Priestley in America, 1794-1804

In Short

This biography reconstructs the final decade of Joseph Priestley, the famed English chemist and Unitarian theologian who sought asylum in Pennsylvania in 1794. Drawing extensively from contemporary letters, published pamphlets, and newspaper accounts, the narrative follows Priestley's life in America as he establishes a home in rural Northumberland, engages in heated political and theological debates, and conducts laboratory research. It survives as a vital historical bridge documenting the birth of American chemistry and the persistence of an unyielding scholar who continued to champion superseded scientific theories until his death in 1804.

The Story

The account begins in April 1794 as Joseph Priestley embarks on an eight-week Atlantic crossing aboard the Sansom. Fleeing hostile political sentiment in England, where his home and laboratory had been destroyed, Priestley spends the long voyage reading classical texts and testing ocean water temperatures. He arrives in New York in June 1794 alongside his wife, receiving an enthusiastic welcome from civic leaders, academic bodies, and political groups who view him as a champion of liberty and reason.

Despite attractive offers to remain in urban centers—including an invitation to take the chair of chemistry at the College of Philadelphia—Priestley opts for the quiet simplicity of rural Pennsylvania. He settles in Northumberland, where his sons have begun clearing land. There, he establishes a home and constructs a laboratory, funding his scholarly work while declining public roles that would force him to spend months away from his books and apparatus.

In Northumberland, Priestley settles into a routine of intense intellectual activity. He writes extensively on church history, translates biblical texts, and corresponds with prominent American figures like Thomas Jefferson and Chancellor Livingston. Jefferson offers political solidarity against conservative attacks from hostile Federalist journalists, most notably William Cobbett, writing under the pseudonym "Peter Porcupine," who publicly attacks Priestley as a dangerous radical.

Concurrently, Priestley throws himself into scientific experimentation. He becomes a central figure in American scientific circles, publishing numerous papers in the Transactions of the American Philosophical Society and the Medical Repository. However, his scientific work places him in a lonely position within the international community. While French chemist Antoine Lavoisier and a younger generation of American scientists embrace the new oxygen-based chemistry, Priestley remains stubbornly devoted to the outdated phlogiston theory. He conducts endless experiments with gaseous compounds, metals, and electrical apparatus, attempting to prove that water is a compound of phlogiston and that metals lose this elusive substance during calcination. Younger American chemists like James Woodhouse admire Priestley's experimental brilliance while methodically dismantling his theoretical conclusions.

As the years pass, Priestley balances his lab work with community efforts, such as founding the Northumberland Academy and tending his garden. Though plagued by failing health, digestive troubles, and growing deafness, he maintains his intellectual output until his final days in February 1804, satisfied that he has dedicated his remaining years to truth, science, and religious inquiry.

How It Unfolds

The voyage begins Priestley boards the Sansom in April 1794, spending his eight weeks at sea reading classical literature, studying the Hebrew Bible, and conducting simple temperature experiments in the ocean water. He arrives in New York to warm receptions from civic and Democratic societies who honor his contributions to science and freedom.

Arrival and settlement After evaluating offers in Philadelphia and New York, Priestley rejects a university professorship to avoid urban distractions. He retreats to the small town of Northumberland, Pennsylvania, where his sons clear land and where he constructs a home and laboratory suited for quiet research.

Scientific defense of phlogiston Entering the American scientific stage, Priestley publishes a series of papers defending the old phlogiston theory against the rising antiphlogistic views of French chemists. He enters into productive, respectful combat with younger American scientists, particularly James Woodhouse and Samuel Latham Mitchill.

Political and theological battles Priestley faces fierce public attacks from Federalist pamphlets written by Peter Porcupine, who labels him a political firebrand. In response, Priestley publishes political tracts and religious works, earning the warm praise and friendship of Thomas Jefferson, who offers encouragement against sectarian intolerance.

