The Wealth of Nations by Part 2 Chapter 4 Page 15

were then, five pounds now can be worth no more than two pounds ten shillings were then. By reducing the rate of interest, therefore, from ten to five per cent, we give for the use of a capital, which is supposed to be equal to one half of its former value, an interest which is equal to one fourth only of the value of the former interest.

Any increase in the quantity of silver, while that of the commodities circulated by means of it remained the same, could have no other effect than to diminish the value of that metal. The nominal value of all sorts of goods would be greater, but their real value would be precisely the same as before. They would be exchanged for a greater number of pieces of silver; but the quantity of labour which they could command, the number of people whom they could maintain and employ, would be