Page:The wealth of nations, volume 1.djvu/337

 the command of a quantity equal to what £88 17s. 9⅓d. would purchase. What occasioned the extravagance of those high prices was, not so much the abundance of silver, as the abundance of labor and subsistence, of which those Romans had the disposal, beyond what was necessary for their own use. The quantity of silver, of which they had the disposal, was a good deal less than what the command of the same quantity of labor and subsistence would have procured to them in the present times.

The second sort of rude produce of which the price rises in the progress of improvement, is that which human industry can multiply in proportion to the demand. It consists in those useful plants and animals, which, in uncultivated countries, nature produces with such profuse abundance, that they are of little or no value, and which, as cultivation advances, are therefore forced to give place to some more profitable produce. During a long period in the progress of improvement, the quantity of these is continually diminishing, while at the same time the demand for them is continually increasing. Their real value, therefore, the real quantity of labor, which they will purchase or command, gradually rises, till at last it gets so high as to render them as profitable a produce as anything else which human industry can raise upon the most fertile and best cultivated land. When it has got so high it cannot well go higher. If it did, more land and more industry would soon be employed to increase their quantity.

When the price of cattle, for example, rises so high that it is as profitable to cultivate land in order to raise food for them, as in order to raise food for man, it cannot well go