102 METHODS OF MICROSCOPICAL RESEARCH. 



GUM AND GLYCERINE. (Warrant's medium). 1 



1. Gum arable (Best picked), 4 ounces. 

 Distilled water, 4 ounces. 

 Glycerine, 2 ounces. 



Keep it in a well stoppered bottle with a lump 

 of camphor in it. 



2. Gum arable, 1 ounce. 2 

 Glycerine, 1 ounce. 

 Distilled water, 1 ounce. 

 Arsenious acid, 1| grains. 



Dissolve the arsenious acid in the water, and the 

 gum in this mixture, without heat, add the glycerine 

 and incorporate with great care to avoid the forma- 

 tion of air-bubbles. 



Glycerine, mixed with distilled water, forms an 

 admirable medium in which to examine tissues and 

 specimens and make minute dissections. It is 

 sometimes used thus diluted as a mounting fluid, 

 but is not to be relied upon as a preservative 

 medium, whereas undiluted glycerine, when once 

 the crucial difficulty of sealing it up and preventing 

 leakage from the preparation has been successfully 

 achieved, may be considered not only unsurpassable 

 as a mounting fluid in cases for which it is suitable, 

 but entirely reliable as a preservative. The her- 

 metically sealing of the glycerine under the cover, 

 or in the cell, must be most carefully done by 

 applying at least three coats of shellac cement to 

 be followed by two or three coats of white zinc 

 cement, the formulae for making which will be given 

 in their places, and the method of applying them 



1 Beale, page 68. 2 Micrographic Dictionary. 



