Note 16 — Chapter IV · AGRICULTURAL TRIBES.

According to Cairnes “slavery, as a permanent system, has need not merely of a fertile soil, but of a practically unlimited extent of it. This arises from the defect of slave labour in point of versatility. As has been already remarked, the difficulty of teaching the slave anything is so great—the result of the compulsory ignorance in which he is kept, combined with want of intelligent interest in his work—that the only chance of rendering his labour profitable is, when he has once learned a lesson, to keep him to that lesson for life. Accordingly where agricultural operations are carried on by slaves, the business of each gang is always restricted to the raising of a single product.… Whatever crop may be best suited to the character of the soil and the nature of slave industry, whether cotton, tobacco, sugar, or rice, that crop is cultivated, and that alone. Rotation of crops is thus precluded by the conditions of the case. The soil is tasked again and again to yield the same product, and the inevitable result follows. After a short series of years its fertility is completely exhausted, the planter—“land-killer” he is called in the picturesque nomenclature of the South—abandons the ground which he has rendered worthless, and passes on to seek in new soils for that fertility under which alone the agencies at his disposal can be profitably employed.… Slave cultivation, wherever it has been tried in the new world, has issued in the same results. Precluding the conditions of rotation of crops or skilful management, it tends inevitably to exhaust the land of a country and consequently requires for its permanent success not merely a fertile soil but a practically unlimited extent of it.” Therefore expansion is a necessity of slave societies16.