TECHNIQUE OF EYE DISSECTIONS 



it will take much longer to clear; it may take 

 a month. 



Cedar oil may also be used for the purpose 

 of clarifying or "clearing" the lens. Harden 

 in the usual way, run through the alcohols, and 



ABC D 



Fig. 21. 



A. Lens hardened in formaldehyde. 



B. Lens hardened in formaldehyde, run through the alcohols, 



and cleared in xylol. 



C. Lens hardened in formaldehyde, run through the alcohols, 



and cleared in cedar oil. 



D. Boiled lens. 



then place in cedar oil. The oil, however, will 

 stain the lens a yellowish brown, and the lens 

 will not be as transparent and clear as when 

 xylol is used. 



The longer a lens is left in either of these 

 two clarifying fluids the harder and smaller it 

 will become. At the end of a month or six 



60 