Final years in Northumberland Despite declining health, progressive deafness, and loss of physical strength, Priestley remains devoted to writing his extensive Church History and carrying out chemical trials. He dies in 1804, leaving behind a profound legacy that reshaped the early trajectory of science in the young American Republic.

The People

• Joseph Priestley: The revered English chemist, Unitarian minister, and natural philosopher. He seeks a peaceful asylum in America to pursue his studies without political harassment. Though his physical health slowly fails and he clings obstinately to the disproven phlogiston theory, his genial demeanor, endless curiosity, and indefatigable work ethic win over even his sharpest intellectual opponents.
• Thomas Jefferson: The American statesman and philosopher who becomes one of Priestley's most prominent supporters. He exchanges warm letters with Priestley, commending his political essays, comforting him against partisan media attacks, and consulting him on the proper curriculum for higher education in the United States.
• James Woodhouse: A brilliant young professor of chemistry in Philadelphia. He acts as Priestley's chief scientific adversary in America, publishing rigorous experimental work to disprove the phlogiston theory while maintaining a deep, magnanimous reverence for Priestley's historical achievements.
• William Cobbett ("Peter Porcupine"): A fierce Loyalist journalist and pamphleteer in Philadelphia. He relentlessly attacks Priestley in print, labeling him a dangerous foreign radical and a "fire-brand philosopher," serving as the chief antagonist to Priestley's peace of mind during his American exile.

In Its Own Voice

When receiving a formal address of welcome upon his arrival in New York in 1794, Priestley framed his migration around his desire to continue his life's work without political disruption:

"In some form or other this has been my employment and delight; and my principal object in flying for an asylum to this country... is that I may, without molestation, pursue my favourite studies."

Reflecting on Priestley's stubborn resistance to the modern revolution in chemistry, the text highlights his unwavering reliance on old theoretical frameworks despite clear experimental evidence to the contrary:

"Still, however, I would not be very positive, as the contrary is maintained by almost all the chemists of the age.... And thus he proceeds, ever doing interesting things, but blind to the patent results because he had phlogiston constantly before him."

Writing to Priestley during a period of intense political hostility, Thomas Jefferson expressed deep sympathy for the scholar's trials in the young nation:

"How deeply have I been chagrined and mortified at the persecutions which fanaticism and monarchy have excited against you, even here!"

What It's Really About

At its core, the book examines the final chapter of a great mind navigating exile, intellectual isolation, and the relentless march of scientific progress. It exposes the tragic irony of a revolutionary thinker who liberated chemistry through his discovery of oxygen, yet spent his twilight years trapped inside an obsolete scientific paradigm. The narrative explores how personal convictions interact with political ideology in a fledgling democracy, showing how Priestley's commitment to free inquiry made him both a beacon for American democrats and a target for conservative partisans. Ultimately, the work reflects on the nature of scientific legacy, illustrating how an individual's intellectual generosity and passion for research can ignite a nation's scientific tradition even when their own theoretical views are proven wrong.

Why Read It Today

This volume appeals to readers of scientific history, early American biography, and the history of ideas. Edgar Fahs Smith constructs his portrait directly from archival documents, giving the text an authentic, primary-source intimacy. The reader feels the dust of old laboratories and hears the echoes of early American political debates through original letters, institutional addresses, and newspaper clippings.

The narrative demands some patience, as it presents eighteenth-century prose styles, lengthy extracts of chemical correspondence, and obscure technical disputes regarding gaseous reactions. Modern readers must navigate archaic chemical nomenclature—such as "dephlogisticated air" and "azote"—and tolerate detailed transcripts of political addresses. However, what remains with the reader is an inspiring portrait of intellectual resilience. Priestley emerges not as a sterile icon, but as a warm, human figure: a man who chopped wood with his young son in the Pennsylvania wilderness, tended his garden while growing deaf, and faced public criticism with unruffled grace, working faithfully at his desk until his final breath.