The Great Mortality: An Intimate History of the Black Death, the Most Devastating Plague of All Time

by John Kelly

  The prosecution’s chief witness was John of Padua, a crusty old former medical adviser to Philip the Fair. Judging from his testimony, John seemed to think that Madame Felicie ought to be convicted on the grounds of gender alone. Women were already barred from law, John thundered; how much more urgent, then, to keep them out of a serious profession like medicine!

  On November 2, 1322, Madame Felicie was convicted of violating an ordinance that prohibited unlicensed healers from visiting, prescribing medications, or performing other duties for a patient, except under the guidance of a university-trained and licensed physician. The conviction was a major victory for the Paris Medical Faculty, a principal architect of the new medical pecking order, which had a pyramidlike shape. At the pinnacle was a relatively small coterie of the university-trained physicians; they practiced what we would call internal medicine. Beneath them were the general surgeons, who usually lacked academic training, although that was changing. By the early fourteenth century surgery was beginning to find a place in the medical schools. A surgeon could treat wounds, sores, abscesses, fractures, and other disorders of the limbs and skin. Beneath the general surgeon was the barber surgeon, a kind of paramedic, who could perform minor operations, including bleeding, cupping, and applying leeches, as well as cutting hair and pulling teeth; next came the apothecary and the empiric, who usually specialized in a single condition, like hernias or cataracts. At the base of the pyramid were thousands of unlicensed healers like Madame Felicie.

  To reflect their new eminence, in the decades prior to the plague, physicians began to adopt a more professional—that is, authoritative—demeanor and code of behavior. A cardinal “don’t” in the new medical etiquette was: don’t jeopardize your professional dignity by visiting patients to solicit business. “Your visit means you are putting yourself in the patient’s hands,” warned William of Saliceto, “and that is just the opposite of what you want to do, which is getting him to express a commitment to you.” A cardinal “do” in the new etiquette was to conduct a comprehensive physical exam on a first visit; the exam should include not just urinalysis, but a detailed medical history and an analysis of the patient’s breath odor, skin color, muscle tone, saliva, sweat, phlegm, and stool. Some physicians also cast a patient’s horoscope on the first visit. Another cardinal “don’t” in the new etiquette was to admit to diagnostic uncertainty. Even when in doubt, said Arnauld of Villanova, a physician should look and act authoritative and confident. For the uncertain physician, Arnauld recommended prescribing a medicine, any medicine, “that may do some good but you know can do no harm.” Another strategy was to “tell the patient and his family that [you are] prescribing this or that drug to cause this or that condition in the patient so that [they] will always be looking for something new to happen.” A third “don’t” in the new etiquette was volubility. Reticence conveyed authority, especially when combined with a grave manner; besides, said one savant, the physician who discusses his medical reasoning with the patient and his family risks letting them think that they know as much as he does, and that may tempt them to dispense with his services.

  What made the university-trained physician such an impressive figure to laymen, however, was not only his authoritative bedside manner but his mastery of the arcanae of the New Galenism. Its signature principle was the theory of the four humors. For the ancient Greeks, whose thinking shaped so much medieval medicine, the number four was, like the atom, a universal building block. Everything, the Greeks believed, was made out of four of something. In the case of the physical world, the four elements were earth, wind, water, and fire; in the case of the human body, the four humors were blood, black bile, yellow bile, and phlegm. An important element in the humoral theory were the four qualities of all matter: hot and cold, wet and dry. Thus, blood was said to be hot and moist; black bile, cold and dry; yellow bile, hot and dry; and phlegm, cold and wet.

  In

  On the Nature of Man, Hippocrates wrote that “health is primarily that state in which [the four] constituent elements [that is, the four humors] are in correct proportion to each other, both in strength and quality, and are well mixed. Pain occurs when one of the substances presents either a deficiency or excess or is separated from the body and not mixed with others.”

