Page:The wealth of nations, volume 1.djvu/279

 exchange for a greater and a greater quantity of food, or, in other words, should gradually become dearer and dearer. This, accordingly, has been the case with most of these things upon most occasions, and would have been the case with all of them upon all occasions, if particular accidents had not upon some occasions increased the supply of some of them in a still greater proportion than the demand.

The value of a freestone quarry, for example, will necessarily increase with the increasing improvement and population of the country round about it; especially if it should be the only one in the neighborhood. But the value of a silver mine, even though there should not be another within a thousand miles of it, will not necessarily increase with the improvement of the country in which it is situated. The market for the produce of a freestone quarry can seldom extend more than a few miles round about it, and the demand must generally be in proportion to the improvement and population of that small district. But the market for the produce of a silver mine may extend over the whole known world. Unless the world in general, therefore, be advancing in improvement and population, the demand for silver might not be at all increased by the improvement even of a large country in the neighborhood of the mine. Even though the world in general were improving, yet, if, in the course of its improvement, new mines should be discovered, much more fertile than any which had been known before, though the demand for silver would necessarily increase, yet the supply might increase in so much a greater proportion that the real price of that metal might gradually fall; that is, any given quantity, a pound weight of it, for example, might gradually purchase or command a smaller and a smaller quantity of labor, or exchange for a smaller