ALBUGO. 545 



dimness or film. The opacity of the cornea caused by an injury 

 often remains as a permanent blemish, being due to the presence 

 of reparative material in the wound, and to a deposition of 

 lymph within the layers of the cornea immediately surround- 

 ing it. An opacity of this nature is at first of a bluish tinge, 

 and is then called a nebula ; as it becomes older it turns to a 

 pearly-white colour, and is then called an albugo. These terms 

 are quite conventional, and perhaps objectionable. The opacities 

 are in fact notliing more than cicatrices, and they undergo 

 the same changes as those of other wounds, namely, they 

 contract with age, become firmer in their structure, but never 

 entirely disappear. 



Occasional touches with the solid nitrate of silver, or a 

 solution of it apphed with a camel-hair pencil, will hasten the 

 absorption of the surrounding lymph. The practice of blowing 

 irritating matters through a quill into the eye is calculated to 

 irritate the whole surface of the conjunctiva, entail suffering 

 upon the animal, and do harm. 



These opacities are, only when sufficiently large, or when so 

 situated as to interfere with sight, to be regarded as causes of 

 unsoundness. 



The true Alhtgo, or Lcucoma, is often seen in dogs, and seems 

 to arise as spontaneous spots of opacity on the cornea, without 

 previous inflammation, and generally as the result of mal- 

 nutrition consequent on debihty or disease, such as the dis- 

 temper. Very young dogs are most prone to them, especially 

 if improperly fed, or taken away from the mother too soon. 

 They are best treated locally by the sohd nitrate of silver, 

 carefully applied, and generally by good diet and cod-liver oU. 



Since Percivall, Coleman, and others have passed away, writers 

 upon veterinary surgery have described simple ophthalmia as 

 if of every-day occurrence; but the fact is, it is a very rare 

 thing to meet with instances of it as an idiopathic disease. ]\Ir. 

 l*ercivall says, writing in 1826 — "First, as it attacks the human 

 eye, it is considered as a spontaneous or idiopathic affection, and 

 has been so named — ophthalmitis idiopathica ; but the affection 

 in horses lias, I beheve I may say unexceptionally, some apparent 

 or assignable cause." Again the same authority writes, " lu 

 regard to the causes of common ophthahnia, I have already 

 averred that they are local, mostly apparent, and not constitu- 

 2n 



