Introduction; 1. The call for a language of public health: Philanthropic foundations, bacteriologists, and health administrators; 2. The language and dialect of health science: Public health schools and their statistical practices; 3. The language of health administrations: The League of Nations Epidemiological Intelligence Service; 4. The language of policy-making: Research and advocacy through health demonstrations; 5. Popularization at a global scale: The WHO and the postwar health statistics reporting system; 6. The art of rhetoric: Statistical standards at work, from fieldwork to world policy-making; 7. Another way of speaking? Public health statistics in the People's Republic of China; Conclusion: Numbers, experts, and policy-making.