Skip to content

Book Review: Caesar's Last Breath by Sam Kean

Sam Kean’s Caesar’s Last Breath is a gas. It’s about gas, too. The title is based on the old idea that every breath you take contains some of the air that Caesar exhaled upon his death.
Steven McCreedy
Steven McCreedy was born in Richmond. He is a library technician at the Cambie branch of the Richmond Public Library and received his diploma from Langara College in 2008. He particularly enjoys reading sci-fi and non-fiction.

Sam Kean’s Caesar’s Last Breath is a gas.  It’s about gas, too.

The title is based on the old idea that every breath you take contains some of the air that Caesar exhaled upon his death.  Seems ridiculous that 2000 years later this could still be possible, but Sam Kean explains quite well how this really works. 

Basically, atoms are really small, and breath, being just air, flows quickly and is easily spread around and diffused.  So, over a surprisingly short amount of time, the billons and billons of atoms that flow with every breath reaches every corner of the Earth.  Some of them escape into space, some combine into other molecules, but most just stay in the air.  We don’t just breathe Caesar’s last breath, we breathe everybody’s breath, all the time.

Over the course of Caesar’s Last Breath, Kean walks us through the history of humankind’s gradual discoveries about the air around us: how it moves, what’s in it, how we interact with it. We learn of the first lighter than air balloons by the Montgolfier brothers (and how Parisian peasants attacked one when it landed thinking it was a monster).  We see how the US military made efforts to create weather control (with little success). Throughout, we are treated to vignettes and anecdotes from the lives of the scientists and inventors who worked with air and air pressure.

Anyone who has even a passing interest in science will enjoy this; it’s accessible and you don’t really need any background to understand what’s going on. Seriously, it’s not a bunch of hot air. 

Sam Kean has a knack for making these topics more fun than you might expect: Kean has previously written similarly interesting looks at genetics (The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of the Elements)  and genetics (The Violinist's Thumb: and Other Lost Tales of Love, War, and Genius, as Written by Our Genetic Code).  Both of these titles are well worth a look too. 

Steven is a Library Technician II at the Cambie Branch.