REPRINTS AND REFLECTIONS The rise and fall of epidemiology,

Bills of Mortality, and thereby established the field of epidemiol-ogy.1 Graunt brought to light a diversity of facts about human life and disease that had not previously been appreciated. He was the first to notice that the number of births and deaths of males exceeded those of females (by the ratio of 14 to 13); he noticed, too, that despite their greater mortality, men had less morbidity than women. Graunt quantified for the first time the high mortality in children, noting that one-third died by the age of five. He documented that plague actually claimed many more deaths than had been ascribed to it, and he demonstrated that the frequency of rickets increased over the span of a few years from zero fatal cases to a level that indicated a serious epidemic. Graunt’s profound observations quickly became the talk of educated London. Within weeks of the publication of his book