TECHNIQUE OF EYE DISSECTIONS 



up as much moisture as it can hold. Be sure 

 that the lens has given up nearly all, if not all, 

 moisture. "Kunning through the alcohols/' 

 as this process is called, is for the purpose of 

 dehydrating the tissue. It will be on the side 

 of safety to let the lens lie exposed on the blot- 

 ting-paper for an hour. Sometimes, if the 

 capsule has not been removed, a small quan- 

 tity of alcohol will remain between the lens 

 and the inner surface of the capsule. This 

 must be removed. It may be done by either 

 puncturing the capsule with a pin or needle, 

 and squeezing out the fluid, or by removing the 

 capsule entirely. The latter is preferable. 



Now drop the lens into xylol. Benzine will 

 answer, though it will not produce quite so 

 clear a lens as the xylol does. At the end of 

 24 or 36 hours the softer cortex will show quite 

 clear, while the harder nucleus will be still 

 cloudy. At the end of a week the whole lens, 

 if it is a small one^-pig, calf, sheep will have 

 become quite clear and transparent; if from a 

 beef eye it will take longer. It sometimes takes 

 nearly two weeks. In the case of a boiled lens 



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