CLEARING AGENTS. 



The function of a clearing agent is to make the tissue trans- 

 parent by penetrating into all parts of it. 



It must be a liquid of high refractive index and miscible with 

 balsam, as well as having the power to drive out all of the alcohol. 

 The agents employed are very numerous, but a successful one 

 should replace the alcohol quickly and yet not destroy the tissue by 

 shrinking. The chief clearing agents are the essential oils. 



Cedar Oil. 



\ 

 This oil is a very good clearing agent but is quite slow in its 



action; however, it does not shrink the tissue nor fade aniline 

 colors. 



Clove Oil. 



This is one of the best clearing agents. The clove oil on the 

 market is usually impure and not suitable for use. The pure oil 

 can be obtained only from reliable dealers. As a clearer, it pene- 

 trates tissue very readily and clears most thoroughly. It has a 

 very high refrative index. 



Collodion is dissolved by this oil, and it is therefore not safe to 

 use with collodion sections unless proper precautions are taken to 

 prevent the displacement of the disconnected parts. 



Tissue that remains in clove oil any length of time is liable to 

 become brittle, and this is sometimes very helpful in minute dis- 

 sections. 



Aniline colors are often faded by the action of this clearer. 



