2S8 Farmyard Manure. 



the analysis made in Auo^ust and in November, 1855, will be 

 found to correspond perfectly in their general bearings with the 

 other analyses. Having obtained the results by carefully exe- 

 cuted analyses, I did not feel justified in introducing corrections, 

 even in case such corrections seemed desirable to be made. A 

 critical mind will derive from the two last analyses as much 

 instruction as from the three preceding. They afford, at the 

 same time, a dii'ect proof of the necessity of not being satisfied 

 with one or two analyses in researches of this kind, and show 

 that trustworthy deductions can be derived only from a series of 

 carefully conducted analyses. It is too often the case that cor- 

 rections are introduced into analyses which cannot always be 

 referred to plain and evident disturbing causes ; and as such a 

 course, if tolerated, opens at once the door to abuse, I have ever 

 set my face against such a practice, and therefore prefer to state 

 my results as I get them, whether or not they agree with others. 



The preceding analyses furnish plain evidence that the consti- 

 tuents of the manure under shed have become far less altered in 

 composition than in the case of the experimental heap No. II. 

 And, indeed, the physical condition of the heap under shed 

 affords a convincing proof of the fact that fresh farmyard manure 

 does not properly ferment when it is kept under cover, and the 

 water, which constantly evaporates from its surface, is not 

 replaced by pumping occasionally water or liquid manure over 

 the heap. 



The fermentation, however, of the dung cannot be entirely 

 prevented by this mode of treatment. As inight have been 

 expected, fermentation is more perceptible in the first experi- 

 mental periods than in the succeeding. By the time the per- 

 centage of water in this manure had become reduced to 56 per 

 cent., practically speaking a stop was put to further fermenta- 

 tion, and the manure remained very much in the same condition, 

 at the end of the experimental year, in which it was found at the 

 end of April. 



In the next Table the composition of the whole heap under 

 shed, as calculated from the preceding analyses, is given (p. 239). 



A reference to the Table will show that the loss incurred in 

 keeping of fresh farmyard manure under cover is greatest in the 

 first experimental period, and that this loss principally affects the 

 insoluble organic matter. Thus, when put under cover, the whole 

 heap contained, in round numbers, 839 lbs. of insoluble organic 

 substances, whilst after a lapse of six months only 41Q lbs. were 

 left over. One half of the total amount of insoluble organic 

 matters thus has been dissipated, in the form of carbonic 

 acid and other gaseous products of decomposition, in the course 



