What name was given to noxious vapour, rising from organic matter, which pollutes the atmosphere?

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 was 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 odour of food.

The miasma theory was accepted from ancient times in Europe, India, and China. The theory was eventually given up by scientists and physicians after 1880. They instead accepted the germ theory of disease: specific germs, not miasma, caused specific diseases. However, the belief that it was the highest urban priority to clean up waste and get rid of odour remained a strong belief in the popular culture.