Exactly three hundred years ago, Paris was the centre of a radical fiscal experiment. The Scottish economist – or, perhaps more correctly, speculator – John Law had been given powers by the regent of the young Louis XV to create the first French national bank. He replaced specie with paper money and began issuing stock certificates for a state-sponsored endeavour that would become known as the Mississippi Company. Inflation soared and intoxicating, acquisitive chaos reigned on the rue Quincampoix, home of France’s brand-new stock exchange. As Joan DeJean puts it, ‘During the dot-com bubble, the NASDAQ index rose from 500 to just over 5,000, but that spectacular climb took place over [nine years] … In just five months, Law’s stock rose from 500 to over 10,000. The velocity of the original stock bubble made Parisians sick with investment fever.’ The word ‘millionaire’ was coined during this period to describe the happy investors in Law’s scheme. Needless to say, it all ended badly.