PREFACE TO THE FOURTH EDITION. The custom of inditing a preface is one which is perhaps more honoured in the breach than in the observance: nevertheless, I cannot allow the present opportunity to pass without returning my hearty thanks and acknowledgments to my Critics, and the Press generally, for the indulgent consideration I have received at their hands, and for the discriminating advice, of which, in revising this edition, I have gladly availed myself. Many of the minor pieces-introduced in the first instance principally as vehicles for illustrations have been omitted, and others of a...