MANUAL OF CATTLE-FEEDIJTG. 41 



diflferent fodders according to tliis method lias a varviiis? 

 appearance and conipobition ; the crude fibre, e. g.^ pre- 

 pared from liay and straw, contains 45 to 46 per cent, of 

 carbon, while that from clover hay and the straw of the 

 legumes contains 48 to 4& per cent, of the same element ; 

 that is, the latter is richer in ligniii than the former. 



It is evident from these considerations that the enxde 

 fibre is not a definite body, but a variable mixture of several 

 substances. The method just described is, indeed, simply 

 a conventional one, agreed on by chemists for lack of a 

 better, and the term crude fibre simply means the residiie 

 obtained by treating the fodder in the prescribed manner. 



The resxdts, especially when combined with digestion ex- 

 periments, are of great value, but it is still nnich to be re- 

 gretted that no more accurate method has yet been devised. 



Stareli. — Next to water and cellulose, starch is the most 

 abxmdant substance in the vegetable world, being found 

 in all plants and in ahnost all parts of them. It appears 

 to be first formed in the green leaves, as tlie product of 

 the reduction of the carbonic acid of the air under the in- 

 fluence of sunlight, and from thence to be distributed, by 

 a process of solution and redeposition, to all the organs of 

 the plant. It is found in large quantity in the seeds of the 

 cereals, wheat, e, ^., containing 61 to 76 per cent, of it in 

 the dry substance, and constitutes a large proportion of the 

 dry matter of potatoes and other tubers.* 



Properties. — Pure starch is an odorless and tasteless 

 white powder, which, when examined under the micro- 

 scope, is seen to consist of minute organized grains. These 

 starch grains are formed in the plant by a process of 



* The artichoke and some other tubers contain, instead of starch, a 

 body closely re«?embhng it, called inulin, Inulin exists in plants both 

 as a liquid and m grains It gives no coloration with lodme 



