Curator's Choice tells the stories behind prized objects and artifacts from the collections of historical organizations and cultural institutions in Pennsylvania.

The achievements of Joseph Priestley (1733–1804) have been committed to memory by generations of American schoolchildren, who for years listened as teachers credited him as the discoverer of oxygen, which he called “dephlogisticated air,” and the inventor of carbonated water. Much of the attention given to Priestley highlighted his scientific work, but his contributions to education, natural history, political theory, metaphysics, and theology were legion.

Born to established English Dissenting parents Mary Swift and Jonas Priestley, who did not conform to the Church of England, the precocious child could flawlessly recite all 107 questions and answers of the Westminster Short Catechism by the age of four. During his theological studies, he joined the Rational Dissenters, noted for their abhorrence of dogma and religious mysticism and emphasis on the rational analysis of the natural world and the Bible. He committed himself fully to the ministry, which he described as “the noblest of all the professions.”

Priestley engaged in numerous religious and political pamphlet wars, and wrote controversial tracts on the Lord’s Supper and on Calvinist doctrine. His writing grew fervent, attracting both adherents and detractors. He eventually supported Unitarianism established by a friend, Theophilus Lindsey (1723–1808).

By 1791, the animus that had been fermenting against Dissenters and supporters of the American and French Revolutions exploded. Rioters in Birmingham burned both the New Meeting and Old Meeting churches. Priestley and his wife Mary fled from their residence, Fairhill, at Sparkbrook, which the mob torched, destroying his library and the family’s possessions. The Priestleys escaped to London where they hid for several days.

Life grew even more difficult for Priestley, and he and his wife moved to America in 1794. After settling in northcentral Pennsylvania, he attempted to continue his scientific investigations with the support of the American Philosophical Society, but was hampered by a lack of news from abroad. Despite his reduced scientific output, his presence in the United States stimulated the nation’s interest in chemistry.

On view at the Joseph Priestley House, administered by the Pennsylvania Historical and Museum Commission (PHMC) and operated by the Friends of the Joseph Priestley House, a membership support organization, is a circa 1780–1790 microscope on an iron base with a single ivory and glass specimen drawer and brass adjustable lens attachments. Accompanied by a wooden case, the microscope was made by brothers William and Samuel Jones, among the most successful scientific equipment makers in London during the late eighteenth and early nineteenth centuries.

Priestley once referred to the exquisite completeness of tiny plants and animals visible through the microscope in an argument about the origins of life with natural philosopher Erasmus Darwin (1731–1802). He contended that a more powerful microscope would reveal the germs or seeds by which organisms are propagated.

Because of severely curtailed hours and programs due to recent state budget cuts, the historic site is staffed by volunteers coordinated by the Friends of the Joseph Priestley House on behalf of PHMC. To confirm visiting hours, telephone (570) 473-9474; e-mail; or visit the Joseph Priestley House website .