Book II.

CHANGES NOW IN PROGRESS IN THE INORGANIC WORLD.

Book III.

CHANGES OF THE ORGANIC WORLD NOW IN PROGRESS.

It will be seen on comparing this analysis of the contents of the "Principles" with the headings of the chapters of the present work (see [p. xxiii.]), that the two treatises have but little in common; or, to repeat what I have said in the Preface to the 8th edition of the "Principles," they have the same kind of connection which Chemistry bears to Natural Philosophy, each being subsidiary to the other, and yet admitting of being considered as different departments of science.[vi-A]

Charles Lyell.

11 Harley Street, London, December 10. 1851.