PROCEEDINGS 
OF THE 
National Academy 
OF Sciences 
OF THE 
UNITED STATES OF AMERICA 
VOLUME 8, 1922 
EXECUTIVE COMMITTEE 
Edwin Bidwei.Iv Wilson, Managing Editor 
Raymond Pearl Vernon Kellogg 
PUBLISHED MONTHLY 
Publication Office: Eschenbach Printing Company, Easton, Pa. 
Editorial Office: Massachusetts Institute of Technology, Cambridge 
Home Office of the Academy: Washington, D. C. 
