The Invention of Air: A Story of Science, Faith, Revolution, and the Birth of America
by Steven Johnson
(Riverhead, 254 pages, $25.95)

Air was nothing to scientists of the early Enlightenment, says author Steven Johnson. A mere century before the English tinkerer Joseph Priestley is said to have discovered oxygen, in the 1770s, air was just the absence between the things worth studying. So when Priestley wrote to his friend Benjamin Franklin about how startled he was to discover that a mint plant left under glass “restored” a candle’s ability to briefly burn inside the jar, he lacked the intellectual framework necessary to make sense of what he’d observed. Franklin instantly intuited larger implications, though. The rehabilitation of the air inside the jar, he wrote to Priestley, seemed “of a piece” with the way water on the Earth’s surface rises as vapor and falls as rain. All life, in short, was sustained by a closed system.

Restoring Priestley to historical prominence may be Johnson’s most straightforward ambition in his trim but wide-ranging new book, said Troy Jollimore in the San Francisco Chronicle. Besides being a “spectacularly productive” writer and kitchen-sink experimenter, Priestley was a freethinking theologian who helped found the Unitarian Church and inspired a famous epistolary debate between his friend Thomas Jefferson and a more skeptical John Adams. Johnson’s bigger subject, though, is how scientific breakthroughs happen and how the resulting insights bleed back into the larger culture, said Alexandra Witze in The Dallas Morning News. The heart of the story is “how ideas flow within an information network, be it the Internet or the salons of 18th-century England.” In the salons, Priestley was everybody’s friend, a “key node” in a fertile network.

Johnson’s passion for the connection between ideas sometimes becomes “less enlightening than annoying,” said Barry Gewen in The New York Times. His latest work can even feel like “a book-length game of Six Degrees of Kevin Bacon, in which everything that ever was and will be is linked to everything else.” Johnson’s under no obligation, though, to write a standard biography of his protagonist, said Andrew O’Hehir in Readers turn to this author because he can be “infectiously exciting” when dramatizing a moment in which a major intellectual paradigm shift occurs. It helps that he, like Priestley, is an instinctive optimist about the long course of human history.