14. Holding diseases such as cholera were transmitted via “bad air”, miasmatic theory – one of the foremost medical traditions of the pre-modern era – blamed powerful miasmas for ill health
A longstanding, and today obsolete, medical opinion, the miasmatic theory asserted diseases and related epidemics, such as of cholera or the Black Death, were caused by a “miasma”. A noxious form of bad air, miasmas were believed to emanate from rotting organic matter and spread harmful diseases to those who inhaled the tainted air. Predating the start of the Common Era, during the first century BCE Roman writer Vitruvius described the effects of potent miasmas, describing how “the morning breezes blow toward the town at sunrise…they bring with the mists…the poisonous breath of creatures of the marshes to be wafted into the bodies of the inhabitants”.
Remaining a popular theory throughout the Middle Ages, even by the 1850s miasmatic theory was still used to explain outbreaks of cholera in both London and Paris. Transmitting infections not person-to-person but environment-to-person, the prevalence of said belief, supported famously by Florence Nightingale, drastically hindered the introduction of basic hygienic standards among humans. Eventually disproved and replaced by germ theory following the discovery of bacteria, as well as the conclusion of John Snow – the father of epidemiology – that cholera was water and not airborne, it was not until the late-nineteenth century unscientific belief in miasmas finally diminished.