Fourteenth-century medical literature indicates that physicians tried many different methods to prevent and treat the plague. People understood that plague and other diseases could be transmitted person to person, and they observed that crowded cities had high death rates, especially when the weather was warm and moist. We now understand that warm, moist conditions make it easier for germs to grow and spread, but fourteenth-century people thought in terms of “poisons” in the air or “corrupted air” coming from swamps, unburied animals, or the positions of the stars. Their treatments thus focused on ridding the air and the body of these poisons and on rebalancing bodily fluids. (See “Living in the Past: Treating the Plague.”)
People tried anything they thought might help. Perhaps loud sounds like ringing church bells or firing the newly invented cannon would clean poisoned air. Medicines made from plants that were bumpy or that oozed liquid might work, keeping the more dangerous swelling and oozing of the plague away. Magical letter and number combinations, called cryptograms, were especially popular in Muslim areas. They were often the first letters of words in prayers or religious sayings, and they gave people a sense of order when faced with the randomness with which the plague seemed to strike.
It is noteworthy that, in an age of mounting criticism of clerical wealth (see “Critiques, Divisions, and Councils”), the behavior of the clergy during the plague was often exemplary. Priests, monks, and nuns cared for the sick and buried the dead. In places like Venice, from which even physicians fled, priests remained to give what ministrations they could. Consequently, their mortality rate was phenomenally high. The German clergy, especially, suffered a severe decline in personnel in the years after 1350.
There were limits to care, however. The Italian writer Giovanni Boccaccio (1313–1375), describing the course of the disease in Florence in the preface to his book of tales, The Decameron, identified what many knew — that the disease passed from person to person:
This pestilence was so powerful that it was transmitted to the healthy by contact with the sick, the way a fire close to dry or oily things will set them aflame. And the evil of the plague went even further: not only did talking to or being around the sick bring infection and a common death, but also touching the clothes of the sick or anything touched or used by them seemed to communicate this very disease to the person involved.2
To avoid contagion, wealthier people often fled cities for the countryside, though sometimes this simply spread the plague faster. Some cities tried shutting their gates to prevent infected people and animals from coming in, which worked in a few cities. They also walled up houses in which there was plague, trying to isolate those who were sick from those who were still healthy. In Boccaccio’s words, “Almost no one cared for his neighbor … brother abandoned brother … and — even worse, almost unbelievable — fathers and mothers neglected to tend and care for their children.”3