PE-ALCOTIOLlS.VI'IOlSr AND OLEARTNOx AGENTS. 71 



a slide^ but has a tendency to form very conve.v drops. This 

 property makes it a very convenient medium for making 

 minute dissections in. It also has the property of makino- 

 tissues that have lain in it for some time very brittle. This 

 brittleness is also sometimes very helpful in minute dissec- 

 tions. 



These qualities may be counteracted if desired by mixing 

 the clove oil with bergamot oil. 



This is one of the most useful of clearers. According to 

 Beheens {Tahellen, 3 ed., 1898, p. 33), it will clear from 

 alcohol of 74 per cent. 



It has a high index of refraction, and clears objects more 

 than balsam mounting media. It dissolves celloidin (or col- 

 lodion), and therefore should not be used for clearing 

 sections cut in that medium, without special precautions. 

 New clove oil washes out basic tar colours more quickly than 

 old. 



123. Cinnamon (or Cassia) Oil greatly resembles clove oil, but is in 

 general thinner, and is more highly refractive. An excellent medium, 

 which I particularly recommend. 



124. Oil of Bergamot (Schiefpeedeckee, J_rc/(. Anat. Phys., 

 1882 [Anat. Abth.J, p. 206).— Clears 95 per cent, alcohol 

 preparations and celloidin preparations quickly, and does 

 not extract anilin colours. 



Bergamot oil is, I believe, the least refractive of these 

 essences, having a lower index than even oil of turpentine. 



SuCHANNEK {Zeit. iciss. Milt., vii, 1890, p. 158) says that 

 bleached, colourless bergamot oil will not take up much 

 water, whereas a green oil will take up as much as 10 per 

 cent. 



Van dee Steicht [Arch, de Biol., xii, 1892, p. 741) says 

 that bergamot oil will, with time, dissolve out the fatty 

 granules of certain ova. 



125. Oil of Origanum (Neblsen and Schieefeedeckee, Arch. 

 Anat. Phys., 1882, p. 204). — Ninety-five per cent, alcohol 

 preparations are cleared quickly, and so are celloidin sec- 

 tions, without solution of the celloidin. Anilin colours are 

 somewhat extracted. 



For work with celloidin sections cnre should be taken to 



