Slavery may, perhaps, be best compared to the infantile disease of measles; a complaint which so commonly attacks the young of humanity in their infancy, and when gone through at that period leaves behind it so few fatal marks; but which when it normally attacks the fully developed adult becomes one of the most virulent and toxic of diseases, often permanently poisoning the constitution where it does not end in death.

A track to the water's edge: the Olive Schreiner reader (ed. HarperCollins Publishers, 1973)