THE SENSES 153 



nerves, in the inner ear, where they produce the 

 sense of sound. 



8. The Eustachian tube leads from the middle ear to the 



back part of the nose. A cold in the head stops 

 the tube and causes earache and deafness. Most 

 earaches are caused by a cold in the throat. 



9. Little particles in the air soak through the wet sides of 



the nose and, touching the nerves beneath, produce 

 the sense of smell. 



10. A substance soaking into the surface of the tongue 



and touching its nerves excites the sense of taste. 



1 1. Smell and taste guard us against bad air and bad food. 



