MAGNETISM. 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. XXI. DEATH BY LIGHTNING. XXII. SCIENCE AND THE BELFAST ADDRESS. XI. THE REV. JAMES MARTINEAU AND THE BELFAST ADDRESS. X. APOLOGY FOR THE BELFAST ADDRESS. X. APOLOGY FOR.