Answer:
The two primary purposes of 'On the Mode of Communication of Cholera' (1855) were to:
1) make people be more conscious about the disease
2) shed light on new ideas about cholera, supported by scientific evidence.
In 1854, only a year before issuing 'On the Mode of Communication of Cholera', Dr. John Snow found that a pump was the main source of cholera epidemic outbreak the same year. In the text, he reminds the readers that cholera is transmitted via dirty environment, and warns them to pay more attention to the sanitation.
