Issue Date: April 7, 2008
Joseph Priestley (1733–1804) is known to many chemists only as the person for whom the highest award of the American Chemical Society is named. A few modern chemists, Roald Hoffmann and Carl Djerassi among them, have devoted major efforts to understanding and appreciating Priestley
In their play, "Oxygen," Hoffmann and Djerassi entertain the idea of awarding Priestley a "retro-Nobel Prize" for his discovery of what he called "dephlogisticated air" (oxygen)-perhaps in combination with Antoine Lavoisier and Carl Scheele. But the play ends inconclusively with issues of priority and the definition of discovery. Perhaps it would be easier to award Priestley a "retro-Priestley Medal." But Priestley was much more than a chemist. The political and theological controversies that swirled around him might well make his candidacy for the Priestley Medal as problematic as Linus Pauling's was during the Cold War (J. Chem. Educ. 1998, 75, 1211).
Priestley was a radical on many counts, not least in the role that was most important to him: Christian minister of Unitarian persuasion. Maybe Priestley would be a suitable candidate for a "retro-Templeton Prize," awarded for "progress toward research or discoveries about spiritual realities"—for, say, his "Disquisitions Relating to Matter and Spirit" (1777).
In fact, Priestley received many honors in his own day; he was also quite a notorious person. Clear evidence exists of both contemporaneous views, which can contribute to our understanding of the whole man.
The Making of an LL.D., an F.R.S., and a Copley Medalist. Until the end of his life, Priestley identified himself on virtually all of his more than 200 books and papers as "LL.D." and "F.R.S."—doctor of laws from the University of Edinburgh and Fellow of the Royal Society.
At Priestley's birth it would have been difficult to predict such recognition coming to him. Born in Fieldhead, near Leeds, England, he was the son of a finisher and dresser of woolen cloth. His family, as Calvinists, were Dissenters from the Church of England. His mother died when he was a young boy, and he was sent to live with his father's childless older sister—a woman whom he remembered fondly as tolerant of diverse theological views.
Priestley benefited from the education provided in the alternative schools founded by Dissenters to give their children appropriate religious formation. In such academies young people studied far more diverse subjects than those taught in state-supported schools, including some study of the sciences. While still at Daventry Academy, Priestley read himself out of a Trinitarian view of God and began to write his most influential theological work, the "Institutes of Natural and Revealed Religion" (published 1772–74).
After Priestley completed his studies at Daventry, which was not permitted to grant academic degrees, he took up appointments as minister in several small towns, where he also conducted classes in a variety of subjects. It became his lifelong practice after he developed a course to turn his course notes into a textbook. His third appointment after leaving Daventry was to Warrington Academy, where, in various years, he taught Latin, Greek, French, English grammar, oratory, history, logic, anatomy, and chemistry.
Although he spoke with a stammer, Priestley was a brilliant, energetic, and ambitious man who attracted patrons and supporters throughout his life. Seeing an opportunity to enhance Priestley's reputation and that of their academy, Warrington's trustees recommended him on the basis of his educational publications for an LL.D. from the University of Edinburgh, which was free as a Presbyterian university to grant degrees to Dissenters, unlike the University of Oxford and the University of Cambridge.
While at Warrington, Priestley conceived a project of writing a history of static electricity by repeating the experiments in the widely scattered literature. Through his Warrington connections, Priestley arranged to meet the grand old man of electricity, Benjamin Franklin, who was then in England representing several of Britain's North American colonies. Franklin knew a good man when he saw one and helped provide Priestley with books and apparatuses to complete his first science book.
Then, Franklin, along with six others, nominated Priestley for membership in the Royal Society. Priestley welcomed this honor not least because he thought "F.R.S." would help sell his forthcoming "History of Electricity." Once the book was published in 1767, Franklin tried to use it to net Priestley the Royal Society's prestigious Copley Medal, but the nomination was turned down on the grounds that the book was insufficiently experimental in content. Franklin did not press the case that the "History of Electricity" did, in fact, include original experiments by Priestley beyond those carried out by the authors under review.
In 1767, Priestley was called to be minister of Mill Hill Chapel in Leeds. Perhaps his most influential work of this period was "Essays on First Principles of Government" (1768), which struck a chord with colonial Americans with its emphasis on civil liberties and the right of an oppressed people to rebel.
