Page images

but for scholars of every class, especially for those who wish to satisfy themselves of the real nature and compass of its facts and reasonings, and of the bearing of its conclusions on questions of Biblical interpretation. It is chiefly with this class in view that we call attention to the volume before us. Men of science are

presumed to be already aware of its merits.

As a Text book,-the use for which it is primarily intended-it seems to us a model. Comprehensive, systematic, logical, admirably clear in its enunciation of principles, and its statement and grouping of facts, condensed almost to a fault, and profuse in its illustrative engravings, it leaves little to be desired, as a lesson book for colleges and schools of science. At the same time, it is so truly philosophical, so broad and striking in its generalizations, so rich in its revelations of the marvelous history of the pre-adamite earth, and withal so thoroughly reverent in spirit, that it will have to the literary scholar, scarcely less value than the scientific. The convenience of both classes is well consulted by putting certain details and matters of secondary importance in smaller type. Especially would we commend it to those theologically nervous people, (happily, of late years, a rapidly diminishing class), who are inclined to look upon geology as hostile to revelation. It is only from some such standard work, that they can learn justly to appreciate the real strength of geological reasoning-the peculiarly cumulative nature of its arguments-the diversity and multiplicity of its data often, the exceeding value, in interpreting geological history, of its apparantly most trivial facts. And it is only from some such unbiassed work-the product of a mind in harmony with both sacred and scientific truth-that they can learn the legitimate teachings of the science on those points where it has been supposed to come in conflict with the Bible. From Professor Dana's teaching they have nothing to fear. With him as interpreter, geology puts forth no infidel or atheistic utterance. The Divine hand is conspicuous in every arrangement; and in the whole grand march of events from the

schools of science. By JAMES D. Dana, M. A., LL. D., Silliman Professor of Geology and Natural History in Yale College; author of a "System of Mineralogy," of Reports of Wilkes' Exploring Expedition on Geology, on Zoophytes, and on Crustacea, etc. Illustrated by a chart of the world, and over one thousand figures, mostly from American sources. Philadelphia: published by Theodore Bliss & Co. London: Trübner & Co., 1863. 8vo. pp. 814. Price, $4.00.

world's chaos to the crowning of man as its lord, the type of being nearest akin to the Creator himself.

In its materials, the work is distinctively American. It is, in fact, an elaborate Geological History of North America; yet it draws sufficiently also from foreign geology, to give it completeness as a manual, and exhibit, in their full comprehensiveness, the great principles of the science.

It treats geology under four general heads: (1), Physiographic Geology; (2), Lithological Geology; (3), Historical Geology; and (4), Dynamical Geology.

Under the first head, we have, in 37 pages, a general survey of the earth's surface-features; in reality, an admirable epitome of Physical Geography, and by an original hand.

The second head (75 pages) describes the rock material of the globe; treating, first, of the Constitution of Rocks: their elements, their minerals, their kinds, (as Fragmental, Metamorphic, Calcareous, and Igneous),-and secondly, of the condition, structure, and arrangement of Rock Masses, including the stratified

and the unstratified.

The third head-Historical Geology, (480 pages)-exhibits, as in a series of visions, or dissolving views, the modus operandi of world making, the grand processes of founding and finishing continents, and peopling them with the various orders of life. The whole range of geological time is considered in five grand divisions: Azoic Time, Palæozoic Time, Mesozoic Time, Cenozoic Time, and the Era of Mind or Age of Man. In the Azoic AGE, we have, chiefly, a world under water, and destitute of life-a wild era of just-emerging, and rudimentary continents—the North America of that day being only a narrow strip of desolation, stretching down from the north to Lake Superior, and thence eastward to Labrador, with a peninsula in Northern New York.

A rapid survey of the Animal Kingdom next prepares the reader for those portions of the history in which Life bears a distinguishing part, and introduces the second grand division of geological time, the PALEOZOIC-the opening Era of organic existence -during the long cycles of which the floor rocks of the greater portion of the United States were laid down and garnished with their wonderful treasures of minerals, and of animal and vegetable fossils;-those of New York, for example, stored with salt; of Pennsylvania with coal, iron, and oil; of Illinois and Missouri

with lead; of Carolina and California with gold. This period of Paleozoic Time, comprises three distinct Ages-named, from the prevailing type of organic life in each, the Age of Mollusks, the Age of Fishes, and the Age of Coal Plants; or, from English Geology, the Silurian, Devonian, and Carboniferous Ages. And these again are subdivided into numerous lesser Periods or Epochs, named chiefly from the places of principal out-crop of their typical rocks.

The struggle of the continent with the elements during these Ages, involving numerous emergings and submergings, with corresponding vicissitudes of its marine and terrestrial life, we see resulting in a large extension of its boundaries southward, and the development of conditions suitable for the incoming of the third grand division of geological time, the MESOZOIC-characterized as the Reptilian Age, and comprising three sub-periods; the Triassic, the Jurassic, and the Cretaceous; during the two former of which such strange tribes of amphibious Reptiles left their tracks in the mud of New Jersey and the Connecticut Valley-regions specially infested to-day by those political reptiles, the Copperheads.

