THE DOORS. . 159 



bitter substances. There is, however, less dan- 

 ger from having insects get into the ear than is 

 commonly supposed ; for when the ear-drum, 

 or membrane of the tympanum, of which I 

 have spoken in another place, is not rup- 

 tured, nothing can get into the head more than 

 three quarters of an inch, and could easily be 

 pushed or washed out. 



If the ears are washed out well every day, 

 and especially if they are syringed out often 

 with weak soap-suds and water, we shall sel- 

 dom have trouble, either from the collection of 

 wax or from insects. Cleanliness is almost 

 everything not only in the case of the ear, but 

 of all parts of the body. 



Beyond the drum is a chamber, called by 

 anatomists the cavity of the tympanum. In 

 this cavity are the little bones which I have 

 formerly described. Here also a small passage 

 commences, which terminates near the back 

 part of the nostrils. The use of this passage 

 from the inside of the mouth to the internal ear 

 is not very well known, but it is believed to be 

 intended principally for the purpose of letting 

 in air, in order that the pressure on both sides 

 of the drum might be alike. 