It was also in Leeds that he began serious investigations of gases. In the course of his experiments with "fixed air" (carbon dioxide), he discovered how to dissolve this gas in water and make soda water like the naturally carbonated water from some spas. In a little pamphlet, "Directions for Impregnating Water with Fixed Air" (1772), Priestley described his method and proposed that, like other spa waters, his product would have important medicinal value—even possibly preventing scurvy, which it did not do.
In papers read before the Royal Society that same year and subsequently published in its Philosophical Transactions, Priestley mentioned his soda water and described others of his investigations on gases. Among these was the discovery that plants can "restore" air in which mice have respired—a piece of the photosynthesis story. This paper also contained his test for the "goodness" of air (that is, its oxygen content, although oxygen had not yet been discovered) by reacting "nitrous air" (NO) with a sample of air and looking for telltale brownish fumes (of NO2). On the basis of these Philosophical Transactions papers, Franklin finally succeeded in his nomination of Priestley for the Copley Medal.
Priestley's most scientifically productive period was the years 1773–80, when he was companion and teacher in the service of William Petty, Earl of Shelburne. Shelburne was a Whig politician eager to defend Parliament's powers against royal infringement.
On Aug. 1, 1774, Priestley produced a gas by using a burning glass to focus sunlight on mercurius calcinatus per se (mercuric oxide). Priestley tested the product with a lit candle to see if it would support combustion. When the candle flared brightly, he assumed that he had made the gas that he had recently isolated, "phlogisticated nitrous air" (N2O). In October 1774, while traveling in France with Shelburne, he discussed this experiment with Lavoisier and others. It was not until March 1775 that Priestley realized through a series of tests that he had earlier discovered an entirely new substance, which he called "dephlogisticated air" (oxygen).
Lavoisier and Priestley exchanged sharp words over the priority of the discovery of this gas. More acrimonious was the battle in which Priestley and Lavoisier engaged over the correct interpretation of the reactions of this gas with other substances, whether "phlogiston," what some defined as the possibly weightless "essence of fire," was involved or not. Priestley was to fight this battle until the end of his life. Back then, no academy gave Priestley, Lavoisier, or Scheele any medals for the discovery of oxygen—the omission that Hoffmann and Djerassi sought to remedy with their play.
Tokens of Esteem and Denigration. Soon Priestley was to receive medals of a different sort—small metallic tokens carrying political messages. Chemist Roy A. Olofson, professor emeritus at Pennsylvania State University, has assembled a wonderful collection of these.
Because the Royal Mint was not able to keep up with the need for small change, especially in the industrializing north of England, private entrepreneurs began to make tokens to be used for small commercial transactions. Early on, such tokens might name the areas where they could be used or carry advertisements for various products, but soon they were being struck for all sort of reasons. Some carried political slogans rather like today's political buttons. These were rarely if ever used to purchase anything and have been called medals or medalets. A great center for manufacturing all tokens was Birmingham, the very city to which Priestley headed in 1780 to become the minister of New Meeting, an important Unitarian congregation.
Until 1791, Priestley's experiences in Birmingham were very positive. He was, for example, invited to join the Lunar Society, an informal group made up mostly of industrialists who met once a month, on the Sunday following the full moon, to discuss scientific and technical matters and drink together. One of the members, Matthew Boulton of steam engine fame, was a leading innovator in token-making machinery (as was Priestley's brother-in-law, John Wilkinson, of iron bridge fame).
The first of the Priestley medals to appear was struck in 1783 in bronze, silver, and gold, in honor of Priestley's 50th birthday. It featured images emblematic of his achievements in science. In this decade, Priestley was chosen as a member of a dozen learned societies, including the Académie Royale des Sciences (1784), the American Philosophical Society (1785), and the American Academy of Arts & Sciences (1785).
But all was not sweetness and light. Certainly the religious works that Priestley was publishing during those years, with titles like "History of the Corruptions of Christianity," raised alarm in many quarters. He had long thought that the Emperor Constantine and subsequent rulers had done Christianity a great disservice by making it a state religion.
Priestley actively participated in the efforts to repeal Britain's Test and Corporation Acts, the laws that repressed Dissenters from the Church of England. Rather rashly, Priestley used a chemical metaphor several times in cheering on the growth of Dissent and the inevitability of repeal: "We are, as it were, laying gunpowder, grain by grain, under the old building of error and superstition"—hence his nickname in conservative circles, "Gunpowder Joe." Priestley got into further trouble because of his enthusiasm for the coming of the French Revolution, expressed in a published battle with Edmund Burke, who had become chief spokesman for conservatism.
