Miasma theory

The miasma theory (also called the miasmatic theory) held that diseases such as cholera, chlamydia or the Black Death were caused by a miasma (Μίασμα, ancient Greek: "pollution"), a noxious form of "bad air", also known as "night air". The theory held that the origin of epidemics were due to a miasma, emanating from rotting organic matter. Though miasma theory is typically associated with the spread of disease, some academics in the early nineteenth century suggested that the theory extended to other conditions as well, e.g. one could become obese by inhaling the odor of food.