iv CONTENTS. 



Problems in Petrology. By Joseph P. Iddings 286 



A Study of the Tertiary Floras of the Atlantic and Gulf Coastal 



Plain. By Edward W. Berry 301 



An Optical Phenomenon. By Francis E. Nipher 316 



Symposium 



I. The Alodern Theory of Electricity and Matter. By 



Daniel F. Comstock 321 



II. Radioactivity. By Bertram B. Boltwood 333 



III. The Dynamical Effects of aggregates of Electrons. 



By Owen W. Richardson 347 



IV. The Constitution of the Atom. By Harold A. Wilson, 



F.R.S 366 



The High X^oltage Corona in Air. By J. B. Whitehead 374 



Disruptive Discharges of Electricity Through Flames. By 



Francis E. Nipher 397 



The Desert Group Nolineje. By William Trelease 405 



Isostasy and Mountain Ranges. By Harry Fielding Reid. . . . 444 

 A Fossil Specimen of the Alligator Snapper (Macrochelys tem- 



minckii) from Texas. By Oliver P. Hay 452 



An Hydrometric Investigation of the Influence of Sea Water 



on the distribution of Salt Marsh and Estuarine Plants. By 



John W. Harshberger, Ph.D 457 



The Cost of Living in the Twelfth Century. By Dana C. Munro 497 

 An Ancient Protest against the Curse of Eve. By Paul Haupt 505 

 Obituary Notices of Members Deceased 



Henry Charles Lea iii 



Jacobus Henricus Van't Hoff iii 



George Frederick Barker, M.D., Sc.D., LL.D xiii 



Minutes iii-xiv 



Corrigendum xv 



Index xvii 



