222 



GENERAL SCIENCE 



and the intestines. Too much protein food will produce indigestion 

 and bacteria decomposition in the intestines. A fetid odor of the 

 intestines is often due to over-eating of protein. 



Digestion of Meat. Meat should be carved across the grain in 

 very thin slices so as to cut the fibers into as many sections as pos- 

 sible. Long fibers digest slowly. The more fat in meat the more 

 slowly it digests. Raw meat would digest more easily than cooked 

 meat, but it is too dense to masticate well. 



Chewing of Food. Food must be chewed so as to break up the 

 particles as much as possible, allowing the digestive fluids to come 

 in contact with all parts of the food material. If the food particles 

 are too large, the digestive fluids reach only the outside, and a great 

 deal of food is wasted because undigested. 



Care of the Teeth. The teeth are an important factor in diges- 

 tion, and great care should be taken of them. Decay is caused by 



J Decay of rhe 

 net-Seethe 

 ist early 

 ly has eaten 

 into the dentine 



Decay has 

 attacked the nerve 

 The dentist must be 

 consulted ar once 

 to save this tooth 



FIG. 145. Why should the teeth be examined frequently? Why should 

 the teeth be cleaned after every meal? 



bacteria growing in the moist, warm food left between the teeth. 

 If, after eating, the food is cleaned from the teeth with the aid 

 of a brush and a good tooth powder, the danger of the presence of 

 bacteria is removed. 



One should avoid biting on threads, nuts, candy or any other 

 hard material, for it is liable to break the enamel, and decay will 

 set in, wherever the /dentine is exposed. Decaying food between the 

 teeth produces an acid which slowly eats away the enamel of the 

 teeth. 



