PARASITES 441 



occurrence, especially in the winter time, and at times has 

 swept over the country as severe epidemics. The organism 

 generally invades only the mouth, throat, and air passages, 

 the toxine being absorbed from such local infection. It follows 

 from this that the organism is expelled from the body of the 

 patient mainly through coughing and sneezing and in the 

 sputum. It has been found that very little drying serves to 

 kill the organism and therefore the disease is generally con- 

 tracted through rather intimate association with a patient or 

 convalescent. Due observance of this fact may enable one 

 to avoid contracting the disease. 



513. Common Colds. What we commonly call "bad colds " 

 are infectious diseases which are due to a variety of organ- 

 isms. Streptococcus, pneumococcus, and the bacilli of in- 

 fluenza and diphtheria as well as other organisms may each 

 be the cause of what is generally regarded as a bad cold. The 

 first stages of the more virulent diseases caused by these 

 organisms show essentially the same symptoms as a cold. 

 This fact makes a cold deserving of more serious attention 

 than it commonly receives. When one goes about his work, 

 mingling with other people, when suffering from a cold, he 

 is, not only running a serious risk himself, but is exposing other 

 people to danger. We should be taking a long stride toward 

 the prevention of seyeral serious diseases, if we could induce 

 everyone to give proper attention to bad colds. 



514. Tuberculosis. This disease is often spoken of as the 

 GREAT WHITE PLAGUE, and it richly deserves that name for it 

 is, each year, responsible for more deaths than any other single 

 cause. It has been estimated that in 1907, 153,000 persons 

 died from tuberculosis in the United States. It has also been 

 estimated that it cost the people of the country annually 

 $200,000,000. Another bad feature of the disease is the fact 

 that it usually results in a comparatively early death. The 

 average age of persons dying from tuberculosis in the U.S. has 

 remained at about 35 years ever since 1860, when statistics 

 first began to be collected. Death at this age is about the 



