364 DISEASES OF THE EYES. 



means of irritants, such as the mild chloride or oxide of mercury or 

 massage. According to Bayer, massage of the cornea has to be 

 performed in the following manner : The points of the fingers are 

 placed on the closed-up eyelids and by a constant circular or cen- 

 trifugal friction move the eyelid for some time. In some cases 

 we may also apply the above-mentioned ointments and powders. 

 The author has obtained far the best results from calomel than 

 anything else. He placed daily a small amount of powder com- 

 posed of equal parts of calomel and sugar (grape sugar) on the 

 cornea, and applied it by massage for some time. 



The following other alterations have been observed in the scle- 

 rotic membrane of the dog : 



Dermoid of the Cornea. We occasionally find a peculiar 

 abnormal collection of true membranous tissue on the cornea which 

 is covered with hair and interferes with the direct action of light, 

 and also produces irritation in the cornea and conjunctiva. The 

 hair should be cut ofE by means of scissors. Thierry observed the 

 same abnormality on the sclerotic membrane of both eyes in a 

 three-months-old dog. There was a slight swelling and enlargement 

 above the surface of the membrane, which was covered with fine 

 hair. This trichiasis bulbus was removed with the scissors. 



Pterygium. By this we mean a malformation of the connective 

 tissues containing bloodvessels and branching over the cornea 

 toward the centre. This growth can be removed by means of 

 caustics or by an operation. 



Injuries to the Cornea. It is not uncommon to observe injuries 

 to the sclerotic membrane of dogs where the epithelium is removed 

 slightly, or where they may have a deep penetration of the mem- 

 brane, and in such cases, such as injuries from cats' claws, it is 

 entirely perforated. Immediately after the injury we observe a 

 great fear of light, closing of the eye, and copious tears. Wounds 

 which have not entirely perforated the sclerotic membrane are 

 rapidly followed by an opacity and swelling in the neighborhood 

 of the injury. When the membrane is perforated the symptoms 

 and results are very similar to ulceration. Superficial and very 

 small wounds which penetrate deeply heal very quickly after a 

 few days, leaving scarcely any opacity. This, of course, must be 

 expected in wounds that have been caused by some object that was 

 clean, while septic large wounds, caused by some unclean object, 



