The Wealth of Nations by Part 1 Chapter 11 Page 241

maintain a cat or a dog without any expense, so the poorest occupiers of land can commonly maintain a few poultry, or a sow and a few pigs, at very little. The little offals of their own table, their whey, skimmed milk, and buttermilk, supply those animals with a part of their food, and they find the rest in the neighbouring fields without doing any sensible damage to anybody.

By diminishing the number of those small occupiers, therefore, the quantity of this sort of provisions, which is thus produced at little or no expense, must certainly have been a good deal diminished, and their price must consequently have been raised both sooner and faster than it would otherwise have risen. Sooner or later, however, in the progress of improvement, it must at any rate have risen to the utmost height to which it is capable of