Nineteenth Century
• 1849 Dr. John Snow
• 1850 Lemuel Shattuck, Massachusetts
• 1862 Louis Pasteur’s germ theory disproved
spontaneous generation
• 1876 Robert Koch: a particular microbe and no
other causes a particular disease
• 1872 American Public Health Association
founded
• 1890 pasteurization of milk
• 1895 septic tanks introduced