CONSTITUENTS OF MANUBES. 175 



alone, especially in analyses of organic manures or those 

 containing nitrates. If the nitrogen content be stated, no 

 error as to its state of existence can be conveyed, and its 

 equivalent in ammonia or nitrogen pentoxide is easily cal- 



N.O- 



culated, since N = NH 8 = or 14 of nitrogen correspond to 



2i 



17 of ammonia or 54 of nitrogen pentoxide. 



The most complete way would be as follows : 



% 

 Total nitrogen 



f Ammoniacal nitrogen 

 of which is-. Organic nitrogen ... 

 I Nitric nitrogen 



The analysis of a manure is usually directed to the determi- 

 nation of the amounts of one or more of the three substances 

 nitrogen, phosphorus pentoxide, or potash present, and to the 

 detection of the presence, and if necessary the determination 

 of the amount, of any possibly harmful or objectionable ingre- 

 dients. 



The following table gives a list of most of the commercial 

 manures, W 7 ith their valuable and objectionable ingredients : 



I. NITROGENOUS MANUBES. 



Name. Constituents of value. Harmful constituents. 



Dried flesh ... 



,, blood 

 Shoddy and woollen 



waste 



Organic nitrogen. Oily matters. 



Hair, horn, and leather 



waste 



Kape and other oil- Organic nitrogen (phos- Oil. 



seedcakes '... phoric acid). 



Sulphate of ammonia Ammoniacal nitrogen. Thiocyanates, 



arsenic. 



Nitrate of soda ... Nitric nitrogen. Perchlorates, 



chlorides. 

 Nitrate of potash ... ,, ,, and potash. 



Soot ... ... Ammoniacal and organic 



nitrogen. 



