The book which now appears before the public may be of interest in relation to a question which the late agitation of the subject of slavery has raised in many thoughtful minds; viz.-Are the race at present held as slaves capable of freedom, self-government, and progress? The author is a coloured young man, born and reared in the city of Philadelphia. This city, standing as it does on the frontier between free and slave territory, has accumulated naturally a large population of the mixed and African race. Being one of the nearest free cities of any considerable size to the slave territory, it has naturally been a resort of escaping fugitives, or of emancipated slaves.