to defray the expense of working, could be brought from the mine by the ordinary, or even less than the ordinary quantity of labour; but in an inland country, thinly inhabited, and without either good roads or water-carriage, this quantity could not be sold." The whole principle of rent is here admirably and perspicuously explained, but every word is as applicable to land as it is to mines; yet he affirms that "it is otherwise in estates above ground. The proportion, both of their produce and of their rent, is in proportion to their absolute, and not to their relative fertility." But suppose that there were no land which did not afford a rent; then, the amount of rent on the worst land would be in proportion to the excess of the value of the produce above the expenditure of capital and the ordinary profits of stock: the same principle would govern the rent of land of a somewhat better quality, or more favourably situated, and therefore the rent of this land would exceed the rent of that inferior to it, by the superior advantages which it possessed; the same might be said of that of the third quality, and so on to the very best. Is it not then as certain that it is the relative fertility of the land which determines the portion of the produce which shall be paid for the rent of land, as it is that the relative fertility of mines determines the portion of their produce, which shall be paid for the rent of mines?
After Adam Smith has declared that there are some mines which can only be worked by the owners, as they will afford only sufficient to defray the expense of working, together with the ordinary profits of the capital employed, we should expect that he would admit that it was these particular mines which regulated the price of the produce. If the old mines are insufficient to supply the quantity of coal required, the price of coal will rise, and will continue rising till the owner of a new and inferior mine finds that he can obtain the usual profits of stock by working his mine. If his mine be tolerably fertile, the rise will not be great before it becomes his interest so to employ his capital; but if it be less productive, it is evident that the price must continue to rise till it will afford him the