Rent is that portion of the produce of the earth which is paid to the landlord for the use of the original and indestructible powers of the soil. - David Ricardo

It has therefore been justly observed that however honestly the coin of a country may conform to its standard, money made of gold and silver is still liable to fluctuations in value, not only to accidental, and temporary, but to permanent and natural variations, in the same manner as other commodities.

Possessing utility, commodities derive their exchangeable value from two sources: from their scarcity, and from the quantity of labour required to obtain them.

Whenever the current of money is forcibly stopped, and when money is prevented from settling at its just level, there are no limits to the possible variations of the exchange.