Just came across this and I thought some people here might enjoy it.
"How the Great Kaan Causeth the Bark of Trees, Made Into Something Like Paper, to Pass for Money All Over his Country"http://en.wikisource.org/wiki/The_Travels_of_Marco_Polo/Book_2/Chapter_24It's Marco Polo trying to explain paper money to contemporary Europeans.
Here are some of my favorite excerpts:
The Emperor's Mint then is in this same City of Cambaluc, and the way it is wrought is such that you might say he hath the Secret of Alchemy in perfection, and you would be right!
Fiat money is "alchemy in perfection"!
And the Kaan causes every year to be made such a vast quantity of this money, which costs him nothing, that it must equal in amount all the treasure in the world.
And the Great Ben causes every year to be made such a vast quantity of this money ...
And all the while they are so light that ten bezants' worth does not weigh one golden bezant.
How convenient!
Now you have heard the ways and means whereby the Great Kaan may have, and in fact has, more treasure than all the Kings in the World; and you know all about it and the reason why.
And the idea caught on!