263 
INDUCTION OF NEBULOUS CORNEA AND CONJUNC- 
TIVAL COUNTER-IRRITATION IN THE TREATMENT 
OF SPECIFIC OPHTHALMIA. 
By Mr. Robert Read, V.S., Crediton. 
It is not my intention to enter into detail as to the symptoms 
and causes of ophthalmia in the horse ; in this Journal it would be 
a waste of its valuable pages. Every member of the profession 
but too well knows the obstinacy of its character. 
For some time past I have adopted a different method of pro- 
cedure, beside that of combatting the disease by bleeding, physic, 
and fomentation. I was induced to do so from observing that, in 
proportion as the cornea became opaque, in the same ratio the pain 
lessened, and the eyelids ceased drooping. Concluding that this 
arose from the stimulus of light being shut out from the optic 
nerve, or its expansion, the retina, it occurred to me that by in- 
ducing mechanically a nebulous cornea of sufficient intensity over 
its entire surface, so as to prevent the entrance of light, I should 
be following Nature in her relief. I have therefore of late, and 
with success, in acute ophthalmia, after depletive measures, about 
the third day injected a solution of the nitrate of silver into the 
eye, which very quickly induces the opacity. It creates at first 
a little pain and irritation. In numerous cases I have found, on 
the absorption of the nebulosity, the eye in its normal condition. 
Sometimes once injecting the nitrate is not sufficient to induce the 
opacity ; occasionally, two or three injections are required to pro- 
duce it to its full extent over the surface of the cornea, that the 
light may be entirely shut out, on which its success depends. 
The injection I have been in the habit of using, is one grain of the 
argentum nitratis to one drachm of water, increasing the strength 
agreeably to the effect produced. On the third day, if the pain is 
not relieved or the eyelids kept open, another injection will be 
required, as in all probability the first injection has not been ef- 
fectual in producing sufficient opacity to shut out the admission of 
light. 
I shall now allude to the treatment of chronic ophthalmia and the 
different forms of cataract. In chronic ophthalmia I have found 
nothing answer so well as strong counter-irritation to the conjunc- 
tival membranes, so as to produce considerable discharge ; in fact, 
you may induce as great a discharge therefrom as from a seton. 
Some may think this a hazardous practice, but there is nothing 
to fear. 
