By this cumulative progress Christianity is working out in human history a demonstration of its divine origin and power. And when it shall have prevailed through the world, the demonstration will be complete. Humanity itself will have become a living epistle, known and read of all men a word of God, declaring Christ the living Word a second incarnation of the divine in humanity, demonstrating the reality of the incarnation in Jesus Christ.

Precisely here is the great want of this age-a demonstration of Christianity by its life-giving power. The Tartars worshipped their own scimetars - the mightiest and best helpers they knew. Civilized men will worship the steamengine, if it prove itself mightiest and best. They must see a power, proving itself divine by its superior beneficence, using the steam-engine itself for high and beneficent ends.

Infidelity itself now unwittingly testifies to the power and truth of Christianity. It has become pious and philanthropic, and claims acceptance on the ground that it does more Christian work than Christianity itself. "The magicians of Egypt did so with their enchantments." When the apostles cast out devils, Simon Magus insists on doing the same. The gospel must silence modern infidelity, not merely by proving that the philanthropy which characterizes modern civilization is the gift of Christianity, but also by showing a benevolence purer, more self-sacrificing, and universal; motives to beneficence more energizing and persistent; philanthropy more wise, comprehensive, and efficient; a character more complete, and a power more divine in the renovation of men. It stands before modern infidelity, as Paul did before the seven sons of Sceva, and must prove its power to cast out devils by doing it, leaving to the pretenders the shame of hearing the devils answer: "Jesus I know, and Paul I know; but who are ye?" Its challenge must always be, like that of Jesus himself: "The works that I do bear witness of me; though ye believe not me, believe the works." The world accepts the challenge: "What dost thou work? Show us the desert blooming beneath thy tread, the dead in

sin living at thy touch, the powers of hell fleeing before thy voice." Faithful Christian workers, mighty in faith and love, are the best evidences of Christianity. We are not to prove that it is from God merely by its great works in the past. We are not to be obliged to point to the primitive church as the most beautiful exhibition and the sufficient proof of the power of the gospel, but to create now an age of Christian purity and power. "The fathers did eat manna in the wilderness"; we thank God for that. "But they are dead"; God now is giving us the living bread, that we may eat thereof, and not die.

ARTICLE V.

LYELL'S STUDENT'S ELEMENTS OF GEOLOGY.

BY JOHN B. PERRY, CAMBRIDGE, MASS.

ANOTHER Volume by Sir Charles Lyell1 appeared a few months ago in England, and is now republished in this country. It is partly a new book, in part a recast and revision of the last edition of the "Elements."2 As its title indicates, it is designed for students. It has been the aim of the author to present the matter in such a light as, without sacrificing substance, to adapt the publication to beginners. By the omission of portions of the earlier work, room has been secured for large additions; while effort has been made to exhibit the subject in fullest consonance with the existing state of knowledge.

Of course, on the appearance of any such work, it is all1 The Student's Elements of Geology, by Sir Charles Lyell, Bart. F.R.S. London. 1871. New York: Harper and Brothers. 1871.

* The latter work which was originally prepared as a "Supplement" to the Principles of Geology, was published as a separate duodecimo volume in 1838, and passing through successive forms reached the sixth and last edition in 1857. There was thus abundant occasion for a recension, and an ample opportunity for improvement, so great has been the progress made in geology during the last decennium.

important to know whether the task, gratefully assumed by the author, have been well executed; whether the subject, as profoundly grasped, have been genially and thoroughly elaborated; and whether the work be adapted to its end. One of the most prominent educators in the country having asked my opinion of the volume, I have read it with care, that my judgment might rest, not simply on familiar acquaintance with previous writings of the author, but especially on the merits of the book in question. In thus examining the work, I have had primary reference to its fitness for its proposed end, namely, to serve as a manual for students in elementary geology.1 Thinking that the results reached might be of benefit to many teachers, and perhaps of interest to others enlisted in studies of this kind, I will transcribe some of the points noted.

