The Invention of Air

by Steven Johnson

  Still there was the matter of that £150 annuity. The Priestleys needed at least twice that to make ends meet. Even before the move to Fair Hill, Priestley had begun supplementing Shelburne’s annuity by building a collection of “subscribers” who supported his work with annual contributions. The eighteenth-century concept of subscribing is one without an exact modern equivalent, falling somewhere between a magazine subscription and a charitable donation to a museum or park or university. The donation came with perks—Priestley’s subscribers were sent first editions of all his writing—but the money contributed generally exceeded by a wide margin the market value of the publications. It was nice to be first in line to read Priestley’s latest, of course, but one subscribed because Priestley himself was a cause worth supporting. For Priestley, subscription was a way of diversifying the patronage system; rather than tying his fortune to the whims of a single aristocrat, Priestley was assembling a broader support network to keep his ideas alive.

  Unfortunately, the first round of subscriptions procured after the break with Shelburne was minimal, and one of his key supporters, the Quaker physician John Fothergill, died shortly after Priestley set out on his own. But word of Priestley’s situation soon began to circulate among the Midlands industrialists, originating most likely with Wilkinson, and by early spring of 1781, a group had formed that would collectively keep Priestley in business for the next thirteen years. These were the shining lights of industrial and intellectual England outside the metropolis of London: Wilkinson; Wedgwood; the “toymaker” Matthew Boulton, whose small metal goods had become the signature export of Birmingham; James Watt, the steam-engine pioneer; and the physician, poet, and naturalist Erasmus Darwin, Charles’s grandfather. The men constituted the core members of the legendary Lunar Society, Birmingham’s version of the Club of Honest Whigs. The Lunaticks—as they playfully referred to themselves—had first assembled in the mid-1760s, scheduling meetings during the full moon to assist their passage home after a long night of boozy debate. The historian Jenny Uglow describes a typical session in her epic account of the society, The Lunar Men:

  They tried to dine at two o’clock, and usually planned to stay until at least eight. The wine flowed . . . and the tables were heavy with fish and capons, Cheddar and Stilton, pies and syllabubs. At dinner the wives sometimes joined the men and the children dashed in and out. But when the meal was cleared away, out came the instruments, the plans and the models, the minerals and machines. In the house and in the workshops they talked long into the evenings.

  Priestley (and Franklin) had been long-distance associates of the society since its inception, but Priestley’s move to Birmingham would quickly establish him as one of the core Lunaticks. They moved their regular sessions from Sunday to Monday to reduce conflicts with the sermons Priestley had begun delivering at the New Meeting house in Birmingham. Priestley’s credentials as a scientist—with Lavoisier, he was now considered the most accomplished chemist on the planet—made him a particularly valuable addition to the group, which was heavy with industrial innovation but weaker when it came to pure natural philosophy. By the 1780s, most of the society could easily afford to endow their new comrade with all the leisure time he needed. In March of 1781, Wedgwood wrote Boulton: “Our good friend, Dr. Darwin, agrees with us in the sentiment, that it would be a pity that Dr. Priestley should have any cares or cramps to interrupt him in the fine vein of experiments he is in the midst of, and is willing to devote his time to the pursuit of, for the public good.” Boulton quickly wrote back with his support for the idea, suggesting that Wedgwood “manage the affair so that we may contribute our mites to so laudable a plan without the Doctor knowing anything of the matter.” The discretion was not merely a question of modesty; Priestley was already controversial enough for his religious and political views that some of his supporters couldn’t risk a public association with him.

  Before long, Priestley was able to write to his old friend, Thomas Percival: “I am as rich as I wish to be. My sons will have employments, which I prefer to estates, under their uncles; so that I really think my lot the happiest in the world, as I can devote my whole time to useful and pleasing pursuits; and if one fails, I can fly to another.”

  Presley soon fell into a routine at Fair Hill that would lead to the happiest years of his life. He rose early and worked for five or six hours on his experiments or writing projects before the midday dinner, “leaving the afternoon for visiting and company.” Joseph and Mary lovingly tended to their garden on the Fair Hill grounds. It was a trifle compared to Capability Brown’s immense landscape at Bowood, of course, but this was their garden, unlike Shelburne’s lavish spread. They had four children now: their daughter Sally was seventeen when they moved to Birmingham, and her younger brother Joseph Jr. eleven; the rambunctious William was almost ten, and little Harry was just a toddler. Practically everyone who left a report of visiting Fair Hill remarked on the playful spirit of the home environment that the Priestleys had built for their family, with its impromptu magic lantern shows and tussles on the lawn. According to Joesph Jr.’s account, a day rarely went by without Priestley spending at least two hours playing games: chess, backgammon, whist. Nearly every night Joseph and Mary would play two or three matches of chess, though as the children grew older, boisterous family card games became more frequent at Fair Hill.

