The Wealth of Nations by Part 5 Chapter 2 Page 96

reduction of rent, the final payment of the tax would fall upon the landlord. If he employed it as a mercantile or manufacturing stock, he could raise the rate of his profit only by raising the price of his goods; in which case the final payment of the tax would fall altogether upon the consumers of those goods. If he did not raise the rate of his profit, he would be obliged to charge the whole tax upon that part of it which was allotted for the interest of money.

He could afford less interest for whatever stock he borrowed, and the whole weight of the tax would in this case fall ultimately upon the interest of money. So far as he could not relieve himself from the tax in the one way, he would be obliged to relieve himself in the other.

The interest of money seems at first sight a