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The kernel of wheat as nature produces it is covered 

 with a tough, almost horny outer layer which in portions of 

 the kernel, especially at its upper end and often within the 

 groove is fringed with hairs. This outer covering, which 

 forms the greater part of the bran when ground, is com- 

 posed of cellulose with more or less hardening elements all 

 of which are indigestible and consequently not suitable for 

 food. Underneath the outer husk is an inner husk that 

 contains considerable gluten and a large part of the 

 phosphates and other mineral elements of the kernel. Un- 

 der these two coverings is a layer rich in the gluten and 

 other nitrogeneous elements of the wheat, and usually of a 

 darker color than the interior which contains principally 

 starch, with a much less proportion of gluten. The nutri- 

 tive food elements of the kernel, therefore, increase from 

 the interior outward. In the ordinary process of making 

 flour, in which whiteness is regarded as a mark of the 

 greatest purity, all the inner covering and much of the 

 nutritive outer layer of the kernel is bolted out and only 

 the inner, whiter portion containing more starch and less 

 proteids is left. In other words the finer and whiter a grade 

 of flour is, the less likely is it to contain the most nourish- 

 ing elements of the wheat.* 



A knowledge of these facts led, many years ago, to the 

 introduction of "Graham" flour, which, for the most part, 

 is either an unbolted flour or one in which only the very 

 coarsest part of the bran or outer husk is removed after the 

 wheat is ground. Graham is an improvement on ordinary 

 white flour, so far as the question of nutritious constituents 

 is concerned, but it contains the indigestible outer coat of 

 the grain which is not only indigestible but irritating to the 

 mucous membrane which lines the alimentary canal. Gra- 

 ham flour, moreover, is usually ground without thorough 

 cleaning of the wheat, and the flour often contains various 

 particles of dust that accumulate in the groove of the kernel 



*It should not be understood that a dark grade of ivhite flour is 

 necessarily better on that account. As a rule it is made of an infe- 

 rior quality of wheat or from wheat improperly cleaned. 



