390 APPLIED PHYSIOLOGY 



diseases to be actively combated. It still causes one tenth of all deaths, 

 and kills more persons than all other infectious diseases combined. 

 Thus in New York State during 1907 there were 147,442 deaths, of 

 which 14,406 were directly due to tuberculosis of the lungs, while all 

 other infectious diseases, including the grippe, caused 10,306 deaths. 

 Either inexcusable ignorance or wilful neglect is responsible for the 

 greater number of these deaths by tuberculosis, for the disease is pre- 

 ventable and in its early stages is usually curable. 



694. Nature of tuberculosis. It is not probable that any 

 person or animal is born with tuberculosis. The disease is 

 caught from tubercle bacteria. Men usually catch it by in- 

 haling bacteria which a consumptive has expectorated on 

 the floor or ground, and which have been dried and blown 

 about as dust ; sometimes, however, tuberculosis is caught 

 through milk or meat from an infected animal. The germs 

 may multiply in almost any tissue in which they find lodg- 

 ment. They cause the growth of white nodules, or tubercles, 

 like pin heads, and do harm in three ways: first, the tu- 

 bercles destroy the tissues of the infected part; second, 

 the tubercles may break down and form abscesses; and 

 third, the bacteria form poisons which circulate in the blood 

 and poison the whole body. The most common seat of 

 the trouble is the lungs, for the bacteria usually enter the 

 body with the air that is breathed. The bones and joints 

 also are often affected, especially in children. 



Usually the first sign given by developing tuberculosis is loss of flesh 

 and strength. Affected bones and joints become sore and swollen. If 

 the lungs are affected, there is a cough with the expectoration of mucus, 

 and there are changes in the breathing sounds. If the temperature of 

 the body is taken at regular intervals, it will be found that there is a fever 

 toward night and after exertion. The continued presence of a slight 

 afternoon fever in a person who has lost strength and weight is sugges- 

 tive of tuberculosis. While some cases of consumption develop and 

 produce death within a very few weeks, the usual course of the disease 



