The horse is next ordered round to the stable window, with the diseased eye toward the light. A pretense is then made of forcing the lid open; if simple ophthalmia be present, the resistance is energetic, but not violent. Should specific ophthalmia be the affection, the horse struggles against the intimation with the wildness of timidity, striving to escape a terrible torture. The animal is, there-upon, brought into some shady corner; its fears are allayed, and it permits the lid to be raised with little difficulty. Should the eye have been injured by an accident, the most prominent part of the ball is likely to be hurt. The internal structures are unaffected; the pupil generally is larger than usual, and the iris is unchanged. The haw may be or may not be projected; but the color, form, and aspect of the iris is unaltered. During the commencement of specific ophthalmia, the center of the cornea may be transparent, but the circumference of the ball is violently inflamed; the reason being that a constitutional disorder always first attacks the more vascular structures, and, therefore, commences in the loose conjunctiva, covering the white of the globe. In specific ophthalmia, the color of the eye has changed to a lighter hue, and the pupillary opening is firmly closed, to prevent the entrance of the dreaded light. [Illustration: DIAGRAM OF THE EYE IN SIMPLE OPHTHALMIA. THE DARK LINE INDICATES THE EXTENT TO WHICH HAW MAY PROTRUDE.] [Illustration: DIAGRAM OF THE HORSE'S EYE WHEN SUFFERING FROM SPECIFIC OPHTHALMIA.] Weakness increases as specific ophthalmia progresses. The attack, however, is seldom stationary; the eye first involved may suddenly become clear and healthy, and the opposite organ may exhibit the ravage of the disease; thus, the affection keeps rapidly moving about; when it suddenly quits both eyes, the inflammation commonly fixes upon some distant part of the body, as the lungs or feet. No one can predicate how short will be its stay or how long the attack may last; it has disappeared in a week, it has continued two months. It seldom reaches its climax during the first assault. It will occur again and again; generally it ends in the destruction of one or both eyes; but never, so far as the author's knowledge extends, causes gutta serena. Like scrofulous affections in the human being, which it greatly resembles, it generally is the inheritance of youth; after maturity or after the eighth year has been attained, it is rarely witnessed. When this terrible affliction visits a stable, let the proprietor firmly oppose all active measures. A shed ought to be procured, cool or shady, and screened on every side, excepting on the north. Every hole, however minute, should be stopped, because light shines through a small opening with a force proportioned to its diminutiveness. The stars and candles in the once popular London Diorama were only small holes cut in the canvas.