360 DISEASES OF CATTLE. 



the lens and the vitreous humor become expelled, thus producing a 

 destruction of the whole organ. 



Treatment. It is of the greatest importance, as soon as an ulcer 

 appears upon the cornea, to prevent its growing larger. The corroding 

 process must be converted into a healthy one. For this purpose noth- 

 ing is more reliable than the use of solid nitrate of silver. A stick of 

 nitrate of silver should be scraped to a point; the animal's head should 

 be firmly secured; an assistant should part the lids; if necessary the 

 haw must be secured within the corner of the eye and then all parts of 

 the ulcer should be lightly touched with the silver. After waiting a 

 few minutes the eye should be thoroughly washed out with warm milk. 

 This operation generally has to be repeated once more at the end of 

 three or four days. If healthy action succeeds, the ulcer assumes a 

 delicate fleshy tint, and the former redness around the ulcer disappears 

 in proportion as the ulcer heals. 



In superficial abrasions of the cornea, where there is no distinct exca- 

 vation, this caustic treatment is not needed. The eye should be bathed 

 with sulphate of zinc, 30 grains to half a pint of soft water, several 

 times a day, and protected against exposure to cold air and sunlight. 

 Excessive ulceration sometimes assumes the form of fungous excres- 

 cence upon the cornea, appearing to derive its nourishment from loops 

 of blood-vessels of the conjunctiva. Under these circumstances the 

 fungoid mass must be cut away, and the wound cauterized with the 

 nitrate of silver, or else the eye will soon be destroyed. When ulcers 

 of the cornea appear indolent, with a tendency to slough, in addition 

 to the treatment already prescribed, tonic powders should be given 

 twice a day mixed with, the feed ; powdered copperas, gentian, and gin- 

 ger, equal parts by weight. Dose, one tablespoonful. 



STAPHYLOMA. 



This is a disease of the eyeball, in which the cornea loses its trans- 

 parency, rises above the level of the eye, and even projects beyond the 

 eyelids, in the form of an elongated, whitish, or pearl-colored tumor, 

 which is sometimes smooth, at other times uneven. 



Causes. Inflammation is the only known cause, although it may not 

 occur immediately; it frequently follows catarrhal conjunctivitis and 

 keratitis as a sequela. 



Treatment. In a few cases restoration of sight may be effected by 

 puncturing the projecting tumor, and treating it afterwards with nitrate 

 of silver in the same manner as prescribed for ulceration of the cornea. 

 I have known a few cases where spontaneous rupture occurred, and 

 healing without any treatment at all. 



CATARACT. 



In cataract the crystalline lens becomes opaque and loses its trans- 

 parency, the power of refraction is lost the animal can not see. 



Causes. Cataract generally arise* from a diminution atrophy or 



