132 AMAUROSIS. 



instantly set in motion to learn whence it proceeds. Such mani- 

 festations as these lead to an examination of the eyes. They are 

 seen to have a ghastly stare : the pupils are widely dilated, 

 insusceptible to light, refusing even to contract when confronted with 

 the glare of a lighted candle. 



The pupils in amaurotic eyes are not always fixedly or even 

 widely dilated : they may prove only to an unnatural degree di- 

 lated, their motions rendered sluggish instead of being destroyed, 

 and their contractions from light less in degree than in a state 

 of health. Instances occur in man of the pupils of amaurotic eyes 

 retaining their contractile powers on the application of light : I 

 cannot say I have observed the same in horses. One eye may 

 be amaurotic, the other remaining unaffected, in which case the 

 pupil of the amaurotic eye does not become dilated to the same 

 degree as when both eyes are paralysed ; and moreover, though 

 insensible to the stimulus of light, the iris of the amaurotic eye 

 may often be observed to move in a degree in concert with the 

 motions of the sound pupil. 



The Treatment of Amaurosis, too often an affair of hope- 

 lessness, must be varied in kind and application with the nature 

 of the case. In retinal affection dependent upon the presence of 

 periodic ophthalmia, we in vain apply any remedies save what 

 tend to the removal of the ophthalmic disease. In amaurosis 

 symptomatic of cerebral disease, our remedies must be directed to 

 the head ; though, in that form which occurs as a sequel of cephalic 

 derangement, much benefit has been obtained from counter-irrita- 

 tion set up in the vicinity of the eye ; such as blisters upon the 

 cheeks, setons through the nape of the neck, and so forth, In 

 human medicine, benefit has resulted from making the blistered 

 surface raw, and besprinkling it with a minute quantity — a 

 quarter of a grain or so — of the powder of strychnine ; and we 

 have Mr. Liston's authority, in his " Elements of Surgery," for 

 saying that " the practice is very far from nugatory :" it would be 

 worth our while to make trial of it. Among surgeons, also, 

 mercury stands in high repute as a remedy for amaurosis, and, 

 therefore, demands attention from us ; for as yet we are, I fear, in 

 much ignorance of what is to be done for the diseases of horses by 

 the exhibition of mercurv. 



