SOOT, DEIED BLOOD, &C. 37 



render the potash and phosphates in the soil available to 

 crops. It is quicker in its action than any other nitro 

 genous manure, and is therefore the best manure to em- 

 ploy when a late dressing has to be given. 



Soot, Dried Blood, Powdered Horn, and Woollen Refuse 



are all purely nitrogenous manures. Soot owes its value 

 to the presence of a small and variable quantity of am- 

 monium salts. In good house soot the nitrogen may be 

 3*5 per cent. Dried blood is an excellent manure, con- 

 taining 9 12 percent, of nitrogen. Hoofs and horns are 

 extremely rich in nitrogen, the proportion being usually 

 15 per cent. Shoddy, and other forms of wool, are very 

 variable in composition, owing to the different proportions 

 of water, cotton, dirt, and grease which they contain ; the 

 nitrogen will generally range from 5 to 8 per cent. 



The nitrogen of blood, horn, wool, and hair is not in a 

 form suitable as plant food. Blood readily decomposes 

 in the soil, yielding first ammonia, and then nitric acid. 

 Horn, wool, and hair decompose much more slowly, and 

 their effect is spread over many years. 



Soot is generally employed as a top dressing for 

 spring corn. Dried blood is an excellent manure for wheat. 

 Wool and hair are chiefly used for hops. 



Meat Meal, Meat Guano. This is the residue from 

 the manufacture of meat extract. It varies in com- 

 position according to the amount of bone ground up with 

 the meat fibre. The nitrogenous kinds contain 11 13 per 

 cent, of nitrogen, and O6 3*0 per cent, of phosphoric acid. 

 The phosphatic kinds contain 6 7 per cent, nitrogen, and 

 14 17 percent, phosphoric acid. 



