254 



Farmyard Manure. 



3. The loss which well-rotten dung sustains affects principally 

 the soluble constituents. 



4. Although rotten dung diminishes less in weight than fresh 

 dung kept in the same manner for the same length of time, yet 

 rotten dung is more readily deteriorated in intrinsic value than 

 li-esh. This arises from the circumstance that in rotten dung the 

 proportion of soluble matters is much larger than in fresh. Thus 

 it will be seen that from 59'83 lbs. of solul^le organic substances 

 originally present in the manure, only 11 '38 lbs. were left over 

 at the conclusion of the experiment, and from 23*71 soluble 

 mineral matters only 10"47 lbs. 



5. It will be seen also that hardly a trace of the free ammonia 

 present in the manure when first used for this series of experi- 

 ments is left over by November, 1855 ; and that also the am- 

 monia present in the form of salts, which are easily decomposed 

 by quicklime, is almost altogether dissipated. 



i 6. Finally, it may be observed that in rotten dung exposed to 

 the weather (rain), the nitrogen present in the form of soluble 

 compounds (principally ammoniacal salts) is much more rapidly 

 wasted than in fresh dung. 



The whole tenor of this fourth series of experiments agrees 

 well with the first series. Having given in the previous pages a 

 detailed account of the changes which fresh manure undergoes in 

 becoming rotten, I shall not offer any further remarks, and con- 

 clude this experimental series by the subjoined tabulated state- 

 ments which may be found acceptable : — 



Table showing Loss in the different component parts of Experimental Heap, Xo. lY., well- 

 rotten Duno;, Exposed, at different periods of the Year, in natural state ; also Percentage 

 of Loss and Loss per Ton of original Rotten Dung. — Expressed in lbs. and fractions 

 of lbs. (N.B. The sign * prefixed to a number expresses Increase, and not Loss.) 



