Vol.LXXIII. No. 2. AUGUST, 1908 



THE 



POPULAR SCIENCE 

 MONTHLY. 



EDITED BY J. McKEEN CATTELL 



CONTENTS 



The History of the Conservation of Energy : the Age of the Earth and 



the Sun. Professor Florian Cajori 97 



Florissant : a Miocene Pompeii. Professor T. D. A. Cockerell , . . 112 

 Crimes and Violence in Chicago and in Greater New York. Maynard 



Shipley 127 



The Movement towards " Physiological Psychology." Professor E. M. 



Wenley 135 



The Nature, Origin and Function of Humor. Dr. Linus W. Kline . . 144 

 A Bacteriological Study of Soiled Paper Money. Warren W. Hilditch. 157 



Facts concerning Milk. Dr. A. E. P. Rockwell 166 



Shall Our Forest Wealth be Destroyed ? Thomas Elmer Will. . . . 176 



The Progress of Science : 



Dartmouth College and the Summer Meeting of the American Association for the Ad- 

 vancement of Science ; International Congresses and Permanent International Bureaus ; 

 Scientific Items 188 



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