The Wealth of Nations by Part 1 Chapter 11 Page 26

In the twelve first years of the last century, therefore, wheat appears to have been a good deal cheaper, and butcher’s meat a good deal dearer, than in the twelve years preceding 1764, including that year.

In all great countries the greater part of the cultivated lands are employed in producing either food for men or food for cattle. The rent and profit of these regulate the rent and profit of all other cultivated land. If any particular produce afforded less, the land would soon be turned into corn or pasture; and if any afforded more, some part of the lands in corn or pasture would soon be turned to that produce.

Those productions, indeed, which require either a greater original expense of improvement, or a greater annual expense of cultivation, in order to fit the land for them,