Eye. 97 



and a half to two hours for a rabbit. Then place it in 

 distilled water, which must be changed once or twice, 

 for 24-36 hours exposed to the light, it will then have 

 become a violet colour. 



It is now placed in a mixture consisting of 

 Pure glycerine, 1 part. 

 Distilled water, 2 parts. 



Let it remain in this for two or three days in the 

 dark. It is then taken out, and gently washed and 

 placed in a wide mouthed vessel containing a filtered 

 nearly saturated solution of tartaric acid. As it ab- 

 sorbs this liquid, the colour will become darker and it 

 will sink to the bottom of the vessel. The vessel is 

 now plunged into water at a temperature of 40 to 50 C. 

 to such a depth that the two fluids will stand at the 

 same height. 



Sections may now be made with a very sharp razor 

 by holding the cornea between the finger and thumb of 

 the left hand. This requires great care, and cannot be 

 done without a good deal of practice. The sections 

 are mounted in glycerine and sealed with Hollis' glue. 



Before cutting the sections, while the cornea is still 

 in the distilled water, it is well to pass a camel's hair 

 pencil gently over the surface, to remove the gold de- 

 posited there. 



IBIS AND SCLEROTIC. 



A portion of the eye containing part of the cornea 

 sclerotic and iris may be cut out, and frozen. Sections 

 of this stained with logwood, show the junction of the 

 cornea and sclerotic, and the structure of the iris. 



H 



