

Nature 



A WEEKLY 



ILLUSTRATED JOURNAL OF SCIENCE 



VOLUME CIV 



SEPTEMBER, 1919, to FEBRUARY, 1920 



" T» th* solid ground 

 Of Nature trusts the mind wkifk builds for a/*."— Wordsworth 



■J? 



%tmtitm 



MACMILLAN AND CO., Limited 

 NEW YORK: THE MACMILLAN COMPANY 



