COMPOSITION OP GRAINS. 265 



quite warm countries. It is larger in Virginia or Mary 

 land wheat than in that of Michigan or the Canadas. 



961. Starch, as we have seen, is a white powder which 

 forms a large part of the substance of most of the grains, 

 as also of the potato. A general idea of the proportion 

 in which it appears in the 



grains, may be obtained 

 from figure 92, in which the 

 grains are magnified, and 

 where a represents the posi 

 tion and comparative quan- Fig. 92. 

 tity of the oily portions of 



a kernel of Indian corn, wheat and barley, the oil being 

 in minute drops enclosed in six-sided cells, which consist 

 chiefly of gluten ; &, the proportion and position of the 

 starch, and c, the germ or chit, which is mainly composed 

 of gluten. 



962. .Gluten, as well as starch, exists in most plants, 

 though the proportion in some is far greater than in others. 

 It may be washed out of dough made of wheat flour, by 

 placing it upon a sieve or a porous cloth tied over a deep 

 dish, and pouring on water as long as it continues to run 

 through of a whitish or milky color. The starch is carried 

 through the clotfi with the water, and the gluten is left 

 on the cloth. The starch will soon settle to the bottom 

 of the dish. 



963. The grinding of the wheat does not wholly crush 

 the outside covering of the grain, which is harder than 

 the rest. This is usually sifted out from the finer portions 

 in the form of bran, and may be fed to horses or other 

 animals. It is often known as shorts. 



964. On mixing water enough to moisten the whole 

 mass of flour, the particles stick to each other and form 



