Horrors of slavery : In two parts. Part I. Containing observations, facts, and arguments, extracted from the speeches of Wilberforce, Grenville, Pitt, Burke, Fox, Martin, Whitehead, and other distinguished members of the British Parliament. Part II. Containing extracts, chiefly American, comp. from authentic sources: demonstrating that slavery is impolitic, antirepublican, unchristian and highly criminal: and proposing measures for its complete abolition through the United States /