72 FOOD AND DRINK. 



articles as have been found good for food, some are more 

 nourishing than others: some require very little prepara- 

 tion for use, while others are hard and indigestible, and 

 can only be used after undergoing many preparatory pro- 

 cesses. Great care must therefore be exercised, and many 

 experiments made, before we can arrive at a complete 

 knowledge in reference to these articles of diet. Tea, 

 coffee, and other substances from which drinks are made, 

 ire of vegetable origin. 



24. Bread. Wheat is the principal and most valuable 

 kind of grain for the service of man. Bread made from 

 wheat-flour has been in use for many hundreds of years, 

 and on this account, as well as because of its highly 

 nourishing properties, has been aptly called " the staff of 

 life." We never become tired of good bread as an article 

 of daily food. 



The white kinds of flour contain more starch and less 

 gluten than the darker, and are therefore less nutritious. 

 The hard-grain wheat yields the best flour. In grinding 

 wheat, the chaff or bran is separated by a process called 

 "bolting." Unbolted flour is used for making brown or 

 Graham bread. 



25. The form of bread most easily digested is that which 

 has been " leavened," or rendered porous by the use of 

 yeast, or by some similar method. Unleavened bread 

 requires much more mastication. Hot bread is unwhole- 

 some, because it is not firm enough to be thoroughly mas- 

 ticated, but is converted into a pasty, heavy mass that is 

 not easily digested. 



26. Wheaten bread contains nearly every principle requi- 

 site for sustaining life, except fat. This is commonly added 

 in other articles of diet, especially in butter, " bread and 

 butter," consequently, forming an almost perfect article of 



24. Wheat? " Staff of life ?" White flour? Hard-grain wheats ? Bolting? 

 Graham bread ? 



25. Leavened bread? Unleavened? Hot bread ? 



26. Wheaten bread ? Bread and butter ? Experiment on the dog ? 



