27Q 



IIOAV CROPS FEED. 



Ammonia, Nitbates, ^yn Organic Nitkogen of various Boils. 



* The same soil whose partial analysis has just been given, but examined for 

 nitrates at another time. 



It is seen that in all cases the nitrogen in the forms of 

 ammonia f and nitrates J is much less than that in organic 

 combination, and in most cases, as in the Liebfrauenberg 

 garden, the disparity is very great. 



Nature of the Nitrogenous Org.anic Matters. Amides. 



— Hitherto we have followed Mulder in assuming that the 

 humic, ulmie, crenie, and apocrenic acids, are destitute of 

 nitrogen. Certain it is, however, that natural humus is 

 never destitute of nitrogen, and, as we have remarked in 

 case of peat, contains this element in considerable quanti- 

 ty, often 3 per cent or more. Mulder teaches that the 

 acids of humus, themselves free from nitrogen, are nat- 

 urally combined to ammonia, but that this ammonia is 

 with difficulty expelled from them, or is indeed impossible to 

 separate completely by the action of solutions of the fixed 

 alkalies. In all chemistry, beside, there is no example 

 of such a deportment, and we may well doubt whether 

 the ammonia that is slowly evolved when natural humus 

 is boiled with potash is thus expelled from a humate of 

 ammonia. It is more accordant with general analogies to 



+ .\mmonia contains 82.4 per cent of iiilroQ-on. 



^ Nitrate ot ootash contains Ti.b pjr cent of nitrogea. 



