CONTENTS 



Original Papers ■» 



Page 

 Radiotelegraphy. — Damped and undamped oscillations. L. W. Austin Ill 



Suitable wire sizes for high frequency resistance. L. W. Austin 112 



Analytical Chemistry. — The accurate volumetric determination of phosphoric 



acid in phosphate rock. John G. Fairchild 114 



Geology. — Age of the Worcester phyllite. David White. 115 ' 



Botany. — Annona diversifolia a custard-apple of the Aztecs. W. E. Safford. 118 



Ethnology. — Definitions of two primitive social states. O. F. Cook 125 



Evolution. — The story of evolution as revealed by a scolytid beetle. 



Andrew D. Hopkins 129 



Abstracts 



Meteorology 133 



Geology 133 



Mineralogy 134 



Terrestrial Magnetism 135 



Physical Chemistry 135 



Proceedings 



Washington Academy of Sciences 136 



Anthropological Society 137 



Philosophical Society 139 



Botanical Society 140 



