CONTENTS ' 



Original Papers 



Page 



Vital Statistics.^A natural population norm. Alfred J. Lotka 241 



Chemistry. — The determination of phosphorus in steels containing vana- 

 dium. J. R. Cain and F. H. Tuttle 249 



Mineralogy. — ^The refractive indices of strengite. Waldemar T. Schaller . . . 249 



Abstracts 



Metallography. . \ 251 



Biological Chemistry .^ 251 



Agricultural Chemistry 252 



Industrial Chemistry 257 



Geology 258 



Proceedings 



The Chemical Society 260 



The Botanical Society of Washington 264 



The Biological Society of Washington 267 



