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VOLUME 8 FEBRUARY, 1922 NUMBER 2 
PROCEEDINGS 
OF THE 
National Academy 
OF Sciences 
OF THE 
UNITED STATES OF AMERICA 
EXECUTIVE COMMITTEE 
Edwin Bidw«i.l Wilson, Managing, Editor 
Raymond Pearl Vernon EIellogg 
m PUBLISHED MONTHLY i 
= — 
1 Publication OflSice: Eschenbach Printing Company, Easton, Pa, 1 
1 Editorial Office: Massachusetts Institute of Technology, Cambridge 1 
1 Home Office of the Academy: Washington, D, C. 1 
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Entered as second-class matter June 21, 1920, at the postoffice at Easton, Pennsylvania, under the act of August 24, 1912- 
Acceptance for mailing at special rate of postage provided for in s&ction 1103, Act of October 3, 1917. Authorized June 18, 1920. 
^ Price per annum, $5.00 
