272 
ON CATARACT. 
The year before last, while the regiment in which I am now 
serving w r as at Windsor, Mr. B. shewed me a favourite blood 
filly of his, three years old, very handsome, and of his own 
breeding. I was “ looking round her,” as the phrase goes, 
when, by mere accident, I discovered that she, in one eye—I 
forget which—had got a cataract: but such a one, I thought, 
and I believe said at the time, as I did not remember to have 
often seen before. It was, to use Mr. Cartwright’s comparison, 
in point of magnitude, “ of the size of a coriander seed,” and 
exhibited to the eye of the observer a well-defined insulated 
J 
white spot, surrounded and rendered still more perceptible by 
the clear blue of the pupil. It seemed to me to present to the 
beholder much the same appearance that a speck upon the cornea 
would produce were it possible to view it through the pupil from 
the back of the eye; a circumstance that (coupled with the 
fact of its occasional disappearance) disposes me to coincide in 
opinion with Mr. Cartwright, and regard it as a capsular not a 
lenticular opacity. I have not had an opportunity of seeing the 
filly since last year, when the cataract still existed, and in statu 
quo: I am, however, now growing very desirous for another 
examination. 
Were I asked, how the practitioner could best distinguish a 
cataract of the above description from that which is of ordinary 
occurrence, and known by us all to constitute the common 
termination of periodical ophthalmia, I should say, in the present 
state of our knowledge, that the unusually lucid and healthy 
aspect every other part of the eye presents at the time, forms, 
abstractedly considered, our best diagnostic sign : the slightest 
indication, or even suspicion, of prior or present inflammation, 
be it understood, being a reason, presumptive at least, for 
coming to a different conclusion. 
In respect to the period of time a cataract of this species— 
supposing it to be membranous,—might take in forming, I should 
apprehend that its production might, as its disappearance often 
would seem to be, be the work of a very short interval : five or 
six days, for example. We know that a speck upon the cornea 
will appear, after an injury, in even less time than this; why* 
