ON THE 



COMPOSITION AND VALUE 



OP 



NORWEGIAN APATITE, 

 SPANISH PHOSPHORITE, COPROLITES, 



AND 



OTHER PHOSPHATIC MATERIALS 



USED IN ENGLAND FOR AGRICULTURAL PURPOSES. 



BY DR. AUGUSTUS YOELCKER. 



LONDON: 

 PRINTED BY W. CLOWES AND SONS, STAMFORD STREET, 



AND CHAB1NQ CROSS. 



1861. 



