The Wealth of Nations by Part 1 Chapter 11 Page 211

increases, may, perhaps, dispose many people to believe that their value still continues to fall in the European market; and the still gradually increasing price of many parts of the rude produce of land may confirm them still further in this opinion.

That that increase in the quantity of the precious metals, which arises in any country from the increase of wealth, has no tendency to diminish their value, I have endeavoured to show already.

Gold and silver naturally resort to a rich country, for the same reason that all sorts of luxuries and curiosities resort to it; not because they are cheaper there than in poorer countries, but because they are dearer, or because a better price is given for them. It is the superiority of price which attracts them, and as soon as that superiority ceases, they necessarily cease to go thither.