Fermentation. 249 



less as manure unless the woody fibre (which is 

 about all that evaporation has left remaining) is 

 decomposed by the aid of lime. 



English farmers undoubtedly prefer using cattle 

 manure considerably fermented, and in the state 

 known by them as " short muck/' so that it can be 

 cut with the spade ; on the grounds that in this 

 condition it contains more humic acid, which with 

 carbonic acid gas constitutes, according to Mr. 

 Loudon, the chief food of plants. That writer 

 remarks, " It has been proved that rotted dung 

 contains more humic acid and carbonic acid gas, 

 weight for weight, than fresh dung." 



Drawing a line between the slight fermentation 

 recommended by Sir Humphrey Davy, and the 

 excessive decomposition required by the English 

 farmer, we may perhaps arrive at the happy 

 medium on this point. 



Mr. Loudon describes a method of manufacturing 

 liquid manure, practised by the farmers in German 

 Switzerland, which might be practised with advan- 

 tage occasionally on estates. The animals are 

 stalled on a boarded floor, having a downward 

 inclination of four inches to the hinder part of the 

 cattle, whose excrement falls into a gutter behind, 

 fifteen inches deep and ten wide. This gutter is so 

 formed as to be capable of receiving water from a 

 reservoir at pleasure, and communicates with four 



