CHAPTER XII. 



THE COVERING. THE WINDOWS. 



General Remarks. The Human Eye. 

 Situation of the Eye. Coats of the Eye* 

 Optic Nerve. The Tears. The Eyelids. 

 The Eyebrows. Reflections. 



GENERAL REMARKS. Before glass was in- 

 vented, the windows of dwelling houses were 

 small, and made in different ways. In sum- 

 mer, they often consisted of a mere hole in 

 the side of the building. In the eastern houses 

 there were no windows of any kind in front, 

 or towards their neighbors ; and in China, this- 

 is the custom to the present day. 



In winter, these holes or windows were 

 closed up with something which would par- 

 tially exclude the cold, the rain and the snow. 

 In some countries of Asia, and in ancient Bri- 

 tain, they used oiled paper for this purpose. 



