I 



1^ i^atnre, 1 



September 20, 1917 J 



Nature 



r \ 



A WEEKLY 



ILLUSTRATED JOURNAL OF SCIENCE 



•^ 



VOLUME XCIX 



MARCH, 1917, to AUGUST, 1917. 



''To the solid ground 

 Of Nature trusts Jhe mind which builds for aye:' — Wordsworth 





MACMILLAN AND CO., Limited 

 NEW YORK: THE MACMILLAN COMPANY 



