University of Virginia Library

PREFACE TO THE FIRST EDITION.

THE lectures now published were first delivered before the Brooklyn Institute on Sunday evenings of January and February, 1861, and the larger part of them were subsequently repeated, during the same winter, before the Lowell Institute in Boston, and before the Mechanics' Association of Lowell. The progress of science since that time has rendered necessary many additions, and in revising the lectures for publication, the material has been thus so greatly increased that what was originally prepared and delivered as six lectures is now distributed over ten. At the time when the lectures were written, Mr. Darwin's book on the Origin of Species, then recently published, was exciting great attention, and was thought by many to have an injurious bearing on the argument for design. It was, therefore, made the chief aim of these lectures to show that there is abundant

evidence of design in the properties of the chemical elements alone, and hence that the great argument of Natural Theology rests upon a basis which no theories of organic development can shake. In illustrating his subject, the author has used freely all the materials at his command, and if, in any case, he has failed to give due acknowledgment, it has been because by long dwelling on the subject the thoughts of others have become blended with his own. He would here acknowledge his repeated indebtedness to Professor Guyot's work on "Earth and Man,'' to Professor Faraday's published Courses of Elementary Lectures, and to Professor Tyndall's Lectures on "Heat considered as a Mode of Motion.'' He would also express his especial obligations to the author of "In Memoriam,'' in whose verses he has discovered a truer appreciation of the difficulties which beset the questions discussed in this volume, than he has ever found in the philosophy of the schools.

CAMBRIDGE, May 3d, 1864