The Popular Science Monthly 



Entered in the Post Ojffloe in Lancaster, Pa., as second-class matter. 



CONTENTS OF APRIL NUMBER 



Recent Discoveries in Radiation and their Signifi- 

 cance. Professor R. A. Millikan. 



Evolution of the Human Form. Charles Morris. 



The Arequipa Station of Ihe Harvard Observatory. 

 Professor Solon I. Bailey. 



The Royal Prussian Academy of Science and the 

 Fine Arts, Berlin. Edward F. Williams. 



The Influence of Liebig on the Development of 

 Chemical Industries. Dr. Carl Duisberg. 



The Conservation of Energy in those of Advancing 

 Years. Dr. Madison J. Taylor. 



The Caucasian in Brazil. Thomas C. Dawson. 



The Air of the Luray Caverns. Dr. Guy L. Hunner. 



The Progress of Science : 



The Centenary of the Death of Priestley ; Pro- 

 fessor Eduard Zeller ; Charles Emerson Beecher ; 

 Science at Colorado College ; The Size of Families 

 of College Graduates ; The Study of the Sciences 

 and of Latin in the Secondary Schools. 



Index to Volume LXIV. 



CONTENTS OF MAY NUMBER 



The Development of a New Method of Research. 

 Professor George E. Hale. 



The College of the West. President David Starr 

 Jordan. 



A Question of Preference in English Spelling. Dr- 

 Edwin W. Bowen. 



Alumna's Children. An Alumna. 



The Study of Physics. Professor Frederick E. 

 Beach. 



English Herbals. Agnes Robertson. 



The Geology and Geo-botany of Asia. Prince P. 

 Kropotkin. 



The Royal Prussian Academy of Science and the Fine 

 Arts. Edward F. Williams. 



The Progress of Science : 



Agricultural Work in the Philippines; Antarctic 

 Exploration ; The Scientific Work of Professor 

 Arrhenius ; Linnseus ; President Eliot; The Will 

 of Herbert Spencer ; Scientific Items. 



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