History
One of the most famous early natural experiments was the 1854 Broad Street cholera outbreak in London, England.
On 31 August 1854, a major outbreak of cholera struck Soho. Over the next three days 127 people near Broad Street died. By the end of the outbreak 616 people died. The physician John Snow identified the source of the outbreak as the nearest public water pump, which he identified using a map of deaths and illness.
In this example, Snow discovered a strong association between the use of the water and deaths and illnesses due to cholera. Snow found that the water company (the Southwark and Vauxhall Company) that supplied water to districts with high attack rates obtained the water from the Thames downstream from where raw sewage was discharged into the river. By contrast, districts that were supplied water by the Lambeth Company, which obtained water upstream from the points of sewage discharge, had low attack rates. Given the near-haphazard patchwork development of the water supply in mid-Nineteenth Century London, Snow viewed the developments as "an experiment...on the grandest scale." Of course, the exposure to the polluted water was not under the control of any scientist. Therefore, this exposure has been recognized as being a natural experiment.
Read more about this topic: Natural Experiment
Famous quotes containing the word history:
“Social history might be defined negatively as the history of a people with the politics left out.”
—G.M. (George Macaulay)
“It would be naive to think that peace and justice can be achieved easily. No set of rules or study of history will automatically resolve the problems.... However, with faith and perseverance,... complex problems in the past have been resolved in our search for justice and peace. They can be resolved in the future, provided, of course, that we can think of five new ways to measure the height of a tall building by using a barometer.”
—Jimmy Carter (James Earl Carter, Jr.)
“The custard is setting; meanwhile
I not only have my own history to worry about
But am forced to fret over insufficient details related to large
Unfinished concepts that can never bring themselves to the point
Of being, with or without my help, if any were forthcoming.”
—John Ashbery (b. 1927)