AS TO SOUADNESS. 13 



first is an erect image of the light, and is produced 

 by reflection from the surface of the cornea ; the second 

 is also erect, and is produced by reflection from the 

 anterior surface of the lens ; the third is inverted, and 

 is due to reflection from the concave posterior surface 

 of the lens. The first two images move in the same 

 direction as the light, the third in the opposite direc- 

 tion. If the lens becomes opaque, of course the image 

 from the posterior surface is lost, and that from the 

 anterior surface also soon becomes indistinct. 



Before proceeding further, let me say, once for all, 

 that this is not a course that admits of any discussion 

 on disease, further than considering those disorders, 

 and their various degrees of intensity, which are open 

 to doubt as to their rendering a horse unfit for the 

 ordinary requirements of work, and therefore unsound. 



The conjunctiva being more vascular, is less liable 

 to permanent change than the cornea, so that we 

 seldom look for alterations in it ; but there are passing 

 emergencies, such as conjunctivitis (cold in the eye), 

 foreign bodies, and wounds inflicted with the whip, 

 which prevent our examining either the conjunctiva 

 or the eye. In these cases, time should be allowed 

 for a cure to be effected before offering an opinion. 

 If, however, the case cannot wait, then examine and 

 give an opinion on the other points of the horse ; but 

 make yourself clearly understood by your client that 

 you give no opinion whatever as to the ultimate sound- 

 ness of the affected eye. I have known a piece of 



