32 THE CHEMISTRY OF THE FARM. 



The treatment of the manure is most important. A 

 large proportion of the nitrogen is voided in the form of 

 urine, and generally the richer the diet the higher will 

 this proportion be. If, therefore, the liquid manure is 

 lost, or the solid matter is washed by rain, and the 

 washings are allowed to drain away, serious losses of 

 nitrogen and potash will occur. Hence the superiority 

 of box manure to that made in an open yard. 



It must also be recollected that the urea, which forms 

 the chief nitrogenous ingredient of urine, is speedily 

 changed by fermentation into carbonate of ammonium, 

 and as this is a volatile substance a considerable loss of 

 nitrogen will easily occur. This loss takes place chiefly 

 in the first few days, while the manure is in the stall ; it 

 is greatest with animals yielding a concentrated urine, as 

 horses and sheep. The loss may be diminished by a 

 liberal use of litter, and especially by using peat, spent 

 tan, sawdust, or peat moss instead of straw. The 

 addition of earth (not sand or chalk) to straw increases 

 its power of retaining ammonia. Sprinkling powdered 

 gypsum also diminishes the loss of ammonia. The am- 

 monia present in fresh manure gradually disappears, 

 apparently combining with the organic substances arising 

 from the decomposition of the litter. 



Farmyard manure rapidly undergoes fermentation. If 

 placed in a heap the mass gets sensibly hot, and a large 

 quantity of carbonic acid, and some marsh gas, are given 

 off. Fermentation is most active when the manure lies 

 loosely, more air then coming in contact with it; it is 

 least active when the manure heap is consolidated. When 

 fermentation occurs in consolidated, moist manure, in 

 a place protected from rain, a considerable part of the 