  The one conspicious absence in this arcadia was Benjamin Franklin, who was stationed across the Channel at Passy, serving as the American ambassador to France. Despite that relative proximity, Priestley had not seen his old collaborator since Franklin’s emotional last day in London in 1775. Franklin often contemplated making the journey, but his gallstones prevented it. In the summer of 1784, he wrote to Richard Price:

  I had indeed Thoughts of visting England once more, and of enjoying the great Pleasure of seeing again my Friends there: But my Malady, otherwise tolerable, is, I find, irritated by Motion in a Carriage, and I fear the Consequences of such a Journey; yet I am not quite resolv’d against it. I often think of the agreeable Evenings I used to pass with that excellent Collection of good Men, the Club at the London, and wish to be again among them. Perhaps I may pop in, some Thursday Evening when they least expect me.

  Even in France, though, Franklin went out of his way to augment Priestley’s reputation as a natural philosopher, lobbying to have him included (alongside Franklin himself ) as one of the foreign members of the Academy of Science. When the Academy members finally agreed to it, Franklin wrote with obviously delight to Price: “I had mention’d him upon every Vacancy that has happen’d since my Residence here, and the Place has never been bestow’d more worthily.”

  Franklin’s last voyage home to Philidelphia in 1785, which he courageously undertook at the age of seventy-nine, made it apparent to the two men that they were not likely to see each other again in person. Priestley continued sending his scientific volumes, and in one of the last surviving letters between them, Franklin offered his thanks, along with a fitting tribute to the unique experimental skills of his fellow Honest Whig. “I know of no Philosopher who starts so much good Game for the Hunters after Knowledge as you do,” he wrote. “Go on and prosper.”

  In 1788, two years before his death, Franklin wrote to Priestley’s former student, Benjamin Vaughan, who had helped Franklin in negotaiting the terms at the end of the war. “Remember me affectionately to good Dr. Price and the the honest heretic Dr. Priestley,” he wrote. “I do not call him honest by way of distinction; for I think all the heretics I have known have been virtuous men. They have the virtue and fortitude or they would not venture to own their heresy; and they cannot afford to be deficient in any of the other virtues, as that would give advantage to their many enemies; and they have not like orthodox sinners, such a number of friends to excuse or justify them. Do not, however mistake me. It is not to my good friend’s heresy that I impute his honesty. On the contrary, ’tis his honesty that has brought upon him the character of heretic.”

  As
his long attachment to the oldest member of the revolutionary generation came to an end, Priestley forged the first links of a new American connection. During his Birmingham years, he kept to his habit of making regular pilgrimages to London, absorbing the eclectic shoptalk of the coffeehouse scene, and meeting with his old friends from the Honest Whigs. A new informal society had sprouted up around the Piccadilly store of the bookseller and publisher James Stockdale, where various London intellectuals would gather to discuss world events and theological musings. On April 19, 1786, John Adams—living in London as America’s ambassador to the Court of St. James’s—recorded in his diary that he had walked to “the booksellers,” where he “met Dr. Priestly for the first time.” They discussed the biblical descriptions of the conquest of Canaan, and the revolutionary battles in South Carolina. “I spent the Day upon the whole agreeably enough,” Adams wrote, adding prophetically: “Seeds were sown, this Day, which will grow.”

  THE LUNAR SOCIETY contributed more than just sterling to Priestley’s “useful pursuits”: Wedgwood built earthenware vessels for the new laboratory; Boulton and his brothers-in-law designed metal goods, and Priestley had state-of-the-art glass instruments manufactured by a local impresario who had built a prosperous business selling equipment for making Priestley’s soda water. The arrangement was not a matter of pure charity, however. Priestley regularly advised his Lunar Society friends on their commercial projects, examining samples of clay and iron ore for Wedgwood and Boulton, and sharing his latest research on combustion with Watt. He became a kind of floating, one-person R&D lab, his time and intellect shared by multiple corporations. Priestley’s chronic intellectual openness occasionally worried his more proprietary colleagues, particularly James Watt. (Industrial secrecy ran quite against the grain of Priestley’s general propensity to share everything with anyone who would listen.) But for the most part, Priestley’s engagement with the Lunar Society proved a brilliant partnership, every bit as collaborative and encouraging as the Club of Honest Whigs had been fifteen years before.

  One of the things that makes Priestley’s career so interesting to us now is that his work lay at the intersection point of four institutional models of idea production, two of which were just emerging into a recognizable shape during his lifetime, and two that were just beginning a long slide into relative obscurity. Today, we take it for granted that advances in science or technology are cultivated in two primary environments: private businesses, or public organizations like universities or research hospitals, the latter often supported by government funding. Priestley’s move to Birmingham planted him squarely at the origin point of the first category, in the fusion of science, technology, and capitalism that the new class of entrepreneur industrialists like Watt and Boulton helped bring about. Priestley had seen the second model at work firsthand during his visit to France with Shelburne in 1774; the planned, state-supported model of innovation that buttressed the work of his great chemical rival, Lavoisier.

  But Priestley was only a tourist in those two soon-to-be-dominant environments; his career mostly flourished in different soil. First, there was the model of the solo, free-agent investigator—working alone in his lab, supported by a single patron or small group of patrons who refrained from meddling with his research objectives. And there was the loose connectivity of the small society—the Honest Whigs and the Lunaticks—a group of intellectual allies with different fields of expertise, sharing insight and inspiration (along with the porter and Stilton), supporting one another emotionally and, at times, financially. That Priestley would spend so much of his career happily ensconced in these less structured environments should come as no surprise to us. The amateur and the small society were the two prevailing frameworks for Enlightenment science, and they were uniquely suited for a maverick, cross-disciplinary thinker like Priestley. In the two centuries that have passed, both models have become as rare and antiquated as one of Priestley’s electrical machines, replaced by the giant turbines of big industry and big government.