  The theory of corrupt or infected air also played an important part in the New Galenism. Bad air was dangerous because it could disrupt the balance of bodily humors, and particularly dangerous was hot and humid air because both heat and humidity corrupted the life force around the heart. Contagion was a by-product of this corruption. People became ill by inhaling not airborne germs but the corrupt vapors emanating from diseased bodies.

  In the new medical schools like the University of Paris, students also learned that earthquakes, unburied corpses, decaying crops, stagnant water, poor ventilation, and even poisons could infect the air; but in the case of epidemics, which affected hundreds of thousands of people in widely separated places, infection was thought to result from a global disturbance, like an unfavorable planetary alignment. The movement of the moon clearly controlled tides; ergo, reasoned medieval (and ancient) man, air quality must also be affected by planetary movements and cycles.

  The

  Compendium de epidemia per Collegium Facultatis Medicorum Parisius, the plague treatise of the Paris medical masters, offers an example of how the new medicine used the theories of astrology and infected air to explain the origins of the pestilence.

  According to the

  Compendium, “the first cause of this pestilence was and is [the] configuration of the heavens [which occurred] in 1345, at one hour after noon on 20 March, [when] there was a major conjunction of three planets in Aquarius.” In the masters’ view, the conjunction caused “a deadly corruption in the air,” and Mars and Jupiter, two of the three planets in the conjunction, played a particularly important role in the corruption. “For Jupiter, being wet and hot draws up evil vapors from the earth and Mars, because it is immoderately hot and dry, then ignites the vapors and as a result there were lightning sparks, noxious vapors and fires throughout the air.”

  The second chapter of the

  Compendium explains how these astrological changes led to the plague. “What happened,” explained the masters, “was that many of the vapors . . . corrupted at the time of the conjunction . . . then mixed with the air and [were] spread abroad by frequent gusts of wind in the wild southerly gales. . . . This corrupted air, when breathed in, necessarily penetrates to the heart and corrupts the substance of the spirit there and the heat thus destroys the life force.”

  Like many contemporaries, the Paris masters believed that the extraordinary ecological upheavals of the 1330s and 1340s—the succession of earthquakes, floods, tidal waves, heavy rains and winds, and unseasonable weather—played an important role in the plague. “Experience,” declared the masters, “tells us that for some time the seasons have not succeeded each other in the proper way. Last winter was not as cold as it should have been with a great deal of rain. . . . Summer was late, not as hot as it should have been and extremely wet. . . . Autumn, too, was very rainy and misty. It is because the whole year here—or most of it—was warm and wet that the air is pestilential. For it is a sign of pestilence for the air to be warm and wet at unseasonable times.”

  How could people protect themselves against the plague?

  Facing its first great public health crisis, the New Galenism was not lacking in ideas. Between 1348 and 1350, twenty-four plague tracts were written, most by university-trained medical professionals. Like the

  Compendium of the Paris masters, some of the tracts took a big- picture view; others dispensed practical advice on how to stay healthy; two examples of the latter are

  Description and Remedy for Avoiding the Disease in the Future, by Ibn Khatimah, a Muslim physician who lived in Grenada, and

  Consilia contra pestilentium, the tract of the Italian master physician Gentile da Foligno. One plague work, Simon of Covino’s
<
br />   Concerning the Judgment of the Sun at the Banquet of Saturn, was written in verse, while others, such as

  A Very Useful Inquiry into the Horrible Sickness and

  Is It from Divine Wrath That the Mortality of These Years Proceeds? convey some of the terror of the time.

  To varying degrees, most plague authors agreed with the Muslim physician Ibn al-Khatib, who described the pestilence as “an acute disease, accompanied by fever in its origin, poisonous in its material, which primarily reaches the vital principal [the heart] by means of the air, spreads in the veins and corrupts the blood, and changes certain humors into a poisonous character, whence follow fever and blood spitting.”

