The Wealth of Nations by Part 1 Chapter 11 Page 97

exchange for a greater and a greater quantity of corn; or, in other words, the average money price of corn would gradually become cheaper and cheaper.

If, on the contrary, the supply by some accident should increase for many years together in a greater proportion than the demand, that metal would gradually become cheaper and cheaper; or, in other words, the average money price of corn would, in spite of all improvements, gradually become dearer and dearer.

But if, on the other hand, the supply of the metal should increase nearly in the same proportion as the demand, it would continue to purchase or exchange for nearly the same quantity of corn, and the average money price of corn would, in spite of all improvements, continue very nearly the same.