<p>Rolla N. Harger (January 14, 1887 – October 14, 1971) was an American chemist and inventor who is best known for the development of the Drunkometer, an early breathalyzer test for measuring blood alcohol content (BAC).</p><p></p><p>Harger received his Ph.D. in chemistry from the University of Chicago in 1915. After a brief stint in private industry, he joined the faculty of Indiana University, where he began working on the development of a tool to measure BAC. In 1931, he developed the Drunkometer, which used a person's breath to measure the amount of alcohol in their bloodstream.</p><p></p><p>The Drunkometer was the first device of its kind and quickly became widely used by law enforcement agencies to measure the BAC of suspected drunk drivers. It was a simple and reliable device that was easy to use and provided accurate results.</p><p></p><p>Harger's invention played a significant role in the fight against drunk driving and helped to raise awareness of the dangers of driving under the influence. The Drunkometer was used in court cases as evidence of a driver's BAC, and its use led to the conviction of many drunk drivers.</p><p></p><p>Harger continued to work on the development of breathalyzer devices throughout his career, and in 1951 he developed the Infrared Breathalyzer, which was even more accurate than the Drunkometer.</p><p></p><p>Harger received many awards and honors for his contributions to the field of chemistry and to the fight against drunk driving. He was inducted into the Indiana Academy of Science Hall of Fame in 1971 and was awarded the National Safety Council's Presidential Citation.</p><p></p><p>Rolla N. Harger's invention of the Drunkometer was a major milestone in the fight against drunk driving. His invention helped to raise awareness of the dangers of driving under the influence and provided law enforcement with a reliable tool to measure blood alcohol content. Harger's legacy continues to have a positive impact on road safety and his contribution to the field of chemistry is remarkable.</p><p></p><p></p>