It’s Saint Patrick’s Day. Let’s dye stuff

Chemistry runs through it If you’ve even been to the Saint Patrick’s Day parade in downtown Chicago, you’ve witnessed to a colorful tradition, bigger even than the whole green beer thing. On the morning of the parade, members of the Chicago Journeymen Plumbers Local 130 of the United Association union make the Chicago River go green. The tradition of dyeing the river for Saint Patrick’s Day goes back to 1962 . According to union lore, the bright-green hue was inspired by an accident: Plumbers have historically used dyes to detect water leaks. A plumber working with a dye spilled it on his white overalls, causing them to turn “Irish green.” The union’s business manager, Stephen Bailey, saw the results and asked about the color. When the plumber explained, Bailey made the logical next step—he called the mayor of Chicago and proposed dyeing the Chicago River green for Saint Patrick’s Day.