It was A.D. 1348, one year after the bubonic plague, or black death, had begun its devastating rampage through Europe. In a famous medical treatise French Surgeon Guy de Chauliac of Avignon recalled his impressions of the horror around him: "The father did not visit the son nor the son the father. Charity was dead and hope abandoned . . . For self-preservation there was nothing better than to flee the region before becoming infected."
Guy's patients died within five days of falling ill. Cities were decimated in a matter of months. The scourge was so contagious that, according to Guy,...