CONTENTS 



Original Papers 



Page 

 Physics. — Note on the vibration frequencies of elastic systems. M. D. 

 Hersey 437 



Crystal Optics. — Dispersion and other optical properties of carborundum. 

 H. E. Merwin 445 



Mineralogy. — The nomenclature and classification of the native element 

 minerals. Edgar T. Wherry 447 



Mineralogy. — The crystal form of spencerite. T. L. Walker 456 



Ethnology. — A prehistoric stone mortar from southern Arizona. J.Walter 

 Fewkes 459 



Abstracts 

 Technology 464 



References 



Astrophysics 465 



Geophysics 465 



Terrestrial Magnetism 466 



Geodesy 466 



Gravitation 466 



Physics 466 



Chemistry .' . ._ 469 



Metallography '. 470 



Technology 470 



Proceedings 

 The Philosophical Society of Washington 473 



