230 EXERCISE. 



passage (by its constant heat and irritation) 

 frequently occasions excoriation ; the eye 

 gradually contracting and sinking in its 

 orbit, in proportion to the length and in- 

 veteracy of disease. This dfefluxion is so 

 very opposite in cause and effect, and re- 

 quires a system of treatment so very different 

 to'the case just described, as arising from a 

 wcidity m ihe blood, (constituting humour of 

 a distinct kind) that a nicer judgment is ne- 

 cessary than is generally exerted in such dis- 

 crimination. 



In cases where one only is affected, in 

 either of the ways before described, it may 

 with a great degree of reason be attributed 

 to external injury, and the resulting pain^ 

 inflammation, or discharge, so far dependent 

 upon the original cause as to be merely symp- 

 tomatic; unless from the great irritability 

 and exquisite sensation of the part, some of 

 the humours of the eye should be so severely 

 injured as to occasion its loss ; a circumstance 

 that is too frequently known to happen by 

 an accidental blow, but undoubtedly many 

 more by those wilfully aimed and fatally 

 executed. 



