I approach the group and say "Everyone calm down! That gold was enchanted to instill rage in anyone nearby." Once the half-elf finishes healing him, I ask the man "Where did you get that gold? Were you the one who enchanted it?" In response to the soldier's question, I say "There is something I can try, but I'm not sure that it will affect everyone." I direct a spell of cleansing at the tavern, attempting to clear away the negative emotions and clam the patrons.