HALF HOURS 



WITH 



MODERN SCIENTISTS. 



LECTURES AND ESSAYS 



BY 



I'ROFS. HUXLEY, BARKER, STIRLING, COPE ANI> 

 TYNDALL. 



WITH 



A GENERAL INTRODUCTION 



BY 

 NOAH PORTER, D.D., LL.D., 



PRESIDENT OF YALE COLLEGE. 



FIRST 



CHARLES C, CHATFIELD & Co., 

 1872. 



