COMPOSITION OF FARMYARD MANURE 213 



characteristic of the urine of herbivorous animals. About 

 I per cent, of sodium chloride is found in urine also, and 

 small amounts of acid sodium phosphate, phosphates of 

 calcium and magnesium, and the sulphates of sodium and 

 potassium. 



The litter which is used to absorb the liquid excretions 

 and provide a dry bed for horses, cattle and other animals 

 kept under cover is usually the straw of some of the 

 cereals ; but peat, bracken fern or dried leaves are used 

 sometimes in place of straw. All these contain large 

 amounts of cellulose with small quantities of other carbo- 

 hydrates and nitrogenous bodies, as well as the ash of the 

 vegetable tissues concerned. 



Under ordinary conditions 'on a farm the faeces, urine 

 and litter become more or less intimately mixed together 

 to form farmyard manure. This mixture is very compli- 

 cated in character and very varied in composition. The 

 amount and nature of the food, and the kind and age of 

 the animal consuming it, as well as the work done by the 

 animal, influence the composition of the manure. The 

 richer the food in proteins the richer will be the excreta 

 in nitrogen : fattening animals extract and retain less of 

 the food constituents than young growing animals, and 

 so on. Careful experiments have shown that, as a rule, 

 about 45 per cent, of the organic matter, 85 to 95 per 

 cent, of the nitrogen, and 95 to 99 per cent, of the 

 mineral constituents of the food are recovered in the 

 faeces and dung where careful arrangements are made 

 for the collection of the latter. The following analyses 

 by Stoeckhardt indicate the chief differences in composi- 

 tion between the faeces and urine of the different farm 

 animals. 



