90 ^ THE AE3IY HOESE. 



to certain soils and climates, and to certain animal systems, in 

 which it shows a strong tendency to recur again and again, 

 usually ending in blindness from cataract or other serious 

 injury. 



Symptoms vary according to the severity of the attack. In 

 some cases there is marked fever. The local symptoms are in 

 the main those of simple ophthalmia; opacity advances from 

 the margin over a part or the whole of the cornea. An attack 

 lasts from ten to fifteen days. The attacks may follow each 

 other at intervals of a month, more or less, but they show no 

 particular relation to any particular phase of the moon. From 

 five to seven attacks usually result in blindness, and then the 

 other eye is liable to be attacked until it also is ruined. 



Treatment. — Is largely the same as that for simple ophthal- 

 mia. During recovery a course of tonics is often very beneficial 

 and acts in assisting to ward off another attack. vSuch a tonic 

 is the following : Sulphate iron 1 ounce, gentian 1^ ounces, nux 

 vomica 1-J- ounces. Make into twelve powders and give one 

 powder, in feed, twice a day. 



If opacity of the cornea remains, benefit may be obtained 

 from the use of silver nitrate, 4 grains to 1 ounce of water, a 

 few drops dropped into the eye twice daily. A saturated 

 solution of iodide of potassium may be used in the same 

 manner. 



CATARACT. 



Cataract is usually the result of repeated attacks of recurrent 

 ophthalmia. It is an opacity, not of the cornea, but of the 

 crystalline lens. No treatment will restore it to its normal con- 

 dition. 