  Priestley actually envisioned another model that “might be favourable to the increase of philosophical knowledge.” He had sketched it out in the opening pages of The History and Present State of Electricity, at the very beginning of his scientific career, in 1767. He began by drawing attention to the existence of institutional systems like Lavoisier’s Académie Française, “large incorporate societies, with funds for promoting philosophical knowledge in general.” Priestley liked the idea of funding innovation, but he objected to the centralized nature of those societies. So he proposed to break them up into smaller and more nimble clusters. “Let philosophers now begin to subdivide themselves, and enter into smaller combinations,” he wrote.

  Let the several companies make small funds, and appoint a director of experiments. Let every member have a right to appoint the trial of experiments in some proportion to the sum he subscribes, and let a periodical account be published of the result of them all, successful or unsuccessful. In this manner, the powers of all the members would be united and increased. Nothing would be left untried, which could be compassed at a moderate expence, and it being one person’s business to attend to these experiments, they would be made, and reported without loss of time.

  This vision is classic Priestley in the way it mirrors his own eclectic, improvisational research style. The diversity of groups, and the diversity of proposed experiments, ensures that a broad mix of interesting problems will be explored, but the accountability of the single “director of experiments” in each cluster wards off the inertia of bureaucracy that drags down so many large collaborations. Suffice it to say that this framework for innovation did not catch on the way the corporate or university model did. Whether that historical non-event is regrettable—or whether Priestley’s vision was ultimately untenable in practice—is a topic for another book. What is important for our current purposes is that Priestley did come close to creating the environment he had outlined in early 1767 with his participation in the Lunar Society. There in the British Midlands, in the lab at Fair Hill, a “director of experiments” (Priestley) was supported financially by a small cluster of members, each of whom proposed different experiments to be carried out, with the results shared with, and analyzed by, the entire group. It had taken him fifteen years, but by the time Priestley settled down to work in his new lab at Fair Hill, in the fine company of the Lunar Men, he had finally established the work environment he had dreamed of as a young man.

  The irony of those years at Fair Hill is that they did not turn out to be the pinnacle of Priestley’s natural philosophy, despite his boast to Wedgwood. He would devise some ingenious experiments in Birmingham, and publish over a dozen papers on a typically diverse array of topics: nitrous oxide, the composition of water, and many iron- and steam-related inquiries inspired by his new environs (and the requests of his patrons and friends in the Lunar Society). He also added two new volumes to his opus Experiments and Observations on Different Kinds of Air. But none of his discoveries from that period would compare to the Leeds innovations in their ultimate social and scientific impact. There are no mint sprigs in the Fair Hill canon, and no soda water. A quiet acknowledgment of this deficiency is visible today in the center of Birmingham, in the statue of Priestley that stands in front of the Birmingham Library. The statue depicts Priestley employing his burning lens to extract pure air from mercury calx—an experiment that took place in Wiltshire, not Birmingham. Priestley spent many of his Birmingham days fighting a losing battle against Lavoisier and his critique of the phlogiston theory, drawing the Lunar Men into the debate for a time, before most of them eventually parted ways—on that one point at least—with their chief scientist. Priestley would cling to the phlogiston model for the rest of life, despite the steady accumulation of data and expert opinion that suggested it was fatally flawed. His refusal to abandon the theory has been the subject of intense commentary over the years, and in certain accounts of the history of science, he has never been fully forgiven for
the error. Even the Lunaticks wondered why their gifted colleague seemed so intent on sticking with what was clearly a losing bet.

  The technological and experimental context that had served him so well during his initial investigation into the mystery of air turned out to be poorly suited to fending off the attacks on phlogiston. Priestley was a qualitative scientist, not a quantitative one. He had access to miraculously precise scales that shaped so many of Lavoisier’s new chemistry, but rarely invoked measurements that exacting in his research. All the classic twists in Priestley’s natural philosophy are almost existential in nature: the plant lived; the mouse died; the flame went out. Lavoisier’s new chemistry, on the other hand, was the story of minutiae: this gas weighed a fraction of a gram less than this gas. Discovering that there was an air purer than pure air required the qualitative analytic skills—and improvisational style—that Priestley possessed in abundance. But defining the chemical composition of that air took a different toolkit, both mental and technological. In Kuhn’s language, Priestley’s skills were optimally suited for uncovering anomalies in the existing paradigm (to the extent that there was anything stable enough to be called a scientific paradigm). In this capacity, he was essential to the revolutionary science of the new chemistry, in that it was his inspired—and somewhat chaotic—explorations that first stumbled on the holes in the model, producing new facts the model couldn’t explain. But when it came time to actually build new explanations, to establish the rules of play for the new paradigm, Priestley’s approach ultimately undermined his efforts.