CLEAEING AGENTS. 



BEFORE MOUNTING IN BALSAM. 



Those most generally recommended are Creosote, Turpen- 

 tine, Xylol, and the Oils of Bergamot, Cedar, Cloves, and 

 Origanum. . 



The object of using a clearing agent is to replace the 

 Alcohol in the dehydrated section by a liquid which has a 

 refractive index about the same as the Balsam into which it is 

 to be placed and which will mix readily with it. 



1. The fluid should clear quickly from a somewhat hydrated 

 Alcohol. 



2. It should not dissolve the aniline colours nor celloidin. 

 No one clearing agent is perfect in both respects, for it 



happens that the more readily the agent mixes with 90 

 p. c. Alcohol, the more liable it is to dissolve the aniline 

 colours. 



For clearing celloidin sections, Bergamot or Cedar Oil 

 are the best. See Dehydration. 



OIL OF BERGAMOT. 



This oil will clear directly from 90 p. c. Alcohol. Its 

 solvent action on Aniline Colours is very slight, except in the 

 case of Methyl Green and the Violet dyes, which may be 

 appreciably dissolved. Apart from this, its powerful odour 

 and high price are the only objections to its general use. 



It clears Celloidin without dissolving it. 



