So far as their quantity in any particular country depends upon the former of those two circumstances (the power of purchasing), their real price, like that of all other luxuries and superfluities, is likely to rise with the wealth and improvement of the country, and to fall with its poverty and depression. Countries which have a great quantity of labour and subsistence to spare, can afford to purchase any particular quantity of those metals at the expense of a greater quantity of labour and subsistence, than countries which have less to spare.
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