182 Agricultural Chemistry. 



abundant constituent in wheat, as it is in all the cereal grains. 

 This constituent is highest in the flour, which represents the in- 

 terior of the kernel. (The composition of grains and other crops 

 and of their more important products will be found in tables in 

 the Appendix. ) 



It is a significant fact that about 80 per cent of the phosphoric 

 acid of this grain is located in the bran. This makes possible 

 the return of much of this important constituent to the farm in 

 wheat bran and its eventual recovery in the manure. The gluten 

 or gum-forming portion of the wheat grain is composed of two 

 proteins, glutenin and gliadin, which form about 85 per cent of 

 the total proteins of the seed. The tenacity of bread dough and 

 of macaroni made from wheat flour, is due to gliadin. Consid- 

 erable attention has been given to the factors affecting the 

 amount and composition of gluten in wheat and to the conse- 

 quent milling qualities of the grain and baking qualities of the 

 flour. According to Snyder, the most valuable wheats for bread 

 making purposes are those in which 80 to 85 per cent of the 

 protein is gluten and the gluten is composed of from 60 to 65 

 per cent of gliadin and 35 to 40 per cent glutenin. 



Wheat straw has little value to the stock feeder except as lit- 

 ter. Experiments have shown that when consumed it leaves 

 little surplus of food value to the animal above the energy re- 

 quired for mastication and digestion. But when the straw is 

 pulped by the process commonly used in paper making, the 

 residual tissue has been shown to have a food value equal to that 

 of starch. The plant food in the straw should be saved by utiliz- 

 ing it as litter or composting in the manner already described. 



Rye, like wheat, is sown chiefly in the fall. It closely re- 

 sembles the latter in its composition and habits of growth. The 

 growth of this crop in early spring may be stimulated by adding 

 TOO to 150 pounds of nitrate of soda per acre. 



Rye grain is slightly lower in fat and protein than is wheat. 

 Its gluten is not so well suited for bread making as that of wheat, 

 but rye flour produces a coarse bread which is consumed to a 



