CURRENT LITERATURE.
Maraud of Geology. By Rev. S. Naughton, M.D., F.R.S., Fellow of Trinity College, Dublin. (Longman.)—This volume, which was origi- nally delivered in the form of lectures at the University of Dublin, con- tains in a small compass all that is known shoat the earth and its successive inhabitants. Starting with the nebular theory of Laplace as a -reasonable account of the origin of our globe, the anther considers that as the mass cooled the layers arranged themselves according to their specific gravities, dependent rather on chemical composition than on, pressure, and adopts the theory of Darocher, that to the first and second layers, called by him the Acid and the Basic Magmas, are to be attributed the igneous rocks,—to the first the granites, to the second the trap rocks and the greenstones,—and that through -fissures formed in them during the process of cooling the metallic ores oozed up, sublimed from the interior of the earth as sulphur salts. He then proceeds to explain the composition of the aqueous cr stratified rocks and the theory of fossilization, and is thus led on to a chapter on geological time and solar heat, in which he discusses Professor Thomson's speculations and introduces some calculations of his own, which give 1,280 millions of years as the probable lapse of time between the commencement of organic life and the London clay tertiary epoch, when tropical mollusks inhabited the seas of Britain. The rest of the volume deals with the classification of the rocks according to the organic remains, and the history of these remains in the usual geological order. We need only mention that in a chapter on the geometrical laws that influence the forms of fossils the author propounds a law of pressure that accounts for the hexagonal shape of the bee's cell, and fends to deprive that in- teresting insect of its mathematical reputation, and that in the conclusion he gives his reasons for differing both from the author of the Vestiges of Creation and from Mr. Darwin as to the theories to be based upon the present collection of geological facts. His own opinion is that for the present we must be content to attribute "the order of life and the succession in which it has appeared on the globe to a direct effort of the Creator's will."
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