peared, and they have not been procurable for several years. The consent of the authors of all the Lectures (or their representatives) to this re-publication has been obtained; and most of the gentlemen have kindly revised their papers for this work. Nearly all the contributions to the present volume have been made within the last dozen years, and several of them quite recently; so that they may be regarded as outgrowths and exponents of the present state of thought. A glance at the names will show that those have spoken who were entitled to speak, and each from his own point of view. Although the reader may miss, in this volume, the connexion and coherency of a systematic treatise on the subject by a single writer, yet he will find that each statement is a section of a comprehensive argument, which presents an attractive variety of treatment; while the stamp of various and powerful minds must give the general discussion far greater authority than the work of any one man, no matter how able, could possibly possess. LONDON, November, 1866. HERBERT SPENCER ON THE ORDER OF DISCOVERY IN THE ON THE IMPORTANCE OF THE STUDY OF PHYSICS. A LECTURE DELIVERED AT THE ROYAL INSTITUTION OF GREAT BRITAIN. BY JOHN TYNDALL, LL.D., F.R.S. B |