English scientist, theologian, and political theorist Joseph Priestley (1733-1804) made numerous contributions to chemistry, physics, and philosophy. Priestley, who was raised in Birstall, West Yorkshire, attended local schools before going to Daventry Academy, where he became very interested in natural philosophy. Priestley made significant scientific advances. His greatest-known distxtery, made in 1774, was oxygen, which he dubbed "dephlogisticated air." His investigations into gases and their characteristics, which are detailed in "Experiments and Observations on Different Kinds of Air," greatly enhanced our knowledge of chemistry. Priestley also studied nitrous oxide and carbon dioxide, among other gases. In addition to his scientific interests, Priestley was a prolific writer on theological and political topics as well as a dissident clergyman. He received criticism for his Unitarian beliefs and his perceived radical religious ideas. Priestley was a liberal and democratic idealist whose political writings shaped the early American history.

Acknowledgements; Introduction; Chronology of Joseph Priestley's life; Biographical guide; Bibliographical guide; Essay on the First Principles; The Present State of Liberty; Index.