n the essay "On the Mode of Communication of Cholera," what is the primary technique that author John Snow uses to support his claim that cholera spreads from person to person?

John Snow is known as the father of epidemiology.

In this essay "On the Mode of Cholera" he used both reasoned argument along with documentary evidence to show that cholera spread from person to person.

He gave examples of rows of houses on opposite sides to each other, and how all of the members in one row contracted cholera, while only one person on the opposite row contracted the disease.