Farmyard Manure. 29 



3. That the total percentage of organic substances decreases, 

 whilst that of mineral matters increases. Thus the fresh manure 

 contained 



In Nov. In Feb. 



Organic matters .. 28-24 22-30 



Mineral matters 5'59 7'87 



And the perfectly dry manure 



Organic matters 83'48 73-91 



Mineral matters 16-52 26'09 



4. That the percentage of nitrogen in the February analysis is 

 slightly greater than in November. 



5. That there is about the same inconsiderable amount of free 

 ammonia, and ammonia in the form of readily decomposable salts, 

 in the manure in February which has been found in November, 

 1854. 



6. With respect to the inorganic constituents, a careful perusal 

 of the furnished ash-analyses will show that the soluble portion 

 of the ash of the February manure contains less phosphates of 

 lime and less soluble silica, but more sulphuric acid, than the 

 soluble ash of the perfectly fresh manure analyzed in November. 

 The insoluble portion of the ash in February likewise contains 

 less phosphates and soluble silica than in November, and the 

 same differences will be observed on comparing the whole ash of 

 February with that of November. It would appear thus that a 

 three months' exposure to the weather has had the effect of 

 removing from the manure an appreciable quantity of two very 

 important fertilizing substances, namely, phosphate of lime (bone- 

 earth) and soluble silica. 



I purposely abstain from pointing out minor differences, 

 which will be observed in the November and February analyses 

 of this manure ; for it must be borne in mind that, in experi- 

 ments with farmyard manure, a perfectly uniform mixture can 

 scarcely be obtained. Minor variations in the composition of 

 the manure of November and February, therefore, may result as 

 likely from purely accidental causes as from any real difference 

 in composition. The particulars, however, just mentioned are 

 sufficiently marked to prove that they are not due to accident, 

 but to a series of changes which the fresh manure has undergone 

 in the course of 3 months and 11 days. 



Fresh Farmyard Manure (No. II.), Under Shed. Put up Nov. 3, 

 1854. Analyzed again in Feb. 14, 1855. 



The fresh manure used for all experiments was rather dry, no 

 rain having fallen during the fortnight, in which the dung was 

 collected from the stable, cow-house, and piggeries. 



