Just as the fear of plague led to the collection and publication of the London bills of mortality, which Graunt had so creatively used in his Natural and Political Observations, smallpox stimulated the development of medical arithmetic during the eighteenth century. Although smallpox had a significantly lower fatality rate than plague, its impact on public life was almost as great. Numerous members of the royalty succumbed to smallpox, including Queen Mary of England in 1694 and Louis XV of France in 1774. Smallpox caused disfigurement, blindness, and widespread suffering, which haunted the popular imagination. But it was not just the experience or fear of smallpox that led individuals to analyze its mortality rates. As with plague, the hope of preventive measures to offset the incidence of smallpox played an important role. Quarantine and fleeing potentially risky environments for safer climes were standard public health measures used to prevent or at least to limit plague epidemics. However, there existed a more potent preventive measure for smallpox: inoculation.

Inoculation provided an individual with a measure of safety – of immunity – against future smallpox epidemics.