MOUNTING MEDIA. 85 



Jelly ; breathe on a cover-glass, place it on the fluid, apply 

 gentle pressure, and set aside to cool. 



FARRANT'S MEDIUM. 



Dissolve 1 grm. of Arsenious Acid in 200 cc. of Distilled 

 Water. In this fluid dissolve, at the ordinary temperature, 

 130 grms. of Gum Acacia, with frequent stirring; add 100 cc. 

 of Glycerine ; mix. Filter the solution through fine Swedish 

 paper upon which has been deposited a thin layer of Talc. 



This reagent is recommended because tissues mounted in it 

 preserve their normal appearance, and it is more convenient 

 than Glycerine in that it dries at the edges, and fixes the cover- 

 glass. 



Tissues may be mounted in this direct from Water, but it 

 is better to soak them for a short time in dilute Glycerine 

 before mounting. 



Place the section on a slide, remove superfluous fluid, add 

 1 or 2 drops of the medium, and apply the cover-glass. 



Formic Parrant. 



Farrant's Medium to which 1 p.c. of Formic Acid (sp. g. 

 1*2) has been added. 



GLYCERINE AND GUM. 



Chloroform Water (1 in 200), 200 cc. Dissolve in this fluid 

 130 grms. of Gum Acacia, with frequent stirring, at the 

 ordinary temperature of the air; add Glycerine, 100 cc. ; mix. 

 Filter as directed for Farrant. 



This may be used in the place of Farrant's Medium when 

 the presence of Arsenious Acid is objectionable. 



IODINE MOUNTING FLUID. 



Liquor lodi B.P., 100 cc. ; Water, 300 cc. ; Glycerine, 200 



