4-2-^r 



JAN 11 1921 

 PROCEEDINGS 



OF THE 



American Philosophical Society 



HELD AT PHILADELPHIA 



FOR PROMOTING USEFUL KNOWLEDGE 

 A^ol. LIX. 1920. No. 6. 



CONTENTS 



PHILADELPHIA 



THE AMERICAN PHILOSOPHICAL SOCIETY 



104 South Fifth Street 



1920 



PAGa 



Interrelation of the Fossil Fuels. IV. By John J. Stevenson - - 405 



Geographic Aspects of the Adriatic Problem. By Douglas Johnson - 512 



Certain Aspects of Recent Spectroscopic Observations of the Gaseous 

 Nebulae which Appear to Establish a Relationship between them 

 and the Stars. By W. H. Wright - - - - - - - -'517 



Minutes ------------ iii 



Index --------------------- xvi 



