The real price of manufactures, the quantity of labour and
capital necessary to produce a given quantity of them, is almost
constantly diminishing; while the quantity of labour and capital,
necessary to procure the last addition that has been made to the
raw produce of a rich and advancing country, is almost constantly
increasing. We see in consequence, that in spite of continued
improvements in agriculture, the money price of corn is ceteris
paribus the highest in the richest countries, while in spite of
this high price of corn, and consequent high price of labour, the
money price of manufactures still continues lower than in poorer
countries.

I cannot then agree with Adam Smith, in thinking that the low
value of gold and silver is no proof of the wealth and
flourishing state of the country, where it takes place. Nothing
of course can be inferred from it, taken absolutely, except the
abundance of the mines; but taken relatively, or in comparison
with the state of other countries, much may be inferred from it.
If we are to measure the value of the precious metals in
different countries, and at different periods in the same
country, by the price of corn and labour, which appears to me to
be the nearest practical approximation that can be adopted (and
in fact corn is the measure used by Adam Smith himself), it
appears to me to follow, that in countries which have a frequent
commercial intercourse with each other, which are nearly at the
same distance from the mines, and are not essentially different
in soil; there is no more certain sign, or more necessary
consequence of superiority of wealth, than the low value of the
precious metals, or the high price of raw produce.(15)