SECTION II. 



COMPOSITION or THE DRY MATTER OF PLANTS AND ANIMALS. 



All plants and animals are made up of water and dry matter. 

 The water is composed of hydrogen and oxygen while the dry 

 matter contains many elements and combinations of elements. 



Composition of the Dry Matter of Plants. — According to Jor- 

 dan,^ a German scientist, Knop, estimated: "That if all the 

 species of the vegetable kingdom, exclusive of the fungi, were 

 fused into one mass, the ultimate composition of the dry matter 

 of this mixture would be the following:" 



Per cent. 



■ 45 



42 



6.5 



1-5 



5-0 



Carbon 



Oxygen 



Hydrogen 



Nitrogen 



Mineral compounds (ash) 



From the above analysis it is readily seen that carbon and 

 oxygen make up the largest proportion of plants. Let us ex- 

 amine the analyses of some farm products that are familiar to us, 

 and find out if this same predominance of carbon and oxygen 

 exists.^ 



Carbon 

 Per cent, 



Oxygen 

 Per cent. 



Hydrogen 

 Per cent. 



Nitrogen 

 Per cent. 



Ash 

 Per cent. 



Clover hay 



Wheat kernel. .. 



Fodder beets 



Fodder beet leaves 

 Wheat straw.... 



47-4 

 46.1 

 42.8 

 38.1 

 48.4 



37.8 

 43-4 

 43-4 

 30.8 



38.9 



5.0 

 5.8 

 5.8 

 5-1 

 5-3 



2.1 

 2-3 

 1-7 

 4-5 

 0.4 



7-7 

 2.4 

 6.3 

 2r.5 

 7.0 



There is some variation in the composition of these farm 

 products but the carbon and oxygen constitute the largest 

 amounts of the elements present. 



This predominance of carbon and oxygen is due to the fact 

 that about nineteen-twentieths of the plant's food is obtained 

 from air and water, and the remaining one-twentieth is derived 

 from mineral compounds of the soil and soil water. 



1 Jordan, " The Feeding of Animals." 



