On September 10, 1897, a London cabdriver named George Smith slams his taxi into a building and is the first person to be arrested for drunk driving. He pled guilty and was fined 25 shillings.
Police officers knew that Smith was drunk because he acted drunk (he had driven that cab into a wall, after all) and because he said he was, but what they lacked was a scientific way to prove someone was too intoxicated to drive, even if he or she wouldn't admit it. Blood tests were soon introduced, but those were messy and needed to be performed by a doctor; there were urine tests, but those were even messier, not to mention unreliable and expensive. In 1931, a toxicologist at Indiana University named Rolla Harger came up with a solution--a device he called the Drunkometer. It was simple: all the suspected drinker had to do was blow into a balloon. The tester then attached the balloon to a tube filled with a purple fluid (potassium permanganate and sulfuric acid) and released its air into the tube. Alcohol on a person's breath changed the color of the fluid from purple to yellow; the quicker the change, the drunker the person.
The Drunkometer was effective but cumbersome, and it required a certain amount of scientific calculation to determine just how much alcohol a person had consumed. In 1954, another Indianan named Robert Borkenstein invented a device that was more portable and easier to use. Borkenstein's machine, the Breathalyzer, worked much like Harger's did--it measured the amount of alcohol in a person's breath--but it did the necessary calculations automatically and thus could not be foiled or tampered with. (One tipsy Canadian famously ate his underwear while waiting to take a Breathalyzer test because he believed that the cotton would somehow absorb the alcohol in his system. It did not.) The Breathalyzer soon became standard equipment in every police car in the nation.
Even in the age of the Breathalyzer, drunk driving remained a problem. In 2007, more than 1.4 million drivers were arrested for driving while intoxicated, and a Centers for Disease Control survey found that Americans drove drunk 159 million times. That same year, about 13,000 people--more than 30 percent of all traffic fatalities--died in accidents involving a drunk driver.