The Invention of Air

by Steven Johnson

  (FROM EARTH SYSTEM SCIENCE: AN OVERVIEW, NASA, 1988)

  Cultural systems, too—the natural history of good (and bad) ideas—require this kind of long thinking as well, from the neural networks of the human brain, to the biographical details of human lives, to the broad ebb and flow of social and physical energy in a changing society. The long zoom of culture looks something like this, moving from the very small to the very large:

  As in Earth System Science, each level operates at different time scales: biographical details of sibling rivalry or traumatic illnesses unfold on the scale of years or decades, while transformations in the flow of energy can take thousands (or millions) of years to play out. The economic base and the scientific paradigm figure prominently in this scheme, but neither has the primacy that Marx and Kuhn accorded to them. When something big happens in the culture—when a man in Leeds goes on a streak of pioneering natural philosophy; when several nations clustered together in a small subsection of the planet simultaneously reinvent science and government—that event is rarely the exclusive result of a single layer: one man’s genius, say, or the rise of a new economic class. Epic breakthroughs happen when the layers align: when energy flows and settlement patterns and scientific paradigms and individual human lives come into some kind of mutually reinforcing synchrony that helps the new ideas both emerge and circulate through the wider society.

  There is some poetry in approaching the mystery of Joseph Priestley’s streak from this ecosystems perspective, because the most groundbreaking and original idea that he had during this period now sits as one of the bedrock principles of twentieth-century ecosystem science. That is the beautiful thing about ideas: sometimes they generate clues that, centuries later, help you understand the mystery of their own origins. The mountain lifts you high enough that you can finally see the land masses that made the mountain in the first place.

  LONG ZOOM HISTORIES don’t dispense altogether with individual lives, of course, and in explaining Joseph Priestley’s streak, it’s best to start with one central biographical fact: he moved. In the summer of 1767, Joseph and Mary packed up their belongings at Warrington—the electrical kits and vials and growing library—so that Joseph could take up residence as minister to a congregation at Mill-Hill Chapel in Leeds. While the new job entailed preaching to a larger group of parishioners than in any of his previous positions, his daily obligations were far less imposing than they had been teaching at Warrington, requiring no more than an hour or two a day. With his wife running the household and tending to their four-year-old daughter, Sally, Priestley simply had more time on his hands to explore, invent, and write. Priestley was retracing a pattern that Franklin had originally carved two decades before, when he handed over day-to-day operation of his printing business to his foreman, David Hall, in 1748 and then spent the next three years transforming the science of electricity. Necessity may be the mother of invention, but most of the great inventors were blessed with something else: leisure time.

  The move also inspired Priestley in more random ways. When the Priestleys first arrived in Leeds, they discovered the official minister’s house on Bansinghall Street was still being renovated for them, and so they took up residence for a short while on Meadow Lane, in a house that happened to border on the public brewery of Jakes and Nell. Ever curious, Priestley quickly discovered that the vats of fermenting liquid emitted a steady supply of “fixed” or “mephitic” air—what we now call carbon dioxide. Fixed air had been discovered only a dozen years before by the Scottish chemist Joseph Black, who had been the first to propose that our atmosphere might in fact be a mixture of different elements, the poisonous “fixed” air intermingling with the common air that all animals require for respiration. Fixed air was almost as tantalizing a subject for inquiry as electricity in those days, and so within a matter of weeks, the puzzled workmen in the brewery were assisting the eccentric minister next door with a battery of experiments over the vats. Priestley discovered that pouring plain water back and forth between two cups while holding it over the vats suffused it with the fixed air after a short amount of time, adding an agreeable fizz that was reminiscent of certain rare mineral waters. In late September, he wrote a note to Canton describing his new fascination with mephitic air that included this aside: “By the way, I make most delightful Pyrmont Water , and can impregnate any water or wine &c. with that spirit in two minutes.” If he had only thought to add fruit juice to the mix, he might have invented the wine cooler as well.

  Priestley would refine his method in the coming years, and eventually mention his technique during a dinner party with the Duke of Northumberland in early 1772, suggesting—incorrectly as it turned out—that his seltzer water might prove a useful weapon in the British navy’s fight against scurvy. Within a matter of days, Priestley was presenting a statement to the Lord Commissioners of the Admiralty on behalf of his concoction. By the time Captain Cook’s vessels, the Resolution and the Adventure, set sail in June of 1772, they were equipped with soda-water machines manned by the watchful eye of the ships’ surgeons. Inspired by the beverage’s enthusiastic reception among the Admiralty, Priestley quickly published a pamphlet: Directions for impregnating water with fixed air, in order to communicate to it the peculiar spirit and virtues of Pyrmont water, and other mineral waters of a similar nature. Priestley’s discovery did nothing to fight scurvy, but it did create a taste for carbonation that would ultimately conquer the planet.

