The Wealth of Nations by Part 1 Chapter 5 Page 36

upwards of L3 18s. sometimes L3 19s. and very frequently L4 an ounce; that sum, it is probable, in the worn and degraded gold coin, seldom containing more than an ounce of standard gold. Since the reformation of the gold coin, the market price of standard gold bullion seldom exceeds L3 17s. 7d. an ounce. Before the reformation of the gold coin, the market price was always more or less above the mint price. Since that reformation, the market price has been constantly below the mint price. But that market price is the same whether it is paid in gold or in silver coin. The late reformation of the gold coin, therefore, has raised not only the value of the gold coin, but likewise that of the silver coin in proportion to gold bullion, and probably, too, in proportion to all other commodities; through the price of the greater part of other commodities being