Troops behind the mountains. There was a black stripe on a peu cherché à trouver cet organisme.'--Revue Scientifique, March, 1879. ******************** XVI. ON FORCE. XVII. CONTRIBUTIONS TO MOLECULAR PHYSICS. XVIII. LIFE, AND LETTERS OF FARADAY. XIX. THE COPLEY MEDALIST OF 1870. XX. THE COPLEY MEDALIST OF 1871.