All around us
As substances go, air is pretty forgettable. It’s invisible, omnipresent, our bodies draw it in automatically — and it’s criminally underappreciated, according to science writer Sam Kean. “The story of Earth is the story of its gases,” he writes in the introduction to “Caesar’s Last Breath: Decoding the Secrets of the Air Around Us.” He goes on, earnestly: “I hope this book compels you to revise your own mental picture of air, and I think your notion of air will indeed shift from chapter to chapter, leaving you with a more holistic view of it.”
A natural response to this might be mild skepticism: Why would anyone be so entirely gung-ho about air? But by the end of this delightful, deeply researched exploration, Kean’s assertions will seem justified — the book brims with such fascinating tales of chemical history that it’ll change the very way you think about breathing.
The stuff we inhale, it turns out, is surprisingly complex. Our atmosphere contains a host of gases with their own origin stories and singular quirks: Oxygen is “volatile, manic, a madman in most every chemical reaction,” while the noble gas argon is so unusually aloof — it reacts with hardly anything — that chemists eventually had to create a new column on the periodic table for it and its ilk. Other gases were instrumental in era-defining human inventions: the steam engine, gas lights, human flight. And that’s not even counting the three previous iterations of Earth’s atmosphere, formed by volcanoes belching up fumes and boiled off by massive asteroid impacts billions of years ago.
This is no dutiful review of scientific touchstones. Take this anecdote of an 18th century English scientist, Humphry Davy, trying out a fullbody “gas-immersion unit” with laughing gas: “Davy entered it half naked, a thermometer tucked in his armpit and a feather fan in his hand to stir the air aside. Over the course of seventy-five minutes an assistant released three hundred quarts of nitrous into the chamber . ... Moments later, [Davy] babbled, “Nothing exists but thoughts! The world is composed of impressions, ideas, pleasures and pains!” (Breathing in or even tasting new compounds to test them wasn’t unusual for scientists at the time, it seems. Most good chemists then, Kean writes, “had a little cowboy” in them.)
All of which is to say, the history of air is bonkers. Kean crams the book full of wild yarns told with humorously dramatic flair. Prostitutes get splashed with sulfuric acid! Countries go to war over bird poop! Peasants attack balloons with pitchforks and scythes! There are vignettes sandwiched between chapters; even the endnotes are a revelation. The effect is oddly intimate, the way all good storytelling is — you feel like you’re sharing moments of geeky amusement with a particularly hip chemistry teacher.
But beyond delight, there are cautionary tales. Kean closely chronicles his characters’ frailties and the way their work messily intertwined with history: Nobel Prize-winning chemist Fritz Haber was a “spiteful genius,” “ripe with talent and ambitious beyond all bounds of decency,” while his partner in science Carl Bosch “made the Nazi blitzkrieg possible” by cooperating with Hitler. One particular American, William Morton, was “a through and through scoundrel” who embezzled money, jilted his fiancees and helped make ether into one of the first anesthetics — for the cash. In every case, Kean takes the measure of the scientists’ accomplishments. “Almost everyone who got to know him regretted it,” Kean writes of Morton. But “in making anesthesia a medical reality, [he] did more to benefit humankind than almost anyone who ever lived.” These assessments are precise and educational, but such sweeping statements about a person’s worth to humanity can get discomfiting at times, too.
“Caesar’s Last Breath” isn’t just a book about air — it also takes on intriguing offshoots of gas research (nitroglycerin, chemical weapons) and related topics like flatulence (featured in a short but riotously funny interlude). Later chapters center on the atmosphere itself, including attempts in the 1940s to control weather. This shifting focus can make the book as a whole hard to grasp. Each separate tale is a treat, but it’s not quite clear how exactly it all fits together.
But one theme does unite the book: Kean’s deep-seated faith in the power of science. Near the end, he argues that the best way to deal with climate change is to get our brightest scientific minds to engineer a way out of the trouble. “Coming up with a technological fix for the problem,” he writes, “while not easy, exploits what humans do well — rally around a cause when things get desperate, then start building s—.” This book is a paean to that human ability to do just that, the dogged spirit of inquiry that prompted the freewheeling chemists of yore to huff mystery gases just to see what would happen.