Before there was a Breathalyzer, there was a Drunkometer.
The Drunkometer was invented by Dr. Rolla N. Harger, an Indiana University biochemist, in 1931 and was patented in 1936.
The Drunkometer was the first tool to successfully measure alcohol levels using breath analysis. The subject being tested blew into a balloon. The captured air was then mixed with a chemical solution, which changed color if alcohol was present. The darker the solution became, the more alcohol was present in the breath.
In 1938 Dr. Harger was one of five members on a subcommittee of the National Safety Council that drafted a model act to legalize the use of evidence from chemical tests for intoxication and to set limits of body alcohol concentration for motorists. The act was incorporated into drunken driving laws nationwide.
Photograph courtesy of Hennepin County Library