a patient could die quickly if an artery were severed, which was the primary reason he rarely attempted opening these thicker vessels with their greater blood volume. (They were also harder to access, anatomically speaking.) As for patient safety, Galen again placed himself above Erasistratus, who “paid little attention to examining patients, but stayed at home and wrote down mere opinions.” Adamant that only an experienced physician should perform phlebotomy—he, of course, being best suited—Galen advised cutting parallel to a vein, never across it, and keeping puncture holes small. Bloodletting sounds ghastly, but, in fact, the amount Galen drained at one sitting was modest—about a pint at most, no more than you’d give today at a blood bank. However, the doctor often chose to repeat the procedure day after day after day.

  Galen saw no stronger argument for venesection than in the seemingly spontaneous bleedings orchestrated by “Nature.” He cites nosebleeds and menstruation as ways the body restores its humoral balance: “Does [nature] not evacuate all women every month by pouring forth the superfluity of the blood?” As a matter of fact, modern medical historians speculate that menstrual bleeding probably not only provided the initial inspiration for drawing blood but also helped reinforce its supposed benefits. After all, as my five sisters and numerous female friends attest, they feel great after their period is over.

  “But enough of women,” Galen says dismissively to the crowd. To further his argument, he calls on a most unlikely ally: the hemorrhoid. “Come now to consider the men, and learn how those who eliminate the excess through a hemorrhoid all pass through their lives unaffected by diseases.” That bleeding hemorrhoids are to be appreciated and even encouraged, I daresay, surprises most of the assembled sufferers.

  His provocative comments did not go unanswered. The Erasistrateans shot back rebuttals and insults, and, outside the hall, rivals spread malicious gossip. In time, Galen began to fear he’d be poisoned by his enemies. For his own safety, after barely a year in Rome, he stopped publicly antagonizing opponents. Galen turned to writing, producing books in which he both challenged the conclusions of the rival sects and put forth his own findings. He began to tutor privately, and his medical practice flourished. Among his patients were members of the royal court, including a son-in-law of Emperor Marcus Aurelius. In less than four years after his arrival in the city, Galen was consulting with the emperor himself. When Marcus Aurelius’s small son fell ill, Galen cured him, earning not only the father’s complete trust but also the title of Emperor’s Personal Physician. Chief among his duties: concocting antidotes for poisons that might be used to assassinate the ruler. Galen made himself an expert at creating a wide range of treatments from herbal extracts. These came to be called galenicals, a term still used for medications made purely from botanical ingredients.

  The same son whose life Galen had saved, Commodus, abruptly fired the doctor upon succeeding his father as emperor at age nineteen. Commodus (portrayed by Joaquin Phoenix in the 2000 film Gladiator) was a brutal, decadent tyrant responsible, historians agree, for leading the Roman Empire into steady decline. Galen remained in Rome but kept a low profile, quietly continuing his scientific work and his ceaseless writing. He wrote eighteen books on the subject of the pulse alone, as well as tomes on fever, anatomy, the nervous system, nutrition, and philosophy. Most of his original manuscripts were stored for safekeeping at a temple guarded by priests. Unfortunately, in the same year as Commodus’s assassination, A.D. 192, a fire destroyed the temple and half of Galen’s life’s work. About 120 books survived.

  With Commodus gone, the doctor, now in his midsixties, slowly reemerged and again began making house calls to the royal palace. Instead of resuming his former duties, however, Galen realized that the new emperor and his wife had other ideas. The queen, aware of his genius for creating botanical remedies, commanded that he concoct equally miraculous beauty potions. Though the assignment was beneath him, Galen must’ve felt he had no choice. He whipped up extractions to turn black hair golden, face paints for eye shadow and rouge, perfumes and pomades. He was the Max Factor of his day, minus the screen credits or royalties. But he made the best of it, funneling what he learned about cosmetics into further research in pharmacology and, of course, into new books.

  By the time of his death at age seventy, no aspect of the human body had escaped Galen’s scrutiny. No organ remained unidentified. No ailment could not be cured by his means. He left behind detailed opinions and instructions on everything from venesection in children to mixing up the perfect eyeliner. He did such a thorough job that, in the fourteen centuries following his passing, few dared challenge Galenism, as his teachings came to be known. His reach even extended to the Eastern world, where his books were translated into Arabic in the ninth century. Whereas Asclepius was the mythical god of medicine, Galen was close to the real thing. Indeed, in the early Middle Ages, church leaders declared his work to have been divinely inspired and thus infallible, dubbing him Galen the Divine. To oppose him was blasphemous, punishable with death—burning at the stake. All of which now seems ironic because Galen had never been a religious man and had, in fact, championed the value of scientific experimentation.

  Still, the question remains, why did Galen hold sway for so long? Why did he, and not others, endure? Part of it was luck, to be sure, plus sheer volume. While half of Galen’s original works were lost, his surviving literary output—some 2.5 million words, according to one count—overwhelmed his competition. But most of all, Galen’s influence rested on his blazing self-confidence. As medical historians have observed, Hippocrates, by contrast, acknowledged the potential for error in his work, areas he did not yet fully understand. But not a whit of doubt appeared under Galen’s name.

  At times I find his arrogance galling (a condition that Galen’s fifteenth-century followers would’ve diagnosed as an enflamed and leaky gallbladder, the repository of this particular emotion). But as a writer, I can’t help bei
ng impressed by the faith he inspired in others through the force of language. It’s all the more amazing to me because Galen was so often dead wrong.

  The circulatory system as conceived by Galen

  Truth be told, I find scientific blunders as fascinating as the great discoveries. It’s the main reason I enjoy reading archaic medical texts, a trusty form of time travel I undertake at libraries. Being in the position of knowing more than Galen did is satisfying, I will not deny. It’s also sobering. Two decades from now I’m sure I’ll look back and shake my head, amazed at the things Steve and I once did in the name of cutting-edge science. But there’s something else. Looking back at Galen looking forward, I am touched by his efforts to treat deadly illnesses, to alleviate suffering, however futile. Finally, he is most impressive not in having come up with so many answers but in taking on so many big questions, such as, What is the essence of life? What makes us human? Galen believed the ingredients were in the bloodstream, where a trio of incorporeal “spirits” flowed. (By contrast to the groupings of four used at that time to describe the inner and outer workings of the universe—the humors, the qualities, the elements—the spirits came in threes, reflecting the tripartite division of the soul theorized by Plato.) The first two ran in the dark, purplish blood of the veins: Natural Spirits, brewed in the liver, providing the body’s mass; and Animal Spirits, fired in the brain, producing movement. Completing the trinity were Vital Spirits, the essence that separated human beings from animals. In its fleet passage through the heart, the scarlet arterial blood was imbued with this zest, which disseminated warmth and verve throughout the body. In Galen’s reckoning, the spirits did not intermingle; the veins and arteries were separate streams.