12 maio 1854 ano - Germ Theory

Descrição:

Snow demonstrates that cholera bacteria is transmitted through contaminated drinking water. His "Grand Experiment" is when he compared two water companies supplying the same neighborhood. One water company moved to a fresh water site while the other remained in a polluted water site. He found out that the company with the polluted water site attained a lot more cholera deaths.
(from https://www.ph.ucla.edu/epi/snow/grand_experiment.html)