Featured on PDR in the essay “Invisible Little Worms”: Athanasius Kircher’s Study of the Plague

Living through the devastating Italian plague of 1656, the great polymath Athanasius Kircher turned his ever-enquiring mind to the then mysterious disease, becoming possibly the first to view infected blood through a microscope. While his subsequent theories of spontaneous generation and “universal sperm” were easily debunked, Kircher’s investigation can be seen as an important early step to understanding contagion, and perhaps even the very first articulation of germ theory. John Glassie explores.