Related Clues:

• Acid, in the 60's
• Battery contents
• With 44-Across, polluted precipitation
• Word with rock, rain or test
• Caustic liquid
• Limelike
• It sends people on trips
• Start of some trips
• Ill-natured
• Etching fluid
• Trip agent?
• One litmus test conclusion
• Caustic compound
• Start of a trip?
• Hydrofluoric ___