William Garden Blaikie,
The Personal Life of David Livingstone…
“ But every fine feature of the country was bathed in gloom by the slave-trade. The image left in Dr. Livingstone's mind was not that of the rich, sunny, luxuriant country, but that of the woe and wretchedness of the people. The real service of the Expedition was, that it had exposed slavery at its fountain-head, and in all its phases. First, there was the internal slave-trade between hostile native tribes. Then, there were the slave-traders from the coast, Arabs, or half-caste Portuguese, for whom natives were encouraged to collect slaves by all the horrible means of marauding and murder. ”
