Caption:
Cholera as Death emanating a deadly black cloud that kills soldiers on both sides of the battlefield. From McLean's Monthly Sheet of Caricatures, October 1st, 1831. Illustration by Robert Seymour (1798-1836). The miasma theory held that diseases such as cholera were caused by a miasma, a noxious form of bad air. In reality, cholera was caused by the consumption of water or food containing the bacterium Vibrio cholerae.