IVojiiids of the Eyelids. 333 



acts on the eye like atropine, but more promptly and transiently. 

 One drop of a solution of one to one hundred and twenty, usually 

 gives in twenty minutes, full pupillary dilation and complete 

 paralysis of accommodation which lasts only for twentj'-four 

 hours. Add to this that there is little danger of constitutional 

 disturbance and poisoning, and homatropine must be accepted as a 

 more desirable agent than atropine. It is especially to be preferred 

 in cases of senility with shallow anterior chambers, and in glau- 

 coma, in which atropine tends to aggravate the lesion. 



Daturine, the alkaloid of datura stramonium is a potent my- 

 driatic, causing pupiliar}' dilatation in a solution of one to one 

 hundred and sixty thousand of water. It appears to be identical 

 with atropine. 



Duboisine the alkaloid of duboisia myoporoides is also a 

 potent mydriatic. Jaarsma found that a solution of the sulphate, 

 of one to three thousand, paralyzed accommodation for twenty- 

 four hours. It acts more promptly than atropine but is more 

 poisonous. 



Hyoscyamine, the alkaloid of hyoscyamus niger, is also 

 stronglv mydriatic. One drop of an one to three hundred solu- 

 tion of the sulphate paral3'zed accommodation for from seventy- 

 five to one hundred hours. Ri.sley found it to act more promptly 

 than atropine, and to be le.ss dangerous than duboisine. 



WOUNDS OF THE EYELIDS. 



Traumas : bites, lacerations, blows, penetrating wounds, gunshot, scratches, 

 kicks. Upper lid or commissure. Reparatory power of eyelid. Danger of 

 distortion. Treatment : sutures, plaster, shellac, collodion, gelatine. Prick's 

 gelatine, birdlime, sterilisation : Quilled and twisted siiture. Position in 

 stall. Metallic guard for eye. 



Causes. Traumatic injuries of the eyelids are e.speciall}' com- 

 mon in the horse mainly because of his exposure in connection 

 with the services required of him. In a team he is liable to be 

 bitten by one of his fellows, or the lid may be caught on nails, 

 in turning, or on hooks upon harness, chains or wagons. It 

 is sometimes injured by a blow from a club or whiplash, or 



