The prefect holds out a large stack of printed paper bills. "I don't recognize this bank-note of yours. But there's a new design each time the printing house issues a new batch."

All right! Even though your money looks unfamiliar, the concept of paper money backed by the government is the same here in ancient China as it is back home. The prefect trusts that your money is good because he trusts the Emperor's bureaucracy.

Here money is a completely abstract idea and isn't tied to any real object of value.