Yes, but also more generally, highly-liquid IOUs ("bills of exchange") as were widely used before the rise of modern banking: http://jpkoning.blogspot.de/2013/

Yes, but also more generally, highly-liquid IOUs ("bills of exchange") as were widely used before the rise of modern banking: http://jpkoning.blogspot.de/2013/02/ripple-or-bills-of-exchange-20.html http://jpkoning.blogspot.de/2013/02/ripple-or-bills-of-excha...