APPENDIX. 109 



eyes injured, and a disease produced by the 

 powerful and penetrating exhalations of the earth 

 which envelop the head in the act of grazing, 

 when the eyes are, more than in any other 

 position, extended and exerted; this is often 

 the unsuspected cause of dimness — opaque 

 films— and ultimate blindness. Therefore horses 

 resident in a stable should not be sent to graze 

 until the vapour has evaporated. It is not, 

 however, beneficial to send horses out to graze 

 for a very short time, which only gives them a 

 mouthful of grass and a belly-full of gripes, 

 with sore eyes, and their mouths become too 

 tender for hard corn and dry hay, for which 

 also they in some degree lose their relish. It 

 is better to give horses while inhabiting the 

 stable all dry food, or in the season all green. 

 Besides, the early exhalations being at the 

 same time suddenly inhaled, cause discharges 

 from the nostrils, and bowel diseases, especially 

 in old horses ; nevertheless the latter are con- 

 siderably renovated by having all green food 

 in the proper season; and when horses have 

 been some time accustomed to green food they 



L 



