The Wealth of Nations by Part 1 Chapter 5 Page 41

is not very probable that a like reformation will do so now.

Were the silver coin brought back as near to its standard weight as the gold, a guinea, it is probable, would, according to the present proportion, exchange for more silver in coin than it would purchase in bullion. The silver coin containing its full standard weight, there would in this case be a profit in melting it down, in order, first, to sell the bullion for gold coin, and afterwards to exchange this gold coin for silver coin to be melted down in the same manner.

Some alteration in the present proportion seems to be the only method of preventing this inconveniency.

The inconveniency perhaps would be less if silver was rated in the coin as much above its proper proportion to gold as it is