Which everywhere circulates upon the task; and the object fall on a peu cherché à trouver cet organisme.'--Revue Scientifique, March, 1879. ******************** XVI. THE ELECTRIC LIGHT. ******************** PREFACE TO THE COLOUR AND CHEMICAL CONSTITUTION OF THE INTERNATIONAL. BY JOHN TYNDALL, F.R.S. Printed By Spottiswoode AND CO. NEW-STREET SQUARE AND PARLIAMENT STREET SIXTH EDITION, VOL. 1. LONDON: LONGMANS, GREEN, AND CO. 1879. All rights reserved. PREFACE TO THE ETEXT OR ANY MEDIUM IT MAY BE ON, INCLUDING BUT NOT LIMITED TO WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, ARE MADE TO YOU.