Final answer:
The relation John Snow established between cholera and the water supply in Soho is a good example of epidemiology. Snow's investigation of the cholera outbreaks in 19th-century London helped to understand the spread of the disease and identify the contaminated water as the source.
Step-by-step explanation:
The relation John Snow established between cholera and the water supply in Soho is a good example of epidemiology. Snow's investigation of the cholera outbreaks in 19th-century London helped to understand the spread of the disease and identify the contaminated water as the source. His mapping of cholera cases and the distribution of homes that received drinking water from a particular contaminated well provided evidence for the transmission of cholera through water.