16 MODERN" HIGH FARMING. 



stoppage of any portion of our culture, will enable us to vastly 

 increase, if not more than double our yearly production . 



Having shown that nitrogen can only enter into combination and 

 be fixed in the presence of combustion, no better agent for 

 helping this process can well be imagined than farm-yard 

 manure, of which in a subsequent chapter we shall have a great 

 deal to say. 



Ploughed into the field, this decomposed, rotting, or carbonized 

 mass attracts the nitrogen during the whole course of its carboniza- 

 tion, and having fixed it, enables it subsequently to undergo the 

 various transformations which render it assimilable, and allow of its 

 passing from the soil into the plant. 



In what form vegetables assimilate the nitrogen thus fixed, 

 it is very difficult to determine ; nor do any of our best authorities 

 seem to agree upon the issue. Our own opinion, based upon the 

 phenomenon of nitrification and the constant formation of nitrates 

 in the soil, is that the nitrogen absorbed into the sap is brought 

 into contact with the oxygen set free by the decomposition of 

 carbonic acid, and thus forms nitric acid, which penetrates into all 

 the tissues. 



It may be urged against us that plants are organs rather of re- 

 duction than of oxidation, and that the nitric acid itself would 

 undergoing a decomposition similar to that of carbonic acid and 

 water be transformed into ammonia by the hydrogen then being 

 produced ; but our own researches have been sufficiently elaborate 

 to justify us in the meantime in maintaining our ground. 



That nitrogen is assimilable in its free and natural state, we posi- 

 tively refuse to admit, and, although it forms four-fifths of the vol- 

 ume of atmospheric air, and exists in appreciable quantities in the 

 soil, only an insignificant portion would, in the absence of all com- 

 bustion, be available for the nourishment of the plants. 



Presuming, therefore, that carbonized materials of any kind are 

 not sufficiently abundant to well cover the ground after each crop 

 and this is generally the case we have to bear in mind that 

 we continually take away large quantities of nitrogen, which 



