MANURE. 157 



Hydrogen. 



r „L nn ) 4-242+0-707= 4-949 Carb. hydrogen. 

 Carbon 'S51-500 5 1-500 Carbon. 



Oxygen 21-288 + 2-661== 23-949 Water. 



Nitrogen 16-143+3-459= 19-602 Ammonia. 



93-173+6-827=100- Protein. 

 This is the agricultural view, and expresses at 

 once that this vast variety of substances are compared 

 to cow dung as 32 to 1, when used dry, as manure. 



220. For the purposes in view, all animal and 

 vegetable products, may be divided into two classes ; 

 those which do, and those which do not contain ni- 

 trogen. The action of these is very distinct, on the 

 elements of soil, and as manures. The first class 

 putrefies, the second does not. The first class forms 

 alkali, the second forms acids. The action of the 

 first depends on nitrogen, that of the second on 

 carbon. 



221. The first class contains flesh in all its vari- 

 eties ; blood, skin, sinew, gristle, cartilage, tendons, 

 hair, feathers, wool, hoofs, horns, nails, scales, and 

 one-third, nearly, of bones and teeth. The second 

 class contains fats and oils in all their variety. 



222. It is easily understood, then, how woollen 

 rags and flocks become powerful manure. They af- 

 ford ammonia, and 100 lbs. containing 17 of nitro- 



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