Farmyard Manure. 225 



Arranged together. 



rSolu1>le silica 12-13 13'76 



Insoluble silicious matter (sand) . . . . 17'12 17*12 



Phosphate of lime I'-iS 



Oxides of iron, alumina, with phosphates 4*08 4'08 



Containin'4 phosphoric acid ("'''1) ('71) 



Equal to bone earth (1-11) (l-ll) 



■^^^Limc 25-05 25-24 



Magnesia -23 -43 



Potash 1-31 11-97 



Soda -17 1-10 



Chloride of sodium -56 



Sulphuric acid 1-09 1-89 



iCarbonic acid and loss 15-97 22-41 



100-00 100-00 



A glance at these analytical results will show that the propor- 

 tion of soluljle orijanic matters in the well-rotten tlung is 

 smaller in February 1855 than in December 1854. It would 

 thus appear tliat a portion of the soluble constituents has been 

 washed away by rain or meltins; snow. As the heap was small, 

 it was no doubt more readily afifected by this deteriorating cause 

 than a large heap would have been. It is moreover probable that 

 the sample of the manure which was analysed in February did 

 not fairly represent the Avhole heap. It appears to me therefore 

 very likely ihat the proportion of soluble matters in the whole 

 heap is in reality larger than is indicated by the foregoing 

 analysis. 



It will further be observed that the dry manure in February 

 contains about 2 per cent, less of organic matters than in 

 December. We have thus here a direct proof that the proportion 

 of organic matters decreases in dung-heaps even in the coldest 

 months of the year — it is true in a less considerable degree than 

 in summer, but yet to an appreciable extent. 



I would call attention to the manner in which the nitrogen is 

 distributed amongst the constituents of this manure. When just 

 removed from a well-constructed dung-pit in December 1854, 

 100 lb. of the perfectly dry manure contained 1-21 per cent, of 

 nitrogen in the form of solulile compounds ; in February 1855, 

 the soluble portion of the manure contained only '57 per cent, of 

 nitrogen, thus showing that a portion of the soluble nitrogenized 

 matters has escaped either into tlie air, or, what is more probable, 

 has been washed out by the rain or melting snow. ISotwith- 

 standing" this loss in nitrogen, the total percentage of nitrogen 

 has beconu! slightly greater bv keeping for 2 uiontlis and 

 9 days. 



With respect to the free ammonia, it will be ()bservc<l tiiat 

 rotten dung contains rather more free ammonia than fresh. The 



VOL. XVII. <l 



