THE STORV^ OF A LOAF OF BREAD. 



Professor Robert Harcourt. 



Every one has seen and handled a grain of wheat. Each little grain 

 is a store-house filled as full as it can be. In each of these little store- 

 houses is ever3'thing- that is needed to make our bodies grow. Some parts 

 are useful in making bone, some in forming flesh, and some in forming 

 fat, while others are useful in keeping up the heat of the body, and in 

 giving us power to walk and run. Each grain of wheat contains every- 

 thing that is necessary for all these different purposes. This is one 

 reason why wheat is worth so much money and why we grow so much 

 of it. The people over in England do not grow enough wheat for their 

 own use ; so we grow some for them and send it across the ocean in big 

 shiploads 



While we use a large amount of wheat, we do not like to eat it until 

 it has been ground and made into flour. Long ago, when people first 

 began to grind wheat, they crushed it between any two flat stones that 



happened to be near at hand. A little latter 

 they kept two flat stones speciallv for the pur- 

 pose, one of which was fixed in the ground 

 while the other was turned on it Methods of 

 grinding in pioneer days are illustrated in Fig. 

 30. When treadmills, windmills, and, later, 

 water-wheels came into use, the grinding was 

 done at mills by men who understood how it 

 should be done. But in all these ways of 

 grinding, all the different parts of the wheat 

 were left together in the flour. Later, the millers 

 found a method of sifting out the coarser parts. 

 The grinding of the grain and the sifting of 

 the flour have gradually been improved, until 

 to-day we have mills covering acres of ground, 

 and making thousands of barrels of flour each 

 Fis- 2t. Loiif,ntuiiinai section of day. In these mills, they are able to separate 

 S^ai™": ltnr!'7c)\%rm fd' the diff-erent parts of the wheat, and can make 

 Endosperm, the part of the wheat ever SO many difi'erent grades of flour. 



from which the flour is made. -.t- ^ 11 1 iiri ^ • ..1 j-rr 



You naturally ask : What is the dinerence 

 between their various grades of flour ? Are they not all made from 

 the same wheat ? Yes, they are ; but to understand the diff'erence, 

 we shall have to learn something about the different parts of a wheat 

 grain. If we cut a wheat grain through from end to end, and place it, 

 properly prepared, under a microscope, which is a wonderful instrument 

 that makes things look larger than they really are, we shall see some- 

 thing like that shown in Fig. 24. If we were to cut the wheat crosswise, 

 it would appear as in Fig. 25. 



Around the outside of the grain, as you see in the picture, there are 

 several thin coverings. Underneath these, there is a row of cells tightly 



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