THE WINDOWS. 153 



nishes the saliva or spittle, only much smaller, 

 over the top of each eye, from which flows in 

 small quantity, a clear liquid, and by means 

 of the eyelids, operating as a cloth would do, 

 this is carried over the whole surface of the 

 eye, and keeps it constantly moist and clean. 

 The dirty water is then carried off through a 

 very narrow passage, and thrown out through 

 a pipe or duct in the nose. 



The little gland, over the eye, is called the 

 lachrymal gland ; the liquor which it furnishes 

 to wash the eye, is called the tears ; and the 

 tube through which the tears escape into the 

 nose, is called the lachrymal duct. 



If this duct gets stopped, as not unfrequently 

 happens, the tears overflow the eye and run 

 down on the cheek; and a hollow piece of 

 silver is sometimes furnished by the surgeon to 

 insert in the duct from the eye to the nose, to 

 keep it open and furnish a passage for the 

 tears. 



THE EYELIDS. The eyelids are to guard 

 the tender eye from injury in various ways. 



One of their uses is to keep off the strong 

 light of the sun. If our eyelids were cut off, 



