The Wealth of Nations by Part 5 Chapter 2 Page 122

For the proper cultivation of this land a certain quantity of stock is necessary, and by withdrawing any part of this necessary quantity, the farmer is not likely to be more able to pay either the rent or the tax. In order to pay the tax, it can never be his interest to diminish the quantity of his produce, nor consequently to supply the market more sparingly than before.

The tax, therefore, will never enable him to raise the price of his produce so as to reimburse himself by throwing the final payment upon the consumer. The farmer, however, must have his reasonable profit as well as every other dealer, otherwise he must give up the trade. After the imposition of a tax of this kind, he can get this reasonable profit only by paying less rent to the landlord. The more he is obliged to pay in the way of tax the less he can