upon Crown control of undeveloped lands. With the growth of full self-government in the colonies the exercise of these Crown functions was transferred from the ministry and parliament of Britain to the ministries and parliaments of the colonies; and this transference put an end to the possibility of a centralised organisation and direction of emigration. A second constructive factor very potently at work during this age was the humanitarian spirit, which had become a powerful factor in British life during the late eighteenth and early nineteenth centuries. It had received perhaps its most practical expression in the abolition of the slave-trade in 1806, and the campaign against the slave-trade in the rest of the world became an important object of British policy from that time onwards. Having abolished the slave-trade, the humanitarians proceeded to advocate the complete abolition of negro slavery throughout the British Empire. They won their victory in 1833, when the British parliament declared slavery illegal throughout the Empire, and voted 20,000,000 pounds--at a time when British finance was still suffering from the burdens of the Napoleonic War--to purchase from their masters the freedom of all the slaves then existing in the Empire. It was a noble deed, but it was perhaps carried out a little too suddenly, and it led to grave difficulties, especially in the West Indies, whose prosperity was seriously impaired, and in South Africa, where it brought about acute friction with the slave-owning Boer farmers. But it gave evidence of the adoption of a new attitude towards the backward races, hitherto mercilessly exploited by all the imperialist powers. One expression of this attitude had already been afforded by the organisation (1787) of the colony of Sierra Leone, on the West African coast, as a place of refuge for freed slaves desiring to return to the land of their fathers.