REPORT 



ON 



FIELD EXPERIMENTS AND LABORATORY RESEARCHES 



ON THE 



CONSTITUENTS OF MANURES 



ESSENTIAL TO CULTIVATED CROPS. 



BY 



Dr. AUGUSTUS VOELCKER, 



ROYAL AGRICULTURAL COLLEGE, CIRENCESTER. 



[From the REPORT of the BRITISH ASSOCIATION for the ADVANCEMENT of SCIENCE 



for 1859.] 



LONDON : 

 PRINTED BY TAYLOR AND FRANCIS, 



RED LION COURT, FLEET STREET. 

 1860. 



