SOILS 



THEIR 



FORMATION, PROPERTIES, COMPOSITION, AND 

 RELATIONS TO CLIMATE AND PLANT GROWTH 



IN THE 



HUMID AND ARID REGIONS 



BY 



E. W. HILGARD, PH.D., LL.D., 



PROFESSOR OF AGRICULTURE IN THE UNIVERSITY OF CALIFORNIA, AND DIRECTOR 

 OF THE CALIFORNIA AGRICULTURAL EXPERIMENT STATION 



THE MACMILLAN COMPANY 



LONDON: MACMILLAN & CO., LTD. 



