

HOW CROPS GROW. 



A. TREATISE ON THE 



CHEMICAL COMPOSITION, STRUCTURE 

 AND LIFE OF THE PLANT, 



FOB STUDENTS OF AGRICULTURE. 



2. 2. / 3 -5 

 BY 



SAMUEL W. JOHNSON, M. A., 



PROFESSOR OF THEORETICAL AND AGRICULTURAL CHEMISTRY TS THE SHOT 



FIELD SCIENTIFIC SCHOOL OF YALE UNIVERSITY ; DIRECTOR O 



THE CONNECTICUT AGRICULTURAL EXPERIMENT STATION; 



MEMBER OF THE NATIONAL ACADEMY OF SCIENCES. 



StVISED AND ENLARGED EDITiqy. 



OEANGE JUDD COMPANY, 



1911 