It may be said, at the outset, that the volume, while in no sense exhaustive, is a repository of important facts. Being familiar with nearly, if not quite, all the previous editions of the "Elements," from the first impression down to the latest, I wish also to premise that each recension has been, as might have been reasonably expected, in some respects, an improvement on what has preceded, and that the volume now under consideration has some features deserving of praise, for which one will vainly look in any of the earlier forms of the work. While Sir Charles has seldom been in advance, he has labored hard to keep fully up with the march of science.

1 Another point which stands specially prominent is not directly mentioned. It will be readily understood when it is added that the present Article is furnished as introductory to a series of papers on the Relations of Natural Science to Theology. As such, it is perhaps well suited to suggest, that while the great principles of geology rest on a substantial basis, there is not a little current in geological literature, and even in the writings of so-called standard authorities, that is by no means trustworthy. In a second introductory Article — which will appear in due time and be devoted to a critical review of Mr. Darwin — the question will be tacitly raised whether, while zoology as a science has a valid foundation, there be not much zoological speculation that is utterly untenable in the light of sound logic, and wholly unsupported by facts. These preliminary Articles will, it is thought, prepare the way for a thorough and impartial consideration of some of the relations of science to religion.

In this way he has been able to evince progress in each new issue of his writings. It is true that the nature of these progressive movements has been largely determined by the labors of others by the progress actually achieved in science by original research. Still, these improvements, as should be added, have been made not merely in the way of supplements and addenda; there have been constant eliminations of obsolete matter, and a real incorporation of new material, as it were an interstitial growth, corresponding with the advance of the times. And this is a marked excellence one too seldom met with in the publications of the day. It is in this direction that the present work has its special claim to favor.

But, while certain commendable points, which began to show themselves in the first edition of the "Principles," some forty years ago, have gradually become more apparent as the author has matured, there were also equally marked defects, some of which have augmented in like proportion with the lapse of time. These, having escaped correction, now reveal themselves with glaring prominence in this his latest work. A few of them, as seen in contrast with what one might expect to find in any widely-used manual of geology, may be now passed in hasty review.

Among these points, the evolution of the subject, including the method adopted, has special claim to attention. As must be evident, a right method is all-important, especially in a work designed for beginners. An examination of the one selected by the author will reveal the character of the work in this direction. To indicate his method, in a word, is not easy. Still, it may be, perhaps, appropriately designated as at once complex and regressive. From the multitudinous objects of to-day the movement is by slow degrees toward the greater simplicity of earlier times. Starting from the present, with all its multiplicity and diversity, the author, if I may so say, advances backward- often backward several steps at once, and then forward, and so gradually toward the more primitive periods by successive hitches. Such a

course almost inevitably necessitates confusion, rendering a mental translation or re-arrangement perpetually needful, if the pupil would get any distinct and just view of the real sequence and progress evinced in nature. Indeed, constant effort is requisite, even on the part of the expert, that he may keep this vast complication, as seen in its reversed order, clear in all its parts. In the "Principles" this regressive movement is appropriate. It is, in fact, admirable; for it is entirely consonant with the aim of the work. But the composition of that book seems to have put the author under a bias from which he has never recovered a bias which appears in other works requiring an entirely different method. For his adoption of this course in the present volume there might be more show of reason, were the student at the start -as ordinarily he is not-thoroughly master of existing forms of life. But even in this case the historic method is far preferable.

Indeed, a few elementary forms need first to be plainly presented. From these there may be a gradual advance to a greater number, and, if the facts allow, to those of a more complicated structure. The advance is naturally made from the more rudimentary to those of greater diversity; from earlier and simpler to later and more complex; from forms, in short, with which the student at first readily associates the great types of the animal kingdom, to others which he may for the time look upon as representative of particular classes, orders, families, and genera; from the trunk, so to speak, of organic existence, to the branches, thence to the twigs and leaves and flowers, and all in the historic order of development.

To put the matter in a more specific shape, the student in geology should start, so far as may be, from the beginning. Going back, with whatever knowledge he has of the present, to the earliest fossiliferous rocks, he fitly commences his study on a few representatives of two, or at the most three, great divisions of the animal kingdom, and thus is not perplexed, much less overwhelmed, by a great multiplicity of