NITEOGENOUS MANUKES 251 



and other scrap manures, but as they are of lower agri- 

 cultural value, such mixture may be regarded as of the 

 nature of adulteration. The action can be hastened by 

 steaming, fermenting, etc., but the difference produced 

 by such treatment is not sufficient to make them suit- 

 able for ordinary agricultural purposes. The proportion 

 of nitrogen varies in commercial samples from about 

 7 to 15 per cent. The average is about 12 per cent. 



Hair and Feathers. Waste hair and feathers are also 

 sometimes used as manure. They have much the same 

 composition and properties as horn. 



Woollen Rags and Shoddy. Wool may be regarded 

 as only a slightly differentiated kind of hair. It has 

 almost exactly the same chemical composition and very 

 similar properties. In the pure dry state, after removal 

 of the fat, it contains over 16 per cent, of nitrogen. 

 Ordinary mixed woollen rags, however, are not so rich 

 because a considerable quantity of cotton is now com- 

 monly woven into many of the so-called "woollen" 

 fabrics. 



Shoddy is the name given to the waste from the woollen 

 factories. It also contains varying quantities of cotton, 

 besides oil, dust, and other impurities, and is of very 

 uncertain composition. The proportion of nitrogen varies 

 from about 4 to 12 per cent., but the average is about 

 6 or 7 per cent. Woollen rags and waste have been used 

 as a nitrogenous manure for root and other crops, but 

 their action is too slow to be of much benefit. They are 

 considered more suitable for hops and garden crops, but 

 should always be composted before use. 



Dried Blood. Dried blood is a substance of very 

 different properties from any of those mentioned above. 

 It is generally richer in nitrogen and more active than 

 the best nitrogenous meat meals, and may be regarded as 

 only slightly inferior to sulphate of ammonia. For 



