122 STALL-MANURE AND STRAW. 



constituents that are always first changed ; for they 

 introduce and transfer to the other ingredients the 

 putrefactive fermentation, by the intervention of vis- 

 ible and invisible animals of all kinds (infusoria, 

 maggots, worms, etc.). If by this means their nitro- 

 gen finally enters into a volatile combination, in other 

 words, into ammonia, then it is evident that the 

 farmer who carelessly abandons his stall-manure to 

 the process of putrefaction, will in the generality of 

 cases lose considerable quantities of the manuring 

 elements it contains, and of these elements, precisely 

 those which have the highest value. With the am- 

 monia other volatile combinations of sulphur and 

 phosphorus (sulphuretted hydrogen, etc.) are simul- 

 taneously generated, and these likewise escape in an 

 aerial form. They possess an extremely offensive 

 odor, the same as that of rotten eggs, which is strong 

 in proportion to the activity of the putrefactive fer- 

 mentation. Hence from the strength of the stench 

 emitted during the putrefaction of animal manure a 

 tolerably accurate conclusion may be drawn with re- 

 spect to the loss of strength which may be feared. 

 The old maxim of the peasantry, " Whatever stinks 

 is good for manuring," is perfectly true ; the more, 

 therefore, stinking gases (containing nitrogen and 

 sulphur) and vapors escape from a dung-heap 

 into the air, the less of course can it continue to 

 retain. 



Those parts of plants which contain little or no 

 nitrogen (for instance, straw, wood, sugar, starch) 



