It was my intention to have prefixed to this edition of the Essay on the Theory of the Earth, a general discourse on Geognosy, with the view of explaining its various relations to the other branches of Natural History, and of examining some of the criticisms that have appeared on the work itself, and the notes and preface accompanying it, but want of leisure has prevented me at present from carrying into effect this plan. I have however enlarged the Notes, and added a series of observations on a very interesting topic; the distribution of fossil organic remains throughout the crust of the Earth, and also as intimately connected with the discussions contained in the Essay of Cuvier; an account of the Mineralogy of the country round Paris; and of some remarkable mineral formations that occur in the South of England.