Miasma was the dominant explanation for communicable disease among the medical establishments of Western Europe and the United States through the first 50-70 years of the nineteenth century. Perhaps, in part, unwittingly anticipating explanations of chronic respiratory disease and cancer related to air pollution, miasmatists attributed many communicable diseases to “bad air” emanating from decaying organic matter. Those who looked for contagion to account for killer communicable diseases, like cholera and puerperal (or childbed) fever, were but a miniscule minority.