OBSERVATIOXS ON SOUNDNESS. 
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that, as veterinary surgeons, we are almost as much in the 
dark as to the true causes of blindness as we were a quarter 
of a century ago. I think we have gained something in the 
way of treatment, however, for it is remarkable, with our 
present store of information, how we can often put off the 
evil day for a considerable time, which so far is gain. 
W riters upon ophthalmic surgery differ as to the name 
this particular kind of disease should be called by. One 
wishes it to be called specific ophthalmia; a second, periodic ; 
a third, odontalgic; a fourth, lunatic; a fifth, constitutional; 
a sixth, hereditary, and so on. I think the term constitutional 
the preferable. I say this with all deference to my teachers, as 
I know it is counter to the opinion of some of them. My 
reason for naming it constitutional is from the fact of there 
being a peculiar idiosyncrasy in the animal to contract this 
particular affection. The term lunatic, or moon-blindness, 
is so absurd that it needs no second thought. Periodic is a 
veiy good term, because the eyes are attacked periodically, but 
for no other reason that I can see. The word hereditary has 
a too sweeping significance to be used generally. If we 
employ the term, it most certainly has reference to the 
whole family. It may be argued, on the other side, that the 
word constitutional will have the same tendency; but I 
cannot agree that it has. The animal affected wfith this 
complaint may be himself alone subject to it. I know of 
several similar instances in the human subject. 
Writers upon the diseases of the eye have mixed up the 
various kinds too confusedly. Although the horse is not liable 
to so many eye-diseases as man, still I am far from believing 
that the several cases I have seen should be treated of so in¬ 
discriminately in books as they are. Percival gives a list of 
about fourteen different diseases, which are insuflacient for 
the present state of our art. The treatment may be alike in 
most cases, but at the same time it behoves us to keep pace 
with the times, and pursue the same course that writers in 
the sister profession have done. The entering thus far upon 
matters surgical may be considered a digression. We have 
merely to consider whether the eyes under examination are 
in a normal or healthy state, for, as I before stated, it is 
seldom we are called upon to inspect eyes until all the acute 
symptoms have disappeared; and when the owner is sanguine 
that his horse will pass, he offers him for sale. It is at this 
juncture the best of our judgment is frequently required to 
be put in force. We will suppose an animal has had an 
attack of, as I must call it, constitutional ophthalmia—he 
may or may not have had the advantage of professional 
