THE EYE. 29 



than suffices for this purpose we are said to liave 

 got a ' cold.' 



24. — Having examined the ej^es in broad daylight, 

 you will have to examine them with a candle within 

 a stable with the door shut. If you can have a 

 choice, choose a stable that has a window above the 

 stable door, as it will be a further aid in using the 

 candle. 



25. — Before going further we shall have to study 

 the mechanism of the eye roughly, or we shall not 

 understand what to look for and expect. 



In Fig. 5. you find diagrams that will aid us in 

 demonstrating the more important parts of the eye. 

 When standing in front of the horse and viewing 

 the eye, you can see an outer circle representing 

 what is called the %vhite of the eye, and is really the 

 outer covering of the eyeball. Perhaps you will 

 understand it better if we take an example. Sup- 

 pose you take an orange, and cut a round piece of the 

 skin or peel out about the size of a half-crown piece, 

 the whole of the peel, or skin, which remains bears 

 the same relation to the orange that the outer coat, 

 or white, bears to the eyeball, that is to say the skin 

 which remains of the orange, and the white tunic of 

 the eye in each case invests five parts out of six 

 perhaps of its respective sphere. 



We must make our orange do further service. 

 When we have taken out the piece of skin we find 

 the white rind underneath. Take a penknife and cut 

 a hole in this white part, the same as in Fig. b A b. 



