THE PEINCIPLES OF MANUEING 205 



II. SPECIAL MANURES. 



1. Phosphatic manures mineral phosphates, phos- 

 phatic guanos, prepared phosphates, etc. 



2. Phospho-nitrogenous manures bones, meatmeals, 

 fish guanos, etc. 



3. Nitrogenous manures nitrogenous organic sub- 

 stances, ammonium salts, nitrates, etc. 



4. Potash manures potash-bearing minerals, potas- 

 sium salts, wood ashes. 



5. Miscellaneous manures common salt, sodium sili- 

 cate, gypsum, magnesium salts, sulphate of iron, etc. 



