Occasionally some of the free blacks become slaves voluntarily by going through the simple but significant ceremony of breaking a spear in the presence of their future master.

A Portuguese officer, since dead, persuaded one of the Makololo to remain in Tette, instead of returning to his own country, and tried also to induce him to break a spear before him, and thus acknowledge himself his slave, but the man was too shrewd for this; he was a great elephant doctor, who accompanied the hunters, told them when to attack the huge beast, and gave them medicine to ensure success.

Unlike the real Portuguese, many of the half-castes are merciless slave-holders; their brutal treatment of the wretched slaves is notorious.

What a humane native of Portugal once said of them is appropriate if not true: "God made white men, and God made black men, but the devil made half-castes." The officers and merchants send parties of slaves under faithful headmen to hunt elephants and to trade in ivory, providing them with a certain quantity of cloth, beads, etc., and requiring so much ivory in return.
These slaves think that they have made a good thing of it, when they kill an elephant near a village, as the natives give them beer and meal in exchange for some of the elephant's meat, and over every tusk that is brought there is expended a vast amount of time, talk, and beer.

Most of the Africans are natural-born traders, they love trade more for the sake of trading than for what they make by it.