184 ADVANCED PHYSIOLOGY 



tirely and complete recovery take place. After recovery, how- 

 ever, the person may have a second attack, for this disease, 

 unlike such diseases as scarlet fever and measles, does not 

 render a person less susceptible to its return. 



Pneumonia is one of the most dangerous of diseases and in 

 some localities more people die from the effects of it than 

 of any other common disease. There is no household remedy 

 which is especially beneficial in a case of pneumonia, and 

 every patient should be promptly placed in the hands of a 

 physician. Every precaution should be taken to avoid the 

 trouble, and the best way to prevent it is to guard against 

 colds. 



Tuberculosis. There is another little germ which may 

 seize the occasion of a cold to attack a person. It is called 

 the tubercle bacillus (Fig. 1 00 b) and is one of man's most deadly 

 foes. It may enter the body in any of several ways, but its 

 chief method of entrance is through the mouth with food, or 

 through the nose with the air. We sometimes hear it said that 

 a person had a cold which developed into consumption. When 

 we remember that consumption is caused by a definite germ 

 and that a cold is something quite different, it is evident 

 that a cold cannot turn into consumption any more than a 

 worm can turn into a snake. But a cold in the lungs inflames 

 all the air passages and these, when inflamed, are much more 

 easily infected by bacteria than when in healthy condition. 

 If one is in good health, the tuberculosis bacilli may frequently 

 be inhaled without harming him. But if the walls of the 

 air passages are weakened in any way, the germs may find a 

 chance for growth. 



This microscopic foe is far more dangerous than any of our 

 larger enemies. After it has once entered the body, it may 

 pass to almost any part of it and, stopping there, produce 

 trouble. It sometimes lodges in the abdomen and produces 

 serious and fatal diseases of the digestive organs. Sometimes 

 it grows in the skin, producing an ugly trouble, called lupus, 



