Related Clues:

• It's dropped
• Trip need, perhaps
• Low pH
• '60s hallucinogen
• Trip cause
• Sulfuric or hydrochloric follower
• Type of rain
• Corrosive chemical
• See 48 Across
• Dr. Leary's drug
• Dropped stuff
• Take it for a trip
• Dropped hallucinogen
• Car battery component
• It was dropped in the 1960s