  Priestley later described his soda-water epiphany as his “happiest” discovery, while acknowledging it had little scientific value. But that chance encounter with the Jakes and Nell Brewery ultimately led to more substantive investigations as well: those fermenting vats with their invisible pool of mephitic air triggered in Priestley a new fascination with the mysteries of air itself, a fascination that would ultimately lead to the greatest discoveries of his career—along with his most vexing blunder. Had the renovations to the minister’s house on Bansinghall Street followed an accelerated timetable, it’s likely that Priestley would have never stumbled across his “delightful Pyrmont water”; without the brewery, it’s possible that Priestley wouldn’t have thrown himself into the study of gases that dominated the next decade of his research. We tend to talk about the history of ideas in terms of individual genius and broader cultural categories—the spirit of the age, the paradigm of research. But ideas happen in specific physical environments as well, environments that bring their own distinct pressures, opportunities, limitations, and happy accidents to the evolution of human understanding. Take Joseph Priestley out of Enlightenment culture, and deprive him of the scientific method, and his legendary streak no doubt disappears, or turns into something radically different. But take Priestley out of Meadow Lane, and deprive him of his hours at the brewery, and you would likely get a different story as well.

  Ideas are situated in another kind of environment as well: the information network. Theoretically, it is possible to imagine good ideas happening in a vacuum—a lone Inuit scientist conjuring up breathtaking discoveries in his igloo, and then keeping them to himself. (Mendel’s pea-pod experiments were not that far from this model.) But most important ideas enter the pantheon because they circulate. And the flow is two-way: the ideas happen in the first place because they are triggered by other people’s ideas. The whole notion of intellectual circulation or flow is embedded in the word “influence” itself (“to flow into,” influere in the original Latin). Good ideas influence, and are themselves influenced by, other ideas. They flow into each other. Different societies at different moments in history have varying patterns of circulation: compare the cloistered, stagnant information pools of the European Dark Ages to the hyper-linked, open-sourced connectivity of the Internet.

  You can see in Priestley’s letters to the electricians where he and his friends fell on the circulation spectrum: every detail of every experiment relayed in the most generous, exhaustive form imaginable. The idea of proprietary secrets, of withholding information f
or personal gain, was unimaginable in that group. Think of the untold trillions of dollars that have been generated by the invention of soda water, and yet Priestley happily revealed his formula in letters, pamphlets, and dinner party chatter to anyone who would listen. This meant that he failed to realize the commercial potential of his invention, a decision that would have lifelong repercussions for him, in that Priestley would remain, in one fashion or another, dependent on the financial patronage of other people. (A certain Johann Schweppes fared better in this regard, patenting a method of carbonating water in 1783; his namesake still enlivens gin-and-tonics to this day.) But Priestley was a compulsive sharer, and the emphasis on openness and general circulation is as consistent a theme as any in his work. The whole genesis of The History had been to inspire new research by conveying the current state of play in intelligible and comprehensive detail. No doubt Priestley saw farther because he stood on the shoulders of giants, but he had another crucial asset: he had a reliable postal service that let him share his ideas with giants. That reliability had its limits, however. Information networks are shaped not only by their speed and connectivity but also by their security. At three points in Priestley’s life, crucial events would unfold precisely because a letter or batch of letters had been stolen or had somehow fallen into the wrong hands—a plot twist that recurs through the epistolary novels of the period. It’s not simply the speed of information that shapes the flow of ideas in a given society, it’s also how vulnerable that information is to attack or misappropriation.

  Thinking about Priestley’s streak in the context of information networks takes us all the way back to that fateful meeting at the London Coffee House. The open circulation of ideas was practically the founding credo of the Club of Honest Whigs, and of eighteenth-century coffeehouse culture in general. With the university system languishing amid archaic traditions, and corporate R&D labs still on the distant horizon, the public space of the coffeehouse served as the central hub of innovation in British society. How much of the Enlightenment do we owe to coffee? Most of the epic developments in England between 1650 and 1800 that still warrant a mention in the history textbooks have a coffeehouse lurking at some crucial juncture in their story. The restoration of Charles II, Newton’s theory of gravity, the South Sea Bubble—they all came about, in part, because England had developed a taste for coffee, and a fondness for the kind of informal networking and shoptalk that the coffeehouse enabled. Lloyd’s of London was once just Edward Lloyd’s coffeehouse, until the shipowners and merchants started clustering there, and collectively invented the modern insurance company. You can’t underestimate the impact that the Club of Honest Whigs had on Priestley’s subsequent streak, precisely because he was able to plug in to an existing network of relationships and collaborations that the coffeehouse environment facilitated. Not just because there were learned men of science sitting around the table—more formal institutions like the Royal Society supplied comparable gatherings—but also because the coffeehouse culture was cross-disciplinary by nature, the conversations freely roaming from electricity, to the abuses of Parliament, to the fate of dissenting churches.

