The miasma theory of disease held that diseases such as cholera were caused by a miasma (Greek language: "pollution"), a noxious form of "bad air".

The miasma theory was consistent with the observations that:

• disease was associated with poor sanitation (and hence foul odours) and that
• sanitary improvements reduced disease,

but not with the observations of microbiology that led to the germ theory of disease.

Although incorrect, the miasma theory helped motivate major improvements in sanitation.

Prominent supporters of the miasma theory included:

• Abaris the Hyperborean, who famously cleaned Sparta under Mount Taygetus from miasmata coming downhill
• William Farr
• Florence Nightingale

So far as cholera is concerned, the miasma theory was disproved by John Snow (physician) following an epidemic in Soho, central London in 1854.

External links

• Prevailing theories before the germ theory