ON PERIODICAL OPHTHALMIA. 381 
conjunctiva. This is seen by a twinkling of the eye and an 
alteration in the size of the pupil. 
It is my opinion, that inflammation first commences in the 
iris. The disease does more damage to the iris than to any other 
part of the organ ; notwithstanding, the loss of sight is effected 
by. opacity of the lens, the sequelae of iritis—probably Nature’s 
resort to abate the inflammation, by exclusion of light from the 
retina. 
If the inflammation commenced first in the conjunctiva lining 
the lid, proceeding to that covering the sclerotica, and then to 
that covering the transparent cornea, as stated in the Professor’s 
lectures, I should expect to find on the onset of the disease 
the pupil and retina for a short time unaffected, although its 
progress be rapid. If I should accidentally give my horse a cut 
in the eye with my whip, severe enough to wound the conjunctiva 
covering the transparent cornea, considerable inflammation rapidly 
extends to the whole membrane ; the tears flow, the lids swell 
and close (not so much for the purpose of excluding light as to 
give ease, for the contraction of the levator palpebrae superioris 
produces pain in this state of the eyelid), but the pupil does not 
contract, nor is the eye impatient of light. 
The inflammation thus produced rarely extends to the internal 
structure of the organ ; on the contrary, it soon subsides on the 
application of a little tepid water, provided the animal is not in- 
flammatorily disposed : and whether that membrane be inflamed 
in simple or periodical ophthalmia, the treatment commonly 
pursued resolves the inflammation of the conjunctiva; the swelling 
of the lids and flow of tears subside ; and the transparent cornea 
is again restored : in fact, no injury is sustained by that mem¬ 
brane during the whole period of internal ophthalmic disease. 
In regard to ophthalmia being hereditary, I think there can be 
no question; at least, a vascular and nervous peculiarity in the 
structure of the organ, favourable to acute inflammation, appears 
to descend from the parents to the progeny. I know of many 
instances strongly in favour of this opinion. A farmer named 
Goodwin, near Walsall, in this county, bred four horses from a blind 
cart-mare, and they all were blind by six years old. There 
was no want of a free circulation of air in Mr. Goodwin’s stables; 
and I think bad food had no share in the cause, as Mr. G. 
appeared fond of horses, and paid them great attention. 
Thomas Bate, Esq. Penn, near Wolverhampton, has at this 
time a two-year-old cart colt by a blind horse in his neighbour¬ 
hood. This colt has had an attack of ophthalmia while at grass: 
in fact, he has never been housed. 
A thorough-bred stallion (blind), two miles from this place, is sire 
