pllllllilllililiiliillillilii 
i 
§ 
VOLUME 8 MAY. 1922 NUMBER 5 
PROCEEDINGS 
OF THE 
National Academy 
OF Sciences 
OF THE 
UNITED STATES OF AMERICA 
I 
EXECUTIVE COMMITTEE 
Edwin Bidwell Wilson, Managing Editor 
Raymond Pearl Vernon Kellogo 
I PUBUSHED MONTHLY | 
I Publication Office: Eschenbach Printing Company, Easton, Pa, 1 
i Editorial Office: Massachusetts Institute of Technology, Cambridge g 
I Home Office of the Academy: Washington, D. C. | 
1 i 
Bntcrcd »s second-class matter June 21, 1920, at the poatof&ce at Easton, Pennsylrania, under the act of August 24. 1912, 
Acceptance for mailing at special rate of postage provided for in section 1103, Act of October 3, 1917. Authorized June 18, 1020. 
Price per annum, $5.00 