A medal from 1790, probably cast at the request of Priestley's friends, uses symbolism from both the French Revolution and England's own 17th-century revolution. However, most allusions to Priestley in pamphlets, medals, and political cartoons of this period portray him as a public enemy. In several instances, links were made between Priestley's radical politics and theology with his chemistry.
Opposition to Priestley and those who thought like him came to a head in the Church and King Riots in Birmingham on the night of July 14, 1791. A destructive mob, demonstrating against a dinner organized to celebrate the second anniversary of Bastille Day, roamed the city, setting fire to churches and homes. Forewarned of the potential violence, Priestley did not attend the dinner. But that did not save his church, home, and laboratory, which the mob sacked and burned to the ground.
Priestley resigned his ministry in Birmingham for fear that his presence would bring further harm to the members of his congregation. For three years, he served as minister and teacher at Hackney, near London, while publishing, among other titles, the syllabus of the chemistry course he taught there.
The ominous drumroll of attacks on him did not cease, as shown in a medal from 1792 based on the false rumor that Priestley inspired an unsuccessful plot to burn down the House of Commons in May 1792.
It could not have helped his situation that in August 1792 Priestley's name led the list of worthies upon whom France's National Convention conferred French citizenship. (Thomas Paine and George Washington were among those also so honored.) A political cartoon published a few months later depicted Priestley and Paine making incendiary plans. It is one of a collection of 18th-century Priestley-related cartoons that Derek A. Davenport, professor emeritus of chemistry at Purdue University, collected and generously presented to the Chemical Heritage Foundation.
After France and Britain went to war in 1793 and British authorities began imprisoning suspected internal enemies, Priestley and his wife decided it was time to leave for America, where their three sons had already immigrated. A 2-inch-diameter medal commemorating his departure could comfort Priestley's saddened supporters.
In the New World. When Priestley arrived on American shores, he was 61 years old and a well-known figure in all his areas of endeavor. He and his wife landed in New York City, where a great civic welcome was organized. They moved on to Philadelphia, where another civic ceremony took place. As planned, they then proceeded up to Northumberland, Pa., to a property chosen by their sons and situated at the joining of the two branches of the Susquehanna River, some 150 miles northwest of Philadelphia.
In this frontier community of about 100 houses, the Priestleys planned a home of generous proportions, complete with a chemical laboratory. Mary Priestley, already ill with tuberculosis when she arrived in the U.S., did not live to see the completion of the house. But Priestley persevered: He invited his son Joseph and his family to live with him, meanwhile writing books and papers and conducting chemical experiments.
Again, Priestley's life was not without controversy. When he arrived in Philadelphia, he was disappointed to learn that none of the churches would let him use its pulpit. But friends sympathetic to Unitarianism banded together and contributed funds to the Universalists, who were then constructing a church building in Philadelphia—on the condition that the Universalists would let Priestley preach from its pulpit. The series of sermons that he preached there in 1796, dedicated to his old friend John Adams, inspired the founding of the first church in America to call itself "Unitarian."
Priestley was always welcome at the American Philosophical Society (APS) during his half-dozen visits to Philadelphia, each lasting two to three months. In 1803, a testimonial dinner was organized in his honor by APS.
Politics, as ever, proved to be perilous for Priestley. Curiously, back in Birmingham he was still being portrayed as a public enemy. Even though he proclaimed his desire as a noncitizen to be above political frays in the U.S., he nevertheless became an actor. During the Federalist presidency of John Adams, Priestley published Jeffersonian sentiments in the Philadelphia newspaper, the Aurora. In 1799, he fell under suspicion under the Alien and Sedition Acts. He had attended an anti-Federalist Fourth-of-July rally in Northumberland and contributed $1.00 toward the publication and distribution of a speech by his chemist-politician friend Thomas Cooper. Adams rejected the suggestion by his secretary of state that Priestley be deported.
When he died in 1804, APS held a memorial service at First Presbyterian Church in Philadelphia. In England, memorial sermons were preached at Priestley's old Unitarian congregations in Leeds and Birmingham. In Birmingham two commemorative medals were struck, one of which was a modification of the medal cast for his immigration to America. No one has ever developed a medal to honor the whole of Priestley—or persons like him of such breadth of achievement.
Mary Ellen Bowden is a senior research fellow at the Chemical Heritage Foundation, Philadelphia.
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