There are a great many different diseases, and accidents, and injuries which they are exposed to, and it requires constant watchfulness, and considerable, intelligence, to guard against them.

This makes a great difference in the character which is required in the laborers, in the different cases.

A cotton plantation in the south can be cultivated by slaves.

A grain farm in the middle states can be worked by hired laborers; but a northern grass farm, with all its oxen, cows, sheep, poultry, and horses, can only be successfully managed by the work of the owner." "Is that the reason why they have slaves at the south ?" asked Marco.
"It is a reason why slaves can be profitable at the south.

In cultivating cotton or sugar, a vast proportion of all the work done in the year is the same.