<P> The Broad Street cholera outbreak ( or Golden Square outbreak ) was a severe outbreak of cholera that occurred in 1854 near Broad Street ( now Broadwick Street ) in the Soho district of London , England . This outbreak , which killed 616 people , is best known for the physician John Snow 's study of its causes and his hypothesis that contaminated water , not air , was the source of cholera . This discovery came to influence public health and the construction of improved sanitation facilities beginning in the mid-19th century . Later , the term `` focus of infection '' would be used to describe sites , such as the Broad Street pump , in which conditions are good for transmission of an infection . John Snow 's endeavor to find the cause of the transmission of cholera caused him to unknowingly create a double - blind experiment . </P>
who was the doctor who identified the cause of the 1854 colera outbreak in england
John Snow