100 PERIODIC OPHTHALMIA. 



tion in the highest degree, verging even 0:1 an escharotic effect, is 

 found to be, in most cases, both warrantable and beneficial. In 

 gonorrhoea, formerly, surgeons would not go farther than a grain or 

 two of sulphate of zinc, or a quarter of a grain of corrosive subli- 

 mate or lunar caustic, to the ounce of water ; but now, there are 

 medical practitioners bold enough to suppress an attack of gonor- 

 rhoea at once by an injection of lunar caustic of the strength even of 

 a scruple to the ounce. Similar changes have taken place in regard 

 to colly ria. Now, a surgeon will order a lotion for the eye, com- 

 posed of five grains of lunar caustic to the ounce of water, and an 

 ointment of double that strength, when, formerly, he would hardly 

 have ventured to use such a potent preparation at all, or certainly 

 not in above half that strength. There is this difference, however, 

 between the surgeon's and the veterinary surgeon's practice in 

 this respect. The former decries the use of local applications — 

 either in their astringent, stimulant, or escharotic forms — in inter- 

 nal ophthalmia; nay, in acute m/e?7ia/ inflammations, positively 

 forbids them ; although he admits that, in conjunctival inflamma- 

 tions, more good is generally done by coUyria and ointments than 

 by any other remedy. 



In Veterinary Practice, however, the case is different. On 

 the principle that no two great actions or diseases can go on at the 

 same time, we shall find it to be good practice to produce a highly 

 stimulant, even an escharotic, effect on the conjunctival membrane, 

 with a view of, by derivation or revulsion, relieving the internal 

 ophthalmia ; and this is a practice that might long ago have sug- 

 gested itself to the veterinarian, from the known advantages which 

 farriers, in their rude way, often obtained from the blisters they so 

 unceremoniously and indiscriminately employed in ophthalmia : 

 indeed, this may be said to constitute one of the few remnants of 

 old practice veterinarians have done wrong to reject. The eye, 

 even in a state of ophthalnlia, will endure and derive advantage 

 from applications of much more potent nature than are commonly 

 ventured upon in practice. I use myself, as my favourite colly- 

 rium, a scruple of nitrate of silver to the ounce of distilled water. 

 Should simple ointment or hogs' lard be used in place of water, as 

 the medium, double and treble that strength of the silver may be 



