In 1854, the causes of disease were not known. Responsible
people maintained contradictory opinions. Most believed that
diseases were caused by bad smells or “miasmas,”
poisonous gases containing particles from decomposed matter or
“miasmata.” Supporters of the miasma theory had
supporting evidence, because removing bad smells by improving
sanitation diminished the problem. Others, the contagionists,
believed that diseases were caused by physical contact. Lastly,
some believed that germs caused disease, and germs could be spread
by contact or by drinking contaminated water. John Snow’s
map showing clusters of cholera cases in the Soho neighborhood of
London disproved the miasma theory.
In 1854, the causes of disease were not known. Responsible people maintained contradictory opinions. Most believed that diseases were caused by bad smells or “miasmas,” poisonous gases containing particles from decomposed matter or “miasmata.” Supporters of the miasma theory had supporting evidence, because removing bad smells by improving sanitation diminished the problem. Others, the contagionists, believed that diseases were caused by physical contact. Lastly, some believed that germs caused disease, and germs could be spread by contact or by drinking contaminated water. John Snow’s map showing clusters of cholera cases in the Soho neighborhood of London disproved the miasma theory.
See also in The book of science:
Readings on wikipedia: