Perhaps no other advancement of public health has been as significant. This book tells the story of disinfecting public water systems with chlorine — beginning with the first large-scale use in Jersey City, New Jersey (1908) — and how that development saved more lives than any other single health advance. It details the people, engineering, trials, and controversies behind the adoption of chlorination and gives recognition to key figures such as Dr. John L. Leal and George W. Fuller.