then be paid for the second 1000 l. and will be equal to the difference between the produce of these two, or ten quarters; and at the same time the rent of the first 1000 l. will rise from fifteen to twenty-five quarters; while the last 1000 l. will pay no rent whatever.
If then good land existed in a quantity much more abundant than the production of food for an increasing population required, or if capital could be indefinitely employed without a diminished return on the old land, there could be no rise of rent; for rent invariably proceeds from the employment of an additional quantity of labour with a proportionally less return.
The most fertile, and most favourably situated land will be first cultivated, and the exchangeable value of its produce will be adjusted in the same manner as the exchangeable value of all other commodities, by the total quantity of labour necessary in various forms, from first to last, to produce it, and bring it to market. When land of an inferior quality is taken into cultivation, the exchangeable value of raw produce will rise, because more labour is required to produce it.