Farmijard Manure. 207 



The comparison of these analytical results Avith the numbers 

 ol)tained in the analysis of the fresh manure, exhibits several 

 strikin<2^ differences, to some of which I he^ to direct attention. 



1. The well-rotten dung contains nearly 10 per cent, more 

 water than tlie fresh. Tiie larger percentage of water, it is true, 

 may be purely accidental ; but, considering the tendency of the 

 liquid excrements to sink to the lower part of the manure pit in 

 which the rotten dung accumulates, I believe rotten dung will 

 always be found moister than fresh dung upon which no rain 

 has fallen. 



2. Notwithstanding the much larger percentage of moisture in 

 the well-rotten dung, it contains in its natural state, wdth 75^ per 

 cent, of water, almost as much nitrogen as the fresh dung, with 

 only 66 per cent, of moisture. Supposing both to be equally 

 moist, there Avould thus be considera!)ly more nitrogen in rotten 

 dung tlian in an equal weight of fresh. This is clearly observed 

 by comparing the total amount of nitrogen in the perfectly dry 

 fresh and rotten dung. In the former it amounts to 1"90 per 

 cent, of nitrogen, in the latter to 2*47. As far as this most 

 valuable element is concerned, farmyard manure becomes much 

 richer, weight for w'cight, in becoming changed from fresh into 

 rotten dung. 



3. Daring the fermentation of the dung the proportion of 

 insoluble organic matters greatly diminishes ; thus the dry fresh 

 manure contained 76 per cent, of insoluble organic matters, whilst 

 there were only 52 per cent, in the dr}'^ rotten dung. 



4. It is especially worthy of observation that, wliilst the inso- 

 luble organic matter is m.uch reduced in quantity during the 

 fermentation, the insoluble organic matter which remains behind 

 in rotten dung is richer in nitrogen than an equal quantity of in- 

 soluljle organic matter from fresh dung. Thus 76 per cent, of 

 insoluble organic matter of fresh dung contain 1"46 per cent., 

 wliilst 52 per cent, of it from rotten dung very nearly contain the 

 same quantity, namely, 1'26. Or, — ■ 



ino iiarts of insoUihlc organic matter \ , .,., i. r -i 



irom fresh auiipi; contain j ^ ^ 



100 ])arts of insohil>lc organic matter ) ,^ .. 



from rotten dung contain .... J " " " 



5. On the other hand, the relative proportion of insoluble 

 inorganic matters increases much during the fermentation of the 

 dung, since dry fresh dung contains about 12 per cent, of 

 insoliiI)l(; mineral matters, and dry well-rotten dungs 2t"c,S per 

 cent., or more than douljle the amount which is found in fresh 

 dung. 



6. But perhaps the most striking diflcrencc in the compo- 



