The Popular Science 



Entered in the Pott Office in Laneatler, Pa., a« teeond-elass matter. 



CONTENTS OF JUNE NUMBER 



Hertzian Wave Wireless Telegraptiy. Professor J. 

 A. Fleming. 



Physiological Economy in Nutrition. Professor R. 



H. Chittenden. 



The Field of Municipal Hygiene. Professor Edwin 

 O. Jordan. 



University Tendencies in America. President 

 David Starr Jordan. 



The Improvement of the City of Washington. 



Changes in the Age ol College Graduation. W. Scott 

 Thomas. 



Education Not the Cause of Race Decline, Dr. Geo. 

 J. Engelmann. 



Discussion and Correspondence : 



Magazine Science: B. F. L. 

 Scientific Literature : 



Hermann von Helmholtz. 

 The Progress of Science : 



Josiah Willard Gibbs; The Scientific Program of 



the Louisiana Purchase Exposition ; Congresses 



of Physicians ; Scientific Items. 



CONTENTS OF JULY NUMBER 



Hertzian Wave Wireless Telegraphy. Professor J. 



A. Fl.KMING. 



Why a Flame emits Light— the Development of the 

 Theory. Professor Robert Montgomery Bird. 



Evolution, Cytology and Mendel's Laws. O. F. Cook. 



The Pearl Fisheries of Ceylon. Professor W. A. 

 Hkrdman. 



A Comparison of Lasd and Water Plants. Profes- 

 sor George James Peirce. 



The Preservation of Wild Flowers. Frances Zirn- 

 qiebel. 



An Untilled Field in American Agricultural Edu- 

 cation. Kenyon L. Butterfield. 



The Story of English Education. J. E. G. de Mont- 

 morency. 



Discussion and Correspondence : 



The Decreasing Size of American Families : C. E. 

 Smith. 



Scientific Literature : 

 Psychology. 



Progress of Science : 



Lord Kelvin on ' Creative Purpose '; Celebrations 

 in honor of Dalton and Llebg; The American 

 Museum of Natural History ; The American Phil- 

 osophical Society ; Scientific Items. 



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