234 THE NATURE AND TREATMENT OP 



or occupied with a mass of imperfectly digested food, the pa- 

 tients bordering on that peculiar condition known, as it occurs 

 in the equine species as " stomach staggers," can easily be ex- 

 plained on the universal law of sympathy which pervades the 

 animal organism. 



I may, however, assign an indir'ect cause for its occurrence 

 in the eyes of excitable and nervous animals; for this very 

 condition, apparently, and truly pathological, which gives rise 

 to the excitability, perhaps goes far to show that the brain is 

 the seat of functional derangement, and this functional difH- 

 culty may have its origin in a deranged condition of the stom- 

 ach or liver. 



Amaurosis can be easily produced by administering a few 

 doses of extract of belladonna. This is a mere artificial state 

 of the retina (pupil), which only continues while the animal is 

 under the influence of the narcotic. This amaurotic vState of 

 the eye is also observed, during certain stages of the etheriza- 

 tion, and disappears as soon as the animal has recovered from 

 the effects of the same. 



Our principal authority on the subject of amaurosis is Per- 

 cival ; he contends that it may proceed from some disease of 

 the retina itself, or from some abnormal condition of the optic 

 nerve or brain ; or it may prove, as he says, the last link of a 

 series of morbid phenomena, originating in some remote part 

 of the body, operating sympathetically on the nervous system 

 and through it, extending to the eye. 



We occasionally meet with cases which may be termed sym- 

 patlietic amaurosis ; occasioned by congestion, tumors, or hydro- 

 cephalus (serum within the verticles of the brain), each one of 

 these pathological conditions requires* special treatment, with 

 very little chances of success. 



Symptomatic amaurosis may be the sequence of cranial frac- 

 ture and consequent depression ; here the skill of a surgeon is 

 called into requisition ; he must trephine in the uninjured region 

 of the cranium, in order to elevate the depressed and fractured 

 parts and thus remove the pressure. 



Amaurosis is frequently associated with the anaemia ; now 



