*>'^ 



33 MANUAL OF aATTLE-FEEDlJN"a, 



? 3. NON-KlTKOGEN^OUS NuiEIENTS. 



Carbitydevtes. — The chief substances composing this 

 group of nou-nitrogenons nutrients are celluloHe^ or woody- 

 jiltm / starch / dextrine / cane^ grajye^ viillt^ and fnoit 

 hufjar ; and the gums. " These bodies, especially cellnlose 

 and starch, form by far the larejer share of all the dry matter 

 of vegetation, and most of them are distribnted through 

 all parts of plants." They owe their name to the fact 

 that tliey all contain, besides carbon, the elements hydrogen 

 and o\ygen in the proportions in which the latter exist in 

 water. This similarity of composition and their ready 

 transformation into each other, both artificially and in the 

 plant, show that they are nearly related chemically. 



Cellulose. — All plants consist of cells or microscopic 

 closed sacks or tubes adhering together. The walls of 

 these cells are composed of cellulose, and hence the latter 

 is a constituent of all vegetable tissue, constituting, as it 

 were, its frame-work. In those parts of the plant where 

 greater strength is needed, the originally thin walls of the 

 cells increase greatly in thickness, and often become im- 

 pregnated with a harder substance or substances known as 

 iignin, makiug them still tougher. This is especially the 

 case with the stems. Foliage, and the husks, etc., of fruits, 

 also contain much cellulose. 



Properties. — Pure cellulose is an odorlesc and tasteless 

 solid, varying somewhat in appearance, according to its 

 source, but usually white in color, and with a silky or 

 horny lustre. Cotton, flax, and hemp, and cloth and unsized 

 paper made from them are examples of nearly pure cellu- 

 jivse. 



It is distinguished from the other bodies of this group 



