The word pound, for instance, was the money-name given to an actual pound weight of silver. As soon as gold had driven out silver as a measure of value, the same name became attached to, say, one fifteenth of a pound of gold, depending on the ratio between the values of gold and silver. Pound as a money-name and pound as the ordinary weight-name of gold are now two different things.

he’s illustrating that, in non-fiat currencies, the name of a certain quantity of money does not necessarily correlate to the actual money commodity