LIST OF REAGENTS. 495 



III. CLEARING REAGENTS 



(i.e. REAGENTS FOR REMOVING ALCOHOL OR PARAFFIN, AND 

 RENDERTNO THE OBJECT PERMEABLE BY BALSAM). 



OIL OP CLOVES. 



Use. To remove alcohol from an object before mounting it in 

 balsam. The object must be left in the oil till it becomes 

 transparent : if left too long the object may become 

 brittle. It is liable to destroy the colour of objects stained 

 with haematoxylin. 



OIL OF CEDAR-WOOD. 



Use. Same as oil of cloves. It is less liable to injure speci- 

 mens stained with haematoxylin, and is also useful for 

 clearing before imbedding. 



XYLOL. 



Use. To remove paraffin from sections (see Introduction, 

 p. xxxiv), which should only remain in it long enough for 

 the paraffin to be dissolved. 



IV. MOUNTING MEDIA. 

 SALT-SOLUTION, '75 per cent. 



Preparation. Dissolve 7*5 grms. common salt in 1 litre water. 

 Use. Living or fresh tissues are usually examined in it. 



GLYCERIN. Used either pure, or diluted with an equal bulk of 

 water. 



Use. For mounting microscopical objects. 



GLYCERIN JELLY. 



Preparation. Soak gelatin in water till soft ; pour off excess 

 of water ; melt, and, while still fluid but cool, add one- 

 eighth of its bulk of white of egg : mix thoroughly : boil : 

 strain through flannel : to strained fluid, while still hot, add 



