So far as their quantity in any particular country depends upon the latter of those two circumstances (the fertility or barrenness of the mines which happen to supply the commercial world), their real price, the real quantity of labour and subsistence which they will purchase or exchange for, will, no doubt, sink more or less in proportion to the fertility, and rise in proportion to the barrenness of those mines.
The fertility or barrenness of the mines, however, which may happen at any particular time to supply the commercial world, is a circumstance which, it is evident, may have no sort of connection with the state of industry in a particular country. It seems even to have no very necessary connection with that of the world in general. As arts and commerce, indeed, gradually spread themselves over a greater and a greater part of the earth, the search for new mines, being extended over a wider surface, may have somewhat a better chance for being successful than when confined within narrower bounds. The discovery of new mines, however, as the old ones come to be gradually exhausted, is a matter of the greatest uncertainty, and such as no human skill or industry can insure. All indications, it is acknowledged, are doubtful; and the actual discovery and successful working of a new mine can alone ascertain the reality of its value, or even of its existence. In this search there seem to be no certain limits, either to the possible success, or to the possible disappointment of human industry. In the course of a century or two, it is possible that new mines may be discovered, more fertile than any that have ever yet been known; and it is just equally possible, that the most fertile mine then known may be more barren than any that was wrought before the discovery of the mines of America. Whether the one or the other of those two events may happen to take place, is of very little importance to the real wealth and prosperity of the world, to the real value of the annual produce of the land and labour of mankind. Its nominal value, the quantity of gold and silver by which this annual produce could be expressed or represented, would, no doubt, be very different; but its real value, the real quantity of labour which it could purchase or command, would be precisely the same. A shilling might, in the one case, represent no more labour than a penny does at present; and a penny, in the other, might represent as much as a shilling does now. But in the one case, he who had a shilling in his pocket would be no richer than he who has a penny at present; and in the other, he who had a penny would be just as rich as he who has a shilling now. The cheapness and abundance of gold and silver plate would be the sole advantage which the world could derive from the one event; and the dearness and scarcity of those trifling superfluities, the only inconveniency it could suffer from the other.