The Wealth of Nations by Part 1 Chapter 10 Page 89

The stock accumulated in them comes in time to be so great that it can no longer be employed with the ancient profit in that species of industry which is peculiar to them. That industry has its limits like every other; and the increase of stock, by increasing the competition, necessarily reduces the profit. The lowering of profit in the town forces out stock to the country, where, by creating a new demand for country labour, it necessarily raises its wages. It then spreads itself, if I may say so, over the face of the land, and by being employed in agriculture is in part restored to the country, at the expense of which, in a great measure, it had originally been accumulated in the town. That everywhere in Europe the greatest improvements of the country have been owing to such overflowings of the stock originally accumulated in the towns, I shall endeavour