134 MANURE. 



due ? To the nitrogen, chiefest and first, and that 

 too, as it exists in the albumenous portion of clung. 

 The nitrogen of the hay contributes very little to the 

 value of manure. The hay furnishes the geine, 

 and probably all its nitrogen is employed in produc- 

 ing those forms of it, which contain that element, 

 that is crenic and apocrenic acids. That it is the 

 nitrogen of dung, only, the part not contained in 

 the hay, which evolves ammonia, is evident ; for if 

 the nitrogen of the hay only, was the essential ele-' 

 ment of manure, then hay, which contains about 

 one per cent, of nitrogen could supply its place ; 50 

 pounds would be equal to 100 pounds of dung. It 

 is well known that such effect, is never produced by 

 planting on hay. 



194. It is not to the nitrogen only, in dung, to 

 which can be referred the action of this manure. It 

 depends on its other elements, salts and geine. The 

 action of nitrogen is referred to its power of forming 

 ammonia, and this then acts in two ways. First, 

 upon geine or the hay part ; secondly, upon silicates. 

 First, it is a powerful alkali. Now it has been 

 shown that all alkalies and alkaline earths convert 

 insoluble, into soluble geine. Secondly, it is a well 

 established fact, that the production of nitre, is not 

 necessarily dependent on the presence of animal 



