In 1546 occurred the great plague which ravaged Marseilles, Lyons, and Aix. So terrible was the scourge that all the doctors fled and left the dying to their fate. The Comités of the towns assembled in despair, ignorant even whether they too were not already in the grip of the disease. Just as the inhabitants of Elatea received the news in the eventide, so the desertion of the doctors struck their bewildered minds with horror. Although they turned to the Church with groans of supplication, the people died, and dying gave to their neighbours the seeds of death. They died as they had died in the past, and they continued to die until the world of medicine perceived the squalor of their living. And it is of this dawning perception that I wish to speak.

The plagues which ravaged the world in the course of the Middle Ages were probably all offshoots of that form of plague known as Bubonic, Oriental, Levantine, or Miliary, and the symptoms were a high fever, accompanied by glandular swellings and carbuncles. It was generally supposed to have originated in Northern Africa, and to have made its first appearance in Europe at Constantinople in the reign of Justinian. The great plague of Athens described by Thucydides seems from its symptoms to have been of a different nature, although equally destructive. In Constantinople, ten thousand persons were carried off in one day; in 1352 Oxford lost two-thirds of her academic population ; at about the same period thirteen millions perished in China from the same disease.