THE USE OF FOOD 381 



from indigestion. The teeth are important factors in 

 the habit of proper chewing. We can form no better 

 habit than that of properly brushing them. The teeth 

 should be brushed at least twice a day, and not only 

 the teeth, but also the gums around them. Brushing 

 up and down rather than across the teeth is of much 

 more value because it dislodges the food particles held 

 between the teeth and thus prevents their decay. The 

 teeth should be examined by a dentist at least twice a 

 year, for this will save much pain and possible loss later 

 on. Decay of the teeth comes as a result of bacteria 

 lodging in the same crevices with food. They pour out 

 an acid waste substance which attacks the hard enamel 

 of the teeth, breaking it down and thus allowing germs 

 gradually to attack the living portion of the teeth under- 

 neath. Upon our teeth depends much of our health 

 later on in life, so let us form habits of proper care of 

 them while we are boys and girls. 



How Digested Food Gets to the Body Cells. We have 

 already seen that the body is well supplied with blood 

 vessels. If we could take away all flesh and bones from a 

 body and fill the blood vessels with something that would 

 hold them in place, they would form a perfect mold of the 

 body, with tiny vessels reaching to all its parts. The 

 fluid part of the blood is the vehicle which carries digested 

 food to all parts of the body. Another solid part of the 

 blood, called the red corpuscles, carries oxygen to the cells 

 so that work can be done there. These red corpuscles 

 are little flattened disks so numerous and small that it is 

 estimated there are about 500,000,000 in a drop of healthy 

 blood. We also find in the blood colorless corpuscles, 

 the body police, which protect the body against harmful 

 bacteria by eating them up. Other bodies called the blood 

 platelets help the blood to clot when a blood vessel is cut, 

 thus keeping us from bleeding to death. 



