vn 1 LOSSES DURING DUNG-MAKING 195 



that urea had been transformed into ammonium 

 carbonate and volatilised, or broken up with loss of 

 free nitrogen — but also that some of the active nitrogen 

 had been converted into an insoluble form, as though 

 the bacteria swarming in the dung had seized upon the 

 active nitrogen and converted it into the insoluble 

 material of their own substance. Of course, this with- 

 drawal of nitrogen from the active into the insoluble 

 form still further reduces the value of the dung as a 

 whole. 



In France, experiments were carried out on the 

 same question by MM. Miintz and Girard, with 

 omnibus horses, cows, and sheep. They showed that 

 with horses and milking cows, where the manure was 

 removed every day, the loss of nitrogen amounted to 

 from 30 to 35 per cent, of the total nitrogen contained 

 in the food. With sheep the losses were still higher. 

 Liberal littering and immediate treading of the excreta 

 into it by the animal greatly reduced this loss. The 

 results are given in Table LV. It is apparent that, on 

 the whole, the proportion of the nitrogen recovered in 

 the manure is about one-half of that supplied in the food. 



Further experiments with sheep show that the loss 

 was greatest with no litter, and could be reduced by 

 using an excess, or particularly by using peat moss or 

 earth. 



Loss I Loss 



per cent. Per cent, 



--No Litter. . 590 Horses ^^" ^^''^^ ' ^^'° 



P ^ J Litter. . . 50-2 • \ » Peat Moss 44-1 



*^' I Litter. . . 44-2 j r On Straw . 502 



'-Abundant Litter 408 | i>heep.| ^^ ^.^^^j^ ^ 



Experiments of the same kind have also been 

 carried out on the farm of the Royal Agricultural 

 Society at Woburn for some years, and the results 

 obtained in 1899, 1900, and 1901, are given in Table LVI. 



