110 THE PRACTICE OF VETERINARY MEDICINE, 



attention to the film or exudate between the layers of the 

 cornea. The removal of this film is frequently attempted 

 by quacks and otlier ignorant persons, who have a cruel, 

 and worse than useless, practice of blowing powdered glass, 

 alum, etc., into the eye, on the supposition that the film is 

 external to the cornea, and that the glass will cut it, or th'i 

 alum, by its corrosive action, will destroy it. For the 

 removal of the exudate it is necessary to ' stimulate ' the 

 eye, a good recipe for the purpose being as follows : Argenti 

 nitras grs. iii. — grs. v. ; aquoe 3i. Touch the parts occa- 

 sionally, using a camel's-hair pencil to apply it with. In 

 some cases it may be necessary to touch the part with a 

 pencil of argenti nitras. Potassse iodidi may also be given 

 internally. If ulceration of the cornea or other parts takes 

 place, use silver nitrate as above to produce healthy action. 



PERIODIC OPHTHALMIA. 



Definitwn. — A constitutional affection operating on the 

 organ of vision, first attacking the internal structures, then 

 gradually extending, attacking various structures in turn, 

 until the whole of the eye becomes involved, the disease sooner 

 or later terminatins; in loss of vision. The disease is known 

 by a great number of names. It w^as spoken of by the old 

 writers as ' moon-blindness ' or ' moon-eyes,' as the moon 

 in its changes was supposed to be the cause of the periodical 

 recurrences which are characteristic of this aff'ection. It is 

 also known as ' constitutional ophthalmia,' which is by no 

 means a bad name ; ' gouty ophthalmia,' on the supposition 

 that it is due to some gouty or rheumatic influence ex- 

 isting within the system. It has been called ' odontalgia,' 

 under the mistaken notion that it was caused through den- 

 tition. It is also spoken of as 'hereditary ophthalmia' 

 and ' specific ophthalmia,' both of which are very good 

 names, as it is undoubtedly transmissible from the parents 



