NATURAL MANURES. 61 



matter are particularly valuable, when properly managed, 

 for growing onions, celery, and potatoes. Large areas of 

 peaty soils in this country, that have been properly 

 drained, are now devoted to these crops ; before draining 

 they were absolutely valueless. 



In addition to the natural farm wastes, farmers fre- 

 quently have easy access to certain factory wastes. These 

 may be divided into two classes, nitrogenous and potassic. 

 Of the nitrogenous materials, wool and hair wastes are 

 probably the most important. These are very rich in 

 nitrogen; both are, however, usually mixed with other 

 materials, and vary widely in their composition. 



Wool Waste. Wool waste contains on an average 

 ten per cent of water, five and one-half per cent of nitro- 

 gen, one per cent of phosphoric acid, and two per cent 

 of potash. 



Hair Waste. An average analysis of hair waste, as 

 determined at the New Jersey Experiment Station, shows 

 it to contain thirty-two per cent of water, seven and two- 

 tenths per cent of nitrogen, and eight-tenths per cent of 

 phosphoric acid. 



Felt Waste. Felt waste is similar to wool waste 

 in that its nitrogen is contained in the wool, though 

 variable in composition on account of the varying pro- 

 portions of cotton used in its manufacture. Analyses 

 show it to contain about eight per cent of nitrogen. 



Leather Meal. Leather meal is a product found in 

 considerable quantities in towns where the manufacture 

 of shoes is an industry. It contains on the average ten 

 per cent of water, and seven of nitrogen. The nitrogen 

 tn the leather meal is even less available than in the 



