The Wealth of Nations by Part 1 Chapter 11 Page 275

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 ensure. All indications, it is acknowledged, are doubtful, and the actual discovery and