18 THE EXTERIOR CONFORMATION 



the critical clearness of the parts immediately on and within 

 the surface, and its freedom from central white specks. 



The cornea, or transparent part of the eye, ought to be 

 perfectly clear throughout its whole extent of surface. 

 Sometimes it will appear so on a slight inspection, but, 

 when more attentively examined, opaque milky lines may 

 be seen crossing its surface. In other cases nearly the 

 whole may be clear, except the extreme limits, which will 

 be found surrounded by a well-defined opaque line : when 

 such an appearance exists, it bespeaks the remains of former 

 inflammation, and a great danger of recurrence. It might, 

 however, be proper to remark, that an accidental blow, as 

 the stroke of a whip, may leave an opaque speck or line 

 without any liability of recurring inflammation ; but then 

 the effect, in such cases, will seldom be found at the 

 circumference. Not only must this exterior glassy covering 

 of the eye be examined, but the attention should be likewise 

 directed to the deeper parts within the pupil, the appear- 

 ance of which, in a moderate light, should be perfectly 

 transparent. In a strong light it should exhibit a lively 

 bluishness ; but if, in a moderate light, it appears turbid or 

 milky, there has been inflammation, which will probably 

 again recur ; but if a speck or line of white more conspi- 

 cuous and deep-seated than the rest should appear, in such 

 case a cataract has already began to form. In other 

 instances, again, though the internal eye should not appear 

 opaque or milky, yet it may exhibit a glassy greenishness, 

 which is a proof of the existence of a most destructive 

 affection, called, by the farriers, glass eye : but, properly, 

 gntta serena. The existence of this may be proved by 

 observing whether the iris, or the curtain forming the 

 pupil, contracts and dilates ; that is, when the hand is 

 placed over a sound eye for a little time, the iris will dilate 

 so as to increase the size of the pupil to admit more rays ; 

 but, on the removal of the hand, will again contract and 

 lessen the pupil, to exclude them. This does well enough 

 for an off-hand or primary trial ; but before the aniuial is 

 purchased, or a decisive opinion delivered, the horse should 

 be placed in a darkened stable for some time, and then the 

 eyes be examined by means of a candle ; when it will be 

 easily observed whether the iris has dilated, and after a 



