COMPOSITION OF FARM- YARD DUNG. 



269 



The average or mean composition of this mixture may be taken 

 as follows : 



On comparing the composition of the dung-heap with that of the 

 different kinds of litter collected in a day, little difference is ob- 

 served ; the larger quantity of saline and earthy matters discovered 

 in the fermented manure is readily explained from the additions of 

 ashes incorporated with it, and also by the accidental admixture of 

 earthy matters proceeding from the sweepings of the court, the 

 earth adhering to the roots consumed as food, &c. — refuse of every 

 kind, the residue after cleansing the various kinds of fodder for the 

 stable and stall, &c., all goes to the dung-heap. Lastly, and with 

 reference to the elements that are liable to be dissipated in the state 

 of gas, or which'may be changed into water, the azote is percepti- 

 bly in larger quantity in the prepared manure than in the unfer- 

 mented litter and excretions. This is at once seen on comparing 

 the composition of these two products after the saline and earthy 

 matters have been deducted. 



The composition of fresh litter, is. 

 That of dung 



Carbon. Hydrogen. 

 .49.3 5.8 



..52.8 6.1 



Oxygen. 

 42.7 

 33.1 



Azote. 



2 



3.0 



Dung is, therefore, somewhat richer in carbon than litter, and it 

 contains less oxygen. It is the property of lignine undergoing de- 

 composition, that it yields a product which relatively abounds more 

 in carbon than the original matter, in spite of the carbonic acid 

 which is formed and thrown off during the alterations undergone ; 

 this is owing to the elements of water being thrown off in relatively 

 still larger quantity at the same time. 



Fermented dung contains less oxygen than that which comes 

 from tb^ stable; it ought also to contain less hydrogen: but this 

 analysis does not proclaim. It must be observed, however, that the 



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