Farmyard Manure. 221 



be seen that the fresh manure contained in November 7*33 of 

 soluble organic matter, and in February hardly 1 per cent, more, 

 namely, 8"04 per cent. 



In the fresh, the percentage of nitrogen in the soluble organic 

 matter is '44, and in the same manure kept 3 months 11 days 

 under shed, the nitrogen amounts to "53 of a per cent. It also 

 contains but a trifling amount of free ammonia, and ammonia in 

 the form of salts. 



Apparently the manure has lost a good deal of organic in- 

 soluble inatter, almost as much as the exposed heap. If, how- 

 ever, we scrutinize the results obtained in the analysis, it will be 

 seen that the manure under shed contains a more considerable 

 proportion of insoluble ash, and in this more lime and insoluble 

 silicious matter, than occurs in the experimental heap (No I.) 

 exposed to the weather for the same length of time. In the 

 latter the mineral insoluble matter we would naturally expect to 

 increase, since the solulile constituents are exposed to the solvent 

 action of falling rain. The manure vindershed cannot be subject 

 to this deteriorating influence. If we find, notwithstanding, more 

 insoluble mineral matters than in the manure exposed to the 

 ■weather, it is plain that the larger amount of insoluble mineral 

 matters, which causes the apparent diminution of insoluble organic 

 compounds, can only be due to a larger proportion of mechanical 

 earthy impurities in the sample analysed. In pi'oof of this view 

 of the matter it may further be stated that the manure kept under 

 shed for another 3 months furnished even a little less insoluble 

 mineral matter than in February. And as in the warmer spring 

 months a more considerable diminution of organic substances 

 has really taken jilace, as shown by the analyses to be mentioned 

 hereafter, the excess of insoluble mineral matters in the February 

 analysis can only be accounted for by mechanical impurities in 

 the sample of wliich the analysis has been made. 



If we make due allowance for this disturbing influence, it will 

 be observed that the composition of the soluble and insoluble 

 portion of the ashes, furnislicd by the fresh manure in Aovember, 

 and of the same heap kept under shed for o montlis 11 days, is 

 almost identical. It deserves to be noticed specially, that the 

 asli of tlie manure kept under shed contains more pliosphate of 

 lime (bone-earth) than the asli produced by the heap exposed to 

 the weather for the same length of time, during which the second 

 experimental heap has been kept under shed. 



1 also beg to direct attention to the fact that this manure, as 

 well as tlie jireceding experimental heap, contains more sul- 

 phuric acid than tlie heap when first put up. On keeping of 

 <lung some of the sulj)hur, which we know occurs in nitrogenized 

 substances in a peculiar state of organic combination, appears to 



