Possible Clues:

• Mixture that dissolves gold
• It dissolves metals for example, in tanks for school
• Corrosive mixture, say, stored in tanks
• It can dissolve metal as used in many tanks
• Both sides leave a quarrel with soldier, a catalyst of Golden Dissolution?
• Nitrohydrochloric acid dissolving gold
• Liquid with bite? Nearly a half-gallon I in time knocked back