The Arab slave-trader bowed to the earth before King M'tesa, who signalled to him to speak.
"I have come," said the Arab, pointing to the guns on the floor, "to bring you these things in exchange for some men and women and children. See, I offer you guns and percussion caps and cloth." And he spread out lengths of the red cloth, and held out one of the guns with its gleaming barrel.
King M'tesa's eyes lighted up with desire as he saw the muskets and the ammunition. These, he thought, are the things that will make me powerful against my enemies.
"I will give you," the Arab slave-trader went on, "one of these lengths of red cloth in exchange for one man to be sold to me as a slave; one of these guns for two men; and one hundred of these percussion caps for a woman as a slave."
Mackay looked into the cruel face of M'tesa, and he could see how the ambitious King longed for the guns. Should he risk the favour of the King by fighting the battle of a few slaves? Yet Mackay remembered as he sat there, how Livingstone's great fight against the slave-traders had made him, as a student, vow that he too would go out and fight slavery in Africa. The memory nerved him for the fight he was now to make.
Mackay turned to M'tesa and said words like these:[55]
"O King M'tesa, you are set as father over all your multitude of people. They are your children. It is they who make you a great King.
"Remember, O King, that the Sultan of Zanzibar himself has signed a decree that no slaves shall be taken in all these lands and sold to other lands down beyond the coast, whither this Arab would lead your children. Therefore if you sell slaves you break his law.
"Will you, then, sell your own people that they may be taken out of their homeland into a strange country? They will be chained to one another, beaten with whips, scourged and kicked, and many will be left at the wayside to die; till the peoples of the coast shall laugh at Uganda and say, 'That is how King M'tesa lets strangers treat his children!'"
We can imagine how the Arab turned and scowled fiercely at Mackay. His heart raged, and he would have given anything to plunge the dagger hidden in his robe into Mackay's heart. Who was this white man who dared to try to stop his trade? But Mackay went on.