  The rise of coffeehouse culture influenced more than just the information networks of the Enlightenment; it also transformed the neurochemical networks in the brains of all those newfound coffee-drinkers. Coffee is a stimulant that has been clinically proven to improve cognitive function—particularly for memory-related tasks—during the first cup or two. Increase the amount of “smart” drugs flowing through individual brains, and the collective intelligence of the culture will become smarter, if enough people get hooked. Create enough caffeine-abusers in your society and you’ll be statistically more likely to launch an Age of Reason. That may itself sound like the self-justifying fantasy of a longtime coffee-drinker, but to connect coffee plausibly to the Age of Enlightenment you have to consider the context of recreational drug abuse in seventeenth-century Europe. Coffee-drinkers are not necessarily smarter, in the long run, than those who abstain from caffeine. (Even if they are smarter for that first cup.) But when coffee originally arrived as a mass phenomenon in the mid- 1600s, it was not seducing a culture of perfect sobriety. It was replacing alcohol as the daytime drug of choice. The historian Tom Standage writes in his ingenious A History of the World in Six Glasses:

  The impact of the introduction of coffee into Europe during the seventeenth century was particularly noticeable since the most common beverages of the time, even at breakfast, were weak “small beer” and wine. . . . Those who drank coffee instead of alcohol began the day alert and stimulated, rather than relaxed and mildly inebriated, and the quality and quantity of their work improved. . . . Western Europe began to emerge from an alcoholic haze that had lasted for centuries.

  Emerging from that centuries-long bender, armed with a belief in the scientific method and the conviction, inherited from Newtonian physics, that simple laws could be unearthed beneath complex behavior, the networked, caffeinated minds of the eighteenth century found themselves in a universe that was ripe for discovery. The everyday world was teeming with mysterious phenomena—air, fire, animals, plants, rocks, weather—that had never before been probed with the conceptual tools of the scientific method. This sense of terra incognita also helps explain why Priestley could be so innovative in so many different disciplines, and why Enlightenment culture in general spawned so many distinct paradigm shifts. Amateur dabblers could make transformative scientific discoveries because the history of each field was an embarrassing lineage of conjecture and superstition. Every discipline was suddenly new again. Priestley said it best in the introduction to his History:

  In electricity, in particular, there is a greatest room to make new discoveries. It is a field but just opened, and requires no great slock of particular preparatory knowledge; so that any person who is tolerably well versed in experimental philosophy may presently be upon a level with the most experienced electricians.

  If Priestley and his comrades unearthed an amazing trove of scientific treasure during these exceptional decades, it was at least in part because the soil was so shallow.

  But to speak of soil in this context is to mix elemental metaphors. Priestley’s two great discoveries from this period were made of air, not earth. One of them—by far the more celebrated of the two—revolutionized chemistry, though Priestley blundered spectacularly in interpreting his findings. But the other one he got right.

  PRIESTLEY’S TOOLS

  CHAPTER TWO

  Rose and Nightshade

  August 1771

  Leeds

  IT ARRIVED THE WAY SO MANY GOOD IDEAS DO, through a brilliant mistake.

  As a child growing up in rural Yorkshire, Priestley had amused himself with the slightly sadistic pastime of trapping spiders in sealed glass jars and observing how long it would take the poor creatures to perish. This hobby made such an impression on Priestley’s brother Timothy that he mentioned it prominently in his funeral oration for Joseph, as evidence of his eleven-year-old brother’s early aptitude for science. The fact that organisms would invariably expire given a finite supply of air was well known to little boys and scientists alike. But the mechanism behind this process was a mystery. Did the creatures somehow exhaust the air they were breathing—in which case, what was left in the jar? Or were they poisoning their environment with some invisible substance they released? Or was some other factor at work? Strangely, the air in the jar didn’t visibly change after the animal’s final convulsions, though it did have one distinct, and puzzling, new attribute: a lit candle would invariably flicker and die in it.

  The Priestleys had finally moved into the minister’s house at Bansinghall Street, where Joseph set up a home laboratory that borrowed quite a bit of its essential gear from Mary Priestley’s kitchen. Even at Bansinghall Street, beer continued to play an amusing side role in Priestley’s research: the mice and frogs he sacrificed in the name of science were often housed in beer glasses that he had pilfered from Mary’s cabine
ts. The most important contraption in his laboratory was the “pneumatic trough”—a device for capturing and manipulating gases first developed by Stephen Hayles fifty years before. Priestley’s first trough was Mary’s laundry sink, though his accelerating research and their growing family would soon necessitate that Priestley construct his own pneumatic troughs, custom designed for his research needs. Priestley tinkered with the design of the trough constantly, but ultimately settled on a rectangular wooden box, two feet long and nine inches deep. At one end of the trough, he built a shelf, with “orifices” cut into it large enough to admit a small tube. Priestley would fill the trough with water—or, if he was working with water-soluble gases, with mercury. With the levels of water or mercury kept just above the shelf, Priestley could place his glass vessels on the shelf and conduct an amazing variety of experiments on the air they contained. The key to the trough was that the water on the bottom of the vessel at once sealed the gas, but at the same time was permeable enough to allow Priestley to insert things into the vessel. He could generate a gas in another container, and then pump it into the vessel on the shelf; or incinerate a material contained in the vessel by using a “burning lens,” which concentrated the sun’s rays enough to set fire to most flammable substances. For the many experiments that involved putting a live mouse into a sealed container, he grabbed the mouse by the neck, swiftly passed the creature through the water into the container, and placed them on the shelf.