The Wealth of Nations by Part 4 Chapter 6 Page 22

coiners, both at home and abroad, might be encouraged, by the great difference between the value of bullion and that of coin, to pour in so great a quantity of counterfeit money as might reduce the value of the government money. In France, however, though the seignorage is eight per cent, no sensible inconveniency of this kind is found to arise from it.

The dangers to which a false coiner is everywhere exposed, if he lives in the country of which he counterfeits the coin, and to which his agents or correspondents are exposed if he lives in a foreign country, are by far too great to be incurred for the sake of a profit of six or seven per cent.

The seignorage in France raises the value of the coin higher than in proportion to the quantity of pure gold which it contains.