Answer
The answer to preventing smallpox contagion, as discovered by Cotton Mather, lies in the practice of variolation, an early form of inoculation. This method involved deliberately infecting a healthy individual with a mild case of smallpox to induce immunity. Although controversial at the time, variolation played a pivotal role in combating the devastating effects of smallpox, paving the way for advancements in vaccination and immunization.