gold-leaf

Gold-leaf should be carried in one's wallet alongside the mandatory collection of credit cards, for those opportune moments when you meet leading Neuro-Physicists on the Tube home, if they should proffer a wrap of finest-grade cocaine all swaddled in laboratory blotting paper, offer to exchange the blotter for your gold-leaf. He'll offer you some coke, you'll offer him some leaf, and everybody's day will be enhanced for the experience of a moment shared with strangers.