From the Reptilian Age we pass to the fourth division of the history-CENOZOIC TIME: characterized as the Mammalian Age, and subdivided into the Tertiary and Post Tertiary Periods, with their subordinate epochs,-the age of the formation and emergence of the Mississippi Valley, and the Gulf and Atlantic margin of the continent from New Jersey down-the age of Mammoths, of Mastodons, and Megatheriums-the strange age when not only New England, but the whole North, was "left out in the cold," and immense Glaciers, pushing and plowing down from the mountains, covered hill and valley with sterile drift, (the ground that raises Freemen),-the age of prairie making and valley excavation, of river terracing and alluvial deposition, in short of the final fitting of the earth for the introduction of the fifth, and last, of the grand divisions of geological time-the Era of Mind or Age of Man.

In describing the progress of life, through these ages, Prof. Dana gives no countenance to the development theories of Darwin and others. Development he finds, indeed,-his work is full of it—but of a kind that nowhere ignores creative power. As here exhibited, the ascent from Mollusks to Man-from Seaweeds to 23


Cedars-is by steps in which the direct exercise of such power is everywhere implied. No theory of natural forces is called in to account for the origination of new species. Such forces are invoked to explain their culmination and extinction, but not their origin. Progress is effected by the introduction of comprehensive types, of successively higher grades, and the unfolding or exhibition of these types in the appearance of new groups or species, in which are fully expressed typical characteristics before only foreshadowed. The extent of such progress and the great diversity of species introduced, in the course of the Zoic ages, may be in a measure understood from the census reported of the living tribes of the current era-approximately as follows:-Plants, 100,000 species; Animals of the sub-kingdom of Radiates about 10,000; of Mollusks 20,000; of Articulates 300,000; of Vertebrates 21,000; (viz, Fishes 10,000, Reptiles 2,000, Birds 7,000, and Mammals 2,000); making a total of the Animal Kingdom of about 350,000 species.

For the creation of Man, no specific date is assigned; but, in geological chronology, it is referred to the Terrace epoch. The view is expressed that, in this epoch, there occurred both the decline of the Post-tertiary races and the introduction of the modern tribes of Mammals, together with the creation of Man. The facts from which Man's excessive antiquity has been so often argued, are many of them assigned to very recent dates, and others set aside as unreliable, or differently interpreted. The unity of the Race, and its probable origin on the Eastern Continent, are points directly maintained; and no evidence is found that any new species of plants or animals have appeared on the earth since the creation of Man.

The fourth, and closing, general division of the work-Dynamical Geology (138 pages)-discusses briefly, but most ably, the agencies or forces that have produced geological changes and the laws and methods of their action. Of these agencies, those chiefly considered, are Life, Water, and Heat ;-the first, as an agent in protecting, destroying, and making rocks-the parent of limestones, coal, and coral islands; the second, as seen in the eroding, transporting, and distributing power of Rivers, in the force of oceanic waves, tides, and currents, and in the action of Frost, Glaciers and Icebergs: and the third, as a cause of volcanic phenomena, igneous eruptions, dykes, metamorphism, etc. Cohesive attraction and Atmospheric

agency, are also included; and especially those great movements of the earth's crust, from whatever cause originating, the consequences of which have been the plication of strata, the origin of mountains and earthquakes, and the evolution of the general features of the globe. Chemical geology is omitted, as too extensive a topic for such a manual. The discussions throughout the work derive great freshness and value from being based so largely on the personal investigations of the author-as those, for example, on volcanic action, coral formations, etc. Few geologists indeed, if any, have ever enjoyed opportunities of examining more extensively the earth's surface than Prof. Dana, and certainly none have ever brought to the investigation of geological problems keener powers of observation, a happier faculty of profound and philosophical analysis, a more untiring industry, or higher attainments in all the tributary departments of science, especially mineralogy and zoology, those chief keys of geological discovery.

The volume closes with a brief synopsis of the harmony of geological and Biblical Cosmogony; an abstract of which-chiefly in the words of the author-we cannot forbear giving, for the sake of those who may not have access to the work itself. The views advanced are essentially also those of Professor Guyot. Assuming, from astronomical and other considerations, the truth of the Nebular Theory, and that the earth has passed through a state of igneous fluidity, the subsequent stages in the earth's progress, as indicated by science, are stated briefly as follows:-(1.) The Beginning of Activity in Matter-molecular action, at once evolving light; (2) The earth made an independent sphere, one of a system of orbs resulting from the dividing and subdividing processes of the Nebular Theory;-(3.) The outlining of the land and water, determining the earth's general configuration;-(4.) The idea of life, expressed in the lowest plants, and afterwards, if not contemporaneously, in the lowest or systemless animals, or Protozoans ;(5.) The energizing light of the sun shining on the earth,-an essential preliminary to the display of the systems of life;-(6.) Introduction of the Systems of Life, in the leading types under the Animal Kingdom;-(7.) The introduction of Mammals-the highest order of Vertebrates-the class afterwards to be dignified by including a being of moral and intellectual nature;-(8.) The introduction of Man.

Assuming, from internal and other evidence, both the Divine

« PreviousContinue »