354 A YEAR IN SCIENCE 



Adenoids. This is the name given to certain growths 

 which appear in the upper part of the throat just 

 behind the nasal opening. They often occur in grow- 

 ing children. Sometimes they become so large that 

 they close the nasal openings, and hence make mouth 

 breathing necessary. By closing the Eustachian tubes 

 they may be the cause of deafness. Adenoids in them- 

 selves are not dangerous. They may shrink and dis- 

 appear. However, they are often the indirect cause 

 of much harm and should then be removed. 



Tonsils. In the throat are the tonsils, which we 

 know often cause much annoyance. If they become 

 repeatedly inflamed, they should be removed. 



Pleurisy. In pleurisy the pleural membranes become 

 inflamed and oftentimes secrete an abnormal amount of 

 fluid. This fluid takes up space which the lungs should 

 occupy. 



Contagious diseases. The so-called impure air dis- 

 eases are all contagious. Since air is the medium 

 through which the germs are carried, it is evident that 

 these diseases are very readily spread. The most 

 common of these diseases are colds, tonsilitis, diph- 

 theria, bronchitis, pneumonia, and tuberculosis. With 

 most of these we are already so familiar that they 

 need little explanation. If we all become impressed 

 with the fact that they are contagious diseases and 

 put forth every effort to prevent their spread, we have 

 gone a long way toward eradicating them. We know 

 what causes them and we know how to prevent their 



