PERIODICAL OPHTHALMIA OF HORSES. 
365 
mares, than any other horse in the country. There was at that 
time living* in the town of Tipperary a person in the form of a 
farrier, who was famous for the operation of what is called “ put¬ 
ting out one eife to save the other: and J was told by a gentle¬ 
man residing in the neighbourhood, that on one occasion, this 
man had actually performed that operation twenty-nine times in 
one week. Now, although it is difficult to credit this statement 
to the full, yet, no doubt, there was a good deal of truth in it; 
and I will venture to say our Tipperary friend would never want 
employment as long as the people of the county took no more care 
to avoid breeding from animals w ith diseased eyes than they did 
at that time : for I repeat, if there be any such tiling as hereditary 
disease,—if gout and scrofula are to be called hereditary com- 
S laints,—so also is the periodical ophthalmia of horses. My friend 
Ir. Watts, of Dublin, however, informs me (and he is very good 
authority, having been long in the habit of examining more horses 
than, perhaps, ail the rest of the profession in Ireland put toge¬ 
ther), that there are not half so many horses brought for his inspec¬ 
tion w ith diseased eyes that there used to be some ten or twenty 
years ago. As far as my ow n observation goes, the evil, 1 think, has 
much diminished w ithin the last ten years: and yet so lately as 
the last Mullengar fair I had occasion to witness two cases of 
blindness in colts only three years old each ; one of which I 
made particular inquiry about. He belonged to a respectable 
farmer, w r ho said the coifs eyes first became bad at grass, and 
before he had ever been housed: at first, they thought it might 
be occasioned by the bite of another horse ; it apparently got 
well, but returned again and again, until the animal became 
blind. Now 7 it is difficult to account for this upon any other prin¬ 
ciple except that of hereditary tendency or predisposition. Die 
good people of Ireland, however, 1 am happy to find, are be¬ 
coming much wiser in this respect. 
But while I say 1 contend that the periodical ophthalmia com¬ 
monly arises from the cause I have mentioned, I freely admit 
that it has various other origins, quite adventitious, and indepen¬ 
dent of this. White enumerates the following: “ Standing still 
in cold w ind or rain, when the animal has been heated, or is sweat¬ 
ing from violent exercise ; or also plunging him in a river when 
sw eating and exhausted by exertion; or tying him up at a stable 
door whilst his legs and thighs are being washed w ith cold 
water.” Now all this may be referred to one head; viz. checked 
perspiration. My ow n experience, however, does not bear Mr. 
White out in this speculation : I cannot say that I have ever seen 
even one single well-marked instance of the malady in question 
arising or originating from this cause. But 1 have several times 
