FOUR LECTURES 



ON 



FARMYARD MANURE, ARTIFICIAL MANURES, 



BARREN AND FERTILE SOILS, 



OIL-CAKES, &c. 



BY DR. AUGUSTUS VOELCKER, F.C.S., 



PROFESSOR OF CHEMISTRY IN THE ROYAL AGRICULTURAL COLLEGE, CIRENCESTER, 



HONORARY MEMBER OF THE HANOVERIAN AGRICULTURAL SOCIETY, AND 



CONSULTING CHEMIST TO THE BATH AND WEST OF ENGLAND 



AGRICULTURAL SOCIETY. 



LONDON: 



PUBLISHED BY J. KIDGWAY, 169, PICCADILLY. 

 1857. 



