222 Farmyard Manure. 



become oxydised and chano:ed into sulphuric acid, which^acid 

 entering into combination with lime, produces in its turn gypsum. 

 Farmyard manure thus contains a quantity of gypsum, which 

 becomes more considerable as the fermentation of the dung pro- 

 ceeds. Without pushing deductions from this fact too far, it 

 may be observed that it is interesting at all events to find that in 

 the fermentation of dung, gypsum, a well known fixer of am- 

 monia, is produced simultaneously with volatile compounds of 

 ammonia. 



Besides the humus-like organic substances which we have 

 seen are produced in fermenting dung-heaps, an additional 

 fixer of ammonia, i. e. gypsum, is generated ; and thus great care 

 is manifested by nature to prevent, if possible, the loss of this 

 valuable fertilizing substance. 



Fresh Farmyard Manure (No. III.), Spread. 



The manure being covered with snow on the 14th of February, 

 when the other experimental heaps were analysed, and it having 

 been found next to impossible to remove the snow completely, 

 or to mix it thoroughly with the manure, nothing was done in 

 this month with the spread experimental farmyard manure. 



Well-rotten Dung (No. IV.), Exposed. — Put up Dec. 5, 1854. 

 Analysed again, Feb. 14, 1855. 



This experimental heap has been exposed to the influence of 

 the weather for a period of 2 months and 9 days. During that 

 time it had shrunk considerably in size. The diminution in bulk, 

 however, I believe, is not so much the result of an actual very 

 great loss, as it is due to the manure gradually settling down 

 and becoming firmer. Still it has undergone some loss in keeping 

 even during the cold time of the year, as will be seen from the 

 subjoined analyses. 



In the state in which the well-rotten dung was analysed on the 

 14th of February it furnished the following results : — 



Wellrrotten Farmyard Manure (No. IV.), Exposed. 



^Analysis made Feb. 14, 1855. 



Composition of Manure inNatural State. 



Water 73-90 



* Soluble organic matter 2*70 



Soluble inorganic matter (ash) : — 



Soluble silica -147 



Phosphate of lime '129 



Lime -018 



Cany forward .. .. 76'60 



