Farmyard Manure. 231 



a period ; for after February neither the percentage of soluble 

 organic nor that of soluble mineral matters has become greater ; 

 and the percentage of nitrogen in the manure of April and 

 August is only a very little higher than in February. 



Weight for weight, the February manure thus will be as good 

 as the manure in April or August, and slightly superior to the 

 manure in November, 1855. The direct weighings, however, 

 of the whole heap have shown us already that a considerable loss 

 in weight is experienced in the different periods during which 

 the manure was kept. And as the fresh manure did not improve 

 in composition after the 14th of February, it is clear that the 

 loss in weight is not due to the mere evaporation of water or the 

 dissipation of other useless constituents, but is a real loss in 

 valuable fertilising constituents. 



That this is reallv the case appears still more decidedly if we 

 consult the direct weighings of the experimental heap, and the 

 composition of tlie manure at the time at which the weighings 

 were made. This will enable us to calculate the composition of 

 the whole heap at the different experimental periods, and we 

 shall then see in what manner the loss in weight is distributed 

 amongst the various constituents of the manure. 



In the following Table the composition which the whole 

 experimental heap, No. I., exhibited at different periods of the 

 year, has been calculated from data already given. The actual 

 weight of the manure heaps is again stated in the first horizontal 

 column ; in the second horizontal column, the actual amount of 

 water in the whole heap is stated ; and in the third, the total 

 amount of dry matter. The next four (bracketed together) show 

 the composition of the dry matter. All numbers in the Table 

 ex})ress pounds or fractions of pounds. 



A careful study of the Table will convince the reader that 

 the real loss in valuable fertilising matters which farmyard 

 manure sustains in keeping is very much greater than is indicated 

 by the direct weighings of the experimental heaj). It will be 

 remembered that the manure, when put up in a heaj) on the 3rd 

 of .November, 1854, contained (i(I-17 per cent, of water, and con- 

 sequently 33*83 per cent, of dry matters. The total amount of 

 dry matter in the perfectly fresh experimental heap amounted 

 to D60'10 11)s. ; but, after having been exposed to the influence 

 of the weatlicr for a period of nine months, only 4887 lbs. of 

 drv sul)stance are left behind. The dire( t weighing of the heaj) 

 in .\ugust indicates a loss of 2'.)'77 per cent., whereas in reality 

 a loss of very nearly 50 per cent, in the solid constituents of the 

 manure has been incurred. 'i'his enormous n-astc in manur- 

 ing matters, it will appear likewise from a careful perusal 

 of the Table, mav lie jirevented, at least to a verv great c\- 



