The ancient Romans used a chemical called ammonia (derived from urine) and fuller's earth (a clay that can absorb grease & oil) to clean their woolen togas. Early dry cleaners used petroleum-based solvents, such as gasoline & kerosene. Fire concerns led William Joseph Stoddard, a dry cleaner from Atlanta, to develop Stoddard solvent as a less flammable alternative to gasoline-based solvents. After World War I, dry cleaners began using chlorinated solvents, which were much less flammable and h