The Wealth of Nations by Part 4 Chapter 3 Page 29

(when made in foreign coin, of which the fineness is well known and ascertained, such as Mexico dollars), is twenty-two guilders the mark; the mint price is about twenty-three guilders, and the market price is from twenty-three guilders six to twenty-three guilders sixteen stivers, or from two to three per cent above the mint price.* The proportions between the bank price, the mint price, and the market price of gold bullion are nearly the same. A person can generally sell his receipt for the difference between the mint price of bullion and the market price.

A receipt for bullion is almost always worth something, and it very seldom happens, therefore, that anybody suffers his receipt to expire, or allows his bullion to fall to the bank at the price at which it had been received, either by not taking it out