  There was also agreement that the best defense against plague was to remain healthy, and above all, this meant avoiding infected air. But how? One way, said the Paris masters, was to avoid marshes, swamps, and other bodies of stagnant water where the air is dense and turgid; another way was by keeping windows with a northern exposure open to let in good air—that is, cool and dry air—and keeping windows with a southern exposure shut to keep out bad air—that is, warm, humid air. To be extra safe, the Paris masters further recommended glazing, or putting a wax cloth over windows with a southern exposure. According to Ibn Khatimah, in plague as in real estate, location was everything. Bad to live in, said the Muslim physician, were cities with a southern coast. The reason? The rays of the sun and other stars bounced off the sea, blanketing such cities in warm, damp air. Also to be avoided were cities facing the south pole, particularly if unprotected on the south side. Cities with an eastern or western exposure occupied a middle ground in the risk spectrum, though a western exposure, which favors dampness, was more dangerous than an eastern exposure.

  A physician named John Colle emerged as a particularly innovative thinker on the question of corrupt air. Noting that the “attendants who take care of latrines and those who serve in hospitals and other malodorous places are nearly all to be considered immune,” John argued that the best antidote to bad air was more bad air. One of the most surreal images to emerge from the Black Death is of knots of people crouched at the edge of municipal latrines inhaling the noxious fumes.

  For Muslims like Ibn Khatimah and his fellow Spanish Arab Ibn al-Khatib, the issue of contagion posed a special problem. According to Islam, God’s will determined who lived and who died in an epidemic. Choosing to play it safe, Ibn Khatimah described contagion as a phenomenon “in which the Arabs in their ignorance” [in other words, before Islam] used to believe but no longer do.” Ibn Khatimah probably did not believe what he wrote, but he knew it would keep him out of trouble. Braver, Ibn al-Khatib said what he thought: contagion’s role in the spread of plague was “firmly established by experience, research, mental perception, autopsy and authentic knowledge of fact.” In 1374, when Ibn al-Khatib was dragged from a prison cell and murdered by a Muslim mob, there were those who said that one factor in the physician’s undoing was his disregard of Islamic teaching during the plague.

  Untroubled by theological dilemmas, Christian writers were free to concentrate their energies on preventive stratagems. To protect against infection indoors, a number of authors recommended burning dry and odiferous woods, such as juniper and ash, vine and rosemary, oak and pine. In winter, this regimen could be supplemented with aromatic substances, such as wood of aloes, amber, musk, laurel, and cypress, and in summer with fragrant flowers and plants sprinkled with vinegar and rosewater. Out of doors, people were advised to carry a smelling apple, a kind of personal scent that, like a gas mask, would protect against noxious fumes. A physician named John Mesue said a very good smelling apple could be made from black pepper, red and white sandal, roses, camphor, and four parts of bol armeniac (Armenian bole). Gentile da Foligno, who liked to keep things simple, said a pleasant-smelling herb—of the type many Florentines used during the plague’s visit—would do. Gentile also recommended streetcorner bonfires, a public health measure already in use in Avignon and other cities.

  Changes in lifestyle could also protect against infected air. The Swedish bishop Bengt Knutsson, for example, recommended avoiding both sex and bathing because “where bodies have open pores as is the case of men who abuse themselves with women or often have baths . . . they are the more disposed to this great sickness.” What if abstinence proved impossible? Ibn Khatimah recommended regular bleedings to purge excess heat and impurities from the body. An energetic self-bleeder himself, the Muslim lost eight pounds via phlebotomy. Also to be avoided—or taken in moderation—was exercise, another pore opener.

  Antidotes were also a popular preventive. For those who liked tasty antidotes, a prebreakfast snack of fig, filbert, and rue was suggested. Pills of aloe, myrrh, and saffron were also recommended by many physicians; but theriac, mithridate, bol armeniac, and terra sigillata—all traditional poison remedies—were the most popular antidotes. In Gentile da Foligno’s view, however, no antidote could rival the power of an emerald ground into a powder; Gentile’s assertion that the remedy could “crack a toad’s eyes” suggests that the “prince of physicians,” a university-trained professional, harbored a secret weakness for black magic.

