182 ANSWERS TO PRACTICAL QUESTIONS 



soundness of teeth is often affected by the general health. It 

 has been said that a man who can preserve his teeth till he is 

 fifty years old may count on keeping them through life. 



32. Should biscuit and cake containing yellow sf>ots of 

 soda be eaten ? 



Certainly not. The alkali neutralizes the acids of the ali- 

 mentary juices, and thus impairs their functions, while it cor- 

 rodes and irritates the delicate mucous lining of the digestive 

 organs. 



33. Tell hoiv the body is composed of organs, how or- 

 gans are made up of tissues, and how tissues consist of 

 cells. 



(See Physiology, p. 175, note.) 



34. Why do we not need to drink three pints of water 



per day ? 



(See Physiology, p. 151.) 



The amount of water one needs depends upon the charac- 

 ter of his food, the nature of his labor, and the activity of the 

 three eliminating organs the skin, the kidneys, and the lungs. 

 One perspiring freely, or eating dry food, needs more drink 

 than one whose skin is inactive, or whose food consists, in 

 part, of soups or watery vegetables. 



35. Why, during a pestilence, are those who use liquor's 

 as a beverage the first, and often the only victims ? 



The nervous system has become impaired, the digestion weak- 

 ened, and the blood impoverished ; hence, the functions of the 

 body being disturbed, its ability to resist disease is greatly less- 

 ened. 



36. What two secretions seem to have the same general 

 use ? 



The saliva and the pancreatic juice both change starch into 

 sugar. They have other important uses, however, .in the pro- 

 cess of digestion. The former softens the food and aids in the 

 work of mastication, while the latter emulsifies the fats. 



37. How may the digestive organs be strengthened ? 



The digestive organs, like the other organs, are strength- 



