The above post reminded me of the Spanish being accused of using "Poison Bullets" in Cuba during the Spanish American War. The 11mm ammunition being used by the Spanish had brass projectiles and in the humid climate, with the ammunition in leather cartridge boxes and belts, they very quickly turned green with verdigris. The American newspapers, not to miss an opportunity, quickly claimed the bullets had been intentionally covered with poison to kill the American solders with even a slight wound!
J.