98 PERIODIC OPHTHALMIA. 



Notwithstanding all that has been said, however, we continue to 

 practise blood-letting, and we do so for two reasons : — first, because 

 we think our patient derives some benefit from it, however transi- 

 tory or unreal that may turn out to be ; and, secondly, because we 

 know of nothing that so summarily confers this apparent relief. 

 And topical evacuations of blood seem to answer this purpose 

 better than any large or general abstractions. Some practitioners 

 open the angular vein of the eye, from which in general, by judi- 

 cious operation and management, quite as much blood can be ob- 

 tained as it seems prudent to take. Others prefer scarification of 

 the conjunctiva; and where that membrane is much reddened, and 

 appears injected or loaded with blood*, this is, perhaps, the best 

 practice. There can be no harm, but may result good, from prac- 

 tising first one and then the other of these operations. 



Fomentations only do good as means of relaxing the blood- 

 vessels, at the time blood is flowing from the eye or the eye-vein, 

 and so enabling us to obtain a much larger efflux than we should 

 without their aid. The best fomentation is warm water applied 

 with a large sponge upon the lids. 



From Purgation I cannot say I have witnessed any benefit. 

 I know it is, or used to be, a common practice to give a dose of 

 physic on an attack of ophthalmia ; but, as there appears so little 

 reason to believe that the disease in the eyes is connected with any 

 ch3dopoietic disorder, and as any evacuation from the bowels is not 

 seen to produce any such effect on this as it does on common oph- 

 thalmia, or any ordinary inflammatory disease, I cannot myself 

 imagine what good is to be answered by purgation. 



What Medicine ought to be given ] — For my own part, 

 I can answer this question only by saying, that none that has hi- 

 therto been exhibited has proved a cure for the disease ; at the same 

 time I would not go so far as to assert that no medicine that has 

 been administered has not done some good. I have, myself, pre- 

 scribed preparations of copper, iron, arsenic, silver, mercury, and 

 iodine, all of them potent in action, and capable of being rendered 

 poisonous ; but, save in the instance of mercury, with nothing 



* I never saw true chemosia in a horse's eve. 



