Rent, considered as the price paid for the use of land, is naturally the highest which the tenant can afford to pay in the actual circumstances of the land. In adjusting the terms of the lease, the landlord endeavours to leave him no greater share of the produce than what is sufficient to keep up the stock from which he furnishes the seed, pays the labour, and purchases and maintains the cattle and other instruments of husbandry, together with the ordinary profits of farming stock in the neighbourhood. This is evidently the smallest share with which the tenant can content himself, without being a loser, and the landlord seldom means to leave him any more. Whatever part of the produce, or, what is the same thing, whatever part of its price, is over and above this share, he naturally endeavours to reserve to himself as the rent of his land, which is evidently the highest the tenant can afford to pay in the actual circumstances of the land. Sometimes, indeed, the liberality, more frequently the ignorance, of the landlord, makes him accept of somewhat less than this portion; and sometimes, too, though more rarely, the ignorance of the tenant makes him undertake to pay somewhat more, or to content himself with somewhat less, than the ordinary profits of farming stock in the neighbourhood. This portion, however, may still be considered as the natural rent of land, or the rent at which it is naturally meant that land should, for the most part, be let.

The rent of land, it may be thought, is frequently no more than a reasonable profit or interest for the stock laid out by the landlord upon its improvement. This, no doubt, may be partly the case upon some occasions; for it can scarce ever be more than partly the case. The landlord demands a rent even for unimproved land, and the supposed interest or profit upon the expense of improvement is generally an addition to this original rent. Those improvements, besides, are not always made by the stock of the landlord, but sometimes by that of the tenant. When the lease comes to be renewed, however, the landlord commonly demands the same augmentation of rent as if they had been all made by his own.

He sometimes demands rent for what is altogether incapable of human improvements. Kelp is a species of sea-weed, which, when burnt, yields an alkaline salt, useful for making glass, soap, and for several other purposes. It grows in several parts of Great Britain, particularly in Scotland, upon such rocks only as lie within the high-water mark, which are twice every day covered with the sea, and of which the produce, therefore, was never augmented by human industry. The landlord, however, whose estate is bounded by a kelp shore of this kind, demands a rent for it as much as for his corn-fields.

The sea in the neighbourhood of the islands of Shetland is more than commonly abundant in fish, which makes a great part of the subsistence of their inhabitants. But, in order to profit by the produce of the water, they must have a habitation upon the neighbouring land. The rent of the landlord is in proportion, not to what the farmer can make by the land, but to what he can make both by the land and the water. It is partly paid in sea-fish; and one of the very few instances in which rent makes a part of the price of that commodity, is to be found in that country.

The rent of land, therefore, considered as the price paid for the use of the land, is naturally a monopoly price. It is not at all proportioned to what the landlord may have laid out upon the improvement of the land, or to what he can afford to take, but to what the farmer can afford to give.

Such parts only of the produce of land can commonly be brought to market, of which the ordinary price is sufficient to replace the stock which must be employed in bringing them thither, together with its ordinary profits. If the ordinary price is more than this, the surplus part of it will naturally go to the rent of the land. If it is not more, though the commodity may be brought to market, it can afford no rent to the landlord. Whether the price is, or is not more, depends upon the demand.

There are some parts of the produce of land, for which the demand must always be such as to afford a greater price than what is sufficient to bring them to market; and there are others for which it either may or may not be such as to afford this greater price. The former must always afford a rent to the landlord. The latter sometimes may and sometimes may not, according to different circumstances.

Rent, it is to be observed, therefore, enters into the composition of the price of commodities in a different way from wages and profit. High or low wages and profit are the causes of high or low price; high or low rent is the effect of it. It is because high or low wages and profit must be paid, in order to bring a particular commodity to market, that its price is high or low. But it is because its price is high or low, a great deal more, or very little more, or no more, than what is sufficient to pay those wages and profit, that it affords a high rent, or a low rent, or no rent at all.

The particular consideration, first, of those parts of the produce of land which always afford some rent; secondly, of those which sometimes may and sometimes may not afford rent; and, thirdly, of the variations which, in the different periods of improvement, naturally take place in the relative value of those two different sorts of rude produce, when compared both with one another and with manufactured commodities, will divide this chapter into three parts.