The Wealth of Nations by Part 5 Chapter 2 Page 151

The rise which such a tax might occasion in the wages of country labour would be advanced by the farmer, who, in order to maintain the same number of labourers as before, would be obliged to employ a greater capital. In order to get back this greater capital, together with the ordinary profits of stock, it would be necessary that he should retain a larger portion, or what comes to the same thing, the price of a larger portion, of the produce of the land, and consequently that he should pay less rent to the landlord. The final payment of this rise of wages, therefore, would in this case fall upon the landlord, together with the additional profit of the farmer who had advanced it.

In all cases a direct tax upon the wages of labour must, in the long-run, occasion both a greater reduction in the rent of land, and a greater