Father of the ecosystem

In "The Invention of Air," Steven Johnson creates a fascinating portrait of Joseph Priestley, a friend of Franklin and Jefferson and a freethinker who changed history.

By Andrew O'Hehir

Read more: Andrew O'Hehir, Books, Science, History, Reviews, Book reviews

Salon composite

Left to right: Benjamin Franklin, Joseph Priestley and Thomas Jefferson

Jan. 9, 2009 | Steven Johnson is that rarest of commodities among 21st century public intellectuals: a progressive -- both in the old-fashioned sense and the synonym-for-liberal sense -- and an optimist. A Web entrepreneur who founded the sites Feed, Plastic and outside.in, and also the author of a book arguing that video games and reality TV are actually making kids smarter ("Everything Bad Is Good for You"), Johnson has sometimes been branded a techno-utopian. But he has none of the dogmatic, self-satisfied certainty that distinguished, say, the pages of Wired magazine during its late-'90s apogee. His is a questing, limber intelligence, eager to consider opposing arguments, explore new terrain and notice underlying patterns he hasn't seen before. I don't know whether it was God or video games that made him so smart, but something did. (I should add here that Johnson has written for Salon and I've exchanged e-mails with him. Beyond that, I don't know him personally.)

As Johnson's new book about 18th-century scientist and freethinker Joseph Priestley, "The Invention of Air," makes clear, Johnson's fascination with the currents of technological and cognitive change is in no way restricted to the computer age. He would certainly agree that the Internet is only a modern manifestation of a primordial human, planetary and indeed cosmological tendency to create information-exchange networks. Johnson clearly identifies a kindred spirit in Priestley, an amateur tinkerer with no formal scientific training who made several important chemical and atmospheric discoveries and also left his mark on Christian theology and revolutionary politics.

If you look up Priestley on Wikipedia right now, you'll learn that he was the discoverer of oxygen, a confidant of Benjamin Franklin, Thomas Jefferson and John Adams, and a foundational figure in the Unitarian religious movement. Johnson's book throws a certain amount of cold water on the oxygen claim, but more important, Johnson sees all of that as secondary to Priestley's greatest accomplishment, a paradigm-changing discovery that neither he nor anyone else in the 18th century was entirely equipped to understand.

Viewed as a modern-day acolyte of Priestley, Johnson no longer seems like such an anomalous figure. At times in "The Invention of Air," you can feel Johnson positively yearning for the prodigious intellectual ferment of England in the 1760s and '70s, when "natural philosophers" like Priestley and his good friend Franklin made explosive advances in all sorts of apparently unrelated fields, with no regard for disciplinary boundaries or established orthodoxy. Not merely were they unlocking the secrets of such mystifying phenomena as oxygen or electricity, they were pioneers in democratic discourse and what we would now call the "open source" model for disseminating and refining ideas. By publishing their ideas in vernacular language aimed at an educated lay readership, they sparked widespread popular interest in science. (Isaac Newton, like other scientists of his time, had written mainly in Latin.)

"The Invention of Air" is a slender, deceptively casual book, easy and indeed delightful to read. But it aims high. It isn't a work of conventional history or biography, though it contains snippets of both, but more like a case study in the history of ideas that hints at a grander analytical theory. Johnson is a wide-ranging enthusiast with a catholic appetite for intriguing facts and a Marxian appetite for searching for structures that underlie social phenomena. This book is full of fascinating asides about the relationship between northern England's coal-based economy, the Industrial Revolution and the culture of scientific inquiry they bred; or about the way London's cultural economy suddenly exploded when coffee replaced beer as the gentleman's beverage of choice.

As for Johnson's title, it's more than a little mysterious at first. Whether or not Priestley discovered oxygen, he certainly didn't invent air. As Johnson recounts in exciting detail, Priestley conducted a series of experiments in his home-built laboratory in Leeds, beginning in the spring of 1771, that started from the well-known fact that animals would die rapidly if sealed in a glass vessel without fresh air. Amazing as this may seem today, nobody understood how or why this happened. Air wasn't merely misunderstood, it wasn't even considered. As Johnson puts it, air was the nothingness between objects; it posed no problems that needed solving. When Priestley tried to grow sprigs of mint in sealed containers of "foul air" in which experimental mice had perished, he expected them to wither quickly. He was startled to learn that they thrived, and even more startled to learn that over time they somehow created "restored air" that his mice could breathe happily.

That round of experiments produced another, more famous round a few years later, the one that put Priestley in the history books. Using a huge magnifying glass an aristocratic patron had purchased for him, Priestley vaporized a kind of ash called mercury calx and produced a mysterious gas that made candle flames flare up and kept mice alive half an hour or longer in a sealed container. But as Johnson puts it, discovering oxygen is something like discovering America; it's largely a question of your perspective and your values. Danish chemist Carl Scheele had actually isolated oxygen a few years before Priestley, and a few years later Antoine Lavoisier would reach a far more accurate understanding of the gas and its properties -- and give it its scientific name.

Priestley, in fact, never grasped oxygen's role in combustion, and continued to cling to the post-medieval notion that burning materials emitted a substance called phlogiston, which was absorbed by the air and made it poisonous. His delicious term for the gas he had discovered was "dephlogisticated air," reflecting his upside-down conception of the relationship between air and candle flame. At best, Priestley was among a trio of researchers who grappled with the same scientific breakthrough in the 1770s, and he understood it far more poorly than the other two. But if Priestley is somewhat overvalued as the discoverer of oxygen, in Johnson's view, he was way ahead of his time with his earlier discovery.

Next page: Demonized as a heretic and a spy