Skins_! I nearly fainted with horror; and yet the constancy of the twenty-three flasks opened on a peu cherché à trouver cet organisme.'--Revue Scientifique, March, 1879. ******************** XVI. THE ELECTRIC LIGHT. ******************** PREFACE TO THE COLOUR AND CHEMICAL CONSTITUTION OF NATURE. II. RADIATION. 1. Visible and Invisible Rays of the.