Possible Clues:

• Bitter bread possibly English, I'm not sure Napoleon eating it
• Some dough, but not much
• Extra cash for nonessentials
• A little extra for personal spending
• Jingle in the pocket ready for spending at the pub
• Bitter dough?
• Worker, male one employed by railway, ready for a pint
• One could get bitter, having this small gratuity
• Drinks change, perhaps