THE CUPOLA. 83 



always rinse them well. And if you rub them 

 with a soft brush several times a day, it may 

 do some good in the way of preserving them. 



BONES or THE EAR. About three quarters 

 of an inch within each of the two side doors of 

 the cupola the ears is a film or membrane 

 drawn tightly across the passage, like a drum 

 head. This is called the membrane of the 

 tympanum tympanum being the Latin word 

 for drum ; and a cavity behind the membrane 

 is, of itself, called the tympanum. 



In this latter cavity are four small bones. 

 For what purpose they were intended by the 

 great Creator, we do not know; but they 

 are undoubtedly somehow concerned with the 

 sense of hearing. Sounds reach the brain 

 through the passage of the ear ; and if there 



