Page:Principles of Political Economy Vol 1.djvu/57

Rh there is more than can be used by the existing population of the country, or by any accession likely to be made to it for generations to come. But even there, land favourably situated with regard to markets or means of carriage, is generally limited in quantity: there is not so much of it as persons would gladly occupy and cultivate, or otherwise turn to use. In all old countries, land capable of cultivation, land at least of any tolerable fertility, must be ranked among agents limited in quantity. Water, for ordinary purposes, on the banks of rivers or lakes, may be regarded as of unlimited abundance; but if required for irrigation, it may even there be insufficient to supply all wants, while in places which depend for their consumption on cisterns or tanks, or on wells which are not copious, or are liable to fail, water takes its place among things the quantity of which is most strictly limited. Where water itself is plentiful, yet water-power, i.e. a fall of water applicable by its mechanical force to the service of industry, may be exceedingly limited, compared with the use which would be made of it if it were more abundant. Coal, metallic ores, and other useful substances found in the earth, are still more limited than land. They are not only strictly local but exhaustible; though, at a given place and time, they may exist in much greater abundance than would be applied to present use even if they could be obtained gratis. Fisheries, in the sea, are in most cases a gift of nature practically unlimited in amount; but the Arctic whale fisheries have long been insufficient for the demand which exists even at the very considerable price necessary to defray the cost of appropriation: and the immense extension which the Southern fisheries have in consequence assumed, is tending to exhaust them likewise. River fisheries are a natural resource of a very limited character, and would be rapidly exhausted, if allowed to be used by every one without restraint. Air, even that state of it which we term wind, may, in most situations, be obtained in a quantity sufficient for every possible use; and so