  Since a good diet kept the four humors in balance, many tracts also stressed the importance of proper eating. Specific dietary recommendations varied according to age, sex, season, and circumstance, but in general, wise to avoid were foods that spoiled easily, like milk, fish, and meat. If meat was one’s choice, then fowl, lamb, and kid were best, and should be tender and digestible. As for preparation, the Paris masters took a firm stand for roasting and against boiling. A little cheese helped digestion, said Ibn Khatimah. The Moor’s stand on eggs, like his stand on contagion, was subtle. Good were eggs dipped in vinegar, bad were eggs dipped in garlic. The anonymous author of

  First About the Epidemic could barely contain himself on the subject of hard-boiled eggs; they were a garden of dangers, he fulminated.

  Everyone liked bread, though good flour and proper baking were important. Wine was another universal recommendation. Best against the pestilence, said Gentile da Foligno, was white wine, preferably, old, light, and aromatic, mixed with water. However, fruits and vegetables produced finger-pointing and argument. The Paris masters took a dim view of lettuce, but Gentile da Foligno was unshakable in his defense of the vegetable. “Cabbage is good for you,” said the anonymous author of

  First About the Epidemic—but not if eaten with eggplant and garlic, warned Ibn Khatimah. Some agreement emerged on figs, dates, raisins, and pomegranates, but the only universally recommended fruit was the filbert.

  The six non-naturals, factors such as personal habits, behaviors, and emotional states were also stressed by the authors of many plague tracts. Thus, the Paris masters urged people to avoid “accidents of the soul,” a far more felicitous description of emotional upset than our dreary modern clinical terms. To be especially eschewed were fear, worry, weeping, speaking ill of others, excessive cogitation, and wrath, which, according to Gentile da Foligno, “overheated the members.” Sadness, which cools the body, dulls the mind, and deadens the spirit, also predisposed a person toward plague. Good, in Ibn Khatimah’s view, was stupidity, which lowered the risk of pestilence; bad was intelligence, which raised it.

  Galen, who lived through the third-century Plague of Antonine* (a devastating outbreak of measles or smallpox) believed that little could be done to cure the pestilence once a person was infected, and his pessimism was reflected in the plague tracts of his medieval disciples. Only a handful of authors even suggested cures, and aside from symptomatic relief, most suggestions revolved around bleeding, which was thought to draw poisons and corrupt humors away from vital organs such as the heart, liver, and brain. With phlebotomy, said John of Penna, a professor at the University of Naples, speed was essential. At the first sign of plague symptoms, the patient should be bled on the same side of the body as the pain; even better than bleeding, said John, were purges. Gentile da Foligno, another advocate of bleeding
, recommended a venesection of the median vein when the course of the disease was unclear. If the bubo was on the neck, Gentile advised a venesection of the cephalic vein; if under the arms, of the pulmonary vein. Gentile said the bleeding should continue until faintness developed.

  Ibn Khatimah, who, unlike many tract authors, seems to have actually treated plague patients, believed that in the bubonic form of the disease, the crisis point arrived on the fourth day. After that, the evil vapors begin to detach from the heart, he said. In the recovery period, the Muslim recommended applying an ointment to the buboes to hasten ripening and then surgical excision on the seventh day.

  How did the New Galenism perform against the plague?

  Some of the advice in the plague tracts was plainly sensible, but, alas, not a great deal—and usually what worked, worked for reasons that would have surprised the tracts’ authors. Diet, for example, was useful because it enhanced immune system function, not because it balanced the four humors, fire because it drove away fleas. For all his careful training and his command of the Arab and Greek masters, the best advice Chaucer’s new medical professional could offer his patients was the commonsensical admonition to “run far and run fast.” And by the time the plague neared Paris in the summer of 1348, even that advice was becoming ineffective since the pestilence was now everywhere, from the Mongolian Plateau to the coast of Greenland.