Of course, the announcement of a “Manual of Geology” by the same author could not fail to excite hopes that a long-felt want on the part of the American public was to be met, a void in our scientific literature to be filled.  Nor are we disappointed in our expectations, now that the work has appeared and time has been given for its careful perusal.  On the contrary, we feel a degree of satisfaction that might perhaps express itself too strongly in praise, if we were not withheld by the supposition that a proper notice of the contents of the volume would do more for its appreciation by the reader than any language of eulogy.

What, then, is the distinctive character of the work, and wherein do the contents so differ from previous publications as to claim our especial notice?

In the first place, we would state, that, while it is a manual of general geological knowledge concerning the history of the earth and of life on its surface, and full of information concerning the strata and geological phenomena of all parts of our globe, it is yet peculiar, inasmuch as it treats of the principles of the science with special reference to American Geological History.  In this will be found its great value to American students; for who of them has not had his patience tried, and his enthusiasm often chilled, in vain attempts to solve the questions which have sometimes arisen in his mind concerning American geology, and has not sought their solution in the only way open to him,—­a consultation of innumerable State Reports, and other publications, not half of which were accessible when required?

Another distinctive feature of the work is the prominence given to Historical Geology, or that portion which treats of the successive formation of the strata of the different periods, and of the development and characteristics of the life upon the surface.  The whole treatment of this exhibits in a marked degree the extended research and philosophical ability of the author.

GENERAL CONTEXTS AND DIVISIONS OF THE WORK.

Physiographic Geology.—­This embraces a general survey of the earth’s features:  its continents, oceans, lakes, river-systems, oceanic and atmospheric currents, climates, distribution of forest-regions, deserts, etc.

Lithological Geology.—­This treats of the rocks, and of their arrangement:  the first embracing an account of all the important chemical elements that enter into their constitution, the minerals and organic materials that occur in their composition, and the kinds and distinguishing characteristics of those that make up the earth’s surface; the second presenting the arrangement of rocks, stratified and unstratified,—­the structure due to deposition and other agencies,—­the dislocations of strata, and the consequent faults and distortions of fossils contained in them,—­together with considerations upon the age and chronological division of all the strata of the earth’s surface.