From 1665 to 1666, the Great Plague spread through London. Caused by a bacteria transmitted by the bite of a rat flea, it killed nearly a quarter of London’s population in the span of 18 months. Such a deadly conflagration must have seemed strange and terrifying to its victims; there was no germ theory to explain its spread, and the bacteria wasn’t even discovered until the late 19th century. Lack of understanding must have greatly amplified the terror caused by the symptoms: fevers,...
