The figure of a fearful comet', from Dr. Ambroise Pare's 'Surgery', gives a subjective impression of the comet that appeared in the winter of 1664-65. Swords, daggers, coffins, and men's heads were supposed to be omens of plague; and plague did indeed break out in London in June of 1665, within 3 months of the comet's visit. Bubonic plague is a serious, sometimes fatal, infection caused by the bacterial toxin Yersinia pestis, transmitted by fleas from infected rodents and characterized by high fever, weakness, and the formation of buboes. The comet of 1665 was said to have been responsible for the Great Plague of London that killed 100 thousand people, a quarter of the city's population. This image has been colorized.