#The money-material in its commodity uses#.

We are now prepared to take up the question: What determines the ratio at which money exchanges for other goods?
And, as money comes to be the unit in which prices are generally expressed, the question becomes: What determines the general level of monetary prices?
We have this problem in its simplest form in the case of a commodity-money such as gold.

It may be looked upon merely as so much precious metal.

The problem of its value as bullion is the same as that of the value of pig iron or of zinc, of meat or of potatoes.

There is here no special monetary problem.
The value of gold as bullion and its value as money are kept in equilibrium by choice and by substitution.