Mauritius, beautiful appearance of-Great crateriform ring of mountains-Hindoos-St. Helena-History of the changes in the vegetation-Cause of the extinction of land-shells-Ascension-Variation in the imported rats-Volcanic bombs-Beds of infusoria-Bahia, Brazil-Splendour of tropical scenery-Pernambuco-Singular reef-Slavery-Return to England-Retrospect